Transient Liquid Phase Bonding (TLPB) is one of the promising processes for interconnecting power semiconductors, which are usually used at high temperature. However, the TLPB process parameters needed to ensure robust interconnection have not been systematically studied. In this study, TLPB was conducted with various bonding temperatures and times. Sandwich structures made of Cu/Sn/Cu, Ag/Sn/Ag, and Ni/Sn/Ni were processed at 250 and 280 ℃ for 1, 2, and 3 h, respectively. The microstructure of the interconnections was analyzed with scanning emission microscopy equipped with energy dispersive spectroscopy. Then dissimilar metalized Cu/Sn/Ag and Ni/Sn/Ag sandwich structures processed at 280 ℃ for 1, 2, and 3 h. The fracture surface of Cu/Sn/Ag consisted of Ag3Sn with shear bands, and the shear strength was 30 MPa on average.
The fracture surface of Ni/Sn/Ag consisted of Ni3Sn4 and Ag3Sn with shear bands, and the shear strength was 31 MPa on average. The minimum bonding time for reliable interconnection was 1 and 2 h for Cu/ Sn/Ag and Ni/Sn/Ag, respectively.