METHOD FOR APPLYING A MOISTUREPROOF COATING TO PRINTED CIRCUIT BOARDS USING TRIANGULAR OR DOVETAIL SHAPED LIQUID FILM EMITTED FROM A FLAT-PATTERN NOZZLE

摘要

A method of applying coating material (S1-S4, S11-S18) to only selected areas of a packaged printed circuit board (B1) wherein the coating material is supplied to a flat-pattern nozzle (Nf) at a pressure sufficient to produce a liquid film emission in a flat triangular or dovetail shaped pattern (Fs) which portion of the nozzle emission is substantially free of atomised particles. The circuit board (B1) is positioned relative the nozzle (Nf) to place the board in the path of the film pattern and relative movement between the nozzle (Nf) and board (B1) is effected in conjunction with controlling the supply of coating to the nozzle (Nf) to coat only desired regions of the board (B1) while avoiding deposit of coating material on areas to be left uncoated.