A circuit board layer 2 in accordance with the present invention includes a conductive sheet 4 sandwiched between an insulating top layer 10 and an insulating bottom layer 14. The top and bottom layers 10 and 14 and the conductive sheet 4 define the circuit board layer 2 having an edge that includes an edge 20 of the conductive sheet 4. An insulating edge layer 18 covers substantially all of the edge 20 of the conductive sheet 4.