<section id="isPasted">Established in 1995, <a href="https://www.zaxisconnector.com/" target="_blank" rel="noopener">Z-Axis Connector Company</a> is a leading privately held corporation specializing in connector manufacturing. Whether for high-volume consumer applications or micro-miniature connectors, their team of skilled scientists, engineers, operators and managers are dedicated to manufacturing innovative and cost-competitive connectors tailored to meet diverse requirements.Z-Axis is often contacted by potential customers in which a typical, off-the-shelf connector won’t work for their application. One of the critical design considerations for Z-Axis was achieving the precise tolerances required for their connectors. With traditional 3D printing methods, tolerances of 5 thousandths were the best they could hope for.</section><section><h2>Looking for a Solution</h2>This prompted them to look for alternative solutions which led them to discover Boston Micro Fabrication’s (BMF) micro-precision 3D printers. They soon learned with BMF’s technology, tolerances of 1 or 2 thousandths became achievable, opening up new possibilities for compact, high-performance connectors.One of the primary challenges Z-Axis faced was ensuring compatibility with traditional electronic assembly techniques. Elastomeric connectors had to withstand high-heat soldering processes without compromising their integrity. With BMF’s open platform, Z-Axis was able to use 3D Systems Figure 4® HI TEMP 300-AMB material, engineered to withstand temperatures up to 300°C. The PC Boards needed to go through a solder reflow oven which reached a temperature of 237°C in a 7.5 minute cycle. The BMF parts were able to withstand the extreme temperature enabling Z-Axis to use standard electronic system manufacturing techniques using 3D printed connectors.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1727055159419-2024-05-03-17-26-45-BR8S4-Edit.jpg" style="width: 100%px;" class="fr-fic fr-dib">3D printed connector mounted on a PC board<h2 id="isPasted">A New Era of Innovation in Connector Manufacturing</h2>BMF’s technology also enabled Z-Axis to transition towards surface mount components, eliminating the need for through-hole accommodations. This not only enhanced the efficiency of electronic assemblies but also allowed for more compact designs, saving valuable board real estate and meeting the demands of modern electronics.By leveraging BMF’s micro 3D printing technology, Z-Axis was able to push the boundaries of what was achievable, delivering solutions that surpassed industry standards. Together, they have laid the foundation for a new era of precision and innovation in connector manufacturing, in much less time and at a much lower cost than traditional manufacturing methods.</section>

The BMF parts were able to withstand the extreme temperature enabling Z-Axis to use standard electronic system manufacturing techniques using 3D printed connectors.

3D Printed High-Heat Resistant Connectors for Soldering

In the world of additive fabrication, two technologies stand out for their transformative potential: 3D printing and PCB (printed circuit board) printing. They share the fundamental principle of additive manufacturing, but are different in a number of ways.&nbsp;In this article, we will delve into the main differences between traditional 3D printing and additive PCB printing, as seen in machines like the Voltera <a href="https://www.voltera.io/v-one" target="_blank">V-One</a>, in order to clarify their distinct roles in modern manufacturing.<h2>How does 3D printing and PCB printing work?</h2><h3>3D Printing</h3>With 3D printing, printers create objects by layering material, typically thermoplastic, from the bottom up. You begin with designing a model using computer-aided design (CAD) software. Next, you export the .stl file to your 3D printer software which will slice the model into thin horizontal layers, generating &nbsp;G-code for each layer. Depending on the type, your 3D printer will then extrude or solidify material layer by layer to form the final object.&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzI0ODMyMzM2NDQwLTNkLXByaW50aW5nLXdvcmtmbG93LndlYnAiLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">3D printing workflow <h3 id="isPasted">PCB printing</h3>Additive PCB printing shares similarities with 3D printing in terms of its workflow. Using electrical computer-aided design (ECAD) software, you design your project, then export the Gerber file and upload it to your printer’s software. PCB fabricators, such as V-One, will then interpret the Gerbers and deposit conductive materials to construct the layers of a printed circuit board.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzI0ODMyMzc3NzAwLXZpZXdpbmcteW91ci1wcm9qZWN0LndlYnAiLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">Viewing your project with V-One software <h2 id="isPasted">Key differences between 3D printing and PCB printing</h2><h3>Materials and substrates</h3>The most apparent difference lies in the materials used. Traditional 3D printers work with a wide array of materials, including plastics such as PLA, PETG, TPU, ABS, and resin, as well as nylons and metals. In contrast, PCB printers utilize conductive inks, such as silver, copper, or graphite, and more to create functional circuit boards.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzI0ODMyNDI0NTY2LXZvbHRlcmEtY29uZHVjdG9yLTMud2VicCIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">Voltera<a href="https://store.voltera.io/products/conductor-3-ink-cartridge-2ml" target="_blank" rel="noopener noreferrer">Conductor 3 ink</a>While you can print a three-dimensional object directly on the heated bed of a 3D printer, PCB printing requires fixing a substrate to the bed. Depending on your specific needs, you can choose more rigid substrates such as FR1, FR4, or more flexible ones such as TPU, paper or fabric.<h3>Precision</h3>3D printers are generally used for larger objects and may not achieve the fine detail required for PCB manufacturing. The <a href="https://www.3erp.com/blog/how-dimensionally-accurate-are-3d-printed-parts/" target="_blank">accuracy of desktop 3D printers</a> varies, ranging from ± 0.1 mm to ± 0.5 mm.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzI0ODMyNTE1MzY5LVJGSUQtdGFnLndlYnAiLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib"><a href="https://www.voltera.io/blog/copper-rfid-tag" target="_blank" rel="noopener noreferrer">RFID tag</a>In contrast, PCB printers are designed for high precision, which is crucial for the intricate pathways and components of circuit boards. Notably, machines that use <a href="https://www.voltera.io/blog/introduction-direct-ink-writing-printing-technology" target="_blank" id="isPasted">direct-ink-writing technology</a>, such as <a href="https://www.voltera.io/nova" target="_blank">NOVA</a>, enable the production of features as small as 100 µm<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1724832788408-conductive-traces-printed-by-NOVA.webp" style="width: 100%px;" class="fr-fic fr-dib">Details of conductive traces printed by NOVA<h3 id="isPasted">Capabilities and applications</h3>3D printers are handy when it comes to producing complex geometries and shapes. Some industries use 3D printing to manufacture the final product, such as architectural models, automotive parts, and dentures.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1724832745696-3d-printed-custom-orthoses.jpeg" style="width: 100%px;" class="fr-fic fr-dib">3D printed custom orthoses (Image:&nbsp;<a href="https://unsplash.com/photos/person-in-black-pants-wearing-white-and-blue-rubber-clogs-13g9FZqVvNY" target="_blank" id="isPasted">Tom Claes</a>) However, these 3D printed projects, on their own, cannot perform functions such as sensing, monitoring, moving, amplifying, controlling, or mirroring, which require a printed circuit board and a range of electronic components. In order to test and iterate electronics projects, you will need a PCB printer.&nbsp;The applications of PCB printers range from simple personal projects such as a weather station that monitors temperature, humidity, and atmospheric pressure, to complex R&amp;D endeavors such as a prototype for robotic arms capable of performing surgeries.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1724832866912-robot-shopping-mall-kyoto.jpeg" style="width: 100%px;" class="fr-fic fr-dib">Robot in shopping mall in Kyoto (Image:&nbsp;<a href="https://unsplash.com/photos/robot-standing-near-luggage-bags-hND1OG3q67k" target="_blank" rel="noopener noreferrer">Lukas</a>)<h3 id="isPasted">Costs</h3>Due to the differences in all the aforementioned aspects, these technologies are available at varying costs. Desktop 3D printers can be priced anywhere from <a href="https://formlabs.com/blog/how-to-calculate-3d-printer-cost/" target="_blank">USD $200 to $2,500</a>, whereas desktop PCB printers tend to range from USD <a href="https://store.voltera.io/products/v-one" target="_blank">$5,199.98</a> to $27,800.<h2>Conclusion</h2>3D printing allows for the creation of a broad spectrum of objects, whereas PCB printing offers a specialized, rapid, and cost-effective solution for circuit board production.&nbsp;Despite their differences, 3D printing and PCB printing can be highly complementary. Leveraging these technologies together will streamline the electronics prototyping process.&nbsp;As the technology continues to evolve, there is tremendous potential for further integration and innovation in both fields. For more insights on additive PCB manufacturing, check out these resources:<ul><li><a href="https://www.voltera.io/blog/what-is-printed-electronics-conductive-inks" target="_blank">What is Printed Electronics? Conductive Inks</a></li><li><a href="https://www.voltera.io/blog/introduction-direct-ink-writing-printing-technology" target="_blank">Introduction to Direct Ink Writing (DIW) Printing Technology</a></li><li><a href="https://www.voltera.io/blog/introduction-inkjet-technology" target="_blank">Introduction to Inkjet Technology</a></li><li><a href="https://www.voltera.io/blog/introduction-screen-printing" target="_blank">Introduction to Screen Printing</a></li><li><a href="https://www.voltera.io/blog/resistance-resistivity-and-sheet-resistance" target="_blank">Resistance, Resistivity &amp; Sheet Resistance</a></li><li><a href="https://www.youtube.com/watch?v=gyICoRTERFI" target="_blank">Webinar: Printing on BEYOLEX™ High-Temperature Stretchable Film with NOVA</a></li></ul><a href="https://meetings.hubspot.com/royperez/v-one-or-nova-demo?utm_campaign=Wevolver&utm_source=Wevolver&utm_medium=Book%20a%20meeting" target="_blank" id="isPasted">Book a call with Voltera today</a> to explore how this innovative tool can meet your prototyping needs.

Exploring the key distinctions between 3D printing and PCB printing, from materials and precision to applications and costs

3D Printing vs. PCB Printing - What's the Difference?

How to extend the pot life of silicone to several months without changing its material properties? Ulrich Trog [Ulrich.Trog@joanneum.at | JOANNEUM RESEARCH] explains in this article how this is possibleJOANNEUM RESEARCH offers the formulation of the appropriate compound based on feasibility studies of the silicones used by its customers. Licences for the Supresil™ technology are available.Platinum (Pt)-cured silicones are gaining in popularity, emphasising addition curing over traditional peroxide methods. This process ensures purity and efficacy, resulting in products with increased strength and superior aesthetics. The rise of Pt-curing marks a significant shift in silicone manufacturing techniques, promising unmatched quality and durability in a variety of applications. When crosslinking is initiated, the curing process starts almost immediately and the resulting silicone typically has a pot life limited to a maximum of a few hours at room temperature. This places significant&nbsp;practical and technological limitations on its use:<ul><li style="font-weight: bold;">short processing time</li><li style="font-weight: bold;">anufacturing waste</li><li style="font-weight: bold;">difficult reproducibility</li><li style="font-weight: bold;">inflexible manufacturing process</li></ul>Our patented formulation greatly increases pot life via reversible inhibition of the crosslinking via hydrosilylation. After deposition, the inhibitors evaporate easily. Normal crosslinking occurs at mild temperatures, even below 80 °C, leading to a fast and complete curing.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyMTM1MDMxNDE2LVNjcmVlbnNob3QgMjAyNC0wNC0wMyAwODM1MjcuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib">Join the Future of Electronics RESHAPED event in Boston on 12 &amp; 13 June 2024. Learn more <a href="https://www.techblick.com/electronicsreshapedusa" target="_blank" rel="noopener noreferrer">https://www.techblick.com/electronicsreshapedusa</a>Benefits<ul><li>reduces production costs: the pot life of silicone mixtures can be extended to several months and beyond</li><li>enables (3D) printing: shelf stable, 1-component silicone inks can be formulated for use with a variety of printing processes including processes like dispensing, screen-printing, aerosoljet-printing, inkjet printing and others</li><li>no change in material properties: through the complete and trace-free removal of the inhibitor during the curing process there is no change in the material or its properties</li><li style="font-weight: bold;">applicable to liquid Silicone rubber (LSR) and high consistency rubber (HCR)</li><li>suitable for all Pt-cure resins: no curing at processing temperature and normal curing at curing temperature, orthogonal with other inhibitors</li><li>environmental: reduction in waste generation in production process</li></ul>Application examples<ul><li>LED production: Supresil™ resins reduce the processing efforts and increase the yield of colour conversion materials without changing their optical properties. The Supresil™ inhibited silicones can be mixed with colour conversion phosphors in large batches, increasing the accuracy and consistency of the colour conversion composites through improved wetting and distribution of the dispensed material and a better dispersion of the phosphors.</li></ul><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyMTM1MjMxMzE4LXVubmFtZWQucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib"><ul><li>3D printing: Standard LSR formulations are optimised for extrusion and injection moulding machines and are not suitable for 3D printing. By adjusting the rheological behaviour and extending the pot life using JOANNEUM RESEARCH‘s proprietary reversible curing inhibition, 3D printing is now possible.</li></ul><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyMTM1MjgxMjMxLXVubmFtZWQgKDEpLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">All material properties of the silicones are preserved (through complete and trace-free removal of the inhibitor):<ul><li>physical: shrinkage, Shore hardness, storage modulus</li><li>optical: UV/VIS transmission, no „yellowing“, refractive index</li><li>biocompatibility: relevant for medical grade resins / formulations</li><li>unaltered production: viscosity, reproducibility</li></ul><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyMTM2MTQzMjU0LXVubmFtZWQgKDYpLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">Fig. 1: Comparison of curing dynamics of standard silicone resins with SupresilTM inhibited resins<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyMTM1ODI4NTM0LVNjcmVlbnNob3QgMjAyNC0wNC0wMyAwODQyNTAuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib"><a href="https://www.techblick.com/exhibitors-2024-berlin" target="_blank" rel="noopener noreferrer">We are Exhibiting in Berlin!</a> Come and visit our booth<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyMTM1OTA5NzAxLXVubmFtZWQgKDMpLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">Fig. 2: UV/VIS Transmission of cast silicones (100 µm) for the LED productionJOANNEUM RESEARCH is a publicly owned, Austrian Research and Technology Organisation. It is successful nationally and internationally in the fields of “Information and Production Technologies”, “Human Technologies and Medicine” and “Society and Sustainability”AUTHOR: Ulrich Trog [Ulrich.Trog@joanneum.at |JOANNEUM RESEARCH]&nbsp; <img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyMTM2MDU0MjI5LXVubmFtZWQgKDQpLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">All images: © JOANNEUM RESEARCH<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyMTM2MTA3NzU0LXVubmFtZWQgKDUpLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">&nbsp;&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1712137051266-Screenshot+2024-04-03+084405.jpg" style="width: 100%px;" class="fr-fic fr-dib">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<a href="https://www.techblick.com/" target="_blank" rel="noopener noreferrer">TechBlick.com</a>

How to extend the pot life of silicone without change in properties for applications in 3D Printing, LED lighting, LED backlights, and others

Extending the pot life of silicones to several months: LEDs, 3D printing and beyond

Author: Masoud Mahjouri-Samani, PhD |&nbsp;NanoPrintek | <a rel="noopener noreferrer" href="mailto:info@nanoprintek.com" target="_blank">info@nanoprintek.com</a>Modern technology and the move toward the Internet of Things have escalated the demand for innovative and efficient printing techniques, particularly in electronics and functional devices. Traditional ink-based printing methods have long been the standard, but now NanoPrintek’s dry multimaterial printing technology has emerged as a disruptive alternative, offering numerous advantages over its ink-based counterparts. The technology’s on-demand and in-situ nanoparticle generation and real-time sintering capability allow the printing of various electronics and functional devices with pure, multifunctional, hybrid materials printing. This thus opens the path to electronics printing and other applications ranging from energy and health to sensing devices.&nbsp;<figure><div contenteditable="false"><button data-test-resize-image-button="true">Minimize image</button><button data-test-edit-image-button="true">Edit image</button><button data-test-delete-image-button="true">Delete image</button><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1711519983710-1711519983710.png" alt="" class="fr-fic fr-dii"></div><figcaption>Figure 1: Dry printing process. &nbsp;On-demand/ in-situ nanoparticle generation and real-time laser sintering that enables the printing of various electronics and functional materials and devices</figcaption></figure>Unveiling a Universe of Materials Beyond the Limitations of Ink: Traditional inks can be restrictive regarding the materials they can accommodate. Dry printing, on the other hand, opens doors to a wider range of possibilities. From semiconductors and conductors to insulators and nanocomposites, dry printing can handle a broader spectrum of functional materials rapidly, enabling the creation of more advanced and innovative functional devices.<figure><div contenteditable="false"><button data-test-resize-image-button="true">Minimize image</button><button data-test-edit-image-button="true">Edit image</button><button data-test-delete-image-button="true">Delete image</button><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1711519984882-1711519984882.png" alt="" class="fr-fic fr-dii"></div><figcaption>Figure 2.&nbsp;The ability to directly print a wide spectrum of materials</figcaption></figure><figure><div contenteditable="false"><button data-test-resize-image-button="true">Minimize image</button><button data-test-edit-image-button="true">Edit image</button><button data-test-delete-image-button="true">Delete image</button><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1711519982775-1711519982775.jpeg" alt="" class="fr-fic fr-dii"></div><figcaption>I will &nbsp;present at the Future of Electronics RESHAPED USA in Boston 12-13 June 2024 --&gt;&nbsp;<a rel="noopener noreferrer" href="https://www.techblick.com/electronicsreshapedusa" target="_blank">https://www.techblick.com/electronicsreshapedusa</a></figcaption></figure>Environmental Friendliness: Ink-based printing often necessitates complex ink formulations, storage, disposal, and cleaning procedures. Solvents and other hazardous materials can pose environmental and health risks. Dry printing, however, bypasses these concerns entirely. By utilizing solid targets as a source for on-demand and in-situ pure nanoparticle generation, dry printing eliminates the need for harmful solvents and additives, leading to a cleaner, more sustainable, and environmentally sustainable manufacturing process.<figure><div contenteditable="false"><button data-test-resize-image-button="true">Minimize image</button><button data-test-edit-image-button="true">Edit image</button><button data-test-delete-image-button="true">Delete image</button><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1711519984450-1711519984450.png" alt="" class="fr-fic fr-dii"></div><figcaption>Figure 3.&nbsp;The game-changing advantages of NanoPrintek’s dry printing technology</figcaption></figure>Cost Efficiency: Dry printing technology significantly reduces production costs compared to traditional ink-based techniques. By eliminating the need for timely and costly ink formulation processes as well as consumables like inks and solvents and minimizing waste and downtime associated with cleaning, dry printing offers a more economical solution, leading to tens of thousands of dollars in savings per year.Potential Precision and Resolution Enhancement: Due to the nanoscale size and purity of the dry nanoparticles, dry printing enables higher precision and resolution in the deposition of electronic materials. This opens the possibility of creating intricate circuit patterns and fine features, leading to improved performance and reliability of electronic devices.<figure><div contenteditable="false"><button data-test-resize-image-button="true">Minimize image</button><button data-test-edit-image-button="true">Edit image</button><button data-test-delete-image-button="true">Delete image</button><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1711519984815-1711519984815.png" alt="" class="fr-fic fr-dii"></div><figcaption>Figure 4.&nbsp;Example of dry printed lines without sintering (a) and with real-time sintering (b, c).&nbsp;</figcaption></figure>Compatibility with Diverse Substrates: Unlike ink-based printing, which may have limitations in terms of substrate compatibility, dry printing offers greater flexibility. It can be used on a wide range of substrates, including flexible materials like plastics and paper, as well as rigid surfaces like glass, ceramics, and even FR4 substrates, expanding the possibilities for product design and innovation.<figure><div contenteditable="false"><button data-test-resize-image-button="true">Minimize image</button><button data-test-edit-image-button="true">Edit image</button><button data-test-delete-image-button="true">Delete image</button><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1711519984945-1711519984945.png" alt="" class="fr-fic fr-dii"></div><figcaption>Figure 5.&nbsp;Enabling the printing on a wide spectrum of substrates c).&nbsp;</figcaption></figure>Improved Durability and Longevity: The materials deposited through dry printing electronics often exhibit superior durability and longevity compared to those applied using ink-based methods. This is due to the lack of surfactant and contaminations during the real-time sintering process, which allows better particle-particle fusion and a cleaner interface with the substrate. This results in electronic devices that are more resistant to wear and environmental factors, prolonging their lifespan and enhancing overall performance.Versatility in Applications: Dry printing electronics offers versatility in its applications across various industries, including consumer electronics, automotive, healthcare, and beyond. Whether manufacturing flexible electronics, RFID tags, sensors, energy devices, or smart packaging, this technology can adapt to diverse needs and requirements.In conclusion, the advantages of dry printing electronics over ink-based techniques are indisputable. From cost efficiency and environmental friendliness to enhanced precision and versatility, this disruptive technology is reshaping the landscape of functional devices and electronic manufacturing. As advancements continue to propel the field forward, NanoPrintek's dry printing technology promises to unlock new possibilities and drive innovation across industries.<a target="_blank" rel="noopener noreferrer" href="https://www.techblick.com/electronicsreshapedusa">We are Exhibiting at the Future of Electronics RESHAPED event in Boston (12 &amp; 13 June 2024) :&nbsp;</a><a rel="noopener noreferrer" href="https://www.techblick.com/electronicsreshapedusa" target="_blank">https://www.techblick.com/electronicsreshapedusa</a><figure><div contenteditable="false"><button data-test-resize-image-button="true">Minimize image</button><button data-test-edit-image-button="true">Edit image</button><button data-test-delete-image-button="true">Delete image</button><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1711519982835-1711519982835.png" alt="" class="fr-fic fr-dii"></div><figcaption data-placeholder="Add caption for image (optional)"> </figcaption></figure>

Multi-material printing without inks? The technology’s on-demand and in-situ nanoparticle generation and real-time sintering capability allow the printing of various electronics and functional devices with pure, multifunctional, hybrid materials printing - without inks and with bulk properties!

Dry Multimaterial Printing Technology: Unraveling New Realm of Possibilities in Printed Electronics

The TechBlick Innovations Festival, happening online on April 25, 2024, is a curated event for engineers, researchers, entrepreneurs, and inventors, focusing on advancements in additive, printed, 3D, and wearable electronics, among other topics.&nbsp;It features networking opportunities and an immersive virtual exhibition. Attendees can expect talks from leading global speakers representing companies like SPGPrints, ACI Materials, and Akoneer, covering topics such as scaling printed electronics from lab to production, transformative conductive inks, and semiconductor packaging innovations. For more details, <a href="https://wevlv.co/techblick24eventdetails" target="_blank" rel="noopener noreferrer">visit the event page</a><a href="https://www.techblick.com/event/spring_innovations_festival" target="_blank" rel="noopener noreferrer"></a><a href="https://www.techblick.com/event/spring_innovations_festival" target="_blank" rel="noopener noreferrer">.</a>The last Innovation event had over 700+ participants [not registrants]! Do not miss this opportunity! There are simultaneous events throughout the day, including presentations from Neibling, NanoPrintek, TracXon, Kimoto, and more.&nbsp;The cutting-edge virtual environment enables you to meet other participants, attend events, and discover new technologies.&nbsp;<a href="https://wevlv.co/techblick_innovation_24" target="_blank" rel="noopener noreferrer" class="button-main-action">Register now!</a><h2 dir="ltr" id="isPasted">Speaker Highlights</h2>The event features a wide range of speakers covering all aspects of the additive and flexible electronics sector. Following are some of the highlights of notable speakers and their topics from Track 1 and Track 2:<h3 dir="ltr">Highlights from Track 1</h3>Innovating with TFT technology in both optoelectronic and biological ways — Partner and Co-CEO of LinkZill,Yixing Yang, will speak about TFT semiconductor technology and its applications in various fields of optoelectronics and life sciences such as large-area bio-sensing, novel display, high-throughput DNA synthesis, and in-vitro diagnostics (IVD).Scalable, customizable, multimodal electrode platform for biosensors and sensors — Healthcare Marketing Director of Linxens,&nbsp;Christelle Robellin, will speak about the latest advancements in Point-of-Care Diagnostics enabled by Linden’s innovative manufacturing process. She will cover recent developments in electrode design, surface coating, microfluidics, and connectivity, highlighting their applications in continuous monitoring of glucose, wound healing, water quality, and sports performance.Advances in wash testing of conductive inks for wearable electronics — Business Development Manager of Nagase ChemteX America Corporation (NCU),Alan Brown, will address the significant challenges faced by conductive inks when applied in wearable applications, with a particular focus on washability—the most formidable obstacle among them.&nbsp;Beyond paper: Inkjet printing is the future in drops — Manager of Sales and Services of Suss MicroTec,&nbsp;Peter de Vrieze, will discuss groundbreaking technologies aimed at advancing the field of printed electronics. De Vrieze will spotlight the latest advancements in analysis tools, ranging from cutting-edge dropwatching technologies to intelligent inspection tools.<h3 dir="ltr">Highlights from Track 2</h3>Demonstration of flexible and printed electronics production using INO PE Line A7 — representing INO Sales US,Nivas Vehar will demonstrate the production process of flexible and printed electronics through three-color screen printing, showcasing zero scrap and exceptional efficiency. After the demonstration, attendees can engage in a Q&amp;A session to explore the complexities of this cutting-edge process.Going maskless for semiconductor packaging with SSAIL — CCO of AkoneerTadas Kildusis, will introduce SSAIL technology, enabling direct copper deposition onto organic and dielectric materials. He'll discuss its applications in RDL, fanouts, and heterogeneous integration, emphasizing high adhesion for reliability in automotive and defense.Laser Patterning of sputtered coatings for high-volume production of flexible devices — Mechanical Engineer at Intellivation LLC,Matthew Kleyn, will discuss advanced roll-to-roll (R2R) solutions using vacuum coatings and laser patterning to meet the demand for high-volume flexible devices across industries. He'll emphasize optimized process controls and the importance of modularity and scalability for high-volume production.High Pressure Forming (HPF) for In-Mold Electronics (IME) processes — Director Sales &amp; Marketing at Niebling GmBH,Udo Weustenhagen, will speak about the importance of precise 3D substrate forming for In-Mold Electronics (IME). He will cover the alignment of conductor tracks, electronic components, and graphics within injection tool cavities. Weustenhagen will introduce the high-pressure forming process, highlighting its benefits over traditional methods, including lower temperatures and clever automation for series production.For the full list of speakers and presentation times, <a href="https://www.techblick.com/event/spring_innovations_festival" target="_blank">visit the event page.</a>

Engineers, researchers, entrepreneurs, inventors, and end users are invited to join TechBlick Innovations Festival, exploring additive, printed, 3D, and wearable electronics on 25 April 2024 online.

TechBlick Innovations Festival

Author: FERNANDO ZICARELLI (Printed Electronics Product Manager) |&nbsp;<a target="_self" href="mailto:f.zicarelli@e2ip.com" data-test-app-aware-link="">f.zicarelli@e2ip.com</a><a href="https://www.linkedin.com/company/e2ip-technologies/" data-test-app-aware-link="" target="_blank">E2IP TECHNOLOGIES</a> manufactures Flexible Heaters using Screen Printing Technology. We use flexible and conformable inks for the manufacturing of our heaters. Printed heaters can be manufactured in high volumes using print processes such as flatbed, rotary, and roll-to-roll presses. The size of the order and complexity of the device determines the equipment that we would use.Typical applications are Airplane/Automotive interiors, Battery and fuel cell heating, Hand tools, De-icing, Defogging, Medical, Display panels or touchscreens, Food and drink tempering, Heating for trains, mobile homes, and caravans.<figure><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1710066396502-1710066396501.png" alt="" class="fr-fic fr-dii"></figure><figure><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1710066396285-1710066396285.png" alt="" class="fr-fic fr-dii"><figcaption>Join us and the global industry in Boston on 12 &amp; 13 June 2024. Register before early bird expires on 22 March 2024. Explore program here&nbsp;</figcaption></figure>Thermal Management Solutions is a hot topic of discussion in recent months; we at E2IP Technologies have multiple solutions for every application. We currently make 4 types of heaters: Serpentine (left picture), Resistive, PTC (right picture) and Transparent heaters (see below).Each type has its advantages and disadvantages which are highlighted below:&nbsp;A. &nbsp; &nbsp; &nbsp;Serpentine heaters are made with metallic pastes which are screen printed with materials such as silver, copper, silver/carbon, graphene, and our own Silver Salt Minks. &nbsp;They are a very cost-effective solution since most of the time you only need one single printed layer of a serpentine pattern (as electricity flows through the conductive traces by applying specific voltage levels will cause the metal to heat up). &nbsp;These types of heaters are usually printed on PI, PC, PET, Kapton and TPUs.&nbsp;B. Fixed Resistance heaters combined a layer of silver paste with a resistive paste to obtain the desired value. Mixing of the resistor inks is one of the most important steps in the manufacturing of these heaters. They normally require only 2 printing steps, but a dielectric layer is sometimes added to protect from physical damage. They can be printed on PI, PC, PET, Kapton and TPUs as well.&nbsp;C. PTC heaters are made with conductive inks and a specialty formulated carbon inks (for temperature output) which are arrayed in parallel as resistors tiles. As electricity flows through the conductive traces to the carbon tiles, the temperature increases in the tiles (and so does the resistance). Both the temperature and the resistance will continue to rise until the resistance is too high for electricity to flow through (this is called the Shut-off point). Afterwards, the tiles begin to cool down until the resistance is low enough for the electricity to begin flowing again. PTC heaters normally require only 2 printing steps, but a dielectric layer is sometimes added to protect from physical damage. They can be printed on PI, PC, PET, Kapton and TPUs as well.&nbsp;D. Transparent Heaters are new to the industry and are becoming essential for LiDAR (Light Detection and Ranging) and other applications. The technology sends beams of light towards and object and then it measures the time it takes for the reflections to be detected by the sensor. These heaters are printed grids of silver with different levels of line widths and pitch distances. 90-100% transparency is not needed for applications where defrosting and defogging is needed, but in the case of cameras and sensors, it is absolutely required. Very specific substrates are used for this technology as the surface tension is extremely important to be able to produce fine line patterns.<figure><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1710066397327-1710066397327.png" alt="" class="fr-fic fr-dii"></figure> Flexible printed heaters rely on a range of conductive, resistive, and dielectric pastes which are deposited on flexible substrates, such as thermoplastic polyurethanes (TPU), polyester (PET) and Kapton. Through specific patterns and deposition levels, our engineers tailor flexible heaters to meet specified operating parameters based on the application. Printed heaters typically have a good bend radius which is a function of the materials used and heater thickness. A good rule of thumb for a flexible printed heater is to have a minimum bend radius of 0.4 in. (1 cm). We recommend that power supplied to the heater to be constant for the temperature to remain constant.For a Typical PTC Heater, the selection of the correct ink is essential to obtaining the desired; below you can see the temperature range and electrical specifications: <ul><li>Input voltage: 5 to 250 V (AC or DC)</li><li>Drive current: at startup less than 2 A</li><li>PTC inks available: 40°-115°C</li></ul> Thermal Management Solutions are different in most cases, we would like to encourage anyone to contact our Technical Team to discuss your application.Author: FERNANDO ZICARELLI (Printed Electronics Product Manager) |&nbsp;<a target="_self" href="mailto:f.zicarelli@e2ip.com" data-test-app-aware-link="">f.zicarelli@e2ip.com</a>Join the global industry in Boston and Berlin and let us RESHAPE the Future of Electronics.&nbsp;<a target="_self" href="https://www.techblick.com/registration" data-test-app-aware-link="">Register before 22 March 2024 for early bird rates</a><figure><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1710066397129-1710066397129.png" alt="" class="fr-fic fr-dii"></figure>

E2IP Technologies manufactures Flexible Heaters using Screen Printing Technology. This is one of the most important segments of printed and additive electronics with applications in cars, homes, and industrial settings. 

Thermal and Heating Solutions for Printed Electronics

Surface energy is a fundamental topic with implications in nearly every field of engineering, and frankly, it can be a bit mind-boggling. In the world of printed electronics, surface energy often comes up around the interactions of materials, specifically when we’re printing conductive inks onto various surfaces (substrates). While there are several factors that determine if an ink and a substrate will work together, surface energy plays its own very specific role. Let’s dig a bit deeper into how surface energy works, and more importantly, how it can impact&nbsp;your&nbsp;work.&nbsp;If you use&nbsp;<a href="https://www.voltera.io/blog/introduction-inkjet-technology" target="_blank">inkjet</a> technology, then the surface energy rating of your materials is a key determinant in whether or not an ink will be compatible with a substrate. Due to their low viscosity, inkjet inks are significantly impacted by surface energy. But, when you read the surface tension rating on your ink, how does it translate into the compatibility of your materials?&nbsp;If you’re using low-viscosity inkjet inks, then read on, because surface energy has a big impact on your materials' compatibility.&nbsp;If you’re using high-viscosity screen-printable inks, surface energy isn’t really a concern for you, but there are several other factors to consider when you’re trying to figure out whether an ink and substrate are compatible. Stay tuned for a future blog post covering this!<h3>Sci-Snack</h3><a href="https://www.voltera.io/blog/what-is-viscosity" target="_blank">Viscosity</a>&nbsp;is the measure of a fluid’s resistance to flow, due to the internal friction of the fluid. Low-viscosity inks, like inkjet inks, have very little friction between the molecules of the ink, so the match or mismatch of surface energy has a significant impact on how your ink and substrate interact.&nbsp;High-viscosity screen-printable inks have a lot of friction between the molecules in the ink. Molecular friction helps these inks hold their shape and stay where you put them, regardless of the surface energy of the substrate to which they are applied.&nbsp;<h2>What is surface energy and how does it work?</h2>Surface area&nbsp;is the measure of the total area that the surface of the object or liquid occupies.Surface energy&nbsp;is the amount of energy required to increase the surface area of a material. It applies to liquids and solids.In other words, it’s the energy required to increase the space between the molecules. The surface energy of your ink and the surface energy of your substrate — and how those two energies interact — will dictate if your ink spreads out on the substrate, forms nice contained traces, or beads up like water on a non-stick pan.&nbsp;Surface energy manifests itself in&nbsp;surface tension&nbsp;— when a liquid minimizes its surface area due to the cohesive forces between the molecules. Surface tension occurs in liquids only, never gasses or solids. Surface tension is calculated by measuring the surface energy over a surface area.&nbsp;This concept might seem complex, but if you look around, you’ll see examples of it everywhere in your day-to-day life. Right now, there’s a viral trend all over TikTok that demonstrates the cohesive forces between water molecules. You’d recognize it as “<a href="https://twitter.com/overtime/status/1509659771993042949?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1509659771993042949%7Ctwgr%5E9eaf2411d9aaf80dbe5a8f8d579d14cedd5f5df6%7Ctwcon%5Es1_c10&ref_url=https%3A%2F%2Fkotaku.com%2Fembed%2Finset%2Fiframe%3Fid%3Dtwitter-1509659771993042949autosize%3D1" target="_blank">The Water Cup Challenge</a>”.&nbsp;In the water cup challenge, players take turns adding drops of water to a full cup. The objective is to gradually add water to the cup, and reach the threshold of surface tension without the water overflowing. The literal tension of the players builds as the surface tension of the water reaches its threshold, mushrooming above the rim of the cup, yet miraculously holding itself together. Eventually the water overflows, and the loser who poured that critical last drop gets thrown into a swimming pool. Fun times.<h3>Sci-Snack</h3><ul><li>Surface area&nbsp;is the measurement of the total area that the surface of the object or liquid occupies.</li><li>Surface energy&nbsp;is the amount of energy required to increase the surface area of a material. It applies to liquids and solids.‍</li><li>Surface tension&nbsp;is when a liquid minimizes its surface area due to the cohesive forces between the molecules. Surface tension occurs in liquids only, never gasses or solids.</li></ul>To demonstrate the concept of surface tension at the molecular level, we’re going to take a look at penguins. When it’s really cold out, penguins form a huddle to share body heat. Think of any material as a penguin huddle and the penguins are molecules. The penguins on the outer edge of the huddle — the ones at the surface — are very tightly packed together, trying to preserve heat. You can imagine that these surface penguins would be pretty difficult to remove or push around. The desire of the penguins to stay close together is like the surface tension or surface energy between molecules or atoms.&nbsp;If it’s a warm day, the penguins spread out, increasing the surface area they occupy.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA3MjEwMzUzODU5LTYzNzNiZDI2YWYwZjkxZjQ2MjUwMDMzY19zN3d6T3ktcDltZHJTTlptTEcxa0l2OFFhRU9FOWVPVnc4ZWprOVpUejZYR21Ia0VEQk5DQnN1LUduNGFPMm81WEZIUUFWellHb2sxTS00QjV2M0IybzZSSmxKSDZCMVZGSWtPWS1ZRVNTaDRQRnpLNERMc2s2c01UcHYtTGpNQ3FzY1Q4NXJ0ejBGeE5TV1RlRjVDX1hpX0xCeVFfRmZMdUxENzMyTE5YTENGSlZDekVQbVRpbXA2Y05TZi5qcGVnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib">If it’s cold outside, the penguins huddle together tightly to share body heat, reducing the surface area they occupy.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA3MjEwMzcxNjQ2LTYzNzNiZDNmNjM5YTUyMjI3ZTc5MjYxOV9mUFVDZTdWLUdObE9MeHY1X3gzV1FkVi1aQlBuaGhzeDJFSDFiRHhyNjFtdXlvUHlfNVRqUXNYUDd6VkNyZldkWTg0d0R2R1lqWFVsblRqYVgydHFLa0hueWZZSlNsTXJ2WFdtLU9EcFlmNllUZGV3Q0JxMjlKdjh0VDNlTl9QLTIzME14NHdyNXZ5RE9qNGYtbTB6REJFTDVmQS14bmY1cmtRNlhZQWlqdmc3aFJaanNodm9McmlDbDhnQS5qcGVnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib"><h3 id="isPasted">Sci-Snack</h3>If a material has&nbsp;high surface energy, that means it’s going to take a lot of energy to change the surface area of the material, so it’s going to be resistant to change. Materials with high surface energy include glass, ceramic, and most metals (and cold penguins).If a material has&nbsp;low surface energy, that means it will change its surface area relatively easily. Materials with low surface energy include soft low-density plastics like vinyl, polystyrene, and polyethylene.&nbsp;Liquid mercury, as another example, has incredibly high surface tension. When poured onto a surface, the liquid mercury pulls itself together into a perfect sphere. A sphere is the easiest way for a substance to minimize its surface area.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA3MjEwMzg2ODY2LTYzNzNiZDU3YTQyMTdmMmEwMTNjZTNiMV8tUTFkNUw3NFhCdlBCdWlYWmZmZlZMYTNLNzJWUXFLTmJGS1RLTDNhdW1aaXFCY29QaUxoRXowd2x5amxySDE4U0RSWjY5UTdNbEdsYXNuS1pHSXhZMEVjcC1PYXEzWWs1eGJRMGU1SkpWb2hlWDZCX0t4RDQyQ0pRYTRRdUpuMTgzc3B1RUNaSEkyRDdBME9iZ1VZRU9HZDdVc0QyQm9HNFZ0cVV4UHpobGZXT2lCa2kxQnhkR3RmNzV3aHYucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib">In the iconic film Terminator 2, the terminator is smashed to pieces, and then liquifies into molten metal and pulls back together into the shape of a man. This is a great science-fiction demonstration of surface tension.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1707210457655-ezgif-3-db889fabbf.gif" style="width: 300px;" class="fr-fic fr-dib">Each material has its own surface energy rating based on the chemical makeup of the material. This applies to liquids (inks) as well as solids (substrates).When you deposit ink onto a substrate, the interaction between the ink and the substrate’s respective surface energies can result in changes to the shape of your traces. This is where you’ll see your ink do one of three things — become very runny and flat, contain itself properly, or bead up.You can determine the difference in surface energies between an ink and a substrate by measuring the contact angle — the angle of the ink droplet relative to the substrate. This angle determines if a liquid is spreading, wetting well, or not wetting at all.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA3MjEwNTAxMDAwLTYzNzNiZDdhNDM1MzkxNWUwY2JkNjI2Nl81a1h4TFExRkZsUEhkQjU2UndUVUNkUWh1cXFIWUFKZ0JjTGZiQ2pnZTIyaGV1UFJoblNlYzZsZ0hlSkNOVUUyMmEweW5UdW1talFYbzcwM0ZVUTBjSzVLcHpacGNlQ0lpZGs2NEF1T29UTVhRQW9UVzJ1LVdPcDNaeDF3TFZEa1QwLUs2Um1leXdvbEJ1ZzRSR3hMSUN4WEh4SldTbkMwQVVOTFJBVDRFRXBDcWVDNVF3aFdQOWRXc1RVMi5qcGVnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib"><h2 id="isPasted">Matching the surface energies of your ink and substrate</h2>The shape-quality of your traces depends on how well you’ve matched the surface energy of your ink and substrate. If the surface energies of these materials are relatively similar, then the ink and substrate will interact compatibly. You’ll get nice traces that contain themselves and stay where you put them.&nbsp;If the surface energies of your ink and substrate are quite different, they are incompatibly matched. Surface energy forces are going to change the shape of the ink and you’ll end up with traces that either bead up, or spread out too much.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA3MjEwNTM2NTIxLTYzNzNiZGE2YzZlOGEzZDBjMjBhNDY5N19FNi0wRVJXd09Eb01yUzh6UXhRNGRhZmVTendxSnl3bWNyNXBBcG9leGJxdXczTVFpRzVqZzhTSXVyMl9oSzJETy1RVHlZbUZ5bEs4WVYzaU1sRG10ZWFlM1I4Vl81ZlVYM294elhNNGVhSHlxZzd4OHExZzVPQlhJclBvNFRjVHpPRU8wc2hpM1ZVYzRHWWVKdXBabTFoc01mWjlFd2NLZDlxLXhCYlotcnoySk55WjhDQjExbXhQRmZ3Y0oucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib">Inks have different surface tension ratings, and substrates have different surface energy ratings, which influence how these materials interact. The objective is to find a match between the surface energy of the substrate and the surface tension of the ink, resulting in traces that make a nice domed shape and hold together properly: &nbsp;Take a look at how inks with surface tension ratings of 30 and 60 interact with different substrates.&nbsp;First, let’s take a look at different inks on polyimide. The ink on the left has a low surface tension rating of 30, and it wets and spreads out a bit too much. The ink on the right has a high surface tension rating of 60, and it beads. Based on how the inks perform, we can deduce that the surface energy of the polyimide substrate is somewhere in between 30 and 60.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1707210551204-6373c500a4217f28973d6f3a_Polyimide+Viscosity_optimized.gif" style="width: 300px;" class="fr-fic fr-dib">In this example, the same inks are applied to a sheet of PET with silica flakes to promote adhesion. The ink with a surface tension of 30 wets out significantly, flooding the substrate. The ink with a surface tension of 60 still beads a bit, but it’s closer to the kind of match you’d want for traces.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1707210574950-6373c54100a60421a99cdfa6_PET+Viscosity_optimized.gif" style="width: 300px;" class="fr-fic fr-dib">Now look at how these inks perform on the same PET, but without the adhesion promoter. The ink with a surface tension of 30 wets out a bit. The ink with a surface tension of 60 beads significantly.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1707210597173-6373c58100a60485769ce6c4_PET+Adhesion+Promoter+Viscosity_optimized.gif" style="width: 300px;" class="fr-fic fr-dib">Next, we tried an ink with a surface tension rating of 44, in between our bookends of 30 and 60. Check out how this one interacts with the three different substrates:<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1707210784581-ezgif-3-e49a46355c.gif" style="width: 300px;" class="fr-fic fr-dib"><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1707210832807-ezgif-3-68b99b268c.gif" style="width: 300px;" class="fr-fic fr-dib"><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1707210877485-ezgif-3-c854dd3a7b.gif" style="width: 300px;" class="fr-fic fr-dib">Based on the way the 44 dyne pen behaves, what does this tell you about the surface energy of each of the substrates? &nbsp;<h2>So what does this mean for choosing an inkjet ink?</h2>If your surface energies don’t match, it can be very challenging to get a good quality print. Unfortunately, every substrate is different, so prepare yourself for a lot of trial and error. There are some options to modify the surface energy of your substrate, if you’re willing to roll up your sleeves and do some lab work. We consulted with a friend, <a href="https://uwaterloo.ca/sensors-integrated-microsystems-lab/people-profiles/krishna-iyer" target="_blank">Krishna Iyer</a>, Optical Systems Engineer at University of Waterloo's <a href="https://uwaterloo.ca/sensors-integrated-microsystems-lab/" target="_blank">Sensors and Integrated Microsystems Laboratory</a>, to learn more about surface energy modification:<ul><li>Surface treatments&nbsp;— substrates can be treated to help match the surface energy of the ink. Surface treatments include surfactants (anionic, cationic, zwitterionic, or amphoteric), as well as plasma, corona, or acid/alkaline surface treatments.&nbsp;</li><li>Temperature —&nbsp;temperature doesn’t directly affect surface energy, but it does affect viscosity. By controlling the processing temperature, you can have a significant impact on the coverage of your ink or coating material.&nbsp;</li><li>Surface coatings —&nbsp;you can add coatings to affect the surface energy of your substrate while still preserving the mechanical properties. For example, coating PET with an adhesion promoter, or coating a surface with Teflon.&nbsp;</li><li>Surface preparation —&nbsp;there are inexpensive, accessible, non-chemical approaches to making a surface more favorable for wetting. For example, a surface with higher roughness increases the surface area and improves wetting without affecting the surface energy, but this can have the opposite effect if roughness is too high (see <a href="https://www.youtube.com/watch?v=54lDqR6LU8E" target="_blank">Wenzel effects</a>).&nbsp;</li></ul>With higher viscosity screen printing inks, like those used with <a href="http://voltera.io/nova" target="_blank">NOVA</a>, the internal friction of the ink makes it less impacted by surface energy effects. This enables you to print on a much wider variety of materials without changing your formulation, so you may want to consider switching technologies to avoid the headache.&nbsp;

In the world of printed electronics, surface energy often comes up around the interactions of materials, specifically when we’re printing conductive inks onto various surfaces (substrates).

What is Surface Energy?

<h2 dir="ltr" id="isPasted">The Evolution of Electronics</h2>The history of electronics dates back to the late 19th century, with the discovery of electrons and the ability to control the electric current flow between them using vacuum tube devices. Of course, electronics today bear little resemblance to turn-of-the-century electronic systems, and this is due in large part to the emergence of printed circuit boards (PCBs). While the first technology to begin to resemble a PCB was patented in 1903 by German inventor Albert Hanson, the electronic devices, which connect wires in a circuit, would not be widespread until the 1960s, with the integration of printed circuit boards into consumer electronics like televisions and home radios. At the time, PCBs offered a number of benefits over existing circuit boards: they were lighter, smaller, and cheaper to produce.&nbsp;Over the next decades, printed circuit boards would continue to evolve, with manufacturers finding ways to make the circuitry even more compact and cost efficient. For example, the ability to create multiple layers within a single PCB opened the door to smaller electronic systems with more capabilities.&nbsp;Flexible electronics were also developing over this time, evolving significantly from their earliest iterations in the early 20th century (metal conductors mounted on wax-coated paper). In the 1960s, for example, flexible solar cells made from thin silicon were invented. Following this, the development of conductive polymers and other material advances paved the way for today’s flexible electronics.Additive technologies, like 3D printing, are now at the cutting edge of both non-flexible and flexible electronics. This technology involves the deposition of conductive and insulating materials onto a substrate to create a circuit. Additive solutions like <a href="https://hubs.ly/Q029xhJN0" target="_blank">Voltera</a>’s high-resolution printing platform are unlocking more opportunities for rigid and flexible electronics by expanding design possibilities and enabling a greater range of materials. In this article, we will be focusing specifically on additively manufactured flexible electronics, looking at how they are made, what benefits they offer, how they can be used, and more.<h2 dir="ltr">What are Flexible Electronics?</h2>Flexible electronics are a type of electronic device characterized by their ability to flex, stretch and/or conform. Unlike rigid PCBs, this means they can bend without breaking, expand or stretch and return to their original shape, and adapt to whatever surface they are applied to. In the simplest terms, flexible electronics are achieved by mounting flexible conductive elements onto a flexible substrate, typically made of plastics like polyimide or polyethylene terephthalate (PET), or other flexible materials like paper or metal foil.<h3 dir="ltr">Materials and Components</h3>Flexible electronics typically utilize a range of specialized materials to achieve their unique properties. The most common substrate material is polyimide, valued for its excellent thermal stability and flexibility. PET is another popular choice, due to its cost effectiveness and good mechanical properties. For the conductive elements, materials like silver, copper, and conductive polymers are widely used as they offer both excellent electrical conductivity and ductility.&nbsp;Transparent conductors like indium tin oxide (ITO) or conductive polymers are used for applications requiring transparency, such as in flexible displays. These materials are carefully chosen to ensure that the final electronic device retains its flexibility, durability, and functionality, meeting the demands of various applications in fields like healthcare, consumer electronics, and wearable technology.In the manufacture of flexible electronics, printing techniques such as inkjet printing, screen printing, and roll-to-roll printing (R2R) are often employed. Inkjet printing, for example, is a non-contact process that involves jetting tiny ink droplets using an array of nozzles onto a substrate. Some specialized inkjet printers, such as Voltera’s NOVA system based on its direct-ink-write technology, are designed to deposit a wide range of materials, such as conductive inks, with ultra-precise accuracy on various substrates.&nbsp;<h2 dir="ltr">Applications of Printed Flexible Electronics</h2>While printed flexible electronics are still in their infancy, the potential applications for these devices is vast. Flexible electronics with small footprints are being investigated across many industries, from healthcare, to energy, to consumer goods, to make more efficient and innovative products. Let’s take a look at some application areas for printed flexible electronics.<h3 dir="ltr">Wearable Technology</h3>Flexible electronics have numerous applications in the field of wearable tech, and have a big impact on how devices fit on our bodies and integrate with our daily lives. For example, fitness trackers made from flexible electronics can be integrated into wearable bands or even clothing that users can wear during exercise or daily activities. The flexibility of these devices ensures they remain unobtrusive, conforming to the body's movements while accurately tracking physical activity and vital signs. For wearable applications, electronics are printed onto a flexible material, which can then be applied directly to the surface of the wearable. In one study, Voltera’s technology was used to print a wearable heater, which was successfully applied to a pair of denim jeans resulting in a functional heating patch.<h3 dir="ltr">Medical Devices</h3>The medical field is also increasingly interested in leveraging flexible electronics for the development of advanced medical devices. Wearable health monitors utilize flexible electronic circuits to conform to the contours of the human body, providing continuous, real-time health monitoring without causing discomfort or hindering the wearer's movement. Such wearable monitors can track a variety of health metrics, including heart rate, blood pressure, oxygen saturation, and even electrocardiogram (ECG) readings. The flexibility of these electronics is crucial, as it allows the sensors to maintain close contact with the skin, ensuring accurate and consistent data collection. For example, a researcher at York University recently investigated &nbsp;the use of printed flexible electronics for <a href="https://youtu.be/MEW3q7GKYQA" target="_blank">biomedical tattoos</a>, which conform to the patient’s skin for greater comfort. These could be used to capture ECG readings, to integrate with prosthetics, and more.<h3 dir="ltr">Consumer Electronics</h3>While still a nascent application area, there is huge potential for flexible electronics in consumer electronics. A striking example is the development of flexible displays used in smartphones, laptops, and televisions. These displays utilize flexible electronic components to create devices that are lighter and thinner than their traditional counterparts and offer new form factors such as foldable or rollable screens. These flexible screens could also be used in cars or in wearables, eliminating previous design restrictions on media and consumer electronics by being more adaptable.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1701871597307-LG+display.jpg" style="width: 300px;" class="fr-fic fr-dib"><figcaption id="isPasted">Smashed phone screens could eventually be a thing of the past thanks to ultra-flexible stretchy display tech.</figcaption>&nbsp;<cite>Image: LG Display</cite> <h3 dir="ltr">Robotics and Automation</h3>Robotics can also benefit from flexible electronics, as the technology opens up the door for pliant and deformable soft robots that can be integrated directly with sensors or electronics components. These soft robots can interact safely and efficiently with humans and complex environments, and can handle even the most fragile components in production or assembly lines. And that’s just the tip of the iceberg: robots with stretchable bodies could also have exciting applications in healthcare, search and rescue, and more.&nbsp;<h3 dir="ltr">Energy</h3>Flexible, stretchable, and conformable electronics also have the potential to transform certain applications in energy. For example, the ability to directly print flexible electronics can enable the seamless integration of solar panels onto various surfaces, from architectural designs to portable applications, and offer improved durability and aesthetic adaptability. There is also growing interest in the development of flexible energy storage devices (FESDs), which could be used to power wearable tech and other flexible electronic products without the need for a bulky power source or wiring.<h1 dir="ltr">Voltera's NOVA&nbsp;</h1>In the rapidly evolving field of printed electronics, Canadian company <a href="https://hubs.ly/Q029xhJN0" target="_blank">Voltera</a> is doing something highly unique. It develops and supplies dispensing systems for the rapid prototyping of printed electronics, from traditional circuit boards to flexible, stretchable, conformable, and biocompatible electronics. Their approach enables users to quickly iterate and test designs, enabling faster design development and a more accessible method for industry experimentation and innovation. Notably, their systems don’t require expert knowledge and they can be used with a broad range of inks and materials enabling unfettered design freedom.&nbsp;<h3 dir="ltr">NOVA Printer</h3>Voltera’s NOVA printer enables high-resolution printing using a range of functional materials and screen-printable inks. The system works with a wide range of conductive and insulating inks, including copper, silver and carbon-based inks ranging from 1,000 to 1,000,000 cps. NOVA deposits these conductive and insulating inks onto various substrates, including flexible, rigid and heat-resistant materials, with incredible precision (capable of printing a line width of 100 µm and a resolution of up to 17 µm/pixel). In terms of flexible substrates, it is possible to print on materials like paper, polyimide films, PET, and more.Used by researchers and product developers to streamline their R&amp;D processes, NOVA enables on-the-fly design changes and immediate feedback on new ideas, significantly accelerating timelines and reducing costs. To date, NOVA has successfully been used to manufacture various printed electronic components, such as RFID tags, ceramic PCBs, strain gauges, electrodes on glass, FSR sensors, and FHE circuits.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1701871678248-splash_NOVA.png" style="width: 302px;" class="fr-fic fr-dib">The NOVA modular dispensing system.<ul><li dir="ltr"><h3 dir="ltr">Direct-Ink-Write Dispensing</h3></li></ul>At the core of the NOVA system is Voltera’s direct-ink-write dispensing technology, which eliminates the need for tooling, waste, and extensive cleanup. This approach results in a 90% faster iteration time and a 96% reduction in material costs, highlighting its efficiency and cost-effectiveness.<ul><li dir="ltr"><h3 dir="ltr">High-Resolution and Closed-Loop Dispensing</h3></li></ul>NOVA offers high-resolution, closed-loop dispensing, which ensures increased material options due to compatibility with a wide range of viscosities. This feature also reduces risk by allowing for the validation of designs and materials in the lab before transitioning to production. The printer achieves consistent results with integrated closed-loop pressure feedback and temperature-controlled dispensing, offering a line width as fine as 100 µm, depending on material properties and nozzle geometry.<ul><li dir="ltr"><h3 dir="ltr">Adaptability</h3></li></ul>The printer's large, configurable print area of 220 x 300 mm makes it adaptable to various applications. It can handle both rigid and compliant substrates, with a porous titanium vacuum table ensuring uniform suction for flexible and soft substrates. The mounting grid features allow for the development of application-specific fixturing, further enhancing the printer's adaptability.With its advanced features and capabilities, NOVA is poised to be a game-changer in the field of printed electronics, offering unparalleled flexibility, efficiency, and innovation in materials and design.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1701871716608-application_flexArduino.webp" style="width: 300px;" class="fr-fic fr-dib">Nova enables streamlined research and development with direct-ink-write dispensing.<h3 dir="ltr">Case Study: Robotic Hand and Control Glove</h3>To demonstrate NOVA's capabilities for flexible electronics, the Voltera team built a robotic hand and a control glove integrated with printed stretchable strain sensors and LED lights. The strain sensors are designed to light up when the glove’s wearer opens or closes their hand, and the brightness of the lights varies depending on the amount of strain on the sensors as the fingers move (i.e. the lights dim when exposed to increased resistance). These strain sensors were cleverly adapted to function as a control mechanism, using the degree of resistance experienced by the glove’s sensor to control the movements of a Bluetooth-connected robotic hand.The glove sensors were made by printing traces of DuPont PE874 stretchable ink on a DuPont TE 11-C TPU substrate, which were then heat-laminated onto the glove using a T-shirt press. Then, wires were attached to the glove traces using MG Chemicals 9400 conductive adhesive. Lastly, the robotic hand was 3D printed and integrated with five servo motors to move the fingers. An Arduino, connected via Bluetooth to the glove, controls the robotic hand’s movements based on the glove’s movements. The whole project took only two months to complete.Interestingly, strain gauges can be made by printing flexible conductive ink onto almost any stretchable material. The sensor-integrated glove demonstrates how this technology can be applied to a real-world robotics use case. It is also a fine example of how accessible the NOVA system is and how it can be used to develop new ideas and products on a rapid timeline.Check out the full case study <a href="https://uploads-ssl.webflow.com/6334888a34bfac03b46aa715/6362829f808f8037c5b5e9d9_NOVA-0094%20-%20Robot%20Glove%20Case%20Study_FINAL%20(4).pdf" target="_blank" data-lf-fd-inspected-kn9eq4roawkarlvp="true">here</a>. In addition, you can also find more case studies on <a href="https://www.voltera.io/case-studies" target="_blank">Voltera’s website</a>.&nbsp;<div dir="ltr" align="left"><table><tbody><tr><td><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzAxNzkzMDM3NzQ4LTE3MDE3OTMwMzc3NDgucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" width="587" height="205" class="fr-fic fr-dii"></td></tr><tr><td>Voltera’s Case Study Robotic Hand and Control Glove. Image credit: <a href="https://uploads-ssl.webflow.com/6334888a34bfac03b46aa715/6362829f808f8037c5b5e9d9_NOVA-0094%20-%20Robot%20Glove%20Case%20Study_FINAL%20(4).pdf" target="_blank" data-lf-fd-inspected-kn9eq4roawkarlvp="true">Voltera</a>.</td></tr></tbody></table></div><h2 dir="ltr">Future Potential &nbsp;</h2>The adaptability, robustness, and versatility of flexible, stretchable, and conformable electronics will positively impact multiple industries, particularly healthcare and wearables.&nbsp;Innovative manufacturing approaches, such as Voltera’s NOVA, enable the industry to advance at a pace unprecedented in electronics.&nbsp;<h2 dir="ltr">References</h2><ol><li dir="ltr"><h2>Zhao, Y., Kim, A., Wan, G. et al., 2019. “<a href="https://nanoconvergencejournal.springeropen.com/articles/10.1186/s40580-019-0195-0#citeas" target="_blank">Design and applications of stretchable and self-healable conductors for soft electronics</a>”</h2></li><li dir="ltr">Global Electronic Services. “<a href="https://gesrepair.com/future-of-flexible-electronic/" target="_blank">The Future of Flexible Electronics</a>”</li><li dir="ltr">Voltera. “<a href="https://uploads-ssl.webflow.com/6334888a34bfac03b46aa715/6362829f808f8037c5b5e9d9_NOVA-0094%20-%20Robot%20Glove%20Case%20Study_FINAL%20(4).pdf" target="_blank" data-lf-fd-inspected-kn9eq4roawkarlvp="true">Case Study: Robotic Hand and Control Glove with Printed Stretchable Strain Sensors</a>”</li><li dir="ltr">Cassiano Ferro Moraes, 2023. “<a href="https://www.wevolver.com/article/flexible-and-printed-electronics-breakthroughs-applications-and-challenges" target="_blank">Flexible and Printed Electronics: Breakthroughs, Applications, and Challenges</a>”</li><li dir="ltr">Guang Z., Wei Q., Tiejun Z. et al., 2014. “<a href="https://pubs.acs.org/doi/10.1021/nl5005652" target="_blank">Self-Powered, Ultrasensitive, Flexible Tactile Sensors Based on Contact Electrification</a>”</li><li dir="ltr">Karsten S., Nils N. and Martin S., 2019. “<a href="https://sci-hub.se/https://www.cambridge.org/core/journals/mrs-communications/article/abs/flexible-stretchable-conformal-electronics-and-smart-textiles-environmental-life-cycle-considerations-for-emerging-applications/9941A32DFC15BDE532DCB830C920AE2E" target="_blank">Flexible, stretchable, conformal electronics, and smart textiles: environmental life cycle considerations for emerging applications</a>”</li><li dir="ltr"><a href="https://www.sciencedirect.com/science/article/abs/pii/B9780128126400000056" target="_blank">Qing-Hua Lu, Feng Zheng, 2018. “Polyimides for Electronic Applications</a>”</li><li dir="ltr">Corzo D, Tostado-Blázquez G, Baran D. Flexible electronics: status, challenges and opportunities. Frontiers in Electronics. 2020 Sep 30;1:594003.</li></ol>

Exploring the transformative journey of flexible electronics and how additive manufacturing is the future.

Beyond Rigidity: The Rise of Flexible Electronics

This article is written by Sahar Al Kamand at Hummink as part of the TechBlick series on additive electronics.&nbsp;The Motivation Behind HPCAPThe evolution of printing technologies has always been driven by an important factor: increasing precision while diversifying applications. To accomplish this, HPCAP (High Precision Capillary Printing) developed by Hummink emerges as a groundbreaking technology that leverages the power of capillary forces and resonance without the need for other external factors reaching high resolutions and expanding the applications.&nbsp;Introducing HPCAP&nbsp;Drawing inspiration from Atomic Force Microscopy (AFM), HPCAP employs a macro-resonator as its primary sensing mechanism to provide feedback during contact and printing processes. What sets this technology apart is its exclusive reliance on capillary forces and resonance as the sole driving forces for printing, completely devoid of UV, laser, or pressure-based dispensing mechanisms. This mechanism employs a glass pipette, filled with various inks, as its printing tip. Its precise control mechanism and compatibility with a wide array of inks make it a promising solution for several high-resolution applications reaching as fine as 100 nanometers. In a way, it can be compared to the world's smallest fountain pen, enabling precision printing on a sub-micron scale.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY3MDgzNjg4LVNjcmVlbnNob3QgMjAyMy0xMS0wNiAxNDU5MDMucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 690px;" class="fr-fic fr-dib">How Does it Work?&nbsp;A macro-resonator (or tuning fork) oscillating at a resonance frequency of about 1 kHz is attached to a mechanical bridge. The oscillation is generated by a piezodither that excites the macro-resonator. The bridge, driven by a piezostage, allows the resonator to move with a 5 nm precision in Z axis (Z-fine). State-of-the-art electronics are used to control the resonance of the macro-resonator through three different parameters: the resonance phase, amplitude, and frequency. Any shift in these values can be controlled to achieve different printing features, indirectly modifying the print geometry (thickness, line width...). Amplitude can be adjusted between 5 nm and 100 nm, and any frequency shift of 100 mHz or more can be accurately detected. A glass pipette is attached to the extremity of the macro-resonator, and oscillates in phase with the latter. This pipette is made of a pulled glass capillary; and despite its fragility, the real-time detection of interaction between the substrate and the pipette avoids any uncontrolled damage to both the substrate and the pipette, while maintaining a high-quality dispensing mechanism. By controlling the pulling parameters (heat, force etc...), a wide range of pipette diameter can be achieved, from 100 nm to 50 μm. The pipette can be filled with various inks. Pipettes are typically filled with a few tens of microliters. Since the dispensed volume is in the nanoliter range (orders of magnitude lower than the pipette volume), a single pipette can print up to hundreds of kilometers, depending on the dispensing diameter.The figures below show that the first step of the HPCAP printing process is to approach the tip to the substrate surface. As the macro-resonator is oscillating at its proper resonance frequency, a slight change of a few hundreds of mHz can be observed once a small meniscus is formed between the ink inside the pipette and the substrate. The formed meniscus is stabilized by the macroresonator's oscillation, and this frequency shift is then locked by the electronic feedback loop. After this initial step, capillary printing can be achieved by moving the substrate in the XY axis. As the frequency shift value must remain constant, the Z-fine bridge will move the resonator (hence the pipette) in the Z direction to perfectly follow the topography of the substrate, while allowing continuous deposition. As explained earlier, the only driving force for printing is the capillary force and the resonance of the macro-resonator.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY3MjMxMDg2LVNjcmVlbnNob3QgMjAyMy0xMS0wNiAyMDEyMTAucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 737px;" class="fr-fic fr-dib"><a href="https://www.techblick.com/electronicsreshapedusa" target="_blank" rel="noopener noreferrer">Save the Date for The Future of Electronics RESHAPED show in Boston and Berlin</a><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699873715385-Screenshot+2023-11-13+120348.png" style="width: 704px;" class="fr-fic fr-dib">HPCAP Stands Out:&nbsp;Unlike inkjet printing technologies, HPCAP is not a drop-on-demand technology. It ensures the continuous printing of any ink on any substrate, without the characteristic defects that can be observed with inkjet printing. Other technologies rely on electric field (EHD) or pressure (robocasting) as a driving force for printing. However, most of these technologies struggle with sub-micronic resolutions and precisions, as the required external energy for dispensing/extruding dramatically increases with smaller printing dimensions. This can be explained by the increased pressure drop as described by the Hagen-Poiseuille equation. For HPCAP technology, the ink is not pushed from the inside of the pipette, but rather pulled by the substrate from the outside, with the pressure drop governed by the Laplace- Young equation. Though both these equations are a simplification of the underlying mechanisms behind ink dispensing through narrow channels, they provide an understanding of the differences in required printing forces between pressure driven (where dp scales with 1/𝑅4) and capillarity (where dp scale with 1/𝑅 ). The strength of capillary forces at these resolutions allows HPCAP to dispense at submicronic resolutions and with high viscosity materials.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY3MzA0MDQxLVNjcmVlbnNob3QgMjAyMy0xMS0wNiAxNTAwNDkucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 134px;" class="fr-fic fr-dib">Hagen-Poiseuille Equation. Where ∆𝑃 is the pressure drop, 𝜂 is the dynamic &nbsp; viscosity, L is the significant length of the channel, Q the volumetric flow rate, and R the pipette radius. &nbsp; &nbsp; <img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY3NDEyMzAzLVNjcmVlbnNob3QgMjAyMy0xMS0wNiAxNTAxMDYucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 99px;" class="fr-fic fr-dib">Laplace-Young Equation. where 𝛾 is the surface tension of the fluid, and R the pipette radius.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY3NDQ4Njg4LVNjcmVlbnNob3QgMjAyMy0xMS0wNiAxNTAxNDMucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 685px;" class="fr-fic fr-dib">HPCAP Applications:&nbsp;&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;Since HPCAP does not need an external source of energy, it is thus unlike other additive manufacturing technologies that use laser or UV for instance not limited to photosensitive material. Polymers (PMMA, SU8, PVP, epoxy...), conductive inks (silver, copper, gold...), 2D materials (nanowires, graphene) with viscosities up to 100,000 cP have been successfully printed using HPCAP technology. With a few adjustments in rheological, capillary, and colloidal properties, any ink can be printed, and any material is potentially processable. This strong versatility allows HPCAP technology to address a broad range of applications where high precision and resolution are required.High resolution interconnects and repair for semiconductor and display applicationsOne of the major applications for HPCAP technology is the dispensing of conductive inks for complex and high- resolution interconnections. The figure below (a, b, and d) shows SEM images of printed examples for such applications. All results were obtained with Hummink manufactured silver ink. A and b in the figure show examples of printed lines used in the repair of open circuit defects in display and packaging and Image d in the figure demonstrates 3D packaging capabilities of HPCAP technology by printing high aspect ratio conductive pillars.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY4NzMwMTY4LVNjcmVlbnNob3QgMjAyMy0xMS0wNiAxNTAyMTUucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 698px;" class="fr-fic fr-dib">Printed BiosensorsFully printed biosensors have gained increasing attention for the past years because of their cost efficiency, design versatility, and possible enhanced performances. As a technology capable of depositing a wide range of active material, such as conductive inks or biomaterials, HPCAP has been used in collaboration with renown labs to demonstrate its ability to print fully functional biosensors. The figure below shows a functional biosensing device printed with HPCAP technology. Gap reduction between electrodes has been a major challenge for fully printed electrodes. It has several positive impacts :<ul><li>It increases the field effect, hence improving the sensitivity of the biosensors</li><li>at comparable field effect and sensitivity, it reduces the energy consumption of biosensors</li><li>with adjusted geometries, selectivity of the biosensors can also be adjusted</li></ul><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY5MDUxOTc3LVNjcmVlbnNob3QgMjAyMy0xMS0wNiAxNTAyMzgucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 721px;" class="fr-fic fr-dib"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY5MDkxNTE2LVNjcmVlbnNob3QgMjAyMy0xMS0wNiAyMDEzMzgucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 700px;" class="fr-fic fr-dib"><a href="https://www.techblick.com/electronicsreshapedusa" target="_blank" rel="noopener noreferrer">Save the Date for The Future of Electronics RESHAPED show in Boston and Berlin</a> Watchmaking&nbsp;Luxury watchmaking predominantly revolves around the production of high-quality, upscale products. The dials of these watches, which are often the centerpieces of their design, are meticulously crafted using expensive, delicate, and fragile materials. The intricate topography of watch dials, as depicted in Figure below has posed challenges for traditional inkjet printing techniques, preventing them from achieving the desired high-resolution decorations. Additionally, newer printing technologies that rely on external energy sources have often been too aggressive, posing significant risks to these delicate substrates.However, as discussed in the prior section, the innovative HPCAP technology offers a solution. It incorporates real- time detection of the interaction between the pipette and the substrate, ensuring no harm comes to the latter. Notably, HPCAP's capabilities extend beyond mere decoration. It can dispense a variety of inks—from precious metals and quantum dots for ornamental purposes to functional materials like resins and glues. Given these attributes, HPCAP is being closely examined as a viable technology for both functionalizing and personalizing watch dials.&nbsp; <img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY5MTQyOTM4LVNjcmVlbnNob3QgMjAyMy0xMS0wNiAxNTAyNTkucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 684px;" class="fr-fic fr-dib">Conclusion: &nbsp; &nbsp;&nbsp;HPCAP technology stands out in the landscape of printing technologies, offering a unique approach that shuns conventional energy sources, relying solely on capillary forces and resonance. Its incredible precision is exemplified by its ability to navigate the Z-axis with a 5 nm accuracy. The versatility of HPCAP is evident in its compatibility with numerous inks, irrespective of their viscosity. This versatility offers a broad spectrum of applications, from the high-stakes realm of semiconductor repair to the intricate world of watchmaking and decoration. As industries continue to demand higher precision and versatility in printing, HPCAP provides a forward-looking solution that is poised to redefine the standards of the printing world.&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk5MzY5MjAwNzk4LVNjcmVlbnNob3QgMjAyMy0xMS0wNiAyMDEyMTAucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 701px;" class="fr-fic fr-dib"><a href="https://www.techblick.com/electronicsreshapedusa" target="_blank" rel="noopener noreferrer">Save the Date for The Future of Electronics RESHAPED show in Boston and Berlin</a> This article originally appeared <a href="https://www.techblick.com/post/introduction-to-high-precision-capillary-printing-hpcap" target="_blank" rel="noopener noreferrer">here</a>

This article discusses how HPCAP technology - inspired by AFM technology and capillary motion- enables additive and digital manufacturing of electronics with unprecedent resolution for application in semiconductor packaging, printed electronics, AR/VR, microLEDs, and beyond. 

HPCAP - combining AFM and capillary technology to push additive electronics to submicron resolution

Andrew Stemmerman &amp; John Yundt SunRay Scientific Inc. Eatontown, NJ USA <a rel="noopener noreferrer" href="mailto:andrew@sunrayscientific.com" target="_blank">andrew@sunrayscientific.com</a> <a rel="noopener noreferrer" href="mailto:johny@sunrayscientific.com" target="_blank">johny@sunrayscientific.com</a>SunRay Scientific of Eatontown, NJ, USA has developed a new and innovative approach to electronic component assembly.&nbsp;This article will outline the developments of this technology and show examples of this magnetically aligned Anisotropic Conductive Epoxy packaging method used on various substrates. Progress will be shared for dense and fine pitch Land Grid Arrays (LGA) on a semi-rigid interposer.<h3>Introduction</h3>Flip-chip die and die-to-die bonding, from dense to fine pitch, typically require solder balls and underfills. Underfill and/or edge encapsulant is often utilized to provide additional mechanical strength and stress reduction. The result is a complex assembly process flow. Localized placement of Anisotropic Conductive Adhesive (ACA) or Anisotropic Conductive Film (ACF) for specific components typically involves the fine-pitchuse of thermocompression bonding, an additional process step that could also be damaging to thin silicon. Another drawback for traditional interconnect materials is relatively slow processes, limiting the utility of such technologies. Development towards a wafer scale compatible packaging method will be shared, using a pressure-less and low-temperature magnetically aligned Anisotropic Conductive Epoxy (ACE).<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTAzNDM5ODc4LUZpZyAxLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 525px;" class="fr-fic fr-dib"><figcaption data-pm-slice='1 1 ["figureImage",null]' id="isPasted">Figure 1. Flip Chip assembly comparisons: traditional solder balls &amp; underfill attachment (Left); Die attach with z-axis magnetically aligned conductive epoxy (Right)</figcaption>A summary of the novel approach is shown above in Figure 1. First, ferro-magnetic particles dispersed within an epoxy are coated onto a substrate. The ferro-magnetic particles form z-axis magnetically aligned columns, fixed in place during the die-to-substrate cure process without any pressure applied. The formation of the columns during the curing process is illustrated in Figure 2. This technology simplifies the assembly process to a single adhesive application, which provides both electrical interconnection and mechanical reinforcement. No additional underfill material is needed. Fine patterning is not required as the entire area of the component target location is deposited with epoxy. The device alignment process is more.forgiving relative to solder ball-to-solder pad alignment. Z-axis columns align after component placement, magnetic pallet exposure and cure is achieved.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTAzNDc0MDUyLUZpZyAyLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 378px;" class="fr-fic fr-dib"><figcaption data-pm-slice='1 1 ["figureImage",null]' id="isPasted">Figure 2. X-Ray photos of Z-axis magnetically aligned particles ferromagnetic in an Anisotropic Conductive Epoxy (ACE)</figcaption><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699453964933-B-and-B-2024%28e-mail%29.jpg" style="width: 739px;" class="fr-fic fr-dib">Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.comThermal or UV curing methods complete the component attachment without any thermocompression (cure method is epoxy formulation dependent). Thermal curing occurs within the 80°C to 160°C temperature range.This article outlines the developments of this technology and shows examples of this magnetically aligned Anisotropic Conductive Epoxy packaging method used on various substrates. Progress will be shared for dense and fine-pitch Land Grid Arrays (LGA) on a semi-rigid interposer. Additionally, advancements made for die-to-die bonding will be presented as well as updates towards achieving ≤ 60-micron pitch. Other proposed direct die-attach packaging concepts will be illustrated.Example #2 covers development work performed on attaching a 126-pin Land Grid Array (LGA) bare die to a polymer semi-rigid multi-layer substrate. The use of the substrate resulted in multiple challenges for bare die attach. The non-planarity of the conductive circuit pads was one issue. The electrical resistance variation between pads had to be minimized for optimum performance. The non-uniformity of the substrate’s conductor pads is evident in the photo on the left. The schematic on the right illustrates how the ACE material allows for “leveling” in connecting the bare die to the non-planar substrate.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTAzNTE3Njg5LUZpZyAzLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 584px;" class="fr-fic fr-dib"><figcaption data-pm-slice='1 1 ["figureImage",null]' id="isPasted">Figure 3. 126-pad semi-rigid substrate (Left) and illustration of bond between die and substrate</figcaption>Additional learning during this work was in identifying trapped moisture within the polymer-based substrate as a cause for voids in the ACE during cure. These bubbles not only prevented connection in some cases but interfered with proper z-axis column formation. Prebake for the substrate was added as a step for this particular type of assembly.Two formulations were the focus of the work in Example #3. These were the Fine particles ACE and the Ultra Fine particles version. Stencil thicknesses of 0.001” to 0.005” were studied, as this tool has the most impact on establishing bond line thickness. The target for choosing the best formulation, tool and bond line thickness was lowest average resistance values with lowest deviation among the 126 pads. Iterative testing was done. “Heat maps” based on the 126 pad locations were created to visually observe resistance values within set target and acceptance ranges. The next two Figures show results from early work on process development with each epoxy formulation and stencil tools, to the progress made with the final choices on material and stencil thickness. Ultimately the Ultra Fine particles ACE with a 0.001” thick stencil was chosen for this LGA-to-substrate assembly application. Summary Table 1 shows the results of the chosen ACE and stencil, and Figure 6 is a cross-section from the development study.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTAzNTQwNDg0LUZpZyA0LnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 598px;" class="fr-fic fr-dib"><figcaption data-pm-slice='1 1 ["figureImage",null]' id="isPasted">Figure 4. Pad-by-pad resistance measurement studies, early iteration (Left: Ultrafine, Right: Fine)</figcaption><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTAzNTcyMzk5LUZpZyA1LnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 601px;" class="fr-fic fr-dib"><figcaption data-pm-slice='1 1 ["figureImage",null]' id="isPasted">Figure 5.&nbsp;Pad-by-pad resistance measurement studies, final iteration (Left: Ultrafine, Right: Fine)</figcaption>Table 1.&nbsp;Summary of performance metrics (continuity, resistance &amp; deviation, pad-to-pad)<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTAzNjAwNzk0LVRhYmxlIDEucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 564px;" class="fr-fic fr-dib"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTAzNjIyODMyLUZpZyA2LnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 559px;" class="fr-fic fr-dib"><figcaption data-pm-slice='1 1 ["figureImage",null]' id="isPasted">Figure 6. Cross-section of component attached and electrically connected with the Z-axis ACE (Photo courtesy of Rochester Institute of Technology)</figcaption>Example #2 takes the LGA and Substrate subassembly to the next level, a large area 8” x 10” circuit board populated with four of the subassemblies plus components of various sizes and function. This larger assembly involves attaching all the multiple components and subassemblies in one ACE attachment process. Passives range in size from as small as 0201 up to 2220. Other devices are a 26-pin SMT connector and SoICs. This project is underway, and results will be shown by SunRay at TechBlick live in October.Fine-pitch die-to-die bonding with the ACE is the third example. The development methodology is like the other projects. An initial focus was on measuring continuity and resistance at pad sites as part of identifying the optimum process parameters and stencil tool for this application. The degree of difficulty is greater with finer pitch. Dense arrays of 60 microns pitch die, with 30 microns pads and 30 microns spacing, were used.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699454054997-B-and-B-2024%28blog%29.jpg" style="width: 761px;" class="fr-fic fr-dib">Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.comA Design of Experiments (DoE) was established for the stencil studies. Laser profilometry was used for 3D and 2D scans of the two surfaces to be bonded, as was employed for observing the non-planarity of the semi-rigid board in Example #1. All initial steps were done manually: hand stencil printing, die placement with die bonder, batch oven cure and electrical probing.Prior to using fully functional devices, Quartz substrates patterned with the top layer of each die in the bond pair, were procured and used in early studies. The purpose was to provide enhanced analysis of the bonded die pair before, during, and after bonding/curing has occurred. Bond parameters were observed at each step of the process: pre-bond, bond, and post alignment &amp; cure.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTAzNjk2MDIyLUZpZyA3LnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 624px;" class="fr-fic fr-dib"><figcaption data-pm-slice='1 1 ["figureImage",null]' id="isPasted">Figure 7. Left: Target overlay of quartz substrates; Middle: ACE deposit before bond; Right: Post-bond, before z-axis alignment and cure</figcaption>Due to the finer pitch requirements, the test vehicles have a nickel layer applied during wafer fabrication, at the bond pad locations. Past experimentation, as pictured in Figure 8, has shown nickel application may lower the resistance of the bonded circuit by directing column formation to the metallized bond pad boundary, the nickel pads, acting as localized magnets, attract column formation during exposure to the magnetic pallet. This only applies to the bond pads themselves, to concentrate the ferromagneticmetalized particles within the ACE more towards the connection points. This creates a higher density of columns within each pad.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTAzNzcyMzM0LUZpZyA4LnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 488px;" class="fr-fic fr-dib"><figcaption data-pm-slice='1 1 ["figureImage",null]' id="isPasted">Figure 8. Left: No nickel interlayer and ACE; Right: ACE after cure with Nickel interlayer layer in pads</figcaption><h3 data-pm-slice="1 1 []" id="isPasted">Conclusion</h3>Besides the addition of the nickel layer to the functional die, key parameter targets were updated for the project’s next phase. In the short-term alignment, fiducials on the quartz plates were updated to improve bonding in X, Y, and theta; and the size of test probe pads were increased to improve accuracy and reduce testing time.The development efforts for all three examples are still underway. The conclusions thus far are:<ul><li>Successful demonstrations of Heterogenous Packaging using z-axis magnetically aligned epoxy for structural &amp; electrical bonding.</li><li>Similar established process techniques and test methodologies are usable across applications, although each has unique requirements.</li><li>The Ultra Fine particles ACE formulation has the best performance for finer pitches and more challenging alignments.</li><li>Uniform bond lines between device pads are critical for optimum electrical performance.</li><li>Excellent performance results were obtained, even with manual assembly techniques. Performance will improve with automation.</li></ul>In concept this z-axis magnetically aligned conductive epoxy approach could integrate multiple silicon wafers on top of each other, creating the possibility for an exceptionally dense integrated System-In-a-Package (SIP). Processing temperatures can be as low as 80°C, opening room for alternate substrates and biocompatible assemblies. This anisotropic epoxy is not limited to specific device attachment; it can be used to bond multiple component sizes and styles across an entire substrate.<hr>Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.com<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699454093608-B-and-B-2024%28small-LinkedIn+for-email%29.jpg" style="width: 709px;" class="fr-fic fr-dib">

Fine-Pitch Direct Die Attach Without Thermal Compression, Alignment or Underfill

Fine-pitch dense die assembly process with only a single adhesive application without pressure, without underfill, without fine patterning, without complex alignment vs solder ball-to-solder pad, etc? Learn here how magnetically aligned Anisotropic Conductive Epoxy (ACE) enable this

<a href="https://www.linkedin.com/in/carolyn-ellinger/" target="_blank" rel="noopener noreferrer">Carolyn Ellinger,</a> <a href="https://www.linkedin.com/in/chris-oconnor-01bb494/" target="_blank" rel="noopener noreferrer">Chris O’Connor</a>, <a href="https://www.linkedin.com/in/christopher-liston-49614326/" target="_blank" rel="noopener noreferrer">Chris Liston</a>, Emily Rej,&nbsp;<a href="https://www.linkedin.com/in/thomas-leblanc-0009a246/" target="_blank" rel="noopener noreferrer">Tom LeBlanc</a> - Eastman Kodak Company&nbsp;Built on expertise in coating, printing, and image quality, Kodak's printed electronics products and contract manufacturing services offer customers modern functionality rooted in decades of manufacturing excellence.Flexible heaters were first developed in the late 1800s, around the same time as Kodak was starting to manufacture film products &nbsp; While these first flexible heaters were textile-based, they operate on the same resistive heating principles as today’s flexible film heaters. &nbsp;With new technologies come new challenges and limitations, and “hidden” heaters are being deployed to improve the functionality of a broad range of electronic systems. &nbsp; Temperature-limited electronic devices, such as LCDs, require heating to be able to operate in cold environments.&nbsp;Outdoor sensors require that ice and snow be removed from their front surface to ensure their operation. Each of these applications (many many more) requires transparency and heating.&nbsp;However, while each application nominally requires “heat” and “transparency” – the requirements and form-factors of these transparent heaters vary across applications, and from device to device.Kodak’s manufacturing process for fabricating highly transparent patterned heating films delivers designs optimized for individual customers, various integration paths, and a myriad of end-devices.&nbsp;The copper micro-wire designs are manufactured with 2-μm imaging resolution, enabling ultimate freedom in macroscale and microscale optimization. &nbsp;The fully additive, roll-to-roll printed electronics manufacturing process produces copper micro-wires by printing a catalytic ink in the desired pattern, and then electrolessly plating copper to the specified height allowing for independent control of transparency and sheet resistance.As described in this white paper, Kodak works with customers to determine the optimum heater design. &nbsp;Figure 1a illustrates a simple approach in designing for a desired power density at a given system voltage. &nbsp;Figure 1b illustrates just a few of the many possible designs for uniform transparent heating.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1NDk5MzQ2MTU2LVNjcmVlbnNob3QgMjAyMy0wOS0yMyAwNzU2NDgucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 628px;" class="fr-fic fr-dib">Figure 1a. &nbsp;Example of heater designs for system optimization. &nbsp;Each heater has the same heated area, same transparency, but have been tuned to a different resistance (R) to achieve the required power density (PD) and the supply voltage of a given application.&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1NDk5Mzc1MzM5LVNjcmVlbnNob3QgMjAyMy0wOS0yMyAwNzU3MTYucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 663px;" class="fr-fic fr-dib">Figure 1b. &nbsp;Example heater patterns.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699454536681-B-and-B-2024%28e-mail%29.jpg" style="width: 738px;" class="fr-fic fr-dib">Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.comHow do resistive heaters work?Resistive heaters function by Joule heating, also known as Ohmic heating, where the flow of electric current through a conductor produces heat. &nbsp;All conductive materials exhibit this resistive heating phenomenon, with the heating response varying based on the specific properties of each material. Resistance is defined as the resistance to the flow of current at a given voltage bias, or R = V/I.&nbsp;Heater power is a function of the amount of current that is driven through an element of a given resistance: &nbsp;P = I2R = V2/R.Therefore, a heater with a higher resistance will require less current to generate the same power. Conversely, a conductive trace with low resistance will have lesser heating when current is applied than a higher resistance trace. In typical operation, heaters are driven by a constant voltage power supply, and a heater with a lower resistance will consume more power and heat to a higher temperature. &nbsp;The resistance of any heater is a combination of the pattern of the resistive element and the electrical properties of the material used. &nbsp;The resistance of conductors of a given thickness can be expressed as sheet resistance (Rs) in Ohm/square, so the end-to-end (terminal) resistance of any conductive pattern is Rs*L/W where L/W is the number of squares. &nbsp;Consequently, at a given operating voltage, the power per unit area or power density (PD) is proportional to 1/R, and 1/Rs for square heater element as shown in Figure 2.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1NDk5NTQwNzA2LVNjcmVlbnNob3QgMjAyMy0wOS0yMyAwNzQ4MTUucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 652px;" class="fr-fic fr-dib">Figure 2. &nbsp;Power density of a square heater at various voltage levels as a function of sheet resistance.What Sets the Kodak Technology Apart?Kodak’s cleanroom manufacturing leverages Kodak’s long history of innovation in material science, image science, printing, deposition, and roll-to-roll manufacturing to produce patterned micro-wire films with the unprecedented combination of high transparency, neutral color, low reflectance, and low sheet resistance. &nbsp;Cleanroom manufacturing minimizes electrical yield losses and ensures that parts will be free of transparency-reducing particulate going into final integration. &nbsp;The fully additive, roll-to-roll process features ~2 µm imaging resolution to produce fine copper micro-wires as narrow as 5 µm in width, by first printing a patented catalytic ink and then electrolessly plating copper to the desired height. The process enables the ability to independently tune sheet resistance and transparency, the ability to manufacture films with highly conductive traces leading to more resistive heating elements, and the ability to form multiple devices or electrical elements on a single substrate in a single roll to roll manufacturing flow – on one or both sides of the substrate.&nbsp;The design tools of the Kodak process enable functional heater designs without sacrificing transparency through a combination of mesh design (line dimensions, gaps, curves and angles), copper thickness, and the resistive path of the heater. &nbsp;Not only can the Kodak process support freeform design--only limited by imagination--other supporting elements such as traces, bond pads and even non-conductive or graphic can be additively included. &nbsp;Transparent mesh designs are readily obtainable with visible light transmission (VLT)&gt;85% with Rs from 1 to 5 Ohm/square, as illustrated in Figure 3.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1NDk5NjY1NDk2LVNjcmVlbnNob3QgMjAyMy0wOS0yMyAwNzQwNTYucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 634px;" class="fr-fic fr-dib">Figure 3. Kodak copper micro-wire mesh performance for a variety of mesh patterns represented the ratio of pitch to linewidth (LW) and copper thicknesses.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699454600236-B-and-B-2024%28blog%29.jpg" style="width: 766px;" class="fr-fic fr-dib">Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.comThe design freedom that comes from patterning via printing enables not only the pattern selection optimized for transparency, but also optimization of the overall design of the heater for a given system. &nbsp;For example, if the application has a square area that requires uniform heating a possible heater design would be a single square patch of resistive heater, but in this case the power density achievable would be limited by both the sheet resistance of the heater and the operating voltage available in the system. &nbsp;Typically, an application will have specified power, temperature and voltage requirements and a heater must be designed to operate at those conditions. &nbsp;Figure 4 illustrates how heaters may be designed using the mesh designs of Figure 3, with a reference shown at 100 W/m2 and the design choices depending on the supply voltage. For example, if a 3V power supply is chosen then a three-leg heater design is preferred, but if a 12V power supply is chosen, then a 3-leg heater would not be suitable and a 7-leg heater is preferred.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1NTAwNjkyMTM2LVNjcmVlbnNob3QgMjAyMy0wOS0yMyAwNzQ5MTEucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 742px;" class="fr-fic fr-dib">Figure 4. Illustration of heater designs to obtain a desired power density versus supply voltage.Ready-to-Integrate Transparent HeatersKodak is seeking strategic integration partners for transparent conductive heaters. &nbsp;Products and devices from this manufacturing line include all benefits discussed above, and ready-to-integrate films can be supplied for evaluation.Contact InformationFor more information on Kodak’s micro-wire technology and enabling manufacturing process, please contact: <a target="_blank" rel="noopener noreferrer" data-fr-linked="true" href="mailto:sales.printedelectronics@kodak.com">sales.printedelectronics@kodak.com</a>. Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.com<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699454617822-B-and-B-2024%28small-LinkedIn+for-email%29.jpg" style="width: 766px;" class="fr-fic fr-dib">

Kodak has a long history of manufacturing quality film products – starting with silver halide imaging films for consumers. Learn how Kodak is continuing that history, manufacturing a variety of industrial film products in many industries – from automotive to batteries to healthcare.

Copper Micro-Wires for Transparent Heater Applications

By Thomas Kolbusch, Director of Sales, Marketing, and Technology, VP1. AbstractThe Roll-to-Roll (R2R) processing methodology, pivotal in the fabrication of printed electronics, particularly 3rd Gen photovoltaics (OPVs), offers significant advantages. Yet, inherent technical challenges pose constraints in achieving optimal device performance. This article delves into the mechanics, advantages, and impediments associated with the R2R method as applied to OPVs.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1Mjc1Mzg0NzY4LVNjcmVlbnNob3QgMjAyMy0wOS0yMSAwNjMwMzIucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 420px;" class="fr-fic fr-dib">2. R2R Process: Operational Mechanics and Implications2.1. MechanismAt its core, R2R involves unreeling a flexible substrate from a source, subjecting it to various fabrication processes, and subsequently reeling the treated substrate. These processes can encompass material deposition, lithographic patterning, and post-fabrication treatments.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1MjkwMDc2MjcwLVNjcmVlbnNob3QgMjAyMy0wOS0yMSAxMDQ2NTUucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 658px;" class="fr-fic fr-dib">2.2. Benefits<ul><li>High Throughput: Continuous production translates to faster manufacturing cycles..</li><li>Economic Viability: Economies of scale achieved reduce per-unit costs.</li><li>Versatility: It enables the creation of lightweight, flexible electronic devices.</li></ul><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699454889606-B-and-B-2024%28e-mail%29.jpg" style="width: 766px;" class="fr-fic fr-dib">Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.com3. Inherent Technical Challenges in R2R Processing for OPVs3.1. Ensuring Quality HomogeneityAttaining uniformity in deposition across vast substrate lengths poses a formidable challenge. Factors like deposition rate, substrate tension, and ambient temperature can influence the end product's quality.3.2. Addressing Material LimitationsFor OPVs, the choice of materials is critical. Many organic materials used in these cells are sensitive to environmental factors like humidity and temperature. The R2R process, being continuous, requires that these materials remain stable over extended periods, a challenge that is currently under intensive research3.3. Guaranteeing Consistent Device PerformanceSecuring uniform device efficiency across an extended substrate requires rigorous quality control. Discrepancies in layer composition or thickness can culminate in efficiency variations, detracting from the overall process yield.4. An Analysis of Two Decades of OPV AdvancementsOver the preceding 20 years, significant strides have been made in OPV technology:<ul><li>Material Evolution: Introduction of novel organic compounds to enhance light absorption and electron mobility.</li><li>Architectural Refinements: Tandem structures, where multiple OPV layers are stacked, have emerged to enhance the cell's absorption spectrum</li><li>Optimization of R2R Processes: Advancements in substrate control, improved coating and printing techniques, and swifter post-deposition treatments have been established.</li></ul>Despite these advancements, the conversion efficiency of R2R-produced OPVs remains an area of ongoing research when compared to other photovoltaic technologies.5. SummaryThe potential of the R2R process in reshaping printed electronics production is clear. However, its broader adoption, especially for OPVs, demands a precise understanding of its challenges and a continuous drive for research and innovation. The advancements over the past 20 years underline the ongoing effort in this field and the need for further refinement to fully exploit R2R's benefits in OPV manufacturing. Coatema is working on all of these topics with cooperation partners in R&amp;D and industry and with the Horizon Europe project Flex2Energy will establish a production line for OPV in Greece with integrated module assembly. This will be a boost to the European efforts to be more independent from imports from China.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1Mjc1NDcwMTE2LVNjcmVlbnNob3QgMjAyMy0wOS0yMSAwNjMyNDAucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 511px;" class="fr-fic fr-dib">Growth rate of the global OPV market<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699454907254-B-and-B-2024%28small-LinkedIn+for-email%29.jpg" style="width: 742px;" class="fr-fic fr-dib">Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.com

Organic Photovoltaics (OPV are a 3rd Gen PV technology with unique attribute. The key to their success is in Roll-to-Roll (R2R) processing. Here you will learn about the advantages and challenges of R2R manufacturing in OPVs and printed electronics

The Roll-to-Roll (R2R) Process in Industrial Scale-Up: A Comprehensive Examination of Its Impacts and Challenges

Author: Author: Aart-Jan Hoeven <a data-hook="linkViewer" href="mailto:aj.hoeven@domicro.nl" target="_blank" rel="noopener noreferrer" id="isPasted">aj.hoeven@domicro.nl</a>&nbsp;| DoMicro&nbsp;Advanced packaging of semiconductor-based sensors brings very specific interconnection requirements. These often are related to a very narrow pitch of the interconnections or the fragility of the sensor. Different interconnection methods may also be needed because of the orientation of the sensing area or the integration of the sensor in Flexible Hybrid Electronics.&nbsp;DoMicro has developed an interconnection process for micro assembly of semiconductor-based sensors. This interconnection process is described as inkjet printed wire bonding. This article highlights results from recent work on an application with complex sensors. Furthermore, it includes a perspective on the competitive advantages brought by inkjet printed wirebonds.Conventional interconnection methods<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1MTkxMTUxNjQzLVNjcmVlbnNob3QgMjAyMy0wOS0xOSAxNzI0NTEucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 488px;" class="fr-fic fr-dib">Figure 1. Inkjet printed wire bonds for the interconnection of microprocessor bare dieFigure 1 shows a sample with interconnections made with inkjet printed wire bonding. This printing method can be considered as 2.5D printing. Depending on the sensor and integration and processing challenges, the inkjet printed wire bond interconnection method brings advantages over conventional interconnection methods.<ul><li>Reduced heights: Thin integration of bare die sensors for flexible hybrid electronics can be done for BGA or QFN packages which are soldered to the PCB. These typically are made with wire-bond interconnections from the sensor die to a lead frame. This results in a relative thick package. Integration of the bare (and thinned) die directly on the flexible circuit reduces the total height. The inkjet printed wirebond interconnection method can be used to interconnect bare dies to the flexible circuit without adding extra height to the package.&nbsp;</li><li>Configuration choices: Some optical sensor chips have their contact pads on the same plane as the sensor area. Interconnection with the (Flexible) PCB can therefore not be done using flip chip methods with anisotropic bonding. An advantage with inkjet printed wire bonds is that different configurations are possible.&nbsp;</li><li>Solutions for heat limitations: The limitations of the processing conditions of some opto-semiconductor sensors do not allow wire bonding or flip chip bonding. The temperature, pressure or ultrasonic energy of these interconnection methods can damage those sensors. Inkjet-printed wire bonds uses less harsh processing conditions. This is a non-contact interconnection method where only limited heat is required.&nbsp;</li></ul><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699455513083-B-and-B-2024%28e-mail%29.jpg" style="width: 765px;" class="fr-fic fr-dib">Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.com<h3>Inkjet printed interconnections enable new (ultra-thin) applications&nbsp;</h3>Using inkjet printing technology, DoMicro has developed a state-of-the-art approach for micro assembly of demonstrators for advanced applications with for example ICs, passive components, sensors and LEDs. In previous work, DoMicro has worked on the integration of thinned bare dies using the inkjet printed wire bond interconnection method. The technology for integrating dies is one of the key enablers for the realization of new applications in flexible hybrid electronics (FHE), e.g. in in-mould electronics or smart glass.&nbsp;This approach was developed for a wireless IoT demonstrator with a face-up thinned bare die. The die was interconnected on its bond pads. This demonstrator is shown in Figure 2. As it is impossible to inkjet print conductive tracks via a steep vertical surface, a dedicated ramp structure guides and supports the inkjet-printed silver conductors. This innovative approach of contacting avoids any regular and height consuming wire bond loops with glob top or as applied in advanced packaging, a redefinition layer or substrate (RDL) interface. The ‘die first’ approach is creating minimal height for assembling and mounting dies in systems. It is very suitable for sensor ICs for which the active side should be face up and it offers a compatibility of material surface interaction.The wireless IoT demonstrator includes touch sensors and a Bluetooth chip. With the integration of ultra-thin bare dies, the total height of the demonstrator could be kept below 0.5 mm. Using a flexible substrate of only 50µm thick and bare dies of 40µm thick, the passive components and crystals are now the thickest parts of this demonstrator. This thin form-factor enables smooth integration of functionality in various surfaces, labels, fabric etc.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1OTczMDA5MTM0LUZpZ18yX8KpRG9NaWNyb19GbGV4X2JhcmVfZGllX2lua2pldF9wcmludGVkX2ludGVyY29ubmVjdGlvbnMuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 458px;" class="fr-fic fr-dib">Figure 2. wireless IoT demonstrator<h3 id="isPasted">Advanced sensor interconnections</h3>Based on the work as described above, DoMicro is currently working on an interconnection solution for advanced photoelectric sensors. These are opto-semiconductor line sensors with a high spatial resolution. The top electrode of the sensor is patterned and consists of more than 250 individual pixels at a fine pitch of 100µm. The pixels need to be interconnected with the read-out electronic device which is packaged as a flexible COF (Chip On Film). This semiconductor sensor cannot withstand high temperature and pressure so the interconnection processes have to be adapted to these constraints. The processing steps are defined:<ol><li>Bonding the COF module on the top electrode of the sensor using a non-conductive adhesive.&nbsp;</li><li>Inkjet printing the ramp structure that allows for a smooth transition in Z-direction from the sensor pixels to the COF contacts.&nbsp;</li><li>Inkjet printing the interconnection traces between the 250 sensor pixels and the COF contacts.&nbsp;</li><li>Sintering of the silver nanoparticle ink: laser sintering allows for low heat impact on the sensor.&nbsp;</li><li>Packaging the sensor assembly.&nbsp;</li></ol><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1MTkxMjY1MzE3LVNjcmVlbnNob3QgMjAyMy0wOS0xOSAxNzI3MDEucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 538px;" class="fr-fic fr-dib">Figure 3. Sensor (1) and the COF (2) on top. Right image shows the alignment of the sensor pixels with the COF contacts at 100µm pitch.Printing the silver interconnection traces is done using a Pixdro LP50 inkjet printer from SÜSS MicroTec. This versatile inkjet printing platform offers benefits like UV pinning, substrate heating, choice of many industrial printheads and high placement accuracy.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1MTkxMzEyMjAxLVNjcmVlbnNob3QgMjAyMy0wOS0xOSAxNzI5MzcucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 558px;" class="fr-fic fr-dib">Figure 4. Inkjet printing on substrate for Flexible Hybrid Electronics using SÜSS MicroTec LP50 advanced research inkjet printerJoin us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.com<div> </div><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699455541074-B-and-B-2024%28blog%29.jpg" style="width: 730px;" class="fr-fic fr-dib">Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.comAlignment of the printing and bonding steps is critical for this interconnection method. The positioning accuracy needs to be within 10µm. Furthermore, the wetting behaviour of the inks needs to be controlled in order to reach the required track gap accuracy.&nbsp;&nbsp;On top of this ramp the silver interconnection traces are printed using a silver nanoparticle ink. The traces are about 2mm long and 50µm wide. They connect each pixel of the sensor to a contact of the COF module. This is schematically shown in Figure 4. Images of the printed interconnections and its height profile are shown in Figure 5. Height profiles of samples were characterized using Keyence 3D Laserscanning microscope.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1MTkxMzYyNjY3LVNjcmVlbnNob3QgMjAyMy0wOS0xOSAxNzMwMzgucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 425px;" class="fr-fic fr-dib">Figure 4. Schematic representation of the printed interconnections between the sensor pixels and the COF contacts. 1: Sensor 2: Ramp 3: Read-out electronics COF&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1MTkxMzg2OTA4LVNjcmVlbnNob3QgMjAyMy0wOS0xOSAxNzMxMjYucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 620px;" class="fr-fic fr-dib"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk1MTkxNDc1NTU1LVNjcmVlbnNob3QgMjAyMy0wOS0xOSAxNzMyMDMucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 654px;" class="fr-fic fr-dib">Figure 5. Top left: 3D image of the printed interconnection. Top right: microscope image of the printed traces on the sensor, ramp and COF contacts. Bottom: height profile of the silver traces (average of the blue lines in the top right image)Alignment of both the ramp print and silver interconnection print with respect to the COF and sensor contacts is possible with the required accuracy. This printing strategy results in sufficient evaporation of solvents of the printed silver ink which is required to minimize ink wetting that could short-circuit the traces. It was found that the resistance for the printed interconnections was ~2 Ω/mm.Following these steps, packaging was done with a combination of potting and encapsulation. This protects the interconnections while providing strain relief for the COF module.Conclusions and outlookA 2.5D inkjet printing process was used for micro-assembly of advanced opto-semiconductor sensors with a large number of fine pitch pixel contacts that needed to be interconnected to an FPC. Using the contactless inkjet technique, it was possible to print interconnections at a 100 µm pitch. Laser sintering can be used for creating conductivity while limiting the heat load on fragile sensors.<ul><li>All individual process steps are shown to be feasible as functionality was shown with the demonstrator sensor assembly.</li><li>Next steps will focus on maturing the process integration, repeatability and reliability aspects.&nbsp;</li></ul>The work demonstrates that inkjet-printed interconnections for advanced sensors are feasible. This alternative interconnection method can be used in situations where conventional wire-bonding packages or flip-chip bonding processes are not applicable.&nbsp;IMAGINE, CREATE, ACCOMPLISHDoMicro BV is a technology company providing innovative manufacturing technology, application solutions and micro assembly technology for flexible hybrid electronics (FHE) and micro devices. DoMicro develops cutting edge inkjet printing processes and technology for micro assembly and 3D packaging. At the forefront of innovation DoMicro offers state-of-the-art R&amp;D services and exploration of new capabilities and applications for customers with manufacturability in mind. The company delivers R&amp;D services, small series production, system architecture and project management. Typically for customers exploring new technologies for circuitry on flexible substrates like transparent conductive films, OPV electrodes, OLED, Lab-on-chip, wearables, in-mould electronics, IC and MEMS integrations.<a href="http://www.domicro.nl" target="_blank" rel="noopener noreferrer">www.domicro.nl</a>Join us in Berlin and/or Boston and lets us RESHAPE the Future of Electronics, making it Additive, Sustainable, Hybrid, Wearable, and 3D - techblick.com<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699455566326-B-and-B-2024%28small-LinkedIn+for-email%29.jpg" style="width: 765px;" class="fr-fic fr-dib"><div> </div>

Advanced packaging of semiconductor-based sensors - specially on flexible substrates- brings very specific interconnection requirements. These often are related to a very narrow pitch of the interconnections or the fragility of the sensor.  Learn how inkjet printing solves the issues 

Inkjet printed wirebonds for sensor interconnections

Cavitation dispersion process improves the properties of materials used in additive manufacturing of circuits. You will learn how one can control hydrodynamic cavitation to produce unique dispersions, formulated inks & pastes, high aspect ratio nanoparticle & ‘2D’ filler particle masterbatches. 



Cavitation dispersion process: how it works and how it improves properties of printed materials

As part of the TechBlick (wwww.TechBlick.com) series we invited Hyun Lee, Ph.D, &nbsp;Lead Scientist at Celanese Micromax&trade; Electronic Inks and Pastes to tell us a special development in the world of additive electronics: high temperature pastes. This article was originally published on TechBlick<a href="https://www.techblick.com/post/innovative-high-temperature-inks-for-printed-electronics" target="_blank" rel="noopener noreferrer"> here. </a>To learn more all aspects of printed and additive electronics, join us in Berlin <a target="_blank" rel="noopener noreferrer noopener noreferrer noopener noreferrer noopener noreferrer noopener noreferrer" data-fr-linked="true" href="https://www.techblick.com/electronicsreshaped" id="isPasted">https://www.techblick.com/electronicsreshaped</a>The global printed electronics market is huge and estimated to reach USD 23 billion in revenue by 2026, growing at a CAGR of 18.3% from 2023 to 2028 [1]. Increased demand for printed electronic products in automotive and the growth of consumer electronics are two key fueling factors to drive the market growth. The two critical segments require various reliable printed electronic products for applications from low temperature to high temperature.&nbsp; <a href="https://www.techblick.com/exhibitors-2023-berlin" target="_blank" rel="noopener noreferrer"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjkxNTkzNTYwMDY1LTE2OTE1OTM1NjAwNjQucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" alt="" data-pin-media="https://static.wixstatic.com/media/090711_5254521966ad48ac916c7baf7ccea480~mv2.png/v1/fill/w_1081,h_265,al_c,lg_1,q_85/090711_5254521966ad48ac916c7baf7ccea480~mv2.png" class="fr-fic fr-dii" style="width: 758px;">Join us and the global additive electronics community in Berlin on 17-18 OCT 2023. Lets RESHAPE the Future of Electronics, making it Additive, Sustainable, Flexible, Hybrid, Wearable, and 3D. &nbsp;</a> The key enabler for reliable device fabrication in printed electronics is functional inks with tunable electrical properties such as conductivity, dielectric strength, and electrical resistance. &nbsp;Celanese Micromax&trade; Electronic Inks and Pastes is a global supplier of thick film pastes/inks and recently launched HT (High Temperature) ink series - HT602/603 resistors, HT702 dielectric and HT802 conductive inks for high-temperature and high-power applications. HT series inks can be printed additively by using screen printing or nozzle dispensing process on various flexible/rigid substrates including Kapton&reg; FPC, Kapton&reg; RS, FR-4, Aluminum, Alumina, and glass. &nbsp;The operation temperature of conventional PTF (Polymer Thick Film) ink is typically limited up to 200&deg;C due to the thermal degradation issue of polymeric&nbsp;resin in ink formulations.&nbsp;In the printed electronic industry, high-temperature and high-power applications often require operation temperatures above 200&deg;C. HT series inks were developed by using novel polyimide resin whose thermal resistant temperature is up to 300&deg;C. &nbsp;Polyimide resin is flexible thermoplastic allowing much more flexibility compared to rigid thermoset Epoxy resins that have been used for the majority of high-temperature applications. Another key benefit of our polyimide resin is its chemical resistance. The unique combination of high-temperature resistance, flexibility and chemical resistance of HT series inks is expected to provide solutions for new high-temperature applications in the printed electronics industry which couldn&rsquo;t be achievable by conventional PTF inks. This article will discuss key technical features of HT inks and their potential applications.&nbsp;<a href="https://www.techblick.com/exhibitors-2023-berlin" target="_blank" rel="noopener noreferrer"></a> HT602/603 resistorsPrintable resistor ink can be used to deposit passive resistive components directly on a substrate. &nbsp;Applications include heated floors, pressure sensors and variable potentiometers. HT602 and HT603 were formulated by adding different types of Carbon black powders in a polyimide medium for high-temperature or high-power applications. The average Rs (Resistivity) is 25 Ω/□/mil for HT602 and 300 Ω/□/mil for HT603, respectively. Two HT resistors may be blended to meet specific Rs targets. If a higher Rs value is required than Rs of HT603, HT702 dielectric can be blended with HT603. Figure 1 shows (a) plot of Rs vs. blend ratio of HT603 and HT602, and (b) Rs vs. blend ratio of HT603 and HT702.&nbsp;<div type="empty-line" data-hook="rcv-block19"> </div><div data-hook="imageViewer" tabindex="0"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjkxNTkzNTU5MzMxLTE2OTE1OTM1NTkzMzEucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" alt="" data-pin-media="https://static.wixstatic.com/media/090711_24a091b42ee94fbc8b1dad56f9794d32~mv2.png/v1/fill/w_1056,h_421,al_c,q_90/090711_24a091b42ee94fbc8b1dad56f9794d32~mv2.png" class="fr-fic fr-dii"></div><div type="image" data-hook="rcv-block21"> </div>Figure 1. (a) Plot of Rs vs. blend ratio between HT602 and HT603; (b) Plot of Rs vs. blend ratio between HT603 and HT702.&nbsp;<div type="empty-line" data-hook="rcv-block23"> </div>For reliable device operation, the resistance variation of the printed resistor should be minimal with temperatures. TCR (Temperature Coefficient of Resistance) of two HT resistors were measured at four different temperatures as shown in Figure 2. TCR data of HT602, 603 showed much lower values vs. conventional resistor inks (7082M, 7102) formulated with non-polyimide resin demonstrating more stable resistance values of HT resistors with temperatures.&nbsp;<div type="empty-line" data-hook="rcv-block26"> </div><div data-hook="imageViewer" tabindex="0"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjkxNTkzNTU5MTU2LTE2OTE1OTM1NTkxNTYucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" alt="" data-pin-media="https://static.wixstatic.com/media/090711_101b2a58975e4fbab04423aeebe44864~mv2.png/v1/fill/w_823,h_555,al_c,q_90/090711_101b2a58975e4fbab04423aeebe44864~mv2.png" class="fr-fic fr-dii"></div><div type="image" data-hook="rcv-block27"> </div>Figure 2. TCR comparison between HT602/603 containing polyimide and 7102/7082M containing non-polyimide resin.&nbsp;<div type="empty-line" data-hook="rcv-block29"> </div>STOL (Short time overload) test was also performed to check how high power HT602 and HT603 could endure without resistance change. Chip resistor&rsquo;s standard criterion is less than +/- 1% of R change up to 2.5 times of desired operating voltage. Different size of HT resistor pattern was screen printed over Ag electrode as shown in Figure 3 and 0.5mm x 0.5mm printed resistor was used to monitor resistance deviation during STOL test. Test condition is 5sec dwelling time with step increase of voltage. Both HT602 and HT603 showed excellent stable resistance up to 200W/cm2 power density (Figure 4).<div type="empty-line" data-hook="rcv-block32"> </div><div data-hook="imageViewer" tabindex="0"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjkxNTkzNTU5OTgwLTE2OTE1OTM1NTk5ODAucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" alt="" data-pin-media="https://static.wixstatic.com/media/090711_29e7cbc68bea4e90b4309dd55b7276d8~mv2.png/v1/fill/w_641,h_673,al_c,lg_1,q_90/090711_29e7cbc68bea4e90b4309dd55b7276d8~mv2.png" class="fr-fic fr-dii" style="width: 624px;"></div><div type="image" data-hook="rcv-block33"> </div>Figure 3. HT603 printed over Ag electrode on Alumina substrate for STOL test.<div type="empty-line" data-hook="rcv-block35"> </div><div data-hook="imageViewer" tabindex="0"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjkxNTkzNTU5ODU1LTE2OTE1OTM1NTk4NTQucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" alt="" data-pin-media="https://static.wixstatic.com/media/090711_a57ecf5c424e421d9b175b2464edff80~mv2.png/v1/fill/w_1136,h_568,al_c,q_90/090711_a57ecf5c424e421d9b175b2464edff80~mv2.png" class="fr-fic fr-dii"></div><div type="empty-line" data-hook="rcv-block37"> </div>Figure 4. STOL test to check Resistance change with step-changing voltage (power density). HT702 dielectricTo prevent mechanical damage or chemical oxidation of electronic circuits on Flex or Rigid PCB (printed circuit board), the protective layer is applied on top of the metalized circuit. &nbsp;A Conventional protective layer in the PCB industry is applied by photoimagible soldermask (typically epoxy material) on the rigid substrate or high-pressure assisted thermal lamination of Coverlay (polyimide with acrylic adhesive) on flex circuit. Both photoimaging of solder mask and coverlay lamination not only require multiple process steps but also generate waste of materials. The incumbent protective layers also have deficiencies on the material side; the thermoset epoxy solder mask is typically not flexible and coverlay contains acrylic adhesive which is not thermal resistant above 200&deg;C. &nbsp;HT702 formulated with thermoplastic polyimide resin is more flexible than thermoset epoxy solder mask and has much higher thermal resistance than acrylic adhesive used in coverlay. The unique combination of flexibility and thermal resistance of HT702 is expected to create new applications in PCB industry where incumbent protective materials have a deficiency. In addition, direct printable HT702 dielectric ink can lower the overall cost of ownership by decreasing process steps and material waste. Good dielectric strength (BDV &gt; 0.5kV), excellent chemical resistance and excellent adhesion on various substrates are additional benefits of HT702. To achieve good dielectric strength and uniform coverage without pinhole defects, 2~3 printing and drying cycles are recommended. &nbsp;HT802 conductorHT802 is highly conducive and thermal-resistant ink formulated with silver powders and polyimide resin. High thermal/chemical resistant polyimide resin enables HT802 to be applicable to high-temperature applications such as electrodes for heaters or platable conductors where the plating process involves a caustic acid/base bath process. For example, figure 5(a) shows the HT802 electrode printed on 16in. x 16in. Kapton&reg; RS flexible heater. Uniform heating performance was achieved up to 240&deg;C (Figure 5(b)).&nbsp;<div type="empty-line" data-hook="rcv-block47"> </div><div data-hook="imageViewer" tabindex="0"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjkxNTkzNTYwMzkwLTE2OTE1OTM1NjAzOTAucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" alt="" data-pin-media="https://static.wixstatic.com/media/090711_9d9b14d321bc430fb26b20f4d99bd5f7~mv2.png/v1/fill/w_1312,h_540,al_c,q_90/090711_9d9b14d321bc430fb26b20f4d99bd5f7~mv2.png" class="fr-fic fr-dii"></div><div type="empty-line" data-hook="rcv-block49">Figure 5. (a) HT802 printed on Kapton&reg; RS film as an electrode for flexible heater fabrication. (b) Uniform heating up to 240&deg;C was demonstrated.&nbsp;</div><div type="empty-line" data-hook="rcv-block51"> </div>Table 1 shows the performance of HT802 with different cure conditions. Resistivity decreased with higher cure temperatures while maintaining excellent adhesion on Kapton&reg; film. Interestingly, crease resistance also became better (lower % increase of electrical resistance) when HT802 was cured at higher temperatures. &nbsp;<div type="empty-line" data-hook="rcv-block53">Table 1. Resistivity, adhesion, and crease resistance of HT802 with cure condition. HT802 was screen printed on Kapton&reg; film.&nbsp;</div><div type="empty-line" data-hook="rcv-block56"> </div><div data-hook="imageViewer" tabindex="0"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjkxNTkzNTU5NDIxLTE2OTE1OTM1NTk0MjAucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" alt="" data-pin-media="https://static.wixstatic.com/media/090711_f1057c15757b49be87f225d832c50c73~mv2.png/v1/fill/w_1313,h_317,al_c,lg_1,q_90/090711_f1057c15757b49be87f225d832c50c73~mv2.png" class="fr-fic fr-dii"></div><div type="empty-line" data-hook="rcv-block58"> </div>SummaryMicromax&trade; Electronic Inks and Pastes launched a new HT product line using noble Polyimide resin chemistry for high-temperature printed electronics applications. &nbsp;The unique combination of high thermal/chemical resistance, flexibility, and additive printability of HT inks is expected to provide solutions for various high-temperature applications on both flexible and rigid substrates. &nbsp;Visit our website: https://www.celanese.com/products/micromax to find a technical datasheet of HT products [2].<div type="paragraph" data-hook="rcv-block60">References</div><div type="paragraph" data-hook="rcv-block62">[1] <a data-hook="linkViewer" href="https://www.marketsandmarkets.com/Market-Reports/printed-electronics-market-197.html?gclid=EAIaIQobChMIrY-Bu_CdgAMVBNzICh1yNA1FEAAYASAAEgKtI_D_BwE" target="_blank" rel="noopener noreferrer">Printed Electronics Market Revenue Trends and Growth Drivers | MarketsandMarkets</a></div><div type="paragraph" data-hook="rcv-block63">[2] <a data-hook="linkViewer" href="https://www.celanese.com/en/products/micromax" target="_blank" rel="noopener noreferrer">Micromax&trade; Electronic Inks and Pastes (celanese.com)</a></div><div type="empty-line" data-hook="rcv-block66"> </div><a href="https://www.techblick.com/electronicsreshaped" target="_blank" rel="noopener noreferrer"></a><div data-hook="imageViewer" tabindex="0"><a href="https://www.techblick.com/electronicsreshaped" target="_blank" rel="noopener noreferrer"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjkxNTkzNTYwODg4LTE2OTE1OTM1NjA4ODgucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" alt="" data-pin-media="https://static.wixstatic.com/media/090711_dc5d68d6d8a849f6a309f71aa7d483e3~mv2.jpg/v1/fill/w_1707,h_1707,al_c,q_90/090711_dc5d68d6d8a849f6a309f71aa7d483e3~mv2.jpg" class="fr-fic fr-dii" style="width: 758px;">Join us and the global community in Berlin on 17-18 OCT 2023. Lets RESHAPE the Future of Electronics together, making it Additive, Sustainable, Hybrid, Wearable and 3D. https://www.techblick.com/electronicsreshaped</a></div> <div type="image" data-hook="rcv-block67"> </div>

The key enabler for reliable device fabrication in printed electronics is functional inks with tunable electrical properties incl. conductivity, dielectric strength & electrical resistance. Here, you will learn about unique polyimide based pastes able to withstand temperatures up to 300°C. 

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