Characterization of polymeric composites with low CTE ceramic particulate fillers

Use of particulate fillers is a potential approach to develop isotropic low coefficient of thermal expansion polymeric composite materials for electronic circuit board applications. Low coefficient of thermal expansion ceramic particulate fillers such as Beta quartz, Cordierite and BS-50 were incorporated into three different epoxy resins. The effect of different particulate fillers on the coefficient of thermal expansion of the resultant composites was studied. In order to promote adhesion with the epoxy resin matrix, particulate fillers were treated with surface-active agents. Fracture study and microstructural analysis of the composites, in addition to coefficient of thermal expansion measurements, revealed dispersion of particulate fillers in the epoxy resin matrix, the nature of interfacial bonding, and their effect on reducing the coefficient of thermal expansion of the composites. The dependence of the coefficient of thermal expansion of the composites on the properties of the epoxy resins as well as on the properties of the particulate fillers along with other factors, is discussed.