Experimental and Simulated Verification of Power Cycling Reliability for Thin and Low Warpage Power Modules

Meeting both high-frequency and high-speed requirements is essential, and the small form factor designs for the architecture of high-powered modules are acknowledged to impact their reliability in subsequent applications. However, conventional power modules utilizing a direct bonded copper substrate still encounter warpage issues stemming from the manufacturing process. This results in suboptimal heat dissipation after heat sink assembly, leading to a failure to meet automotive specifications for high voltage and high current resistance. To address this concern, our research proposes a thin and low warpage power module with an insulating metal substrate and a thermal interface material structural design. This aims to enhance heat dissipation capacity while maintaining low warpage and ensuring high mechanical reliability. The study employs coupling simulation technology integrating a process-oriented approach with a follow-up automotive specification power cycle reliability test. This allows for estimation of the warpage behavior caused by the power module process and the mechanical response of the solder layer within the module. To validate the accuracy and credibility of the simulation results, actual vehicle fabrication and related power cycling experiments are conducted. Furthermore, an improvement solution for the power module is proposed to offer a high industrial competitiveness of the long-term packaging reliability.