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Relief Coating for Disk Storage Technology

IP.com Disclosure Number: IPCOM000109055D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 46K

Publishing Venue

IBM

Related People

Babich, ED: AUTHOR [+5]

Abstract

Paralyne C (a trademark of Union Carbide) is a vapor-deposited polymeric conformable coating, deposited from vapor phase pyrolysis of the dimer on cooled surfaces, to form a high molecular weight linear poly-p-xylylene.

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Relief Coating for Disk Storage Technology

      Paralyne C (a trademark of Union Carbide) is a vapor-deposited
polymeric conformable coating, deposited from vapor phase pyrolysis
of the dimer on cooled surfaces, to form a high molecular weight
linear poly-p-xylylene.

      This material absorbs in the U.V., and upon exposure to U.V., a
change in volume occurs.  This change is due to crosslinking and
densification of the material, and results in visualization of the
image.  The measured thickness loss is approximately 10% of the
initial thickness, and it is possible to image 1 micron lines.  The
relief pattern formed by the U.V.  radiation can be read using
optical methods of the type used in disk storage technology.
Patterns can be read in the visible range, and contrast can be
enhanced by the addition of dyes.

      Other materials have also been found to form relief images.
For example, photosensitive polymides (i.e., polyomic acid polymers
with photoreactive side groups) will form relief images upon exposure
to 4047o (95 MJ/CM2)and baking to 225~.  The unexposed area will lose
thickness, and the exposed area will be thicker due to crosslinking
and increased thermal stability.  After continued baking for 1 hour
at 225~C no change in the pattern is detected.

      The relief image is a function of exposure.  For example, a 2.5
micron thick film will show relief images of about 1500Ao at 90
MJ/CM2, and 3000~ at 260 MJ/CM2 .  Thus, the relief imag...