High-Performance Reworkable Underfill Adhesives Based on Dicyclopentadiene Epoxy Thermoset

Abstract

A highly reliable and reworkable underfill adhesive based on thermoset epoxy resin possessing thermally reversible dicyclopentadiene (DCPD) moiety is described. The adhesive can be cured rapidly at moderate temperatures resulting in high Tg cured network, which gives high reliability to the bonded semiconductor components. The inherent thermal reversibility of DCPD moiety causes network breakdown at high temperatures enabling easy removal of defective semiconductor chips. A discernible trend between loading level of the thermally reversible epoxy resin and high-temperature die shear strength was observed. Using this novel adhesive system, both high reliability and reworkability can be achieved concurrently, which is normally not possible with other thermoset adhesive systems. The epoxy resin used in the study was scaled up to multi-kg quantities demonstrating industrial applicability of the approach.