Removable foams based on an epoxy resin incorporating reversible Diels-Alder adducts

We have successfully incorporated Diels-Alder reversible chemistry into epoxy resins. The Diels-Alder chemistry goes in the forward direction at 60 degreesC and reverses at or above 90 degreesC. One resin was formulated with other commercial ingredients into foamed epoxy. The foam, shown to have mechanical properties similar to foams formed with conventional epoxy resins, is being utilized for electronic encapsulation. Because of the built-in reversible chemistry, the foams can be easily removed by dissolution in 1-butanol at 90 degreesC. Removal allows for the rework, upgrading, or dismantlement of the electronic components. (C) 2002 Wiley Periodicals, Inc.