Embedded wiring board and a manufacturing method thereof

Abstract

An embedded wiring board includes an upper wiring layer, a lower wiring layer, an insulation layer, a first conductive pillar and a second conductive pillar. The upper wiring layer contains an upper pad, the lower wiring layer contains a lower pad, and the insulation layer contains an upper surface and a lower surface opposite to the upper surface. The upper pad is embedded in the upper surface and the lower pad is embedded in the lower surface. The first conductive pillar is located in the insulation layer and includes an end surface which is exposed by the upper surface. A height of the first conductive pillar relative to the upper surface is larger than a depth of the upper pad relative to the upper surface. In addition, the second conductive pillar is located in the insulation layer and is connected between the first conductive pillar and the lower pad.

Dependencies are inferred from the claim text.