International Business Machines Corporation

Richard E Krebs

Mark Anthony Church

Alain M Desouches

Alain Michel Louis Desouches

An in-situ (result-directed/predictive) MR stripe height calibration method capable of operating on the fly during lapping operation. The method involves utilization of an interval sampling technique, which provides a high number of data points. The data provided are filtered and averaged at each kerf location to provide a much higher calibration accuracy than previously available. The primary advantage is to create an accurate relationship between MR element resistance and its stripe height while the MR element is being lapped. The method thus provides the ability to target either resistance or stripe height or a combination of both during the lapping process. Finally, the system is completely self-contained and does not required wafer data.

In-situ stripe height calibration of magneto resistive sensors

A lapping control system for accurately obtaining a desired throat height of each of a plurality of batch fabricated thin film magnetic transducers, comprises a row of thin film transducers formed on a substrate, the row comprising a height defining edge and at least four spaced sensing devices, a first two of the sensing devices comprising switch devices each offset a predetermined amount from the height defining edge, and a second two of the sensing devices comprising resistive devices each offset a predetermined amount from the height defining edge, a support of mounting the row of thin film magnetic transducers in a position to lap the height defining edge of each of the thin film magnetic transducers and the sensing devices, a measuring device for measuring the resistance of the resistive devices during lapping of the height defining edge, apparatus responsive to the measured resistance and to a selected state of at least one of the two switch devices for calibrating resistance versus throat height characteristics for each of the thin film magnetic transducers in the row, and for terminating the lapping process when a predetermined throat height is reached for each of the thin film magnetic transducers.

Ultimate inductive head integrated lapping system

A lapping control system for accurately obtaining a desired throat height of each of a plurality of batch fabricated thin film magnetic transducers, comprises a row of thin film transducers formed on a substrate, the row comprising a height defining edge and at least four spaced sensing devices, a first two of the sensing devices comprising switch devices each offset a predetermined amount from the height defining edge, and a second two of the sensing devices comprising resistive devices each offset a predetermined amount from the height defining edge, a support of mounting the row of thin film magnetic transducers in a position to lap the height defining edge of each of the thin film magnetic transducers and the sensing devices, a measuring device for measuring the resistance of the resistive devices during lapping of the height defining edge, apparatus responsive to the measured resistance and To a selected sate of at least one of the two switch devices for calibrating resistance versus throat height characteristics for each of the thin film magnetic transducers in the row, and for terminating the lapping process when a predetermined throat height is reached for each of the thin film magnetic transducers.

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San Jose, CA, United States of America

Richard E Krebs