Die-attach on nickel substrate by pressureless sintering a trimodal silver paste

Most of the reported sintered-silver bonding was done on substrates metallized with silver or gold. There is lacking in reports of strong sintered-silver bonding on nickel (Ni), a common and low-cost metallization on substrates, due to nickel oxidation at sintering temperature. In this study, we proposed a die-attach method on nickel by pressureless in-air sintering a trimodal hybrid-silver paste. Thanks to the strong cohesion of densification bond-line from close packing of trimodal-silver particles and adhesion from metallic bonds at Ag-Ni interface by prevention nickel from extensive oxidation, strong die-shear strength above 40 MPa was achieved. The results presented in this study open a way to achieve strong sintered-silver bonding on nickel metallization.