Electroplating of Thick and Ductile Palladium‐nickel Alloys

Electroplating of palladium‐nickel alloy is becoming widely used, mainly for interconnection applications in the electronics industry and for decorative purposes. Enhanced hardness and brightness combined with superior wear properties compared with hard gold deposits make this alloy desirable in many applications. Like pure palladium, palladium‐nickel is frequently covered with a thin layer of hard gold to improve contact reliability; this results in a much less expensive and longer‐lasting contact material than hard gold on its own. In response to the growing demand, the authors have developed a palladium‐nickel alloy electroplating process that can plate alloys of varying composition (10–50 w % Ni) at current densities ranging from <5 mA/cm to >500 mA/cm. This process produces specular, hard and ductile deposits up to a thickness of ‐25 ?m. The new palladium‐nickel alloy electroplating process is described with regard to its chemistry, operating conditions, bath maintenance and regeneration, diagnostic measures, and properties of the electrodeposits.