Browse Prior Art Database

Take-Off Time Measurement Technique of Contact Stop/Start Testing

IP.com Disclosure Number: IPCOM000101243D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Chen, MM: AUTHOR [+3]

Abstract

Disclosed is a method of determining the time it takes for a slider to begin flying after rest on a recording disk (take-off time) during contact stop/start testing. The take-off time can be determined by analyzing the waveform generated from a strain gauge used to measure tangential force on the slider.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Take-Off Time Measurement Technique of Contact Stop/Start Testing

       Disclosed is a method of determining the time it takes
for a slider to begin flying after rest on a recording disk (take-off
time) during contact stop/start testing.  The take-off time can be
determined by analyzing the waveform generated from a strain gauge
used to measure tangential force on the slider.

      Contact stop/start testing of recording disks involves the
measurement of tangential force on a slider versus time as the disk
is rotated from a stopped position.  The initial peak of the waveform
of force versus time is the measured instantaneous stiction force
(F1), or the force required to release the resting slider from the
disk surface (Fig. 1). This peak occurs in approximately the first 20
ms (T1).  By further analyzing the force versus time curve, a
take-off time (T2) can be defined.  This is the time required for the
force (F2) to return to zero.  In addition to plotting instantaneous
stiction versus stop/start cycles, take-off time versus stop/start
cycles can be plotted.  Data show that increased take-off time is a
precursor to catastrophic stop/ start failures (Fig. 2) associated
with wear of the media, which is not always evident from only
stiction data (Fig. 3).  This early detection provides a means of
stopping the test prior to an actual failure, allowing subsequent
failure analysis of the head and disk.