A circuit board includes a substrate, a conductive pattern arranged on the substrate that includes an interconnecting circuit. The circuit board also includes a plurality of land pads having a pair of first land pads on which no electronic components are mounted and electrically connected to each other through the interconnecting circuit. The circuit board further includes an insulating layer on the substrate. The insulating layer has first openings that allow the pair of the first land pads to be exposed through the insulating layer.