Enhanced thermomechanical and dielectric properties of the epoxy composites by incorporating SiO2 and BaTiO3 fillers

As the pace of Moore's Law slows down, the importance of electronic packaging increases and has further become one of the key forces driving the development of semiconductors. The high-density integration and high-performance requirements of chips have brought new challenges to advanced packaging materials. Polymer-based film capacitors which can be embedded in the substrates are highly desired to meet the requirement of miniaturization of the package. Traditional polymer materials are difficult to meet the requirements due to their shortcomings such as low dielectric constant, high loss and high coefficient of thermal expansion (CTE). In this study, high permittivity, low loss and low CTE are simultaneously obtained by introducing BaTiO3 and SiO2 fillers into epoxy resins. The results show that the filling of SiO2 and BaTiO3 can significantly increase the dielectric constant and improve the thermal mechanical properties, while maintaining a low dielectric loss. After adding 45.8 vol% SiO2 and 11.2 vol% BaTiO3, the permittivity of the composite is 8.1 at 1 KHz, and the loss is 0.009, which is decreased by 18.2% compared with pure epoxy resin. And the CTE of 31 ppm/K is reduced by 63% compared to the pure epoxy resin. The results demonstrate great application prospects for the miniaturization of electronic devices.