| 摘要 |
PURPOSE:To cope with a high speed signal by forming a hollow part in the interface of a substratum, connecting and retaining wiring patterns by vias, and arranging them in the hollow part. CONSTITUTION:A multilayer ceramic board is formed by laminating and baking a plurality of printed sheets wherein a wiring pattern 1 is formed on each surface layer. The wiring patterns 1 formed on lamination interfaces of the substratums 3 are interlayer-connected by using vias 4. A hollow part 5 is formed on the interface of the substratum 3. The wiring patterns are connected and retained by using the vias, and arranged in the hallow part 5. As the result, the wiring pattern 1 is arranged in the separated state from the ceramic substratum 3, so that the permittivity of an insulating layer can be made approximate to that of the air, thereby increasing the signal propagation speed. |
