Abstract: The disclosure is directed to a method for identifying and classifying data surface defects on the disks of a rigid disk data storage device. By partitioning each surface into cells and sub-sampling every Nth track, the number and location of defects can be determined. The number of stored defects is then examined to determine whether clusters of contiguous cells exist wherein defect totals exceed a predetermined threshold number. This enables the location of clusters on multiple surfaces to be examined for axial alignment, radial alignment or random occurrence as an indication of the source of damage. To obtain further verification of the data surface condition, the location of a defect cluster can be scanned using a utility that evaluates each track within the defect cluster or area.

Abstract: A disk drive data security system provides for inactivating the disk drive by landing and stopping the transducer heads on the highly polished disk data surface causing adhesion or stiction between head and disk that cannot be overcome by starting the spindle motor that rotates the disks. To provide maximum resistance to starting torque, the heads are landed near the outer diameter of the highly polished disk data storage surface portion. Instead of avoiding adhesion, the maximum stiction is sought to prevent disk drive operation in those environments requiring a high level of security such as extremely sensitive data or portable computers containing sensitive data which are stolen and beyond the possession and control of the individuals entitled to use the data. The disablement of the drives may be invoked by the occurrence of a predetermined number of successive unsuccessful attempts to enter a password that facilitates access to the data stored on the drive.

Abstract: A direct chip attach to heatsink structure is shown and described which implements rework when the chip must be removed and replaced. A laminated heatsink includes a metal heatsink with a foil layer adhered to the chip attachment surface with the assembly secured to a carrier at a cutout opening therein that defines the chip attach site. The adhesive, either a dry film adhesive or a pressure sensitive adhesive, secures foil layer to heatsink and provides the interface of separation when a chip must be removed and replaced. By peeling the foil away from the heatsink, the foil, chip and non-reworkable die attach adhesive are removed as a unit, leaving no chip attach adhesive residue at the attachment site to be scraped or abraded away. The replacement chip can be installed either by directly installing with new die attach adhesive or by first restoring the foil layer prior to chip installation.

Abstract: A semiconductor package includes a circuit chip which presents electrical contacts configured and aligned for attachment to corresponding contacts on a supporting substrate. The semiconductor package further includes an interposer with upper surface contacts aligned with the circuit chip contacts and lower surface contacts aligned with the corresponding contacts on the supporting substrate. The interposer includes a series of ground plane layers which are capacitively coupled to the conductors that connect the upper surface contacts to the lower surface contacts. The ground plane layers closest to the circuit chip have plates therebetween and electrically separated therefrom which are connected to the power input supply lines to form decoupling capacitances. The ground plane layers more remote from the circuit chip have, therebetween and electrically separated therefrom, conductive flange portions attached to individual signal lines to form a low pass feed through filter for each signal line.

Abstract: A data storage disk drive array is synchronized using drives wherein each has an onboard oscillator assembly which is connected either for independent operation of each drive or synchronization of all or any selected drives of the array using a common or slave sync line that can supply an index signal to all or any portion of the drives of the array and is capable of using the oscillator assembly of any drive in the synchronized array as the source of the common precision index signal. The system can also be partitioned in subarrays with synchronization of the entire system, of individual subarrays or any mix of subarray combinations while retaining the capability for any drive of the system to function independent of the synchronization of any group of drives within the system.

Abstract: Fine pitch area array packaging is achieved using a via-in-pad design within the area array attach portion of a printed circuit board (PCB). The limitation of the design is the wicking action, whereby solder applied to the capture pad contact surface is depleted by capillary action into the via hole when reflowed, causing insufficient solder to be present at the contact surface to effect reliable and repeatable electrical connections. In one implementation, an initial application of solder is applied to plug the via hole with a material having a higher final melting temperature than eutectic solder, thereby providing a stable plug. This plug is formed by the initial solder application that may be either a eutectic solder containing a third metal that forms intermetallic compounds, when reflowed, that elevate the liquidus temperature or a solder having a different formulation with an inherent higher melting temperature.

Abstract: A flex cable pad on pad terminal structure is shown having raised connector pads formed using a rigid stiffener with raised features or bumps formed integral with the stiffener; aligned with the connector pad surfaces; and laminated to the flex cable surface opposite the surface presenting the exposed connector pad surfaces, to create raised contact pads that are not subject to relaxation over time when subjected to high contact normal forces. The use of a metal stiffener which has been coined to produce the raised features aligned with the contact pad locations and lamination using a film or layer of thermocuring adhesive affords an economical process and assembly technique that also effects hot deformation of the flex cable at the contact pad locations.

Abstract: A cooling system for a host device affords enhanced reliability using multiple blower units mounted in parallel between a low pressure plenum and a high pressure plenum and a control system that senses when a blower unit is failing or has failed and responds by shutting down the failed unit and increasing the speed of the remaining blowers to maintain the air flow volume delivered to the cooling path. To maintain the integrity of the cooling air path while affording continuous operation of the host device, a spring biased closure door seals the access opening through which the blower is mounted when a blower unit is removed and displaced by the blower unit to an inoperative position against the biasing force of the spring when the blower unit is installed or replaced. To prevent recirculation through a vacated blower unit mounting space, a one way air flow device, in the form of a shutter assembly including plural pivoting louvers or vanes is mounted at the exhaust location of each blower.

Abstract: A multiple supply voltage peripheral component interconnect (PCI) connector is disclosed which replaces connectors that are keyed for a specific signaling voltage. A single connector receives all current types of PCI keyed card edge connectors and supplies the correct signaling voltage thereto. The type of PCI card is identified and the appropriate signaling voltage is switched to the signaling power input (Vio) using industry standard conditions at selected pin locations rather than using unique keying of cards and connectors to assure a match between the signaling voltage required by the card and the signaling voltage supplied at the connector. As shown, detection and control circuitry senses the presence of grounded or open conditions at selected pin locations indicative of the type card present in the connector and switches the signaling power supply to the correct voltage source.

Abstract: A printed circuit connector terminal pad coating technique is disclosed which functions as a single universal pad surface which supports multiple electrical connection practices including wirebonding, soldering, and wear resistant, pad on pad mechanical connection. The tri-plate surface treatment includes an initial diffusion resistant coating of nickel; an intermediate layer of hard, wear resistant noble or semi-noble metal that provides pad on pad connector reliability and affords a metallurgically stable solder joints and wirebond interfaces; and a final coating of soft gold. The intermediate layer may be pure palladium having a nominal thickness of 35 microinches or a layer of gold, hardened by cobalt, nickel, iron or a combination of these dopants to effect a hardness of 200 to 250 (Knoop scale). The use of a common surface treatment for the multiple attachment processes is implemented with a single masking step, rather than a sequence of selective masking, plating and stripping operations.

Abstract: A hot docking mechanism enables a PCI type card with an edge connector to be inserted into an enclosure and docked in a card socket on the motherboard without operator access to the enclosure interior. A card holder carries the card and is supported on a card guide for sliding motion into the enclosure to a position at which the edge connector is aligned with the socket secured to the device motherboard. A camming assembly includes a sliding cam operable from outside the enclosure to convert horizontal sliding motion to vertical motion of the card into and out of the socket. The card holder is cammed out of the sliding support of the card guide during docking and returned to sliding support when the camming mechanism undocks the card. The card guide also comprises a rail that guides the card holder within the enclosure during both card docked and card undocked conditions.

Abstract: A direct chip attach to heatsink structure is shown and described which implements rework when the chip must be removed and replaced. A laminated heatsink includes a metal heatsink with a foil layer adhered to the chip attachment surface with the assembly secured to a carrier at a cutout opening therein that defines the chip attach site. The adhesive, either a dry film adhesive or a pressure sensitive adhesive, secures foil layer to heatsink and provides the interface of separation when a chip must be removed and replaced. By peeling the foil away from the heatsink, the foil, chip and non-reworkable die attach adhesive are removed as a unit, leaving no chip attach adhesive residue at the attachment site to be scraped or abraded away. The replacement chip can be installed either by directly installing with new die attach adhesive or by first restoring the foil layer prior to chip installation.

Abstract: A rotating magnetic storage device is shown wherein the transducer and media are separated during operation by a thin film of low viscosity liquid lubricant that is recirculated from a reservoir within the head-media enclosure. Lubricant recirculation can be effected by capillary action using a wick, mechanical pumping and metering or distillation techniques. As compared to devices using air bearing separation, the transducer carrying slider has very small bearing surfaces which may be in the form of narrow rails or small depending foot elements. This enables fly heights of 2 microinches using a film of one micron thickness.

Abstract: A high density data storage tape drive includes an actuator which carries the read/write head, is driven by a voice coil and enables translational movement of the head in a direction transverse to the direction of tape travel as the tape is scrolled by the head. This permits the head to follow a servo track and position the head with a data track without skewing the transducer gap with respect to the data track. Since the actuator moving portion has stiffness and mass, it is subject to vibration at resonant frequencies, with the first or lowest resonant frequency commonly occurring within the operating bandwidth of the device. To attenuate the vibration amplitude during resonance, a damping device is provided to enable greater use of the servo system potential for track and bit density enhancement, rather than diminishing storage density performance to accommodate a worst case condition.

Abstract: Photographic films, such as X-rays, are duplicated by exposing an unexposed copy film in the presence of an intimately overlying developed film to be copied. The device exposure station has a pair of rollers at the entrance to drive the film pair and to remove from the interface between the films trapped air that would compromise the accuracy of resolution and contrast of the copy. Another pair of rollers at the outlet from the exposure station cooperates with the roller pair at the exposure station inlet to maintain the film pair within the exposure station in a planar orientation to avoid curvature which is another principal source of compromised resolution in film copies.

Abstract: A magnetic fluid seal is provided by mounting an annular, axially polarized magnet mounted on the device base member and an annular ring pole piece with an inner diameter that cooperates with an outer diameter surface of the hub assembly to form a fluid gap that is radially outward and within the axial extent of the spindle bearings. The secondary gap of the seal assembly is within the bearing assembly sealed volume while the principal sealing gap is within the hub assembly to confine any debris or aerosols resulting from high rotational velocity or shock to be contained in proximity to the flux fields that can recapture any magnetic material. The assembly also inherently presents an effective conductive path to provide enhanced grounding of the rotating assembly through the magnetic fluid in the second gap which is not subject to impairment caused by bonding materials.

Abstract: A starting sequence is provided for a rotating disk data storage device by providing a low level sensing current to the spindle motor which is able to initiate rotation of the disk spindle assembly when, absent stiction between head and confronting disk surface, it is only necessary to overcome disk assembly inertia and head drag. A sensing device is provided to sense a back electromotive force (EMF) in the spindle motor windings which indicates the start of disk rotation when any stiction condition has been terminated. A sequence of alternating current pulse bursts are applied to the actuator motor to impart a dithering action to the heads which induces axial vibration of the disks to break the stiction between the heads and confronting disk surfaces.

Abstract: A data storage disk drive array is synchronized using drives wherein each has an onboard oscillator assembly which is connected either for independent operation of each drive or synchronization of all or any selected drives of the array using a common or slave sync line that can supply an index signal to all or any portion of the drives of the array and is capable of using the oscillator assembly of any drive in the synchronized array as the source of the common precision index signal. The system can also be partitioned in subarrays with synchronization of the entire system, of individual subarrays or any mix of subarray combinations while retaining the capability for any drive of the system to function independent of the synchronization of any group of drives within the system.

Abstract: A clamp for securing one or more data storage disks to a hub is formed as a slightly frusto-conical shaped annulus of resilient material with inwardly and upwardly extending lobes that are displaced radially outward during installation about a hub. Clamping force is derived from the compression of the lobes which are captured by the hub and the twisting of the annulus from the frusto-conical configuration to a substantially radial orientation. The clamp is formed of a material that is softer than the disk to cause the clamp to be compliant and conform to the disk irregularities and thereby avoid compromising disk flatness. The clamp component material composition is also modified to achieve a coefficient of linear expansion that is identical to the disk. The outer periphery of the clamp presents an interrupted flange that permits a tool to engage the clamp, perform the assembly about the hub and be disengaged using automated equipment.

Abstract: The linear range of a servo system for a magnetic storage device using a compared amplitude burst servo pattern and a magneto resistive (MR) sensor is enhanced by reversing the bias current. With the servo bursts displaced to opposite sides of the track centerline, the bias current is reversed to have the read function occur when the sensor is electrically biased to present the higher gain, more uniform end portion of the readback sensitivity profile at the side of the track at which the burst is written. Reversing the bias current in an MR sensor causes the readback sensitivity profile to be mirrored about the sensor center enabling the more uniform portion of the sensor response to be used to sense the respective servo pattern bursts. Where differences occur in MR gain between bias current directions, normalization or other correction is provided to compensate for variation in sensor gain.