Kabushiki Kaisha Toshiba

Tokyo Shibaura Electric Co., Ltd.

Tokyo Shibaura Denki Kabushiki Kaisha

Minami Takeuchi

Akio Nakagawa

Takashi Shinohe

Ichiro Omura

Mitsuhiko Kitagawa

Masakazu Yamaguchi

Kazuya Nakayama

Katsuhiko Takigami

Yoshio Kamei

Minoru Kuriki

Disclosed herein is an insulated-gate thyristor comprising a base layer of a first conductivity type, having first and second major surfaces, a first main-electrode region of the first conductivity type, formed in the first major surface of the base layer, a second main-electrode region of a second conductivity type, formed in the second major surface of the base layer, at least a pair of grooves extending from the first main-electrode region into the base layer, and opposing each other and spaced apart by a predetermined distance, insulated gate electrodes formed within the grooves, and a turn-off insulated-gate transistor structure for releasing carriers of the second conductivity type from the base layer.

Insulated-gate thyristor

A drive circuit for a voltage-controlled type semiconductor device is provided which comprises ON gate drive circuit for supplying an ON control signal to a control electrode of the semiconductor device which performs a current switching, OFF gate drive circuit for supplying an OFF control signal to the control electrode of the semiconductor device, high voltage power source, connected to at least one of the ON gate drive circuit and OFF gate drive circuit, for supplying a control current of a predetermined current increase rate to the control electrode of the semiconductor device through at least one of the ON gate drive circuit and OFF gate drive circuit, low voltage power source, provided in juxtaposition with the high voltage power source, for supplying, to the control electrode, enough control current to hold the semiconductor device in a normal state, and switch for supplying an output of the high voltage power source to the control electrode in an earlier portion of a turn ON or a turn OFF period, and an output of the low voltage power source to the control electrode in a normally ON or a normally OFF state.

Drive circuit for a semiconductor device with high voltage for turn-on

A protecting device includes a discriminating circuit and a protecting circuit. The GTO thyristor is operated in such a manner that a carrier storing is completed from a first time point at which the supply of a negative gate current is started to a second time point, an anode-cathode voltage increases from the second time point to a third time point and decreases from the third time point to a fourth time point, and increases again from the fourth time point. The discriminating circuit includes a circuit for obtaining an amount of change between the anode-cathode voltages at the third and fourth time points, a circuit for obtaining a ratio of the amount of change to the anode-cathode voltage at the third time point, and a comparing circuit for producing a control signal when the ratio is smaller than a given value. The protecting circuit, when receiving the control signal, stops the conduction of the GTO thyristor. It is judged whether or not the GTO thyristor is operated at a critical point to its break-down.

Protecting device for a gate turn-off thyristor

A reverse conducting thyristor includes a thyristor section, a diode section and a semiconductor separator section for electrically separating both the sections. The thyristor section includes: a first region of first conductivity type, a second region of a second conductivity type, a third region of the first conductivity type, a main emitter region of the second conductivity type, an auxiliary emitter region formed, with intervention of the exposed portion of said third region, facing at least a part of the periphery of said main emitter region which does not contact the separate section and a cathode electrode, an auxiliary gate electrode contacting the auxiliary emitter region and enclosing, with intervention of the exposed portion of the third region, at least a part of the periphery of said main emitter region which does not contact the separate section, and a main gate electrode formed on the exposure surface of the third region contacting the side wall of the auxiliary emitter region which does not face the main emitter region. The respective components are successively layered on a first electrode acting as an anode electrode. The diode section includes a fourth region of the second conductivity type formed on the first or anode electrode, a fifth region of the first conductivity type formed on the fourth region, and a second electrode formed on the fifth region and connected to the cathode electrode. The separate section includes a sixth region formed on the first electrode and of the first conductivity type, a seventh region formed on the sixth region and of the second conductivity type and an eighth region formed on the seventh region and of the first conductivity type. The resistance values of the semiconductor layers between the cathode electrode and the second electrode and between the cathode electrode and the auxiliary gate electrode are each 2 to 18 Ohms.

Reverse conducting thyristor with specific resistor structures between

A reverse conducting thyristor comprises a thyristor section, a diode section and a separator section. The three sections are integrally formed into a cylindrical body. The thyristor section is constituted by a first region of a first conductivity type, a second region of the second conductivity type, a third region of the first conductivity type, a main emitter region of the second conductivity type, a cathode electrode, an auxiliary emitter region, an auxiliary gate electrode and a main gate electrode. The first region is formed on a first electrode, the second region on the first region, and the third region on the second region. The main emitter region is so formed in the third region as to have its surface on the same level with that of the third region. The auxiliary emitter region is similarly formed in the third region and faces at least a part of that periphery of the main emitter region which does not contact the separator section. The cathode electrode is formed on the main emitter region. The auxiliary gate electrode is formed partly on the third region and partly on the auxiliary emitter region and is arched concentrically with the cylindrical body so as to surround at least a part of said periphery of the main emitter region. The main gate electrode is formed on that surface portion of the third region which is adjacent to that lateral surface of the auxiliary emitter region which does not face the main emitter region. The diode section comprises a fourth region of the second conductivity type, a fifth region of the first conductivity type and a second electrode. The fourth region is formed on the first electrode, the fifth region on the fourth region, and the second electrode on the fifth region. The separator section is a plate which is constituted by a sixth region of the first conductivity type, a seventh region of the second conductivity type and an eight region of the first conductivity type. The sixth region is formed on the first electrode, the seventh region on the sixth region, and the eighth region on the seventh region.

Growing community of inventors

Tokyo, Japan

Minami Takeuchi