Effects of Trace Elements in Copper Fillers on the Electrical Properties of Conductive Adhesives

The properties of electrically conductive adhesives (ECAs) filled with Cu and Cu alloy fillers (with alloy elements Ag, Ge, Mg, and Zn) were investigated in terms of electrical conductivity, thermal stability, and the effects of the trace alloy elements on the oxidation resistance of the metallic fillers. Oxidation of metallic fillers under high-temperature exposure at 125°C was considered as the main reason that led to degradation of electrical conductivity in the ECAs. Cu fillers alloyed with a trace amount of Ag and Mg, respectively, had significant effects on the electrical conductivity and thermal stability of the ECAs as the electrical resistivity was substantially suppressed and a consistently high electrical conductivity could be maintained even after aging for 1000 h at 125°C.