Removable foam encapsulants

This paper describes the use of two different expandable bead foams as solvent removable encapsulants; specifically they are polystyrene (STYROPOR BF-414, BASF Wyandotte) and a styrenemaleic anhydride copolymer (DYTHERM X214, ARCO/Polymers). These expandable bead foams are commercially available and normally used in insulating applications. However, they have been adapted to the unusual task of encapsulating sophisticated and expensive electronic hardware which requires a rework capability. The respective foams processing, resultant properties and removal methods are discussed in detail in this paper.