Mask assembly for thin film deposition

1. A mask assembly for thin film deposition, comprising:

a frame; and

a mask supported by the frame and comprising a plurality of deposition patterns, each of the plurality of deposition patterns comprising:

a first pattern portion disposed in an active area corresponding to a display area of a display substrate;

a second pattern portion disposed in a dummy area corresponding to a non-display area of the display substrate; and

a third pattern portion disposed in a dummy outer area also corresponding to the non-display area of the display substrate,

wherein the dummy area extends from the active area to the dummy outer area and the dummy outer area extends from the dummy area to an edge of each of the plurality of deposition patterns,

wherein the first pattern portion comprises a plurality of first holes, the second pattern portion comprises a plurality of second holes, and the third pattern portion comprises a plurality of grooves, each of the plurality of grooves penetrating the mask,

wherein the mask comprises a first surface facing the display substrate and a second surface facing away from the display substrate,

wherein each of the plurality of first holes and each of the plurality of second holes are simultaneously etched from the first surface,

wherein each of the plurality of first holes and each of the plurality of second holes are simultaneously etched from the second surface,

wherein each of the plurality of grooves is etched only from the second surface, and

wherein a minimum width of each of the plurality of grooves is less than a minimum width of each of the plurality of first holes.

2. The mask assembly of claim 1 , wherein the first surface contacts the display substrate for the thin film deposition.

3. The mask assembly of claim 1 , wherein the minimum width of each of the plurality of grooves corresponds to a penetration of the first surface of the mask by each of the plurality of grooves.

4. The mask assembly of claim 1 , wherein the plurality of grooves are recessed in the mask and do not penetrate the first surface of the mask.

5. The mask assembly of claim 1 , wherein:

each of the plurality of first holes comprise a first etching portion etched from the first surface of the mask and a second etching portion etched from the second surface of the mask, and

the first etching portion and the second etching portion penetrate an entire depth of the mask.

6. The mask assembly of claim 5 , wherein the minimum width of each of the plurality of first holes corresponds to a protrusion portion where the first etching portion and the second etching portion are connected to each other.

7. The mask assembly of claim 5 , wherein each of the plurality of first holes and each of the plurality of second holes comprise a same shape.

8. The mask assembly of claim 5 , wherein:

each of the plurality of second holes comprise a third etching portion etched from the first surface and a fourth etching portion etched from the second surface, and

the third etching portion and the fourth etching portion penetrate the entire depth of the mask.

9. The mask assembly of claim 8 , wherein a minimum width of each of the plurality of second holes corresponds to a protrusion portion where the third etching portion and the fourth etching portion are connected to each other.

10. The mask assembly of claim 1 , wherein:

each of the plurality of deposition patterns is separately disposed and arranged in a first direction having a plurality of ribs disposed between adjacent deposition patterns of the plurality of deposition patterns,

the first pattern portion, the second pattern portion, and the third pattern portion are continuously arranged in a second direction crossing the first direction, and

the dummy outer area contacts a rib, among the plurality of ribs, disposed between the dummy outer area and the dummy area of the mask.

11. The mask assembly of claim 1 , wherein the plurality of grooves, the plurality of first holes, and the plurality of second holes are arranged in corresponding rows.

12. The mask assembly of claim 11 , wherein the plurality of grooves comprise:

first grooves arranged in the corresponding rows with the plurality of first holes and the plurality of second holes,

second grooves arranged in different rows from the plurality of first holes and the plurality of second holes, and

the first grooves and the second grooves are arranged in different columns.

13. The mask assembly of claim 1 , wherein:

the plurality of first holes and the plurality of second holes are arranged in a lattice, and

at least some grooves among the plurality of grooves are arranged in a zigzag pattern.

14. The mask assembly of claim 1 , wherein each of the plurality of grooves comprise at least one of a non-polygonal shape and a polygonal shape.

15. The mask of claim 1 , wherein:

each of the plurality of second holes and each of the plurality of first holes have a same shape, and

each of the plurality of grooves has a different shape than the plurality of second holes.

16. The mask of claim 1 , wherein the minimum width of the plurality of grooves is less than a minimum width of each of the plurality of second holes.

17. The mask of claim 16 , wherein each of the plurality of second holes comprises a same shape as each of the plurality of first holes.