| 摘要 |
PURPOSE:To improve insulation between conductors in reliability even if pinholes occur at the burning of a ceramic layer by a method wherein an insulating layer, which is burnable at a temperature lower than the lowest temperature at which the ceramic layer can be burned, is formed on the surface of the ceramic layer. CONSTITUTION:An alumina printed layer 4a, to which an opening is provided so as to expose a part of a high melting metal inner conductor 3, is formed, and a via-fill conductor layer 5 of high melting point metal conductor is formed in the opening so as to be electrically connected to the inner conductor 3. In the same manner as above, an alumina printed layer 4b, a via-fill conductor 5b, and an alumina printed layer 4c are successively formed. A high melting point metal inner conductor 6 is formed into a prescribed pattern, an alumina printed layer 7a, a via-fill conductor layer 8a, an alumina printed layer 7b,... are successively formed, and a glass printed layer 9 is formed on the uppermost layer 7c. By this setup, even if defects such as pinholes or the like occur in the alumina printed layers 7a, 7b, and 7c, the glass printed layer 9 gets into the defects concerned to prevent a ceramic laminated board of this design from decreasing in insulation. |
