Patents by Inventor Masakazu Sagawa

Masakazu Sagawa 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: 20230417819
    Abstract: An electric connection inspection device includes: a cooling plate; an insulating plate provided on the cooling plate; a first measurement electrode provided on the insulating plate; and a second measurement electrode and a third measurement electrode provided above the first measurement electrode and located apart from the first measurement electrode. The insulating plate includes a variable thermal resistance mechanism. A semiconductor device can be installed between the first measurement electrode and the second measurement electrode and between the first measurement electrode and the third measurement electrode.
    Type: Application
    Filed: February 24, 2022
    Publication date: December 28, 2023
    Applicant: Hitachi Power Semiconductor Device, Ltd.
    Inventors: Masakazu Sagawa, Kumiko Konishi, Hiroshi Miki, Yuki Mori
  • Patent number: 10529813
    Abstract: A semiconductor device including an n-type semiconductor layer formed on a substrate, having a cell region and a gate pad region, and including silicon carbide, and a unit cell formed in the cell region is configured as follows. A p-type body region formed in the semiconductor layer of the gate pad region, a first insulating film formed on the p-type body region, a conductive film formed on the first insulating film, and a second insulating film formed on the conductive film, and a gate pad formed on the second insulating film. Then, the film thickness of the first insulating film is 0.7 ?m or more, and more favorably 1.5 ?m or more. In addition, the electric field strength of the first insulating film is 3 MV/cm or less. Then, an opening portion is formed on the first insulating film in the gate pad region, and a resistance portion and a connection portion corresponding to the conductive film are formed in the opening portion.
    Type: Grant
    Filed: November 13, 2018
    Date of Patent: January 7, 2020
    Assignee: HITACHI POWER SEMICONDUCTOR DEVICE, LTD.
    Inventors: Masakazu Sagawa, Takashi Ishigaki
  • Patent number: 10522638
    Abstract: A semiconductor chip includes a semiconductor substrate made of SiC, a front surface electrode formed in a principal surface of the semiconductor substrate, and a rear surface electrode (drain electrode) formed in a rear surface of the semiconductor substrate. The front surface electrode is bonded to a wire, and includes an Al alloy film containing a high melting-point metal. The Al alloy film contains a columnar Al crystal which extends along a thickness direction of the Al alloy film, and an intermetallic compound is precipitated therein.
    Type: Grant
    Filed: October 5, 2018
    Date of Patent: December 31, 2019
    Assignee: HITACHI POWER SEMICONDUCTOR DEVICE, LTD.
    Inventors: Masakazu Sagawa, Takahiro Morikawa, Motoyuki Miyata, Kan Yasui, Toshiaki Morita
  • Publication number: 20190288082
    Abstract: A semiconductor device including an n-type semiconductor layer formed on a substrate, having a cell region and a gate pad region, and including silicon carbide, and a unit cell formed in the cell region is configured as follows. A p-type body region formed in the semiconductor layer of the gate pad region, a first insulating film formed on the p-type body region, a conductive film formed on the first insulating film, and a second insulating film formed on the conductive film, and a gate pad formed on the second insulating film. Then, the film thickness of the first insulating film is 0.7 ?m or more, and more favorably 1.5 ?m or more. In addition, the electric field strength of the first insulating film is 3 MV/cm or less. Then, an opening portion is formed on the first insulating film in the gate pad region, and a resistance portion and a connection portion corresponding to the conductive film are formed in the opening portion.
    Type: Application
    Filed: November 13, 2018
    Publication date: September 19, 2019
    Inventors: Masakazu SAGAWA, Takashi ISHIGAKI
  • Publication number: 20190157412
    Abstract: A semiconductor chip includes a semiconductor substrate made of SiC, a front surface electrode formed in a principal surface of the semiconductor substrate, and a rear surface electrode (drain electrode) formed in a rear surface of the semiconductor substrate. The front surface electrode is bonded to a wire, and includes an Al alloy film containing a high melting-point metal. The Al alloy film contains a columnar Al crystal which extends along a thickness direction of the Al alloy film, and an intermetallic compound is precipitated therein.
    Type: Application
    Filed: October 5, 2018
    Publication date: May 23, 2019
    Inventors: Masakazu SAGAWA, Takahiro MORIKAWA, Motoyuki MIYATA, Kan YASUI, Toshiaki MORITA
  • Patent number: 8803423
    Abstract: To obtain effective luminance and light efficiency while avoiding discharge, it is necessary to sufficiently increase a current luminous efficiency of gas and an electron emission efficiency of an electron source. In a fluorescent lamp, an anode electric field is increased by setting a pressure of a noble gas or a molecular gas enclosed to 10 kPa or higher, setting an anode voltage to 240 V or lower, and setting a substrate distance to 0.4 mm or smaller. Furthermore, the resulting effect that the current luminous efficiency is increased in proportion to the electric field is used. Also, by applying a MIM electron source having an electron emission efficiency exceeding 10% as an electron source, a non-discharge fluorescent lamp having a light emission luminance equal to or larger than 104 [cd/m2] and a light emission efficiency equal to or larger than 120 [lm/W] is achieved.
    Type: Grant
    Filed: February 23, 2010
    Date of Patent: August 12, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Masakazu Sagawa, Shin Imamura, Toshiaki Kusunoki
  • Publication number: 20120200613
    Abstract: To obtain effective luminance and light efficiency while avoiding discharge, it is necessary to sufficiently increase a current luminous efficiency of gas and an electron emission efficiency of an electron source. In a fluorescent lamp, an anode electric field is increased by setting a pressure of a noble gas or a molecular gas enclosed to 10 kPa or higher, setting an anode voltage to 240 V or lower, and setting a substrate distance to 0.4 mm or smaller. Furthermore, the resulting effect that the current luminous efficiency is increased in proportion to the electric field is used. Also, by applying a MIM electron source having an electron emission efficiency exceeding 10% as an electron source, a non-discharge fluorescent lamp having a light emission luminance equal to or larger than 104 [cd/m2] and a light emission efficiency equal to or larger than 120 [lm/W] is achieved.
    Type: Application
    Filed: February 23, 2010
    Publication date: August 9, 2012
    Inventors: Masakazu Sagawa, Shin Imamura, Toshiaki Kusunoki
  • Patent number: 8098013
    Abstract: A plasma display device includes: a front substrate and a back substrate facing each other and interposing a discharge gap; and a plurality of discharge cells formed by the front substrate and the back substrate, wherein a mixture gas containing Xe is filled in the discharge gap, and a red, green, or blue phosphor materials is arranged in each of the discharge cells. The plasma display device performs a reset operation by, at least, a weak discharge. A crystal material is arranged in the red, green, and blue phosphor materials so as to make weak discharge firing voltages for reset discharges in respective discharge cells uniform.
    Type: Grant
    Filed: July 14, 2009
    Date of Patent: January 17, 2012
    Assignee: Hitachi Consumer Electronics Co., Ltd.
    Inventors: Norihiro Uemura, Shunichiro Nobuki, Naoya Tokoo, Masakazu Sagawa
  • Patent number: 8085220
    Abstract: A plasma display apparatus having a priming discharge region PDC partitioned from a display discharge cell DDC, by a traverse rib, at a side where the second electrode between the display discharge cell DDC adjacent in a row direction is adjacent; a second longitudinal rib partitioning the priming discharge region PDC; a third longitudinal rib, further partitioning a region partitioned by the second longitudinal rib into two sections; a convex electrode; and a gap connecting the display discharge cell DDC and the priming discharge cell PDC, wherein a sum of a width in a line direction of a nearly rectangular space region containing adjacent two priming discharge cells PDCs, and a pattern width of the second longitudinal rib is designed larger than a sum of a width in the row direction and a pattern width of the traverse rib.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: December 27, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Shunichiro Nobuki, Norihiro Uemura, Masakazu Sagawa, Keizo Suzuki, Yoshiro Mikami, Hideto Momose, Shirun Ho
  • Publication number: 20110155226
    Abstract: As an n-type buffer layer, a material including TiO2 as a base material with addition of one or plurality of ZrO2, HfO2, GeO2, BaTiO3, SrTiO3, CaTiO3, MgTiO3, K(Ta, Nb)O3, and Na(Ta, Nb)O3 for band gap control, a material including BaTiO3 as a base material with addition of one or plurality of SrTiO3, CaTiO3, and MgTiO3 for band gap control, or a material comprising K(Ta, Nb)O3 as a base material with addition of Na(Ta, Nb)O3 for band gap control is used.
    Type: Application
    Filed: August 13, 2010
    Publication date: June 30, 2011
    Inventors: Toshiaki KUSUNOKI, Masakazu Sagawa, Masaaki Komatsu
  • Patent number: 7919911
    Abstract: By making Nd concentration in the tunneling insulating film 11 smaller than Nd concentration in the base electrode first layer 16, the accumulated electric charge amount in the tunneling insulating film 11 is reduced and afterimage is decreased. By setting a relation between a position of a stack interface of the base electrode 13 and a thickness of an insulating layer properly, the generation of a device defect is prevented.
    Type: Grant
    Filed: May 20, 2008
    Date of Patent: April 5, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Mutsumi Suzuki, Masakazu Sagawa, Toshiaki Kusunoki
  • Patent number: 7750548
    Abstract: An image display device in which each pixel has a thin-film electron source composed of a lower electrode (which is a signal wire), an electron accelerating layer (which is formed by anodizing the surface of said signal wire), and an upper electrode (which covers said electron accelerating layer and releases electrons), in which the anodized film constituting said electron accelerating layer contains hydrated alumina component and anhydrous alumina component such that their ratio in the side close to the upper electrode is greater than that in the side close to the lower electrode. This structure prevents said thin-film electron source from being deteriorated in diode characteristics by said electron accelerating layer, thereby enhancing the reliability of said image display device.
    Type: Grant
    Filed: November 21, 2007
    Date of Patent: July 6, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Takuo Tamura, Masakazu Sagawa, Hiroshi Kikuchi
  • Publication number: 20100013370
    Abstract: Provided is a plasma display device which is bright and has high contrast and high image quality. A plasma display device includes: a front substrate and a back substrate facing each other interposing a discharge gap; and a plurality of discharge cells formed by the front substrate and the back substrate, wherein a mixture gas containing Xe is filled in the discharge gap, and each of a plurality of phosphor layers of red, green, and blue is arranged in the discharge cell. And, the plasma display device performs a reset operation by, at least, a weak discharge. A crystal material is arranged in the phosphor layers of red, green, and blue so as to uniform weak discharge firing voltages for reset discharges in respective discharge cells.
    Type: Application
    Filed: July 14, 2009
    Publication date: January 21, 2010
    Applicant: HITACHI CONSUMER ELECTRONICS CO., LTD.
    Inventors: Norihiro UEMURA, Shunichiro NOBUKI, Naoya TOKOO, Masakazu SAGAWA
  • Publication number: 20090225008
    Abstract: A plasma display apparatus having a priming discharge region PDC partitioned from a display discharge cell DDC, by a traverse rib, at a side where the second electrode between the display discharge cell DDC adjacent in a row direction is adjacent; a second longitudinal rib partitioning the priming discharge region PDC; a third longitudinal rib, further partitioning a region partitioned by the second longitudinal rib into two sections; a convex electrode; and a gap connecting the display discharge cell DDC and the priming discharge cell PDC, wherein a sum of a width in a line direction of a nearly rectangular space region containing adjacent two priming discharge cells PDCs, and a pattern width of the second longitudinal rib is designed larger than a sum of a width in the row direction and a pattern width of the traverse rib.
    Type: Application
    Filed: November 26, 2008
    Publication date: September 10, 2009
    Inventors: Shunichiro Nobuki, Norihiro Uemura, Masakazu Sagawa, Keizo Suzuki, Yoshiro Mikami, Hideto Momose, Shirun Ho
  • Publication number: 20090184895
    Abstract: A high-definition, high-quality, and high-contrast PDP that features high brightness, guaranteed long life, and stable driving, is provided by improving the time-dependent degradation of address discharge delay. The PDP includes: a front substrate having bus electrodes, and sustain discharge electrodes extending in a lateral direction of the bus electrodes to form display lines; a back substrate having address electrodes facing the sustain discharge electrodes in the lateral direction of the bus electrodes; and discharge cells formed between the substrates. Each of the discharge cells includes a sustain discharge cell and a priming discharge cell, in which a protruding electrode is formed to extend in a direction opposite to the discharge gap from the bus electrode, and a predetermined space is provided between the two cells to supply priming. The shape and size of the space are optimized so that the sustain discharge does not spread to the address discharge cell through the space.
    Type: Application
    Filed: December 29, 2008
    Publication date: July 23, 2009
    Inventors: Norihiro Uemura, Shunichiro Nobuki, Masakazu Sagawa, Shirun Ho, Keizo Suzuki, Yoshiro Mikami
  • Publication number: 20090039761
    Abstract: By making Nd concentration in the tunneling insulating film 11 smaller than Nd concentration in the base electrode first layer 16, the accumulated electric charge amount in the tunneling insulating film 11 is reduced and afterimage is decreased. By setting a relation between a position of a stack interface of the base electrode 13 and a thickness of an insulating layer properly, the generation of a device defect is prevented.
    Type: Application
    Filed: May 20, 2008
    Publication date: February 12, 2009
    Inventors: Mutsumi Suzuki, Masakazu Sagawa, Toshiaki Kusunoki
  • Publication number: 20090001870
    Abstract: A protruded portion of an adjacent scan line is provided along one of longer sides of an electron emission area, for functioning as a focusing electrode. A feeding electrode is provided along the other longer side of the electron emission part. Use of this arrangement improves the ability to feed current from a scan line(s). Thus, a distribution of drive current within an element electrode is dispersed, thereby to improve the reliability of an electron emission element. Additionally, in the case of a thin-film electron source being used as this element, the improvement in current feeding ability enables a top electrode to decrease in thickness, thus increasing the electron emission efficiency.
    Type: Application
    Filed: May 28, 2008
    Publication date: January 1, 2009
    Inventors: Mutsumi Suzuki, Masakazu Sagawa, Yoshiro Mikami
  • Publication number: 20080290781
    Abstract: There is disclosed a display apparatus using a long-lived MIM electron source that is excellent in grayscale controllability. In a device including an MIM dielectric layer having a film thickness of 9.6 nm, the diode current Id rises exponentially from around 4.8 V together with the voltage. The emission current Ie rises exponentially from 4.7 V. That is, VthIe<VthId or VthIe?VthId. A detailed measurement has shown that the difference between VthIe and VthId is less than 0.3 V.
    Type: Application
    Filed: May 21, 2008
    Publication date: November 27, 2008
    Inventors: Yoshiro MIKAMI, Toshiaki Kusunoki, Katsuhide Aoto, Tomoki Nakamura, Masakazu Sagawa
  • Patent number: 7442961
    Abstract: The present invention provides an image display device, by which it is possible to prevent dielectric breakdown between a bottom electrode and a top electrode (top electrode bus line), which make up thin-film type electron sources, and which is free of display defect and has longer service life. On a cathode substrate 10, a bottom electrode 11, a tunneling insulator 12, and a top electrode 13 are prepared. On a lower layer of the top electrode 13, a top electrode bus line 16 is formed, and the top electrode 13 is reliably connected to the top electrode bus line 16 via a contact electrode 15. A field insulator 12A, a lower layer 14a of the interlayer insulator deposited by sputtering and an upper layer 14b of the interlayer insulator are laminated between the top electrode 13 and the contact electrode and the bottom electrode 11, and the bottom electrode 11 is insulated from the top electrode 13 (top electrode bus line 16).
    Type: Grant
    Filed: January 6, 2006
    Date of Patent: October 28, 2008
    Assignee: Hitachi Displays, Ltd.
    Inventors: Masakazu Sagawa, Toshiaki Kusunoki, Kazutaka Tsuji, Mutsumi Suzuki
  • Patent number: RE41828
    Abstract: The present invention provides an image display capable of enhancing a production yield. The image display comprises a display device including a first plate which has a plurality of electron-emitter elements each having a structure comprised of a base electrode, an insulating layer and a top electrode stacked on one another in this order, the electron-emitter element emitting electrons from the surface of the top electrode when a voltage of positive polarity is applied to the top electrode; a plurality of first electrodes for respectively applying driving voltages to the base electrodes of the electron-emitter elements lying in a row (or column) direction; and a plurality of second electrodes for respectively applying driving voltages to the top electrodes of the electron-emitter elements lying in the column (or row) direction, a frame component, and a second plate having phosphors, wherein a space surrounded by the first plate, the frame component and the second plate is brought into vacuum.
    Type: Grant
    Filed: September 4, 2000
    Date of Patent: October 19, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Mutsumi Suzuki, Masakazu Sagawa, Toshiaki Kusunoki