Patents by Inventor Andrew Ching Tam

Andrew Ching Tam 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: 7170714
    Abstract: A magnetic head for thermally-assisted writing of data to a disk is disclosed. In one illustrative example, the magnetic head includes a write head element and a heating element which is a resistive infared radiator. The heating element is coupled to at least one via pad which is exposed on an outer surface of the magnetic head. This via pad may be the same pad utilized for the write head element or for a read sensor. The heating element is formed beneath or within the pole tip such that it is able to transfer heat to a portion of the disk before the write head element can write data to it Advantageously, the heater facilitates the writing of data to high coercivity media.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: January 30, 2007
    Assignee: International Business Machines Corporation
    Inventors: Kevin Robert Coffey, Jeffrey Scott Lille, Andrew Ching Tam
  • Patent number: 7006336
    Abstract: A magnetic head for thermally-assisted writing of data to a disk is disclosed. In one illustrative example, the magnetic head includes a write head element and a heating element which is a resistive infared radiator. The heating element is coupled to at least one via pad which is exposed on an outer surface of the magnetic head. This via pad may be the same pad utilized for the write head element or for a read sensor. The heating element is formed beneath or within the pole tip such that it is able to transfer heat to a portion of the disk before the write head element can write data to it Advantageously, the heater facilitates the writing of data to high coercivity media.
    Type: Grant
    Filed: August 6, 2002
    Date of Patent: February 28, 2006
    Assignee: International Business Machines Corporation
    Inventors: Kevin Robert Coffey, Jeffrey Scott Lille, Andrew Ching Tam
  • Publication number: 20040265646
    Abstract: A magnetic disk is provided which comprises a nonmetallic glass or glass ceramic substrate having one or more under layers, a magnetic layer applied over the under layers, and a hard carbon layer applied over the magnetic layer. A plurality of bumps are formed on the magnetic disk by applying a beam from a near infrared wavelength laser to the surface of the carbon layer.
    Type: Application
    Filed: May 28, 2004
    Publication date: December 30, 2004
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Iraj E. Kavosh, James Shuster, Andrew Ching Tam
  • Patent number: 6831249
    Abstract: A method and apparatus for producing very high crown and camber curvature in slider materials using a laser processing system which produces fluence which is variable in a controllable manner, by applying a laser beam to the flex side of the slider material and varying the fluence of the laser beam to optimize the curvature in the slider material. The fluence is variable by finely controlling the power output of the laser or by changing the spot size of the laser beam. The beam spot size can be changed by using a focusing lens to establish a focal plane and then varying the relative positions of the slider relative and the focal plane. An apparatus for producing high crown and camber is also disclosed, as well as a slider produced by the process of applying a laser beam to the flex side of the slider material and varying the fluence of the laser beam to optimize the curvature in the slider material.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: December 14, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Andrew Ching Tam, Chie Ching Poon, Ping-Wei Chang
  • Patent number: 6797130
    Abstract: A magnetic disk is provided which comprises a nonmetallic glass or glass ceramic substrate having one or more under layers, a magnetic layer applied over the under layers, and a hard carbon layer applied over the magnetic layer. A plurality of bumps are formed on the magnetic disk by applying a beam from a near infrared wavelength laser to the surface of the carbon layer.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: September 28, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Iraj Kavosh, James Shuster, Andrew Ching Tam
  • Publication number: 20040091662
    Abstract: A magnetic disk is provided which comprises a nonmetallic glass or glass ceramic substrate having one or more under layers, a magnetic layer applied over the under layers, and a hard carbon layer applied over the magnetic layer. A plurality of bumps are formed on the magnetic disk by applying a beam from a near infrared wavelength laser to the surface of the carbon layer.
    Type: Application
    Filed: June 27, 2003
    Publication date: May 13, 2004
    Inventors: Iraj Kavosh, James Shuster, Andrew Ching Tam
  • Patent number: 6710295
    Abstract: A method and apparatus for producing very high crown and camber curvature in slider materials using a laser processing system which produces fluence which is variable in a controllable manner, by applying a laser beam to the flex side of the slider material and varying the fluence of the laser beam to optimize the curvature in the slider material. The fluence is variable by finely controlling the power output of the laser or by changing the spot size of the laser beam. The beam spot size can be changed by using a focusing lens to establish a focal plane and then varying the relative positions of the slider relative and the focal plane. An apparatus for producing high crown and camber is also disclosed, as well as a slider produced by the process of applying a laser beam to the flex side of the slider material and varying the fluence of the laser beam to optimize the curvature in the slider material.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: March 23, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Andrew Ching Tam, Chie Ching Poon, Ping-Wei Chang
  • Publication number: 20040050831
    Abstract: A method and apparatus for producing very high crown and camber curvature in slider materials using a laser processing system which produces fluence which is variable in a controllable manner, by applying a laser beam to the flex side of the slider material and varying the fluence of the laser beam to optimize the curvature in the slider material. The fluence is variable by finely controlling the power output of the laser or by changing the spot size of the laser beam. The beam spot size can be changed by using a focusing lens to establish a focal plane and then varying the relative positions of the slider relative and the focal plane.
    Type: Application
    Filed: August 29, 2003
    Publication date: March 18, 2004
    Inventors: Andrew Ching Tam, Chie Ching Poon, Ping-Wei Chang
  • Publication number: 20040027728
    Abstract: A magnetic head for thermally-assisted writing of data to a disk is disclosed. In one illustrative example, the magnetic head includes a write head element and a heating element which is a resistive infared radiator. The heating element is coupled to at least one via pad which is exposed on an outer surface of the magnetic head. This via pad may be the same pad utilized for the write head element or for a read sensor. The heating element is formed beneath or within the pole tip such that it is able to transfer heat to a portion of the disk before the write head element can write data to it Advantageously, the heater facilitates the writing of data to high coercivity media.
    Type: Application
    Filed: August 6, 2002
    Publication date: February 12, 2004
    Inventors: Kevin Robert Coffey, Jeffrey Scott Lille, Andrew Ching Tam
  • Patent number: 6614519
    Abstract: An inspection system using laser light directed at an off-axis parabolic mirror which focuses the beam on the surface being inspected and also serves as the collector for scattered and specular light returned from the surface is described. Specular and scattered light returned from the surface onto the parabolic mirror is divided into appropriate fields and directed onto detectors. In the preferred embodiment a polarized laser is used in conjunction with a polarizing beam splitter and a quarter-wave plate to route the reflected beam to a detector while allowing the original beam to be directed through the same optics. The parabolic mirror and selected additional components may be commonly mounted on a translatable stage which is moved along a radius of the disk when the optical inspection is being performed. Other components of the system such as the laser can remain in a fixed position.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: September 2, 2003
    Assignee: International Business Machines Corporation
    Inventors: Milton Russell Latta, Wai Cheung Leung, Bob C. Robinson, Timothy Carl Strand, Andrew Ching Tam
  • Patent number: 6538857
    Abstract: A read head is provided with an N-cycle switch for sequentially shorting and unshorting a sense current circuit of a read head so that the read head will be protected from electrostatic discharges (ESDs) by shorting when the read head is not being tested and unshorted during tests of the read head. The shorting and unshorting switches, which are mounted on or in a slider carrying the read head, are activated by a laser beam.
    Type: Grant
    Filed: September 14, 2000
    Date of Patent: March 25, 2003
    Assignee: International Business Machines Corporation
    Inventors: Saad Doss, Glen Adam Garfunkel, Edward Hin Pong Lee, Chie Ching Poon, Neil Leslie Robertson, Andrew Ching Tam
  • Publication number: 20030044647
    Abstract: A magnetic disk is provided which comprises a nonmetallic glass or glass ceramic substrate having one or more under layers, a magnetic layer applied over the under layers, and a hard carbon layer applied over the magnetic layer. A plurality of bumps are formed on the magnetic disk by applying a beam from a near infrared wavelength laser to the surface of the carbon layer.
    Type: Application
    Filed: September 5, 2001
    Publication date: March 6, 2003
    Inventors: Iraj Kavosh, James Shuster, Andrew Ching Tam
  • Patent number: 6321440
    Abstract: A method for adjusting the curvature of an air bearing surface (ABS) of a slider having a back surface opposite the ABS. The method includes steps of repeatedly measuring the curvature of the ABS and scribing lines (e.g. with a laser scribing tool) on the back surface to partially adjust the curvature of the ABS. In each measuring/scribing installment, the curvature of the ABS is measured and compared with a final target curvature to determine a curvature difference between the measured curvature and final target curvature. Each installment of scribing lines corrects for a predetermined percentage of the curvature difference. The predetermined percentage may be different in succeeding installments. Alternatively, each installment changes the curvature of the slider to match an intermediate target curvature. In a three-installment process, for example, there will be two intermediate target curvatures and a final target curvature.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: November 27, 2001
    Assignee: International Business Machines Corporation
    Inventors: Linden James Crawforth, Chie Ching Poon, Andrew Ching Tam
  • Patent number: 6288873
    Abstract: A method for changing the curvature of an air bearing surface (ABS) of a slider after the slider is attached to a suspension. The method includes the step of scribing a surface of the suspension to alter the stress on the suspension to change the curvature of the suspension and thus cause a change in the curvature of the slider ABS. The method includes producing scribe lines by ablation and melting/resolidification of the suspension to alter the stress on the suspension, thereby also causing a change of curvature in the ABS. Scribing is performed within a scribe region, which is defined according to a slider footprint. The curvature of a suspension can be altered by scribing before the slider is attached to it thus adjusting the curvature of the suspension to reduce any undesirable slider curvature changes caused by the attachment process. The present invention also includes suspensions processed according to the method.
    Type: Grant
    Filed: October 18, 1999
    Date of Patent: September 11, 2001
    Assignee: International Business Machines Corporation
    Inventors: Paul Matthew Lundquist, Andrew Ching Tam
  • Patent number: 6255621
    Abstract: A method for cutting a ceramic wafer to form individual sliders for use in supporting the read/write heads in magnetic recording disk drives uses multiple parallel scans of a pulsed laser to ablate the ceramic material. After the wafer has been cut into individual rows, a pulsed laser beam is directed to that surface of the row that will become the disk sides of the sliders (i.e., the sides of the sliders that will face the disks in the disk drive). The laser is pulsed as the laser spot is moved along a first scan line across the surface of the wafer row to form a generally V-shaped trench. The laser spot is then moved in a direction generally perpendicular to the first scan line a distance less than the laser beam diameter, and then pulsed while the laser spot is scanned along a second line generally parallel to the first scan line.
    Type: Grant
    Filed: January 31, 2000
    Date of Patent: July 3, 2001
    Assignee: International Business Machines Corporation
    Inventors: Paul Matthew Lundquist, Andrew Ching Tam
  • Patent number: 6246543
    Abstract: A magnetic recording disk with a glass substrate is textured by a process which creates an array of bumps in a magnetic head contact start and stop (CSS) region of the disk. The texturing process uses a laser to provide pulses of predetermined energy fluence on the glass substrate to produce a plurality of raised bumps in the substrate surface, each bump having a surface elevation controllable to within a few nanometers. The bumps are created without unwanted micro-cracking or ejection of surface material by exploiting a narrow operating region below the abrupt thermal shock fluence threshold of the glass substrate. This textured glass substrate provides the magnetic recording disk with improved stiction, wear, coatability and sensor flying height properties.
    Type: Grant
    Filed: September 17, 1996
    Date of Patent: June 12, 2001
    Assignee: International Business Machines Corporation
    Inventors: Peter Michael Baumgart, Wing Pun Leung, Hung Viet Nguyen, Thao Anh Nguyen, Andrew Ching Tam, Anthony Wu
  • Patent number: 6205002
    Abstract: A disk drive having a disk with a contact start/stop (CSS) region on which a slider can rest is described. The CSS region is divided into at least three zones with the inner and outer zones having a surface topography which is different from the surface topography of the middle zone. The middle zone of the CSS region may be textured with bumps having a lower average height, a lower average density and/or a different bump diameter. The middle zone may also be left untextured. The slider is maintained over the CSS region during spin up and/or spin down.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: March 20, 2001
    Assignee: International Business Machines Corporation
    Inventors: Peter Michael Baumgart, Thomas Allen Gregory, Ulla Vasant Nayak, Thao Anh Nguyen, Michael Luis Ramirez, Andrew Ching Tam, Run-Han Wang
  • Patent number: 6118632
    Abstract: A magnetic disk with nonmagnetic information encoded under, in or above the magnetic layer of the disk is described along with the disk drive using the magnetic disks. The information may be stored as a series of laser-written marks (e.g., bumps, oxidized spots or spots with altered reflectivity) upon the surface(s) of each disk of the disk stack. The set of marks may be a series of laser bumps which serve a dual purpose as a landing zone or contact start/stop (CSS) zone for the slider and as encoded identifying information. During the manufacturing process for disk drives containing the disks, each disk's identifier can be read using outboard equipment such as an HRF tester or by means contained in the drive itself. Each disk identifier can then be stored magnetically in a special region of the hard disk reserved for use by the drive and/or within the flash memory of the hard drive. The drive can then communicate the identifier(s) to a host computer using the conventional communication hardware and firmware.
    Type: Grant
    Filed: February 12, 1997
    Date of Patent: September 12, 2000
    Assignee: International Business Machines Corporation
    Inventors: Thomas Robert Albrecht, Peter Michael Baumgart, Thao Anh Nguyen, Kurt Allen Rubin, Andrew Ching Tam
  • Patent number: RE37145
    Abstract: A disk texturing tool is used, for example, to provide textured spots in an annular portion of both sides of a hardfile disk. Disks are moved into and out of the texturing process in cassettes, through two disk-handling stations. In each disk-handling station, a lifter raises each individual disk from the cassette. The individual disk is then transferred to a pick-and-place mechanism, which moves it to a spindle. The spindle spins and translates the disk, so that both sides of the disk are exposed to beams derived from a pulsed laser. The pick-and-place mechanism then returns the disk to the lifter, which lowers it into the cassette pocket from which it was taken. The pick-and-place mechanism simultaneously moves one disk from the lifter to the spindle and another from the spindle to the lifter. While disks are moved by the pick-and-place mechanism of one disk-handling station, a disk in the spindle of the other disk-handling station is exposed to the laser beams.
    Type: Grant
    Filed: August 13, 1999
    Date of Patent: April 24, 2001
    Assignee: International Business Machines Corporation
    Inventors: Michael Barenboim, Peter Michael Baumgart, Peter Paul Chrusch, Benjamin Karni, Pieter J. M. Kerstens, Thao Anh Nguyen, Hong S. Seing, Andrew Ching Tam
  • Patent number: RE39001
    Abstract: A method for cutting a ceramic wafer to form individual sliders for use in supporting the read/write heads in magnetic recording disk drives uses multiple parallel scans of a pulsed laser to ablate the ceramic material. After the wafer has been cut into individual rows, a pulsed laser beam is directed to that surface of the row that will become the disk sides of the sliders (i.e., the sides of the sliders that will face the disks in the disk drive). The laser is pulsed as the laser spot is moved along a first scan line across the surface of the wafer row to form a generally V-shaped trench. The laser spot is then moved in a direction generally perpendicular to the first scan line a distance less than the laser beam diameter, and then pulsed while the laser spot is scanned along a second line generally parallel to the first scan line.
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: March 7, 2006
    Assignees: Electro Scientific Industries, Inc., Hitachi Global Storage Technologies, Netherlands B.V.
    Inventors: Paul Matthew Lundquist, Eugenia Tam, Yunlong Sun, Andrew Ching Tam