Electroplating of Cu/Sn layers for hermetic encapsulation for vacuum applications

摘要

Surface modification with Cu and Sn followed by bonding provides a suitable method to create a hermetic package in MEMS. By using the eutectic phase of these two materials the bonding temperature can be limited by 300℃, which is in working range for the most micro electro-mechanical systems (MEMS) applications. In this investigation Si chips are bonded using electroplated Cu on the one part and a stacked combination of sputter deposited Sn and electroplated Cu on the counterpart. For analyzing the bond quality, the shear tests are carried out to find the optimum thickness of the bonding materials and characterize the package.