Organic light emitting display apparatus including viscoelastic layer and method for manufacturing the same
Disclosed is an organic light emitting display (OLED) apparatus that includes a substrate; an organic light emitting element on the substrate, the organic light emitting element including a first electrode, an organic light emitting layer and a second electrode; a viscoelastic layer on the organic light emitting element, wherein an elastic portion of the viscoelastic layer is about 30% or more, the elastic portion being defined by <Equation 1>: Elastic portion (E p ) (%)=(σ/σ 0 )×100, wherein σ 0 is an initial stress generated when a strain of about 50% is applied to the viscoelastic layer and σ is a final stress measured after the strain is continuously applied thereto for about 180 seconds, with the initial stress σ 0 and the final stress σ being measured at about 80° C. through a relaxation modulus test.
1. An organic light emitting display (OLED) apparatus, comprising:
a substrate;
an organic light emitting element on the substrate, the organic light emitting element including a first electrode, an organic light emitting layer and a second electrode;
a viscoelastic layer on the organic light emitting element, wherein an elastic portion of the viscoelastic layer is about 30% or more, the elastic portion being defined by Equation 1:
Elastic portion( E p )(%)=(σ/σ 0 )×100, <Equation 1>
wherein σ 0 is an initial stress generated when a strain of about 50% is applied to the viscoelastic layer and σ is a final stress measured after the strain is continuously applied thereto for about 180 seconds, with the initial stress σ 0 and the final stress σ being measured at about 80° C. through a relaxation modulus test.
2. The OLED apparatus according to claim 1 , further comprising a passivation layer between the organic light emitting element and the viscoelastic layer, wherein the passivation layer has a combination of an organic layer and an inorganic layer.
3. The OLED apparatus according to claim 1 , wherein the viscoelastic layer satisfies at least one of a water vapor transmissibility of about 10 g/m 2 /day or less, a visible light transmissibility of about 95% or more, and a modulus of about 0.3 MPa or less.
4. The OLED apparatus according to claim 1 , wherein the viscoelastic layer includes at least one of acryl resin, olefin resin and synthetic rubber.
5. The OLED apparatus according to claim 1 , further comprising an encapsulation film on the viscoelastic layer.
6. The OLED apparatus according to claim 5 , wherein the encapsulation film has a combination of an organic layer and an inorganic layer.
7. The OLED apparatus according to claim 6 , wherein the organic layer of the encapsulation film is in contact with the viscoelastic layer.
8. The OLED apparatus according to claim 6 , wherein the organic layer of the encapsulation film includes at least one of acryl resin, epoxy resin, polyimide resin and polyethylene.
9. The OLED apparatus according to claim 6 , wherein the inorganic layer of the encapsulation film includes at least one of Al 2 O 3 , SiO 2 , Si 3 N 4 , SiON, AlON, AlN, TiO 2 , ZrO, ZnO and Ta 2 O 5 .
10. The OLED apparatus according to claim 5 , further comprising a circular polarizing plate on the encapsulation film, and a touch film on the polarizing plate.