PURPOSE: To omit power and grounding wirings, to simplify the arrangement of a bypass capacitor and to improve the reliability of a circuit by a method wherein penetrated holes for mounting IC and penetrated holes for mounting, which come into contact with a power layer and a grounding layer, are provided in a substrate body, which is constituted by laminating the power layer and the grounding layer interposing an intermediate insulating layer between the layers.

CONSTITUTION: A universal substrate body 10 is constituted by laminating a power layer 12 and a grounding layer 14 interposing an intermediate insulating layer 13 between the layers. A plurality of pieces of penetrated holes 16a, 16b, 16c, 16d, 26a, 26b, 26c, 26d,... for IC mounting, which penetrate the substrate body between both main surfaces of the substrate body, are bored on the main surfaces; and a plated layer 18b which comes into contact with the power layer 12 is exposed its end parts on the main surfaces in the penetrated holes in the following line (b) adjacent to the penetrated holes in the line (a) of each penetrated hole group, such as 16b-26b...n6b, 17b-27b...n7b, and is connected to a plated layer 18a on the inner surface of each penetrated hole in the line (a) of each penetrated hole group through a solder 19b. Similarly, a plated layer 18c which comes into contact to the grounding layer 14 is exposed its end parts on the main surfaces in the penetrated holes in the line (c) on the previous side adjacent to the line (d) of each penetrated hole group, such as 16c-26c...n6c, 17c-27c...n7c,... and is connected to a plated layer 18d on the inner surface of each penetrated hole in the line (d) of each penetrated hole group through a solder 19c.