Manufactural Technology and Characterization of Highly Conductive Ag–Graphene Composite Plating for Electrical Connecting Components

Abstract

Silver electroplating films are widely used in various electronic/electrical devices owing to their excellent conductivity. This study is to verify the practicability of Ag–Graphene plating films by using cyanide and cyanide–free plating baths and to investigate the effects of plating bath and graphene inclusion on their properties. Uniform Ag–Graphene composite films with hardness of 130〜155 Hv can be produced in both cyanide and cyanide–free baths containing graphene sheets with mixed sizes. It was found that the conductivity of Ag–Graphene composite films was both improved by combining graphene, up to 35% and 51% in the cyanide and cyanide–free baths compared to the pure Ag film. In particular, the electrical contact resistance of the composite films can be maintained as the same levels as the as–plated states even after heating at 200°C for 1500 h due to the excellent thermal stability of graphene. Moreover, the wear resistance of Ag–Graphene composite films from both plating baths improved greatly and the improvement related to the orientation of graphene sheets in Ag matrix films, which can be controlled by stirring methods. Therefore, the Ag–Graphene composite films can be applied as a promising plating material for improving connecting reliability and reducing power consumption.