Revolutionary G785 Series Solid Epoxy Resin for SiC Power Modules Launched with Record Tg of 230°C

Sumitomo Bakelite Launches G785 Series

Sumitomo Bakelite Co., headquartered in Shinagawa, Tokyo, has officially launched the G785 series of solid epoxy resin encapsulation materials, specifically designed for next-generation silicon carbide (SiC) power modules. This groundbreaking product achieves a glass transition temperature (Tg) of 230°C, making it the first of its kind in the industry. The G785 series excels in both ultra-high heat resistance and low stress properties, key features that greatly enhance the performance and reliability of power modules.

Background of Development: Breaking the Heat Resistance Barrier

As society moves towards carbon neutrality, the adoption of SiC power semiconductors is accelerating across various sectors, including electric vehicles (xEVs), data centers, and renewable energy, due to their ability to significantly reduce power loss. However, while SiC semiconductors can operate at high temperatures (above 200°C), it has been a challenge to find encapsulation materials that provide the necessary heat resistance.

Traditionally, increasing the Tg of epoxy resin above 200°C would lead to higher crosslink density, consequently increasing the elastic modulus (hardness), making delamination and cracking due to stress from thermal cycles more likely. Thus, achieving high Tg materials has been deemed feasible, yet practically challenging.

Technical Features and Breakthroughs of the G785 Series

Superior Heat Resistance

The G785 series achieves an impressive Tg of 230°C by rigidifying the main chain structure of the resin and optimizing crosslink density. This exceptional heat resistance ensures that the physical characteristics of SiC power modules are preserved, even in high-temperature operating environments, thereby securing long-term insulation reliability.

Resolving Trade-offs Between High Tg and Low Stress

Typically, the challenge of increasing the Tg of epoxy resin has been its correlation with rising elastic modulus. However, the G785 series employs cutting-edge low-stress technology, preventing increases in elastic modulus and achieving reduced stress. This minimizes internal distortion within the power module and prevents delamination of chips and substrates as well as cracking of the resin itself. The G785 series epitomizes the ideal properties of modern power modules—being both rigid and flexible—thus providing advanced mounting reliability.

Contributing to the Miniaturization and High Output of Next-Generation Devices

Due to its high heat resistance, the G785 series allows for the bonding of cooling units using sintering materials or solder, enhancing heat dissipation. As a result, it enables the miniaturization (higher power density) of power modules, allowing SiC chips to realize their full potential.

Feature	Unit	G720 Series	G780 Series	G785 Series
-	-	-	-	---
Status	-	Mass Production	Mass Production	Mass Production Started
Tg	°C	195	195	230
Weight Reduction at 250°C for 1000hr	%	>2	>2	>2

Future Prospects

Sumitomo Bakelite positions the G785 series as a strategic product for next-generation power electronics, targeting 10 billion yen in sales by the fiscal year 2030. The company is committed to supporting structural innovations in power modules through material development, contributing to energy conservation across various fields.

For inquiries regarding this matter:
Contact: Sumitomo Bakelite Co., Ltd. Power Electronics Solution Development Department
Phone: 03-5462-4015
Inquiry Form: https://inquiry.sumibe.co.jp/m/j_pes