Electroless gold plating process

Abstract

Abstract An Electroless plating bath, and processes for the autocatalytic deposition of Group IB metals upon various substrates using such a bath, are disclosed. The electroless plating bath disclosed includes an aqueous solution of an imide complex of the Group IB metal to be plated, an alkali metal cyanide, and a reducing agent, and is maintained at a pH of from about 11 to 14 by the addition of alkali metal hydroxides. In a preferred embodiment, an electroless gold plating bath is disclosed, including an aqueous solution of an alkali metal gold imide complex. Methods for plating various substrates from such electroless plating baths are also disclosed. Where non-metallic substrates are to be plated, the surfaces are rendered catalytically active prior to immersion in the electroless plating baths, and where metallic substrates are plated, they are preferably pre-coated with a thin plate by immersion in an aqueous plating bath including a soluble gold salt, an ammonium buffering agent, and an organic chelating agent, prior to immersion in the electroless plating baths of the present invention.

Inventors

• 👤 Kenneth D Baker

Bibliographic Details