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Bump Disks for Glide Height Test

IP.com Disclosure Number: IPCOM000118171D
Original Publication Date: 1996-Oct-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Comita, PB: AUTHOR [+4]

Abstract

Disclosed is a method to make bump disks for calibrating sliders or glide heads. These heads, in turn, are used in the glide height test to screen out asperity defects on hard disks in order to ensure head-disk interface mechanical reliability in the files. In this process, a disk is placed in a vacuum chamber with the surface of the disk to be processed in contact with a vapor of a organo-metallic compound. The region of the disk where the bump is to be placed is then exposed to focussed laser light, through a window of the vacuum chamber. A photochemical vapor deposition takes place at the illuminated disk surface to form a bump on the disk surface.

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Bump Disks for Glide Height Test

      Disclosed is a method to make bump disks for calibrating
sliders or glide heads.  These heads, in turn, are used in the glide
height test to screen out asperity defects on hard disks in order to
ensure head-disk interface mechanical reliability in the files.  In
this process, a disk is placed in a vacuum chamber with the surface
of the disk to be processed in contact with a vapor of a
organo-metallic compound.  The region of the disk where the bump is
to be placed is then  exposed to focussed laser light, through a
window of the vacuum chamber.  A photochemical vapor deposition takes
place at the illuminated  disk surface to form a bump on the disk
surface.

      The position of the disk in the vacuum chamber is adjustable
using X-Y translation stages.  The bump location on the disk is
identified through an optical system.  The chamber is evacuated and
then back-filled with molybdenum hexacarbonyl, Mo(CO) sub 6, which is
known to photodissociate when exposed to UV light.  The disk is then
exposed to excimer laser (UV) light through a shutter controlled
aperture.  The laser beam excites and dissociates the reactant vapor
and metallic molybdenum deposits on the disk surface, forming a very
precisely controllable bump in the exposed area.  The lateral
dimensions of the bump are controlled by the focussed image of the
aperture.  This allows the lateral size of the bump to be tailored
down to micron dimensions.  The he...