Organic light-emitting display device and manufacturing method thereof

Abstract

The present disclosure relates to an organic light-emitting display device and a method for manufacturing the same. The organic light-emitting display device includes: a first substrate on which a plurality of organic light-emitting diodes are disposed; a second substrate bonded to the first substrate via a sealant, and on which a plurality of light-coloring units corresponding to the plurality of organic light-emitting diodes are disposed; and a plurality of spacers disposed between the plurality of organic light-emitting diodes and the plurality of light-coloring units to maintain a space between the first and second substrates.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0160340 filed on December 12, 2018, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] One or more embodiments relate to an organic light emitting display device and a method of manufacturing the same, and more particularly, to an organic light emitting display device using a quantum dot thin film layer and a method for manufacturing the same. Background Art

[0004] Typically, an organic light-emitting display device produces an image by emitting light based on the principle that holes and electrons injected from an anode and cathode, respectively, recombine with each other in an organic emission layer. For example, an organic light-emitting display device includes pixels that emit red, green, or blue light, and combines these colored lights to represent a desired color.

[0005] To this end, each pixel includes an organic light-emitting diode (OLED) that emits a single color of light, such as white or blue, as well as a quantum dot film layer and a color filter layer. These layers serve as a light coloring unit for converting the monochromatic light into a desired color, such as red, green, or blue, to emit light. That is, when the OLED in each pixel generates monochromatic light, as the monochromatic light passes through the quantum dot film layer and the color filter layer, it is converted into red, green, or blue light, thereby emitting colored light. Thus, by combining the colors of the individual pixels, an image with the desired color can be created. Summary of the Invention

[0006] Filler is used between the OLED and the light tinting unit to maintain a clear space between them. If this space is too large, light generated by the OLED may not only be emitted by the light tinting unit for that pixel, but also by the light tinting unit for another pixel. Consequently, the desired color may not be accurately produced, resulting in an image with undesirable mixed colors. This can result in product defects.

[0007] One or more embodiments include an organic light emitting display device enhanced to effectively suppress undesired color mixing between adjacent pixels and a method for manufacturing the organic light emitting display device.

[0008] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosed embodiments.

[0009] According to one or more embodiments, an organic light-emitting display device includes: a first substrate on which a plurality of organic light-emitting diodes are disposed; a second substrate bonded to the first substrate via a sealant, and on which a plurality of light-coloring units respectively corresponding to the plurality of organic light-emitting diodes are disposed; and a plurality of gap retainers disposed between the plurality of organic light-emitting diodes and the plurality of light-coloring units and maintaining a space between the first substrate and the second substrate.

[0010] Each of the space maintainers may include: a spacer disposed between the plurality of organic light emitting diodes and protruding toward the second substrate; and a coating layer disposed between the plurality of light tinting units and contacting the spacer.

[0011] The organic light emitting display device may further include a thin film encapsulation layer covering the plurality of organic light emitting diodes, wherein the spacer is disposed on the thin film encapsulation layer.

[0012] The thin film encapsulation layer may not directly contact the plurality of light tinting units.

[0013] The organic light-emitting display device may further include an inorganic layer disposed on an inner surface of the second substrate, wherein the coating layer is disposed on the inorganic layer.

[0014] The space maintainer may comprise an opaque material.

[0015] The organic light emitting display device may further include a filler disposed between the plurality of organic light emitting diodes and the plurality of light coloring units.

[0016] Each of the plurality of organic light emitting diodes may generate monochromatic light of the same color.

[0017] The monochromatic light may include one of white light or blue light.

[0018] Each of the plurality of light-coloring units may include a quantum dot film layer facing the plurality of organic light-emitting diodes and a color filter layer disposed between the second substrate and the quantum dot film layer. The quantum dot film layer and the color filter layer may color the monochromatic light generated by the plurality of organic light-emitting diodes into red, green, or blue light.

[0019] The organic light emitting display device may further include a black matrix disposed between the light coloring units of the second substrate, wherein the black matrix blocks light transmission.

[0020] According to one or more embodiments, a method for manufacturing an organic light-emitting display device includes: forming a plurality of organic light-emitting diodes on a first substrate, wherein each of the plurality of organic light-emitting diodes generates monochromatic light of the same color; forming a plurality of spacers between the plurality of organic light-emitting diodes on the first substrate; forming a plurality of light-coloring units on a second substrate and corresponding to the plurality of organic light-emitting diodes; forming a plurality of coating layers between the plurality of light-coloring units on the second substrate and corresponding to the plurality of spacers; and bonding the first substrate to the second substrate by using a sealant so that the spacers are in contact with the coating layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a cross-sectional view of an organic light emitting display device according to an embodiment.

[0022] Figure 2 yes Figure 1 An enlarged cross-sectional view of the internal structure of an organic light-emitting diode.

[0023] Figures 3A to 3F It is used for manufacturing Figure 1 A cross-sectional view of a process for an organic light-emitting display device.

[0024] Figure 4 is a cross-sectional view of an organic light emitting display device according to another embodiment. DETAILED DESCRIPTION

[0025] Reference will now be made in detail to the exemplary embodiments, examples of which are shown in the accompanying drawings, wherein like reference numerals may refer to like elements throughout. In this regard, the exemplary embodiments may have different forms and should not be construed as limited to the description set forth herein. Therefore, the exemplary embodiments are described below solely with reference to the accompanying drawings to explain various aspects of the present disclosure.

[0026] Because the present disclosure allows for various variations and numerous embodiments, exemplary embodiments will be illustrated in the accompanying drawings and described in detail in the written description. The effects and features of the present disclosure and methods for achieving the same will be readily apparent to those skilled in the art from the following detailed description, which, in conjunction with the accompanying drawings, discloses exemplary embodiments. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0027] Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings may represent the same elements, and thus description thereof may be omitted.

[0028] The sizes of elements in the drawings may be exaggerated for convenience of explanation.

[0029] It will be understood that when a layer, region or component is referred to as being “connected” or “coupled to” another layer, region or component, it can be “directly connected or coupled” to the other layer, region or component or “indirectly connected to” the other layer, region or component with intervening elements therebetween.

[0030] Figure 1 is a cross-sectional view of an organic light emitting display device according to an embodiment. Figure 1 A set of red, green and blue pixels is shown. However, it will be appreciated that there may be multiple sets of colored pixels in a product.

[0031] As shown in the figure, in this embodiment, the organic light-emitting display device includes a first substrate 110, which is bonded to a second substrate 210 via a sealant 300. A plurality of organic light-emitting diodes 120 are disposed on the first substrate 110, and a plurality of light-coloring units such as quantum dot film layers 230R, 230G, and 230B and color filter layers 220R, 220G, and 220B are disposed on the second substrate 210. The quantum dot film layers 230R, 230G, and 230B are also labeled as QD-R, QD-G, and QD-B, respectively; and the color filter layers 220R, 220G, and 220B are also labeled as CF-R, CF-G, and CF-B, respectively.

[0032] like Figure 2 As shown in , in the present embodiment, the organic light emitting diode 120 includes an organic emission layer 122 provided between an anode electrode 121 and a cathode electrode 123. When electrons and holes injected from the anode electrode 121 and the cathode electrode 123, respectively, recombine with each other in the organic emission layer 122 to emit light, the organic light emitting diode 120 generates light. Reference numeral 124 denotes an insulating layer. The light generated by the organic light emitting diode 120 is monochromatic light such as white light or blue light. Red, green, and blue pixels generate monochromatic light of the same color. That is, the organic light emitting diode 120 generates monochromatic light, and the light coloring unit of each pixel converts the monochromatic light into red light, green light, or blue light. Reference numeral 130 denotes a thin film encapsulation layer, which protects the organic light emitting diode 120 by covering the organic light emitting diode 120. The thin film encapsulation layer 130 may include a single organic layer or an inorganic layer or include a multilayer in which an organic layer and an inorganic layer are stacked in sequence.

[0033] In this embodiment, the light tinting unit includes quantum dot film layers 230R, 230G and 230B and color filter layers 220R, 220G and 220B. The quantum dot film layers 230R, 230G and 230B convert the monochromatic light generated by the organic light emitting diode 120 into red light, green light or blue light. The color filter layers 220R, 220G and 220B filter out scattered light that may be partially mixed in the conversion result (i.e., red light, green light or blue light). Reference numeral 250 denotes a black matrix that is provided between each pixel and provides light shielding. Reference numeral 260 denotes an inorganic layer covering the color filter layers 220R, 220G and 220B and the black matrix 250.

[0034] In the present embodiment, a plurality of spacers 140 are disposed on the thin film encapsulation layer 130 and a plurality of coating layers 240 are disposed on the inorganic layer 260 as gap maintainers for maintaining an appropriate interval between the first substrate 110 and the second substrate 210 .

[0035] In this embodiment, the spacer 140 and coating layer 240 comprise an opaque material. When the first substrate 110 is bonded to the second substrate 210, the spacer 140 contacts the coating layer 240, thereby maintaining the gap G between the first and second substrates 110, 210. In other words, rather than using a separate filler between the first and second substrates 110, 210 to maintain the gap, the spacer 140 and coating layer 240 are positioned so as to contact each other between the organic light-emitting diodes 120 and between the light-tinting units to maintain the gap. This allows the gap G to be maintained without using a separate filler between the first and second substrates 110, 210. Consequently, the gap G between the organic light-emitting diodes 120 and the quantum dot thin film layers 230R, 230G, and 230B can be reduced. Placing a filler between the first and second substrates 110, 210 to maintain a uniform spacing between them would not maintain the narrow spacing between the organic light-emitting diodes 120 and the quantum dot thin film layers 230R, 230G, and 230B of the light-tinting units. Therefore, the gap G may be expanded to at least 10 μm. Thereafter, the light generated by the organic light emitting diode 120 propagates not only through the light tinting unit disposed above the organic light emitting diode 120 but also through the light tinting units of adjacent pixels.

[0036] However, in this embodiment, because the spacer 140 and the coating layer 240 maintain the gap G without using a filler, the space between the first substrate 110 and the second substrate 210, and in particular the gap G between the organic light-emitting diode 120 and the quantum dot thin film layers 230R, 230G, and 230B, can be kept very narrow, for example, from about 1 μm to about 2 μm. Consequently, the amount of light generated by the organic light-emitting diode 120 and transmitted through the light-coloring unit of adjacent pixels is reduced. As a result, undesirable color mixing can be effectively suppressed.

[0037] In addition, in this embodiment, since the spacer 140 and the coating layer 240 include an opaque material, the spacer 140 and the coating layer 240 can function as a light shielding wall, thereby improving the function of preventing color mixing.

[0038] Therefore, in the present embodiment, when the organic light emitting display device having such a structure is used, an image with pure and clear colors can be displayed by suppressing color mixing between pixels.

[0039] Can be referenced Figures 3A to 3F The organic light emitting display device having the above structure is manufactured by the described process.

[0040] like Figure 3A As shown in FIG, in this embodiment, the organic light emitting diode 120 is disposed on the first substrate 110. Thereafter, the thin film encapsulation layer 130 covers the organic light emitting diode 120.

[0041] Next, in this embodiment, Figure 3B As shown in FIG, a spacer 140 is formed on the thin film encapsulation layer 130 using a photolithography process. In the image area, the spacer 140 is disposed at a position that does not overlap with the organic light emitting diodes 120, that is, between the organic light emitting diodes 120.

[0042] like Figure 3C As shown in FIG, on the second substrate 210, color filter layers 220R, 220G, and 220B and a black matrix 250 are formed by a photolithography process.

[0043] Next, if Figure 3D As shown in FIG, in this embodiment, an inorganic layer 260 is formed to cover the color filter layers 220R, 220G, and 220B and the black matrix 250. On the inorganic layer 260, quantum dot thin film layers 230R, 230G, and 230B are formed. The quantum dot thin film layers 230R, 230G, and 230B are respectively arranged at positions overlapping with the color filter layers 220R, 220G, and 220B. For example, the color filter layers 220R, 220G, and 220B, the black matrix 250, and the quantum dot thin film layers 230R, 230G, and 230B can be formed by using a photolithography process or an inkjet process.

[0044] Thereafter, in this embodiment, as Figure 3E As shown in FIG, a coating layer 240 is formed on the inorganic layer 260. In the image area, the coating layer 240 is formed at a position corresponding to the spacer 140, that is, between the quantum dot thin film layers 230R, 230G, and 230B of the light tinting unit.

[0045] In this embodiment, the sealant 300 is attached between the first substrate 110 and the second substrate 210, and the first substrate 110 is bonded to the second substrate 210. Thereafter, as shown in FIG. Figure 3F As shown, the organic light emitting display device is implemented such that the organic light emitting diode 120 , the quantum dot thin film layers 230R, 230G, and 230B, and the color filter layers 220R, 220G, and 220B are aligned to overlap with each other.

[0046] In addition, in this embodiment, the spacer 140, coating layer 240, and black matrix 250 are aligned in a position that overlaps one another. The spacer 140 and coating layer 240 contact each other and act as a gap maintainer. As described above, since no separate filler is placed between the first substrate 110 and the second substrate 210, the gap G between the organic light-emitting diode 120 and the quantum dot thin film layers 230R, 230G, and 230B of the light tinting unit can be kept narrow, at approximately 1 μm to approximately 2 μm. This prevents undesirable color mixing. In addition, since the spacer 140 and coating layer 240 are made of opaque material, they act as light-shielding walls. As a result, accurate colors can be presented.

[0047] In this embodiment, a structure in which an air gap rather than a separate filler exists in the space between the first substrate 110 and the second substrate 210 is described as an example. Figure 4 As shown in FIG, a filler 400 may be inserted into the space between the first substrate 110 and the second substrate 210. In this case, the filler 400 does not function as a gap maintainer, but rather as an additional functional element such as an absorbent material. Similar to the above exemplary embodiment, the function of a gap maintainer can be performed by the spacer 140 and the coating layer 240. In other words, even if a filler is not used to maintain the gap between the substrates, the empty space in the gap can be utilized when there is an additional need for, for example, an absorbent function.

[0048] Therefore, in the organic light-emitting display device and manufacturing method according to the above exemplary embodiments, by reducing the gap between the organic light-emitting diode and the light tinting unit, light generated by the organic light-emitting diode of a pixel can be prevented from propagating to adjacent pixels. Therefore, by using the organic light-emitting display device and manufacturing method according to the exemplary embodiments, color mixing between pixels can be suppressed, thereby displaying an image with pure and clear colors. As a result, product performance and reliability can be improved.

[0049] It should be understood that the exemplary embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as applicable to other similar features or aspects in other embodiments.

[0050] Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope defined by the present disclosure.

Claims

1. An organic light-emitting display device, wherein the organic light-emitting display device comprises: a first substrate, a plurality of organic light emitting diodes being disposed on the first substrate; a second substrate bonded to the first substrate through a sealant, and a plurality of light coloring units respectively corresponding to the plurality of organic light emitting diodes being disposed on the second substrate; as well as a plurality of space maintainers disposed between adjacent ones of the plurality of organic light emitting diodes and between adjacent ones of the plurality of light tinting units and maintaining a space between the first substrate and the second substrate, wherein each of the plurality of space maintainers comprises: a spacer disposed between the plurality of organic light emitting diodes and protruding toward the second substrate; and a coating layer disposed between the plurality of light tinting units and directly contacting the spacer, wherein an air gap without filler exists in the space between the first substrate and the second substrate, The plurality of space maintainers include an opaque material, and the plurality of space maintainers maintain a gap between the plurality of organic light emitting diodes and the plurality of light coloring units to be 1 μm to 2 μm.

2. The organic light emitting display device according to claim 1 , further comprising a thin film encapsulation layer covering the plurality of organic light emitting diodes, wherein the spacer is disposed on the thin film encapsulation layer, The thin film encapsulation layer does not directly contact the plurality of light tinting units.

3. The organic light-emitting display device according to claim 1 , further comprising an inorganic layer disposed on an inner surface of the second substrate, The coating layer is disposed on the inorganic layer. 4 . The organic light emitting display device according to claim 1 , wherein each of the plurality of organic light emitting diodes generates monochromatic light of the same color. 5 . The organic light emitting display device according to claim 4 , wherein the monochromatic light comprises one of white light or blue light.

6. An organic light-emitting display device according to claim 4, wherein each of the plurality of light coloring units includes a quantum dot thin film layer facing the plurality of organic light-emitting diodes and a color filter layer arranged between the second substrate and the quantum dot thin film layer, wherein the quantum dot thin film layer and the color filter layer color the monochromatic light generated by the plurality of organic light-emitting diodes into red light, green light or blue light. 7 . The organic light emitting display device of claim 1 , further comprising a black matrix disposed between the light tinting units of the second substrate, wherein the black matrix blocks light transmission.

8. A method for manufacturing an organic light-emitting display device, wherein the method comprises: forming a plurality of organic light emitting diodes on a first substrate, wherein each of the plurality of organic light emitting diodes generates monochromatic light of the same color; forming a plurality of spacers between the plurality of organic light emitting diodes on the first substrate; forming a plurality of light coloring units on the second substrate and corresponding to the plurality of organic light emitting diodes; forming a plurality of coating layers between the plurality of light tinting units on the second substrate and corresponding to the plurality of spacers; and The plurality of spacers are in direct contact with the plurality of coating layers by bonding the first substrate to the second substrate using a sealant, wherein the plurality of spacers and the plurality of coating layers maintain a space between the first substrate and the second substrate, an air gap exists in the space between the first substrate and the second substrate without a filler, The plurality of spacers and the plurality of coating layers include an opaque material, and the plurality of spacers and the plurality of coating layers maintain a gap between the plurality of organic light emitting diodes and the plurality of light coloring units at 1 μm to 2 μm.

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