Browse Prior Art Database

H sub2 O Barrier on Polyimide Films

IP.com Disclosure Number: IPCOM000112000D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Feger, C: AUTHOR

Abstract

Very few choices are available to passivate polyimide films against moisture in applications where temperature excursions above 350 deg C are encountered. Particularly organic barrier layers such as thick Teflon* AF layers begin to decompose at such high temperatures. Therefore, removal of barrier layers is necessary before high temperature chip rework.

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H sub2 O Barrier on Polyimide Films

      Very few choices are available to passivate polyimide films
against moisture in applications where temperature excursions above
350 deg C are encountered.  Particularly organic barrier layers such
as thick Teflon* AF layers begin to decompose at such high
temperatures.  Therefore, removal of barrier layers is necessary
before high temperature chip rework.

      These problems can be circumvented by using an ultra-thin layer
of Teflon AF.  Such layers are fabricated by exposing dry polyamic
acid films to very dilute solutions of Teflon AF in Fluorinert**.
After cure of the polyimide layer at 400 deg C for up to 1 h the
polyimide is impervious to water (room temperature exposure, 95%
relative humidity, 30 min).  By using ultra-thin layers the price of
the water barrier is low compared to thick Teflon AF barriers.

*  Trademark of E. I. DuPont De Nemours & Co.

** Trademark of 3M Company.