A reactive solder bonding technique using a self-propagating exothermic multilayer film

Abstract

Self-propagating exothermic multilayer films are very attractive as a heat source because they can produce the heat by applying a small external energy. The heat performance is dependent on the combination of two metals, the atomic ratio, the bilayer thickness and the overall thickness, which indicates that the performance is tunable to match the application. The authors are using a sputtered Al/Ni multilayer film for reactive solder bonding. The film can melt solder within a second, so two Si wafers can be solder-bonded quickly without a furnace. Furthermore, no emissions are generated during the exothermic reaction. The environment-friendly reactive soldering technique has potential as one of the future key semiconductor packaging technologies.