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Toshiba Electronic Devices & Storage Corporation has developed a new silicon carbide (SiC) power module technology for high-frequency inverter applications that delivers lower power losses and enhanced reliability. The technology combines Toshiba’s proprietary Schottky barrier diode (SBD)-embedded SiC MOSFET with an optimized module design to achieve highly reliable and low-loss operation during high-speed switching.
According to simulation results, the new technology can reduce total inverter power losses by approximately 30% during 60 kHz high-frequency operation compared with power modules utilizing conventional SBD-embedded SiC MOSFET structures.
The rapid adoption of artificial intelligence and the continued expansion of data center infrastructure are driving significant increases in electricity consumption. As a result, power systems are under growing pressure to deliver higher efficiency and greater power density. This trend is increasing the importance of power semiconductors capable of operating at higher switching frequencies, particularly in critical applications such as inverters and uninterruptible power supplies (UPS), where both efficiency and compactness are key requirements.
Within this environment, 1200 V-class SiC power modules are expected to play a central role in next-generation power systems. However, further advances in both semiconductor devices and module design are required to fully realize their potential.
Toshiba has previously addressed reliability challenges associated with diode conduction in SiC devices through the development of SBD-embedded SiC MOSFET technology. Conventional structures, however, impose limitations on the layout of channel and SBD regions, making it difficult to simultaneously achieve low on-resistance and high diode reliability. In addition, efforts to reduce total chip area within a power module can improve switching speed but often introduce trade-offs, including higher on-resistance, reduced diode reliability, and compromised thermal performance.
To overcome these challenges, Toshiba developed a new SBD-embedded SiC MOSFET structure that combines a checkerboard-pattern SBD layout with a deep p-type barrier region. By utilizing the electric-field suppression effect of the deep p-type barrier region, the company achieved greater design flexibility and enabled the integrated optimization of multiple device parameters, including the channel, drift layer, JFET region, and gate-drive conditions.
This architecture suppresses localized current concentration, improves current flow through both the channel and drift layer, and enables stable current operation during both on-state and diode conduction modes. As a result, the trade-off between on-resistance and diode reliability is significantly improved.
The new device achieves a specific on-resistance of 1.8 mΩ·cm² at 25°C and 2.7 mΩ·cm² at 150°C, representing approximately a 50% reduction compared with conventional device structures. In addition, SBD current conduction capability per unit area has been increased by approximately 40%.
The newly developed device has been incorporated into a 1200 V-class SiC power module. Through this implementation, Toshiba reduced the total chip area within the module by approximately 36% compared with conventional designs. Despite the reduction in chip area, improvements in device performance, including lower on-resistance and enhanced reliability, enabled lower conduction losses at the module level while maintaining diode reliability.
Toshiba also enhanced the packaging structure and module design through the adoption of a resin-insulated substrate. These improvements reduced thermal resistance per unit area by approximately 25%, improving heat spreading performance and maintaining effective heat dissipation despite the higher thermal density associated with smaller chip dimensions.
The combined device and packaging innovations also contributed to further reductions in switching losses. Simulation results demonstrated that total inverter power losses can be reduced by approximately 30% during 60 kHz high-frequency operation. Additional reductions in switching losses are expected through further optimization of operating conditions, including gate-drive speed.
The company believes the technology will serve as an important platform for achieving higher efficiency and greater miniaturization in power conversion systems, including data center UPS systems, industrial equipment, and renewable energy applications.
Toshiba plans to continue advancing the technology toward practical deployment and mass production while pursuing further improvements in high-frequency operation and overall system performance. The company aims to contribute to higher energy efficiency across power systems and support the development of a more sustainable society.
Original – Toshiba
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Innoscience has announced that China’s Supreme People’s Court has upheld a sales injunction against certain gallium nitride (GaN) products manufactured by Infineon Technologies AG, bringing the patent infringement dispute between the two companies to a final conclusion within China.
The decision follows a ruling issued on May 27 by the Intermediate People’s Court of Suzhou, which determined that specified Infineon GaN products infringed an Innoscience patent related to GaN device technology.
As part of the original judgment, the Suzhou court ordered Infineon to cease the sale, offer for sale, and importation of the products found to infringe the patent within China. The court also awarded damages of RMB 10 million to Innoscience.
Following the ruling, Infineon filed a request for reconsideration with China’s Supreme People’s Court. After reviewing the case, the Supreme People’s Court upheld the lower court’s decision in its entirety, maintaining the injunction and confirming the original judgment.
With the Supreme People’s Court’s ruling, the legal proceedings have reached a final conclusion in China. The decision is now legally effective and enforceable.
As a result, the Infineon GaN products covered by the ruling are prohibited from being sold, offered for sale, or imported into the Chinese market in accordance with the court’s decision.
Original – Innoscience Technology
