The invention relates to the technical field of PCB structures, discloses a PCB. The PCB includes a substrate, a
metal block, and a heat dissipating hole; the substrate has a stepped groove; the metalblock is arranged in the stepped groove and same as the stepped groove in shape, and a heat conduction medium is arranged between the top surface of the
metal block and a component; the heat dissipating hole is formed in the substrate, and the heat dissipating hole and the
metal block can be used for heat conduction. By forming a groove in the PCB, embedding the metal block making direct contactwith the component and forming the heat dissipating hole which can be used for heat conduction with the metal block, heat generated by the component and heat in a metal layer in the PCB can be timelyand rapidly dissipated, the heat dissipation performance of the PCB is improved, and the service life of the PCB and the component is prolonged.