Patents by Inventor Siu Yin Ngan

Siu Yin Ngan 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: 11289116
    Abstract: A PMR, TAMR or MAMR (Perpendicular Magnetic Recording, Thermally Assisted Magnetic Recording or Microwave Assisted Magnetic Recording) slider-mounted read/write head produces less heat during operation by using magnetic read shields in which are embedded a patterned layer of thermally absorbing material. At least one shield includes a heating coil which is used to adjust the fly-height of the slider by creating a thermal protrusion at the slider ABS. When additional sources of energy, such as laser heating, microwave heating or the write coil itself, are applied to the recording medium, the shields can overheat, adversely affecting their performance. The patterned layer of heat absorbing material reduces the flow of heat from the thermal heating coil to the air bearing surface (ABS) thus cooling the region around the write head while not adversely affecting the shape of the thermal protrusion.
    Type: Grant
    Filed: November 20, 2020
    Date of Patent: March 29, 2022
    Assignee: Headway Technologies, Inc.
    Inventors: Kowang Liu, Yuhui Tang, Siu Yin Ngan, Qinghua Zeng, Ellis Cha
  • Patent number: 11211084
    Abstract: A Perpendicular Magnetic Recording (PMR) head is configured for use in Thermally Assisted Magnetic Recording (TAMR). Two or three contiguous write shields, of various widths and thicknesses, formed on a leading edge side of the write gap (WG), main pole (MP) and near-field transducer (NFT), protect the head during write touchdowns (TD) and signal the approach of such a touchdown. Moreover during a write touchdown the contact with the head is restricted to the large write shields, producing a large touchdown area (TDA) and insuring the lifetime of the head.
    Type: Grant
    Filed: October 16, 2020
    Date of Patent: December 28, 2021
    Assignees: SAE Magnetics (H.K.) Ltd., Headway Technologies, Inc.
    Inventors: Qinghua Zeng, Siu Yin Ngan, Ellis Cha, Kowang Liu
  • Patent number: 10679653
    Abstract: A method of operating a HDD having a read/write head configured for Perpendicular Magnetic Recording (PMR) and configured for use in Thermally Assisted Magnetic Recording (TAMR). By using selected settings of a power ratio (PR) value to ensure that accurate fly height (FH) measurements of head-disk interference (HDI) can be taken during write touchdowns (TDs), head damage can be eliminated during HDI events. Under normal operating conditions the PMR head develops a sharp protrusion due to heating from the TAMR apparatus as well as the write current and read and write heaters. The sharp protrusion is prone to striking the disk surface, instead of the shields doing so. The shields would be more capable of absorbing the HDI, which would allow the HDI sensors (HDIs) to provide a more sensitive reading of the HDI which would prevent head wear caused by the sharp protrusion.
    Type: Grant
    Filed: March 8, 2019
    Date of Patent: June 9, 2020
    Assignees: SAE Magnetics (H.K.) Ltd., Headway Technologies, Inc.
    Inventors: Qinghua Zeng, Siu Yin Ngan, Soramany Ka, Ellis Cha
  • Patent number: 10629233
    Abstract: A PMR read/write head configured for thermally assisted recording (TAMR) includes thermally active bumper pads formed to each side of a write element to provide enhanced touchdown (TD) protection to the write head element where it emerges adjacent to the plasmon near-field spot produced by the TAMR apparatus. The bumper pads are disposed about the write head and absorb heat energy generated by active heating elements, the write current and the energy generated by the TAMR apparatus. Absorption of this energy causes the bumper pads to expand and protrude outward from the slider ABS to protect the read/write head from both intentional and unanticipated touchdown events. The PMR read/write head is then mounted on a slider and the assembly is incorporated into a hard disk drive (HDD).
    Type: Grant
    Filed: March 8, 2019
    Date of Patent: April 21, 2020
    Assignees: SAE Magnetics (H.K.) Ltd., Headway Technologies, Inc.
    Inventors: Siu Yin Ngan, Qinghua Zeng, Ellis Cha, Kowang Liu, Xuhui Jin
  • Patent number: 10360935
    Abstract: A dual perpendicular magnetic recording writer is disclosed wherein first and second dynamic fly height (DFH) heaters WDFH1 and WDFH2, are formed in first and second writers, respectively, on a slider in a head gimbal assembly. In one embodiment, WDFH1 and WDFH2 have front sides that are recessed behind first and second back gap connections (BGC), respectively, and join together at their respective backsides behind the interconnect which connects a bucking coil and driving coil each symmetrically disposed about a center plane separating the two writers. In another embodiment with a separate bucking coil in each writer, WDFH1 and WDFH2 are formed behind separate interconnects. Magnetic spacing loss is reduced compared with a single DFH heater spread across both writers. Close point at touchdown in a cross-track direction and the size of the touchdown area are controlled by applying a WDFH1:WDFH2 power ratio from 100:0 to 0:100.
    Type: Grant
    Filed: May 22, 2018
    Date of Patent: July 23, 2019
    Assignee: Headway Technologies, Inc.
    Inventors: Kowang Liu, Siu Yin Ngan, Qing Hua Zeng, Ellis Cha
  • Patent number: 9251829
    Abstract: Dynamic fly height (DFH) controlled read/write heads using multiple heaters have their heater powers set within a range of ratios that allows minimum clearances to be set between the read-gap and the write-gap and the surface of a disk, thereby providing improved touch-down detection. Determining the correct range of power ratios requires varying the ratio to create an adjustable protrusion profile for the read and write elements in the head and measuring values of the ratio and corresponding values of read gap and write gap clearances that create points of minimum clearance. By adjusting the ratio of power supplied to the heaters, different protrusion profiles can be produced, clearance control for sigma reduction can be obtained and read/write readiness and operation consistency and reliability can be improved.
    Type: Grant
    Filed: October 17, 2011
    Date of Patent: February 2, 2016
    Assignees: SAE Magnetics (HK) Ltd., Headway Technologies, Inc.
    Inventors: Siu Yin Ngan, Qinghua Zeng, Ellis Cha
  • Publication number: 20130094104
    Abstract: Dynamic fly height (DFH) controlled read/write heads using multiple heaters have their heater powers set within a range of ratios that allows minimum clearances to be set between the read-gap and the write-gap and the surface of a disk, thereby providing improved touch-down detection. Determining the correct range of power ratios requires varying the ratio to create an adjustable protrusion profile for the read and write elements in the head and measuring values of the ratio and corresponding values of read gap and write gap clearances that create points of minimum clearance. By adjusting the ratio of power supplied to the heaters, different protrusion profiles can be produced, clearance control for sigma reduction can be obtained and read/write readiness and operation consistency and reliability can be improved.
    Type: Application
    Filed: October 17, 2011
    Publication date: April 18, 2013
    Inventors: Siu Yin Ngan, Qinghua Zeng, Ellis Cha