Circuit board and manufacturing method thereof

The invention discloses a circuit board. The circuit board comprises a circuit substrate, a conductive polymeric membrane layer and a copper plating shielding layer, wherein the circuit substrate comprises a conductive circuit layer and a third insulating layer; the conductive circuit layer and the conduction circuit layer are formed on the two opposite sides of the third insulating layer; the conductive circuit layer comprises a signal circuit and a grounding circuit; the copper plating shielding layer is formed on the surface of the copper plating shielding layer in an electroplating way; a second conductive hole is formed in the third insulating layer; the grounding circuit is electrically connected to the copper plating shielding layer through the second conductive hole. The invention also provides a manufacturing method of the circuit board.