Synthesis and properties of a low hygrothermal stress epoxy molding compound for electronic encapsulation

Abstract

A vinyl siloxane-modified cresol novolac epoxy (CNE)/cresol novolac hardener (CNH) molding compound with both siloxane and epoxy components capable of further crosslinking is synthesized. Through careful adjustment of TPP dosage, the Tg of CNE/CNH resins can be effectively controlled. The VS-modified CNE/CNH compound possesses a lower Young's modulus, a lower linear coefficient of thermal expansion (LCTE), and a higher break strain than those of its unmodified counterpart. The combination of lower mechanical moduli and lower LCTE results in a 33% reduction in thermal stress caused by thermal mismatch. In addition to thermal mismatch, chemical shrinkage in a molding process is also an important factor that affects the interfacial strain between a compound and a substrate. The incorporation of vinyl siloxane (VS) incurs a 25% reduction in the equilibrium moisture uptake and a 16% reduction in the coefficient of diffusion for the VS-modified compound. This modified compound can help alleviate the popcoming problems in IC packages resulting from hygrothermal stresses.

New triepoxy monomer and composites for thermal and corrosion management

“…[11,12] Epoxy resins have found wide applications in electronic packaging as epoxy molding compounds, thermally conductive potting compounds, electrically conductive paste, and die attached adhesives. [13][14][15] Many efforts are being made on developing epoxy resins with enhanced mechanical and thermal properties for next-generation electronic packaging.…”

Synthesis, characterization, and properties of a novel epoxy resin containing both binaphthyl and biphenyl moieties

“…Moisture resistance is another key property. Absorbed moisture in packaging resin layers would be explosively vaporized during reflow soldering process, causing such package reliability problems such as package cracks, delamination, and package warpage 3. Therefore, it is imperative to develop epoxy resins with high thermal resistance and low water absorption.…”