Patent ID: 8455770

Claim:
A wiring board, comprising: an insulating layer; a first solder resist layer formed on a first surface of the insulating layer and defining a first opening portion; a first electrode formed on the first surface of the insulating layer and within the first opening portion such that a front surface of the first electrode is exposed from the first opening portion and a back surface of the first electrode directly abuts the first surface of the insulating layer, the back surface of the first electrode being opposite to the front surface of the first electrode; a wiring portion having a via plug and a pattern wiring, the via plug being formed within the insulating layer and being connected to the back surface of the first electrode, the pattern wiring being formed on a second surface of the insulating layer, the second surface of the insulating layer being opposite to the first surface of the insulating layer; a second solder resist layer formed on the second surface of the insulating layer and covering part of the wiring portion, the second solder resist layer defining a second opening portion through which part of the wiring portion is exposed; and a second electrode formed on the part of the wiring portion exposed through the second opening portion, wherein at least part of the first electrode is embedded within the first opening portion of the first solder resist layer, and an outermost side surface of the first electrode is in contact with an inner wall surface of the first solder resist layer defining the first opening portion, the outermost side surface of the first electrode extending between the front surface and the back surface of the first electrode.