RECENT ADVANCES IN HERMETIC EQUIVALENT FLIP-CHIP HYBRID IC PACKAGING OF MICROELECTRONICS

Recent advances in polymeric materials and integrated circuit (IC) enc apsulants have made high-reliability very large-scale integration (VLS I) plastic packaging a reality. High-performance silicone gel possesse s excellent electrical and physical properties for IC protection. With their intrinsic low modulus and soft gel-like nature, silicone gels h ave become very effective encapsulants for larger, high I/O, wire-bond ed and flip-chip VLSI chips. Furthermore, the recently developed silic a-filler modified epoxies, with the well-controlled thermal coefficien t of expansion (TCE), have enhanced the flip-chip and chip-on-board hy brid IC encapsulation. Recent studies indicate that, with adequate IC chip surface protection with high-performance silicone gels and epoxie s, plastic packages could replace conventional ceramic hermetic packag es. This paper reviews the IC technological trends, and IC encapsulati on materials and processes. Special focus is placed on the highperform ance silicone gel, epoxies and polyimides, their chemistry and use as VLSI device encapsulants for single and multi-chip module applications .