Patent ID: 8598698

Claim:
An integrated circuit (IC) package substrate, comprising: a core layer with a through-hole extending between opposing surfaces of the core layer; a stiffener embedded in the core layer, wherein the stiffener material surrounds a perimeter of the core layer; a plurality of metal layers with a plurality of transmission traces placed on each side of the opposing surfaces of the core layer; and a plurality of build-up layers, each having a plurality of vias, stacked alternately with the plurality of metal layers, the plurality of vias on each of the plurality of build-up layers connecting the plurality of transmission traces on one adjacent build-up layer to the plurality of transmission traces on another adjacent metal layer, wherein one or more of the plurality of vias at least partially overlaps an inner peripheral surface of the stiffener, and the inner peripheral surface of the stiffener conforms to a shape of an outer surface of the overlapping one or more of the plurality of vias.