A display device includes: a panel substrate configured to display an image; a control printed circuit board to receive an image signal from an external source, to generate data and a control signal based on the image signal, and to provide the data and the control signal to the panel substrate; and a flexible printed circuit board (FPCB) electrically connected to the panel substrate and electrically connected to the control printed circuit board. A first align mark is disposed on the FPCB and a second align mark is disposed on the control printed circuit board.