International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Hitachi Global Storage Technologies

Timothy C O'Sullivan

Chih-Kung Lee

Karl Arthur Flechsig

Ullal Vasant Nayak

Andrew Ching Tam

Gurinder P Singh

Peter Michael Baumgart

Thao Anh Nguyen

Wing P Leung

Sylvia Lui Lee

Michael F Lee

Satya Prakash Arya

Lee K Dorius

Francis Chee-Shuen Lee

Douglas J Krajnovich

Pantelis Alexopoulos

Pantelis S Alexopoulos

Thomas R Albrecht

Moris Musa Dovek

Andrew M Homola

John S Foster

Laurence S Samuelson

Howell B Schwartz

Matthias C Krantz

Vlad J Novotny

Archibald C Munce, Jr

Michael Lee McGhee

Josef Walian

The present invention provides a non-actuatable, self-limiting wear contact pad slider and method for making the same. A protruding element surrounding the transducer is fabricated using a third etch step so that the protruding element has a height that is greater than or equal to the designed fly height of the aerodynamic lift surface minus the disk roughness.

Self-limiting wear contact pad slider and method for making the same

An apparatus and method for automatically adjusting the gram load and static attitude in a head suspension assembly comprising one or more lasers, a fiber optic switch, a measurement apparatus and a computer control means. The fiber optic switch includes a plurality of fiber optic lines which direct the output of the laser to well-defined regions on the suspensions in a disk drive. Irradiation of the suspension by the laser causes a load change which alters the static attitude change in the slider. In the method of the present invention, the initial gram load or static attitude is measured by the measurement apparatus and the control means calculates how much energy is required to cause the change needed to achieve the desired condition. Other information, such as the type of laser to be used is also specified by the control means. The laser then delivers output to the suspension through the fiber optic line having an angled end and the static attitude or gram load is remeasured to determine if additional adjustment is required.

Laser apparatus and method adjusting the gram load, static attitude and

A diverging rail edge geometry for an air bearing slider. The air bearing slider provides reduced sensitivity to skew and roll static attitude without contributing to significant increases in cost and complexity. A support structure is formed with an air bearing surface having at least one air bearing rail, pad or other structure disposes thereon. The air bearing pad or rail is formed having at least one edge diverging from the side edges of the support structure. The edges of the rails may also be curved.

Method and apparatus for providing diverging rail edge geometry for air

An apparatus and method for automatically adjusting the gram load, static attitude and the flying height of the slider in a head suspension assembly comprising one or more lasers, a fiber optic switch, a measurement apparatus and a computer control device. The fiber optic switch includes a plurality of fiber optic lines which direct the output of the laser to well-defined regions on the suspensions in a disk drive. Irradiation of the suspension by the laser causes a load change which alters the flying height, and/or a static attitude change in the slider. In the method of the present invention, the initial gram load, flying height or static attitude of the slider is measured by the measurement apparatus and the control means calculates how much energy is required to cause the change needed to achieve the desired condition. Other information, such as the type of laser to be used is also specified by the control device. The laser then delivers output to the suspension through the fiber optic line and the static attitude, flying height, or gram load is remeasured to determine if additional adjustment is required.

Laser apparatus and method for adjusting the gram load static attitude

Crater shaped bumps are made on a calibration disk which can be used for calibrating a PZT slider, the PZT slider in turn being used for detecting predetermined asperities on a production run magnetic disk. The crater shaped bumps emulate predetermined asperities of production run magnetic disks and especially asperities which are undesirable and would cause the production run disk to be discarded after testing by the PZT slider. Crater shaped bumps which emulate undesirable asperities on current production runs of magnetic disks have a diameter in the range of 10 to 25 .mu.m and a peripheral ridge with a height h.sub.r above a nominal surface of the calibration disk in the range of 75 to 120 nm. Close tolerance crater shaped bumps with this configuration can be made by impinging two or more pulses of laser energy on the same location of a calibration disk. By increasing the number of pulses the height of the peripheral ridge progressively increases. By employing multiple pulses, the height of the peripheral ridge is increased while the diameter of the crater shaped bump stays substantially constant. Further, by employing multiple pulses diameters and heights of crater shaped bumps can be produced with close tolerances within a diameter range of 5 to 20 .mu.m and a height range of 2 to 120 nm. Different arrangements of the crater shaped bumps on a calibration disk are provided for increasing the range of calibration of the PZT slider.

Calibration disk with disk bumps for calibrating PZT sliders

A method is provided for making crater shaped bumps on a magnetic disk. The crater shaped bumps have a diameter in the range of 10 to 25 .mu.m and a peripheral ridge with a height h.sub.r above a nominal surface of the calibration disk in the range of 75 to 120 nm. Close tolerance crater shaped bumps with this configuration can be made by impinging two or more pulses of laser energy on the same location of the disk. By increasing the number of pulses the height of the peripheral ridge progressively increases. By employing multiple pulses, the height of the peripheral ridge is increased while the diameter of the crater shaped bump stays substantially constant. Further, by employing multiple pulses diameters and heights of crater shaped bumps can be produced with close tolerances within a diameter range of 5 to 20 .mu.m and a height range of 2 to 120 nm.

Method of making disk bumps with laser pulses

Disclosed is a method and apparatus for sensing the vibrational response of a slider of predetermined dimensions during contact with one or more surface asperities on a recording surface, separating the response into its individual bending mode frequency component responses, determining one or more bending mode frequency responses which display monotonic behavior with increasing asperity interference, and designing a mode selection sensor optimized to detect the monotonic bending mode frequency identified. The mode enhanced sensor is designed by first analyzing the stress distribution of the slider corresponding to the monotonic bending mode frequency, identifying regions of the slider which experience substantially positive or substantially negative stress, and partitioning the upper conductive layer of a piezoelectric sensor to form a partitions corresponding to each of the identified regions. The sensor may be further enhanced by tailoring the partitions to exclude undesirable stress contributions.

Method and apparatus for optimizing piezoelectric surface asperity

A method is provided for making crater shaped bumps on a calibration disk which can be used for calibrating a PZT slider, the PZT slider in turn being used for detecting predetermined asperities on a production run magnetic disk. The crater shaped bumps emulate predetermined asperities of production run magnetic disks and especially asperities which are undesirable and would cause the production run disk to be discarded after testing by the PZT slider. Crater shaped bumps which emulate undesirable asperities on current production runs of magnetic disks have a diameter in the range of 10 to 25 .mu.m and a peripheral ridge with a height h.sub.r above a nominal surface of the calibration disk in the range of 75 to 120 nm. Close tolerance crater shaped bumps with this configuration can be made by impinging two or more pulses of laser energy on the same location of a calibration disk. By increasing the number of pulses the height of the peripheral ridge progressively increases. By employing multiple pulses, the height of the peripheral ridge is increased while the diameter of the crater shaped bump stays substantially constant. Further, by employing multiple pulses diameters and heights of crater shaped bumps can be produced with close tolerances within a diameter range of 5 to 20 .mu.m and a height range of 2 to 120 nm. Different arrangements of the crater shaped bumps on a calibration disk are provided for increasing the range of calibration of the PZT slider.

Method of making disk bumps with laser pulses for calibrating PZT sliders

A data recording disk drive includes acceleration rate sensing for controlling or modifying one or more disk drive operations in response to external shock or vibration. An acceleration rate sensor is mounted on the disk drive housing and provides direct detection of acceleration rate of the disk drive when subjected to external shock or vibration. The sensor includes two spaced-apart piezoelectric transducers that operate in current mode. The transducers are connected to an interface circuit that generates two voltage signals that are directly proportional to the angular and linear acceleration rates, respectively, when the disk drive is subjected to an external force. The disk drive microcontroller uses the voltage signals to inhibit writing of data or modify the servo control signal to maintain the heads on track during track seeking or following. The microcontroller can also combine the two signals to determine the acceleration rate of an unbalanced rotary actuator, which can then be used to modify the servo control signal. This permits the use of an unbalanced rotary actuator, which makes the disk drive smaller and lighter and reduces power consumption.

Disk drive with accerleration rate sensing

A method and apparatus for sensing the vibrational response of a slider of predetermined dimensions during contact with one or more surface asperities on a recording surface, separating the response into its individual bending mode frequency component responses, determining one or more bending mode frequency responses which display monotonic behavior with increasing asperity interference, and designing a mode selection sensor optimized to detect the monotonic bending mode frequency identified. The mode enhanced sensor is designed by first analyzing the stress distribution of the slider corresponding to the monotonic bending mode frequency, identifying regions of the slider which experience substantially positive or substantially negative stress, and partitioning the upper conductive layer of a piezoelectric sensor to form a partitions corresponding to each of the identified regions. The sensor may be further enhanced by tailoring the partitions to exclude undesirable stress contributions.

Method for optimizing piezoelectric surface asperity detection sensor

An enhanced piezoelectric sensor for detecting a predetermined bending mode frequency in the vibrational response of a slider with dimensions smaller than the conventional 100% slider during contact with one or more surface asperities on a recording surface. A method for making the enhanced sensor is also disclosed. The sensor comprises a substantiality rectangular slab of piezoelectric material having a charge response which corresponds to in-plane stress under free boundary conditions. Enhancement is achieved by partitioning an upper conductive layer along the lines of symmetry of the slider's stress distribution, which is related to the piezoelectric material's generated charge. In the preferred embodiment, the conductive layer is partitioned into two electrically isolated regions symmetric about the sensor's lateral axis. The design facilitates the isolation of a high frequency bending component which has been found to be monotonic with increasing surface asperity interference.

Advanced PZT glide head design and implementation for a small slider

Slider disk stiction is reduced in a disk-based storage device by providing one or more step projections on the air bearing surface of a slider. The rear part of the step projections which rest on the disk surface projections are forward of the slider pivot point. When the slider rests on a disk surface, the step projections elevate the leading edge of the slider, which imposes a static pitch angle on the slider, reducing the slider/disk contact area. Provision is also made for contouring the slider air bearing surface adjacent to the slider leading edge, using a taper or the step projection leading face, to compress the airflow and provide a stable slider air bearing during disk file operation.

Step projection air bearing slider with improved stiction performance

A data recording disk file of the liquid-bearing type has an improved head-disk interface provided in by a transducer carrier with new properties. The carrier supports a conventional head for reading and writing data to the disk. The carrier has an air-bearing surface near its front end, a ski pad near its rear end, and a plurality of ski feet or struts which support the air-bearing surface off the liquid film of the disk when the disk file is not operating. The air-bearing surface is in the form of a pair of air-bearing rails located outboard of the rear ski pad so that no air-bearing effect occurs in the rearward region of the carrier to assure the skiing action of the rear ski pad. As operational speed is approached the air-bearing lifts the struts off the disk and the rear ski pad is the sole ski foot on the liquid film. The rear ski pad has a convexly shaped leading edge which is wider than its trailing edge to minimize static friction and lubricant thinning during skiing, and the angle between the leading and trailing edges of the pad is selected to enable the pad to ski over the wide ranges of carrier-disk velocity which occur as the carrier moves from disk ID to OD.

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San Jose, CA, United States of America

Timothy C O'Sullivan