931results about "Protective measures for recording heads" patented technology

A hard disk drive having a housing with a base and a cover connected to each other, a spindle motor connected to the base, a disk mounted on the spindle motor and rotating with respect to the base, and an actuator rotatably connected to the base and supporting a slider with a magnetic head mounted on a front end thereof. The magnetic head writes and / or reads data to and / or from the disk. The hard disk drive also has a blade protruding from a surface of the base and / or a portion of the cover facing the disk. The blade guides an air flow caused by rotation of the disk toward an outer edge of the disk.

A magnetic disk including a substrate, a recording track section which is made of a magnetic member for recording and reproducing information magnetically and is provided on the substrate, and a guard band member which is provided between the recording track sections adjacent to each other so that they are substantially continued in a track direction and is harder than the magnetic member and is made of a non-magnetic material. Moreover, the magnetic member is not provided or magnetic members with a different thickness from the magnetic member forming the recording track section is provided on a lower area of the guard band member.

An enchance recording head design provides conduction and mechanical restraint control in order to minimize the pole tip protrusion and the head temperature resulting from the thermal heating of the magnetic recording head during operation. In one embodiment, the recording head includes a hybrid diffuser formed within an insulation layer, at a predetermined distance from the head write section. The hybrid diffuser is comprised of a thermal conduction layer with high thermal conductivity, such as gold or copper, and a mechanical restraint layer having near zero CTE, such as a 60-80% face-centered-cubic NiFe (Invar) material. The hybrid diffuser is recessed from the ABS to prevent the delamination of the hybrid diffuser due to the otherwise displacement incompatibility between the inner insulating layer and the hybrid diffuser at the ABS.

A thin film magnetic head includes a slider body having a trailing surface meeting an air-bearing surface at a trailing edge. A magnetic read and write elements are disposed along the trailing surface near the trailing edge. The magnetic write element includes write poles and a coil. A portion of a heating element is disposed in a first general plane beneath the coil and above the magnetic read element. At least one thermally-insulating layer of material having a thermal conductivity of less than about 2.0 W / m-K extends in a second general plane substantially beneath the heating element.

A disk drive includes a disk having a recording surface, a head stack assembly that includes a body portion, an actuator arm cantilevered from the body portion and a head gimbal assembly supported at the actuator arm. The head gimbal assembly includes a suspension having a first end and a second end, the first end being attached to the actuator arm, a slider coupled to the second end of the suspension, the slider comprising a transducer for reading from and writing to the recording surface. A gimbal is coupled to the second end of the suspension and to the slider. An array of diodes is attached to the suspension to protect the transducer from electrostatic discharge or electrical overstress events.

An enhanced recording head design provides thermal diffusion and thermal expansion control in order to minimize the pole tip protrusion resulting from the thermal heating of the magnetic recording head during operation. In one embodiment, the recording head a thermal restraint section formed above a write section, and is made of a 60–80% face-centered-cubic NiFe (Invar) material. According to another embodiment, the thermal restraint section is formed under the read section. According to yet another embodiment, one thermal restraint section is formed above the write section, and another thermal restraint section formed under the read section.

Embodiments in accordance with the thin film write head of the present invention have a lower pole structure, an upper pole structure, and a multilayer write gap extending from an air bearing surface between the upper and lower pole structures. In preferred embodiments, the write gap comprises at least two of: (a) a first layer covering a lower pole tip portion of the lower pole structure, (b) a second layer covering turns of a semiconductor winding, or (c) a third layer covering a winding insulation stack. In more preferred embodiments, the write gap is formed of the first, the second, and the third write gap layers. An advantage of a write head with a multilayer write gap is that it allows better control of write gap thickness. As such, loss of write gap thickness can be compensated for by deposition of the second write gap layers, or by deposition of the third write gap layer. Some embodiments have one or more additional advantages in providing increased corrosion prevention, improving the integrity of conductor insulation, and / or improving the top pole magnetic material characteristics.

A disk drive is disclosed comprising a disk and a head actuated over the disk. The head comprising a first head terminal and a second head terminal. The disk drive further comprises an electrostatic discharge (ESD) protection circuit comprising a first depletion mode metal oxide semiconductor field effect transistor (MOSFET) and a second depletion mode MOSFET. A first transistor terminal of the depletion mode MOSFETs are coupled to respective head terminals, and a second transistor terminal of the depletion mode MOSFETs are coupled to ground. The gate terminals of the first and second depletion mode MOSFETs are biased to turn on the depletion mode MOSFETs while the disk drive is powered down, thereby grounding the first and second head terminals to protect the head from ESD.

A disk drive is disclosed comprising a disk and a head actuated over the disk. The head comprising a first head terminal and a second head terminal. The disk drive further comprises an electrostatic discharge (ESD) protection circuit comprising a first depletion mode metal oxide semiconductor field effect transistor (MOSFET) comprising a gate terminal and a first and second transistor terminals. The first transistor terminal of the first depletion mode MOSFET is coupled to the first head terminal, and the second transistor terminal of the first depletion mode MOSFET is coupled to the second head terminal. The gate terminal is biased to turn on the first depletion mode MOSFET while the disk drive is powered down, thereby shorting the first and second head terminals to protect the head from ESD.

An inductive write head structure incorporating a high moment film in conjunction with at least one pole (e.g., the bottom pole) for use with magnetic storage media and a process for producing the same in which a lift-off photoresist mask is used prior to the deposition of the high moment sputtered film. Following the lift-off process, the high moment film remains on the bottom pole (“P1”) pedestal (in the case of a PDZT type write head) or on the P1 itself (in the case of a Stitched Pole write head). The edge of the lift-off sputtered film is then covered by cured photoresist insulation which is placed at a distance away from the air bearing surface (“ABS”). The coverage of insulation at the edge of the sputtered film is desirable in order to avoid forming a topographic step which may have undesired consequences in the subsequent top pole formation processes.

A filled-gap magnetic recording head is provided comprising a flat or cylindrical contour head having a row of magnetic transducers in a gap region disposed between a rowbar substrate and a closure. The gap region is intentionally recessed to have a predetermined recess profile below a tape support surface. An electrical insulation layer is deposited on the tape support surface and on the recess profile of the gap region. The insulation layer prevents electrical shorting between the magnetic transducers and other conductive elements in the gap due to accumulations of conductive debris from the magnetic recording tape. A method of making the filled-gap magnetic recording head by intentionally recessing the gap region, cleaning the recessed profile and depositing an insulator layer is provided.

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. When using a center tapped write transducer, currents in phase with one another are provided to perform a write operation. When not performing the write operation, the same currents are provided, but out of phase.

A head is fabricated using photolithography, and the head is purposely powered up during a material removal process, such as lapping, so that the head's expansion (that would be formed on being powered up during normal usage in a drive) is planarized. Specifically, the head is energized in a manner identical (or similar) to energization of circuitry in the head during normal operation in a drive, even though fabrication of the head has not yet been completed. When energized, a shape that the head would have during normal operation is replicated (or approximated). Therefore, the head's shape includes a expansion of the pole tip region, although the head is only partially fabricated. Thereafter, a portion of the head in the expansion is partially or completely removed, by lapping while energized. The depth of material removal from the head is monitored e.g. by a controller sensitive to a change in electrical characteristic of a device (such as a resistor) that is normally fabricated during photolithography of the head.

A disk drive is disclosed comprising a spindle motor for rotating a disk and a voice coil motor (VCM) for actuating a head over the disk. The spindle motor comprises a plurality of windings, and the VCM comprises a voice coil. If the current flowing from a supply voltage exceeds a threshold, the windings are disconnected from the supply voltage, the voice coil is disconnected from the supply voltage, and the first and second ends of the voice coil are connected to ground.

A disk drive includes a disk drive base, a disk, and a head stack assembly rotatably coupled to the base adjacent the disk surface of the disk. The disk drive includes an airflow channeling enclosure. The enclosure includes an airflow inlet disposed downstream of the head stack assembly and configured to receive the disk rotation induced airflow therethrough. The enclosure further includes an airflow channel extending along the disk surface from the airflow inlet. The enclosure further includes an outer wall extending along the disk surface from the airflow inlet and defining the airflow channel radially interior to the outer wall. The enclosure further includes an airflow outlet disposed upstream of the head stack assembly extending from the outer wall and the channel opposite the airflow inlet for modifying the disk rotation induced airflow passing from the channel.

A method of connecting a plurality of probe pins to a plurality of first external connection pads, which are provided on a head gimbal assembly and are electrically connected to a plurality of terminal electrodes of a write magnetic head element, respectively, and a plurality of second external connection pads, which are provided on the head gimbal assembly and are electrically connected to a plurality of terminal electrodes of a read magnetic head element. In the connection method, an approach direction of the probe pins to the first external connection pads and an approach direction of the probe pins to the second external connection pads are made different from each other.

Method and apparatus for predicting future failure of a disc drive head from degradation in a head readback response characteristic, such as electrical resistance, readback signal amplitude, asymmetry or nonlinearity. During manufacturing, the disc drive determines and store a baseline level for a selected readback response characteristic of the head indicative of head performance as data are read back from a disc. During subsequent data processing use, the disc drive subsequently periodically determines a subsequent level for the readback response characteristic of the head. The possibility of a future failure of the drive is next predicted in relation to a difference between the baseline level and the subsequent level for the readback response characteristic of the head. An indication of the possibility of the future failure is provided to allow a host device to reallocate data stored on the disc before the failure of the head.

Techniques for preventing electrostatic discharge (ESD) and circuit noise are provided. More particularly, the present invention provides a method to prevent ESD damage during the assembly of computer disk commonly called a hard disk for memory applications. The coating mainly involves a ion-deposition process. Merely by way of example, the present invention is implemented by using filtered cathodic vacuum arc (FCVA) with a dissipative crystalline and / or amorphous carbon base thin film coating on a flexible circuit to drain the potential electrostatic charges during circuit assembly and interconnect processes, yet it would be recognized that the invention has a much broader range of applicability on any electronic apparatus that is susceptible to electrostatic damage and static noise.

There is disclosed a magnetic recording medium in which a seed layer, under layer, intermediate layer, first magnetic layer, nonmagnetic layer, second magnetic layer, protective layer, and lubricant layer are successively laminated on a glass substrate, the nonmagnetic layer is constituted of an alloy containing Cr and C, and the magnetic layer is constituted of an alloy containing Co and Pt. The under layer includes at least the seed layer for finely dividing the crystal particles of the magnetic layer, the seed layer includes at least two or more layers of nonmagnetic films, and the intermediate layer formed of the material different from that of the nonmagnetic film is interposed between the nonmagnetic films. In measurement of the thermal stability of the magnetic recording medium, a head is used, the head includes a read / write element, and a write track width is twice or more as large as a read track width in the head.

A disk drive includes an enclosure, a rotatable disk and an actuator arm, and also includes a plurality of arcuate channels. Airflow is created within the enclosure when the disk rotates. The plurality of arcuate channels facing the disk to decrease the turbulence of the airflow with respect to the actuator arm. The arcuate channels are formed on at least one portion of the enclosure.

In a magnetic read / write assembly, the magnetoresistive (G)MR sensor element is protected against electrostatic discharge (ESD) and electrical overstress (EOS) by using a low resistance bypass. The low resistance bypass shunts current away from the magnetoresistive sensor element during an ESD or EOS event. This low resistance bypass is made up of two or more resistors connected in series, and positioned in parallel to the magnetoresistive sensor element. The use of electronic circuitry to temporarily disable this low resistance bypass allows the magnetoresistive sensor element to be tested during manufacturing. The low resistance bypass is removed prior to placing the (G)MR head into operation in the magnetic storage system or at any other desired step in the manufacturing process.

An object of the present invention is to prevent a spacing between a magnetic head and a writing medium at low temperature from increasing to cause a writing / reading error, and to prevent the magnetic head element protruded by a temperature increase from colliding with small protrusions on a magnetic disk surface, and to prevent damage on the element, and to prevent the occurrence of thermal asperity. In order to attain the object, a magnetic head slider is provided, which includes a magnetic head element supported on a rotating magnetic disk via a gap to write or read information on the magnetic disk, and a heat source for heating the magnetic head element. A magnetic disk device is further provided, which includes a magnetic head slider.

A method in one embodiment includes applying an organic coating to a magnetic head for reducing exposure of the head to oxidation promoting materials; and storing the magnetic head. A method in another embodiment includes applying an organic coating to a magnetic head for reducing exposure of the head to oxidation promoting materials, the organic coating being applied to the magnetic head after the head is installed in the magnetic storage system. Another method includes fabricating a tape having an applicator portion for applying an organic coating to a magnetic head for reducing exposure of the head to oxidation promoting materials; applying the organic coating to the applicator portion of the tape; and applying a lubricant to a data portion of the tape. A method in another embodiment includes fabricating a tape having a data portion, and a cleaning portion for removing an organic coating from a magnetic head.

The present invention provides an improved magnetic disk drive manufacturing method that is to be employed during an interval between magnetic disk drive assembly completion and shipment. In one embodiment, a magnetic disk drive has an interface connector. The magnetic disk drive is retained by a shock absorber so that the interface connector is exposed. A testing side connector mounted on a base plate is connected to the interface connector of the magnetic disk drive that is retained by the shock absorber. A host apparatus transfers a test / adjustment program to the magnetic disk drive via the testing side connector. The magnetic disk drive executes the test / adjustment program.

A system includes a magnetic device for writing to and reading from a magnetic medium and a sensor disposed adjacent to the magnetic device and proximate to the magnetic medium. The sensor generates signals related to thermal variations in the sensor caused by changes in a distance between the magnetic device and the magnetic medium.

A method of assembling a disk drive includes providing a disk drive base. The method further includes providing a disk drive cover having an inside face and an outside face. The inside face is coated with an electrically insulative material. The method further includes contacting, continuously during a period, the outside face with an electrically conductive grounding element that is part of an assembly fixture that is not part of the disk drive being assembled. The method further includes attaching the disk drive cover to the disk drive base during the period.

Methods, circuits, and systems for processing a preamble field in a read channel (e.g., in a magnetic storage device such as a hard disk drive). The methods generally include the steps of (a) reading the preamble field, wherein the preamble field comprises a repetitive bit pattern having a logical transition every x bit periods, where x is an integer of at least 3 when d is 0 or 1, or where x is an integer of at least d+2 when d is greater than 1, and (b) processing the repetitive bit pattern. The methods may further relate to processing the preamble for synchronization with the read channel and / or for measuring the fly height of a read / write head. The invention also relates to methods of enabling read channel synchronization and / or fly height measurement. The circuitry for fly height measurement generally includes (a) reading logic configured to read a preamble field from a read channel, wherein the preamble field comprises a repetitive bit pattern, (b) determination logic configured to determine a characteristic of the repetitive bit pattern, and (c) correlation logic configured to correlate the characteristic to the fly height. The systems generally comprise those that include a circuit embodying one or more of the inventive concepts disclosed herein. The present invention advantageously provides improved resolution of signals resulting from the preamble fields and of harmonics of said signals, and enables fly height measurement and improved channel synchronization without consuming dedicated tracks, platters, etc. on a magnetic recording medium.

Embodiments of the invention improve the power consumption and response speed of a heater for the gap flying height (hg) adjustment, to minimize an influence that the heater has on a life of a read element, and to provide a heater having resistance lines reduced in breaking and ensuring higher reliability. In one embodiment, a read / write element is formed near an air bearing surface (ABS) on a slider, and the circumference of the read / write element is filled with alumina. The read / write element includes an upper magnetic pole piece, a lower magnetic pole piece, a coil, and a resist filling around the coil, and a read element (MR) for performing reading, and an upper shield and lower shield for protecting the read element from an external magnetic field. A heater for adjusting the flying height is provided between the slider and the read / write element but near the read / write element. A temperature gradient relaxing material having a thermal conductivity higher than that of the heater and that of a material (alumina) filling around the heater is formed near the heater.