Browse Prior Art Database

Texture for Thin Film Magnetic Recording Disks

IP.com Disclosure Number: IPCOM000116786D
Original Publication Date: 1995-Nov-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 97K

Publishing Venue

IBM

Related People

Gregory, TA: AUTHOR [+2]

Abstract

Methods for texturing magnetic recording disks in the landing zone are disclosed.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Texture for Thin Film Magnetic Recording Disks

      Methods for texturing magnetic recording disks in the landing
zone are disclosed.

      Magnetic recording disks require a texture in the landing zone
to prevent stiction.  The present means of manufacture do not provide
a good enough texture for very low flyheight operation.

The texture pattern meeting the following criteria:
  1.  Simple topology.
  2.  Easily reproducible with 4 nanometer tolerance on peak height,
       and 0.5 micron tolerance on lateral dimensions.
  3.  The bearing area is large enough to keep stresses below the
level
       needed to produce wear particles bigger than 5A, but small
enough
       to prevent stiction from occurring.
  4.  No load bearing summit is more than a certain maximum distance
       from a lube reservoiring valley.  This ensures that lube will
be
       able to diffuse to summits as needed so that none will go into
a
       catastrophic wear regime due to lube starvation.
  5.  Well-defined valleys are provided to retain lube, wear debris,
       and spurious contamination.

      The importance of Point 1 is evident when studying today's
texture.  That topology is so complex that it is not known what
parameters should even be measured to characterize it in a meaningful
way.  With a simple geometry, it will be much easier to monitor the
manufacturing process.

      Point 2 represents a tremendous improvement in peak height
control over present methods.  It is the peaks that actually support
the slider, so it is crucial that the correct bearing area be
provided by the correct number of peaks.  Otherwise, we have the
situation as today where excess pressures are initially exerted on
the highest peaks in the texture.

      Figs. 1 through 4 depict example patterns.  The lateral
dimensions are of the order easily attainable by photolithography
(1-10 microns), and the vertical dimensions are easily attained by
sputtering (2-30 nanometers).  For Fig. 1, example dimensions would
be m = 5 microns, n = 2 microns, h = 10 nanometers.  For Fig. 4,
expected dimensions would be on the order of d = 2 microns, D = 5
microns, and H = 10 nanometers.  By keeping height 0.1 to 0.3 of the
minimum sliding height of the slider, accessing on and off the
landing zone can be accomplished without contact.

      The end result is a microscopic version of a standard
hydrodynamic thrust bearing.  There are well defined...