Printed circuit board

A printed circuit board comprises a grounding layer, a top layer, a bottom layer and a connector footprint. The connector footprint is used for installation of a connector and comprises two metal sheets arranged on the top layer. Multiple first passing holes penetrate through the first metal sheet and are electrically connected to the grounding layer. Multiple second passing holes penetrate through the second metal sheet and are electrically connected to the grounding layer. The joint of one first passing hole and the grounding layer and the joint of one second passing hole and the grounding layer are hollowed out respectively, so that a first groove and a second groove are formed. The first groove is communicated with the second groove through a third groove formed in the grounding layer. The joint of another first passing hole and the grounding layer and the joint of another second passing hole and the grounding layer are hollowed out respectively, so that a fourth groove and a fifth groove are formed. The fourth groove and the fifth groove extend so that a sixth groove, a seventh groove, an eighth groove, a ninth groove, a tenth groove and an eleventh groove can be formed. The printed circuit board of an electromagnetic band gap structure can well lower noise, well restrain common-mode noise, and improve signal integrity.