Browse Prior Art Database

Silicone Overcoat Material Application Process

IP.com Disclosure Number: IPCOM000048326D
Original Publication Date: 1982-Jan-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Audi, R: AUTHOR [+3]

Abstract

With the advent of denser circuits having smaller devices, a problem has been encountered with soft failures due to alpha-particle emissions from the substrate material penetrating the silicon chip mounted on the substrate. In order to prevent or reduce such soft failures, a barrier layer can be applied between the chip and the substrate. This barrier layer must itself not be an alpha-particle emitter, must flow well, conform to the space between the chip and substrate, and be chemically and physically stable under operating and processing conditions.

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Silicone Overcoat Material Application Process

With the advent of denser circuits having smaller devices, a problem has been encountered with soft failures due to alpha-particle emissions from the substrate material penetrating the silicon chip mounted on the substrate. In order to prevent or reduce such soft failures, a barrier layer can be applied between the chip and the substrate. This barrier layer must itself not be an alpha-particle emitter, must flow well, conform to the space between the chip and substrate, and be chemically and physically stable under operating and processing conditions.

It has been found that the silicone polymer SYLGARD* provides an excellent alpha-particle barrier, when interposed between a chip and a substrate. It has further been found that in order to provide a void free barrier, the polymer must be dispensed either by inert gas pressure or by a mechanical plunger to prevent bubble formation. Also, after the SYLGARD is applied, the assembled module is placed in a vacuum which will cause the SYLGARD to spread and eliminate any voids which may have occurred between the chip and the substrate after application of the SYLGARD. (*) Trademark of Dow Corning Corporation.

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