Au-Sn solid-liquid-interdiffusion (SLID) bonding is a novel and promising Interconnect technology for high temperature (HT) applications. In combination with Silicon Carbide (SiC) devices, Au-Sn SLID has the potential of being a key technology for the next generation of innovative, cost effective and environmentally friendly drilling and well intervention systems for the oil industry. However, limited knowledge about Au-Sn SLID bonding for HT applications is a major restriction to fully realize the high temperature potential of SiC devices. A uniform Au-rich Au-Sn bond interface is produced (the æ phase with a melting point of 522°C). The importance of excess Au on both substrate and chip side in the final bond is demonstrated. It is shown that Au-Sn SLID can absorb thermo-mechanical stresses induced by large CTE mismatches (up to 12 ppm/K) in a package during HT thermal cycling. The bonding strength of Au-Sn SLID is shown to be superb, exceeding 78 MPa. Importantly, Au-Sn SLID is shown to be an excellent bonding technology for HT packaging. The project is carried out within the collaboration program between Vestfold University College (Norway) and UC Berkeley and is partially funded by The Norwegian Centre for International Cooperation in Higher Education (SIU).
Project end date: 01/30/13