A display device comprising: a first substrate; a flexible printed circuit disposed on a first area of the first substrate; and a film disposed on the first substrate and the flexible printed circuit, wherein: the flexible printed circuit comprises: a second substrate; a pad unit comprising pads disposed on the second substrate, the pads extending in a first direction and spaced apart from one another in a second direction crossing the first direction; and characterized in that the flexible printed circuit further comprises a dummy pad disposed on the second substrate, the dummy pad being spaced apart from the pad unit; the pads in the pad unit are electrically connected to pads or lines or bumps on the first substrate; this electrical connection is achieved via an adhesive layer, in particular an anisotropically conductive adhesive layer; the dummy pad is spaced apart from the adhesive layer; a first air path is formed between the dummy pad and the pad unit; the first air path is configured to discharge air bubbles disposed between the first substrate and the film to an ambient environment. a first substrate; a flexible printed circuit disposed on a first area of the first substrate; and a film disposed on the first substrate and the flexible printed circuit, wherein: the flexible printed circuit comprises: a second substrate; a pad unit comprising pads disposed on the second substrate, the pads extending in a first direction and spaced apart from one another in a second direction crossing the first direction; and characterized in that the flexible printed circuit further comprises a dummy pad disposed on the second substrate, the dummy pad being spaced apart from the pad unit; the pads in the pad unit are electrically connected to pads or lines or bumps on the first substrate; this electrical connection is achieved via an adhesive layer, in particular an anisotropically conductive adhesive layer; the dummy pad is spaced apart from the adhesive layer; a first air path is formed between the dummy pad and the pad unit; the first air path is configured to discharge air bubbles disposed between the first substrate and the film to an ambient environment. the flexible printed circuit comprises: a second substrate; a pad unit comprising pads disposed on the second substrate, the pads extending in a first direction and spaced apart from one another in a second direction crossing the first direction; and a second substrate; a pad unit comprising pads disposed on the second substrate, the pads extending in a first direction and spaced apart from one another in a second direction crossing the first direction; and characterized in that the flexible printed circuit further comprises a dummy pad disposed on the second substrate, the dummy pad being spaced apart from the pad unit; the pads in the pad unit are electrically connected to pads or lines or bumps on the first substrate; this electrical connection is achieved via an adhesive layer, in particular an anisotropically conductive adhesive layer; the dummy pad is spaced apart from the adhesive layer; a first air path is formed between the dummy pad and the pad unit; the first air path is configured to discharge air bubbles disposed between the first substrate and the film to an ambient environment.