Research of 3.3kV, 60A H-Bridge High-Voltage SiC Diode Modules

The simulation, fabrication and measurement of the high-voltage H-bridge SiC diode module is reported. The SiC module is consisted with 8 self-designed 3.3 kV30 A SiC Schottky diodes (SBDs), in which each bridge arm is connected by double SBD chips to achieve 60A current. Q3D is used to establish simulation model and make network division of the module. Two parasitic parameters, parasitic inductor and circuit resistance, are extracted from the circuits, which are about 37.5 nH and 1.9 mΩ, respectively. By establishing the geometric model and finite element model, finite element analysis software ANSYS is used to calculate steady-state thermal conduction, and the temperature gradient distribution of the formed chips. The results show that the maximum junction temperature of the chip is about 100°C, and the distribution of the temperature field is reasonable. As the lateral conduction of heat increases the effective heat dissipation area, there is no obvious concentration of heat. Under the condition of the test at room temperature and static, the module voltage drop is about 2.1 V, the leakage current is less than 5 uA, and the breakdown voltage is more than 3700 V, respectively. The fabricated 3300 V devices exhibit large safety margin. The insulation voltage exceeds 7000V, thus ensure the safety of the system. The thermal resistance of the chip is about 0.21 K/W, which is basically consistent with the simulation results.