| 摘要 |
Disclosed is an aluminum nitride substrate for a circuit board, the substrate having aluminum nitride crystal grains with an average grain size of 2 to 5 µm and a thermal conductivity of at least 170 W/m·K. The aluminum nitride substrate does not include a dendritic grain boundary phase and has a breakdown voltage of at least 30 kV/mm at 400 °C. Also provided is a method for producing the aluminum nitride substrate, including the steps of heating a raw material containing an aluminum nitride powder to 1500 °C at a pressure of at most 150 Pa, then increasing and holding the temperature at 1700 to 1900 °C in a pressurized atmosphere of at least 0.4 MPa using a non-oxidizing gas, then cooling to 1600 °C at a cooling rate of at most 10 °C/min. |
