How to Clean Printed Circuit Boards
Why do you need to know how to clean printed circuit boards? The answer is simple: unless you’re an electronics hobbyist, you generally have printed circuits in the boards of some common equipment such as computers, printers, hi-fi, boilers and various other appliances. In some of this equipment, a certain amount of air circulation is generated to cool the components present on the circuit (typical in the case of a computer) so that a certain amount of dust inevitably settles on the printed circuit boards, even if the equipment is provided with special filters.
Dust can be dangerous because it can be full of electrostatic charges which can interfere, also severely, with the operation of the circuit. In addition to dust, oxidation phenomena may occur, especially on the feet that fit into the various “slots” of the equipment. Periodically cleaning these printed circuit boards is therefore necessary to always maintain equipment which functions well.
Things you will need
- Vacuum
- Compressed Air
- Isopropyl alcohol
- Small brush
- Manual blower
Step 1
VACUUM OR BLOW
Before removing (possibly) a printed circuit board by removing it from its seat, eliminate the dust deposited on it and in the immediately surrounding areas using a good vacuum cleaner that doesn’t have a metal connector, but a plastic one. Cleaning a printed circuit board inside equipment with compressed air is not recommended, as the dust would be distributed elsewhere. If you can’t extract the circuit board, then it’s best to use a hand blower. Compressed air must only be used after having removed the printed circuit board and distanced it from the equipment. Be careful when you extract a printed circuit board, noting the presence of any other loose connections that must be carefully marked.
Step 2
CLEANING PRINTED CIRCUIT BOARDS WITH A BRUSH
Dust can be strongly anchored to certain areas, so it’s useful to use a brush (in addition to a vacuum cleaner) to remove it. In some parts of the circuit board it may be best to use a cotton swab, carefully cleaning with it in order not to cause damage to the circuit board. Use a brush to remove the dust in the cavities of the slots that receive the printed circuit board as well.
Step 3
WHAT TO DO ON OXIDISED PARTS
If you notice a layer of oxidation on the feet or on other parts, it can be left there, as the metal is passive and its surface layer protects the underlying ones. Any yellow, greenish or brown deposits made up of carbonates and sulphides (due to a corrosive atmosphere or saltiness) should be treated with WD-40 Specialist Rapid-Drying Contact Cleaner, which has a formulation capable of effectively dissolving grease, grease deposits, welding flux residues and condensation on electrical or electronic equipment, including delicate materials. It quickly penetrates into the most difficult to reach areas, drying quickly and without leaving residues. It is excellent at restoring electrical conductivity. Its non-conducting formula with rapid evaporation leaves no residue and is compatible with all metals, plastics and rubbers.
Step 4
RUBBERY LAYERS
The rubbery-looking layers of decomposed grease dissolve with isopropyl alcohol and a nylon brush. But they can also be treated with the WD-40 Specialist Rapid Drying Contact Cleaner. Avoid trichlorethylene and other diluents (synthetic, nitro, etc.) when cleaning printed circuit boards, as they can be very harmful for some components such as electrolytic capacitors.
Step 5
THOROUGH WASHING
If the equipment containing the printed circuit boards can be kept off for a few days, you can also wash the printed circuit boards with water and a neutral detergent. It may seem strange, but this type of cleaning is recommended by several manufacturers. Naturally, after washing the circuit board it must be dried with compressed air and left inactive for a few days before being reinserted into the appliance.
Step 6
CLEANING THE APPLIANCE
The inside of the appliance must be thoroughly cleaned before re-inserting the circuit board using the same steps and means indicated above. The slots where the printed circuit boards are to be inserted must be treated with WD-40 Specialist Rapid-Drying Contact Cleaner, as well as the various loose connectors that start from or attach to the printed circuit board.
Step 7
CHECK GRILLES AND FILTERS
Before turning the equipment back on, check the ventilation grilles, fans and any filters present: their thorough and regular cleaning is the best guarantee against the rapid formation of a new layer of dust on the printed circuit boards.
Simply Done!
In conclusion, understanding how to clean printed circuit boards is essential for maintaining the optimal functionality of electronic equipment. Dust accumulation, oxidation, and decomposed grease can interfere with circuit operations, posing potential risks. By following the outlined steps, including vacuuming or blowing away dust, using brushes and cotton swabs for detailed cleaning, addressing oxidation with WD-40 Specialist Rapid-Drying Contact Cleaner, and even considering thorough washing when appropriate, you ensure a reliable and efficient performance from your electronic devices.
Disclaimer
The uses shown and described for WD-40 Multi-Use Product were provided to WD-40 Company by the users themselves. These uses haven’t been tested by WD-40 Company and do not constitute a recommendation of suggestion for use by WD-40 Company. Common sense should be exercised whenever using WD-40 Company products. Always follow the instructions and take heed of any warnings printed on the packaging.
Need some advice?
Come and discover all our DIY, maintenance, auto, bicycle tutorials!
Language
Contact Us
© 2025 WD-40 Company.
All Rights Reserved