09549466 cites 6 patents.
A circuit board includes a circuit board plate, a conductive ring, a solder mask and at least one insulating pad. The circuit board plate includes a surface and a conductive through hole passing through the surface and the circuit board plate, wherein the conductive through hole have a conductive layer disposed on a wall thereof. The conductive ring on the surface surrounds an opening of the conductive through hole on the surface and electrically connects to the conductive layer. The solder mask is disposed on the surface. The conductive ring is exposed outside of the solder mask. The insulating pad has a thickness. The first surface of the insulating pad is adapted to contact the solder mask or the surface and sited at periphery of the conductive ring. The second surface of the insulating pad is adapted for spacing a distance between a solder coating tool and the solder mask.