Electrical Properties of Copper-Filled Electrically Conductive Adhesives and Pressure-Dependent Conduction Behavior of Copper Particles

This study focuses on the effects of particle composition, particle shape, particle size and oxidizing temperature on the electrical properties of copper-filled electrically- conductive adhesives (CFECAs) and the pressure-dependent conduction behavior of compressed copper particles (CCPs). Silver-coated copper particles and un-coated copper particles of both spherical and flake-shaped types were oxidized at 30 degrees C, 175 degrees C and 240 degrees C for two hours. The copper particles were dispersed in an epoxy matrix for CFECAs or compressed in a mold for CCPs. Silver-coated copper particles showed significantly greater oxidation resistance than un-coated copper particles since the silver coating provides good oxidation resistance at temperatures lower than 175 degrees C. Thermogravimetric Analysis (TGA), X-ray diffraction (XRD) and Auger Electron Spectroscopy were used to observe how metal oxides such as AgO and Cu2O affected the electrical properties of CFECAs and the conduction behavior of CCPs. The electrically-conductive adhesives (ECAs) filled with flake-shaped copper particles offer better electrical conduction than the ECAs filled with spherical copper particles. (c) Koninklijke Brill NV, Leiden, 2008