Characterization of Facets in Direct Access Storage Device Heads by Trailing Edge and Leading Edge Slopes
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Carlson, JB: AUTHOR [+2]
Disclosed is a method that quantitatively determines if a slider has a facet.
Characterization of Facets in Direct Access Storage
by Trailing Edge and Leading Edge Slopes
a method that quantitatively determines if a
slider has a facet.
Bearing Surface (ABS) of a slider is supposed to be
lapped to a single plane (with some length-wise curvature called
crown). Problems in the lapping process can cause a second plane to
be lapped into the ABS. When this happens, the slider is said to
have a facet. Facets seriously impact magnetic performance (by
increasing magnetic spacing) and may have long-term durability
Facets can be
detected by measuring the slope of the leading
edge of the center rail and the slope of the trailing edge of the
center rail, then summing the slopes together. If the sum is with-in
0 3 milli-degrees (mdeg), then the part does NOT have a facet.
If the sum is outside 0 3 mdeg, then the part DOES have a facet.
This solution is quantitative and is effective whether the part is at
slider level or at head suspension assembly (HSA) level. It is a
relative measurement (i.e., leading edge slope relative to trailing
edge slope); therefore, it has little sensitivity to tester
repeatability. It also has little operator dependence.
To find the
slopes, the center rail of the ABS is first
(mentally) sectioned length-wise. The taper is ignored. The 20% of
the length at the leading edge is the leading edge section. The 20%
of the length at t...