R. Eaton et M. Baldwinson, IMAGING OF MEDIA LUBRICANT SPACING CONTRIBUTIONS BY READBACK SIGNAL ANALYSIS, IEEE transactions on magnetics, 33(1), 1997, pp. 974-977
An in situ method for measuring media lubricant spacing contributions
in a hard disk drive by analysis of the magnetic readback signal Is pr
esented. Amplitude modulation (AM) is mapped over an area of the disk
and the image is scaled into equivalent spacing loss using the known t
ransition length and the Wallace spacing loss equation. The first imag
e acquired is used as a reference for all subsequent measurements, Cha
nges in head to media spacing is created by the removal of a localized
area of lubricant in the imaged region on the disk. The area is reima
ged and subtracted from the reference in order to measure the resultin
g changes in head/media spacing. Spacing changes from 0.6 nm to 0.7 mm
were measured after either a Freon TF or a trifluoroethanol wash.