- Published 9 Jan 2025
- Last Modified 9 Jan 2025
- 8 min
How to Clean A Circuit Board
Need to know how to clean a circuit board? Learn here about caring for your electronics’ insides using circuit board cleaning: the cleaning fluids, tools, steps, and tips.
Reviewed by Peter Kendall, Technical Support Engineer (December 2024)
Have you ever wondered how to clean electronics on their insides? Cleaning circuit boards is important maintenance for keeping your electronic devices running smoothly and safely. This guide will explain the tools and products to use for cleaning electronics and lead you through the best way to clean circuit boards.
Why Should You Clean Circuit Boards?
Electronics give us great comforts and conveniences in life and do their work mostly out of sight, but cleaning electronics is important for ensuring these devices stay functional, efficient, and safe.
What Accumulates on Circuit Boards?
- Dust drawn in from onboard fans
- Flux residue left behind from the soldering in printed circuit board (PCB) manufacturing
- Corrosion formed from dust or flux attracting airborne moisture
- Contaminants lingering from improper cleaning
- Chemicals from harsh industrial working environments
- Spilled liquids
- Component debris from shocks the electronics accidentally experience, such as from being dropped
- Dendritic growth, which is the buildup of metal filament due to an electrolysis reaction on the PCB. This reaction, enabled through moisture or other contaminants, makes the metal in electronics migrate into tendrils and paths along the board. These dendrites are conductive and cause current leakage and short circuits due to electricity not flowing where it should. Stresses on the metal from the hotspots of inefficiently running electronics can also promote dendritic growth.
Benefits of Cleaning Circuit Boards
Electric and electronic devices, at their core, direct electricity to perform functions, and they consume energy to get that electricity flowing. If that electrical flow is inhibited or misdirected, this leads to various negative effects:
- Waste energy: Dust and corrosion buildup add resistance to a PCB’s connections. This makes it harder for electrical energy to flow through it, and that energy has to go somewhere: as heat that builds on the PCB. This inefficiency means energy, which costs money and potentially creates emissions, wasn’t put to good use.
- Component damage: As PCB components run hotter than they’re meant to, they’ll wear and eventually fail more quickly, leading to premature device replacement.
- Loss of functionality: Dendritic growth (metal filament buildup) is conductive and allows current to escape to ground (current leakage, another form of waste energy) or even to other components on the circuit board (a short circuit). This means the device will fail to perform as expected, and the hazards there go beyond the inconvenience of faulty personal computers. PCBs used in planes, emergency services, military equipment, and even pacemakers all must have clean circuit boards to deliver their essential services. This makes cleaning circuit boards equally essential during maintenance (and at the point of manufacture for things like pacemakers).
- Fire hazards: Heat building up on electronics also risks fire, along with the health risks of the plastics and chemicals in electronics smoke — and the further damage smoke can do to other nearby electronics.
- Aesthetics: Clean circuit boards look slick, but dirty PCBs (if they’re visible) can diminish your workplace’s appearance.
Circuit Board Cleaning Products
We’ve established the importance of PCB cleaning, but how about what to use to clean circuit boards? RS can help you with the specialised PCB cleaning fluids and PCB cleaning tools for keeping your circuit boards clean and functional.
Electronics cleaners vary based on the type of contaminants to be cleaned:
Always familiarise yourself with the health and safety risks of PCB cleaning fluids, though. Study their safety data sheets (SDSs) and ensure you take appropriate measures like ventilation and PPE such as anti-static gloves.
Circuit Board Cleaning Tools
PCB cleaning tools are highly specialised for drawing contaminants away from circuit boards and keeping static electricity from reaching the board. They include:
- Anti-static wrist straps: These are essential for preventing electrostatic discharge (ESD) from your body onto the PCB, which can seriously damage it.
- Anti-static brushes: These let you clean away contaminants and avoid ESD due to their dissipative bristles.
- Compressed air supply: For blowing away dust without contacting the PCB, though seek out moisture-free compressed air cans to avoid adding contaminants as you clean circuit boards.
- Cotton swabs: For applying PCB cleaning fluids.
- Tweezers: For extracting large, stubborn contaminants.
- Lint-free cloth: For wiping away electronic cleaning solvents afterwards.
PCB cleaning tools don’t stop at hand tools, though. If you have a large batch of circuit boards to clean or prefer the thoroughness of automation, you can invest in the following equipment:
- Ultrasonic cleaner: Break apart flux with sound waves.
- Vapour degreaser: Give your PCBs a bath in boiling solvent.
- Batch flux remover: Sort of like a circuit dishwasher, these spray flux remover automatically.
How to Clean Circuit Boards
Here are some procedures and tips for how to clean electronics’ circuit boards:
Circuit Board Cleaning Steps
Let’s go through the steps of how to clean a PCB:
- Disconnect the device from power. You may be directly contacting conductive materials, so first remove all shock hazards.
- Take the electronic device apart and remove the PCB to be cleaned.
- Inspect the PCB for the types of contaminants present and areas with large buildups.
- Blow away dust and debris with compressed air. Keep the air source a safe distance from the PCB and use short bursts to avoid damaging it.
- Gently clean the PCB using an anti-static brush to remove stubborn dirt and pre-clean things like corrosion and flux, which will require PCB cleaning fluids.
- Apply electronic cleaning solvents or flux removers as needed. You can dampen a lint-free cloth or a cotton swab with these products or spray directly through a straw attachment on the can.
- Scrub the contaminated areas using the swab or cloth, though only gently to avoid component damage. Spraying directly from pressurised cans may give enough agitation to avoid scrubbing.
- Rinse the circuit board using a solvent cleaner or deionised water. Again, only gently and sparingly.
- Leave the PCB to dry where it will get plenty of ventilation. You can speed this process by drying the board gently with a clean lint-free cloth.
- Once the PCB is fully dry, reassemble it in the device and reconnect the power.
Circuit Board Cleaning Tips
What are some tips for the best way to clean a circuit board?
Let’s start with tips for how to remove flux:
- Avoid direct contact: Swabs or cloths may clean flux from the target area but spread some to the surrounding area. Spraying flux cleaner from a can better ensures flux washes away.
- Flux type: Use the right kind of cleaner for the type of flux you’re dealing with. Lead-free fluxes need more aggressive cleaners.
- Solder temperature: Solder placed with more heat can need more time spent soaking and cleaning due to the flux being baked on.
- Flux thickness: Larger flux masses also need more cleaning fluid and more soaking and cleaning time.
- Cleaning angles: Hold the PCB at an angle to allow cleaning fluids to drain off, and spray from an attack angle that will let fluids get under dirty components.
How about tips for how to clean circuit board corrosion?
- Use a 1:2 to 1:4 mixture of baking soda and deionised or distilled water. Mix it into a paste.
- Apply the mixture with a cotton swab, let the board dry for up to 30 minutes, and rinse it away with a solvent cleaner.
- Assess your device’s operating conditions to try to prevent further corrosion. The PCBs need to be kept clean, dry, and free of ionic contamination.
Here are a few more general tips for cleaning circuit boards:
- Clean and dry your hands before handling the PCBs to avoid adding more contaminants to clean away. Using protective, anti-static gloves is even better and protects you from the hazards of PCB cleaning fluids.
- Be gentle and careful through every step of the cleaning process. These are delicate components.
- Use PCB cleaning fluids and rinsing agents sparingly. Anything you apply needs to be cleaned away and dried correctly.
- Avoid applying heat to accelerate drying time, such as from a heat gun or oven. This can work if done correctly for the PCB’s properties, but air drying in good ventilation is a less hazardous approach.
Along with PCB cleaning fluids, RS also carries protective coatings for electronics to further enhance their functionality and appearance. Browse our selections today.
