How to Clean a Circuit Board

Occasionally, we receive e-mail requests asking if we offer PCB cleaning services once electronic devices become erratic. If you are one of those who have ever wondered how PCBs get dirty or abused and what it takes to clean a PCB, this post is for you. Today’s discussion will be centered around how PCBs get contaminated, the different types of contaminants and the cleaning techniques required to clean them.

Starting with the devices susceptible to contamination, you have your regular smartphones, tablets, smart readers, and traditional electronic hardware. The regular use that comes with owning any of these devices in diverse locations means that dust particles, splashes of liquid, and debris could contaminate the PCBs in these devices. When this occurs, the affected device is unlikely to perform in its optimal settings and this is where a little spring cleaning may be needed.

Understanding The Different Types of Contaminants

To effectively provide a solution to any challenge including a contaminated PCB, some knowledge of the contaminant is needed. Once the contaminant has been identified, then you can easily apply the recommended cleaning solution to tackle the problem. The different types of contaminant likely to affect your PCB’s performance include:

  • Dry Contaminants – Dust is the natural enemy of PCBs and electronic hardware worldwide. This is because of the uncanny ability of dust to invade the tiniest of spaces. Dry contaminants refer to the different particles associated with dust or dirt such as; debris, dry particle, and sand. Dry contaminants are the most common type of contaminants you are likely to encounter when cleaning PCBs.
  • Liquid Contaminants – The possibility of liquid contaminants getting into your device is generally determined by how you use your device. In situations where liquid contaminants such as grime, sludge, soda, and water ingress your device, it is most likely your fault. When liquid contaminants or sludge gets into a device, cleaning the PCB is recommended for eliminating any errant behavior. The end product of liquid contaminants is corrosion and this also affects the PCB’s functions.

So here you have it. The different types of contaminants you will be dealing with are generally dry or liquid in nature. Once identified, you can move to the next stage of cleaning the erring contaminants.

The Top 5 Options for Cleaning PCBs

In high end devices, cleaning the PCB is usually the least of your problems. This is because you will have to open a device you had no hand in building or designing. To help you accomplish the task of dismantling the affected device, you can either refer to the maintenance manual –if available – or search for solutions on YouTube. Once you have opened the device, you can now carry out a diagnosis to determine what contaminant has clogged your PCB.

Brushing Dry Contaminants – If your inspection leads to the discovery of dust films or debris, you can choose the simple option of brushing out the contaminant off the PCB. Here, you will need:

  • A soft brush or
  • A horse hair brush

With these tools in hand, you can proceed to gently wiping or brushing off the contaminants around the PCB’s surface and electrical components. It is important to note that smaller PCBs have blind spots the smallest brush wont reach. In this situation, you will require more fire power for your cleaning task.

Flushing with Compressed Air –  The next option for dislodging dry contaminants from hard to reach areas is by making use of an electronics vacuum cleaner. The vacuum cleaner is used to shoot compressed air through the PCB to dislodge debris. In situations where a vacuum cleaner must be used, you may not even need to dismantle the device. Note that you must use the recommended vacuum cleaner because applying too much compressed air can damage the PCB and its electronic components. You can also apply brushing and compressed air simultaneously if needed.

Brushing off Contaminants with Solvents – Cleaning PCBs with wet contaminants is a bit more difficult than cleaning off dry contaminants. This is because grime or sludge really sticks and need more than the average brushing to remove. To accomplish this task you will need the following tools:

  • A soft brush.
  • A clean cotton cloth
  • A solvent – Isopropyl Alcohol, acetone or any other solvent.

The cleaning process involves applying your chosen solvent to the cleaning material. The solvent-soaked brush or cloth can then be used to wipe off wet contaminants from the PCB’s surface. A lot of care must also be taken to ensure you do not damage the electrical components or tracks on the PCB. Also note that using the wrong or a harsh cleaning solvent will damage the PCB. So, you can first apply it on an older PCB to observe the reaction of PCBs to the solvent you intend to use.

Ultrasonic Cleaning with PCB Ultrasonic Cleaners – The use of ultrasonic cleaners cleanses the PCB of both dry and liquid contaminants. With the right PCB ultrasonic cleaning device, the process is rather simple as you only need to put the PCB into the device and start it using the correct settings. The ultrasonic cleaning device works by using high-frequency to move bubbles that cleanse the PCB surface. The bubbles are generally formed by transducers bonded to the bottom of the tank. Although ultrasonic PCB cleaning devices are going out of favor –because of the damage they can cause – this cleaning option is still capable of dislodging debris and grime.

Cleaning Corrosion Stains and Corrosive Agents – Corrosion spots can be cleaned using a pencil eraser. Here, you should carefully and gently apply the eraser to the corrosion spot till the signs of rust is removed. You can also choose to spray or brush a corrosion inhibiting sealant on the PCB to protect it from the effects of moisture and water. Applying a sealant is a difficult task which must be carefully executed.


Performing regular maintenance tasks on your PCB increases the lifespan of your favorite device. So, you can eliminate contamination and corrosion, as well as, their effects by applying any of the five procedures highlighted in this article.

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