Syntheses and characterizations of thermally reworkable epoxy resins. PartI

To meet the need for reworkable epoxy resins, a series of cycloaliphatic di epoxides containing thermally cleavable carbamate linkages were synthesized and characterized. These materials were shown to undergo curing reactions with cyclic anhydride in a similar fashion as a commercial cycloaliphatic e poxide, except that the carbamate group within the diepoxides can act as th e internal catalyst. Furthermore, cured samples of the formulations from th ese diepoxides started to decompose at lower temperatures, i.e., between 20 0-300 degrees C as compared with 350 degrees C for the cured sample of the commercial cycloaliphatic epoxide, which showed their potential to be used as reworkable underfill encapsulants in the electronic packaging area. (C) 1999 John Wiley & Sons, Inc.