| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively provide a circuit board of high reliability and high thermal conductivity. SOLUTION: In a circuit board, a metallic circuit is formed on one face of an aluminium nitride substrate and a metallic radiation plate on the other face by using Al-Si system wax materials. The materials of the metallic circuit and the metallic radiation plate are aluminium or aluminium alloy. In the aluminium nitride substrate, the intensity peak ratio (IYA/IAlN) of the X-ray diffraction intensity IYA of Y2O3.Al2O3 (121) with respect to the X-ray diffraction intensity IAlN of aluminium nitride (101) is 0.07-0.25, thermal conductivity is not less than 160 W/mK and bending strength is not less than 35 kg/mm2. Copper, nickel, copper-nickel alloy or copper-nickel clad layers are formed on the upper face of the metallic circuit and/or the metallic radiation plate. |
