Study On Preparation And Properties Of Halogen-free Flame Retardant Epoxy Encapsulating Material

Epoxy resin, having outstanding dielectric properties, adhesive propertiesand various physical and mechanical properties, are widely used formanufacturing sealing and perfusion materials in electric and electronic field. Butwith the thermal class increasing, environmental protection and the relatedtechnical safety regulations, the flame resistance is threatened with greatchallenge. Therefore, improving the flame-retardant effect and making epoxyresin keep a good comprehensive performance is a hot and difficult problemnowadays.In this paper, a phosphorus-containing epoxy resin was prepared by the ringopening reaction of DOPO and epoxy resin. The melamine, formaldehyde,bisphenol A as raw materials, the MF-BPA was prepared and added it to epoxyresin system. And at the same time the inorganic powder was used to enhance theflame retardant of epoxy resin. The structure and performance ofphosphorus-containing epoxy resin, organic/inorganic flame retardant epoxy resincontaining phosphorus, nitrogen were tested and characterized by FT-IR, TG,DSC, LOI and Voltage Resistance Meter. The effects of phosphorus content,nitrogen content, phosphorus-nitrogen synergy effect and inorganic powdervarieties, dosage, inorganic/organic flame retardant on the flame retardant,thermal stability, dielectric properties, mechanical properties were discussed inthis paper. Through experiments we determined the best raw materials ratio,reaction time temperature and other synthesis conditions.According to the results, with the increasing of DOPO content, the flameretardant was enhanced, but the thermal stability, mechanical properties, Tg, dielectric properties were reduced. But the addition of nitrogen containingphenolic slowed down this phenomenon. The thermal stability, flame retardant ofsystem were significantly improved. In addition, the inorganic powder can trulyimprove the flame retardant of system, but the excessive addition can have anegative impact on the mechanical properties of system. On the one hand thesystem can have better flame retardant and other properties can meet therequirements of electronic packaging materials at the same time, on the otherhand the using of inorganic powder can significantly reduce the cost.