Patents by Inventor Yimin Hsu

Yimin Hsu 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: 20050068671
    Abstract: The invention is a magnetic transducer with separated read and write heads for perpendicular recording. The write head has a trailing shield that extends from the return pole piece toward the main pole piece to form the write gap at the air-bearing surface. One embodiment of the trailing shield is a two part structure with a pedestal and a much smaller tip that confronts the main pole piece at the gap. In one embodiment a sink of non-magnetic, electrically conductive material is disposed in the separation gap between the read head and the flux bearing pole piece. The sink is preferably made of copper and does not extend to the ABS.
    Type: Application
    Filed: September 29, 2003
    Publication date: March 31, 2005
    Inventors: Yimin Hsu, Quang Le, Hin Lee, James Nix, Aron Pentek, Kurt Rubin, Neil Smith, Nian Sun, Walter Weresin, Mason Williams
  • Publication number: 20050007697
    Abstract: A magnetic transducer with a write head with one or more coil layers and a pedestal pole piece on P1 is disclosed. In one embodiment the first and second coils and the P1 pedestal are formed on essentially planarized surfaces. The P1 pedestal defines the zero throat height (ZTH) with a 90 degree apex angle which cuts down flux leakage and improves efficiency. The first and second coils are disposed on opposite sides of the gap layer. The write head preferably has upper and lower back flux closure pieces in contact with the pole pieces to complete the back of the yoke. Various combinations of these features allow heads according to the invention to be made with a very short yoke with resulting improved efficiency. In alternative embodiments the coil below the gap layer may be omitted and/or an additional coil above the gap layer may be added.
    Type: Application
    Filed: August 4, 2004
    Publication date: January 13, 2005
    Inventors: Yimin Hsu, Hugo Santini, Neil Smith, Mason Williams
  • Publication number: 20040257699
    Abstract: A thin film inductive write head for magnetic recording has a write gap formed as a lamination of alternating layers of a nonmagnetic gap layer and a ferromagnetic spacer layer. There are N gap layers and N-1 spacer layers, with each pole tip of the write head being located adjacent to a gap layer. The spacer layers in the gap structure are formed of a ferromagnetic material with a high saturation moment density (Bs) that is close to the Bs of the spacer material from which the pole tips are formed. Unlike the pole tips, the spacer layers are not part of a magnetic circuit and are magnetically isolated, i.e., completely surrounded by nonmagnetic gap material. The effect of the spacer layers is to effectively divide the gap into a plurality of smaller gaps. The write head with the laminated gap creates a write bubble that is narrower in the off-track direction and wider in the in-track direction.
    Type: Application
    Filed: July 13, 2004
    Publication date: December 23, 2004
    Inventors: Yimin Hsu, Ching Hwa Tsang
  • Patent number: 6833976
    Abstract: A thin film inductive write head for magnetic recording has a write gap formed as a lamination of alternating layers of a nonmagnetic gap layer and a ferromagnetic spacer layer. There are N gap layers and N−1 spacer layers, with each pole tip of the write head being located adjacent to a gap layer. The spacer layers in the gap structure are formed of a ferromagnetic material with a high saturation moment density (BS) that is close to the BS of the spacer material from which the pole tips are formed. Unlike the pole tips, the spacer layers are not part of a magnetic circuit and are magnetically isolated, i.e., completely surrounded by nonmagnetic gap material. The effect of the spacer layers is to effectively divide the gap into a plurality of smaller gaps. The write head with the laminated gap creates a write bubble that is narrower in the off-track direction and wider in the in-track direction.
    Type: Grant
    Filed: May 15, 2002
    Date of Patent: December 21, 2004
    Assignee: International Business Machine Corporation
    Inventors: Yimin Hsu, Ching Hwa Tsang
  • Publication number: 20040252410
    Abstract: A magnetic head which includes a pole piece with a double pedestal structure has improved overwrite capabilities and reduced fringing fields. The magnetic head has first and second pole pieces and a gap layer which separates the first and the second pole pieces. The first pole piece includes a first pole piece layer, a bottom pedestal portion formed over the first pole piece layer at an air bearing surface (ABS), and a top pedestal portion formed over the bottom pedestal portion. The top pedestal portion has a thickness that is no more than half of that of the bottom pedestal portion and a length that is no more than half of that of the bottom pedestal portion. Advantageously, a throat height of the magnetic head is reduced from use of the top pedestal portion whereas the mechanical reliability of the first pole piece is increased from use of the bottom pedestal portion.
    Type: Application
    Filed: June 16, 2003
    Publication date: December 16, 2004
    Inventors: Yimin Hsu, Gautam Mohan Khera, Yong Shen
  • Publication number: 20040070872
    Abstract: A magnetic head assembly includes first and second pole pieces and first and second coil layers wherein the second pole piece has a ferromagnetic pole tip which forms a portion of an air bearing surface and defines a track width of a write head. A write gap layer is located between the first pole piece and the pole tip. A dielectric first insulation layer interfaces first and second side surfaces of the pole tip and is located between the first and second coil layers. The second pole piece has a ferromagnetic second pole piece structure which is magnetically connected to each of the pole tip and the first pole piece and extends across the second coil layer. In a first embodiment the second pole piece structure is a single layer and in a second embodiment the second pole piece structure has front and back components with a flat laminated second pole piece yoke layer located therebetween.
    Type: Application
    Filed: June 30, 2003
    Publication date: April 15, 2004
    Applicant: Hitachi Global Storage Technologies
    Inventors: Yimin Hsu, Hugo Alberto Emilio Santini, Neil Smith, Mason Lamar Williams
  • Patent number: 6693769
    Abstract: A magnetic head assembly includes first and second pole pieces and first and second coil layers wherein the second pole piece has a ferromagnetic pole tip which forms a portion of an air bearing surface and defines a track width of a write head. A write gap layer is located between the first pole piece and the pole tip. A dielectric first insulation layer interfaces first and second side surfaces of the pole tip and is located between the first and second coil layers. The second pole piece has a ferromagnetic second pole piece structure which is magnetically connected to each of the pole tip and the first pole piece and extends across the second coil layer. In a first embodiment the second pole piece structure is a single layer and in a second embodiment the second pole piece structure has front and back components with a flat laminated second pole piece yoke layer located therebetween.
    Type: Grant
    Filed: June 18, 2001
    Date of Patent: February 17, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yimin Hsu, Hugo Alberto Emilio Santini, Neil Smith, Mason Lamar Williams
  • Patent number: 6671127
    Abstract: A thermally-assisted magnetic recording (TAMR) write head simultaneously generates heat and a magnetic write field to the recording layer on a magnetic recording disk. The write head is located on the trailing face of a head carrier in a TAMR disk drive and comprises a single turn coil, part of which is a current strip having an edge located at the disk-facing surface of the head carrier. When write current is passed through the current strip heat is generated at the edge of the strip and a magnetic write field is induced at the disk surface. The strip edge has a predetermined width that substantially corresponds to the desired track width of the data bits. Because both heat and the magnetic write field are generated by the same element, the heat gradient and the magnetic write field gradient are co-located on the spot where the data bit is written.
    Type: Grant
    Filed: July 25, 2001
    Date of Patent: December 30, 2003
    Assignee: International Business Machines Corporation
    Inventors: Yimin Hsu, Andreas Moser, Hemantha K. Wickramasinghe, Xiao Z. Wu
  • Publication number: 20030214753
    Abstract: A thin film inductive write head for magnetic recording has a write gap formed as a lamination of alternating layers of a nonmagnetic gap layer and a ferromagnetic spacer layer. There are N gap layers and N−1 spacer layers, with each pole tip of the write head being located adjacent to a gap layer. The spacer layers in the gap structure are formed of a ferromagnetic material with a high saturation moment density (BS) that is close to the BS of the spacer material from which the pole tips are formed. Unlike the pole tips, the spacer layers are not part of a magnetic circuit and are magnetically isolated, i.e., completely surrounded by nonmagnetic gap material. The effect of the spacer layers is to effectively divide the gap into a plurality of smaller gaps. The write head with the laminated gap creates a write bubble that is narrower in the off-track direction and wider in the in-track direction.
    Type: Application
    Filed: May 15, 2002
    Publication date: November 20, 2003
    Inventors: Yimin Hsu, Ching Hwa Tsang
  • Publication number: 20030021191
    Abstract: A thermally-assisted magnetic recording (TAMR) write head simultaneously generates heat and a magnetic write field to the recording layer on a magnetic recording disk. The write head is located on the trailing face of a head carrier in a TAMR disk drive and comprises a single turn coil, part of which is a current strip having an edge located at the disk-facing surface of the head carrier. When write current is passed through the current strip heat is generated at the edge of the strip and a magnetic write field is induced at the disk surface. The strip edge has a predetermined width that substantially corresponds to the desired track width of the data bits. Because both heat and the magnetic write field are generated by the same element, the heat gradient and the magnetic write field gradient are co-located on the spot where the data bit is written.
    Type: Application
    Filed: July 25, 2001
    Publication date: January 30, 2003
    Inventors: Yimin Hsu, Andreas Moser, Hemantha K. Wickramasinghe, Xiao Z. Wu
  • Publication number: 20020191349
    Abstract: A magnetic head assembly includes first and second pole pieces and first and second coil layers wherein the second pole piece has a ferromagnetic pole tip which forms a portion of an air bearing surface and defines a track width of a write head. A write gap layer is located between the first pole piece and the pole tip. A dielectric first insulation layer interfaces first and second side surfaces of the pole tip and is located between the first and second coil layers. The second pole piece has a ferromagnetic second pole piece structure which is magnetically connected to each of the pole tip and the first pole piece and extends across the second coil layer. In a first embodiment the second pole piece structure is a single layer and in a second embodiment the second pole piece structure has front and back components with a flat laminated second pole piece yoke layer located therebetween.
    Type: Application
    Filed: June 18, 2001
    Publication date: December 19, 2002
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Yimin Hsu, Hugo Alberto Emilio Santini, Neil Smith, Mason Lamar Williams
  • Publication number: 20020191334
    Abstract: A magnetic transducer with a write head with one or more coil layers and a pedestal pole piece on P1 is disclosed. In one embodiment the first and second coils and the P1 pedestal are formed on essentially planarized surfaces which allows maximum precision to be obtained from the photolithography. The P1 pedestal defines the zero throat height (ZTH) with a 90 degree apex angle which cuts down flux leakage and improves efficiency. The P1 pedestal allows the coil turns to be located close to the write gap to increase the magnetic efficiency. The P1 pedestal also acts as a domain control element. The first and second coils are disposed on opposite sides of the gap layer. The write head preferably has upper and lower back flux closure pieces in contact with the pole pieces to complete the back of the yoke. Various combinations of these features allow heads according to the invention to be made with a very short yoke with resulting improved efficiency.
    Type: Application
    Filed: June 18, 2001
    Publication date: December 19, 2002
    Inventors: Yimin Hsu, Hugo Alberto Emilio Santini, Neil Smith, Mason Lamar Williams
  • Patent number: 6259583
    Abstract: The present invention is a magnetic head which has a preferably planar pole member having a yoke and a tip with a first planar pole P1 and a second planar pole P2 positioned above pole P1. The pole member is built up of two types of layers: a first type of layer with high magnetic permeability &mgr; and low anisotropy Hk, with the easy axis oriented substantially perpendicular to the flux propagation direction to ensure rapid response, and a second layer type which is non-magnetic. The magnetic head also has a domain control element whose magnetization in the vicinity of the pole tip P2 and in the absence of applied field is aligned along the length of the element so as to facilitate the conduction of flux between poles P1 and P2. The domain control element can be a non-laminated element made of a material with high saturation magnetization MS such as NiFe, Ni80Fe20, Ni45Fe55, NiFeCo, FeCo, CoZrNb, FeAlN and FeTaN and proper dimensioning of the element further increases the flux conduction efficiency.
    Type: Grant
    Filed: September 16, 1998
    Date of Patent: July 10, 2001
    Assignee: International Business Machines, Corporation
    Inventors: Robert Edward Fontana, Jr., Yimin Hsu, Prakash Kasiraj, Mason Lamar Williams
  • Patent number: 5703485
    Abstract: A method for determining through a test structure a longitudinal magnetic exchange field within a patterned exchange biased magnetoresistive (MR) sensor element. To practice the method, there is first provided a substrate. Formed upon the substrate is a patterned magnetoresistive (MR) layer which has a projected length upon the substrate and a projected width upon the substrate. There is formed at a pair of separated locations over the patterned magnetoresistive (MR) layer a pair of patterned conductor lead layers. The pair of patterned conductor lead layers is separated by a track width of the patterned magnetoresistive (MR) layer, where the track width is smaller than the projected width.
    Type: Grant
    Filed: July 29, 1996
    Date of Patent: December 30, 1997
    Assignee: Headway Technologies, Inc.
    Inventors: Yimin Guo, Kochan Ju, Yimin Hsu
  • Patent number: 5684658
    Abstract: A method for forming a dual stripe magnetoresistive (DSMR) sensor element, and the dual stripe magnetoresistive (DSMR) sensor element formed through the method. To practice the method, there is formed upon a substrate a first magnetoresistive (MR) layer, where the first magnetoresistive (MR) layer has a first sensor region longitudinally magnetically biased in a first longitudinal bias direction through a patterned first longitudinal magnetic biasing layer. There is then formed a second magnetoresistive (MR) layer parallel with and separated from the first magnetoresistive (MR) layer by an insulator layer. The second magnetoresistive (MR) layer has a second sensor region longitudinally magnetically biased in a second longitudinal bias direction through a patterned second longitudinal magnetic biasing layer. The first longitudinal bias direction and the second longitudinal bias direction are substantially parallel. In addition, the first sensor region and the second sensor region are physically offset.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: November 4, 1997
    Assignee: Headway Technologies, Inc.
    Inventors: Xizeng Shi, Yimin Guo, Kochan Ju, Cherng-Chyi Han, Yimin Hsu, Jei-Wei Chang