Abstract: The present invention relates to a radiation sensitive photoresist composition. The composition comprises a polymer comprising at least two monomers. The first monomer has an acid cleavable tertiary ester group. The second monomer is an acidic monomer. The acid cleavable ester group of the polymer has a surprisingly low activation energy which results in improved resist images in lithographic processes.

Abstract: A method is provided for planarization of structures which minimizes step heights, reduces process steps, improves cleanliness, and provides increased ease of debond. Structures are placed with working surfaces facing down onto an adhesive layer such that structures remain fixed during heating. A bi-layer encapsulating film is used to achieve planarization. A carrier is bi-laminated with a thermoplastic film layer followed by a chemically inert protective polymer film layer that can withstand etch and cleaning processes. The thermoplastic layer is laminated on top of the carrier; the polymer layer is laminated on top of the joined thermoplastic layer and carrier. The carrier with bi-layer film is then placed onto the backside of the structures to resist chemical attack from the front side during photostrip and enable planarization. When heat is applied, the bi-layer encapsulating film melts and pushes the polymer layer into the gaps between structures thereby achieving complete planarization.

Abstract: The present invention provides a magnetic disk device which firmly fixes the yokes of a rotary actuator between a base and a cover. The yoke can be made compact and the movable range of the rotary actuator can be wide. An attaching screw attaches a first yoke to a base and fixing screws passing through the second yoke and the first yoke from a cover are screwed to the base.

Abstract: A clamping device for clamping disks uses a flexible lock member, a hub, and a cap. The hub is mounted to a spindle, which defines a rotational axis for the hub. The upper portion of the hub has a recess including a guide in which the lock member is axially introduced. A clamping effect of the lock member in the recess is preferably achieved by selecting outer diameter of the lower portion of the lock member greater than the diameter of the cylindrical recess. The hub has a disk seating surface proximate to the base of the upper portion. The lock member is a unitary cap-shaped member made of flexible material, and preferably includes a plurality of axial fingers extending the disk-seating surface. The fingers are preferably a lower and an upper portion. The lower portion comprises an outer stiffening area forming a greater diameter than the upper portion.

Abstract: A hard disk drive has an enclosure with disk construction members and is characterized by covering the enclosure with an electrically conductive sheet. The electrically conductive sheet protects the drive regardless of which direction an ESD charge is applied. The electrically conductive sheet does not permit ESD to pass through the disk construction members stored in the enclosure. Therefore, it is possible to form a structure in which a GMR head or the like in an enclosure is not damaged due to ESD even if the enclosure is handled by a general end user. Moreover, the present invention relates to an electrically conductive sheet for covering at least both principal planes of the enclosure of a hard disk drive constituted as described above. Other modes of the invention include at least both principal planes of an enclosure being covered by the electrically conductive sheet in such a way that both sheets on both principal planes are electrically connected.

Abstract: A disk drive which incorporates separate actuators for each recording head so as to only place required recording heads over the recording media of multiple surface hard disk drives. The reduction in recording heads that are placed over the recording media reduces drag on the rotating disk holding the recording media and thereby reduces the power consumption. Reducing the number of recording heads over the recording media also reduces damage to the recording media surfaces in the event of a physical shock to the drive since inactive transducer heads are not in a position to damage the recording media.

Abstract: A spindle design for a hard disk drive assembly constructed in accordance with the present invention includes a significantly large gap between the rotating, ferromagnetic hub with its permanent magnet rotor and the rotating sleeve of the fluid bearing journal member. The large gap may be filled with a medium, such as air, or a non-permeable material. The large gap is preferably on the order of several hundred microns. Because of the large gap, the magnetic flux leakage from the rotating hub members and sleeve into the stationary shaft at the center of the spindle is negligible. Consequently, iron loss in the shaft caused by magnetic flux leakage into the shaft is reduced to acceptable noise levels.

Abstract: A method is provided of smoothing the perturbations on a surface, in particular the surface of a magnetic head slider, the method comprising several steps. At least one air-bearing surface to be smoothed is exposed to an ion species generated from a defined source to form a beam of incident radiation. The beam has a linear axis emanating from the source and thus forms an angle of incident radiation with respect to the surface to be smoothed. The at least one surface is smoothed by exposing the surface(s) to be smoothed to the beam of incident radiation, where the angle of incident radiation is less than 90° relative to a vertical axis drawn perpendicular to the surface to be smoothed. To make a corrosion resistant magnetic head slider, the method further comprises coating the smoothed surface with a layer of amorphous carbon.

Abstract: A component has three, two-dimensional arrays that each contain three characters of its nine character, alphanumeric serial number. The first three characters of the serial number must be constant for all parts of this type. As a result, the serial number can be divided among the arrays by using the first character as the first digit in the first array, the second character as the first digit in the second array, and the third character as the first digit in the third array. The remaining characters of the serial number are interleaved in the arrays in the following pattern: the fourth and fifth characters are the second and third digits in the first array, the sixth and seventh characters are the second and third digits in the second array, and the eighth and ninth characters are the second and third digits in the third array.

Abstract: A lapping plate has photolithographically defined patterns that are electroplated to produce lands with well-defined channels. By choosing a particular geometry, the retention force is significantly reduced over prior art options, while still retaining a high land area fraction. In some versions, the material is electroplated onto sufficiently thin substrates to allow conformation to a curved vacuum chuck. This configuration provides a very large reduction in retraction force when compared to smooth, flat lapping plates. In addition, the substrate used to form the lapping plate has reduced thickness, and a vacuum chuck is used to pull the thin, flat lapping plate against it to define the curvature. This allows the lapping plate to be charged by a flat charging ring. The substrate used is typically glass and has been sputter-metallized on both sides. The resist is then patterned, leaving an exposed pattern in the metallization on both sides.

Abstract: A method for controlling write current to a write head during data write on a hard disk drive is disclosed. A direct access storage device includes a rotating storage medium in which data are magnetically written, a write head for writing data in the rotating storage medium, and a write current control circuit for changing write current-value settings to be supplied to the write head according to a predetermined elapsed time from the beginning of a write operation.

Abstract: A disk drive system and method for implementing the same. The disk drive system of the present invention includes a discoid medium which rotates about its rotation axis and stores data. An actuator includes a head for reading or writing data from or in the discoid medium as it bidirectionally rotates about its bidirectional-rotation axis. The disk drive system further includes a housing which has a predetermined width and houses the discoid medium and the actuator, wherein the rotation axis of the discoid medium and the bidirectional-rotation axis of the actuator are arranged at the center in the width direction of the housing, and wherein size of the discoid medium is smaller than that of a discoid medium corresponding to a form factor of the housing.

Abstract: A method and system for reading data from a redundant array of computer data storage media elements without having to wait for a timeout in a drive in the redundant array. If the requested data is from a drive that is temporarily in a timeout, the requested data is reconstructed using other drives in the redundant array, and the reconstructed data is sent to the requester via an array controller. When the drive holding the originally requested data comes back from the timeout and responds to the original request by transmitting the original data, the array controller ignores the original data since the request has already been fulfilled by the reconstructed data.

Abstract: A disk clamp has a data position in a recording track that is resistant to positional deviations even after temperature cycling is conducted. The distribution of data positions can be centered in the vicinity of the center position. A disk top clamp and hub are made from materials that are stable in terms of chemical properties over a temperature range in which the disk recording apparatus is used and have such a coefficient of elasticity that a clamping force required to clamp the recording disks while the disk recording apparatus is in use can be obtained from the tightening force to tighten the screws. The material of the top clamp and the hub has a thermal expansion coefficient that is close to that of the recording disk.

Abstract: A slider 3a is disposed to face a disk-like recording medium and enabled to support a read/write head. The slider 3a has an air bearing surface formed between a leading edge 10 and a trailing edge 11; side rails 20 and 21 formed on the air bearing surface almost like a U-letter so as to dispose its tip at the trailing edge side 11; a cross rail 22; and a pair of landing pads 30a and 31a formed between the tip of each of the side rails and the cross rail 20 to 22 and the trailing edge 11. One of the pair of landing pads 30a and 31a is formed as a convex surface at its side facing the rail of the landing pad 31a disposed at the outer periphery side of the disk-like recording medium while the slider is disposed so as to face the disk-like recording medium.

Abstract: A method for patterning a recording medium selectively thermally couples a recording medium and a heat source to alter a chemical composition of the recording medium. An apparatus for patterning a recording medium has a heat source for generating and directing an incident thermal wave to a recording medium so as to alter a chemical composition of the recording medium, and a controller for coordinating a mutual position of the incident thermal wave and the recording medium for inducing a direct thermal coupling between the recording medium and the heat source.

Abstract: A method and apparatus for controlling an access mechanism within a disk drive are disclosed. A servo apparatus comprises a first detection module for discretely detecting a displacement value of an access mechanism from a target position at predetermined time intervals, a first feedback module for calculating a first feedback value on the basis of the detected displacement value, a second detection module for discretely detecting a physical value, including the speed of the access mechanism, at least once at each of the predetermined time intervals, a second feedback module for calculating a second feedback value on the basis of the physical value, including the speed, and a motor driving module for driving a motor according to the first feedback value and the second feedback value.

Abstract: A head suspension assembly for a disk drive includes an actuator arm, a suspension having one end connected to the actuator arm, and flexure at the other end of the suspension for supporting a slider having a magnetic head to access and record data on a rotating magnetic disk. The suspension is manufactured from a flat sheet of resilient spring material, such a stainless steel. The side edges of the suspension are formed into longitudinal stiffeners that have aerodynamic cross-sections, so that the transverse airflow across the top and bottom of the suspension, generated by the rotating magnetic disk, is laminar and substantially free of turbulence.

Abstract: An integrated suspension for a hard disk drive is formed as a single-piece flat assembly. The design eliminates the need for mechanical reinforcement such as flange forming, and requires no additional weld processing to form the functional portion of the assembly. A partial etch process is used to reduce local thicknesses in the gimbal and hinge areas to reduce the overall stiffness of the suspension. The proximal end structure of the suspension is also built by partial etching to achieve higher natural frequencies. The suspension design also incorporates built-in load/unload features and two-sided, opposite-facing limiters to limit excessive slider displacement during the manufacturing process, loading/unloading, and non-operational shock environments.

Abstract: A disk drive has a data recording medium such as a disk, a spindle motor for rotating the disk, disk rotation speed controlling logics for supplying a spindle current to the above described spindle motor to rotate the disk at a constant speed, a head unit for accessing the disk, an actuator for moving the head unit, and head position controlling logics for driving the actuator and controlling the position of the head unit. The head position controlling logic obtains the value of the spindle current and controls the position of the head unit on the basis of the above described spindle current value by using the fact that the spindle current varies according to variations in the position of the head unit.