Patents Assigned to WD Media, LLC
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Patent number: 8993133Abstract: A perpendicular magnetic recording (PMR) media including a non-magnetic or superparamagnetic grain isolation magnetic anisotropy layer (GIMAL) to provide a template for initially well-isolated small grain microstructure as well as improvement of Ku in core grains of a magnetic recording layer. The GIMAL composition may be adjusted to have lattice parameters similar to a bottom magnetic recording layer and to provide a buffer for reducing interface strains caused by lattice mismatch between the bottom magnetic recording layer and an underlying layer.Type: GrantFiled: December 23, 2010Date of Patent: March 31, 2015Assignee: WD Media, LLCInventors: Shaoping Li, B. Ramamurthy Acharya
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Publication number: 20150082858Abstract: Systems and methods for performing in situ testing of a load cell disposed within a disk burnishing machine are provided. One such system includes a load cell bracket attached to a component of the disk burnishing machine, where the load cell is mounted within the load cell bracket and has a force measuring surface. The load cell bracket can be oriented such that the force measuring surface faces a direction that is about opposite to a direction of gravity. The system can further include a preselected weight and a weight holder configured to receive the preselected weight, to be mounted to the load cell bracket, and to be aligned with the load cell. The preselected weight can be positioned within the weight holder and on the force measuring surface of the load cell. The load cell can then be tested, calibrated, and/or replaced if necessary.Type: ApplicationFiled: March 7, 2014Publication date: March 26, 2015Applicant: WD Media, LLCInventor: JINMIN ZHAO
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Patent number: 8980076Abstract: A method of fabricating a magnetic recording disk including providing a magnetic recording layer having a pattern of raised areas and recessed areas formed thereon and providing a mask layer on the raised areas of the magnetic recording layer. The method further including electrodepositing a first protection layer on the magnetic recording layer, removing the mask layer, and depositing a second protection layer above the first protection layer.Type: GrantFiled: January 11, 2013Date of Patent: March 17, 2015Assignee: WD Media, LLCInventors: Andrew Homola, Chunbin Zhang, Paul C. Dorsey, David Treves
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Patent number: 8956741Abstract: Media may be produced with narrow c-axis dispersion while having small grain size and high grain density. A dual seed layer design and a substrate bias voltage may be applied during deposition of the seed layer are used in the media. In some embodiments, the first seed layer is an amorphous material because of a high content of elements with large atomic sizes. Application of the substrate bias during deposition of the second seed layer may reduce the grain size and may narrow c-axis dispersion.Type: GrantFiled: June 30, 2011Date of Patent: February 17, 2015Assignee: WD Media, LLCInventors: Tuqiang Li, Donald C. Stafford, Sudhir S. Malhotra, Tsutomu T. Yamashita
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Publication number: 20150036240Abstract: Systems and methods are illustrated for manufacturing hard disks with double lubrication layers that allow minimization of a HDD head DFH touchdown point while maintaining good tribology performance for HDD reliability. An exemplary hard disk includes a magnetic recording layer, a carbon overcoat, and a double lubrication layer: a bonded lubrication layer and a mobile lubrication layer. The bonded lubrication layer includes a high conformity and high density first lubricant. The mobile layer include a high lubricity lubricant that promotes HDI reliability.Type: ApplicationFiled: March 4, 2014Publication date: February 5, 2015Applicant: WD Media, LLCInventors: YASUO SAKANE, KIM THUY THI LAI, SHAUN H. CHEN, BING-SHIUAN CHANG
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Patent number: 8945732Abstract: A recording medium comprising a magnetic recording layer having an axis of magnetic anisotropy substantially perpendicular to the surface thereof, a soft magnetic underlayer disposed under the magnetic recording layer and physically coupled to the magnetic recording layer through one or more intermediate layers magnetically decoupling the soft magnetic underlayer from the magnetic recording layer, and an orientation initialization layer disposed between the magnetic recording layer and the soft magnetic underlayer.Type: GrantFiled: August 5, 2010Date of Patent: February 3, 2015Assignee: WD Media, LLCInventors: Hua Yuan, Alexander Chernyshov, B. Ramamurthy Acharya
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Patent number: 8947987Abstract: Aspects of the present invention are directed to heat assisted magnetic recording (HAMR) media with a CoCrPtB based capping layer design that is capable of reducing switching field distribution and boosting signal-to-noise ratio of HAMR media. In one embodiment of the invention, a recording medium for heat assisted magnetic recording (HAMR) includes a substrate, a magnetic recording layer on the substrate, and a capping layer on and directly in contact with the magnetic recording layer. The capping layer includes CoCrPtB.Type: GrantFiled: July 1, 2013Date of Patent: February 3, 2015Assignee: WD Media, LLCInventors: Bincheng Wang, Alexander S. Chernyshov, Hua Yuan, Tomoko Seki, Antony Ajan, B. Ramamurthy Acharya
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Patent number: 8941950Abstract: Various embodiments provide for a heat assisted magnetic recording (HAMR) media comprising: a magnetic recording layer; a barrier layer disposed under the magnetic recording layer; a first underlayer disposed under the barrier layer; and an amorphous seedlayer disposed under the first underlayer. For some embodiments, the recording medium may comprise: a magnetic recording layer including FePt alloy, a CoPt alloy, or a FePd alloy; a barrier layer including MgO, TiC, TiN, CrN, TiCN, ?-WC, TaC, HfC, ZrC, VC, NbC, or NiO; a first underlayer including RuAl-oxide, NiAl, FeAl, AlMn, CuBe, or AlRe; or an amorphous seedlayer including a Cr—X alloy, where X comprises Al, B, C, Cu, Hf, Ho, Mn, Mo, Ni, Ta, Ti, V, W, or Ru.Type: GrantFiled: May 23, 2012Date of Patent: January 27, 2015Assignee: WD Media, LLCInventors: Hua Yuan, Antony Ajan, Alexander S. Chernyshov, B. Ramamurthy Acharya
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Patent number: 8940418Abstract: A perpendicular magnetic recording (PMR) media structure with multiple exchange couple composite (ECC) layer structure is described. The PMR disk structure may include multiple soft magnetic layers with intervening hard magnetic layers and in between. The interface between the soft magnetic layers and the hard magnetic layers may be separated by exchange coupled layers.Type: GrantFiled: December 23, 2010Date of Patent: January 27, 2015Assignee: WD Media, LLCInventor: Johannes van Ek
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Patent number: 8929008Abstract: Systems and methods for testing magnetic media disks during manufacturing using sliders with temperature sensors are provided. One such method involves scanning a surface of a selected disk of a plurality of magnetic media disks using a slider including a magnetic transducer and a temperature sensor, counting a number of the surfaces scanned, determining, during the scanning, whether a threshold crossing event has occurred by determining whether a signal from the temperature sensor signal is not within a preselected range, counting, during the scanning, a number of threshold crossing events, storing, if the number of threshold crossing events is greater than a preselected events limit, the number of surfaces scanned, stopping, if the number of surfaces scanned is greater than a surfaces scanned threshold, the scanning, and returning, if the number of surfaces scanned is less than or equal to the surfaces scanned threshold, to scan a next selected disk.Type: GrantFiled: June 26, 2013Date of Patent: January 6, 2015Assignee: WD Media, LLCInventors: Thomas A. O'Dell, Balvinder Singh
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Patent number: 8919279Abstract: A processing system for and a method of producing ions inside a process chamber and shielding the ions from a magnetic field by directing the magnetic field through a magnet keeper is described.Type: GrantFiled: September 30, 2010Date of Patent: December 30, 2014Assignee: WD Media, LLCInventors: Allen J. Bourez, Robert D. Hempstead, Jinliang Chen, Yew Ming Chiong
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Patent number: 8900465Abstract: Methods for reducing the surface roughness of magnetic media to be used in storage drives are described. One such method includes forming a recording media on a substrate, the recording media including at least one recording layer configured to store information magnetically, depositing a first layer of carbon on the recording media, the first carbon layer having a first average preselected thickness, etching the first carbon layer to have a second average preselected thickness less than the first average preselected thickness, depositing a second layer of carbon on the etched first carbon layer, the second carbon layer having a third average preselected thickness that is less than the first average preselected thickness, and implanting nitrogen in the second carbon layer.Type: GrantFiled: June 29, 2012Date of Patent: December 2, 2014Assignee: WD Media, LLCInventors: Yang Yun, Xiaofeng Yao, Yi Chen, Paul C. Dorsey
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Patent number: 8893527Abstract: A method for annealing a glass disk is disclosed. The glass disk is placed on a base, whereby the bottom surface of the glass disk makes a contact with the base, and the top surface of the glass disk is exposed to air. The glass disk is heated with thermal energy supplied to the glass disk, the thermal energy comprising first thermal energy supplied from the air through the top surface and second thermal energy supplied from the base through the bottom surface.Type: GrantFiled: July 21, 2011Date of Patent: November 25, 2014Assignee: WD Media, LLCInventors: Richie Y. Chan, Magenthiran Verapatran, Mohamad F. Azmi, Beehuah Ong
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Patent number: 8889275Abstract: FePt-based heat assisted magnetic recording (HAMR) media comprising a thick granular FePt:C magnetic recording layer capable of maintaining a single layer film having desirable magnetic properties. According to one embodiment, the thick granular FePt:C magnetic recording layer comprises a plurality of carbon doped FePt alloy columnar grains, where the plurality of carbon doped FePt alloy columnar grains comprise a carbon gradient along the thickness of the hard magnetic recording layer.Type: GrantFiled: August 20, 2010Date of Patent: November 18, 2014Assignee: WD Media, LLCInventors: Hua Yuan, Alexander Chernyshov, B. Ramamurthy Acharya
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Patent number: 8867322Abstract: Systems and methods for providing thermal barrier bilayers for heat assisted magnetic recording (HAMR) media are provided. One such HAMR medium includes a substrate, a heat sink layer on the substrate, a thermal barrier bilayer on the heat sink layer, the bilayer comprising a first thermal barrier layer on the heat sink layer and an amorphous underlayer on the first thermal barrier layer, and a magnetic recording layer on the amorphous underlayer, wherein a thermal conductivity of the first thermal barrier layer is less than a thermal conductivity of the amorphous underlayer.Type: GrantFiled: July 1, 2013Date of Patent: October 21, 2014Assignee: WD Media, LLCInventors: Alexander S. Chernyshov, Hua Yuan, Bincheng Wang, Tomoko Seki, Antony Ajan, B. Ramamurthy Acharya, Gerardo A. Bertero, David Treves
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Patent number: 8863763Abstract: A sonication cleaning tank containing a liquid is monitored. A first opacity count is generated indicative of contaminants and/or bubbles in the liquid. At least some of the liquid is filtered to remove contaminants from the liquid, and a second opacity count indicative of contaminants and/or bubbles in the filtered liquid is generated. Based at least in part on the first and second opacity counts, a contaminant count corresponding to an estimated number of contaminants in the liquid is then determined.Type: GrantFiled: May 27, 2009Date of Patent: October 21, 2014Assignee: WD Media, LLCInventors: Chaoyuan Chen, Rhownica A. Lund, Atul K. Trivedi
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Patent number: 8834962Abstract: Methods for improving the strength of glass substrates are described. One such method for strengthening a glass disk substrate for a storage device includes immersing at least a portion of the glass substrate in a solution, the solution including a solvent and a coating material selected from the group consisting of NaOH, KOH, and KNO3, removing the glass substrate from the solution, allowing the solvent to evaporate from the glass substrate, and heating the glass substrate at a preselected temperature for a preselected duration, where the preselected temperature is sufficient to substantially melt the coating material and is less than a transition temperature of the glass substrate.Type: GrantFiled: June 3, 2011Date of Patent: September 16, 2014Assignee: WD Media, LLCInventors: Shoji Suzuki, Chris Brisko
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Patent number: 8837065Abstract: Systems and methods for making fast measurements of channel performance metrics such as error margin and off-track recording capability in shingled magnetic recording are provided. One such method involves writing a plurality of shingled tracks on the disk, measuring an off track read capability (OTRC) of each of the plurality of shingled tracks, determining radial endpoints of the measured OTRC for each of the plurality of shingled tracks, determining an approximate radial center for each of the plurality of shingled tracks based on the respective OTRC radial endpoints, and measuring a channel performance metric at a range centered around the approximate radial center for each of the plurality of shingled tracks. In one such case, the channel performance metric involves error margin. One such system includes a processor coupled to a memory, a magnetic transducer, and a test platform, where the processor is configured to perform the method.Type: GrantFiled: December 18, 2013Date of Patent: September 16, 2014Assignee: WD Media, LLCInventors: Dragos I. Mircea, Andreas Moser, Harold H. Gee
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Patent number: 8828482Abstract: A disk for a hard disk drive is provided. The disk comprises a substrate comprising aluminum, and a coating layer disposed over the substrate. The coating layer comprises an alloy of Ni, X1 and X2, wherein X1 comprises one or more elements selected from the group consisting of Ag, Au, B, Cr, Cu, Ga, In, Mn, Mo, Nb, Pb, Sb, Se, Sn, Te, W, Zn and Zr, and wherein X2 comprises either B or P, and wherein X1 and X2 do not comprise the same elements.Type: GrantFiled: March 4, 2013Date of Patent: September 9, 2014Assignee: WD Media, LLCInventors: Alan J. Ruffini, Lindsey A. Hamilton, Dorothea Buechel-Rimmel, Jean M. Laplante, Ambrose Schaffer, Frederick K. Lowes
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Patent number: 8817410Abstract: Systems and methods for improving accuracy of head positioning using existing servo patterns are provided. In one embodiment, a method for improving read head positioning is provided that comprises: writing a series of tracks over a range of read offsets to be calibrated; measuring a set of raw track profiles from the series of tracks; sampling the set of raw track profiles at a series of signal amplitude levels; constructing a reference track profile from the set of sampled track profiles; calculating a set of read offset deltas from each sampled track profile; merging the sets of read offset deltas into a set of average read offset deltas; and converting the set of average read offset deltas into a read offset correction table. A similar method for improving disk write head positioning is also provided which utilizes such a read offset correction table to eventually create write offset correction table.Type: GrantFiled: September 27, 2013Date of Patent: August 26, 2014Assignee: WD Media, LLCInventors: Andreas Moser, Harold H. Gee, Steven E. Lambert, Dragos I. Mircea