| 摘要 |
PURPOSE:To provide the aluminum nitride substrate capable of assuring excellent electrical conduction by oxidizing the alimunum substrate in nitrogen atmosphere in low oxygen concentration. CONSTITUTION:Within the aluminum nitride substrate, inner conductors 2 are formed between insulating layers 1 comprising aluminum nitride made sintered body while the inner conductors 2 in respective layers are connected by through holes 3 filled up with a conductor to be led out as a surface conductors 4 on the substrate surface. Next, the aluminum nitride substrate on whose surface the conductor is formed is heat-treated to form an Al2O3 film in the nitrogen atmosphere in oxygen concentration of 50-1500ppm at the temperature exceeding 1100 deg.C thereby enabling an oxide film 5 to be formed without increasing the resistance. Accordingly, the chemical resistance of the substrate can be stiffened without disturbing the electrical connection between conductors due to lamination thereby enabling the reliability upon the substrate to be enhanced. |
