A novel double-sided cooling packaging structure of SiC-based half bridge module integrating the laminated busbar

Abstract

This paper presents a novel double-sided cooling SiC-based half-bridge (HB) module with laminated busbar. The novelty of this module lies in the integration of a laminated busbar which can result in a significant reduction of the module parasitic inductance. Moreover, a 3D vertical structure design can reduce the commutation loop area inside the module, thereby further achieving a lower commutation loop inductance. Meanwhile, this module achieves wire-free bonding that can improve the reliability of the power module to a certain extent. A fan-shaped DBC layout is designed to ensure the symmetrical layout of the paralleled chips, which can realize a better current sharing performance. In fact, an unbalanced junction temperature can also affect the current balance of each parallel device, resulting in unequal turn-on and turn-off losses. Therefore, a three-outlet circular water-cooled heat sink is proposed to ensure the junction temperature balance of the parallel chips, which is demonstrated by thermal simulation. Then, by the Ansys Q3D, the extracted parasitic inductance of the module is about 5.63 nH, and the imbalance degree between each parallel branch is about 5.8%. Finally, the low parasitic inductance and highly symmetry of the module are verified by the experimental tests.