Sumitomo Bakelite Develops Compact 3D SiC-MOSFET Power Module

Compact 3D SiC-MOSFET Power Module Development

On August 18, the 3D SiC-MOSFET Power Module was announced by Sumitomo Bakelite following joint research with Tohoku University. The development combines a resin-insulated dual-layer structure with compact packaging and high power density. By optimizing the thermal expansion characteristics and elastic modulus of the resin-insulated substrate and epoxy molding compound, the company successfully suppressed power module warpage to 20 μm or less. The adoption of an Ag semi-sintering bonding material also improved bonding reliability with the heat sink, addressing important mechanical and thermal requirements for advanced vehicle power electronics.

Reduced Power Unit Volume and Higher Density

The technology developed by Sumitomo Bakelite enables a reduction in power unit volume of approximately 50% compared with industry-standard solutions. By reducing the physical footprint of the power unit, the approach can contribute to more effective utilization of vehicle interior space while also supporting improvements in passenger comfort and storage capacity. The technology also supports realization of an inverter power density of 300 kVA/L. These characteristics are particularly relevant as electric vehicles require increasingly compact powertrain systems capable of delivering higher performance without adding unnecessary packaging volume or compromising the available space within the vehicle.

Addressing EV Powertrain Thermal Challenges

The development comes as electric vehicles continue to pursue higher performance and longer driving ranges, increasing the importance of reducing vehicle weight and minimizing the footprint of powertrain systems. In power electronics applications such as motor drive inverters, higher system efficiency must be achieved while managing the growing heat generated by power devices. Sumitomo Bakelite addressed these requirements by combining material-property optimization with a more reliable bonding approach. The resulting module architecture is intended to help power electronics systems manage thermal and mechanical demands while maintaining the compactness required for increasingly space-constrained vehicle platforms.

Research Collaboration Supporting the Technology

This achievement was realized under the framework of the Co-creation Research Center established by Sumitomo Bakelite and Tohoku University in January 2025. The research collaboration provides the foundation for developing the resin-insulated dual-layer structure, controlling warpage through optimized material characteristics, and applying Ag semi-sintering bonding to improve heat-sink reliability. Together, these technologies target the packaging challenges associated with high-power-density SiC devices. The approximately 50% reduction in power unit volume and the 300 kVA/L inverter power-density target demonstrate the intended contribution toward more compact and efficient electric vehicle powertrain systems.

Frequently Asked Questions

What does the new 3D SiC-MOSFET power module achieve?
The module combines a resin-insulated dual-layer structure with optimized material properties and Ag semi-sintering bonding to deliver compact packaging and improved thermal-mechanical reliability. Sumitomo Bakelite reported that the design suppresses module warpage to 20 μm or less and can reduce power unit volume by approximately 50% compared with industry-standard solutions. It also supports an inverter power density of 300 kVA/L, helping address the need for smaller, more efficient powertrain systems as electric vehicles pursue higher performance and longer driving ranges.