Method of coating ridged plates, particularly printed circuit boards

摘要

Method for applying liquid varnish coating over raised conductor pattern of a printed circuit board. The circuit board is passed through nip rolls at least one of which has a coating of liquid varnish thereon. The thickness of the coating on the nip roll is adjusted to between 5 and 100 mu m by adjusting the thickness of liquid varnish on an applicator roll in contact with the nip roll. The flow of liquid varnish applied to the applicator roll is at least 1.5 times the rate of transfer from the nip rolls to the circuit board.