Patent ID: 9392692
Filing Date: 2016-07-12
CPC Classification: H01L,H05K,Y10T

Claim Text:
1. A wiring substrate comprising: a resin substrate in which a first through hole and a second through hole are formed; a metallic foil that is formed on one surface of the resin substrate, coats the first and second through holes, and is separated into a first side metallic foil and a second side metallic foil by a border portion existing in an area between the first through hole and the second through hole; a first connecting portion formed by a plating film connected to the first side metallic foil inside the first through hole; a second connecting portion formed by a plating film connected to the second side metallic foil inside the second through hole; a first slit formed so as to face the border portion across the first connecting portion and penetrate through the metallic foil and the first connecting portion; a second slit formed in parallel with the first slit so as to face the border portion across the second connecting portion and penetrate through the metallic foil and the second connecting portion; a first plating layer that is directly formed on a front surface of the first side metallic foil, a bottom surface of the first connecting portion, a side surface of the first connecting portion, and a side surface of the first side metallic foil, the side surfaces of the first connecting portion and the first side metallic foil being exposed inside the first slit, prior to the first plating layer being formed; and a second plating layer that is directly formed on a front surface of the second side metallic foil, a bottom surface of the second connecting portion, a side surface of the second connecting portion, and a side surface of the second side metallic foil, the side surfaces of the second connecting portion and the second side metallic foil being exposed inside the second slit, prior to the first plating layer being formed, wherein the first slit and the second slit are arranged so that the border portion separating the first side metallic foil from the second side metallic foil is positioned in an area between the first slit and the second slit.