Method of fabricating organic light emitting display device
View Patent ↗The present invention relates to a flat panel display, and more particularly, to a method of fabricating an organic light emitting display device so as to improve device characteristics by patterning a plurality of organic layers using a heat transfer method to optimize thicknesses according to R, G and B pixels. The method includes: forming lower electrodes of R, G and B pixels on an insulating substrate; forming an organic layer on the insulating substrate; and forming an upper electrode on the organic layer. Formation of the organic layer includes forming a hole injection layer and a hole transport layer of the R, G and B pixels on the entire surface of the substrate as a common layer. The R and G emission layers are patterned by a heat transfer method using a heat transfer device having a transfer layer such that an organic layer is patterned to a thickness obtained by subtracting a thickness of the B emission layer from the thicknesses of the R and G emission layers required in R and G colors.
1. A method of fabricating an organic light emitting display device, comprising the steps of:
forming lower electrodes of R, G and B pixels on a substrate;
forming an organic layer on the substrate; and
forming an upper electrode on the organic layer;
wherein the step of forming the organic layer comprises:
forming hole injection layers and hole transport layers of the R, G and B pixels on an entire surface of the substrate as a common layer;
forming R and G emission layers on the hole transport layers of the R and C pixels, respectively; and
forming a B emission layer as a common layer on an entire surface of the substrate which includes the R and G emission layers;
wherein the R and G emission layers are formed by patterning through a heat transfer method using a heat transfer device having a transfer layer so that the R and G emission layers are patterned to a thickness obtained by subtracting the thickness of the B emission common layer from optically optimized thicknesses of an R emission layer and a G emission layer required in R and G colors in a case where the B emission layer is patterned and not common.
2. The method according to claim 1 , wherein the organic layer is formed of a thin film, the R and G emission layers required in R and G colors have thicknesses in a range of 300˜400 Å and 250˜350 Å, respectively, the B emission layer has a thickness in a range of 100˜200 Å, and the patterned R and G emission layers have thicknesses in a range of 100˜300 Å and 50˜250 Å, respectively.
3. The method according to claim l, wherein the R and G emission layers are made of phosphorescent material and the B emission layer is made of fluorescent material.
4. The method according to claim l, wherein the B emission layer is made of fluorescent material so as to act as a hole blocking layer.
5. A method of fabricating an organic light emitting display device, comprising the steps of:
forming lower electrodes of R, G and B pixels on a substrate;
forming an organic layer on the substrate; and
forming an upper electrode on the organic layer;
wherein the step of forming the organic layer comprises forming hole injection layers of the R, G and B pixels on an entire surface of the substrate, patterning hole transport layers of the R and G pixels, patterning emission layers of the R and G pixels, and forming an emission layer of the B pixel as a common layer over the entire surface of the substrate which includes the emission layers of the R and G pixels; an
wherein the hole transport layers and the emission layers of the R and G pixels are simultaneously formed by a heat transfer method using a heat transfer device having an organic layer as a transfer layer in which the hole transport layers and the emission layers are respectively patterned, and wherein thicknesses of the hole transport layers of the R and G pixels respectively are equal to a difference between a sum of optically optimized thicknesses of the hole injection layer and the hole transport layers of the R and G pixels respectively when the hole transport layer and the hole injection layer are formed as a common layer and a thickness of the hole injection layer of the B pixel.
6. The method according to claim 5 , wherein the emission layers of the R, G and B pixels, the hole injection layers of the R and G pixels, and the hole transport layers of the R and G pixels are formed of thick organic films, the B pixel has a hole transport layer with a zero thickness, the hole injection layer has a thickness of about 1350 Å, and the hole transport layers of the R and G pixels have thicknesses of about 1000 Å and 350 Å, respectively.
7. The method according to claim 5 , wherein the R and G emission layers are patterned to a thickness obtained by subtracting the thickness of the emission layer of the B pixel from thicknesses of emission layers of R and G pixels required in the R and G colors in a case where the hole transport layer and the hole injection layer are formed as a common layer.
8. The method according to claim 7 , wherein the emission layers of the R and G pixels required in the R and G colors have thicknesses in a range of 300˜400 Å and 250˜350 Å, respectively, the emission layer of the B pixel has a thickness in a range of 100˜200 Å, and the patterned emission layers of the R and G pixels have thicknesses in a range of 100˜300 Å and 50˜250 Å, respectively.
9. The method according to claim 5 , wherein the emission layers of the R and G pixels are made of phosphorescent material and the emission layer of the B pixel is made of fluorescent material.
10. The method according to claim 5 , wherein the emission layer of the B pixel is made of fluorescent material so as to act as a hole blocking layer.