Patents by Inventor Yuichi Watabe

Yuichi Watabe 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: 8064163
    Abstract: Provided are a perpendicular magnetic write head capable of achieving the high performance and stability in the writing performance, and a method of manufacturing the same. On a trailing side of a main magnetic pole layer, disposed are a gap layer extending backward from an air bearing surface and an auxiliary magnetic pole layer extending backward from a position recessed from the air bearing surface. The auxiliary magnetic pole layer is partially overlapped on the gap layer. In case the auxiliary magnetic pole layer is formed using etching method in the process of manufacturing the perpendicular magnetic write head, the gap layer has a function as an etching stopper layer so that the main magnetic pole layer is protected; thereby the already-formed main magnetic pole layer is not subjected to etching.
    Type: Grant
    Filed: January 22, 2008
    Date of Patent: November 22, 2011
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Tetsuya Roppongi, Yuichi Watabe
  • Patent number: 7974046
    Abstract: The present invention provides a thin-film magnetic head which surely improves the writing and reading characteristic with reducing the flying height and surely handles the contact or collision with the magnetic recording medium. A thin-film magnetic head is provided, which includes, an substrate with ABS; a read or write head element provided on an element-formed surface of the substrate; at least one protrusion adjustment portion whose end reaches a slider end surface on the ABS side, which provides on an element-formed surface of the substrate; at least one heating portion provided rear at least one protrusion adjustment portion viewed from the slider end surface on the ABS side.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: July 5, 2011
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Tetsuya Roppongi, Hiraku Hirabayashi, Yuichi Watabe
  • Patent number: 7920357
    Abstract: Provided is a thin-film magnetic head capable of writing data with high accuracy on a magnetic recording medium having high coercive force without heating. The head comprises an electromagnetic coil element comprising: a main magnetic pole; an auxiliary magnetic pole; and a write coil formed so as to pass through at least between the main magnetic pole and the auxiliary magnetic pole, for generating the write magnetic field. In this head, a part of the write coil has a layered structure of: a resonance coil layer for generating a resonance magnetic field having ferromagnetic resonance frequency of a magnetic recording layer of a magnetic recording medium or having a frequency in the vicinity thereof; and a write coil layer. And further, the resonance coil layer and the write coil layer sandwich an insulating layer therebetween.
    Type: Grant
    Filed: October 9, 2007
    Date of Patent: April 5, 2011
    Assignee: TDK Corporation
    Inventors: Isamu Sato, Tetsuya Roppongi, Yuichi Watabe, Norikazu Ota, Hiroshi Ikeda, Mikio Matsuzaki
  • 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: 7832085
    Abstract: A method of manufacturing a magnetic head includes the steps of: fabricating a substructure in which pre-head portions are aligned in a plurality of rows by forming components of a plurality of magnetic heads on a single substrate; and fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure. In the step of fabricating the substructure, the resistance of an MR film that will be formed into an MR element by undergoing lapping later is detected to determine the target position of the boundary between a track width defining portion and a wide portion of a pole layer based on the resistance detected, and the pole layer is thereby formed. In the step of fabricating the magnetic heads, the surface formed by cutting the substructure is lapped such that the MR film is lapped and the resistance thereof thereby reaches a predetermined value.
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: November 16, 2010
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Tetsuro Sasaki, Yuichi Watabe, Takamitsu Sakamoto
  • Patent number: 7518826
    Abstract: A perpendicular magnetic recording head capable of preventing information erasing without intention at the time of non-recording through making the magnetic domain structure of a pole layer appropriate is provided. A main pole layer is formed so as to include a first pole layer portion having a first width W1 which determines the recording track width of a recording medium and a length L1, a second pole layer portion having a width which gradually expands from the first width W1 to a second width W2 larger than the first width W1 (W2>W1) and a length L2, and a third pole layer portion having a third width W3 larger than the second width W2 (W3>W2) and a length L3. When the ratio W3/(L1+L2+L3) satisfies a relationship of W3/(L1+L2+L3)?1.0, on the basis of the shape magnetic anisotropy of the main pole layer, the magnetic domain structure of the main pole layer is made appropriate so that an unnecessary magnetic flux is not easily leaked at the time of non-recording.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: April 14, 2009
    Assignees: TDK Corporation, SAE Magnetics (H.K.), Ltd.
    Inventors: Naoto Matono, Yuichi Watabe
  • Publication number: 20080291582
    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: Application
    Filed: May 21, 2007
    Publication date: November 27, 2008
    Applicant: 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: 7457080
    Abstract: A perpendicular magnetic recording head capable of minimizing the possibility of erasing recorded information without intention at the time of recording information is provided. A pole layer has a structure in which a main pole layer disposed on a leading side and an auxiliary pole layer disposed on a trailing side are laminated. Even if a part of a magnetic flux contained in the auxiliary pole layer is directly emitted from an air bearing surface to outside not via the main pole layer, as the magnetic flux is contained in the magnetic layer, the magnetic flux is not easily emitted from the air bearing surface to the outside directly. Therefore, an unnecessary perpendicular magnetic field is not easily generated by the magnetic flux. Thereby, a recording medium is not easily magnetized again by the unnecessary magnetic field, so information recorded on the recording medium is not easily erased without intention.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: November 25, 2008
    Assignee: TDK Corporation
    Inventors: Yuichi Watabe, Susumu Aoki, Reiichi Kurumisawa, Yasuyuki Notsuke, Norikazu Ota
  • Patent number: 7453668
    Abstract: The present invention provides a method of manufacturing a thin film magnetic head capable of assuring recording characteristics by determining throat height with high precision. A TH specifying layer is formed so as to extend to a position P1 while being adjacent to a gap layer, and an auxiliary insulating layer is similarly formed so as to extend from the position P1 while being adjacent to the gap layer and specify throat height on the basis of the position P1. After that, a main insulating layer is formed so as to cover a thin film coil on the auxiliary insulating layer, and a yoke layer is formed so as to extend while being partially on the TH specifying layer. The throat height is determined accurately and stably on the basis of the position P1 by the auxiliary insulating layer.
    Type: Grant
    Filed: October 18, 2005
    Date of Patent: November 18, 2008
    Assignee: TDK Corporation
    Inventors: Susumu Aoki, Reiichi Kurumisawa, Norikazu Ota, Yasuyuki Notsuke, Yuichi Watabe
  • Patent number: 7433152
    Abstract: A perpendicular magnetic recording head capable of minimizing the possibility of erasing recorded information without intention at the time of recording information is provided. A pole layer has a structure in which a main pole layer disposed on a leading side and an auxiliary pole layer disposed on a trailing side are laminated. Even if a part of a magnetic flux contained in the auxiliary pole layer is directly emitted from an air bearing surface to outside not via the main pole layer, as the magnetic flux is contained in the magnetic layer, the magnetic flux is not easily emitted from the air bearing surface to the outside directly. Therefore, an unnecessary perpendicular magnetic field is not easily generated by the magnetic flux. Thereby, a recording medium is not easily magnetized again by the unnecessary magnetic field, so information recorded on the recording medium is not easily erased without intention.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: October 7, 2008
    Assignee: TDK Corporation
    Inventors: Yuichi Watabe, Susumu Aoki, Reiichi Kurumisawa, Yasuyuki Notsuke, Norikazu Ota
  • Publication number: 20080222878
    Abstract: A method of manufacturing a magnetic head includes the steps of: fabricating a substructure in which pre-head portions are aligned in a plurality of rows by forming components of a plurality of magnetic heads on a single substrate; and fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure. In the step of fabricating the substructure, the resistance of an MR film that will be formed into an MR element by undergoing lapping later is detected to determine the target position of the boundary between a track width defining portion and a wide portion of a pole layer based on the resistance thus obtained, and the pole layer is thereby formed. In the step of fabricating the magnetic heads, the surface formed by cutting the substructure is lapped such that the MR film is lapped and the resistance thereof thereby reaches a predetermined value.
    Type: Application
    Filed: March 16, 2007
    Publication date: September 18, 2008
    Applicant: TDK CORPORATION
    Inventors: Takeo Kagami, Tetsuro Sasaki, Yuichi Watabe, Takamitsu Sakamoto
  • Publication number: 20080222879
    Abstract: A method of manufacturing a magnetic head includes the steps of: fabricating a substructure in which pre-head portions are aligned in a plurality of rows by forming components of a plurality of magnetic heads on a single substrate; and fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure. In the step of fabricating the substructure, the resistance of an MR film that will be formed into an MR element by undergoing lapping later is detected to determine the target position of the boundary between a track width defining portion and a wide portion of a pole layer based on the resistance detected, and the pole layer is thereby formed. In the step of fabricating the magnetic heads, the surface formed by cutting the substructure is lapped such that the MR film is lapped and the resistance thereof thereby reaches a predetermined value.
    Type: Application
    Filed: December 27, 2007
    Publication date: September 18, 2008
    Applicant: TDK CORPORATION
    Inventors: Takeo Kagami, Tetsuro Sasaki, Yuichi Watabe, Takamitsu Sakamoto
  • Publication number: 20080180858
    Abstract: Provided are a perpendicular magnetic write head capable of achieving the high performance and stability in the writing performance, and a method of manufacturing the same. On a trailing side of a main magnetic pole layer, disposed are a gap layer extending backward from an air bearing surface and an auxiliary magnetic pole layer extending backward from a position recessed from the air bearing surface. The auxiliary magnetic pole layer is partially overlapped on the gap layer. In case the auxiliary magnetic pole layer is formed using etching method in the process of manufacturing the perpendicular magnetic write head, the gap layer has a function as an etching stopper layer so that the main magnetic pole layer is protected; thereby the already-formed main magnetic pole layer is not subjected to etching.
    Type: Application
    Filed: January 22, 2008
    Publication date: July 31, 2008
    Applicant: TDK CORPORATION
    Inventors: Norikazu Ota, Tetsuya Roppongi, Yuichi Watabe
  • Publication number: 20080151436
    Abstract: Provided is a thin-film magnetic head capable of writing data with high accuracy on a magnetic recording medium having high coercive force without heating. The head comprises an electromagnetic coil element comprising: a main magnetic pole; an auxiliary magnetic pole; and a write coil formed so as to pass through at least between the main magnetic pole and the auxiliary magnetic pole, for generating the write magnetic field. In this head, a part of the write coil has a layered structure of: a resonance coil layer for generating a resonance magnetic field having ferromagnetic resonance frequency of a magnetic recording layer of a magnetic recording medium or having a frequency in the vicinity thereof; and a write coil layer. And further, the resonance coil layer and the write coil layer sandwich an insulating layer therebetween.
    Type: Application
    Filed: October 9, 2007
    Publication date: June 26, 2008
    Applicant: TDK CORPORATION
    Inventors: Isamu Sato, Tetsuya Roppongi, Yuichi Watabe, Norikazu Ota, Hiroshi Ikeda, Mikio Matsuzaki
  • Patent number: 7379268
    Abstract: A thin-film magnetic head comprises first and second magnetic layers, a gap layer provided between the first and second magnetic layers, a coupling portion for magnetically coupling the first and second magnetic layers to each other at a distance from a medium facing surface ABS, and a thin-film coil, part of which is disposed between the first and second magnetic layers. The second magnetic layer has a pole portion layer and a yoke portion layer. The thin-film magnetic head further comprises a non-magnetic layer that is in contact with the surface of the pole portion layer farther from the gap layer. The non-magnetic layer prevents the surface of the pole portion layer farther from the gap layer from being damaged during the manufacturing process of the head, and thereby maintains the flatness of the surface.
    Type: Grant
    Filed: November 5, 2001
    Date of Patent: May 27, 2008
    Assignee: TDK Corporation
    Inventors: Yoshikazu Sato, Tetsuya Roppongi, Yuichi Watabe
  • Publication number: 20080094755
    Abstract: The present invention provides a thin-film magnetic head which surely improves the writing and reading characteristic with reducing the flying height and surely handles the contact or collision with the magnetic recording medium. A thin-film magnetic head is provided, which includes, an substrate with ABS; a read or write head element provided on an element-formed surface of the substrate; at least one protrusion adjustment portion whose end reaches a slider end surface on the ABS side, which provides on an element-formed surface of the substrate; at least one heating portion provided rear at least one protrusion adjustment portion viewed from the slider end surface on the ABS side.
    Type: Application
    Filed: October 17, 2007
    Publication date: April 24, 2008
    Applicant: TDK CORPORATION
    Inventors: Norikazu OTA, Tetsuya ROPPONGI, Hiraku HIRABAYASHI, Yuichi WATABE
  • Patent number: 7245454
    Abstract: A write head of a magnetic head for vertical magnetic recording comprises: a coil; a main pole layer that allows the magnetic flux corresponding to the magnetic field generated by the coil to pass therethrough and generates a write magnetic field; an auxiliary pole layer; a gap layer provided between the main pole layer and the auxiliary pole layer; and a yoke layer for magnetically coupling the main pole layer to the auxiliary pole layer. The main pole layer has a flat top surface. In the main pole layer the position in which the thickness starts to increase is located between the medium facing surface and the position in which the width starts to increase.
    Type: Grant
    Filed: April 27, 2004
    Date of Patent: July 17, 2007
    Assignee: TDK Corporation
    Inventors: Susumu Aoki, Yasuyuki Notsuke, Yuichi Watabe, Norikazu Ota, Tetsuya Roppongi
  • Patent number: 7219414
    Abstract: A main pole layer of a magnetic head includes a first portion disposed at a distance from a medium facing surface, and a second portion that is smaller in thickness than the first portion and disposed between the first portion and the medium facing surface. The step of forming the main pole layer includes the steps of forming a plating layer such that one of ends of the plating layer closer to the medium facing surface is located at a position that coincides with the position of one of ends of the first portion closer to the medium facing surface; forming a first nonmagnetic layer to cover the plating layer; polishing the first nonmagnetic layer and the plating layer; forming a space by removing the plating layer; forming a magnetic layer, which will be the main pole layer, in the space and on the top surface of the first nonmagnetic layer; forming a second nonmagnetic layer to cover the magnetic layer; and polishing the second nonmagnetic layer and the magnetic layer.
    Type: Grant
    Filed: January 25, 2005
    Date of Patent: May 22, 2007
    Assignee: TDK Corporation
    Inventors: Yuichi Watabe, Susumu Aoki, Yasuyuki Notsuke, Tetsuya Roppongi
  • Patent number: 7154707
    Abstract: Provided is a thin film magnetic head capable of securing recording characteristics even in the case where a return pole layer is disposed on a medium-outgoing side of the pole layer. The return yoke layer is disposed on a trailing side of the pole layer, and a neck height NH is within a range of NH?W1 (a width of a front end portion in a main pole layer)+0.05 ?m, and a height ratio (a ratio of the neck height NH to a throat height TH) NH/TH is within a range of 0.5<NH/TH<1.6. Thereby, the neck height NH and the height ratio NH/TH which have an influence on the recording characteristics can become appropriate, so even if the thickness of the gap layer is 0.2 ?m or less to bring the return yoke layer closer to the pole layer, overwrite characteristics can be secured.
    Type: Grant
    Filed: March 22, 2004
    Date of Patent: December 26, 2006
    Assignees: TDK Corporation, SAE Magnetics (H.K) Ltd.
    Inventors: Yuichi Watabe, Norikazu Ota, Yasuyuki Notsuke, Susumu Aoki, Tetsuya Roppongi, Naoto Matono
  • Publication number: 20060250712
    Abstract: A perpendicular magnetic recording head capable of preventing information erasing without intention at the time of non-recording through making the magnetic domain structure of a pole layer appropriate is provided. A main pole layer is formed so as to include a first pole layer portion having a first width W1 which determines the recording track width of a recording medium and a length L1, a second pole layer portion having a width which gradually expands from the first width W1 to a second width W2 larger than the first width W1 (W2>W1) and a length L2, and a third pole layer portion having a third width W3 larger than the second width W2 (W3>W2) and a length L3. When the ratio W3/(L1+L2+L3) satisfies a relationship of W3/(L1+L2+L3)?1.0, on the basis of the shape magnetic anisotropy of the main pole layer, the magnetic domain structure of the main pole layer is made appropriate so that an unnecessary magnetic flux is not easily leaked at the time of non-recording.
    Type: Application
    Filed: November 2, 2005
    Publication date: November 9, 2006
    Applicants: TDK CORPORATION, SAE Magnetics (H.K.) Ltd.
    Inventors: Naoto Matono, Yuichi Watabe