Patents by Inventor Changqing Shi

Changqing Shi 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: 8179634
    Abstract: Methods and structures for the fabrication of a thin film, perpendicular recording write head are disclosed. The structure provides a pole tip separated from a rear pole by a non-magnetic separation layer located adjacent the flare point. The rear pole contains an imbedded non-magnetic layer. The separated pole tip and imbedded layer aid in the high data rate recording as well as the erasure performance of the write pole structure. The fabrication involves the deposition of two different oxide layers which have mutually high etch selectivities. This characteristic allows a write pole structure to be built wherein the track width is independent of the location of the flare point. The process also produces a structure wherein the placement of the throat height of the shield is self aligned to the flare point of the write pole.
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: May 15, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Wen-Chien David Hsiao, Ming Jiang, Changqing Shi
  • Patent number: 8111479
    Abstract: A magnetic write head for perpendicular magnetic data recording having a trailing shield with a two step throat height. The trailing shield is formed over a non-magnetic bump that forms a notch in the leading edge of the trailing shield. This notch defines a first, smaller throat height closest to the write pole and a larger throat height away from the write pole. The smaller throat height near the write pole prevents excess magnetic flux from leaking to the write pole, thereby ensuring efficient strong write field. The larger trailing shield throat height away from the write pole prevents magnetic saturation of the trailing shield and also greatly facilitates manufacturing avoiding problems related to variations and deviations in manufacturing processes used to define the trailing shield.
    Type: Grant
    Filed: October 23, 2007
    Date of Patent: February 7, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tsung Yuan Chen, Wen-Chien David Hsiao, Yimin Hsu, Vladimir Nikitin, Changqing Shi
  • Patent number: 8068312
    Abstract: A magnetic write head for perpendicular magnetic recording having a stitched notched trailing shield. The trailing shield includes a first pedestal portion having sides that are self aligned with the sides of the write pole and having a back edge that extends a first shield throat height. The shield further includes a second shield portion stitched onto the pedestal portion, the second shield portion having a back edge that extends beyond the back edge of the pedestal portion.
    Type: Grant
    Filed: November 21, 2007
    Date of Patent: November 29, 2011
    Assignee: Hitachi Global Technologies Netherlands B.V.
    Inventors: Ming Jiang, Changqing Shi
  • Patent number: 8049989
    Abstract: Methods and structures for the fabrication of a thin film, perpendicular recording write head are disclosed. The fabrication involves the deposition of two different oxide layers which have mutually high etch selectivities. This characteristic allows a write pole structure to be built wherein the track width is independent of the location of the flare point. The process also produces a structure wherein the throat height of the shield is self aligned to the location of the flare point of the write pole.
    Type: Grant
    Filed: December 26, 2007
    Date of Patent: November 1, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ming Jiang, Changqing Shi
  • Patent number: 8000059
    Abstract: A magnetic write head for perpendicular magnetic recording having a thin wrap-around magnetic shield. The small thickness and forming method of the thin wrap-around magnetic shield allow it to be electroplated using a thin photoresist frame mask. The thin photoresist frame mask has better critical dimension and straight wall control than a thicker mask, which allows the wrap-around magnetic shield to be constructed with much more straight and uniform back edge for shield throat height control than is possible when forming a thicker (i.e. taller) shield. The thin wrap-around magnetic shield can be stitched to a trailing return pole to avoid magnetic saturation of the wrap-around shield.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: August 16, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ming Jiang, Changqing Shi
  • Patent number: 7990652
    Abstract: A magnetic write head for perpendicular magnetic data recording having a notched write pole for reduced magnetic core width (MCW) dependence on skew. The write pole is configured with a notch that can extend to or slightly beyond the flare point of the write pole, and is formed on the leading portion of the write pole. The notch can have a notch depth, as measured from the ABS of 50-200 nm or about 120 nm. The notch can have a notch height, measured in the down track direction that is 40-90 nm or 20-90 percent of the write pole height.
    Type: Grant
    Filed: December 3, 2007
    Date of Patent: August 2, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Wen-Chien David Hsiao, Yimin Hsu, Quan-chiu Harry Lam, Yansheng Luo, Vladimir Nikitin, Changqing Shi
  • Patent number: 7982989
    Abstract: A method for measuring a magnetic interference width for a magnetic recording head is described. The method includes writing a first track at a first frequency on a magnetic disk, writing a second track at the first frequency on the magnetic disk, and writing a third track at a second frequency on the magnetic disk between the first track and the second track. The third track partially overlaps both the first track and the second track and the second frequency is different from the first frequency. The method further includes measuring a readback profile across the first, second and third tracks on the magnetic disk.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: July 19, 2011
    Assignee: Western Digital (Fremont), LLC
    Inventors: Changqing Shi, Jimmy Wong, David D. Terrill
  • Patent number: 7927724
    Abstract: The recording medium according to the invention has a magnetic recording layer, an exchange coupling layer and an enhancement or bias layer with an anisotropy orthogonal to the recording layer. The enhancement layer is designed to have no significant remanent magnetization and preferably to saturate under the write head. The enhancement layer creates an exchange field normal to the anisotropy of the recording layer and has the effect of rotating the magnetization of the recording layer and lowering the required switching field, i.e., the coercivity. The invention can be embodied in a longitudinal recording medium or a perpendicular recording medium. The exchange coupling can either ferromagnetic or antiferromagnetic. The bias layer has a high KuV and anisotropy and is designed to have high thermal stability and minimize the rotation of magnetization with the head field.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: April 19, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Vladimir R. Nikitin, Changqing Shi
  • Patent number: 7920358
    Abstract: A perpendicular magnetic recording write head that may be used in magnetic recording disk drives has a magnetic write pole (WP) with an end that is generally the same width as the width of the data tracks on the disk. A trailing shield (TS) is spaced from the WP in the along-the-track direction, a pair of side shields are located on opposite sides of the WP in the cross-track direction, and an optional leading shield (LS) is located on the opposite side of the WP from the TS in the along-the-track direction. The TS, side shields and LS are formed of magnetically permeable soft ferromagnetic material and are separated from each other by nonmagnetic separation layers. The TS, side shields and LS each has a throat height (TH) thickness in its region facing the WP. The throat heights for the shields may be different.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: April 5, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ming Jiang, Changqing Shi
  • Patent number: 7889456
    Abstract: A perpendicular magnetic recording write head having a flux shaping layer located on the write pole which has an end located substantially at the surface of the head carrier that faces the recording medium. The write head includes a main pole, on which the write pole is formed, that has an end recessed from the write pole end, and at least one flux return pole. In one implementation a first flux shaping layer is located between the main pole and the write pole. A second flux shaping layer may be located on the write pole with both shaping layers having an end recessed from the write pole end. The first and second flux shaping layers may also be tapered in the direction of the recording medium and cover the sides of the write pole in the cross-track direction to substantially surrounded the write pole with flux shaping material.
    Type: Grant
    Filed: November 13, 2007
    Date of Patent: February 15, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ming Jiang, Changqing Shi
  • Patent number: 7889458
    Abstract: A magnetic write head having a magnetic cross yoke arranged to provide a cross magnetic field in a pole tip region of the magnetic head. The cross field, which is perpendicular to the magnetization of write pole, reduces the switching time of the write field, thereby increasing the speed with which the write head can record data. The write head can be a longitudinal write head or a perpendicular write head. In the case of a perpendicular write, the write head can include a write pole arranged to provide a magnetic write field that emits a magnetic field substantially perpendicular with an Air Bearing Surface (ABS). A magnetic cross yoke is formed having ends that are disposed at opposite sides of the pole tip region of the write pole.
    Type: Grant
    Filed: November 13, 2006
    Date of Patent: February 15, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Wen-Chien David Hsiao, Terence Tin-Lok Lam, Changqing Shi
  • Patent number: 7788798
    Abstract: A method for manufacturing a magnetic write head having a wrap around magnetic shield. The method allows a highly accurate short wavelength such as 193 mm photolithography to be used to accurately define the placement and critical dimension of wrap around magnetic shield. The method includes the formation of a magnetic write pole, top gap, and side gap and the deposition of a RIEable fill layer thereover, and CMP to planarization. A 193 nm photolithography and ion milling is used to form a mask over the RIEable layer and one or more reactive ion etching processes are performed to pattern the RIEable layer through 193 nm photolithography mask. A wrap around shield can then be electroplated into the opening formed in the RIEable layer.
    Type: Grant
    Filed: November 21, 2007
    Date of Patent: September 7, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hung-Chin Guthrie, Ming Jiang, Changqing Shi, Sue Siyang Zhang
  • Patent number: 7768743
    Abstract: A perpendicular magnetic recording write head supported on an air-bearing slider has a magnetic write pole (WP) with a WP end at the air-bearing surface (ABS) having a width generally equal to the data track width and a trailing shield (TS) with a TS end generally coplanar with the WP end. The TS has a first portion with a width at the TS end substantially wider than the width of the WP end and a TS notch (TSN) portion with a width at the TS end generally equal to the width of the WP end. The TS first portion has a height in a direction perpendicular to the ABS, and the TSN portion has a throat height (TH) in a direction perpendicular to the ABS that is less than the height of the TS first portion. A nonmagnetic gap layer separates the WP from the TSN portion and a nonmagnetic pad layer separates the WP from the TS first portion.
    Type: Grant
    Filed: May 11, 2007
    Date of Patent: August 3, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hung-Chin Guthrie, Ming Jiang, Changqing Shi
  • Publication number: 20100187199
    Abstract: In one embodiment of the present invention, a write head includes a first pole P1, a P1 pedestal, a first back gap layer plated on top of the first pole P1 leaving a region between the P1 pedestal and the first back gap layer for plating a coil, a first insulation layer applied on top of the P1 pedestal and the first back gap layer and the region between the P1 pedestal and the first back gap layer. The write head further includes a coil, patterned at least partially on top of the P1 pedestal and the first back gap layer and the region between the P1 pedestal and the first back gap layer, copper plated in the coil patterns, and a second insulation layer applied to fill the spaces in between the coil turns. The resulting structure is planarized via chemical mechanical polishing.
    Type: Application
    Filed: April 2, 2010
    Publication date: July 29, 2010
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
    Inventors: Terence Tin-Lok Lam, David Kaimon Lee, Edward Hin Pong Lee, Changqing Shi
  • Publication number: 20090168237
    Abstract: Methods and structures for the fabrication of a thin film, perpendicular recording write head are disclosed. The structure provides a pole tip separated from a rear pole by a non-magnetic separation layer located adjacent the flare point. The rear pole contains an imbedded non-magnetic layer. The separated pole tip and imbedded layer aid in the high data rate recording as well as the erasure performance of the write pole structure. The fabrication involves the deposition of two different oxide layers which have mutually high etch selectivities. This characteristic allows a write pole structure to be built wherein the track width is independent of the location of the flare point. The process also produces a structure wherein the placement of the throat height of the shield is self aligned to the flare point of the write pole.
    Type: Application
    Filed: December 27, 2007
    Publication date: July 2, 2009
    Inventors: Wen-Chien David Hsiao, Ming Jiang, Changqing Shi
  • Publication number: 20090168236
    Abstract: Methods and structures for the fabrication of a thin film, perpendicular recording write head are disclosed. The fabrication involves the deposition of two different oxide layers which have mutually high etch selectivities. This characteristic allows a write pole structure to be built wherein the track width is independent of the location of the flare point. The process also produces a structure wherein the throat height of the shield is self aligned to the location of the flare point of the write pole.
    Type: Application
    Filed: December 26, 2007
    Publication date: July 2, 2009
    Inventors: Ming Jiang, Changqing Shi
  • Publication number: 20090154026
    Abstract: A magnetic write head for perpendicular magnetic recording having a thin wrap-around magnetic shield. The small thickness and forming method of the thin wrap-around magnetic shield allow it to be electroplated using a thin photoresist frame mask. The thin photoresist frame mask has better critical dimension and straight wall control than a thicker mask, which allows the wrap-around magnetic shield to be constructed with much more straight and uniform back edge for shield throat height control than is possible when forming a thicker (i.e. taller) shield. The thin wrap-around magnetic shield can be stitched to a trailing return pole to avoid magnetic saturation of the wrap-around shield.
    Type: Application
    Filed: December 12, 2007
    Publication date: June 18, 2009
    Inventors: Ming Jiang, Changqing Shi
  • Publication number: 20090147410
    Abstract: A perpendicular magnetic recording write head that may be used in magnetic recording disk drives has a magnetic write pole (WP) with an end that is generally the same width as the width of the data tracks on the disk. A trailing shield (TS) is spaced from the WP in the along-the-track direction, a pair of side shields are located on opposite sides of the WP in the cross-track direction, and an optional leading shield (LS) is located on the opposite side of the WP from the TS in the along-the-track direction. The TS, side shields and LS are formed of magnetically permeable soft ferromagnetic material and are separated from each other by nonmagnetic separation layers. The TS, side shields and LS each has a throat height (TH) thickness in its region facing the WP. The throat heights for the shields may be different.
    Type: Application
    Filed: December 6, 2007
    Publication date: June 11, 2009
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
    Inventors: Ming Jiang, Changqing Shi
  • Publication number: 20090141397
    Abstract: A magnetic write head for perpendicular magnetic data recording having a notched write pole for reduced magnetic core width (MCW) dependence on skew. The write pole is configured with a notch that can extend to or slightly beyond the flare point of the write pole, and is formed on the leading portion of the write pole. The notch can have a notch depth, as measured from the ABS of 50-200 nm or about 120 nm. The notch can have a notch height, measured in the down track direction that is 40-90 nm or 20-90 percent of the write pole height.
    Type: Application
    Filed: December 3, 2007
    Publication date: June 4, 2009
    Inventors: Wen-Chien David Hsiao, Yimin Hsu, Quan-chiu Harry Lam, Yansheng Luo, Vladimir Nikitin, Changqing Shi
  • Publication number: 20090128964
    Abstract: A method for manufacturing a magnetic write head having a wrap around magnetic shield. The method allows a highly accurate short wavelength such as 193 mm photolithography to be used to accurately define the placement and critical dimension of wrap around magnetic shield. The method includes the formation of a magnetic write pole, top gap, and side gap and the deposition of a RIEable fill layer thereover, and CMP to planarization. A 193 nm photolithography and ion milling is used to form a mask over the RIEable layer and one or more reactive ion etching processes are performed to pattern the RIEable layer through 193 nm photolithography mask. A wrap around shield can then be electroplated into the opening formed in the RIEable layer.
    Type: Application
    Filed: November 21, 2007
    Publication date: May 21, 2009
    Inventors: Hung-Chin Guthrie, Ming Jiang, Changqing Shi, Sue Siyang Zhang