Patents by Inventor Yanning Liu
Yanning Liu 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: 8547657Abstract: A disk drive is disclosed comprising a disk surface comprising a plurality of tracks, each track comprising a plurality of servo sectors. The disk drive further comprises a head coupled to a distal end of an actuator arm, and a voice coil motor (VCM) and a microactuator operable to actuate the head over the disk surface. The head is first servoed in response to the servo sectors, and after first servoing the head, a manufacturing procedure is executed by controlling the VCM and the microactuator to servo the head while accessing the disk surface. After executing the manufacturing procedure, the head is second servoed in response to the servo sectors, and the microactuator is evaluated in response to the first and second servoing.Type: GrantFiled: June 10, 2010Date of Patent: October 1, 2013Assignee: Western Digital Technologies, Inc.Inventors: Yanning Liu, Rainer H. Laatsch, Andrew H. Tong
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Patent number: 8542465Abstract: A novel suspension assembly includes a suspension assembly mounting plate, a microactuator mounting structure extending from the suspension assembly mounting plate, a load beam extending from the microactuator mounting structure, and a laminated flexure attached to the load beam. The laminated flexure includes a tongue that has a read head bonding surface. The suspension assembly includes a stainless steel surface having a gold coating, and a piezoelectric microactuator attached to the microactuator mounting structure and electrically connected to the gold coating.Type: GrantFiled: March 17, 2010Date of Patent: September 24, 2013Assignee: Western Digital Technologies, Inc.Inventors: Yanning Liu, Wing C. Shum, John E. Scura
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Patent number: 8499652Abstract: A test ramp is disclosed comprising a plurality of planar surfaces, wherein each planar surface comprises at least one impediment. Each impediment is offset along a planar axis from the other impediments, and each impediment is operable to contact part of a respective actuator arm of a disk drive in order to excite a microactuator coupled to the actuator arm.Type: GrantFiled: April 21, 2010Date of Patent: August 6, 2013Assignee: Western Digital Technologies, Inc.Inventors: Gregory Tran, Yanning Liu, Sivabalan Ganisen, Mukesh Patel
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Patent number: 8339748Abstract: Disclosed is a suspension assembly for a disk drive that includes: a mounting plate having a top-side and a bottom-side; a microactuator mounting structure formed in the mounting plate; a microactuator mounted in the microactuator mounting structure in which the microactuator has a top-side and a bottom-side; and a flexure attached to the bottom-side of the of mounting plate and the microactuator. The flexure includes a pad layer and a through-hole, in which the through-hole extends through the pad layer. An epoxy on the pad layer bonds widely to the microactuator and extends through the through-hole.Type: GrantFiled: June 29, 2010Date of Patent: December 25, 2012Assignee: Western Digital Technologies, Inc.Inventors: Wing C. Shum, Yanning Liu, John E. Scura
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Patent number: 8335049Abstract: A disk drive is disclosed comprising a first disk surface, a first head coupled to a distal end of an actuator arm, and a voice coil motor (VCM) and a first microactuator operable to actuate the first head over the first disk surface. A servo loop for servoing the head in response to the servo sectors is disabled, and after disabling the servo loop, the first microactuator is excited with a control signal at a test frequency in order to accentuate a crack in the first microactuator. After exciting the first microactuator, the servo loop is enabled, and after enabling the servo loop, the first microactuator is evaluated to detect the crack in the first microactuator.Type: GrantFiled: June 7, 2010Date of Patent: December 18, 2012Assignee: Western Digital Technologies, Inc.Inventors: Yanning Liu, Chuanwen Ji, Nathan J. Santee
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Patent number: 8325446Abstract: A head gimbal assembly for a disk drive includes a read head and a suspension assembly. The suspension assembly includes a load beam and a laminate flexure. The laminate flexure includes a structural layer, a dielectric layer, and a conductive layer that includes a plurality of electrical traces. The laminate flexure includes a tongue portion that connects to the read head and a flexure tail that extends away from the tongue portion. The flexure tail includes a plurality of flexure bond pads. Each of the plurality of flexure bond pads includes a widened region of a corresponding one of the plurality of electrical traces in the conductive layer, and a corresponding one of a plurality of segments or discontinuous islands in the structural layer.Type: GrantFiled: June 21, 2011Date of Patent: December 4, 2012Assignee: Western Digital Technologies, Inc.Inventors: Yanning Liu, Wing C. Shum, Tzong-Shii Pan, Kia Moh Teo
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Patent number: 8320084Abstract: A head gimbal assembly for a disk drive includes a read head and a suspension assembly. The suspension assembly includes a load beam and a laminate flexure. The laminate flexure includes a structural layer, a dielectric layer, and a conductive layer that includes a plurality of electrical traces. The laminate flexure includes a tongue portion that connects to the read head and a flexure tail that extends away from the tongue portion. The flexure tail includes a plurality of flexure bond pads. Each of the plurality of flexure bond pads includes a widened region of a corresponding one of the plurality of electrical traces in the conductive layer, and a corresponding one of a plurality of segments or discontinuous islands in the structural layer.Type: GrantFiled: April 1, 2011Date of Patent: November 27, 2012Assignee: Western Digital Technologies, Inc.Inventors: Wing C. Shum, Yanning Liu, Tzong-Shii Pan, Kia Moh Teo, Brian P. Schott
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Patent number: 8300348Abstract: A disk drive is disclosed comprising a disk, an actuator arm, a head coupled to a distal end of the actuator arm, a voice coil motor (VCM) operable to actuate the head over the disk in coarse movements by rotating the actuator arm about a pivot, and a microactuator operable to actuate the head over the disk in fine movements. A disk boundary condition is detected by moving the actuator arm toward one of an outer diameter of the disk and an inner diameter of the disk, and monitoring an induced voltage generated by the microactuator. The disk boundary condition is detected when the induced voltage exceeds a threshold.Type: GrantFiled: June 25, 2010Date of Patent: October 30, 2012Assignee: Western Digital Technologies, Inc.Inventors: Yanning Liu, Norman D. Gardner
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Patent number: 8295014Abstract: A head gimbal assembly for a disk drive includes a read head, a load beam, and a laminate flexure. The laminate flexure includes a structural layer, a dielectric layer, and a conductive layer that includes a plurality of electrical traces. The laminate flexure includes a tongue portion that connects to the read head, and a flexure tail that extends away from the tongue portion and includes a plurality of flexure bond pads that may facilitate ultrasonic or ACF bonding. Each of the plurality of flexure bond pads consists of a widened region of a corresponding one of the plurality of electrical traces in the conductive layer, and a gold coating upon the widened region. The widened region of each of the plurality of electrical traces extends transverse to the flexure tail's longitudinal axis at least 2.5 times more than it extends parallel to the flexure tail's longitudinal axis.Type: GrantFiled: June 21, 2011Date of Patent: October 23, 2012Assignee: Western Digital Technologies, Inc.Inventors: Kia Moh Teo, Yanning Liu, Tzong-Shii Pan, Wing Chun Shum
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Publication number: 20120188664Abstract: Examples of the present invention relate to reduction in acoustic noise by tuning seek characteristics of a servo controller, depending on a radial position of a head relative to a disk. The servo controller can provide compensation for acoustic resonance modes.Type: ApplicationFiled: March 27, 2012Publication date: July 26, 2012Applicant: SEAGATE TECHNOLOGY LLCInventors: Yu SUN, Yanning LIU
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Patent number: 8208224Abstract: Suspension assemblies for minimizing stress on slider solder joints in a disk drive are described. One such suspension assembly includes a flexure including a gimbal area having a leading end and a trailing end, a metal support layer including a flexure tongue, a flexure tip disposed at the trailing end and including first and second isolation arms extending from the flexure tongue, and a bond pad support including a support arm extending from the flexure tongue, and a load beam including an elongated flat surface having a protrusion extending therefrom and having a cut-out section, where the leading end of the flexure gimbal area is attached along the flat surface, where the flexure is configured to retain contact with the protrusion, and where the cut-out section is configured to receive a portion of the bond pad support when the flexure rotates about a long axis of the suspension assembly.Type: GrantFiled: August 29, 2011Date of Patent: June 26, 2012Assignee: Western Digital Technologies, Inc.Inventors: Kia Moh Teo, Yanning Liu, Wing C. Shum
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Patent number: 8144421Abstract: Examples of the present invention relate to reduction in acoustic noise by tuning seek characteristics of a servo controller, depending on a radial position of a head relative to a disk. The servo controller can provide compensation for acoustic resonance modes.Type: GrantFiled: March 1, 2007Date of Patent: March 27, 2012Assignee: Seagate Technology LLCInventors: Yu Sun, Yanning Liu
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Patent number: 8144419Abstract: A disk drive is disclosed comprising a head actuated over a disk surface by a microactuator, and a fly height actuator operable to adjust a fly height of the head. A servo control voltage is applied to the microactuator, and the fly height actuator is adjusted to decrease a fly height of the head. The servo control voltage is filtered to generate a filtered voltage. A touchdown signal is generated in response to the microactuator and the filtered voltage, wherein the touchdown signal indicates when the head contacts the disk.Type: GrantFiled: April 23, 2010Date of Patent: March 27, 2012Assignee: Western Digital Technologies, Inc.Inventor: Yanning Liu
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Publication number: 20120002329Abstract: Disclosed is a suspension assembly for a disk drive that includes: a mounting plate having a through-hole extending from a top-side of the mounting plate to a bottom-side of the mounting plate; a microactuator mounting structure formed in the mounting plate; a microactuator mounted in the microactuator mounting structure; and a flexure attached to the bottom-side of the of mounting plate. The flexure includes: a metal layer; an insulator layer; a trace layer that includes a ground trace; and an opening, wherein the opening extends through the metal layer and the insulator layer to a gold-plated ground trace. A conductive epoxy is bonded to the microactuator and extends through the through-hole to bond to the flexure, wherein the epoxy extends through the opening of the flexure to the gold-plated ground trace of the flexure such that the microactuator is grounded to the flexure.Type: ApplicationFiled: June 30, 2010Publication date: January 5, 2012Applicant: WESTERN DIGITAL (FREMONT), LLCInventors: Wing C. Shum, Yanning Liu, John E. Scura
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Publication number: 20110317309Abstract: Disclosed is a suspension assembly for a disk drive that includes: a mounting plate having a top-side and a bottom-side; a microactuator mounting structure formed in the mounting plate; a microactuator mounted in the microactuator mounting structure in which the microactuator has a top-side and a bottom-side; and a flexure attached to the bottom-side of the of mounting plate and the microactuator. The flexure includes a pad layer and a through-hole, in which the through-hole extends through the pad layer. An epoxy on the pad layer bonds widely to the microactuator and extends through the through-hole.Type: ApplicationFiled: June 29, 2010Publication date: December 29, 2011Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Wing C. Shum, Yanning Liu, John E. Scura
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Publication number: 20110228425Abstract: A novel suspension assembly includes a suspension assembly mounting plate, a microactuator mounting structure extending from the suspension assembly mounting plate, a load beam extending from the microactuator mounting structure, and a laminated flexure attached to the load beam. The laminated flexure includes a tongue that has a read head bonding surface. The suspension assembly includes a stainless steel surface having a gold coating, and a piezoelectric microactuator attached to the microactuator mounting structure and electrically connected to the gold coating.Type: ApplicationFiled: March 17, 2010Publication date: September 22, 2011Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: YANNING LIU, WING C. SHUM, JOHN E. SCURA
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Patent number: 7633707Abstract: A hard disk drive with a voice coil motor coupled to a head. The head moves relative to a disk. The voice coil motor receives a biasing voltage and has a back emf voltage. A test circuit is coupled to the voice coil motor to determine the back emf voltage. The back emf voltage can be used to analyze low frequency vibration in the disk drive. The test circuit can be constructed so that the back emf voltage is proportional to a pair of test resistors and/or a pair of test inductors. The biasing voltage allows the back emf voltage to be measured and analyzed while the head is at any location from the ID to the OD of the disk.Type: GrantFiled: February 5, 2008Date of Patent: December 15, 2009Assignee: Samsung Electronics Co., Ltd.Inventors: Yanning Liu, Seong Woo Kang, Seungman Chang
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Publication number: 20090195901Abstract: A hard disk drive with a voice coil motor coupled to a head. The head moves relative to a disk. The voice coil motor receives a biasing voltage and has a back emf voltage. A test circuit is coupled to the voice coil motor to determine the back emf voltage. The back emf voltage can be used to analyze low frequency vibration in the disk drive. The test circuit can be constructed so that the back emf voltage is proportional to a pair of test resistors and/or a pair of test inductors. The biasing voltage allows the back emf voltage to be measured and analyzed while the head is at any location from the ID to the OD of the disk.Type: ApplicationFiled: February 5, 2008Publication date: August 6, 2009Applicant: Samsung Electronics Co., Ltd.Inventors: Yanning Liu, Seong Woo Kang, Seungman Chang
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Patent number: 7548391Abstract: An apparatus and method for latching an actuator arm assembly can position a read/write head relative to a data storage disk in a disk drive. A latch arm is configured to be moved between a closed position that inhibits movement of an actuator arm assembly in a landing zone and an open position that does not inhibit movement of the actuator arm assembly in the landing zone. A coil is configured to generate an electromagnetic force on the latch arm responsive to a coil current. A bias device is configured to provide a bias force on the latch arm that is substantially opposed to the electromagnetic force from the coil. The latch operating current/voltages is controlled and modified according to environmental conditions such as temperature.Type: GrantFiled: April 23, 2007Date of Patent: June 16, 2009Assignee: Seagate Technology, LLCInventors: Yanning Liu, Yanchu Xu, Mike Leis
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Publication number: 20080278849Abstract: Disclosed is a hard disk drive that includes at least one disk enclosed by a cover and a disk. A damper is separated from the disk by an air gap about 1.0 mm. The damper and air gap reduce the velocity of the air flow and any vibration associated with the flow of air.Type: ApplicationFiled: May 7, 2007Publication date: November 13, 2008Applicant: Samsung Electronics Co., Ltd.Inventors: Haesung Kwon, Yun-Sik Han, Yanning Liu, Sean Kang, Hyung Jai Lee