Patents by Inventor Nozomu Sennenbara

Nozomu Sennenbara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5574297
    Abstract: In order to compatibly implement improvement in withstand voltage and ON-state resistance as well as reduction in turnon loss and improvement in di/dt resistance, an n buffer layer (12) is locally exposed on a lower surface of a semiconductor substrate (160), while a polysilicon additional resistive layer (104) is formed to cover the exposed surface. An anode electrode (101) covering the lower surface of the semiconductor substrate (160) is connected to a p emitter layer (11) and the additional resistive layer (104). Thus, the n buffer layer (12) and the anode electrode (101) are connected with each other through the additional resistive layer (104), whereby a gate trigger current is reduced. Thus, turnon loss is reduced and di/dt resistance is increased. At the same time, the withstand voltage and the ON-state resistance are excellent due to provision of the n buffer layer (12).
    Type: Grant
    Filed: March 21, 1995
    Date of Patent: November 12, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Nozomu Sennenbara, Kouji Niinobu, Kazuhiko Niwayama, Futoshi Tokunoh