Method for applying a moistureproof insulator coating on packaged circuit boards

摘要

A method of applying coating material to only selected areas of a packaged printed circuit board wherein the coating material is supplied to a flat-pattern nozzle at a pressure sufficient to produce a liquid film emission in a flat leaf-shaped pattern which portion of the nozzle emission is substantially free of atomized particles. The circuit board is positioned relative the nozzle to place the board in the path of the film pattern and relative movement between the nozzle and board is effected in conjunction with controlling the supply of coating to the nozzle to coat only desired regions of the board while avoiding deposit of coating material on areas to be left uncoated.