Electroplating of Pd/Sn multilayers for reactive bonding in packaging and assembly applications

The reactive bonding is a joining technology carried out at room temperature. With further diversity of electronic modules, the joining temperature becomes more important for heat sensitive componentsIn this paper, the electroplating of palladium (Pd) and tin (Sn) reactive multilayer systems for the use in electronic assembly is described. The Pd/Sn multilayers can be deposited reproducible on silicon chips using two separate metal electrolytes. It is shown that 425 nm and 510 nm bilayer periods produces ignitable reactive systems. The bonding can be achieved with 60 bilayers of 425 nm bilayer period at a reaction velocity of 5.7 m/s.