Effect of ether solvent regulation on the microstructure and properties of pressureless sintered joints with submicron silver paste
摘要
As power semiconductors evolve toward higher frequencies and higher power densities, conventional soldering technologies—characterized by low melting points, poor thermal conductivity, and inadequate reliability—can no longer meet the packaging requirements of third-generation semiconductors such as SiC and GaN. In response, this study adopts sintered silver technology as a promising alternative. Three silver paste formulations were prepared using ether-based solvents with distinct evaporation characteristics, and the effect of solvent volatility on the low-temperature pressureless sintering performance of submicron silver particles was systematically evaluated. Variations in volatilization temperature and thermal energy requirements among the three solvents led to distinct microstructural morphologies and densification behaviors, revealing a correlation between electrical resistivity and void evolution. Notably, Ether I exhibits an exothermic peak during volatilization, along with low latent heat of evaporation and an appropriate volatilization temperature. The sintered joint prepared with this solvent achieved a shear strength of 79.61 MPa, a thermal conductivity of 221.17 W m−1 K−1, and a volume resistivity of 4.86 × 10−6 Ω cm at a sintering temperature of 220 °C. These results demonstrate the considerable potential of pressureless silver sintering technology for interconnections in power electronics packaging applications.