Why It is Required to Clean a Circuit Board?
It is a necessary job to clean a circuit board. No matter during the PCB manufacturing and assembly or during the use under electricity, contamination will inevitably occur, including residues of flux and adhesives, metal debris, dust, etc., if not cleaned in time, it is likely to cause failure in use and accelerate the aging of a circuit board. There are many ways to clean a circuit board.
It is often-seen on Youtube that someone directly soaks or rinses the computer motherboard with water, and it can be used normally after drying the moisture. This obviously runs counter to the theoretical knowledge of many people. Is this true? Is it possible to clean a circuit board directly with water? It will get clarified in this article.
How to Clean a Circuit Board – The Proper Methods
1 Clean a motherboard with compressed air
For simple repairs, compressed air provides an easy-going way to blow the dust that remains inside the electronics or machine away by releasing the air through ventilation holes into the devices.
If you are not satisfied with the dust removal, please open the device with a screwdriver, work around the components, and clean the circuit carefully with air, but note that disassembling also means risk. For complicated mechanical structures, you might likely not be able to re-assemble it after disassemble, so make a record during disassembling, and avoid damage and missing parts.
2 Clean a circuit board with baking soda
Baking soda is an effective way to remove dirt with minimal risk of damaging the PCB board. It is good at removing corrosion or residues that cannot be removed with simple methods such as brushes and distilled water. Baking soda is most effective when dealing with corrosion because it dissolves problem areas and neutralizes the acidity of the residue.
3 Clean a circuit board with isopropyl alcohol (IPA)
Isopropyl alcohol is a standard cleaner for PCBs and is used to remove flux because it is cheap and quickly evaporates. IPA contains fewer chemicals than other cleaners used for similar purposes. The purity of isopropyl alcohol used to clean a circuit board must be 90% or higher. High isopropyl alcohol content might cause adverse effects on humans, so note to use latex gloves and goggles.
4 Clean a circuit board with water
Yes, you can use water to clean a circuit board, but must be ultrapure water (distilled water).
Since there are no conductive ions, distilled water is good for removing dust and the water-soluble flux residue on the board, which will not damage electronic equipment because it has poor electrical conductivity. Please be careful to flush the circuit board only for a short time, and ensure there are no water sensitive components on the board.
Therefore, all of the videos you saw that using tap water to clean a circuit board directly are wrong, just because their boards have been pre-coat with waterproof materials, and washing time is short, but even so, this is not recommended.
The disadvantage of water cleaning are that rosin flux residues are usually insoluble in water, and the water in the fine gaps often cannot effectively evaporate during drying
5 Clean a circuit board with WD-40 or other similar cleaners
WD-40 contains substances of petroleum preparations, so it has a considerable degree of solvent effect, especially for substances such as adhesive, which is suitable for circuit board surface cleaning.
The Tools You Will Need
One or more of the above cleaners
For example, first, use water-soluble detergent to clean a circuit board, and then use water to remove detergent residue.
A soft bristle brush can help you remove dirt in the gap without harming the surface of the circuit board or parts
Used to wipe off agglomerated stains or dry circuit boards quickly without leaving fiber debris
After cleaning a circuit board, it is usually required to remove the surface moisture, or there is wax on the surface. You can use a hairdryer or a lamp for heating.
Fine cotton swabs
Usually used with a cleaning solution to remove water-insoluble stains
Another tool for removing grease or waxy stains
Can I clean a circuit board with alcohol?
Of course, you can use methyl alcohol or alcohol to clean the PCB, but remember to use it only for spot cleaning of stains or corrosion points, and better to use anhydrous alcohol.
Another thing is no cleaning the stains in the power voltage area using alcohol.
How Do the PCB Plants Clean the PCB Board?
PCB Plants use special cleaners to clean a circuit board, which is mainly used for removing the flux and rosin remaining on the surface of the PCB circuit board after soldering.
It can be divided into:
- Chlorinated solvent, is a mixture of chlorinated solvent and other solvents that can dissolves rosin and removes the flux quickly, without residue, volatility and no need to dry after cleaning.
- Hydrocarbon solvent, is environmentally friendly, non-toxic, low odor, and can be recycled for distillation, which is mostly used for cleaning high-end HDI circuit boards.
- Water-based cleaners, due to water-based cleaners are environmentally friendly, safe, non-toxic, and non-irritating gas volatilization, it is now mainly used in SMT soldering cleaning. If the water-based cleaner does not have the anti-rust function, it should be used with caution, because it will easily accelerate the corrosion and rust of the pins.
PS Electronics uses a typical method to clean circuit boards, that is, ultrasonic + manual brushing. In the liquid medium, ultra-high frequency converts the kinetic energy into a cavitation effect, the formation of countless tiny bubbles hit the stains on the circuit board surface to achieve the effect of cleaning, then manual inspection and brushing are performed for removing the residues.