Patents by Inventor Vladimir Nikitin

Vladimir Nikitin has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20070217080
    Abstract: A current perpendicular to plane (CPP) magnetoresistive sensor having a free layer that is magnetically coupled with a magnetic shield, thereby providing the free layer with a large effective flux guide. Sensor performance is improved by virtually eliminating demagnetization fields at the back edge of the sensor. The free layer can be magnetically connected with the shield by a magnetic coupling layer or shunt structure that is disposed between the free layer and the shield behind the capping layer.
    Type: Application
    Filed: March 14, 2006
    Publication date: September 20, 2007
    Inventors: Wipul Jayasekara, Vladimir Nikitin
  • Publication number: 20070211384
    Abstract: A perpendicular magnetic write head having a conformal wrap around trailing shield. The write head includes a write pole that can be configured with a trapezoidal shape as viewed from the Air Bearing Surface (ABS) and which includes a wrap around trailing magnetic shield. The magnetic shield has a trailing portion that is separated from the leading edge of the writ pole by a non-magnetic trailing gap, and has side shield portions that are separated from first and second side portions of the write pole by first and second non-magnetic side gaps. The magnetic shield can be configured with notches at either side of the trailing portion of magnetic shield. These notches can extend in the trailing direction by a distance that is preferably ¼ to 1 times the trailing gap thickness. The width of the straight, trailing portion of the shield is preferable ½ to 1 times of the main pole width.
    Type: Application
    Filed: May 3, 2007
    Publication date: September 13, 2007
    Inventors: Wen-Chien Hsiao, Yimin Hsu, Vladimir Nikitin, Aron Pentek, Yi Zheng
  • Publication number: 20070188942
    Abstract: In a tunnel magnetoresistive (TMR) device, free sublayers are separated by an intermediate spacer layer that serves to ensure a uniform circumferential magnetization in the free stack, counterbalancing orange-peel coupling by antiferromagnetic exchange coupling. Thus, a CPP MR device may have a seed stack, a pinned stack on the seed stack, and a tunnel barrier on the pinned stack. A free stack can be on the tunnel barrier, and the free stack can include structure for promoting uniform circumferential magnetization in the free stack.
    Type: Application
    Filed: February 14, 2006
    Publication date: August 16, 2007
    Inventors: Robert Beach, David Heim, Vladimir Nikitin, David Seagle
  • Publication number: 20070188939
    Abstract: 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: Application
    Filed: February 10, 2006
    Publication date: August 16, 2007
    Inventors: Robert Beach, Wipul Jayasekara, Vladimir Nikitin
  • Publication number: 20070188940
    Abstract: In a tunnelmagneto resistive (TMR) device, free stack sublayers are separated by an intermediate spacer layer that serves to ensure a uniform circumferential magnetization in the free stack, counterbalancing orange-peel coupling by anti ferromagnetic exchange coupling. On top of the upper free stack sublayer a thin upper anti ferromagnetic layer may be formed to act as a hard bias layer and suppress side reading. The thickness of the upper AFT layer is established to tune sensor sensitivity to external fields as well as to promote greater sensor sensitivity.
    Type: Application
    Filed: February 10, 2006
    Publication date: August 16, 2007
    Inventors: Robert Beach, Vladimir Nikitin
  • Publication number: 20070183092
    Abstract: A multi-step process for notching the P1 pole of the write head element of a magnetic head. In a first step following the fabrication of the P2 pole tip, a layer of protective material is deposited on the approximately vertical side surfaces of the P2 pole tip. Thereafter, a first ion milling step, utilizing a species such as argon, is performed to mill through the write gap layer and to notch into the P1 pole layer therebelow. The removal of redeposited material from the side surfaces of the P2 pole tip is thereafter accomplished and the protective material formed on the side surfaces of the P2 pole tip protects the P2 pole tip during the redeposition clean up step. Thereafter, the protective material is removed from the side surfaces of the P2 pole tip, and a second ion milling step is performed to further notch the P1 pole material.
    Type: Application
    Filed: February 3, 2006
    Publication date: August 9, 2007
    Inventors: Daniel Bedell, Vladimir Nikitin, Aron Pentek
  • Patent number: 7251106
    Abstract: A magnetic head slider including a central pad that is disposed at the trailing edge of the slider and designed to increase the flying height of the slider in response to heat induced protrusion of the head elements. The central pad of the present invention includes a body portion and two arm portions which project forwardly from a leading edge of the body portion, such that the leading portion of the central pad is formed with a generally U-shaped profile. The length of the arm members is preferably from approximately ¼ of the total length of the central pad to approximately ¾ of the total length of the central pad.
    Type: Grant
    Filed: May 12, 2004
    Date of Patent: July 31, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Vladimir Nikitin, Oscar Jaime Ruiz
  • Publication number: 20070146932
    Abstract: A magnetic medium for use in data recording that has a series of concentric magnetic track portions separated from one another by non-magnetic portions or gap portions. The magnetic portions define data tracks and prevent signals from one track from bleeding into another track. Because the data tracks are distinctly separated, adjacent track interference is completely avoided. The disk may be manufactured by depositing first and second materials sequentially onto a rotating tube, the first and second materials having different etch rates. The tube may then be slided into disks and the disks subjected to a reactive ion etch (RIE) to form a disk surface having concentric raised portions separated by concentric recessed portions. A magnetic material can then be deposited. An optional chemical mechanical polishing process can then be performed to planarize the surface, resulting in a planar surface having rings of magnetic material separated by rings of non-magnetic material.
    Type: Application
    Filed: December 28, 2005
    Publication date: June 28, 2007
    Inventor: Vladimir Nikitin
  • Patent number: 7212380
    Abstract: A magnetoresistive read/write head having a first layer of alumina and a second layer of silicon dioxide overlaying a P3 layer of the head. In a preferred embodiment, the silicon dioxide layer is recessed away from an Air Bearing Surface (ABS) to reduce protrusion of a P2 layer and the P3 layer in the head, and to reduce degradation in the magnetic properties of the pole tips of the P2 and P3 layer ends.
    Type: Grant
    Filed: April 26, 2004
    Date of Patent: May 1, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Wen-Chien David Hsiao, Wipul Pemsiri Jayaekara, Edward Hin Pong Lee, Vladimir Nikitin, Patrick Rush Webb, Sue Siyang Zhang
  • Publication number: 20070081277
    Abstract: Methods and apparatus provide a magnetic head that includes a magnetoresistive read sensor disposed between a first magnetic shield and a second magnetic shield. The second magnetic shield is configured to reduce effects on the read sensor due to unevenness in a topography of the read sensor.
    Type: Application
    Filed: October 6, 2005
    Publication date: April 12, 2007
    Inventors: Liesl Folks, Guohan Hu, Yinshi Liu, Kenneth Mackay, Vladimir Nikitin, James Nix, Neil Smith
  • Patent number: 7190552
    Abstract: Magnetic heads having write coil structures with reduced electrical resistances for reducing thermal protrusion are disclosed. In one illustrative example, a magnetic head includes a magnetic yoke; a write gap layer formed between upper and lower poles of the magnetic yoke; and a write coil having a plurality of coil layers. Each coil layer of the write coil extends continuously between the upper and the lower poles through a plane defined by the write gap layer. Preferably, the write coil is formed using a damascene process, such that each coil layer is wider than each coil separating layer. Such a structure provides for a relatively large amount of coil materials to be used, which reduces the coil's electrical resistance. This, in turn, reduces the heat generated by the write coils during operation.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: March 13, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Wen-chien David Hsiao, Edward Hin Pong Lee, Vladimir Nikitin, Samuel Weisan Yuan
  • Patent number: 7187520
    Abstract: A magnetic head including a media heating device that is fabricated within the magnetic head structure. The media heating device includes an electrically resistive element that is fabricated above the first magnetic pole layer close to the ABS surface of the head. A P1 pole pedestal is fabricated above the heating element. Electrical insulation layers are fabricated beneath and above the heating element to prevent electrical shorting to the P1 pole layer and the P1 pole pedestal that are disposed beneath and above the heating element, respectively.
    Type: Grant
    Filed: March 1, 2004
    Date of Patent: March 6, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Edward Hin Pong Lee, Jeffrey S. Lille, Vladimir Nikitin, Hugo Alberto Emilio Santini
  • Publication number: 20070025026
    Abstract: 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: Application
    Filed: July 28, 2005
    Publication date: February 1, 2007
    Inventors: Gity Hosseinali, Vladimir Nikitin, Robert Smith
  • Patent number: 7170713
    Abstract: An effective heat sink is provided for a magnetic recording head. The heat sink conducts heat away from the recording head thus limiting the range of temperatures to which the recording head is subjected. A heat sink on a recording head significantly reduces heat induced protrusion.
    Type: Grant
    Filed: August 8, 2002
    Date of Patent: January 30, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Savas Gider, Wenchein Hsiao, Vladimir Nikitin
  • Patent number: 7154696
    Abstract: A new structure for adjusting flying height using a magnetomechanical effect. A head includes a magnetomechanically active structure and a coil coupled to the magnetomechanically active structure, the magnetomechanically active structure responding to a magnetic field generated by the coil to expand and/or contract.
    Type: Grant
    Filed: February 11, 2004
    Date of Patent: December 26, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Vladimir Nikitin, Savas Gider, Wen-chien Hsiao
  • Publication number: 20060273066
    Abstract: A method for constructing a device such as a magnetoresistive sensor having an extremely narrow width (track width). A photoresist mask is deposited with an edge where an edge of the device is to be located. A layer of material that is susceptible to removal by reactive ion etch (RIEable material) is then deposited over this first mask. The RIEable material is deposited by a conformal deposition method so that it covers the edge of the first mask substantially the same thickness as it covers the other areas. A reactive ion etch (RIE) is then performed to remove horizontally disposed portions of the RIEable layer intact, while leaving at least a portion of the RIEable material at the edge of the sensor intact. This remaining portion of the RIEable material can then be used as a very narrow mask for defining a device such as a magnetoresitive sensor by ion milling.
    Type: Application
    Filed: June 1, 2005
    Publication date: December 7, 2006
    Inventors: Daniel Wayne Bedell, Vladimir Nikitin
  • Patent number: 7138797
    Abstract: A method is disclosed for testing pinned layers of magnetic disk drive read heads having at least one pinned layer, where the magnetic orientation of the pinned layers has been set in an initial direction. The method includes applying a large magnetic test field at a reverse canted reset angle. First test responses from the disk drive read heads are then measured in a small magnetic test field. A large magnetic test field is applied at normal canted reset angle. The disk drive heads are then subjected to a full suite of performance tests in a small magnetic test field to verify their acceptability. These second test responses are then compared to the first test responses to identify read heads having weakly pinned layers.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: November 21, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Ciaran Avram Fox, Kenneth David Mackay, Vladimir Nikitin
  • Publication number: 20060221498
    Abstract: A magnetic read/write head is produced with an insert layer between the substrate and the magnetic transducer. The insert layer has a lower coefficient of thermal expansion than the substrate, which reduces the temperature pole tip recession (T-PTR) of the head because the insert layer is an intervening layer between the substrate and magnetic transducer. The insert layer is produced by plating, e.g., an Invar layer over the substrate prior to fabricating the magnetic transducer. The Invar layer is annealed and the structure planarized prior to depositing a non-magnetic gap layer followed by the fabrication of the magnetic transducer.
    Type: Application
    Filed: March 30, 2005
    Publication date: October 5, 2006
    Inventors: Christian Bonhote, Malika Carter, David Dudek, Wen-Chien Hsiao, John Lam, Vladimir Nikitin
  • Publication number: 20060164760
    Abstract: A recording head is disclosed that includes electrical pads on multiple surfaces. The recording head includes a substrate portion abutting a deposited portion. The deposited portion includes an air bearing surface (ABS) (or bottom surface), an end surface, and at least one other surface. The end surface is the surface traditionally used by head designers for electrical pads. In accord with the invention, one or more electrical pads are included on the other surfaces of the deposited portion (i.e., a surface other than the end surface). Electrical pads may also be included on the end surface.
    Type: Application
    Filed: January 26, 2005
    Publication date: July 27, 2006
    Inventors: Vladimir Nikitin, David Seagle
  • Patent number: 7079344
    Abstract: A magnetic recording disk drive has a disk with the magnetizations in the concentric data tracks oriented in the cross-track direction. The concentric data tracks are magnetically separated from each other by guard bands. An inductive write head has its write poles and write gap oriented to generate magnetic fields in the cross-track direction. The guard bands may provide magnetic separation by containing along-the-track magnetizations, in which case the write head also has an erase pole and an erase gap to generate magnetic fields in an along-the-track direction on the sides of the data tracks. A magnetoresistive 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: Grant
    Filed: November 30, 2004
    Date of Patent: July 18, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Vladimir Nikitin