Patents by Inventor Kuok San Ho

Kuok San Ho 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: 10388305
    Abstract: Disclosed herein are apparatuses and methods for writing to a magnetic medium, and data storage devices comprising such apparatuses and methods. An apparatus comprises a main pole, a trailing shield, a write-field-enhancing structure, a write coil, a write current control circuit configured to supply a write current to the write coil to record a bit to a magnetic medium, and a driving current control circuit configured to supply a driving current to the write-field-enhancing structure, wherein the driving current comprises a driving pulse. A method of writing to a magnetic medium comprises supplying a write current to a write coil of a magnetic write head, and supplying a driving current to a free layer disposed in a write gap between a main pole and a trailing shield of the magnetic write head, wherein the driving current comprises an AC component.
    Type: Grant
    Filed: March 12, 2018
    Date of Patent: August 20, 2019
    Assignee: Western Digital Technologies, Inc.
    Inventors: Gonçalo Marcos Baião De Albuquerque, Yunfei Ding, Alexander Goncharov, Kuok San Ho, Daniele Mauri, Goran Mihajlovic, Suping Song, Petrus Antonius Van Der Heijden
  • Publication number: 20190251991
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, side shields surrounding at least a portion of the main pole, and a structure disposed between the trailing shield and the main pole. The structure includes one or more layers and a seed layer. The seed layer is connected to one or more electrical leads to provide an electrical path from the leads to the one or more layers during operation. The seed layer guides the electrical current to the one or more layers and improves heat dissipation of the one or more layers, leading to a reduction in hot spots formed in the one or more layers.
    Type: Application
    Filed: February 15, 2019
    Publication date: August 15, 2019
    Inventors: Quang LE, Hongquan JIANG, Michael Kuok San HO
  • Publication number: 20190251992
    Abstract: The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The head includes a main pole at a media facing surface (MFS), a trailing shield at the MFS, and a MAMR stack disposed between the main pole and the trailing shield at the MFS. The MAMR stack includes a seed layer and at least one magnetic layer. The seed layer is fabricated from a thermally conductive material having electrical resistivity lower than that of the main pole. The seed layer has a stripe height greater than a stripe height of the at least one magnetic layer. With the extended seed layer, the bias current from the trailing shield to the main pole spreads further away from the MFS along the extended seed layer before flowing into the main pole, reducing temperature rise at or near the MAMR stack, leading to improved write head reliability.
    Type: Application
    Filed: February 14, 2019
    Publication date: August 15, 2019
    Inventors: Michael Kuok San HO, Yunfei DING, Zhigang BAI, Yaguang WEI, Terence LAM, Goncalo BAIAO DE ALBUQUERQUE, Xinjiang SHEN, Feng Q. LIU
  • Publication number: 20190147907
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a main pole, a trailing shield, and an oscillator located between the main pole and the trailing shield. The oscillator is disposed at a media facing surface (MFS). The oscillator includes a spin-torque layer sandwiched between two distinct spin Hall layers. The two distinct spin Hall layers generate spin-orbit torque (SOT) that induces in-plane precessions on opposite surfaces of the spin-torque layer, and both in-plane precessions are in the same direction. The same-direction in-plane precessions on opposite surfaces of the spin-torque layer reduce the critical current of the oscillation of the oscillator, leading to high quality recording.
    Type: Application
    Filed: January 9, 2019
    Publication date: May 16, 2019
    Inventors: Zhanjie LI, Suping SONG, Michael Kuok San HO
  • Patent number: 10276208
    Abstract: A data storage device is disclosed comprising a head actuated over a disk surface comprising a first magnetic recording layer and a second magnetic recording layer. Data is encoded into a codeword comprising a plurality of non-binary symbols wherein each symbol represents one of a plurality of symbol values comprising a first symbol value, a second symbol value, and a third symbol value. The first symbol value is written to the disk surface by magnetizing the first and second magnetic recording layers, and the second symbol value is written to the disk surface by magnetizing the first magnetic recording layer without substantially affecting the magnetization of the second magnetic recording layer. The encoding into the codeword codes out at least one sequence of symbol values to prevent an ambiguity between detecting the first symbol value and the second symbol value during a read operation.
    Type: Grant
    Filed: May 25, 2018
    Date of Patent: April 30, 2019
    Assignee: Western Digital Technologies, Inc.
    Inventors: Zhigang Bai, Yaguang Wei, Terence Tin Lok Lam, Kuok San Ho, Lijie Guan
  • Patent number: 10210888
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a main pole, a trailing shield, and an oscillator located between the main pole and the trailing shield. The oscillator is disposed at a media facing surface (MFS). The oscillator includes a spin-torque layer sandwiched between two distinct spin Hall layers. The two distinct spin Hall layers generate spin-orbit torque (SOT) that induces in-plane precessions on opposite surfaces of the spin-torque layer, and both in-plane precessions are in the same direction. The same-direction in-plane precessions on opposite surfaces of the spin-torque layer reduce the critical current of the oscillation of the oscillator, leading to high quality recording.
    Type: Grant
    Filed: June 23, 2017
    Date of Patent: February 19, 2019
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Zhanjie Li, Suping Song, Michael Kuok San Ho
  • Patent number: 10181334
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a main pole, a spin Hall structure surrounding at least a portion of the main pole at a location that is recessed from a media facing surface (MFS), and a spin-torque structure surrounding at least a portion of the main pole at the MFS. Spin-orbit torque (SOT) is generated from the spin Hall structure. The spin-torque structure magnetization switching (or precession) is induced by the SOT. The SOT based head with the spin-torque structure increases both track density (tracks per inch) and linear density (bit per inch). The areal density capability (ADC), which is the product of tracks per inch and bit per inch, can be further improved by removing the side shield and the leading shield, when the spin-torque structure is utilized in the SOT based head.
    Type: Grant
    Filed: June 23, 2017
    Date of Patent: January 15, 2019
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Suping Song, Zhanjie Li, Michael Kuok San Ho
  • Patent number: 10157632
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a main pole, a heavy metal structure surrounding at least a portion of the main pole at a media facing surface (MFS), and two magnetic structures sandwiching the heavy metal structure. Spin-orbit torque (SOT) is generated from the heavy metal structure, inducing magnetization switching (or precession) in the magnetic structures. The SOT reduces the magnetic flux shunting from the main pole to the trailing shield, and the magnetization switching sharpens the write field profile in the cross-track direction. The SOT based head with the magnetic structures sandwiching the heavy metal structure increases both track density (tracks per inch) and linear density (bit per inch), which in turn increases the areal density capability (ADC), which is the product of tracks per inch and bit per inch.
    Type: Grant
    Filed: June 23, 2017
    Date of Patent: December 18, 2018
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Suping Song, Zhanjie Li, Michael Kuok San Ho, Quang Le, Alexander M. Zeltser
  • Patent number: 10014012
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a main pole, a spin-torque structure surrounding at least a portion of the main pole at a media facing surface (MFS), and a spin Hall structure surrounding the spin-torque structure. Strong spin-orbit torque (SOT) is generated from the spin Hall structure, enforcing in-plane magnetization oscillation in the spin-torque structure. The SOT based head with the spin Hall structure surrounding the spin-torque structure utilizes less current flowed to the spin Hall structure due to the strong SOT generated by the spin Hall structure.
    Type: Grant
    Filed: June 23, 2017
    Date of Patent: July 3, 2018
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Suping Song, Zhanjie Li, Michael Kuok San Ho
  • Patent number: 9953675
    Abstract: A system, according to one embodiment, includes: a main pole; and a trailing shield. A first distance D1 is defined in a track direction between the trailing shield and a pole tip region of the main pole; and a second distance D2 is defined in the track direction between the trailing shield and a second region of the main pole located behind the pole tip region, where D2 is greater than D1. Other systems, and methods are described in additional embodiments.
    Type: Grant
    Filed: October 9, 2017
    Date of Patent: April 24, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Kuok San Ho, Suping Song, Petrus Antonius Van Der Heijden
  • Patent number: 9947347
    Abstract: A magnetic sensor that generates a signal based on inverse spin Hall effect. The sensor includes a magnetic free layer and a non-magnetic, electrically conductive spin Hall layer located adjacent to the magnetic free layer. Circuitry is configured to supply an electrical current that travels through the magnetic free layer and the spin Hall layer in a direction that is generally perpendicular to the plane of the layers or perpendicular to a plane defined by an interface between the magnetic free layer and the spin Hall layer. The inverse spin Hall effect causes an electrical voltage in the spin Hall layer as a result of the current, and the voltage changes relative to the orientation of magnetization of the magnetic free layer. Circuitry is provided for measuring the voltage in the spin Hall layer in a direction that is generally perpendicular to the direction of the electrical current.
    Type: Grant
    Filed: December 20, 2016
    Date of Patent: April 17, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Petrus Antonius Van Der Heijden, Quang Le, Kuok San Ho, Xiaoyong Liu, Gonçalo Marcos Baião De Albuquerque
  • Publication number: 20180033458
    Abstract: A system, according to one embodiment, includes: a main pole; and a trailing shield. A first distance D1 is defined in a track direction between the trailing shield and a pole tip region of the main pole; and a second distance D2 is defined in the track direction between the trailing shield and a second region of the main pole located behind the pole tip region, where D2 is greater than D1. Other systems, and methods are described in additional embodiments.
    Type: Application
    Filed: October 9, 2017
    Publication date: February 1, 2018
    Inventors: Kuok San HO, Suping SONG, Petrus Antonius Van Der Heijden
  • Patent number: 9805753
    Abstract: A system, according to one embodiment, includes: a main pole; and a trailing shield. A first distance D1 is defined in a track direction between the trailing shield and a pole tip region of the main pole; and a second distance D2 is defined in the track direction between the trailing shield and a second region of the main pole located behind the pole tip region, where D2 is greater than D1. Other systems, and methods are described in additional embodiments.
    Type: Grant
    Filed: March 23, 2016
    Date of Patent: October 31, 2017
    Assignee: Western Digital Technologies, Inc.
    Inventors: Kuok San Ho, Suping Song, Petrus Antonius Van Der Heijden
  • Publication number: 20170278532
    Abstract: A system, according to one embodiment, includes: a main pole; and a trailing shield. A first distance D1 is defined in a track direction between the trailing shield and a pole tip region of the main pole; and a second distance D2 is defined in the track direction between the trailing shield and a second region of the main pole located behind the pole tip region, where D2 is greater than D1. Other systems, and methods are described in additional embodiments.
    Type: Application
    Filed: March 23, 2016
    Publication date: September 28, 2017
    Inventors: Kuok San Ho, Suping Song, Petrus Antonius Van Der Heijden
  • Patent number: 9269382
    Abstract: A method and system provide a magnetic read transducer having an air-bearing surface (ABS). The magnetic read transducer includes a read sensor stack and a pinning structure. The read sensor stack includes a pinned layer, a spacer layer, and a free layer. The spacer layer is nonmagnetic and between the pinned layer and the free layer. A portion of the read sensor stack is at the ABS. The pinning structure includes a hard magnetic layer recessed from the ABS, recessed from the free layer and adjacent to a portion of the pinned layer.
    Type: Grant
    Filed: December 1, 2014
    Date of Patent: February 23, 2016
    Assignee: Western Digital (Fremont), LLC
    Inventors: Gerardo A. Bertero, Kuok San Ho
  • Patent number: 9001473
    Abstract: The embodiments disclosed generally relate to a read head in a magnetic recording head. The read head utilizes a sensor structure having: a pinned magnetic structure recessed from a media facing surface; and a reader gap structure. The reader gap structure has a spacer layer recessed from the media facing surface and disposed on top of the pinned magnetic structure, a recessed first free layer partially recessed from the media facing surface and disposed on top of the barrier layer, a second free layer extending to the media facing surface an disposed on top of the barrier layer, and a cap layer extending to the media facing surface disposed atop the second free layer. The pinned magnetic structure, the spacer, and the first free layer have a common face which is on an angle relative to the media facing surface.
    Type: Grant
    Filed: March 21, 2014
    Date of Patent: April 7, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Zheng Gao, James Mac Freitag, Kuok San Ho, Ching Hwa Tsang, Kochan Ju
  • Patent number: 8860407
    Abstract: A method and system for testing a read transducer are described. The read transducer includes a read sensor fabricated on a wafer. A system includes a test structure that resides on the wafer. The test structure includes a test device and a heater. The test device corresponds to the read sensor. The heater is in proximity to the test device and is configured to heat the test device substantially without heating the read sensor. Thus, the test structure allows for on-wafer testing of the test device at a plurality of temperatures above an ambient temperature.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: October 14, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Changhe Shang, Daniele Mauri, Kuok San Ho
  • Patent number: 8675318
    Abstract: A method and system for providing a read magnetic transducer having an air-bearing surface (ABS) is described. The magnetic read transducer includes a first shield, a read sensor stack, an antiferromagnetic (AFM) tab, and a second shield. The read sensor stack includes a pinned layer, a spacer layer, and a free layer. The spacer layer is nonmagnetic and between the pinned layer and the free layer. A portion of the read sensor stack is at the ABS. The AFM tab is recessed from the ABS and adjacent to a portion of the pinned layer. The read sensor resides between the first shield and the second shield.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: March 18, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Kuok San Ho, Savas Gider, Daniele Mauri, Ming Mao, Sining Mao
  • Patent number: 8630068
    Abstract: A method and system for providing a magnetic transducer having an air-bearing surface (ABS) is described. The magnetic read transducer includes a first shield, a magnetoresistive sensor, at least one soft magnetic side shield, and a second shield. The magnetoresistive sensor includes a sensor layer having at least one edge in the track width direction along the ABS. The at least one soft magnetic side shield is adjacent to the at least one edge of the sensor layer. The at least one soft magnetic side shield has a full film permeability of at least ten. The magnetoresistive sensor is between the first shield and the second shield and free of an in-stack hard bias layer.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: January 14, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Daniele Mauri, Chih-Ching Hu, Ming Mao, Kuok San Ho, Savas Gider
  • Patent number: 8611054
    Abstract: A magnetic read transducer is described with a magnetoresistive sensor that has a free layer, and an antiferromagnetically-coupled (AFC) soft bias layer for magnetically biasing the free layer. The free layer has a first edge in a track width direction along an air-bearing surface (ABS). At least a portion of the AFC soft bias layer is conformal to at least a portion of a second edge of the free layer, and situated to form a magnetic moment at an angle with respect to a center line of the free layer. The center line of the free layer extends in the same direction as the free layer first edge that is in the track width direction along the ABS.
    Type: Grant
    Filed: April 11, 2012
    Date of Patent: December 17, 2013
    Assignee: Western Digital (Fremont), LLC
    Inventors: Changhe Shang, Daniele Mauri, Kuok San Ho, Anup G. Roy, Ming Mao