Deposition mask

1. A deposition mask used in depositing a depositing material onto a deposition target substrate, comprising a first surface facing to the deposition target substrate, and a second surface opposite to the first surface,

wherein:

the deposition mask includes:

an effective area in which a plurality of through holes are formed;

a longitudinal direction in which one or more of the effective areas are arranged along the longitudinal direction, the longitudinal direction extending from a first end of the deposition mask, through a central portion of the deposition mask, to a second end of the deposition mask; and

a width direction orthogonal to the longitudinal direction;

wherein:

at least in the central portion of the longitudinal direction, the deposition mask is warped to be convex on the first surface in a cross section in the width direction, and

the extent to which the deposition mask is warped is larger in the central portion than in the first and second ends.

2. The deposition mask according to claim 1 , further including a peripheral area surrounding the effective area and a plurality of pitch marks disposed in the peripheral area,

wherein one pitch mark disposed on one side of the effective area in the width direction and closest to the central portion of the longitudinal direction is represented as a first total pitch mark;

wherein one pitch mark disposed on the other side of the effective area in the width direction and corresponding to the first total pitch mark is represented as a second total pitch mark;

wherein D 1 is a measured distance along the width direction between the first total pitch mark and the second total pitch mark when the deposition mask is in a warped state;

wherein D 2 is a measured distance on the first surface of the deposition mask between the first total pitch mark and the second total pitch mark when the deposition mask is in a flat state; and

wherein a value of a difference (D 2 −D 1 ) between a distance D 2 and a distance D 1 is larger than 0 mm and smaller than 0.05 mm.

3. The deposition mask according to claim 1 , further including through holes,

wherein a through hole located closest to an edge on one side of the deposition mask in the width direction and closest to the central portion of the longitudinal direction is represented as a first through hole;

wherein a through hole located closest to an edge on the other side of the deposition mask in the width direction and having a shortest separation distance to the first through hole along the longitudinal direction is represented as a second through hole;

wherein D 1 is a measured distance along the width direction between the first through hole and the second through hole when the deposition mask is in a warped state;

wherein D 2 is a measured distance on the first surface of the deposition mask between the first through hole and the second through hole when the deposition mask is in a flat state; and

a value of a difference (D 2 −D 1 ) between a distance D 2 and a distance D 1 is larger than 0 mm and smaller than 0.05 mm.

4. The deposition mask according to claim 1 ,

wherein the deposition mask includes the central portion and end portions, and wherein the end portions are flat.