A New Economic and Reliable Contact Alloy for Connectors

The development of a new AuAgPd-base alloy for connectors is presented. The 70 weight percent (wt%) gold content, normally considered necessary for high quality connectors, has been successfully reduced to 39 wt% without causing any deterioration in the properties of the alloy. Indeed a marked improvement has been achieved with reference to strength and certain contact-specific features; this particularly relates to the edge creep behavior, tarnishing at elevated temperatures, and ductility. The steps involved in the metallurgical development are described. The alloy composition was optimized by systematically carrying the main constituents Au, Ag, Pd, and the alloying additions of Cd, In, Sn, Sb, Ge, and Pb. In particular, a full report is given on the mechanical and contact-specific properties of the resulting multicomponent alloy 39AuAgPd with defined additions of In and Sn. The alloy with this compositions, which was specified on the basis of the work described here, has the designation Hera® 277 S.