Epoxy Molding Compounds as Encapsulation Materials for Microelectronic Devices

Epoxy molding compounds for microelectronic devices have been and will continue to be the main stay of encapsulation materials in view of their cost and productivity advantages. On the other hand, as chip sizes become larger due to increased integration of devices, compacter packages are in demand to realize the higher integration. Advances in surface mounting technologies demand encapsulation materials which have extremely low thermal stress and excellent stability at the elevated temperatures used in reflow soldering. Many new technologies have been developed to meet these desires in microelectronic encapsulation. This paper reviews the fundamental properties of epoxy molding compounds and explains the roles and characteristics of the following components which represent encapsulation materials; epoxy resins, hardeners, accelerators, flexibilizers, fillers, flame retardants, coupling agents, and release agents.