Application of Vapor-plated Zinc as a Substitute for Palladium Catalyst in the Nickel-Phosphorus Electroless Plating

Colloidal mixing hydroxide, which consists of nickel ions and copper ions, was allowed to adsorb onto an ABS resin. After making these colloids dry up, carbon and then zinc were deposited on it using the physical vapor deposition technique. Articles containing the colloids, carbon and zinc were used as substitutes for palladium catalyst in the electroless nickel plating. In the 90° peeling strength test, all of these electroless plated nickel films showed about 200kg/m compared with the peeling strength obtained by the conventional method which couples tin (2+) as a sensitizer with palladium (2+) as an activator. The strong adhesion resulted in a cohesive fracture of the ABS resin during the peeling test. Such a result shows the following; (1) the colloids invaded and adsorbed into the etching holes which occurred in the etching of the ABS resin by the chromic acid, (2) the colloids were reduced to nickel and copper by the electrons produced by dissolution of the zinc in the plating solution, and then the nickel and copper worked as an anchor for the plated nickel films. Also the nickel naturally worked as a self-catalyst for continuing the electroless nickel plating.