The present invention relates to printed circuit boards (PCBs), and more particularly, to methods of forming high aspect ratio through holes and high precision stub removal in a printed circuit board (PCB). The high precision stub removal processes may be utilized in removing long stubs and short stubs. In the methods, multiple holes of varying diameter and depth are drilled from an upper and/or lower surface of the printed circuit board utilizing drills of different diameters.

A method for making an interconnection component includes forming a mask layer that covers a first opening in a sheet-like element that includes a first opening extending between the first and second surfaces of the element. The element consists essentially of a material having a coefficient of thermal expansion of less than 10 parts per million per degree Celsius. The first opening includes a central opening and a plurality of peripheral openings open to the central opening that extends in an axial direction of the central opening. A conductive seed layer can cover an interior surface of the first opening. The method further includes forming a first mask opening in at least a portion of the mask layer overlying the first opening to expose portions of the conductive seed layer within the peripheral openings; and forming electrical conductors on exposed portions of the conductive seed layer.

A method is disclosed for making an interconnection component. The steps include forming a mask layer covering a first opening in a sheet-like element that has first and second opposed surfaces; forming a plurality of mask openings in the mask layer, wherein the first opening and a portion of the first surface are partly aligned with each mask opening; and forming electrical conductors on spaced apart portions of the first surface and on spaced apart portions of the interior surface within the first opening which are exposed by the mask openings. The element may consist essentially of a material having a coefficient of thermal expansion of less than 10 parts per million per degree Celsius. Each conductor may extend along an axial direction of the first opening and the first conductors may be fully separated from one another within the first opening.

A method and structure are provided for implementing enhanced via creation without creating a via barrel stub. The need to backdrill during printed circuit board (PCB) manufacturing is eliminated. After the vias have been drilled, but before plating, a via plug with a specialized geometry and including a capillary is inserted into each via to allow electroplating on only preferred wall surfaces of the vias. Then a board plating process of the PCB manufacturing is performed.

A method and structure are provided for implementing enhanced via creation without creating a via barrel stub. The need to backdrill during printed circuit board (PCB) manufacturing is eliminated. After the vias have been drilled, but before plating, a via plug with a specialized geometry and including a capillary is inserted into each via to allow electroplating on only preferred wall surfaces of the vias. Then a board plating process of the PCB manufacturing is performed.

A method and structure are provided for implementing enhanced via creation without creating a via barrel stub. The need to backdrill during printed circuit board (PCB) manufacturing is eliminated. After the vias have been drilled, but before plating, a via plug with a specialized geometry and including a capillary is inserted into each via to allow electroplating on only preferred wall surfaces of the vias. Then a board plating process of the PCB manufacturing is performed.

In some aspects, the techniques described herein relate to an apparatus including: a printed circuit board connector structure, comprising: an outer ground defining a receiving area; and a pair of traces located in the receiving area, the pair of traces collectively having a first side, a second side, a third side, and a fourth side, wherein the outer ground extends around each of the first side, the second side, and the third side of the pair of traces.

A high-speed router backplane is disclosed. The router backplane uses differential signal pairs on multiple signal layers, each sandwiched between a pair of digital ground layers. Thru-holes are used to connect the differential signal pairs to external components. To reduce routing complexity, at least some of the differential signal pairs route through a via pair, somewhere along their path, to a different signal layer. At least some of the thru-holes and vias are drilled to reduce an electrically conductive stub length portion of the hole. The drilled portion of a hole includes a transition from a first profile to a second profile to reduce radio frequency reflections from the end of the drilled hole.

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.

The present invention relates to printed circuit boards (PCBs), and more particularly, to methods of forming high aspect ratio through holes and high precision stub removal in a printed circuit board (PCB). The high precision stub removal processes may be utilized in removing long stubs and short stubs. In the methods, multiple holes of varying diameter and depth are drilled from an upper and/or lower surface of the printed circuit board utilizing drills of different diameters.