公开(公告)号：US20190115465A1

公开(公告)日：2019-04-18

申请号：US16025656

申请日：2018-07-02

Applicant: HITACHI, LTD.

Inventor： Kumiko KONISHI ,  Ryuusei FUJITA ,  Kazuki TANI ,  Akio SHIMA

IPC: H01L29/78 ,  H01L29/16

CPC classification number: H01L29/7805 ,  H01L29/1095 ,  H01L29/1608 ,  H01L29/66068

Abstract: Provided is a silicon carbide semiconductor device in which SiC-MOSFETs are formed within an active region of an n-type silicon carbide semiconductor substrate, and a p+-type semiconductor region is formed on an upper surface of an epitaxial layer so as to surround the active region.

公开(公告)号：US20210021227A1

公开(公告)日：2021-01-21

申请号：US16629328

申请日：2018-03-05

Applicant: Hitachi, Ltd.

Inventor： Yoshinobu KIMURA ,  Kazuki TANI ,  Takashi OGAWA ,  Hiroshi SUZUKI ,  Junichi SAKANO

IPC: H02P29/68 ,  H02P27/08

Abstract: A temperature abnormality of the power module is accurately detected. A power conversion device including a power semiconductor module with a switching element, includes: a gate driver circuit configured to drive a switching element and transmitting a response signal upon a switching operation of the switching element; a control unit device configured to output to a gate driver circuit an instruction signal for switching; a temperature detection unit configured to calculate a bonding temperature of the switching element based on a response signal to the instruction signal; and a calculation unit configured to determine a state of a power semiconductor module according to a bonding temperature calculated by the temperature detection unit and the response signal.

公开(公告)号：US20170082877A1

公开(公告)日：2017-03-23

申请号：US15311434

申请日：2014-06-19

Applicant: HITACHI, LTD.

Inventor： Hideo ARIMOTO ,  Kazuki TANI ,  Takashi TAKAHAMA ,  Daisuke RYUZAKI ,  Yoshitaka SASAGO

IPC: G02F1/025 ,  G02F1/225

CPC classification number: G02F1/025 ,  G02F1/2257 ,  G02F2001/0151 ,  G02F2001/212 ,  G02F2202/104

Abstract: In an optical modulator 115 of an embodiment, an optical waveguide core 121 is configured from an n− type semiconductor region 134, a gate insulating film 136 on the n− type semiconductor region 134, and a p− type semiconductor region 137 on the gate insulating film 136. Further, a width W1 of the n− type semiconductor region 134 and a width W1 of the p− type semiconductor region 137 are equally formed and are layered without being shifted. Therefore, an optical modulator having stable optical characteristics can be provided.

公开(公告)号：US20190310322A1

公开(公告)日：2019-10-10

申请号：US16360046

申请日：2019-03-21

Applicant: Hitachi, Ltd.

Inventor： Kazuki TANI ,  Yoshinobu KIMURA ,  Takashi OGAWA

IPC: G01R31/40 ,  H02M7/5395 ,  H02M1/088

Abstract: A power converter is provided with a power semiconductor module having a switching element. The power converter includes a gate drive circuit, a first detection unit, a second detection unit, a time measuring unit, and an abnormality diagnostic unit. The gate drive circuit drives the switching element and outputs a feedback signal based on a switching operation of the switching element. The first detection unit detects a change in a feedback signal of an upper arm of the power converter. The second detection unit detects a change in a feedback signal of a lower arm of the power converter. The time measuring unit measures a difference between detection timings of a signal change by the first detection unit and a signal change by the second detection unit. The abnormality diagnostic unit performs diagnosis of the power converter based on a measurement result by the time measuring unit.