Despite the coating with solder mask, a circuit board can still be prone to dirt and other forms of contaminants. Using the effective PCB cleaning process helps you get rid of the dirt and keep the surfaces cleaner than they were.
In this article, we reveal some of the possible reasons why your circuit board is unclean and the best possible ways to fix it.
Are Circuit Boards Unclean?
Yes, Printed Circuit Boards (PCBs) are unclean if they are kept or used in unclean environments. Certain factors could also lead to the deposition of dirt or dust on the surface.
As a consumer, you want to make sure that your boards are well-cleaned and with the right hands handling it; you don’t have any problems with that.
The Types of PCB Contaminants
Both the dry and wet contaminants are responsible for the dust, dirt or debris lurking on the surface of a circuit board.
Here is a summary of how each of these contribute to the uncleanliness of PCBs:
The Wet Contaminants
As the name suggests, these are the pitfalls that necessarily have to do with water. Here are some important points worth noting about the wet contaminants of PCBs:
- Examples of wet contaminants are soda, grime, waxy oil, water, and flux.
- They become sources of contamination for the PCB when they are used in higher operating temperatures.
- It is common for the wet contaminants to have difficult removal processes.
- The best way to handle such contaminants is to get rid of them with either a vacuum or brush.
- Leaving the contaminants for a long time tends to affect the circuit board’s performance.
How to Tackle the Wet Contaminants
The best way to clean flux from PCB is to use either a vacuum or a brush. This is the best option when you notice the contamination on time.
However, if the contaminants have been there for a while, you may consider different other approaches, such as:
Demineralized Water
This is always the best option if you want to remove moisture and contaminants from the PCB at lower operating temperatures.
Once the residual moisture is removed, make sure to properly dry the circuit board.
Use the IPA Cleaning Agent
Isopropyl Alcohol (IPA) is one of the PCB cleaning agents you can use too. You can dip a clean cotton cloth or a small brush into the alcohol and apply on the surface where the contaminants are.
Dry Contaminants
These are the circuit board contaminants that have to do with the likes of dirt and dust. Since they don’t deal with water, one may be misled to think they don’t cause much harm. On the contrary, these contaminants tend to have negative impacts on the electronic components’ overall performances.
A few things you should know about the dry contaminants are:
- The dust and dirt accumulate around and inside the PCB.
- The cleaning process is usually hard, as these contaminants are more of particulates. As such, they often reach into the deepest parts of the circuit board.
How to Get Rid of Dry Contaminants in a PCB
Due to the far-reaching potentials of these contaminants, it is possible for them to get deeper into the PCB.
If you must get rid of them, quit using a brush. Instead, use a specially-designed vacuum cleaner or compressed air.
Other Possible Ways for a PCB to be Contaminated
The dry and wet methods are not the only ways your circuit board can become unclean. Other ways include:
- The possibility of short-circuiting when a liquid with conductive properties enters the electronic components.
- Drawing-in of debris and dust when the circuit board’s fan blows higher than expected.
The Best Cleaning Methods for Your PCB
Once you’ve ascertained that your circuit board is in danger due to the contamination; the next step would be to get rid of them.
There are different ways to do this and we would like to start with the easiest.
1. The Manual PCB Cleaning Process
This is often the easiest and yet, the most tactical. The manualized process takes time and works best if you are looking to get rid of wet contaminants.
You need a tiny brush and a solution, such as Acetone or Isopropyl Alcohol (IPA). To begin with, you have to:
- Soak the circuit board in the solution (IPA or Acetone). Leave it to sit for like 10 minutes.
- Next, use the tiny brush to work through the pathways or routes that have been contaminated.
- Once the cleaning process is over, use a demineralized water to rinse the PCB.
- Place it under the sun to dry for a few minutes.
Advantages of Manual PCB Cleaning
Consider the following to be some good reasons to manually remove dirt from your circuit board:
- It doesn’t require the use of specialized pieces of equipment.
- You only need a few items – a brush and a solution, such as IPA or Acetone.
- The cleaning solution evaporates quickly and doesn’t pose much harm to human beings.
Downsides to Manual PCB Cleaning
As much as the manualized process comes in handy and can be completed in a short time, it also has some downsides.
Here are some of the reasons why it may not be a good option:
- Using high percentages of the solution could have negative effects on the human body.
- The cleaning process is limited to only the components and surfaces you could see.
- As a manualized process, it takes a lot of time to complete.
2. Cleaning a PCB with Sodium Bicarbonate (NaHCO3)
Sodium Bicarbonate, also called baking soda, can be an effective cleaning agent for your Printed Circuit Board (PCB).
It is best used for the following:
- When getting rid of corrosion on the PCB.
- You can also use it if you want to remove the accumulated grime on the circuitry.
Here are some of the benefits to using baking soda for PCB cleaning:
- It helps in neutralizing the acidic properties of dirt.
- Thanks to the mild abrasive properties, it doesn’t put the PCB at risk when removing grime.
How to Clean Circuit Board Using Compressed Air
Using compressed air is a faster and unobstructive method of getting rid of dirt lurking in and around a PCB.
Here are some of the points to note:
- Compressed air is best used if you want to clean a small amount of dirt from the circuit board.
- Use short bursts to apply the compressed air into the circuit board’s ventilation ports.
- You can also consider reassembling the PCB to make further applications of the compressed air. This way, you get to remove more of the dirt and dust inside the board.
3. Clean Your PCB with Distilled Water
You can use distilled water to get rid of dirt in your PCB, but this has to be done with some moderations. Worthy of mentioning is that distilled water is a “poor conductor of ions,” which is why mixing it with some cleaning solution is advised.
Here are some points to note:
- Always protect your hands with gloves to prevent a physical contact with the solution.
- Always seal the distilled water when it’s not in use.
4. Use PCB Ultrasonic Cleaners
Consider using ultrasonic cleaners if your Printed Circuit Board (PCB) suffers bubbles during the operation.
The use of these cleaners can help the PCB cleaning process in a number of ways, such as blasting away the contaminants on the PCB components’ surface.
Here is a summary of how the PCB ultrasonic cleaners are designed to work:
- The cleaners use ultrasonic sound waves of up to 20,000 Hz. These help to deploy the use of high-frequency signals to create cavitation.
- Cavitation refers to the process of generating bubbles that are popped and leveraged to remove the additives and contaminants on the PCB’s surface.
Best Practices for PCB Ultrasonic Cleaners
You can get the best results from the use of circuit board ultrasonic cleaners when you consider the following:
- The ultrasonic cleaning process works best for the dense and complex circuit boards.
- It is always better to use the PCB ultrasonic cleaners when cleaning boards made with the Through-Hole Technology (THT) process.
Downsides to Using PCB Ultrasonic Cleaners
It doesn’t make sense to use these cleaners because of some possible disadvantages. These include:
- The sound waves possibly cause damages to the electronic components, especially when removing dirt or grime.
- The process is best-suited for both high-volume and dense circuit boards.
What is the Difference between Cleaning PCB and Cleaning PCBA?
There is a bit of difference between cleaning a Printed Circuit Board (PCB) and cleaning a Printed Circuit Board Assembly (PCBA).
From the surface-meaning, the former refers to the method of cleaning an ordinary circuit board, while the latter refers to the cleaning process for an assembled circuit board.
For clarity, here are the major differences between cleaning a PCB and cleaning a PCBA:
Differences in the Types of Boards
This refers to the difference in the type of circuit board. While the cleaning process of a PCB is for the basic board during the production, the PCBA cleaning process is used for the circuit board that are used with applications that have a difficult assembly process.
Differences in the Cleaning Processes
The common PCB cleaning processes are ultrasonic cleaning, the uses of distilled water, baking soda and manual cleaning. On the contrary, you are introduced to a wide range of options for the PCBA cleaning processes. These options include:
- Aqueous Cleaning: this entails the combination of detergent and heated, deionized water to subject the PCBA to a series of rinsing cycles.
- Vapor Degreasing: this refers to the use of an environmentally-sustainable cleaning fluid to get rid of dirt on the surfaces of miniature components.
The Basic PCB Cleaning Tools
Irrespective of the type of PCB cleaning process, the choice of tools or pieces of equipment is important. The use of these tools helps to facilitate the process of getting rid of dirt, dust and other forms of contaminants from the PCB and the components.
Here are some of the tools you need to get the job done:
1. Isopropyl Alcohol (IPA)
You need IPA if you are using the manualized process of cleaning circuit boards.
2. Flux Remover
This comes in handy when looking for how to clean circuit board after soldering. The function of the flux remover is to facilitate the removal of flux, after the circuit board has been soldered.
3. Cotton Swab
Either the cotton swab or cotton clothing can be used with the Isopropyl Alcohol (IPA), Acetone or any other solution.
Dip the cotton swab or cotton cloth into the solution/solvent and use it to wipe the surface of the board where the contaminants are.
4. Blow Dryer
Once the PCB has been cleaned, the next process is to get it dried. The drying options often include a blow dryer and an oven.
It is advised to use a blow dryer because of the excellent performance in sucking out the moisture inside the board after the cleaning process is over.
5. Towel
You also need an alternative for drying the Printed Circuit Board (PCB). Consider getting a lint-free towel, which doesn’t leave much debris behind after wiping the surface of the circuit board.
Why PCB Cleaning is Important
Cleaning the surface of a Printed Circuit Board (PCB) is important for a wide range of reasons. These reasons range from the removal of contaminants and the prevention of the same from causing negative damages to the board.
For the Printed Circuit Board Assembly (PCBA), the cleaning process does a lot of “miracles.” The benefits include but are not limited to making the boards more reliable and elongating the shelf life. The benefits of cleaning a PCBA also include:
- Boosting the chances of enhancing the PCBA’s lifespan, especially after the application of the three anti-paints.
- The PCBA cleaning process helps to bolster the reliability and high-precision required of the medical-grade and military PCBs.
Conclusion: Clean Your PCB the Right Way
The task of cleaning your circuit board appropriately lies with the manufacturer. Smart consumers work with RayPCB. We help you clean the surface of the circuits and get the dirt and other forms of contaminants away from the PCB components.
