Patents by Inventor Yuu YAMAHIRA

Yuu YAMAHIRA 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).

  • Publication number: 20200036297
    Abstract: In a power converter, a control circuit has a speed adjustment resistor that limits a control current to adjust a switching speed of each of first and second switching elements. The speed adjustment resistor has a resistance that varies depending on a voltage at the control electrode of each of the first and second switching elements. A feedback route connects between the control electrode of the first switching element and the control electrode of the second switching element. The feedback route has a resistance that is set to be lower than a value of the resistance of the speed adjustment resistor during a predetermined Miller period of each of the first and second switching elements.
    Type: Application
    Filed: July 30, 2019
    Publication date: January 30, 2020
    Applicant: DENSO CORPORATION
    Inventors: Yuu YAMAHIRA, Tetsuya MATSUOKA, Kazuma FUKUSHIMA, Akifumi ARARAGI, Noriyuki KAKIMOTO, Masakiyo SUMITOMO
  • Patent number: 10469020
    Abstract: A power conversion apparatus includes a power conversion circuit and a control unit. The power conversion circuit converts electric power supplied from a power supply and outputs the converted electric power. The control unit controls the power conversion circuit. The power conversion circuit has at least one phase that is configured as a parallel-connection phase in which two semiconductor elements are connected in parallel to each other in each of an upper arm connected to a high potential-side wiring of the power supply and a lower arm connected to a low potential-side wiring of the power supply. The control unit detects temperature information related to element temperatures of all of the plurality of semiconductor elements of a target arm that is either of the upper arm and the lower arm of the parallel-connection phase, and performs overheating protection control of the power conversion circuit based on the detected temperature information.
    Type: Grant
    Filed: April 24, 2017
    Date of Patent: November 5, 2019
    Assignees: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tomohisa Sano, Yuu Yamahira, Yoshihito Mizuno
  • Patent number: 10454386
    Abstract: A plurality of semiconductor elements and a control circuit unit are provided. The plurality of semiconductor elements which are connected in parallel are configured to perform switching at the same time. The control circuit unit includes a drive circuit connected to the plurality of semiconductor elements which perform operation at the same time, control wirings and reference wirings. The control wirings connect control electrodes of the semiconductor elements to the drive circuit. The reference wirings connect reference electrodes of the semiconductor elements to the drive circuit. A parasitic inductance in the reference wiring is made smaller than a parasitic inductance in the control wiring.
    Type: Grant
    Filed: March 10, 2017
    Date of Patent: October 22, 2019
    Assignee: DENSO CORPORATION
    Inventors: Tomoya Miura, Yuu Yamahira, Kazuma Fukushima
  • Patent number: 10424570
    Abstract: A power conversion apparatus performs power conversion. The power conversion apparatus includes a semiconductor module and a cooler. The semiconductor module includes an insulated-gate bipolar transistor, a metal-oxide-semiconductor field-effect transistor, and a lead frame. The insulated-gate bipolar transistor and the metal-oxide-semiconductor field-effect transistor are connected in parallel to each other and provided on the same lead frame. The cooler has a coolant flow passage. The coolant flow passage extends such that the coolant flow passage and the lead frame of the semiconductor module are opposed to each other. The semiconductor module is configured such that the metal-oxide-semiconductor field-effect transistor is not disposed further downstream than the insulated-gate bipolar transistor in a flow direction of a coolant in the coolant flow passage of the cooler.
    Type: Grant
    Filed: April 17, 2017
    Date of Patent: September 24, 2019
    Assignee: DENSO CORPORATION
    Inventors: Mitsunori Kimura, Hiroshi Shimizu, Kengo Mochiki, Yasuyuki Ohkouchi, Yuu Yamahira, Tetsuya Matsuoka, Kazuma Fukushima
  • Patent number: 10396651
    Abstract: A power conversion apparatus includes a semiconductor module including a semiconductor device and a control circuit unit controlling the semiconductor module. The semiconductor module has main and subsidiary semiconductor devices connected in parallel. The control circuit unit performs control such that the subsidiary semiconductor device is turned on after the main semiconductor device is turned on, and the main semiconductor device is turned off after the subsidiary semiconductor device is turned off. The control circuit unit performs control such that, one of the turn-on and turn-off switching timings has a switching speed faster than that of the other of the switching timings. The semiconductor module is configured such that, at a high-speed switching timing, an induction current directed to turn off the subsidiary semiconductor device is generated in a control terminal of the subsidiary semiconductor device depending on temporal change of a main current flowing to the main semiconductor device.
    Type: Grant
    Filed: July 26, 2018
    Date of Patent: August 27, 2019
    Assignee: DENSO CORPORATION
    Inventors: Kengo Mochiki, Mitsunori Kimura, Hiroshi Shimizu, Yasuyuki Ohkouchi, Yuu Yamahira, Tetsuya Matsuoka, Kazuma Fukushima
  • Patent number: 10305466
    Abstract: A semiconductor module including a semiconductor element, a controller, a cooler, and a temperature sensor are included. The controller is connected to the semiconductor module and controls switching operation of the semiconductor element. The temperature sensor measures a coolant temperature, which is a temperature of the coolant. The controller controls turn-off speed of the semiconductor element based on the coolant temperature. The controller increases the turn-off speed as the coolant temperature rises.
    Type: Grant
    Filed: February 21, 2017
    Date of Patent: May 28, 2019
    Assignee: DENSO CORPORATION
    Inventor: Yuu Yamahira
  • Patent number: 10291149
    Abstract: A power converter is provided with semiconductor devices, a capacitor, a positive bus bar, and a negative bus bar. The negative bus bar includes a negative side body and a plurality of negative side branches. The negative side branches include an interposed negative side branch interposed between two positive side branches connected to the upper arm semiconductor devices that belong to the same semiconductor device group as the lower arm semiconductor devices connected to the negative side branches, and include an end negative side branch that is not interposed between two positive side branches. The self-inductance of the end negative side branch is smaller than the self-inductance of the interposed negative side branch.
    Type: Grant
    Filed: November 4, 2016
    Date of Patent: May 14, 2019
    Assignee: DENSO CORPORATION
    Inventors: Kengo Mochiki, Yuu Yamahira, Tomohisa Sano, Yohei Kondo
  • Publication number: 20190123657
    Abstract: A plurality of semiconductor elements and a control circuit unit are provided. The plurality of semiconductor elements which are connected in parallel are configured to perform switching at the same time. The control circuit unit includes a drive circuit connected to the plurality of semiconductor elements which perform operation at the same time, control wirings and reference wirings. The control wirings connect control electrodes of the semiconductor elements to the drive circuit. The reference wirings connect reference electrodes of the semiconductor elements to the drive circuit. A parasitic inductance in the reference wiring is made smaller than a parasitic inductance in the control wiring.
    Type: Application
    Filed: March 10, 2017
    Publication date: April 25, 2019
    Applicant: DENSO CORPORATION
    Inventors: Tomoya MIURA, Yuu YAMAHIRA, Kazuma FUKUSHIMA
  • Publication number: 20190013744
    Abstract: A power converter is provided with semiconductor devices, a capacitor, a positive bus bar, and a negative bus bar. The negative bus bar includes a negative side body and a plurality of negative side branches. The negative side branches include an interposed negative side branch interposed between two positive side branches connected to the upper arm semiconductor devices that belong to the same semiconductor device group as the lower arm semiconductor devices connected to the negative side branches, and include an end negative side branch that is not interposed between two positive side branches. The self-inductance of the end negative side branch is smaller than the self-inductance of the interposed negative side branch.
    Type: Application
    Filed: November 4, 2016
    Publication date: January 10, 2019
    Applicant: DENSO CORPORATION
    Inventors: Kengo MOCHIKI, Yuu YAMAHIRA, Tomohisa SANO, Yohei KONDO
  • Publication number: 20180331617
    Abstract: A power conversion apparatus includes a semiconductor module including a semiconductor device and a control circuit unit controlling the semiconductor module. The semiconductor module has main and subsidiary semiconductor devices connected in parallel. The control circuit unit performs control such that the subsidiary semiconductor device is turned on after the main semiconductor device is turned on, and the main semiconductor device is turned off after the subsidiary semiconductor device is turned off. The control circuit unit performs control such that, one of the turn-on and turn-off switching timings has a switching speed faster than that of the other of the switching timings. The semiconductor module is configured such that, at a high-speed switching timing, an induction current directed to turn off the subsidiary semiconductor device is generated in a control terminal of the subsidiary semiconductor device depending on temporal change of a main current flowing to the main semiconductor device.
    Type: Application
    Filed: July 26, 2018
    Publication date: November 15, 2018
    Applicant: DENSO CORPORATION
    Inventors: Kengo MOCHIKI, Mitsunori KIMURA, Hiroshi SHIMIZU, Yasuyuki OHKOUCHI, Yuu YAMAHIRA, Tetsuya MATSUOKA, Kazuma FUKUSHIMA
  • Patent number: 10116213
    Abstract: A semiconductor module includes an IGBT and a MOSFET. The IGBT is made of a silicon semiconductor. The MOSFET is made of a wide-bandgap semiconductor having a wider bandgap than the silicon semiconductor. The IGBT and the MOSFET are connected in parallel to each other to form a semiconductor element pair. The IGBT has a greater surface area than the MOSFET. The semiconductor module is configured to operate in a region that includes a low-current region and a high-current region. Electric current flowing through the semiconductor element pair is higher in the high-current region than in the low-current region. In the low-current region, the on-resistance of the MOSFET is lower than the on-resistance of the IGBT. In contrast, in the high-current region, the on-resistance of the IGBT is lower than the on-resistance of the MOSFET.
    Type: Grant
    Filed: April 19, 2017
    Date of Patent: October 30, 2018
    Assignee: DENSO CORPORATION
    Inventors: Hiroshi Shimizu, Mitsunori Kimura, Kengo Mochiki, Yuu Yamahira, Tetsuya Matsuoka, Kazuma Fukushima, Yasuyuki Ohkouchi
  • Patent number: 10103723
    Abstract: In a driving apparatus for switches connected in parallel to each other, drivers respectively turn on or off the switches. A temperature obtainer obtains a value of a temperature parameter correlating with a temperature of at least one of the first and second switches. A selector selects at least one of the switches as at least one drive target switch. A driver causes at least one of the drivers to turn on the at least one drive target switch during an on duration and thereafter turn off the at least one drive target switch in each target switching cycle. The selector adjusts the number of the selected at least one drive target switch based on the value of the temperature parameter.
    Type: Grant
    Filed: November 16, 2017
    Date of Patent: October 16, 2018
    Assignee: DENSO CORPORATION
    Inventors: Hiroshi Shimizu, Kengo Mochiki, Yuu Yamahira, Tetsuya Matsuoka, Kazuma Fukushima, Mitsunori Kimura, Yasuyuki Ohkouchi
  • Patent number: 10090761
    Abstract: A power conversion apparatus includes a first semiconductor element pair that includes a MOSFET made of wide bandgap semiconductor material and a wide bandgap diode made of wide bandgap semiconductor material which is reverse parallel-connected to the MOSFET, a second semiconductor element pair that includes an IGBT made of silicon semiconductor material and a silicon diode made of silicon semiconductor material which is reverse parallel-connected to the IGBT, and a control circuit section for controlling switching operation of the MOSFET and the IGBT. The first and second semiconductor element pairs are connected in series to each other.
    Type: Grant
    Filed: April 18, 2017
    Date of Patent: October 2, 2018
    Assignee: DENSO CORPORATION
    Inventors: Hiroshi Shimizu, Mitsunori Kimura, Kengo Mochiki, Yuu Yamahira, Tetsuya Matsuoka, Kazuma Fukushima, Yasuyuki Ohkouchi
  • Patent number: 10050512
    Abstract: A power conversion apparatus includes a semiconductor module including a semiconductor device and a control circuit unit controlling the semiconductor module. The semiconductor module has main and subsidiary semiconductor devices connected in parallel. The control circuit unit performs control such that the subsidiary semiconductor device is turned on after the main semiconductor device is turned on, and the main semiconductor device is turned off after the subsidiary semiconductor device is turned off. The control circuit unit performs control such that, one of the turn-on and turn-off switching timings has a switching speed faster than that of the other of the switching timings. The semiconductor module is configured such that, at a high-speed switching timing, an induction current directed to turn off the subsidiary semiconductor device is generated in a control terminal of the subsidiary semiconductor device depending on temporal change of a main current flowing to the main semiconductor device.
    Type: Grant
    Filed: April 19, 2017
    Date of Patent: August 14, 2018
    Assignee: DENSO CORPORATION
    Inventors: Kengo Mochiki, Mitsunori Kimura, Hiroshi Shimizu, Yasuyuki Ohkouchi, Yuu Yamahira, Tetsuya Matsuoka, Kazuma Fukushima
  • Publication number: 20180145672
    Abstract: In a driving apparatus for switches connected in parallel to each other, drivers respectively turn on or off the switches. A temperature obtainer obtains a value of a temperature parameter correlating with a temperature of at least one of the first and second switches. A selector selects at least one of the switches as at least one drive target switch. A driver causes at least one of the drivers to turn on the at least one drive target switch during an on duration and thereafter turn off the at least one drive target switch in each target switching cycle. The selector adjusts the number of the selected at least one drive target switch based on the value of the temperature parameter.
    Type: Application
    Filed: November 16, 2017
    Publication date: May 24, 2018
    Applicant: DENSO CORPORATION
    Inventors: Hiroshi SHIMIZU, Kengo MOCHIKI, Yuu YAMAHIRA, Tetsuya MATSUOKA, Kazuma FUKUSHIMA, Mitsunori KIMURA, Yasuyuki OHKOUCHI
  • Publication number: 20180041107
    Abstract: The semiconductor device is provided with a plurality of switching elements connected in parallel to each other, and a plurality of recirculation element connected in parallel to the aforementioned plurality of switching elements. An emitter electrode serves as a reference potential of the aforementioned plurality of switching elements and an anode electrode serves as a reference potential of the aforementioned plurality of recirculation elements are electrically connected by the same plate-like member consisting of a conductive material. The aforementioned switching elements and the aforementioned recirculation elements which are connected in parallel on the lowest potential side are constituted so that the distance from the emitter terminal connected to the aforementioned emitter electrode to the aforementioned recirculation element becomes no greater than the distance from the aforementioned emitter terminal.
    Type: Application
    Filed: August 2, 2017
    Publication date: February 8, 2018
    Applicant: DENSO CORPORATION
    Inventors: Yuu YAMAHIRA, Tetsuya MATSUOKA
  • Patent number: 9881852
    Abstract: A semiconductor module of an electric power converter includes an IGBT and a MOSFET which are connected in parallel to each other and provided on the same lead frame, either one of the IGBT and the MOSFET is a first switching element and the remaining one is a second switching element, and the conduction path of the second switching element is disposed at a position that is separated from a conduction path of the first switching element in the same lead frame.
    Type: Grant
    Filed: April 19, 2017
    Date of Patent: January 30, 2018
    Assignee: DENSO CORPORATION
    Inventors: Mitsunori Kimura, Hiroshi Shimizu, Kengo Mochiki, Yasuyuki Ohkouchi, Yuu Yamahira, Tetsuya Matsuoka, Kazuma Fukushima
  • Publication number: 20170310270
    Abstract: A power conversion apparatus includes a power conversion circuit and a control unit. The power conversion circuit converts electric power supplied from a power supply and outputs the converted electric power. The control unit controls the power conversion circuit. The power conversion circuit has at least one phase that is configured as a parallel-connection phase in which two semiconductor elements are connected in parallel to each other in each of an upper arm connected to a high potential-side wiring of the power supply and a lower arm connected to a low potential-side wiring of the power supply. The control unit detects temperature information related to element temperatures of all of the plurality of semiconductor elements of a target arm that is either of the upper arm and the lower arm of the parallel-connection phase, and performs overheating protection control of the power conversion circuit based on the detected temperature information.
    Type: Application
    Filed: April 24, 2017
    Publication date: October 26, 2017
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tomohisa SANO, Yuu YAMAHIRA, Yoshihito MIZUNO
  • Publication number: 20170302153
    Abstract: A power conversion apparatus includes a semiconductor module including a semiconductor device and a control circuit unit controlling the semiconductor module. The semiconductor module has main and subsidiary semiconductor devices connected in parallel. The control circuit unit performs control such that the subsidiary semiconductor device is turned on after the main semiconductor device is turned on, and the main semiconductor device is turned off after the subsidiary semiconductor device is turned off. The control circuit unit performs control such that, one of the turn-on and turn-off switching timings has a switching speed faster than that of the other of the switching timings. The semiconductor module is configured such that, at a high-speed switching timing, an induction current directed to turn off the subsidiary semiconductor device is generated in a control terminal of the subsidiary semiconductor device depending on temporal change of a main current flowing to the main semiconductor device.
    Type: Application
    Filed: April 19, 2017
    Publication date: October 19, 2017
    Applicant: DENSO CORPORATION
    Inventors: Kengo MOCHIKI, Mitsunori KIMURA, Hiroshi SHIMIZU, Yasuyuki OHKOUCHI, Yuu YAMAHIRA, Tetsuya MATSUOKA, Kazuma FUKUSHIMA
  • Publication number: 20170301662
    Abstract: A power conversion apparatus performs power conversion. The power conversion apparatus includes a semiconductor module and a cooler. The semiconductor module includes an insulated-gate bipolar transistor, a metal-oxide-semiconductor field-effect transistor, and a lead frame. The insulated-gate bipolar transistor and the metal-oxide-semiconductor field-effect transistor are connected in parallel to each other and provided on the same lead frame. The cooler has a coolant flow passage. The coolant flow passage extends such that the coolant flow passage and the lead frame of the semiconductor module are opposed to each other. The semiconductor module is configured such that the metal-oxide-semiconductor field-effect transistor is not disposed further downstream than the insulated-gate bipolar transistor in a flow direction of a coolant in the coolant flow passage of the cooler.
    Type: Application
    Filed: April 17, 2017
    Publication date: October 19, 2017
    Applicant: DENSO CORPORATION
    Inventors: Mitsunori KIMURA, Hiroshi SHIMIZU, Kengo MOCHIKI, Yasuyuki OHKOUCHI, Yuu YAMAHIRA, Tetsuya MATSUOKA, Kazuma FUKUSHIMA