Abstract: An improved additive process for metallization of substrates is described whereby a catalyst solution is applied to a surface of a substrate. Metallic catalytic clusters can be formed in the catalyst solution on the substrate surface by heating the substrate. Electroless plating can then deposit metal onto the portion of the substrate surface coated with catalyst solution. Additional metallization thickness can be obtained by electrolytically plating the substrate surface after the electroless plating step.

Abstract: An improved additive process for metallization of substrates is described whereby a catalyst solution is applied to a surface of a substrate. Metallic catalytic clusters can be formed in the catalyst solution on the substrate surface by irradiating the substrate. Electroless plating can then deposit metal onto the portion of the substrate surface having metallic clusters. Additional metallization thickness can be obtained by electrolytically plating the substrate surface after the electroless plating step.

Abstract: Electroless deposition-catalyzing film-forming solutions comprising polyamic acid and noble metal, e.g. palladium complexed with ammonia, in an aprotic solvent, e.g. N-methyl-2-pyrrolidone with a surfactant. Such solutions are used to provide articles having a coating or patterned image of a electrolessly-depositable element such as copper, nickel and the like on high heat resistant substrates, e.g. metals, ceramics, glass, silicon, high heat polymers and thermoset polymers. In the methods of this invention a polyamic acid/noble metal solution is applied as a coating or patterned image to provide a coherent polyamic acid film which can be imidized, e.g. by heat treatment at 250.degree. C. or higher, providing a tough, adhesive polyimide film that can catalyze electroless deposition.