Effects of Trace Element Ag on Oxidation Failure of Copper Lead Frame

The effects of trace element Ag on oxidation failure of copper lead frame were studied. It was found that trace Ag on surface has great effect on the oxidation failure of copper alloy lead frame. In dry condition, trace Ag on the surface increase its resistance of peeling. However, under hygrothermal aging, trace Ag on surface decrease its resistance of peeling. The oxide thickness, morphology and elements compositions were examined to see which one is the key factor leaded to peel of the oxide film. As a results, it become evident that Ag has the ability to block the diffusion of copper atoms, and consequently hold back the oxidation of copper, but the adhesive strength between copper and its oxide layer has little relation with oxide thickness and more important influence come from internal compressive stress which have great relations with initial structure of the copper lead frame