Patent ID: 8552308

Claim:
A differential signal pair transmission structure adapted to be disposed on a wiring board and transmit a differential signal pair, the wiring board including a circuit stack and the circuit stack comprising an upper surface and a lower surface opposing the upper surface, the differential signal pair transmission structure comprising: a first signal path used to transmit one of the differential signal pair, the first signal path comprising: a first upper trace adapted to be disposed on the upper surface; a first lower trace adapted to be disposed on the lower surface; and a first conductive through via adapted to pass through the circuit stack and extending from the upper surface to the lower surface, and connecting an end of the first upper trace and an end of the first lower trace; and a second signal path used to transmit the other of the differential signal pair, the second signal path comprising: a second upper trace adapted to be disposed on the upper surface; a second lower trace adapted to be disposed on the lower surface; and a second conductive through via adapted to pass through the circuit stack and extending from the upper surface to the lower surface, and connecting an end of the second upper trace and an end of the second lower trace, wherein a portion of the first signal path and a portion of the second signal path overlap in the normal projection onto the upper surface, and the normal projection of the first signal path and the normal projection of the second signal path projecting onto the upper surface are substantially symmetric with respect to a line which is perpendicular to a segment connecting the normal projection of axis of the first through via and the normal projection of axis of the second through via onto the upper surface and passes through the midpoint of the segment.