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).
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Patent number: 7170714Abstract: 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: GrantFiled: October 17, 2005Date of Patent: January 30, 2007Assignee: International Business Machines CorporationInventors: Kevin Robert Coffey, Jeffrey Scott Lille, Andrew Ching Tam
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Patent number: 7006336Abstract: 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: GrantFiled: August 6, 2002Date of Patent: February 28, 2006Assignee: International Business Machines CorporationInventors: Kevin Robert Coffey, Jeffrey Scott Lille, Andrew Ching Tam
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Publication number: 20040265646Abstract: 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: ApplicationFiled: May 28, 2004Publication date: December 30, 2004Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Iraj E. Kavosh, James Shuster, Andrew Ching Tam
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Patent number: 6831249Abstract: 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: GrantFiled: August 29, 2003Date of Patent: December 14, 2004Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Andrew Ching Tam, Chie Ching Poon, Ping-Wei Chang
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Patent number: 6797130Abstract: 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: GrantFiled: June 27, 2003Date of Patent: September 28, 2004Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Iraj Kavosh, James Shuster, Andrew Ching Tam
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Publication number: 20040091662Abstract: 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: ApplicationFiled: June 27, 2003Publication date: May 13, 2004Inventors: Iraj Kavosh, James Shuster, Andrew Ching Tam
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Patent number: 6710295Abstract: 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: GrantFiled: June 15, 2000Date of Patent: March 23, 2004Assignee: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Andrew Ching Tam, Chie Ching Poon, Ping-Wei Chang
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Publication number: 20040050831Abstract: 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: ApplicationFiled: August 29, 2003Publication date: March 18, 2004Inventors: Andrew Ching Tam, Chie Ching Poon, Ping-Wei Chang
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Publication number: 20040027728Abstract: 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: ApplicationFiled: August 6, 2002Publication date: February 12, 2004Inventors: Kevin Robert Coffey, Jeffrey Scott Lille, Andrew Ching Tam
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Patent number: 6614519Abstract: 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: GrantFiled: October 25, 2000Date of Patent: September 2, 2003Assignee: International Business Machines CorporationInventors: Milton Russell Latta, Wai Cheung Leung, Bob C. Robinson, Timothy Carl Strand, Andrew Ching Tam
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Patent number: 6538857Abstract: 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: GrantFiled: September 14, 2000Date of Patent: March 25, 2003Assignee: International Business Machines CorporationInventors: Saad Doss, Glen Adam Garfunkel, Edward Hin Pong Lee, Chie Ching Poon, Neil Leslie Robertson, Andrew Ching Tam
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Publication number: 20030044647Abstract: 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: ApplicationFiled: September 5, 2001Publication date: March 6, 2003Inventors: Iraj Kavosh, James Shuster, Andrew Ching Tam
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Patent number: 6321440Abstract: 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: GrantFiled: November 10, 1998Date of Patent: November 27, 2001Assignee: International Business Machines CorporationInventors: Linden James Crawforth, Chie Ching Poon, Andrew Ching Tam
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Patent number: 6288873Abstract: 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: GrantFiled: October 18, 1999Date of Patent: September 11, 2001Assignee: International Business Machines CorporationInventors: Paul Matthew Lundquist, Andrew Ching Tam
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Patent number: 6255621Abstract: 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: GrantFiled: January 31, 2000Date of Patent: July 3, 2001Assignee: International Business Machines CorporationInventors: Paul Matthew Lundquist, Andrew Ching Tam
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Patent number: 6246543Abstract: 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: GrantFiled: September 17, 1996Date of Patent: June 12, 2001Assignee: International Business Machines CorporationInventors: Peter Michael Baumgart, Wing Pun Leung, Hung Viet Nguyen, Thao Anh Nguyen, Andrew Ching Tam, Anthony Wu
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Patent number: 6205002Abstract: 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: GrantFiled: June 13, 1997Date of Patent: March 20, 2001Assignee: International Business Machines CorporationInventors: Peter Michael Baumgart, Thomas Allen Gregory, Ulla Vasant Nayak, Thao Anh Nguyen, Michael Luis Ramirez, Andrew Ching Tam, Run-Han Wang
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Patent number: 6118632Abstract: 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: GrantFiled: February 12, 1997Date of Patent: September 12, 2000Assignee: International Business Machines CorporationInventors: Thomas Robert Albrecht, Peter Michael Baumgart, Thao Anh Nguyen, Kurt Allen Rubin, Andrew Ching Tam
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Patent number: RE37145Abstract: 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: GrantFiled: August 13, 1999Date of Patent: April 24, 2001Assignee: International Business Machines CorporationInventors: Michael Barenboim, Peter Michael Baumgart, Peter Paul Chrusch, Benjamin Karni, Pieter J. M. Kerstens, Thao Anh Nguyen, Hong S. Seing, Andrew Ching Tam
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Patent number: RE39001Abstract: 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: GrantFiled: December 26, 2002Date of Patent: March 7, 2006Assignees: Electro Scientific Industries, Inc., Hitachi Global Storage Technologies, Netherlands B.V.Inventors: Paul Matthew Lundquist, Eugenia Tam, Yunlong Sun, Andrew Ching Tam