Assessing the Fatigue Life of SiC Power Modules in Different Package Structures

Advanced power module packaging technology is demanded with the commercialization of silicon carbide (SiC) power devices with superior performance. This paper presents an overview of currently available packaging structures suitable for SiC power modules that can deliver good performance during operation at a high temperature, frequency, and power density while incurring low loss at a high switching speed. Four typical structures—the common single-sided cooling package structure, and three double-sided cooling package structures—were chosen for comparative thermal reliability analysis that was conducted by using a finite element simulation. One of the double-sided cooling 3D package structures yielded good thermal performance, and was highly reliable. It not only lowered the junction temperature by using a single heat source but also reduced the stress and strain of the chip and the solder layer, respectively, by nearly 30% less than the single-sided cooling structure. In addition, the fatigue life of the solder under thermal cycling was significantly longer than in the other structures.