Seagate Technology Incorporated

Chiu-Shing Frank Poon

Zhu Feng

Chung Yuang Shih

Vidyadhara K Gubbi

Dallas W Meyer

Mark James Schaenzer

Vidya K Gubbi

Tan Guo Liu

An apparatus and method for evaluating surface characteristics of a recording disc prior to incorporation into a disc drive. A glide test system includes a glide test head supportable over the disc, the glide test head having a negative-pressure air bearing slider and a contact sensor which outputs a signal when the glide test head contacts a feature of the disc surface. The glide test head and the disc are characterized as opposing plates of a variable capacitor with a dielectric layer therebetween including at least a layer of air supporting the glide test head. A voltage source, operably coupled to the glide test head and the disc, applies a fly height control voltage across the capacitor to adjust the fly height of the glide test head. The disc surface preferably comprises a data region configured to magnetically store data as the disc is rotated and a texturized landing zone configured to support the disc drive read/write head when the disc is stopped. The voltage source accordingly applies a first fly height control voltage to maintain the glide test head at a first glide distance over the data region and a second fly height control voltage to maintain the glide test head at a second, greater glide distance over the landing zone.

Head with active fly height control

A method for controlling flying height at the interface of a magnetic head and a magnetic storage medium is described. The flying height is controlled by applying a voltage between head and medium. This controls the vertical movement of the head, and thus, may increase or decrease the flying height. For example, the flying height may be changed with surface texture to achieve high writing/reading density, where the flatness of the medium is high. Also, the contact between the head and medium may be limited where the texture includes projections such as laser bumps.

Method for controlling flying height of a magnetic head

Glide test head with active fly height control

Disclosed is anew technique for measuring the resistivity of ultra-thin carbon films (less than 200 &angst;). The technique involves using a probe with very smooth surface, a thin layer lubricant (20-30&angst;)that enables the intimate and stable electrical contact between probe and the thin film, and measurement of I-V curve to determine resistance. Resistivity measurements were conducted on carbon films doped with hydrogen and nitrogen at different mixture ratios and different thicknesses, and the results were compared with those obtained on a commercially available machine that uses a mercury probe. The advantages of the present technique include simple in use, less expensive and quick measurements with reasonably good accuracy.

Technique for measuring resistivity

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Pleasanton, CA, United States of America

Chiu-Shing Frank Poon