Method and apparatus for manufacturing mask assembly and method of manufacturing display device

A method of manufacturing a mask assembly, the method comprising:

• preparing a mask frame comprising at least one opening;
• preparing a mask sheet comprising a cell area corresponding to the at least one opening and a dummy portion arranged outside the cell area;
• tensioning the mask sheet;
• aligning the mask sheet to a side of the mask frame;
• pressing the dummy portion of the mask sheet toward the mask frame;
• and
• fixing the mask sheet to the mask frame by irradiating a laser beam to the dummy portion,
• wherein the pressing the dummy portion comprises bending a portion of the dummy portion relative to the cell area.

A method of manufacturing a display device, the method comprising:

• preparing a mask assembly;
• placing and aligning a substrate and the mask assembly inside a chamber;
• and
• supplying a deposition material from a deposition source to the substrate through the mask assembly,
• wherein the preparing the mask assembly comprises:
• tensioning a mask sheet comprising a cell area and a dummy portion arranged outside the cell area;
• aligning the mask sheet above a mask frame comprising at least one opening;
• pressing the dummy portion of the mask sheet toward the mask frame;
• and
• fixing the mask sheet to the mask frame by irradiating a laser beam to the dummy portion,
• wherein the pressing the dummy portion comprises bending a portion of the dummy portion relative to the cell area.