A circuit board device includes a transition region that includes a first conductive layer at a first level, a second conductive layer at a second level, and conductive vias. The first conductive layer includes a pad connected to the solderless connector, a transmission line, and a first reference layer. The transmission line includes first and second segments. A second width of the second segment is the same as or less than a first width of the first segment. The first reference layer has a first anti-pad region for the pad and the transmission line disposed therein. In a plan view, the first anti-pad region surrounding the pad is completely located within a second anti-pad region of a second reference layer of the second conductive layer. The conductive vias are disposed between the first and second conductive layers and surround the pad.