A New Concept for Electroplated Electronic Contact Golds

Abstract

Due to the shortcomings of the present-day standard gold/cobalt and gold/nickel low-alloy contact golds, especially from aspects of high-temperature storage (approximately 125°C for 1000 h plus) and also their consistent risk of spontaneous cracking and solution operating difficulties, efforts were made to deviate from this thinking. The deposit was required to have low porosity at approximately 2-2.5-µm deposit thicknesses. Solution parameters were required to be broad without adverse influence on deposit characteristics. The resistance of the solution to metallic and organic contamination was also considered. A bath of high-cathode efficiency with good throwing power and with a wide permissible current density spectrum was also regarded as essential to the industry. A deposit of gold of approximately one percent cadmium and one percent organic polymer was finally selected, being plated from solutions based on neutral cyanide systems. It is considered that this alloy heralds a new generation of gold deposits for electrical contacts.