Air-assisted 'airless' conformal coating process

The current process to conformally coat PCBs consists of spraying a conventional, air drying acrylic material from an aerosol can. This process requires extensive masking to ensure areas such as connectors do not become coated. The objective of the program is to select a suitable production line to optimize the application of the conformal coating, and minimize waste products, hazardous air pollutant emissions, the need to mask and turnaround time. A UV curable conformal coating with a shadow cure capability was selected. This solvent-free coating was found to be compatible with the automated coating module, coupled with the CPX air-assisted airless applicator.