A circuit board assembly in a camera module for blocking unwanted light when images are captured includes a circuit board, a sensor, and an optical blocking body connecting the circuit board and the sensor. The circuit board includes a base board and a photomask. The photomask is arranged on a surface of the base board, the base board includes conductive circuit layers and dielectric layers, the conductive circuit layers and the dielectric layers are alternately arranged, the sensor being electronically connected to the conductive layers. The optical blocking body, the photomask, and the dielectric layers block ambient light entering the camera module other than through the lens assembly of the camera module.