Some recent topics in gold plating for electronics applications

A review is presented of selected recent topics in electrolytic and electroless gold plating for electronics applications. The topics covered include developments of non-cyanide electroplating baths for plating soft gold suitable for fabricating microbumps on silicon wafers, electroplating of hard gold and alternative materials with thermally stable electrical contact resistance and wear resistance for use on connectors exposed to elevated temperatures, and neutral, non-cyanide electroless processes for plating pure, soft gold on isolated areas of circuit boards. The development of the new electroless processes has been a subject of great interest and activity, and therefore an extensive survey of the progress in this field is included.