Layer-layer registration coupon for printed circuit boards

An apparatus comprising:

• a printed circuit board (PCB) panel including at least one PCB, wherein the PCB panel includes a plurality of internal layers, wherein the PCB panel includes:
• a DC resistance coupon, wherein the DC resistance coupon includes:
• first and second terminals electrically coupled to one another by a first circuit trace on the first one of the plurality of internal layers, wherein the first and second terminals are accessible for performing resistance measurements on the first circuit trace;
• and
• third and fourth terminals electrically coupled to one another by a second circuit trace on the second one of the plurality of internal layers, wherein the third and fourth terminals are accessible for performing resistance measurements on the second circuit trace;
• and
• a first registration coupon including a center terminal and a plurality of peripheral terminals surrounding the center terminal, wherein the plurality of peripheral terminals are grouped into pairs, each pair of peripheral terminals is electrically coupled to the center terminal on a corresponding one of the plurality of internal layers, and wherein the center terminal is accessible for performing resistance measurements between itself and any one of the plurality of peripheral terminals;
• wherein the plurality of peripheral terminals includes a first pair of terminals accessible for determining misregistration, if any, of a first one of the plurality of internal layers along a first axis, and further comprises a second pair of terminals accessible for determining a misregistration, if any, of a second one of the plurality of internal layers along a second axis.

A method comprising:

• determining an amount of resistance per unit of distance on each of a first internal layer and a second internal layer of a printed circuit board (PCB) panel including at least one PCB;
• measuring first and second resistances on a first registration coupon, wherein the first resistance is measured between a center and first peripheral terminals of the first registration coupon, and wherein the second resistance is measured between the center terminal and a second peripheral terminal of the first registration coupon, wherein each of the first and second peripheral terminals are electrically connected to the center terminal on the first internal layer;
• determining a difference between the first and second resistances;
• and
• determining a distance and direction of misregistration of the first internal layer, along a first axis, based on the difference between the first and second resistances and the amount of resistance per unit of distance of the first internal layer.