What is Electronics Manufacturing Services (EMS): A Comprehensive Guide for Engineers
21 Jun, 2024
This article serves as a valuable resource for engineers, delving deep into the world of EMS manufacturing and exploring its significant role in bringing electronic products from ideation to realization.
Introduction
The electronics industry thrives on continuous innovation and efficient production. However, bringing a groundbreaking concept to market often requires specialized expertise beyond the realm of design and development. This is where Electronic Manufacturing Services (EMS) come into play!
EMS encompasses a broad spectrum of services provided by specialized companies to design, manufacture, test, and distribute electronic components and assemblies. Originally developed to support the growing demand for electronic products, EMS manufacturing has evolved to become a critical element in modern engineering. These services allow companies to focus on innovation and product development while maintaining high-quality production standards.
By utilizing EMS manufacturing, companies can reduce time-to-market, manage costs effectively, and scale their operations seamlessly. This partnership not only optimizes the manufacturing process but also enhances product reliability and performance. Let’s understand the foundational concepts of EMS manufacturing!
Understanding EMS: Foundational Concepts
What Defines Electronics Manufacturing Services?
Electronics Manufacturing Services (EMS), also referred to as Electronic Contract Manufacturing (ECM), refers to a wide range of services offered by specialized companies to Original Equipment Manufacturers (OEMs). [1] These services support various stages of the electronic product lifecycle, from conception to after-sales support.
EMS has evolved significantly since its inception, becoming a cornerstone of the modern electronics industry. Initially developed to meet the growing demand for electronic products, EMS providers now offer comprehensive solutions that cover the entire product lifecycle. These services range from design and prototyping to full-scale production and rigorous testing, ensuring that electronic products meet high-quality standards and adhere to industry specifications.
Here's a breakdown of the key aspects that define EMS manufacturing:
Contracted Services: EMS companies function as partners rather than internal production lines for OEMs. They handle specific tasks through a formal agreement.
Value-added Engineering: Beyond simple assembly, EMS providers often offer expertise in design for manufacturability (DFM) and other engineering support, adding significant value to the process.
Complete Production Cycle: EMS capabilities often span the entire product journey, which includes procurement, PCB assembly, and system integration.
Testing and Quality Control: Implementing rigorous testing procedures to ensure product functionality and adherence to quality standards.
- Flexibility and Scalability: EMS providers cater to diverse project needs, offering flexible production lines that can adapt to varying volumes and product complexities.
The core services offered by EMS providers include:
PCB Assembly: PCBA involves placing and soldering electronic components onto printed circuit boards (PCBs). This process adheres to the IPC-A-610 standard, ensuring quality and reliability. [2]. Key techniques include:
Surface-Mount Technology (SMT): SMT involves mounting electronic components directly onto the PCB surface, which allows for higher component density and smaller PCB sizes. This technique is essential for modern, compact electronic devices.
Through-Hole Technology (THT): In THT, component leads are inserted into holes drilled in the PCB and soldered to pads on the opposite side. This method provides strong mechanical bonds, making it suitable for components subjected to mechanical stress.
Automated Optical Inspection (AOI): AOI systems use high-resolution cameras and sophisticated algorithms to inspect PCBs for defects during manufacturing. This technology ensures that issues like soldering defects and component misalignments are detected and corrected early in the production process.
Prototyping: Rapid prototyping services are crucial for the development of new products. EMS providers create functional prototypes that allow companies to evaluate performance and manufacturability, facilitating quick iterations and improvements.
Testing: Rigorous testing ensures that electronic products function as intended and meet safety and reliability standards. EMS providers conduct various tests, including in-circuit testing (ICT), functional testing, and environmental stress screening (ESS), to identify and rectify potential issues before mass production.
EMS providers act as a one-stop shop, managing various stages of the electronic product lifecycle across various sectors, from consumer electronics to automotive and industrial applications. Real-world examples include the manufacturing of smartphones, automotive control units, and industrial automation systems, highlighting the diverse applications and critical importance of EMS in advancing technology.
Recommended Reading: Enhancing Industrial Processes through Design for Manufacturing: A Comprehensive Guide
Key Players in the EMS Industry
The Electronics Manufacturing Services (EMS) industry includes several key players that dominate the market. These companies provide comprehensive services ranging from product design and manufacturing to logistics and post-manufacturing services.
Major Companies and Service Providers
Several manufacturing companies dominate the EMS sector, each contributing uniquely to the industry's advancement. Notable among them are Foxconn, Flex, Jabil, Sanmina, and Celestica. These companies are renowned for their extensive capabilities, global reach, and robust infrastructure, enabling them to handle large-scale manufacturing projects for leading brands.
Foxconn: Foxconn is one of the largest EMS providers globally, best known for assembling products for major international brands like Apple, Sony, and Dell. The company is known for high-volume production, advanced automation, comprehensive testing, and assembly services. Based in Taiwan, it operates numerous factories across various countries, particularly in China.
Flex: Flex offers end-to-end solutions across various sectors including electronics, automotive, telecommunications, and healthcare. It is known for its global supply chain services and design-led manufacturing. Their involvement in developing innovative medical devices highlights its diverse technical capabilities.
Jabil: Known for its end-to-end manufacturing solutions, Jabil emphasizes innovation and sustainability. Their services include product design, engineering, manufacturing, and logistics. Jabil’s advancements in additive manufacturing and smart factory solutions are crucial in pushing the boundaries of modern manufacturing.
Sanmina: Specializing in high-reliability products and complex manufacturing processes, Sanmina offers services that include PCB fabrication, system assembly, and testing. Its strong presence in communications, defense, and industrial markets underscores its ability to handle demanding and intricate projects.
Celestica: Celestica provides comprehensive product lifecycle solutions, from design and prototyping to manufacturing and after-market services. Their capabilities include advanced interconnect technology, microelectronics, and optical assemblies. Celestica’s role in producing components for aerospace and defense applications highlights its technical proficiency.
Roles of OEMs and CMs
Original Equipment Manufacturers (OEMs) and Contract Manufacturers (CMs) serve distinct but complementary roles within the EMS industry: [3]
OEMs: Original Equipment Manufacturers are companies that design and develop products which are then manufactured by EMS providers. They focus on innovation, product development, and brand management, outsourcing the manufacturing process to EMS companies to leverage their specialized expertise and efficiencies.
CMs: Contract Manufacturers are specialized firms that produce goods on behalf of OEMs. They handle the manufacturing, assembly, and testing processes, ensuring that products meet required specifications and quality standards. CMs offer technical capabilities such as advanced material handling, in-circuit testing (ICT), and failure analysis.
Comparison of Services and Technical Capabilities
Here's a comparative table of services and technical capabilities for some of the major EMS providers: Foxconn, Flex, Jabil, Sanmina, and Celestica.
| EMS Provider | Advanced Material Handling | In-Circuit Testing (ICT) | Failure Analysis |
| Failure Analysis | Yes | Yes | Yes |
| Flex | Yes | Yes | Yes |
| Jabil | Yes | Yes | Yes |
| Sanmina | Yes | Yes | Yes |
| Celestica | Yes | Yes | Yes |
This table highlights the comprehensive services and technical capabilities offered by leading EMS providers. Advanced material handling systems, in-circuit testing (ICT), and failure analysis are critical components of the manufacturing process, ensuring that electronic products are produced efficiently and meet the set quality standards. These capabilities enable EMS providers to support the development of cutting-edge technologies and high-quality electronic products across various sectors.
Recommended Reading: What Is In-Circuit Testing? An Essential Guide for Engineers
Innovations in Electronics Manufacturing Services
Cutting-Edge Technologies in EMS
Recent advancements in Electronics Manufacturing Services (EMS) have revolutionized the industry, driving efficiency, precision, and scalability. Key innovations include automation, artificial intelligence (AI) integration, and advanced testing techniques.
Automation in EMS has significantly enhanced production capabilities. Automated pick-and-place machines have transformed the assembly process by rapidly placing components on PCBs with high precision. These machines use sophisticated vision systems and algorithms to ensure accuracy and speed, drastically reducing manual labor and error rates. Reflow soldering ovens, another critical innovation, use of controlled heat profiles to solder surface-mounted components onto PCBs reliably, ensuring consistent quality across large production runs.
Artificial intelligence integration in EMS is another groundbreaking advancement. AI algorithms optimize various stages of the manufacturing process, from component placement to predictive maintenance. Machine learning models analyze vast amounts of production data to predict potential equipment failures before they occur, minimizing downtime and maintenance costs. For instance, AI-driven inspection systems use neural networks to detect defects in PCBs often missed by human inspectors, significantly improving product reliability and yield rates. [4]
Additive Manufacturing technology is finding its place in EMS, enabling rapid prototyping, low-volume production, and complex component manufacturing. EMS providers can create prototypes quickly and efficiently, enabling faster design iterations and time-to-market for new products. 3D printing is ideal for low-volume or customized production runs, catering to niche markets or personalized electronics. Similarly, it enables the creation of intricate components with geometries that might be difficult or impossible to achieve with traditional manufacturing methods.
Advanced testing techniques have also seen substantial innovation. In-circuit testing (ICT) and automated optical inspection (AOI) have become more sophisticated, leveraging cutting-edge technologies to ensure product quality. ICT now includes features like boundary scan testing, allowing for the testing of complex PCB assemblies without physical test probes. AOI systems employ high-resolution cameras and AI algorithms to detect even the smallest defects, ensuring that only flawless products reach the market.
Let’s talk about their applications in real life. Foxconn introduced fully automated assembly lines for smartphones, utilizing AI to monitor and optimize the entire production process. This approach speeds up production and ensures higher quality and consistency.
Similarly, Jabil is known for using smart factory solutions. By integrating IoT devices, AI, and advanced robotics, Jabil has created a highly efficient and adaptable manufacturing environment. This smart factory approach enables real-time monitoring and control of production processes, leading to improved efficiency, reduced waste, and faster time-to-market for new products.
These are just a few of the cutting-edge technologies shaping the future of EMS. As these technologies continue to evolve and become more cost-effective, we can expect even more advancements in the way electronic products are designed, manufactured, and delivered.
Recommended Reading: What are Robotic Assembly Lines? History, Components, Advantages, Limitations, Applications, and Future
The Impact of Industry 4.0 on EMS
Industry 4.0, also known as the fourth industrial revolution, marks a new era of manufacturing where advanced digital technologies are integrated into production processes. This transformation, which began in the early 2010s, aims to create smart factories characterized by connectivity, data-driven decision-making, and enhanced automation.
Industry 4.0 principles are revolutionizing Electronics Manufacturing Services (EMS) by incorporating the Internet of Things (IoT), data analytics, and smart manufacturing techniques. IoT devices collect real-time data from machines and production lines, enabling detailed monitoring and control. Data analytics processes this information to uncover insights, optimize operations, and predict potential issues. Smart manufacturing leverages these insights to create highly adaptable and efficient production environments.
Key Industry 4.0 Technologies Influencing EMS
Cyber-Physical Systems (CPS): These systems integrate physical processes with digital systems, enabling real-time interaction and control. CPS improves manufacturing precision and allows for the development of smart factories where machines and systems communicate seamlessly.
Edge Computing: By processing data closer to the source, edge computing reduces latency and bandwidth use. This technology enables faster decision-making and more efficient management of manufacturing operations. For example, real-time data from IoT sensors can be processed at the edge to make immediate adjustments to production lines.
Advanced Robotics: Modern robots equipped with AI and machine learning capabilities perform complex tasks with high precision and flexibility. In EMS, advanced robotics improves productivity and quality by automating repetitive and intricate tasks, reducing the risk of human error.
Technical Integration in EMS
Predictive Maintenance: Utilizing sensors and IoT devices, predictive maintenance systems continuously monitor equipment health. Data analytics models predict failures before they occur, reducing downtime and maintenance costs. This approach has been successfully implemented in factories where machinery uptime is critical, such as semiconductor fabrication plants.
Digital Twins: Digital twins are virtual replicas of physical assets, systems, or processes. They allow manufacturers to simulate, analyze, and optimize production in a virtual environment, leading to improved decision-making and operational efficiency. In EMS, digital twins can model the entire production line to identify bottlenecks and optimize workflows.
Real-Time Monitoring Systems: These systems use IoT sensors to provide live data on production status, machine performance, and environmental conditions. Real-time monitoring enhances visibility, allowing for immediate adjustments to maintain optimal operation. An example includes automated feedback loops in PCB assembly lines that adjust soldering parameters on-the-fly to maintain quality.
Benefits and Challenges
The integration of Industry 4.0 into EMS offers numerous benefits, such as increased productivity, reduced operational costs, and enhanced product quality. However, it also presents challenges, including the need for significant investment in new technologies, potential cybersecurity risks, and the requirement for skilled personnel to manage and maintain these advanced systems.
By embracing Industry 4.0, EMS providers can create a more connected, intelligent, and efficient manufacturing ecosystem, driving innovation and competitiveness in the electronics industry.
Recommended Reading: The engineer's guide to Industrial IoT and Industry 4.0
Real-World Applications of EMS in Engineering
EMS in Consumer Electronics
Electronics Manufacturing Services (EMS) have become indispensable in the production of consumer electronics, playing a pivotal role in the development and mass production of smartphones, laptops, and wearable devices. The history of EMS in consumer electronics dates back to the late 19th century when the growing demand for electronic products required more efficient and scalable manufacturing solutions. This evolution has enabled consumer electronics companies to innovate rapidly and meet the high standards of quality, performance, and durability demanded by today's market.
EMS providers are integral to the smartphone industry. Companies like Foxconn and Pegatron are renowned for assembling millions of units annually for leading brands such as Apple and Samsung. The engineering challenges in smartphone manufacturing are significant, particularly in areas like miniaturization and thermal management. Smartphones are expected to be lightweight and compact while housing powerful processors and large batteries. EMS providers employ advanced techniques like high-density interconnect (HDI) PCBs and efficient thermal management solutions, such as heat pipes and thermal interface materials, to overcome these challenges.
Laptops, another cornerstone of consumer electronics, benefit greatly from the expertise of EMS providers. Companies like Compal and Quanta manufacture laptops for major brands like Dell, HP, and Lenovo. The engineering challenges in laptop manufacturing include ensuring high performance while maintaining a sleek form factor. Effective thermal management is crucial as laptops need to dissipate heat efficiently to prevent overheating. EMS providers implement solutions like vapor chambers, advanced cooling fans, and conductive heat spreaders to maintain optimal operating temperatures.
Wearable devices, such as smartwatches and fitness trackers, also rely heavily on EMS. These devices pose unique challenges due to their small size and the need for durability and water resistance. Notable products, like the Apple Watch and Fitbit devices, are manufactured by EMS providers who specialize in miniaturization and robust assembly techniques. Electromagnetic interference (EMI) shielding is essential in these devices to prevent signal disruption from other electronic components. EMS providers use advanced shielding materials and design practices to ensure reliable performance.
The real-world impact of EMS in consumer electronics is profound. By leveraging the advanced capabilities of EMS providers, consumer electronics companies can focus on innovation and market expansion while ensuring that their products meet stringent quality standards. This collaboration results in the production of high-quality, reliable consumer electronics that continue to drive technological advancement and improve user experiences worldwide.
EMS in Industrial and Automotive Sectors
Electronics Manufacturing Services (EMS) have significantly evolved to become a cornerstone in the industrial and automotive sectors. Historically, the integration of electronics in these sectors was driven by the need for more efficient, reliable, and intelligent systems. Over the decades, advancements in electronic manufacturing have enabled the production of increasingly sophisticated machinery and vehicles, making EMS indispensable.
In the industrial sector, EMS providers contribute to the development of advanced machinery and automation systems. These systems require precise and reliable electronic components to function effectively. For example, EMS providers are pivotal in creating control units for industrial robots, which are essential for modern manufacturing lines. These control units incorporate sensors, processors, and communication interfaces that must be assembled with high precision to ensure optimal performance and reliability.
The automotive sector relies heavily on EMS for the production of critical electronic systems such as engine control units (ECUs), power electronics, and advanced driver-assistance systems (ADAS). ECUs are central to managing engine performance, emissions control, and fuel efficiency. EMS providers handle the complex assembly and testing of these units, ensuring they meet the stringent standards required for automotive applications.
Power electronics, including inverters and converters, are vital for the operation of electric and hybrid vehicles. These components need to handle high power levels efficiently and safely. EMS providers specialize in producing these components with rigorous design and testing protocols to ensure they perform reliably under various operating conditions.
ADAS enhances vehicle safety and functionality through technologies like adaptive cruise control, lane-keeping assistance, and automated braking systems. These systems rely on a network of sensors, cameras, and control units. EMS providers are responsible for the intricate assembly and testing of these components, ensuring they work seamlessly together to improve vehicle safety and performance.
Steps Involved in an EMS Project for Automotive Electronics
Design for Manufacturability (DFM):
Collaborate with OEMs to design components that are easy to manufacture and assemble.
Optimize designs to reduce complexity and improve reliability.
Ensure compliance with automotive industry standards.
Component Selection:
Identify and source high-quality components that meet performance and reliability requirements.
Evaluate suppliers to ensure they adhere to industry standards and quality control measures.
Balance cost, performance, and availability in selecting components.
Environmental Stress Screening (ESS):
Conduct rigorous testing to simulate the harsh operating conditions of automotive environments.
Perform thermal cycling, vibration testing, and humidity exposure to identify potential failures.
Ensure that components can withstand real-world conditions and maintain performance over time.
The integration of EMS in the industrial and automotive sectors has led to significant advancements in technology and efficiency. By leveraging the expertise of EMS providers, these sectors can develop and deploy complex electronic systems that enhance functionality, safety, and reliability.
Recommended Reading: Improving emergency response in the era of ADAS vehicles in the Smart City
Navigating the Challenges in EMS
Overcoming Technical and Logistical Challenges
Electronics Manufacturing Services (EMS) face numerous technical and logistical challenges that require innovative solutions to ensure efficiency and product quality.
Key technical challenges include miniaturization and complex assembly processes.
Technical Challenges
Miniaturization: As electronic devices become smaller and more powerful, components must also be miniaturized. This requires precise placement of tiny components on PCBs, demanding advanced equipment and highly skilled technicians. Techniques like surface-mount technology (SMT) and high-density interconnect (HDI) PCBs are essential to address these challenges.
Complex Assembly Processes: Modern electronic devices contain numerous components, each with specific assembly requirements. Managing the integration of these components into a cohesive system is complex. Advanced automation, robotics, and precision engineering ensure correct assembly and functionality.
Logistical Challenges
Supply Chain Management: Efficient supply chain management is crucial for ensuring that all necessary components are available on time. This involves managing relationships with multiple suppliers, coordinating deliveries, and maintaining inventory levels. Delays or shortages can significantly impact production schedules and costs.
Global Sourcing: Sourcing components globally introduce complexities like quality variations, longer lead times, and geopolitical risks. EMS providers must navigate these challenges to maintain a steady supply of high-quality components.
Solutions and Strategies
To mitigate these challenges, EMS providers use various strategies and engineering techniques:
Just-In-Time (JIT) Manufacturing: JIT reduces inventory costs by receiving goods only as needed in the production process. This requires precise coordination with suppliers for timely deliveries, minimizing waste and storage needs.
Design for Testability (DFT): DFT involves designing electronic components and systems with testing in mind, facilitating defect identification during manufacturing. Incorporating test points and diagnostics improves product reliability and speeds up time-to-market.
Supplier Quality Management (SQM): SQM evaluates and monitors suppliers to ensure they meet stringent quality standards. Regular audits, performance reviews, and clear quality requirements help maintain a consistent supply of high-quality components, reducing defects and delays.
By addressing these technical and logistical challenges with innovative solutions, EMS providers enhance their production capabilities, ensuring high-quality, reliable electronic products.
Quality Control and Regulatory Compliance
Quality control in Electronics Manufacturing Services (EMS) is crucial for ensuring that electronic products meet the highest standards of performance, reliability, and safety. Rigorous quality control measures help prevent defects, reduce waste, and ensure customer satisfaction. Adhering to stringent regulatory requirements and industry standards is essential for EMS providers to maintain credibility and competitiveness.
Regulatory Requirements and Standards
EMS providers must comply with a range of regulatory requirements and standards to ensure product quality and safety. Key standards include:
ISO 9001: This international standard specifies requirements for a quality management system (QMS). It helps organizations ensure that they consistently provide products and services that meet customer and regulatory requirements. EMS providers use ISO 9001 to enhance customer satisfaction through effective application of the system, including processes for improvement and assurance of conformity to customer and regulatory requirements. [5]
IPC-A-610: This standard outlines the acceptability of electronic assemblies. It provides criteria for the assembly process and ensures that the products meet high-quality standards. IPC-A-610 is widely used in the electronics industry to standardize and improve the reliability of electronic assemblies.
RoHS Compliance: The Restriction of Hazardous Substances Directive restricts the use of specific hazardous materials found in electrical and electronic products. Compliance with RoHS ensures that products are environmentally safe and free from harmful substances like lead, mercury, and cadmium.
Key Quality Control Measures and Compliance Standards
Automated Inspection Systems: These systems, including Automated Optical Inspection (AOI) and Automated X-ray Inspection (AXI), are used to detect defects in PCBs and assemblies. AOI uses high-resolution cameras to inspect the boards for issues such as misaligned components, solder defects, and missing parts. AXI is particularly useful for inspecting hidden solder joints in complex assemblies.
Statistical Process Control (SPC): SPC involves using statistical methods to monitor and control the manufacturing process. By collecting data from various stages of production, EMS providers can identify trends and variations that may indicate potential issues. This proactive approach helps in maintaining consistent product quality and reducing defects.
Traceability Systems: Traceability is critical for tracking the history, application, or location of a product. In EMS, traceability systems record the origin of components, the manufacturing process, and the final product's distribution. This information is vital for managing recalls, ensuring accountability, and complying with regulatory requirements.
By implementing these quality control measures and adhering to regulatory standards, EMS providers can ensure the production of high-quality, reliable electronic products. These practices not only enhance product performance and customer satisfaction but also help EMS providers maintain compliance with global industry standards.
Recommended Reading: How AI is Accelerating Advancements in Electronics Manufacturing
Conclusion
Electronics Manufacturing Services (EMS) have emerged as a pivotal component in modern engineering, driving innovation and efficiency across various sectors. Through advanced manufacturing techniques, quality control measures, and adherence to regulatory standards, EMS providers ensure the production of high-quality, reliable electronic products. The transformative potential of EMS in engineering cannot be overstated, as it enables companies to focus on innovation while leveraging the expertise of specialized manufacturing partners. Staying informed about ongoing advancements in EMS is crucial for professionals in the field, as the industry continues to evolve and introduce new technologies that will shape the future of electronics manufacturing.
Frequently Asked Questions (FAQs)
Q. What are the main services provided by EMS companies?
A. EMS companies offer a wide range of services to support the entire lifecycle of electronic products. These include:
PCB Layout Design: EMS providers design the layout of printed circuit boards (PCBs), optimizing the arrangement of components to ensure efficient manufacturing and reliable performance.
Firmware Development: EMS companies develop software that controls the hardware functions of electronic devices, ensuring seamless integration and operation.
Conformal Coating: This process involves applying a protective coating to PCBs to prevent damage from environmental factors such as moisture, dust, and chemicals.
Q. How do EMS companies ensure quality and reliability?
A. EMS providers implement stringent quality control processes and reliability testing methods to ensure product excellence. Key methods include:
Automated Optical Inspection (AOI): AOI uses high-resolution cameras to inspect PCBs for defects such as misaligned components, soldering issues, and missing parts.
X-ray Inspection: This method allows for the inspection of hidden solder joints and internal structures of complex assemblies, identifying defects that are not visible to the naked eye.
Functional Testing: EMS companies perform functional testing to verify that electronic products operate correctly under specified conditions, ensuring they meet performance standards.
Q. What are the benefits of outsourcing to an EMS provider?
A. Outsourcing electronics manufacturing to EMS providers offers several advantages:
Advanced Manufacturing Technologies: EMS companies have access to state-of-the-art manufacturing technologies that can enhance product quality and efficiency.
Expertise in High-Volume Production: EMS providers are experienced in managing large-scale production runs, ensuring consistency and reliability across high volumes.
Scalability: Outsourcing allows companies to scale production up or down based on demand without the need for significant capital investment in manufacturing infrastructure.
Q. How is EMS evolving with new technologies?
A. The EMS industry is continually evolving with the integration of emerging technologies, which are shaping its future direction. Key advancements include:
Additive Manufacturing: Also known as 3D printing, this technology allows for the rapid prototyping and production of complex components, reducing lead times and costs.
Flexible Electronics: Innovations in flexible electronics enable the creation of bendable and stretchable devices, expanding the possibilities for new applications and form factors.
Advanced Packaging Techniques: These techniques improve the performance and miniaturization of electronic components, enabling more compact and efficient designs.
References
[1] Hilelectronic. What is Electronic Manufacturing Services? [Cited 2024 June 13] Available at: Link
[2] JHDPCB. IPC Class Standards For PCB Manufacturing [Cited 2024 June 13] Available at: Link
[3] ESCATEC. What is meant by the terms OEM, EMS, CEM, ODM, CMO and why does it matter? [Cited 2024 June 13] Available at: Link
[4] ResearchGate. A Comprehensive Review of Deep Learning-based PCB Defect Detection [Cited 2024 June 13] Available at: Link
[5] ASQ. What is ISO 9001:2015 – Quality Management Systems? [Cited 2024 June 13] Available at: Link