Detail Of Magnetic Shielding Patents (Class 360/319)
-
Patent number: 7813085Abstract: A thin-film magnetic head having an MR element in which the tolerance of external magnetic field is improved even under the condition that shields have smaller areas. The head includes: an MR element includes lower and upper shield layers provided so as to sandwich an MR multilayer, one of edges of each of the layers reaching a head end surface on an ABS side; and an electromagnetic transducer including main and auxiliary magnetic pole layers, one of edges of each of the layers reaching the head end surface, wherein at least one laminate shield layer for tolerating an external magnetic field is provided adjacently on one side or on both sides in a track width direction of at least one layer out of the upper and lower shield layers and the auxiliary magnetic pole layer, and one edge of the at least one laminate shield layer reaching the head end surface.Type: GrantFiled: March 30, 2007Date of Patent: October 12, 2010Assignee: TDK CorporationInventors: Kenkichi Anagawa, Hiraku Hirabayashi
-
Patent number: 7805828Abstract: A method of manufacturing a thin-film magnetic head including forming the first shield layer; forming the magnetoresistive device, carried out after forming the first shield layer, a heat treatment providing exchange coupling between the ferromagnetic layer and the antiferromagnetic layer so as to magnetize the ferromagnetic layer in a predetermined direction; forming the domain control layer so as to hold the magnetoresistive device in a track width direction; magnetizing the domain control layer in a direction yielding a magnetic field in the same direction as with a magnetic field received by the ferromagnetic layer upon exchange-coupling with the antiferromagnetic layer, forming the second shield layer, carried out after magnetizing the domain control layer, and remagnetizing the domain control layer in a direction yielding the longitudinal bias magnetic field, carried out after forming the second shield layer.Type: GrantFiled: May 23, 2007Date of Patent: October 5, 2010Assignee: TDK CorporationInventors: Koji Shimazawa, Yoshihiro Tsuchiya
-
Patent number: 7804666Abstract: Improved writability and a substantial reduction in adjacent track erasure are achieved by incorporating a composite shield structure in a PMR writer. There is a trailing shield formed a certain distance above the top surface of a write pole, a leading shield formed a certain distance below the bottom surface of the write pole, and a partial side shield having a section formed on each side of the write pole. The partial side shield thickness is less than that of the write pole. Each partial side shield section has a side that is parallel to the nearest write pole side and a top surface that is offset from the write pole top surface by 0 to 0.15 microns. A plurality of magnetic connections between two or more shield elements is employed to ensure correct magnetic potential. The large write pole has a flare angle of 45 to 75 degrees.Type: GrantFiled: April 13, 2007Date of Patent: September 28, 2010Assignee: Headway Technologies, Inc.Inventors: Lijie Guan, Morris Dovek, Joe Smyth, Yoshitaka Sasaki
-
Publication number: 20100232072Abstract: A magnetic sensor includes a freelayer, a reference layer and a front shield. The freelayer has a magnetization direction substantially perpendicular to the planar orientation of the layer and extends to the media confronting surface. The reference layer has a magnetization direction substantially in the plane of the layer and substantially perpendicular to the magnetization direction of the freelayer. The reference layer is recessed from the media confronting surface and a front shield is positioned between the reference layer and the media confronting surface thereby reducing the shield-to-shield spacing and increasing the areal density of the reader.Type: ApplicationFiled: March 16, 2009Publication date: September 16, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Dimitar Velikov Dimitrov, Zheng Gao, Wonjoon Jung, Sharat Batra, Olle Gunnar Heinonen
-
Patent number: 7796364Abstract: A current-perpendicular-to-plane (CPP) magnetoresistance sensor and a method for forming a current-perpendicular-to-plane (CPP) magnetoresistance sensor. The method includes providing a ferromagnetic shield layer and disposing one or more seed layers on the ferromagnetic shield layer. The method also includes disposing a pinning layer on the one or more seed layers, wherein the pinning layer excludes PtMn, and disposing a pinned layer on the pinning layer. The shield layer, each of the one or more seed layers, the pinning layer, and the pinned layer are comprised of compounds having face-centered-cubic structures.Type: GrantFiled: December 29, 2006Date of Patent: September 14, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Tsann Lin
-
Patent number: 7791842Abstract: In a read-write head, the shields can serve as magnetic flux conductors for external fields, so that they direct a certain amount of flux into the recording medium. This problem has been overcome by the addition to the shields of a pair of tabs located at the edges closest to the ABS. These tabs serve to prevent flux concentrating at the edges so that horizontal fields at these edges are significantly reduced. Said tabs need to have aspect ratios of at least 2 and may be either triangular or rectangular in shape. Alternatively, the tabs may be omitted and, instead, outer portions of the shield's lower edge may be shaped so as to slope upwards away from the ABS.Type: GrantFiled: September 1, 2009Date of Patent: September 7, 2010Assignee: Headway Technologies, Inc.Inventors: Lijie Guan, Moris Dovek
-
Publication number: 20100220415Abstract: A magnetic recording head includes: a main magnetic pole; a laminated body; and a pair of electrodes. The laminated body includes a first magnetic layer having a coercivity lower than magnetic field applied by the main magnetic pole, a second magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. The pair of electrodes are operable to pass a current through the laminated body.Type: ApplicationFiled: May 14, 2010Publication date: September 2, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Kenichiro Yamada, Hitoshi Iwasaki, Junichi Akiyama, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu, Shuichi Murakami, Tadashi Kai
-
Publication number: 20100214698Abstract: A shield for a read element of a magnetic recording head includes a first domain with boundaries remote from the read element and stabilized with a patterned bias element. The patterned bias element comprises a topographical pattern of grooves formed on the shield substrate.Type: ApplicationFiled: February 24, 2009Publication date: August 26, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Declan Macken, Eric W. Singleton
-
Publication number: 20100214699Abstract: A magnetic head according to one embodiment includes a first magnetic shield; a first insulation layer disposed above said first magnetic shield; a plurality of sensor layers disposed above said first insulation layer; two electrical leads overlying a majority of a surface of the sensor layers, the electrical leads being formed of a magnetic material and serving as a second magnetic shield; and a read width insulation member disposed above said sensor layers and between said two electrically conductive members, the read width insulation members lying in a common plane with the electrically conductive members, the common plane being oriented parallel to a plane of deposition of the read width insulation member. Other systems and methods are also presented.Type: ApplicationFiled: May 11, 2010Publication date: August 26, 2010Inventors: Kuok San Ho, Edward Hin Pong Lee, David John Seagle, Ching Hwa Tsang
-
Patent number: 7773349Abstract: In a CPP MR device such as a tunnel magnetoresistive (TMR) device, shoulders that have a magnetic moment that is matched to the magnetic moments of the free layer extend between the free layer and the S2 shield to provide an electrical path from one shoulder, through the shield, to the other shoulder for dissipating edge charges. Thus, a CPP MR device may include a seed stack, a pinned stack on the seed stack, and a tunnel barrier on the pinned stack. A free stack may be on the tunnel barrier, and the free stack can include a free sublayer separated from a magnetic shield and a path for dissipating edge charges in the free stack through the magnetic shield.Type: GrantFiled: February 10, 2006Date of Patent: August 10, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Robert Stanley Beach, Wipul Pemsiri Jayasekara, Vladimir Nikitin
-
Patent number: 7773347Abstract: A thin-film magnetic head has a plurality of MR read head elements. Each MR read head element includes shield layers electrically insulated from the ground. An electrical resistor layer is electrically connected between the shield layer of one of the plurality of MR read head elements and the shield layer of the other one of the plurality of MR read head elements.Type: GrantFiled: March 16, 2007Date of Patent: August 10, 2010Assignee: TDK CorporationInventors: Kazuhiko Maejima, Hiroshi Kamiyama, Tomonaga Nishikawa
-
Patent number: 7768747Abstract: A thin-film magnetic head includes a lower magnetic shield layer, an MR multi-layered structure formed on the lower magnetic shield layer so that current flows in a direction perpendicular to surfaces of laminated layers, and an upper magnetic shield layer formed on the MR multi-layered structure. The lower magnetic shield layer consists of a first soft magnetic layer and a second soft magnetic layer laminated on and magnetically connected with the first soft magnetic layer. A part of an upper surface of the first soft magnetic layer outside both side ends in a track-width direction of the MR multi-layered structure is located lower in height than an upper surface within a region where the MR multi-layered structure is formed, of the lower magnetic shield layer. The second soft magnetic layer is formed outside both side ends in a track-width direction of the MR multi-layered structure.Type: GrantFiled: April 16, 2007Date of Patent: August 3, 2010Assignee: TDK CorporationInventors: Takeo Kagami, Takayasu Kanaya
-
Publication number: 20100188783Abstract: According to one embodiment, a magnetic head of a disk apparatus includes a main magnetic pole, a recording coil, a return magnetic pole, and a side shield provided on both sides of the main magnetic pole in the width direction, apart magnetically away from the main magnetic pole. The side shield includes on each side of the main magnetic pole a first shield edge which extends from a leading side end face of the return magnetic pole toward the main magnetic pole and opposes the main magnetic pole in at least a part with a gap smaller than the write gap, and a second shield edge which extends from the first shield edge in a direction opposite to the leading side end face of the return magnetic pole and opposes the main magnetic pole with a gap larger than the write gap.Type: ApplicationFiled: November 13, 2009Publication date: July 29, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventor: Tomoko TAGUCHI
-
Patent number: 7764469Abstract: A magnetic structure for use in a magnetic head for avoiding stray field writing. The magnetic structure can be for example a magnetic shield or could be a magnetic pole of a write head and is particularly advantageous for use in a perpendicular recording system, because such perpendicular recording systems are especially susceptible to stray field writing. The magnetic structure includes a forward protruding portion that extends toward the air bearing surface (ABS) of the head also includes first and second wing portions that extend laterally from the forward protruding portion. The wing portions each have a front edge that is recessed from the ABS. The wings are tapered so that the amount of recess of the front edge of the wings increases with lateral distance from the center of the magnetic structure.Type: GrantFiled: October 29, 2004Date of Patent: July 27, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Kuok San Ho, Yimin Hsu, Ching Hwa Tsang
-
Publication number: 20100177447Abstract: An MR element includes a lower shield layer, a magnetization free function part stacked on the lower shield layer, an upper shield layer stacked on the magnetization free function part, a nonmagnetic intermediate layer stacked on a surface, that is opposite to a magnetically sensitive surface, of the magnetization free function part, and a magnetization fixed function part stacked on the nonmagnetic intermediate layer. The nonmagnetic intermediate layer and the magnetization fixed function part are formed only within an outer region of the magnetization free function part, located opposite side to the magnetically sensitive surface.Type: ApplicationFiled: January 9, 2009Publication date: July 15, 2010Applicant: TDK CORPORATIONInventor: Takumi YANAGISAWA
-
Patent number: 7751155Abstract: In an ink-jet printing device which has an ink-jet recording head in which a plurality of nozzles are formed, and forms an image based on multi-level image data, a gamma correction parameter is selected according to discharging characteristics of the recording head to an input gradation level or according to lightness characteristics of a printed image to an input gradation level, and an image is formed based on the selected gamma correction parameter. For example, even when there is a variation in lightness characteristics of recording heads as in FIG. 9, an optimal gamma correction parameter is selected for each recording head and the image is formed. Thus, a constant image quality is obtained even if the recording heads are exchanged.Type: GrantFiled: September 18, 2003Date of Patent: July 6, 2010Assignee: Ricoh Company, Ltd.Inventors: Takashi Kimura, Masakazu Yoshida, Masanori Hirano, Toshihito Kamei, Mikio Ohashi, Taeko Takahashi
-
Publication number: 20100165517Abstract: A magnetic head includes a side shield layer and an encasing layer. The side shield layer has a first end face located in the medium facing surface, a second end face opposite to the first end face, and a first groove accommodating a portion of a pole layer. The first end face includes two portions located on both sides of an end face of the pole layer that are opposite to each other in a track width direction. The encasing layer is formed of a nonmagnetic material and disposed on a side of the side shield layer opposite to a medium facing surface. The encasing layer has a front end face touching the second end face of the side shield layer, and a second groove accommodating another portion of the pole layer. The distance from the medium facing surface to an arbitrary point on the second end face of the side shield layer decreases with decreasing distance from the arbitrary point to the top surface of a substrate.Type: ApplicationFiled: December 29, 2008Publication date: July 1, 2010Applicant: HEADWAY TECHNOLOGIES, INC.Inventors: Hironori Araki, Yoshitaka Sasaki, Hiroyuki Ito, Shigeki Tanemura, Kazuo Ishizaki, Takehiro Horinaka
-
Publication number: 20100157484Abstract: A perpendicular recording magnetic head is provided, according to one embodiment, in which even if a thickness of a main pole is reduced corresponding to a reduction in a recording track width, recording performance is not degraded. A magnetic-field auxiliary pole and a nonmagnetic layer are stacked on a main pole, and a nonmagnetic portion is provided on each side face on a flying surface side of the magnetic-field auxiliary pole and the nonmagnetic layer, in one approach. In all regions except for a region near a flying surface, an interval between the main pole and a shield is increased by the nonmagnetic portion and the nonmagnetic layer, so that magnetic field loss is prevented, and consequently magnetic field strength and a magnetic field gradient are increased. Other systems and methods are also disclosed for retaining magnetic recording performance while reducing a thickness of a main pole.Type: ApplicationFiled: December 11, 2009Publication date: June 24, 2010Inventors: Kimitoshi Etoh, Mikito Sugiyama, Isao Nunokawa, Tomohiro Okada
-
Publication number: 20100157465Abstract: One general embodiment of the present invention is a magnetic read head including a magnetoresistive sensor where sense current flows in a stacking direction of the magnetoresistive sensor, i.e., perpendicular to the plane of the layers of the head. The magnetoresistive sensor comprises a free layer having a magnetization direction that is affected by external magnetic fields and includes a Heusler alloy layer and a Co-based amorphous metal layer, a fixed layer which is stacked with the free layer and has a fixed magnetization direction, and a non-magnetic intermediate layer between the free layer and the fixed layer.Type: ApplicationFiled: December 18, 2009Publication date: June 24, 2010Inventors: Koji Sakamoto, Koichi Nishioka, Katsuya Mitsuoka, Katsumi Hoshino, Yo Sato
-
Publication number: 20100149697Abstract: A recording head having a narrowed track has a high recording magnetic field strength and a high recording magnetic field gradient has certain problems which may be difficult to overcome. In one embodiment, a magnetic film, which overhangs from a track width, is provided on a trailing side of a region retracted from an ABS of a main pole facing a recording medium. Thereby, a magnetic field strength on the trailing side is increased so that a difference in distribution of magnetic field strength defined by a geometrical Bevel angle given to the main pole is increased. Consequently, writing performance of the main pole is improved while forming a large magnetic clearance angle with respect to an adjacent track and suppresses writing into an adjacent track when skew occurs. Other systems and methods are also disclosed regarding a head with a high recording magnetic field using an overhanging magnetic film.Type: ApplicationFiled: December 11, 2009Publication date: June 17, 2010Inventors: Isao Nunokawa, Mikito Sugiyama, Kikuo Kusukawa, Kimitoshi Etoh
-
Publication number: 20100128400Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic amorphous buffer and polycrystalline seed layers is disclosed for reducing a read gap, in order to perform magnetic recording at higher linear densities. The ferromagnetic amorphous buffer and polycrystalline seed layers couples to a ferromagnetic lower shield, thus acting as part of the ferromagnetic lower shield and defining the upper surface of the ferromagnetic polycrystalline seed layer as the lower bound of the read gap. In addition, a CPP TMR or GMR read sensor with nonmagnetic and ferromagnetic cap layers is also disclosed for reducing the read gap, in order to perform magnetic recording at even higher linear densities. The ferromagnetic cap layer couples to a ferromagnetic upper shield, thus acting as part of the ferromagnetic upper shield and defining the lower surface of the ferromagnetic cap layer as the upper bound of the read gap.Type: ApplicationFiled: November 21, 2008Publication date: May 27, 2010Inventor: Tsann Lin
-
Publication number: 20100123977Abstract: In one embodiment, a vertical-current-type reproducing magnetic head includes a sensor film, an upper shield paired with a lower shield that together flow a current into the sensor film in a thickness direction of the sensor film, and magnetic-domain control magnetic films provided above both sides of the sensor film in a track width direction of the sensor film. The shield is formed via a nonmagnetic adhesion layer including a discontinuous region near the sensor film, and the sensor film contacts the upper shield. In another embodiment, a method includes forming a resist layer, etching a sensor film while using the resist layer as a mask, forming first insulating films, domain-control magnetic films, and nonmagnetic adhesion layers in a stacked manner, lifting-off the resist layer, and forming an upper shield that together with a lower shield flow current into the sensor film in a thickness direction of the sensor film.Type: ApplicationFiled: November 9, 2009Publication date: May 20, 2010Inventors: Kenichi Akita, Nobuo Yoshida, Katsuro Watanabe
-
Patent number: 7715152Abstract: Embodiments of the invention provide a perpendicular magnetic writing head with a suppressed effective track width to be written on a magnetic medium while increasing writing magnetic field gradient. In one embodiment a trailing side shield is disposed by way of a gap film to a main pole of a perpendicular writing magnetic head. A gap distance (Gt) on a trailing side of the main pole and a gap distance (Gs) on a lateral side of the main pole is defined as Gt<Gt, and a thickness (Gd) from an air bearing surface of the shield is made equal to or less than a throat height. Alternatively, the thickness of Gd on the side of the main pole is reduced to less than that on the trailing side of the main pole. Further, for preventing defoliation of the shield upon fabrication of the air bearing surface, a thickness for a portion away from the main pole is increased.Type: GrantFiled: December 14, 2004Date of Patent: May 11, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Tomohiro Okada, Isao Nunokawa, Masafumi Mochizuki
-
Publication number: 20100110582Abstract: A multi-channel thin-film magnetic head includes a substrate, a plurality of MR read head elements, a plurality of first resistive elements, and a plurality of second resistive elements. Each MR read head element includes a lower magnetic shield layer, an upper magnetic shield layer, and an MR layer arranged between the lower magnetic shield layer and the upper magnetic shield layer. Each first resistive element has a first resistance value. One ends of the plurality of first resistive elements are connected to the lower magnetic shield layers or the upper magnetic shield layers of the plurality of MR read head elements, respectively. Each second resistive element has a second resistance value that is higher than the first resistance value. One ends of the plurality of second resistive elements are commonly connected to the other ends of the plurality of first resistive elements. The other ends of the plurality of second resistive elements are grounded.Type: ApplicationFiled: October 30, 2008Publication date: May 6, 2010Applicant: TDK CORPORATIONInventor: Nozomu Hachisuka
-
Magnetoresistive element including a pair of ferromagnetic layers coupled to a pair of shield layers
Publication number: 20100103563Abstract: A magnetoresistive element includes first and second shield portions and an MR stack. Each of the first and second shield portions includes a shield bias magnetic field applying layer, and a closed-magnetic-path-forming portion that forms a closed magnetic path in conjunction of the shield bias magnetic field applying layer. The closed-magnetic-path-forming portion includes a single magnetic domain portion. The MR stack is sandwiched between the respective single magnetic domain portions of the first and second shield portions. The closed-magnetic-path-forming portion includes a magnetic-path-expanding portion that forms a magnetic path, the magnetic path being a portion of the closed magnetic path and located between the shield bias magnetic field applying layer and the single magnetic domain portion. The magnetic-path-expanding portion has two end portions located at both ends of the magnetic path, and a middle portion located between the two end portions.Type: ApplicationFiled: October 29, 2008Publication date: April 29, 2010Applicant: TDK CORPORATIONInventors: Takahiko Machita, Daisuke Miyauchi, Tsutomu Chou, Toshiyuki Ayukawa -
Publication number: 20100103564Abstract: As recording density of sensors is increased, it is desired to lower the areal resistivity (RA) of TMR sensors. Decreasing RA to 1.0 ??m2 or below badly influences the read signal since the interlayer coupling magnetic field (Hint) between the pinned layer and the free layer increases sharply and impedes the free rotation of magnetization of the free layer. According to one embodiment, a tunnel junction type magneto-resistive head solves this problem by having a layered film comprising an underlying layer, a crystalline orientation control layer, an antiferromagnetic layer, a first ferromagnetic layer, an antiparallel coupling layer, a second ferromagnetic layer, an insulation barrier layer, and a third ferromagnetic layer between a lower magnetic shield layer and an upper magnetic shield layer, wherein a crystallographic plane of the antiferromagnetic layer is directed parallel to a film surface by growing the antiferromagnetic layer substantially conformably on the crystalline orientation control layer.Type: ApplicationFiled: September 21, 2009Publication date: April 29, 2010Inventors: Koichi Nishioka, Hiroaki Chihaya
-
Patent number: 7706108Abstract: One embodiment of the present invention is directed to a read head for a data storage device including a sensor for reading data from a data storage medium, a first shield disposed adjacent to the sensor and characterized as moment-compensated, and a second shield disposed adjacent to the sensor, the second shield being moment-compensated.Type: GrantFiled: February 24, 2006Date of Patent: April 27, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Hardayal (Harry) Singh Gill
-
Magnetic Recording Head, Method of Manufacturing the Same, and Magnetic Recording/Reproducing Device
Publication number: 20100091413Abstract: According to one embodiment, a magnetic recording head includes a main pole having a throat height portion and a flare portion that is connected to the throat height portion, the flare portion gradually being expanded in width to an upper part in an element height direction. The head also includes a sub pole, magnetic shields disposed via a nonmagnetic layer on a trailing side of the main pole and on both sides in a track width direction of the main pole, and a coil for generating a recording magnetic field from the main pole. The nonmagnetic layer has an upper portion of which the thickness is increased stepwise or in a tapered manner in the element height direction with respect to an ABS side, and each portion of the magnetic shields adjacent to the main pole has a shape corresponding to a surface shape of the nonmagnetic layer.Type: ApplicationFiled: September 14, 2009Publication date: April 15, 2010Inventors: Isao Nunokawa, Mikito Sugiyama, Kikuo Kusukawa, Hiroyuki Hoshiya -
Publication number: 20100079917Abstract: A first shield portion located below an MR stack includes a first main shield layer, a first antiferromagnetic layer, and a first magnetization controlling layer including a first ferromagnetic layer exchange-coupled to the first antiferromagnetic layer. A second shield portion located on the MR stack includes a second main shield layer, a second antiferromagnetic layer, and a second magnetization controlling layer including a second ferromagnetic layer exchange-coupled to the second antiferromagnetic layer. The MR stack includes two free layers magnetically coupled to the two magnetization controlling layers. Only one of the two magnetization controlling layers includes a third ferromagnetic layer that is antiferromagnetically exchange-coupled to the first or second ferromagnetic layer through a nonmagnetic middle layer. The first shield portion includes an underlayer disposed on the first main shield layer, and the first antiferromagnetic layer is disposed on the underlayer.Type: ApplicationFiled: September 29, 2008Publication date: April 1, 2010Applicant: TDK CORPORATIONInventors: Daisuke Miyauchi, Yoshihiro Tsuchiya, Tsutomu Chou, Shinji Hara, Takahiko Machita, Koji Shimazawa
-
Publication number: 20100073826Abstract: A method for manufacturing a magnetic head with an electrostatic discharge resistor for preventing electrostatic discharge damage to magnetic head. The electrostatic discharge resistor is formed by a processes that saves manufacturing time and cost by forming resistor in the same deposition and patterning steps used to form the magnetoresistive sensor. However, the resistor includes only a portion of the layers used to form the magnetoresistive sensor, thereby ensuring that the resistor will have sufficient resistivity.Type: ApplicationFiled: September 24, 2008Publication date: March 25, 2010Inventors: Satoru Araki, David John Seagle
-
Patent number: 7684159Abstract: A lower shield layer and an upper shield layer are formed to have a planar shape, and a detecting element is provided between the lower shield layer and the upper shield layer. End faces of the upper shield layer may extend farther in a depthwise direction from a surface facing a recording medium than end faces of the lower shield layer. A lower conductive electrode may be disposed directly adjacent to a facing inner surface of the lower shield layer. An upper conductive electrode may be disposed adjacent to a portion of the upper shield layer. Therefore, the lower shield layer and the upper conductive electrode may be insulated from each other.Type: GrantFiled: December 6, 2006Date of Patent: March 23, 2010Assignee: TDK CorporationInventors: Yoshihiro Nishiyama, Daigo Aoki, Toru Takahashi
-
Publication number: 20100067148Abstract: A thin film magnetic head comprises an MR laminated body that has first and second magnetic layers, a nonmagnetic middle layer, and the first and second magnetic layers and the nonmagnetic middle layer are laminated to make contact with each other in respective order. First and second antiferromagnetic layers are provided with the first and second magnetic layers respectively. The first antiferromagnetic layer and/or the second antiferromagnetic layer contains a void part or a thin portion at least in a portion of the projection area toward the orthogonal direction to the film surface of the MR laminated body.Type: ApplicationFiled: September 16, 2008Publication date: March 18, 2010Applicant: TDK CORPORATIONInventors: Yoshihiro Tsuchiya, Tsutomu Chou, Shinji Hara, Daisuke Miyauchi, Takahiko Machita
-
Patent number: 7675716Abstract: A composite thin-film magnetic head includes a substrate, an under layer formed on the substrate, an MR read head element formed on the under layer and provided with a lower shield layer, an upper shield layer and an MR layer in which a sense current flows in a direction perpendicular to a surface of the MR layer through the upper shield layer and the lower shield layer, an inter-shield insulation layer laminated on the MR read head element, an inductive write head element formed on the inter-shield insulation layer and provided with a first magnetic pole layer, a nonmagnetic layer, a second magnetic pole layer whose end portion is opposed to an end portion of the first magnetic pole layer through the nonmagnetic layer, and a write coil, and an additional shield layer formed between the upper shield layer and the first magnetic pole layer.Type: GrantFiled: March 31, 2006Date of Patent: March 9, 2010Assignee: TDK CorporationInventors: Takeo Kagami, Hiroshi Kiyono, Hiraku Hirabayashi, Eiichi Omata, Seiji Yari, Takamitsu Sakamoto
-
Patent number: 7675715Abstract: In one embodiment, a seed layer, an underlayer, and a magnetic domain control layer are laminated on both sides of a magnetoresistive sheet unit. A lower electrode film is thinly formed on an upper portion of the magnetic domain control film. A portion of the lower electrode film near the magnetoresistive sheet unit does not protrude substantially from an upper surface of the magnetoresistive sheet unit. Should the portion protrude, a step from the upper surface of the magnetoresistive sheet unit is about 14 nm or less. This portion and the upper surface of the magnetoresistive sheet unit are formed into a flat surface. An upper electrode film is formed thickly on an upper portion of the lower electrode film on an outside thereof so as to circumvent the flat surface. A protective layer, an upper gap film, and an upper magnetic shield film are also formed.Type: GrantFiled: September 14, 2005Date of Patent: March 9, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masatoshi Arasawa, Izuru Ishii, Shuichi Kojima, Naoki Koyama, Norihiro Ookawa
-
Magnetoresistive element including a pair of ferromagnetic layers coupled to a pair of shield layers
Publication number: 20100053820Abstract: A magnetoresistive element includes first and second shield layers, an MR stack disposed therebetween, a first hard magnetic layer for setting the magnetization direction of the first shield layer, and a second hard magnetic layer for setting the magnetization direction of the second shield layer. The MR stack includes a first ferromagnetic layer magnetically coupled to the first shield layer, a second ferromagnetic layer magnetically coupled to the second shield layer, and a spacer layer between the first and second ferromagnetic layers. The first and second ferromagnetic layers have magnetizations that are in antiparallel directions when any external magnetic field other than a magnetic field resulting from the first and second hard magnetic layers is not applied to the two ferromagnetic layers, and that change their directions in response to an external magnetic field other than the magnetic field resulting from the first and second hard magnetic layers.Type: ApplicationFiled: September 2, 2008Publication date: March 4, 2010Applicant: TDK CORPORATIONInventors: Daisuke Miyauchi, Yoshihiro Tsuchiya, Tsutomu Chou, Shinji Hara, Takahiko Machita, Koji Shimazawa -
Publication number: 20100053821Abstract: According to one embodiment, a magnetoresistive head has a magnetoresistive sensor film between a lower shield layer and an upper shield layer. The magnetoresistive sensor film is formed by stacking at least a pinning layer, a first ferromagnetic layer, an intermediate layer, and a second ferromagnetic layer, in which a sense current flows so as to pass through an interface between the intermediate layer and the second ferromagnetic layer, and a resistance change of the magnetoresistive sensor film in accordance with the change of an external magnetic field is detected. Also, a lateral side metal layer having an electric resistivity lower than the electric resistivity of the pinning layer is disposed at least on a side wall of the pinning layer among side walls of layers constituting the magnetoresistive sensor film, the lateral side metal layer being in contact with the lower shield layer. Other embodiments are described as well.Type: ApplicationFiled: August 25, 2009Publication date: March 4, 2010Inventors: Katsuro Watanabe, Shigeo Fujita, Norihiro Ookawa, Kenichi Meguro
-
Publication number: 20100053819Abstract: The invention is devised to provide a method of manufacturing a thin film magnetic head including a magnetoresistive element having higher reading performance. In manufacturing the thin film magnetic head, after forming an MR element 15, a pair of magnetic domain controlling layers 16 are formed by stacking a buffer layer 161, a magnetic bias layer 162 and a cap layer 163 in this order on both sides, in a track-width direction, of the MR element 15 via an insulating layer 14 respectively. Then, a cap layer 17 is formed so as to cover the upper surface of the MR element 15 and connect the pair of cap-layers 163. After that, a gap adjustment layer 18 and a top shielding layer 19 are formed in order so as to cover the pair of cap layers 163 and the cap layer 17, thereby a read head section 10 is completed.Type: ApplicationFiled: September 4, 2008Publication date: March 4, 2010Applicant: TDK CORPORATIONInventors: Kei Hirata, Takayasu Kanaya, Kosuke Tanaka, Shinji Hara
-
Publication number: 20100046120Abstract: Disk drive systems and associated methods of fabrication are disclosed for a write head having an integrated coil and shield structure. The write head includes a write pole having a pole tip adjacent to an air bearing surface, and a return pole having a surface adjacent to the air bearing surface. The write pole and the return pole are connected to one another by a back gap section that is distal from the air bearing surface. The write head also includes a coil formed from electrically conductive materials. The coil includes a segment that is formed proximate to the air bearing surface. The coil segment is formed from a ferromagnetic material so that the coil segment acts as a shield for the write pole.Type: ApplicationFiled: August 19, 2008Publication date: February 25, 2010Inventors: Jeffrey S. Lille, Petrus A. Van Der Heijden
-
Publication number: 20100039734Abstract: A thin film magnetic head includes a magneto-resistance (MR) laminated body, a lower shield layer and an upper shield layer that face the first MR magnetic layer. The lower and upper shield layers respectively have first and second exchange coupling magnetic field application layers and first and second antiferromagnetic layers. An exchange coupling intensity relating to an antiferromagnetic coupling between the second exchange coupling magnetic field application layer and the second antiferromagnetic layer is greater in the peripheral area of a projection area than that of the projection area of the upper shield layer side end surface of the MR laminated body to the film surface's orthogonal direction.Type: ApplicationFiled: August 12, 2008Publication date: February 18, 2010Applicant: TDK CORPORATIONInventors: Shinji Hara, Yoshihiro Tsuchiya, Tsutomu Chou, Daisuke Miyauchi, Takahiko Machita
-
Patent number: 7663845Abstract: 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: GrantFiled: December 27, 2006Date of Patent: February 16, 2010Assignee: TDK CorporationInventors: Kei Hirata, Koji Shimazawa, Atsushi Yamaguchi, Kiyoshi Noguchi
-
Publication number: 20100033879Abstract: A perpendicular magnetic head for writing information on a magnetic recording medium comprises an ABS, a coil for generating a magnetic flux, a magnetic pole layer, a magnetic shield layer, and a gap layer disposed between the magnetic pole layer and the magnetic shield layer. Further the magnetic head has a non-magnetic region of a non-magnetic material. The non-magnetic region is disposed in the magnetic shield layer and positioned behind the ABS at a predetermined distance. The non-magnetic region is also disposed in the magnetic shield layer and has a predetermined width. With such a configuration, an undesirable concentration of the magnetic flux on the ABS is prevented.Type: ApplicationFiled: August 8, 2008Publication date: February 11, 2010Applicant: TDK CORPORATIONInventors: Norikazu OTA, Tatsuhiro NOJIMA, Tsuyoshi UMEHARA
-
Publication number: 20100027158Abstract: A magnetic recording head includes: a magnetic pole; a magnetic shield forming a magnetic circuit with the magnetic pole; and a spin torque oscillator provided between the magnetic pole and the magnetic shield, and formed with a stack structure including a first magnetic layer, a second magnetic layer, and an intermediate layer interposed between the first magnetic layer and the second magnetic layer. The first magnetic layer is made of a magnetic material of 200 Oe or smaller in coercive force. A cross-sectional area of the first magnetic layer in a direction perpendicular to a stack layer face of the first magnetic layer is four or more times greater than a cross-sectional area of the second magnetic layer in a direction perpendicular to a stack layer face of the second magnetic layer.Type: ApplicationFiled: July 29, 2009Publication date: February 4, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masayuki Takagishi, Kenichiro Yamada, Hitoshi Iwasaki, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu
-
Publication number: 20100027168Abstract: A thin film magnetic head comprise an MR laminated body composed of a first and second MR magnetic layers, first and second shield layers, and a bias magnetic field application layer provided on an opposite side of an air bearing surface (ABS) of the MR laminated body in order to apply a bias magnetic field orthogonal relative to the ABS. The first shield layer comprises a first exchange coupling magnetic field application layer, a first antimagnetic layer, a second exchange coupling magnetic field application layer, and a second antimagnetic layer. The first antimagnetic layer is provided in contact with the first exchange coupling magnetic field application layer on the rear face of the first exchange coupling magnetic field application layer and which is antimagnetically coupled with the first exchange coupling magnetic field application layer. The second shield layer has the same configuration as that of the first shield layer.Type: ApplicationFiled: July 29, 2008Publication date: February 4, 2010Applicant: TDK CORPORATIONInventors: Tsutomu Chou, Yoshihiro Tsuchiya, Shinji Hara, Daisuke Miyauchi, Takahiko Machita
-
Publication number: 20100027167Abstract: A current to perpendicular to plane (CPP) magnetoresistance (MR) read head using current confinement proximal to an air bearing surface (ABS) is disclosed. A CPP MR read head includes a first shield, an MR sensor formed on the first shield, and a second shield contacting the MR sensor proximal to an ABS. The CPP MR read head further includes insulating material between the MR sensor and the second shield, where the insulating material is distal to the ABS to electrically isolate the MR sensor from the second shield distal to the ABS. Sense current injected from the second shield through the MR sensor and into the first shield is confined proximal to the ABS at a location where the second shield contacts the MR sensor.Type: ApplicationFiled: July 30, 2008Publication date: February 4, 2010Inventors: Hardayal S. Gill, Werner J. Douglas, Wipul P. Jayasekara, Wen-Chien Hsiao
-
Patent number: 7656620Abstract: A lower shield layer has a substantially flat shape, and an upper shield layer has a front portion and a rear portion, where the front portion is disposed closer to the lower shield layer than the rear portion. A lower conductive electrode and an upper conductive electrode are disposed between the lower shield layer and the upper shield layer. The lower conductive electrode is electrically connected to the lower shield layer, and the upper conductive electrode is electrically connected to the upper shield layer. Since the lower and upper conductive electrodes are disposed between the upper and lower shield layers, each of the lower shield layer and the upper shield layer may be formed to have a small area and a simple shape.Type: GrantFiled: December 6, 2006Date of Patent: February 2, 2010Assignee: TDK CorporationInventors: Yoshihiro Nishiyama, Yasuo Hayakawa, Daigo Aoki
-
Patent number: 7652854Abstract: A tunneling magneto-resistive element includes: a tunneling magneto-resistive film including an antiferromagnetic layer, a pinned layer, a barrier layer and a free layer; and a lower magnetic shielding film disposed below the tunneling magneto-resistive film with respect to a lamination direction. The barrier layer is constituted of magnesium oxide. The lower magnetic shielding film has a multi-layer structure including a crystalline layer and an amorphous layer disposed above the crystalline layer with respect to the lamination direction. The crystalline layer contains at least one crystal grain having a grain size of 500 nm or more.Type: GrantFiled: August 8, 2006Date of Patent: January 26, 2010Assignee: TDK CorporationInventors: Takeo Kagami, Naoki Ohta, Kazuki Sato, Satoshi Miura
-
Patent number: 7652853Abstract: A magnetic data recording head having reduced thermally induced shield (pole tip) protrusion. The head includes a magnetoresistive sensor sandwiched between first and second shield. The shields have a substantially reduced thickness. The distance between the shields defines a gap (G) and the shields each have a thickness (ST) such that the ratio ST/G is greater than 2, but less than 50. More preferably the ratio ST/G is greater than 2, but less than 20, and yet more preferably, the ratio ST/G is greater than 2 and less than 10.Type: GrantFiled: July 28, 2005Date of Patent: January 26, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Gity Samadi Hosseinali, Vladimir Nikitin, Robert Langland Smith
-
Publication number: 20100007995Abstract: A magnetic sensor comprises a nonmagnetic conductive layer, a free magnetization layer disposed on a first part of the nonmagnetic conductive layer, a fixed magnetization layer disposed on a second part of the nonmagnetic conductive layer different from the first part, upper and lower first magnetic shield layers opposing each other through the nonmagnetic conductive layer and free magnetization layer interposed therebetween, upper and lower second magnetic shield layers opposing each other through the nonmagnetic conductive layer and fixed magnetization layer interposed therebetween, a first electrically insulating layer disposed between the lower second magnetic shield layer and nonmagnetic conductive layer, and a first electrode layer for electrically connecting the lower second magnetic shield layer and nonmagnetic conductive layer to each other, while the fixed magnetization layer and first electrode layer oppose each other through the nonmagnetic conductive layer.Type: ApplicationFiled: May 26, 2009Publication date: January 14, 2010Applicant: TDK CORPORATIONInventor: Tomoyuki SASAKI
-
Publication number: 20090323228Abstract: A tunneling magnetoresistance (TMR) device, like a TMR read head for a magnetic recording hard disk drive, has a magnesium oxide (MgO) tunneling barrier layer and a ferromagnetic underlayer beneath and in direct contact with the MgO tunneling barrier layer. The ferromagnetic underlayer comprises a crystalline material according to the formula (CoxFe(100-x))(100-y)Gey, where the subscripts represent atomic percent, x is between about 45 and 55, and y is between about 26 and 37. The ferromagnetic underlayer may be the CoxFe(100-x))(100-y)Gey portion of a bilayer of two ferromagnetic layers, for example a CoFe/(CoxFe(100-x))(100-y)Gey bilayer. The specific composition of the ferromagnetic underlayer improves the crystallinity of the MgO tunneling barrier after annealing and improves the tunneling magnetoresistance of the TMR device.Type: ApplicationFiled: September 3, 2009Publication date: December 31, 2009Applicant: Intellectual Property LawInventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
-
Publication number: 20090323229Abstract: In a read-write head, the shields can serve as magnetic flux conductors for external fields, so that they direct a certain amount of flux into the recording medium. This problem has been overcome by the addition to the shields of a pair of tabs located at the edges closest to the ABS. These tabs serve to prevent flux concentrating at the edges so that horizontal fields at these edges are significantly reduced. Said tabs need to have aspect ratios of at least 2 and may be either triangular or rectangular in shape. Alternatively, the tabs may be omitted and, instead, outer portions of the shield's lower edge may be shaped so as to slope upwards away from the ABS.Type: ApplicationFiled: September 1, 2009Publication date: December 31, 2009Inventors: Lijie Guan, Moris Dovek