The cleaning method for PCBs needs to be selected appropriately based on the type of contamination and the usage scenario; a one-size-fits-all approach is not possible. For routine cleaning after production or repair, the most common method is to wipe with anhydrous alcohol or specialized electronic cleaners. These solvents evaporate quickly and leave little residue, making them suitable for removing flux residue, light oil stains, and dust. During operation, a lint-free cloth or soft brush is usually used to gently wipe along the direction of the circuit lines, avoiding excessive force that could loosen components or damage solder joints. For areas with severe localized contamination, a point-to-point cleaning method can be used, addressing the issue gradually rather than repeatedly wiping large areas.
If there are stubborn contaminants on the PCB, such as rosin buildup, industrial oil stains, or residues formed by long-term oxidation, ultrasonic cleaning can be considered. This method involves immersing the circuit board in a specialized cleaning solution, where the cavitation effect generated by high-frequency vibrations dislodges contaminants from tiny crevices, resulting in a more thorough cleaning than manual methods. However, it is crucial to control the cleaning time and liquid formulation to avoid damaging sensitive components (such as connectors, relays, and microphones). After cleaning, thorough drying is essential; otherwise, residual moisture may cause short circuits or corrosion.
