Selective-area electroless copper plating on polyimide employing laser patterning of a catalytic film

Abstract

A scanned, focused argon ion laser beam is used to locally heat a thin polymer/palladium film applied to a polyimide-coated substrate, thereby reducing chemically bound palladium to palladium metal. The metallic palladium is resistant to a caustic etchant that removes the unirradiated film; the residual patterned palladium then acts as a catalyst for conventional electroless plating. As an alternate patterning method a laser may be used to selectively deposit the thin polymer film on the substrate from a surrounding liquid solution.