LASER-INDUCED PRENUCLEATION AND OR METALLIZATION OF ALUMINA SUBSTRATES BY A NEW PALLADIUM RESIN

The prenucleation or metallization of rough and porous alumina ceramic surfaces is induced by the laser irradiation of a new palladium resin. This new resin is formed from a homogeneous and stable mixture of palladium acetate, N,N-dimethylformamide and a chemically derived cellulose. Metallization with this resin works in four ways. (1) Excimer laser-irradiation through an appropriate mask induces selective prenucleation of alumina and this treatment is followed by electronics plating. (2) Argon ion laser direct-writing induces selective prenucleation of alumina, again for electroless plating. (3) Argon ion laser direct-writing induces selective metallization of alumina without the need of a sequential electroless plating step. (4) The resin is used as catalyst for non-selective electroless plating. Different patterns were obtained depending on the method used, leading to adhesive layers of electroless copper or nickel coatings or adhesive palladium layers. Thin layers displaying metallic conductivity are obtained.