Underfills Support Flip-Chip Apps

For securing packages such as BGAs and CSPs as well as larger ASICs and microprocessors, the Hysol FP4581 and Hysol FP4583 liquid epoxy encapsulants perform as underfills for flip chip devices. The FP4581, described as a high-purity, liquid epoxy encapsulant, meets the requirements of high-lead, large-die bumped packages. It forms a rigid, low-stress seal that dissipates stress on solder joints and extends thermal cycling performance. The material is also compatible with most no-clean flux systems. For situations requiring a fine filler, Hysol FP4583 exhibits many of the characteristics as its FP4581 counterpart. The material contains fillers that are less than or equal to 2 µm in diameter and is suitable for use with over-molded components in both high-lead and lead-free applications. HENKEL LOCTITE CORP., Rocky Hill, CT. (949) 789-3500.