Circuit boards are integral components of electronic devices and are responsible for controlling the flow of electricity between different parts of the device. However, over time, these circuit boards can become corroded due to exposure to moisture, dust, and other environmental factors. Corrosion can lead to malfunctioning of the device or even render it completely unusable. It is, therefore, essential to clean the circuit board regularly to maintain the device’s longevity and performance.
Cleaning a circuit board of corrosion may seem like a daunting task, but it is a relatively straightforward process that can be accomplished with the right tools and techniques. In this article, we will explore the different types of corrosion that can affect a circuit board and the methods used to clean them. We will discuss the tools and materials required for cleaning, including specialized cleaning solutions and brushes, and explain how to properly disassemble the device to access the circuit board.
Furthermore, we will cover the different cleaning methods, including mechanical, chemical, and ultrasonic cleaning, and when each method is appropriate. We will also provide tips for preventing future corrosion, such as storing the device in a dry and cool environment and using protective coatings on the circuit board.
What Is PCB Corrosion?
Corrosion often appears as green or blue streaks along the connected parts of the circuit board. This type of damage can cause a wide range of issues from preventing your device from powering up to causing permanent damage to other components [1].
What Does PCB Corrosion Mean?
PCB corrosion means that the circuit board has been exposed to moisture or chemical damage over time. This type of exposure damages the copper traces and components on the board, thus compromising its ability to conduct electricity properly. This can lead to an electrical short or a complete failure of your device [2].
What Causes PCB Corrosion?
PCB corrosion is most commonly caused by exposure to water, moisture, or chemicals. Over time these sources can damage the copper traces and components on the circuit board which can lead to electrical shorts or a complete failure of your device. In addition to this direct exposure, high levels of humidity in the environment can also contribute to PCB corrosion.
One common cause of PCB corrosion is exposure to moisture and humidity, which can cause oxidation and corrosion of the metal components on the board. This can lead to problems such as short circuits, signal interference, and reduced functionality.
Other environmental factors that can contribute to PCB corrosion include exposure to salt, pollutants, and high temperatures. For example, circuit boards used in marine or coastal environments may be more susceptible to corrosion due to exposure to saltwater and salt spray.
Manufacturing defects can also contribute to PCB corrosion. For example, if the board is not properly cleaned and dried after soldering, residual flux can react with moisture and other contaminants to create a corrosive environment [3].
Improper maintenance can also contribute to PCB corrosion. For example, using the wrong cleaning solution or not drying the board thoroughly after cleaning can lead to the buildup of moisture and other contaminants, which can cause corrosion over time.
How To Determine the Types of PCB Corrosion:
Atmospheric Corrosion
Atmospheric corrosion is the most common type of PCB corrosion. It occurs when the PCB is exposed to the atmosphere, and it reacts with oxygen, moisture, and other environmental pollutants. The corrosion appears as a thin, greenish film on the surface of the PCB. In severe cases, it can cause rusting and pitting of the metal components, leading to a complete breakdown of the PCB.
To determine if a PCB has atmospheric corrosion, look for discoloration, rusting, or pitting on the metal components of the board. It is also essential to check for any visible corrosion on the circuit board’s surface.
Galvanic Corrosion
Galvanic corrosion occurs when two different metals come into contact with each other and an electrolyte (a liquid that conducts electricity) is present. The result is a flow of electrons from the metal that is more reactive to the metal that is less reactive. Galvanic corrosion can occur on a PCB when two different metals are used for the components or connectors [4].
To determine if a PCB has galvanic corrosion, look for discoloration or corrosion on the metal components or connectors. There may also be visible signs of rust or pitting.
Electrolytic Corrosion
Electrolytic corrosion occurs when a direct current (DC) passes through a conductive liquid or solution and causes the metal to dissolve. This type of corrosion can occur when a PCB is exposed to moisture or a conductive liquid.
To determine if a PCB has electrolytic corrosion, look for discoloration or corrosion on the metal components or connectors. There may also be visible signs of rust or pitting.
Fretting Corrosion
Fretting corrosion occurs when two surfaces repeatedly rub against each other, causing tiny metal particles to break away from the surface. These metal particles can cause corrosion, which can damage the PCB’s components and connectors.
To determine if a PCB has fretting corrosion, look for signs of wear or damage to the metal components or connectors. There may also be visible signs of rust or pitting [5].
Why Should You Regularly Clean a Circuit Board:
Enhance the Aesthetic Appearance of the PCB
Regular cleaning of a PCB improves its aesthetic appearance. Over time, PCBs can become discolored due to the accumulation of dirt and dust. The buildup can also hide the component labels, making it difficult to identify specific parts on the board. By cleaning the PCB regularly, you can maintain its original appearance and make it easier to identify the components.
Improve the Reliability of Circuit Boards
Regular cleaning of a PCB can improve its reliability. Dust and debris can accumulate in the PCB’s components, affecting the device’s electrical conductivity. Over time, this buildup can lead to short circuits or other electrical problems that can cause the device to fail. By regularly cleaning the PCB, you can prevent these issues and ensure the device’s optimal performance.
Prevent PCB Component Corrosion
PCB components are vulnerable to corrosion caused by environmental factors such as humidity, moisture, and other contaminants. Corrosion can cause the device to malfunction or even fail completely. Regular cleaning of a PCB removes contaminants that can cause corrosion, protecting the device’s components and prolonging its lifespan.
Prevent Adhesion Issues with Conformal Coating
However, if the PCB is not cleaned regularly, the buildup of contaminants can prevent the conformal coating from adhering to the PCB’s surface. This can cause the coating to peel off or not provide adequate protection, leaving the device vulnerable to damage. Regular cleaning of the PCB can prevent this issue and ensure that the conformal coating adheres properly [6].
Avoid Dendritic Growth from Ionic Residues
Ionic residues are contaminants that can accumulate on PCBs during the manufacturing process. Over time, these residues can cause dendritic growth, which can lead to electrical shorts and other issues. Regular cleaning of the PCB removes these contaminants, preventing dendritic growth and ensuring the device’s optimal performance.
Tools for Cleaning Circuit Boards:
Baking Soda
Baking soda is an effective tool for cleaning circuit boards. It is a mild abrasive that can remove grime and dirt without causing damage to the PCB. Baking soda can be used by mixing it with water to form a paste. The paste is then applied to the circuit board with a soft-bristled brush and gently scrubbed. Once the cleaning is complete, the board should be rinsed with distilled water and dried thoroughly before reassembly.
Isopropyl Alcohol
Isopropyl alcohol (IPA) is a commonly used solvent for cleaning circuit boards. It is an effective cleaner that can dissolve many types of dirt, grease, and grime. IPA is available in different concentrations, with 99% being the most common. To use IPA for cleaning circuit boards, it should be applied to a lint-free cloth or a cotton swab and wiped on the surface of the board. Once the cleaning is complete, the board should be left to dry for some time before reassembly [7].
Distilled or Deionized Water
Distilled or deionized water is a tool that can be used for cleaning circuit boards. It is used to rinse the board after cleaning with other solvents such as IPA. Distilled or deionized water is free from impurities, and hence it is safe to use on PCBs. The board should be rinsed thoroughly with distilled or deionized water and left to dry before reassembly.
Compressed Air
Compressed air is a tool that is used to blow off dust and other particles from the surface of a circuit board. It is a quick and effective way to remove debris without having to touch the board. Compressed air should be used with caution, as it can blow off small surface-mounted components. It is advisable to hold the board securely and use compressed air from a safe distance.
PCB Ultrasonic Cleaners
PCB ultrasonic cleaners are specialized tools that use sound waves to clean the surface of a PCB. They work by creating high-frequency vibrations that generate small bubbles that dislodge dirt and other contaminants from the surface of the circuit board. The bubbles are so small that they can penetrate even the tightest spaces, ensuring that every part of the circuit board is cleaned thoroughly [8].
Using a PCB ultrasonic cleaner is a straightforward process. First, you need to fill the tank with the cleaning solution recommended for your PCB. You then need to immerse the PCB in the solution and switch on the ultrasonic cleaner. The device will do the rest, using sound waves to agitate the cleaning solution and dislodge any dirt or debris on the PCB. Once the process is complete, you can rinse the PCB in distilled water and leave it to dry.
PCB Cleaning Brushes
PCB cleaning brushes are small brushes that are specifically designed for cleaning circuit boards. They come in a variety of sizes and shapes, including angled, flat, and tapered brushes, to make it easy to clean different parts of the PCB. They are typically made of materials such as nylon or natural hair, which are gentle enough not to damage the circuit board.
To use a PCB cleaning brush, you need to dip it in a cleaning solution and gently scrub the surface of the PCB. You should avoid using too much pressure or scrubbing too hard, as this can damage the components on the board. Instead, use a light touch and work in a circular motion, making sure to clean every part of the PCB.
Household Cleaners
In some cases, you may be able to use household cleaners to clean your circuit board. However, you need to be careful when using these cleaners, as some can damage the components on the PCB. For example, cleaners that contain bleach, ammonia, or acids should be avoided, as they can corrode the copper traces on the circuit board.
Instead, you should look for household cleaners that are safe for use on electronics. One option is to use mild dish soap and warm water to clean the PCB. You can also use a mixture of vinegar and water or isopropyl alcohol to remove stubborn stains. However, you should always test the cleaner on a small area of the PCB first to make sure that it does not cause any damage [9].
Lintel-Free Towels/Microfiber Cloths
Lint-free towels or microfiber cloths are essential tools for cleaning circuit boards. They are designed to be gentle and non-abrasive, making them ideal for cleaning delicate components. Lint-free towels are made of materials such as cotton or polyester and are designed to be highly absorbent, which helps to remove dirt and debris from the surface of the PCB.
When using a lint-free towel or microfiber cloth to clean a circuit board, you should be careful not to apply too much pressure or use a rough cloth, as this can cause damage to the components on the board. Instead, use a gentle touch and work in a circular motion, making sure to clean every part of the PCB.
An Oven or Blow Dryer
Another tool that you can use to clean a circuit board is an oven or blow dryer. This method is particularly effective for removing moisture from the surface of the PCB, which can cause corrosion and other issues. To use this method, you need to place the PCB in an oven or use a blow dryer on the cool setting to dry the PCB thoroughly. You should be careful not to overheat the PCB or use a high-temperature setting, as this can damage the components on the board.
Gas-Phase Cleaners
Gas-phase cleaners are an excellent tool for cleaning circuit boards, as they can remove dirt and other contaminants without damaging the delicate components on the board. These cleaners use a pressurized gas to blow away any loose debris, making them ideal for cleaning sensitive electronics that cannot be exposed to moisture or other liquids.
One of the primary benefits of gas-phase cleaners is that they are non-abrasive, which means that they will not scratch or damage the surface of the circuit board. This is particularly important when working with delicate electronics, as even small scratches or nicks can cause irreparable damage to the device.
Gas-phase cleaners also work quickly and efficiently, making them a time-saving tool for cleaning circuit boards. They can remove dirt, dust, and other contaminants in just a few seconds, without the need for extensive scrubbing or wiping.
Removing Corrosion From a Circuit Board:
Method #1: Applying Compressed Air
The first method for removing corrosion from a circuit board is by using compressed air.
This method is effective in removing loose debris and dirt from the circuit board:
- To begin, turn off the power source and disconnect the circuit board from any power source;
- Then, use compressed air to blow away any dust and debris from the circuit board;
- Make sure to hold the can of compressed air upright and use short bursts of air. It is essential to be gentle while using compressed air to avoid damaging any components on the circuit board [10];
Method #2: Using Isopropyl Alcohol
Another effective method for removing corrosion from a circuit board is by using isopropyl alcohol.
Isopropyl alcohol is a common solvent that is widely used in electronic cleaning:
- To begin, turn off the power source and disconnect the circuit board from any power source;
- Then, using a clean and lint-free cloth, apply isopropyl alcohol to the affected area of the circuit board;
- Rub gently until the corrosion is removed. It is essential to use 90% or higher concentration of isopropyl alcohol for best results;
- Once the corrosion is removed, let the circuit board dry for at least an hour before reconnecting the power source;
Method #3: Using Water and Baking Soda
The third method for removing corrosion from a circuit board is by using water and baking soda. Baking soda is an effective cleaning agent that can remove corrosion without damaging the circuit board:
- Turn off the power source and disconnect the circuit board from any power source;
- Then, mix baking soda with distilled water to create a paste;
- Apply the paste to the affected area of the circuit board and rub gently until the corrosion is removed. It is essential to be careful while using this method as excess water can cause damage to the circuit board;
Safety Guidelines While Cleaning Circuit Boards:
- Turn Off the Power: Always turn off the power supply to the circuit board before cleaning it. This is especially important if you are using liquid cleaners or other substances that could cause a short circuit;
- Wear Protective Gear: Wear protective gloves and goggles to protect your hands and eyes from any harmful chemicals or debris that may be present on the circuit board;
- Work in a Well-Ventilated Area: Ensure that the area where you are working is well-ventilated. This will help prevent the buildup of fumes or vapors that could be harmful to your health;
- Use the Right Tools: Use the right tools for cleaning circuit boards, such as lint-free cloths, brushes, or compressed air. Using the wrong tools could cause damage to the board or its components;
- Avoid Excessive Force: Do not use excessive force when cleaning circuit boards, as this could damage the components on the board or cause the board to crack or break;
- Use Approved Cleaners: Use only approved cleaners that are safe for use on circuit boards. Avoid using household cleaners or abrasive materials that could scratch or damage the board;
- Handle Batteries Carefully: If you are cleaning a circuit board that has batteries, handle them carefully. Batteries can leak corrosive chemicals that can damage the board, so make sure to remove them before cleaning the board;
- Store Chemicals Safely: Store all cleaning chemicals and tools in a safe and secure location, away from children and pets. Label them clearly to avoid confusion and ensure that they are not accidentally ingested [11];
5 Effective Tips To Remove PCB Corrosion:
Always Remove the Device’s Batteries and Power Source First
Before attempting to remove PCB corrosion, it is important to turn off and unplug the device and remove any batteries or power sources. This will ensure your safety while working with the device and prevent any damage to the device or yourself. Failure to do so can result in electrical shock, damage to the device, or injury.
Corrosion is a White/Greenish Substance that Looks and Feels “Crusty”
Corrosion on PCBs typically appears as a white or greenish substance that looks and feels “crusty”. The substance can be powdery or flaky and may cause the device to malfunction or stop working altogether.
Use Cotton Swabs or Q-Tips
To remove corrosion from a PCB, use a cotton swab or Q-tip dipped in a solution of isopropyl alcohol (IPA) or white vinegar. IPA is a common cleaning solution used to remove dirt, grime, and other contaminants from electronic devices. White vinegar is also an effective cleaning solution that can help remove corrosion from PCBs.
Gently rub the cotton swab or Q-tip over the affected area of the board, being careful not to apply too much pressure. This can cause damage to the board or its components. Repeat the process until the corrosion is completely removed. Be sure to use a fresh cotton swab or Q-tip for each pass to avoid spreading the corrosion to other areas of the board.
To Dry the Device, Use a Hair Dryer on the Cool Setting (or a Soft Cloth)
After removing the corrosion, it is important to dry the device thoroughly to prevent further damage. One way to do this is to use a hair dryer in a cool setting. Hold the hair dryer about six inches away from the device and move it around to evenly distribute the cool air. This will help dry the device without damaging any components.
Another option is to use a soft cloth to gently wipe the device dry. Be sure to use a lint-free cloth to avoid leaving any fibers on the board. Make sure the device is completely dry before replacing the batteries or powering it back on.
Replace Damaged Batteries with a New One
If the corrosion has caused damage to the batteries or other components, it may be necessary to replace them. Do not attempt to use damaged batteries as this can cause further damage to the device or pose a safety risk. Always use new, high-quality batteries recommended by the manufacturer to ensure proper function and safety.
How to Prevent Corrosion on PCBs?
Preventing corrosion on PCBs (Printed Circuit Boards) involves taking steps to protect the board from environmental factors and implementing good maintenance practices.
Here are some tips to help prevent corrosion on PCBs:
- Protective Coatings: Applying protective coatings to the board can help protect against corrosion. Some common coatings include conformal coatings, which are designed to protect against moisture and other environmental factors, and solder masks, which can help protect against oxidation and other forms of corrosion;
- Storage: Proper storage of the board can also help prevent corrosion. Store the board in a dry and dust-free environment, and avoid exposing it to extreme temperatures or direct sunlight;
- Cleaning: Regularly cleaning the board using appropriate methods and solutions can help prevent the buildup of contaminants that can cause corrosion. Use a cleaning solution that is safe for the board and follow the manufacturer’s recommendations for cleaning;
- Drying: After cleaning the board, it is important to dry it thoroughly to prevent the buildup of moisture, which can lead to corrosion. Use a lint-free cloth or compressed air to remove any excess moisture;
- Maintenance: Regularly inspecting the board for signs of corrosion or damage and addressing any issues promptly can help prevent further damage. Additionally, following good maintenance practices such as replacing damaged components or parts can help prevent corrosion from spreading [12];
FAQ
1. How do you clean corrosion off electronics?
To clean corrosion off electronics, first, disconnect the device from the power source. Then, disassemble the device to access the affected circuit board. Use a soft-bristled brush to remove loose debris and corrosion from the circuit board.
For heavier corrosion, use a specialized cleaning solution, such as a mixture of water and isopropyl alcohol, or a commercial circuit board cleaner. Apply the solution using a soft cloth or brush, taking care not to damage the circuit board. Once the corrosion has been removed, use compressed air or a dry cloth to dry the board thoroughly before reassembling the device.
2. What is the best chemical to clean circuit boards?
The best chemical to clean circuit boards is isopropyl alcohol (also known as rubbing alcohol) with a concentration of at least 90%. It is effective at dissolving and removing contaminants and evaporates quickly, leaving no residue. Avoid using harsh chemicals such as bleach or ammonia, as these can damage the circuit board [13].
3. Can you spray WD-40 on circuit boards?
No, it is not recommended to spray WD-40 on circuit boards. WD-40 is a lubricant and can leave a residue that can interfere with the electrical contacts on the board. Additionally, some components on the board may be sensitive to the solvents in WD-40 and can become damaged [14].
4. Is vinegar safe for circuit boards?
Vinegar is not recommended for cleaning circuit boards. Although it is an acidic solution and can dissolve some forms of corrosion, it can also damage the metal components on the board and leave a residue that can interfere with the electrical contacts.
5. Can I use acetone to clean a circuit board?
Acetone is not recommended for cleaning a circuit board. While it can dissolve some contaminants, it is a strong solvent and can damage the plastic components and the circuit board’s protective coatings.
6. Can I use 70% isopropyl alcohol to clean a circuit board?
70% isopropyl alcohol can be used to clean a circuit board, but it is not as effective as higher concentrations. The lower concentration means that there is a higher water content, which can leave residue or cause corrosion to return if the board is not dried thoroughly [15].
7. Can you clean a circuit board with soap and water?
It is generally not recommended to clean a circuit board with soap and water. Water can cause further damage to the board and components if it is not dried thoroughly. Additionally, soap can leave a residue that can interfere with the electrical contacts on the board.
8. Can a hand sanitizer clean a circuit board?
No, a hand sanitizer is not recommended for cleaning circuit boards. It can contain ingredients that can damage the board and leave a residue that can interfere with the electrical contacts.
9. Can soda remove corrosion?
Soda is not an effective method for removing corrosion from electronics. In fact, the sugar and other ingredients in soda can make the problem worse by leaving behind a sticky residue that can attract dust and other contaminants.
10. What acid will dissolve circuit boards?
No acid should be used to dissolve circuit boards. Acids such as sulfuric acid or hydrochloric acid are highly corrosive and can cause serious harm to both the board and the person using them. Instead, use a specialized circuit board cleaner or isopropyl alcohol to remove contaminants.
11. How do you remove the coating from a circuit board?
To remove the coating from a circuit board, first, remove any loose debris or corrosion with a soft-bristled brush. Then, apply a specialized circuit board stripper or an acetone-based nail polish remover to the coating. Use a soft cloth or brush to apply the solution, taking care not to damage the circuit board. Once the coating has been removed, use isopropyl alcohol to clean the board thoroughly.
12. Will water damage a circuit board?
Yes, water can damage a circuit board if it is not dried thoroughly or if the board is powered on while still wet. Water can cause corrosion, short circuits, and damage to the components on the board.
13. Is 91% isopropyl alcohol safe for cleaning electronics?
Yes, 91% isopropyl alcohol is safe for cleaning electronics. It is effective at dissolving and removing contaminants and evaporates quickly, leaving no residue. However, it is recommended to use a higher concentration of isopropyl alcohol if possible for best results.
14. Can you use vodka to clean circuit boards?
Vodka is not recommended for cleaning circuit boards. While it contains alcohol, the concentration is usually not high enough to be effective. Additionally, vodka can contain other ingredients that can leave a residue or damage the board.
15. Is hydrogen peroxide safe for circuit boards?
Hydrogen peroxide can be used to clean circuit boards, but it should be used with caution. While it can be effective at removing contaminants, it is a strong oxidizer and can damage some components on the board. It is recommended to use a specialized circuit board cleaner or isopropyl alcohol instead [16].
16. Can white vinegar clean electronics?
White vinegar is not recommended for cleaning electronics. While it is acidic and can dissolve some contaminants, it can also damage the metal components and leave a residue that can interfere with the electrical contacts.
17. Can you use nail polish remover to clean electronics?
Nail polish remover can be used to clean electronics, but it should be an acetone-based product without added fragrances or moisturizers. It is important to use it sparingly and with caution, as it can dissolve some plastics and damage the finish of the device.
18. How do you clean electronics without alcohol?
There are several alternatives to alcohol for cleaning electronics. One option is to use specialized electronics-ready cleaners, which are designed to be safe for sensitive components. Another option is to use a mixture of water and mild dish soap, applied with a soft cloth or brush. Always ensure that the device is completely dry before turning it on [17].
19. Can you brush a circuit board?
Yes, a soft-bristled brush can be used to remove loose debris and corrosion from a circuit board. It is important to use a gentle touch to avoid damaging the components on the board.
20. How do you repair a damaged circuit board?
Repairing a damaged circuit board can be a complex process that requires specialized equipment and knowledge. If the damage is minor, such as a broken trace or a damaged component, it may be possible to repair it using a soldering iron and replacement parts.
Attempting to repair a circuit board without the proper knowledge or equipment can cause further damage and may be dangerous. It is important to ensure that the device is unplugged and all power sources are disconnected before attempting any repairs. Additionally, it is important to follow proper safety protocols and wear protective equipment, such as gloves and eye protection.
Useful Video: how to clean corroded sockets on your PCBs
References
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