Improving Adhesion of Copper Plating on Polyimide Film
Original Publication Date: 1988-Dec-01
Included in the Prior Art Database: 2005-Feb-15
A technique is described whereby high temperature polyimide film surfaces, as used in printed circuit boards, are prepared in such a way so as to improve the adhesion to additive copper. The improvement enables full-additive or semi-additive processes to be used on polyimide films without vacuum metallization. High temperature polyimide films, as used as insulators in the circuit packaging of high density printed circuits, generally have the polymer dielectric surface classified in three processing groups: subtractive, semi-additive and full-additive. The processes typically involve the lamination of copper foil with a polymer, followed by the application of a photoresist on the copper surface. The circuit pattern is defined in the photoresist by means of an ultraviolet exposure through a mask, followed by resist development.