Comparative performance study of different conventional silver and hard silver-plating processes for connector applications

Overview & Synopsis

Silver plating processes have become key technologies for connector applications in the past 10 years. The signif- icant utilization increase of various pure silver plating types and various silver alloys, for electrical contact surface finishing, can be attributed to several factors such as the development of electrical vehicles, the continuous rise of many connector operating temperatures up to 150°C and 180°C, where Tin plating cannot be used anymore, the increase of smaller-size power connectors requiring higher electrical conductivity than what can be provided by hard gold plating, and finally the severe increase of Gold and Palladium metal prices. Connector users sometimes have difficulties to understand the performance differences between all the existing silver-based plating offering. This work presents a summary between several widely used commercial silver-based deposits such as soft or hard pure silver, Antimony or Bismuth based silver alloys as well low friction silver coatings. Some key tribological, electrical and mechanical characteristics are compared. Some structural surface analysis is carried out to under- stand certain behaviour differences. The objective is to better define the optimal performance domain of each type of silver-plating technologies.