Gold Connector Contacts: Developments in the Search for Alternate Materials

The characteristics of electroplated and wrought gold-based contact materials for high reliability connectors in low energy circuit applications are reviewed. To insure that contacts do not degrade by film formation due to corrosion, diffusion, or wear processes, certain practices have evolved on the compositions, ´thicknesses, porosities, hardnesses and manufacturing methods for the golds, and for underplatings that are used with them. Recently, however, its escalating cost has stimulated intensive work which shows that the thickness of gold required for satisfactory performance can often be reduced. In addition, manufacturing techniques which selectively locate gold to the, mating area of a contact have come into vogue. Other routes to cost reduction include the use of nonnoble materials, palladium, or golds alloyed with large amounts of base metals.