How to Clean a Circuit Board: A Comprehensive Guide

Understanding Circuit Boards

A circuit board, also known as a printed circuit board (PCB), is a fundamental component of modern electronic devices. It serves as the backbone of electronics, providing a platform for the layout and connection of different electronic components. Cleaning circuit boards is essential to maintain their functionality, as it ensures the efficient distribution of power and enables communication among soldered components, such as resistors, capacitors, and integrated circuits.

Circuit boards are made from a non-conductive substrate, often fiberglass, with conductive pathways etched or printed onto it. These pathways, or traces, are usually made of copper and are responsible for directing the flow of electricity through the device. Cleaning circuit boards regularly helps maintain the integrity of these pathways, ensuring that the layout of the traces effectively determines the way components interact with each other.

Circuit boards have enabled the miniaturization and performance improvements of electronic devices over the past few decades. Cleaning circuit boards is a critical step in ensuring the optimal performance and longevity of our electronic gadgets. Understanding the anatomy of circuit boards is the first step towards mastering the art of cleaning them effectively.

How do Circuit Boards Get Dirty?

Printed circuit boards get dirty over time with dust, water, and other contaminations that may lead to ineffective operation of the device. Devices with onboard fans are particularly at risk, as they can draw in airborne debris, contributing to overheating and component failure. Here are some of the reasons: 

Airborne debris caught by the onboard fan on a notebook motherboard. 

During manufacturing, circuit boards can become contaminated with residues from various chemicals and fluxes used in soldering and cleaning. These residues can attract dust and moisture, leading to corrosion and electrical breakdowns. Improper cleaning or inadequate rinsing after manufacturing can leave behind a harmful layer of contaminants on the board's surface.

The working environment plays a significant role in circuit board contamination. [1] Dust-filled,  humid, or chemically laden environments can accelerate the deposition of contaminants on circuit boards. Poor ventilation and excessive exposure to heat can also contribute to component degradation and contamination buildup. For instance, an IEEE study found that dust accumulation can cause up to a 20% decrease in airflow, leading to overheating of electronic components.

Negligent or improper use of electronic devices can lead to premature contamination and damage to circuit boards. Spills of liquids, exposure to extreme temperatures, and mechanical shock can introduce various contaminants and cause physical damage to the board's components.

Circuit board contamination stems from various sources, including manufacturing residues, working environment factors, and improper user practices. Understanding the causes of electronic device failure is essential for developing effective cleaning and maintenance strategies to ensure optimal performance.

Recommended Reading: PCB Manufacturing Process: Everything You Need to Know

Why is Cleaning Circuit Boards Essential?

One of the primary reasons for PCB cleaning is to ensure optimal performance. Dust and dirt can interfere with the electrical connections on the board, causing resistance and heat buildup. This can lead to slower performance and, in severe cases, can cause components to fail. For example, a study by ASHRAE found that dust accumulation of 0.42 g/m2 can cause a 1°C increase in temperature, which can affect the performance of sensitive electronic components. [2]

Dust and other contaminations on the surface of PCB assembly.

Another reason for cleaning circuit boards is to prevent corrosion. Circuit boards collect many particulates that can absorb moisture from the air, making corrosion more likely. Corrosion can damage the copper traces on the board, leading to open circuits and device failure. A study published in the Journal of The Electrochemical Society found that even a small amount of chloride, a common component of dust, can initiate corrosion on copper surfaces. Epoxy coating, aerosol spray coating, and solder masks are commonly used to prevent oxidation and clean corrosion.

Cleaning circuit boards is essential to avoiding dendritic growth from ionic residues. Researchers found that high ionic contamination on circuit boards results in deteriorated insulation resistance and dielectric strength. Dendrite growth on the PCB surface reduces the lifetime of the electronic product. IPC defines dendritic growth as the growth of conductive metal filament on the PCB through an electrolytic solution under the influence of a DC voltage bias. To prevent this, the fabricator must adhere to IPC-5704.

Cleaning circuit boards also help in extending their lifespan. Accumulated dust and dirt can cause premature wear and tear on the components, leading to a shorter lifespan for the device. To ensure the reliability and durability of integrated circuits, clean all flux residues from the printed circuit board.

Lastly, cleaning circuit boards is essential for safety reasons. Accumulated dust can be flammable and can cause a fire if it comes into contact with a hot component. According to the National Fire Protection Association (NFPA), electrical fires account for 13% of all home fires, many of which are caused by dust accumulation on electrical components. [3]

In conclusion, cleaning circuit boards is essential for maintaining optimal performance, preventing corrosion, extending the lifespan of the device, and ensuring safety. Regular cleaning should be part of the maintenance routine for any electronic device.

When to Clean Circuit Boards?

Identifying the right time to clean a circuit board is crucial to maintaining its performance and longevity. There are several signs that indicate when a circuit board may require cleaning.

One of the most apparent signs is visible dust and dirt accumulation on the circuit board. This  can be seen as dust on components and traces or as clumps in the corners and crevices of the board. Dust can cause resistance and heat buildup on the board, leading to slower performance and, in severe cases, component failure.

Another sign that a circuit board needs cleaning is when the device malfunctions or performs poorly. This could manifest as the device overheating, slowing down, or crashing. These issues can be caused by dust and dirt interfering with the electrical connections on the board or causing components to overheat. 

The frequency of cleaning can also depend on the environment in which the device is used. Devices used in dusty or industrial environments may require more frequent cleaning than those used in cleaner, controlled environments. For instance, a computer used in a construction site office may need to be cleaned every month, while a computer in a clean, air-conditioned office may only need to be cleaned every six months. [4]

In addition to these signs, it's also recommended to have a regular cleaning schedule for circuit boards. Regular cleaning can prevent the accumulation of dust and dirt, reducing the risk of performance issues and extending the lifespan of the device. 

In conclusion, the right time to clean a circuit board can be determined by visible dust accumulation, device performance issues, the operating environment, and the recommended cleaning frequency. Regular cleaning can help maintain the performance and extend the lifespan of electronic devices.

Precautions Before Cleaning Circuit Boards

Cleaning a circuit board is not as straightforward as cleaning other objects. It involves dealing with delicate components and potentially harmful substances. Therefore, certain precautions must be taken before starting the cleaning process.

Technician cleaning circuit board of disassembled laptop.

The first and foremost precaution is to disconnect the power supply. Circuit boards are electrical components, and cleaning them while they are powered can lead to electrical shocks or short circuits. It's important to turn off the device and unplug it from the power source. 

Another crucial precaution is the use of anti-static tools and equipment. Static electricity can cause damage to the sensitive electronic components on a circuit board. According to a report by the Electrostatic Discharge Association (ESDA), electrostatic discharge (ESD) is one of the major causes of device failures in the electronics industry. Anti-static brushes and wrist straps are recommended to prevent static electricity from building up on your body. [5]

Lastly, it's important to know the potential risks associated with the cleaning agents used. Some cleaning agents can be harmful if inhaled, ingested, or come into contact with skin. Therefore, it's important to use them in a well-ventilated area, to wear protective gloves and goggles, and to follow the safety instructions provided by the manufacturer. The National Institute for Occupational Safety and Health (NIOSH) recommends using a safety data sheet (SDS) to understand the hazards of a chemical product and to take the necessary precautions.

In conclusion, taking precautions before PCB cleaning is crucial to ensure personal safety and to prevent damage to the device. These precautions include disconnecting the power supply, using anti-static tools, and handling cleaning agents safely. Following these precautions can help ensure safe and effective cleaning methods.

Tools Needed for Cleaning Circuit Boards

Cleaning electronic circuit boards requires a set of specialized tools to ensure that the process is effective and does not damage the delicate components. The following tools are commonly used for cleaning circuit boards:

Technician using a bristle brush and air blower ball to clean dust in circuit board computer.

Anti-static brushes: These brushes are designed to prevent the buildup of static electricity, which can damage sensitive electronic components. They come in various sizes and shapes to reach different areas of the circuit board. Anti-static brushes are typically made with conductive fibers, such as carbon or metal, to dissipate static charges. 

Compressed air: Compressed air is used to blow away dust and debris from the circuit board without touching the components. It is important to use a can of compressed air specifically designed for electronics, as it contains no moisture or contaminants that could harm the board. [6] When using compressed air, it's essential to hold the can upright and maintain a safe distance from the board to avoid damage.

Cotton swabs and lint-free cloths: Cotton swabs and lint-free cloths are useful for cleaning hard-to-reach areas and for wiping away cleaning agents. They can be used in conjunction with cleaning solutions to remove dirt and grime from the circuit board. Using lint-free materials is important to prevent fibers from getting caught in the components.

Anti-static wrist strap: While not a cleaning tool per se, an anti-static wrist strap is essential for preventing electrostatic discharge (ESD) when handling circuit boards. The strap is worn around the wrist and connected to a grounded surface, ensuring that any static charge on the body is safely dissipated.

Tweezers and picks: Tweezers and picks can be used to remove larger debris or to dislodge stubborn dirt from the circuit board carefully. It's important to use non-conductive materials, such as plastic or ceramic, to avoid causing short circuits.

These tools are widely available and can be purchased from electronics stores, online retailers, or specialized suppliers. The right tools are crucial for effectively cleaning circuit boards and maintaining their performance and longevity.

Recommended Reading: What are Circuit Boards Made Of? An Extensive Guide to Materials and Manufacturing Processes

Cleaning Agents for Circuit Boards

Cleaning agents play a crucial role in the process of cleaning electronic circuit boards. They help dissolve and remove various types of contaminants that can interfere with the performance of the board. However, not all cleaning agents are suitable for circuit boards. It's important to choose a cleaning agent that is effective in removing contaminants but does not damage the components or leave residues. Here are some commonly used cleaning agents for circuit boards:

Cleaning Circuit Board with Isopropyl Alcohol (IPA).

Isopropyl Alcohol (IPA): IPA is one of the most commonly used cleaning agents for circuit boards. It is a solvent that can dissolve a wide range of non-polar compounds. IPA or Phosphates are particularly effective in removing oils, greases, and clean flux residues from the board. They evaporate quickly, leaving no residue, which makes it ideal for cleaning circuit boards. It's important to use a high-purity IPA (typically 99% or higher) to ensure that no impurities are introduced to the board.

Deionized Water: Deionized water is often used in conjunction with other cleaning agents to rinse the circuit board after cleaning. Deionized water is water that has had its ions removed, making it a poor conductor of electricity. This makes it safe to use on circuit boards. However, it's important to dry the board thoroughly after rinsing to prevent water damage.

Flux Removers: Flux is a substance that is used during the soldering process to improve the flow of the solder. However, flux residues can remain on the board after soldering, which can lead to corrosion and other issues. Flux removers are specially designed to dissolve and remove these residues. They are typically available in spray form for easy application.

Electronics Contact Cleaners: These are specialized cleaning agents designed for use on electronic components. They are typically non-conductive and leave no residue, making them safe for use on circuit boards. They effectively remove dust, dirt, and other contaminants from the board.

Ultrasonic Cleaning Solutions: These are cleaning agents designed for use in ultrasonic cleaning machines. They are typically a mixture of distilled water and a mild detergent or baking soda, and they work by creating microscopic bubbles that dislodge dirt and contaminants from the board.

PCB Ultrasonic Cleaner.

It's important to note that not all cleaning agents are suitable for all types of circuit boards. Some boards may have specific cleaning requirements due to the materials used or the nature of the components. Therefore, it's always recommended to check the manufacturer's instructions or consult with a professional before choosing a cleaning agent.

Step-by-Step Guide to Cleaning Circuit Boards

Cleaning circuit boards is a delicate process that requires attention to detail and the use of appropriate tools and cleaning agents. The following step-by-step guide outlines the process of cleaning a circuit board effectively and safely:

Cleaning a printed circuit board using a paintbrush.

Step 1: Disconnect power and remove the circuit board

• Ensure that the device is turned off and unplugged from the power source.

• Carefully disassemble the device to access the circuit board.

• Remove the circuit board from the device, taking care not to damage any components.

Step 2: Inspect the circuit board

• Visually inspect the circuit board for any signs of damage, corrosion, or excessive dirt accumulation.

• Identify areas that require special attention during the cleaning process.

Step 3: Use compressed air to remove loose dust and debris

• Hold the can of compressed air upright and at a safe distance from the board.

• Use short bursts of air to blow away loose dust and debris from the circuit board, focusing on areas with visible accumulation.

Step 4: Clean the circuit board with an anti-static brush

• Gently brush the surface of the circuit board with the soft bristles of an anti-static brush to remove any remaining dust and debris.

• Pay special attention to areas with visible dirt or between tightly spaced components. Don’t forget to clean corroded areas or solder joints. 

Step 5: Apply a cleaning agent

• Dampen a lint-free towel or cotton swab with a suitable cleaning agent, such as isopropyl alcohol (IPA), acetone, or baking soda.

• Gently wipe the surface of the circuit board, focusing on areas with visible dirt or residue.

• Avoid applying excessive pressure or scrubbing, as this can damage the components.

Step 6: Clean hard-to-reach areas

• Use cotton swabs or tweezers to clean hard-to-reach areas, such as under components or between tightly spaced traces.

• Apply the cleaning agent sparingly to avoid leaving residue or causing damage.

Step 7: Rinse the circuit board (if necessary)

• If the cleaning agent used requires rinsing, gently rinse the circuit board with distilled water.

• Ensure that the water does not pool on the board or enter any connectors or sockets.

Step 8: Dry the circuit board

• Allow the circuit board to air dry in a well-ventilated area, or use a lint-free or microfiber cloth to pat it dry gently.

• Ensure that the board is completely dry before reassembling the device.

Step 9: Reassemble the device

• Carefully reassemble the device, ensuring that all components and connectors are properly seated.

• Reconnect the power supply and test the device to ensure proper functionality.

By following this step-by-step guide, you can effectively clean your circuit board and maintain its performance and longevity. Remember to use appropriate tools and cleaning agents, and always follow safety precautions to prevent damage to the board or personal injury.

Drying and Reassembling Circuit Boards

After cleaning the circuit board, it is essential to ensure that it is completely dry before reassembling the device. Any remaining moisture on the board can cause short circuits or corrosion, leading to potential damage or device failure. The following steps outline the proper drying and reassembling process for circuit boards:

Step 1: Air-dry the circuit board

• Place the circuit board in a well-ventilated area and allow it to air dry. This process can take several hours, depending on the ambient temperature and humidity.

• Avoid using heat sources, such as hair dryers or heaters, to speed up the drying process, as excessive heat can damage the components.

Step 2: Inspect the circuit board for moisture

• Visually inspect the circuit board to ensure that it is completely dry. Pay special attention to areas under components or in tight spaces where moisture may be trapped.

• Use a lint-free cloth or cotton swab to remove any remaining moisture gently.

Step 3: Reassemble the device

• Carefully reassemble the device, ensuring that all components are properly seated and that connectors are correctly aligned.

• Double-check that all screws and fasteners are securely tightened to prevent loose connections or rattling.

Step 4: Reconnect the power supply and test the device

• Reconnect the power supply to the device and turn it on.

• Test the device to ensure that it is functioning properly and that no issues result from the cleaning process.

By following these steps, you can ensure that your circuit board is properly dried and reassembled, minimizing the risk of damage or device failure. Proper drying and reassembly are crucial to maintaining the performance and longevity of your electronic devices after cleaning.

Recommended Reading: PCB Testing: A Comprehensive Guide to Techniques, Tools, and Best Practices

Maintaining Clean Circuit Boards

Maintaining the cleanliness of circuit boards is an ongoing process that extends beyond the initial cleaning. Regular maintenance can help prevent the accumulation of dust and debris, reduce the risk of corrosion, and improve the performance and longevity of the board. Here are some strategies for maintaining clean circuit boards:

Regular cleaning of printed circuit board.

Regular Inspection: Regularly inspect the circuit board for signs of dust, dirt, or corrosion. This can help identify potential issues before they become serious problems. Use a magnifying glass or microscope if necessary to inspect small or densely packed components.

Use of Dust Covers: Dust covers can be used to protect circuit boards from dust and debris when they are not in use. These covers are typically made of plastic or other non-conductive materials and are designed to fit over the circuit board or the entire device.

Proper Storage: Circuit boards should be stored in a clean, dry environment when not in use. Avoid areas with high humidity or temperature fluctuations, as these conditions can lead to condensation and corrosion. [7]

Regular Cleaning: Depending on the environment in which the device is used, it may be necessary to clean the circuit board using PCB cleaner regularly. This could be every few months for devices in dusty or dirty environments or every few years for devices in clean, controlled environments.

Use of Anti-Static Equipment: Static electricity can attract dust and other particles to the circuit board. Using anti-static mats, wrist straps, and other equipment can help reduce the buildup of static electricity and keep the board clean.

Proper Handling: Always handle the circuit board with clean, dry hands. Oils and dirt from your hands can contaminate the board. Use gloves if necessary.

By following these strategies, you can maintain the cleanliness of your circuit boards and ensure their optimal performance and longevity. Remember, prevention is often the best strategy for keeping circuit boards clean. Regular maintenance and proper handling can go a long way in preventing the need for extensive cleaning.

Professional Circuit Board Cleaning Services

In some cases, it may be necessary to seek the help of professional circuit board cleaning services. These services use specialized equipment and techniques to clean and maintain electronic components. Here are some scenarios when professional cleaning services are needed, and what to consider when choosing a service provider: 

Complex or High-Value Devices: Some electronic devices, such as high-end audio equipment or industrial control systems, may have complex or delicate circuit boards that require specialized cleaning. In these cases, it's best to rely on professionals with the expertise and equipment to handle such tasks.

Severe Contamination or Damage: If a circuit board is severely contaminated, it may need professional cleaning to restore functionality. Professionals have access to specialized cleaning agents and equipment that can effectively remove dry contaminants without causing further damage.

Lack of Experience or Confidence: If you're not confident in your ability to clean a circuit board safely and effectively, it's best to seek the help of professionals. They have the experience and knowledge to handle the task, ensuring that your device is properly cleaned and maintained.

When choosing a professional circuit board cleaning service, consider the following factors:

Experience and Expertise: Look for a service provider with a proven track record in cleaning circuit boards and electronic components. They should have experience working with various devices and be familiar with the specific cleaning requirements of different types of circuit boards.

Equipment and Techniques: A professional cleaning service should have access to specialized equipment, such as ultrasonic cleaners, and use industry-standard cleaning techniques to ensure the best possible results.

Certifications and Standards: Check if the service provider adheres to industry standards and holds relevant certifications, such as ISO 9001 or IPC certification. This can help ensure that they follow best practices and maintain high quality in their services.

Turnaround Time and Cost: Inquire about the turnaround time for cleaning services and the associated costs. Compare quotes from multiple service providers to find the best value for your needs.

Customer Reviews and Testimonials: Look for customer reviews and testimonials to gauge the quality of the service provider's work. This can help you make an informed decision when choosing a professional cleaning service for your circuit board.

Considering these factors, you can find a professional circuit board cleaning service that meets your needs and ensures your electronic devices' optimal performance and longevity.

Recommended Reading: How Do Circuit Boards Work: A Comprehensive Guide to the Heart of Electronics

Conclusion

Cleaning and maintaining circuit boards is essential for ensuring the optimal performance and longevity of electronic devices. By following the proper cleaning procedures, using appropriate tools and cleaning agents, and adhering to safety precautions, you can effectively clean your circuit boards and prevent potential issues such as corrosion, overheating, and device failure. In some cases, professional cleaning services may be necessary for complex or high-value devices or when dealing with severe contamination or damage. By understanding the importance of circuit board cleanliness and implementing regular maintenance practices, you can help extend the life of your electronic devices and maintain their functionality.

FAQs

Q: Can I use household cleaning products to clean circuit boards? 

A: Household cleaning products are generally not recommended for cleaning circuit boards, as they may contain chemicals that can damage the components or leave residues. Instead, use specialized cleaning agents such as isopropyl alcohol (IPA) or electronics contact cleaners.

Q: How often should I clean my circuit board? 

A: The frequency of cleaning depends on the environment in which the device is used and the specific requirements of the circuit board. In general, cleaning electronic devices at least once every six months is recommended to maintain optimal performance. However, devices used in dusty or industrial environments may require more frequent cleaning.

Q: Can I use a hairdryer to dry my circuit board after cleaning? 

A: Using a hairdryer or other heat sources is not recommended to dry circuit boards, as excessive heat can damage the components. Instead, allow the board to air dry in a well-ventilated area or gently pat it dry with a lint-free cloth.

Q: What should I do if I accidentally damage my circuit board during cleaning? 

A: If you accidentally damage your circuit board during cleaning, it's best to consult with a professional technician or the device manufacturer for guidance on repair or replacement options.

Q: Can I clean a circuit board without removing it from the device? 

A: While it's possible to clean a circuit board without removing it from the device, it's generally not recommended, as it can be difficult to access all areas of the board and may increase the risk of damage. Removing the circuit board from the device before cleaning is best to ensure a thorough and safe cleaning process.

References

[1] Proto-Electronics. PCB in harsh environment: which precautions shall be taken? [Cited 2023 November 04] Available at: Link

[2] ASHRAE. DESCRIPTION 2021 ASHRAE HANDBOOK—FUNDAMENTALS [Cited 2023 November 04] Available at: Link

[3] NFPA. NFPA RESEARCH [Cited 2023 November 04] Available at: Link

[4] Kingston. How to Clean Your PC System [Cited 2023 November 04] Available at: Link

[5] Gesrepair. How to Clean a Circuit Board [Cited 2023 November 04] Available at: Link

[6] Microcare. 4 Types of PCB Contamination and How to Remove Them [Cited 2023 November 04] Available at: Link

[7] Mclpcb. PCB Corrosion Causes [Cited 2023 November 04] Available at: Link