Patent ID: 7554040

Claim:
A printed circuit board comprising: a first insulating plate having first and second surfaces, the first surface forming a front surface of the printed circuit board; a first metal foil formed on the first surface of the first insulating plate; a second insulating plate having third and fourth surfaces, the fourth surface forming a back surface of the printed circuit board; a second metal foil formed on the fourth surface of the second insulating plate; a third metal foil formed between the second surface of the first insulating plate and third surface of the second insulating plate; a through hole formed through the first and second insulating plates, in which a lead is inserted and dip soldered using lead free solder, the through hole having a first tubular metal foil formed on a first inner surface of the through hole, and a plurality of via holes formed through the first and second insulating plates around the through hole, each of the plurality of the via holes having a second tubular metal foil formed on a second inner surface of the corresponding via hole, wherein the first metal foil includes an annular metal foil located around the through hole and spaced from the plurality of via holes by a predetermined distance, wherein the first metal foil has an annular area, located around the annular metal foil, exposing a part of the first surface of the first insulating plate, wherein the plurality of via holes are formed within the annular area, and wherein the first tubular metal foil of the through hole and the second tubular metal foil of each of the plurality of via holes are directly connected to both the second and third metal foils.