Patents by Inventor Ciuter Chang

Ciuter Chang 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: 7918013
    Abstract: A system and method for the production level screening of low flying magnetic heads in the manufacture of disk drive head disk assemblies (HDAs) is disclosed. A test disk is provided and has a plurality of bumps extending from at least one surface thereof to a predetermined height between 2 and 12 nanometers. The test disk is rotated to fly a head of a head gimbal assembly selected from the group adjacent the surface of the test disk. An interaction of the head with one or more of the plurality of bumps may be sensed and the head gimbal assembly may be screened out from the group in response to the sensing of the interaction.
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: April 5, 2011
    Assignee: Western Digital (Fremont), LLC
    Inventors: Victor K. F. Dunn, Ciuter Chang
  • Patent number: 7363697
    Abstract: A system and method for the production level screening of low flying magnetic heads in the manufacture of disk drive head disk assemblies (HDAs) is disclosed. A test disk is provided and has a plurality of bumps extending from at least one surface thereof. The test disk is rotated to fly a head of a head gimbal assembly selected from the group adjacent the surface of the test disk. An interaction of the head with one or more of the plurality of bumps may be sensed and the head gimbal assembly may be screened out from the group in response to the sensing of the interaction.
    Type: Grant
    Filed: February 18, 2005
    Date of Patent: April 29, 2008
    Assignee: Western Digital (Fremont), LLC
    Inventors: Victor K. F. Dunn, Ciuter Chang
  • Patent number: 7019945
    Abstract: An aspect of the invention can be regarded an air bearing slider for use in a disk drive including a rotatable magnetic disk. The slider includes a leading side and a trailing side. The slider further includes opposing lateral sides extending between the leading and trailing sides. The slider further includes a transducer pad disposed adjacent the trailing side. The transducer pad includes a transducer for reading and writing data from and to the magnetic disk. The slider further includes a pair of pressurized side pads each respectively disposed laterally between the transducer pad and a respective one of the lateral sides. Each side pad includes a forward shallow etched surface, a trailing shallow etched surface extending from adjacent the trailing side toward the leading side, and a side pad air bearing surface disposed between and above the forward and trailing shallow etched surfaces.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: March 28, 2006
    Assignee: Western Digital Technologies, Inc.
    Inventors: Jih-Ping Peng, Ciuter Chang, Ji-Feng Ying, Hung-Chang Ward Huang
  • Patent number: 6937439
    Abstract: A disk drive includes a disk having a recording surface and a head stack assembly. The head stack assembly includes a body portion that includes a bore defining a pivot axis, an actuator arm cantilevered from the body portion and a head gimbal assembly supported at the actuator arm. The head gimbal assembly includes a load beam, a gimbal coupled to the load beam and a slider coupled to the gimbal, the slider including a transducer for reading and writing on the recording surface. The slider includes an air bearing surface that is configured to form a shallow recessed surface and a deep recessed surface. The air-bearing surface includes a leading air bearing region and one or more insular regions configured to reduce stiction with the disk. The shallow recessed surface is disposed between the air bearing surface and the deep recessed surface.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: August 30, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Ciuter Chang, Jih-Ping Peng, Ming-Ching Tang
  • Patent number: 6912103
    Abstract: A method of operating a disk drive. The disk drive includes a disk having a disk surface, a slider disposable adjacent the disk surface, and a slider loading/unloading ramp for the slider. The method includes rotating the disk at a loading speed. The method further includes loading the slider from the loading/unloading ramp at a loading fly height above the disk surface. The method further includes rotating the disk at an operational speed greater than the loading speed. The method further includes operating the slider at an operational fly height above the disk surface less than the loading fly height above the disk surface. The method further includes rotating the disk at an unloading speed less than the operational speed. The method further includes unloading the slider from the disk to the loading/unloading ramp at an unloading fly height greater than the operational fly height.
    Type: Grant
    Filed: July 31, 2002
    Date of Patent: June 28, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Jih-Ping Peng, Ciuter Chang, Ji-Feng Ying
  • Patent number: 6690545
    Abstract: An air bearing slider for use in a disk drive that includes a rotatable magnetic disk. The slider includes a leading side and a trailing side. The slider further includes a pressurized pad including a pressurized pad air bearing surface. The pressurized pad is disposed between the leading and trailing sides. The slider further includes a contact pad disposed adjacent the trailing side and including a contact surface for sliding contact with the magnetic disk during operation of the disk drive. The contact pad includes a transducer disposed within the contact pad for reading and writing data from and to the magnetic disk. The slider further includes a depressed region disposed between the pressurized pad and the contact pad for mitigating air pressure adjacent the contact surface relative to air pressure adjacent the pressurized pad air bearing surface during operation of the disk drive.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: February 10, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Ciuter Chang, Ming-Ching Tang, Martin J. Smallen, Jih-Ping Peng
  • Patent number: 6339518
    Abstract: An air bearing slider used with a thin film magnetic head is formed with a corner recess and a taper at the leading edge. The taper is disposed between the corner recess and one side of the slider. A central polygon-shaped recess is bounded by pads which are joined by a connecting section. In an alternative embodiment, a recess at the leading edge separates the taper into sections. In another embodiment, a second corner recess is provided at the leading edge and the taper is disposed between the first and second corner recesses. The shaped recesses and tapers improve the flying characteristics of the slider and enhance air bearing stiffness. A single etch process is used to form the recesses and side reliefs of the slider.
    Type: Grant
    Filed: September 1, 1998
    Date of Patent: January 15, 2002
    Assignee: Read-Rite Corporation
    Inventors: Ciuter Chang, Christopher A. Lee, Mark J. Donovan
  • Patent number: 6229672
    Abstract: An air bearing slider for a magnetic head is defined by a leading edge and a trailing edge and has a central longitudinal axis extending from the leading edge to the trailing edge. A pair of side pads, and a center pad between the side pads that is disposed substantially on the center axis, are formed on the air bearing surface of the slider. A first central recess having a T-shaped configuration is etched to a first depth, preferably in the range of 5-30 micro-inches with reference to the air bearing surface. A second major recess portion is etched to a second depth in the range of 60-150 micro-inches. The air bearing surface is configured for high load applications and maintains a flat flying height profile. The configured slider is particularly useful with small size sliders, such as picosliders.
    Type: Grant
    Filed: October 19, 1998
    Date of Patent: May 8, 2001
    Assignee: Read-Rite Corporation
    Inventors: Christopher A. Lee, Ciuter Chang, Pablo G. Levi, Pravin P. Prabhu, Manuel Anaya-Dufresne
  • Patent number: 6178064
    Abstract: An air bearing slider used with a thin film magnetic head is formed with a corner recess and a taper at the leading edge. The taper is disposed between the corner recess and one side of the slider. A central polygon-shaped recess is bounded by pads which are joined by a connecting section. In an alternative embodiment, a recess at the leading edge separates the taper into sections. In another embodiment, a second corner recess is provided at the leading edge and the taper is disposed between the first and second corner recesses. The shaped recesses and tapers improve the flying characteristics of the slider and enhance air bearing stiffness. A single etch process is used to form the recesses and side reliefs of the slider.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: January 23, 2001
    Assignee: Read-Rite Corporation
    Inventors: Ciuter Chang, Christopher A. Lee, Mark J. Donovan
  • Patent number: 6147838
    Abstract: An air bearing slider used with a thin film magnetic head is formed with a corner recess and a taper at the leading edge. The taper is disposed between the corner recess and one side of the slider. A central polygon-shaped recess is bounded by pads which are joined by a connecting section. In an alternative embodiment, a recess at the leading edge separates the taper into sections. In another embodiment, a second corner recess is provided at the leading edge and the taper is disposed between the first and second corner recesses. The shaped recesses and tapers improve the flying characteristics of the slider and enhance air bearing stiffness. A single etch process is used to form the recesses and side reliefs of the slider.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: November 14, 2000
    Assignee: Read-Rite Corporation
    Inventors: Ciuter Chang, Christopher A. Lee, Mark J. Donovan
  • Patent number: 5889634
    Abstract: The air bearing surface of an air bearing slider is formed with first and second leading end tapers that are spaced from the sides of the slider. Air bearing pads are formed with transverse sections and longitudinal legs which define a major recessed central region. The leading end tapers and the transverse sections delineate a narrow recessed channel extending from the slider leading end to the recessed central region. Angled recessed areas are formed between the legs and sides of the slider. A third pad is located at the trailing end of the slider. As a result, the slider has virtually no roll and improved stiffness for pitch and vertical characteristics of the slider over a large range of altitudes, including sea level to about 10,000 feet above sea level.
    Type: Grant
    Filed: October 22, 1996
    Date of Patent: March 30, 1999
    Assignee: Read-Rite Corporation
    Inventors: Ciuter Chang, Yiao-Tee Hsia
  • Patent number: 5889637
    Abstract: An air bearing slider is designed with two rails and a central pad that provide positive air bearing regions to the air bearing surface of the slider, and three recess regions that are etched to a constant depth. The rails are identical and are symmetrically disposed relative to a central longitudinal axis. Each rail includes three sections: a pitch adjustment pad, a leg, and a roll adjustment pad. The pitch adjustment pad provides a balanced pressure distribution at the leading edge and optimizes the overall pitch angle of the slider. The leg extends from the pitch adjustment pad and generates counter-pressure that partially opposes the load applied by the suspension. The roll adjustment pad extends from the leg and generates an air bearing force that compensates for roll generated during slider operation. This air bearing slider design achieves constant flying height and less vertical and pitch stiffness, which will result in low contact force for pseudo-contact applications.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: March 30, 1999
    Assignee: Read-Rite Corporation
    Inventors: Ciuter Chang, Yiao-Tee Hsia, Mark J. Donovan, Pablo G. Levi
  • Patent number: 5754367
    Abstract: The air bearing surface (ABS) of an air bearing slider is formed with etched pads and a leading edge shaped shallow etch step taper region that extends continuously between first and second sides of the slider. A first pad is formed on the slider and extends from the trailing edge between the first side and a central axis and has a first extension at the step taper region. The first extension has a leading edge that is angled toward the first side of the slider. A second pad is formed on the slider and extends from the trailing edge between the second side and the central axis and has a second extension at the step taper region. The second extension has a leading edge that is angled inwardly toward the central axis. The first pad and the second pad provide an air bearing surface (ABS) for the slider. A deep central recess is bounded by the first pad, the second pad, and the step taper region.
    Type: Grant
    Filed: May 19, 1997
    Date of Patent: May 19, 1998
    Assignee: Read-Rite Corporation
    Inventors: Ciuter Chang, Pablo Gabriel Levi
  • Patent number: 5704715
    Abstract: The air bearing surface of an air bearing slider is configured with a taper formed at the slider leading end and a rail that is formed with a base and two legs. One leg extends from the base partially toward the trailing end. The other leg extends from the base to the trailing end and is integrally formed of a rectangularly shaped section and one or more polygon-shaped sections. Inner and outer recesses are defined and separated by the rail, such that the slider is effectively insensitive to changes in ambient pressure, particularly from variations in altitude, so that a substantially constant flying height can be maintained.
    Type: Grant
    Filed: December 9, 1996
    Date of Patent: January 6, 1998
    Assignee: Read-Rite Corporation
    Inventors: Ciuter Chang, Yiao-Tee Hsia, Pablo G. Levi, Christopher A. Lee
  • Patent number: 5685645
    Abstract: A sub-ambient pressure air bearing slider is configured with longitudinal air-bearing rails that have angular side recesses near the trailing end of the slider. Sub-ambient pressure regions formed within the side recesses during disk operation oppose the asymmetrical lift forces which cause undesirable roll. The slider provides improved roll and flying height characteristics.
    Type: Grant
    Filed: August 13, 1996
    Date of Patent: November 11, 1997
    Assignee: Read-Rite Corporation
    Inventors: Daniel A. Nepela, Ciuter Chang
  • Patent number: 5606476
    Abstract: The air bearing surface of an air bearing slider is formed with first and second side rails and a central recess. The rails are configured to have an inverted U-shaped section and a connecting partial trapezoidal-type section. The U-shaped section has a base joined to two spaced legs, wherein one leg is preferably longer than the other. A continuous recess is provided between the legs of each side rail and extends from the base towards the trailing end of the slider and adjacent to the trapezoidal-type section. The slider is effectively insensitive to changes in air pressure, particularly in variations in altitude, so that a substantially constant flying height can be maintained.
    Type: Grant
    Filed: July 13, 1995
    Date of Patent: February 25, 1997
    Assignee: Read-Rite Corporation
    Inventors: Ciuter Chang, Yiao-Tee Hsia
  • Patent number: 5568981
    Abstract: A negative pressure air bearing slider is provided with side rails, a central negative pressure cavity between the side rails and one or more relief vents at the leading edge of the slider. The side rails extend fully or partially from tapered regions at the leading edge of the slider to the trailing edge of the slider. Air bearing pads disposed adjacent to the front tapered regions and/or the slider trailing edge may be configured with the side rails. By virtue of the slider design, variations in flying height and roll are minimized.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: October 29, 1996
    Assignee: Read-Rite Corporation
    Inventors: Daniel A. Nepela, Ciuter Chang, Yiao-Tee Hsia, Rajendra Bhadra
  • Patent number: 5359480
    Abstract: An air bearing slider of a thin film magnetic head assembly is configured with tapered portions at its leading edge and with two side rails extending from the tapers to the trailing edge of the slider. Recesses that are formed in the rails are spaced from the tapered portions. Each rail may be configured with one or more recesses. In one embodiment, the two recesses of each rail are asymmetrically disposed relative to the tapered portion of the rail and to the trailing edge of the slider. In such embodiment, the recesses do not extend to the slider trailing edge. In alternative embodiments, the recesses are spaced from the tapered portions but extend to the trailing edge of the slider. The recesses may be arcuately shaped or have angled portions or other geometries.
    Type: Grant
    Filed: December 21, 1992
    Date of Patent: October 25, 1994
    Assignee: Read-Rite Corporation
    Inventors: Daniel A. Nepela, Chak M. Leung, Ciuter Chang