Provided is a flat panel display device and a method for making the display device that can prevent misalignment of each of the pixels or sub-pixels of a display unit during a manufacturing process. The flat panel display device includes a substrate, a display array unit formed on the substrate, and at least one mark or trace of such a mark formed outside of the display unit. The array includes a plurality of pixels. The plurality of pixels has a layer of a material. The mark has reference for referencing in determining whether a position on a deposition mask relative to the reference means is within a predetermined tolerance limit. The deposition mask is for use in depositing the material to form the layer