Development of Next-Generation 3D Power Modules with High Power Density

Sumitomo Bakelite Co., Ltd., headquartered in Shinagawa, Tokyo, has collaborated with Tohoku University to introduce a breakthrough in power electronics: a compact 3D SiC-MOSFET power module characterized by exceptional output density. This new technology is a product of their joint research efforts and will be a cornerstone for future electric vehicles and energy solutions.

Contributions to the Industry

Understanding the increasing significance of lightweight vehicles and compact power systems due to rising demands for electric vehicle (EV) efficiency and range, Sumitomo Bakelite has taken a proactive role in the design phase of the module. The company’s expertise in resin materials has enabled optimal structural proposals, enhancing their competitive edge in the power electronics sector. This initiative is not just about product innovation; it’s a step towards meeting the diverse needs of the market while supporting the development of a more electrified society.

Background of the Development

With advancements in electric vehicle performance and extended travel ranges, the need for lighter vehicle designs and efficient power systems has escalated. In power electronics, particularly for inverter applications, enhancing system efficiency and managing power device heat generation has become crucial.

The pursuit of next-generation power modules, which ensure compact and high-output designs, is gaining momentum globally, highlighting the necessity of research and development in inverter miniaturization and output density improvement.

Overview of the New Module

Sumitomo Bakelite combined its unique high-performance resin products with Tohoku University’s cutting-edge high-output density inverter concepts. By optimizing the thermal expansion characteristics and elastic modulus of resin insulated substrates and epoxy encapsulating resins, module warping was substantially reduced. The implementation of silver semi-sintering joint materials significantly improved the reliability of connections with cooling systems. Consequently, the inverter’s output density has reached an impressive 300 kVA/L, establishing a highly reliable power module.

Key Technical Features

1. Warping Suppression with Resin Insulated Substrates
By switching from traditional ceramic to resin insulated substrates, thermal expansion mismatches with copper are drastically reduced, keeping module warping to below 20 µm.

2. Reduced Thermal Resistance and Improved Mountability
The introduction of resin insulated substrates minimizes warping related to thermal expansion differences among substrate materials. This allows for thinner thermal interface materials (TIM), drastically reducing thermal resistance while ensuring highly reliable connections with cooling systems, thus greatly enhancing mountability.

3. Low-Temperature, Pressure-Free Silver Semi-Sintering Joint Materials
The newly developed low-temperature, pressure-free silver semi-sintering joint materials create connections with reduced thermal stress on the module. Their high adhesion and low elasticity contribute to enhanced reliability and durability, even with joint layers thinner than 100 µm.

Impact on the Market

The new technology can potentially halve the size of power units compared to industry standards. This reduction supports better utilization of cabin space in vehicles, enhancing comfort and storage capabilities for consumers.

Presentation at PCIM Europe 2026

This significant advancement was showcased at PCIM Europe 2026, one of the world's largest trade fairs for power electronics, held in Nuremberg, Germany, from June 9 to 11, 2026. This event serves as a platform for industry and academic professionals to exchange the latest technologies, research achievements, and industry trends spanning the entire power semiconductor and module value chain.

Research Collaboration Overview

The Sumitomo Bakelite and Tohoku University joint research lab, launched in January 2025, targets innovations in power modules, power semiconductors, and AI-related devices. They focus on materials development, structural design, process development, performance evaluation, and societal implementation, aiming to accelerate advancements in next-generation power semiconductor technologies.

For inquiries, contact:
Sumitomo Bakelite Co., Ltd.
Information Communication Materials Sales Division
Phone: 03-5462-4015