On June 1, 2026, Japan's Sumitomo Bakelite announced the development of the SUMIKON EME-G785 series of solid epoxy molding compounds for next-generation SiC power modules. The new material combines a high glass transition temperature (Tg) of 230°C with low internal stress—a combination that had been difficult to achieve with conventional epoxy molding compounds.

Why High-Tg Materials Have Been Difficult to Commercialize

SiC power semiconductors are increasingly being adopted in xEVs, data centers, and renewable energy applications because they help reduce power loss. While SiC devices offer excellent heat resistance and can operate at temperatures above 200°C, the encapsulation materials used to protect the modules have faced limitations in heat resistance.

For example, raising the Tg of an epoxy resin above 200°C increases crosslink density and elastic modulus, making the material more susceptible to stress-induced delamination and cracking during thermal cycling. This trade-off has long limited the practical use of high-Tg materials.

Achieving Both High Heat Resistance and Low Stress

The G785 series achieves a Tg of 230°C by increasing the rigidity of the polymer backbone while optimizing crosslink density, up from 195°C in the company's earlier G720 and G780 series.

The material retains its mechanical properties even under high-temperature operating conditions, helping maintain long-term electrical insulation reliability in SiC power modules. It also incorporates the company's latest low-stress technology to limit increases in elastic modulus, reducing module warpage while preventing delamination at chip and substrate interfaces and suppressing resin cracking.

SiC Power Semiconductor Market Projected to Reach ¥1.8749 Trillion by 2035

According to FUJI KEIZAI, a Japanese market research firm, the global power semiconductor market is expected to reach ¥7.3495 trillion by 2035. The forecast appears in the company's 2026 report on the current status and future outlook of markets related to next-generation power devices. Within the global total, the SiC power semiconductor market is projected to expand to ¥1.8749 trillion—approximately five times the 2025 level. As the semiconductor market continues to grow, demand for related materials is also expected to increase, and suppliers are preparing to meet the rising demand.

Resonac, a major supplier of semiconductor materials, offers the CEL-400 series of epoxy molding compounds with a Tg of 175–190°C. Panasonic Industry's CV8540 series, a high-heat-resistance semiconductor encapsulation material based on a new epoxy resin system, achieves a Tg of 185–205°C.

Sumitomo Bakelite positions the G785 series as a strategic product for next-generation power electronics. Mass production has already begun, and the company aims to achieve sales of ¥10 billion in fiscal 2030.