Patents by Inventor Yimin Hsu
Yimin Hsu 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: 8947827Abstract: In one general embodiment, a magnetic head includes a stitch pole; and a main pole formed adjacent the stitch pole, wherein an end region of the stitch pole closest to an air bearing surface of the head tapers towards the main pole. In another general embodiment, a magnetic head includes a stitch pole being a laminate of at least two magnetic layers separated by a nonmagnetic layer; and a main pole formed adjacent the stitch pole. An end region of the stitch pole closest to an air bearing surface of the head tapers towards the main pole. An average angle of the taper of the end region of the stitch pole is between about 20 and about 45 degrees. Such head may be implemented in a data storage system.Type: GrantFiled: July 24, 2013Date of Patent: February 3, 2015Assignee: HGST Netherlands B.V.Inventors: Venkata R. K. Gorantla, Wen-Chien D. Hsiao, Yimin Hsu, Terence T. L. Lam, Yansheng Luo, Aron Pentek, Katalin Pentek
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Publication number: 20150029611Abstract: In one general embodiment, a magnetic head includes a stitch pole; and a main pole formed adjacent the stitch pole, wherein an end region of the stitch pole closest to an air bearing surface of the head tapers towards the main pole. In another general embodiment, a magnetic head includes a stitch pole being a laminate of at least two magnetic layers separated b a nonmagnetic layer; and a main pole formed adjacent the stitch pole. An end region of the stitch pole closest to an bearing surface of the bead tapers towards the main pole. An average angle of the taper of the end region of the stitch pole is between about 20 and about 45 degrees. Such head may be implemented in a data storage system.Type: ApplicationFiled: July 24, 2013Publication date: January 29, 2015Applicant: HGST Netherlands B.V.Inventors: Venkata R. K. Gorantla, Wen-Chien D. Hsiao, Yimin Hsu, Terence T. L. Lam, Yansheng Luo, Aron Pentek, Katalin Pentek
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Patent number: 8929028Abstract: A perpendicular magnetic write head having a laminated trailing return pole structure that reduces magnetic eddy currents in the return pole for improved write head efficiency. The trailing magnetic return pole includes multiple magnetic layers. Each magnetic layer is separated from an adjacent magnetic layer of the return pole by a non-magnetic layer. The non-magnetic layer terminates at a region that is removed from the air bearing surface in order to allow contact between the magnetic layers at the ABS, thereby preventing stray magnetic fields from emitting from the magnetic layers of the write pole.Type: GrantFiled: December 21, 2010Date of Patent: January 6, 2015Assignee: HGST Netherlands B.V.Inventors: Wen-Chien D. Hsiao, Yimin Hsu, Jennifer Leung
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Patent number: 8836059Abstract: The present invention generally relates to a magnetic sensor in a read head having a hard or soft bias layer that is uniform in thickness within the sensor stack. The method of making such sensor is also disclosed. The free layer stripe height is first defined, followed by defining the track width, and lastly the pinned layer stripe height is defined. The pinned layer and the hard or soft bias layer are defined in the same process step. This approach eliminates a partial hard or soft bias layer and reduces potential instability issues.Type: GrantFiled: December 21, 2012Date of Patent: September 16, 2014Assignee: HGST Netherlands B.V.Inventors: Yongchul Ahn, Xiaozhong Dang, Yimin Hsu, Quang Le, Thomas Leong, Simon Liao, Guangli Liu, Aron Pentek
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Publication number: 20140175576Abstract: The present invention generally relates to a magnetic sensor in a read head having a hard or soft bias layer that is uniform in thickness within the sensor stack. The method of making such sensor is also disclosed. The free layer stripe height is first defined, followed by defining the track width, and lastly the pinned layer stripe height is defined. The pinned layer and the hard or soft bias layer are defined in the same process step. This approach eliminates a partial hard or soft bias layer and reduces potential instability issues.Type: ApplicationFiled: December 21, 2012Publication date: June 26, 2014Applicant: HGST Netherlands B.V.Inventors: Yongchul AHN, Xiaozhong DANG, Yimin HSU, Quang LE, Thomas LEONG, Simon LIAO, Guangli LIU, Aron PENTEK
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Patent number: 8638530Abstract: A current-perpendicular-to-the-plane magnetoresistive sensor structure includes at least an improved top shield structure and optionally also a similar bottom shield structure. The top shield structure includes an antiparallel structure (APS) of two ferromagnetic films and a nonmagnetic antiparallel coupling (APC) film between them. The APC film induces antiferromagnetic (AF) coupling between the two ferromagnetic films so that they have their respective magnetizations oriented antiparallel. An important aspect of the APS is that there is no antiferromagnetic layer adjacent the upper ferromagnetic film, so that the upper ferromagnetic film does not have its magnetization pinned by an antiferromagnetic layer. An electroplated shield layer is formed above the APS.Type: GrantFiled: February 20, 2013Date of Patent: January 28, 2014Assignee: HGST Netherlands B.V.Inventors: Yimin Hsu, Stefan Maat, Arley Cleveland Marley, Alexander M. Zeltser
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Patent number: 8619391Abstract: Magnetic write heads and corresponding fabrication methods for bi-layer wrap around shields resulting in dissimilar shield layer widths are disclosed. A gap structure is formed around a main write pole for a magnetic write head. A wrap around shield for the main write pole is fabricated to include a first magnetic layer proximate to the main write pole and a second magnetic layer on the first magnetic layer. A width of the first magnetic layer is less than the width of the second magnetic layer, and back edges of the first and second magnetic layers are coplanar. Further, a throat height of the wrap around shield is maintained between the first and the second magnetic layers because their back edges are coplanar.Type: GrantFiled: October 28, 2010Date of Patent: December 31, 2013Assignee: HGST Netherlands, B.V.Inventors: Yimin Hsu, Aron Pentek, Thomas Roucoux, Jing Zhang, Honglin Zhu
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Patent number: 8503131Abstract: A magnetic write head for perpendicular magnetic data recording. The write head includes a substrate and a magnetic write pole formed on the substrate, the write pole having a trailing edge and first and second sides. A magnetic stitched pole is formed over a portion of the magnetic write pole, the stitched pole having a front edge that defines a secondary flare point. First and second non-magnetic side walls are formed at the first and second sides of the write pole. The non-magnetic side walls extend from the substrate at least to the trailing edge of the write pole in a first region near an air bearing surface and wherein the first and second non-magnetic side walls extend from the substrate to a point between the substrate and the trailing edge, allowing the stitched magnetic pole to extend partially over the sides of the write pole.Type: GrantFiled: December 28, 2011Date of Patent: August 6, 2013Assignee: HGST Netherlands B.V.Inventors: Yi Zheng, Yimin Hsu, Wen-Chien David Hsiao, Ming Jiang, Aron Pentek, Sue Siyang Zhang, Edward Hin Pong Lee, Hung-chin Guthrie, Ning Shi, Vladimir Nikitin, Prabodh Ratnaparkhi, Yinshi Liu
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Patent number: 8441757Abstract: A magnetic write head having a write pole with a tapered trailing edge. The write head has a non-magnetic step layer and a non-magnetic bump formed on the front edge of the magnetic step layer. A non-magnetic trailing gap layer is formed over the tapered trailing edge of the write pole and over the non-magnetic bump and over the non-magnetic step layer. A magnetic trailing shield is formed over at least a portion of the non-magnetic gap layer.Type: GrantFiled: December 9, 2009Date of Patent: May 14, 2013Assignee: HGST Netherlands B.V.Inventors: Yingjian Chen, Liubo Hong, Yimin Hsu, Edward Hin Pong Lee, Katalin Pentek
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Patent number: 8349197Abstract: A method for manufacturing a magnetic write head having a write pole and a trailing wrap around magnetic shield, and having a non-magnetic step layer and a non-magnetic bump to provide additional spacing between the write pole and the trailing wrap around shield at a location removed from the air bearing surface. A magnetic write pole material is deposited on a substrate and a non-magnetic step layer is deposited over the write pole. A reactive ion milling can he used to pattern the non-magnetic step layer to have a front edge that is located a desired distance from an air hearing surface. A patterning and ion milling process is then performed to define a write pole, and then a layer of alumina is deposited and ion milled to from a tapered, non-magnetic bump at the front the non-magnetic step layer.Type: GrantFiled: November 20, 2009Date of Patent: January 8, 2013Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Liubo Hong, Wen-Chien D. Hsiao, Yimin Hsu, Yi Zheng
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Patent number: 8254066Abstract: A method for determining a magnetic anisotropy of a free layer of a magnetoresistive sensor. The method includes forming a functional magnetoresistive sensor and also a test sensor on a wafer. The test sensor has a sensor stack that is identical to that of the functional sensor, however the test head does not have a magnetic bias structure for biasing the free layer. A series of tests can be performed to construct a transfer curve for the test sensor. This can then be used to determine a magnetic anisotropy of the test head, which also corresponds to a magnetic anisotropy of the functional head.Type: GrantFiled: December 30, 2008Date of Patent: August 28, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Yimin Hsu, Arley Cleveland Marley
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Patent number: 8233235Abstract: Methods for fabrication of tapered magnetic poles with a non-magnetic front bump layer. A magnetic pole may have a tapered surface at or near an air bearing surface (ABS), wherein a thickness of the write pole increases in a direction away from the ABS. A non-magnetic front bump layer may be formed on the tapered surface of the magnetic pole and away from the ABS. The front bump layer may increase the separation distance between a shield layer and the magnetic pole near the tapered surface, thereby improving the performance of the write head.Type: GrantFiled: December 9, 2009Date of Patent: July 31, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Yingjian Chen, Liubo Hong, Yimin Hsu
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Publication number: 20120154954Abstract: A perpendicular magnetic write head having a laminated trailing return pole structure that reduces magnetic eddy currents in the return pole for improved write head efficiency. The trailing magnetic return pole includes multiple magnetic layers. Each magnetic layer is separated from an adjacent magnetic layer of the return pole by a non-magnetic layer. The non-magnetic layer terminates at a region that is removed from the air bearing surface in order to allow contact between the magnetic layers at the ABS, thereby preventing stray magnetic fields from emitting from the magnetic layers of the write pole.Type: ApplicationFiled: December 21, 2010Publication date: June 21, 2012Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Wen-Chien D. Hsiao, Yimin Hsu, Jennifer Leung
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Publication number: 20120107645Abstract: A method for manufacturing a magnetic write head for perpendicular magnetic recording. The method includes forming a write pole, and then depositing a refill layer. A mask structure can be formed over the writ pole and refill layer, the mask structure being configured to define a stitched pole. An ion milling or reactive ion milling can then be performed to remove portions of the refill layer that are not protected by the mask structure. Then a magnetic material can be deposited to form a stitched write pole that defines a secondary flare point. The stitched pole can also be self aligned with an electrical lapping guide in order to accurately locate the front edge of the secondary flare point relative to the air bearing surface of the write head.Type: ApplicationFiled: December 28, 2011Publication date: May 3, 2012Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Yi Zheng, Yimin Hsu, Wen-Chien David Hsiao, Ming Jiang, Aron Pentek, Sue Siyang Zhang, Edward Hin Pong Lee, Hung-Chin Guthrie, Ning Shi, Vladimir Nikitin, Prabodh Ratnaparkhi, Yinshi Liu
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Publication number: 20120106002Abstract: Magnetic write heads and corresponding fabrication methods for bi-layer wrap around shields resulting in dissimilar shield layer widths are disclosed. A gap structure is formed around a main write pole for a magnetic write head. A wrap around shield for the main write pole is fabricated to include a first magnetic layer proximate to the main write pole and a second magnetic layer on the first magnetic layer. A width of the first magnetic layer is less than the width of the second magnetic layer, and back edges of the first and second magnetic layers are coplanar. Further, a throat height of the wrap around shield is maintained between the first and the second magnetic layers because their back edges are coplanar.Type: ApplicationFiled: October 28, 2010Publication date: May 3, 2012Inventors: Yimin Hsu, Aron Pentek, Thomas Roucoux, Jing Zhang, Honglin Zhu
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Patent number: 8139319Abstract: A perpendicular magnetic recording system has a write head with a main perpendicular write pole connected to a yoke with first and second electrical coils. The first coil is wrapped around the yoke on one side of the main pole, and the second coil is wrapped around the yoke on the other side of the main pole. The first end of each coil is connected to a respective terminal. The second ends of the two coils are connected together and connected to a common terminal. A lead-time circuit is connected between the common terminal and the first end of one of the coils. Immediately after the direction of write current is switched by the write driver, the lead-time circuit causes the current in one of the coils to lead the current in the other coil. The current displacement between the two coils creates a precession of the magnetic flux reversal, thereby reducing the switching time of the write head.Type: GrantFiled: February 23, 2009Date of Patent: March 20, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.VInventors: John Thomas Contreras, Yimin Hsu, Manfred Ernst Schabes, Xinzhi Xing
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Publication number: 20120063034Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor, like a CPP MR disk drive read head, has an improved insulating structure surrounding the stack of layers making up the sensor. The sensor has a first silicon nitride layer with a thickness between about 1 and 5 nm on the side edges of the sensor and on regions of the bottom shield layer adjacent the sensor below the sensor's ferromagnetic biasing layer. The sensor has a second silicon nitride layer with a thickness between about 2 and 5 nm on the back edge of the sensor and on the region of the bottom shield layer adjacent the sensor back edge, and a substantially thicker metal oxide layer on the second silicon nitride layer. The insulating structure prevents edge damage at the perimeter of the sensor and thus allows for the fabrication of CPP MR read heads with substantially smaller dimensions.Type: ApplicationFiled: September 13, 2010Publication date: March 15, 2012Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.Inventors: Yimin Hsu, Cherngye Hwang, Simon Huangchung Liao, Stefan Maat
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Patent number: 8108985Abstract: A method for manufacturing a magnetic write head for perpendicular magnetic recording. The method includes forming a write pole, and then depositing a refill layer. A mask structure can be formed over the writ pole and refill layer, the mask structure being configured to define a stitched pole. An ion milling or reactive ion milling can then be performed to remove portions of the refill layer that are not protected by the mask structure. Then a magnetic material can be deposited to form a stitched write pole that defines a secondary flare point. The stitched pole can also be self aligned with an electrical lapping guide in order to accurately locate the front edge of the secondary flare point relative to the air bearing surface of the write head.Type: GrantFiled: November 2, 2007Date of Patent: February 7, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Yi Zheng, Yimin Hsu, Wen-Chien David Hsiao, Ming Jiang, Aron Pentek, Sue Siyang Zhang, Edward Hin Pong Lee, Hung-Chin Guthrie, Ning Shi, Vladimir Nikitin, Prabodh Ratnaparkhi, Yinshi Liu
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Patent number: 8111479Abstract: 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: GrantFiled: October 23, 2007Date of Patent: February 7, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Tsung Yuan Chen, Wen-Chien David Hsiao, Yimin Hsu, Vladimir Nikitin, Changqing Shi
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Patent number: 8066892Abstract: A method for manufacturing a write pole for a perpendicular magnetic write head. The method employs a damascene process to construct the write pole with a very accurately controlled track width. The method includes depositing a layer of material that can be readily removed by reactive ion etching. This material can be referred to as a RIEable material. A mask is formed over the RIEable material and a reactive ion etching is performed to form a tapered trench in the RIEAble material. A CMP stop layer can the be deposited, and a write pole plated into the trench. A CMP can then be performed to define the trailing edge of the write pole. Another masking, etching and plating step can be performed to form a trailing, wrap-around magnetic shield.Type: GrantFiled: September 30, 2008Date of Patent: November 29, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hung-Chin Guthrie, Yimin Hsu, Ming Jiang, Sue Siyang Zhang