Mask assembly and deposition apparatus of the same
A mask assembly includes a first mask having a first opening and at least one second mask disposed on the first mask, each at least one second mask including a deposition area having second openings, an inner area surrounding the deposition area, and an outer area having third openings which surround the margin area. A line defining the outer boundary of an inner surface which defines the first opening overlaps the inner area when viewed in plan.
1 . A mask assembly comprising:
a first mask having a first opening; and
at least one second mask disposed on the first mask, each of the at least one second mask comprising a deposition area having second openings, an inner area surrounding the deposition area, and an outer area having third openings which surround the inner area,
wherein a line defining an outer boundary of an inner surface which defines the first opening overlaps the inner area when viewed in plan,
wherein the at least one second mask defines a thickness direction,
wherein the inner area is solid with no openings formed therein, and
wherein a minimum width of the inner area in a direction orthogonal to the thickness direction is greater than a maximum separation distance between adjacent second openings of the seconds openings.
2 . The mask assembly of claim 1 , wherein the inner area has a closed-line shape when viewed in plan.
3 . The mask assembly of claim 1 , wherein the third openings are covered by the first mask when viewed from a rear side of the first mask.
4 . The mask assembly of claim 1 , wherein the inner area has a width between about 200 micrometers and about 500 micrometers when viewed in plan.
5 . The mask assembly of claim 1 , wherein each of the second openings has a size different from a size of each of the third openings.
6 . The mask assembly of claim 1 , wherein a separation distance between the second openings adjacent to each other among the second openings is different from a separation distance between the third openings adjacent to each other among the third openings.
7 . The mask assembly of claim 1 , wherein the second openings have a shape different from a shape of the third openings.
8 . The mask assembly of claim 1 , wherein each of the second mask further comprises a welding area attached to the first mask and surrounding the outer area.
9 . The mask assembly of claim 1 , wherein a boundary between the deposition area and the inner area is defined as a first boundary line, a boundary between the inner area and the outer area is defined as a second boundary line when viewed in plan, and the first boundary line comprises a portion projecting toward the deposition area.
10 . The mask assembly of claim 9 , wherein the second boundary line comprises a portion projecting toward the deposition area to correspond to the projecting portion of the first boundary line.
11 . The mask assembly of claim 1 , further comprising a module area surrounded by the deposition area and provided with module openings formed therein, wherein the module openings have a shape different from a shape of the second openings.
12 . The mask assembly of claim 1 , further comprising a non-deposition area surrounded by the deposition area.
13 . The mask assembly of claim 1 , wherein the second mask has a thickness in at least a portion of the inner area smaller than a thickness of the second mask in the deposition area.
14 . The mask assembly of claim 1 , wherein the second mask comprises at least one of stainless steel, Invar, nickel, cobalt, nickel alloy, and nickel-cobalt alloy.