Magnetoresistive (mr) Reproducing Head Patents (Class 360/313)
  • Publication number: 20030124387
    Abstract: To provide an information recording medium which permits high density recording/reproduction, which has good thermal stability, and which, due to the use of an interface layer with a high sputter rate, has good recording/reproduction characteristics and is excellent for mass production. An information recording medium wherein the thickness of an interface layer 3 is 0.25 or more but 0.67 or less of the total thickness of a first protective layer 2 and the interface layer 3, and the interface layer 3 contains at least tantalum (Ta) and oxygen (O). The medium is excellent for mass production and has good recording/reproduction characteristics for high density recording/reproduction.
    Type: Application
    Filed: February 26, 2002
    Publication date: July 3, 2003
    Inventors: Akemi Hirotsune, Makoto Miyamoto, Toshimichi Shintani, Keikichi Andoo, Yumiko Anzai, Takahiro Kurokawa
  • Publication number: 20030123197
    Abstract: A magnetoresistive element including a free layer having rotatable magnetization, in which information is recorded in the magnetoresistive element by the rotation of the magnetization of the free layer, is provided. The free layer is a laminate that includes at least one ferromagnetic sublayer composed of a ferromagnetic material and at least one low-saturation-magnetization ferromagnetic sublayer having a lower saturation magnetization than that of the ferromagnetic sublayer.
    Type: Application
    Filed: December 23, 2002
    Publication date: July 3, 2003
    Applicant: Sony Corporation
    Inventors: Tetsuya Mizuguchi, Kazuhiro Bessho
  • Patent number: 6587314
    Abstract: An enhanced silicon and ceramic magnetoresistive read/write head and method for making the same is disclosed. The present invention provides reliable chemical mechanical polish etch stop by etching deep trenches into the silicon at the surrounding edges of the magnetic write and read device and filling it with a refractory metal (e.g. tungsten) so that the silicon wafer thickness will not significantly add to the length of the ABS nor to the gram load of the slider. An imbedded deformable pad will allow these bonded heads to have a high average fly height and reduce to near contact recording when reading and writing through an applied potential across a deformable pad in the silicon. The epoxy bond of the silicon to the ceramic slider consists of polymethyl methracrylate (PMMA) which can be spun on a wafer or a row of wafers with nanometer thickness repeatability and using low temperatures, i.e., <200° C.
    Type: Grant
    Filed: May 16, 2000
    Date of Patent: July 1, 2003
    Assignee: International Business Machines Corporation
    Inventor: Jeffrey S. Lille
  • Publication number: 20030112563
    Abstract: A head substrate and a protective substrate are formed of an electrostatic-discharge resistant conductive material having an electrical resistivity of 102 to 1010 &OHgr;cm. These substrates are electrically connected to a base metal through the use of conductive paste and are set to a ground potential via the base metal and a rotating drum. This suppresses a discharge current flowing through an MR element when an electrostatically charged substance touches or approaches a magnetic reproducing head, a terminal, a conducting wire, etc. to generate an electrostatic discharge. The magnetic reproducing head including an MR element and the like is prevented against an electrostatic discharge damage. It is possible to provide the magnetic reproducing head, a head drum apparatus, and a magnetic recording-reproducing apparatus which can highly effectively prevent an electrostatic discharge damage.
    Type: Application
    Filed: October 9, 2002
    Publication date: June 19, 2003
    Inventors: Yutaka Souda, Yoshimi Takahashi, Susumu Sato, Seiji Onoe
  • Patent number: 6580587
    Abstract: A magnetoresistive (GMR) sensor includes a substrate and a first trilayer disposed on the substrate. A first spacer layer is disposed on the first trilayer. A first magnetic layer is disposed on the first spacer. A second spacer layer is disposed on the first magnetic layer. A second magnetic layer is disposed on the second spacer layer. A third spacer layer is disposed on the second magnetic layer. A second trilayer is disposed on the third spacer layer and a cap layer is disposed on the second trilayer. The first and second trilayers include, a first ferromagnetic layer, a second ferromagnetic layer and an anti-parallel coupling layer disposed between and in contact with the first and second ferromagnetic layers.
    Type: Grant
    Filed: May 17, 2001
    Date of Patent: June 17, 2003
    Assignee: Seagate Technology LLC
    Inventor: Brenda A. Everitt
  • Patent number: 6574060
    Abstract: In a magnetic storage apparatus having a magnetic recording medium, a drive unit for driving this medium in a prespecified recording direction, a magnetic head assembly including a recorder section and reproduction section, a way to cause the magnetic head to move relatively with respect to the magnetic record medium, and a record/playback signal processor for performing signal inputting to the magnetic head and for effecting reproduction of an output signal from the magnetic head, the reproduction section of said magnetic head is composed of a magnetic head of the magnetoresistance effect type, while said magnetic record medium is structured including a substrate and a magnetic layer formed thereover with one or several underlayers being sandwiched therebetween, wherein at least one of hte underlayers is a specific layer that is made of amorphous or microcrystalline materials containing therein Ni as the principal or main component thereof and further containing at least one kind of element as selected from
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: June 3, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuya Kanbe, Ichiro Tamai, Yuzuru Hosoe, Kiwamu Tanahashi, Yoshio Takahashi, Fumiyoshi Kirino, Nagatugu Koiso, Satoshi Matsunuma
  • Publication number: 20030099069
    Abstract: A method of manufacturing a magnetic head manufactures a magnetic head having a base, and a laminate stacked on the base and including a magneto-resistive device. The method mechanically polishes a surface of a structure including the base and the laminate close to a magnetic recording medium, wherein the surface of the structure includes an end face of the laminate including an end face of the magneto-resistive device and a surface of the base. Next, the method selectively etches a first region on the surface of the structure close to the magnetic recording medium, wherein the first region includes the surface of the base but does not include the end face of the magneto-resistive device. Subsequently, the method entirely etches the surface of the structure close to the magnetic recording medium.
    Type: Application
    Filed: October 3, 2002
    Publication date: May 29, 2003
    Applicant: TDK Corporation
    Inventors: Takeo Kagami, Kunihiro Ueda, Kentaro Nagai, Shunji Saruki
  • Patent number: 6567246
    Abstract: A magnetoresistance effect element includes a free layer, in which a magnetization direction thereof is easily rotated in response to an external magnetic field, a first non-magnetic layer, and a first pinned layer provided on a side opposite to the free layer of the first non-magnetic layer, in which a magnetization direction of the first pinned layer is not easily rotated in response to the external magnetic field. At least one of the first pinned layer and the free layer includes a first metal magnetic film contacting the first non-magnetic layer, and a first oxide magnetic film.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: May 20, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Sakakima, Yasunari Sugita, Mitsuo Satomi, Yasuhiro Kawawake, Masayoshi Hiramoto, Nozomu Matsukawa
  • 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
  • Publication number: 20030053267
    Abstract: A method for forming top and bottom spin valve sensors and the sensors so formed, the sensors having a strongly coupled SyAP pinned layer and an ultra-thin antiferromagnetic pinning layer. The two strongly coupled ferromagnetic layers comprising the SyAP pinned layer in the top valve configuration are separated by a Ru spacer layer approximately 3 angstroms thick, while the two layers in the bottom spin valve configuration are separated by a Rh spacer layer approximately 5 angstroms thick. This allows the use of an ultra thin MnPt antiferromagnetic pinning layer of thickness between approximately 80 and approximately 150 angstroms. The sensor structure produced thereby is suitable for high density applications.
    Type: Application
    Filed: September 17, 2001
    Publication date: March 20, 2003
    Applicant: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Kochan Ju, Mao-Min Chen, Min Li, Ru-Ying Tong, Simon Liao
  • Patent number: 6534159
    Abstract: An apparatus in accordance with this invention includes an alignment mark that is formed in a substrate. The alignment mark extends across a dice line so that, upon dicing the substrate, the mark is exposed in the substrate's side edge. The mark is formed at a predetermined distance from a position at which a feature is desired to be formed on the substrate's side edge using a mask. Accordingly, the mark is a positional reference that can be used for highly accurate placement of the feature on the side surface of the substrate with the mask. Preferably, the mark is formed of metal or other material enhanced to a size that is readily detectable by an alignment system with which the mark is to be used. The invention also includes methods for making the alignment mark.
    Type: Grant
    Filed: September 10, 1999
    Date of Patent: March 18, 2003
    Assignee: Ultratech Stepper, Inc.
    Inventors: Thomas H Newman, Norbert Kappel
  • Patent number: 6532646
    Abstract: The method of manufacturing a magnetic head comprises the steps of: forming a plurality of layers, which are made from prescribed materials, on a substrate; and forming a plurality of magnetic head elements 12 on the substrate. Using a first ELG element 20, whose size in a prescribed direction is bigger than that of the magnetic head elements 12, and a second ELG element 22, whose size is equal to that of the magnetic head elements, on the substrate, a work piece is lapped, while monitoring resistance of the first ELG element 20 when the resistance of the first ELG element 20 reaches a prescribed value, the amount of lapping the work piece is adjusted on the basis of resistance of the second ELG element 22. Thus, a bar-shaped member can be precisely lapped, the magnetic heads can be manufactured without scattering their characteristics, and yield rate of manufacturing can be improved.
    Type: Grant
    Filed: October 8, 1999
    Date of Patent: March 18, 2003
    Assignee: Fujitsu Limited
    Inventor: Motoichi Watanuki
  • Publication number: 20030046807
    Abstract: The present invention is a method for fabricating a magnetoresistive reader having a sensor, current contacts with low parasitic resistance and a top shield with substantially planar topology. First, a stripe height back edge of the sensor is defined, and second, a reader width of the sensor is defined. The current contacts are deposited to a thickness such that a top surface of the current contacts is substantially level with a top surface of the sensor. The top shield is deposited over the sensor and the current contacts. Defining the stripe height back edge prior to the reader width results in current contacts with low parasitic resistance and inhibits the formation of magnetic domains in the top shield.
    Type: Application
    Filed: January 15, 2002
    Publication date: March 13, 2003
    Applicant: Seagate Technology LLC
    Inventors: Dimitar V. Dimitrov, Daniel P. Burbank, Paul E. Anderson, Richard P. Larson, Kenneth P. Naughton, Insik Jin
  • Patent number: 6532130
    Abstract: A head (130) for a disk storage device having a plurality of tracks (117) divided into memory cells (234), including a magnetic circuit (205, 230a, 230b, 250a, 250b) for reading the memory cells (234) in succession, the magnetic circuit (205, 230a, 230b, 250a, 250b) for reading the memory cells (234) including at least two partial reading components (206a, 230a, 250a; 206b, 230b, 250b) each for reading a portion (234a; 234b) of each memory cell (234), the portions (234a; 234b) being arranged transversely relative to the longitudinal axis (233) of the corresponding track (117).
    Type: Grant
    Filed: July 16, 1998
    Date of Patent: March 11, 2003
    Assignee: STMicroelectronics, S.r.l.
    Inventors: Bruno Murari, Benedetto Vigna, Paolo Ferrari
  • Publication number: 20030043512
    Abstract: A method of magnetic recording/reproducing is disclosed, which comprises reproducing with a magnetoresistive head (MR head) signals recorded in a magnetic recording medium comprising a support having thereon a magnetic layer comprising mainly ferromagnetic particles and a binder, wherein the MR head has an element thickness of 50 nm or smaller and the ferromagnetic particles are hexagonal-ferrite magnetic particles having an average tabular diameter of from 10 to 40 nm and an average tabular thickness smaller than the element thickness of the MR head used for reproduction.
    Type: Application
    Filed: June 19, 2002
    Publication date: March 6, 2003
    Applicant: FUJI PHOTO FILM CO., LTD.
    Inventor: Kiyomi Ejiri
  • Patent number: 6529352
    Abstract: The present invention is intended to improve the linear response characteristics of resistance changes to the magnetic field. According to the present invention, an MR sensing element 10 comprises a sensing pattern 12 consisting of a magnetoresistive layer whose resistance changes in accordance with the direction of magnetization M, and an electrode layer for applying a sense current J to the sensing pattern 12. The sensing pattern 12 is formed to be of circular shape. According to the present invention, since the demagnetic field within the sensing pattern is made constant with respect to the direction of the magnetization M, the improved linear response characteristics of resistance changes to an external magnetic field Hs can be realized.
    Type: Grant
    Filed: May 13, 1997
    Date of Patent: March 4, 2003
    Assignee: NEC Corporation
    Inventor: Haruo Urai
  • Publication number: 20030039064
    Abstract: A perpendicular magnetic recording head having an air bearing surface and comprising a substantially planar top pole and a shared pole is disclosed. The top pole and shared pole are connected distally from the air bearing surface by a yoke. A conductive coil wraps around the top pole and is positioned adjacent to the air bearing surface, with a lower portion of the coils extending between the top pole and the shared pole.
    Type: Application
    Filed: October 24, 2002
    Publication date: February 27, 2003
    Inventors: Sakhrat Khizroev, Dmitri Litvinov, Billy Wayne Crue
  • Publication number: 20030039078
    Abstract: Within a method for forming a magnetoresistive (MR) sensor element there is first provided a substrate. There is then formed over the substrate a first magnetoresistive (MR) layer having formed contacting the first magnetoresistive (MR) layer a magnetically biased first magnetic bias layer biased in a first magnetic bias direction with a first magnetic bias field strength. There is also formed separated from the first magnetoresistive (MR) layer by a spacer layer a second magnetoresistive (MR) layer having formed contacting the second magnetoresistive (MR) layer a magnetically un-biased second magnetic bias layer.
    Type: Application
    Filed: August 2, 2001
    Publication date: February 27, 2003
    Applicant: HEADWAY TECHNOLOGIES, INC.
    Inventors: Min Li, Simon H. Liao
  • Publication number: 20030035253
    Abstract: A magnetoresistance sensor structure is formed of a magnetoresistance sensor having a transverse biasing stack including a transverse pinning layer made of a transverse-pinning-layer antiferromagnetic material, and a transverse pinned layer structure overlying the transverse pinning layer, a spacer layer overlying the transverse pinned layer structure, a sensing stack overlying the spacer layer, and a decoupling layer overlying the sensing stack. A longitudinal biasing stack overlies the magnetoresistance sensor and includes a longitudinal pinned layer, and a longitudinal pinning layer overlying the longitudinal pinned layer and made of a longitudinal-pinning-layer antiferromagnetic material. The transverse-pinning-layer antiferromagnetic material and the longitudinal-pinning-layer antiferromagnetic material are preferably Pt—Mn or Ni—Mn.
    Type: Application
    Filed: August 17, 2001
    Publication date: February 20, 2003
    Inventors: Tsann Lin, Daniele Mauri
  • Patent number: 6515836
    Abstract: A magneto-resistive effect type magnetic head (12) has a head width Wh greater than the track width Wt of a magnetic tape (5), as measured in the width direction of the tape (5). The head (12) has a magneto-resistive effect element, which has a magnetism-detecting section arranged at the prescribed azimuth angle. A signal reproduced from the magnetic tape as the head (12) is moved while off-tracked in the widthwise direction Wh of the recording track T1. The signal has a specific characteristic that falls within a predetermined range for a reference value, provided that it has been generated from the magnetism the head (12) has detected over its effective width We.
    Type: Grant
    Filed: June 7, 2001
    Date of Patent: February 4, 2003
    Assignee: Sony Corporation
    Inventors: Tadashi Ozue, Shinichi Fukuda, Toshio Shirai
  • Publication number: 20030011941
    Abstract: A second antiferromagnetic layer formed on a free magnetic layer has a blocking temperature lower than that of a first antiferromagnetic layer. The exchange anisotropic magnetic field between the free magnetic layer and the second antiferromagnetic layer is smaller than the exchange anisotropic magnetic field between the first antiferromagnetic layer and the pinned magnetic layer. By applying an annealing treatment utilizing the blocking temperature difference between the first and second antiferromagnetic layers, the magnetization direction and the strength of the pinned magnetic layer and the free magnetic layer can be controlled appropriately.
    Type: Application
    Filed: March 29, 2000
    Publication date: January 16, 2003
    Inventors: Yukie Nakazawa, Masamichi Saito, Naoya Hasegawa, Akihiro Makino
  • Publication number: 20020196583
    Abstract: A pinned layer structure of a spin valve sensor is formed by sputter deposition of cobalt iron (CoFe) in a nitrogen (N2) atmosphere. This method permits a wider range of deposition times of a copper spacer layer to achieve a desirable ferromagnetic coupling field (HF) between the pinned layer structure and a free layer structure in the spin valve sensor.
    Type: Application
    Filed: June 26, 2001
    Publication date: December 26, 2002
    Applicant: INTERNATINAL BUSINESS MACHINES CORPORATION
    Inventor: Mustafa Pinarbasi
  • Patent number: 6495275
    Abstract: A magnetoresistance effect element includes a free layer, a pinned layer and a non-magnetic intermediate layer interposed between the free layer and the pinned layer. Additionally, a metal barrier layer is provided adjacent to the first magnetic layer. An electron reflecting layer located adjacent to the metal barrier layer contains at least one selected from oxides, nitrides, carbides, fluorides, chlorides, sulfides and borides.
    Type: Grant
    Filed: August 13, 2001
    Date of Patent: December 17, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuzo Kamiguchi, Akiko Saito, Katsuhiko Koui, Masatoshi Yoshikawa, Hiromi Yuasa, Hideaki Fukuzawa, Susumu Hashimoto, Hitoshi Iwasaki, Hiroaki Yoda, Masashi Sahashi
  • Patent number: 6493193
    Abstract: In order to improve reliability of an MR head including a substrate, an MR element formed on the substrate, a reinforcing body, and a sliding surface with respect to a magnetic recording medium, in which the substrate and the MR element are exposed to the sliding surface, the substrate and the reinforcing body are bonded to each other by using a non-organic film, for example, a multi-layered film including metal layers. Alternatively, the substrate and the reinforcing body are bonded to each other via an adhesive film not exposed to the sliding surface.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: December 10, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshiyasu Honma, Hiroyuki Hasegawa
  • Patent number: 6490115
    Abstract: A method and apparatus for recovering from operation errors arising in an information recording and reproducing unit using a head with a GMR sensor is described. The read and write operations of the unit comprise executing a first error recovery procedure for recovering the operation error, executing a first GMR evaluation procedure for evaluating the performance of the GMR sensor when the operation error cannot be recovered by the first error recovery procedure, and applying a resetting pulse to the GMR sensor in accordance with the first GMR evaluation procedure.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: December 3, 2002
    Assignee: International Business Machines Corporation
    Inventors: Hiroaki Suzuki, Koji Kurachi, Katsumi Suda, Hideo Asano, Kenji Okada, Makoto Takase, Akira Kibashi, Hiromi Nishimiya, Takao Matsui, Tatsuya Endo, Kenji Kuroki
  • Publication number: 20020177013
    Abstract: The invention provides a magnetoresistive element in which the pinned magnetic layer includes at least one non-magnetic film and magnetic films sandwiching that non-magneticfilm, and the magnetic films are coupled with one another by magnetostatic coupling via the non-magnetic film. This element has an improved thermal resistance. Furthermore, the invention provides a magnetoresistive element in which the pinned magnetic layer is as described above. The magnetic films can be coupled with one another by magnetostatic coupling or antiferromagnetic coupling generating negative magnetic coupling. In this element, the magnetic field shift is reduced. Furthermore, the invention provides a magnetoresistive element in which at least one of the magnetic layers sandwiching the intermediate layer includes an oxide ferrite having a plane orientation with a (100), (110) or (111) plane. A magnetic field is introduced in a direction of the axis of easy magnetization in the plane.
    Type: Application
    Filed: September 6, 2001
    Publication date: November 28, 2002
    Inventors: Masayoshi Hiramoto, Hiroshi Sakakima, Hideaki Adachi, Nozomu Matukawa, Kenji Iijima, Mitsuo Satomi
  • Publication number: 20020176213
    Abstract: A non-magnetic layer is integrated with a magnetoresistive element to form a scanning surface which is slid on a magnetic recording medium. The non-magnetic layer made of a material having a hardness higher than a hardness of Al2O3. Such hardness is represented by a Vickers hardness in a range of 8 GPa to 18 GPa.
    Type: Application
    Filed: May 22, 2002
    Publication date: November 28, 2002
    Inventors: Satoshi Ajiki, Koichi Hosoya
  • Patent number: 6483672
    Abstract: Both the read and write heads are trimmed to approximately 100 nm wide, indicated by Wr and Ww, respectively. The etch depth for the MR element, MR Trenches, is 200 nm and the etch depth for the write head, Write Trenches, is 1 &mgr;m. In order to confirm that inactive regions are actually those selected for irradiation, during trimming the center of the trimmed MR element has been offset by approximately 300 nm from the center of the original MR element. This offset is observed in the final result.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: November 19, 2002
    Assignee: International Business Machines Corporation
    Inventors: Patrick Clinton Arnett, David Cheekit Cheng, Sakhrat Khizroev, David Allen Thompson
  • Publication number: 20020167764
    Abstract: A suspended resist bridge suitable for lithographically patterning MR sensors having trackwidths narrower than 0.2 micron is fabricated using the method of the present invention. First, PMGI is spun onto a substrate to form a first thin resist layer. Next, PMMA is spun onto the first resist layer to form a second resist layer. The PMMA layer is exposed to an electron beam to pattern the trackwidth of the MR sensors. E-beam exposed PMMA is then developed in an IPA solution. The resist structure is then placed in a basic solution for dissolving PMGI, which results in a fully undercut resist bridge that is used for patterning the MR sensors.
    Type: Application
    Filed: May 10, 2001
    Publication date: November 14, 2002
    Inventors: Robert Edward Fontana, Jordan A. Katine, Jennifer Lu, Scott A. MacDonald, Michael J. Rooks, Hugo Alberto Emilio Santini
  • Publication number: 20020159200
    Abstract: A merged read/write magnetic recording head comprises a low magnetic moment first magnetic shield layer over a substrate. A read gap layer with a magnetoresistive head is formed over the first shield layer. A shared pole comprises a low magnetic moment second magnetic shield layer plated on a sputtered seed PLM layer over the read gap layer, a non-magnetic layer plated over the PLM layer and a HMM lower pole layer plated over the second magnetic shield layer. A write gap layer is formed over the first high magnetic moment pole layer of the shared pole. An upper pole comprises a high magnetic moment pole layer over the write gap layer.
    Type: Application
    Filed: April 24, 2002
    Publication date: October 31, 2002
    Applicant: HEADWAY TECHNOLOGIES, INC.
    Inventors: Kochan Ju, Cherng-Chyi Hau, Po-Kang Wang, Mao-Min Chen, Chun Liu, Jei Wei Chang
  • Publication number: 20020159198
    Abstract: A pinning layer structure is provided for a spin valve sensor of a read head which has a reactively deposited nickel oxide first film which underlies a reactively sputter deposited second film of iron oxide (FeXOY). In the preferred embodiment the pinning layer is composed of cobalt (Co) or cobalt iron (CoFe) which is exchange coupled to the iron oxide (FeXOY) second film of the pinning layer. This structure results in an improved magnetoresistive coefficient (dr/R) which is substantially maintained after annealing so that the magnetic head has good thermal stability when subjected to high temperatures in the presence of a field that is antiparallel to the pinned orientation of the magnetic moment of the pinned layer.
    Type: Application
    Filed: May 13, 2002
    Publication date: October 31, 2002
    Inventor: Mustafa Pinarbasi
  • Publication number: 20020145832
    Abstract: A perpendicular magnetic recording head includes a read head having means for generating a magnetic field which reduces noise from a soft magnetic underlayer of a recording medium during operation of the recording head. The means for generating a magnetic field includes a current perpendicular to the plane read sensor of the read head. The electrical current generates a magnetic field which biases the magnetization of the soft magnetic underlayer. By controlling the amount of current or current density that is passed through the read sensor, the magnitude of the magnetic field for biasing the soft magnetic underlayer may be controlled. A method of using a perpendicular magnetic recording head to magnetically bias a soft magnetic underlayer of a recording medium is also disclosed.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 10, 2002
    Applicant: Seagate Technology LLC
    Inventors: Michael A. Seigler, Dieter K. Weller, Robert E. Rottmayer
  • Publication number: 20020138970
    Abstract: The magnetoresistance is measured for a magnetoresistive layered-structure, such as a spin valve film, prior to formation of an upper shield layer as well as patterning of a lower shield layer. The magnetic influence of the upper and lower shield layers can completely be eliminated during the measurement of the magnetoresistance. The magnetoresistive layered-structure is allowed to reliably receive the magnetic field over a wider range including a lower magnetic field range. It is accordingly possible to measure the magnetoresistance properly reflecting the magnetic characteristic of the magnetoresistive layered-structure. It is possible to find deficiency of a magnetoresistive read element at an earlier stage of the method.
    Type: Application
    Filed: September 12, 2001
    Publication date: October 3, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Naoki Mukoyama, Kenichiro Yamada, Hitoshi Kanai, Manabu Watanabe, Norikazu Ozaki, Kazuaki Satoh
  • Patent number: 6459551
    Abstract: The present invention provides a thin film magnetic head that can efficiently dissipate the heat generated by the stationary sensing current, suppress heat diffusion, firing loss, decrease of output levels and deterioration of exchange anisotropic magnetic field as well as being excellent in linear responses and having suppressed Barkhausen noises, wherein the magnetic head comprises at least the magnetoresistive element layer deposited on the lower shield layer via lower gap layer, and the upper shield layer deposited on the electrode layer via the upper gap layer, at least one of the lower gap layer and upper gap layer comprising the highly heat-conductive insulation layer containing at least Al, N, X and O, wherein X is one or plural kinds of the element selected from Si, B, Ge and C.
    Type: Grant
    Filed: December 20, 1999
    Date of Patent: October 1, 2002
    Assignee: Alps Electric Co., Ltd.
    Inventor: Yasuo Hayakawa
  • Publication number: 20020131202
    Abstract: A method employs an RF magnetron sputtering system under specific process conditions for making shield and pole piece ferromagnetic layers of a read write magnetic head wherein the magnetic anisotropy HK of the ferromagnetic layers is substantially maintained without easy axes switching when annealed along their hard axes in the presence of a magnetic field (hard axis annealing).
    Type: Application
    Filed: March 16, 2002
    Publication date: September 19, 2002
    Inventor: John David Westwood
  • Patent number: 6451215
    Abstract: The present invention relates to a method of producing a magneto-resistive tunnel junction head comprising a tunnel multilayered film having a tunnel barrier layer, a ferromagnetic free layer and a ferromagnetic pinned layer such that the tunnel barrier layer is held between the ferromagnetic free layer and the ferromagnetic pinned layer. The method comprises a laminating step of forming the tunnel barrier layer and a non-magnetic metal protect layer in turn on the ferromagnetic pinned layer, an insulating layer forming step of forming side insulating layers on both sides of a lamination body having the ferromagnetic pinned layer, the tunnel barrier layer and the non-magnetic metal protect layer, a cleaning step of cleaning the surface of the non-magnetic metal protect layer, and a ferromagnetic free layer forming step of forming the ferromagnetic free layer such that the ferromagnetic free layer faces the ferromagnetic pinned layer via the cleaned surface.
    Type: Grant
    Filed: April 4, 2000
    Date of Patent: September 17, 2002
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Satoru Araki, Haruyuki Morita
  • Publication number: 20020126421
    Abstract: An L-shaped slide plate mounted with a workpiece holding device on a slide guide is firmly attached to an angle adjustment mechanism, and a reciprocating motion drive unit mounted with the angle adjustment mechanism on a slider table is firmly attached to a bridge so that an angle between a surface of a workpiece to be lapped and a surface of a lapping plate is kept substantially constant, and also the bridge is disposed so as to stride the lapping plate. Thereby, in a state of row bar in which a plurality of magnetic head sliders run in a line, an air bearing surface of magnetic head can be lapped with high accuracy with an element recession being decreased and an occurrence of a scratch being restrained.
    Type: Application
    Filed: December 18, 2001
    Publication date: September 12, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Toshio Takahashi, Hiromu Chiba, Takateru Seki, Hideaki Tanaka, Toshio Tamura, Minoru Yamasaka, Akio Takakura
  • Patent number: 6427319
    Abstract: A method for protecting magnetic read/write head assembly against electrostatic discharge during disk drive manufacturing are disclosed. The magnetic head assembly is supported on a substrate having a magnetoresistive sensor element disposed in spaced relationship between several magnetic shield elements. Before a focused ion beam fabrication operation, at least a portion of an air bearing surface of the magnetic head assembly is coated with a thin and transparent layer of conductive material. This layer of conductive material is subsequent removed after the focused ion beam fabrication operation.
    Type: Grant
    Filed: May 15, 2000
    Date of Patent: August 6, 2002
    Assignee: International Business Machines Corporation
    Inventors: Jack Dana Cook, Grace Lim Gorman, Cherngye Hwang
  • Patent number: 6428714
    Abstract: An improved process for manufacturing a spin valve structure that has buried leads is disclosed. A key feature is the inclusion in the process of a temporary protective layer over the seed layer on which the spin valve structure will be grown. This protective layer remains in place while the buried leads as well as longitudinal bias means are formed. Processing includes use of photoresist liftoff. The protective layer is removed as a natural byproduct of surface cleanup just prior the formation of the spin valve.
    Type: Grant
    Filed: June 5, 2000
    Date of Patent: August 6, 2002
    Assignee: Headway Technologies, Inc.
    Inventors: Chyu-Jiuh Torng, Chen-Jung Chien, Kochan Ju, Jei-Wei Chang
  • Patent number: 6426848
    Abstract: The present invention improves the wear resistance and machining characteristic of a non-magnetic substrate. The non-magnetic substrate as a guard member of a magnetic layer constituting a magnetic core is formed by a non-magnetic material containing TiO2 as a main content. Moreover, when the non-magnetic substrate is formed by a non-magnetic material containing TiO2 and NiO as main contents, a content of TiO2 is set to 70 mol % or above.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: July 30, 2002
    Assignee: Sony Corporation
    Inventors: Takashi Tamura, Yukari Nihei
  • Publication number: 20020080533
    Abstract: When a magneto-resistance effect type magnetic head is used as a magnetic tape reproducing head, a contact noise which occurs when a magnetic tape contacts with a magneto-resistance effect element poses a problem. The invention provides a magneto-resistance effect type magnetic head which hardly causes such contact noise and a magnetic signal reproducing apparatus comprising such magneto-resistance effect type magnetic head. A part where a magneto-resistance effect element is formed in a magnetic tape sliding face of the magneto-resistance effect type magnetic head is formed to be a concave of 3 to 30 nm in depth. The contact noise hardly occurs even when the magnetic tape is slid by forming the part where the magneto-resistance effect element is formed into the concave. Still more, almost no output drops due to a spacing loss and a fully large reproduced output may be obtained by defining the depth t1 of the concave within a range of 3 to 30 nm.
    Type: Application
    Filed: June 9, 1999
    Publication date: June 27, 2002
    Inventors: TADASHI OZUE, TOSHIO SHIRAI, YOSHITERU KAMATANI, NOBUYUKI NAGAI
  • Publication number: 20020067576
    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 11, 1999
    Publication date: June 6, 2002
    Inventors: KAZUYOSHI KUBOTA, MASAYUKI HAMAKAWA
  • Patent number: 6400519
    Abstract: A spin valve magnetoresistive effect type element assessment device includes a head assaying device having a magnetic disk provided with an assaying track where magnetic information is recorded, an oscilloscope for receiving a reproducing signal from an SV head employing an SV element through an amplifier, and a PC for measuring a track profile, namely, data representing relative position dependency of an output from the SV head with respect to the assaying track by controlling the head assaying device and oscilloscope.
    Type: Grant
    Filed: January 31, 2001
    Date of Patent: June 4, 2002
    Assignee: Fujitsu Limited
    Inventor: Naoki Mukoyama
  • Patent number: 6396773
    Abstract: The present invention relates to a rigid disc substrate for use in a magneto-optical drive, and two methods and apparatus to solve the above-mentioned problems. A method for writing a servo pattern on a magneto-optical rigid media, after the media optical film is deposited. The method involves an image transfer process, wherein a light source provides an energy pulse to heat up the magneto-optical film above its compensation temperature. Light is directed onto the film through a photo mask which has a prewritten servo pattern on it. The image on the mask is transferred to the magneto-optic disc when an external field is applied by a magnetic field generating coil which defines the area illuminated by the source where the pattern is to be written. In an alternative approach, the mask may be in contact with the media while the light exposure and magnetic field are applied.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: May 28, 2002
    Assignee: Seagate Technology LLC
    Inventor: David S. Kuo
  • Patent number: 6396669
    Abstract: A spin valve sensor of a read head has a platinum manganese (PtMn) pinning layer that pins a magnetic moment of an antiparallel (AP) pinned layer structure. The pinned layer structure has a first AP pinned layer exchange coupled to the pinning layer so that the magnetic moment of the first AP pinned layer is pinned in a first direction and has a second AP pinned layer that has a magnetic moment pinned in a second direction antiparallel to the first direction. A free layer structure of the spin valve sensor is located asymmetrically between first and second shield layers so that when a sense current is conducted through the sensor a net image current field is executed on the free layer structure by the shield layers.
    Type: Grant
    Filed: February 8, 2000
    Date of Patent: May 28, 2002
    Assignee: International Business Machines Corporation
    Inventor: Hardayal Singh Gill
  • Publication number: 20020057537
    Abstract: A method for producing magneto resistive heads includes the steps of positioning at least two magneto resistive elements in spaced relation to one another and placing the at least two magneto resistive elements in an ion milling environment where material is removed nonselectively from items in the environment. A property of at least two of the plurality of magneto resistive elements is monitored. In response to monitoring, one of the at least two magneto resistive elements is dynamically covered to prevent additional removal of material from the covered magneto resistive element.
    Type: Application
    Filed: August 15, 2001
    Publication date: May 16, 2002
    Applicant: Seagate Technology LLC
    Inventors: Edwin Frank Rejda, Joel William Hoehn, Shanlin Hao, Lance Eugene Stover, Todd Arthur Luse, James Richard Peterson
  • Patent number: 6387285
    Abstract: It is an object of a method of manufacturing a thin-film magnetic head of the invention to improve the insulating property between an electrode connected to a magnetoresistive element and a shield layer without increasing the thickness of an insulating layer between the magnetoresistive element and the shield layer. In the method, a pair of conductive layers to be the electrode (lead) connected to the MR element are formed on an insulating layer. Magnetic layers are formed to surround the conductive layers while an insulating film is placed between the magnetic layers and the conductive layers. Next, an insulating layer of alumina, for example, is formed over the entire surfaces of the magnetic layers. This insulating layer is polished to the surfaces of the conductive layers and flattened.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: May 14, 2002
    Assignee: TDK Corporation
    Inventor: Yoshitaka Sasaki
  • Publication number: 20020054460
    Abstract: The present invention provides a structure in which the coil center of a first coil layer is formed on a planarized surface, a first contact portion is formed by plating on the coil center, and the coil center of a second coil layer is conductively connected to the upper surface of the first contact portion. This structure can exhibit a stable DC resistance value and good conductivity.
    Type: Application
    Filed: November 5, 2001
    Publication date: May 9, 2002
    Applicant: Alps Electric Co., Ltd.
    Inventors: Toru Takahashi, Hisayuki Yazawa, Kiyoshi Kobayashi, Hideki Gochou
  • Publication number: 20020054459
    Abstract: The use of a Nd-YAG laser or excimer laser enables easy formation of protrusions on a protecting layer and a portion of an opposite surface near the trailing side end thereof and a thin film element. It is thus possible to avoid direct contact between the thin film element and the disk surface, and thus prevent damage to the thin film element and wearing thereof even if a slider and the disk surface repeatedly slide on each other.
    Type: Application
    Filed: April 14, 1999
    Publication date: May 9, 2002
    Inventors: HIROHISA ISHIHARA, TAKAO SOMA, TADASHI OTAGIRI, SOICHIRO MATSUZAWA
  • Publication number: 20020039262
    Abstract: A magnetic head is provided that has a smaller amount of change in asymmetry with respect to the MR height, and has an improved resolution for a reproduction signal. In a magnetic head including a magnetoresistive device as a read device for reading magnetic recording information recorded on a magnetic recording medium, the magnetostriction constant of a soft magnetic substance forming the magnetoresistive device is 0 or below. Since the magnetostriction constant of the magnetoresistive device is 0 or below, the amount of change in asymmetry with respect to the MR height is reduced. Therefore, even when the MR height is slightly changed, the asymmetry does not vary significantly.
    Type: Application
    Filed: August 23, 2001
    Publication date: April 4, 2002
    Applicant: Alps Electric Co., Ltd.
    Inventor: Tsutomu Takeya