Patents by Inventor Akio Iwabuchi

Akio Iwabuchi 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: 9293570
    Abstract: The operation of a HEMT is monitored on an on-chip basis without increasing the power consumption rate. In a semiconductor device 10, an electron supply layer 12 is formed on a channel layer 11. A two-dimensional electron gas (2DEG) layer 13 is formed at the side of the channel layer of the hetero-junction interface. Electrons flow through the 2DEG layer 13 between a source electrode 14 formed on the surface of the electron supply layer 12 and a drain electrode 15 that is formed on the same surface. A potential detection electrode 17 is arranged on the electron supply layer 12 between the gate electrode 16 and the source electrode 14. A resistor 18 having a sufficiently high resistance value makes the electric current flowing to the potential detection electrode 17 negligible relative to the drain current in operation.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: March 22, 2016
    Assignee: SANKEN ELECTRIC CO., LTD.
    Inventors: Akio Iwabuchi, Hironori Aoki
  • Patent number: 9153682
    Abstract: A semiconductor device protects against concentration of electric current at a front end portion of one of the electrodes thereof. The semiconductor device includes a substrate, a compound semiconductor layer formed on the substrate and having a channel layer based on a hetero junction, a first main electrode formed on the compound semiconductor layer, a second main electrode formed on the compound semiconductor surrounding the first main electrode and having a linear region and an arc-shaped region, a control electrode formed on the compound semiconductor layer and disposed opposite to the first main electrode and the second main electrode, an electric current being made to flow between the first main electrode and the second main electrode, and an electric current limiting section formed between the first main electrode and the arc-shaped region of the second main electrode.
    Type: Grant
    Filed: August 8, 2013
    Date of Patent: October 6, 2015
    Assignee: SANKEN ELECTRIC CO., LTD.
    Inventors: Akio Iwabuchi, Hironori Aoki
  • Patent number: 9093432
    Abstract: A semiconductor device is free from degradation of characteristics attributable to a manufacturing process thereof and its characteristics are hardly affected by changes in electric potentials of bonding pads. The semiconductor device 10 includes an active region 12, a first insulating layer 13 covering the active region 12, a floating conductor 14 formed on the first insulating layer 13, a second insulating layer 15 formed on the first insulating layer 13 and the floating conductor 14, a bonding pad 18 formed on the second insulating layer 17 and interconnection vias 19, 20 for electrically connecting the active region 12 and the bonding pad 18.
    Type: Grant
    Filed: September 23, 2011
    Date of Patent: July 28, 2015
    Assignee: SANKEN ELECTRIC CO., LTD.
    Inventors: Akio Iwabuchi, Hironori Aoki
  • Patent number: 9025348
    Abstract: A drive circuit drives a normally-on high-side switch Q1 and a normally-off low-side switch Q2 that form a series circuit connected in parallel with a DC power source. The drive circuit includes a controller 10 that outputs a control signal to turn on/off the high- and low-side switches, a rectifier D2 having a first end connected to a connection point of the high- and low-side switches, a capacitor C2 that is connected to a second end of the rectifier and a first end of the DC power source and serves as a power source for the controller, and a driver (A1, AND1, Q3, Q4) that turns on/off the high- and low-side switches according to the control signal from the controller and a voltage from the capacitor.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: May 5, 2015
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Keiichiro Ozawa, Akio Iwabuchi, Yasushi Tasaka, Ryuichi Furukoshi
  • Patent number: 8823061
    Abstract: A semiconductor device includes: a first semiconductor layer; a second semiconductor layer; a two-dimensional carrier gas layer; a source electrode; a drain electrode; a gate electrode; and an auxiliary electrode located above the two-dimensional carrier gas layer between the gate electrode and the drain electrode. Channel resistance of the two-dimensional carrier gas layer between the gate electrode and the auxiliary electrode is set higher than channel resistance of the two-dimensional carrier gas layer between the gate electrode and the source electrode.
    Type: Grant
    Filed: August 16, 2011
    Date of Patent: September 2, 2014
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Akio Iwabuchi, Hironori Aoki
  • Patent number: 8642447
    Abstract: A method of manufacturing a semiconductor device includes preparing a semiconductor wafer including a silicon substrate and a laminate having a compound semiconductor layer; etching and removing a part of the laminate in a thickness direction to form trench regions in a grid, each trench region including a plurality of stripe grooves extending in parallel to each other; filling the groove with a material having a lower hardness than the compound semiconductor layer to form a buried region; and dividing the semiconductor wafer into a plurality of chips by dicing using a blade at a dicing line which is defined within the trench region and includes a plurality of the buried regions.
    Type: Grant
    Filed: February 9, 2011
    Date of Patent: February 4, 2014
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Hironori Itou, Akio Iwabuchi
  • Publication number: 20130328107
    Abstract: A semiconductor device protects against concentration of electric current at a front end portion of one of the electrodes thereof. The semiconductor device includes a substrate, a compound semiconductor layer formed on the substrate and having a channel layer based on a hetero junction, a first main electrode formed on the compound semiconductor layer, a second main electrode formed on the compound semiconductor surrounding the first main electrode and having a linear region and an arc-shaped region, a control electrode formed on the compound semiconductor layer and disposed opposite to the first main electrode and the second main electrode, an electric current being made to flow between the first main electrode and the second main electrode, and an electric current limiting section formed between the first main electrode and the arc-shaped region of the second main electrode.
    Type: Application
    Filed: August 8, 2013
    Publication date: December 12, 2013
    Applicant: SANKEN ELECTRIC CO., LTD.
    Inventors: Akio IWABUCHI, Hironori AOKI
  • Patent number: 8519442
    Abstract: A semiconductor device includes a first semiconductor layer, a second semiconductor layer, a two-dimensional carrier gas layer, a first main electrode, a second main electrode, a first gate electrode, and a second gate electrode. The first gate electrode is provided between a part of the first main electrode and a part of the second main electrode opposite to the part of the first main electrode. The second gate electrode is provided between another part of the first main electrode and another part of the second main electrode opposite to the another part of the first main electrode with a separation region interposed between the first gate electrode and the second gate electrode. The second gate electrode is controlled independently of the first gate electrode.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: August 27, 2013
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Akio Iwabuchi, Hironori Aoki
  • Patent number: 8492792
    Abstract: A manufacturing method of a semiconductor device 10 includes forming a plurality of second conductive second semiconductor regions at specific intervals on one main surface of a first conductive first semiconductor region, the plurality of second conductive second semiconductor regions being opposite to the first conductive first semiconductor region, forming a plurality of the first conductive third semiconductor regions on a main surface of the second semiconductor region, the plurality of the first conductive third regions being separated from each other, forming a plurality of holes at specific intervals on an another main surface which faces the one main surface of the first semiconductor region, the plurality of holes being separated from each other, forming a pair of adjacent second conductive fourth semiconductor regions which are alternately connected at a bottom part of the hole within the first semiconductor region, and burying an electrode within the hole.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: July 23, 2013
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Akio Iwabuchi, Shuichi Kaneko
  • Patent number: 8476677
    Abstract: An aspect of the present invention inheres in a semiconductor device includes a semiconductor region, a source electrode and a drain electrode, which are provided on a main surface of the semiconductor region, a gate electrode exhibiting normally-off characteristics, the gate electrode being provided above the main surface of the semiconductor region while interposing a p-type material film therebetween, and being arranged between the source electrode and the drain electrode, and a fourth electrode that is provided on the main surface of the semiconductor region, and is arranged between the gate electrode and the drain electrode.
    Type: Grant
    Filed: May 8, 2012
    Date of Patent: July 2, 2013
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Osamu Machida, Akio Iwabuchi
  • Patent number: 8421123
    Abstract: A semiconductor device having a transistor and a rectifier includes: a current path; a first main electrode having a rectifying function and arranged on one end of the current path; a second main electrode arranged on the other end of the current path; an auxiliary electrode arranged in a region of the current path between the first main electrode and the second main electrode; a third main electrode arranged on the one end of the current path apart from the first main electrode along a direction intersecting the current path; and a control electrode arranged in a region of the current path between the second main electrode and the third main electrode. The transistor includes the current path, the second main electrode, the third main electrode, and the control electrode. The rectifier includes the current path, the first main electrode, the second main electrode, and the auxiliary electrode.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: April 16, 2013
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Osamu Machida, Akio Iwabuchi
  • Publication number: 20130075925
    Abstract: A semiconductor device is free from degradation of characteristics attributable to a manufacturing process thereof and its characteristics are hardly affected by changes in electric potentials of bonding pads. The semiconductor device 10 includes an active region 12, a first insulating layer 13 covering the active region 12, a floating conductor 14 formed on the first insulating layer 13, a second insulating layer 15 formed on the first insulating layer 13 and the floating conductor 14, a bonding pad 18 formed on the second insulating layer 17 and interconnection vias 19, 20 for electrically connecting the active region 12 and the bonding pad 18.
    Type: Application
    Filed: September 23, 2011
    Publication date: March 28, 2013
    Applicant: SANKEN ELECTRIC CO., LTD.
    Inventors: Akio IWABUCHI, Hironori AOKI
  • Publication number: 20130070487
    Abstract: A drive circuit drives a normally-on high-side switch Q1 and a normally-off low-side switch Q2 that form a series circuit connected in parallel with a DC power source. The drive circuit includes a controller 10 that outputs a control signal to turn on/off the high- and low-side switches, a rectifier D2 having a first end connected to a connection point of the high- and low-side switches, a capacitor C2 that is connected to a second end of the rectifier and a first end of the DC power source and serves as a power source for the controller, and a driver (A1, AND1, Q3, Q4) that turns on/off the high- and low-side switches according to the control signal from the controller and a voltage from the capacitor.
    Type: Application
    Filed: September 10, 2012
    Publication date: March 21, 2013
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Keiichiro OZAWA, Akio Iwabuchi, Yasushi Tasaka, Ryuichi Furukoshi
  • Patent number: 8399913
    Abstract: A field-effect semiconductor device such as a HEMT or MESFET is monolithically integrated with a Schottky diode for feedback, regeneration, or protection purposes. The field-effect semiconductor device includes a main semiconductor region having formed thereon a source, a drain, and a gate between the source and the drain. Also formed on the main semiconductor region, preferably between gate and drain, is a Schottky electrode electrically coupled to the source. The Schottky electrode provides a Schottky diode in combination with the main semiconductor region. A current flow is assured from Schottky electrode to drain without interruption by a depletion region expanding from the gate.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: March 19, 2013
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Mio Suzuki, Akio Iwabuchi
  • Publication number: 20120217546
    Abstract: An aspect of the present invention inheres in a semiconductor device includes a semiconductor region, a source electrode and a drain electrode, which are provided on a main surface of the semiconductor region, a gate electrode exhibiting normally-off characteristics, the gate electrode being provided above the main surface of the semiconductor region while interposing a p-type material film therebetween, and being arranged between the source electrode and the drain electrode, and a fourth electrode that is provided on the main surface of the semiconductor region, and is arranged between the gate electrode and the drain electrode.
    Type: Application
    Filed: May 8, 2012
    Publication date: August 30, 2012
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Osamu Machida, Akio Iwabuchi
  • Patent number: 8217687
    Abstract: A capacitive load driver includes a first switching element whose first end receives positive potential, an EL element arranged between a second end of the first switching element and the ground, a charge collecting capacitor whose first end is connected to a positive electrode terminal of the EL element, a voltage source connected between a second end of the charge collecting capacitor and the ground, and a controller. The controller charges a parasitic capacitance of the EL element and the charge collecting capacitor, and thereafter, applies negative potential from the voltage source to the second end of the charge collecting capacitor. Thereafter, the controller brings the output voltage of the voltage source to ground potential so that the charge collecting capacitor is discharged to charge the EL element. The capacitance of the charge collecting capacitor is set to be sufficiently greater than that of the parasitic capacitance.
    Type: Grant
    Filed: October 19, 2010
    Date of Patent: July 10, 2012
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Akio Iwabuchi, Shohei Osaka, Satoru Washiya
  • Patent number: 8188515
    Abstract: An aspect of the present invention inheres in a semiconductor device includes a semiconductor region, a source electrode and a drain electrode, which are provided on a main surface of the semiconductor region, a gate electrode exhibiting normally-off characteristics, the gate electrode being provided above the main surface of the semiconductor region while interposing a p-type material film therebetween, and being arranged between the source electrode and the drain electrode, and a fourth electrode that is provided on the main surface of the semiconductor region, and is arranged between the gate electrode and the drain electrode.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: May 29, 2012
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Osamu Machida, Akio Iwabuchi
  • Publication number: 20120080724
    Abstract: A semiconductor device includes a first semiconductor layer, a second semiconductor layer, a two-dimensional carrier gas layer, a first main electrode, a second main electrode, a first gate electrode, and a second gate electrode. The first gate electrode is provided between a part of the first main electrode and a part of the second main electrode opposite to the part of the first main electrode. The second gate electrode is provided between another part of the first main electrode and another part of the second main electrode opposite to the another part of the first main electrode with a separation region interposed between the first gate electrode and the second gate electrode. The second gate electrode is controlled independently of the first gate electrode.
    Type: Application
    Filed: October 3, 2011
    Publication date: April 5, 2012
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Akio Iwabuchi, Hironori Aoki
  • Publication number: 20120056648
    Abstract: The operation of a HEMT is monitored on an on-chip basis without increasing the power consumption rate. In a semiconductor device 10, an electron supply layer 12 is formed on a channel layer 11. A two-dimensional electron gas (2DEG) layer 13 is formed at the side of the channel layer of the hetero-junction interface. Electrons flow through the 2DEG layer 13 between a source electrode 14 formed on the surface of the electron supply layer 12 and a drain electrode 15 that is formed on the same surface. A potential detection electrode 17 is arranged on the electron supply layer 12 between the gate electrode 16 and the source electrode 14. A resistor 18 having a sufficiently high resistance value makes the electric current flowing to the potential detection electrode 17 negligible relative to the drain current in operation.
    Type: Application
    Filed: September 1, 2011
    Publication date: March 8, 2012
    Inventors: Akio IWABUCHI, Hironori Aoki
  • Publication number: 20120043588
    Abstract: A semiconductor device includes: a first semiconductor layer; a second semiconductor layer; a two-dimensional carrier gas layer; a source electrode; a drain electrode; a gate electrode; and an auxiliary electrode located above the two-dimensional carrier gas layer between the gate electrode and the drain electrode. Channel resistance of the two-dimensional carrier gas layer between the gate electrode and the auxiliary electrode is set higher than channel resistance of the two-dimensional carrier gas layer between the gate electrode and the source electrode.
    Type: Application
    Filed: August 16, 2011
    Publication date: February 23, 2012
    Applicant: Sanken Electric Co., Ltd.
    Inventors: Akio IWABUCHI, Hironori Aoki