Circuit board, a semiconductor device and the circuit board assembly

The present invention relates to a circuit board, the circuit board assembly and semiconductor device. Disclosed a circuit board comprising: a substrate including a wiring; a plurality of electrode pads, formed on a surface of the substrate, and external connection terminals to be combined with the electronic component; and a groove formed in the surface of the substrate around the respective electrode pads. Further, the groove is formed a void, the void to a lower element of the electrode pads on the substrate and spaced apart from the surrounding.