Browse Prior Art Database

Adhesion of Molded Polymers

IP.com Disclosure Number: IPCOM000078757D
Original Publication Date: 1973-Mar-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 19K

Publishing Venue

IBM

Related People

Jenkins, JB: AUTHOR [+3]

Abstract

Many semiconductor devices are encapsulated using transfer molded thermosetting polymers, particularly epoxy resins. A major problem in this packaging technique is caused by poor adhesion of the polymer to the device and pin lead, thus allowing moisture and contamination to effect the reliability of the encapsulated component. The poor adhesion problem is due primarily to the internal mold release that is compounded into the molding compound. This compound is useful in assuring part release from the mold but reduces component reliability.

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Adhesion of Molded Polymers

Many semiconductor devices are encapsulated using transfer molded thermosetting polymers, particularly epoxy resins. A major problem in this packaging technique is caused by poor adhesion of the polymer to the device and pin lead, thus allowing moisture and contamination to effect the reliability of the encapsulated component. The poor adhesion problem is due primarily to the internal mold release that is compounded into the molding compound. This compound is useful in assuring part release from the mold but reduces component reliability.

The present procedure greatly reduces this problem by creating active lead surfaces with a hydrolyzed N beta-aminoethyl (gama) aminopropyltrimethoxysilane which reacts with the molding compound (encapsulant), an epoxyalated novolac resin cured with a novalac curing agent. Similar adhesion improvements are also obtained by using molding compounds formulated from epoxyalated novalac cured with methylene dianiline.

Using these compounds, a molded epoxy material 10 bonded to a molybdenum gold-plated member 12 improved adhesive strength, from 0 PSI to an average of 4,000 PSI.

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