Patents Assigned to Headway Technologies, Inc.
  • Patent number: 10832707
    Abstract: A perpendicular magnetic recording writer has a main pole (MP) with a first flux guiding (FG) device in a write gap between the MP trailing side and a trailing shield, and a second FG device in the leading gap (LG) and each side gap (SG). The SG angle is reduced to 15° to 45° to enable conformal and more uniform FG device layers to be formed in the SG and LG. As a result, the MP shape and write field are more reproducible. To compensate for a thinner MP thickness at the air bearing surface that results from maintaining the track width at a shallower SG angle, an upper MP tip may be formed on the lower MP tip thereby generating a hexagonal shape for the combined MP tip. In this case, the second FG device conforms to the shape of the two upper MP tip sides and trailing side.
    Type: Grant
    Filed: June 30, 2020
    Date of Patent: November 10, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Ying Liu, Yan Wu, Yuhui Tang
  • Patent number: 10811046
    Abstract: A slider design for a hard disk drive (HDD) features a shallow cavity adjacent to a leading edge that has patterns of sub-cavities of various shapes etched into its base to reduce its original surface area. The presence of these patterns of sub-cavities significantly reduces the probability that the slider will capture particles on the surface of a rotating disk and thereby reduces the corresponding probability of surface scratches that such captured particles inevitably produce.
    Type: Grant
    Filed: July 12, 2018
    Date of Patent: October 20, 2020
    Assignees: SAE Magnetics (H.K.) Ltd., Headway Technologies, Inc.
    Inventors: Ben Ng Kwun Pan, Ellis Cha
  • Patent number: 10811034
    Abstract: A microwave-assisted magnetic recording writer is disclosed wherein a heat sink is formed in a write gap (WG) and adjacent to a spin torque oscillator (STO) formed between a main pole (MP) trailing side and a trailing shield (hot seed layer). The WG comprises an electrically insulating layer with thickness of 5-80 Angstroms on the MP trailing side and STO sides. The heat sink layer may be separate coplanar layers on each STO side, or a single layer wrapping around the STO. A Ru or Cu heat sink has sufficient thermal conductivity to reduce STO temperature rise by 11% and 20%, respectively. Accordingly, the STO has longer lifetime at the same bias current density, or higher buffer head voltage is possible while maintaining STO device reliability. Each heat sink has a front side at an air bearing surface, and a stripe height (SH)?to the STO SH.
    Type: Grant
    Filed: April 1, 2019
    Date of Patent: October 20, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Yan Wu, Kowang Liu
  • Patent number: 10803888
    Abstract: A manufacturing method for a magnetic head includes the steps of: forming a main pole; forming a spin torque oscillator; and forming a trailing shield. The step of forming the spin torque oscillator includes: a step of forming a layered film; a step of forming an interposition layer; a step of forming a mask; a first etching step of etching a portion of the interposition layer using the mask; a second etching step of etching a portion of the layered film using the mask and the interposition layer as an etching mask; a step of removing the interposition layer and the mask; and a patterning step of patterning the layered film into the spin torque oscillator.
    Type: Grant
    Filed: September 18, 2019
    Date of Patent: October 13, 2020
    Assignee: HEADWAY TECHNOLOGIES, INC.
    Inventors: Yoshitaka Sasaki, Hiroyuki Ito, Kazuki Sato, Shigeki Tanemura, Hironori Araki, Yoji Nomura, Tetsuya Roppongi, Atsushi Yamaguchi
  • Patent number: 10777220
    Abstract: Dual and triple PMR writers are disclosed wherein the number of writer pads required to energize the selected PMR writer is minimized to three or four, respectively, with a coil configuration wherein separate top coils are connected by separate interconnects or side taps to separate bottom coils. Either top coils or bottom coils may be linked to a common W? pad. Alternatively, there may be one bottom coil that allows all output current to flow to a common W? pad. Coils may have a pancake or helical shape. In dual PMR writer embodiments, there may be one or two dynamic fly height heater coils. Magnetic performance in the selected writer of a dual PMR writer is similar to that of a single PMR writer with regard to erase width in AC mode (EWAC), Hy field, trailing and side shield return fields, down-track and cross-track gradient.
    Type: Grant
    Filed: April 30, 2018
    Date of Patent: September 15, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Yue Liu, Ying Liu, Yuhui Tang
  • Patent number: 10770103
    Abstract: A PMR writer is disclosed wherein the trailing shield (TS) structure has a high moment trailing shield (HMTS) with a saturation (Bs) from 19 kiloGauss (kG) to 24 kG and a width (w) from 10 nm to 500 nm and is separated from the main pole (MP) trailing side at an air bearing surface (ABS) by a first write gap (WG) portion of thickness t1. A second WG portion of thickness t2 where t2>t1 adjoins the sides of the first WG portion, and has an outer side at a cross-track distance ½ w1 from a center plane that bisects the MP trailing side where w1>w. A first TS layer is formed on the HMTS and on the second WG portion, and has an outer side coplanar with the second WG portion outer side. Accordingly, there is improvement in tracks per inch capability and adjacent track interference.
    Type: Grant
    Filed: May 28, 2019
    Date of Patent: September 8, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Ying Liu, Jiun-Ting Lee, Min Li, Yuhui Tang
  • Patent number: 10770104
    Abstract: A Spin Hall Effect (SHE) assisted magnetic recording device is disclosed wherein a SHE layer comprising a giant Spin Hall Angle material is formed between a main pole (MP) trailing side and trailing shield (TS) bottom surface. The SHE layer may contact one or both of the MP and TS, and has a front side at the air bearing surface (ABS) or recessed therefrom. A first current (I1) is applied between the MP trailing side and SHE layer and is spin polarized to generate a first spin transfer torque that tilts a local MP magnetization to a direction that enhances a MP write field. A second current (I2) is applied between the SHE layer and TS and is spin polarized to generate a second spin transfer torque that tilts a local TS magnetization to a direction that increases the TS return field and improves bit error rate.
    Type: Grant
    Filed: September 6, 2019
    Date of Patent: September 8, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Yan Wu
  • Patent number: 10762916
    Abstract: A disk drive head assembly includes a spin torque oscillator (STO) situated between a main pole and a trailing shield. A head-disk interference (HDI) sensor is placed between the main pole and a read sensor shield. A trace is connected between a preamplifier and the head assembly for providing a first biasing voltage level to the spin torque oscillator (STO) and to the head-disk interference (HDI) sensor for determining resistance changes in the head-disk interference (HDI) sensor. Further, the preamplifier is configured for determining a resistance change in the head-disk interference (HDI) sensor based on a change in current through the head-disk interference (HDI) sensor. The spin torque oscillator (STO) and the head-disk interference (HDI) sensor are connected in parallel to two connectors from the two contacting pads on the preamplifier.
    Type: Grant
    Filed: March 5, 2019
    Date of Patent: September 1, 2020
    Assignee: Headway Technologies, Inc.
    Inventor: Yan Wu
  • Patent number: 10756137
    Abstract: A MTJ stack comprising at least a pinned layer, a barrier layer, and a free layer is deposited on a bottom electrode. A top electrode layer, a carbon-based hard mask, and a dielectric hard mask are deposited in order on the MTJ stack. First, the hard masks and MTJ stack are etched. The etched MTJ stack has a first width. During the first etching, chemical damage forms on sidewalls of the MTJ stack. Next, the carbon-based hard mask is trimmed to a second width smaller than the first width. Then in a second etching, the top electrode and free layer of said MTJ stack not covered by the trimmed carbon-based hard mask are etched to complete formation of the MTJ structure wherein during the second etching of the free layer, chemical damage is removed from the free layer and metal re-deposition is formed on sidewalls of the free layer.
    Type: Grant
    Filed: December 10, 2018
    Date of Patent: August 25, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Yi Yang, Dongna Shen, Yu-Jen Wang
  • Patent number: 10748562
    Abstract: A Spin Hall Effect (SHE) assisted magnetic recording device is disclosed wherein a stack of two SHE layers (SHE1 and SHE2) with an intermediate conductor layer is formed between a main pole (MP) trailing side and trailing shield (TS) bottom surface. SHE1 is a negative Spin Hall Angle (SHA) material while SHE2 is a positive SHA material. Current (Ia) flows from SHE1 across the conductor layer to SHE2. In one embodiment, spin polarized current in SHE1 applies spin transfer torque that tilts a local MP magnetization to a direction that enhances a MP write field, and spin polarized current in SHE2 generates spin transfer torque that tilts a local TS magnetization to a direction that increases the TS return field and improves bit error rate. In alternative embodiments, one of SHE1 and SHE2 is omitted so that only one of the MP write field and TS return field is enhanced.
    Type: Grant
    Filed: November 12, 2019
    Date of Patent: August 18, 2020
    Assignee: Headway Technologies, Inc.
    Inventor: Wenyu Chen
  • Patent number: 10748559
    Abstract: A magnetic head includes a main pole, a trailing shield, a spin torque oscillator, and a buffer layer. The buffer layer is interposed between the main pole and the spin torque oscillator. The spin torque oscillator has first and second side surfaces. The first and second side surfaces respectively form first and second angles with respect to a direction perpendicular to a top surface of a substrate. The first and second angles each fall within a range of 0° to 10°. The buffer layer has third and fourth side surfaces. The third side surface includes a first inclined portion forming a third angle greater than the first angle. The fourth side surface includes a second inclined portion forming a fourth angle greater than the second angle.
    Type: Grant
    Filed: February 26, 2020
    Date of Patent: August 18, 2020
    Assignee: HEADWAY TECHNOLOGIES, INC.
    Inventors: Hironori Araki, Yoshitaka Sasaki, Hiroyuki Ito, Yoji Nomura, Shigeki Tanemura, Kazuki Sato, Tetsuya Roppongi, Atsushi Yamaguchi
  • Patent number: 10714129
    Abstract: A microwave assisted magnetic recording writer has a main pole (MP) with a write gap formed between the MP trailing side and a trailing shield, a side gap between each MP side and a side shield, and a leading gap between the MP leading side and a leading shield. A spin torque oscillator (STO) is formed in at least each side gap and recessed from the air bearing surface to reduce wear. Each STO has a flux guiding layer (FGL) with a magnetization that flips to a direction substantially opposite to the gap field when a current of sufficient density is applied from the adjacent shield towards the MP thereby forcing additional flux out of the MP at the ABS to enhance writability on a magnetic recording medium. Accordingly, the gap between the recessed STO and ABS is reduced to provide enhanced area density capability without sacrificing overwrite.
    Type: Grant
    Filed: April 2, 2019
    Date of Patent: July 14, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Yuhui Tang, Ying Liu
  • Patent number: 10714127
    Abstract: A perpendicular magnetic recording writer has a main pole (MP) with a first flux guiding (FG) device in a write gap between the MP trailing side and a trailing shield, and a second FG device in the leading gap (LG) and each side gap (SG). The SG angle is reduced to 15° to 45° to enable conformal and more uniform FG device layers to be formed in the SG and LG. As a result, the MP shape and write field are more reproducible. To compensate for a thinner MP thickness at the air bearing surface that results from maintaining the track width at a shallower SG angle, an upper MP tip may be formed on the lower MP tip thereby generating a hexagonal shape for the combined MP tip. In this case, the second FG device conforms to the shape of the two upper MP tip sides and trailing side.
    Type: Grant
    Filed: June 25, 2019
    Date of Patent: July 14, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Ying Liu, Yan Wu, Yuhui Tang
  • Patent number: 10714132
    Abstract: A perpendicular magnetic recording writer has a main pole (MP) with a first flux guiding (FG) device in a write gap between the MP trailing side and a trailing shield, a second FG device in each side gap and adjoining a MP side, and third FG device in the leading gap and adjoining the MP leading side. At least one of a first and second non-magnetic conductive layer (NMC1 and NMC2) contacts the third FG device and second FG devices, respectively, instead of a conventional leading shield and side shield. Each FG device has a flux guiding layer (FGL) with a magnetization that flips to oppose a gap flux field when a current is applied across the respective gap thereby enhancing the MP write field. NMC1 and NMC2 allow better wear and corrosion resistance in addition to improved return field and down-track field gradient, and acceptable side shield stray field.
    Type: Grant
    Filed: June 25, 2019
    Date of Patent: July 14, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Ying Liu, Yan Wu, Yuhui Tang
  • Patent number: 10714130
    Abstract: An MTJ or MR read sensor is formed by depositing a stack in a reverse order with a free layer (FL) deposited on a lower shield, followed by a tunneling barrier layer (for an MTJ) or a conducting spacer layer (for an MR) and, finally, an antiferromagnetically coupled pinning structure and an upper shield. This reverse order permits a series of etching processes to be accurately performed on the lower shield and the stack together with the formation of biasing layers that are coupled to the lower shield and the stack, without adversely affecting the stability of the pinning structure. Further, the distance between the FL and the shield is accurately determined and repeatable even down to the sub-nm regime. An upper shield can then be formed and also coupled to the biasing layers.
    Type: Grant
    Filed: May 7, 2019
    Date of Patent: July 14, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Yan Wu
  • Patent number: 10714131
    Abstract: Reader-to-reader separation (RRS) is substantially decreased, and cross-track alignment of top and bottom sensors is improved with a process where a sidewall on the two sensors is formed during a single photolithography and ion beam etch sequence. RRS is minimized since the two sensors share a common reference layer (RL), and shields between the readers are omitted. A RL front portion is formed on a first stack of layers with a first free layer and uppermost first tunnel barrier, and a RL back portion is on a second stack comprising a reference layer and antiferromagnetic coupling layer sequentially formed on an antiferromagnetic layer. The RL may be a single layer or a synthetic antiferromagnetic structure so that the sensors operate in a common mode or differential mode, respectively. A third stack with a bottom second tunnel barrier and overlying second free layer is formed on the RL front portion.
    Type: Grant
    Filed: February 14, 2019
    Date of Patent: July 14, 2020
    Assignee: Headway Technologies, Inc.
    Inventor: Yan Wu
  • Patent number: 10714136
    Abstract: A Spin Hall Effect (SHE) assisted magnetic recording device is disclosed wherein a stack of two SHE layers with an intermediate insulation layer is formed between a main pole (MP) trailing side and trailing shield (TS) bottom surface. Both SHE layers are a Spin Hall Angle (SHA) material with an absolute value for SHA>0.05 and each have front sides at the air bearing surface (ABS) or recessed therefrom. One current (I1) is applied between the MP trailing side and the first SHE layer and is spin polarized to generate spin transfer torque that tilts a local MP magnetization to a direction that enhances a MP write field. Second current (I2) is applied between the second SHE layer and TS and is spin polarized to generate spin transfer torque that tilts a local TS magnetization to a direction that increases the TS return field and improves bit error rate.
    Type: Grant
    Filed: September 6, 2019
    Date of Patent: July 14, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Wenyu Chen, Yan Wu
  • Patent number: 10706878
    Abstract: A junction shield (JS) structure is disclosed for providing longitudinal bias to a free layer (FL) having a width (FLW) and magnetization in a cross-track direction between sidewalls in a sensor. The sensor is formed between bottom and top shields and has sidewalls extending from a front side at an air bearing surface (ABS) to a backside that is a stripe height (SH) from the ABS. The JS structure has a lower layer (JS1) with a magnetization parallel to that of the FL, and a tapered top surface such that JS1 has decreasing thickness with increasing height from the ABS. As aspect ratio or AR (SH/FLW) increases above 1, longitudinal bias increases proportionally to slow an increase in asymmetry as AR increases, and without introducing a loss in amplitude for a reader with low AR. The JS1 layer may be antiferromagnetically coupled to an upper JS layer for stabilization.
    Type: Grant
    Filed: June 4, 2019
    Date of Patent: July 7, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Urmimala Roy, Yan Wu
  • Patent number: 10699731
    Abstract: A perpendicular magnetic recording writer is disclosed with a permanent magnet (PM) formed within a write gap (WG) that is between a main pole (MP) trailing side and a trailing shield. The PM has a magnetization that is anti-parallel to a WG field (HWG) when a transition is written thereby enhancing the MP field on a magnetic bit, and generates a PM field that assists the MP field. When HWG becomes saturated after the transition is written and exceeds PM coercivity that is from 500 Oe to 8000 Oe, PM magnetization flips to an opposite direction and reduces the MP field thereby improving adjacent track erasure. The PM may be at the air bearing surface (ABS) or recessed up to 50 nm from the ABS, and has a down-track thickness less than the WG thickness, and a cross-track width?to the track width of the MP trailing side.
    Type: Grant
    Filed: January 17, 2019
    Date of Patent: June 30, 2020
    Assignee: Headway Technologies, Inc.
    Inventor: Yan Wu
  • 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