A method of manufacturing a display device including the steps of providing a lower substrate having a display area and a pad area, forming a display structure in the display area of the lower substrate, forming pad electrodes in the pad area of the lower substrate to be spaced apart from each other in a first direction parallel to a top surface of the lower substrate, forming an upper substrate on the display structure to face the lower substrate in the display area, forming a conductive film member including a non-cured resin layer and conductive balls arranged in a lattice shape on the pad electrodes, the non-cured resin layer overlapping the pad electrodes, and forming a film package on the non-cured resin layer, the film package including bump electrodes overlapping the pad electrodes.