The properties of a silicone-based elastomeric thermal pad filled with inexpensive ceramic additives were studied in this research. The effects of the content, particle size and mixing ratio of two additives upon the thermal and di-electrical property of the thermal pad are investigated. The result shows that the higher the content, the higher the thermal and dielectric properties are. In addition, the thermal conductivity of two particles filled thermal pads are higher than that of a single particle filled thermal pad. The thermal conductivity of the two kind of particle sizes (14 and 2 um) of 60 % (vol.) SiC filled thermal pad is the highest (2.14 W/m·K).