A synergistic model for thermal conductivity with hybrid fillers in polymeric matrix composites

Polymeric matrix composites have been widely used in electronics packaging. As thermal management becomes more important, the demand for high thermal conductivity materials continues to increase. Improvement in thermal conductivity in the past years has been built upon fundamental understanding of a few important aspects. Besides the improvement based on high thermal conductivity filler selection, chemical functionalization, and the concept of percolation, hybrid fillers were studied for further benefits. This study of hybrid fillers is able to model synergistic effects. A simplified method of computing synergistic effects is proposed in this work by modifying Nielsen's composite model so that it is not necessary to curve fit all parameters. The model using the modified Lewis- Nielsen's equation is verified with a few experimental results from surveyed articles. A reasonable agreement between the results based on the simplified method and the experimental results demonstrated that the proposed model can simplify the prediction of thermal conductivity improvement and improve the efficiency of designing new polymeric matrix composite with hybrid fillers. This proposed model explains the synergistic effects being achieved in a multipliable manner by hybrid fillers.