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 Cordierite, Beta quartz and BS-50 were incorporated into three different epoxy resins. The effect of different particulate fillers on the coefficient of thermal expansion of resultant composites was studied. In order to promote the adhesion with epoxy resin matrix, particulate fillers were treated with surface-active agents. Fracture study and microhardness testing of the composites in addition to coefficient of thermal expansion measurements revealed the dispersion of particulate fillers, nature of interfacial bonding and its effect on reducing coefficient of thermal expansion of the composites. The dependence of 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.