Electrical connector system

A header assembly for mounting an electrical connector to a substrate, the header assembly comprising:

• a plurality of ground shields, each ground shield defining at least one ground substrate engagement element at a mounting face of the header assembly;
• and
• a plurality of signal pins, each signal pin defining a signal substrate engagement element at the mounting face of the header assembly;
• wherein each signal pin of the plurality of signal pins is associated with another signal pin of the plurality of signal pin to define a signal pin pair;
• wherein the ground substrate engagement elements and signal substrate engagement elements are positioned on the mounting face of the header assembly such that there is at least one ground substrate engagement element positioned directly between each signal substrate engagement element and any of the closest non-paired signal substrate engagement element neighbors.

A substrate configured to receive an electrical component, the substrate comprising:

• a plurality of first vias positioned on the substrate, the first vias arranged in a matrix of rows and columns and configured to provide mounting of the electric component, each first via associated with one of its closest neighbor first vias in a horizontal manner to form a pair of first vias;
• and
• a plurality of second vias capable of being electrically commoned to one another;
• wherein the second vias are positioned amongst the plurality of first vias such that each second via is positioned between a first via of a first pair of first vias and a first via of a second pair of first vias that is adjacent to the first pair of first vias.