Silver nanoporous sheet for solid-state die attach in power device packaging

A novel die attach process that utilizes an Ag nanoporous sheet has been investigated for power device packaging. This Ag nanoporous sheet, which has a ligament size of about 110 nm, was fabricated through the dealloying of Al–Ag precursor in hydrochloric acid. When used as a die attach layer, no large voids or gaps were observed in the interfacial area, and a shear strength equivalent to conventional Pb–5Sn solder could be achieved without the need for any organic substances.