Browse Prior Art Database

Protective Film Ceramic Substrates

IP.com Disclosure Number: IPCOM000044286D
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Lavin, AJ: AUTHOR

Abstract

The application of a thin cured polyimide surface film to ceramic substrates reduces chipped, cracked and broken substrates during line handling and processing, avoids field problems resulting from gas-, corrosion- or moisture-induced crack propagation, and provides a smooth surface on standard ceramics for fine line metallization. The polyimide has a higher thermal expansion coefficient then the ceramic and produces a compressive stress in the ceramic surface, thereby strengthening the flexure and improving resistance to static and dynamic fatigue failure. The polyimide film protects against impact cracking of the ceramic substrate by reducing impact stress concentration and distributing the impact force, on the brittle ceramic, over a larger area as well as by absorbing the impact energy itself.

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Protective Film Ceramic Substrates

The application of a thin cured polyimide surface film to ceramic substrates reduces chipped, cracked and broken substrates during line handling and processing, avoids field problems resulting from gas-, corrosion- or moisture- induced crack propagation, and provides a smooth surface on standard ceramics for fine line metallization. The polyimide has a higher thermal expansion coefficient then the ceramic and produces a compressive stress in the ceramic surface, thereby strengthening the flexure and improving resistance to static and dynamic fatigue failure. The polyimide film protects against impact cracking of the ceramic substrate by reducing impact stress concentration and distributing the impact force, on the brittle ceramic, over a larger area as well as by absorbing the impact energy itself. Bonding between the polyimide and the ceramic in the vicinity of surface defects reduces their effectiveness as stress concentrators and thus reduces stress-induced cracks and fractures. The polyimide surface film, acting as a gas, liquid and moisture barrier, protects the ceramic from chemical-, moisture- or corrosion-induced crack propagation.

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