Thermal shock behavior of Al-Y2O3 doped aluminum nitride ceramics

Abstract

Thermal shock resistance and mechanical reliability of aluminum nitride (AlN) ceramic substrates are essential in electronic device modules. In this study, the thermal shock behavior of AlN doped with aluminum - yttrium oxide (Al - Y2O3) was explored. The results indicate that adding Al to AlN ceramics increases its flexural strength, thermal conductivity, and thermal expansion coefficient. The microcracks caused by thermal mismatch between the AlN matrix and the secondary phases relieved internal stress, thereby improving thermal shock resistance of AlN ceramics. Furthermore, the addition of Al isolates and homogenizes the secondary phases, resulting in a more uniform microstructure and strengthened grain boundaries, which enhance the flexural strength, Weibull modulus, and thermal shock resistance. After introducing 0.5 wt% Al, the Weibull modulus of AlN ceramics increased by 73.37%, and their critical thermal shock temperature difference exceeded 800°C, with a maximum residual strength of 488.01 ± 48.26 MPa at 600°C. Overall, an appropriate amount of Al improves the reliability and thermal shock resistance of AlN ceramics.