Abstract: Isothermal imprint embossing system. In one embodiment, the system includes a heater to pre-heat a disk substrate to an embossing temperature, a die assembly with an embossing foil to imprint the embossable film disposed on the disk substrate, and a heat tunnel disposed between the heater and the die assembly to maintain the embossing temperature.

Abstract: A press system that reduces contamination of workpieces and/or compliant members used in die assemblies of the press from the pressing process. The die assemblies may utilize annular or hole-less stampers in which the compliant member is sealed in the die assembly. The compliant member may have be annular having a cavity at approximately its center. A gap may be generated at the cavity of the compliant member between a constraint member and the stamper. The gap, for example, may be filled with a plug to prevent significant distortion of the stamper over a hole of a disk shaped workpiece due to the pressure induced force generated by the press system. An outer diameter ring surrounding a workpiece may be used to prevent collapse of the stampers outside the diameter of the workpiece to insure uniform pressing out to the outer diameter of the workpiece.

Abstract: A burnishing head comprises at least two rails, each rail having an inner wall and an outer wall. The outer walls are at an angle relative to one another and relative to a central axis of the burnishing head. This angle permits the burnishing head to exhibit improved recovery time if it contacts a disk being burnished. The rail walls are vertical, and the corner between the rail walls and the top surface of the rails is sharp.

Abstract: Apparatus for simultaneously optically inspecting top and bottom surfaces of a workpiece comprise upper and lower test heads, each head comprising at least one laser for providing a laser beam that scans its associated workpiece surface and at least one detector for detecting reflected laser light. The directions of the laser beams are selected so as to reduce or prevent cross-talk interference between the upper and lower test heads.

Abstract: An optical test head comprises a block of material with a plurality of optical paths extending therethrough. At least one of the optical paths is an input optical path for receiving laser light and holding a lens for focusing the laser light on a workpiece that is proximate the head. At least another of the optical paths is an output path for receiving light that is reflected off of the workpiece and providing that light to a detector. (In one embodiment, several detectors are provided to direct specularly reflected light, narrow angle scattered light, wide angle scattered light and back scattered light to associated detectors.) Other optical elements can be affixed within or to the block of material. The test head can be used without requiring the individual optical elements to be aligned or adjusted.

Abstract: A magnetic recording disk having a non laser zone texturing (LZT) band in the contact-start-stop (CSS) zone. The width of the non-LZT band in the CSS zone may be greater than the width of a read and/or write element of a head and less than the width of a center pad on the head in order to prevent contact between the read and/or write element and the CSS zone's textured surface. The width of the non-LZT band may also be designed to account for head skew angle and positioning error due to movement of a suspension arm supporting the head.

Abstract: An optical test head comprises a laser source for providing a laser beam. The laser beam passes through a cylindrical lens for modifying the shape of the beam and a spherical lens for concentrating the beam onto a workpiece (typically a magnetic disk platter). The cylindrical lens both a) elongates the laser beam along the radial direction of the platter (by reducing the effective numerical aperture in the radial direction); and b) causes the beam to be out of focus in the radial direction (although the beam is typically in focus in the circumferential direction). The size of the beam in the radial direction is substantially insensitive to the position of the cylindrical lens.

Abstract: A die for a press system. The die may include a stamper and a housing, having a cavity disposed therein, coupled to the stamper. The die may also include a gasket disposed within the cavity. The gasket may be coupled to the stamper at a position above a workpiece to be imprinted by the stamper.

Abstract: A manufacturing cell for inspecting workpieces such as magnetic disk substrates comprises an input conveyor for providing workpieces to be tested, one or more testers for inspecting the workpieces, and three or more output receptacles for receiving tested workpieces. One or more robotic arms move the workpieces from the input conveyor to the tester and from the tester to one of the output receptacles depending upon the results of the test performed by the tester. The output receptacles include a pass receptacle, a reject receptacle, and at least an additional receptacle for workpieces that are to be re-worked or studied further. If the additional receptacle is full, workpieces that would otherwise be provided to the additional bin are placed in the reject receptacle. The reject receptacle is very large, so that it is rarely filled to capacity.

Abstract: A die press is described. In one embodiment, the die press includes an alignment mechanism having one or more flexure members coupled to a die to maintain coupling with the die during a pressing operation.

Abstract: A disk drive having a magnetic recording disk with a transition zone is described. A surface texture of the transition zone induces the head to fly at a greater height than when operating over a data zone, while transitioning the head to a landing zone to park.

Abstract: An apparatus and method write data to a storage medium, and subsequently automatically refresh the data to avoid loss of the data due to spontaneous thermal degradation. The apparatus and method may check whether an indicator (also called “refresh indicator”) if saved contemporaneous with writing of the data satisfies a predetermined condition indicating that the data needs to be refreshed. If so, a “refresh” operation is performed, wherein the to-be-refreshed data is read from and written back to the same storage medium. The refresh indicator can be any parameter that indicates a need to refresh the data prior to occurrence of one or more soft errors. In one example, the apparatus and method read the data back contemporaneous with writing of the data, and measure an amplitude of a readback signal and store, as the refresh indicator, a predetermined fraction (e.g. half) of the measured value (i.e., a threshold number). When a current value of the amplitude falls below the stored value, the data is refreshed.

Abstract: An optical test apparatus comprises: a) a motor rotating a spindle which in turn rotates a workpiece such as a magnetic disk substrate; b) an upper test head comprising a laser for providing an upper laser beam to the upper surface of the workpiece, an upper lens for receiving light reflected from the upper surface, and an upper detector for generating a signal indicative of the received light; and c) a lower test head comprising a lower laser providing a laser beam to the lower surface of the workpiece, a lower lens for receiving light reflected from the lower surface and a lower detector for generating a signal indicative of the received light. The path of the lower laser beam is displaced from a radial direction of the workpiece so that the lower lens can be placed closer to the laser spot than if it was not displaced.

Abstract: A magnetic recording medium constructed in accordance with the invention comprises a substrate, first, second and third underlayers formed over the substrate, and a magnetic data recording layer formed over the underlayers. The underlayers typically have a bcc crystal structure, and comprise Cr or Cr alloys. The magnetic data recording layer has a hcp crystal structure and comprises a Co alloy. The second underlayer typically comprises a material such as B, which tends to reduce the crystal size of the second underlayer and the layers deposited thereon, and also to increase crystal spacing.

Abstract: A magnetic recording medium comprising a non-ferromagnetic substrate and a magnetic recording film formed on the substrate with an underlayer interposed therebetween, wherein the magnetic recording film comprises a plurality of magnetic layers and an interlayer made of a material having a B2 crystal structure or an interlayer made of Ru, disposed between the adjacent magnetic layers.

Abstract: A discrete-track-recording (DTR) disk (also called “patterned” disk) has a sectored servo formed by modulation of its sidewalls in a predetermined manner, whereas sidewalls of data sectors are not modulated in this manner. Each servo sector has two side walls that are each respectively modulated in two different ways. Hence, a readback signal from a given servo sector contains components of each of the two different modulations, even in case of “DC” erase initiation. Therefore, the just-described modulated servo sectors eliminate servowriting. Moreover, data signals are read without filtering the modulation, because data sector sidewalls are not modulated.

Abstract: A method of forming a discrete track recording pattern on a soft magnetic underlayer of a perpendicular magnetic recording disk. In one embodiment, the soft magnetic underlayer is continuous throughout the discrete track recording pattern.

Abstract: A head for use in a drive includes a heating element capable of generating heat sufficient to cause the head to have a shape that is similar or identical to the shape that the head has when performing an operation (e.g. writing) on a recording medium in the drive. The heating element is activated when the operation is not being performed. Hence, a head generates the same amount (or similar amount) of heat and is therefore at the same temperature (also called “operating temperature”), regardless of whether or not an operation (such as writing) is being performed. Therefore, the head maintains a fixed shape or has a shape that varies minimally, within a predetermined range around the fixed shape, that in turn results in maintaining fly height (distance between the head and the recording medium). The heating element may be implemented to use loss mechanisms inherent in a write transducer, e.g. by providing a center tap to the write transducer.

Abstract: An apparatus and method for balancing a disk are described. A balance ring may be a circular band for placement along the inner diameter of a disk. On the outer diameter of the balance ring, one or more clamp structures may extend outward to attach the balance ring to the inner diameter of a disk. The inner diameter of the balance ring may have a number of protuberances that, when trimmed, establish a new rotational center of the disk/balance ring coincident with the mass center. The disk and balancing ring may be mounted on a disk balancing system to determine a mass center and trim the protuberances, accordingly, to establish adjust the rotational center of the disk/balance ring to be coincident with the mass center. The protuberances may be trimmed using, for example, laser energy.

Abstract: A magnetic recording medium includes a substrate, an underlayer, a lower magnetic layer formed on the underlayer, an intermediate layer, and an upper magnetic layer formed on the intermediate layer. The intermediate layer is typically Ru, and promotes anti ferromagnetic coupling between the upper and lower magnetic layers. The upper and lower magnetic layers are typically Co alloys. The lower magnetic layer has a high saturation magnetization Ms to promote high exchange coupling between the upper and lower magnetic layers. The dynamic coercivity of the lower magnetic layer is lower than the exchange field to ensure rapid switching of the lower magnetic layer.