Thermo-Mechanical Coupling-Based Optimization and Reliability Assessment of Cu Clip Packaging Structures

Silicon carbide (SiC), a third-generation wide bandgap semiconductor, excels in high-frequency, high-temperature, and high-efficiency operations, making it ideal for renewable energy and electric vehicles. However, traditional aluminum wire bonding limits SiC power modules due to parasitic inductance and reliability issues. Cu-clip packaging improves thermal and mechanical performance but faces challenges such as stress concentration. This study uses finite element analysis to investigate the effect of Cu-clip geometry on stress distribution. An optimized design (400 μm thickness, 1200 μm height, 30° chamfer angle) improved the solder layer's fatigue life by 17.8%, from 405,431 cycles (traditional) to 477,772 cycles (optimized) under power cycling conditions (ΔT = 120 °C). These results provide valuable insights for enhancing SiC power module reliability.