Novel Ag-Cu foam sheet with multi-layer composite structure for high performance joining of SiC power chips

Conventional packaging materials are difficult to support long-lasting service in high-temperature environments. In this study, the novel nano Ag-Cu foam sheet was prepared by dealloying etching, and achieved joining chips and substrates by sintering at low temperature. The microstructure, mechanical properties and fracture path of the sintered joint were analyzed. The grain size in the sintered interface showed a gradient change, which brought excellent shear strength. The sintered joint showed that the oxidation behavior caused during the high-temperature aging tests would reduce the shear strength. The energy absorption effect of the sintered layer could alleviate joint fatigue under thermal shock conditions, thus ensuring the robust lifetime of the sintered joint for high-temperature application.