Patents Represented by Attorney Leslie G. Murray
  • Patent number: 5559051
    Abstract: A process of making an MR head having its MR stripe protected from electro-static discharge (ESD) on a slider, such as titanium carbide. The MR stripe is protected by a plurality of silicon integrated circuit devices which conduct ESD-induced current from the MR stripe to larger components in the MR head such as the first and second shield layers and the coil layer. In a preferred embodiment the integrated circuit devices and interconnects are constructed in a single crystal silicon chip. The silicon chip is fixedly mounted to a trailing edge of the slider and the MR head is mounted on a trailing edge of the silicon chip adjacent the integrated circuit devices. The invention includes a method of mass producing sliders by combining thin film technology for making MR heads with integrated circuit technology for making integrated circuit devices. These technologies are combined at the row level to ultimate completion of individual sliders.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: September 24, 1996
    Assignee: International Business Machines Corporation
    Inventors: Steven H. Voldman, Albert J. Wallash, Reginald B. Wilcox, Jr.
  • Patent number: 5545478
    Abstract: The present invention is a method for bonding a lubricant onto the surface of rotating storage media. In particular, the method bonds reactive and non-reactive lubricants onto the carbon based protective coating of a magnetic storage disk. The lubricant is first applied onto the disk surface through conventional coating techniques, such as dipping, spinning, spraying, or vapor deposition. The thickness of the applied coating is thicker than the final bonded thickness of the lubricant. Typically, the applied thickness of the film is approximately 30 Angstroms. The lubricant coated disk surface is then exposed to low energy electron irradiation. The energy level of the accelerated electrons is below 100 eV. The lubricated film is exposed to a dosage level of approximately 1000 microcoulombs per square centimeter. This dosage level bonds approximately 15 Angstroms of lubricant to the disk surface. The non-bonded or excess lubricant is then rinsed off in a liquid freon or other suitable rinse.
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: August 13, 1996
    Assignee: International Business Machine Corporation
    Inventors: Li-Ju J. Lin, John S. Foster, Christopher S. Gudeman, Gerard H. Vurens
  • Patent number: 5543989
    Abstract: Laminated films of SiAlFe alloy (sendust) providing optimized magnetic and mechanical properties for magnetic shield and magnetic pole tip applications are described. A multilayered magnetic structure including a seed layer of a first sendust alloy and a bulk layer of a second sendust alloy overlying the seed layer provides provides greatly improved anisotropic field and soft magnetic characteristics for the structure over a relatively wide range of compositions for the sendust material used for the bulk layer. The seed layer can be a single sendust layer or, alternatively, can be a multilayered structure including layers of a gas-doped sendust material and layers of non-doped sendust material formed in an alternating sequence. The dopant gas is a gas such as nitrogen, oxygen or air, for example. Because of the hardness exhibited by sendust films, the described multilayered sendust films are excellent candidates for magnetic shields and inductive pole tips exposed at the air bearing surface of a transducer.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: August 6, 1996
    Assignee: International Business Machines Corporation
    Inventor: John D. Westwood
  • Patent number: 5535073
    Abstract: A contact magnetic storage system in which the slider, which supports the magnetic read/write head, is in physical contact with a rigid magnetic storage medium during system operation at a selected operating speed. The slider material has a load versus friction characteristic that is non-linear in the negative load region. This characteristic allows the slider to be suspended from an access arm with zero or negative external loading. In a conventional magnetic storage system, at operating speed the slider is lifted away from the surface of the storage medium by at least the thickness of the air film adjacent the moving storage medium surface. In the present invention, due to the non-linear load versus friction characteristics of the slider material, a restoring force is generated at system operating speed which overcomes the lift of the air bearing and maintains the slider in contact with the storage medium surface without substantial wear or damage to either the slider or the storage medium.
    Type: Grant
    Filed: March 31, 1995
    Date of Patent: July 9, 1996
    Assignee: International Business Machines Corporation
    Inventors: Blasius Brezoczky, Hajime Seki
  • Patent number: 5532109
    Abstract: In a bi-layer lift-off process, the adhesion characteristics of a PMGI release layer are substantially improved by the use of ortho-hydroxy substituted 4-phenylazo compounds (azo dyes), a class of nonactinic dyes, as an adhesion promoter additive. These azo dyes, due to their chemical structure, exhibit selective binding to various metals by acting as a chelating ligand to the metal surface. Formulations of a specific azo dye, Sudan Orange G, at concentrations from 0.25 to 1.0 percent (by weight) in PMGI exhibits no loss of adhesion at prebake temperatures in the range of 120 to 160 degrees C.
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: July 2, 1996
    Assignee: International Business Machines Corporation
    Inventors: Mohamad T. Krounbi, Alfred F. Renaldo, Douglas J. Werner
  • 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: 5523898
    Abstract: In a magnetoresistive read/inductive write magnetic transducer, magnetic stability of the magnetoresistive read sensor is improved by reducing the bias current to the magnetoresistive read sensor to a predetermined value during a period when a write current signal is applied to the inductive write head. The reduced bias current is greater than zero, but less than that required for reading data stored in a magnetic storage media. The reduced bias current is about 30% of the full bias current applied during the read operation of the magnetoresistive head.
    Type: Grant
    Filed: November 8, 1994
    Date of Patent: June 4, 1996
    Assignee: International Business Machines Corporation
    Inventors: Stephen A. Jove, Albert J. Wallash
  • Patent number: 5512394
    Abstract: A method for fabricating a thin-film magnetic read/write head that eliminates contrast effects producing notching in a thin-film magnetic head coil caused by subsurface reflectivity at a reflective layer step during a photolithography step in the fabrication of the coil is provided. The method comprises the steps of forming a first permalloy yoke on a substrate, wherein the edges of the first yoke create steps from the top of the first yoke down to the substrate, forming a partial conformal layer of an electric insulation material over the first permalloy yoke and the substrate, forming a conformal copper seed layer over the electric insulation layer, forming a conductive coil on the electric insulation layer, wherein the copper coil is fabricated using a lithography process including placing a phase-shifting mask, formed in the image of the coil and containing non-printable openings covered by transparent material of a thickness that creates a 180.degree.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: April 30, 1996
    Assignee: International Business Machines Corporation
    Inventors: Marc D. Levenson, Hugo A. E. Santini
  • Patent number: 5508866
    Abstract: In a magnetoresistive (MR) read sensor in which the MR layer is transversely biased by a soft magnetic layer separated from the MR layer by a nonmagnetic spacer layer an antiferromagnetic stabilization layer of NiO provides a stabilizing exchange-coupled magnetic field to the transverse bias layer insuring that the transverse bias layer is fully saturated in a preferred direction during sensor operation.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: April 16, 1996
    Assignee: International Business Machines Corporation
    Inventors: Hardayal S. Gill, Tsann Lin, Ching H. Tsang, Albert J. Wallash
  • Patent number: 5503870
    Abstract: A method for producing a magnetic structure, such as a thin film magnetic head, in which the magnetic and electrical characteristics of magnetic material are tailored to produce magnetic and electrical characteristics in selected localized areas of the magnetic material. In a specific embodiment, the structure comprises a layer of magnetic material having an overlayer and an underlayer, and the magnetic characteristics of the material are modified by rapid thermal annealing.
    Type: Grant
    Filed: December 21, 1994
    Date of Patent: April 2, 1996
    Assignee: International Business Machines Corporation
    Inventors: Robert E. Fontana, Jr., Frances A. Houle, Ching H. Tsang
  • Patent number: 5492605
    Abstract: An ion beam sputter deposition system and method for the fabrication of multilayered thin film structures is described. Selected combinations of ion beam gases and energies matched to the selected target materials optimize the physical, magnetic and electrical properties of the deposited thin film layers. Matching the ion beam gas atomic mass to the target material atomic mass provides thin metal films having densities and resistivities very close to their bulk property values. Utilizing low ion beam energies in combination with high-mass ion beam gases results in the deposited thin films having low internal stress. The ratio of the ion beam gas mass to the target material mass is shown to be the determining factor for achieving the desired thin film properties in the described ion beam sputtering system.
    Type: Grant
    Filed: July 27, 1994
    Date of Patent: February 20, 1996
    Assignee: International Business Machines Corporation
    Inventor: Mustafa Pinarbasi
  • Patent number: 5492720
    Abstract: In a magnetoresistive (MR) read sensor in which the MR layer is transversely biased by a soft magnetic layer separated from the MR layer by a nonmagnetic spacer layer an antiferromagnetic stabilization layer of NiO provides a stabilizing exchange-coupled magnetic field to the transverse bias layer insuring that the transverse bias layer is fully saturated in a preferred direction during sensor operation.
    Type: Grant
    Filed: April 6, 1995
    Date of Patent: February 20, 1996
    Assignee: International Business Machines Corporation
    Inventors: Hardayal S. Gill, Tsann Lin, Ching H. Tsang, Albert J. Wallash
  • Patent number: 5491605
    Abstract: In a magnetic read/write transducer, the elements of the magnetoresistive (MR) and inductive heads are shorted together and to the slider substrate to provide a low resistance, conductive path bypassing the MR sensor element and minimizing electrical current through the MR sensor element during discharge of static electric charge. The MR sensor element, the MR conductive leads, the MR magnetic shield elements and inductive pole tips exposed at the slider air bearing surface are shorted together and to the slider substrate by a layer of conductive material, such as tungsten, formed over the slider air bearing surface. The conductive layer shorts the head elements together and to the slider substrate thus protecting the head against ESD/EOS damage during subsequent handling and assembly. The conductive layer is removed by wet etching prior to placing the magnetic head into operation in a magnetic storage system.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: February 13, 1996
    Assignee: International Business Machines Corporation
    Inventors: Timothy S. Hughbanks, Hin Pong E. Lee, Peter B. P. Phipps, Neil L. Robertson, Albert J. Wallash
  • Patent number: 5491600
    Abstract: A magnetoresistive sensor includes a magnetoresistive material, formed on a substrate, and having a first edge and a second edge. A first multilayered conductive lead structure is electrically connected to the first edge, and a second multilayered conductive lead structure is electrically connected to the second edge. The first and second conductive lead structures are constructed of multiple layers of thin film materials that alternate between at least one layer of a thin film of a refractory metal interlaid between at least two thin film layers of a highly conductive metal.
    Type: Grant
    Filed: May 4, 1994
    Date of Patent: February 13, 1996
    Assignee: International Business Machines Corporation
    Inventors: Mao-Min Chen, Mary K. Gutberlet, Mohamad T. Krounbi, Jacqueline K. Latimer, Mustafa Pinarbasi
  • Patent number: 5476680
    Abstract: A magnetoresistive read sensor incorporates a granular multilayer sensing element comprising a plurality of layers of generally flat particles of a ferromagnetic material embedded in a nonmagnetic electrically conductive material. A bias layer separated from the magnetoresistive sensing element by a spacer layer provides a magnetic field to bias the magnetoresistive sensing element at a desired non-signal point. The ferromagnetic and the nonmagnetic materials are mutually immiscible, or may be miscible or partially miscible and processed in a manner to control interdiffusion. The magnetoresistive sensing element is formed by alternatively despositing layers of ferromagnetic material and layers of nonmagnetic conductive material on a substrate and then annealing the structure.
    Type: Grant
    Filed: April 14, 1995
    Date of Patent: December 19, 1995
    Assignee: International Business Machines Corporation
    Inventors: Kevin R. Coffey, James K. Howard, Todd L. Hylton, Michael A. Parker
  • Patent number: 5465186
    Abstract: The magnetoresistive (MR) sensor in a magnetic read/write transducer is protected against the effects of electrical overstress and electrostatic discharge during the manufacture and assembly of a magnetic storage system. The conductive leads of a magnetoresistive (MR) sensor element are shorted together to provide a low resistance, conductive path bypassing the MR element and minimizing electrical current through the MR sensing element during discharge of static electrical charge. The MR sensor lead terminal pads provided on the transducer/slider surface are shorted together by soldering. The other transducer elements such as the MR magnetic shields, the inductive coil and the inductive magnetic yoke structure can also be shorted to the MR sensor leads by soldering together the lead terminal pads at the slider surface. Alternatively, a twisted conductor pair may be used to short the MR terminals together.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: November 7, 1995
    Assignee: International Business Machines Corporation
    Inventors: Christopher H. Bajorek, A. David Erpelding, Glen A. Garfunkel, Surya Pattanaik, Neil L. Robertson, Albert J. Wallash
  • Patent number: 5452163
    Abstract: A magnetoresistive read sensor incorporates a multilayer sensing element formed of one or more magnetoresistive elements in a planar array, each magnetoresistive element having a multilayer structure of at least two ferromagnetic layers separated by a nonmagnetic layer. The ferromagnetic layers are coupled antiferromagnetically by magnetostatic coupling at opposing edges of the ferromagnetic layers. A bias layer separated from the magnetoresistive sensing element by a spacer layer provides a magnetic field to bias the magnetoresistive sensing element at a desired non-signal point for linear response. The magnetoresistive sensing element is formed by alternatively depositing layers of ferromagnetic material and layers of nonmagnetic material on a substrate and then patterning the resulting structure using photolithographic techniques to provide a planar array of magnetoresistive elements.
    Type: Grant
    Filed: December 23, 1993
    Date of Patent: September 19, 1995
    Assignee: International Business Machines Corporation
    Inventors: Kevin R. Coffey, Robert E. Fontana, James K. Howard, Todd L. Hylton, Michael A. Parker, Ching H. Tsang
  • Patent number: 5448571
    Abstract: A synchronization pattern is provided within an incoming waveform which represents a serial data stream transmitted at a rate determined by a data clock. The synchronization pattern includes a periodic training portion and a sync word portion. The periodic training portion is periodic and has a preselected period. As the periodic training portion is received, a receiver clock phase-locks to the periodic training portion of the incoming waveform, and a sampling circuit periodically samples the incoming waveform relative to the phase and frequency of the receiver clock to produce sample words. Thereafter, a subset of the sample words are selected utilizing a selection pattern having a period equal to the period of the periodic training portion of the incoming waveform. Utilizing the selected subset of sample words, a sync indicator word is produced and compared to preselected criteria. Such a sync indicator word may be produced with reference to the sign of each sample word of the subset of sample words.
    Type: Grant
    Filed: April 26, 1994
    Date of Patent: September 5, 1995
    Assignee: International Business Machines Corporation
    Inventors: Ju-Hi J. Hong, Roger W. Wood
  • Patent number: 5436778
    Abstract: A magnetic disk storage system wherein a magnetic includes a magnetoresistive sensor is described. The MR sensor comprises a sputtered layer of ferromagnetic material and a sputtered layer of antiferromagnetic nickel-manganese (Ni-Mn) to provide an exchange coupled longitudinal bias field in the MR element. The antiferromagnetic layer overlays the MR layer and may be patterned to provide the longitudinal bias field only in the end regions of the MR layer. Alternatively, the antiferromagnetic layer can underlay the MR layer with a Zr underlayer to enhance the exchange-coupled field. As initially deposited, the Ni-Mn layer has a face-centered-cubic crystalline structure and exhibits little or no exchange-coupled field. After one annealing cycle at a relatively low temperature, the Ni-Mn layer crystalline structure is face-centered-tetragonal and exhibits increased crystallographic ordering and provides sufficient exchange coupling for the MR element to operate.
    Type: Grant
    Filed: March 15, 1994
    Date of Patent: July 25, 1995
    Assignee: International Business Machines Corporation
    Inventors: Tsann Lin, James K. Howard, Cherngye Hwang, Daniele Mauri, Norbert Staud
  • Patent number: 5422767
    Abstract: A multiple disk drive system having two disk-head assemblies (HDA) internally mounted on a rigid frame and accessible via a common industry-standard interface connector is provided. Each HDA is enclosed in a separate housing which is mounted on the disk drive system frame. A vibration damper mounted on the disk drive system frame physically contacts each HDA housing providing a spring force which minimizes the effects of shock and vibration on the operation of the HDAs. The vibration damper is coated with a low-wear, electrically insulating material to provide electrical isolation between the vibration damper and the HDAs housings. The coating material is chosen to also provide a desired coefficient of friction between the vibration damper and the HDA housings. A single electronic controller board is shared by both HDAs and is mounted on the bottom side of the frame underlying the HDAs. The controller board may implement SCSI or IPI interfaces in either differential or single-ended versions.
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: June 6, 1995
    Assignee: International Business Machines Corporation
    Inventors: Michael R. Hatchett, John S. Heath, Hubert C. Lee, Eun K. Row, Roger D. Spencer, Michael L. Workman