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Multiphase Block Polymers as a Means of Reducing Solvent Uptake for the Preparation of Multilayer Structures

IP.com Disclosure Number: IPCOM000111079D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Hedrick, JL: AUTHOR [+2]

Abstract

Polyimides have been employed in applications as the interlayer dielectric for both multichip packaging technologies and chip BEOL.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 63% of the total text.

Multiphase Block Polymers as a Means of Reducing Solvent Uptake for
the Preparation of Multilayer Structures

      Polyimides have been employed in applications as the interlayer
dielectric for both multichip packaging technologies and chip BEOL.

Polyimides as a class of materials best satisfy the material
requirements necessary for these applications which include thermal
stability, good mechanical properties and low thermal expansion
coefficient.  These good mechanical properties result, in part, from
the molecular packing or ordering.  As the number of polyimide layers
increase, the ability to control both the swelling characteristics
and residual stress upon thermal cycling becomes important.  It has
been shown that PMDA/ODA polyimide takes up approximately 35 wt. %
solvent at equilibrium.  This swelling behavior is attributable to an
unusual molecular ordering coupled with molecular orientation.  Films
cast and cured on a substrate are known to possess a pronounced
orientation of the molecules parallel to the film surface.  In such
films, swelling occurs only in the thickness direction and is limited
by the presence of ordered regions which act effectively as
crosslinks.  The swelling behavior of polyimide is currently being
controlled by the use of rigid-rod polyimides (i.e., BPDA/PDA
polyimide), where the high degree of cystalline order minimizes the
solvent uptake.  This strategy tends to limit the material selection
for these applications to highly orde...