Patent ID: 8237056

Claim:
A multilayer printed wiring board, comprising: a plurality of resin insulation layers including an outermost resin insulation layer; a plurality of pads configured to mount an electronic component and being formed in a pad-forming region on the outermost resin insulation layer; a stiffener formed in a stiffener region on the outermost resin insulation layer; an inner-layer resin insulation layer formed underneath the outermost resin insulation layer; an inner-layer conductive circuit formed on the inner-layer resin insulation layer; and a via conductor formed in the outermost resin insulation layer and connecting one of the plurality of pads to the inner-layer conductive circuit, wherein the upper surface of the stiffener and the upper surfaces of the pads are positioned at substantially the same level, wherein the total area of an upper-surface of the stiffener is substantially the same as the total area obtained by adding together an area of an upper surface of each of the plurality of pads.