Substrate and manufacturing method of the same

A method of manufacturing a substrate, comprising the steps of:

• forming, on a first surface of a substrate, a plurality of internal terminals and a first conducting wire for electric connection to the internal terminals,
• forming, on a second surface of the substrate opposite to the first surface, a plurality of external terminal electrodes and a second conducting wire for electric connection to the external terminal electrodes, and
• forming a plurality of first through-holes electrically connecting the first conducting wire to the second conducting wire, in a region surrounded by the external terminal electrodes so that the first through-holes are collectively arranged in the region;
• forming an outer peripheral wire for plating on a peripheral portion of the first surface,
• forming at least one wire for plating extending from the outer peripheral wire for plating to electrically connect the outer peripheral wire for plating and the collectively arranged plurality of first through-holes together so that the wire for plating branches on the second surface at one position in a middle of the wire via a second through-hole and then connects to the respective first through-holes, and electrically connecting the outer peripheral wire for plating, the first conducting wire and the second conducting wire together through the wire for plating and then subjecting the outer peripheral wire for plating, the first conducting wire, the second conducting wire and the wire for plating to electroplating;
• and
• forming a penetrating hole in the second through-hole portion of the wire for plating and cutting the second through-hole portion off to make the wire for plating and the collectively arranged plurality of first through-holes independent of each other as different wires so that no electric conduction occurs among the wire for plating and the first through-holes.