New electrically conductive adhesives filled with low-melting-point alloy fillers

A new class of electrically conductive adhesives (ECAs) has been developed using two different resin materials and a low-melting-point alloy filler powder. The curing or cross-linking behaviors of base resin materials and the melting behavior of filler metal were examined using a differential scanning calorimetry (DSC) instrument. The effects of the reduction capability of base resin material, metal filler volume fraction, and joint height on the coalescence of filler, and morphology of conductive path were examined using a cross-sectional optical laser microscope. The two different types of conductive paths (necking-type and bump-type) were achieved by the coalescence and wetting characteristics of melted fillers into new formulations. The results show a good metallurgical connection and a low contact resistance even at a low filler metal volume fraction of 30%.