1. Introduction

When it comes to maintaining PCB/PCBA reliability, knowing how to clean electronic circuit boards is essential. Whether you’re removing dust, flux residues, or corrosion, choosing the right printed circuit board cleaner makes all the difference. This guide will explain each step—from circuit board cleaner selection to deep-clean techniques like ultrasonic cleaning—so professionals can effectively restore electronics.

2. Understand Common Contaminants

Circuit boards suffer from various contaminants, including:

    Dust and debris: Blocks ventilation and causes overheating.

    Flux residues and oils: Remain sticky and can become conductive over time.

    Corrosion and oxidation: Forms crusty layers, increasing resistance or causing shorts.

These issues can degrade performance or lead to circuit failure. Proper circuit board cleaning prevents such risks, especially when flux from soldering remains or corrosion worsens over time.

3. Choose the Right Printed Circuit Board Cleaner

Recommended Cleaners & Solvents

    (1)Isopropyl Alcohol (IPA)
      High-purity (90% or above) IPA is the go-to electronic circuit board cleaner. It dissolves flux, oils, and light grime and evaporates quickly without residue.

    (2)Deionized/Distilled Water
      Safe for rinsing, especially after IPA or detergent cleaning. Since it lacks conductive ions, it’s suitable for boards if thoroughly dried.

    (3)Specialized PCB Cleaning Solutions
      Commercial cleaners—such as flux removers and circuit board cleaning solutions—work efficiently, including aerosol sprays that require minimal wipe-off.

    (4)Ultrasonic Cleaning Solutions
      Used in ultrasonic tanks, typically water-based with low-concentration surfactants, along with IPA or detergents. This method deeply cleans through cavitation.

    (5)Baking Soda Paste
      Effective for removing corrosion by acting as a mild abrasive and neutralizing acid, especially for battery leakage cleanup.

4. Tools and Equipment for Cleaning

Essential tools for safe and effective PCB cleaning include:

    Anti-static brushes or soft nylon brushes for dust removal.

    Compressed air or electronics-grade vacuum for dislodging debris.

    Lint-free swabs and cloths, such as foam swabs, for precise solvent application.

    Ultrasonic cleaner, oven (low heat), or desk lamps for thorough drying.

5. Step-by-Step Cleaning Process

5.1. Preparation

    Ensure the board is powered off and disconnected from any source.

5.2. Remove Dust and Loose Debris

    Use compressed air or a soft brush to clear dust. Take care not to dislodge small components.

5.3. Wet Cleaning for Grime and Flux

    3–4. Apply IPA with lint-free swabs or a soft brush. Use heavier cleaning solutions or mild detergents for oily residue.

5.4. Corrosion Treatment

    For corrosion, apply a baking soda paste or mix IPA with water. In serious cases, let it sit, then brush and rinse gently.

5.5. Final Rinse & Drying

    Rinse with deionized water if needed, then dry thoroughly using low heat or airflow. Avoid closed ovens due to alcohol vapor risk.

6. Advanced Techniques: Ultrasonic Cleaning

Ultrasonic cleaning uses high-frequency sound waves to create cavitation bubbles that dislodge grime. Ideal for intricate boards, it delivers deep cleaning but may damage sensitive components like MEMS sensors or capacitors.

7. Safety Precautions & Best Practices

    Always work in a well-ventilated area when using IPA.

    Avoid harsh solvents like acetone or vinegar, which can damage PCB materials.

    Use ESD-safe tools to prevent static damage.

    Do not dry IPA-soaked boards in sealed ovens—risks of vapor ignition are real.

8. When to Clean—or Skip Cleaning

    Always clean flux residues for high-frequency or critical applications—even “no-clean” flux may impact surface insulation or coating adhesion.

    For routine dust removal in non-critical settings, gentle dry cleaning may suffice.

9. Summary Table of Cleaning Methods