Embedded Integrated 10 kW Power Module with SiC MOSFETs

Purpose and goal

10 kW low inductive embedded compact power module with measured leak inductance of 7.7 nH suited for modular system architecture and next generation electric drive line in vehicles and for power conversion, has been build and verified. The leak inductance is 5 times lower compared to the reference module with wirebonds (CAS300M12). Each module contains 4 SiC MOSFET chips and patterned DCB and PCB substrates. An electrically isolated gate driver for future integration in the module has been developed and evaluated as well. Gate driver contains overcurrent and undervoltage protection.

Expected results and effects

Module was designed using ANSYS Q3D. The measured inductance value agrees with simulations. Thermal simulations show that the maximum module temperature of 175 °C corresponds to the 1.55 kW of power losses. The expected value of power losses is less than 0.5 kW which gives good thermal safety margins. Important findings related to the choice of the materials and packaging technology will be guiding the construction of the next module generation. The low leak inductance facilitates faster switching, lower switching losses and thus higher efficiency compared to the standard module.

Planned approach and implementation

Obtaining a module design and PCB layout satisfying different requirements demanded a close cooperation of the project partners. Packaging technology had to be modified in order to solve problems related to the mechanical stresses in different materials (DCB and PCB). Module design was done by Acreo, thermal simulations by IVF. Acreo acquired MOSFET chips and SEPS PCB substrates. IVF ensured DBC substrates and assembly of modules. SEPS has developed the gate driver. The industrial partners contributed experience and knowhow. Electrical evaluation is done by industrial partners.