International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Maxtor Corporation

Robert Langland Smith

Vladimir Nikitin

Edward Hin Pong Lee

Jih-Shiuan Luo

Chin-Yu Yeh

Naum V Gitis

R Larry Comstock

Mustafa Pinarbasi

Glen A Garfunkel

Michael Paul Salo

Ciaran Avram Fox

Samuel Weisan Yuan

Donald E Horne

David Ernest Call

Mark Allen Burleson

Gity Samadi Hosseinali

A method for testing a magnetic head to determine whether the magnetic head is unacceptably affected by temperature variations. The test includes testing the magnetic head at different temperatures and measuring either or both of a signal amplitude and a signal asymmetry of a signal from the magnetic head at the different temperatures. If signal amplitude or signal asymmetry vary excessively as a result of the temperature change then the head can be scrapped.

Method for testing the acceptability of a magnetic read sensor

A magnetic data recording head having reduced thermally induced shield (pole tip) protrusion. The head includes a magnetoresistive sensor sandwiched between first and second shield. The shields have a substantially reduced thickness. The distance between the shields defines a gap (G) and the shields each have a thickness (ST) such that the ratio ST/G is greater than 2, but less than 50. More preferably the ratio ST/G is greater than 2, but less than 20, and yet more preferably, the ratio ST/G is greater than 2 and less than 10.

Thin shield structure for reduced protrusion in a magnetoresistive head

Disclosed is a system and a method for reducing high frequency interference pickup by the read element of the magneto-recording head. The reduction is achieved by reducing the parisitic capacitance between certain elements of the magnetic head. In one embodiment, the areas of the pads and leads, including the areas of the leads over the S1 and the areas of the sensor leads, are reduced. A second implementation involves increasing the separation between the pads and leads and the substrate material. Copper studs or vias may be used to connect the contact pads and the underlying layers. A third implementation includes using a low dielectric constant material as a spacer layer between conductors (leads, pads, magnetic shields) and the substrate.

Reduction of interference pickup in heads for magnetic recording by minimizing parasitic capacitance

A symmetrical read element circuit for reducing electrical and magnetic noise using signal processing, such as a differential preamplifier. The circuits are symmetrically created on both sides of the read element so that the noise is balanced on both sides of the read element to allow substantial noise reduction by the signal processing.

Method and apparatus for balanced shield shunts, leads and pads for electrical noise reduction in read heads

A symmetrical read element circuit for reducing electrical and magnetic noise using signal processing, such as a differential preamplifier. The circuits are symmetrically created on both sides of the read element so that the noise is balanced on both leads of the sensor element allowing substantial noise reduction by the signal processing. That is, the present invention provides symmetrical leads and pads designed for equal noise pickup, and for cancellation of the balanced noise.

Disk drive with reduced electrostatic charge on slider-head assembly

A method of making a keeper layer for a spin valve sensor sputter deposits a layer of cobalt iron niobium hafnium (CoFeNbHf) in the presence of a first magnetic field that is in a first direction, the CoFeNbHf keeper layer is then first annealed in the presence of a second field that is in a second direction and the keeper layer is then subsequently second annealed in the presence of a third field that is in a third direction. The first direction is preferably perpendicular to an air bearing surface of a read head employing the spin valve sensor and the third direction is preferably parallel to the first direction. The second direction is preferably perpendicular to the first direction. This method of making significantly reduces the intrinsic anisotropy (H,) of the keeper layer and also stabilizes the magnetic moment of the keeper layer in a direction which is perpendicular to the ABS.

Method of making a keeper layer for a spin valve sensor with low intrinsic anisotropy field

A method, apparatus and computer program product for identifying electrostatic discharge (ESD) damage to a thin film device. The method includes (1) determining a cold resistance of the thin film device, (2) determining a hot resistance of the thin film device, (3) calculating a heating delta resistance (HDR) from the hot and cold resistances and (4) comparing the HDR to a threshold value to ascertain if the thin film device has suffered ESD damage. The HDR of the thin film device is characterized by the following relationship: HDR&equals;(hot resistance-cold resistance)/(cold resistance).

Method, apparatus and computer program product for identifying electrostatic discharge damage to a thin film device

A common cause for catastrophic failure in a magnetic disk storage system is due to the collection of debris on the slider/head assembly. Two factors contributing to these failures are:

Magnetic recorder apparatus with reduced debris accumlation on the

The present invention provides a test circuit and method for testing for short circuits in an MR head, merged MR head or piggyback MR head without contacting either of the shield layers. This is accomplished by a bridge circuit which employs part of the components of the head. The bridge circuit has four consecutively arranged branches which are interconnected by four consecutively arranged terminals. The first terminal comprises the substrate or one of the write pads and the second and fourth terminals comprise the first and second read pads. A signal generator is connected across the first and third terminals and a detector, such as a differential amplifier, is connected across the read pads. With this arrangement the first branch of the bridge circuit includes a capacitance which is formed by one of the gap layers between one of the shield layers and a first one of the leads and the second branch of the bridge circuit includes a capacitance which is formed by said one of the gap layers between said one of the shield layers and a second one of the leads. The differential amplifier detects any impedance imbalance in the bridge circuit which indicates that coupling between one or more of the shields and one or more of the leads has changed. Most likely the head has a shield short circuit and can be discarded.

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Cupertino, CA, United States of America

Robert Langland Smith