Patent ID: 8692135

Claim:
A wiring board, constituted by stacking at least one conductor wiring layer and at least one insulating resin layer, comprising: at least one metal via penetrating the insulating resin layer; at least one functional element inside said insulating resin layer, wherein; the insulating resin layer includes a reinforcing component, and a boundary surface between the metal via and the insulating resin layer has a strengthened structure in which the metal via internally engages the reinforcing component, wherein the reinforcing component includes at least one of a particulate reinforcement and a fibrous reinforcement, wherein at least one electrode terminal is formed on an active surface of said functional element embedded, and a first conductor wiring layer disposed nearest to the active surface of the functional element and the active surface of the functional element are wired to each other via the electrode terminal, wherein a second conductor wiring layer disposed on the outermost surface of said wiring board opposite to the active surface of said functional element is covered with said insulating resin except for a wiring surface of the second conductor wiring layer, wherein said first conductor wiring layer and said second conductor wiring layer are wired to each other via said metal via disposed away from said functional element, wherein said metal via does not have any plating seed layer on a boundary surface with insulating resin in contact with a side of the metal via and on a boundary surface with said second conductor wiring layer, and has a plating seed layer on a boundary surface with said first conductor wiring layer.