Abstract: AlN/PE composite substrate was made by mould pressing. The influences of AlN percentage and morphology on the thermal conductivity were studied and the model for predicting thermal conductivity was discussed. The results demonstrate that with the increasing of AlN percentage, the thermal conductivity remains the same initially, after that it increases sharply, and then the rate slows down. The AlN whisker increases the thermal conductivity most efficiently, the second is that AlN fiber and AlN powder are of less efficiency.

Key words: aluminum nitride, thermal conductivity, composite substrat