Patents by Inventor Tetsuya Roppongi

Tetsuya Roppongi 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: 20240029759
    Abstract: The present embodiments relate to write heads implementing microwave-assisted magnetic recording utilizing multiple spin torque oscillators (STOs). Each STO can include a field-generation layer (FGL) that can oscillate in a same frequency and out of phase with one another. The layers in each STO can enable mutual spin transfer torques between adjacent layers, which can drive the FGLs into a large angle oscillation. The oscillation between the FGLs can cause a magnetic field to be generated that can assist in writing to a magnetic recording medium.
    Type: Application
    Filed: July 25, 2022
    Publication date: January 25, 2024
    Inventors: Wenyu Chen, Zhenyao Tang, Shohei Kawasaki, Tetsuya Roppongi
  • Publication number: 20230178103
    Abstract: A STRAMR structure is disclosed. The STRAMR structure can include a spin torque oscillator (STO) device in a WG provided between the mail pole (MP) trailing side and a trailing shield. The STO device, includes: a flux guiding layer that has a negative spin polarization (nFGL) with a magnetization pointing substantially parallel to the WG field without the current bias and formed between a first spin polarization preserving layer (ppL1) and a second spin polarization preserving layer (ppL2); a positive spin polarization (pSP) layer that adjoins the TS bottom surface; a non-spin polarization preserving layer (pxL) contacting the MP trailing side; a first negative spin injection layer (nSIL1) between the ppL2 and a third spin polarization preserving layer (ppL3); and a second negative spin injection layer (nSIL2) between the ppL3 and the pxL, wherein the nFGL, nSIL1, and nSIL2 have a spin polarization that is negative.
    Type: Application
    Filed: January 30, 2023
    Publication date: June 8, 2023
    Inventors: Wenyu Chen, Shohei Kawasaki, Tetsuya Roppongi
  • Patent number: 11568891
    Abstract: A STRAMR structure is disclosed. The STRAMR structure can include a spin torque oscillator (STO) device in a WG provided between the mail pole (MP) trailing side and a trailing shield. The STO device, includes: a flux guiding layer that has a negative spin polarization (nFGL) with a magnetization pointing substantially parallel to the WG field without the current bias and formed between a first spin polarization preserving layer (ppL1) and a second spin polarization preserving layer (ppL2); a positive spin polarization (pSP) layer that adjoins the TS bottom surface; a non-spin polarization preserving layer (pxL) contacting the MP trailing side; a first negative spin injection layer (nSIL1) between the ppL2 and a third spin polarization preserving layer (ppL3); and a second negative spin injection layer (nSIL2) between the ppL3 and the pxL, wherein the nFGL, nSIL1, and nSIL2 have a spin polarization that is negative.
    Type: Grant
    Filed: November 30, 2021
    Date of Patent: January 31, 2023
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Shohei Kawasaki, Tetsuya Roppongi
  • Patent number: 11514931
    Abstract: A magnetic head includes a main pole, a trailing shield, and a spin torque oscillator. A top surface of the main pole includes a first inclined portion, a second inclined portion, and a third inclined portion arranged in order of closeness to a medium facing surface. Each of the first to third inclined portions has a front end closest to the medium facing surface and a rear end farthest from the medium facing surface. Each of the first to third inclined portions is inclined relative to the medium facing surface and a direction orthogonal to the medium facing surface so that its rear end is located forward relative to its front end in a direction of travel of a recording medium.
    Type: Grant
    Filed: February 22, 2022
    Date of Patent: November 29, 2022
    Assignee: HEADWAY TECHNOLOGIES, INC.
    Inventors: Hironori Araki, Yoshitaka Sasaki, Tetsuhito Shinohara, Shigeki Tanemura, Kazuki Sato, Yoji Nomura, Yukinori Ikegawa, Tetsuya Roppongi
  • Patent number: 11289117
    Abstract: A magnetic head includes a medium facing surface, a main pole, a trailing shield, and a spin torque oscillator. A bottom surface of the trailing shield includes a first portion that includes an end located in the medium facing surface and is in contact with the spin torque oscillator at least in part. An element height that is a dimension of the spin torque oscillator in a direction perpendicular to the medium facing surface and a writer height that is a dimension of the first portion in the direction perpendicular to the medium facing surface are different from each other.
    Type: Grant
    Filed: February 8, 2021
    Date of Patent: March 29, 2022
    Assignee: HEADWAY TECHNOLOGIES, INC.
    Inventors: Yoshitaka Sasaki, Hiroyuki Ito, Kazuki Sato, Shigeki Tanemura, Hironori Araki, Yoji Nomura, Tetsuya Roppongi, Tetsuhito Shinohara, Ying Liu, Min Li, Alain Truong, Yuhui Tang, Wenyu Chen
  • Patent number: 11211082
    Abstract: A magnetic head includes a medium facing surface, a main pole, a trailing shield, a spin torque oscillator, and a first insulating layer. The first insulating layer is interposed between a portion of the main pole and a portion of the spin torque oscillator. The first insulating layer has a first end closest to the medium facing surface. The spin torque oscillator has a rear end farthest from the medium facing surface. The first end of the first insulating layer is located closer to the medium facing surface than the rear end of the spin torque oscillator is.
    Type: Grant
    Filed: February 8, 2021
    Date of Patent: December 28, 2021
    Assignee: HEADWAY TECHNOLOGIES, INC.
    Inventors: Yoshitaka Sasaki, Hiroyuki Ito, Tetsuhito Shinohara, Shigeki Tanemura, Kazuki Sato, Yoji Nomura, Hironori Araki, Tetsuya Roppongi
  • Patent number: 10937450
    Abstract: A spin transfer torque reversal assisted magnetic recording (STRAMR) device is disclosed wherein a flux guiding layer (FGL) magnetization flips to an opposite direction opposing the write gap (WG) field because of spin torque from an adjacent spin polarization (SP) layer and spin injection layer (SIL) when a current (Ia) of sufficient density is applied across the device and between the main pole (MP) and trailing shield (TS) thereby enhancing the MP write field. The SP layer adjoins the MP or TS and maintains a magnetization in the WG field direction. One or both of the SIL and FGL has a spin polarization from ?0.4 to 0.3 and may be doped with C, N, or B so that the extent of FGL flipping is greater at a given current density than in the prior art where all magnetic layers within the STRAMR device have a positive spin polarization ?0.4.
    Type: Grant
    Filed: July 13, 2020
    Date of Patent: March 2, 2021
    Assignee: Headway Technologies, Inc.
    Inventors: Shohei Kawasaki, Wenyu Chen, Tetsuya Roppongi
  • Patent number: 10839829
    Abstract: A magnetic head includes a medium facing surface, a coil, a main pole, and a substrate. The main pole includes a first layer, and a second layer lying on the first layer. The first layer includes a thickness-changing portion whose dimension in a direction perpendicular to a top surface of the substrate decreases with decreasing distance to the medium facing surface. At least part of the second layer is located on the thickness-changing portion.
    Type: Grant
    Filed: September 27, 2019
    Date of Patent: November 17, 2020
    Assignee: HEADWAY TECHNOLOGIES, INC.
    Inventors: Yoshitaka Sasaki, Hiroyuki Ito, Kazuki Sato, Shigeki Tanemura, Tetsuya Roppongi, Kei Hirata, Atsushi Yamaguchi, Michitaka Nishiyama
  • Patent number: 10803888
    Abstract: A manufacturing method for a magnetic head includes the steps of: forming a main pole; forming a spin torque oscillator; and forming a trailing shield. The step of forming the spin torque oscillator includes: a step of forming a layered film; a step of forming an interposition layer; a step of forming a mask; a first etching step of etching a portion of the interposition layer using the mask; a second etching step of etching a portion of the layered film using the mask and the interposition layer as an etching mask; a step of removing the interposition layer and the mask; and a patterning step of patterning the layered film into the spin torque oscillator.
    Type: Grant
    Filed: September 18, 2019
    Date of Patent: October 13, 2020
    Assignee: HEADWAY TECHNOLOGIES, INC.
    Inventors: Yoshitaka Sasaki, Hiroyuki Ito, Kazuki Sato, Shigeki Tanemura, Hironori Araki, Yoji Nomura, Tetsuya Roppongi, Atsushi Yamaguchi
  • Patent number: 10748559
    Abstract: A magnetic head includes a main pole, a trailing shield, a spin torque oscillator, and a buffer layer. The buffer layer is interposed between the main pole and the spin torque oscillator. The spin torque oscillator has first and second side surfaces. The first and second side surfaces respectively form first and second angles with respect to a direction perpendicular to a top surface of a substrate. The first and second angles each fall within a range of 0° to 10°. The buffer layer has third and fourth side surfaces. The third side surface includes a first inclined portion forming a third angle greater than the first angle. The fourth side surface includes a second inclined portion forming a fourth angle greater than the second angle.
    Type: Grant
    Filed: February 26, 2020
    Date of Patent: August 18, 2020
    Assignee: HEADWAY TECHNOLOGIES, INC.
    Inventors: Hironori Araki, Yoshitaka Sasaki, Hiroyuki Ito, Yoji Nomura, Shigeki Tanemura, Kazuki Sato, Tetsuya Roppongi, Atsushi Yamaguchi
  • Patent number: 10559412
    Abstract: At least one magnetoresistance effect element and a magnetic field applying unit to apply a magnetic field to the magnetoresistance effect element, the magnetic field applying unit includes a first ferromagnetic material having a portion protruding to the magnetoresistance effect element side in a stacking direction of the magnetoresistance effect element, a second ferromagnetic material sandwiching the magnetoresistance effect element with the first ferromagnetic material, and a coil wound around the first ferromagnetic material, a first magnetization free layer of the magnetoresistance effect element has a portion free of overlapping with at least one of a second surface of the protruding portion on the magnetoresistance effect element side and a third surface of the second ferromagnetic material on the magnetoresistance effect when viewed in the stacking direction, and a center of gravity of the first magnetization free layer, positioned in a region connecting the second surface and the third surface.
    Type: Grant
    Filed: November 29, 2018
    Date of Patent: February 11, 2020
    Assignee: TDK CORPORATION
    Inventors: Akimasa Kaizu, Naomichi Degawa, Tetsuya Roppongi
  • Patent number: 10522174
    Abstract: A spin torque transfer (STT) assisted magnetic recording structure is disclosed wherein a magnetic flux guiding (MFG) device is formed between a main pole (MP) trailing side and a trailing shield (TS). The MFG device has a field generation layer (FGL) separated from first and second spin polarization (SP) layers by first and second non-magnetic layers, respectively. First and second SP layers have magnetizations in opposite directions so that when a direct current of sufficient magnitude is applied from the MP to TS, or from the TS to MP in other embodiments, FGL magnetization flips to a direction toward the MP and opposes a write gap field flux thereby enhancing the write field. Additive torque from two SP layers on the FGL enables lower current density for FGL flipping or a greater degree of FGL flipping at a given current density compared with MFG schemes having a single SP layer.
    Type: Grant
    Filed: August 23, 2019
    Date of Patent: December 31, 2019
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Shohei Kawasaki, Tetsuya Roppongi, Yan Wu
  • Patent number: 10490216
    Abstract: A spin torque transfer (STO) assisted magnetic recording structure is disclosed wherein a STO device has capability to generate a radio frequency (RF) field on a magnetic bit to lower the required write field during a write process. The STO device contains a field generation layer (FGL) with a magnetization that flips to a direction opposite to the write gap field when a current of sufficient current density is applied thereby increasing reluctance in the write gap and causing a larger write field output at the air bearing surface. A key feature is that a single spin polarization (SP) layer and an antiferromagnetically coupled SP layer comprised of SP1 and SP2 layers are formed on opposite sides of the FGL. SP1 magnetization is greater than SP2 magnetization. Additive torque from SP and SP2 layers on the FGL enables FGL flipping while SP1 and SP2 precessional states provide the RF field.
    Type: Grant
    Filed: December 4, 2018
    Date of Patent: November 26, 2019
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Shohei Kawasaki, Tetsuya Roppongi, Yan Wu
  • Patent number: 10424326
    Abstract: A spin torque transfer (STT) assisted magnetic recording structure is disclosed wherein a magnetic flux guiding (MFG) device is formed between a main pole (MP) trailing side and a trailing shield (TS). The MFG device has a field generation layer (FGL) separated from first and second spin polarization (SP) layers by first and second non-magnetic layers, respectively. First and second SP layers have magnetizations in opposite directions so that when a direct current of sufficient magnitude is applied from the MP to TS, or from the TS to MP in other embodiments, FGL magnetization flips to a direction toward the MP and opposes a write gap field flux thereby enhancing the write field. Additive torque from two SP layers on the FGL enables lower current density for FGL flipping or a greater degree of FGL flipping at a given current density compared with MFG schemes having a single SP layer.
    Type: Grant
    Filed: November 21, 2018
    Date of Patent: September 24, 2019
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Shohei Kawasaki, Tetsuya Roppongi, Yan Wu
  • Publication number: 20190180901
    Abstract: At least one magnetoresistance effect element and a magnetic field applying unit to apply a magnetic field to the magnetoresistance effect element, the magnetic field applying unit includes a first ferromagnetic material having a portion protruding to the magnetoresistance effect element side in a stacking direction of the magnetoresistance effect element, a second ferromagnetic material sandwiching the magnetoresistance effect element with the first ferromagnetic material, and a coil wound around the first ferromagnetic material, a first magnetization free layer of the magnetoresistance effect element has a portion free of overlapping with at least one of a second surface of the protruding portion on the magnetoresistance effect element side and a third surface of the second ferromagnetic material on the magnetoresistance effect when viewed in the stacking direction, and a center of gravity of the first magnetization free layer, positioned in a region connecting the second surface and the third surface.
    Type: Application
    Filed: November 29, 2018
    Publication date: June 13, 2019
    Applicant: TDK CORPORATION
    Inventors: Akimasa KAIZU, Naomichi DEGAWA, Tetsuya ROPPONGI
  • Patent number: 10121497
    Abstract: A magnetic recording head has a main magnetic pole that generates a recording magnetic field applied on a magnetic recording medium from an end surface that is one portion of an air bearing surface facing the magnetic recording medium; a trailing shield provided on the trailing side of the main magnetic pole with a write gap interposed therebetween; and a spin torque oscillator that is provided in the write gap to be interposed between the main magnetic pole and the trailing shield and that generates a magnetic field that exerts an interaction on the recording magnetic field applied on the magnetic recording medium.
    Type: Grant
    Filed: October 12, 2017
    Date of Patent: November 6, 2018
    Assignee: TDK Coporation
    Inventors: Hirokazu Takahashi, Zhengyao Tang, Tetsuya Roppongi, Shinji Hara
  • Patent number: 10109302
    Abstract: A magnetic recording head is provided with a main magnetic pole that generates a recording magnetic field to be applied to a magnetic recording medium from an end surface which makes a portion of an air bearing surface, a trailing shield that is placed by interposing a write gap at a trailing side of the main magnetic pole, a spin torque oscillator that is placed within the write gap to be between the main magnetic pole and the trailing shield, and two side shields that are placed at both sides of the main magnetic pole in the cross track direction, and when viewed from the air bearing surface side, at least a portion of the trailing-side end surfaces of the side shields are offset toward a leading-side of the main magnetic pole from the leading-side end surface of the spin torque oscillator.
    Type: Grant
    Filed: July 18, 2017
    Date of Patent: October 23, 2018
    Assignee: TDK Corporation
    Inventors: Tetsuhito Shinohara, Tetsuya Roppongi, Naomichi Degawa
  • Patent number: 10032470
    Abstract: A magnetic recording head comprises: a main magnetic pole for generating a recording magnetic field applied to a magnetic recording medium from an end surface that is one part of an air bearing surface facing the magnetic recording medium; a trailing shield that is placed by interposing a write gap at a trailing side of the main magnetic pole; and a spin torque oscillator provided in the write gap; wherein, when viewed from the air bearing surface side, the length in the down-track direction between the trailing shield and the cross-track direction end portion of a first end face positioned at the main magnetic pole side of the spin torque oscillator is longer than the length in the down-track direction between the trailing shield and the main magnetic pole at a center position in the cross-track direction of the spin torque oscillator.
    Type: Grant
    Filed: July 14, 2017
    Date of Patent: July 24, 2018
    Assignee: TDK Corporation
    Inventors: Naomichi Degawa, Tetsuhito Shinohara, Shinji Hara, Tetsuya Roppongi
  • Patent number: 9934797
    Abstract: A base multilayer body is made by laminating a seed layer and a buffer layer in respective order. The seed layer is an alloy layer containing tantalum (Ta) and at least one type of other metal, and having an amorphous structure or a microcrystal structure. The buffer layer is an alloy layer having a [001] plane orientation hexagonal close-packed structure and containing at least one type of a group VI metal and at least one type of a group IX metal in the periodic table. With this configuration, a magnetic layer providing a desired magnetic characteristic(s) can be laminated on the thinned base multilayer body.
    Type: Grant
    Filed: April 26, 2016
    Date of Patent: April 3, 2018
    Assignee: TDK Corporation
    Inventors: Hirokazu Takahashi, Tetsuya Roppongi, Yoshikazu Soeno
  • Patent number: 9824701
    Abstract: A microwave assisted magnetic head includes a main magnetic pole; a trailing shield; and a spin torque oscillator provided between the main magnetic pole and the trailing shield. The spin torque oscillator has a first end surface configuring a part of an air bearing surface, a second end surface facing the main magnetic pole, and a third end surface facing the first end surface, the first angle ?1 made by the first end surface and the second end surface is smaller than the second angle ?2 formed by the second end surface and the third end surface, and the second angle ?2 is 80 to 100 degrees.
    Type: Grant
    Filed: April 26, 2016
    Date of Patent: November 21, 2017
    Assignee: TDK Corporation
    Inventors: Zhenyao Tang, Tetsuya Roppongi, Yoshikazu Soeno, Hironobu Matsuzawa, Hirokazu Takahashi