Patents by Inventor Xiao Z. Wu
Xiao Z. Wu 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).
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Patent number: 9368131Abstract: A data storage device is disclosed wherein when a first head is over a top disk surface, a first undershoot of a first cross-track profile is closer to an inner diameter of a disk and a second undershoot of the first cross-track profile is closer to an outer diameter of the disk. When a second head is over a bottom disk surface, a second undershoot of a second cross-track profile is closer to the inner diameter of the disk and a first undershoot of the second cross-track profile is closer to the outer diameter of the disk.Type: GrantFiled: April 3, 2015Date of Patent: June 14, 2016Assignee: Western Digital (Fremont), LLCInventors: Kathy X. Tang, Xiao Z. Wu, Hong Pan
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Patent number: 8953277Abstract: A data storage device is disclosed comprising a head actuated over a disk. A plurality of data tracks on the disk are first written, and a metric representing a spacing between at least two of the first written data tracks is generated. At least two of the plurality of data tracks are rewritten based on the generated metric such that the rewritten data tracks comprise a more equal spacing compared to the first written data tracks.Type: GrantFiled: June 16, 2014Date of Patent: February 10, 2015Assignee: Western Digital Technologies, Inc.Inventors: Xiao Z. Wu, David D. Terrill, Huaan Zhang
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Patent number: 8634168Abstract: A structure for preventing Electrostatic Discharge (ESD) damage to a magnetoresistive sensor during manufacture. The structure includes a switching element that can be switched off during testing of the sensor and then switched back on to provide ESD shunting to the sensor. The switch can be a thermally activated mechanical relay built onto the slider. The switch could also be a programmable resistor that includes a solid electrolyte sandwiched between first and second electrodes. One of the electrodes functions as an anode. When voltage is applied in a first direction an ion bridge forms across through the electrolyte across electrodes making the resistor conductive. When a voltage is applied in a second direction, the ion bridge recedes and the programmable resistor becomes essentially non-conductive.Type: GrantFiled: March 28, 2012Date of Patent: January 21, 2014Assignee: HGST Netherlands B.V.Inventors: Thomas Robert Albrecht, Robert E. Fontana, Jr., Bruce Alvin Gurney, Timothy Clark Reiley, Xiao Z. Wu
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Patent number: 8546001Abstract: Patterned media and associated methods of fabrication are provided in which vertical magnetic grains are grown on a patterned seed layer. The patterned seed layer includes a matrix of islands of a first seed material. Each island of first seed material is separated from other islands by a region of second seed material. The first seed material is selected to initiate growth of magnetic material, and the second seed material is selected to initiate growth of non-magnetic material. Subsequently, magnetic material is grown on the first seed material and non-magnetic material is grown on the second seed material. Deposition may be simultaneously. The magnetic and non-magnetic materials form well-defined vertical columns over the first and second seed materials respectively. Thus, each island behaves as an isolated magnetic unit, which switches independently from its neighbor units, which are magnetically separated by the non-magnetic material.Type: GrantFiled: June 30, 2010Date of Patent: October 1, 2013Assignee: HGST Netherlands, B.V.Inventors: Elizabeth Dobisz, David Margulies, Olav Hellwig, Xiao Z. Wu
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Patent number: 8441758Abstract: Methods of defining servo patterns and data patterns for forming patterned magnetic media are described. For one method, a lithographic process is performed to define a servo pattern in servo regions on a substrate. The lithographic process also defines a first data pattern in data regions of the substrate. The first data pattern is then transferred to (i.e., etched into) the data regions. Self-assembly structures are then formed on the data pattern in the data regions to define a second data pattern. The servo pattern is then transferred to the servo regions and the second data pattern is transferred to the data regions. Thus, the servo pattern is defined through lithographic processes while the data pattern is defined by a combination of lithographic processes and self-assembly.Type: GrantFiled: May 16, 2011Date of Patent: May 14, 2013Assignee: HGST Netherlands, B.V.Inventors: Thomas R. Albrecht, Xiao Z. Wu, Henry Hung Yang
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Patent number: 8405927Abstract: A low flying slider detector is disclosed. In one embodiment a surface is provided. In addition, a suspender is provided for receiving and flying a slider above the surface. A detector is also provided for detecting a low flying slider flying above the surface wherein the detector does not require measuring of the slider fly height to detect the low flying slider and wherein the detecting of the low flying slider is performed at least at a slider level of assembly.Type: GrantFiled: October 2, 2006Date of Patent: March 26, 2013Assignee: HGST Netherlands B.V.Inventors: Xiaodong Che, Xiao Z. Wu
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Patent number: 8390962Abstract: A station for performing a lapping method to achieve tight dimension controls for both read and write elements of magnetic recording heads is disclosed. A recording head having a read head stripe height and a write head throat height is lapped using a plurality of lapping forces. At least one of the plurality of lapping forces includes a torque force. A lapping wedge angle is controlled using at least one torque force, which controls the offset between the recording head read head stripe height and the write head throat height.Type: GrantFiled: September 29, 2005Date of Patent: March 5, 2013Assignee: HGST Netherlands B.V.Inventors: Jeffrey P. Gunder, Ian R. McFadyen, Darrick T. Smith, Scott A. Thomas, Xiao Z. Wu
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Patent number: 8286334Abstract: Various embodiments of the present invention pertain to manufacturing pre-sliders by annealing to saturation. According to one embodiment, pre-sliders are lapped to prepare for air bearing surfaces for the pre-sliders. The pre-sliders are annealed to saturation to level off the amount of overcoat expansion for the pre-sliders.Type: GrantFiled: July 14, 2006Date of Patent: October 16, 2012Assignee: Hitachi Global Storage Technologies, Netherlands B.V.Inventors: Damaris Davis, Hardayal S. Gill, Kenneth D. MacKay, Xiao Z. Wu
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Publication number: 20120243125Abstract: A structure for preventing Electrostatic Discharge (ESD) damage to a magnetoresistive sensor during manufacture. The structure includes a switching element that can be switched off during testing of the sensor and then switched back on to provide ESD shunting to the sensor. The switch can be a thermally activated mechanical relay built onto the slider. The switch could also be a programmable resistor that includes a solid electrolyte sandwiched between first and second electrodes. One of the electrodes functions as an anode. When voltage is applied in a first direction an ion bridge forms across through the electrolyte across electrodes making the resistor conductive. When a voltage is applied in a second direction, the ion bridge recedes and the programmable resistor becomes essentially non-conductive.Type: ApplicationFiled: March 28, 2012Publication date: September 27, 2012Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Thomas Robert Albrecht, Robert E. Fontana, JR., Bruce Alvin Gurney, Timothy Clark Reiley, Xiao Z. Wu
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Patent number: 8179635Abstract: A thin film, perpendicular write head for use with recording media with or without a soft under layer is disclosed. The present invention comprises an tapered auxiliary pole, situated below the main write pole and separated from the write pole by a lower non-magnetic gap. The auxiliary pole alleviates problems such as erasure after write, and cross track stray erasure fields, associated with operating conventionally designed perpendicular writes heads with media having no soft under layer.Type: GrantFiled: January 28, 2008Date of Patent: May 15, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Manfred Ernst Schabes, Petrus Antonius Van Der Heijden, Xiao Z. Wu
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Patent number: 8169751Abstract: A structure for preventing Electrostatic Discharge (LSD) damage to a magnetoresistive sensor during manufacture. The structure includes a switching element that can be switched off during testing of the sensor and then switched back on to provide ESD shunting to the sensor. The switch can be a thermally activated mechanical relay built onto the slider. The switch could also be a programmable resistor that includes to solid electrolyte sandwiched between first and second electrodes. One of the electrodes functions as an anode. When voltage is applied in a first direction an ion bridge forms across through the electrolyte across electrodes making the resistor conductive. When a voltage is applied in a second direction, the ion bridge recedes and the programmable resistor becomes essentially non-conductive.Type: GrantFiled: June 27, 2006Date of Patent: May 1, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Thomas Robert Albrecht, Robert E. Fontana, Jr., Bruce Alvin Gurney, Timothy Clark Reiley, Xiao Z. Wu
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Patent number: 8047894Abstract: Embodiments of the present invention pertain to a evaluating the quality of a lapping plate. In one embodiment, an information receiver receives information while the lapping plate is being used to lap a slider. The information indicates the quality of a lapping plate. A quality determiner that evaluates the quality of the lapping plate based on the information while the lapping plate is being used to lap the slider.Type: GrantFiled: November 30, 2005Date of Patent: November 1, 2011Assignee: Hitachi Global Storage Technologies, Netherlands, B.V.Inventors: Richard Dale Bunch, Linden James Crawforth, Eduardo Padilla, Xiao Z. Wu
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Publication number: 20110215070Abstract: Methods of defining servo patterns and data patterns for forming patterned magnetic media are described. For one method, a lithographic process is performed to define a servo pattern in servo regions on a substrate. The lithographic process also defines a first data pattern in data regions of the substrate. The first data pattern is then transferred to (i.e., etched into) the data regions. Self-assembly structures are then formed on the data pattern in the data regions to define a second data pattern. The servo pattern is then transferred to the servo regions and the second data pattern is transferred to the data regions. Thus, the servo pattern is defined through lithographic processes while the data pattern is defined by a combination of lithographic processes and self-assembly.Type: ApplicationFiled: May 16, 2011Publication date: September 8, 2011Inventors: Thomas R. Albrecht, Xiao Z. Wu, Henry Hung Yang
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Patent number: 7969686Abstract: Methods of defining servo patterns and data patterns for forming patterned magnetic media are described. For one method, a lithographic process is performed to define a servo pattern in servo regions on a substrate. The lithographic process also defines a first data pattern in data regions of the substrate. The first data pattern is then transferred to (i.e., etched into) the data regions. Self-assembly structures are then formed on the data pattern in the data regions to define a second data pattern. The servo pattern is then transferred to the servo regions and the second data pattern is transferred to the data regions. Thus, the servo pattern is defined through lithographic processes while the data pattern is defined by a combination of lithographic processes and self-assembly.Type: GrantFiled: December 26, 2007Date of Patent: June 28, 2011Assignee: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Thomas R. Albrecht, Xiao Z. Wu, Henry Hung Yang
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Patent number: 7948701Abstract: Servo patterns and associated methods of fabricating servo patterns are described. For patterned storage media, data sectors and servo sectors may be patterned using self-assembly. In one embodiment, self-assembly is used to form a first array of islands and a second array of islands in servo sectors that are track-wise offset. A servo writing process is then performed to write a desired servo pattern in the arrays, such as for burst fields, synchronization fields, etc.Type: GrantFiled: November 30, 2009Date of Patent: May 24, 2011Assignee: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Thomas R. Albrecht, Zvonimir Z. Bandic, Xiao Z. Wu
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Patent number: 7914362Abstract: Embodiments of the present invention pertain to a evaluating the quality of a lapping plate. In one embodiment, information that indicates the quality of a lapping plate is received while the lapping plate is being used to lap a slider, and the information is used to evaluate the quality of the lapping plate while the lapping plate is being used to lap the slider.Type: GrantFiled: November 30, 2005Date of Patent: March 29, 2011Assignee: Hitachi Global Storage Technologies, Netherlands B.V.Inventors: Richard Dale Bunch, Linden James Crawforth, Eduardo Padilla, Xiao Z. Wu
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Patent number: 7880998Abstract: Two pass writing system and method for patterned media. In a first step, a write head of a hard disk drive writes with a strong write field. In a second step, a write head of the hard disk drive writes with a weak field. In this manner, magnetic islands of patterned media are written in the first step. In the second step, only those magnetic islands with a low switching field are written.Type: GrantFiled: December 21, 2007Date of Patent: February 1, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Xiao Z. Wu
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Publication number: 20100273028Abstract: Patterned media and associated methods of fabrication are provided in which vertical magnetic grains are grown on a patterned seed layer. The patterned seed layer includes a matrix of islands of a first seed material. Each island of first seed material is separated from other islands by a region of second seed material. The first seed material is selected to initiate growth of magnetic material, and the second seed material is selected to initiate growth of non-magnetic material. Subsequently, magnetic material is grown on the first seed material and non-magnetic material is grown on the second seed material. Deposition may be simultaneously. The magnetic and non-magnetic materials form well-defined vertical columns over the first and second seed materials respectively. Thus, each island behaves as an isolated magnetic unit, which switches independently from its neighbor units, which are magnetically separated by the non-magnetic material.Type: ApplicationFiled: June 30, 2010Publication date: October 28, 2010Inventors: Elizabeth Dobisz, David Margulies, Olav Hellwig, Xiao Z. Wu
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Patent number: 7782561Abstract: A patterned magnetic recording medium has discrete data islands arranged in spaced-apart tracks, with the tracks being arranged in multi-track groups or “hypertracks”. The islands have an equal island-spacing (IS) distance in the along-the-track direction and within each hypertrack the tracks are spaced-apart an equal track-spacing (TS) distance. If there are N tracks in a hypertrack then the islands in each track of a hypertrack are shifted in the along-the-track direction by 1/N times IS from the islands in adjacent tracks in the same hypertrack. The read and write heads have a lateral or cross-track width generally equal to the cross-track width of a hypertrack, so the read and write heads span all the individual tracks in a hypertrack. The hypertracks are spaced apart cross-track direction by a group-spacing (GS) distance, with GS being greater than TS. The islands in a hypertrack may be shifted in the along-the-track direction by approximately ½N times IS from the islands in adjacent hypertracks.Type: GrantFiled: February 28, 2007Date of Patent: August 24, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Thomas R. Albrecht, Michael A. Moser, Manfred Ernst Schabes, Xiao Z. Wu
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Patent number: 7776388Abstract: Patterned media and associated methods of fabrication are provided in which vertical magnetic grains are grown on a patterned seed layer. The patterned seed layer includes a matrix of islands of a first seed material. Each island of first seed material is separated from other islands by a region of second seed material. The first seed material is selected to initiate growth of magnetic material, and the second seed material is selected to initiate growth of non-magnetic material. Subsequently, magnetic material is grown on the first seed material and non-magnetic material is grown on the second seed material. Deposition may be simultaneously. The magnetic and non-magnetic materials form well-defined vertical columns over the first and second seed materials respectively. Thus, each island behaves as an isolated magnetic unit, which switches independently from its neighbor units, which are magnetically separated by the non-magnetic material.Type: GrantFiled: September 5, 2007Date of Patent: August 17, 2010Assignee: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Elizabeth Dobisz, David Margulies, Olav Hellwig, Xiao Z. Wu