Patents by Inventor Noriaki Kasahara

Noriaki Kasahara 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).

  • Patent number: 8303780
    Abstract: The present invention relates to a method for forming a dry etching mask. A plurality of aluminum oxide films are sequentially sputtered on a material to be dry etched in such a manner that etching rate with respect to reactive ion etching increases toward a lower layer. On a laminated film of the plurality of aluminum oxide films, there is formed a first mask that has etching resistance with respect to the reactive ion etching. Reactive ion etching is performed from above the first mask to form a second mask of the laminated film.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: November 6, 2012
    Assignee: TDK Corporation
    Inventors: Kento Edakara, Hiromichi Umehara, Noriaki Kasahara, Michitaka Nishiyama
  • Patent number: 8000064
    Abstract: A perpendicular recording thin-film magnetic head comprises a main magnetic pole having a tip main magnetic pole part extending in a height direction from a medium-opposing surface and a base main magnetic pole part connected to the tip main magnetic pole part on a side opposite from the medium-opposing surface side and wider than the tip main magnetic pole part in a track width direction; a return yoke extending in the height direction from the medium-opposing surface and magnetically coupling with the base main magnetic pole part at a position distanced from the medium-opposing surface in the height direction, while opposing the tip main magnetic pole part through a write gap layer in a bit length direction in the medium-opposing surface; and a main magnetic pole adjacent magnetic shield layer extending along at least part of side faces of the main magnetic pole other than the medium-opposing surface as seen in a laminating direction, while holding a nonmagnetic layer between the main magnetic pole and the
    Type: Grant
    Filed: December 13, 2007
    Date of Patent: August 16, 2011
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Hidetaka Kawano, Hiromichi Umehara, Takamitsu Sakamoto, Koichi Otani, Noriaki Kasahara, Naoto Matono
  • Patent number: 7948716
    Abstract: A magnetic head includes: a coil; a pole layer; a shield having an end face located in a medium facing surface forward of an end face of the pole layer along a direction of travel of a recording medium; a gap layer between the shield and the pole layer; and a substrate on which the foregoing elements are stacked. The top surface of the pole layer includes: first and second portions with a difference in height therebetween; and a third portion connecting the first and second portions to each other. The first portion has an edge located in the medium facing surface, and the second portion is located farther from the medium facing surface and from the substrate than the first portion. The magnetic head further includes a nonmagnetic layer disposed between the second portion and the gap layer. The nonmagnetic layer has a surface touching the second portion, the surface having an edge located at the boundary between the second and third portions.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: May 24, 2011
    Assignees: SAE Magnetics (H.K.) Ltd., TDK Corporation
    Inventors: Naoto Matono, Koichi Otani, Tatsuya Harada, Noriaki Kasahara, Takamitsu Sakamoto, Hiroaki Kawashima, Hirotaka Gomi, Kenkichi Anagawa, Norikazu Ota
  • Patent number: 7848056
    Abstract: A thin film magnetic head includes a main magnetic pole layer conducting a magnetic flux to the recording medium so that the recording medium an be magnetized in a direction orthogonal to a surface thereof; a return yoke layer disposed on a trailing side of the main magnetic pole layer; an intermediate protective layer partially disposed on a magnetic shield layer; and a thermal expansion suppressing layer having an edge located on the intermediate protective layer and being in contact with the return yoke layer in an area where the intermediate protective layer is not formed. If the thin film magnetic head is affected by ambient temperature environment, the thermal expansion suppressing layer suppresses the shift of the main magnetic pole layer and the return yoke layer toward the air bearing surface. This suppresses thermal protrusion from occurring on the thin film magnetic head due to ambient temperature environment.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: December 7, 2010
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Takamitsu Sakamoto, Naoto Matono, Noriaki Kasahara, Shin Narushima, Hiromichi Umehara
  • Patent number: 7843667
    Abstract: Provided is a thin film magnetic head capable of suppressing an occurrence of a track erase, decreasing an influence on a magnetoresistive element caused by a magnetic flux generated from a thin film coil, and further decreasing the parasitic capacity. The thin film magnetic head has, in order in a stacked direction, a first magnetic shield layer, a magnetoresistive element, a second magnetic shield layer, a third magnetic shield layer, a main magnetic pole layer and a return yoke layer. A width in a track width direction of at least one of the first and the second magnetic shield layers is smaller than widths in a track width direction of the third magnetic shield layer and the return yoke layer.
    Type: Grant
    Filed: May 21, 2007
    Date of Patent: November 30, 2010
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Norikazu Ota, Yuichi Watabe, Tetsuro Sasaki, Takeo Kagami, Tetsuya Roppongi, Kazuki Sato, Yuji Otsubo, Sohei Horiuchi, Yoshiaki Tanaka, Kenji Yokoyama, Noriaki Kasahara
  • Patent number: 7808743
    Abstract: A perpendicular magnetic write head includes an auxiliary magnetic pole layer disposed on a trailing or leading side of a main magnetic pole layer, the auxiliary magnetic pole layer being recessed from the main magnetic pole layer. A nonmagnetic layer is disposed in a layer same as the auxiliary magnetic pole layer and in front of the auxiliary magnetic pole layer, the nonmagnetic layer having an internal stress of a direction same as that of the main magnetic pole layer, and a write shield layer is disposed in a layer same as the auxiliary magnetic pole layer and in front of the auxiliary magnetic pole layer, the write shield layer being separated from the main magnetic pole layer with a gap layer in between. The nonmagnetic layer is arranged to fill up a space between the auxiliary magnetic pole layer and the write shield layer.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: October 5, 2010
    Assignees: TDK Corporation, Sae Magnetics (H.K.) Ltd.
    Inventors: Naoto Matono, Noriaki Kasahara, Shin Narushima, Takamitsu Sakamoto, Koichi Otani
  • Patent number: 7796359
    Abstract: A magnetic head includes a pole layer, a first and a second shield disposed to sandwich the pole layer, and a nonmagnetic layer disposed around the first shield. The pole layer includes a first portion having an end face located in a medium facing surface, and a second portion that is located farther from the medium facing surface than is the first portion. The second portion is greater in thickness than the first portion. A bottom surface of the second portion is located closer to a substrate than is a bottom surface of the first portion. The first shield has a first top surface portion opposed to the bottom surface of the first portion with the first gap layer in between. The nonmagnetic layer has a second top surface portion opposed to the bottom surface of the second portion with the first gap layer in between.
    Type: Grant
    Filed: August 23, 2007
    Date of Patent: September 14, 2010
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Koichi Otani, Hiromichi Umehara, Naoto Matono, Takamitsu Sakamoto, Noriaki Kasahara, Hidetaka Kawano
  • Patent number: 7787215
    Abstract: A thin film magnetic head is provided, in which thermal protrusion can be suppressed. The thin film magnetic head includes a main magnetic pole layer which conducts a magnetic flux into the recording medium so that the recording medium is magnetized in a direction perpendicular to a surface of the recording medium, a first return yoke layer provided in a trailing side of the main magnetic pole layer, and has a recess in a top surface, a second return yoke layer provided so as to fill at least the recess of the first return yoke layer, and a thermal expansion suppression layer provided in a trailing side of the second return yoke layer. Thus, since the thermal expansion suppression layer can be provided on a surface having no recess, a possibility of a crack in the thermal expansion suppression layer can be eliminated.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: August 31, 2010
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Shin Narushima, Naoto Matono, Takamitsu Sakamoto, Noriaki Kasahara, Koichi Otani
  • Publication number: 20100084262
    Abstract: The present invention relates to a method for manufacturing a perpendicular recording magnetic head. The method for manufacturing a perpendicular recording magnetic head according to the present invention includes first to third steps. At the first step, a main magnetic pole layer is formed on a foundation layer. At the second step, a main magnetic pole forming mask whose recording-medium-facing surface is of an inverted trapezoidal shape is formed on the main magnetic pole layer. At the third step, a main magnetic pole whose recording-medium-facing surface is of an inverted trapezoidal shape is formed by performing ion milling on a laminated structure including the foundation layer and the main magnetic pole layer from a direction which makes a given angle with a lamination direction according to a bevel angle of the inverted trapezoidal shape.
    Type: Application
    Filed: October 2, 2008
    Publication date: April 8, 2010
    Applicant: TDK CORPORATION
    Inventors: Hiromichi Umehara, Shin Narushima, Michitaka Nishiyama, Noriaki Kasahara, Koichi Otani
  • Publication number: 20100078316
    Abstract: The present invention relates to a method for forming a dry etching mask. A plurality of aluminum oxide films are sequentially sputtered on a material to be dry etched in such a manner that etching rate with respect to reactive ion etching increases toward a lower layer. On a laminated film of the plurality of aluminum oxide films, there is formed a first mask that has etching resistance with respect to the reactive ion etching. Reactive ion etching is performed from above the first mask to form a second mask of the laminated film.
    Type: Application
    Filed: September 30, 2008
    Publication date: April 1, 2010
    Applicant: TDK CORPORATION
    Inventors: Kento EDAKAWA, Hiromichi Umehara, Noriaki Kasahara, Michitaka Nishiyama
  • Patent number: 7672084
    Abstract: Composite thin-film magnetic head includes a substrate; a first insulation layer on the substrate; an MR read head element on the first insulation layer and provided with a lower shield layer, an upper shield layer and an MR layer with a sense current flowing perpendicular to a surface of the MR layer though the upper and lower shield layers; a second insulation layer on the MR read head element; an inductive write head element on the second insulation layer and provided with a lower magnetic pole layer, a recording gap layer, an upper magnetic pole layer with end portion opposed to an end portion of the lower magnetic pole layer through the recording gap layer and a write coil; and a nonmagnetic conductive layer electrically conducted with the lower shield layer and opposed to the substrate to increase the electrode area between the lower shield layer and the substrate.
    Type: Grant
    Filed: April 21, 2009
    Date of Patent: March 2, 2010
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Noriaki Kasahara, Tetsuya Kuwashima
  • Publication number: 20090273863
    Abstract: A perpendicular recording thin-film magnetic head comprises a main magnetic pole having a tip main magnetic pole part extending in a height direction from a medium-opposing surface and a base main magnetic pole part connected to the tip main magnetic pole part on a side opposite from the medium-opposing surface side and wider than the tip main magnetic pole part in a track width direction; a return yoke extending in the height direction from the medium-opposing surface and magnetically coupling with the base main magnetic pole part at a position distanced from the medium-opposing surface in the height direction, while opposing the tip main magnetic pole part through a write gap layer in a bit length direction in the medium-opposing surface; and a main magnetic pole adjacent magnetic shield layer extending along at least part of side faces of the main magnetic pole other than the medium-opposing surface as seen in a laminating direction, while holding a nonmagnetic layer between the main magnetic pole and the
    Type: Application
    Filed: December 13, 2007
    Publication date: November 5, 2009
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Hidetaka Kawano, Hiromichi Umehara, Takamitsu Sakamoto, Koichi Otani, Noriaki Kasahara, Naoto Matono
  • Publication number: 20090237833
    Abstract: Provided is a magnetic tape apparatus using perpendicular magnetic recording, which has the function corresponding to an soft-magnetic under layer with sufficiently large thickness and enables the magnetic tape to maintain life sufficiently. This magnetic tape apparatus comprises: a tape head comprising at least one write head element for perpendicular magnetic recording; and a soft-magnetic capstan belt having a surface contact with the magnetic tape and pressing the magnetic tape to the tape head at least during recording, for controlling running speed of the magnetic tape by causing the magnetic tape to run together with the soft-magnetic capstan belt. Further it is preferable that at least two capstan-belt axes are further provided, and the soft-magnetic capstan belt is a loop running among the at least two capstan-belt axes.
    Type: Application
    Filed: March 19, 2008
    Publication date: September 24, 2009
    Applicant: TDK CORPORATION
    Inventors: Hideaki SATO, Naoki OHTA, Hiraku HIRABAYASHI, Nozomu HACHISUKA, Noriaki KASAHARA
  • Publication number: 20090213501
    Abstract: A composite thin-film magnetic head includes a substrate; a first insulation layer laminated on the substrate; an MR read head element formed on the first insulation 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; a second insulation layer laminated on the MR read head element; an inductive write head element formed on the second insulation layer and provided with a lower magnetic pole layer, a recording gap layer, an upper magnetic pole layer whose end portion is opposed to an end portion of the lower magnetic pole layer through the recording gap layer and a write coil; and a nonmagnetic conductive layer electrically conducted with the lower shield layer and opposed to the substrate in order to increase substantially countered area between the lower shield layer and the substrate.
    Type: Application
    Filed: April 21, 2009
    Publication date: August 27, 2009
    Applicant: TDK Corporation
    Inventors: Takeo Kagami, Noriaki Kasahara, Tetsuya Kuwshima
  • Patent number: 7573675
    Abstract: A thin film magnetic head has an air bearing surface and comprises magnetic shield layers, an MR element, bias-applying layers, and a hard magnetic layer. Each of the magnetic shield layers has an end face forming the air bearing surface, and an end face located opposite to the end face. The MR element is located between the magnetic shield layers and on the end face side. The bias-applying layers are located between the magnetic shield layers and are arranged to apply a bias magnetic field to the MR element. The hard magnetic layer is located between the magnetic shield layers and on the end face side. A height of the hard magnetic layer is larger than ? and smaller than ½ of a height of each magnetic shield layer.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: August 11, 2009
    Assignee: TDK Corporation
    Inventors: Naoki Ohta, Kazuki Sato, Noriaki Kasahara, Takeo Kagami
  • Patent number: 7548400
    Abstract: The thin-film magnetic head of the present invention comprises an MR sensor wherein a first ferromagnetic layer in which a magnetization direction is fixed with respect to external magnetic fields, a non-magnetic intermediate layer, and a second ferromagnetic layer in which a magnetization direction changes with respect to the external magnetic fields are stacked, and wherein a sense current flows substantially parallel to the stacked layer surface.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: June 16, 2009
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Noriaki Kasahara, Kazuki Sato, Takayasu Kanaya
  • Patent number: 7542245
    Abstract: Composite thin-film magnetic head includes a substrate; a first insulation layer on the substrate; an MR read head element on the first insulation layer and provided with a lower shield layer, an upper shield layer and an MR layer with a sense current flowing perpendicular to a surface of the MR layer though the upper and lower shield layers; a second insulation layer on the MR read head element; an inductive write head element on the second insulation layer and provided with a lower magnetic pole layer, a recording gap layer, an upper magnetic pole layer with end portion opposed to an end portion of the lower magnetic pole layer through the recording gap layer and a write coil; and a nonmagnetic conductive layer electrically conducted with the lower shield layer and opposed to the substrate to increase the electrode area between the lower shield layer and the substrate.
    Type: Grant
    Filed: February 7, 2006
    Date of Patent: June 2, 2009
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Noriaki Kasahara, Tetsuya Kuwashima
  • Publication number: 20090052094
    Abstract: A magnetic head includes a pole layer, a first and a second shield disposed to sandwich the pole layer, and a nonmagnetic layer disposed around the first shield. The pole layer includes a first portion having an end face located in a medium facing surface, and a second portion that is located farther from the medium facing surface than is the first portion. The second portion is greater in thickness than the first portion. A bottom surface of the second portion is located closer to a substrate than is a bottom surface of the first portion. The first shield has a first top surface portion opposed to the bottom surface of the first portion with the first gap layer in between. The nonmagnetic layer has a second top surface portion opposed to the bottom surface of the second portion with the first gap layer in between.
    Type: Application
    Filed: August 23, 2007
    Publication date: February 26, 2009
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Koichi Otani, Hiromichi Umehara, Naoto Matono, Takamitsu Sakamoto, Noriaki Kasahara, Hidetaka Kawano
  • Patent number: 7489481
    Abstract: A magnetic head is provided for further improving a correlation between the dynamic characteristics and static characteristics. A lower magnetic shield layer, a magneto-resistive layer, and an upper magnetic shield layer are laminated on a base in this order. A lower lead layer and an upper lead layer apply a sense current to the magneto-resistive layer in a direction substantially perpendicular to the film plane thereof through the magnetic shield layers. The lower magnetic shield layer and upper magnetic shield layer have their shapes and sizes which substantially exactly overlap each other, when viewed in a laminating direction. The lower lead layer is electrically connected to the lower magnetic shield layer. At least a portion of the lower lead layer closer to the lower magnetic shield layer is made of a non-magnetic conductive material. The upper lead layer is electrically connected to the upper magnetic shield layer.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: February 10, 2009
    Assignee: TDK Corporation
    Inventors: Kentaro Nagai, Takeo Kagami, Noriaki Kasahara, Naoki Ohta, Satoshi Miura
  • Publication number: 20080297953
    Abstract: A magnetic head includes: a coil; a pole layer; a shield having an end face located in a medium facing surface forward of an end face of the pole layer along a direction of travel of a recording medium; a gap layer between the shield and the pole layer; and a substrate on which the foregoing elements are stacked. The top surface of the pole layer includes: first and second portions with a difference in height therebetween; and a third portion connecting the first and second portions to each other. The first portion has an edge located in the medium facing surface, and the second portion is located farther from the medium facing surface and from the substrate than the first portion. The magnetic head further includes a nonmagnetic layer disposed between the second portion and the gap layer. The nonmagnetic layer has a surface touching the second portion, the surface having an edge located at the boundary between the second and third portions.
    Type: Application
    Filed: June 4, 2007
    Publication date: December 4, 2008
    Applicants: SAE MAGNETICS (H.K.) LTD., TDK CORPORATION
    Inventors: Naoto Matono, Koichi Otani, Tatsuya Harada, Noriaki Kasahara, Takamitsu Sakamoto, Hiroaki Kawashima, Hirotaka Gomi, Kenkichi Anagawa, Norikazu Ota