Thermal and dielectric behaviour of polypropylene composites reinforced with ceramic fillers

This study aims at investigating the thermal and dielectric behaviour of thermoplastic polymer based packaging materials for microelectronics applications. Thermally conducting, but electrically insulating, polymer matrix composites that exhibit low value of coefficient of thermal expansion (CTE) are needed for electronic packaging. For developing such composites, two different ceramics i.e. micro-sized aluminium nitride and aluminium oxide (Al₂O₃) are reinforced in polypropylene individually. Compression moulding technique is used for fabrication purpose. Thermal properties like effective thermal conductivity (k_eff), glass transition temperature (T_g), CTE and electrical property like dielectric constant (ε_c) of composites are measured and reported. In addition, physical properties and morphological features are also studied. The experimental findings are interpreted using appropriate theoretical models. The results show that, while the incorporation of filler improves the k_eff and T_g, the CTE decreases favourably and also increase in dielectric constant is suitably controlled. It is found that the measured properties of the composites are suitable for certain applications like electronic packaging and printed circuit boards.