A printed circuit board includes a plurality of layers including attachment layers and routing layers; first and second signal vias forming a differential signal pair, the first and second signal vias extending through the attachment layers and connecting to respective signal traces on a breakout layer of the routing layers; an antipad of a first type around and between the first and second signal vias in one or more of the attachment layers; and antipads of a second type around the first and second signal vias in at least one routing layer adjacent to the breakout layer.