Thermal Properties of Low Loss PTFE-CeO2 Dielectric Ceramic Composites for Microwave Substrate Applications

Polytetrafluroethylene (PTFE) composites filled with CeO2 were prepared by powder processing technique. The PTFE is used as the matrix and the loading fraction of CeO2 in the composite varied up to 0.6 volume fraction. The thermal conductivity and coefficient of thermal expansion were studied in relation to filler concentration. The thermal conductivity increased and coefficient of thermal expansion decreased with increase in CeO2 content. For 0.6 volume fraction loading of the ceramic, the composite has a thermal conductivity of 3.1 W/m degrees C and coefficient of thermal expansion 19.6 ppm/degrees C. Different theoretical approaches have been employed to predict the effective thermal conductivity and coefficient of thermal expansion of composite systems and the results were compared with the experimental data. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 751-758, 2010