A SiC half-bridge power module based on liquid metal packaging for high performance and low thermal stress

Power electronics modules and converters are subjected to significant thermomechanical stress during operation, primarily due to the rigid bonding of multiple material layers with differing coefficients of thermal expansion (CTE). This stress arises when each material layer expands and contracts at different rates during thermal cycling, which induces mechanical strain. This issue is particularly critical for silicon carbide (SiC) power modules, which are known for their notably high Young’s Modulus, making them more susceptible to stress-related failures such as cracking or delamination. To address this challenge, this paper demonstrates the integration of a liquid metal (LM)-based SiC packaging design into a half-bridge power module, featuring integrated gate drivers and water cooling. The LM-based package incorporates a floating die structure and LM fluidic connections, which act to decouple thermal strain, thereby allowing for significantly reduced thermal stress and minimized warpage during operation. This design suggests enhanced reliability, improved thermal management, and an extended operational lifetime for the module. Experimental testing conducted on half-bridge LM module prototypes validates that the proposed LM-based SiC package delivers uncompromised electrical performance under various operating conditions, emphasizing its suitability for next-generation power electronics applications.