Assembly and packaging of micro systems by using reactive bonding processes

In this work, the process technology for fabricating reactive multilayer systems (RMS) has been developed, and the application of reactive bonding on the assembly of micro systems has been demonstrated. RMS have been fabricated by physical vapor deposition and have been provided as foils as well as direct coatings on the bond partners. Alternatively, RMS coatings by electroplating have been demonstrated. Besides the already established Al/Ni-RMS, new reactive materials as Zr/Al/Si, Pd/Sn and Pd/Al have been evaluated for the bonding process. For structuring the RMS chemical etching, lift-off-techniques, and laser structuring have been used on chip-scale as well as on wafer level up to 8 inches. As application examples, where the high thermal conductivity of reactive bonds is very useful, the mounting of Peltier coolers could be demonstrated. Furthermore, silicon-based acceleration sensors showed low mechanical stress after reactive bonding on ceramic substrates.