Organic light emitting display and method of fabricating the same

Abstract

An organic light emitting display in which differential pressure is controlled to prevent Newton's rings from being generated and a method of fabricating the same are provided. The organic light emitting display includes a first substrate including a pixel region in which at least one organic light emitting diode (OLED) is formed and a non-pixel region, a second substrate attached to one region including the pixel region of the first substrate, and a frit provided between the non-pixel region of the first substrate and the second substrate. At least one of the first substrate and the second substrate is formed to be convex outward.

1 . An organic light emitting display (OLED) device, comprising:
 a first substrate comprising a first outer surface and a first inner surface;   a second substrate generally opposing the first substrate, the second substrate comprising a second outer surface and a second inner surface;   an array of organic light emitting pixels interposed between the first and second substrates; and   a frit seal interposed between the first and second substrates while surrounding the array, wherein the frit seal, the first substrate, and the second substrate in combination define an enclosed space in which the array is located;   wherein the second substrate has a curvature sufficient to substantially reduce Newton's rings on the second substrate compared to when there is no curvature in the second substrate.   
     
     
         2 . The device of  claim 1 , wherein the second substrate bends outward. 
     
     
         3 . The device of  claim 1 , wherein the second substrate bends inward. 
     
     
         4 . The device of  claim 1 , wherein the second substrate is more flexible than the first substrate. 
     
     
         5 . The device of  claim 1 , wherein the enclosed space has a gas pressure substantially the same as the atmospheric pressure. 
     
     
         6 . The device of  claim 1 , wherein a distance between the first and second inner surfaces is greater than about 10 μm. 
     
     
         7 . The device of  claim 6 , wherein the first substrate has a reflectance of about 60% to about 70%, and wherein the second substrate has a reflectance of about 4%. 
     
     
         8 . The device of  claim 1 , wherein the second substrate comprises a material selected from the group consisting of bare glass and edge glass. 
     
     
         9 . The device of  claim 1 , further comprising another sealing structure interposed between the first and second substrates, wherein the other sealing structure surrounds the frit seal. 
     
     
         10 . The device of  claim 9 , wherein the other sealing structure and the frit seal forms a gap therebetween. 
     
     
         11 . The device of  claim 1 , wherein the frit seal comprises one or more materials selected from the group consisting of magnesium oxide (MgO), calcium oxide (CaO), barium oxide (BaO), lithium oxide (Li 2 O), sodium oxide (Na 2 O), potassium oxide (K 2 O), boron oxide (B 2 O 3 ), vanadium oxide (V 2 O 5 ), zinc oxide (ZnO), tellurium oxide (TeO 2 ), aluminum oxide (Al 2 O 3 ), silicon dioxide (SiO 2 ), lead oxide (PbO), tin oxide (SnO), phosphorous oxide (P 2 O 5 ), ruthenium oxide (Ru 2 O), rubidium oxide (Rb 2 O), rhodium oxide (Rh 2 O), ferrite oxide (Fe 2 O 3 ), copper oxide (CuO), titanium oxide (TiO 2 ), tungsten oxide (WO 3 ), bismuth oxide (Bi 2 O 3 ), antimony oxide (Sb 2 O 3 ), lead-borate glass, tin-phosphate glass, vanadate glass, and borosilicate. 
     
     
         12 . An organic light emitting display (OLED) device, comprising:
 a first substrate comprising a first outer surface and a first inner surface;   a second substrate generally opposing the first substrate, the second substrate comprising a second outer surface and a second inner surface;   an array of organic light emitting pixels interposed between the first and second substrates; and   a frit seal interposed between the first and second substrates while surrounding the array, wherein the frit seal, the first substrate, and the second substrate in combination define an enclosed space in which the array is located,   wherein the second substrate has a curvature, wherein a tangential line at an edge of the second inner surface and the first outer surface have an angle therebetween, the tangential line being perpendicular to the edge of the second inner surface, and wherein the angle is greater than 0° and is sufficient to substantially reduce Newton's rings on the second substrate compared to when the angle is 0°.   
     
     
         13 . The device of  claim 12 , wherein the second substrate bends outward. 
     
     
         14 . The device of  claim 12 , wherein the second substrate bends inward. 
     
     
         15 . The device of  claim 12 , wherein the enclosed space has a gas pressure substantially the same as the atmospheric pressure. 
     
     
         16 . The device of  claim 12 , wherein the second substrate is substantially more flexible than the first substrate. 
     
     
         17 . A method of making an organic light emitting display (OLED) device, the method comprising:
 providing a first substrate and an array of organic light emitting pixels, the array being formed over the first substrate;   placing a second substrate over the first substrate so as to interpose the array between the first and second substrates;   interposing a frit between the first and second substrates while surrounding the array, wherein the frit, the first substrate, and the second substrate in combination define an enclosed space in which the array is located, wherein the frit substantially hermetically seals the enclosed space, wherein the enclosed space has a predetermined gas pressure; and   subjecting the device to the atmospheric pressure so as to form a curvature in the second substrate.   
     
     
         18 . The method of  claim 17 , wherein the atmospheric pressure is 760 Torr. 
     
     
         19 . The method of  claim 17 , wherein after forming the curvature, the gas pressure within the enclosed space is substantially equal to the atmospheric pressure outside the enclosed space. 
     
     
         20 . The method of  claim 17 , wherein the predetermined gas pressure is sufficiently different from the atmospheric pressure given pliability of the second substrate so as to form such a curvature in the second substrate when subjecting the device to the atmospheric pressure. 
     
     
         21 . The method of  claim 17 , wherein the second substrate generally bends outward after subjecting the device to the atmospheric pressure. 
     
     
         22 . The method of  claim 21 , wherein the predetermined gas pressure is higher than the atmospheric pressure. 
     
     
         23 . The method of  claim 17 , wherein the second substrate generally bends inward after subjecting the device to the atmospheric pressure. 
     
     
         24 . The method of  claim 23 , wherein the predetermined air pressure is lower than the atmospheric pressure. 
     
     
         25 . The method of  claim 17 , wherein the second substrate is substantially more flexible than the first substrate. 
     
     
         26 . The method of  claim 17 , further comprising providing a second seal interposed between the first and second substrates, wherein the second seal surrounds the frit before subjecting the device to the atmospheric pressure. 
     
     
         27 . The method of  claim 17 , further comprising holding one of outer surfaces of the first and second substrates by suction during interposing the frit.