Light emitting display device and method of manufacturing same

Abstract

The invention provides a light emitting display device and a method of manufacturing the same. According to an aspect of the present disclosure, a light emitting display device includes: a substrate defined by a plurality of sub-pixels and a first overcoat layer disposed on the substrate; a connection electrode and a sacrificial layer disposed on the first overcoat layer and a first electrode disposed on the connection electrode; a second overcoat layer disposed on the sacrificial layer and including an opening exposing a portion of the first electrode; a dummy first electrode disposed on a top surface of the second overcoat layer and a side surface of the opening, and separated from the first electrode; a bank layer covering a portion of the first electrode and the dummy first electrode; and a light emitting layer and a second electrode disposed on the first electrode and the bank layer.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 202011110964.3, filed on October 16, 2020, entitled "Light Emitting Display Device and Manufacturing Method Thereof". The priority date of the parent application is October 17, 2019.

[0002] Cross Reference to Related Applications

[0003] This application claims priority to Korean Patent Application No. 10-2019-0128964, filed on October 17, 2019, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0004] The present disclosure relates to a light emitting display device, and more particularly, to a light emitting display device having enhanced light extraction efficiency through an improved process and a manufacturing method thereof. BACKGROUND

[0005] With the development of the information age, the field of display devices for visually displaying electrical information signals is rapidly developing. Accordingly, research into various display devices is being conducted to improve performance, such as thinness, weight reduction, and low power consumption.

[0006] Among various display devices, a light emitting display device is a self-emissive display device, and unlike a liquid crystal display device, does not require a separate light source. Accordingly, a light emitting display device can be manufactured in a light weight and thin form. Furthermore, since an organic light emitting display device is driven at a low voltage, it is advantageous in terms of power consumption. In addition, an organic light emitting display device has excellent color expression ability, a high response speed, a wide viewing angle, and a high contrast ratio (CR). Accordingly, it is expected that an organic light emitting display device will be applied to various fields.

[0007] Meanwhile, light emitted from a light emitting layer of a light emitting display device is output to the outside of the light emitting display device through each component of the light emitting display device. However, a portion of the light emitted from the light emitting layer can not be output to the outside of the light emitting display device, but can be confined in the light emitting display device. This causes a problem of light extraction efficiency of the light emitting display device.

[0008] For example, a portion of light emitted from the light emitting layer can be confined in the light emitting display device due to total reflection loss, waveguide loss, and surface plasmon loss. Here, the total reflection loss refers to a decrease in light extraction efficiency caused by confinement of light in the light emitting display device due to total reflection at an interface between the substrate and air among light emitted from the light emitting layer. The waveguide loss refers to a decrease in light extraction efficiency caused by confinement of light in the light emitting display device due to total reflection at an interface between components in the light emitting display device. The surface plasmon loss occurs due to a phenomenon in which light cannot be reflected or transmitted because the light is absorbed onto a metal surface when the light is projected and propagated when the light makes free electrons of the metal surface vibrate, which causes a decrease in light extraction efficiency. SUMMARY

[0009] An object to be achieved by the present disclosure is to provide a light emitting display device and a manufacturing method thereof in which total reflection loss and waveguide loss are improved using a dummy anode in a side mirror shape.

[0010] Another object to be achieved by the present disclosure is to provide a light emitting display device and a manufacturing method thereof in which an anode has an undercut structure at an edge thereof to be separated from a dummy anode.

[0011] The objects of the present disclosure are not limited to the above-mentioned objects, and other objects not mentioned above will be clearly understood by those skilled in the art from the following description.

[0012] According to an aspect of the present disclosure, a light emitting display device includes a substrate defined by a plurality of sub-pixels and a first overcoat layer disposed on the substrate. The light emitting display device further includes a connection electrode and a sacrificial layer disposed on the first overcoat layer, and a first electrode disposed on the connection electrode. The light emitting display device further includes a second overcoat layer disposed on the sacrificial layer and including an opening exposing a portion of the first electrode. The light emitting display device further includes a dummy first electrode disposed on a top surface of the second overcoat layer and a side surface of the opening and separated from the first electrode. The light emitting display device further includes a bank layer covering a portion of the first electrode and the dummy first electrode, and a light emitting layer and a second electrode disposed on the first electrode and the bank layer.

[0013] According to another aspect of this disclosure, a method of manufacturing a light-emitting display device includes forming a first outer coating on a substrate on which thin-film transistors are provided. The method further includes forming a connection electrode on the first outer coating and forming an insulating layer on the entire surface of the substrate on which the connection electrode and the first outer coating are provided. The method further includes forming a second outer coating including openings on the insulating layer. The method further includes etching the insulating layer using the second outer coating as a mask to form an undercut structure at the bottom of a side surface of the second outer coating. The method further includes forming a first electrode on the connection electrode and inside the undercut structure, and simultaneously forming a dummy first electrode on the top and side surfaces of the second outer coating. The method further includes forming a dam layer covering a portion of the dummy first electrode and the first electrode, and forming a light-emitting layer and a second electrode on the first electrode and the dam layer. The first electrode can be separated from the dummy first electrode by the undercut structure.

[0014] According to another aspect of this disclosure, a light-emitting display device includes: a substrate including a light-emitting region and a non-light-emitting region, wherein the light-emitting region is defined by a plurality of sub-pixels; a thin-film transistor disposed on the substrate; a first outer coating disposed on the thin-film transistor; a first electrode disposed on the first outer coating and electrically connected to the thin-film transistor; a sacrificial layer disposed on the first outer coating and including an opening exposing a portion of the first electrode; a second outer coating disposed on the sacrificial layer and including an opening exposing a portion of the first electrode; a light-emitting layer and a second electrode disposed on the first electrode; and an encapsulation layer disposed on the second electrode; wherein the second outer coating has an undercut structure at the bottom end of a side surface, and wherein the thickness of the first electrode is 92.3% or less of the thickness of the sacrificial layer.

[0015] Further details of the exemplary implementation are included in the detailed implementation and the accompanying drawings.

[0016] According to this disclosure, a side-mirror-shaped dummy anode is used. Therefore, the light extraction efficiency of the light-emitting display device can be improved.

[0017] According to this disclosure, the anode has an undercut structure at its edge to separate it from the dummy anode. Therefore, contact resistance and leakage problems can be suppressed.

[0018] According to this disclosure, the anode can be formed without performing a separate patterning process, meaning that one photolithography process can be omitted. Therefore, processability can be improved and manufacturing costs reduced.

[0019] According to this disclosure, the process of forming holes in the double outer coating can be omitted. Therefore, machinability can be improved and design margins for high resolution can be ensured.

[0020] The effects of this disclosure are not limited to those illustrated above, and include many more effects described herein. Attached Figure Description

[0021] The above and other aspects, features and advantages of this disclosure will become clearer from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0022] Figure 1 This is a plan view of a light-emitting display device according to an exemplary embodiment of the present disclosure;

[0023] Figure 2 yes Figure 1 A schematic enlarged plan view of area "A";

[0024] Figure 3 It is along Figure 2 A cross-sectional view of the light-emitting display device taken from line III-III';

[0025] Figure 4 This is a cross-sectional view of a light-emitting display device according to another exemplary embodiment of the present disclosure;

[0026] Figure 5 This is a photograph illustrating an example of the undercut structure of the anode of this disclosure;

[0027] Figure 6 This is a cross-sectional view illustrating an example of an uneven structure on the outer periphery of the anode according to another exemplary embodiment of the present disclosure;

[0028] Figure 7 The results of a light extraction simulation using an uneven structure on the outer periphery of the anode are shown.

[0029] Figure 8A , Figure 8B , Figure 8C , Figure 8D , Figure 8E , Figure 8F , Figure 8G and Figure 8H It is a photograph showing the positive taper formation and etch bias level according to the thickness of the sacrificial layer;

[0030] Figure 9 This is a plan view of a light-emitting display device according to yet another exemplary embodiment of the present disclosure;

[0031] Figure 10A , Figure 10B , Figure 10C , Figure 10D , Figure 10E , Figure 10F and Figure 10GThis is a cross-sectional view showing a method of manufacturing a light-emitting display device according to another exemplary embodiment of the present disclosure;

[0032] Figure 11 This is a plan view of a light-emitting display device according to yet another exemplary embodiment of the present disclosure; and

[0033] Figure 12 It is along Figure 11 A cross-sectional view of the light-emitting display device taken by line XII-XII'. Detailed Implementation

[0034] The advantages and features of this disclosure, as well as methods for achieving such advantages and features, will become clear from the following detailed description of exemplary embodiments and accompanying drawings. However, this disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. Exemplary embodiments are provided by way of example only so that those skilled in the art can fully understand the disclosure and scope of this disclosure. Therefore, this disclosure is limited only by the scope of the appended claims.

[0035] The shapes, dimensions, ratios, angles, quantities, etc., shown in the accompanying drawings to describe exemplary embodiments of this disclosure are merely examples, and this disclosure is not limited thereto. Throughout the specification, the same reference numerals generally denote the same elements. Furthermore, in the following description of this disclosure, detailed descriptions of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of this disclosure. Terms such as “comprising,” “having,” and “consisting of” as used herein are generally intended to allow for the addition of additional components, unless the term is used in conjunction with the term “only.” Unless otherwise expressly stated, any reference to the singular may include the plural.

[0036] Even if not explicitly stated, components are interpreted as including the normal tolerance range.

[0037] When using terms such as “on,” “above,” “below,” and “adjacent” to describe the positional relationship between two parts, one or more parts may be located between the two parts unless these terms are used in conjunction with the terms “immediately adjacent” or “directly.”

[0038] When an element or layer is placed "on" another element or layer, other layers or other elements may be placed directly on that other element or placed between them.

[0039] Although the terms "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from other components. Therefore, in the technical concept of this disclosure, the first component mentioned below can be the second component.

[0040] For ease of description, the dimensions and thickness of each component shown in the accompanying drawings are illustrated, and this disclosure is not limited to the dimensions and thickness of the components shown.

[0041] Features of various embodiments of this disclosure may be partially or wholly attached to or combined with each other, and may be interlocked and operated in various technical ways, and these embodiments may be implemented independently or in association with each other.

[0042] In the following, an exemplary embodiment of a light-emitting display device according to the present disclosure will be described in detail with reference to the accompanying drawings.

[0043] Figure 1 This is a plan view of a light-emitting display device according to an exemplary embodiment of the present disclosure.

[0044] Figure 2 yes Figure 1 A schematic enlarged plan view of area "A".

[0045] Figure 3 It is along Figure 2 A cross-sectional view of the light-emitting display device taken from line III-III'.

[0046] For ease of explanation, Figure 2 Only three sub-pixels of SPX are shown. Additionally, Figure 3 It is a cross-sectional view of the first sub-pixel among the three sub-pixels SPX.

[0047] Reference Figure 1 to Figure 3 The light-emitting display device 100 according to an exemplary embodiment of the present disclosure may include a substrate 110 and a thin-film transistor 120. In addition, the light-emitting display device 100 includes a light-emitting element 130, a first outer coating 141 and a second outer coating 142, a dam layer 114, a sacrificial layer 145 and an encapsulation layer 150.

[0048] The light-emitting display device 100 can be implemented as a top-emitting type light-emitting display device.

[0049] The substrate 110 may include an active region A / A and an inactive region N / A.

[0050] The active area A / A is the area in the light-emitting display device 100 where an image is displayed.

[0051] In the active region A / A, display elements and various driving elements for driving the display elements can be disposed. For example, the display element can be configured as a light-emitting element 130 including a first electrode 131, a light-emitting layer 132, and a second electrode 133. In addition, various driving elements for driving the display elements, such as thin-film transistors 120, capacitors, wiring, etc., can be disposed in the active region A / A.

[0052] In the active region A / A, multiple sub-pixels SPX can be defined.

[0053] Each subpixel SPX is the smallest unit for displaying an image. Each of the multiple subpixel SPXs may include a light-emitting element 130 and driving circuitry. Furthermore, the multiple subpixel SPXs may emit light of different wavelengths. For example, the multiple subpixel SPXs may include a first subpixel SPX1 as a red subpixel, a second subpixel SPX2 as a green subpixel, and a third subpixel SPX3 as a blue subpixel, but are not limited thereto. The multiple subpixel SPXs may also include a white subpixel.

[0054] The driving circuitry for each sub-pixel SPX is configured to control the driving of the light-emitting element 130. For example, the driving circuitry may include, but is not limited to, thin-film transistor 120 and capacitors.

[0055] The non-active area N / A is an area in the light-emitting display device 100 where no image is displayed. Various components for driving the multiple sub-pixels SPX disposed in the active area A / A can be provided in the non-active area N / A. For example, a driver IC configured to provide signals for driving the multiple sub-pixels SPX, a flexible film, etc., can be provided in the non-active area N / A.

[0056] like Figure 1 As shown, the non-active region N / A can be a region surrounding the active region A / A, but is not limited to this. For example, the non-active region N / A can be a region extending from the active region A / A.

[0057] Reference Figure 3 The substrate 110 is used to support and protect various components of the light-emitting display device 100.

[0058] The substrate 110 can be formed of glass or a flexible plastic material. If the substrate 110 is formed of a plastic material, it can be formed of, for example, polyimide (PI), but is not limited thereto.

[0059] A buffer layer 111 may be disposed on the substrate 110. The buffer layer 111 is used to enhance the adhesion between the substrate 110 and the layer formed on the buffer layer 111, and to block alkali metal elements from being discharged from the substrate 110.

[0060] The buffer layer 111 can be formed as a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. Depending on the type and material of the substrate 110 and the structure and type of the thin-film transistor 120, the buffer layer 111 may be omitted.

[0061] The thin-film transistor 120 can be disposed on the substrate 110.

[0062] The thin-film transistor 120 can be used as a driving element of the light-emitting display device 100. The thin-film transistor 120 may include a gate electrode 121, an active layer 122, a source electrode 123, and a drain electrode 124. In an exemplary embodiment of the light-emitting display device 100 according to the present disclosure, the thin-film transistor 120 is configured as a bottom-gate thin-film transistor, wherein the active layer 122 is disposed on the gate electrode 121, the source electrode 123 and the drain electrode 124 are disposed on the active layer 122, and the gate electrode 121 is disposed at the bottom, but is not limited thereto.

[0063] The gate electrode 121 may be disposed on the substrate 110. The gate electrode 121 may be formed of any of a variety of metallic materials such as molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu) or alloys of two or more of them, or multilayers thereof, but is not limited thereto.

[0064] A gate insulating layer 112 may be disposed on the gate electrode 121. The gate insulating layer 112 is an insulating layer used to electrically insulate the gate electrode 121 from the active layer 122. The gate insulating layer 112 may be formed of an insulating material. For example, the gate insulating layer 112 may be formed as a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto.

[0065] The active layer 122 can be disposed on the gate insulating layer 112.

[0066] The active layer 122 can be configured to overlap with the gate electrode 121.

[0067] For example, the active layer 122 can be formed of oxide semiconductor, amorphous silicon (a-Si), polycrystalline silicon (poly-Si) or organic semiconductor.

[0068] The etch stop layer 117 can be disposed on the active layer 122.

[0069] When the source electrode 123 and the drain electrode 124 are patterned by etching, an etch stop layer 117 can be formed to suppress plasma damage to the back channel surface of the active layer 122.

[0070] One end of the etch stop layer 117 may overlap with the source electrode 123, and the other end may overlap with the drain electrode 124. Alternatively, the etch stop layer 117 may be omitted.

[0071] The source electrode 123 and the drain electrode 124 can be disposed on the active layer 122 and the etch stop layer 117. The source electrode 123 and the drain electrode 124 can be disposed separately from each other on the same layer.

[0072] The source electrode 123 and the drain electrode 124 can be electrically connected to the active layer 122 by contacting it.

[0073] The source electrode 123 and the drain electrode 124 may be formed of any of a variety of metallic materials such as molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu), or alloys of two or more of them, or multilayers thereof, but are not limited thereto.

[0074] Passivation layer 113 may be disposed on thin-film transistor 120. Passivation layer 113 may be used to protect thin-film transistor 120 and may be formed as a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. Passivation layer 113 may also be omitted.

[0075] The first outer coating 141 may be disposed on the passivation layer 113. The first outer coating 141 is an insulating layer used to protect the thin-film transistor 120 and reduce the step difference between layers disposed on the substrate 110. The first outer coating 141 may be formed from any one of acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, benzocyclobutene, photoresist, and polyphenylene sulfide resin, but is not limited thereto.

[0076] A first outer coating 141 may be disposed on the thin-film transistor 120. The top surface of the first outer coating 141 may be parallel to the substrate 110. Therefore, the first outer coating 141 can flatten the step difference caused by components disposed below the first outer coating 141.

[0077] The connecting electrode 125 can be disposed on the first outer coating 141.

[0078] The connecting electrode 125 can be electrically connected to the drain electrode 124 through contact holes formed in the first outer coating 141 and the passivation layer 113, but is not limited thereto. The connecting electrode 125 can also be electrically connected to the source electrode 123 through contact holes formed in the first outer coating 141 and the passivation layer 113.

[0079] The connecting electrode 125 may be formed of any of, but is not limited to, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu) or alloys of two or more of these, or multilayers of such metallic materials.

[0080] The sacrificial layer 145 can be disposed on the connecting electrode 125 and the first outer coating 141.

[0081] A sacrificial layer 145 may be disposed on the first outer coating 141 to cover the edge of the connecting electrode 125. That is, the sacrificial layer 145 can expose at least the surface of the connecting electrode 125 in the light-emitting region EA.

[0082] The sacrificial layer 145 may be formed to be thicker than the first electrode 131 to form an undercut structure at the edge of the first electrode 131. For example, the undercut structure of this disclosure may be formed if the thickness of the first electrode 131 is set to 92.3% or less of the thickness of the sacrificial layer 145.

[0083] The sacrificial layer 145 can be patterned to have a positive taper at its edges.

[0084] The sacrificial layer 145 can be formed as a monolayer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. For example, the sacrificial layer 145 can be formed as a bilayer of silicon nitride (SiNx) and silicon oxide (SiOx) with a thickness of 1300 Å to 2500 Å.

[0085] The first electrode 131 can be disposed on the connecting electrode 125.

[0086] The first electrode 131 can be disposed on the surface of the connecting electrode 125 that is not covered by the sacrificial layer 145 and whose surface is exposed. The first electrode 131 can also be disposed at the bottom of the side surface of the second outer coating 142 inside the undercut structure, so as to contact the side surface of the sacrificial layer 145.

[0087] The first electrode 131 can be formed by deposition without performing a masking process.

[0088] In contrast to the sacrificial layer 145, the first electrode 131 can be deposited with an inverted taper at its edges.

[0089] The thickness of the first electrode 131 can be set to 92.3% or less of the thickness of the sacrificial layer 145 to form an undercut structure at the edge of the first electrode 131.

[0090] The surface of the first electrode 131 may be substantially flat, but is not limited thereto. A portion of the edge of the first electrode 131 may have an uneven structure.

[0091] Although not shown in the accompanying drawings, a reflective layer electrically connected to the thin-film transistor 120 and a transparent conductive layer disposed on the reflective layer may be included in the first electrode 131. However, this disclosure is not limited thereto. The first electrode 131 may have a three-layer structure including a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0092] A reflective layer may be disposed on the connecting electrode 125. The light-emitting display device 100 according to an exemplary embodiment of the present disclosure is a top-emitting type light-emitting display device. Therefore, the reflective layer can reflect light emitted from the light-emitting element 130 in an upward direction.

[0093] The reflective layer can be formed from metallic materials such as aluminum (Al), silver (Ag), copper (Cu), magnesium-silver alloys, etc., but is not limited to these.

[0094] The reflective layer can be electrically connected to the drain electrode 124 via the connecting electrode 125, but is not limited thereto. The reflective layer can also be electrically connected to the source electrode 123 via the connecting electrode 125.

[0095] A transparent conductive layer can be disposed on the reflective layer. The transparent conductive layer can be disposed on the reflective layer and electrically connected to the drain electrode through the reflective layer and the connecting electrode 125. The transparent conductive layer can be formed of a conductive material with a high work function to provide holes to the light-emitting layer 132.

[0096] For example, the transparent conductive layer can be formed from transparent conductive oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), and tin oxide (TO), but is not limited thereto.

[0097] The second outer coating 142 can be disposed on the first electrode 131 and the sacrificial layer 145.

[0098] The second outer coating 142 can be formed to expose the entire surface of the first electrode 131 except for the edge of the first electrode 131.

[0099] The side surface of the second outer coating 142 that exposes the first electrode 131 may have a taper at a predetermined angle. For example, the side surface of the second outer coating 142 may taper at an angle of 30° to 60°, but is not limited thereto.

[0100] The second outer coating 142 may include a top surface and a side surface.

[0101] The top surface of the second outer coating 142 is located at the uppermost part of the second outer coating 142 and can be substantially parallel to the substrate 110.

[0102] The side surface of the second outer coating 142 may be a surface extending from the top surface of the second outer coating 142.

[0103] The second outer coating 142 may be formed of the same material as the first outer coating 141.

[0104] For example, the second outer coating 142 may be formed from any one of acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, benzocyclobutene, photoresist, and polyphenylene sulfide resin, but is not limited thereto.

[0105] The second outer coating 142 can have an undercut structure at the bottom of the side surface by further etching the sacrificial layer 145 from the side surface of the second outer coating 142 to the interior of the second outer coating 142.

[0106] The etching bias, which is the distance from the end of the side surface of the second outer coating 142 to the end of the sacrificial layer 145, varies depending on the process conditions and can be in the range of 0.8 μm to 1.3 μm.

[0107] A dummy first electrode 131' formed of the same material as the first electrode 131 can be disposed on the top and side surfaces of the second outer coating 142. Therefore, similar to the first electrode 131, the dummy first electrode 131' can include, but is not limited to, a reflective layer and a transparent conductive layer disposed on the reflective layer. The dummy first electrode 131' can have a three-layer structure including a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0108] When the first electrode 131 is deposited, the dummy first electrode 131' can be deposited on the top and side surfaces of the second outer coating 142. Moreover, the dummy first electrode 131' can be separated from the first electrode 131 by the undercut structure of the second outer coating 142.

[0109] In this way, the first electrode 131 and the dummy first electrode 131' are separated in the sub-pixel, so the first electrode 131 and the dummy first electrode 131' can be formed by full-surface deposition without a mask.

[0110] The dummy first electrode 131' can be disposed on the top and side surfaces of the second outer coating 142 along the shape of the second outer coating 142.

[0111] The dummy first electrode 131' disposed on the side surface of the second outer coating 142 may taper at an angle of 30° to 60°, but is not limited thereto.

[0112] The light-emitting display device 100 according to an exemplary embodiment of this disclosure is a top-emitting type light-emitting display device. Therefore, the reflective layer of the dummy first electrode 131' can reflect light emitted from the light-emitting element 130 in an upward direction. Light generated from the light-emitting layer 132 of the light-emitting element 130 is emitted not only in the upward direction but also in the lateral direction. Light emitted in the lateral direction may propagate into the interior of the light-emitting display device 100 and may be confined within the interior of the light-emitting display device 100 by total internal reflection. Furthermore, light may disappear as it travels into the interior of the light-emitting display device 100. Therefore, the reflective layer of the dummy first electrode 131' can be configured to cover the side surface of the second outer coating 142. Thus, the direction of light travel can change from the lateral direction to the upward direction (see...). Figure 3 (The arrow in the image).

[0113] The embankment 114 can be disposed on the second outer coating 142.

[0114] A dam layer 114 may be disposed on the second outer coating layer 142 to cover the entire dummy first electrode 131' and a portion of the edge of the first electrode 131. The dam layer 114 may fill the interior of the undercut structure at the bottom end of the side surface of the second outer coating layer 142. The dam layer 114 may be inserted between the first electrode 131 and the dummy first electrode 131'.

[0115] The dam layer 114 can cover a portion of the edge of the first electrode 131 covering multiple sub-pixels SPX to define the light-emitting area EA and the non-light-emitting area NEA. For example, in the non-light-emitting area NEA, the dam layer 114 is disposed on the first electrode 131 to block the generation of light from the non-light-emitting area NEA. Meanwhile, in the light-emitting area EA, the dam layer 114 is not disposed, but the light-emitting layer 132 is located precisely on the first electrode 131. Therefore, light can be generated from the light-emitting layer 132.

[0116] The dam layer 114 can be formed from organic or inorganic materials.

[0117] For example, the dam layer 114 may be formed of organic materials such as polyimide, acrylic acid or benzocyclobutene or inorganic materials such as silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

[0118] The light-emitting layer 132 and the second electrode 133 can be disposed on the embankment layer 114. The light-emitting layer 132 and the second electrode 133 can form a light-emitting element 130 together with the first electrode 131.

[0119] The light-emitting layer 132 can be configured to contact the first electrode 131 covering a plurality of sub-pixels SPX. For example, the light-emitting layer 132 can be disposed on the first electrode 131 covering the entire surface of the substrate 110, but is not limited thereto. The light-emitting layer 132 can be disposed only on the first electrode 131 in the light-emitting region EA. In this case, the light-emitting layer 132 can be configured to be surrounded by the embankment layer 114.

[0120] The light-emitting layer 132 is used to emit light of a specific color and has a structure that is separate for each sub-pixel SPX. For example, the light-emitting layer 132 provided in the first sub-pixel SPX1, which is a red sub-pixel, is a red light-emitting layer, and the light-emitting layer 132 provided in the second sub-pixel SPX2, which is a green sub-pixel, is a green light-emitting layer. In addition, the light-emitting layer 132 provided in the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 can be configured to be separate from each other.

[0121] The light-emitting layer 132 may also include various layers, such as a hole transport layer, a hole injection layer, a hole blocking layer, an electron injection layer, an electron blocking layer, and an electron transport layer. Furthermore, the light-emitting layer 132 may be an organic light-emitting layer formed of organic materials, but is not limited thereto. For example, the light-emitting layer 132 may also be formed of a quantum dot light-emitting layer or a micro-LED.

[0122] The second electrode 133 may be disposed on the light-emitting layer 132 in the sub-pixel SPX. For example, the second electrode 133 may be disposed in contact with the light-emitting layer 132 along the shape of the light-emitting layer 132 in the light-emitting region EA and the non-light-emitting region NEA, but is not limited thereto.

[0123] The second electrode 133 can provide electrons to the light-emitting layer 132. The second electrode 133 can be formed of a metallic material such as silver (Ag), copper (Cu), or a magnesium-silver alloy, but is not limited to this. In this regard, if the second electrode 133 is formed of a metallic material, it has a very low refractive index. For example, if the second electrode 133 is formed of silver (Ag), it can have a refractive index of approximately 0.13.

[0124] The light-emitting display device 100 according to an exemplary embodiment of this disclosure is a top-emitting type light-emitting display device. Therefore, it can be manufactured to realize a microcavity. For example, in the light-emitting display device 100 according to an exemplary embodiment of this disclosure, the distance between the reflective layer of the first electrode 131 and the second electrode 133 is set to achieve constructive interference of light emitted from the light-emitting layer 132. Therefore, light efficiency can be improved. Therefore, in the light-emitting display device 100 according to an exemplary embodiment of this disclosure, the light-emitting layer 132 has a different thickness for each sub-pixel SPX to realize a microcavity.

[0125] Reference Figure 3 An encapsulation layer 150 may be disposed on the second electrode 133. The encapsulation layer 150 can prevent oxygen and moisture from penetrating into the light-emitting display device 100 from the outside. For example, if the light-emitting display device 100 is exposed to moisture or oxygen, pixel shrinkage may occur, resulting in a reduction in the light-emitting area EA, or black spots may appear in the light-emitting area EA. Therefore, the encapsulation layer 150 can block oxygen and moisture to protect the light-emitting display device 100.

[0126] Although not shown, the encapsulation layer 150 may include a first encapsulation layer, a second encapsulation layer, and a third encapsulation layer.

[0127] The first encapsulation layer can be disposed on the second electrode 133 to inhibit the penetration of moisture or oxygen.

[0128] In this document, the first encapsulation layer may be formed of an inorganic material such as silicon nitride (SiNx), silicon nitride oxide (SiOxNy), or aluminum oxide (AlyOz), but is not limited thereto. The first encapsulation layer may be formed of a material having a higher refractive index than the second encapsulation layer. For example, if the first encapsulation layer is formed of silicon nitride (SiNx) or silicon nitride oxide (SiOxNy), the refractive index of the first encapsulation layer may be approximately 1.8.

[0129] The second encapsulation layer can be disposed on the first encapsulation layer to planarize the surface of the first encapsulation layer. Furthermore, the second encapsulation layer can cover foreign matter or particles that may be generated during the manufacturing process. The second encapsulation layer can be formed of organic materials such as silicon carbide oxide (SiOxCz), acrylic resin, or epoxy resin, but is not limited thereto. The second encapsulation layer can be formed of a material having a lower refractive index than the first encapsulation layer. For example, if the second encapsulation layer is formed of an acrylic resin, the refractive index of the second encapsulation layer can be from about 1.5 to about 1.6.

[0130] The third encapsulation layer can be disposed on the second encapsulation layer and can prevent moisture or oxygen from penetrating into the first encapsulation layer.

[0131] For example, the third encapsulation layer may be formed of an inorganic material such as silicon nitride (SiNx), silicon nitride oxide (SiOxNy), silicon oxide (SiOx), or aluminum oxide (AlyOz), but is not limited thereto. The third encapsulation layer may be formed of the same material as the first encapsulation layer, or it may be formed of a different material than the first encapsulation layer.

[0132] In conventional light-emitting display devices, some light emitted from the emissive layer is confined and lost within the device, leading to reduced luminous efficiency. For example, some light emitted from the emissive layer may not be extracted to the outside of the device due to total internal reflection loss or waveguide loss. Therefore, the light extraction efficiency of the device is reduced. For instance, in conventional light-emitting display devices, the first electrode is only disposed on an outer coating having a flat top surface. Therefore, due to total internal reflection loss or waveguide loss, the second light emitted from the emissive layer, output at a low output angle, can be confined within the device.

[0133] Therefore, the light-emitting display device 100 according to an exemplary embodiment of the present disclosure uses a second outer coating 142 having side surfaces to improve the light extraction efficiency of the light-emitting element 130. For example, in the light-emitting display device 100 according to an exemplary embodiment of the present disclosure, a second outer coating 142 having a top surface and side surfaces is disposed on a first outer coating 141. Moreover, the reflective layer of the dummy first electrode 131' is disposed to at least cover the side surfaces of the second outer coating 142. Therefore, in the light emitted from the light-emitting layer 132 of the light-emitting display device 100, the second light output at a low output angle can be extracted toward the top surface by the dummy first electrode 131' disposed on the side surface of the second outer coating 142. For example, if the first electrode is disposed on a flat outer coating as in a conventional light-emitting display device, the light propagating toward the side surface, such as light output at a low output angle, may not propagate toward the top surface. Moreover, due to total internal reflection loss or waveguide loss, the light may not be extracted to the outside of the light-emitting display device. However, in the light-emitting display device 100 of the exemplary embodiment of the present disclosure, the first light output from the light-emitting layer 132 toward the top surface and the second light output from the light-emitting layer 132 at a low output angle can be reflected by the reflective layer of the dummy first electrode 131' disposed on the side surface of the second outer coating layer 142 and extracted toward the top surface.

[0134] Therefore, in the light-emitting display device 100 according to an exemplary embodiment of the present disclosure, the reflective layer of the dummy first electrode 131' provided on the side surface of the second outer coating 142 serves as a side mirror. Thus, light that may be lost in the light-emitting display device 100 can be extracted towards the top surface. Therefore, light extraction efficiency can be improved and power consumption can be reduced.

[0135] In the light-emitting display device 100 according to an exemplary embodiment of the present disclosure, the first electrode 131 is separated from the dummy first electrode 131' disposed on the side surface of the second outer coating 142. Therefore, contact resistance and leakage problems can be suppressed.

[0136] Meanwhile, an OLED side mirror (OSM) structure in which a mirror anode is additionally formed on the side surface of the light-emitting layer can be achieved by stacking two outer coatings or by adding a connecting electrode between the anode and the drain electrode.

[0137] In this case, if two outer coatings are stacked, the anode may not emit light when it comes into contact with the drain electrode due to the residual film of the outer coating in the contact hole area.

[0138] Therefore, a connecting electrode can be inserted between the anode and the drain electrode, and each of the first and second outer coatings can be used in a masking process to reduce the formation of residual film on the outer coatings. However, in this case, if the margin between the dam layer and the second outer coating is small, leakage current may occur from the reflective layer of the anode. Otherwise, foreign matter may cause a short circuit between the light-emitting layer and the anode and cathode.

[0139] Therefore, in this disclosure, the first electrode 131 is separated from the dummy first electrode 131' disposed on the side surface of the second outer coating 142 to improve short-circuit faults and increase contact resistance. Furthermore, in this disclosure, the first electrode 131 and the dummy first electrode 131' are formed by deposition without using a mask, and the sacrificial layer 145 is patterned without performing additional masking processes. Therefore, processability can be improved and manufacturing costs reduced.

[0140] In other words, the present disclosure is characterized by a reflective layer of a dummy first electrode 131' formed on the side surface of the second outer coating 142.

[0141] Furthermore, a feature of this disclosure is the undercut structure formed at the bottom end of the side surface of the second outer coating 142. Therefore, the dummy first electrode 131' and the first electrode 131 are formed separately using the same process.

[0142] Furthermore, a feature of this disclosure is that the first electrode 131 is electrically connected to the drain electrode 124 via a connecting electrode 125 located below the first electrode 131.

[0143] Furthermore, this disclosure is characterized in that a dummy first electrode 131' is disposed on the side surface of the second outer coating 142 and tapers at an angle of 30° to 60°.

[0144] In addition, in this disclosure, the distance between the embankment 114 and the dummy first electrode 131' can be controlled within the range where the first electrode 131 does not cover all exposed openings.

[0145] Furthermore, in this disclosure, the sacrificial layer 145 has a greater thickness than the first electrode 131 to form an undercut structure at the edge of the first electrode 131.

[0146] Furthermore, in this disclosure, the connecting electrode 125 is formed to be larger than the first electrode 131 in order to improve the contact resistance.

[0147] Furthermore, in the light-emitting display device according to the exemplary embodiments of this disclosure, the entire surface of the first electrode is substantially flat, but it is not limited thereto. In this disclosure, a portion of the edge of the first electrode may have an uneven structure. This will be described in detail with reference to another exemplary embodiment of this disclosure.

[0148] Figure 4 This is a cross-sectional view of a light-emitting display device according to another exemplary embodiment of the present disclosure.

[0149] Figure 5 This is a photograph illustrating an example of the undercut structure of the anode of this disclosure.

[0150] Figure 6 This is a cross-sectional view illustrating an example of an uneven structure on the outer periphery of the anode according to another exemplary embodiment of the present disclosure.

[0151] Figure 7 The results of a light extraction simulation using a non-uniform structure on the outer periphery of the anode are shown.

[0152] Figure 8A to Figure 8H It is a photograph showing the formation of a positive taper and the etching bias level based on the thickness of the sacrificial layer.

[0153] In addition to forming an uneven structure 231” at the edge of the first electrode 231 Figure 4 The light-emitting display device 200 shown is Figure 2 and Figure 3 The light-emitting display device 100 shown is basically the same.

[0154] Reference Figure 4 According to another exemplary embodiment of the present disclosure, the light-emitting display device 200 may include a substrate 110, a thin-film transistor 120, a light-emitting element 230, a first outer coating 141 and a second outer coating 142, a dam layer 114, a sacrificial layer 145 and an encapsulation layer 150.

[0155] The light-emitting display device 200 can be implemented as a top-emitting type light-emitting display device.

[0156] The substrate 110 is used to support and protect various components of the light-emitting display device 200.

[0157] A buffer layer 111 may be disposed on the substrate 110. The buffer layer 111 is used to enhance the adhesion between the substrate 110 and the layer formed on the buffer layer 111, and to block alkali metal elements from being discharged from the substrate 110.

[0158] The thin-film transistor 120 can be disposed on the substrate 110.

[0159] The thin-film transistor 120 can be used as a driving element of the light-emitting display device 200. The thin-film transistor 120 may include a gate electrode 121, an active layer 122, a source electrode 123, and a drain electrode 124. In another exemplary embodiment of the light-emitting display device 200 according to this disclosure, the thin-film transistor 120 is configured as a bottom-gate thin-film transistor, wherein the active layer 122 is disposed on the gate electrode 121, the source electrode 123 and the drain electrode 124 are disposed on the active layer 122, and the gate electrode 121 is disposed at the bottommost position, but is not limited thereto.

[0160] The gate electrode 121 can be disposed on the substrate 110.

[0161] A gate insulating layer 112 may be disposed on the gate electrode 121. The gate insulating layer 112 is an insulating layer used to electrically insulate the gate electrode 121 from the active layer 122. The gate insulating layer 112 may be formed of an insulating material.

[0162] The active layer 122 can be disposed on the gate insulating layer 112.

[0163] The active layer 122 can be configured to overlap with the gate electrode 121.

[0164] The etch stop layer 117 can be disposed on the active layer 122.

[0165] When the source electrode 123 and the drain electrode 124 are patterned by etching, an etch stop layer 117 can be formed to suppress plasma damage to the back channel surface of the active layer 122.

[0166] One end of the etch stop layer 117 may overlap with the source electrode 123, and the other end may overlap with the drain electrode 124. Alternatively, the etch stop layer 117 may be omitted.

[0167] The source electrode 123 and the drain electrode 124 can be disposed on the active layer 122 and the etch stop layer 117. The source electrode 123 and the drain electrode 124 can be disposed separately from each other on the same layer.

[0168] The source electrode 123 and the drain electrode 124 can be electrically connected to the active layer 122 by contacting it.

[0169] Passivation layer 113 may be disposed on thin-film transistor 120. Passivation layer 113 may be used to protect thin-film transistor 120, or it may be omitted.

[0170] The first outer coating 141 may be disposed on the passivation layer 113. The first outer coating 141 is an insulating layer used to protect the thin film transistor 120 and reduce the step difference between layers disposed on the substrate 110.

[0171] A first outer coating 141 may be disposed on the thin-film transistor 120. The top surface of the first outer coating 141 may be parallel to the substrate 110. Therefore, the first outer coating 141 can flatten the step difference caused by components disposed below the first outer coating 141.

[0172] The connecting electrode 125 can be disposed on the first outer coating 141.

[0173] The connecting electrode 125 can be electrically connected to the drain electrode 124 through contact holes formed in the first outer coating 141 and the passivation layer 113, but is not limited thereto. The connecting electrode 125 can also be electrically connected to the source electrode 123 through contact holes formed in the first outer coating 141 and the passivation layer 113.

[0174] The sacrificial layer 145 can be disposed on the connecting electrode 125 and the first outer coating 141.

[0175] A sacrificial layer 145 may be disposed on the first outer coating 141 to cover the edge of the connecting electrode 125. That is, the sacrificial layer 145 can expose at least the surface of the connecting electrode 125 in the light-emitting region EA.

[0176] The sacrificial layer 145 may be formed to be thicker than the first electrode 231 to form an undercut structure at the edge of the first electrode 231. For example, the undercut structure of this disclosure may be formed if the thickness of the first electrode 231 is set to 92.3% or less of the thickness of the sacrificial layer 145.

[0177] The sacrificial layer 145 can be patterned to have a positive taper at its edges.

[0178] The sacrificial layer 145 can be formed as a monolayer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. For example, the sacrificial layer 145 can be formed as a bilayer of silicon nitride (SiNx) and silicon oxide (SiOx) with a thickness of 1300 Å to 2500 Å.

[0179] The first electrode 231 can be disposed on the connecting electrode 125.

[0180] The first electrode 231 can be disposed on the surface of the connecting electrode 125 that is not covered by the sacrificial layer 145 and whose surface is exposed. The first electrode 231 can also be disposed at the bottom of the side surface of the second outer coating 142 inside the undercut structure, so as to contact the side surface of the sacrificial layer 145.

[0181] The first electrode 231 can be formed by deposition without performing a masking process.

[0182] In contrast to the sacrificial layer 145, the first electrode 231 can be deposited with an inverted taper at its edges.

[0183] The thickness of the first electrode 231 can be set to 92.3% or less of the thickness of the sacrificial layer 145 to form an undercut structure at the edge of the first electrode 231.

[0184] A portion of the surface of the first electrode 231 may be substantially flat, but a portion of the edge of the first electrode 231 may have an uneven structure 231 (see reference). Figure 6 ).

[0185] Reference Figure 7 In the simulation results, dashed lines represent flat structures, and solid lines represent non-flat structures.231”

[0186] In a flat structure, light is confined within the waveguide and SP mode, making it difficult to extract to the outside, which may lead to reduced external light extraction efficiency. However, by applying a non-flat structure 231", the light confined inside can be extracted toward the top surface, thereby improving the light extraction efficiency.

[0187] In other words, if a portion of the edge of the first electrode 231 is not flat and has an uneven structure 231", waveguide and SP modes can be extracted. Therefore, this can help improve the efficiency of the top surface.

[0188] Reference Figure 4 The first electrode 231 may include a reflective layer electrically connected to the thin-film transistor 120 and a transparent conductive layer disposed on the reflective layer, but is not limited thereto. The first electrode 231 may have a three-layer structure including a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0189] A reflective layer may be disposed on the connecting electrode 125. Another exemplary embodiment of the light-emitting display device 200 according to this disclosure is a top-emitting type light-emitting display device. Therefore, the reflective layer can reflect light emitted from the light-emitting element 230 in an upward direction.

[0190] The reflective layer can be electrically connected to the drain electrode 124 via the connecting electrode 125, but is not limited thereto. The reflective layer can also be electrically connected to the source electrode 123 via the connecting electrode 125.

[0191] A transparent conductive layer can be disposed on the reflective layer. The transparent conductive layer can be disposed on the reflective layer and electrically connected to the drain electrode through the reflective layer and the connecting electrode 125. The transparent conductive layer can be formed of a conductive material with a high work function to provide holes to the light-emitting layer 232.

[0192] The second outer coating 142 can be disposed on the first electrode 231 and the sacrificial layer 145.

[0193] The second outer coating 142 can be formed to expose the entire surface of the first electrode 231 except for the edge of the first electrode 231, i.e., the uneven structure 231”.

[0194] The side surface of the second outer coating 142 that exposes the first electrode 231 may have a taper at a predetermined angle. For example, the side surface of the second outer coating 142 may taper at an angle of 30° to 60°, but is not limited thereto.

[0195] The second outer coating 142 may include a top surface and a side surface.

[0196] The top surface of the second outer coating 142 is located at the uppermost part of the second outer coating 142 and can be substantially parallel to the substrate 110.

[0197] The side surface of the second outer coating 142 may be a surface extending from the top surface of the second outer coating 142.

[0198] The second outer coating 142 may be formed of the same material as the first outer coating 141.

[0199] The second outer coating 142 can have an undercut structure at the bottom of the side surface by further etching the sacrificial layer 145 from the side surface of the second outer coating 142 to the interior of the second outer coating 142.

[0200] The etching bias, which is the distance from the end of the side surface of the second outer coating 142 to the end of the sacrificial layer 145, varies depending on the process conditions and can be in the range of 0.8 μm to 1.3 μm.

[0201] In this disclosure, the sacrificial layer 145 is formed as a bilayer of silicon nitride (SiNx) and silicon oxide (SiOx) of various thicknesses to evaluate the undercut structure.

[0202] For example, the sacrificial layer 145 is formed as a bilayer of silicon nitride (SiNx) and silicon oxide (SiOx) with thicknesses of 300 Å and 1000 Å, 500 Å and 1000 Å, 300 Å and 2000 Å, and 500 Å and 2000 Å, respectively.

[0203] In addition, each of the first electrode 331 and the dummy first electrode 331' is deposited as three layers of ITO, a reflective layer and ITO, with thicknesses of 100 Å, 1000 Å and 100 Å respectively.

[0204] In this case, it can be seen that the thickness ratio of each of the first electrode 331 and the dummy first electrode 331' to the sacrificial layer 145 is 92.3%, 80.0%, 52.2%, and 48.0%, respectively.

[0205] Reference Figure 8A to Figure 8H It can be seen that when the thickness ratio of each of the first electrode 331 and the dummy first electrode 331' to the sacrificial layer 145 is 92.3% or less, a positive taper is formed by etching the sacrificial layer 145. Furthermore, the first electrode 331 and the dummy first electrode 331' can be separated from each other. Additionally, it can be seen that the etching bias, which is the distance from the end of the side surface of the second outer coating 142 to the end of the sacrificial layer 145, varies depending on the process conditions and is in the range of 0.8 μm to 1.3 μm.

[0206] Figure 8A An example with an etching bias of 0.8 μm is shown. Figure 8B An example with an etching bias of 1.2 μm is shown. Figure 8C An example with an etching bias of 0.75 μm is shown. Figure 8D An example with an etching bias of 1.1 μm is shown.

[0207] in addition, Figure 8E An example with an etching bias of 0.9 μm is shown. Figure 8F An example with an etching bias of 1.3 μm is shown. Figure 8G An example with an etching bias of 0.9 μm is shown, and Figure 8H An example with an etching bias of 1.3 μm is shown.

[0208] Refer again Figure 4 A dummy first electrode 231' formed of the same material as the first electrode 231 can be disposed on the top and side surfaces of the second outer coating 142. Therefore, similar to the first electrode 231, the dummy first electrode 231' can include a reflective layer and a transparent conductive layer disposed on the reflective layer, but is not limited thereto. The dummy first electrode 231' can have a three-layer structure including a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0209] When the first electrode 231 is deposited, the dummy first electrode 231' can be deposited on the top and side surfaces of the second outer coating 142. Moreover, the dummy first electrode 231' can be separated from the first electrode 231 by the undercut structure of the second outer coating 142.

[0210] In this way, the first electrode 231 and the dummy first electrode 231' are separated in the sub-pixel, so the first electrode 231 and the dummy first electrode 231' can be formed by full-surface deposition without a mask.

[0211] The dummy first electrode 231' can be disposed on the top and side surfaces of the second outer coating 142 along the shape of the second outer coating 142.

[0212] The dummy first electrode 231' disposed on the side surface of the second outer coating 142 may taper at an angle of 30° to 60°, but is not limited thereto.

[0213] According to another exemplary embodiment of this disclosure, the light-emitting display device 200 is a top-emitting type light-emitting display device. Therefore, the reflective layer of the dummy first electrode 231' can reflect light emitted from the light-emitting element 230 in an upward direction. Light generated from the light-emitting layer 232 of the light-emitting element 230 is emitted not only in an upward direction but also in a side direction. Light emitted in the side direction can travel into the interior of the light-emitting display device 200 and can be confined within the light-emitting display device 200 by total internal reflection. Furthermore, light may disappear when traveling into the interior of the light-emitting display device 200. Therefore, the reflective layer of the dummy first electrode 231' can be configured to cover the side surface of the second outer coating 142. Therefore, the direction of light travel can change from the side direction to the upward direction (see...). Figure 4 (The arrow in the image).

[0214] The embankment 114 can be disposed on the second outer coating 142.

[0215] A dam layer 114 can be disposed on the second outer coating layer 142 to cover the entire dummy first electrode 231' and a portion of the edge of the first electrode 231. The dam layer 114 can fill the interior of the undercut structure at the bottom end of the side surface of the second outer coating layer 142. Therefore, the dam layer 114 can be inserted between the first electrode 231 and the dummy first electrode 231'.

[0216] The dam layer 114 can cover a portion of the edge of the first electrode 231 covering multiple sub-pixels SPX to define the light-emitting area EA and the non-light-emitting area NEA. For example, in the non-light-emitting area NEA, the dam layer 114 is disposed on the first electrode 231 to block the generation of light from the non-light-emitting area NEA. Meanwhile, in the light-emitting area EA, the dam layer 114 is not disposed, but the light-emitting layer 232 is located precisely on the first electrode 231. Therefore, light can be generated from the light-emitting layer 232.

[0217] The light-emitting layer 232 and the second electrode 233 can be disposed on the embankment layer 114. The light-emitting layer 232 and the second electrode 233 can form a light-emitting element 230 together with the first electrode 231.

[0218] The light-emitting layer 232 can be configured to contact the first electrode 231 covering a plurality of sub-pixels SPX. For example, the light-emitting layer 232 can be disposed on the first electrode 231 covering the entire surface of the substrate 110, but is not limited thereto. The light-emitting layer 232 can be disposed only on the first electrode 231 in the light-emitting region EA. In this case, the light-emitting layer 232 can be configured to be surrounded by the embankment layer 114.

[0219] The second electrode 233 may be disposed on the light-emitting layer 232 in the sub-pixel SPX. For example, the second electrode 233 may be disposed in contact with the light-emitting layer 232 along the shape of the light-emitting layer 232 in the light-emitting region EA and the non-light-emitting region NEA, but is not limited thereto.

[0220] The light-emitting display device 200 according to another exemplary embodiment of the present disclosure is a top-emitting type light-emitting display device. Therefore, it can be manufactured to realize a microcavity. For example, in the light-emitting display device 200 according to another exemplary embodiment of the present disclosure, the distance between the reflective layer of the first electrode 231 and the second electrode 233 is set to achieve constructive interference of light emitted from the light-emitting layer 232. Therefore, light efficiency can be improved. Therefore, in the light-emitting display device 200 according to another exemplary embodiment of the present disclosure, the light-emitting layer 232 has a different thickness for each sub-pixel SPX to realize a microcavity.

[0221] Reference Figure 4 The encapsulation layer 150 can be disposed on the second electrode 233. The encapsulation layer 150 can prevent oxygen and moisture from penetrating into the light-emitting display device 200 from the outside.

[0222] Although not shown in the accompanying drawings, the encapsulation layer 150 may include a first encapsulation layer, a second encapsulation layer, and a third encapsulation layer.

[0223] A light-emitting display device 200 according to another exemplary embodiment of the present disclosure uses a second outer coating 142 having side surfaces to improve the light extraction efficiency of the light-emitting element 230. For example, in the light-emitting display device 200 according to another exemplary embodiment of the present disclosure, a second outer coating 142 having a top surface and side surfaces is disposed on a first outer coating 141. Moreover, a reflective layer of the dummy first electrode 231' is disposed to at least cover the side surfaces of the second outer coating 142. Therefore, in the light emitted from the light-emitting layer 232 of the light-emitting display device 200, the second light emitted at a low output angle can be extracted toward the front surface by the reflective layer of the dummy first electrode 231' disposed on the side surface of the second outer coating 142. That is, in the light-emitting display device 200 of another exemplary embodiment of the present disclosure, the first light emitted from the light-emitting layer 232 toward the front surface and the second light emitted from the light-emitting layer 232 at a low output angle can be reflected by the reflective layer of the dummy first electrode 231' disposed on the side surface of the second outer coating 142 and extracted toward the front surface.

[0224] Therefore, in another exemplary embodiment of the light-emitting display device 200 according to this disclosure, the reflective layer of the dummy first electrode 231' provided on the side surface of the second outer coating 142 serves as a side mirror. Thus, light that may be lost in the light-emitting display device 200 can be extracted towards the front surface. Therefore, light extraction efficiency can be improved and power consumption can be reduced.

[0225] In another exemplary embodiment of the light-emitting display device 200 according to this disclosure, the first electrode 231 is separated from the dummy first electrode 231' disposed on the side surface of the second outer coating 142. Therefore, contact resistance and leakage problems can be suppressed.

[0226] In other words, in this disclosure, the first electrode 231 is separated from the dummy first electrode 231' disposed on the side surface of the second outer coating 142 to improve short-circuit faults and increase contact resistance. Furthermore, in this disclosure, the first electrode 231 and the dummy first electrode 231' are formed by deposition without using a mask, and the sacrificial layer 145 is patterned without performing additional masking processes. Therefore, processability can be improved and manufacturing costs reduced.

[0227] In other words, the present disclosure is characterized by a reflective layer of a dummy first electrode 231' formed on the side surface of the second outer coating 142.

[0228] Furthermore, a feature of this disclosure is the undercut structure formed at the bottom end of the side surface of the second outer coating 142. Therefore, the dummy first electrode 231' and the first electrode 231 are formed separately using the same process.

[0229] Furthermore, a feature of this disclosure is that the first electrode 231 is electrically connected to the drain electrode 124 via a connecting electrode 125 located below the first electrode 231.

[0230] Furthermore, this disclosure is characterized in that a dummy first electrode 231' is disposed on the side surface of the second outer coating 142 and tapers at an angle of 30° to 60°.

[0231] In addition, in this disclosure, the distance between the embankment 114 and the dummy first electrode 231' can be controlled within the range where the first electrode 231 does not cover all exposed openings.

[0232] Furthermore, in this disclosure, the sacrificial layer 145 has a greater thickness than the first electrode 231 to form an undercut structure at the edge of the first electrode 231.

[0233] Furthermore, in this disclosure, the connecting electrode 125 is formed to be larger than the first electrode 231 in order to improve the contact resistance.

[0234] Meanwhile, in the light-emitting display device according to the exemplary embodiments and another exemplary embodiment of this disclosure, a light-emitting layer is formed on the entire surface of the substrate including the non-light-emitting region NEA and the light-emitting region EA. However, this disclosure is not limited thereto. In this disclosure, the light-emitting layer may be formed only in the light-emitting region EA, which will be described in detail with reference to yet another exemplary embodiment of this disclosure.

[0235] Figure 9 This is a plan view of a light-emitting display device according to yet another exemplary embodiment of the present disclosure.

[0236] In addition to the light-emitting layer 332 of the light-emitting element 330, Figure 9 The light-emitting display device 300 shown is... Figure 4 The light-emitting display device 200 shown is essentially the same. Therefore, its repeated description will be omitted.

[0237] Reference Figure 9 According to another exemplary embodiment of the present disclosure, the light-emitting display device 300 may include a substrate 110, a thin-film transistor 120, a light-emitting element 330, a first outer coating 141 and a second outer coating 142, a dam layer 114, a sacrificial layer 145 and an encapsulation layer 150.

[0238] In this configuration, the light-emitting layer 332 and the second electrode 333 can be disposed on the embankment layer 114. The light-emitting layer 332 and the second electrode 333 can together with the first electrode 331 form a light-emitting element 330.

[0239] The light-emitting layer 332 can be configured to contact the first electrode 331 that covers multiple sub-pixels SPX. For example, the light-emitting layer 332 can be disposed only on the first electrode 331 in the light-emitting area EA. In this case, the light-emitting layer 332 can be configured to be surrounded by the embankment layer 114.

[0240] The emissive layer 332 is used to emit light of a specific color and has a separate structure for each sub-pixel SPX. For example, the emissive layer 332 disposed in the first sub-pixel SPX1, which is a red sub-pixel, is a red emissive layer, and the emissive layer 332 disposed in the second sub-pixel SPX2, which is a green sub-pixel, is a green emissive layer. Additionally, the emissive layer 332 disposed in the third sub-pixel SPX3, which is a blue sub-pixel, is a blue emissive layer. The emissive layers 332 disposed in the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 can be disposed separately from each other. For each sub-pixel SPX, the emissive layer 332 can be patterned using an open mask (e.g., a fine metallic mask (FMM)) and deposited in the corresponding emissive region EA.

[0241] The light-emitting layer 332 may also include various layers, such as a hole transport layer, a hole injection layer, a hole blocking layer, an electron injection layer, an electron blocking layer, and an electron transport layer. The light-emitting layer 332 may be an organic light-emitting layer formed of organic materials, but is not limited thereto. For example, the light-emitting layer 332 may also be formed of a quantum dot light-emitting layer or a micro-LED.

[0242] The second electrode 333 can be disposed on the entire surface of the substrate 110, which includes a light-emitting layer 332 patterned in each light-emitting region EA.

[0243] In the following, a method for manufacturing the light-emitting display device of the present disclosure will be described in detail according to another exemplary embodiment of the present disclosure.

[0244] Figure 10A to Figure 10G This is a cross-sectional view showing a method of manufacturing a light-emitting display device according to another exemplary embodiment of the present disclosure.

[0245] Reference Figure 10A A buffer layer 111 is formed on the substrate 110, and a first metal layer is stacked on the buffer layer 111, and then patterned.

[0246] The substrate 110 is used to support and protect various components of the light-emitting display device 300.

[0247] The substrate 110 can be formed of glass or a flexible plastic material. If the substrate 110 is formed of a plastic material, it can be formed of, for example, polyimide (PI), but is not limited thereto.

[0248] The buffer layer 111 is used to enhance the adhesion between the substrate 110 and the layer formed on the buffer layer 111, and to block alkali metal elements from being discharged from the substrate 110.

[0249] The buffer layer 111 can be formed as a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. Depending on the type and material of the substrate 110 and the structure and type of the thin-film transistor 120, the buffer layer 111 may be omitted.

[0250] The first metal layer may be formed of any of, but is not limited to, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or alloys of two or more of these, or a variety of other metallic materials in multiple layers thereof.

[0251] Then, the gate electrode 121 of the thin-film transistor is formed by patterning the first metal layer.

[0252] Although not shown in the accompanying drawings, a photoresist can be coated on the first metal layer, and the first metal layer can be patterned using a photolithography process with a photomask to form the aforementioned gate electrode 121. The photolithography process can be performed by the following steps: after exposure using an exposure apparatus with a photomask, a series of processes such as development, etching, stripping, or ashing are performed.

[0253] Then, a gate insulating layer 112 is formed on the substrate 110, and a semiconductor layer is formed on the gate insulating layer 112, and then patterned to form the active layer 122 of the thin film transistor.

[0254] The gate insulating layer 112 is an insulating layer used to electrically insulate the gate electrode 121 from the active layer 122. The gate insulating layer 112 can be formed of an insulating material. For example, the gate insulating layer 112 can be formed as a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto.

[0255] The active layer 122 can be configured to overlap with the gate electrode 121.

[0256] For example, the active layer 122 can be formed of oxide semiconductor, amorphous silicon (a-Si), polycrystalline silicon (poly-Si) or organic semiconductor.

[0257] Then, an etch stop layer 117 can be formed on the active layer 122.

[0258] When the source electrode 123 and the drain electrode 124 are patterned by etching, an etch stop layer 117 can be formed to suppress plasma damage to the back channel surface of the active layer 122.

[0259] One end of the etch stop layer 117 may overlap with the source electrode 123, and the other end may overlap with the drain electrode 124. Alternatively, the etch stop layer 117 may be omitted.

[0260] Then, a second metal layer is formed on the substrate 110 on which the etch stop layer 117 has been formed, and the second metal layer is patterned to form the source electrode 123 and the drain electrode 124.

[0261] The second metal layer may be formed of any of, but is not limited to, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or alloys of two or more of these, or a variety of other metallic materials in which multiple layers are formed.

[0262] Then, a passivation layer 113 can be formed on the substrate 110.

[0263] The passivation layer 113 can be used to protect the thin-film transistor 120. The passivation layer 113 can be formed as a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. The passivation layer 113 may also be omitted.

[0264] Then, a first outer coating 141 can be formed on the passivation layer 113. The first outer coating 141 is an insulating layer used to protect the thin-film transistor 120 and reduce the step difference between layers disposed on the substrate 110. The first outer coating 141 can be formed from any one of acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenyl resin, benzocyclobutene, photoresist, and polyphenylene sulfide resin, but is not limited thereto.

[0265] A first outer coating 141 may be disposed on the thin-film transistor 120. The top surface of the first outer coating 141 may be parallel to the substrate 110. Therefore, the first outer coating 141 can flatten the step difference caused by components disposed below the first outer coating 141.

[0266] Then, a third metal layer is formed on the first outer coating 141, and the third metal layer is patterned to form the connecting electrode 125.

[0267] The connecting electrode 125 can be electrically connected to the drain electrode 124 through contact holes formed in the first outer coating 141 and the passivation layer 113, but is not limited thereto. The connecting electrode 125 can also be electrically connected to the source electrode 123 through contact holes formed in the first outer coating 141 and the passivation layer 113.

[0268] The third metal layer may be formed of, but is not limited to, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or alloys of two or more of these, or a variety of other metallic materials in which multiple layers are formed.

[0269] Then, refer to Figure 10B An insulating layer 140 is deposited on the entire surface of a substrate 110 on which the connecting electrode 125 and the first outer coating 141 have been formed.

[0270] The insulating layer 140 may be formed to be thicker than the first electrode 231 to form an undercut structure at the edge of the first electrode 231. For example, the undercut structure of this disclosure may be formed if the thickness of the first electrode 231 is set to 92.3% or less of the thickness of the insulating layer 140.

[0271] The insulating layer 140 may be formed as a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. For example, the insulating layer 140 may be formed as a bilayer of silicon nitride (SiNx) and silicon oxide (SiOx) with a thickness of 1300 Å to 2500 Å.

[0272] Then, refer to Figure 10C An organic insulating layer is formed on the insulating layer 140, and the organic insulating layer is patterned to form a second outer coating 142. Dry etching can be performed to pattern the organic insulating layer.

[0273] The second outer coating 142 may also be formed of the same material as the first outer coating 141.

[0274] For example, the second outer coating 142 may be formed from any one of acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, benzocyclobutene, photoresist, polyphenylene sulfide resin, but is not limited thereto.

[0275] The side surface of the second outer coating 142 may have a taper at a predetermined angle. For example, the side surface of the second outer coating 142 may taper at an angle of 30° to 60°, but is not limited thereto.

[0276] The second outer coating 142 may include a top surface and a side surface.

[0277] The top surface of the second outer coating 142 is located at the uppermost part of the second outer coating 142 and can be substantially parallel to the substrate 110.

[0278] The side surface of the second outer coating 142 may be a surface extending from the top surface of the second outer coating 142.

[0279] Then, refer to Figure 10D The second outer coating 142 can be used as a mask to etch the insulating layer 140 separately. Wet etching can be performed to etch the insulating layer 140.

[0280] The second outer coating 142 can have an undercut structure at the bottom of the side surface to form a sacrificial layer 145 by further etching the insulating layer 140 from the side surface of the second outer coating 142 into the interior in the horizontal direction.

[0281] The etching bias, which is the distance from the end of the side surface of the second outer coating 142 to the end of the sacrificial layer 145, varies depending on the process conditions and can be in the range of 0.8 μm to 1.3 μm.

[0282] Then, refer to Figure 10E A fourth metal layer and a fifth metal layer are deposited on the entire surface of the substrate 110 to form a first electrode 231 on the connection electrode 125.

[0283] The first electrode 231 can be disposed on the surface of the connecting electrode 125 that is not covered by the sacrificial layer 145 and whose surface is exposed. The first electrode 231 can also be disposed at the bottom of the side surface of the second outer coating 142 inside the undercut structure, so as to contact the side surface of the sacrificial layer 145.

[0284] When the first electrode 231 is formed, a dummy first electrode 231' can be formed on the top and side surfaces of the second outer coating 142. When the first electrode 231 is deposited, the dummy first electrode 231' can be deposited on the top and side surfaces of the second outer coating 142. Moreover, the dummy first electrode 231' can be separated from the first electrode 231 by the undercut structure of the second outer coating 142.

[0285] The dummy first electrode 231' disposed on the side surface of the second outer coating 142 may taper at an angle of 30° to 60°, but is not limited thereto.

[0286] According to another exemplary embodiment of the present disclosure, the light-emitting display device 200 is a top-emitting type light-emitting display device. Therefore, the reflective layer of the dummy first electrode 231' can reflect light emitted from the light-emitting element 230 in an upward direction. Light generated from the light-emitting layer 232 of the light-emitting element 230 is emitted not only in an upward direction but also in a side direction. Light emitted in the side direction can travel into the interior of the light-emitting display device 200 and can be confined within the interior of the light-emitting display device 200 by total internal reflection. Furthermore, the light may disappear when traveling into the interior of the light-emitting display device 200. Therefore, the reflective layer of the dummy first electrode 231' can be configured to cover the side surface of the second outer coating 142. Therefore, the direction of light travel may change from the side direction to the upward direction.

[0287] The first electrode 231 and the dummy first electrode 231' can be formed by deposition without performing a masking process.

[0288] In contrast to the sacrificial layer 145, the first electrode 231 may be formed to have an anti-tapered edge.

[0289] The thickness of the first electrode 231 can be set to 92.3% or less of the thickness of the sacrificial layer 145 to separate the first electrode 231 from the dummy first electrode 231'.

[0290] A portion of the surface of the first electrode 231 can be substantially flat, but a portion of the edge of the first electrode 231 can have a non-flat structure 231". If a portion of the edge of the first electrode 231 is non-flat and has a non-flat structure 231", waveguide and SP modes can be extracted. Therefore, this can help improve the efficiency of the top surface.

[0291] Although not shown in the accompanying drawings, each of the first electrode 231 and the dummy first electrode 231' may include a reflective layer and a transparent conductive layer disposed on the reflective layer. However, this disclosure is not limited thereto. Each of the first electrode 231 and the dummy first electrode 231' may have a three-layer structure including a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0292] A reflective layer may be disposed on the connecting electrode 125. Another exemplary embodiment of the light-emitting display device 200 according to this disclosure is a top-emitting type light-emitting display device. Therefore, the reflective layer can reflect light emitted from the light-emitting element 230 in an upward direction.

[0293] The reflective layer, which serves as the fourth metal layer, can be formed from metallic materials such as aluminum (Al), silver (Ag), copper (Cu), or magnesium-silver alloys, but is not limited to these.

[0294] The reflective layer can be electrically connected to the drain electrode 124 via the connecting electrode 125, but is not limited thereto. The reflective layer can also be electrically connected to the source electrode 123 via the connecting electrode 125.

[0295] A transparent conductive layer, serving as the fifth metal layer, can be disposed on the reflective layer. This transparent conductive layer can be disposed on the reflective layer and electrically connected to the drain electrode via the reflective layer and the connecting electrode 125. The transparent conductive layer can be formed of a conductive material with a high work function to provide holes to the light-emitting layer 232.

[0296] For example, the transparent conductive layer can be formed from transparent conductive oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), and tin oxide (TO), but is not limited thereto.

[0297] Then, refer to Figure 10F A dam layer 114 can be formed on the second outer coating 142.

[0298] A dam layer 114 can be disposed on the second outer coating layer 142 to cover the entire dummy first electrode 231' and a portion of the edge of the first electrode 231. The dam layer 114 can fill the interior of the undercut structure at the bottom end of the side surface of the second outer coating layer 142. Therefore, the dam layer 114 can be inserted between the first electrode 231 and the dummy first electrode 231'.

[0299] The dam layer 114 can cover a portion of the edge of the first electrode 231 covering multiple sub-pixels SPX to define the light-emitting area EA and the non-light-emitting area NEA. For example, in the non-light-emitting area NEA, the dam layer 114 is disposed on the first electrode 231 to block the generation of light from the non-light-emitting area NEA. Meanwhile, in the light-emitting area EA, the dam layer 114 is not disposed, but the light-emitting layer 232 is located precisely on the first electrode 231. Therefore, light can be generated from the light-emitting layer 232.

[0300] The dam layer 114 can be formed from organic or inorganic materials.

[0301] For example, the dam layer 114 may be formed of organic materials such as polyimide, acrylic acid or benzocyclobutene or inorganic materials such as silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

[0302] Then, refer to Figure 10G A light-emitting layer 232 and a second electrode 233 can be formed on the embankment layer 114. The light-emitting layer 232 and the second electrode 233 can be together with the first electrode 231 to form a light-emitting element 230.

[0303] The light-emitting layer 232 can be configured to contact the first electrode 231 covering multiple sub-pixels SPX. For example, the light-emitting layer 232 can be disposed on the first electrode 231 covering the entire surface of the substrate 110, but is not limited thereto. The light-emitting layer 232 can also be disposed only on the first electrode 231 in the light-emitting region EA. In this case, the light-emitting layer 232 can be configured to be surrounded by the embankment layer 114.

[0304] The second electrode 233 may be disposed on the light-emitting layer 232 in the sub-pixel SPX. For example, the second electrode 233 may be disposed in contact with the light-emitting layer 232 along the shape of the light-emitting layer 232 in the light-emitting region EA and the non-light-emitting region NEA, but is not limited thereto.

[0305] The second electrode 233 can provide electrons to the light-emitting layer 232. The second electrode 233 can be formed of a metallic material such as silver (Ag), copper (Cu), or a magnesium-silver alloy, but is not limited to this. If the second electrode 233 is formed of a metallic material, it has a very low refractive index. For example, if the second electrode 233 is formed of silver (Ag), it can have a refractive index of approximately 0.13.

[0306] Then, an encapsulation layer 150 can be formed on the second electrode 233.

[0307] The encapsulation layer 150 can prevent oxygen and moisture from penetrating into the light-emitting display device 200 from the outside.

[0308] Although not shown in the accompanying drawings, the encapsulation layer 150 may include a first encapsulation layer, a second encapsulation layer, and a third encapsulation layer.

[0309] The first encapsulation layer can be disposed on the second electrode 233 to inhibit the penetration of moisture or oxygen.

[0310] In this document, the first encapsulation layer may be formed of an inorganic material such as silicon nitride (SiNx), silicon oxide nitride (SiOxNy), or aluminum oxide (AlyOz), but is not limited thereto. The first encapsulation layer may be formed of a material having a higher refractive index than the second encapsulation layer. For example, if the first encapsulation layer is formed of silicon nitride (SiNx) or silicon oxide nitride (SiOxNy), the refractive index of the first encapsulation layer may be approximately 1.8.

[0311] The second encapsulation layer can be disposed on the first encapsulation layer to planarize the surface of the first encapsulation layer. Furthermore, the second encapsulation layer can cover foreign matter or particles that may be generated during the manufacturing process. The second encapsulation layer can be formed of organic materials such as silicon carbide oxide (SiOxCz), acrylic resin, or epoxy resin, but is not limited thereto. The second encapsulation layer can be formed of a material having a lower refractive index than the first encapsulation layer. For example, if the second encapsulation layer is formed of an acrylic resin, the refractive index of the second encapsulation layer can be from about 1.5 to about 1.6.

[0312] The third encapsulation layer can be placed on the second encapsulation layer and can inhibit the penetration of moisture or oxygen, just like the first encapsulation layer.

[0313] For example, the third encapsulation layer may be formed of an inorganic material such as silicon nitride (SiNx), silicon oxide nitride (SiOxNy), silicon oxide (SiOx), or aluminum oxide (AlyOz), but is not limited thereto. The third encapsulation layer may be formed of the same material as the first encapsulation layer, or it may be formed of a different material than the first encapsulation layer.

[0314] Furthermore, the light-emitting display device of this disclosure can also be applied to situations where a touch unit is added to the encapsulation layer. This will be described in detail with reference to yet another exemplary embodiment of this disclosure.

[0315] Figure 11 This is a plan view of a light-emitting display device according to yet another exemplary embodiment of the present disclosure.

[0316] Figure 12 It is along Figure 11 A cross-sectional view of the light-emitting display device taken by line XII-XII'.

[0317] In addition to the touch unit 460 Figure 11 and Figure 12 The light-emitting display device 400 shown is... Figure 4 The light-emitting display device 200 shown is basically the same. Therefore, its redundant description will be omitted. For ease of explanation, Figure 11 Only multiple sub-pixels SPX and touch line 464 are shown.

[0318] Reference Figure 11 and Figure 12 The touch unit 460 can be disposed on the encapsulation layer 150. The touch unit 460 can be disposed in the active region A / A including the light-emitting element 230 to sense touch input. The touch unit 460 can sense external touch information provided by the user's finger or stylus. The touch unit 460 may include a first inorganic insulating layer 461, a second inorganic insulating layer 462, a touch line 464, and a touch electrode 465.

[0319] The first inorganic insulating layer 461 is disposed on the encapsulation layer 150.

[0320] A first inorganic insulating layer 461 may be disposed on and in contact with the third encapsulation layer 150. The first inorganic insulating layer 461 may be formed of an inorganic material. For example, the first inorganic insulating layer 461 may be formed of an inorganic material such as silicon nitride (SiNx) or silicon oxide nitride (SiOxNy). For example, if the first inorganic insulating layer 461 is formed of silicon nitride (SiNx), the refractive index of the first inorganic insulating layer 461 may be approximately 1.8.

[0321] The touch line 464 can be disposed on the first inorganic insulating layer 461.

[0322] Touch line 464 can be disposed on the first inorganic insulating layer 461 in the non-light-emitting area NEA. Touch line 464 can be disposed along the row direction or along the column direction. Touch line 464 provides touch drive signals for driving touch unit 460. In addition, touch line 464 can send touch information sensed by touch unit 460 to driver IC.

[0323] The second inorganic insulating layer 462 can be disposed on the touch line 464 and the first inorganic insulating layer 461. The second inorganic insulating layer 462 can be disposed on the first inorganic insulating layer 461 and the touch line 464 to flatten their top surfaces.

[0324] The second inorganic insulating layer 462 is used to suppress short circuits in the touch line 464 disposed adjacent to the second inorganic insulating layer 462. The second inorganic insulating layer 462 can be formed of the same material as the first inorganic insulating layer 461. For example, the second inorganic insulating layer 462 can be formed of an inorganic material such as silicon nitride (SiNx) or silicon oxide nitride (SiOxNy). For example, if the second inorganic insulating layer 462 is formed of silicon nitride (SiNx), the refractive index of the second inorganic insulating layer 462 can be approximately 1.8. If the second inorganic insulating layer 462 has the same refractive index as the first inorganic insulating layer 461, the material of the second inorganic insulating layer 462 is not limited to this.

[0325] The touch electrode 465 can be disposed on the touch line 464 and the second inorganic insulating layer 462.

[0326] Touch electrodes 465 can be arranged along either the row or column direction. For example, touch electrodes 465 arranged in either the row or column direction can be arranged on touch lines 464. Alternatively, touch electrodes 465 arranged in the other of the row or column direction can be arranged on the second inorganic insulating layer 462. Touch electrodes 465 arranged in the column direction and touch electrodes 465 arranged in the row direction can be connected to each other by bridging electrodes to form a mesh structure. Figure 12The touch electrode 465 is shown to be disposed in the light-emitting area EA. However, the touch electrode 465 may not be disposed in the light-emitting area EA, but is not limited thereto.

[0327] Exemplary implementations of this disclosure can also be described as follows:

[0328] According to one aspect of this disclosure, a light-emitting display device includes a substrate defined by a plurality of sub-pixels and a first outer coating disposed on the substrate. The light-emitting display device further includes a connecting electrode and a sacrificial layer disposed on the first outer coating, and a first electrode disposed on the connecting electrode. The light-emitting display device further includes a second outer coating disposed on the sacrificial layer and including an opening exposing a portion of the first electrode. The light-emitting display device further includes a dummy first electrode disposed on the top surface of the second outer coating and on the side surface of the opening, and separated from the first electrode. The light-emitting display device further includes a dam layer covering the dummy first electrode and a portion of the first electrode, and a light-emitting layer and a second electrode disposed on the first electrode and the dam layer.

[0329] The connecting electrode can be electrically connected to the drain electrode of the thin-film transistor.

[0330] By removing the sacrificial layer from the side surface to the interior of the second outer coating, the second outer coating can have an undercut structure at the bottom end of the side surface.

[0331] The first electrode can also be located inside the undercut structure.

[0332] The first electrode inside the undercut structure can have an uneven structure on its surface.

[0333] In addition to the uneven structure of the first electrode, the second outer coating can expose the entire surface of the first electrode.

[0334] The second outer coating tapers at an angle of 30° to 60° on the side surface that exposes the first electrode.

[0335] The embankment layer fills the interior of the undercut structure.

[0336] The distance from the end of the side surface of the second outer coating to the end of the sacrificial layer can be in the range of 0.8 μm to 1.3 μm.

[0337] The thickness of the first electrode can be 92.3% or less of the thickness of the sacrificial layer.

[0338] The sacrificial layer may have a positive taper at its edges, and the sacrificial layer may be disposed on the first outer coating to cover the edges of the connecting electrodes.

[0339] The first electrode can be configured to contact the side surface of the sacrificial layer and be placed on a connecting electrode that is not covered by the sacrificial layer and has its surface exposed.

[0340] The dam layer can be disposed on the second outer coating to cover the entire dummy first electrode and a portion of the edge of the first electrode.

[0341] The light-emitting layer can be disposed only on the first electrode inside the opening.

[0342] The light-emitting display device may also include an encapsulation layer disposed on the second electrode; and a touch unit disposed on the encapsulation layer.

[0343] The touch unit may include a first inorganic insulating layer on the encapsulation layer; a second inorganic insulating layer on the first inorganic insulating layer; and touch lines and touch electrodes disposed on the first inorganic insulating layer or the second inorganic insulating layer.

[0344] According to another aspect of this disclosure, a method of manufacturing a light-emitting display device includes forming a first outer coating on a substrate on which thin-film transistors are provided. The method further includes forming a connection electrode on the first outer coating and forming an insulating layer on the entire surface of the substrate on which the connection electrode and the first outer coating are provided. The method further includes forming a second outer coating including openings on the insulating layer. The method further includes etching the insulating layer using the second outer coating as a mask to form an undercut structure at the bottom of a side surface of the second outer coating. The method further includes forming a first electrode on the connection electrode and inside the undercut structure, and simultaneously forming a dummy first electrode on the top and side surfaces of the second outer coating. The method further includes forming a dam layer covering the dummy first electrode and a portion of the first electrode, and forming a light-emitting layer and a second electrode on the first electrode and the dam layer. The first electrode can be separated from the dummy first electrode by the undercut structure.

[0345] The first electrode and the dummy first electrode are fabricated by deposition without performing a masking process.

[0346] The first electrode inside the undercut structure can have an uneven structure on its surface.

[0347] The thickness of the first electrode can be 92.3% or less of the thickness of the insulating layer.

[0348] By using wet etching with a second outer coating as a mask, an undercut structure can be created at the bottom of the side surface of the second outer coating by removing the insulating layer from the side surface of the second outer coating to the inside.

[0349] The present invention can also be implemented through the following embodiments.

[0350] 1. A light-emitting display device, comprising: a substrate defined by a plurality of sub-pixels; a first outer coating disposed on the substrate; a connecting electrode and a sacrificial layer disposed on the first outer coating; a first electrode disposed on the connecting electrode; a second outer coating disposed on the sacrificial layer and including an opening exposing a portion of the first electrode; a dummy first electrode disposed on a top surface of the second outer coating and a side surface of the opening, and separate from the first electrode; a dam layer covering a portion of the first electrode and the dummy first electrode; and a light-emitting layer and a second electrode disposed on the first electrode and the dam layer.

[0351] 2. The light-emitting display device according to embodiment 1, wherein the connecting electrode is electrically connected to the drain electrode of the thin-film transistor.

[0352] 3. The light-emitting display device according to embodiment 1, wherein the second outer coating has an undercut structure at the bottom end of the side surface by removing the sacrificial layer from the side surface to the interior of the second outer coating.

[0353] 4. The light-emitting display device according to embodiment 3, wherein the edge of the first electrode is disposed inside the undercut structure.

[0354] 5. The light-emitting display device according to embodiment 4, wherein the edge of the first electrode inside the undercut structure has an uneven structure on its surface.

[0355] 6. The light-emitting display device according to embodiment 5, wherein the second outer coating exposes the entire surface of the first electrode except for the uneven structure of the first electrode.

[0356] 7. The light-emitting display device according to embodiment 5, wherein the side surface of the second outer coating that exposes the first electrode tapers at an angle of 30° to 60°.

[0357] 8. The light-emitting display device according to embodiment 3, wherein the embankment layer fills the interior of the undercut structure.

[0358] 9. The light-emitting display device according to embodiment 1, wherein the distance from the end of the side surface of the second outer coating to the end of the sacrificial layer is in the range of 0.8 μm to 1.3 μm.

[0359] 10. The light-emitting display device according to embodiment 1, wherein the thickness of the first electrode is 92.3% or less of the thickness of the sacrificial layer.

[0360] 11. The light-emitting display device according to embodiment 1, wherein the sacrificial layer has a positive taper at its edge, and

[0361] The sacrificial layer is disposed on the first outer coating layer to cover the edge of the connecting electrode.

[0362] 12. The light-emitting display device according to embodiment 11, wherein the first electrode is configured to contact the side surface of the sacrificial layer and is disposed on the connecting electrode which is not covered by the sacrificial layer and whose surface is exposed.

[0363] 13. The light-emitting display device according to embodiment 1, wherein the dam layer is disposed on the second outer coating layer to cover the entire dummy first electrode and a portion of the edge of the first electrode.

[0364] 14. The light-emitting display device according to embodiment 1, wherein the light-emitting layer is disposed only on the first electrode inside the opening.

[0365] 15. The light-emitting display device according to embodiment 1 further includes:

[0366] An encapsulation layer disposed on the second electrode; and

[0367] The touch unit on the encapsulation layer,

[0368] The touch unit includes:

[0369] A first inorganic insulating layer on the encapsulation layer;

[0370] A second inorganic insulating layer on the first inorganic insulating layer; and

[0371] The touch wire and touch electrode are disposed on the first inorganic insulating layer or the second inorganic insulating layer.

[0372] 16. The light-emitting display device according to embodiment 1, wherein at least one of the first electrode and the first dummy electrode includes a reflective layer.

[0373] 17. A light-emitting display device, comprising:

[0374] A substrate defined by multiple sub-pixels;

[0375] A first outer coating is disposed on the substrate;

[0376] Connecting electrodes and a sacrificial layer disposed on the first outer coating layer;

[0377] The first electrode is disposed on the connecting electrode;

[0378] A second outer coating is disposed on the sacrificial layer and includes an opening that exposes a portion of the first electrode, the second outer coating having an undercut structure at the bottom end of the side surface of the opening;

[0379] A dummy first electrode is disposed on the top surface of the second outer coating and the side surface of the opening;

[0380] A dike layer, which covers a portion of the first electrode and the dummy first electrode; and

[0381] A light-emitting layer and a second electrode are disposed on the first electrode and the dam layer.

[0382] 18. A method for manufacturing a light-emitting display device, comprising:

[0383] A first outer coating is prepared on a substrate on which a thin-film transistor has already been provided;

[0384] A connecting electrode is fabricated on the first outer coating;

[0385] An insulating layer is formed on the entire surface of the substrate on which the connecting electrode and the first outer coating have been provided;

[0386] A second outer coating including openings is prepared on the insulating layer;

[0387] By using the second outer coating as a mask to etch the insulating layer, an undercut structure is created at the bottom of the side surface of the second outer coating;

[0388] A first electrode is fabricated on the connecting electrode and inside the undercut structure, and a dummy first electrode is fabricated simultaneously on the top and side surfaces of the second outer coating.

[0389] Prepare a dam layer covering a portion of the first electrode and the dummy first electrode; and

[0390] A light-emitting layer and a second electrode are fabricated on the first electrode and the dam layer.

[0391] The first electrode is separated from the dummy first electrode by the undercut structure.

[0392] 19. The method of manufacturing the light-emitting display device according to embodiment 18, wherein the first electrode and the dummy first electrode are prepared by deposition without performing a masking process.

[0393] 20. The method of manufacturing the light-emitting display device according to embodiment 18, wherein the edge of the first electrode inside the undercut structure has an uneven structure on its surface.

[0394] 21. The method of manufacturing the light-emitting display device according to embodiment 18, wherein the thickness of the first electrode is 92.3% or less of the thickness of the insulating layer.

[0395] 22. The method of manufacturing the light-emitting display device according to embodiment 18, wherein the undercut structure is formed at the bottom of the side surface of the second outer coating by removing the insulating layer from the side surface of the second outer coating to the interior through wet etching using the second outer coating as a mask.

[0396] Although exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto, and the present disclosure can be implemented in many different forms without departing from the technical concept of the present disclosure. Therefore, exemplary embodiments of the present disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are illustrative in all respects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the appended claims, and all technical concepts within the scope of their equivalents should be interpreted as falling within the scope of the present disclosure.

Claims

1. A light-emitting display device, comprising: A substrate, including a light-emitting area and a non-light-emitting area, wherein the light-emitting area is defined by a plurality of sub-pixels; Thin-film transistors disposed on the substrate; A first outer coating is disposed on the thin-film transistor; It is disposed on the first outer coating and electrically connected to the first electrode of the thin-film transistor; A sacrificial layer is disposed on the first outer coating and includes an opening that exposes a portion of the first electrode; A second outer coating is disposed on the sacrificial layer and includes an opening that exposes a portion of the first electrode; A light-emitting layer and a second electrode disposed on the first electrode; as well as An encapsulation layer disposed on the second electrode; The second outer coating has an undercut structure at the bottom end of its side surface. The thickness of the first electrode is 92.3% or less of the thickness of the sacrificial layer.

2. The light-emitting display device according to claim 1, wherein, The side end of the second outer coating protrudes from the end of the sacrificial layer.

3. The light-emitting display device according to claim 1, wherein, The encapsulation layer comprises inorganic materials, such as aluminum oxide.

4. The light-emitting display device according to claim 1, wherein, The encapsulation layer comprises a first encapsulation layer, a second encapsulation layer, and a third encapsulation layer stacked sequentially, and The first encapsulation layer has a higher refractive index than the second encapsulation layer.

5. The light-emitting display device according to claim 1, wherein, The edge of the first electrode is disposed inside the undercut structure.

6. The light-emitting display device according to claim 5, wherein, The first electrode inside the undercut structure has a non-uniform structure on its surface.

7. The light-emitting display device according to claim 1, wherein, The sacrificial layer is a multilayer structure consisting of silicon nitride and silicon oxide layers.

8. The light-emitting display device according to claim 1, wherein, The second outer coating is made of the same material as the first outer coating.

9. The light-emitting display device according to claim 1, further comprising: A dummy first electrode is disposed on the top surface of the second outer coating and the side surface of the opening, and is separate from the first electrode.

10. The light-emitting display device according to claim 9, further comprising: A dike layer is set on the dummy first electrode. The embankment layer fills the interior of the undercut structure of the second outer coating layer.

11. The light-emitting display device according to claim 9, wherein, The dummy first electrode has a three-layer structure including a transparent conductive layer, a reflective layer, and a transparent conductive layer.

12. The light-emitting display device according to claim 1, wherein, The light-emitting layer has a different thickness for each sub-pixel.

13. The light-emitting display device according to claim 1, further comprising: A connecting electrode is disposed on the first outer coating. The connecting electrode is disposed in the light-emitting region and is electrically connected to the drain electrode of the thin-film transistor. The first electrode is disposed on the surface of the connecting electrode that is not covered by the sacrificial layer.

14. The light-emitting display device according to claim 1, further comprising: The touch unit on the encapsulation layer, The touch unit includes: a first insulating layer on the encapsulation layer; a second inorganic insulating layer on the first insulating layer; and touch lines and touch electrodes disposed on the first insulating layer or the second insulating layer.

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