| CPC H05K 1/113 (2013.01) [H05K 2201/0266 (2013.01); H05K 2201/09563 (2013.01)] | 20 Claims |
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1. A wiring substrate, comprising:
a first conductor pattern;
a second conductor pattern facing the first conductor pattern;
an insulating layer interposed between the first conductor pattern and the second conductor pattern and having a through hole; and
a plating conductor integrally formed with the second conductor pattern and filling the through hole formed in the insulating layer such that the plating conductor is in contact with the first conductor pattern,
wherein the through hole has an expansion part such that an opening width of the through hole on a first conductor pattern side is widened, and the plating conductor includes a first plating film directly formed on an inner wall of the through hole and a second plating film formed on the first plating film such that a minimum thickness of the first plating film in the expansion part is in a range of 55% to 95% of a minimum thickness of the first plating film in the through hole other than the expansion part.
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