IPC PCB Cleaning Recommendations

IPC PCB Cleaning Recommendations

The IPC lists several contaminants that can affect PCB performance and longevity. According to IPC, the following contaminants must be removed from circuit boards using cleaning techniques that are safe for workers and environmentally sustainable.

l Polar residues – etch materials, flux components, chemicals in the substrate, etc.

l Non-polar water-soluble residues – welding oils and waxes

l Non-polar water-insoluble residues – SMT adhesives, synthetic resins, greases and mold release agents.

l Insoluble residues – silica and clay-type fillers and glass fibers in laminates.

l No reflow solder paste

l Reflow flux residue

l Uncured (wet) SMT adhesive

IPC Recommendations for Cleaning Residues

Consider the following when cleaning your PCB.

l Make sure to clean both sides of the PCB. This is important, especially when using a spray air cleaning system.

lUse a spray air cleaning system equipped with a filter. This helps remove fine particles from the cleaning solution, thereby improving the quality of the cleaning process.

l When cleaning internal electrical components, be sure to maintain the correct flush pressure and duration for thorough cleaning.

l During the entire cleaning process, the PCB must be properly placed and properly secured. This allows for a smoother cleaning process without damaging the PCB assembly from any vibrations or shocks.

l Cleaning systems using ultrasonic technology must have an ultrasonic frequency of 40 kHz or higher to ensure effective cleaning.

l Make sure there is no adhesive residue in the pads or vias. Vias are one of those hard-to-reach places and must be cleaned carefully.

Debris can hinder the operational excellence and efficiency of the PCB. Also, the mess of the PCB will cause its failure in the near future. Therefore, IPC strongly emphasizes the need to clean the PCB without damaging it in the process. You can follow manual or benchtop cleaning, ultrasonic and batch immersion cleaning, and air spray cleaning methods. However, the choice of cleaning process must depend on the type of PCB material, the assembly process used, and the type of components being mounted.