Patents Assigned to Read-Rite Corporation
  • Patent number: 6873547
    Abstract: A magnetic memory is disclosed. The magnetic memory includes a first magnetic tunneling junction and a reference magnetic tunneling junction. The first magnetic tunneling junction includes a first ferromagnetic layer, a second ferromagnetic layer and a first insulating layer between the first ferromagnetic layer and the second ferromagnetic layer. The reference magnetic tunneling junction includes a third ferromagnetic layer, a fourth ferromagnetic layer and a second insulating layer between the third ferromagnetic layer and the fourth ferromagnetic layer. The magnetic memory also includes means for comparing a first output of the first magnetic tunneling junction with a reference output of the reference magnetic tunneling junction.
    Type: Grant
    Filed: February 22, 2002
    Date of Patent: March 29, 2005
    Assignee: Read Rite Corporation
    Inventors: Xizeng(Stone) Shi, Hua-Ching Tong, Aric K. Menon
  • Patent number: 6650503
    Abstract: An inductive write element for use with a magnetic data recording and retrieval system is provided. The write element includes a magnetic yoke having an electrically conductive coil passing there through. The yoke is constructed of first and second magnetic poles, and performance of the write element is improved by the inclusion of a very thin pedestal of a high magnetic moment material on the first pole in the pole tip region. Further performance gains are realized by providing a tapered edge on the pedestal to facilitate magnetic flux flow through the pedestal.
    Type: Grant
    Filed: June 13, 2002
    Date of Patent: November 18, 2003
    Assignee: Read-Rite Corporation
    Inventors: Yingjian Chen, Ron Barr, Hua-Ching Tong, Stone Shi, Kyusik Sin
  • Patent number: 6633464
    Abstract: A magnetoresistive (MR) device includes a synthetic antiferromagnetic (AFM) layer having an Fe/FeSi/Fe construction. A first Fe layer of the synthetic AFM layer has a magnetization substantially in a first direction, while a second Fe layer of the synthetic AFM layer has a magnetization substantially in a second direction that is substantially antiparallel to the first direction. The magnetoresistive device can be a spin valve in which a first surface of the synthetic AFM layer is adjacent to a pinning layer, and a second surface of the synthetic AFM layer is adjacent to a spacer layer. Further, the spin valve includes a free layer that overlies the spacer, thereby being separated from the synthetic AFM layer by the spacer. The pinning layer, synthetic AFM layer, spacer, and free layer can be bounded by a first shield and a second shield to provide magnetic shielding of the spin valve sensor.
    Type: Grant
    Filed: December 9, 1998
    Date of Patent: October 14, 2003
    Assignee: Read-Rite Corporation
    Inventors: Chih-Huang Lai, Zhupei Shi, Hua-Ching Tong, Robert E. Rottmayer, Charles W. Miller
  • Patent number: 6618223
    Abstract: An inductive write element is disclosed for use in a magnetic data recording system. The write element provides increased data rate and data density capabilities through improved magnetic flux flow through the element. The write element includes a magnetic yoke constructed of first and second magnetic poles. The first pole includes a pedestal constructed of a high magnetic moment (high Bsat) material, which is preferably FeRhN nanocrystalline films with lamination layers of CoZrCr. The second pole includes a thin inner layer of high Bsat material (also preferably FeRhN nanocrystalline films with lamination layers of CoZrCr), the remainder being constructed of a magnetic material capable of being electroplated, such as a Ni—Fe alloy. An electrically conductive coil passes through the yoke between the first and second poles to induce a magnetic flux in the yoke when an electrical current is caused to flow through the coil.
    Type: Grant
    Filed: July 18, 2000
    Date of Patent: September 9, 2003
    Assignee: Read-Rite Corporation
    Inventors: Yingjian Chen, Hua-Ching Tong, Lei Wang, Xizeng Shi
  • Patent number: 6583961
    Abstract: An air bearing surface for use on a magnetic read/write head. The air bearing surface provides a stable flight profile while exhibiting exception load/unload characteristics through the use of a plurality of pads providing high pressure areas as well as a central cavity providing a sub-ambient pressure to counter the high pressure areas. The channel is set a predetermined distance from the leading edge of the air bearing, the predetermined distance being greater than with prior art designs. A channel extends from the leading edge to the cavity to allow airflow into the cavity. The channel and the set back of the cavity both act in conjunction to facilitate unloading of the air bearing by preventing excessive sub ambient pressures.
    Type: Grant
    Filed: September 19, 2001
    Date of Patent: June 24, 2003
    Assignee: Read-Rite Corporation
    Inventors: Pablo G. Levi, Manuel Anaya-Dufresne, Wuxing Gan, Jesse Jianxian Dong
  • Patent number: 6577470
    Abstract: A method and system for providing a tape head subassembly is disclosed. The method and system include providing a device, a left head block segment and a right head block segment. The device is for writing to a media. The left head block segment includes an integrated outrigger rail and has a first space. The right head block segment includes a first wear bar and a second wear bar and has a second space therein. The first and second wear bars are integrated as part of the right head block segment. The second space separating the first wear bar from the second wear bar and is configured to fit the device. The tape head subassembly is formed by bonding the device, the right head block segment and the left head block segment such that the device fits into the first space and the second space.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: June 10, 2003
    Assignee: Read-Rite Corporation
    Inventor: Allen G. Rumpler
  • Publication number: 20030074785
    Abstract: An apparatus and method for manufacturing magnetic head device. In one embodiment, the magnetic head device includes a thin film magnetic head element having a reproduction element part comprised of a magnetoresistance effect element formed by layering on one surface of a slider. The magnetoresistance effect element is exposed on a side to oppose a magnetic recording media. Dry etching is used to remove a degenerated layer produced on the exposed side of the magnetoresistance effect element by polishing the surface of the side opposing the magnetic recording media.
    Type: Application
    Filed: November 21, 2001
    Publication date: April 24, 2003
    Applicant: Read-Rite Corporation
    Inventors: Kazuyoshi Kubota, Masayuki Hamakawa
  • Patent number: 6552874
    Abstract: The present invention provides a shared pole magnetic read/write head for achieving optimized erase band width and a method for fabricating same. It has been found that there exists a relationship between a quantity delta defined as the difference between the width of the first pole and the width of the second pole and the resultant erase band width. The method of the present invention optimizes the erase band width by adjusting the value of delta and results in a read/write head useful in circumstances where the servo does not require small erase bands such as those resulting from a self-aligned pole structure having equal widths. Additionally, the alignment of the second pole relative to the first pole is not of critical importance in the read/write head of the present invention, the first pole being wider than the second pole.
    Type: Grant
    Filed: May 17, 2000
    Date of Patent: April 22, 2003
    Assignee: Read-Rite Corporation
    Inventors: Wenjie Chen, Renuka Apparao, Bill Crue
  • Patent number: 6552928
    Abstract: An MRAM data storage device has at least one digit line, at least one bit line, and at least one MRAM cell disposed proximate to a digit line and electrically connected to a bit line. Each end of each digit line is connected to a write current source and a write current sink. One end of each bit line is connected to a write current source and a read current source while the other end of each bit line is connected to a write current sink. Two logic signals R and D are used to determine the direction of the write current in the digit line, to select between the read current and the write current in the bit line. The state of the MRAM cell is read by detecting the voltage drop across the cell when a read current is applied.
    Type: Grant
    Filed: November 8, 2001
    Date of Patent: April 22, 2003
    Assignee: Read-Rite Corporation
    Inventors: Qiuqun Qi, Xizeng Shi
  • Publication number: 20030058581
    Abstract: Windage proximate to a spinning disk within a disk drive is directed through a plurality of apertures in a ramp situated near the outside diameter of the disk. A tab extending from a load beam that supports a slider rests on the ramp when the drive is not in use. When the drive is started the disk begins to spin and an actuator moves the load beam to bring the slider over the surface of the disk. As the load beam moves, the tab is guided along the ramp and cushioned by the air flow emerging from apertures in the ramp beneath it. When the drive is stopped the actuator brings the load beam back so that the tab engages the ramp. A cushion of air is again provided as the tab is moved along the ramp as the tab is returned to a parked position.
    Type: Application
    Filed: June 24, 2002
    Publication date: March 27, 2003
    Applicant: READ-RITE CORPORATION
    Inventors: Muhammad A. Hawwa, Jamshid Bozorgi, Aric Menon
  • Patent number: 6538850
    Abstract: In one embodiment the apparatus is a head gimbal assembly for use in a disk drive having a load/unload ramp, and includes a load beam having a pivot point, a flexure/slider assembly having a flexure and a slider, at least one limiter mounted between the flexure/slider assembly and the load beam, and a lifter tab extending from the load beam so as to be engagable with the load/unload ramp. The flexure is connected to the load beam and to the slider. The slider is positioned by the flexure to be capable of moving about the pivot point. The at least one limiter is positioned to limit movement of the flexure/slider assembly relative to the load beam. The head gimbal assembly can have a low profile by having the lifter tab extend from the load beam substantially at or below the upper surface of the load beam.
    Type: Grant
    Filed: October 6, 1999
    Date of Patent: March 25, 2003
    Assignee: Read-Rite Corporation
    Inventors: Jafar Hadian, Jamshid Bozorgi
  • Patent number: 6532823
    Abstract: A magnetoresistive (MR) transducer has at least one insulative layer made of tetrahedral amorphous carbon (ta-C). The ta-C layer is formed by filtered cathodic arc deposition, has an essentially zero concentration of hydrogen and can serve as a read gap for the transducer. The hydrogen-free t-aC read gap has high thermal conductivity, keeping an adjoining MR sensor from overheating during operation. This extends sensor lifetimes and/or improves sensor performance. The read gap also has low defects and porosity, preventing unwanted electrical conduction or shorting between a sensor and a shield. The high hardness of the read gap resists plasma and chemical etching processes such as ion milling that are used to form the sensor. The increased hardness and reduced defects and porosity allow the read gaps to be made thinner without risking electrical shorting. Other hydrogen-free t-aC layers are employed for other sensor elements where electrical insulation and reduced thickness are important.
    Type: Grant
    Filed: March 18, 1999
    Date of Patent: March 18, 2003
    Assignee: Read-Rite Corporation
    Inventors: Kenneth E. Knapp, Liubo Hong, Robert E. Rotmayer
  • Patent number: 6515791
    Abstract: An active, optical, piezoelectric actuated modulator allows switching between a reflecting state and an anti-reflecting state. The modulator, or switch, is based on the precise controlling of an air gap between a thin film membrane and a substrate. The thin film membrane is deformed by a miniaturized adaptive material, such as electrostrictive or piezoelectric (PZT) material. Maximum optical reflection is realized when the air gap is equal to a multiple of a quarter wavelength of an impinging optical beam, while anti-reflection is achieved when the thickness of the air gap is equal to zero or is different from a multiple of the quarter wavelength of the optical beam.
    Type: Grant
    Filed: February 11, 2002
    Date of Patent: February 4, 2003
    Assignee: Read-Rite Corporation
    Inventors: Muhammad A. Hawwa, Aric Menon
  • Patent number: 6515573
    Abstract: A method and system for providing a magnetoresistive sensor for reading data from a recording media is disclosed. The method and system include providing at least one barrier layer and a free layer having at least one edge. The at least one edge of the free layer is adjacent to the at least one barrier layer. The free layer is ferromagnetic and has a low coercivity. The method and system also include providing at least one hard magnetic layer. The at least one hard magnetic layer has a coercivity greater than the free layer coercivity. The at least one barrier layer is disposed between the at least one hard magnetic layer and the free layer. The at least one barrier layer is sufficiently thin to allow tunneling of charge carriers between the at least one hard magnetic layer and the free layer.
    Type: Grant
    Filed: June 19, 2000
    Date of Patent: February 4, 2003
    Assignee: Read-Rite Corporation
    Inventors: Zi-Wen Dong, Zhupei Shi, Qunwen Leng
  • Patent number: 6512659
    Abstract: The present invention is embodied in an actuator arm which is mounted to a primary actuator. The primary actuator positions the actuator arm, with a read/write head mounted to the actuator arm, across a data storage disk. The actuator arm comprises an inboard portion, an outboard portion and a pair of bimorph actuators. The inboard portion has a longitudinal axis and is attached to the primary actuator. The outboard portion has the read/write head mounted onto it. The pair of bimorph actuators are deflectable together in a common direction and are connected between the inboard and the outboard portions. Upon deflection of the bimorph actuators in the same direction, the outboard portion is translated along an at least nearly straight line transverse to the longitudinal axis of the inboard portion.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: January 28, 2003
    Assignee: Read-Rite Corporation
    Inventors: Muhammad A. Hawwa, Jamshid Bozorgi
  • Patent number: 6512690
    Abstract: In the present invention, a magnetic random access memory (MRAM) cell includes a magnetic tunnel junction (MTJ) and a transistor. This memory cell provides a boosted output signal between different MTJ states stored. A method that is used by MRAM array for providing larger output voltage signal is also disclosed. The memory may comprise a plurality of such cells which are wired to form XY array. The source of the transistor is coupled to one end of the magnetic tunneling junction, while the drain of the transistor is coupled with an output for reading the magnetic memory cell. Another end of the magnetic tunneling junction is grounded. During reading, a constant voltage is applied to the gate of the transistor in selected memory cell. The drain of the transistor is connected to supply voltage via a load. The transistor functions both as switching element and amplifier to boost the output signal between different MTJ states. Either voltage or current at output can be detected to determine MTJ state.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: January 28, 2003
    Assignee: Read-Rite Corporation
    Inventors: Qiuqun (Kevin) Qi, Xizeng Shi
  • Patent number: 6512661
    Abstract: A method and system for providing a magnetoresistive head that reads data from a recording media is disclosed. The method and system include providing a first shield, a second shield, a magnetoresistive sensor, at least one insulating bias layer and a lead. The first shield has a first end, a central portion and a second end. The first end is closer to the recording media during use than the second end. The second shield has a first end, a central portion, and a second end. The first end of the second shield is preferably separated from the first end of the first shield by a read gap. The central portion of the second shield is preferably separated from the central portion of the first shield by a distance that is greater than the read gap. The magnetoresistive sensor is disposed between the first shield and the second shield and has a front end and a back end. The front end of the magnetoresistive sensor is electrically coupled with the first end of the first shield or the first end of the second shield.
    Type: Grant
    Filed: August 10, 2000
    Date of Patent: January 28, 2003
    Assignee: Read-Rite Corporation
    Inventor: Ernest Antony Louis
  • Patent number: 6512657
    Abstract: A suspension assembly for a magnetic head reduces isolation forces caused by swaging the suspension to an actuator arm of a disk drive. The suspension is formed with a first end, and a second end having an inner periphery which defines an opening. Tabs extend from the inner periphery into the opening. A base plate with a cylindrical hub is welded to the tabs and the hub extends through the inner periphery. Multiple isolation welds formed on the suspension cooperate with the tabs to isolate forces and limit force propagation when the hub is swaged to the actuator arm.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: January 28, 2003
    Assignee: Read-Rite Corporation
    Inventors: William P. Heist, Kim Aimonetti, Dominic S. Biondo, Larry E. Tucker
  • Publication number: 20030016472
    Abstract: Windage proximate to a spinning disk within a disk drive is directed through a plurality of apertures in a ramp situated near the outside diameter of the disk. A tab extending from a load beam that supports a slider rests on the ramp when the drive is not in use. When the drive is started the disk begins to spin and an actuator moves the load beam to bring the slider over the surface of the disk. As the load beam moves, the tab is guided along the ramp and cushioned by the air flow emerging from apertures in the ramp beneath it. When the drive is stopped the actuator brings the load beam back so that the tab engages the ramp. A cushion of air is again provided as the tab is moved along the ramp as the tab is returned to a parked position.
    Type: Application
    Filed: June 24, 2002
    Publication date: January 23, 2003
    Applicant: READ-RITE CORPORATION
    Inventors: Muhammad A. Hawwa, Jamshid Bozorgi, Aric Menon
  • Patent number: 6504676
    Abstract: A magnetic head includes pole tips with aligned sidewalls and a low head profile. The aligned sidewalls are formed by depositing a stack of pole tip layers on a substrate. The stack of layers are etched through a common overlying mask. The stack of layers is covered over and around with a protective layer which is then planarized such that the stack of layers is exposed. The protective layer is etched to a predetermined thickness above the substrate, which is thinner than the thickness of the stack of layers. An inductive coil layer is deposited on the etched protective layer and covered with an overlying magnetic yoke layer which is dielectrically separated from the coil layer. The yoke layer thus formed assumes a low profile curvature due to the thin structure of the protective layer on the substrate.
    Type: Grant
    Filed: December 10, 1999
    Date of Patent: January 7, 2003
    Assignee: Read-Rite Corporation
    Inventors: Hugh C. Hiner, Billy Wayne Crue, William D. Jensen, Lien-Chang Wang, Durga P. Ravipati