FLAT MASK, METHOD FOR ASSEMBLING FLAT MASK AND MASK ASSEMBLY MANUFACTURED BY THE SAME

摘要

PURPOSE: A flat mask, a method for assembling a flat mask, and a mask assembly manufactured by the same are provided to minimize the initial landing error between the center and upper and lower sides of the periphery of the effective portion. CONSTITUTION: A flat mask(10') comprises an effective portion(12) including strips(12b) having slots(12a) for passage of electron beams and real bridges(12c) for interconnecting adjacent strips and defining the slots; and a non-effective portion(14) arranged at the outer edge of the effective portion, and curved at a predetermined curvature(R) toward the effective portion. The vertical curvature of the shorter side non-effective portion satisfies the range of (140xX4)mm<(R/1000)<(2350xX1)mm within the range of the ratio of the length of minor axis of the effective portion of the mask with respect to the sum of bridge of the real bridge. The curvature increases/decreases in an inverse proportion to the ratio.