Abstract
Self-propagating exothermic reactive films are one of attractive functional materials in MEMS field. The reactive materials with nanometer-thick multilayers consisting of light metal and transition metal possess attractive features, such as instant heat generation, self-propagation of reaction, rapid cooling, reactive in every atmosphere, and no emissions. The authors propose the use of the reactive materials as local heat source for soldering in hermetic packages for MEMS. However, it is often seen that the propagation of the reaction stops at the half-way. In this paper, the size limit of Al/Ni reactive films for self-propagating explosive reaction on a Si wafer is reported first, to investigate the cause of the reaction stop. Then the influence of bonded area size on cracking in reactive soldering is presented.
