Improvement of electrical and material properties of epoxy resin/aluminum nitride nanocomposites for packaging materials

摘要

This paper presents the influence of Aluminum Nitride (AlN) nanoparticles on the electrical and material properties of epoxy resin (EP). The EP/AlN nanocomposites with different concentrations of nano-AlN fillers are prepared. The dispersion of the nano-AlN particles in the composites is analyzed by a field emission scanning electron microscope (FESEM). The electrical properties are investigated by the space charge and DC conductivity measurements, whereas the material properties are studied by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The results show that the homo-charge accumulation appears near both electrodes during the polarization, but there are limited negative charges left near both electrodes in the depolarization for the pure EP sample. There is no space charge accumulation in the 1 wt% and 2 wt% EP/AlN nanocomposites. The electric field distortion of the pure EP sample is 20%. Moreover, the electric field distortion initially decreases with the increase of the nano-AlN content, but it increases for the 2 wt% nano-AlN sample. Temperature has a dominant influence on the DC conductivity of the EP/AlN nanocomposites comparing to the pure EP. However, the DC conductivity of the nanocomposites becomes stable at high temperatures. It is also found that the weight loss of the samples decreases with the addition of the nano-AlN and the 1 wt% nano-AlN sample has the highest glass transition temperature. It is elucidated that the high apparent mobility and activation energy facilitate the space charge transport and suppressing the space charge accumulation. Furthermore, the nano-AlN filler can increase the trap level and trap energy density of the deep traps in the sample. The dielectric loss of the EP at high frequency is reduced with the content of 1 wt% nano-AlN. Furthermore, the addition of the nano-AlN can improve the thermal stability of the EP. The 1 wt% nano-AlN sample has the superior electrical insulation and material performance amongst the tested materials.