Title :
Imaging of media lubricant spacing contributions by readback signal analysis
Author :
Eaton, Robert ; Baldwinson, Michael
Author_Institution :
Quantum Corp., Milpitas, CA, USA
fDate :
1/1/1997 12:00:00 AM
Abstract :
An in situ method for measuring media lubricant spacing contributions in a hard disk drive by analysis of the magnetic readback signal is presented. Amplitude modulation (AM) is mapped over an area of the disk and the image is scaled into equivalent spacing loss using the known transition length and the Wallace spacing loss equation. The first image acquired is used as a reference for all subsequent measurements. Changes in head to media spacing are created by the removal of a localized area of lubricant in the imaged region on the disk. The area is re-imaged and subtracted from the reference in order to measure the resulting changes in head/media spacing. Spacing changes from 0.6 mm to 0.7 mm were measured after either a Freon TF or a trifluoroethanol wash
Keywords :
amplitude modulation; hard discs; lubrication; magnetic recording; thickness measurement; AM; Wallace spacing loss equation; amplitude modulation; hard disk drive; head/media spacing; imaged disc region; in situ method; magnetic readback signal; media lubricant spacing; readback signal analysis; spacing loss analysis; Amplitude modulation; Attenuation; Equations; Lubricants; Magnetic analysis; Magnetic films; Magnetic heads; Signal analysis; Surface topography; Wavelength measurement;
Journal_Title :
Magnetics, IEEE Transactions on
