| 摘要 |
PROBLEM TO BE SOLVED: To obtain the highly reliable product, by decreasing the number of wiring layers constituting a multi-layer circuit board and increasing the manufacturing yield rate. SOLUTION: A via connecting land, which has the interval larger than the interval of vias 16 provided at a core substrate 10 at wiring layers 12a and 12b formed on one surface of the core substrate 10 and is selected at the arrangement, where the maximum number of the land can be selected, and the drawing land, to which a wiring is connected, other than these via-connecting lands, are selected. For the land located at the outer surface of the region where the above described lands are arranged, the wirings are withdrawn from both the drawing land and the via connecting land at the same time. For the drawing lands which are aligned in the inside of the above described region, at least one wiring is aligned between the neighboring lands, and the lands which are arranged at the diagonal-line position in the above described region and the vicinity hereof are withdrawn preferentially. Thus, the wirings are withdrawn from all the drawing lands and electrically connected to the vias 16 penetrating the core substrate 10. For the via-connecting lands, where the wirings are not withdrawn at the wiring layers 12a and 12b formed on one surface, the lands are electrically connected to the vias 16 penetrating the core substrate 10. |
