Abstract: A spindle motor for a disk drive includes a shaft, a stator, a hub, an upper bearing, a lower bearing, means for defining a gap and an ionization source. The stator is concentrically positioned about the shaft. The upper and lower bearings rotatably maintain the hub relative to the shaft and each include a plurality of balls, each ball made from a high resistivity material. The ionization source ionizes air in the gap for allowing static electric charge to dissipate through a conductive path provided by the ionized air in the gap.

Abstract: A magnetic disk drive with a head stack assembly having a pass-through flex circuit cable is disclosed. The pass-through flex circuit cable is mounted to a side of the head stack assembly to extend straight forward in an initial unfolded position during handling and assembly and to then be folded over into a final position in a substantially opposite direction and with a desired flex cable trajectory. The head stack assembly includes a post, preferably of rectangular profile, that is integrally formed and spaced away from the actuator body. An outer surface of the post defines the flex cable trajectory. The flex circuit cable, located in the space between the actuator body and the post, extends past the post in the initial position and wraps around the post in the final folded over position. The flex circuit cable is secured to the post in the final folded over position, preferably with a flex clip that removably mounts to the post.

Abstract: The invention is a method of calibrating a position error signal (PES) to overcome the problem of a measured displacement or PES that varies as a non-linear function of real displacement when the read transducer is positioned to either side of a null position where the PES equals zero. The PES is notably nonlinear while reading servo burst information with a Magneto-Resistive (MR) head which has nonlinear magnetic characteristics. The method uniquely calibrates the measured PES to provide a corrected PES without requiring any knowledge of the actual displacement from the position where the measured PES equals 0. The calibration according to this method, therefore, may be performed at anytime without need for real displacement information from a servowriter or any sort of special calibration track.

Abstract: A method and apparatus for texturing a landing zone on a substrate of a magnetic disk to reduce stiction between a magnetic transducer head and the disk is provided. The method includes projecting discrete pressurized fluid droplets to impact a substrate surface of the substrate with sufficient momentum to form cavities in a selected annular area of the substrate surface, the selected annular area with cavities therein being of sufficient width to provide a textured landing zone for the magnetic transducer head. A magnetic disk for storing data readable by a transducer head is also provided. The disk includes a rigid substrate. A textured landing zone is provided on the disk for engaging the transducer head. The textured landing zone is formed by the steps of directing a stream of discrete pressurized fluid droplets against the substrate to create roughness therein and moving the substrate and stream of droplets relative to one another in order to create an annular area of roughness.

Abstract: A hard disk drive has an intelligent interface for communicating with a host, a magnetic disk, disk side programs and host side programs, and a cache. The cache is divisible into a number of segments, and the number of segments may be varied. The cache employs a cache control structure including a cache entry table, and the hard disk drive receives commands from the host in a queue. The method comprises the steps of. (a) receiving a first command and a second command from the host; (b) determining a scan first state; (c) determining if there are any commands in the queue; (d) waiting for a first command to complete and performing a seek if there are no commands in the queue and the scan first state is false; (e) performing a scan of the cache entry table to assign the second command to a segment; and () checking if a seek is needed for the second command and if a seek is needed for the second command performing a seek for the second command after the first command has completed.

Abstract: The invention resides in a magnetic disk drive having a load beam assembly that forms a part of a head gimbal assembly and head stack assembly in a magnetic disk drive.The load beam assembly is uniquely mass balanced to prevent head slap by preventing an acceleration in the Z-direction from causing the transducer head to separate from the disk. The load beam assembly is preferably mass balanced by providing a load beam balancing member that is rigidly connected to the elongated load beam about a transverse axis of the hinge member. The balancing member can form the balancing mass or the balancing member can carry a discrete balancing mass. The balancing member may be divided into two halves that move on either side of the base portion, but is preferably comprised of a narrow, centrally located member that moves within an aperture formed in the base portion. The mass balanced load beam assembly can beneficially be manufactured from the same stainless steel sheets used to form conventional load beam assemblies.

Abstract: A method provides for waiting for a cache hit in the operation of a disk drive. The drive has an intelligent interface for communicating with a host, a magnetic disk, and a cache. The cache is divisible into a number of segments, and the cache employs a cache control structure. The drive receives a first command and a second command wherein the second command has a requested data range. The method comprises the steps of: (a) initializing a read in response to the first command to provide prefetch data to the cache in a prefetch data range wherein the prefetch data range has a first logical block address; and (b) waiting for a cache hit in response to the second command wherein the beginning of the requested data is within the prefetch data range and does not request the first logical block address.

Abstract: A disk drive has a base, a cover, a spindle motor mounted to the base, and a disk coupled to the spindle motor. A rotary actuator comprising a head stack assembly is coupled to the base by a pivot bearing assembly. The pivot bearing assembly provides a stationary member, a bearing, and a sleeve member for rotatably supporting the actuator. The pivot bearing assembly further provides an elastomeric interface between the stationary member and the actuator such that vibratory motion imparted to the head stack assembly is dampened by the elastomeric interface.

Abstract: A method is practiced in a disk drive in which a cache is divided into segments each having a segment priority. The method provides for managing the segment priority. The drive has an intelligent interface for communicating with a host, and a magnetic disk. The cache employs a cache control structure including a cache array with a cache array entry. There is a cache array entry for each one of the number of segments. The method comprises the steps of: maintaining the cache array entry wherein each cache array entry classifies a segment by a cache access type, wherein the cache access type is selected from a plurality of access types including sequential and random; and determining whether to change the scan priority of each segment based on the cache access type.

Abstract: A stationary vacuum deposition machine is used in a method for controlling the height of bumps formed in annular regions of substrates; the substrates are transported to the machine in a first condition in which each substrate is subject to a chemicapillary effect when subjected to localized thermal heating and melting. The machine includes a series of stations including an entrance station for receiving substrates into the machine, first and second predetermined stations, and a transport for operating in a cycle with each cycle including a transport phase and a stationary phase such that the transport causes all the substrates that are in the machine to be moved during the transport phase, and be temporarily held stationary during the stationary phase, such that during each stationary phase a predetermined one of the stations is occupied by one of the substrates while each of a plurality of others of the stations is occupied by a respective one of a plurality of others of the substrates.

Abstract: A magnetic disk drive includes a base which supports a head stack assembly having a coil portion, a flex circuit cable having a grounding portion, and a flex clamp. The disk drive further includes a voice coil motor (VCM) formed from the coil portion's interaction with upper and lower VCM plates that carry at least one permanent magnet. The disk drive includes a Z-shaped grounding portion which wraps around one end of the flex clamp and permits a single screw to secure that end of the flex clamp to the base and simultaneously make grounding contact with the grounding portion and an elongated protrusion extending from one of the VCM plates that is adjacent to the flex clamp to hold that end of the flex clamp against the base when the VCM plates are fastened to the base.

Abstract: A magnetic disk drive includes a base which supports a head stack assembly having a coil portion, a flex circuit cable having a grounding portion, and a flex clamp and in which a voice coil motor (VCM) is formed from the coil portion's interaction with upper and lower VCM plates that carry at least one permanent magnet. The disk drive includes a Z-shaped grounding portion which wraps around one end of the flex clamp and permits a single screw to secure that end of the flex clamp to the base and simultaneously make grounding contact with the grounding portion and an elongated protrusion extending from one of the VCM plates that is adjacent to the flex clamp to hold that end of the flex clamp against the base when the VCM plates are fastened to the base.

Abstract: A magnetic disk drive with a head stack assembly includes a body portion, a coil portion cantilevered from one side of the body portion, and an actuator arm cantilevered to the opposite side of the body portion, wherein the body portion includes a plastic inner sleeve to provide a quick, press-fit connection with a pivot bearing cartridge. The body portion further includes a non-plastic outer portion which is preferably part of an aluminum E-block having integrally formed actuator arms. The plastic inner sleeve and non-plastic outer portion preferably include a spline and a recess, respectively, that are firmly compressed together by the press-fit connection to prevent relative angular motion. The plastic inner sleeve preferably includes a flat that is aligned with the spline and recess in order to contact the pivot cartridge along the flat and thereby ensure that the press-fit forces are focused onto the spline and recess.

Abstract: A method of managing commands is provided for a disk drive having an intelligent interface for communicating with a host. The drive also has a magnetic disk, host side programs, disk side programs, and a cache wherein the cache is divisible into a number of segments. The cache employs a cache control structure including a cache entry table, a buffer counter, a block count, a host pointer and a disk pointer. The drive receives a first command and a second command with a cache access type. The method of managing commands comprises the steps of: processing the first command to assign the first command to a cache segment having a prefetch area; determining the cache access type of the second command; and if the cache access type of the second command is a skip ahead sequential access then decrementing the buffer counter and incrementing the host pointer to skip leading nonrequested data in the prefetch area for the first command.

Abstract: A method of operating a disk drive having a cache provides for adapting the amount of prefetch. The drive also has an intelligent interface for communicating with a host, and a magnetic disk. The cache is divisible into a number of segments, and employs a cache control structure including a cache array with a cache array entry. When the drive receives a first command, the method provides a step of performing a scan of the cache to assign the first command to a segment. The method further includes the step of maintaining the cache array with a cache array entry for each one of the number of segments, where each cache array entry classifies a segment by a cache access type, wherein the cache access type is selected from a plurality of access types including sequential and random. The method further includes the step of determining a limit on the amount of prefetch based on the cache access type for the first command and a cache environment variable. The limit may be a minimum prefetch or a maximum prefetch.

Abstract: A head disk assembly includes a base, a cover attached to the base and a spindle motor mounted to the base. The spindle motor includes a shaft, an inner cylindrical portion surrounding the shaft, and an outer cylindrical portion surrounding the inner cylindrical portion. The outer cylindrical portion has an annular surface and the inner cylindrical portion has a cylindrical surface which extends above the annular surface. The head disk assembly also includes a disk mounted on the spindle motor such that the disk surrounds the outer cylindrical portion; the disk includes a recording surface which is substantially co-planar with the annular surface. The head disk assembly also includes a disk clamp for clamping the disk to the spindle motor and a washer positioned between the disk clamp and the recording surface for transferring radial loads to the inner cylindrical portion of the spindle motor.

Abstract: A disk drive actuator assembly adapted for assembly in one of several configurations from a single line of modular components without a manually-supervised aligning step. The actuator improves manufacturability and inertia by introducing a common set of self-aligning modular piece parts. Each of several self-aligning modular components can be used to assemble any of several different actuator assembly designs. That is, a head-stack assembly (HSA) providing from one to six heads can be assembled using elements selected from single set of standardized modular components. The assembly process relies entirely on the self-aligning features of the standardized modular components, thereby eliminating the elaborate and error-prone manual assembly and alignment procedures known in the art.

Abstract: The invention resides in a load beam assembly forming part of a head stack assembly in a magnetic disk drive, the load beam assembly biasing a transducer head against a rotating magnetic disk. The load beam assembly normally has spring and hinge functions combined in a single "spring/hinge" portion of a load beam stamped from a stainless steel sheet. Here, however, the spring and hinge functions are uniquely separated from one another in separate spring and hinge members. The preferred load beam assembly has a base portion, a load beam, and a hinge member joining them so that the load beam pivots relative to the base portion. The load beam is further provided with a bearing surface that cooperates with a preferred spring member, one end of the spring member being fixed relative to the base portion and the other end contacting the bearing surface of the load beam.

Abstract: A disk clamp for holding a recording disk in a disk drive. The clamp is ring-shaped and includes stiffened inner and outer regions with a softened middle region located in between. The inner region is stiffened by bending the inner edge. The outer region is stiffened by involuting the outer edge back on itself A disk contact zone is included in this outer region. The clamps may be made of sheet metal, such as stainless steel.

Abstract: A disk drive includes an enclosure having a base, a spindle motor fixed to the base, a disk mounted on the spindle motor, a pivot bearing cartridge, and a head stack assembly. The pivot bearing cartridge includes a shaft fixed to the enclosure, and the head stack assembly is connected to the pivot bearing cartridge for rotation relative to the shaft. The head stack assembly includes a body portion having a bore which surrounds the pivot bearing cartridge, a plurality of actuator arms with each arm cantilevered from the body portion, and a coil portion. The coil portion is cantilevered from the body portion in an opposite direction from the plurality of arms and provides damping of vibrations induced in the head stack assembly. The coil portion includes a plastic portion having a thickness, and a coil embedded in the plastic portion. The plastic portion includes a plurality of openings where each opening extends through the entire thickness of the plastic portion.