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One Step Burnish Mapping

IP.com Disclosure Number: IPCOM000108895D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 53K

Publishing Venue

IBM

Related People

Hamond, RB: AUTHOR [+5]

Abstract

Thin film disks are burnished after carbon overcoat deposition to remove particles from target spitting, asperities from the texturing process, and to precipitate any coating delaminations. Burnishing is currently done by accessing while flying a special burnish slider head on a spring suspension surface. The effect of burnishing is measured in another processing step referred to as the Glide Height Test (GHT). In the GHT a slider with a mounted accelerometer is flown low over the disk and the number and intensity of slider disk contacts is recorded as a measure of the burnishing effectiveness. If the disks are insufficiently burnished, they must be scrapped for rework, or sent back for more burnish. In either case, the additional processing steps increase the cost of manufacturing.

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This is the abbreviated version, containing approximately 76% of the total text.

One Step Burnish Mapping

      Thin film disks are burnished after carbon overcoat deposition
to remove particles from target spitting, asperities from the
texturing process, and to precipitate any coating delaminations.
Burnishing is currently done by accessing while flying a special
burnish slider head on a spring suspension surface.  The effect of
burnishing is measured in another processing step referred to as the
Glide Height Test (GHT).  In the GHT a slider with a mounted
accelerometer is flown low over the disk and the number and intensity
of slider disk contacts is recorded as a measure of the burnishing
effectiveness.  If the disks are insufficiently burnished, they must
be scrapped for rework, or sent back for more burnish.  In either
case, the additional processing steps increase the cost of
manufacturing.

      Our alternative method consists of combining the burnish and
surface evaluation into one step, such that the burnish conditions
can be adjusted in-situ to meet the GHT criterion.  This is done by
using a load application system such as a pneumatic cylinder to
increase the slider load. This lowers the slider below its normal
flying height.  The extra load also increases the air bearing
stiffness and the energy of slider disks contacts which effect the
burnishing. At the same time, the slider disk contacts are measured
by an accelerometer or other acceleration or displacement sensing
device such as laser doppler vibrometer.  This provides th...