A method for manufacturing a FPCB substrate includes the following steps. First, a FPCB material including an insulation layer and an electrically conductive layer formed on the insulation layer is provided. The electrically conductive layer has a first surface and an opposite second surface. The insulation layer has a third surface and an opposite fourth surface. The third surface comes into contact with the second surface. Secondly, a through hole extends from the first surface to the fourth surface is formed. The through hole includes a metal hole in the electrically conductive layer and an insulation hole in the insulation layer. Thirdly, the insulation hole is enlarged to expose a portion of the electrically conductive layer around the metal hole. Finally, the exposed portion is bent to form a hook which passes through the enlarged insulation hole and protrudes out from the fourth surface of the insulation layer.