Seagate Technology Incorporated

David Shiao-Min Kuo

Wei Hsin Yao

Koichi R Wago

Li-Ping Wang

Ramesh Sundaram

Bruno Jean Marchon

Gennady G Gauzner

Yuan Xu

Chiao-Ping (Roger) Ku

Lawrence Matthias Bryant

Sundeep Chauhan

Justin Jia-Jen Hwu

Wei Hu

Gene Gauzner

Michael Joseph Stirniman

Dallas W Meyer

Jianwei Liu

Neil Deeman

Samuel John Falcone

Christopher Formato

Xinwei Li

Thomas Roy Pitchford

A planarization process may planarize a media disk that has data trenches between data features and larger servo trenches between servo features. A filler material layer is deposited on the media disk and provides step coverage of the trenches. The filler material has data recesses over the data trenches and servo recesses over the servo trenches that must be removed to produce a planar media surface. A first planarization process is used to remove the data recesses and a second planarization process is used to remove the servo recesses.

Magnetic device with different planarization areas

Planarization method for media

A rotating recording device, such as an electron beam recorder, is provided with a dual encoder arrangement. A first encoder is employed as a spindle motor controller and located at a first end of a spindle. A second encoder is mounted at a turntable adjacent to a recording surface and used as a position, velocity or clock source for recording the pattern on the substrate. Eccentricity of the mounting of the second encoder is measured against the more accurately mounted spindle control encoder and compensated by a digital clock generating system using a digital phase locked loop.

Rotating recorder with dual encoder arrangement having eccentricity compensation

Embodiments of the invention generally provide an electron beam substrate processing system. In one embodiment, the present invention provides an electron beam substrate processing system where a spindle shaft used to rotate substrates during processing includes two encoder wheels. One encoder wheel is configured to provide a rotational speed data signal to a rotational speed control system. Another encoder wheel is configured to provide a pattern generator clock signal at a higher frequency than the rotational speed data signal to a pattern generator. In one embodiment of the present invention, at least one of the encoder wheels is positioned adjacent the substrate to minimize torsional and differential movements between the at least one encoder wheel and the substrate.

Method and apparatus for electron beam processing of substrates

A device for use in performing simultaneous contact printing of magnetic patterns in opposing surfaces of a dual-sided magnetic or magneto-optical (MO) recording medium, comprising:

Device and method for contact patterning of dual-sided magnetic media

A method of performing thermal imprint lithography of a surface of a thermoplastic layer-coated workpiece for forming a pattern therein comprises pre-heating the workpiece to a pre-selected high temperature prior to inserting the workpiece in a stamping/imprinting tool maintained at a predetermined lower temperature, whereby the interval for thermal cycling of the stamping/imprinting tool between higher and lower temperatures is eliminated or at least reduced. Applications of the method include forming servo patterns in disk-shaped substrates for hard disk recording media.

Heat-transfer-stamp process for thermal imprint lithography

A method for measuring servo pattern irregularity and other servo information of pre-patterned servo media mounted on a spindle with the center of the pre-pattern tracks off center from the axis rotation of the spindle. An actuator is stepped radially while measuring the PES signals from the servo sectors of at least one highly eccentric track to form a cross track profile of the PES signals for each sector. A mathematical algorithm removes step measurement error from the data. A second mathematical algorithm removes non-repeatable random noise from the data. The amount of phase-in that radially aligns the respective cross track profiles is computed. Servo pattern written-in repeatable runout is determined by unwrapping the phase-in values to form a periodic curve.

Method for measuring PES noise of servo patterned media

Resist removal from patterned recording media

Method and apparatus for enhanced sensitivity fly height testing and measurement

A combination glide test/burnishing head can be utilized in a glide test/burnishing system. The combination glide test/burnishing head includes two piezo-electric elements, which can be utilized in a passive mode as sensors for detecting contacts between the glide test/burnishing head and asperities on the surface of a magnetic recording disc. Contact between the glide test/burnishing head and disc asperities results in generation of a defect detection signal, which can be utilized by associated test logic to define the location of the detected asperities on the disc surface. The piezo-electric elements of the glide test/burnishing head can also be utilized in an active mode to cause yaw variation in the flight attitude of the glide test/burnishing head, in turn causing a burnishing pad on the glide test/burnishing head to be moved radially into contact with a detected disc asperity. Once an active, burnishing operation has been performed, the piezo-electric elements of the glide test/burnishing head are returned to passive mode, to determine if the burnishing operation was successful in removing the asperity on the disc surface. Combining the glide test and burnishing functions in a common head assembly allows the glide test and burnishing functions to be performed using a single actuator for the glide test/burnishing head, simplifying and reducing the cost of a glide test/burnishing system.

Combination glide test/burnishing head and head suspension

A storage medium is provided that includes a texture zone having a plurality of protrusions. Each of the protrusions is separated by a short circumferential pitch. Alternatively, the texture zone includes a plurality of protrusions with a circumferential pitch less than the diameter of any protrusion. The resonance excitation between the magnetic head and the storage medium in the data storage system is reduced by forming the texture zone with the protrusions that cause the excitation frequencies of the data storage system to shift away from its resonance frequencies.

Magnetic storage medium having a textured zone

A method and apparatus for data disks adapted to compensate for effects of shock loads imparted to a disk drive which are of sufficient magnitude to cause disk shifts. A series of topographical features are formed on the disk surface or edge to cause signal fluctuation in a sensor during read-back mode operation. An initial signal profile is stored as a map indicative of track or disk alignment with respect to the actuator assembly. Selectively, such as after a known shock event, the topographical features are re-profiled. A comparison of the profiles provides a measure of any track distortion which must be compensated for in future read-write operations by adjustments to data track servo follower algorithms.

Recognizing and compensating for disk shift in computer disk drives

A method for producing a substantially smooth surface on a computer disk media comprises providing a substantially smooth master surface. A curable polymer dielectric composition is applied to the master surface as well as the surface of the disk to be smoothed. The master surface is then pressed onto the disk surface and the polymer is cured. The master surface is then removed and the cured polymer forms a smooth surface on the disk.

Surface planarization of magnetic disk media

A method and apparatus for calibrating a glide head and detector system performs a pre-screening to ensure the quality of the glide head and the piezoelectric sensor in the detection system. The glide head and the piezoelectric sensor detect a signal when the glide head makes contact with the disk, such as a magnetic recording disk. Calibration of the detection system utilizes a specially made bump disk that has asperities of desired height and size that protrude out of a flat disk surface. The glide head is flown over the bump disk, and by gradually reducing the disk spinning velocity, the head is brought closer to the disk and eventually into contact with the asperity. The onset of contact, as detected by the piezoelectric sensor, defines a disk spinning velocity for the head to fly at the desired height. In order to decouple the glide head flying characteristics and the piezoelectric quality and transfer function from other factors that affect the calibration of the detection system, laser pulses are directed at the glide head. Head vibrations are introduced in the glide head and detected by the piezoelectric sensor. The head excitations are recorded as a spectrogram in which the resonance frequencies are observed. From the amplitude and frequency readings, head resonance frequencies are identified and the piezoelectric sensor response is characterized. This allows the pre-screening of the head/sensor system and the decoupling of the glide head flying characteristics and the piezoelectric sensor quality from the asperity integrity effects on the calibration of the detection system.

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Palo Alto, CA, United States of America

David Shiao-Min Kuo