Light emitting display apparatus and method of fabricting the same

Abstract

A light-emitting display device according to one embodiment of the present invention comprises a substrate divided into a plurality of subpixels, a first overcoating layer disposed on the substrate, a connecting electrode and a sacrificial layer disposed on the first overcoating layer, a first electrode disposed on the connecting electrode, a second overcoating layer disposed on the sacrificial layer and including an opening that exposes a portion of the first electrode, a dummy first electrode disposed on the upper surface of the second overcoating layer and on the side of the opening and separated from the first electrode, a bank layer covering a portion of the dummy first electrode and the first electrode, and a light-emitting layer and a second electrode disposed on the first electrode and the bank layer.

Description

Technology Field

[0001] The present invention relates to a light-emitting display device, and more specifically, to a light-emitting display device that improves light extraction efficiency and simultaneously improves the process, and a method for manufacturing the same. Background Technology

[0002] As we enter the full-scale information age, the field of display devices that visually represent electrical information signals is developing rapidly, and research is continuing to improve the performance of various display devices, such as miniaturization, lightweighting, and low power consumption.

[0003] Among various display devices, light-emitting displays are self-emissive devices that, unlike liquid crystal displays, do not require a separate light source, allowing them to be manufactured in lightweight and thin forms. Furthermore, light-emitting displays are not only advantageous in terms of power consumption due to low-voltage driving, but also offer excellent color reproduction, response speed, viewing angle, and contrast ratio (CR), making them promising for use in a wide range of fields.

[0004] Meanwhile, light emitted from the light-emitting layer of a light-emitting display device passes through various components of the light-emitting display device and exits to the outside of the light-emitting display device. However, some of the light emitted from the light-emitting layer is trapped inside the light-emitting display device and cannot exit to the outside of the light-emitting display device, which causes problems with the light extraction efficiency of the light-emitting display device.

[0005] For example, there is a problem where some of the light emitted from the light-emitting layer is trapped inside the light-emitting display device due to total reflection loss, waveguide loss, and surface plasmon loss. Here, total reflection loss refers to the reduction in light extraction efficiency caused by light emitted from the light-emitting layer being trapped inside the light-emitting display device due to total reflection at the interface between the substrate and air. Waveguide loss refers to the reduction in light extraction efficiency caused by light trapped inside due to total reflection at the interfaces of components within the light-emitting display device. Surface plasmon loss refers to the reduction in light extraction efficiency caused by the phenomenon of light absorption at the metal surface during the process of incident and propagation, which causes the light to vibrate free electrons on the metal surface, preventing the light from being reflected or transmitted. The problem to be solved

[0006] The problem that the present invention aims to solve is to provide a light-emitting display device and a method for manufacturing the same, which improves total reflection loss and optical waveguide loss by using a dummy anode with a side mirror shape.

[0007] Another problem that the present invention aims to solve is to provide a light-emitting display device and a method for manufacturing the same, wherein an undercut structure is applied to the edge of the anode to separate it from the dummy anode.

[0008] The problems of the present invention are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0009] A light-emitting display device according to one embodiment of the present invention comprises a substrate divided into a plurality of subpixels, a first overcoating layer disposed on the substrate, a connecting electrode and a sacrificial layer disposed on the first overcoating layer, a first electrode disposed on the connecting electrode, a second overcoating layer disposed on the sacrificial layer and including an opening that exposes a portion of the first electrode, a dummy first electrode disposed on the upper surface of the second overcoating layer and on the side of the opening and separated from the first electrode, a bank layer covering a portion of the dummy first electrode and the first electrode, and a light-emitting layer and a second electrode disposed on the first electrode and the bank layer.

[0010] A method for manufacturing a light-emitting display device according to one embodiment of the present invention comprises the steps of: forming a first overcoating layer on a substrate having a thin-film transistor; forming a connecting electrode on the first overcoating layer; forming an insulating layer on the front surface of the substrate on which the connecting electrode and the first overcoating layer are formed; forming a second overcoating layer including an opening on the insulating layer; etching the insulating layer using the second overcoating layer as a mask to form an undercut structure on the lower side of the second overcoating layer; forming a first electrode on the connecting electrode including the inside of the undercut structure, while simultaneously forming a dummy first electrode on the upper surface and side of the second overcoating layer; forming a bank 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 bank layer, wherein the first electrode can be separated from the dummy first electrode by the undercut structure.

[0011] Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention

[0012] The present invention can improve the light extraction efficiency of a light-emitting display device by using a dummy anode with a side mirror shape.

[0013] The present invention can prevent contact resistance and leakage issues by applying an undercut structure to the edge of the anode to separate it from the dummy anode.

[0014] The present invention can eliminate the photolithography process once by forming an anode without separate patterning, thereby improving processability and reducing manufacturing costs.

[0015] The present invention allows for the omission of the hole formation process for the two-layer overcoat layer, thereby improving processability and securing high-resolution design margins.

[0016] The effects according to the present invention are not limited to those exemplified above, and a wider variety of effects are included within the present invention. Brief explanation of the drawing

[0017] FIG. 1 is a plan view of a light-emitting display device according to one embodiment of the present invention. Figure 2 is a schematic enlarged plan view of area 'A' in Figure 1. FIG. 3 is a cross-sectional view of a light-emitting display device according to III-III' of FIG. 2. FIG. 4 is a cross-sectional view of a light-emitting display device according to another embodiment of the present invention. Figure 5 is a photograph showing an example of the undercut structure of the anode of the present invention. FIG. 6 is a cross-sectional view showing an example of an uneven structure of the outer part of an anode according to another embodiment of the present invention. Figure 7 shows the results of a light extraction simulation based on the uneven structure of the outer edge of the anode. Figures 8a to 8h are photographs showing examples of positive taper formation and etch bias levels according to the thickness of the sacrificial layer. FIG. 9 is a plan view of a light-emitting display device according to another embodiment of the present invention. FIGS. 10a to 10g are cross-sectional views sequentially showing a method for manufacturing a light-emitting display device according to another embodiment of the present invention. FIG. 11 is a plan view of a light-emitting display device according to another embodiment of the present invention. FIG. 12 is a cross-sectional view of a light-emitting display device according to XII-XII' of FIG. 11. Specific details for implementing the invention

[0018] The advantages and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0019] Shapes, areas, ratios, angles, numbers, etc. disclosed in the drawings for describing embodiments of the present invention are exemplary, and therefore the present invention is not limited to the depicted details. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present invention, if it is determined that a detailed description of related known technology may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" mentioned above are used, other parts may be added unless "only" is used. When a component is expressed in the singular, it includes cases where it is included in the plural unless specifically stated otherwise.

[0020] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0021] In the case of describing positional relationships, for example, when the positional relationship between two parts is described using expressions such as 'on top of,' 'on the upper part of,' 'on the lower part of,' or 'next to,' one or more other parts may be located between the two parts unless 'immediately' or 'directly' is used.

[0022] When an element or layer is referred to as "on" another element or layer, it includes all cases where another layer or element is placed directly on top of or in the middle of another element.

[0023] Furthermore, terms such as "first," "second," etc. are used to describe various components, but these components are not limited by these terms. These terms are used merely to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the technical scope of the present invention.

[0024] Throughout the specification, the same reference numerals refer to the same components.

[0025] The area and thickness of each component shown in the drawings are illustrated for convenience of explanation, and the present invention is not necessarily limited to the area and thickness of the illustrated components.

[0026] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and may technically enable various interlocking and operation. Each embodiment may be implemented independently of one another or may be implemented together in an associated relationship.

[0027] Various embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0028] FIG. 1 is a plan view of a light-emitting display device according to one embodiment of the present invention.

[0029] Figure 2 is a schematic enlarged plan view of area 'A' in Figure 1.

[0030] FIG. 3 is a cross-sectional view of a light-emitting display device according to III-III' of FIG. 2.

[0031] In FIG. 2, only three subpixels (SPX) are shown for convenience of explanation. Also, FIG. 3 is a cross-sectional view of an arbitrary first subpixel among the three subpixels (SPX).

[0032] Referring to FIGS. 1 to 3, a light-emitting display device (100) according to one embodiment of the present invention may be configured to include a substrate (110), a thin-film transistor (120), a light-emitting element (130), first and second over-coating layers (141, 142), a bank layer (114), a sacrificial layer (145), and an encapsulation layer (150).

[0033] The light-emitting display device (100) can be implemented as a top emission light-emitting display device.

[0034] The substrate (110) may include a display area (A / A) and a non-display area (N / A).

[0035] The display area (A / A) is an area where an image is displayed on the light-emitting display device (100).

[0036] In the display area (A / A), a display element and various driving elements for driving the display element may be disposed. For example, the display element may be composed of a light-emitting element (130) including a first electrode (131), a light-emitting layer (132), and a second electrode (133). Additionally, various driving elements such as a thin-film transistor (120), a capacitor, and wiring for driving the display element may be disposed in the display area (A / A).

[0037] Multiple subpixels (SPX) can be partitioned in the display area (A / A).

[0038] A subpixel (SPX) is a minimum unit that constitutes a screen, and each of the plurality of subpixels (SPX) may include a light-emitting element (130) and a driving circuit. Additionally, each of the plurality of subpixels (SPX) may emit light of different wavelengths. For example, the plurality of subpixels (SPX) may include a first subpixel (SPX1) which is a red subpixel, a second subpixel (SPX2) which is a green subpixel, and a third subpixel (SPX3) which is a blue subpixel. However, the plurality of subpixels (SPX) may further include a white subpixel, not limited thereto.

[0039] The driving circuit of the subpixel (SPX) is a circuit for controlling the driving of the light-emitting element (130). For example, the driving circuit may be configured to include a thin-film transistor (120) and a capacitor, but is not limited thereto.

[0040] The non-display area (N / A) is an area where an image is not displayed, and various components for driving a plurality of subpixels (SPX) placed in the display area (A / A) may be placed therein. For example, a driving IC that supplies a signal for driving a plurality of subpixels (SPX), a flexible film, etc., may be placed in the non-display area (N / A).

[0041] The non-display area (N / A) may be an area surrounding the display area (A / A), as illustrated in FIG. 1. However, it is not limited thereto. For example, the non-display area (N / A) may be an area extending from the display area (A / A).

[0042] Referring to FIG. 3, the substrate (110) is a component for supporting and protecting various components of the light-emitting display device (100).

[0043] The substrate (110) may be made of glass or a plastic material having flexibility. If the substrate (110) is made of a plastic material, for example, it may be made of polyimide (PI). However, it is not limited thereto.

[0044] A buffer layer (111) may be disposed on a substrate (110). The buffer layer (111) can improve the adhesion between the layers formed on the upper part of the buffer layer (111) and the substrate (110), and can block alkaline components, etc., from leaking out from the substrate (110).

[0045] The buffer layer (111) may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or multiple layers of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. The buffer layer (111) may be omitted based on the type and material of the substrate (110), the structure and type of the thin-film transistor (120), etc.

[0046] A thin-film transistor (120) can be placed on the upper surface of the substrate (110).

[0047] A thin-film transistor (120) can be used as a driving element of a 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 a light-emitting display device (100) according to one embodiment of the present invention, the thin-film transistor (120) is a thin-film transistor with a bottom gate structure in which the gate electrode (121) is placed at the bottom, such that the active layer (122) is placed on top of the gate electrode (121), and the source electrode (123) and drain electrode (124) are placed on top of the active layer (122). However, it is not limited thereto.

[0048] A gate electrode (121) may be disposed on the substrate (110). The gate electrode (121) may be any one of various metallic materials, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy of two or more of these, or a multilayer thereof, but is not limited thereto.

[0049] A gate insulating layer (112) may be disposed on a gate electrode (121). The gate insulating layer (112) is an insulating layer for electrically insulating the gate electrode (121) and the active layer (122), and may be made of an insulating material. For example, the gate insulating layer (112) may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or multiple layers of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto.

[0050] An active layer (122) can be placed on the gate insulating layer (112).

[0051] The active layer (122) can be positioned to overlap with the gate electrode (121).

[0052] For example, the active layer (122) may be formed of an oxide semiconductor, amorphous silicon (a-Si), polycrystalline silicon (poly-Si), or an organic semiconductor.

[0053] An etch stopper (117) may be placed on the active layer (122).

[0054] The etch stopper (117) can be formed to prevent damage to the back channel surface of the active layer (122) caused by plasma when the source electrode (123) and drain electrode (124) are formed by patterning using an etching method.

[0055] One end of the etch stopper (117) may overlap with the source electrode (123), and the other end may overlap with the drain electrode (124). The etch stopper (117) may be omitted.

[0056] A source electrode (123) and a drain electrode (124) may be disposed on the active layer (122) and the etch stopper (117). The source electrode (123) and the drain electrode (124) may be disposed spaced apart from each other on the same layer.

[0057] The source electrode (123) and the drain electrode (124) can be electrically connected to the active layer (122) in a manner that contacts the active layer (122).

[0058] The source electrode (123) and drain electrode (124) may be any one of various metallic materials, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy of two or more of these, or a multilayer thereof, but are not limited thereto.

[0059] A protective layer (113) may be disposed on the thin-film transistor (120). The protective layer (113) may be disposed to protect the thin-film transistor (120) and may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or multiple layers of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. The protective layer (113) may be omitted.

[0060] A first overcoating layer (141) may be disposed on the protective layer (113). The first overcoating layer (141) is an insulating layer for protecting the thin-film transistor (120) and smoothing out the step difference between the layers disposed on the substrate (110). The first overcoating layer (141) may be formed from one of an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, an unsaturated polyester resin, a polyphenylene resin, a benzocyclobutene, a photoresist, and a polyphenylene sulfide resin, but is not limited thereto.

[0061] The first overcoating layer (141) can be placed on top of the thin-film transistor (120). The upper surface of the first overcoating layer (141) may have a surface parallel to the substrate (110). Accordingly, the first overcoating layer (141) can flatten the step difference that may occur due to the component placed below.

[0062] A connecting electrode (125) can be placed on the first overcoating layer (141).

[0063] The connecting electrode (125) may be electrically connected to the drain electrode (124) through a contact hole formed in the first overcoating layer (141) and the protective layer (113). However, not limited thereto, the connecting electrode (125) may also be electrically connected to the source electrode (123) through a contact hole formed in the first overcoating layer (141) and the protective layer (113).

[0064] The connecting electrode (125) may be any one of various metallic materials, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy of two or more of these, or a multilayer thereof, but is not limited thereto.

[0065] A sacrificial layer (145) may be placed on the connecting electrode (125) and the first overcoating layer (141).

[0066] The sacrificial layer (145) may be placed over the first overcoating layer (141) to cover the edge of the connecting electrode (125). That is, the sacrificial layer (145) may expose the surface of the connecting electrode (125) within at least the light-emitting region (EA).

[0067] The sacrificial layer (145) may be formed with a thickness greater than that of the first electrode (131) to create an undercut structure at the edge of the first electrode (131). For example, if the thickness of the first electrode (131) relative to the sacrificial layer (145) is set to 92.3% or less, the undercut structure of the present invention is possible.

[0068] The sacrificial layer (145) can be patterned so that the edges have a positive taper.

[0069] The sacrificial layer (145) may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or multiple layers of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. For example, the sacrificial layer (145) may be formed as a double layer of silicon nitride (SiNx) and silicon oxide (SiOx) with a thickness of 1300 Å to 2500 Å.

[0070] A first electrode (131) can be placed on the connecting electrode (125).

[0071] The first electrode (131) can be positioned to be in contact with the side of the sacrificial layer (145), not only on the surface of the connecting electrode (125) which is not covered by the sacrificial layer (145) and whose surface is exposed, but also inside the undercut structure on the lower side of the second overcoating layer (142).

[0072] The first electrode (131) can be formed by deposition without a mask process.

[0073] The first electrode (131) can be deposited such that, contrary to the sacrificial layer (145), the edges have an inverse taper.

[0074] The first electrode (131) can be set to have a thickness of 92.3% or less relative to the sacrificial layer (145) for an undercut structure at the edge.

[0075] The first electrode (131) may have a surface that is substantially flat, but is not limited thereto, and may have an uneven surface on part of its edge.

[0076] Although not illustrated, the first electrode (131) may include a reflective layer electrically connected to the thin-film transistor (120) and a transparent conductive layer disposed on the reflective layer. However, it is not limited thereto, and the first electrode (131) may be formed with a three-layer structure of a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0077] A reflective layer can be placed on a connecting electrode (125). Since the light-emitting display device (100) according to one embodiment of the present invention is a top-emission light-emitting display device, the reflective layer can reflect light emitted from a light-emitting element (130) upward.

[0078] The reflective layer may be made of a metallic material, for example, aluminum (Al), silver (Ag), copper (Cu), magnesium-silver alloy, etc., but is not limited thereto.

[0079] The reflective layer may be electrically connected to the drain electrode (124) through the connecting electrode (125). Not limited thereto, the reflective layer may also be electrically connected to the source electrode (123) through the connecting electrode (125).

[0080] A transparent conductive layer may be placed on top of a reflective layer. The transparent conductive layer may be placed on top of the reflective layer and may be electrically connected to a drain electrode through the reflective layer and a connecting electrode (125). The transparent conductive layer may be made of a conductive material with a high work function to supply holes to the light-emitting layer (132).

[0081] For example, the transparent conductive layer may be composed of transparent conductive oxides of the indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), and tin oxide (TO) series, but is not limited thereto.

[0082] A second overcoating layer (142) can be placed on the first electrode (131) and the sacrificial layer (145).

[0083] The second overcoating layer (142) can be formed to expose the entire surface except for the edges of the first electrode (131).

[0084] The side of the second overcoating layer (142) to which the first electrode (131) is exposed may have a taper at a predetermined angle. For example, the side of the second overcoating layer (142) may have a taper at an angle of 30° to 60°. However, it is not limited thereto.

[0085] The second overcoating layer (142) may include an upper surface and a side surface.

[0086] The upper surface of the second overcoating layer (142) is a surface located at the top of the second overcoating layer (142) and may be a surface substantially parallel to the substrate (110).

[0087] The side of the second overcoating layer (142) may be a side extending laterally from the upper surface of the second overcoating layer (142).

[0088] The second overcoating layer (142) may be formed of the same material as the first overcoating layer (141).

[0089] For example, the second overcoating layer (142) may be formed from one of an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, an unsaturated polyester resin, a polyphenylene resin, a benzocyclobutene, a photoresist, and a polyphenylene sulfide resin, but is not limited thereto.

[0090] By additionally etching the sacrificial layer (145) from the side of the second overcoating layer (142) inwardly, the lower side of the second overcoating layer (142) may have an undercut structure.

[0091] The etch bias, which is the distance from the side end of the second overcoating layer (142) to the end of the sacrificial layer (145), varies depending on the process conditions but can be 0.8㎛ to 1.3㎛.

[0092] A dummy first electrode (131') made of the same material as the first electrode (131) may be disposed on the upper and side surfaces of the second overcoating layer (142). Accordingly, the dummy first electrode (131') may include a reflective layer and a transparent conductive layer disposed on top of the reflective layer, just like the first electrode (131). However, it is not limited thereto, and the dummy first electrode (131') may be formed with a three-layer structure of a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0093] The dummy first electrode (131') can be deposited on the upper and side surfaces of the second overcoating layer (142) during the deposition of the first electrode (131), and can be separated from the first electrode (131) according to the undercut structure of the second overcoating layer (142).

[0094] In this way, as the first electrode (131) and the dummy first electrode (131') are separated within the subpixel, the first electrode (131) and the dummy first electrode (131') can be formed through full-surface deposition without a mask.

[0095] The dummy first electrode (131') can be placed on the upper surface and side of the second overcoating layer (142) along the shape of the second overcoating layer (142).

[0096] The dummy first electrode (131') placed on the side of the second overcoating layer (142) may have a taper at an angle of 30° to 60°. However, it is not limited thereto.

[0097] Since the light-emitting display device (100) according to one embodiment of the present invention is a top-emission type light-emitting display device, the reflective layer of the dummy first electrode (131') can reflect light emitted from the light-emitting element (130) upward. The light generated from the light-emitting layer (132) of the light-emitting element (130) is not emitted only upward, but can also be emitted sideways. The light emitted sideways is directed into the interior of the light-emitting display device (100), can be trapped inside the light-emitting display device (100) by total reflection, and may further proceed into the interior of the light-emitting display device (100) and be extinguished. Accordingly, the reflective layer of the dummy first electrode (131') is arranged to cover the side of the second over-coating layer (142), thereby changing the direction of travel of the light proceeding sideways to an upward direction (see arrow shown in FIG. 3).

[0098] A bank layer (114) may be disposed on top of the second overcoating layer (142).

[0099] The bank layer (114) may be positioned on top of the second overcoating layer (142) to cover the entire dummy first electrode (131') and a portion of the edge of the first electrode (131). The bank layer (114) may also be filled within the undercut structure at the bottom side of the second overcoating layer (142). Accordingly, the bank layer (114) may be interposed between the first electrode (131) and the dummy first electrode (131').

[0100] The bank layer (114) covers a portion of the edge of the first electrode (131) in a plurality of subpixels (SPX) and can define a light-emitting region (EA) and a non-light-emitting region (NEA). For example, in the non-light-emitting region (NEA), the bank layer (114) is placed over the first electrode (131), thereby blocking the generation of light in the non-light-emitting region (NEA). On the other hand, in the light-emitting region (EA), the bank layer (114) is not placed, and the light-emitting layer (132) is positioned directly over the first electrode (131), so that light can be generated in the light-emitting layer (132).

[0101] The bank layer (114) can be made of organic or inorganic material.

[0102] For example, the bank layer (114) may be made of an organic material such as polyimide, acrylic or benzocyclobutene, or an inorganic material such as silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

[0103] A light-emitting layer (132) and a second electrode (133) may be disposed on the bank layer (114). The light-emitting layer (132) and the second electrode (133) together with the first electrode (131) may form a light-emitting element (130).

[0104] The light-emitting layer (132) may be positioned to be in contact with the first electrode (131) at a plurality of subpixels (SPX). For example, the light-emitting layer (132) may be positioned on the front surface of the substrate (110) above the first electrode (131). However, it is not limited thereto, and the light-emitting layer (132) may be positioned only in the light-emitting region (EA) above the first electrode (131). In this case, the light-emitting layer (132) may be positioned to be surrounded by the bank layer (114).

[0105] The light-emitting layer (132) is a layer for emitting light of a specific color and has a structure separated for each subpixel (SPX). For example, the light-emitting layer (132) placed in the first subpixel (SPX1), which is a red subpixel, is a red light-emitting layer; the light-emitting layer (132) placed in the second subpixel (SPX2), which is a green subpixel, is a green light-emitting layer; and the light-emitting layer (132) placed in the third subpixel (SPX3), which is a blue subpixel, is a blue light-emitting layer. The light-emitting layer (132) placed in the first subpixel (SPX1), the light-emitting layer (132) placed in the second subpixel (SPX2), and the light-emitting layer (132) placed in the third subpixel (SPX3) can be separated and arranged.

[0106] The light-emitting layer (132) may further 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, an electron transport layer, etc. Additionally, the light-emitting layer (132) may be an organic light-emitting layer made of organic material, but is not limited thereto. For example, the light-emitting layer (132) may be made of a quantum dot light-emitting layer or a micro LED, etc.

[0107] The second electrode (133) may be placed on the light-emitting layer (132) in the subpixel (SPX). For example, the second electrode (133) may be placed in contact with the light-emitting layer (132) in the light-emitting region (EA) and the non-light-emitting region (NEA) according to the shape of the light-emitting layer (132). However, it is not limited thereto.

[0108] The second electrode (133) can supply electrons to the light-emitting layer (132). The second electrode (133) may be made of a metallic material such as silver (Ag), copper (Cu), or a magnesium-silver alloy, but is not limited thereto. When the second electrode (133) is made of a metallic material, it has a very low refractive index, and for example, when silver (Ag) is used as the second electrode (133), the refractive index of the second electrode (133) may be about 0.13.

[0109] Since the light-emitting display device (100) according to one embodiment of the present invention is a top-emission light-emitting display device, it can be manufactured to implement a micro cavity. For example, in the light-emitting display device (100) according to one embodiment of the present invention, by setting the distance between the reflection layer of the first electrode (131) and the second electrode (133), constructive interference for the light emitted from the light-emitting layer (132) can be implemented, thereby improving light efficiency. Accordingly, in the light-emitting display device (100) according to one embodiment of the present invention, the thickness value of the light-emitting layer (132) can be implemented differently for each subpixel (SPX) to implement a micro cavity.

[0110] Referring to FIG. 3, a sealing layer (150) may be disposed on the second electrode (133). The sealing layer (150) can block oxygen and moisture from penetrating into the interior of the light-emitting display device (100) from the outside. For example, if the light-emitting display device (100) is exposed to moisture or oxygen, a pixel shrinkage phenomenon may occur in which the light-emitting area (EA) shrinks, or a problem may occur in which black spots appear within the light-emitting area (EA). Accordingly, the sealing layer (150) can protect the light-emitting display device (100) by blocking oxygen and moisture.

[0111] Although not shown, the bag layer (150) may include a first bag layer, a second bag layer, and a third bag layer.

[0112] The first sealing layer is placed on the second electrode (133) to prevent the penetration of moisture or oxygen.

[0113] At this time, the first encapsulation layer may be made of an inorganic material such as silicon nitride (SiNx), silicon oxynitride (SiOxNy), or aluminum oxide (AlyOz), but is not limited thereto. The first encapsulation layer may be made of a material with a higher refractive index than the second encapsulation layer, and for example, when the first encapsulation layer is made of silicon nitride (SiNx) or silicon oxynitride (SiOxNy), the refractive index of the first encapsulation layer may be about 1.8.

[0114] The second encapsulation layer can be placed on the first encapsulation layer to flatten the surface. Additionally, the second encapsulation layer can cover foreign matter or particles that may occur during the manufacturing process. The second encapsulation layer may be composed of organic materials, for example, silicon oxycarbon (SiOxCz), acrylic or epoxy-based resins, but is not limited thereto. The second encapsulation layer may be composed of a material with a lower refractive index than the first encapsulation layer. For example, if the second encapsulation layer is an acrylic-based resin, the refractive index of the second encapsulation layer may be approximately 1.5 to approximately 1.6.

[0115] The third bag layer is placed on top of the second bag layer and, like the first bag layer, can inhibit the penetration of moisture or oxygen.

[0116] For example, the third encapsulation layer may be composed of inorganic materials such as silicon nitride (SiNx), silicon oxynitride (SiOxNy), silicon oxide (SiOx), or aluminum oxide (AlyOz), but is not limited thereto. The third encapsulation layer may be composed of the same material as the first encapsulation layer or may be composed of a different material.

[0117] In previous light-emitting display devices, light emitted from the light-emitting layer that is trapped and lost within the light-emitting display device became a factor in reducing light efficiency. For example, light emitted from the light-emitting layer that cannot be extracted outside the light-emitting display device due to total reflection loss or light waveguide loss occurs, thereby reducing the light extraction efficiency of the light-emitting display device. For example, in previous light-emitting display devices, since the first electrode is placed only on the overcoating layer with a flat top surface, the second light emitted from the light-emitting layer at a low emission angle could be trapped in the light-emitting display device due to total reflection loss or light waveguide loss.

[0118] Accordingly, a light-emitting display device (100) according to one embodiment of the present invention can improve the light extraction efficiency of a light-emitting element (130) by using a second over-coating layer (142) having a side surface. For example, in a light-emitting display device (100) according to one embodiment of the present invention, a second over-coating layer (142) having a top surface and a side surface is placed on top of a first over-coating layer (141), and a reflective layer of a dummy first electrode (131') is arranged to cover at least the side surface of the second over-coating layer (142). Accordingly, among the light emitted from the light-emitting layer (132) of the light-emitting display device (100), a second light emitted at a low emission angle can be extracted in the direction of the top surface by the reflective layer of the dummy first electrode (131') placed on the side surface of the second over-coating layer (142). For example, if only the first electrode is placed on an overcoating layer with a flat shape, as in a previous light-emitting display device, light directed in a side direction, for example, light emitted at a low emission angle, may not proceed in the direction of the upper surface and may not be extracted outside the light-emitting display device due to total reflection loss or light waveguide loss. However, in the light-emitting display device (100) according to one embodiment of the present invention, the first light emitted in the direction of the upper surface from the light-emitting layer (132) and the second light emitted at a low emission angle from the light-emitting layer (132) can be reflected from the reflection layer of the dummy first electrode (131') placed on the side of the second overcoating layer (142) and extracted in the direction of the upper surface.

[0119] Accordingly, in a light-emitting display device (100) according to one embodiment of the present invention, the reflective layer of the dummy first electrode (131') disposed on the side of the second overcoating layer (142) functions as a side mirror, thereby enabling light that may be lost within the light-emitting display device (100) to be extracted in the direction of the upper surface, thus improving light extraction efficiency and increasing power consumption.

[0120] In a light-emitting display device (100) according to one embodiment of the present invention, contact resistance and leakage issues can be prevented as the first electrode (131) is separated from a dummy first electrode (131') disposed on the side of the second overcoating layer (142).

[0121] Meanwhile, an OSM (OLED Side Mirror) structure, which additionally forms a mirror-shaped anode on the side of the light-emitting layer, can be implemented by stacking the overcoating layer in double layers or by adding a connecting electrode between the anode and the drain electrode.

[0122] In this case, when the overcoating layer is double-layered, a failure to light up may occur due to residual film of the overcoating layer in the contact hole area during the contact process between the anode and drain electrodes.

[0123] Accordingly, by inserting a connecting electrode between the anode and the drain electrode and masking the first and second overcoating layers respectively, the occurrence of residual film in the overcoating layer may be reduced. However, in this case, if the margin between the bank layer and the second overcoating layer is small, leakage current may occur in the reflection layer of the anode, or a short circuit may occur between the light-emitting layer and the anode and cathode due to foreign matter.

[0124] Accordingly, in the present invention, the first electrode (131) is separated from the dummy first electrode (131') placed on the side of the second overcoating layer (142), thereby improving short-circuit failure and contact resistance. In addition, in the present invention, the first electrode (131) and the dummy first electrode (131') are formed by deposition without a mask, and the sacrificial layer (145) is patterned without an additional mask process, thereby improving processability and reducing manufacturing costs.

[0125] That is, the present invention is characterized by forming a reflective layer of a dummy first electrode (131') on the side of the second overcoating layer (142).

[0126] In addition, the present invention is characterized in that, by forming an undercut structure on the lower side of the second overcoating layer (142), the dummy first electrode (131') is formed separately in the same process together with the first electrode (131).

[0127] In addition, the present invention is characterized in that the first electrode (131) is electrically connected to the drain electrode (124) through the connecting electrode (125) at its lower end.

[0128] In addition, the present invention is characterized in that a dummy first electrode (131') disposed on the side of the second overcoating layer (142) has a taper at an angle of 30° to 60°.

[0129] In addition, the present invention is characterized in that the gap between the bank layer (114) and the dummy first electrode (131') can be adjusted to the extent that it does not cover all of the openings where the first electrode (131) is exposed.

[0130] In addition, the present invention is characterized in that the sacrificial layer (145) has a thickness greater than that of the first electrode (131) to create an undercut structure at the edge of the first electrode (131).

[0131] In addition, the present invention is characterized in that the connecting electrode (125) is formed with a larger area than the first electrode (131) to improve contact resistance.

[0132] Meanwhile, the light-emitting display device according to one embodiment of the present invention is exemplified by the case where the entire surface of the first electrode is substantially flat, but is not limited thereto. The present invention may have an uneven structure in part of the edge of the first electrode, which will be explained in detail through other embodiments of the present invention.

[0133] FIG. 4 is a cross-sectional view of a light-emitting display device according to another embodiment of the present invention.

[0134] Figure 5 is a photograph showing an example of the undercut structure of the anode of the present invention.

[0135] FIG. 6 is a cross-sectional view showing an example of an uneven structure of the outer part of an anode according to another embodiment of the present invention.

[0136] Figure 7 shows the results of a light extraction simulation based on the uneven structure of the outer edge of the anode.

[0137] Figures 8a to 8h are photographs showing examples of positive taper formation and etch bias levels according to the thickness of the sacrificial layer.

[0138] The light-emitting display device (200) of FIG. 4 is different from the light-emitting display device (100) of FIG. 2 and FIG. 3 in that an uneven structure (231) is formed on the edge of the first electrode (231), and other configurations are substantially the same.

[0139] Referring to FIG. 4, a light-emitting display device (200) according to another embodiment of the present invention may be configured to include a substrate (110), a thin-film transistor (120), a light-emitting element (230), first and second over-coating layers (141, 142), a bank layer (114), a sacrificial layer (145), and an encapsulation layer (150).

[0140] The light-emitting display device (200) can be implemented as a top emission light-emitting display device.

[0141] The substrate (110) is a component for supporting and protecting various components of the light-emitting display device (200).

[0142] A buffer layer (111) may be disposed on a substrate (110). The buffer layer (111) can improve the adhesion between the layers formed on the upper part of the buffer layer (111) and the substrate (110), and can block alkaline components, etc., from leaking out from the substrate (110).

[0143] A thin-film transistor (120) can be placed on the upper surface of the substrate (110).

[0144] A thin-film transistor (120) can be used as a driving element of a 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 a light-emitting display device (200) according to another embodiment of the present invention, the thin-film transistor (120) is a thin-film transistor with a bottom gate structure in which the gate electrode (121) is placed at the bottom, such that the active layer (122) is placed on top of the gate electrode (121), and the source electrode (123) and drain electrode (124) are placed on top of the active layer (122), but is not limited thereto.

[0145] The gate electrode (121) can be placed on the upper surface of the substrate (110).

[0146] A gate insulating layer (112) may be disposed on the gate electrode (121). The gate insulating layer (112) is an insulating layer for electrically insulating the gate electrode (121) and the active layer (122), and may be made of an insulating material.

[0147] An active layer (122) can be placed on the gate insulating layer (112).

[0148] The active layer (122) can be positioned to overlap with the gate electrode (121).

[0149] An etch stopper (117) may be placed on the active layer (122).

[0150] The etch stopper (117) can be formed to prevent damage to the back channel surface of the active layer (122) caused by plasma when the source electrode (123) and drain electrode (124) are formed by patterning using an etching method.

[0151] One end of the etch stopper (117) may overlap with the source electrode (123), and the other end may overlap with the drain electrode (124). The etch stopper (117) may be omitted.

[0152] A source electrode (123) and a drain electrode (124) may be disposed on the active layer (122) and the etch stopper (117). The source electrode (123) and the drain electrode (124) may be disposed spaced apart from each other on the same layer.

[0153] The source electrode (123) and the drain electrode (124) can be electrically connected to the active layer (122) in a manner that contacts the active layer (122).

[0154] A protective layer (113) may be placed on the thin-film transistor (120). The protective layer (113) may be placed to protect the thin-film transistor (120), and the protective layer (113) may be omitted.

[0155] A first overcoating layer (141) may be disposed on the protective layer (113). The first overcoating layer (141) is an insulating layer for protecting the thin-film transistor (120) and smoothing out the step difference between the layers disposed on the substrate (110).

[0156] The first overcoating layer (141) can be placed on top of the thin-film transistor (120). The upper surface of the first overcoating layer (141) may have a surface parallel to the substrate (110). Accordingly, the first overcoating layer (141) can flatten the step difference that may occur due to the component placed below.

[0157] A connecting electrode (125) can be placed on the first overcoating layer (141).

[0158] The connecting electrode (125) may be electrically connected to the drain electrode (124) through a contact hole formed in the first overcoating layer (141) and the protective layer (113). However, not limited thereto, the connecting electrode (125) may also be electrically connected to the source electrode (123) through a contact hole formed in the first overcoating layer (141) and the protective layer (113).

[0159] A sacrificial layer (145) may be placed on the connecting electrode (125) and the first overcoating layer (141).

[0160] The sacrificial layer (145) may be placed over the first overcoating layer (141) to cover the edge of the connecting electrode (125). That is, the sacrificial layer (145) may expose the surface of the connecting electrode (125) within at least the light-emitting region (EA).

[0161] The sacrificial layer (145) may be formed with a thickness greater than that of the first electrode (231) to create an undercut structure at the edge of the first electrode (231). For example, if the thickness of the first electrode (231) relative to the sacrificial layer (145) is set to 92.3% or less, the undercut structure of the present invention is possible.

[0163] * The sacrificial layer (145) can be patterned so that the edges have a positive taper.

[0164] The sacrificial layer (145) may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or multiple layers of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. For example, the sacrificial layer (145) may be formed as a double layer of silicon nitride (SiNx) and silicon oxide (SiOx) with a thickness of 1300 Å to 2500 Å.

[0165] A first electrode (231) can be placed on the connecting electrode (125).

[0166] The first electrode (231) can be positioned to be in contact with the side of the sacrificial layer (145), not only on the surface of the connecting electrode (125) which is not covered by the sacrificial layer (145) and whose surface is exposed, but also inside the undercut structure of the lower side of the second overcoating layer (142).

[0167] The first electrode (231) can be formed by deposition without a mask process.

[0168] The first electrode (231) can be deposited such that, unlike the sacrificial layer (145), the edges have an inverse taper.

[0169] The first electrode (231) can be set to have a thickness of 92.3% or less relative to the sacrificial layer (145) for an undercut structure at the edge.

[0170] The first electrode (231) may have a partially flat surface, but the edges may have an uneven structure (231) (see FIG. 6).

[0171] Referring to Fig. 7, the dotted line in the simulation result represents a flat structure, and the solid line represents an uneven structure (231).

[0172] First, in a flat structure, light is trapped inside in a wave guide and SP mode, making it difficult to extract to the outside, which can reduce the external light extraction efficiency. However, when an uneven structure (231) is applied, the light trapped inside can be extracted to the upper surface, thereby improving the light extraction efficiency.

[0173] That is, if a portion of the edge of the first electrode (231) is not flat but has an uneven structure (231), it is possible to extract wave guides and SP modes, which can contribute to improving upper surface efficiency.

[0174] Referring to FIG. 4, the first electrode (231) may include a reflective layer electrically connected to a thin-film transistor (120) and a transparent conductive layer disposed on the reflective layer. However, it is not limited thereto, and the first electrode (231) may be formed with a three-layer structure of a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0175] A reflective layer may be placed on the connecting electrode (125). Since the light-emitting display device (200) according to another embodiment of the present invention is a top-emission light-emitting display device, the reflective layer may reflect light emitted from the light-emitting element (230) upward.

[0176] The reflective layer may be electrically connected to the drain electrode (124) through the connecting electrode (125). Not limited thereto, the reflective layer may also be electrically connected to the source electrode (123) through the connecting electrode (125).

[0177] A transparent conductive layer may be placed on top of a reflective layer. The transparent conductive layer may be placed on top of the reflective layer and may be electrically connected to a drain electrode through a connecting electrode (125) with the reflective layer. The transparent conductive layer may be made of a conductive material with a high work function to supply holes to the light-emitting layer (232).

[0178] A second overcoating layer (142) can be placed on the first electrode (231) and the sacrificial layer (145).

[0179] The second overcoating layer (142) can be formed to expose the entire surface except for the edge of the first electrode (231), i.e., the uneven structure (231).

[0180] The side of the second overcoating layer (142) to which the first electrode (231) is exposed may have a taper at a predetermined angle. For example, the side of the second overcoating layer (142) may have a taper at an angle of 30° to 60°. However, it is not limited thereto.

[0181] The second overcoating layer (142) may include an upper surface and a side surface.

[0182] The upper surface of the second overcoating layer (142) is a surface located at the top of the second overcoating layer (142) and may be a surface substantially parallel to the substrate (110).

[0183] The side of the second overcoating layer (142) may be a side extending laterally from the upper surface of the second overcoating layer (142).

[0184] The second overcoating layer (142) may be formed of the same material as the first overcoating layer (141).

[0185] By additionally etching the sacrificial layer (145) from the side of the second overcoating layer (142) inwardly, the lower side of the second overcoating layer (142) may have an undercut structure.

[0186] The etch bias, which is the distance from the side end of the second overcoating layer (142) to the end of the sacrificial layer (145), varies depending on the process conditions but can be 0.8㎛ to 1.3㎛.

[0187] In the present invention, the sacrificial layer (145) was formed as a double layer of silicon nitride (SiNx) and silicon oxide (SiOx) at various thicknesses to evaluate the undercut structure.

[0188] For example, the sacrificial layer (145) was formed as a double layer 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.

[0189] Then, the first electrode (331) and the dummy first electrode (331') were deposited as three layers of ITO, a reflective layer, and ITO, with thicknesses of 100 Å, 1000 Å, and 100 Å, respectively.

[0190] In this case, it can be seen that the thickness ratios of the first electrode (331) and the dummy first electrode (331') to the sacrificial layer (145) are 92.3%, 80.0%, 52.2%, and 48.0%, respectively.

[0191] Referring to FIGS. 8a through 8h, it can be seen that when the thickness ratio of the first electrode (331) and the dummy first electrode (331') to the sacrificial layer (145) is 92.3% or less, a regular taper is formed during the etching of the sacrificial layer (145), and separation between the first electrode (331) and the dummy first electrode (331') is possible. Additionally, it can be seen that the etch bias, which is the distance from the side end of the second overcoating layer (142) to the end of the sacrificial layer (145), can be 0.8 μm to 1.3 μm, although it varies depending on the process conditions.

[0192] At this time, Fig. 8a shows a case with an etch bias of 0.8 μm, Fig. 8b shows a case with an etch bias of 1.2 μm, Fig. 8c shows a case with an etch bias of 0.75 μm, and Fig. 8d shows a case with an etch bias of 1.1 μm.

[0193] In addition, Fig. 8e shows a case with an etch bias of 0.9 μm, Fig. 8f shows a case with an etch bias of 1.3 μm, Fig. 8g shows a case with an etch bias of 0.9 μm, and Fig. 8h shows a case with an etch bias of 1.3 μm.

[0194] Referring again to FIG. 4, a dummy first electrode (231') made of the same material as the first electrode (231) may be disposed on the upper and side surfaces of the second overcoating layer (142). Accordingly, the dummy first electrode (231') may include a reflective layer and a transparent conductive layer disposed on top of the reflective layer, just like the first electrode (231). However, it is not limited thereto, and the dummy first electrode (231') may be formed with a three-layer structure of a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0195] The dummy first electrode (231') can be deposited on the upper and side surfaces of the second overcoating layer (142) during the deposition of the first electrode (231), and can be separated from the first electrode (231) according to the undercut structure of the second overcoating layer (142).

[0196] In this way, as the first electrode (231) and the dummy first electrode (231') are separated within the subpixel, the first electrode (231) and the dummy first electrode (231') can be formed through full-surface deposition without a mask.

[0197] The dummy first electrode (231') can be placed on the upper surface and side of the second overcoating layer (142) along the shape of the second overcoating layer (142).

[0198] The dummy first electrode (231') placed on the side of the second overcoating layer (142) may have a taper at an angle of 30° to 60°. However, it is not limited thereto.

[0199] Since the light-emitting display device (200) according to another embodiment of the present invention is a top-emission type light-emitting display device, the reflective layer of the dummy first electrode (231') can reflect light emitted from the light-emitting element (230) upward. The light generated from the light-emitting layer (232) of the light-emitting element (230) is not emitted only upward, but can also be emitted sideways. The light emitted sideways is directed into the interior of the light-emitting display device (200), can be trapped inside the light-emitting display device (200) by total reflection, and may further proceed into the interior of the light-emitting display device (200) and be extinguished. Accordingly, the reflective layer of the dummy first electrode (231') is arranged to cover the side of the second over-coating layer (142), thereby changing the direction of travel of the light proceeding sideways to an upward direction (see arrow shown in FIG. 4).

[0200] A bank layer (114) may be disposed on top of the second overcoating layer (142).

[0201] The bank layer (114) may be positioned on top of the second overcoating layer (142) to cover the entire dummy first electrode (231') and a portion of the edge of the first electrode (231). The bank layer (114) may also be filled within the undercut structure at the bottom side of the second overcoating layer (142). Accordingly, the bank layer (114) may be interposed between the first electrode (231) and the dummy first electrode (231').

[0202] The bank layer (114) covers a portion of the edge of the first electrode (231) in a plurality of subpixels (SPX) and can define a light-emitting region (EA) and a non-light-emitting region (NEA). For example, in the non-light-emitting region (NEA), the bank layer (114) is placed over the first electrode (231), thereby blocking the generation of light in the non-light-emitting region (NEA). On the other hand, in the light-emitting region (EA), the bank layer (114) is not placed, and the light-emitting layer (232) is positioned directly over the first electrode (231), so that light can be generated in the light-emitting layer (232).

[0203] A light-emitting layer (232) and a second electrode (233) may be disposed on the bank layer (114). The light-emitting layer (232) and the second electrode (233) together with the first electrode (231) may form a light-emitting element (230).

[0204] The light-emitting layer (232) may be positioned to be in contact with the first electrode (231) at a plurality of subpixels (SPX). For example, the light-emitting layer (232) may be positioned on the front surface of the substrate (110) above the first electrode (231). However, it is not limited thereto, and the light-emitting layer (232) may be positioned only in the light-emitting region (EA) above the first electrode (231). In this case, the light-emitting layer (232) may be positioned to be surrounded by the bank layer (114).

[0205] The second electrode (233) may be placed on the light-emitting layer (232) in the subpixel (SPX). For example, the second electrode (233) may be placed in contact with the light-emitting layer (232) in the light-emitting region (EA) and the non-light-emitting region (NEA) according to the shape of the light-emitting layer (232). However, it is not limited thereto.

[0206] Since the light-emitting display device (200) according to another embodiment of the present invention is a top-emission light-emitting display device, it can be manufactured to implement a micro cavity. For example, in the light-emitting display device (200) according to another embodiment of the present invention, by setting the distance between the reflection layer of the first electrode (231) and the second electrode (233), constructive interference for the light emitted from the light-emitting layer (232) can be implemented, thereby improving light efficiency. Accordingly, in the light-emitting display device (200) according to another embodiment of the present invention, the thickness value of the light-emitting layer (232) can be implemented differently for each sub-pixel (SPX) to implement a micro cavity.

[0207] Referring to FIG. 4, a sealing layer (150) may be placed over the second electrode (233). The sealing layer (150) can block oxygen and moisture from penetrating into the interior of the light-emitting display device (200) from the outside.

[0208] Although not shown, the bag layer (250) may include a first bag layer, a second bag layer, and a third bag layer.

[0209] A light-emitting display device (200) according to another embodiment of the present invention can improve the light extraction efficiency of a light-emitting element (230) by using a second over-coating layer (142) having a side surface. For example, in a light-emitting display device (200) according to another embodiment of the present invention, a second over-coating layer (142) having a top surface and a side surface is placed on top of a first over-coating layer (141), and a reflective layer of a dummy first electrode (231') is placed to cover at least the side surface of the second over-coating layer (142). Accordingly, among the light emitted from the light-emitting layer (232) of the light-emitting display device (200), a second light emitted at a low emission angle can be extracted in the front direction by the reflective layer of the dummy first electrode (231') placed on the side surface of the second over-coating layer (142). That is, in a light-emitting display device (200) according to another embodiment of the present invention, a first light emitted in the front direction from the light-emitting layer (232) and a second light emitted at a low emission angle from the light-emitting layer (232) can be reflected from the reflection layer of a dummy first electrode (231') disposed on the side of the second overcoating layer (142) and extracted in the front direction.

[0210] Accordingly, in the light-emitting display device (200) according to another embodiment of the present invention, the reflective layer of the dummy first electrode (231') disposed on the side of the second overcoating layer (142) functions like a side mirror, thereby enabling light that may be lost within the light-emitting display device (200) to be extracted in the front direction, so the light extraction efficiency can be improved and the power consumption can be improved.

[0211] A light-emitting display device (200) according to another embodiment of the present invention can prevent contact resistance and leakage issues as the first electrode (231) is separated from a dummy first electrode (231') disposed on the side of the second overcoating layer (142).

[0212] That is, in the present invention, the first electrode (231) is separated from the dummy first electrode (1231') placed on the side of the second overcoating layer (142), thereby improving short-circuit failure and contact resistance. In addition, in the present invention, the first electrode (231) and the dummy first electrode (231') are formed by deposition without a mask, and the sacrificial layer (145) is patterned without an additional mask process, thereby improving processability and reducing manufacturing costs.

[0213] That is, the present invention is characterized by forming a reflective layer of a dummy first electrode (231') on the side of the second overcoating layer (142).

[0214] In addition, the present invention is characterized in that, by forming an undercut structure on the lower side of the second overcoating layer (142), the dummy first electrode (231') is formed separately together with the first electrode (231) in the same process.

[0215] In addition, the present invention is characterized in that the first electrode (231) is electrically connected to the drain electrode (124) through the connecting electrode (125) at its lower end.

[0216] In addition, the present invention is characterized in that the dummy first electrode (231') disposed on the side of the second overcoating layer (142) has a taper at an angle of 30° to 60°.

[0217] In addition, the present invention is characterized in that the gap between the bank layer (114) and the dummy first electrode (231') can be adjusted to the extent that it does not cover all of the openings where the first electrode (231) is exposed.

[0218] In addition, the present invention is characterized in that the sacrificial layer (145) has a thickness greater than that of the first electrode (231) to create an undercut structure at the edge of the first electrode (231).

[0219] In addition, the present invention is characterized in that the connecting electrode (125) is formed with a larger area than the first electrode (231) to improve contact resistance.

[0220] Meanwhile, the light-emitting display device according to one embodiment and another embodiment of the present invention is exemplified by a case in which the light-emitting layer is formed on the entire surface of the substrate including not only a light-emitting region (EA) but also a non-light-emitting region (NEA), but is not limited thereto. The present invention may form the light-emitting layer limited only to the light-emitting region (EA), and this will be explained in detail through another embodiment of the present invention.

[0221] FIG. 9 is a plan view of a light-emitting display device according to another embodiment of the present invention.

[0222] The light-emitting display device (300) of FIG. 9 is different from the display device (200) of FIG. 4 only in the light-emitting layer (332) of the light-emitting element (330), and since the other components are substantially the same, a redundant description will be omitted.

[0223] Referring to FIG. 9, a light-emitting display device (300) of another embodiment of the present invention may be configured to include a substrate (110), a thin-film transistor (120), a light-emitting element (330), first and second over-coating layers (141, 142), a bank layer (114), a sacrificial layer (145), and an encapsulation layer (150).

[0224] At this time, a light-emitting layer (332) and a second electrode (333) may be disposed on the bank layer (114). The light-emitting layer (332) and the second electrode (333) together with the first electrode (331) may form a light-emitting element (330).

[0225] The light-emitting layer (332) may be positioned to be in contact with the first electrode (331) at a plurality of subpixels (SPX). For example, the light-emitting layer (332) may be positioned only in the light-emitting region (EA) on the first electrode (331). In this case, the light-emitting layer (332) may be positioned to be surrounded by the bank layer (114).

[0226] The light-emitting layer (332) is a layer for emitting light of a specific color and has a structure separated for each subpixel (SPX). For example, the light-emitting layer (332) placed in the first subpixel (SPX1), which is a red subpixel, is a red light-emitting layer; the light-emitting layer (332) placed in the second subpixel (SPX2), which is a green subpixel, is a green light-emitting layer; and the light-emitting layer (332) placed in the third subpixel (SPX3), which is a blue subpixel, is a blue light-emitting layer. The light-emitting layer (332) placed in the first subpixel (SPX1), the light-emitting layer (332) placed in the second subpixel (SPX2), and the light-emitting layer (332) placed in the third subpixel (SPX3) can be separated and placed apart. Each light-emitting layer (332) can be pattern-deposited in each light-emitting region (EA) using a mask that is open for each subpixel (SPX), for example, a fine metal mask (FMM).

[0227] The light-emitting layer (332) may further 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, an electron transport layer, etc. Additionally, the light-emitting layer (332) may be an organic light-emitting layer made of organic material, but is not limited thereto. For example, the light-emitting layer (332) may be made of a quantum dot light-emitting layer or a micro LED, etc.

[0228] A second electrode (333) may be disposed on the front surface of the substrate (110), including a patterned light-emitting layer (332) in each light-emitting region (EA).

[0229] Hereinafter, the method for manufacturing a light-emitting display device of the present invention will be described in detail with reference to other embodiments of the present invention.

[0230] FIGS. 10a to 10g are cross-sectional views sequentially showing a method for manufacturing a light-emitting display device according to another embodiment of the present invention.

[0231] Referring to FIG. 10a, a buffer layer (111) is formed on a substrate (110), and a first metal layer is laminated on the buffer layer (111) and then patterned.

[0232] The substrate (110) is a component for supporting and protecting various components of the light-emitting display device (200).

[0233] The substrate (110) may be made of glass or a plastic material having flexibility. If the substrate (110) is made of a plastic material, for example, it may be made of polyimide (PI). However, it is not limited thereto.

[0234] The buffer layer (111) can improve the adhesion between the layers formed on the upper part of the buffer layer (111) and the substrate (110), and can block alkaline components, etc., from leaking out from the substrate (110).

[0235] The buffer layer (111) may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or multiple layers of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. The buffer layer (111) may be omitted based on the type and material of the substrate (110), the structure and type of the thin-film transistor (120), etc.

[0236] The first metal layer may be any one of various metallic materials, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy of two or more of these, or a multilayer thereof, but is not limited thereto.

[0237] Next, the first metal layer is patterned to form the gate electrode (121) of the thin-film transistor.

[0238] Although not shown in the drawing, after a photoresist is applied on the first metal layer, the first metal layer can be patterned by a photolithography process using a photomask to form the aforementioned gate electrode (121). The mask process by photolithography can be carried out through a series of processes such as developing, etching, stripping, or ashing after exposure to an exposure device through a photomask.

[0239] Afterwards, a gate insulating layer (112) is formed on the substrate (110), and after forming a semiconductor layer, the active layer (122) of the thin-film transistor is formed by patterning.

[0240] The gate insulating layer (112) is an insulating layer for electrically insulating the gate electrode (121) and the active layer (122), and may be made of an insulating material. For example, the gate insulating layer (112) may be composed of 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.

[0241] The active layer (122) can be positioned to overlap with the gate electrode (121).

[0242] For example, the active layer (122) may be formed of an oxide semiconductor, amorphous silicon (a-Si), polycrystalline silicon (poly-Si), or an organic semiconductor.

[0243] Next, an etch stopper (117) can be formed on the active layer (122).

[0244] The etch stopper (117) can be formed to prevent damage to the back channel surface of the active layer (122) caused by plasma when the source electrode (123) and drain electrode (124) are formed by patterning using an etching method.

[0245] One end of the etch stopper (117) may overlap with the source electrode (123), and the other end may overlap with the drain electrode (124). The etch stopper (117) may be omitted.

[0246] Afterwards, a second metal layer is formed on the substrate (110) on which the etch stopper (117) is formed, and the second metal layer is patterned to form a source electrode (123) and a drain electrode (124).

[0247] The second metal layer may be any one of various metallic materials, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy of two or more of these, or a multilayer thereof, but is not limited thereto.

[0248] Next, a protective layer (113) can be formed on the substrate (110).

[0249] The protective layer (113) may be formed to protect the thin-film transistor (120) and may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or multiple layers of silicon nitride (SiNx) and / or silicon oxide (SiOx), but is not limited thereto. The protective layer (113) may be omitted.

[0250] Next, a first overcoating layer (141) can be formed on the protective layer (113). The first overcoating layer (141) is an insulating layer for protecting the thin-film transistor (120) and smoothing out the step difference between the layers placed on the substrate (110). The first overcoating layer (141) may be formed from one of an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, an unsaturated polyester resin, a polyphenylene resin, a benzocyclobutene, a photoresist, and a polyphenylene sulfide resin, but is not limited thereto.

[0251] The first overcoating layer (141) can be placed on top of the thin-film transistor (120). The upper surface of the first overcoating layer (141) may have a surface parallel to the substrate (110). Accordingly, the first overcoating layer (141) can flatten the step difference that may occur due to the component placed below.

[0252] Next, a third metal layer is formed on the first overcoating layer (141), and the third metal layer is patterned to form a connecting electrode (125).

[0253] The connecting electrode (125) may be electrically connected to the drain electrode (124) through a contact hole formed in the first overcoating layer (141) and the protective layer (113). However, not limited thereto, the connecting electrode (125) may also be electrically connected to the source electrode (123) through a contact hole formed in the first overcoating layer (141) and the protective layer (113).

[0254] The third metal layer may be any one of various metallic materials, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy of two or more of these, or a multilayer thereof, but is not limited thereto.

[0255] Next, referring to FIG. 10b, an insulating layer (140) is deposited on the front surface of a substrate (110) on which a connecting electrode (125) and a first overcoating layer (141) are formed.

[0256] The insulating layer (140) may be formed with a thickness greater than that of the first electrode (231) to create an undercut structure at the edge of the first electrode (231). For example, if the thickness of the first electrode (231) relative to the insulating layer (140) is set to 92.3% or less, the undercut structure of the present invention is possible.

[0257] The insulating layer (140) may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or multiple layers 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 double layer of silicon nitride (SiNx) and silicon oxide (SiOx) with a thickness of 1300 Å to 2500 Å.

[0258] Then, referring to FIG. 10c, an organic insulating layer is formed on the insulating layer (140), and the organic insulating layer is patterned to form a second overcoating layer (142). Dry etching may be applied to the patterning of the organic insulating layer.

[0259] The second overcoating layer (142) may be formed of the same material as the first overcoating layer (141).

[0260] For example, the second overcoating layer (142) may be formed from one of an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, an unsaturated polyester resin, a polyphenylene resin, a benzocyclobutene, a photoresist, and a polyphenylene sulfide resin, but is not limited thereto.

[0261] The side of the second overcoating layer (142) may have a taper at a predetermined angle. For example, the side of the second overcoating layer (142) may have a taper at an angle of 30° to 60°. However, it is not limited thereto.

[0262] The second overcoating layer (142) may include an upper surface and a side surface.

[0263] The upper surface of the second overcoating layer (142) is a surface located at the top of the second overcoating layer (142) and may be a surface substantially parallel to the substrate (110).

[0264] The side of the second overcoating layer (142) may be a side extending laterally from the upper surface of the second overcoating layer (142).

[0265] Referring to FIG. 10d thereafter, the insulating layer (140) can be further etched using the second overcoating layer (142) as a mask. Wet etching can be applied to the etching of the insulating layer (140).

[0266] The lower side of the second overcoating layer (142) may have an undercut structure by additional etching in the horizontal direction of the insulating layer (140) from the side of the second overcoating layer (142) in the inner direction.

[0267] The etch bias, which is the distance from the side end of the second overcoating layer (142) to the end of the sacrificial layer (145), varies depending on the process conditions but can be 0.8㎛ to 1.3㎛.

[0268] Then, referring to FIG. 10e, a fourth metal layer and a fifth metal layer are deposited on the front surface of the substrate (110) to form a first electrode (231) on the connecting electrode (125).

[0269] The first electrode (231) can be formed to be in contact with the side of the sacrificial layer (145), not only on the surface of the connecting electrode (125) which is not covered by the sacrificial layer (145) and whose surface is exposed, but also inside the undercut structure on the lower side of the second overcoating layer (142).

[0270] Along with the formation of the first electrode (231), a dummy first electrode (231') may be formed on the upper and side surfaces of the second overcoating layer (142). The dummy first electrode (231') may be deposited on the upper and side surfaces of the second overcoating layer (142) during the deposition of the first electrode (231), and may be separated from the first electrode (231) according to the undercut structure of the second overcoating layer (142).

[0271] The dummy first electrode (231') placed on the side of the second overcoating layer (142) may have a taper at an angle of 30° to 60°. However, it is not limited thereto.

[0272] Since the light-emitting display device (200) according to another embodiment of the present invention is a top-emission type light-emitting display device, the reflective layer of the dummy first electrode (231') can reflect light emitted from the light-emitting element (230) upward. The light generated from the light-emitting layer (232) of the light-emitting element (230) is not emitted only upward, but can also be emitted sideways. The light emitted sideways is directed into the interior of the light-emitting display device (200) and can be trapped inside the light-emitting display device (200) by total reflection, and furthermore, may be extinguished while proceeding into the interior of the light-emitting display device (200). Accordingly, the reflective layer of the dummy first electrode (231') is arranged to cover the side of the second over-coating layer (142), thereby changing the direction of travel of the light proceeding sideways to the upward direction.

[0273] The first electrode (231) and the dummy first electrode (231') can be formed by deposition without a mask process.

[0274] The first electrode (231) can be formed so that its edge has an inverse taper, contrary to the sacrificial layer (145).

[0275] The first electrode (231) can be set to have a thickness of 92.3% or less relative to the sacrificial layer (145) for separation from the dummy first electrode (231').

[0276] The first electrode (231) may have a partially flat surface, but a portion of the edge may have an uneven structure (231"). If a portion of the edge of the first electrode (231) is not flat but has an uneven structure (231"), it is possible to extract wave guides and SP modes, thereby contributing to improved surface efficiency.

[0277] Although not illustrated, the first electrode (231) and the dummy first electrode (231') may include a reflective layer and a transparent conductive layer disposed on top of the reflective layer. However, this is not limited thereto, and the first electrode (231) and the dummy first electrode (231') may be formed with a three-layer structure of a transparent conductive layer, a reflective layer, and a transparent conductive layer.

[0278] A reflective layer may be placed on the connecting electrode (125). Since the light-emitting display device (200) according to another embodiment of the present invention is a top-emission light-emitting display device, the reflective layer may reflect light emitted from the light-emitting element (230) upward.

[0279] The reflective layer composed of the fourth metal layer may be made of a metallic material, for example, aluminum (Al), silver (Ag), copper (Cu), magnesium-silver alloy, etc., but is not limited thereto.

[0280] The reflective layer may be electrically connected to the drain electrode (124) through the connecting electrode (125). Not limited thereto, the reflective layer may also be electrically connected to the source electrode (123) through the connecting electrode (125).

[0281] A transparent conductive layer composed of a fifth metal layer may be placed on top of a reflective layer. The transparent conductive layer is placed on top of the reflective layer and may be electrically connected to a drain electrode through a connecting electrode (125) with the reflective layer. The transparent conductive layer may be made of a conductive material with a high work function to supply holes to the light-emitting layer (232).

[0282] For example, the transparent conductive layer may be composed of transparent conductive oxides of the indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), and tin oxide (TO) series, but is not limited thereto.

[0283] Next, referring to FIG. 10f, a bank layer (114) can be formed on top of the second overcoating layer (142).

[0284] The bank layer (114) may be positioned on top of the second overcoating layer (142) to cover the entire dummy first electrode (231') and a portion of the edge of the first electrode (231). The bank layer (114) may also be filled within the undercut structure at the bottom side of the second overcoating layer (142). Accordingly, the bank layer (114) may be interposed between the first electrode (231) and the dummy first electrode (231').

[0285] The bank layer (114) covers a portion of the edge of the first electrode (231) in a plurality of subpixels (SPX) and can define a light-emitting region (EA) and a non-light-emitting region (NEA). For example, in the non-light-emitting region (NEA), the bank layer (114) is placed over the first electrode (231), thereby blocking the generation of light in the non-light-emitting region (NEA). On the other hand, in the light-emitting region (EA), the bank layer (114) is not placed, and the light-emitting layer (232) is positioned directly over the first electrode (231), so that light can be generated in the light-emitting layer (232).

[0286] The bank layer (114) can be made of organic or inorganic material.

[0287] For example, the bank layer (114) may be made of an organic material such as polyimide, acrylic or benzocyclobutene, or an inorganic material such as silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

[0288] Next, referring to FIG. 10g, a light-emitting layer (232) and a second electrode (233) may be formed on the bank layer (114). The light-emitting layer (232) and the second electrode (233) together with the first electrode (231) may form a light-emitting element (230).

[0289] The light-emitting layer (232) may be positioned to be in contact with the first electrode (231) at a plurality of subpixels (SPX). For example, the light-emitting layer (232) may be positioned on the front surface of the substrate (110) above the first electrode (231). However, it is not limited thereto, and the light-emitting layer (232) may be positioned only in the light-emitting region (EA) above the first electrode (231). In this case, the light-emitting layer (232) may be positioned to be surrounded by the bank layer (114).

[0290] The second electrode (233) may be placed on the light-emitting layer (232) in the subpixel (SPX). For example, the second electrode (233) may be placed in contact with the light-emitting layer (232) in the light-emitting region (EA) and the non-light-emitting region (NEA) according to the shape of the light-emitting layer (232). However, it is not limited thereto.

[0291] The second electrode (233) can supply electrons to the light-emitting layer (232). The second electrode (233) may be made of a metallic material such as silver (Ag), copper (Cu), or a magnesium-silver alloy, but is not limited thereto. When the second electrode (233) is made of a metallic material, it has a very low refractive index, and for example, when silver (Ag) is used as the second electrode (233), the refractive index of the second electrode (233) may be about 0.13.

[0292] Next, a sealing layer (150) can be formed on the second electrode (233).

[0293] The encapsulation layer (150) can block oxygen and moisture from penetrating into the interior of the light-emitting display device (200) from the outside.

[0294] Although not shown, the bag layer (150) may include a first bag layer, a second bag layer, and a third bag layer.

[0295] The first sealing layer is placed on the second electrode (233) to prevent the penetration of moisture or oxygen.

[0296] At this time, the first encapsulation layer may be made of an inorganic material such as silicon nitride (SiNx), silicon oxynitride (SiOxNy), or aluminum oxide (AlyOz), but is not limited thereto. The first encapsulation layer may be made of a material with a higher refractive index than the second encapsulation layer, and for example, when the first encapsulation layer is made of silicon nitride (SiNx) or silicon oxynitride (SiOxNy), the refractive index of the first encapsulation layer may be about 1.8.

[0297] The second encapsulation layer can be placed on the first encapsulation layer to flatten the surface. Additionally, the second encapsulation layer can cover foreign matter or particles that may occur during the manufacturing process. The second encapsulation layer may be composed of organic materials, for example, silicon oxycarbon (SiOxCz), acrylic or epoxy-based resins, but is not limited thereto. The second encapsulation layer may be composed of a material with a lower refractive index than the first encapsulation layer. For example, if the second encapsulation layer is an acrylic-based resin, the refractive index of the second encapsulation layer may be approximately 1.5 to approximately 1.6.

[0298] The third bag layer is placed on top of the second bag layer and, like the first bag layer, can inhibit the penetration of moisture or oxygen.

[0299] For example, the third encapsulation layer may be composed of inorganic materials such as silicon nitride (SiNx), silicon oxynitride (SiOxNy), silicon oxide (SiOx), or aluminum oxide (AlyOz), but is not limited thereto. The third encapsulation layer may be composed of the same material as the first encapsulation layer or may be composed of a different material.

[0300] Meanwhile, the light-emitting display device of the present invention is applicable even when a touch portion is additionally configured on the encapsulation layer, and this is explained in detail through another embodiment of the present invention below.

[0301] FIG. 11 is a plan view of a light-emitting display device according to another embodiment of the present invention.

[0302] FIG. 12 is a cross-sectional view of a light-emitting display device according to XII-XII' of FIG. 11.

[0303] The light-emitting display device (400) of FIGS. 11 and FIGS. 12 differs from the light-emitting display device (200) of FIGS. 4 in that the touch portion (460) is different, and since other components are substantially the same, a redundant description will be omitted. In FIGS. 11, only a plurality of subpixels (SPX) and a touch line (464) are shown for convenience of explanation.

[0304] Referring to FIGS. 11 and 12, a touch portion (460) may be disposed on a sealing layer (150). The touch portion (460) may be disposed in a display area (A / A) including a light-emitting element (230) to sense touch input. The touch portion (460) may detect external touch information using a user's finger or a touch pen, etc. The touch portion (460) may include a first inorganic insulating layer (461), a second inorganic insulating layer (462), a touch line (464), and a touch electrode (465).

[0305] A first inorganic insulating layer (461) is placed on the encapsulation layer (150).

[0306] The first inorganic insulating layer (461) may be positioned to be in contact with the third encapsulation layer of the encapsulation layer (150). The first inorganic insulating layer (461) may be made of an inorganic material. For example, the first inorganic insulating layer (461) may be made of an inorganic material such as silicon nitride (SiNx), silicon oxynitride (SiOxNy), etc. For example, when silicon nitride (SiNx) is used as the first inorganic insulating layer (461), the refractive index of the first inorganic insulating layer (461) may be about 1.8.

[0307] A touch line (464) can be placed on the first inorganic insulating layer (461).

[0308] The touch line (464) may be placed on the first inorganic insulating layer (461) in the non-emissive region (NEA). The touch line (464) may be placed in a row direction or a column direction. The touch line (464) supplies a touch driving signal to drive the touch portion (460). Additionally, the touch line (464) may transmit touch information detected by the touch portion (460) to the driving IC.

[0309] A second inorganic insulating layer (462) may be placed over the touch line (464) and the first inorganic insulating layer (461). The second inorganic insulating layer (462) may be placed over the first inorganic insulating layer (481) and the touch line (464) to flatten the upper surface.

[0310] The second inorganic insulating layer (462) can prevent a short circuit of an adjacently positioned touch line (464). The second inorganic insulating layer (462) may be made of the same material as the first inorganic insulating layer (461). For example, the second inorganic insulating layer (462) may be made of an inorganic material such as silicon nitride (SiNx) or silicon oxynitride (SiOxNy). For example, if silicon nitride (SiNx) is used as the second inorganic insulating layer (462), the refractive index of the second inorganic insulating layer (462) may be approximately 1.8. However, if the second inorganic insulating layer (462) has the same refractive index as the first inorganic insulating layer (461), the constituent material of the second inorganic insulating layer (462) is not limited thereto.

[0311] A touch electrode (465) can be placed on the touch line (464) and the second inorganic insulating layer (462).

[0312] The touch electrodes (465) may be arranged in a row direction and a column direction. For example, a touch electrode (465) arranged in either the row direction or the column direction may be placed on the touch line (464), and a touch electrode (465) arranged in the other direction may be placed on the second inorganic insulating layer (462). The touch electrode (465) arranged in the column direction and the touch electrode (465) arranged in the row direction may be connected to each other through a bridge electrode to form a mesh-like structure. Although FIG. 12 shows the touch electrode (465) arranged in the light-emitting region (EA), the touch electrode (465) may not be arranged in the light-emitting region (EA) and is not limited thereto.

[0313] A light-emitting display device according to embodiments of the present invention can be described as follows.

[0314] A light-emitting display device according to one embodiment of the present invention comprises a substrate divided into a plurality of subpixels, a first overcoating layer disposed on the substrate, a connecting electrode and a sacrificial layer disposed on the first overcoating layer, a first electrode disposed on the connecting electrode, a second overcoating layer disposed on the sacrificial layer and including an opening that exposes a portion of the first electrode, a dummy first electrode disposed on the upper surface of the second overcoating layer and on the side of the opening and separated from the first electrode, a bank layer covering a portion of the dummy first electrode and the first electrode, and a light-emitting layer and a second electrode disposed on the first electrode and the bank layer.

[0315] According to another feature of the present invention, the connecting electrode can be electrically connected to the drain electrode of a thin-film transistor.

[0316] According to another feature of the present invention, the lower side of the second overcoating layer may have an undercut structure in which the sacrificial layer is removed inwardly from the side of the second overcoating layer.

[0317] According to another feature of the present invention, the first electrode may also be disposed within the undercut structure.

[0318] According to another feature of the present invention, the first electrode within the undercut structure may have an uneven surface structure.

[0319] According to another feature of the present invention, the second overcoating layer can expose the entire surface except for the uneven structure of the first electrode.

[0320] According to another feature of the present invention, the side of the second overcoating layer to which the first electrode is exposed may have a taper at an angle of 30° to 60°.

[0321] According to another feature of the present invention, the bank layer can also be filled within the undercut structure.

[0322] According to another feature of the present invention, the distance from the side end of the second overcoating layer to the end of the sacrificial layer may be 0.8㎛ to 1.3㎛.

[0323] According to another feature of the present invention, the first electrode may have a thickness of 92.3% or less relative to the sacrificial layer.

[0324] According to another feature of the present invention, the sacrificial layer has a positive taper at its edge, and the sacrificial layer may be positioned to cover the edge of the connecting electrode on the first overcoating layer.

[0325] According to another feature of the present invention, the first electrode may be placed on the connecting electrode, which is in contact with the side of the sacrificial layer and whose surface is exposed as it is not covered by the sacrificial layer.

[0326] According to another feature of the present invention, the bank layer may be disposed on the second overcoating layer to cover the entirety of the dummy first electrode and a portion of the edge of the first electrode.

[0327] According to another feature of the present invention, the light-emitting layer may be disposed only on the first electrode within the opening.

[0328] According to another feature of the present invention, the light-emitting display device further comprises an encapsulation layer disposed on the second electrode and a touch portion disposed on the encapsulation layer, wherein the touch portion may include a first inorganic insulating layer disposed on the encapsulation layer, a second inorganic insulating layer disposed on the first inorganic insulating layer, and a touch line and a touch electrode disposed on the first inorganic insulating layer or the second inorganic insulating layer.

[0329] A method for manufacturing a light-emitting display device according to one embodiment of the present invention comprises the steps of: forming a first overcoating layer on a substrate having a thin-film transistor; forming a connecting electrode on the first overcoating layer; forming an insulating layer on the front surface of the substrate on which the connecting electrode and the first overcoating layer are formed; forming a second overcoating layer including an opening on the insulating layer; etching the insulating layer using the second overcoating layer as a mask to form an undercut structure on the lower side of the second overcoating layer; forming a first electrode on the connecting electrode including the inside of the undercut structure, while simultaneously forming a dummy first electrode on the upper surface and side of the second overcoating layer; forming a bank 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 bank layer, wherein the first electrode can be separated from the dummy first electrode by the undercut structure.

[0330] According to another feature of the present invention, the first electrode and the dummy first electrode can be formed by deposition without a mask process.

[0331] According to another feature of the present invention, the surface of the first electrode within the undercut structure may have an uneven structure.

[0332] According to another feature of the present invention, the thickness of the first electrode relative to the insulating layer can be formed to be 92.3% or less.

[0333] According to another feature of the present invention, the insulating layer can be removed from the side of the second overcoating layer in an inward direction through wet etching using the second overcoating layer as a mask, thereby forming the undercut structure on the lower side of the second overcoating layer.

[0334] Although embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments and may be modified in various ways within the scope of the technical spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not to limit, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of protection of the present invention shall be interpreted by the claims below, and all technical spirits within the equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0335] 100, 200, 300, 400: Light-emitting display device 110: Substrate 111: Buffer layer 112: Gate insulation layer 113: Protection layer 114: Bank layer 117: H-stopper 120: Thin-film transistor 121: Gate electrode 122: Active layer 123: Source electrode 124: Drain electrode 130, 230, 330: Light-emitting elements 131, 231, 331: First electrode 131', 231', 331': Dummy first electrode 132, 232, 332: Emitting layer 133, 233, 333: Second electrode 141: First overcoating layer 142: Second overcoating layer 145: Sacrifice Layer 150: Bag layer 231", 331": Uneven structure 460: Touch section 461: Inorganic insulating layer 462: Second inorganic insulating layer 464: Touch Line 465: Touch electrode A / A: Display area N / A: Non-display area SPX: Subpixel SPX1: 1st subpixel SPX2: Second subpixel SPX3: 3rd subpixel EA: Luminous area NEA: Non-luminescent region

Claims

Claim 1 A light-emitting display device comprising: a substrate partitioned into a plurality of subpixels; a thin-film transistor disposed on the substrate; a first overcoating layer disposed on the thin-film transistor; a first electrode and a sacrificial layer disposed on the first overcoating layer; a second overcoating layer disposed on the first electrode and the sacrificial layer and including an opening that exposes a portion of the first electrode; a light-emitting layer located on the first electrode exposed by the opening and generating light; a second electrode disposed on the light-emitting layer; and a bank layer disposed on the upper side of the second overcoating layer and on the side of the opening, wherein the first electrode is connected to the thin-film transistor and has a thickness smaller than that of the sacrificial layer, the side end of the second overcoating layer protrudes beyond the end of the sacrificial layer, and the lower side end of the second overcoating layer has an undercut structure. Claim 2 A light-emitting display device according to claim 1, wherein the first electrode is also disposed within the undercut structure. Claim 3 A light-emitting display device according to claim 1, wherein the first electrode comprises a reflective layer electrically connected to the thin-film transistor and a conductive layer disposed on the reflective layer. Claim 4 A light-emitting display device according to claim 1, further comprising a dummy first electrode disposed on the upper surface of the second overcoating layer and on the side of the opening of the second overcoating layer and separated from the first electrode, wherein the dummy first electrode is made of the same material as the first electrode. Claim 5 A light-emitting display device according to claim 4, wherein the bank layer covers the dummy first electrode and a part of the first electrode, and the light-emitting layer is disposed on the bank layer. Claim 6 In claim 5, the bank layer is a light-emitting display device that is also filled within the undercut structure. Claim 7 A light-emitting display device according to claim 1, wherein the side of the second overcoating layer to which the first electrode is exposed has a taper at an angle of 30° to 60°. Claim 8 A light-emitting display device according to claim 1, wherein the distance from the side end of the second overcoating layer to the end of the sacrificial layer is 0.8㎛ to 1.3㎛. Claim 9 A light-emitting display device according to claim 1, wherein the first electrode has a thickness of 92.3% or less relative to the sacrificial layer. Claim 10 A light-emitting display device according to claim 1, wherein the sacrificial layer is a double layer of silicon nitride and silicon oxide. Claim 11 In claim 1, the sacrificial layer has a regular taper edge, in a light-emitting display device. Claim 12 A light-emitting display device according to claim 1, further comprising a sealing layer disposed on the second electrode, wherein the sealing layer comprises a first sealing layer, a second sealing layer, and a third sealing layer stacked in order, and wherein the first sealing layer is made of a material having a higher refractive index than the second sealing layer.

Images