A circuit board comprises a substrate with opposite first and second sides. A pair of plated through holes (PTHs) extends along z-axis. A pair of signal traces are made on the first side of the substrate and electrically coupled to the pair of the PTHs respectively to form a differential pair. A ground metal is made on the second side of the substrate, the ground metal has a clearance made therein. The ground metal extends fully overlapping with the full signal traces to eliminate reflection noise caused by a boundary between the clearance and the metal ground.

A circuit board comprises a substrate with opposite first and second sides. A pair of plated through holes (PTHs) extends along z-axis. A pair of signal traces are made on the first side of the substrate and electrically coupled to the pair of the PTHs respectively to form a differential pair. A ground metal is made on the second side of the substrate, the ground metal has a clearance made therein. The ground metal extends fully overlapping with the full signal traces to eliminate reflection noise caused by a boundary between the clearance and the metal ground.

A printed circuit board (PCB) may include a plurality of horizontally disposed signal layers. The PCB may include a first vertically disposed differential via electrically connected to a first horizontally disposed signal layer, of the plurality of horizontally disposed signal layers, and a second horizontally disposed signal layer of the plurality of horizontally disposed signal layers. The PCB may include a second vertically disposed differential via electrically connected to the first signal horizontally disposed layer and the second horizontally disposed signal layer. The PCB may include a first set of clearances encompassing the first vertically disposed differential via and the second vertically disposed differential via, a second set of clearances encompassing the first vertically disposed stub, and a third set of clearances encompassing the second vertically disposed stub.

A multilayer printed wiring board including insulating layers, ground layers thereon, and at least one via hole. The ground layers include a wiring layer and a first impedance adjustment layer. The wiring layer includes a solid conductor and a conductive line. The conductive line is disposed inside an opening and a passage of the solid conductor. The first impedance adjustment layer includes a solid conductor having an opening. The via hole is located inside the openings of the wiring layer and the first impedance adjustment layer and is connected to the conductive line. A first distance is smaller than a second distance, where the first distance is a distance from an outline of the opening of the wiring layer to the via hole, and the second distance is a distance from an outline of the opening of the first impedance adjustment layer to the via hole.

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.

An electronic device includes a printed circuit board. The printed circuit board includes a plurality of different signaling planes and a plurality of different reference planes. A single ended via interconnects the plurality of different signaling planes. A return via interconnects the plurality of different reference planes. The electronic device includes a shared void that includes the single ended via and the return via.

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.

A printed circuit board (PCB) may include a plurality of horizontally disposed signal layers. The PCB may include a first vertically disposed differential via electrically connected to a first horizontally disposed signal layer, of the plurality of horizontally disposed signal layers, and a second horizontally disposed signal layer of the plurality of horizontally disposed signal layers. The PCB may include a second vertically disposed differential via electrically connected to the first signal horizontally disposed layer and the second horizontally disposed signal layer. The PCB may include a first set of clearances encompassing the first vertically disposed differential via and the second vertically disposed differential via, a second set of clearances encompassing the first vertically disposed stub, and a third set of clearances encompassing the second vertically disposed stub.

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.