Self-Extinguishing of Phenol-Aralkyl-Type Epoxy Resin Compounds and Their Application to Electronics Packaging Materials

We have clarified that phenol aralkyl-type epoxy resin compounds show high flame retardancy without toxic flame retardants such as halogen compounds (self-extinguishment) and good other characteristics, including water absorption resistance and pyrolysis resistance. Such properties allow their applications as principal electronic packaging materials. The self-extinguishment of the epoxy resin compounds was mainly due to the stable foam layers that form during ignition because of the low elasticity at high temperatures and the high pyrolysis resistance of the compounds. A silica particle filler and a benzoguanamine-modified phenol resins further improved their flame retardancy. The additional use of a multi-functional epoxy resin containing four glycidyloxy groups increased the glass transition temperatures and the modulus at high temperatures, while maintaining the excellent flame retardancy. Using the epoxy resin compounds for integrated circuit (IC) molding compounds and printed wiring boards (glass-epoxy laminates) produces high flame retardancy without halogen-flame retardants and other good practical characteristics such as humidity resistance and solder heat resistance.