METHOD FOR ELECTROLESS PLATING ALUMINUM SURFACE AND CATALYST FOR ELECTROLESS PLATING

摘要

Disclosed is a novel electroless plating method which has solved the conventional problems zincate treatments involve. This electroless plating method enables to obtain a plating film having a uniform thickness without producing nodules, while melting only small amount of Al or an Al alloy. Also disclosed is a palladium catalyst used in such an electroless plating method. Specifically, this electroless plating method is characterized in that after activating the surface of an Al or Al alloy, the surface is treated with a palladium solution using one of palladium chloride, palladium sulfate, palladium nitrate and an ammine palladium, and then electroless nickel plating or displacement gold plating is performed. The palladium solution preferably has a palladium concentration of 0.005-20 g/L. When the palladium concentration is not less than 10 g/L, the palladium solution is preferably added with a chelating agent. Examples of such a chelating agent include organic acids and organic acid salts such as citric acid and citrate, malic acid and malate, and lactic acid and lactate; amino acid salts such as glycine and alanine; and amines such as ethylenediamine, salts thereof, and ethanolamines.