FPC 12 layers

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Circuit boards are an essential component of most modern electronic devices. Over time, circuit boards can accumulate dirt, dust, oil, and other contaminants that can negatively impact performance. Regular cleaning helps maintain conductivity, prevents short circuits, and extends the life of electronic components. This article provides a step-by-step guide to safely cleaning circuit boards using common household items.

Reasons to Clean Circuit Boards

Here are some of the main reasons to regularly clean circuit boards:

  • Improve conductivity – Dust, dirt, and grime are insulating materials that can cause resistance on circuit paths. Cleaning removes these contaminants and allows electricity to flow freely.
  • Prevent short circuits – Built-up debris can cause short circuits between closely spaced components and traces. Cleaning removes particulates that could lead to dangerous shorts.
  • Extend component life – Contaminants retain heat and cause components to run hotter. Regular cleaning maintains cooler temperatures and prevents thermal damage.
  • Restore performance – As contaminants accumulate, they can interfere with performance, cause crashes, and affect the accuracy of readings from sensors and other components.
  • Eliminate odors/smoke – Dust burning off components can create unpleasant odors and smoke. Cleaning removes the contaminants that burn and cause these issues.
  • Improve aesthetics – Clean circuit boards simply look more professional and well-maintained. This is important for resale value.

Regular cleaning addresses all of these issues and helps electronic devices run safely and optimally.

Supplies Needed

Cleaning circuit boards is a delicate process that requires specific supplies and solvents. Here are the recommended items to have on hand:

  • Isopropyl alcohol – This is the preferred cleaning agent for electronics. 99% isopropyl alcohol evaporates quickly and leaves no residue.
  • Cotton swabs – The soft cotton tips allow you to gently scrub components and reach tight spaces.
  • Small paintbrush or toothbrush – For lightly brushing away loose contaminants. Should have soft, static-free bristles.
  • Compressed air – Dusting spray or a can of compressed air helps dislodge particulates.
  • Anti-static brush or cloth – These tools prevent static buildup which attracts contaminants.
  • Lint-free cloths – Soft microfiber cloths cleanly absorb cleaning agents.
  • Safety glasses – For eye protection from debris or splashed liquids.
  • Latex/nitrile gloves – Prevents skin oils from transferring to the circuit board.
  • Baking soda – For soaking up spills and neutralizing acids.
  • Distilled water – For rinsing when needed. Does not leave mineral deposits.

Safety Precautions

Cleaning circuit boards requires care to avoid damaging sensitive components. Follow these precautions:

  • Wear gloves to avoid transferring skin oils.
  • Use adequate ventilation if using spray solvents.
  • Keep cleaning agents away from open flames as they are flammable.
  • Power down and unplug the device before cleaning.
  • Avoid soaking the board or oversaturating components with liquid.
  • Let the board fully dry before reconnecting power.
  • Work in a clean, organized manner to avoid losing small components.
  • Avoid touching soldered connections or bending pins when scrubbing.
  • Prevent ESD damage by using antistatic tools and wrist straps.
  • Carefully reseat components that may have loosened during cleaning.

Working cautiously protects the delicate electronics and ensures safe operation after cleaning.

How to Clean Circuit Boards

Step 1 – Power Down and Disassemble

Turn off and unplug the device. Disassemble the case and locate the circuit board(s) to be cleaned. Make note of how components are seated so you can properly reassemble later. For difficult builds, take photos at each stage. Remove any batteries connected to the board as well.

Place the board on a clean, flat, ESD-safe mat. Have your cleaning supplies staged nearby. Put on latex or nitrile gloves to keep skin oils off the board.

Step 2 – Use Compressed Air

Use short bursts of compressed air to dislodge dust and debris on the board. Slowly wave the nozzle across the full area of the board to kick up particulates. Avoid blowing too forcefully as this can dislodge small components.

Work above a waste bin and tilt the board so particulates fall away as you spray. Spend extra time blowing out areas with dense components like ICs or tightly spaced solder pads.

Compressed air alone often removes a significant amount of contaminants from circuit boards.

Step 3 – Loosen Stubborn Debris

For more stubborn deposits, use a soft paintbrush or toothbrush. Lightly brush across the board to loosen stuck-on dirt and grime. Again, avoid forceful scrubbing on delicate areas.

An anti-static brush is ideal since it will not generate static as you brush. Maintain a downward angle so particulates fall away as you work. Switch to new areas of the brush as it picks up debris.

For especially dirty boards, you can use a small vacuum nozzle at this stage to suction away loosened contaminants. Keep the nozzle a couple inches above the board so you don’t accidentally suck up any components.

Step 4 – Wet Clean With Solvent

When air and brushing alone are not sufficient, wet cleaning with solvent is required. Isopropyl alcohol is the preferred choice for electronics.

Moisten a lint-free cloth with a small amount of solvent – it should not be dripping wet. Gently wipe down the board to dissolve oily residue and remaining contaminants. Take care around adjustment pots, sensors, and other delicate components.

Cotton swabs are useful for cleaning in crevasses and tight spaces. Never submerge the board in solvent. Work in small sections so that wet areas can fully air dry before moving on.

For stubborn deposits, moisten the paint or toothbrush with solvent and use gentle back-and-forth motions to clean. Avoid scrubbing solder joints or bending component leads.

Step 5 – Rinse and Dry

After wet cleaning with solvent, it is generally recommended to do a final rinse with distilled water. This prevents any trapped residue from being left behind.

Lightly dampen a new cloth with distilled water. Gently wipe the same areas that were cleaned with solvent. This lifts away remaining contaminants dissolved by the solvent.

Thoroughly dry the board with a new lint-free cloth.Compressed air can speed up drying in hard to reach areas. Inspect closely for any remaining moisture or wetness. Allow at least 15-20 minutes for the board to fully air dry before reconnecting power.

Step 6 – Reassemble and Test

Once completely dry, visually inspect that all components are still firmly seated in their correct positions. Reinstall the board and reconnect any wiring or cables. Reassemble the outer case.

Reconnect power and turn on the device to verify normal operation. Test all functions, especially those impacted most by contaminants like sensor readings or audio quality. The electronics should now operate smoothly without noise, smoke, or other issues.

Schedule periodic cleaning intervals based on your environment and typical usage. More frequent cleaning is needed in harsh, contaminated environments. Annual or biannual cleanings are usually sufficient for gently used electronics.

Cleaning Agents to Avoid

Certain chemicals can damage circuit boards and components. Avoid the following:

  • Water – Plain water is corrosive due to mineral content. Only use distilled water for rinsing.
  • Soap – Soap leaves an insulating film even after drying. Use only solvents designed for electronics.
  • Acetone – Too harsh for most circuit boards. Reserved for exceptional circumstances requiring heavy degreasing.
  • Abrasives – Never use abrasive pads, scouring powders, etc. as they damage components.
  • Oxidizing agents – Chemicals like bleach or hydrogen peroxide can corrode metal.
  • Ammonia – Can dissolve copper traces and pads when used long-term.
  • Heat – Avoid heat guns, torches, or open flame which can scorch boards.

With proper solvents and gentle scrubbing, these harsh chemicals are not needed for routine cleaning. Stick to isopropyl alcohol as the main cleaning agent.

Cleaning Different Component Types

Certain components on circuit boards require special attention or alternative cleaning methods:

Display screens – Use a microfiber cloth dampened with distilled water or isopropyl alcohol. Avoid excessive pressure.

Frames/casings – For plastic or metal, wipe with isopropyl alcohol and lint-free cloth. Avoid other solvents which can damage finishes.

HBCCs – Requires desoldering to fully clean hidden surfaces. Use minimal solvent and dry immediately.

Motors – Blow out dust using compressed air. Do not immerse in solvent. Lubricate per manufacturer instructions.

Speakers – Use a soft brush and vacuum nozzle. Swab outer surfaces lightly with solvent.

Battery compartments – Clean using cotton swabs and low-pressure compressed air. Ensure no fibers are left behind.

Fabric/membrane surfaces – Carefully brush and gently swab with a 25% isopropyl alcohol solution. Rinse with distilled water.

Research the proper cleaning methods for specialized components like sensors or switches. Improper cleaning can degrade calibration or sensitivity.

Cleaning Smoky/Burned Boards

Circuit boards with smoke or burn damage require additional steps for thorough cleaning. Here is a safe process:

  1. Brush away loose charred material with short stiff-bristle brush. Avoid creating airborne particulates.
  2. Vacuum both sides of board with fine nozzle to remove soot.
  3. Use compressed air to blow out crevasses and gaps.
  4. Prepare baking soda paste by stirring powder into distilled water.
  5. Liberally apply paste to burnt areas using toothbrush or swab. Let soak 5 minutes.
  6. Scrub gently with toothbrush to lift carbon deposits. Rinse with distilled water.
  7. Swab with 99% isopropyl alcohol to remove remaining soot or baking soda residue.
  8. Allow a full 24 hours to thoroughly dry before reconnecting power. Test insulation integrity where traces are damaged.

Damaged or broken traces may need repaired before the board can be safely returned to service. Handle severely burned boards with care as they are more fragile.

Tips for Preventing Dirty Boards

Routine cleaning removes existing contaminants, but preventing dirt buildup is ideal:

  • Use dust covers when electronics are not in use
  • Store boards in ESD bags when not installed
  • Work on boards only in clean conditions
  • Handle boards by the edges to avoid finger oils
  • Keep fans and vents consistently cleared of dust
  • Ensure air filters are functioning properly
  • Replace filters on enclosures per manufacturer recommendations
  • Seal electronics in protective cases or potting when possible
  • Fix damaged casings that allow dirt ingress
  • Shut down rather than leave gear running 24/7

Proper maintenance extends the lifespan of electronics even in harsh conditions. Set schedule reminders to clean boards on a regular basis.

Frequently Asked Questions

What is the best way to dry circuit boards after cleaning?

Allow boards to fully air dry for at least 15-20 minutes. Aiming a fan across the surface speeds evaporation. Compressed air also helps blow residual moisture out of tight spaces. Avoid heat sources which could damage components.

How often should I clean circuit boards?

A good rule of thumb is to clean boards whenever visible dirt, dust, or grime accumulates, or once or twice per year. Boards in harsh environments may need cleaning every 3-6 months.

What solvents can I use if I don’t have isopropyl alcohol?

Electronic contact cleaners are the next best option after isopropyl alcohol. Avoid acetone or chlorinated solvents which are too harsh and leave residues. In a pinch, you can use vodka or high-proof rum as they contain ethanol and water.

How do I clean old oxidized or corroded circuit boards?

Use white vinegar dampened into a soft toothbrush to gently lift oxidation on traces and pads. Isopropyl alcohol helps dissolve any oily residue. Avoid abrasives that will scratch the board.

Is it safe to use a disinfectant spray on electronics to kill germs?

No. Many disinfectants like Lysol are too harsh and can damage insulation or leave residue. 70% isopropyl alcohol is a safer option since it quickly evaporates. Ensure the board is fully dry before reconnecting power.


Regular cleaning extends the lifespan of circuit boards and prevents avoidable electronic failures. Using compressed air, soft brushes, and isopropyl alcohol allows safe and effective cleaning. Work slowly and cautiously around delicate components. Allow sufficient drying time before reassembly. Set reminders to make circuit board cleaning part of your routine maintenance plan. The small time investment saves money and prevents problems down the road.