Sae Magnetics (h.k.) Limited

Headway Technologies, Incorporated

Seagate Technology Incorporated

Conner Peripherals, Inc.

Other

Sae Magnetics (hk) Lid.

Samsung Electronics, North America

Ellis T Cha

Yen Fu

Qinghua Zeng

Zhu Feng

Chao-Hui Yang

Li-Yan Zhu

Siu Yin Ngan

Xiaofeng Zhang

Guoqiang Zheng

Kowang Liu

Jia-Kuen Jerry Lee

Sindy Yeung

Manuel Hernandez

Yaw-Shing Tang

Soramany Ka

Shide Cheng

Po-Kang Wang

Xinjiang Shen

Hong Tian

Ben Hu

Michael Lee Workman

Luis P Franco

Ben Kwun Pan Ng

Ben Ng Kwun Pan

Lijie Guan

Yuhui Tang

Xuhui Jin

David Hu

Shoji Toyoda

Kwun Pan Ng

Zhijun Liu

Mannuel Hernandez

Manny Hernandez

Yong Luo

Wan Ting Looi

Hao Qing Pan

Qing Hua Zeng

Penny Wan Ting Looi

Robert Chu

Collins Lee

Niraj Mahdev

Kasumaza Yasuda

A PMR read/write transducer head configured for heat assisted recording (HAMR) includes thermally active nano-bumper pads formed from a thermally active bulge that protrudes proximally to each side of a read element to provide enhanced touchdown (TD) protection to the transducer head element where it emerges adjacent to the HAMR apparatus. The bumper pads, which can be multiple, are disposed about the transducer head and absorb heat energy generated by active heating elements, including the write current. Absorption of this energy causes the bulge to expand and vary its shape and protrude proximally 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).

DFH heater design

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.

Patterned reader shields for a cooler reader

A slider-mounted read/write transducer for a hard disk drive (HDD) has a topology that mitigates attraction and accumulation of lubricant and hydrocarbons during the HDD operation. The slider topology may include a pattern of cavities and channels symmetrically disposed about a central longitudinal axis. The slider may also have a transverse channel extending perpendicularly inward from an opening in each side edge of the slider to intersect a channel that extends longitudinally along a middle axis towards a leading-edge pad in which a read/write transducer is embedded. The ends of the transverse channel open into an air-carrying groove extending vertically upward in the side of the slider in which a side flow blocker (SFB) restricts the air flow into the channel portion.

Air-bearing surface (ABS) design with side flow blocker for mitigating lube and hydrocarbon accumulation in hard disk drives (HDD)

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.

Protective shields under touchdown conditions for thermally assisted perpendicular magnetic recording

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.

Air-bearing surface (ABS) design to reduce particle scratch risk

A method of operating an HDD having a slider-mounted read/write head that is configured for dynamic fly-height operation (DFH) and includes at least one head-disk interference sensor (HDIs). By operating the DFH to lower the head and subjecting the HDIs signal to a power-law enhancement, a consistent and accurate determination of the touchdown power (TDP) can be obtained. Combining absolute TDP determination with a method for measuring relative changes of FH, an absolute determination of FH can be determined.

TD detection with enhanced HDIs signal

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. By adjusting the power ratio (PR) to be at least the turning point (TP) value, the write shield will approach the disk surface before the sharp protrusion.

High power ratio mode for TAMR drives

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).

Bumper pad design for TAMR drives

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.

Dual write heater for slider surface topography control in double perpendicular magnetic recording (PMR) writers

A slider design for a hard disk drive (HDD) features an air-bearing surface (ABS) topography with arrays of micro-dots formed on bases of a multiplicity of cavities at different depths. The design eliminates the accumulation of hydrocarbons (e.g., spindle oil and disk lubricant) deposits in regions of air stagnation within the cavities where backflows and foreflows of air meet and cancel during HDD operation. The micro-dots are small raised regions of various shapes having sizes and spacings in the range between 2 and 100 microns and, in a preferred embodiment, heights of 0.15 microns above the cavity bases.

Air-bearing design for hydrocarbon and lube pick-up improvements in hard disk drive (HDD)

A slider design for a hard disk drive (HDD) features an air-bearing surface (ABS) topography with soft bumper pads (SBP) formed proximally to corners of the leading edge and the trailing edge. The bumper pads are formed by a process that combines the use of a first photomask for subtractive etching of the ABS to form pedestals, followed by additive depositions onto the pedestals using a second lift-off photomask. The additive process deposits sequences of Si layers and diamond-like carbon (DLC) layers to produce a soft bumper pad that is energy absorbing and heat conducting, thereby protecting the recording media from surface damage and thermal erasures.

ABS design with soft bumper pads (SBP) for mitigating media damage and thermal erasure in hard disk drives (HDD)

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.

Head DFH protrusion shape calibration by HDI sensor

Methods are provided for determining the heater power level of a dynamic flying height (DFH) type write head at which a touch down (TD) occurs. Each method makes use of the DC component of a head-disk interference (HDI) sensor and the determination of the TD heater energy is deduced from certain characteristics of the function relating heater power to HDI DC signal strength. Characteristics that provide reliable indication of a TD include points of minimum slope, structure of the slope's slope and the properties of a linear fit to the slope if the slope does not converge to a consistent value. It is found that the use of all methods in combination allow a reliable TD determination under virtually all conditions.

Touch down detection with HDI sensor DC mode

A DFH (Dynamic Flying Height) type slider ABS design has significantly improved DFH efficiency and back-off efficiency as well as uniform touchdown detectability. This is the result of decoupling the local pressure variations at the read/write head that result from skew angle variations across a disk, from local stiffness due to ABS protrusion caused by heater activation. The decoupling, which allows the heater activation stiffness to be carefully tuned, is a result of the effects of airflow channeled by a wide down-track channel onto a narrow down-track channel formed in an extended finger of the central pad of the slider. Airflow impinges on the finger channel in a manner that eliminates variations in air pressure at the central pad due to variations in skew angle.

ABS design for uniform touch-down and back-off in DFH applications

Growing community of inventors

San Jose, CA, United States of America

Ellis T Cha