Detail Of Magnetic Shielding Patents (Class 360/319)
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Publication number: 20080148552Abstract: A method for manufacturing a magnetic write pole and trailing wrap around magnetic shield for use in a perpendicular magnetic data recording system. The method includes the use of a hard mask structure with end point detection material embedded in a hard mask material. The novel hard mask structure provides the mill resistance of a hard mask, with the end point detection advantages of an end point detection layer.Type: ApplicationFiled: December 22, 2006Publication date: June 26, 2008Inventors: Aron Pentek, Yi Zheng, Howard Gordon Zolla
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Publication number: 20080151438Abstract: The invention provides a magnetoresistive element including a seed layer having a flat surface, which makes it possible to improve the flatness of all of the elements. A seed layer is formed in a two-layer structure of a first seed layer that is formed on a lower shield layer and a second seed layer that is formed underneath an anti-ferromagnetic layer, and the second seed layer is formed of ruthenium (Ru). According to this structure, the flatness of the surface of the seed layer is improved, which makes it possible to improve the flatness of interfaces between layers of an element formed on the seed layer. As a result, it is possible to manufacture a magnetoresistive element having a high dielectric breakdown voltage and high operational reliability.Type: ApplicationFiled: November 28, 2007Publication date: June 26, 2008Inventors: Kenichi Tanaka, Eiji Umetsu, Kazuaki Ikarashi, Kota Asatsuma
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Publication number: 20080144229Abstract: An improved magnetic head for a hard disk drive including a lead overlaid read head in which the read width and read gap are reduced. The read width, which corresponds to the distance between the inner ends of the overlaid electrical leads, is reduced by the fabrication of a thin read width insulation member prior to the fabrication of the overlaid electrical leads. The read gap is reduced by fabricating the overlaid electrical leads from a magnetic, electrically conductive material such as NiFe, whereby the overlaid electrical leads also function as a magnetic shield. The read gap, which is the distance between the first and second magnetic shields is thus reduced as compared to the prior art by the thickness of the electrical leads and the thickness of the prior art second insulation layer formed between the electrical leads and the second magnetic shield.Type: ApplicationFiled: December 14, 2006Publication date: June 19, 2008Inventors: Kuok San Ho, Edward Hin Pong Lee, David John Seagle, Ching Hwa Tsang
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Publication number: 20080144230Abstract: A magnetic recording-reproducing apparatus includes: a magnetic recording medium in which portions corresponding to track portions serve as recording areas and in which portions between the recording areas serve as non-recording areas; and a magnetic head having a main pole and a side shield disposed on both sides of the main pole in a cross-track direction. In the magnetic recording-reproducing apparatus, following inequality (I) is satisfied: S>Tw/2+Gw ??(I) where Tw is a track width, Gw is a gap width, and S is a distance between the center of the main pole of the magnetic head and an edge on the main pole side of each of the side shields.Type: ApplicationFiled: December 11, 2007Publication date: June 19, 2008Applicant: TDK CORPORATIONInventors: Akimasa Kaizu, Yoshikazu Soeno, Kazuya Shimakawa
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Patent number: 7383993Abstract: A magnetic shield member for a device with a magnetic reader, the magnetic shield member includes a biasing member including a first end, a second end opposite to the first end and an intermediate portion disposed between the first and second ends, the first end configured to be attached within the device with a magnetic reader, the second end configured to face the magnetic reader and a shielding member including a first end, a second end opposite to the first end and an arched portion disposed between the first end and the second end, wherein the first end of the shielding member extends integrally from the second end of the biasing member, the arched portion includes a concave portion which faces the magnetic reader, wherein the shielding member applies a force to conform a document against the magnetic reader and shields the magnetic reader from magnetic interference.Type: GrantFiled: November 2, 2007Date of Patent: June 10, 2008Assignee: International Business Machines CorporationInventors: Richard H. Harris, Robert A. Myers
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Patent number: 7382575Abstract: A transducing head has a main pole and at least one magnetic element (such as a return pole or a shield) which provides a potential return path for a magnetic field produced by the main pole. The magnetic element is spaced from the main pole. The magnetic element has a first edge closest to the main pole and a second edge furthest from the main pole. Permeability of the magnetic element increases from the first edge to the second edge.Type: GrantFiled: September 26, 2003Date of Patent: June 3, 2008Assignee: Seagate Technology LLCInventors: Nurul Amin, Yuming Zhou, Kaizhong Gao, Patrick J. Ryan, Steven Kalderon, Song S. Xue, Shaoping Li, Mark T. Kief
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Patent number: 7379276Abstract: Provided is a magnetic recording head including a return pole, a writing pole spaced by a predetermined distance from the return pole, an induction writing coil for inducing a magnetic field to be formed across the writing pole, and a plurality of shield layers formed on the writing pole. Accordingly, magnetic fields generated inside and outside the magnetic recording head are prevented from concentrating on the return pole, and information is effectively written on and erased from an information recording media.Type: GrantFiled: September 17, 2004Date of Patent: May 27, 2008Assignees: Samsung Electronics Co., Ltd., Institute for Information Technology AdvancementInventors: Young-hun Im, Yong-su Kim
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Patent number: 7377024Abstract: A method of fabricating a magnetic transducer is described which uses a trailing shield throat pad to set the trailing shield throat height. The trailing shield throat pad is used as a part of the structural form over which the material for the trailing shield is formed. The trailing shield throat pad is preferably made of a material which can selectively be removed from the gap layer with a selective etching process such as reactive-ion etching (RIE). The front edge of the trailing shield throat pad is used to define a peninsula on the trailing shield and thereby the throat of the trailing shield.Type: GrantFiled: March 25, 2005Date of Patent: May 27, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Tsung Yuan Chen
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Patent number: 7379277Abstract: A magnetic sensing device includes a first electrode, a second electrode, a first magnetic shield, a second magnetic shield, and a sensor. The first magnetic shield forms at least a portion of the first electrode. The second magnetic shield includes a first region that forms at least a portion of the first electrode and a second region that forms at least a portion of the second electrode. The sensor is positioned between the first and second magnetic shields and is electrically connected in series between the first and second electrodes.Type: GrantFiled: June 30, 2005Date of Patent: May 27, 2008Assignee: Seagate Technology LLCInventors: Daniel Paul Burbank, Declan Macken, Harry Sam Edelman
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Publication number: 20080117552Abstract: A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.Type: ApplicationFiled: November 16, 2006Publication date: May 22, 2008Inventors: Yuchen Zhou, Kenichi Takano, Kunliang Zhang
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Patent number: 7375932Abstract: A magnetoresistive read head is capable of reading cross-track magnetizations in a magnetic recording disk drive that has the magnetized regions or magnetizations in the magnetic recording layer of the disk oriented in the cross-track direction. The magnetic recording disk has the magnetizations in the concentric data tracks oriented in the radial or cross-track direction. The read head has its free-layer magnetization direction perpendicular to the disk surface and its pinned-layer magnetization direction parallel to the disk surface and orthogonal to the free-layer magnetization direction. The read head may have magnetic side shields spaced from it in the cross-track direction to prevent magnetic flux from adjacent data tracks from reaching the read head.Type: GrantFiled: November 30, 2004Date of Patent: May 20, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Vladimir Nikitin
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Publication number: 20080112088Abstract: A magnetic write head for perpendicular magnetic recording that has write pole, a return pole and a trailing shield that is magnetically connected with magnetic return pole. The write head includes a magnetic pedestal and first and second magnetic studs that connect the trailing shield with the pedestal. The studs are laterally spaced a distance that is not greater than 5 um from the nearest side of the write pole. In other words, the studs are spaced from each other a distance that is no greater than the width of the leading edge of the write pole plus 10 um. This spacing of the studs prevents saturation of the trailing shield, maximizing field gradient and ensuring optimal magnetic write performance.Type: ApplicationFiled: November 13, 2006Publication date: May 15, 2008Inventors: Wen-Chien David Hsiao, Yimin Hsu, Edward Hin Pong Lee, Vladimir Nikitin, Aron Pentek, Yi Zheng
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Publication number: 20080100970Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) read head structure has the MR read head located between first and second shields (S1, S2) on a substrate with a shunt resistor R1 connecting S1 to the substrate and a shunt resistor R2 connecting S2 to the substrate, with R1 and R2 being approximately equal. Because R1 and R2 are close enough in value there is no significant interference pickup in the low frequency region. The shunt resistors can be formed from high-resistivity metal nitrides or cermets. The spacing between the substrate and S1 may be selected to make the capacitance between S1 and the substrate approximately equal to the capacitance between S2 and the substrate to substantially reduce interference pickup in the high frequency region.Type: ApplicationFiled: October 30, 2006Publication date: May 1, 2008Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.Inventors: Satoru Araki, John Contreras, Klaas Berend Klaassen, Ramona Marie Patterson, David John Seagle, Howard Gordon Zolla
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Publication number: 20080080099Abstract: The magnetic head is capable of effectively applying a bias magnetic field of a hard magnetic layer to the read-head so as to improve and stabilize detection performance. The magnetic head of the present invention comprises: a lower shielding layer; a read-element being formed on the lower shielding layer; an insulating layer continuously coating side faces of the read-element a surface of the lower shielding layer; a base layer being formed on the insulating layer; and a hard magnetic layer being formed on the base layer. Parts of the insulating layer, which coat the side faces of the read-element, are coated with no base layer.Type: ApplicationFiled: January 10, 2007Publication date: April 3, 2008Inventor: Masanori Akie
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Patent number: 7336450Abstract: A magnetic head contains a write magnetic head and a read magnetic head. The write magnetic head includes a lower core layer, an upper core layer arranged over the lower core layer, and a coil layer for applying a magnetic field to the lower and upper core layers. The read magnetic head includes an upper shield layer, a lower shield layer, and a reproducing device arranged between the upper shield layer and the lower shield layer. The upper shield layer has a dimension A in a direction of track width and a dimension B in a direction of height and has an aspect ratio B/A ranging from 0.6 to 1.2. The dimension A ranges from 75 ?m to 150 ?m.Type: GrantFiled: August 15, 2005Date of Patent: February 26, 2008Assignee: Alps Electric Co., Ltd.Inventors: Tomohiro Yamashita, Akira Takahashi, Shuji Yanagi
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Publication number: 20080043377Abstract: The magnetic head is capable of stabilizing arrangement of magnetic domains in a shield layer of a read-head, preventing variation of characteristics of the read-element and improving reliability. The magnetic head comprises the read-head, in which the read-element is magnetic-shielded by a shield layer. A step-shaped section is formed in a base layer, on which the shield layer is formed, and the step-shaped section corresponds to a border of at least one of domain areas, which are defined by desired magnetic domains to be formed in the shield layer after a magnetizing process.Type: ApplicationFiled: December 18, 2006Publication date: February 21, 2008Inventors: Shigeru Yoshiike, Hirofumi Nagai, Motonori Ueda
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Publication number: 20080037181Abstract: A method of forming a plating film capable of improving magnetic properties is provided. A photoresist pattern, having a first opening with an aspect ratio greater than 1 and a second opening with an aspect ratio smaller than that of the first opening, is formed on a surface of a substrate. A seed film is formed to cover an exposed surface of the substrate in the openings and an inner wall of the photoresist pattern in the openings. On the seed film in the openings, the plating film of magnetic material is deposited such that the first opening is filled under application of a magnetic field in the direction intersecting the surface of the substrate, and the second opening is filled under application of the magnetic field in the direction along the surface of the substrate.Type: ApplicationFiled: July 12, 2007Publication date: February 14, 2008Applicant: TDK CORPORATIONInventor: Akifumi Kamijima
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Patent number: 7325296Abstract: A magnetic head having a magnetic shield and/or pole layer that is fabricated as a plurality of laminated layers, in which each layer includes a sublayer thickness of Fe(N) and a sublayer thickness of NiFe(N), and where the relative thickness of these two sublayers is graduated. Particularly, the initially deposited laminations include sublayers of NiFe(N) having a thickness that is substantially greater than the thickness of the Fe(N) sublayers, whereas the finally deposited laminations include sublayers having an Fe(N) thickness that is substantially greater than the thickness of the NiFe(N) sublayers.Type: GrantFiled: May 19, 2005Date of Patent: February 5, 2008Assignee: International Business Machines CorporationInventor: Robert Glenn Biskeborn
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Publication number: 20080024936Abstract: The present invention provides a tunnel-effect type magnetoresistive head which can prevent degradation of a tunnel-effect type magnetoresistive effect element caused by contact with a magnetic recording medium without degrading a shielding effect. In this tunnel-effect type magnetoresistive head, for the above purpose, an exposed surface area of a shield and electrode layer, which is viewed from an air bearing surface, is decreased, and a shield layer is also provided outside the shield and electrode layer.Type: ApplicationFiled: March 22, 2007Publication date: January 31, 2008Inventor: Masamitsu Kitajima
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Patent number: 7324309Abstract: A magnetoresistive read/write head includes an integral top and side shields deposited on top of and substantially surrounding the multiple layers of the MR sensor stack. Such a design is particularly advantageous in CPP designs in which the only spacing necessary between the side shields and the bottom shield is due to a gap layer. The integral top and side shields design works both with CPP heads having pile bias stabilization as well as those having permanent magnet abutted junctions or patterned exchange bias stabilization. In addition, the design is also advantageous in CIP heads having permanent magnet abutted junctions or patterned exchange bias stabilization. In this latter embodiment, it may be possible to reduce the profile of the permanent magnet and any conductors to increase the efficacy of the side shields.Type: GrantFiled: September 24, 2003Date of Patent: January 29, 2008Assignee: Maxtor CorporationInventors: Kurt Wiesen, William R. Cross
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Publication number: 20080019056Abstract: A thin-film magnetic head provided with at least one MR read head element includes a lower shield layer, an upper shield layer, and an MR layer formed between the lower shield layer and the upper shield layer. A profile of the upper shield layer, appeared at an ABS, has obtuse or rounded upper corners at end edges of the upper shield layer along a track-width direction.Type: ApplicationFiled: July 9, 2007Publication date: January 24, 2008Applicant: TDK CORPORATIONInventors: Naoki OHTA, Kosuke TANAKA, Takayasu KANAYA, Kazuki SATO, Yasufumi UNO, Tetsuya KUWASHIMA
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Patent number: 7320168Abstract: Problems such as thermal pole tip protrusion result from thermal mismatch between the alumina and pole material during the writing process. This, and similar problems due to inadequate heat dissipation, have been overcome by dividing the bottom shield into two pieces both of which sit on top of a non-magnetic heat sink. Heat generated by the coil during writing is transferred to the non-magnetic heat sink whence it gets transferred to the substrate. With this approach, the head not only benefits from less field disturbance due to the small shield but also improves heat dissipation from the additional heat sink.Type: GrantFiled: October 29, 2003Date of Patent: January 22, 2008Assignee: Headway Technologies, Inc.Inventors: Cherng-Chyi Han, Rod Lee, Mao-Min Chen, Pokang Wang
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Publication number: 20080013221Abstract: The present invention relates to a thin-film magnetic head which prevents leakage of magnetic fluxes from an edge area of a lower and/or an upper shield layers of a magnetoresistive effect read head element. The thin-film magnetic head have a magnetoresistive effect read head element that includes a lower shield layer, an upper shield layer, a magnetoresistive effect layer, which is formed between the lower shield layer and the upper shield layer, and a lower antiferromagnetic layer which is contacted with the lower shield layer only at an edge area of the lower shield layer.Type: ApplicationFiled: June 8, 2007Publication date: January 17, 2008Applicant: TDK CORPORATIONInventors: Naoki OHTA, Kosuke Tanaka, Takayasu Kanaya, Kazuki Sato, Yasufumi Uno, Tetsuya Kuwashima
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Publication number: 20080013220Abstract: A method for manufacturing a magnetoresistive device that includes a spin-valve film, and a terminal layer that applies a sense current in a direction of a lamination surface in the spin-valve film, the spin-valve film including a pair of uncoupled ferromagnetic layers, and a non-magnetic metal layer that separates the pair of uncoupled ferromagnetic layers from each other, one of the ferromagnetic layers having a fixed direction of magnetization, and the other of the ferromagnetic layers having a freely variable direction of magnetization includes the steps of forming the terminal layer through sputtering, and preventing a formation of a sharp part on the terminal layer while interrupting the forming step.Type: ApplicationFiled: November 10, 2006Publication date: January 17, 2008Inventor: Tomohisa Yasukawa
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Publication number: 20080007875Abstract: A read head for a rotating magnetic storage system including concentric tracks is disclosed. The read head comprises a magnetoresistive (MR) sensor that reads information from a read track of the magnetic storage medium. First and second shields have a length greater than two tracks in a track width direction and define a gap therebetween, wherein the MR sensor is arranged in the gap. Inner magnetic portions of the first and second shields are spaced a first distance from the read track. Outer magnetic portions of the first and second shields are spaced a second distance from adjacent tracks to the read track, wherein the first distance is less than the second distance.Type: ApplicationFiled: July 6, 2007Publication date: January 10, 2008Inventors: Naoki Sato, Yasuyuki Ito
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Patent number: 7317596Abstract: A continuous-media or patterned-media disk drive with a low ratio of linear bit density in bits per inch (BPI) in the along-the-track direction to track density in tracks per inch (TPI) in the cross-track direction has a magnetoresistive read head with high cross-track spatial resolution. The read head is located between two magnetic shields, with the shields and read head formed on a side surface of the head carrier perpendicular to the carrier's disk-facing surface. The carrier is supported by the disk drive actuator with the side surface of the carrier oriented generally parallel to the data tracks. In this arrangement the high-spatial-resolution direction of the read head (the transverse direction perpendicular to the side surface on which the head is formed) is in the radial or cross-track direction.Type: GrantFiled: June 21, 2005Date of Patent: January 8, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Thomas R. Albrecht, Robert E. Fontana, Jr., Ching Hwa Tsang, Mason L. Williams, Bruce Alexander Wilson
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Publication number: 20080002306Abstract: The magnetic head is capable of preventing variation of magnetic fields working to a read-element, stably generating output signals and improving production yield. The magnetic head comprises: a read-head including a read-element; and a shield for magnetic-shielding the read-element, the shield has a hexagonal planar shape, and one side of the shield is flush with an air bearing surface of the magnetic head.Type: ApplicationFiled: September 7, 2006Publication date: January 3, 2008Inventors: Mitsuru Otagiri, Hideyuki Akimoto, Masaya Kato, Hiroshi Shirataki
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Publication number: 20080002307Abstract: The method of producing a thin film magnetic head is capable of highly precisely flattening an upper shielding layer without badly influencing a read-element, etc. The method comprises the steps of: forming a read-element on a wafer substrate; forming a hard bias film on the both sides of the read-element; forming an upper shielding layer in a specific area, which is located on the read-element and the hard bias film and defined by outer edges of the hard bias film in a plane-direction; and removing parts of the upper shielding layer, which are outwardly projected from outer edge of the upper shielding layer in the plane-direction, by etching, wherein the upper shielding layer is used as a mask of the etching process.Type: ApplicationFiled: October 4, 2006Publication date: January 3, 2008Inventor: Masanori Akie
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Publication number: 20070297096Abstract: In the magnetic head, characteristics of a read-element is not badly influenced by external electromagnetic waves, and the magnetic head is highly resistant to external electromagnetic waves. The magnetic head comprises: a write-head; a read-head having a read-element, which is grounded to a substrate via a resistance; and an electromagnetic wave shielding layer covering over a resistance area, in which the resistance is formed.Type: ApplicationFiled: October 5, 2006Publication date: December 27, 2007Inventors: Tomoka Aoki, Ryuei Ono
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Publication number: 20070242391Abstract: A magneto-resistive element includes a lower magnetic shield film and a magneto-resistive film disposed above the lower magnetic shield film. The lower magnetic shield film includes a lower shield layer and an upper shield layer. The upper shield layer is amorphous or microcrystalline, made of a NiFe or CoFe composition containing B or P, and deposited on the lower shield layer. The lower shield layer is a magnetic conductive layer which is amorphous or microcrystalline with a crystal grain size equal to or less than 20 nm.Type: ApplicationFiled: January 16, 2007Publication date: October 18, 2007Applicant: TDK CORPORATIONInventors: Atsushi YAMAGUCHI, Kei Hirata, Satoshi Miura, Yoshihiro Tsuchiya, Kiyoshi Noguchi
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Publication number: 20070242392Abstract: A shield in a magnetic reader includes a magnetic layer having a first surface and a second surface. The magnetic layer includes at least one aperture that extends through the magnetic layer from the first surface to the second surface.Type: ApplicationFiled: January 23, 2007Publication date: October 18, 2007Applicant: Seagate Technology LLCInventor: Mourad Benakli
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Patent number: 7280320Abstract: A lower shield layer is formed by being embedded in a first recess formed in an under layer. Accordingly, the distance between the lower shield layer and a slider can be reduced. Also, a second metal layer is formed from above a gap layer covering an electrode extracting layer over above the under layer hindwards therefrom. Accordingly, the second metal layer can be brought closer to the slider side than an upper shield layer. Consequently, the thermal dissipation effects of the thin-film magnetic head can be improved.Type: GrantFiled: March 5, 2004Date of Patent: October 9, 2007Assignee: Alps Electric Co., Ltd.Inventors: Kiyoshi Sato, Hideki Gochou, Hisayuki Yazawa
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Patent number: 7280325Abstract: A CPP magnetic sensor is disclosed with a ferromagnetic layer that extends in a first direction a first distance; a nonferromagnetic spacer layer that adjoins the ferromagnetic layer and extends in the first direction a second distance that is substantially equal to the first distance; and a ferromagnetic structure that is separated from the ferromagnetic layer by the spacer layer, the ferromagnetic structure having a first section that extends in the first direction a third distance that is substantially equal to the second distance, the ferromagnetic structure having a second section that is disposed further than the first section from the spacer layer, the second section extending at least twice as far as the first section in the first direction. The ferromagnetic structure can be used for in-stack bias or pinning of free or pinned layers, respectively, and side shields can be provided for high areal density.Type: GrantFiled: March 31, 2004Date of Patent: October 9, 2007Assignee: Western Digital (Fremont), LLCInventor: Tao Pan
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Publication number: 20070230064Abstract: A polishing method includes the steps of, performing a chemical-mechanical polishing with a first acid slurry, in the case of polishing soft magnetic layer with iron alloy that contains silicon and aluminum, and performing a mechanical polishing with a second weak acid or neutral slurry with a pH different from that of the first slurry.Type: ApplicationFiled: February 27, 2007Publication date: October 4, 2007Applicant: TDK CorporationInventors: Kazukiko Maejima, Makoto Hasegawa, Atsuhiro Nonaka, Hiroshi Kamiyama, Teruhisa Shindo, Hiroshi Yamazaki
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Patent number: 7274541Abstract: In formation of an upper shield of a magnetic thin film head by electroplating, a current density of electroplating is regulated stepwise with time. Thus, in the upper shield formation, a film composition and magnetic characteristic with respect to the direction of film thickness can be controlled precisely, making it possible to provide a magnetic thin film head featuring significantly reduced noise-after-write and output fluctuation.Type: GrantFiled: April 1, 2005Date of Patent: September 25, 2007Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Gen Oikawa, Shuichi Kojima, Harunobu Saito, Noriyuki Saiki, Masayasu Kagawa, Akira Kondo, Kenji Ishikake, Hiromi Shiina
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Patent number: 7274539Abstract: A composite type thin-film magnetic head is provided, which comprises: a MR read head element having an upper shield layer, a lower shield layer, an MR layer in which a sense current flows in a direction perpendicular to a surface of the layer through the upper shield layer and the lower shield layer; an inductive write head element formed on the MR read head element, having an upper magnetic pole layer, a recording gap layer, a lower magnetic pole layer where end portion is opposed to an end portion of the upper magnetic pole layer through the recording gap layer, and a write coil; and a capacitance C12 between the write coil and the upper shield layer, set to 0.1 pF or less.Type: GrantFiled: March 15, 2005Date of Patent: September 25, 2007Assignee: TDK CorporationInventors: Hiroshi Kiyono, Nozomu Hachisuka, Shunji Saruki, Noriaki Kasahara
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Patent number: 7274540Abstract: A magnetoresistive device includes a first shield layer and a second shield layer disposed at a specific distance from each other, an MR element disposed between the first and second shield layer, and an underlying layer disposed between the first shield layer and the MR element. The underlying layer, the MR element and the second shield layer are stacked on the first shield layer. The underlying layer includes a first layer having a bottom surface that is in contact with the first shield layer, and a second layer having a bottom surface that is in contact with a top surface of the first layer and a top surface that is adjacent to the MR element with a conductive layer disposed in between. The first layer is made of a material including at least one of Ta, Ti, W, HF and Y. The second layer is an alloy including Ni and Cr.Type: GrantFiled: October 19, 2004Date of Patent: September 25, 2007Assignee: TDK CorporationInventor: Masashi Sano
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Publication number: 20070211391Abstract: A current-perpendicular-to-plane magneto-resistive element includes a magneto-resistive film and a pair of upper and lower magnetic shielding films holding the magneto-resistive film therebetween for current feeding. The lower magnetic shielding film has an at least two-layer structure including a crystalline material layer and an amorphous material layer disposed below the crystalline material layer.Type: ApplicationFiled: December 27, 2006Publication date: September 13, 2007Applicant: TDK CORPORATIONInventors: Kei HIRATA, Koji Shimazawa, Atsushi Yamaguchi, Kiyoshi Noguchi
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Patent number: 7268663Abstract: A precision AC input voltage divider of input resistance RI and feedback resistance RF on a substrate is printed as a serpentine pattern for a thin line of resistive material. The input resistance is formed between a first and second terminal, and feedback resistance is formed between the second terminal and a third terminal. A first metallic conductor is formed on the substrate, connected to the first terminal, disposed to be adjacent to the input resistance, and having a distributed capacitive coupling to the input resistance that compensates for corresponding distributed stray capacitance from the input resistance to a circuit ground. A second metallic conductor is formed on the substrate, connected to the third terminal, disposed to be adjacent the feedback resistance, and having a distributed capacitive coupling to the feedback resistance that compensates for corresponding distributed stray capacitance from the feedback resistance to the circuit ground.Type: GrantFiled: October 25, 2005Date of Patent: September 11, 2007Assignee: Agilent Technologies, Inc.Inventors: Sylvia J. Budak, Joe E. Marriott
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Patent number: 7236333Abstract: A magnetic reader of the present invention comprises an MR sensor shielded by a magnetic shield including single domain soft magnetic materials. The domain wall free magnetic shield includes an unbiased soft magnetic layer and a biased soft magnetic layer separated by a non-magnetic layer. The easy axis of the biased layer is oriented to create a path for magnetic flux through the biased and unbiased layers thereby reducing the demagnetization field of the shield. A biasing layer maintains the first and second magnetic layers as single domain magnets. The biasing layer is further shaped to define a quiet zone where the biasing layer does not overlay the MR sensor.Type: GrantFiled: December 11, 2003Date of Patent: June 26, 2007Assignee: Seagate Technology LLCInventor: Declan Macken
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Patent number: 7212382Abstract: A magnetic head includes a metallic material layer between a lower core layer and an upper shield layer. This metallic material layer extends to the rear of the magnetic head in the height direction to overlap with a first metal layer. The metallic material layer can therefore efficiently dissipate joule heat generated from a write head section to the outside of the magnetic head through the first metal layer. In addition, the metallic material layer can block a fluctuating magnetic field generated from the write head section. Thus, this magnetic head can reduce variations in the magnetic domain structures of upper and lower shield layers to stabilize the read output of a read head section.Type: GrantFiled: May 24, 2004Date of Patent: May 1, 2007Inventor: Katsuhiko Otomo
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Patent number: 7203036Abstract: An extraordinary magnetoresistance (EMR) sensor has a planar shunt and planar leads formed on top of the sensor and extending downward into the semiconductor active region, resulting. Electrically conductive material, such as Au or AuGe, is first deposited into lithographically defined windows on top of the sensor. After liftoff of the photoresist a rapid thermal annealing process causes the conductive material to diffuse downward into the semiconductor material and make electrical contact with the active region. The outline of the sensor is defined by reactive etching or other suitable etching techniques. Insulating backfilling material such as Al-oxide is deposited to protect the EMR sensor and the edges of the active region. Chemical mechanical polishing of the structure results in a planar sensor that does not have exposed active region edges.Type: GrantFiled: July 30, 2004Date of Patent: April 10, 2007Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Amitava Chattopadhyay, Robert E. Fontana, Jr., Bruce A. Gurney, Stefan Maat, Ernesto E. Marinero
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Patent number: 7190556Abstract: A method for preventing electrostatic discharge (ESD) damage in the head-suspension assembly (HSA) construction process. The method teaches the formation of a novel GMR magnetic recording head on a conductive slider substrate, the GMR head being electrically connected to the substrate and its conducting leads having balanced resistances between the leads and the substrate. By establishing an electrical connection between the GMR head and the slider substrate, the entire HSA can be grounded during its construction. By also grounding any nearby conducting elements that could inadvertently contact the HSA or its parts, no accumulated tribocharges can discharge through the sensitive GMR sensor element.Type: GrantFiled: February 28, 2005Date of Patent: March 13, 2007Assignee: Headway Technologies, Inc,Inventor: Li-Yan Zhu
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Patent number: 7180712Abstract: A method for forming a laminated shield to improve the stability and performance of an MR read head and the MR read head formed using that shield. The shield consists of two layers of ferromagnetic material separated by a layer of ruthenium, allowing the ferromagnetic layers to form an antiferromagnetic configuration by means of a quantum mechanical exchange interaction. The antiferromagnetic configuration has a stable domain structure and a magnetization that forms closed loops around the shield edges thereby reducing noise in the readback signal and reducing disturbances to the magnetic state of the sensor element.Type: GrantFiled: February 28, 2000Date of Patent: February 20, 2007Assignee: Headway Technologies, Inc.Inventors: Min Li, Simon H. Liao, Cheng T. Horng, Kochan Ju
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Patent number: 7170720Abstract: It is known that the magnetic shields, between which CPP GMR stacks are sandwiched, can be a source of AMR (anisotropic magneto-resistance) noise. This has been significantly reduced by coating both the magnetic shields with highly conductive layers. If the guidelines disclosed in the invention are followed, the read head can exhibit AMR noise reduced by about 14 to 20. Additionally, the total thickness of the read gap can be maintained to be as low as 300 to 400 Angstroms.Type: GrantFiled: August 28, 2003Date of Patent: January 30, 2007Assignee: Headway Technologies, Inc.Inventors: Charles C. Lin, Min Li, Simon Liao
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Patent number: 7158351Abstract: A magnetic recording head includes an upper shield layer, a lower shield layer, a magnetoresistive film interposed between the upper shield layer and the lower shield layer, and a pair of leads electrically coupled to the magnetoresistive film, in which a pair of side shield layers constituted by portions of the upper shield layer is formed on both sides of the magnetoresistive film, and a spacing between each side shield layer and the magnetoresistive film is formed to be narrower than twice of a spacing between the upper shield layer and the lower shield layer, thereby a side reading amount can be made smaller than a conventional side reading value determined from the spacing between the upper and lower shield layers and a magnetic spacing between the head and a medium.Type: GrantFiled: August 3, 2005Date of Patent: January 2, 2007Assignee: Hitachi Global Storage TechnologiesInventors: Kazuhiro Nakamoto, Hiroyuki Hoshiya, Chiaki Ishikawa
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Patent number: 7154713Abstract: A high output, magnetoresistive head with a CPP structure is disclosed which reduces or prevents deformation near the air bearing surface of the read element portion layer at the time of air bearing surface processing. In the CPP structure magnetoresistive head, the deformation near the air bearing surface as a result of mechanical polishing during the air bearing surface processing can be reduced by forming deformation prevention layers having a higher shear modulus than the first ferromagnetic layer, and a second ferromagnetic layer between a magnetoresistive film and at least one of a lower shield layer and an upper shield layer.Type: GrantFiled: January 3, 2006Date of Patent: December 26, 2006Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Katsuro Watanabe, Kikuo Kusukawa, Taku Shintani, Kenichi Meguro
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Patent number: 7152305Abstract: A magnetoresistive (MR) read head is disclosed including a shield layer with a recessed portion and a protruding portion defined by the recessed portion. Also included is an MR sensor located in vertical alignment with the protruding portion of the shield layer. Further provided is at least one gap layer situated above and below the MR sensor. At least one of such gap layers is positioned in the recessed portion of the shield layer. By this design, a combined thickness of the gap layers is thinner adjacent to the MR sensor and the protruding portion of the shield layer, while being thicker adjacent to the recessed portion of the shield layer. As such, optimum insulation is provided while maintaining planar gap layer surfaces to avoid the detrimental ramifications of reflective notching and the swing curve effect.Type: GrantFiled: June 19, 2003Date of Patent: December 26, 2006Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Douglas Werner
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Patent number: 7151651Abstract: A read/write head for a disk drive having a shorting conductor from a shield of the read element to a conductor that runs from the write element to an external electrical contact pad. This allows for the measurement of the electrical isolation between the read sensor and the read shield via the external contact pads. Such a capability allows the electrical isolation to be measured both during the lapping process and subsequent to the heads being diced into separate sliders. This shorting conductor may be in the form of an internal shorting stud or in the form of an interim conductor that passes through the parting zone between adjacent heads. In the latter case, the shorting conductor is broken when the heads are diced so that a head of this embodiment can only be measured for electrical isolation prior to dicing.Type: GrantFiled: January 18, 2006Date of Patent: December 19, 2006Assignee: Maxtor CorporationInventors: Ralph W. Cross, Chris Broussalian
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Patent number: 7146711Abstract: A method for forming a planar GMR read-head having a narrow read gap, a narrow track-width and being well insulated from its lower shield. The method requires the formation of a planarized bottom magnetic shield in which concave regions, symmetrically disposed about a track-width region, are filled with a layer of dielectric to provide added insulation. The dielectric filled shield is planarized and an additional planar dielectric layer, a thin planar GMR sensor layer and a planar PMGI layer of uniform thickness is formed on it. A layer of photoresist is deposited on the PMGI layer and a bi-layer lift-off stencil of uniform height above the GMR layer and symmetric overhang regions is formed. The uniformity of the lift-off stencil, which is a result of the planarity of the layers on which it is formed, allows the deposition of conductive lead and biasing layers with controlled overspread.Type: GrantFiled: December 13, 2002Date of Patent: December 12, 2006Assignee: Headway Technologies, Inc.Inventors: Cherng Chyi Han, Mao-Min Chen, Jiun-Ting Lee