Yahei Takase

Title: Yahei Takase and His Semiconductor Patents.

Introduction

Yahei Takase is an inventor associated with Itami, Japan, and Mitsubishi Electric Corporation. His work includes patent inventions concerning PNPN semiconductor devices and the control of silicon-controlled rectifiers (SCRs). The supplied information lists 2 patents.

Latest Patents

**Method of Controlling Switching of PNPN Semiconductor Switching Device.** This invention describes controlling an SCR’s turn-off by first reducing its principal current to zero through reversal of the voltage polarity between its main terminals. A reverse gate-bias pulse is applied around the time the anode voltage crosses zero toward the positive direction. A lower-amplitude direct-current gate-bias signal is also applied, which may continue after the pulse and remain active until at least the end of the OFF-state voltage.

**PNPN Semiconductor Device.** This invention describes a device with a cathode base layer, cathode emitter layer, and auxiliary emitter layer on one main face. An auxiliary electrode is placed on the cathode base layer beside the cathode electrode, and a diode is formed in the base layer between the gate and auxiliary electrodes. The diode includes a portion of the cathode base layer and a PN junction arranged to be forward-biased when reverse bias is applied to the gate electrode.

Career Highlights

Takase’s listed patents address semiconductor switching and device structure. Together, they describe approaches to controlling SCR turn-off and configuring a PNPN semiconductor device’s gate and auxiliary-electrode circuitry.

Collaborations

The supplied information identifies Akira Kawakami and Hiroshi Gamo as Takase’s coworkers. It does not specify their roles in the listed inventions.

Conclusion

Yahei Takase’s two listed patents reflect work on PNPN semiconductor technology, with particular attention to SCR switching control and device design.