Microstructural control of electrically conductive adhesives with Ag micro-fillers by binder chemistry

Variations in the electrical resistivity and microstructural evolution in epoxy-based adhesives containing Ag micro-fillers (flakes and micro-particles) were investigated during curing and post-annealing. Sintering of micro-fillers was successfully induced in the adhesive binders, although the sintering behavior varied depending on the matrix chemistry. The electrical resistivity of the adhesives was markedly reduced as a result of filler sintering. When we used some polymer alloy binders, such as poly-urethane based binder, ultra high conductivity (below 10 μΩcm) was achieved by curing at 150°C Thus, binder chemistry is one of the important factors for design of electrically conductive adhesive materials.