Mitsubishi Electric to add high-isolation XB HVIGBT modules

New RFC diode and CSTBT1 design shrinks chip edge 30% and cuts switching loss 5% for rail and industrial inverters.

Mitsubishi Electric Corp. said it will launch new standard-isolation (6.0 kVrms) and high-isolation (10.2 kVrms) modules for its 4.5 kV, 1,200A XB Series high-voltage insulated-gate bipolar transistors on Dec. 9. The high-capacity power semiconductors are designed to improve moisture resistance for inverters used in large industrial equipment, including railcars, operating in outdoor and other varied environments. Mitsubishi Electric plans to showcase the modules at the 40th Nepcon Japan R&D and Manufacturing show in Tokyo from Jan. 21-23, 2026, and at additional exhibitions in North America, Europe, China and India.

The new modules use IGBT elements that incorporate Mitsubishi Electric’s proprietary relaxed field of cathode (RFC) diode and carrier-stored trench-gate bipolar transistor (CSTBT¹) structure. New structures for electric field relaxation² and surface charge control³ enabled Mitsubishi Electric to reduce the chip’s termination region size by about 30% while also achieving about 20 times⁴ greater moisture resistance than existing products. In addition, the module reduces total switching loss by approximately 5%⁵ compared to previous models, and reverse-recovery safe-operating area (RRSOA) tolerance is about 2.5 times⁶ greater than that of compared to previous models.

As a result of improving the efficiency and reliability of inverters in large industrial equipment operating in environments where conditions can vary, such as outdoors, the modules will contribute to carbon neutrality.

For more information, visit mitsubishielectric.com.

^{1 Proprietary IGBT structure utilizing the carrier storage effect.}

^{2 Proprietary structure with optimally arranged p-type semiconductor regions that gradually widen the spacing.}

^{3 Proprietary structure where the semi-insulating film is in direct contact with the semiconductor region, ensuring stable charge dissipation.}

^{4 Results of the condensation resistance verification test for XB Series and existing H Series products with a voltage rating of 3.3kV (Termination design is identical at 3.3kV and 4.5kV).}

^{5 Comparison with legacy CM1200HC-90R in terms of Eon+Eoff+Erec at Tj=125°C, VCC=2,800V, and IC=1,200A.}

^{6 Comparison with legacy CM1200HC-90R in terms of Prr, which is the product of VCE and Irr in the RRSOA.}