| 摘要 |
PURPOSE:To obtain a circuit substrate having excellent high heat conductivity, high withstand voltage and the like by a method wherein conductive paste or dielectric paste is printed on the aluminum nitride ceramic substrate formed by calcinating by adding a kind selected from yttrium, rare-earth metal and alkaline earth metal, and they are calcined at the specific or lower temperature. CONSTITUTION:Yttrium oxide equipment 5wt.% of Y-element is added to aluminum nitride AlN raw material powder of 95wt.%, and after they have been mixed and molded, the molded body is sintered at 1800 deg.C in nitrogen gas, and a dense Al substrate is obtained. Then, the AlN substrate is coated with Au paste, an Au thick film conductor path pattern of about 15mum thick is formed, and it is calcined at 580 deg.C for ten minutes. The metal wettability of a sintered body, which is substantially consisting of AlN only, is very poor, but by adding yttrium, rare-earth metal and alkaline earth metal, a conductor path in which thick film conductive paste is used, can be formed without deterioration in characteristics of the AlN substrate of high heat conductivity. |
