Thermal conductivity of epoxy composites with controlled high loading of ceramic particles

Thermal conductivity and viscosity of epoxy composites were measured in order to study the effects of particle size distribution, by filled with the combination of two different particle sizes of Al₂O₃ ceramic powders. Via the design of different size and weight ratio of fillers, the results showed that the fillers loading have been reached 50~75 wt %, the relative thermal conductivity are in a range of 0.314 to 0.960 W/mK from the original epoxy matrix of 0.20 W/mK and the SEM morphologies showed obviously filler networks with micron and sub-micron size of hybrid fillers. It can be concluded that addition of partial sub-micron size with micron size particles in epoxy composite leads a higher particle packing and exhibits a better thermal performance than the composite filled with only a single size distribution of filler. In processability, the epoxy composites can also adjust the flowability through the design of different particle size distribution for electronic packaging applications.