Analysis of local heat transfer properties of tape-cast AlN ceramics using photothermal reflectance microscopy

Photothermal reflectance microscopy was applied to the analysis of local thermal diffusivity on tape-cast AIN ceramics. The materials were obtained from three different commercial powders, two sintering temperatures (1750 and 1800 degrees C), and 3 wt % Y2O3 sintering aid. Owing to the high spatial resolution of the technique (similar to 30 mu m in the present case), measurements in different positions on the sample surface were carried out. In this way a study of the homogeneity of thermal properties was performed.