Recent advances in hermetic equivalent flip-chip hybrid IC packaging of microelectronics

Abstract

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