Organic EL display provided with gel-state encapsulant incorporating a desiccant and a high molecular-weight medium
View Patent ↗A sealing substrate is arranged to oppositely face an element substrate on which organic EL layers are formed in a matrix array with a sealing material sandwiched therebetween. A gel-state desiccant is filled in an inner space surrounded by the element substrate, the sealing substrate and the sealing material. Since the gel-state desiccant is in a gel state, the gel-state desiccant is flexibly filled in the inner space of the organic EL display device thus completely eliminating a gap. Since the inner space is filled with the gel-state desiccant, moisture hardly intrudes into the inner space from the outside and, at the same time, a mechanical strength of the organic EL display device is also enhanced.
1. A manufacturing method of an organic EL display device which includes a first substrate on which organic EL layers are formed in a matrix array, a second substrate which is flat and faces the first substrate in an opposed manner, and a sealing material which is formed in an annular shape between inner peripheries of the first substrate and the second substrate, the manufacturing method of an organic EL display device comprising the steps of:
forming the organic EL layers on a lower electrode, an upper electrode on the organic EL layers, and a protective film on the upper electrode, wherein the second substrate is flat;
forming a sealing material made of an ultraviolet-ray curing resin in an annular shape on the periphery of the second substrate, and forming a half-cured sealing material for stopping a gel-state desiccant by radiating ultraviolet rays to the sealing material;
arranging the gel-state desiccant inside the half-cured sealing material using the half-cured sealing material as a stopper;
adhering the first substrate and the second substrate, and filling a region surrounded by the first substrate, the second substrate and the sealing material with the gel-state desiccant; and
forming the half-cured sealing material into a completely cured sealing material, wherein
the gel-state desiccant is sandwiched between the protective film and the second substrate.
2. A manufacturing method of an organic EL display device according to claim 1 , wherein in the step of adhering the first and second substrates, the first substrate and the second substrate are laminated to each other in a reduced pressure atmosphere, and the gel-state desiccant is filled in the region surrounded by the first substrate, the second substrate and the sealing material in an atmospheric-pressure atmosphere.
3. A manufacturing method of an organic EL display device according to claim 1 , wherein at least the steps of forming the sealing material, arranging the gel-state desiccant and adhering the first and second substrates are performed in a nitrogen atmosphere.