Youichi Ishimura

Low turn-off switching energy 1200 V IGBT module

A new 5th generation IGBT module with low turn-off energy has been developed. The module utilizes IGBT chips optimized for high frequency industrial power supplies in applications such as X-ray, MRI (magnetic resonance imaging), and induction heating. This technology is designed to provide a simplified cost effective alternative to parallel discrete MOSFETs in these applications.

A high performance IGBT with new n+buffer structure

An advanced IGBT with a new n+buffer structure has been developed. The new n+buffer structure is that some n+buried layers are formed at the boundary between a p+substrate and a n+buffer layer. The concentration of the n+buried layers is almost the same as that of the p+substrate. The fabrication of the IGBT with the new n+buffer structure used a 3rd gen 600 V/100 A chip. Taking the VVVF inverter as an application, total power loss generated was about 12% less compared to the conventional IGBT, only changing the n+buffer structure. And the short circuit safe operating area of the new IGBT was almost similar to the conventional IGBT. Moreover, we discussed differences between the new IGBT and the conventional IGBT using a 3D simulator, DAVINCI.

A 1700 V LPT-CSTBT with low loss and high durability

This paper describes a new 1700 V power device based on a wide cell pitch carrier stored trench bipolar transistor (CSTBT). The new chip also utilizes a light punch through (LPT) vertical structure that is produced using low cost single crystal (nonepitaxial) wafer material. The device is optimized to provide the best trade-off between losses and ruggedness for industrial power conversion applications. A new gate process that enhances the reliability of the gate isolation film is another key technology utilized in the development of this device. The new 1700 V device demonstrates the successful extension of technologies previously used for 1200 V CSTBT devices to higher blocking voltages.