In this paper, we report our development on making of nanoscale silver pastes and their low-temperature sintering for semiconductor device interconnections. The nanoscale silver pastes were prepared by dispersing 30-nm silver powder under ultrasonic vibration and mechanical agitation in an organic vehicle. Sintering of the silver paste prints at 280°C for 10 minutes resulted in a density of ~80% in the air ambient. Some important properties of the low-temperature sintered silver include ~2.4 W/K-cm for thermal conductivity, ~3.8 × 10−6 Ω-cm for electrical resistivity, and ~9 GPa for the effective elastic modulus. SiC Schottky rectifiers attached to either silver- or gold-coated direct bond copper (DBC) substrates show low forward voltage drops. The silver joints do not contain large voids but rather uniformly distributed microscale pores. Die-shear tests showed that bonding strengths of the silver joints were around 21 MPa on the gold-coated DBC substrates and 38 MPa on the silver-coated DBC substrates, respectively. The latter is comparable to that of reflowed eutectic lead-tin solder joints. Based on the findings in this work, the low-temperature sintering of nanoscale silver pastes is promising to be a high performance and highly-reliable semiconductor device bonding solution for high power packages.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.