Patents by Inventor Andrew C. Tam

Andrew C. 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: 7239481
    Abstract: A magnetic head including a media heating device that is preferably fabricated within the magnetic head structure. The heating device preferably includes an electrical heating element and electrical leads, where an insulation layer disposed above the heating element is 2 to 4 times thicker than the heating element. The electrical leads preferably overlay the heating element in an overlay area of at least 1 ?m2. The heating device may be fabricated upon the surface of the magnetic head substrate prior to the fabrication of magnetic head components. The media heating device is fabricated with diffusion barrier layers and/or adhesion layers beneath the heating device layers, between heating device layers and/or above the heating device layers.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: July 3, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Jeffrey S. Lille, Andrew C. Tam
  • Patent number: 7133257
    Abstract: Embodiments include a method for adjusting the twist, crown and camber of an air bearing surface a slider to substantially match final target values for twist, crown and camber, the slider having a back surface opposite the air bearing surface. The method includes the steps of measuring the twist, crown and camber of the at least one slider. A first group of twist scribes may be formed on the back surface. A first group of crown and camber scribes are formed on the back surface. The twist, crown and camber of the slider are measured and comparing to the final target values. Additional twist scribes may be formed if the final target value for twist is not reached or if the final target value is exceeded. Additional crown and camber scribes may be formed if the final target values for crown and camber are not obtained.
    Type: Grant
    Filed: January 18, 2005
    Date of Patent: November 7, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ping-Wei Chang, Chie Ching Poon, John Raniseski, Andrew C. Tam
  • Patent number: 6888701
    Abstract: Embodiments include a method for adjusting the twist of an air bearing surface of at least one slider to substantially match a target values for twist, the at least one slider having a back surface opposite the air bearing surface, the back surface including two sets of diagonally opposite corner regions, with each set including one corner region adjacent to a leading edge of the slider and one corner region adjacent to a trailing edge of the slider. The method includes forming a first mechanical scribe on the back surface extending through at least a portion of the corner regions adjacent to the leading edge of the slider and forming a second mechanical scribe on the back surface extending through at least a portion of the corner regions adjacent to the trailing edge of the slider.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: May 3, 2005
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ping-Wei Chang, Chie Ching Poon, Andrew C. Tam
  • Patent number: 6631548
    Abstract: Methods for adjusting the curvature of a slider may include providing a first slider including an air bearing surface and a back surface opposite the air bearing surface. The camber and crown of the first slider are measured, and a plurality of scribes are made at positions on the back surface of the first slider. The change in camber and crown due to each scribe on the first slider is measured. The scribe position and change in crown and camber per position is recorded in a data structure. A second slider is provided, the second slider including an air bearing surface and a back surface opposite the air bearing surface. The camber and crown of the second slider are measured. A desired amount of change in crown and camber is determined. Scribe positions are selected based on information from the data structure so that the desired amount of change in crown and camber will be obtained. The back surface of the second slider is scribed at the selected scribe positions.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: October 14, 2003
    Assignee: International Business Machines Corporation
    Inventors: Ping-Wei Chang, Chie Ching Poon, Andrew C. Tam
  • Publication number: 20030021067
    Abstract: Embodiments include a method for adjusting the twist, crown and camber of an air bearing surface a slider to substantially match final target values for twist, crown and camber, the slider having a back surface opposite the air bearing surface, the back surface including two sets of diagonally opposite corner regions. The method includes the steps of measuring the twist, crown and camber of the at least one slider. A first group of twist scribes are formed on the back surface in one of the two sets of diagonally opposite corner regions. A first group of crown and camber scribes are formed on the back surface. The twist, crown and camber of the slider are measured and comparing to the final target values. Additional twist scribes are formed if the final target value for twist is not reached. Additional crown and camber scribes are formed if the final target values for crown and camber are not reached.
    Type: Application
    Filed: July 27, 2001
    Publication date: January 30, 2003
    Inventors: Ping-Wei Chang, Chie Ching Poon, John Raniseski, Andrew C. Tam
  • Publication number: 20030021068
    Abstract: Embodiments include a method for adjusting the twist of an air bearing surface of at least one slider to substantially match a target values for twist, the at least one slider having a back surface opposite the air bearing surface, the back surface including two sets of diagonally opposite comer regions, with each set including one comer region adjacent to a leading edge of the slider and one comer region adjacent to a trailing edge of the slider. The method includes forming a first mechanical scribe on the back surface extending through at least a portion of the corner regions adjacent to the leading edge of the slider and forming a second mechanical scribe on the back surface extending through at least a portion of the comer regions adjacent to the trailing edge of the slider.
    Type: Application
    Filed: July 27, 2001
    Publication date: January 30, 2003
    Inventors: Ping-Wei Chang, Chie Ching Poon, Andrew C. Tam
  • Publication number: 20030019095
    Abstract: Methods for adjusting the curvature of a slider may include providing a first slider including an air bearing surface and a back surface opposite the air bearing surface. The camber and crown of the first slider are measured, and a plurality of scribes are made at positions on the back surface of the first slider. The change in camber and crown due to each scribe on the first slider is measured. The scribe position and change in crown and camber per position is recorded in a data structure. A second slider is provided, the second slider including an air bearing surface and a back surface opposite the air bearing surface. The camber and crown of the second slider are measured. A desired amount of change in crown and camber is determined. Scribe positions are selected based on information from the data structure so that the desired amount of change in crown and camber will be obtained. The back surface of the second slider is scribed at the selected scribe positions.
    Type: Application
    Filed: July 27, 2001
    Publication date: January 30, 2003
    Inventors: Ping-Wei Chang, Chie Ching Poon, Andrew C. Tam
  • Patent number: 5631408
    Abstract: A method is provided for making crater shaped bumps on a magnetic disk. The crater shaped bumps have a diameter in the range of 10 to 25 .mu.m and a peripheral ridge with a height h.sub.r above a nominal surface of the calibration disk in the range of 75 to 120 nm. Close tolerance crater shaped bumps with this configuration can be made by impinging two or more pulses of laser energy on the same location of the disk. By increasing the number of pulses the height of the peripheral ridge progressively increases. By employing multiple pulses, the height of the peripheral ridge is increased while the diameter of the crater shaped bump stays substantially constant. Further, by employing multiple pulses diameters and heights of crater shaped bumps can be produced with close tolerances within a diameter range of 5 to 20 .mu.m and a height range of 2 to 120 nm.
    Type: Grant
    Filed: February 27, 1996
    Date of Patent: May 20, 1997
    Assignee: International Business Machines Corporation
    Inventors: Peter M. Baumgart, Karl A. Flechsig, Michael F. Lee, Wing P. Leung, Ullal V. Nayak, Thao A. Nguyen, Timothy C. O'Sullivan, Andrew C. Tam
  • Patent number: 5595791
    Abstract: A process for creating an array of bumps to texture a brittle nonmetallic surface, such as a glass substrate for data recording disks. The texturing process uses a laser to provide pulses of proper energy fluence to the brittle glass surface to produce a plurality of raised bumps in the surface. The bump creation is accomplished without unwanted micro-cracking or ejection of surface material by limiting the laser pulse fluence to a value in a narrow operating region discovered below the abrupt thermal shock fluence threshold for the brittle nonmetallic surface material. The process is also applicable to other brittle surface textures, such as those intended for use as "stamping surfaces" for the contact reproduction of the negative of a surface pattern, such as an optical disk.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: January 21, 1997
    Assignee: International Business Machines Corporation
    Inventors: Peter M. Baumgart, Wing P. Leung, Hung V. Nguyen, Thao A. Nguyen, Andrew C. Tam, Anthony Wu
  • Patent number: 5586040
    Abstract: Controlled laser texturing of a magnetic recording disk is accomplished by use of a textured test band on the disk and an analyzing laser system to provide feedback to the texturing laser. The analyzing laser system determines, from diffracted laser light, the average height of the laser-induced bumps formed in the test band by the texturing laser. The analyzing laser beam is directed to the substrate surface and overlaps a group of individual bumps formed in a repetitive pattern. A scanning linear photodector array receives light diffracted from the surface. The digitized output of the array is the angular distribution of diffracted light intensities and is used to compute the average height of the bumps in the test band. The disk is then translated radially so that the texturing laser is aligned with the region of the disk where the textured landing zone is to be placed.
    Type: Grant
    Filed: April 11, 1995
    Date of Patent: December 17, 1996
    Assignee: International Business Machines Corporation
    Inventors: Peter M. Baumgart, Christopher S. Gudeman, Douglas J. Krajnovich, Steven W. Meeks, Thao A. Nguyen, Fior D. Sargent, Andrew C. Tam, Gerard H. Vurens
  • Patent number: 5567484
    Abstract: A process for creating an array of bumps to texture a brittle nonmetallic surface, such as a glass substrate for data recording disks. The texturing process uses a laser to provide pulses of proper energy fluence to the brittle glass surface to produce a plurality of raised bumps in the surface. The bump creation is accomplished without unwanted micro-cracking or ejection of surface material by limiting the laser pulse fluence to a value in a narrow operating region discovered below the abrupt thermal shock fluence threshold for the brittle nonmetallic surface material. The process is also applicable to other brittle surface textures, such as those intended for use as "stamping surfaces" for the contact reproduction of the negative of a surface pattern, such as an optical disk.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: October 22, 1996
    Assignee: International Business Machines Corporation
    Inventors: Peter M. Baumgart, Wing P. Leung, Hung V. Nguyen, Thao A. Nguyen, Andrew C. Tam, Anthony Wu
  • Patent number: 5544775
    Abstract: A method is provided for making a high definition, high aspect ratio amorphous carbon element, such as a slider, which carries one or more magnetic heads in a disk drive. A special gaseous environment is provided during laser etching which results in virtually no redeposition of the etched material. The result is a carbon element which has good edge definition for establishing desirable flying characteristics of a slider. In a preferred embodiment the laser etching, which is preferably implemented by an excimer laser, is performed in an gaseous environment of oxygen saturated with water vapor at a pressure above ambient. Significant improvements were also realized with nitrogen saturated with water vapor at a pressure above ambient and steam at ambient pressure. High aspect ratios were achieved, namely slope angles of 50.degree. to 60.degree..
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: August 13, 1996
    Assignee: International Business Machines Corporation
    Inventors: Randall T. Kerth, Douglas J. Krajnovich, Murlidhar V. Kulkarni, Wing P. Leung, Andrew C. Tam
  • Patent number: 5528922
    Abstract: A method is provided for making crater shaped bumps on a calibration disk which can be used for calibrating a PZT slider, the PZT slider in turn being used for detecting predetermined asperities on a production run magnetic disk. The crater shaped bumps emulate predetermined asperities of production run magnetic disks and especially asperities which are undesirable and would cause the production run disk to be discarded after testing by the PZT slider. Crater shaped bumps which emulate undesirable asperities on current production runs of magnetic disks have a diameter in the range of 10 to 25 .mu.m and a peripheral ridge with a height h.sub.r above a nominal surface of the calibration disk in the range of 75 to 120 nm. Close tolerance crater shaped bumps with this configuration can be made by impinging two or more pulses of laser energy on the same location of a calibration disk. By increasing the number of pulses the height of the peripheral ridge progressively increases.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: June 25, 1996
    Assignee: International Business Machines Corporation
    Inventors: Peter M. Baumgart, Karl A. Flechsig, Michael F. Lee, Wing P. Leung, Ullal V. Nayak, Thao A. Nguyen, Timothy C. O'Sullivan, Andrew C. Tam
  • Patent number: 5528819
    Abstract: A disk drive assembly in which the suspension, slider and transducer are integrated and fabricated to produce a combination assembly. The combination transducer-slider-suspension assembly is batch produced by forming a plurality of the combination assemblies onto a single wafer. The wafer is then diced to separate the assemblies into individual sections. The transducers are deposited onto the wafer and the air bearing surface formed. Conductors to interconnect each transducer with the external circuits are insulated from the wafer and deposited along a path which will form the suspension. A spring-like resilient layer is then deposited over and electrically insulated from the conductors. The wafer is then pattern etched to remove a portion of the wafer backside to form the suspension and provide a transducer/slider combination having an air bearing surface after the wafer is diced to separate the individual combination assemblies.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: June 25, 1996
    Assignee: International Business Machines Corporation
    Inventors: Jeffrey M. McKay, Henry S. Nishihira, Andrew C. Tam
  • Patent number: 5421943
    Abstract: Controlled current pulses applied to a shaped resistive heating element formed on the bonding surface of a base or substrate component provide sufficient heat to the bonding interface formed between a chip and the base bonding surface to produce a high bonding temperature at the bonding interface while maintaining an opposite surface of the chip at or below a relatively low temperature critical for components formed or mounted on the chip surface. A layer of a thermally setting thin-film bonding agent is applied over a serpentine-shaped resistive heating element having a relatively narrow linewidth formed on the base component bonding surface. The chip to be bonded is retained in a desired position against the bonding surface over the heating element and bonding agent layer while a current pulse is applied to the heating element via contact pads.
    Type: Grant
    Filed: November 8, 1993
    Date of Patent: June 6, 1995
    Assignee: International Business Machines Corporation
    Inventors: Andrew C. Tam, Celia E. Yeack-Scranton
  • Patent number: 5345353
    Abstract: Slider disk stiction is reduced in a disk-based storage device by providing one or more step projections on the air bearing surface of a slider. The rear part of the step projections which rest on the disk surface projections are forward of the slider pivot point. When the slider rests on a disk surface, the step projections elevate the leading edge of the slider, which imposes a static pitch angle on the slider, reducing the slider/disk contact area. Provision is also made for contouring the slider air bearing surface adjacent to the slider leading edge, using a taper or the step projection leading face, to compress the airflow and provide a stable slider air bearing during disk file operation.
    Type: Grant
    Filed: September 21, 1992
    Date of Patent: September 6, 1994
    Assignee: International Business Machines Corporation
    Inventors: Matthias C. Krantz, Vlad J. Novotny, Timothy C. O'Sullivan, Andrew C. Tam
  • Patent number: 5326426
    Abstract: A mask for use with high energy radiation sources in precision projection processing by excimer lasers, for example, is described. The mask comprises a suitable substrate, such as silicon, upon which a multilayer dielectric stack is formed which acts as a reflective coating for the impinging excimer laser radiation, minimizing energy absorption by the mask substrate. The mask transparent areas are defined by the through-holes in the mask. The through-holes are formed with a conically undercut edge profile to define a thin object plane for the mask and minimize scattering of the radiation from the through-hole sidewalls. A method for fabricating the mask is also described.
    Type: Grant
    Filed: November 14, 1991
    Date of Patent: July 5, 1994
    Inventors: Andrew C. Tam, Gerhard E. Wolbold, Werner Zapka
  • Patent number: 4577503
    Abstract: A method and device for detecting a narrow acoustic spectral feature in a sample as described. The method uses an electrical frequency modulated (FM) signal that is obtained from a voltage controlled oscillator. The Fourier spectrum of this wave is a main frequency f.sub.c with two small sidebands at frequencies f.sub.c .+-.f.sub.s. This whole triplet is slowly swept in frequency by a slow sawtooth generator. The electrical signal is fed into a flat acoustic transducer; the acoustic wave is then transmitted through an acoustically active medium, i.e. the sample, and detected by another flat acoustic transducer which produces an FM signal with a superposed amplitude modulated (AM) signal if one of the sidebands overlaps an acoustic feature. This electrical signal is then demodulated to give a pure AM signal which can be phase sensitive detected by using a lock-in amplifier.
    Type: Grant
    Filed: September 4, 1984
    Date of Patent: March 25, 1986
    Assignee: International Business Machines Corporation
    Inventors: Wayne I. Imaino, Andrew C. Tam
  • Patent number: 4303343
    Abstract: Method and apparatus for high-sensitivity (.alpha..ltorsim.10.sup.-6 cm.sup.-1) optoacoustic (OA) spectroscopy of substantially transparent bulk condensed matter. Part of the sample to be investigated is irradiated by pulses of radiation, typically from a pulsed dye laser. The small amount of energy absorbed by the sample causes thermal expansion of the irradiated region, resulting in cylindrical stress waves being radiated from that region. These stress waves can be observed with appropriate detection means at a location remote from the source. The method is applicable to essentially transparent liquids, and solids, and to absorptive solids suspended in liquids, and the like. Possible choices of probe radiation are not only the conventional ones of visible, near UV, and near infrared electromagnetic radiation, but also, for instance, .gamma.-rays, x-rays, vacuum UV, and far infrared.
    Type: Grant
    Filed: February 29, 1980
    Date of Patent: December 1, 1981
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Chandra K. N. Patel, Andrew C. Tam
  • Patent number: RE36538
    Abstract: A disk drive assembly in which the suspension, slider and transducer are integrated and fabricated to produce a combination assembly. The combination transducer-slider-suspension assembly is batch produced by forming a plurality of the combination assemblies onto a single wafer. The wafer is then diced to separate the assemblies into individual sections. The transducers are deposited onto the wafer and the air bearing surface formed. Conductors to interconnect each transducer with the external circuits are insulated from the wafer and deposited along a path which will form the suspension. A spring-like resilient layer is then deposited over and electrically insulated from the conductors. The wafer is then pattern etched to remove a portion of the wafer backside to form the suspension and provide a transducer/slider combination having an air bearing surface after the wafer is diced to separate the individual combination assemblies.
    Type: Grant
    Filed: June 24, 1998
    Date of Patent: February 1, 2000
    Assignee: International Business Machines Corporation
    Inventors: Jeffrey M. McKay, Henry S. Nishihira, Andrew C. Tam