A display device is disclosed. In one aspect, the display device comprises a display panel, a window cover, at least one align key and a sealing portion. The display panel includes a substrate, a display unit formed over the substrate, and an encapsulation portion formed over the display unit. The window cover is formed over the display panel. The at least one align key is formed on the encapsulation portion and configured to align the display panel with the window cover. The sealing portion is formed between the substrate and the encapsulation portion, wherein the align key has at least one laser beam through portion passing through the encapsulation portion and is connected to the sealing portion.