Patents by Inventor Xiaozhong Dang

Xiaozhong Dang 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: 6791793
    Abstract: A read/write head and method of making the same, are used in a data storage system, such as a disk drive, for perpendicular magnetic recording of data. The head employs a two-layer pole design with a main pole made of sputtered high moment magnetic material, and an adjunct pole made of electroplated soft magnetic film. The adjunct pole is substantially recessed from the air bearing surface. The present head design significantly enhances the magnetic write field, and substantially reduces side-writing that result in accidental erasure of data in adjacent tracks on the magnetic recording medium.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: September 14, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Yingjian Chen, Xiaozhong Dang, Francis H. Liu, Kroum Stoev, Hai Jiang, Yugang Wang, Xizeng Shi
  • Patent number: 6778358
    Abstract: In one aspect, a laminated structure including a first plurality of layers containing primarily-iron FeCoN interleaved with a second plurality of layers containing primarily iron FeNi is disclosed. The structure has an easy axis of magnetization and a hard axis of magnetization, has a magnetic saturation of at least about twenty-three-thousand Gauss, and has a magnetic coercivity measured substantially along its hard axis of magnetization that is less than two Oersted. Additional elements can be added in minority concentrations to form primarily-iron FeCoN layers with increased resistivity. The laminated structure has applicability in various fields in which high saturation magnetization, magnetically soft materials are advantageous, particularly for inductive heads.
    Type: Grant
    Filed: May 1, 2002
    Date of Patent: August 17, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Hai Jiang, Yingjian Chen, Xiaozhong Dang, Mohamad T. Krounbi
  • Patent number: 6737281
    Abstract: A method of making an inductive transducer having inorganic nonferromagnetic material disposed in an apex region adjacent to a submicron nonferromagnetic gap in a magnetic core. The inorganic nonferromagnetic apex region can be made by chemical etching of a layer of inorganic nonferromagnetic material, deposition of inorganic nonferromagnetic material through a mask that is then lifted-off, or anisotropic etching of a layer of inorganic nonferromagnetic material that is covered by a hardbaked photoriesist mask.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: May 18, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Xiaozhong Dang, Yingjian Chen, Aiguo Feng
  • Publication number: 20040075943
    Abstract: A method and system for providing a thin film recording head are disclosed. The method and system include providing a first pole, providing a second pole and providing a write gap separating the first pole from the second pole. The method and system further include providing at least one coil having a plurality of turns. A portion of each of the plurality of turns is between the first and the second pole. The plurality of turns wind around the second pole.
    Type: Application
    Filed: October 21, 2002
    Publication date: April 22, 2004
    Inventors: Hai Jiang, Yingjian Chen, Xiaozhong Dang, James Wang
  • Patent number: 6724572
    Abstract: In one aspect, an inductive transducer is disclosed having a leading pole layer and a leading pole tip, with the pole layer being further removed than the pole tip from a media-facing surface. In another aspect, an inductive transducer is disclosed having a magnetic pedestal disposed between a leading pole layer and a leading pole tip, with at least one of the pedestal and pole layer being further removed than the pole tip from a media-facing surface. In another aspect, a leading pole layer or pedestal may have a surface that slopes away from the media-facing surface with increasing distance forward from the leading pole tip.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: April 20, 2004
    Assignee: Western Digital, Inc.
    Inventors: Kroum Stoev, Yugang Wang, Francis Liu, Yingjian Chen, Xiaozhong Dang
  • Publication number: 20040027716
    Abstract: A writer for high frequency, data storage heads. The writer includes a first magnetic pole upon which a write gap pedestal is formed with an upper pedestal layer of high moment material with a planar upper surface. An electrical coil is formed on the first magnetic pole. A write gap layer is deposited on the upper surface of the upper pedestal layer. The writer includes a second magnetic pole disposed above the first magnetic pole with a magnetic, flat, top pole layer. The second magnetic pole includes a bottom shaper fabricated from high moment material positioned between the coil and the top pole layer. An insulation insert separates the bottom shaper from the upper pedestal layer. The second magnetic pole includes a thin dielectric lamination layer that separates the top pole layer from the bottom shaper to disrupt the path of eddy current in the second magnetic pole.
    Type: Application
    Filed: August 6, 2002
    Publication date: February 12, 2004
    Inventors: Yingjian Chen, Xiaozhong Dang, Mohamad T. Krounbi, George V. Kelley
  • Publication number: 20030202278
    Abstract: An inductive write head structure incorporating a high moment film in conjunction with at least one pole (e.g., the bottom pole) for use with magnetic storage media and a process for producing the same in which a lift-off photoresist mask is used prior to the deposition of the high moment sputtered film. Following the lift-off process, the high moment film remains on the bottom pole (“P1”) pedestal (in the case of a PDZT type write head) or on the P1 itself (in the case of a Stitched Pole write head). The edge of the lift-off sputtered film is then covered by cured photoresist insulation which is placed at a distance away from the air bearing surface (“ABS”). The coverage of insulation at the edge of the sputtered film is desirable in order to avoid forming a topographic step which may have undesired consequences in the subsequent top pole formation processes.
    Type: Application
    Filed: April 29, 2002
    Publication date: October 30, 2003
    Inventors: Yingjian Chen, Xiaozhong Dang
  • Patent number: 6624452
    Abstract: A GaN-based HFET includes a set of layers all having a common face polarity, i.e., all being either Ga-face or N-face. One of the layers is a thin barrier layer having a first face with a positive charge and a second face with a negative charge thereby causing a potential change to occur between the two faces. The if potential change causes the barrier layer to prevent electron flow from a channel layer into a buffer layer. The GaN-based HFET may also be fabricated without a top barrier layer to obtain an inverted GaN-based HFET.
    Type: Grant
    Filed: July 30, 2001
    Date of Patent: September 23, 2003
    Assignee: The Regents of the University of California
    Inventors: Edward T. Yu, Peter M. Asbeck, Silvanus S. Lau, Xiaozhong Dang
  • Publication number: 20020036287
    Abstract: A GaN-based HFET includes a set of layers all having a common face polarity, i.e., all being either Ga-face or N-face. One of the layers is a thin barrier layer having a first face with a positive charge and a second face with a negative charge thereby causing a potential change to occur between the two faces. The if potential change causes the barrier layer to prevent electron flow from a channel layer into a buffer layer. The GaN-based HFET may also be fabricated without a top barrier layer to obtain an inverted GaN-based HFET.
    Type: Application
    Filed: July 30, 2001
    Publication date: March 28, 2002
    Applicant: The Regents of the University of California
    Inventors: Edward T. Yu, Peter M. Asbeck, Silvanus S. Lau, Xiaozhong Dang