Patent ID: 8729407

Claim:
A wiring substrate comprising: a substrate body including first and second surfaces; a trench having an opening part formed on the first surface and including an inner bottom surface, an inner side surface, and a slope surface that connects a peripheral part of the inner bottom surface to a one end part of the inner side surface, and widens from the peripheral part of the inner bottom surface to the one end part of the inner side surface, the one end part of the inner side surface being an end part that is opposite from the first surface of the substrate body; a penetration hole including a first end that communicates with the inner bottom surface and a second end that is open on the second surface; a first conductive layer filling at least a portion of the penetration hole and including a top surface toward the trench; a second conductive layer covering the top surface of the first conductive layer and formed on at least a portion of the trench except for a part of the inner side surface; and a third conductive layer covering the second conductive layer and filling the trench.