Tension mask assembly for use in vacuum deposition of thin film of organic electroluminescent device

1. A mask frame assembly for use in vacuum deposition of thin films of an organic electroluminescent device, the mask frame assembly comprising:

a frame having an opening; and

at least two unit masks, each unit mask comprising:

at least one unit masking pattern portion for the deposition of the thin films, the at least one unit masking pattern portion formed in a length direction of the unit mask, and

two edges which are fixed to the frame under tension applied in the length direction, wherein the at least two unit masks are spaced apart from each other in the opening of the frame.

2. The mask frame assembly according to claim 1 , wherein the at least two unit masks are formed by strips in the length direction.

3. The mask frame assembly according to claim 1 , wherein the frame comprises:

support members arranged parallel to each other; and

elastic members which connect the edges of said support members.

4. The mask frame assembly according to claim 3 , wherein the support members and the elastic members are formed as a single body.

5. The mask frame assembly according to claim 1 , wherein said at least one unit masking pattern portion comprises slits defined by stripe extending in the direction of the unit masking pattern portion parallel to each other.

6. The mask frame assembly according to claim 5 , wherein said strips of said at least two masking pattern portions have non-uniform widths in consideration of tension to be exerted thereon.

7. The mask frame assembly according to claim 1 , wherein said at least one unit masking pattern portion comprises openings in a predetermined pattern.

8. The mask frame assembly according to claim 1 , wherein the at least two unit masks are joined at opposite ends of the unit masks by a connecting portion which maintains the unit masks transversely spaced apart from each other in the opening of the frame.

9. A mask frame assembly for use in vacuum deposition of thin films of an organic electroluminescent device, the mask frame assembly comprising:

a frame having an opening; and

at least two unit masks, each unit mask having two opposing edges fixed to said frame under tension, wherein adjacent unit masks are spaced apart within the opening of the frame so as to have a gap in a predetermined interval between the adjacent unit masks.

10. The mask frame assembly according to claim 9 , wherein each said unit mask has at least one pattern portion in a direction of the unit mask.

11. The mask frame assembly according to claim 9 , wherein each said unit mask is welded to said frame by spot welding.

12. The mask frame assembly according to claim 9 , wherein each said unit mask is welded to said frame by YAG laser welding.

13. The mask frame assembly according to claim 9 , wherein each said unit mask has at least one masking pattern including strips in a direction of the length of said unit mask such that the length of said strips is determined in consideration of Poisson's contraction caused by the tension exerted on each said unit mask.

14. The mask frame assembly according to claim 9 , wherein a gap between the adjacent masks is maintained in a range of 0.01-1 mm.

15. The mask frame assembly according to claim 9 , wherein the adjacent unit masks are joined at opposite ends of the unit masks by a connecting portion which spaces the adjacent unit masks apart.

16. A mask frame assembly for use in vacuum deposition of thin films of an organic electroluminescent device, the mask frame assembly comprising:

a frame having a rectangular opening; and

at least two unit masks for the deposition of the thin films, each unit mask having two opposing edges fixed to the frame under tension applied in a length direction of each unit mask,

wherein portions of the frame, to which each unit mask is fixed, are parallel to each other.

17. The mask frame assembly according to claim 16 , wherein the at least two unit masks are formed by strips in the length direction and are fixed to the frame such that the unit masks do not physically contact each other.