Patent ID: 7307437

Claim:
A multi-layer circuit board, comprising: a plurality of conductive layers; one or more non-conductive layers, wherein a non-conductive layer of the one or more non-conductive layers is located between first and second conductive layers of the plurality of conductive layers; and a test-signal passage that comprises: a conductive pad located on the second conductive layer; a through-opening in the non-conductive layer; a through-opening in the first conductive layer; wherein the conductive pad comprises an exposed conductive face in a general direction toward the first conductive layer; wherein the through-openings of the non-conductive layer and the first conductive layer cooperate to expose the exposed conductive face through the non-conductive layer to an exterior face of the first conductive layer; wherein the test-signal passage avoids conductive contact with the exposed conductive face and walls of the through-openings of the non-conductive layer and the first conductive layer.