How to Clean a PCB?
- Flex Plus Tech team
- 4 days ago
- 3 min read
You'll find printed circuit boards (PCBs) in pretty much every electronic device we use - from your phone and laptop to factory machines. When they're new, these boards are completely clean. But after years of use, dust, oil, and other gunk slowly build up on them. You know how, when you open up an old computer, the motherboard is always covered in dust? These small amounts of buildup may seem harmless at first, but over time, they can lead to serious issues with the circuit board and ultimately affect the performance of the entire device.
Why PCBs Need Cleaning – But Not at Manufacturing Stage
Good PCB manufacturers, like Flex Plus, make sure every board is spotless before shipping. They remove flux residues, check for defects, and follow strict quality checks. So if you get a new PCB, it shouldn’t need cleaning. The real issue is what happens after, like exposure to dust, moisture, or sloppy repairs. That’s why cleaning is usually part of maintenance, not manufacturing.
When Should You Clean a PCB?
Common scenarios where PCB cleaning may be required include:
After a liquid spill or exposure to moisture
During repair or rework
When refurbishing old or second-hand electronics
If flux residues are present after hand soldering
Methods to Clean a PCB
1. Manual Cleaning (Isopropyl Alcohol Method)
Materials Needed:
Isopropyl Alcohol (preferably 99%)
Anti-static brush or soft toothbrush
Microfiber cloth or lint-free wipes- Gloves (optional)
Steps:
Power off the device completely.
Use compressed air or a soft brush to remove dust.
Dampen a cloth or brush with IPA and gently scrub.
Dry thoroughly with air or let it air dry in a dust-free environment.
2. Contact Cleaner Spray
Contact cleaners are convenient for quick maintenance and hard-to-reach areas. Spray lightly, let the solvent evaporate, and avoid overuse. These are best for spot cleaning in the field.
3. Ultrasonic Cleaning – Use with Extreme Caution
Ultrasonic cleaning uses high-frequency sound waves in a liquid bath to remove contaminants. While effective, it is not safe for all components. MEMS sensors, oscillators, and many modern ICs can be damaged by cavitation.
This method is discouraged or prohibited in:
Aerospace and military electronics
Medical devices
Automotive safety systems
Always check component specifications before using ultrasonic cleaners.
What to Avoid When Cleaning a PCB
- Do not use tap water (it leaves conductive residues)
- Avoid household cleaners (they may be corrosive)
- Do not use abrasive materials
- Avoid high heat from tools like hair dryers or heat guns
Special Consideration: Cleaning Flexible PCB
Flexible PCBs are used in compact and dynamic applications like wearable devices, cameras, and medical sensors. Due to their thin structure and bending capability, they require gentle handling during any cleaning process. Cleaning can help when repairing or maintaining PCBs, but the real secret to long-lasting performance? Start with well-made flex PCB boards from trusted manufacturers.
At Flex Plus, we specialize in high-quality flexible circuit boards. While we don't offer cleaning services, our boards are built to last, with careful design, top-grade materials, and durable construction that naturally resists contamination and makes upkeep simpler.
FAQ
Q1: Can I use water or vinegar to clean a PCB?
A: No. Tap water contains minerals that can leave conductive residues. Vinegar is acidic and can damage components. Use only 99% isopropyl alcohol or approved electronic cleaners.
Q2: How long should I wait after cleaning before powering the board?
A: Ensure the board is completely dry. This may take from 30 minutes to several hours, depending on the cleaning method.
Q3: Should I clean the new PCB before use?
A: No. Professionally manufactured PCBs are shipped clean and ready to use. Cleaning is only necessary after usage or exposure.
Conclusion
Cleaning a PCB is an important maintenance step, but only under the right conditions. Modern PCBs, especially flexible ones, are manufactured to be clean and reliable from the start. If cleaning is needed during repairs or refurbishing, choose the safest method for your specific components. For the best results in high-reliability applications, choose a flexible PCB supplier that prioritizes durability and clean manufacturing processes. Ready to design your next flexible circuit? Reach out to Flex Plus for expert manufacturing and design support.
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