Design and characterization of an aluminium nitride vapor chamber for power electronics thermal management

To solve the dual problem of thermal management and electromagnetic compatibility (EMC) in power electronics, an innovative electrically insulating vapor chamber concept based on ceramic materials is proposed. This approach targets EMC challenges associated with wide-bandgap semiconductor devices while providing enhanced thermal spreading capability. The study focuses on its design, as well as the electric and thermal characterization of the device. Numerical thermal and fluid models are developed, together with the calculation of the parasitic electrical capacitance of such a device, in order to identify a design compromise that satisfies multiple coupled constraints. After fabrication, the prototypes are experimentally characterized. At an optimal filling ratio of 37 %, the vapor chamber exhibits a thermal resistance of 0.84 K⋅W −1 and a capacitance of 18.8 pF at 10 7 Hz. These performances are compared with those obtained with a reference aluminum nitride baseplate. While the AlN baseplate shows a lower overall thermal resistance, the proposed vapor chamber achieves a significantly improved temperature uniformity on the condenser side. In addition, its electrical capacitance remains only slightly higher than that of the AlN baseplate. Overall, despite a higher thermal resistance in its current configuration, the proposed ceramic vapor chamber demonstrates strong potential as a multifunctional thermal management solution, combining EMC compatibility and improved thermal spreading performance. These results highlight its relevance for future power electronics packaging applications where temperature uniformity and electrical constraints are critical design drivers.