Common application methods for conformal coatings

Methods of Conformal Coating · Brush Method · Spray Method · Dipping Method · Selective Coating Method.

Common application methods for conformal coatings:

Manual spraying - For low volume production when capital equipment is not available, conformal coating can be applied by an aerosol can or handheld spray gun. This can be time-consuming and may need to be masked. Also, quality and consistency of outcome is operator-dependent, so variations are common from board to board.

Automated spraying - Programmed spray systems can move PCBs on a conveyor under a reciprocating spray head.

Selective coating – An automated spray system can actually be programmable, with a robotic spray nozzle applying the conformal coating to specific areas on the PCB. This is popular for high volume assembly because it eliminates the laborious masking process.          

Dipping – This is a popular conformal coating method for high volume assembly. Masking is usually necessary before PCBs are coated. Dipping is only practical when coating both sides of the board. Immersion speed, withdrawal speed, immersion time, and viscosity determine the resulting film formation.    

Brushing - Brushing is used mostly for repair and rework. Conformal coating is brushed onto specific areas on the board, not generally the entire PCB. While low-cost, brushing is both a labor intensive and highly variable method, so it more appropriately suits small production runs.