A method of fabricating a multilayer circuit board is provided which includes forming a layer of a the multilayer circuit board with an internal clearance region having a modified voltage-to-ground clearance of conductive material adjacent to an aperture of the multilayer circuit board. The modified voltage-to-ground clearance of conductive material is based on a configuration of a connector pin to be press-fit connected within the aperture of the multilayer circuit board, and the internal clearance region is enlarged in a direction of greatest normal force outward from the aperture with insertion of the connector pin into the aperture.

Disclosed is an attenuation reduction structure for high-frequency connection pads of a circuit board with an insertion component. The circuit board includes at least one pair of differential mode signal lines formed thereon. A substrate has upper and lower surfaces respectively provided with at least one pair of upper connection pads and lower connection pads. A first metal layer is formed on the lower surface of the substrate. The first metal layer includes an attenuation reduction grounding pattern structure. The attenuation reduction grounding pattern structure includes a hollow area and at least one protruded portion. The protruded portion extends from the first metal layer in a direction toward the lower connection pads.

A circuit board comprises a plurality of layers, first and second reference conductive vias extending in a vertical direction through at least a portion of the plurality of layers, first and second signal conductive vias extending in the vertical direction between and spaced apart in a horizontal direction from the first and second reference conductive vias through at least a portion of the plurality of layers, and a dielectric region extending in the vertical direction between the first and second signal conductive vias. An air via extends in the vertical direction through the dielectric region between the first and second signal conductive vias. An anti-pad extends in the horizontal direction between the first and second reference conductive vias and surrounding in the horizontal direction the first and second signal conductive vias, the air via, and the dielectric region.

In accordance with the various embodiments disclosed herein, electrical connector footprints, such as printed circuit boards, is described comprising one or more of signal traces that each include a first section that extends parallel to the linear array direction and a second section extends in a direction that is different than the linear array direction.

An electrical connector footprint on a printed circuit board (PCB) can include vias and antipads surrounding those vias. While conventional antipads surrounding vias are large in order to improve impedance of the PCB, the presence of the antipads can compromise the integrity of the ground plane and can permit cross talk to arise between differential pairs on different layers in the PCB. Antipads can be constructed and arranged so as to limit cross talk between layers in a PCB, while also maximizing impedance.

A printed circuit board includes a plurality of layers including attachment layers and routing layers; and via patterns formed in the plurality of layers, each of the via patterns including first and second signal vias forming a differential signal pair, the first and second signal vias extending through at least the attachment layers; ground vias extending through at least the attachment layers, the ground vias including ground conductors; and shadow vias located adjacent to each of the first and second signal vias, wherein the shadow vias are free of conductive material in the attachment layers. The printed circuit board may further include slot vias extending through the attachment layers and located between via patterns.

A printed circuit board includes a plurality of layers including attachment layers and routing layers; and via patterns formed in the plurality of layers, each of the via patterns including first and second signal vias forming a differential signal pair, the first and second signal vias extending through at least the attachment layers; ground vias extending through at least the attachment layers, the ground vias including ground conductors; and shadow vias located adjacent to each of the first and second signal vias, wherein the shadow vias are free of conductive material in the attachment layers. The printed circuit board may further include slot vias extending through the attachment layers and located between via patterns.

Provided in the present disclosure are a via hole structure of a circuit board, and a circuit board. The via hole structure comprises at least one pair of differential signal holes, wherein each pair of differential signal holes comprises a first differential signal hole and a second differential signal hole. In a thickness direction of the circuit board, there are several distances between the central axis of the first differential signal hole and the central axis of the second differential signal hole, and numerical values of at least two distances are different.

A wiring board includes a first insulating layer, a second insulating layer, a first ground conductor, and a first signal conductor. The first insulating layer includes a first upper surface and a first lower surface. The second insulating layer is positioned on the first insulating layer and includes a second upper surface and a second lower surface. The first ground conductor is positioned on the first lower surface and includes a first opening and a second opening. The first signal conductor includes a first line positioned on the first upper surface and a second line positioned on the second lower surface. The first line includes a first end portion and a first line portion. The second line includes a second end portion electrically connected to the first end portion, and a second line portion. The first opening is larger in area than the second opening in a planar view.