METHOD FOR PRODUCING CIRCUIT BOARDS WITH DEPOSITED METAL PATTERNS AND CIRCUIT BOARDS PRODUCED THEREBY

A process for producing circuit boards involves the coating of a resinous substrate with a fluid mixture of an epoxy polymer component and a rubber polymer which is interactive therewith at temperatures of at least 180.degree.F. Preferably the rubber is a low molecular weight polyfunctional reactive butadiene/acrylonitrile interpolymer which is terminated by vinyl or carboxyl functional groups. The rubber component comprises at least 70 percent by weight of the epoxy polymer component, and the coating has a thickness of 0.001-0.015 inch. The coating is partially cured to effect partial polymerization of the epoxy prepolymer, further polymerization of the rubber, if it is low molecular weight, and interaction of the rubber and epoxy polymer to form a matrix of the interacted rubber/epoxy. The exposed surface of this coating is then etched, and metal is deposited on the surface to form a conductive layer. A conductive pattern is formed therein, and heat and pressure is applied to at least the conductive layer and coating to fully cure the coating and bond the coating to the conductive layer, and thus the conductive pattern to the resinous substrate. The metal layer may be deposited chemically or by vacuum metallizing and like techniques.