Recent advances in plastic packaging of flip-chip and multichip modules (MCM) of microelectronics

The success in consumer electronics in the 1990's will be focused on low-co st and high performance electronics. Recent advances in polymeric materials (plastics) and integrated circuit (IC) encapsulants have made high-reliabi lity very-large-scale integration (VLSI) plastic packaging a reality. High- performance polymeric materials possess excellent electrical and physical p roperties for IC protection. With their intrinsic low modulus and soft gel- like nature, silicone gels have become very effective encapsulants for larg er, high input/output (I/O) (in excess of 10 000), wire-bonded and flip-chi p VLSI chips. Furthermore, the recently developed silica-filled epoxies und erfills, with the well-controlled thermal coefficient of expansion (TCE), h ave enhanced the hip-chip and chip-on-board, direct chip attach (DCA) encap sulations. Recent studies indicate that adequate IC chip surface protection with high-performance silicone gels and epoxies plastic packages could rep lace conventional ceramic hermetic packages. This paper will review the IC technological trends, and IC encapsulation materials and processes. Special focus will be placed on the high-performance silicone and epoxy underfills , their chemistries and use as VLSI device encapsulants for single and mult ichip module applications.