Hitachi Global Storage Technologies Netherlands B.v.

International Business Machines Corporation

Hgst Netherlands, B.v.

Charles Mathew Mate

Bernhard E Knigge

Robert Nolan Payne

Dan Saylor Kercher

Zvonimir Z Bandic

Kurt A Rubin

Bruno Jean Marchon

Peter Michael Baumgart

Tsai-Wei Wu

Xing-Cai Guo

James L Hedrick

Thomas R Albrecht

Tzong-Shii Pan

Bruce Alexander Wilson

Weidong Huang

Gary Allan Herbst

Thomas Edward Karis

Margaret E Best

Francis Chee-Shuen Lee

Franck Rose

Junhua Wu

Charles Raymond Davis

Toshiko Hirano

Sang Hoon Kim

Steven Gary Schmid

Tushar Keshubhai Suther

In a magnetic recording disk drive, a disk with equally angularly spaced regions that have topography different from the other regions of the disk is used to detect head-disk contact. In one embodiment of a bit-patterned media (BPM) disk, equally angularly spaced servo sectors have topography different from the data regions of the disk. A head-disk spacing sensor detects the topography of the servo sectors as the servo sectors pass the sensor during rotation of the disk. This results in the head-disk spacing sensor generating an output signal with a fundamental frequency f=NX/60 Hz, where N is the number of servo sectors and X is the disk rotation rate in RPM. A second or higher harmonic or harmonics of the fundamental frequency fare filtered from the output of the head-disk spacing sensor and used to identify the initiation of head-disk contact.

System and method for determining head-disk contact in a magnetic recording disk drive having a fly-height actuator

Nanoimprint lithography using resist material with the addition of a surfactant is described. A template release layer is formed on a pattern of a template. A non-ionic surfactant is added to a resist material to form a mixed resist material. The resist material may comprise a hydrocarbon material having an unsaturated bond, such as an acrylate material. The surfactant may comprise polyalkylene glycol or an organically modified polysiloxane. A resist layer is then formed on a substrate from the mixed resist material. The surfactant added to the resist material forms a resist release layer on the surface of the resist layer. The template is then pressed into the resist layer, where the template release layer and the resist release layer are between the pattern of the template and the resist layer.

Self-releasing resist material for nano-imprint processes

A method and apparatus for controlling lubrication in hard disk drives. Hard disk drives often include lubrication on the disks to protect the disks from incidental contact with the head slider. Embodiments of the invention include lubrication control recesses on the air bearing surface (ABS) of the head slider. The recesses reduce air stagnation on the ABS and/or store excess lubrication that migrates from the disk to the head slider. By reducing build-up of lubrication and storing excess lubrication, the lubrication control recesses avoid failure that may occur as a result of the lubrication interfering with the ABS or the read/write elements of the head.

ABS with lubricant control trenches for hard disk drives

A magnetic recording disk with pre-patterned surface features of elevated lands and recessed grooves or trenches, like a discrete-track media (DTM) or bit-patterned media (BPM) disk, has a planarized surface. A multilayered disk overcoat is used to protect the recording layer, and at least one of the overcoat layers functions as a stop layer for terminating a chemical-mechanical polishing (CMP) process that substantially planarizes the disk. All of the layers of the multilayered overcoat are located above the lands, but none of the overcoat layers, or a number of layers less than the number of layers over the lands, is located above the recesses.

Magnetic recording disk having pre-patterned surface features and planarized surface

A method for patterning and forming very small structures on a substrate such as a wafer. The process uses a difference in surface energy between a mask and the substrate to selectively deposit a hard mask material such as a metal onto the surface of the substrate. The mask can be formed extremely thin, such as only an atomic mono-layer thick, and can be patterned by ion beam photolithography. The pattern can, therefore, be formed with extremely high resolution. The thin mask layer can be constructed of various materials and can be constructed of perfluoropolyether diacrylate (PDA), which can be dip coated to and exposed to form a desirable positive photoresist mask layer.

High resolution patterning of surface energy utilizing high resolution monomolecular resist for fabrication of patterned media masters

Magnetic disk drives and associated methods are described for an improved process for dissipating liquid droplets that may accumulate on a slider of the magnetic disk drive. For the droplet removal process, the slider having the liquid droplet is unloaded from the magnetic disk. For example, the slider may be unloaded from the magnetic disk and onto a ramp assembly. While unloaded from the magnetic disk, a heating power is applied to a TFC heating element in the slider to increase the temperature of the slider. The temperature is increased to a threshold temperature which dissipates any liquid droplets that may have accumulated on the slider. After the liquid droplets have dissipated, the slider may again be loaded onto the magnetic disk.

Dissipation of liquid droplets in a magnetic disk drive

A method according to one embodiment comprises detecting a change in a rotational velocity of a magnetic disk or a spindle coupled to the magnetic disk, the change being caused by head-disk contact. A method for detecting head-disk contact according to another embodiment comprises measuring a rotational velocity of a magnetic disk or a spindle coupled to the magnetic disk; detecting a change in the rotational velocity, the change being caused by head-disk contact; and correlating the change in rotational velocity with the head-disk contact.

Method and system for detecting a change in a rotational velocity of a magnetic disk or a spindle coupled to the magnetic disk

Methods of performing nanoimprint lithography are described. For one method, a master tool and a stamper tool are formed to provide nanometer-scale imprinting. A release layer comprised of a perfluoropolyether diacrylate material is formed on the master tool and the stamper tool. The master tool and the stamper tool are used to form patterns in resist material, such as hole or pillar patterns. The resist material as described herein has lower viscosity and lower surface tension than prior resist materials allowing for more uniform replication of the patterns.

Release layer and resist material for master tool and stamper tool

Systems and methods are provided for burnishing a recording head in-situ in a magnetic recording disk drive. The burnishing process generates a tribocurrent, which is electricity generated by the rubbing of dissimilar materials. Different materials exhibit widely different tribocurrent characteristics while in sliding contact. The tribocurrent thus acts as an indicator of the particular materials of the recording head making contact with the magnetic recording media during different stages of the burnishing process. The tribocurrent is thus monitored to determine when it reaches a threshold value. The threshold value indicates that the burnishing has exposed a particular material of the recording head. Thus, the burnishing process may be stopped upon the tribocurrent reaching the threshold value so that the read sensor of the recording head is not burnished and inadvertently damaged.

Systems and methods for in-situ recording head burnishing

A method for patterning and forming very small structures on a substrate such as a wafer. The process uses a difference in surface energy between a mask and the substrate to selectively deposit a hard mask material such as a metal onto the surface of the substrate. The mask can be formed extremely thin, such as only an atomic mono-layer thick, and can be patterned by ion beam photolithography. The pattern can, therefore, be formed with extremely high resolution. The thin mask layer can be constructed of various materials and can be constructed of perfluorpolyether diacrylate (PDA), which can be dip coated to and exposed to form a desirable positive photoresist mask layer.

A method and system for determining contact potential voltages between a slider body and a hard disk of a hard disk drive. In embodiments of the present invention, at least one continuous negative direct current (DC) voltage is applied between a slider body and a hard disk of a hard disk drive. Then, at least one continuous positive direct current (DC) voltage is applied between the slider body and the hard disk. A contact potential voltage between the slider body and the hard disk is then determined in response to the applying of the direct current voltages.

Method and system for determining contact potential in a hard disk drive

A magnetic recording disk drive has a negative-pitch slider in near-contact or continuous-contact with the disk during reading and writing of data. When the disk is rotating at its operating speed, the slider has its upstream or leading portion located closer to the disk surface than its downstream or trailing portion. Both the leading and trailing portions have air-bearing surfaces that enable the slider to be partially supported above the disk surface. A contact pad that provides no substantial air-bearing support is located at the leading portion and supports or contains the magnetic elements of the read/write head. The contact pad protrudes beyond the air-bearing surface of the leading portion and is in contact with the disk. For near-contact recording the contact pad partially wears away during an initial wear-in period. For continuous-contact recording the contact pad is wear-resistant and remains in substantially continuous contact with the disk during reading and writing of data.

Disk drive with negative-pitch slider having protrusion pad contacting the disk when the disk is rotating at operating speed

A slider-disk interface tester for measuring the friction force at the interface uses a 'negative-pitch' slider in contact with a rotating disk. The tester includes a base that supports a motor for rotating the disk and an actuator for supporting the slider and moving it to a desired radial location on the disk surface. The slider is connected to the actuator by a rigid arm and a suspension like the suspension used in disk drives. When the disk is rotating, the negative-pitch slider has its upstream or leading portion in contact with the disk surface and its downstream or trailing portion not in contact with the disk surface. A contact pad is located at the leading portion of the slider and is in contact with the disk surface. The tester includes a friction-force sensor and associated measurement circuitry, such as strain gauge, piezoelectric and temperature sensors, and is located at one of several locations on the rigid arm, suspension or slider.

Apparatus for measurement of friction force at the interface of a slider and rotating disk

A magnetic recording disk drive achieves continuous contact recording with a head-suspension assembly that compensates for the moment generated from an adhesive force between the head carrier or slider and the disk. The slider pivot point, which is the point where the load force is applied to the flexure that supports the slider, is located closer to the front end of the slider than the net force applied by the air-bearing surface of the slider when the disk is rotating at its operational speed. This assures that the net air-bearing force generates a moment about the pivot point to partially counteract the flexure moment and the moment generated from the adhesive force between the disk and the slider's contact pad.

Magnetic recording disk drive with continuous contact air-bearing slider

A micro-electro-mechanical systems (MEMS) type electrostatic microactuator has a fixed electrode and a movable electrode, with the movable electrode being attached to the substrate by a flexure. Each electrode has a plurality of fingers with the fixed electrode fingers and the movable electrode fingers interleaved in a comb-like arrangement. A nonconductive viscous liquid is located between the fingers for damping motion of the movable electrode relative to the fixed electrode. The liquid is held in a reservoir attached to the movable electrode. Capillary pressure pulls the liquid from the reservoir into the small gaps between the interleaved fingers.

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San Jose, CA, United States of America

Charles Mathew Mate