Patents by Inventor Shunji Kuwahara

Shunji Kuwahara 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: 11705432
    Abstract: Systems, apparatuses, and methods using wire bonds and direct chip attachment (DCA) features in stacked die packages are described. A stacked die package includes a substrate and at least a first semiconductor die and a second semiconductor die that are vertically stacked above the substrate. An active surface of the first semiconductor die faces an upper surface of the substrate and the first semiconductor die is operably coupled to the substrate by direct chip attachment DCA features. A back side surface of the second semiconductor die faces a back side surface of the first semiconductor die. The second semiconductor die is operably coupled to the substrate by wire bonds extending between an active surface thereof and the upper surface of the substrate.
    Type: Grant
    Filed: July 1, 2021
    Date of Patent: July 18, 2023
    Assignee: Micron Technology, Inc.
    Inventors: Hiroki Fujisawa, Raj K. Bansal, Shunji Kuwahara, Mitsuaki Katagiri, Satoshi Isa
  • Publication number: 20210327856
    Abstract: Systems, apparatuses, and methods using wire bonds and direct chip attachment (DCA) features in stacked die packages are described. A stacked die package includes a substrate and at least a first semiconductor die and a second semiconductor die that are vertically stacked above the substrate. An active surface of the first semiconductor die faces an upper surface of the substrate and the first semiconductor die is operably coupled to the substrate by direct chip attachment DCA features. A back side surface of the second semiconductor die faces a back side surface of the first semiconductor die. The second semiconductor die is operably coupled to the substrate by wire bonds extending between an active surface thereof and the upper surface of the substrate.
    Type: Application
    Filed: July 1, 2021
    Publication date: October 21, 2021
    Inventors: Hiroki Fujisawa, Raj K. Bansal, Shunji Kuwahara, Mitsuaki Katagiri, Satoshi Isa
  • Patent number: 11081468
    Abstract: Systems, apparatuses, and methods using wire bonds and direct chip attachment (DCA) features in stacked die packages are described. A stacked die package includes a substrate and at least a first semiconductor die and a second semiconductor die that are vertically stacked above the substrate. An active surface of the first semiconductor die faces an upper surface of the substrate and the first semiconductor die is operably coupled to the substrate by direct chip attachment DCA features. A back side surface of the second semiconductor die faces a back side surface of the first semiconductor die. The second semiconductor die is operably coupled to the substrate by wire bonds extending between an active surface thereof and the upper surface of the substrate.
    Type: Grant
    Filed: August 28, 2019
    Date of Patent: August 3, 2021
    Assignee: Micron Technology, Inc.
    Inventors: Hiroki Fujisawa, Raj K. Bansal, Shunji Kuwahara, Mitsuaki Katagiri, Satoshi Isa
  • Publication number: 20210066247
    Abstract: Systems, apparatuses, and methods using wire bonds and direct chip attachment (DCA) features in stacked die packages are described. A stacked die package includes a substrate and at least a first semiconductor die and a second semiconductor die that are vertically stacked above the substrate. An active surface of the first semiconductor die faces an upper surface of the substrate and the first semiconductor die is operably coupled to the substrate by direct chip attachment DCA features. A back side surface of the second semiconductor die faces a back side surface of the first semiconductor die. The second semiconductor die is operably coupled to the substrate by wire bonds extending between an active surface thereof and the upper surface of the substrate.
    Type: Application
    Filed: August 28, 2019
    Publication date: March 4, 2021
    Inventors: Hiroki Fujisawa, Raj K. Bansal, Shunji Kuwahara, Mitsuaki Katagiri, Satoshi Isa
  • Patent number: 9041436
    Abstract: To reduce power supply noises occurring in a control circuit unit for controlling an output buffer. A semiconductor device includes unit buffers for driving a data output terminal, impedance control circuits for controlling the unit buffers, and a control circuit unit for controlling the impedance control circuits. The impedance control circuits and the control circuit unit operate by mutually-different power supplies, the control circuit unit supplies pull-up data and pull-down data in mutually reverse phase to the impedance control circuits, and the impedance control circuits convert the pull-up data and the pull-down data from reverse phase to in-phase and supply the same to the unit buffers. Thereby, a noise is difficult to occur in a power supply VDD used for the control circuit unit.
    Type: Grant
    Filed: October 26, 2011
    Date of Patent: May 26, 2015
    Assignee: PS4 Luxco S.a.r.l.
    Inventors: Shunji Kuwahara, Hiroki Fujisawa
  • Patent number: 8461867
    Abstract: To include an output terminal, unit buffers, and plural output-wiring paths that respectively connect the unit buffers and the output terminal. The output wiring paths have individual output wiring sections individually allocated to corresponding unit buffers. Unit buffers corresponding to these output wiring paths are common output wiring sections shared by the output wiring paths, and are connected to the output terminal without via a common output wiring section having a higher resistance value than those of the individual output wiring sections. Accordingly, an deviation of impedance due to a parasitic resistance between the output terminal and the unit buffers is suppressed.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: June 11, 2013
    Assignee: Elpida Memory, Inc.
    Inventors: Shunji Kuwahara, Hiroki Fujisawa
  • Patent number: 8278973
    Abstract: To include two counter circuits that change impedances of two replica circuits, respectively, and an impedance adjustment control circuit that controls the counter circuits to update count values of the counter circuits. The impedance adjustment control circuit controls one of the counter circuits to finish updating the count value of the counter circuit in response to a change of the impedance of the corresponding replica circuit from a state of being lower than an impedance of an external resistor to a state of being higher than the impedance of the external resistor, and controls the other counter circuit to finish updating the count value of the other counter circuit in response to a change of the impedance of the other replica circuit from a state of being higher than the impedance of the former replica circuit to a state of being lower than the impedance of the former replica circuit. With this configuration, the adjust errors generated in the replica circuits are canceled.
    Type: Grant
    Filed: February 17, 2010
    Date of Patent: October 2, 2012
    Assignee: Elpida Memory, Inc.
    Inventors: Shunji Kuwahara, Hiroki Fujisawa
  • Publication number: 20120119578
    Abstract: To reduce power supply noises occurring in a control circuit unit for controlling an output buffer. A semiconductor device includes unit buffers for driving a data output terminal, impedance control circuits for controlling the unit buffers, and a control circuit unit for controlling the impedance control circuits. The impedance control circuits and the control circuit unit operate by mutually-different power supplies, the control circuit unit supplies pull-up data and pull-down data in mutually reverse phase to the impedance control circuits, and the impedance control circuits convert the pull-up data and the pull-down data from reverse phase to in-phase and supply the same to the unit buffers. Thereby, a noise is difficult to occur in a power supply VDD used for the control circuit unit.
    Type: Application
    Filed: October 26, 2011
    Publication date: May 17, 2012
    Applicant: Elpida Memory, Inc.
    Inventors: Shunji Kuwahara, Hiroki Fujisawa
  • Publication number: 20110062984
    Abstract: To include an output terminal, unit buffers, and plural output-wiring paths that respectively connect the unit buffers and the output terminal. The output wiring paths have individual output wiring sections individually allocated to corresponding unit buffers. Unit buffers corresponding to these output wiring paths are common output wiring sections shared by the output wiring paths, and are connected to the output terminal without via a common output wiring section having a higher resistance value than those of the individual output wiring sections. Accordingly, an deviation of impedance due to a parasitic resistance between the output terminal and the unit buffers is suppressed.
    Type: Application
    Filed: September 10, 2010
    Publication date: March 17, 2011
    Applicant: Elpida Memory, Inc.
    Inventors: Shunji Kuwahara, Hiroki Fujisawa
  • Patent number: 7902858
    Abstract: A calibration circuit includes: a replica buffer that drives a calibration terminal; a pre-emphasis circuit connected in parallel to the replica buffer; and an up-down counter that changes impedances of the replica buffer and the pre-emphasis circuit. A replica control circuit causes the replica buffer to conduct based on an impedance code, and a pre-emphasis control circuit causes the pre-emphasis circuit to conduct in an initial stage of a conducting period of the replica buffer. Thereby, even when an external resistor is shared among a plurality of semiconductor devices, for example, a voltage appearing in the calibration terminal can be stabilized at a higher speed.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: March 8, 2011
    Assignee: Elpida Memory, Inc.
    Inventors: Shunji Kuwahara, Hiroki Fujisawa
  • Patent number: 7872493
    Abstract: In a calibration control circuit, a first clock gate circuit restricts passage of reference update clocks during a calibration period so as to stop a first one of the reference update clocks and supplies the restricted reference update clocks as first update clocks CLK1 to both a hit determination circuit and a second clock gate circuit. The second clock gate circuit 110 passes through the first update clocks CLK1 until reception of a hit signal from the hit determination circuit and delivers second update clocks CLK2 to an up/down counter 106. The up/down counter 106 is operated by the second update clocks CLK2. With this structure, the second update clocks used for adjustment steps can be increased in number during the calibration period.
    Type: Grant
    Filed: May 20, 2009
    Date of Patent: January 18, 2011
    Assignee: Elpida Memory, Inc.
    Inventors: Shunji Kuwahara, Hiroki Fujisawa
  • Publication number: 20100207680
    Abstract: To include two counter circuits that change impedances of two replica circuits, respectively, and an impedance adjustment control circuit that controls the counter circuits to update count values of the counter circuits. The impedance adjustment control circuit controls one of the counter circuits to finish updating the count value of the counter circuit in response to a change of the impedance of the corresponding replica circuit from a state of being lower than an impedance of an external resistor to a state of being higher than the impedance of the external resistor, and controls the other counter circuit to finish updating the count value of the other counter circuit in response to a change of the impedance of the other replica circuit from a state of being higher than the impedance of the former replica circuit to a state of being lower than the impedance of the former replica circuit. With this configuration, the adjust errors generated in the replica circuits are canceled.
    Type: Application
    Filed: February 17, 2010
    Publication date: August 19, 2010
    Applicant: ELPIDA MEMORY, INC.
    Inventors: Shunji KUWAHARA, Hiroki FUJISAWA
  • Publication number: 20090289659
    Abstract: In a calibration control circuit, a first clock gate circuit restricts passage of reference update clocks during a calibration period so as to stop a first one of the reference update clocks and supplies the restricted reference update clocks as first update clocks CLK1 to both a hit determination circuit and a second clock gate circuit. The second clock gate circuit 110 passes through the first update clocks CLK1 until reception of a hit signal from the hit determination circuit and delivers second update clocks CLK2 to an up/down counter 106. The up/down counter 106 is operated by the second update clocks CLK2. With this structure, the second update clocks used for adjustment steps can be increased in number during the calibration period.
    Type: Application
    Filed: May 20, 2009
    Publication date: November 26, 2009
    Inventors: Shunji Kuwahara, Hiroki Fujisawa
  • Publication number: 20090015312
    Abstract: A calibration circuit includes: a replica buffer that drives a calibration terminal; a pre-emphasis circuit connected in parallel to the replica buffer; and an up-down counter that changes impedances of the replica buffer and the pre-emphasis circuit. A replica control circuit causes the replica buffer to conduct based on an impedance code, and a pre-emphasis control circuit causes the pre-emphasis circuit to conduct in an initial stage of a conducting period of the replica buffer. Thereby, even when an external resistor is shared among a plurality of semiconductor devices, for example, a voltage appearing in the calibration terminal can be stabilized at a higher speed.
    Type: Application
    Filed: July 9, 2008
    Publication date: January 15, 2009
    Applicant: ELPIDA MEMORY, INC.
    Inventors: Shunji Kuwahara, Hiroki Fujisawa