Self-oxygenation silver paste for SiC power modules with high thermal dissipation reliability

The high-power density of silicon carbide (SiC) devices requires the development of thermal interface materials (TIM) for rapid heat dissipation between direct bond copper (DBC) substrate and heat sink. However, the insufficient oxygen in the central bonding layer prevents the complete decomposition of organic solvents in silver paste, resulting in weak thermal dissipation. In this study, the Self-Oxygenation silver paste (SO-Ag) was successfully developed to promote the complete decomposition of organic solvents in N 2 environment, with -C-O- peak energy residual of 0.35 %. The in-situ generation of silver nanoparticles effectively enhanced the necking growth and achieved a highly reliable large-area bonding of 25 × 25 mm 2 under a pressureless sintering process. Taking advantage of the dense bonding layer and uniform porosity distribution, the proposed SO-Ag paste effectively mitigates the heat accumulation and reduces the chip temperature from 314 °C to 47 °C under forced water convection conditions. Furthermore, after 1000 cycles of thermal shock test (TST), the thermal resistance of SO-Ag increased by only 28 % without heat accumulation, indicating superior thermal reliability. The results confirm the superior thermal dissipation reliability of proposed SO-Ag, which enables the long-term operation of SiC devices.