Abstract:
At least one modified strain region having a damage depth between 0.1 and 2 microns in a disk drive slider is created by implantation with ions, electrons or neutral atoms. The modified strain region induces a deformation of the disk drive slider. The nature and extent of this deformation is determined by the interaction between the slider and the modified strain region.
Abstract:
A rotary microactuator includes a stationary structure formed on a substrate, a movable structure, and at least a pair of wires connected to the movable structure that conduct a signal associated with the movable structure. Each wire of the pair of wires has a first end that is connected in a cantilever manner to the substrate and a second end that is connected to the movable structure. The wires each have a serpentine shape between the first end and the second end, a predetermined spring stiffness, and a predetermined electrical characteristic. The microactuator also includes a magnetic head slider that is attached to the movable structure, and at least another pair of wires conducting a signal associated with a magnetic head of the slider. Each of the another pair of wires has a first end that is connected in a cantilever manner to the substrate and a second end that is connected to the movable structure. Like the first pair of wires, each of the another pair of wires has a serpentine shape between the first end and the second end of the wire. Electronic circuitry for conditioning the electrical signals associated with the magnetic head can be fabricated as part of the substrate and be connected to one of the pair of wires. The electronic circuitry can, for example, amplify electrical drive signals associated with the magnetic head, be a recording sensor preamplifier, and/or provide ESD protection for the electrical signals associated with the magnetic head.
Abstract:
A method and apparatus for controlling a multiple-stage actuator for a disk drive which does not require an additional sensor for measuring the relative position between adjacent actuator stages. In a two-stage actuator system, a position-type secondary actuator (SA) rides piggyback on a primary actuator (PA). The repeatable runout is measured and used as a feedforward signal to the PA. If the PA is a rotary actuator, the feedforward signal is preferably arc corrected for the arc that the head transverses from the inner radius to the outer radius of the disk. Added to the feedforward signal is the moving average of the drive signal applied to the SA. Because the SA is of the position-type having a neutral position, this moving average is proportional to the time cumulative drift present in the two-stage actuator system, and forces the PA in a direction that minimizes deviation of the SA from its neutral position. This minimizes the range requirement for the SA, the main purpose of which is to reduce non-repeatable runout.
Abstract:
A magnetic recording disk drive with a magnetoresistive (MR) read sensor or head has a shock and vibration detection circuitry responsive to a thermoresistive signal contained in the signal from the head. The MR head is heated by an electrical bias current and is supported on the head carrier near the surface of the disk. External shock or vibration to the disk drive alters the spacing between the carrier and the disk, which causes fluctuations in the head temperature due to cooling of the heated head by the disk. These temperature fluctuations are reflected in the signal from the head as a thermoresistive signal comprising modulation of a baseline voltage level. The shock detection circuitry compares positive and negative excursions of this thermoresistive signal with a predetermined threshold voltage level. When the threshold is exceeded, indicating an external shock or vibration in excess of an allowable limit, writing of data is inhibited.
Abstract:
A structure for preventing Electrostatic Discharge (ESD) damage to a magnetoresistive sensor during manufacture. The structure includes a switching element that can be switched off during testing of the sensor and then switched back on to provide ESD shunting to the sensor. The switch can be a thermally activated mechanical relay built onto the slider. The switch could also be a programmable resistor that includes a solid electrolyte sandwiched between first and second electrodes. One of the electrodes functions as an anode. When voltage is applied in a first direction an ion bridge forms across through the electrolyte across electrodes making the resistor conductive. When a voltage is applied in a second direction, the ion bridge recedes and the programmable resistor becomes essentially non-conductive.
Abstract:
A structure for preventing Electrostatic Discharge (LSD) damage to a magnetoresistive sensor during manufacture. The structure includes a switching element that can be switched off during testing of the sensor and then switched back on to provide ESD shunting to the sensor. The switch can be a thermally activated mechanical relay built onto the slider. The switch could also be a programmable resistor that includes to solid electrolyte sandwiched between first and second electrodes. One of the electrodes functions as an anode. When voltage is applied in a first direction an ion bridge forms across through the electrolyte across electrodes making the resistor conductive. When a voltage is applied in a second direction, the ion bridge recedes and the programmable resistor becomes essentially non-conductive.
Abstract:
To smooth silicon sliders that have been parted from each other on a wafer by DRIE, an isotropic etch using fluorine either in a gas or in an aqueous solution is performed prior to separating the individual sliders from the wafer.
Abstract:
A method for manufacturing thin-film magnetic head sliders is disclosed. Initially, an elastic layer, which may be made of poly-dimethyl siloxane (PDMS), is spun on a wafer and is thermally cured. Then, a resist layer is spun on the elastic layer. Both the resist layer and the elastic layer are subsequently peeled off together from the wafer. Next, the peeled resist layer/elastic layer is applied onto a group of magnetic heads with the resist layer in direct contact with the magnetic heads. Finally, the elastic layer is peeled off from the resist layer such that the resist layer remains attaching to the magnetic heads.
Abstract:
A lapping monitor for monitoring the lapping of a lapping surface of a body having at least one transducer which has a height that has to be lapped. The lapping monitor has a lap unit for lapping the lapping surface, at least one lapping indicator mounted close to the transducer to indicate the height of the transducer and a control block in the body at a certain distance from the lapping indicator or indicators. It is also possible to use a property of the transducers themselves, e.g., their resistance, to indicate their height. The control block receives indication of the height of the transducers being lapped from the lapping indicators or from the transducers via an electrical connection. The control block is further equipped with test contacts for establishing an external connection. The lapping monitor is particularly well-suited for performing 4-point resistance tests of the lapping indicators or transducers and can be effectively employed in lapping rows of magnetoresistive transducers such as MR or GMR heads to accurate heights.
Abstract:
A contact recording disk file uses an integrated head-suspension assembly having a head carrier with a dual-layer wear pad for contacting the disk during read and write operations. The outer wear layer of the pad is relatively soft and wear prone compared to a harder and more wear-resistant inner layer. The outer wear layer wears away at a relatively rapid rate during initial wear-in of the head carrier. In this manner the head pole pieces, which extend into the wear pad, are rapidly put into contact with the disk, thereby compensating for initial misalignment of the wear pad with the surface of the disk. The inner wear layer then provides wear resistance over the life of the disk file. In the preferred embodiment, both the outer and inner wear layers are formed of essentially amorphous carbon doped with different amounts of hydrogen.