The present disclosure relates, according to some embodiments, to the fabrication of a flexible circuit board, which includes forming a base layer comprising polyimide, forming a polyimide layer on the base layer, the polyimide layer having a first surface and a second surface opposite to each other, the first surface being peelably adhered in contact with the base layer, forming a metal layer on the second surface of the polyimide layer, and peeling the base layer from the polyimide layer with the metal layer remaining on the second surface of the polyimide layer.