Au-Sn fluxless SLID bonding: Effect of bonding temperature for stability at high temperature, above 400 °C

Fluxless SLID (Solid-Liquid InterDiffusion) bonding based on Au and Sn is presented, using two different processes, and bonding temperatures in the range 300–350 °C. The decomposition of the bond was tested by applying shear force while heating the samples. No bond delamination was observed for temperatures up to 350–400 °C, with 95 % of the tested samples surviving 400 °C without bond delamination. This is more than 100 °C higher than the melting temperature of the commonly used eutectic Au-Sn bond (80 wt% Au, melting at 278 °C). The Au-Sn system is particularly interesting since it is oxidation resistant, allowing fluxless bonding. With the SLID process, the metal system is applicable for true high-temperature applications.