Abstract: A system and method for reducing and controlling the number of defects due to carbon inclusions on magnetic media is disclosed. A diamond like carbon protective layer is deposited on magnetic media using a rotary cathode target assembly. The target and cathode are cylindrical in shape and are mounted on holder that allows the target and cathode to rotate while holding a magnet fixed. The target surface is periodically swept in through a plasma which sputters off the surface of the target. This prevents the build up of redeposited material on the target and consequently keeps the target surface cleaner. The reduction of redeposited material on the target surface reduces the number of unwanted particulates which are ejected from the surface, manifesting themselves as disk defects.

Abstract: A method for preventing migration of lubrication molecules into adjacent process chambers while coating a thin layer of lubricant over a storage surface of a disc using a vapor lubrication process. The method includes trapping the lubrication molecules that are not deposited onto the storage surface of the discs during the vapor lubrication process by using one or more cold traps including cold trapping surfaces in a vapor lubrication station.

Abstract: A magnetic media structure 200 deposited on glass substrates without a NiP layer having oriented media (ORMRT>1), high coercivity and high SMNR is presented. This media will significantly reduce the cost of making high quality media on glass substrates by eliminating the cost associated with additional steps of depositing a NiP layer and texturing that layer. First glass substrates are mechanically textured to have a surface roughness of about 1 Å to about 12 Å. The first layer of the magnetic structure contains Cr and Ti with a Ti content of 27 to 63 atomic percentage. The second layer contains Co and Ti with a Ti content of 43 to 55 atomic percentage. The third layer is a Cr-alloy layer wherein the alloy is an element chosen from W, Mo, V, Si, Ti, Mn, Ru, B, Nb, Ta, Zr, and Pt. The fourth layer is Co58Cr37Pt5 and the fifth layer is Co61Cr15Pt12B12. Finally, the protective overcoat is typically a hard material that contains hydrogenated carbon.

Abstract: The present invention provides a hydrodynamic bearing design which is simple and reliable in design, while incorporating a shaft with a plug of high elastic modulus material fitted within a cylinder of a lower elastic modulus material than that of the plug, thereby compensating for temperature variations while maintaining radial stiffness of the system over a wide range of temperatures. The design is relatively inexpensive and easy to replicate in a high volume manufacturing process.

Abstract: A circular magnetizer is disclosed comprising circular insulating inset holding pans of axially disposed wires, each pair carrying a current oppositely directed from the adjacent pair, the insert being disposed within and facing a back iron across a circular gap of sufficient width to allow a circular magnet to be disposed therein and spaced by a gap from the insert and/or back iron. The pan's of wires are arranged to create flux lines which will establish alternating magnetic poles separated by null zones in the magnet.

Abstract: A bearing system in which an axially stiff narrow gap fluid dynamic gas bearing. As an example two fluid dynamic bearings are provided spaced apart along a shaft, one of the bearings comprising a fluid dynamic bearing, the other comprising an air bearing. The fluid dynamic bearing has a larger gap, while the air bearing has a relatively small gap. The overall working surface area of the air bearing may be twice as much or more than the working surface area of the fluid bearing.

Abstract: A method for detecting air-contamination within a hydrodynamic bearing used with a disc drive comprises in one embodiment, a method to detect air-contamination with hydrodynamic fluid by measuring operating signals of the disc drive between different external air pressure conditions (including ambient) on the hydrodynamic bearing and comparing the operating signals to predetermined threshold values. In another aspect, the invention provides an air-contamination detecting apparatus adapted to detect air-contamination within the fluid of a hydrodynamic bearing. In another aspect, the invention provides a method to determine air-contamination within hydrodynamic bearings using the change in disc drive input/output signals responsive to air-pressure changes on the hydrodynamic bearings.

Abstract: A bearing system in which an axially stiff narrow gap fluid dynamic gas bearing is preloaded by an axially less stiff larger gap fluid dynamic bearing. As an example two fluid dynamic bearings are provided spaced apart along a shaft, one of the bearings comprising a fluid dynamic bearing, the other comprising an air bearing. The fluid dynamic bearing has a larger gap, while the air bearing has a relatively small gap. The overall working surface area of the air bearing may be twice as much or more than the working surface area of the fluid bearing.

Abstract: The counterplate and/or sleeve are modified to reduce or eliminate distortion in the counterplate in a laser welded fluid bearing design. It is known to directly weld the counterplate which lies across the end of the shaft and the thrust plate to a wall or shoulder of the sleeve in which the counterplate is fit. The radial stiffness of the sleeve is weakened by cutting grooves or the like at or near the interface between the sleeve wall and the counterplate, or on the outer diameter of the sleeve wall to essentially weaken the sleeve wall. This weakening of the sleeve wall prevents bowing or distortion of the counterplate being imposed by the sleeve.

Abstract: A very thin lubricant coating is applied to one or both of the facing surfaces defining the gap of a hydrodynamic bearing to prevent wear of these surfaces. The lubricant film is necessarily very thin, in the range of about 10 Å to 1000 Å, so that the film is thin enough that it does not materially affect the performance of the hydrodynamic bearing gap which is about typically 1-10 &mgr;m. The thin lubricant film could be a perfluoropolyether (PFPE) or a mixture of PFPE or a phosphazine derivative. To improve the adhesion and lubricating performance, functional PFPE can be used. For pure metallic surface like steel, phosphate esters can also be used because of its affinity with the metallic surface, e.g., ferrous. For example, the film could be PFPE, or a mixture of PFPE and a phosphazine derivative. The lubricant should be chosen to be thermally stable, and non-reactive with the typical ambient environment.

Abstract: The present invention is related to a disk drive hub/back iron configuration that resists distortion upon changinging temperature of the disk drive. The hub/back iron configuration thus prevents distortion of the disks, reducing HDI problems.

Abstract: A system and method for improving the durability and reliability of recording media used in hard drives is disclosed. A protective overcoat made by depositing a diamond like carbon (DLC) layer over a magnetic layer and then depleting the DLC protective layer of hydrogen before it is coated with a Perfluoropolyethers (PFPE) using an in-situ vapor lubrication technique.

Abstract: A patterned media having recordable and non-recordable regions is initialized by first erasing (e.g. DC magnetizing) at least a portion of the recordable regions. At least one offset may then be determined. The at least one offset may compensate for a read to write delay in the electronics and/or at least one delay caused by the space separation between a read and a write head. A plurality of position error signal (PES) bursts may then be written on at least a portion of the recordable regions. During the write process, the previously written PES bursts are read and used to determine PES signals (e.g. servo signals) in order to guide the write head while writing new PES bursts. Magnetically written gray code may then be written on the media. The magnetically written gray code may be used to define a track number for the data tracks with no eccentricity.

Abstract: A method for non-destructive measurement of dynamic coercivity is disclosed. In this method, magnetic media is DC erased by applying a forward DC magnetic field to the magnetic media such that the magnetic moments in the magnetic media are substantially aligned. A specified number of reversed magnetic field pulses are then applied to the magnetic media in a direction opposite to the forward DC magnetic field, wherein the intensity of the reversed magnetic field pulses is less than the remanent coercivity of the magnetic media. The broadband medium noise of the magnetic media is measured. The intensity of the reversed magnetic field pulses is then repeatedly and incrementally increased and applied to the write head for the specified number of pulses, the intensity of the reversed magnetic field pulses eventually exceeding the remanent coercivity of the magnetic media. For each intensity level of the reversed magnetic field pulses, the broadband medium noise is again measured.

Abstract: The active vibration suppression of a slider suspension arm is achieved by including as part of the suspension arm two bimorph piezoelectric elements. A first bimorph piezoelectric element is attached to the top of the suspension arm and acts as a sensor. A second bimorph piezoelectric element is attached to the bottom of the suspension arm and acts as an actuator. The actuator is controlled as a function of a voltage measured by the sensor so that the actuator damps periodic vibrations occurring in the suspension arm.

Abstract: A magnetic data recording medium substrate has a contact zone and a data zone. The contact zone is textured by forming multiple texturing features, each having a bell-shaped profile resembling a Gaussian curve. The features preferably are formed by pulsed laser energy applied to a glass substrate, or to an aluminum nickel-phosphorous substrate coated with a glass layer. As compared to previous laser texturing approaches, the laser beam is less narrowly focused to provide a beam impingement area with a diameter of at least three microns, forming texturing features with diameters of at least three microns. The texturing features preferably are uniform in height and diameter, and may be symmetrical or have asymmetrical aspects, so long as bell-shaped profiles are present in the direction of travel of the recording medium, relative to transducing heads.

Abstract: A system for transferring information to and from a magnetic disk is disclosed wherein the information may be encoded on a data track in a large number of polarization orientations in comparison to conventional bidirectional recording schemes. In one embodiment of the present invention, it is contemplated that a single segment may be polarized in eight different orientations, each of which being distinguishable from each other by a read/write head. Polarization of a segment in one of eight different orientations significantly increases the amount of information which can be stored in any given segment relative to conventional systems which are polarized in only one of two orientations. Thus, the amount of information which may be stored on a disk may be increased without having to alter the linear or radial density of the disk.

Abstract: A servo sector format for a patterned media, such as a magnetic media, includes a first patterned servo timing mark, a patterned gray code, a plurality of PES burst separators, and a second patterned servo timing mark. The first patterned servo timing mark indicates the start of a servo sector. The plurality of PES burst separators are areas where no data can be written. A plurality of servo burst fields are written magnetically between the plurality of PES burst separators, and are used to determine at least one position error signal. The servo sector format further includes magnetically written gray code positioned after the second servo timing mark. The patterned gray code is used in addressing the tracks located on the surface of a disk when the magnetically written gray code is self-written.

Abstract: A system and method for forming servo patterns on magnetic medium is disclosed. A magnetic film coated with a layer of styrene-acrylonitrile is stamped with a nickel stamper reproducing the negative image of the stamper pattern on the styrene-acrylonitrile. Ions are then accelerated towards the surface of the styrene-acrylonitrile, which stops the ions in the areas where the styrene-acrylonitrile is thick and allows the ions to penetrate through to the magnetic layer in the areas where the styrene-acrylonitrile is thin. The ions, which penetrate through to the magnetic layer, interact with the magnetic layer altering the magnetic layer's structure reducing its coercivity (Hc) and remnant moment (Mrt). This reproduces the stamped styrene-acrylonitrile pattern on the magnetic layer. The styrene-acrylonitrile is then removed by oxygen plasma etching the surface leaving behind a patterned magnetic medium.

Abstract: A sputtering apparatus for depositing layers of material onto a substrate includes a vacuum chamber, a first target and a second target positioned within the vacuum chamber. A source of power is placed in electrical communication with the first target and the second target. A switch alternately connects the source of power between the first target and the second target. The first target and the second target are different materials. The switch connects power to the first target when the transport mechanism positions the substrate near the first target and the switch connects power to the second target when the transport mechanism positions the substrate closer to the second target.