Treating To Affect Magnetic Properties Patents (Class 29/603.08)
  • Patent number: 7275302
    Abstract: A method of forming a disc pack for use in a disc drive is provided. The method includes forming at least one alignment feature between an inner diameter and an outer diameter of each of a plurality of discs. The at least one alignment feature of a first disc of the plurality of discs and the at least one alignment feature of a second disc of the plurality of discs are utilized to substantially vertically align servo patterns on the first disc with servo patterns on the second disc. A disc pack having discs that include alignment features for aligning servo patterns on the discs is also provided.
    Type: Grant
    Filed: December 9, 2003
    Date of Patent: October 2, 2007
    Assignee: Seagate Technology LLC
    Inventor: Hwaliang Ng
  • Patent number: 7275304
    Abstract: A hard bias (HB) structure for biasing a free layer in a MR sensor within a magnetic read head is comprised of a main biasing layer with a large negative magnetostriction (?S) value. Compressive stress in the device after lapping induces a strong in-plane anisotropy that effectively provides a longitudinal bias to stabilize the sensor. The main biasing layer is formed between two FM layers, and at least one AFM layer is disposed above the upper FM layer or below the lower FM layer. Additionally, there may be a Ta/Ni or Ta/NiFe seed layer as the bottom layer in the HB structure. Compared with a conventional abutted junction exchange bias design, the HB structure described herein results in higher output amplitude under similar asymmetry sigma and significantly decreases sidelobe occurrence. Furthermore, smaller MRWu with a similar track width is achieved since the main biasing layer acts as a side shield.
    Type: Grant
    Filed: March 4, 2005
    Date of Patent: October 2, 2007
    Assignee: Headway Technologies, Inc.
    Inventors: Masanori Sakai, Kunliang Zhang, Kenichi Takano, Chyu-Jiuh Torng, Yunfei Li, Po-Kang Wang
  • Patent number: 7248445
    Abstract: A magnetic sensing element includes a composite film, a lower shield layer, and a lower electrode layer and an upper electrode layer for supplying a current perpendicular to the composite film. The composite film has an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic layer, and a free magnetic layer. The composite film has a top face and two side faces in a track width direction. Each of the two side faces has a bent position. The angle defined by the side face below the bent position and the top face is larger than the angle defined by the side face above the bent position and the top face. The bent portion preferably lies on the lower electrode layer or the lower shield layer.
    Type: Grant
    Filed: September 11, 2002
    Date of Patent: July 24, 2007
    Assignee: Alps Electric Co., Ltd.
    Inventor: Yoshihiro Nishiyama
  • Patent number: 7237320
    Abstract: A pole piece of a magnetic write head is formed over a substrate and includes a pole tip having a width that is less than its height which is normal the substrate. Due to stress-anisotropy, the pole tip structure has an inherent easy-axis which is oriented in an unfavorable direction (i.e. perpendicular to the ABS and almost collinear with a driving field of the write head). To alleviate this problem, during electroplating or annealing of the pole piece a magnetic field is applied to the pole tip in a direction which is out-of-plane from the substrate but in-plane with a side wall of the pole tip which vertically projects from the substrate. By applying the magnetic field in this manner, the easy axis of the pole piece is oriented in the direction of the applied magnetic field to facilitate more efficient switching in the write head. Ideally, the angle ? is about 90° for Hexagonal-Closed Packed (HCP) materials or about 50° for Face-Centered Cubic or Body-Centered Cubic (BCC) materials (e.g. NiFe and CoFe).
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: July 3, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Quan-chiu Harry Lam
  • Patent number: 7234228
    Abstract: A method for forming a bottom spin valve sensor element with a novel seed layer and synthetic antiferromagnetic pinned layer. The novel seed layer comprises an approximately 30 angstrom thick layer of NiCr whose atomic percent of Cr is 31%. On this seed layer there can be formed either a single bottom spin valve read sensor or a symmetric dual spin valve read sensor having synthetic antiferromagnetic pinned layers. An extremely thin (approximately 80 angstroms) MnPt pinning layer can be formed directly on the seed layer and extremely thin pinned and free layers can then subsequently be formed so that the sensors can be used to read recorded media with densities exceeding 60 Gb/in2. Moreover, the high pinning field and optimum magnetostriction produces an extremely robust sensor.
    Type: Grant
    Filed: December 3, 2002
    Date of Patent: June 26, 2007
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Hui-Chuan Wang, Ru-Ying Tong, Chyu-Jiuh Trong
  • Patent number: 7219415
    Abstract: The method of manufacturing a thin film magnetic head is capable of precisely forming a core section with preventing the variation of the write-core head caused by ion milling for removing an electric conductive film and capable of improving yield of products. The method of manufacturing a thin film magnetic head, in which a core section having prescribed write-core width is formed by applying ion milling to an upper magnetic pole and a lower magnetic pole, comprises the steps of examining the write-core width of the core section; covering a surface of the core section with a protection film except an electric conductive film for preventing electro static charge of a wafer; and removing the exposed electric conductive film by ion milling.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: May 22, 2007
    Assignee: Fujitsu Limited
    Inventor: Masahiro Kakehi
  • Patent number: 7210217
    Abstract: A wire gap film is formed on a flat coplanar surface formed on a bottom pole by a bottom track pole and a thin film coil, first and second magnetic material films constituting a top pole are formed on a flat surface of the thin film coil, and the first and second magnetic material films, write gap film and bottom track pole are partially removed forming a top track pole and trim structure. The thin film coil is formed by first and second thin film coil halves having self-aligned coil windings and have a CVD formed first conductive film, and an electrolytic plating formed second conductive film. A thin insulating film is interposed between successive coil windings of the first and second thin film coil halves. Jumper wirings, formed with the top pole, connect innermost and outermost coil windings of the first and second thin film coil halves respectively.
    Type: Grant
    Filed: September 21, 2005
    Date of Patent: May 1, 2007
    Assignees: Headway Technologies, Inc., SAE Magnetics (H.K.), Ltd.
    Inventors: Yoshitaka Sasaki, Takehiro Kamigama
  • Patent number: 7204013
    Abstract: In a method of forming a magnetoresistive sensor, first and second magnetic leads are formed. Next, a junction of magnetic and electrically conductive material is formed between the first and second magnetic leads. Finally, the magnetic and electrical conductivity of an outer shell portion of the junction is reduced to form a constricted junction comprising a magnetic and electrically conductive junction core that is at least partially surrounded by the outer shell portion. Another aspect of the present invention is directed to the magnetoresistive sensor that is formed using the method.
    Type: Grant
    Filed: July 29, 2003
    Date of Patent: April 17, 2007
    Assignee: Seagate Technology LLC
    Inventors: Ge Yi, Suguo Huo
  • Patent number: 7204014
    Abstract: A method for fabricating a magnetic head wherein a read head portion of the magnetic head includes a second gap insulation layer that includes a first portion that is fabricated upon the electrical leads of the read head and a second portion that is fabricated upon both a sensor portion of the read head and the first portion of the insulation layer. Both the first portion and the second portion of the insulation layer are made up of multi-layered laminations. Each said lamination is fabricated by depositing a thin film of metal, followed by the oxidation of that metallic thin film.
    Type: Grant
    Filed: December 9, 2003
    Date of Patent: April 17, 2007
    Assignee: Interntional Business Machines Corporation
    Inventors: Hardayal Singh Gill, Douglas Johnson Werner
  • Patent number: 7180716
    Abstract: A method for fabricating a stitched CPP synthetic spin-valve sensor with in-stack stabilization of its free layer. The method can also be applied to the formation of a stitched tunneling magnetoresistive sensor. The free layer is strongly stabilized by magnetostatic coupling through the use of a longitudinal biasing formation that includes a ferromagnetic layer, denoted LBL, within the pillar portion of the sensor and a synthetic exchange coupled tri-layer within the stitched portion of the sensor. The tri-layer consists of two ferromagnetic layers, FM1 and FM2 separated by a coupling layer and magnetized longitudinally in antiparallel directions. A criterion for the magnetic thicknesses of the layers: [t(LBL)+t(FM1)]/t(FM2)=70/90 angstroms of CoFe insures a strong exchange coupling. The magnetization of the tri-layer is done in a low field anneal that does not disturb the previous magnetization of the ferromagnetic free layer.
    Type: Grant
    Filed: March 30, 2004
    Date of Patent: February 20, 2007
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Youfeng Zheng, Kunliang Zhang, Simon Liao, Kochan Ju
  • Patent number: 7178222
    Abstract: Insulating layers are formed on both sides of a multilayer film, and bias layers are formed in contact with at least portions of both end surfaces of a free magnetic layer. The bias layers are formed so as not to extend to the upper surface of the multilayer film. In this construction, a sensing current from electrode layers appropriately flows through the multilayer film, and a bias magnetic field can be supplied to the free magnetic layer from the bias layers through both side surfaces of the free magnetic layer. Furthermore, the magnetic domain structure of the free magnetic layer can be stabilized to permit an attempt to decrease instability of the reproduced waveform and Barkhausen noise.
    Type: Grant
    Filed: September 5, 2003
    Date of Patent: February 20, 2007
    Assignee: Alps Electric Co., Ltd.
    Inventor: Naoya Hasegawa
  • Patent number: 7152304
    Abstract: Patterned, longitudinally and transversely antiferromagnetically exchange biased GMR sensors are provided which have narrow effective trackwidths and reduced side reading. The exchange biasing significantly reduces signals produced by the portion of the ferromagnetic free layer that is underneath the conducting leads while still providing a strong pinning field to maintain sensor stability. In the case of the transversely biased sensor, the magnetization of the free and biasing layers in the same direction as the pinned layer simplifies the fabrication process and permits the formation of thinner leads by eliminating the necessity for current shunting.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: December 26, 2006
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Min Li, Ru-Ying Tong, Yun-Fei Li, You Fong Zheng, Simon Liao, Kochan Ju, Cherng Chyi Han
  • Patent number: 7150092
    Abstract: A method of manufacturing a spin-valve thin-film magnetic element is provided. The spin-valve thin-film magnetic element includes a free magnetic layer and laminates of pinned magnetic layers and antiferromagnetic layers formed on two surfaces of the free magnetic layer.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: December 19, 2006
    Assignee: Alps Electric Co., Ltd.
    Inventor: Naoya Hasegawa
  • Patent number: 7146712
    Abstract: A metal film made of a metal material (e.g., NiFe, CoFeNi, or FeCo) including an iron atom is formed on a substrate (S101). Subsequently, the metal film formed on the substrate is plasma-processed in an environment including a gas (e.g., an oxygen gas having a tetrafluoromethane or trifluoromethane gas added thereto) containing oxygen and fluorine atoms (S103). Then, a resist material (e.g., a chemically amplified positive resist material) is applied onto the plasma-processed metal film, so as to form a resist film (S105). Thereafter, the resist film is partly removed, so as to expose a part of the surface of metal film in conformity to a desirable pattern, thereby forming a resist frame (S107).
    Type: Grant
    Filed: May 8, 2003
    Date of Patent: December 12, 2006
    Assignee: TDK Corporation
    Inventor: Akifumi Kamijima
  • Patent number: 7140095
    Abstract: The present invention provides a method of manufacturing a thin film magnetic head, capable of easily manufacturing a thin film magnetic head with high precision, in which a magnetic shield layer is disposed so as to surround a magnetic pole layer from three directions of a medium outflow direction and two side directions. In a magnetic pole formation region surrounded by a first gap layer portion, a magnetic pole layer and a second gap layer portion are formed and the magnetic pole layer is covered with the first and second gap layer portions. After that, a write shield layer is formed on the first and second gap layer portions so as to surround the magnetic pole layer from three directions (a trailing direction and two side directions).
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: November 28, 2006
    Assignee: SAE Magnetics (H.K.) Ltd.
    Inventor: Naoto Matono
  • Patent number: 7137190
    Abstract: A process is described for fabricating magnetic transducers with metallic thin films with a corrosion resistant surface produced by exposing the thin films to a nitrogen in a plasma chamber. The exposure to the nitrogen is believed to increase the corrosion resistance of the metallic thin films by causing nitrides to form in a thin surface region. In the preferred embodiment the thin film metals of a magnetic transducer are treated with the nitrogen after being cut from the wafer and lapped. Typical metals used in magnetic transducers are NiMn, FeMn, NiFe, cobalt, CoFe, copper, IrMn and PtMn. The films may be further protected by the addition of prior art protective layers such as carbon.
    Type: Grant
    Filed: October 3, 2002
    Date of Patent: November 21, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yiping Hsiao, Cherngye Hwang, Jila Tabib
  • Patent number: 7134186
    Abstract: Patterned, longitudinally and transversely antiferromagnetically exchange biased GMR sensors are provided which have narrow effective trackwidths and reduced side reading. The exchange biasing significantly reduces signals produced by the portion of the ferromagnetic free layer that is underneath the conducting leads while still providing a strong pinning field to maintain sensor stability. In the case of the transversely biased sensor, the magnetization of the free and biasing layers in the same direction as the pinned layer simplifies the fabrication process and permits the formation of thinner leads by eliminating the necessity for current shunting.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: November 14, 2006
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Min Li, Ru-Ying Tong, Yun-Fei Li, You Fong Zheng, Simon Liao, Kochan Ju, Cherng Chyi Han
  • Patent number: 7123452
    Abstract: A GMR bottom spin valve sensor longitudinally exchange biased with a zero net magnetic moment biasing multi-layer is provided, together with a method of forming said sensor. The sensor may be additionally biased with a hard biasing layer formed against an abutted junction. The exchange biasing provides the advantages of a highly sensitive free layer in the bottom spin valve sensor element, while producing very strong exchange pinning of the lateral ends of the free layer. The zero net magnetic moment assures stability in the lateral edge and central region of the free layer.
    Type: Grant
    Filed: September 10, 2002
    Date of Patent: October 17, 2006
    Assignee: Headway Technologies, Inc.
    Inventor: Yimin Guo
  • Patent number: 7120990
    Abstract: A method of manufacturing a thin film magnetic head. The method includes forming, near a pole portion: a first magnetic layer supported by a base substrate; a first insulating layer on the first magnetic layer with an end edge which forms a reference position for an air bearing surface; a gap layer on the pole portion of the first magnetic layer and the first insulation layer; a second magnetic layer that extends to a region beyond the pole portion; a thin film coil isolated by a second insulation layer located above the first insulation layer; a third magnetic layer on the second insulation layer. The air bearing surface is formed by grinding in part an end face of the pole portion of the first magnetic layer and an end face of the pole portion of the second magnetic layer and the gap layer placed therebetween.
    Type: Grant
    Filed: September 27, 2004
    Date of Patent: October 17, 2006
    Assignee: TDK Corporation
    Inventors: Yoshitaka Sasaki, Atsushi Iijima, Kazumasa Fukuda
  • Patent number: 7107667
    Abstract: A first and a second longitudinal bias-applying films are formed via a first mask at both sides of a magnetoresistive effective element film so that the difference in surface level between the magnetoresistive effective element film and the first and the second longitudinal bias-applying films is set within ±20 nm. Then, a first and a second electrode films are formed so as to cover edge portions of the magnetoresistive effective element film and the first and the second longitudinal bias-applying films.
    Type: Grant
    Filed: April 20, 2004
    Date of Patent: September 19, 2006
    Assignee: TDK Corporation
    Inventors: Noriyuki Ito, Kosuke Tanaka, Koichi Terunuma
  • Patent number: 7093347
    Abstract: A magnetoresistive (MR) sensor having a decreased electrical profile due to a confining of the device sense current within a conductive nanoconstriction. The MR sensor includes a giant magnetoresistive (GMR) stack and a layer of high resistivity material within the GMR stack. The layer of high resistivity material includes a nanoconstriction precursor. When a punch current is applied at the nanoconstriction precursor, a conductive nanoconstriction is formed through the layer of high resistivity material at the nanoconstriction precursor.
    Type: Grant
    Filed: December 5, 2003
    Date of Patent: August 22, 2006
    Assignee: Seagate Technology LLC
    Inventors: Janusz J. Nowak, Konstantin R. Nikolaev, Khoung T. Tran, Mark T. Kief
  • Patent number: 7089651
    Abstract: A method for forming at least two layers of electrical coils and their supportive resistive layers for a magnetic write head having an ultra-short yoke so that the second and any additional coil layers are formed on flat resistive surfaces to eliminate problems associated with inter- and intra-layer shorting and with shorting between coil and yoke. The resistive layers are formed with flat surfaces and desired apex angles by using a novel two-step photoresist scheme in which a layer of photoresist is first photoexposed and developed, then photoexposed a second time to cure a surface region that will remain flat during a final low temperature curing process.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: August 15, 2006
    Assignee: Headway Technologies, Inc.
    Inventors: Yi Zheng, Yi-Chun Liu
  • Patent number: 7089648
    Abstract: There is provided a magnetoresistive head which can realize high sensitivity and low noise even when the reading track is being reduced. Longitudinal biasing is performed to a ferromagnetic free layer whose magnetization is rotated according to an external magnetic field by providing unidirectional magnetic anisotropy by exchange coupling to an antiferromagnetic layer. A hard magnetic film is arranged at the edge of a magnetoresistive film to reduce an effective reading track width.
    Type: Grant
    Filed: July 23, 2004
    Date of Patent: August 15, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Kenichi Meguro, Hisashi Kimura, Katsuro Watanabe
  • Patent number: 7092219
    Abstract: A magnetic head having a spin valve sensor that is fabricated utilizing an Al2O3, NiMnO, NiFeCr seed layer upon which a typical PtMn spin valve sensor layer structure is subsequently fabricated. The preferred embodiment fabrication process of the NiFeCr layer includes the overdeposition of the layer to a first thickness of from 15 ? to 45 ? followed by the etching back of the seed layer of approximately 5 ? to approximately 15 ? to its desired final thickness of approximately 10 ? to 40 ?. The Cr at. % composition in the NiFeCr layer is preferably from approximately 35 at. % to approximately 46 at. %. The crystal structure of the surface of the etched back NiFeCr layer results in an improved crystal structure to the subsequently fabricated spin valve sensor layers, such that the fabricated spin valve exhibits increased ?R/R and reduced coercivity.
    Type: Grant
    Filed: July 6, 2001
    Date of Patent: August 15, 2006
    Assignee: International Business Machines Corporation
    Inventor: Mustafa Pinarbasi
  • Patent number: 7086140
    Abstract: A method of fabricating a thin film magnetic recording head including a perpendicular recording head having an auxiliary pole, a main pole and a shield against an external magnetic field. The shield against the external magnetic field is formed so that an edge of the shield against the external magnetic field is disposed at a position recessed at least from an edge of the main pole relative to a surface against a medium.
    Type: Grant
    Filed: August 25, 2004
    Date of Patent: August 8, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Tomohiro Okada, Yoshiaki Kawato, Kaori Suzuki, Hiroshi Fukui, Isao Nunokawa
  • Patent number: 7068478
    Abstract: Replacing ruthenium with rhodium as the AFM coupling layer in a synthetically pinned CPP GMR structure enables the AP1/AP2 thicknesses to be increased. This results in improved stability and allows the free layer and AFM layer thicknesses to be decreased, leading to an overall improvement in the device performance. Another key advantage of this structure is that the magnetic annealing requirements (to establish antiparallelism between AP1 and AP2) can be significantly relaxed.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: June 27, 2006
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Kunliang Zhang, Rachid Sbiaa, Cheng T. Horng, Simon Liao, Kochan Ju
  • Patent number: 7042686
    Abstract: The present invention provides a magnetoresistive element that includes a pair of magnetic layers and an intermediate layer between the magnetic layers. The intermediate layer contains at least three elements selected from Groups 2 to 17, and the elements include at least one selected from the group consisting of F, O, N, C and B. According to the invention, a magnetoresistive element with high magnetoresistance change ratio and low resistance can be provided. The invention also provides a method for producing a magnetoresistive element. The method includes forming a precursor and forming at least one part of the intermediate layer from the precursor. The precursor is reacted with at least one reactive species selected from the group consisting of oxygen atoms, nitrogen atoms and carbon atoms in a reactive atmosphere containing the reactive species.
    Type: Grant
    Filed: June 18, 2004
    Date of Patent: May 9, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Akihiro Odagawa, Nozomu Matukawa, Kenji Iijima, Hiroshi Sakakima
  • Patent number: 7040004
    Abstract: Longitudinal edges of an actuator arm are provided with stiffening elements in order to raise natural resonant frequencies of the arm so as to prevent resonance from occurring. The stiffening element is shaped and positioned so as to be able to individually “tune” the natural resonant frequency of a given bending mode without significantly affecting the natural frequencies in other bending modes.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: May 9, 2006
    Assignee: Seagate Technology LLC
    Inventors: Andre Liem, CheeWai Seetoh, Niroot Jierapipatanakul, Michael JooChiang Toh
  • Patent number: 6993827
    Abstract: Two embodiments of a GMR sensor of the bottom spin valve (BSV) spin filter spin valve (SFSV) type are provided, together with methods for their fabrication. In one embodiment, the sensor has an ultra thin (<20 angstroms) single free layer and a composite high-conductance layer (HCL), providing high output, low coercivity and positive magnetostriction. In a second embodiment, the sensor has a composite free layer and a single HCL, also having high output, low coercivity and positive magnetostriction. The sensors are capable of reading densities exceeding 60 Gb/in2.
    Type: Grant
    Filed: June 12, 2003
    Date of Patent: February 7, 2006
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 6988308
    Abstract: Hard biasing of a magnetoresistive sensor or a spin valve sensor in a magnetic read head is initialized by repeatedly applying a magnetic field to the hard biasing at any level of fabrication of the magnetic read head or any combination of levels of fabrication of the read head such as at the wafer level, row bar level, single slider level, head gimbal assembly (HGA) level and/or head stack assembly (HSA) level.
    Type: Grant
    Filed: January 18, 2002
    Date of Patent: January 24, 2006
    Assignee: International Business Machines Corporation
    Inventors: Christopher William Bergevin, Carol Inouye Chiu, Robert Yuan-Shih Li, Albert Shou-Chi Su
  • Patent number: 6982042
    Abstract: A method for reducing noise in a lapping guide. Selected portions of a Giant magnetoresistive device wafer are masked, thereby defining masked and unmasked regions of the wafer in which the unmasked regions include lapping guides. The wafer is bombarded with ions such that a Giant magnetoresistive effect of the unmasked regions is reduced.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: January 3, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Mark A. Church, Wipul Pemsiri Jayasekara, Howard Gordon Zolla
  • Patent number: 6940701
    Abstract: The present invention aims to provide a magnetic sensor provided with a magnetoresistive effect element capable of stably maintaining a direction of magnetization in a magnetic domain of a free layer. The magnetic sensor includes a magnetoresistive effect element provided with narrow zonal portions 11a . . . 11a including a pinned layer and a free layer. Disposed below both ends of the free layer are bias magnet films 11b . . . 11b composed of a permanent magnet that applies to the free layer a bias magnetic field in a predetermined direction and an initializing coil 31 that is disposed in the vicinity of the free layer and applies to the free layer a magnetic field having the direction same as that of the bias magnetic field by being energized under a predetermined condition.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: September 6, 2005
    Assignee: Yamaha Corporation
    Inventors: Toshiyuki Oohashi, Yukio Wakui
  • Patent number: 6935014
    Abstract: An electrode film and a protective electrode film are formed on an insulating film and a first magnetic film in turn. Then, a first photoresist layer, an intermediate layer and a second photoresist layer are formed on the protective electrode film in turn. The intermediate layer is formed by a sputtering method so that the surface temperature of the intermediate layer is set to 140° C. or below. Then, the first photoresist layer is exposed and developed, to fabricate a photoresist pattern. Then, the intermediate layer is partially etched and removed via the photoresist pattern as a mask by a reactive ion etching method using a chlorine-based gas.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: August 30, 2005
    Assignee: TDK Corporation
    Inventors: Kazuya Maekawa, Akio Iijima, Junichi Sato, Hiroyuki Miyamoto
  • Patent number: 6920681
    Abstract: An electromagnetic actuator includes a stationary member, a movable member magnetically coupled with the stationary member with a gap therebetween, and a support member for displaceably supporting the movable member relative to the stationary member. Both the stationary member and the movable member have a core section carrying a coil wound around its periphery. As the coil of the stationary member and that of the movable member are energized with electric current, the movable member is either attracted toward or repulsed from the stationary member. The electromagnetic actuator can be used for an optical scanner by providing a mirror and a lens on the movable member.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: July 26, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Futoshi Hirose, Takayuki Yagi, Susumu Yasuda, Takahisa Kato
  • Patent number: 6915559
    Abstract: A method of manufacturing an active element for use with a magnetic head includes depositing a magnetic material to form a magnetic member, and nitriding the magnetic member after the depositing step. Preferably, the depositing step comprises depositing nickel-iron alloy, and the nitriding step comprises plasma nitriding the magnetic member. Advantageously, plasma nitriding may be performed at a temperature below 300 degrees Celsius to avoid adverse effects to components of the active element, such as organic planars. Active elements manufactured according to the method of the invention are also disclosed.
    Type: Grant
    Filed: August 16, 2002
    Date of Patent: July 12, 2005
    Assignee: Storage Technology Corporation
    Inventors: Bradford C. Schwartz, Steven C. Herrera
  • Patent number: 6910259
    Abstract: An antiferromagnetic stabilization scheme is employed in a magnetic head for magnetically stabilizing a free layer of a spin valve. This is accomplished by utilizing an antiferromagnetic oxide film below a spin valve sensor in a read region and first and second lead layers in end regions and a ferromagnetic film in each of the lead layers that exchange couples to the antiferromagnetic oxide film in the end regions. The ferromagnetic films are pinned with their magnetic moments oriented parallel to an air bearing surface (ABS) of the magnetic head. The ferromagnetic films magnetostatically couple to the free layer which causes the free layer to be in a single magnetic domain state. Accordingly, when the free layer is subjected to magnetic incursions from a rotating disk in a disk drive, the free layer maintains a stable magnetic condition so that resistance changes of the free layer are not altered by differing magnetic conditions of the free layer.
    Type: Grant
    Filed: November 24, 2000
    Date of Patent: June 28, 2005
    Assignee: International Business Machines Corporation
    Inventors: Tsann Lin, Daniele Mauri
  • Patent number: 6906894
    Abstract: A read/write head and method of making the same are used in a data storage system, such as a disk drive, for perpendicular magnetic recording of data. The head employs a two-layer pole design with a main pole made of sputtered high moment magnetic material, and an adjunct pole made of electroplated soft magnetic film. The main pole is used to write data onto the medium, and is formed over the write coil. The adjunct pole is substantially recessed from the air bearing surface and is formed over the main pole. The present head design significantly enhances the magnetic write field, and substantially reduces side-writing that result in accidental erasure of data in adjacent tracks on the magnetic recording medium.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: June 14, 2005
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Yingjian Chen, Xiaozhong Dang, Francis H. Liu, Kroum Stoev, Hai Jiang, Yugang Wang, Xizeng Shi
  • Patent number: 6895657
    Abstract: A method for producing a slider for an optical head includes a slider member adapted for floating and running over a recording medium during recording and/or reproduction of information signals for the recording medium. An optical lens is bonded to the slider member and a magnetic field generator provided on a surface of the slider member carrying the optical lens facing the recording medium. A first step is forming a groove presenting a bottom surface inclined in the depth-wise direction by ejecting a polishing agent dispersed in a compressed gas on a substrate. A second step is charging an electrically conductive material, which proves a terminal electrically connected to the magnetic field generator in the inside of the groove formed in the substrate. A third step is cutting the substrate in the vicinity of an end of the groove to form a plurality of individual slider members.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: May 24, 2005
    Assignee: Sony Corporation
    Inventors: Akio Mishima, Toru Katakura
  • Patent number: 6857180
    Abstract: Patterned, longitudinally and transversely antiferromagnetically exchange biased GMR sensors are provided which have narrow effective trackwidths and reduced side reading. The exchange biasing significantly reduces signals produced by the portion of the ferromagnetic free layer that is underneath the conducting leads while still providing a strong pinning field to maintain sensor stability. In the case of the transversely biased sensor, the magnetization of the free and biasing layers in the same direction as the pinned layer simplifies the fabrication process and permits the formation of thinner leads by eliminating the necessity for current shunting.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: February 22, 2005
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Min Li, Ru-Ying Tong, Yun-Fei Li, You Feng Zheng, Simon Liao, Kochan Ju, Cherng Chyi Han
  • Patent number: 6857937
    Abstract: A head is fabricated using photolithography, and the head is purposely powered up during a material removal process, such as lapping, so that the head's expansion (that would be formed on being powered up during normal usage in a drive) is planarized. Specifically, the head is energized in a manner identical (or similar) to energization of circuitry in the head during normal operation in a drive, even though fabrication of the head has not yet been completed. When energized, a shape that the head would have during normal operation is replicated (or approximated). Therefore, the head's shape includes a expansion of the pole tip region, although the head is only partially fabricated. Thereafter, a portion of the head in the expansion is partially or completely removed, by lapping while energized. The depth of material removal from the head is monitored e.g.
    Type: Grant
    Filed: May 30, 2002
    Date of Patent: February 22, 2005
    Assignee: Komag, Inc.
    Inventor: Christopher H. Bajorek
  • Patent number: 6836956
    Abstract: A method of manufacturing a thin film magnetic head in which a top pole is divided into a pole tip and a tope pole layer, and the pole tip is formed on the flat surface of a bottom pole with a write gap layer in between. An insulating layer is formed in a region adjacent to the pole tip. A first layer of thin film coil is formed in a region wherein the insulating layer is formed. The thin film coil is covered by the insulating layer whose surface is flattened. A surface of the top pole layer facing the recording medium can be formed recessed from a surface of the pole tip facing the recording medium.
    Type: Grant
    Filed: December 6, 2001
    Date of Patent: January 4, 2005
    Assignee: TDK Corporation
    Inventor: Yoshitaka Sasaki
  • Publication number: 20040264070
    Abstract: A magnetic head including a spin valve sensor having a sensor layer stack that includes a pinned magnetic layer, a spacer layer formed on the pinned magnetic layer, and a free magnetic layer formed on the spacer layer. In a preferred embodiment the spacer layer is comprised of CuOx. Plasma smoothing of the upper surface of the pinned magnetic layer is conducted prior to depositing the spacer layer, and a preferred plasma gas is a mixture of argon and oxygen.
    Type: Application
    Filed: July 16, 2004
    Publication date: December 30, 2004
    Inventors: Wen-Yaung Lee, Tsann Lin, Danielle Mauri, Alexander Michael Zeltser
  • Publication number: 20040257717
    Abstract: A coupled ferromagnetic structure includes a first ferromagnetic layer, a spacer layer on a first surface of the first ferromagnetic layer, and a second ferromagnetic layer on the spacer layer. Interlayer exchange coupling occurs between the first and second ferromagnetic layers. The coupling may be ferromagnetic or antiferromagnetic. Morphology of the first surface is modified to tailor the interlayer exchange coupling. The structure may form a part of a magnetoresistive device such as a magnetic tunnel junction.
    Type: Application
    Filed: June 18, 2003
    Publication date: December 23, 2004
    Inventors: Manish Sharma, Janice H. Nickel
  • Publication number: 20040252419
    Abstract: It is necessary to stabilize the free layer of GMR or TMR devices by providing a longitudinal bias field. As read tracks become very narrow, this field can drastically reduce the strength of the output signal. This problem has been overcome by adding an additional, compensatory, bias layer. This layer is permanently magnetized in the same direction as the main bias magnet. Through control of the magnetization strength and location of the compensatory bias layer, cancellation of the field induced in the free layer, by the main bias layers, is achieved. A process for manufacturing the devices is also described.
    Type: Application
    Filed: June 12, 2003
    Publication date: December 16, 2004
    Applicant: Headway Technologies, Inc.
    Inventor: Kenichi Takano
  • Publication number: 20040252418
    Abstract: Two embodiments of a GMR sensor of the bottom spin valve (BSV) spin filter spin valve (SFSV) type are provided, together with methods for their fabrication. In one embodiment, the sensor has an ultra thin (<20 angstroms) single free layer and a composite high-conductance layer (HCL), providing high output, low coercivity and positive magnetostriction. In a second embodiment, the sensor has a composite free layer and a single HCL, also having high output, low coercivity and positive magnetostriction. The sensors are capable of reading densities exceeding 60 Gb/in2.
    Type: Application
    Filed: June 12, 2003
    Publication date: December 16, 2004
    Applicant: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Publication number: 20040246632
    Abstract: A magnetoresistive head in which a pinned layer comprises two films, i.e., a ferromagnetic film A and a ferromagnetic B anti-ferromagnetically coupled to each other and a anti-ferromagnetic coupling film for separating the two ferromagnetic films A and B, where the coercivity of the ferromagnetic film alone is 200 (Oe) or more and the coercivity of the ferromagnetic film alone is 20 (Oe) or less. The compositions for the ferromagnetic film A and the ferromagnetic film B, when expressed by Co100-YFeY (at %) are: ferromagnetic film A: 80≧Y≧40, and ferromagnetic film B: 20≧Y≧0, where the material for the film in contact with the ferromagnetic film A is Ru, Ta, NiFeCr, Cu or NiFe.
    Type: Application
    Filed: March 18, 2004
    Publication date: December 9, 2004
    Applicant: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Koichi Nishioka, Satoshi Shigematsu
  • Publication number: 20040240096
    Abstract: A system, method and computer program product provide an annealing process for setting a magnetization condition of a read head. An amount of heat for stabilizing magnetization condition of a read head is calculated. A width and amplitude of a voltage pulse that generates the calculated amount of heat in the read head are calculated. A voltage pulse of the calculated width and amplitude is applied to the read head for generating Joule heating in the read head. The width of the voltage pulse is less than one second.
    Type: Application
    Filed: July 9, 2004
    Publication date: December 2, 2004
    Inventors: Lydia Baril, Ciaran A. Fox, Jih-Shiuan Luo, Peter J. Melz, Chin-Yu Yeh
  • Publication number: 20040228044
    Abstract: A fixed magnetic layer contains a first magnetic layer formed on a non-magnetic metal layer. The non-magnetic metal layer is composed of an X-Mn alloy (where X is selected from Pt, Pd, Ir, Rh, Ru, Os, Ni, and Fe). While atoms forming the first magnetic layer and atoms forming the non-magnetic metal layer are being aligned with each other, strains are generated in the individual crystal structures. By generating the strain in the crystal structure of the first magnetic layer, the magnetostriction constant &lgr; is increased. As a result, a magnetic sensor having a large magnetoelastic effect can be provided.
    Type: Application
    Filed: February 20, 2004
    Publication date: November 18, 2004
    Applicant: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Eiji Umetsu, Masamichi Saito, Yosuke Ide
  • Publication number: 20040228046
    Abstract: The present invention provides a magnetoresistive element that includes a pair of magnetic layers and an intermediate layer between the magnetic layers. The intermediate layer contains at least three elements selected from Groups 2 to 17, and the elements include at least one selected from the group consisting of F, O, N, C and B. According to the invention, a magnetoresistive element with high magnetoresistance change ratio and low resistance can be provided. The invention also provides a method for producing a magnetoresistive element. The method includes forming a precursor and forming at least one part of the intermediate layer from the precursor. The precursor is reacted with at least one reactive species selected from the group consisting of oxygen atoms, nitrogen atoms and carbon atoms in a reactive atmosphere containing the reactive species.
    Type: Application
    Filed: June 18, 2004
    Publication date: November 18, 2004
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masayoshi Hiramoto, Akihiro Odagawa, Nozomu Matukawa, Kenji Iijima, Hiroshi Sakakima
  • Publication number: 20040223266
    Abstract: A method for forming an NiCr seed layer based bottom spin valve sensor element having a synthetic antiferromagnet pinned (SyAP) layer and a capping layer comprising either a single specularly reflecting nano-oxide layer (NOL) or a bi-layer comprising a non-metallic layer and a specularly reflecting nano-oxide layer and the sensor element so formed. The method of producing these sensor elements provides elements having higher GMR ratios and lower resistances than elements of the prior art.
    Type: Application
    Filed: May 28, 2004
    Publication date: November 11, 2004
    Applicant: HEADWAY TECHNOLOGIES, INC.
    Inventor: Min Li