Method of forming shadow mask pattern

1. A method of forming a pattern on a mask sheet including an attaching portion fastened to a mask frame, and a pattern area in which the pattern is formed, the method comprising:

positioning the mask sheet on an auxiliary sheet with a thickness greater than the thickness of the mask sheet;

fastening the auxiliary sheet to the mask frame;

applying a stretching force to the mask sheet and the auxiliary sheet; and

forming the pattern on the pattern area of the mask sheet.

2. The method of claim 1 , wherein the forming the pattern comprises:

setting an initial point to start forming the pattern on the pattern area of the mask sheet; and

forming the pattern along a spiral line from the initial point.

3. The method of claim 2 , wherein the initial point is approximately the center of the pattern area of the mask sheet, and the spiral line transits spirally outward toward an edge thereof.

4. The method of claim 2 , wherein the initial point is approximately an edge of the pattern area of the mask sheet, and the spiral line transits spirally inward toward the center thereof.

5. The method of claim 1 , wherein the stretching force is applied bi-directionally to the mask sheet and the auxiliary sheet.

6. The method of claim 1 , wherein the mask sheet is formed of invar, elinvar, or a stainless steel selected from the group consisting of SUS 304, SUS 430 and SUS 304+SUS 430.