Mask assembly having a plurality of projections at a boundary of adjacent two deposition masks

A mask assembly including:

• a plurality of deposition masks each defined with an aperture region and a shielding region which is a periphery of the aperture region, at least one of opposite ends of each of the plurality of deposition masks is formed to have a pattern with a plurality of projections;
• a frame coupled to the plurality of deposition masks arranged continuously,
• wherein the plurality of projections of each of the plurality of deposition masks and the plurality of projections of an adjacent deposition mask are arranged to face each other, to form at least one boundary aperture region at a boundary of the adjacent two deposition masks,
• wherein the aperture region and the at least boundary aperture region are arranged respectively according to a plurality of cells formed on an active region of the substrate for receiving an organic material,
• wherein the plurality of projections of each of the plurality of deposition masks includes two faced curves meeting at a contact point which a width between the two faced curves becomes the smaller as the two curves come closer to the contact point,
• wherein apexes of the boundary aperture regions are contacted with each other along the boundary, and
• wherein each of the plurality of projections has a pointed horn shape at the boundary of the adjacent two deposition masks at the contact point.