Patent ID: 7183491

Claim:
A printed wiring board, comprising: at least two conductor layers spaced from each other in a thickness direction and parallel to a top surface of the printed wiring board, and embedded in a dielectric; a plurality of pads formed on the top surface with a plurality of wires extending from the pads, wherein at least two of the plurality of pads are adjacent to each other to form a pad group where differential signals pass and each of the at least two of the plurality of pads have an impedance value, and a hole formed in the dielectric and filled with the dielectric to define a first area below the pad group; wherein a first conductor layer of the at least two conductor layers is closest to the top surface and extends over a second area of the dielectric outside of the first area, a second conductor layer of the at least two conductor layers is formed below the first conductor layer and extends below the first area, a sum of the impedance values for each of the at least two of the plurality of pads is a predetermined impedance, and the predetermined impedance is set by the differential signals sent by the at least two of the plurality of pads to the second conductor layer.