Experimental analysis demonstrates enhanced thermal stability and extended lifespan in cerium dioxide-doped silicone gel, suggesting viable encapsulants for high-density power electronics.
Key Points
Investigate whether low-concentration ceramic particle fillers can improve the thermal stability and high-temperature electrical performance of silicone gel encapsulants without substantially increasing viscosity.
Incorporated low concentrations of CeO2, modified AlN, and Al2O3 particles into silicone gel encapsulants.
Evaluated viscosity, decomposition temperature at 95% mass, methyl oxidation activation energy, thermal expansion, electrical conductivity, and dielectric properties under high-temperature conditions.
Silicone gel filled with 0.5 wt% CeO2 achieved the highest decomposition temperature and activation energy for methyl oxidation while limiting viscosity increase to only 10%.
The estimated operating lifespan at 250 °C for 0.5 wt% CeO2-filled silicone gel increased by approximately 150 times compared to undoped silicone gel.
The 0.5 wt% CeO2 composite maintained low electrical conductivity and low thermal expansion coefficients at elevated temperatures alongside substrate-compatible dielectric constants.