Electroluminescent display device

Abstract

An electroluminescent display device, comprising: a substrate including a plurality of sub-pixel regions each including a light-emitting region and a non-light-emitting region surrounding the light-emitting region, and a cathode contact region located at least one side between the plurality of sub-pixel regions; a planarization layer disposed above the substrate and configured to overlap at least a portion of each of the light-emitting regions and the cathode contact region; a light-emitting device disposed above the planarization layer and configured to overlap at least a portion of the light-emitting region, and including a pixel electrode and a cathode facing the pixel electrode; and a cathode contact electrode formed above the planarization layer and formed to overlap at least a portion of the non-light-emitting region, wherein the cathode contact electrode includes one side surface exposed toward the cathode contact region, and the cathode is in contact with the one side surface of the cathode contact electrode.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0169660, filed on December 7, 2020, which is incorporated herein by reference as if fully set forth herein. Technical Field

[0003] This disclosure relates to an electroluminescent display device, and more specifically, to an electroluminescent display device in which a moisture-proof structure is disposed in the cathode contact area. Background Technology

[0004] With the development of the information society, the demand for display devices that display images has increased in various forms. In recent years, various display devices such as liquid crystal displays (LCDs), plasma displays, and organic light-emitting displays (OLEDs) have been used.

[0005] An electroluminescent display device includes an array device and a light-emitting device. The array device includes a switching thin-film transistor (TFT) connected to a gate line and a data line, and at least one driving TFT connected to the light-emitting device. The light-emitting device includes a pixel electrode, a light-emitting layer, and a cathode connected to the driving TFT.

[0006] However, electroluminescent display devices with the above configuration suffer from the following problem: uneven brightness occurs due to increased resistance of the cathode of the light-emitting device. Therefore, a cathode structure with uniform resistance across the entire display area of ​​the electroluminescent display device is needed. Furthermore, the cathode contact structure located on at least one side of the electroluminescent display serves as a path for moisture movement, leading to reliability issues. Summary of the Invention

[0007] Existing electroluminescent display devices suffer from the following problems: uneven brightness due to increased resistance of the cathode in the light-emitting device, and reliability issues related to moisture permeability caused by the structure used to reduce cathode resistance. Therefore, the inventors of this disclosure provide an electroluminescent display device that exhibits high reliability in terms of moisture permeability while providing uniform cathode resistance across the entire active area of ​​the electroluminescent display device.

[0008] Therefore, this disclosure aims to provide an electroluminescent display device that substantially eliminates one or more problems caused by the limitations and disadvantages of the prior art.

[0009] One aspect of this disclosure aims to provide an electroluminescent display device that has high reliability in terms of moisture permeability, while the cathode and auxiliary power line are in stable contact with each other.

[0010] The problems to be solved according to the embodiments of this disclosure are not limited to those described above, and other problems not mentioned will be clearly understood by those skilled in the art through the following description.

[0011] Further advantages and features of this disclosure will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art upon examination of the following, or may be learned from practice of this disclosure. The objects and other advantages of this disclosure may be realized and obtained from the written description and its claims, as well as the structures specifically pointed out in the accompanying drawings.

[0012] To achieve these and other advantages and in accordance with the purposes of this disclosure, as specifically implemented and generally described herein, an electroluminescent display device is provided, comprising: a substrate including a plurality of sub-pixel regions and a cathode contact region, each of the sub-pixel regions including a light-emitting region and a non-light-emitting region surrounding the light-emitting region, the cathode contact region being located on at least one side between the plurality of sub-pixel regions; a planarization layer disposed above the substrate and configured to overlap at least a portion of each of the light-emitting regions and the cathode contact region; a light-emitting device disposed above the planarization layer and configured to overlap at least a portion of the light-emitting regions, and including a pixel electrode and a cathode facing the pixel electrode; and a cathode contact electrode formed above the planarization layer and formed to overlap at least a portion of the non-light-emitting region, wherein the cathode contact electrode includes a side surface exposed toward the cathode contact region, and the cathode contacts the side surface of the cathode contact electrode.

[0013] In another embodiment, a display device includes: a substrate including a plurality of sub-pixel regions and a contact region, the plurality of sub-pixel regions including a first sub-pixel region and a second sub-pixel region, the contact region being located between the first sub-pixel regions and the second sub-pixel region; a light-emitting device disposed on an insulating layer and located in the first sub-pixel region, the light-emitting device including a first electrode, a light-emitting layer, and at least a portion of a second electrode; a first contact electrode configured to receive a voltage from a first power line on the substrate, wherein at least a portion of the first contact electrode extends from a region within a contact hole formed in the insulating layer to an upper surface of the insulating layer; and a dam portion at least on the first electrode and the first contact electrode of the light-emitting device, wherein a portion of the dam portion protrudes beyond a side surface of the first contact electrode, wherein at least a portion of a second electrode contacts a side surface of the first contact electrode in a region below the dam portion.

[0014] It should be understood that the foregoing general description and the following detailed description of this disclosure are exemplary and explanatory, and are intended to provide further explanation of the claimed disclosure. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the present disclosure and, together with the specification, serve to explain the principles of the disclosure. In the drawings: Figure 1 This is a plan view of an electroluminescent display device according to an embodiment of the present disclosure; Figure 2 It is along the embodiments according to this disclosure Figure 1 A sectional view taken by line I-I'; Figure 3 According to embodiments of this disclosure Figure 2 A magnified view of part A; Figures 4A to 4D This is a diagram illustrating a method of manufacturing an electroluminescent display device according to an embodiment of the present disclosure. Detailed Implementation

[0016] Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used in all the drawings to denote the same or similar parts.

[0017] The advantages and features of this disclosure, as well as its implementation methods, will be illustrated by the following embodiments described in conjunction with the accompanying drawings. However, this disclosure may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make this disclosure thorough and complete, and to fully convey the scope of this disclosure to those skilled in the art. Furthermore, this disclosure is limited only by the scope of the claims.

[0018] The shapes, dimensions, ratios, angles, and quantities disclosed in the accompanying drawings used to describe embodiments of this disclosure are merely examples, and therefore, this disclosure is not limited to the illustrated details. Throughout the specification, similar reference numerals denote similar elements. In the following description, detailed descriptions of relevant known functions or configurations will be omitted where it is determined that such detailed descriptions unnecessarily obscure the essential points of this disclosure. Where terms such as “comprising,” “having,” and “including” are used in this disclosure, another component may be added unless “only” is used. Singular terms may include plural forms unless the opposite is mentioned.

[0019] When interpreting a component, even without an explicit description, the component is interpreted as including a range of error.

[0020] When describing positional relationships, for example, when the positional relationship between two parts is described as "on ~", "above ~", "below ~", and "next to ~", one or more parts can be placed between the two parts unless "only" or "directly" is used.

[0021] When describing temporal relationships, such as when time sequence is described as “after,” “following,” “next,” and “before,” discontinuous cases may be included unless “only” or “directly” is used.

[0022] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0023] In describing the elements of this disclosure, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are used only to distinguish the corresponding element from other elements, and the nature, order, or priority of the corresponding element is not limited by these terms. It should be understood that when an element or layer is referred to as being "on" or "connected to" another element or layer, it may be directly on or directly connected to the other element or layer, or there may be intermediate elements or layers. Furthermore, it should be understood that when an element is disposed above or below another element, this may indicate a situation where the elements are disposed in direct contact with each other, but it may also indicate a situation where the elements are disposed in no direct contact with each other.

[0024] The term "at least one" should be understood to include any and all combinations of one or more associated listed items. For example, "at least one of the first, second, and third items" means all items drawn from two or more of the first, second, and third items, as well as combinations of the first, second, or third items.

[0025] Features of the various embodiments of this disclosure may be coupled or combined with each other in part or in whole, and may interact and be technically driven differently from each other, as will be fully understood by those skilled in the art. Embodiments of this disclosure may be performed independently of each other, or may be performed together in a mutually dependent manner.

[0026] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0027] Figure 1 This is a plan view according to an embodiment of the present disclosure.

[0028] refer to Figure 1 An electroluminescent display device according to an embodiment of the present disclosure may include a light-emitting display panel 1 and a panel driving circuit unit 3.

[0029] The display panel 1 may include a substrate 10, an active area AA, an active area, a first power line 60, a second power line 70, and a gate driving circuit 50.

[0030] The substrate 10 can be a glass substrate, a flexible thin glass substrate, a plastic substrate, or a silicon wafer substrate.

[0031] The active region AA is the area where the image is displayed, and can also be referred to as a first region, display section, display area, or active section. For example, the active region AA can be provided in the portion of the substrate 10 excluding the edge portion.

[0032] The non-active region IA is the area where no image is displayed, and can also be referred to as a second region, a non-display portion, a non-display area, or a non-active portion. For example, the non-display portion can be provided at the edge of the substrate 10 to surround the active region AA.

[0033] The active region AA may include multiple sub-pixels and may include a cathode contact region CCA formed in at least a portion between the multiple sub-pixels.

[0034] exist Figure 1 In the active region AA, the structure may include a first sub-pixel region SPA1, a second sub-pixel region SPA2 adjacent to the first sub-pixel region SPA1, and a cathode contact region CCA located between the first sub-pixel region SPA1 and the second sub-pixel region SPA2.

[0035] Here, the cathode contact region CCA can be defined as a specific region including the area in which a portion of the side surface of the cathode contact electrode 270 (described later) is exposed to contact the first power connection line 62 and the cathode 250 of the light-emitting device 200. Reference will be made later. Figure 2 and Figure 3 Describe the detailed structure of the cathode contact region (CCA).

[0036] In addition, Figure 1 In the diagram, the cathode contact area CCA is shown positioned relative to the first sub-pixel region SPA1 and the second sub-pixel region SPA2, but embodiments of this disclosure are not limited thereto. The cathode contact area CCA can be applied to different locations based on the first sub-pixel region SPA1 without any specific location restrictions. For example, the cathode contact area CCA can be located relative to the second direction Y on one side or the other side of the first sub-pixel region SPA1. Alternatively, the cathode contact area CCA can be arranged facing the edge of the first sub-pixel region SPA1.

[0037] An electroluminescent display device according to an embodiment of the present disclosure may include a first power line 60 and a second power line 70 disposed in a non-active region IA. Here, a base voltage VSS and a source voltage VDD may be applied to the first power line 60 and the second power line 70, respectively. The first power line 60 and the second power line 70 may be controlled by a panel driving circuit unit 3 to provide the base voltage VSS and the source voltage VDD to the pixels in the active region AA, respectively.

[0038] like Figure 1 As shown, a pair of first power lines 60 can be arranged in strips at the top and bottom of the display panel 1 in the non-active area IA, and can include multiple first power connection lines 62 connecting the pair of first power lines 60. Additionally, a pair of second power lines 70 can be arranged in strips at the top and bottom of the display panel 1 in the non-active area IA, and can include multiple second power connection lines 72 connecting the pair of second power lines 70.

[0039] exist Figure 1 In this embodiment, the first power connection line 62 may be configured to overlap with or be adjacent to at least a portion of the cathode contact region CCA. In this disclosure, the cathode contact region CCA can have improved reliability and reduced cathode resistance by providing a structure in which the first power connection line 62 can make electrical contact with the cathode (described later). Therefore, a display device with improved brightness uniformity can be provided.

[0040] The gate driving circuit 50 provides gate signals to the gate lines via a plurality of gate pads and connecting lines of the pad portion PP according to the gate control signal provided from the driving circuit unit 3. For example, the gate driving circuit 50 may be disposed in at least one non-active region IA on each side of the substrate 10 facing each other. The gate driving circuit 50 may be formed in the non-display area on one or both sides of the display area of ​​the display panel 1 by means of the gate in panel (GIP) method. Alternatively, the gate driver may be manufactured as a driving chip, mounted above the flexible layer, and attached to the non-display area outside one or both sides of the active area of ​​the display panel 1 by means of the tape auto-bonding (TAB) method.

[0041] According to one example, the driving circuit unit 3 may include multiple flexible circuit films 31, multiple data driving integrated circuits (ICs) 33, printed circuit boards (PCBs) 35, timing controllers 37, and power supply circuit units 39.

[0042] Each of the plurality of flexible circuit films 31 can be attached to a pad portion PP disposed on the substrate 10 and a printed circuit board PCB 35. For example, one side (or output junction) of each of the plurality of flexible circuit films 31 can be attached to the pad portion PP disposed on the substrate 10 by a layer attachment process using an anisotropic conductive layer. The other side (or input junction) of each of the plurality of flexible circuit films 31 can be attached to the printed circuit board PCB 35 by a layer attachment process using anisotropic conductive layer.

[0043] Multiple data driver ICs 33 are independently mounted on multiple flexible circuit films 31. Each of the multiple data driver ICs 33 can receive pixel data and data control signals provided by the timing controller 37, convert the pixel data into analog data voltage for each pixel according to the data control signals, and provide the data voltage to the corresponding data line.

[0044] The printed circuit board PCB 35 can be connected to the other side of each of the multiple flexible circuit films 31. The printed circuit board PCB 35 can be used to transmit signals and voltages between components of the drive circuit unit 3.

[0045] The timing controller 37 can be mounted on the printed circuit board 35 and receive image data and timing synchronization signals from the display driving system through a connector located on the printed circuit board 35.

[0046] The timing controller 37 can generate pixel data by aligning image data to a pixel arrangement structure suitable for the active region AA based on a timing synchronization signal, and provide the generated pixel data to each of the multiple data driver ICs 33.

[0047] The timing controller 37 can generate data control signals and gate control signals based on timing synchronization signals, and control the driving timing of each of the multiple data driver ICs 33 through the data control signals. Additionally, the timing controller 37 can control the driving timing of the gate driver circuit 50 through the gate control signals. For example, the timing synchronization signals may include a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, and a master clock (or dot clock).

[0048] The power supply circuit unit 39 can be mounted on top of the printed circuit board PCB 35. Furthermore, the power supply circuit unit 39 can use externally supplied input power to generate various power supply voltages required for displaying images in the pixels, and can supply the generated voltages to the corresponding circuits.

[0049] Figure 2 It is along the embodiments according to this disclosure Figure 1 A cross-sectional view taken by line I-I'. Figure 3According to embodiments of this disclosure Figure 2 A magnified view of part A.

[0050] refer to Figure 2 and Figure 3 An electroluminescent display device according to an embodiment of the present disclosure may include a driving TFT T, a planarization layer 160, a light-emitting device 200, a dam 180, a cathode contact electrode 270, and an auxiliary power line EVSS formed on a substrate 110.

[0051] Here, the substrate 110 may have the same characteristics as the reference above. Figure 1 The substrate 110 has the same configuration as the substrate 10 described. Therefore, the substrate 110 can be a glass substrate, a flexible thin glass substrate, a plastic substrate, or a silicon substrate.

[0052] The driving TFT T can be disposed in the active region AA in the buffer layer 120 and can be configured to correspond to each sub-pixel. According to one example, the driving TFT T may include an active layer ACT, a gate GE, a source SE, and a drain DE. Although the driving TFT T is in Figures 4A to 4D The TFT is shown as a top-gate structure, but the embodiments of this disclosure are not limited thereto, and various known structures can be applied to drive TFTs. However, in this disclosure, a drive TFT having a top-gate structure will be described.

[0053] The buffer layer 120 can be disposed above the substrate 110 and the light-blocking layer LS. According to one example, the buffer layer 120 can be formed by stacking multiple inorganic layers. For example, the buffer layer 120 can be formed as a multilayer, wherein one or more inorganic layers of silicon oxide (SiOx), silicon nitride (SiN) and silicon oxynitride (SiON) are stacked.

[0054] An active layer ACT can be disposed above buffer layer 120. The active layer ACT can be configured to overlap with the gate GE, source SE, and drain DE, and the active layer ACT can include a channel region and source / drain regions. The channel region of the active layer ACT can be formed to overlap with the gate GE, wherein a gate insulating layer 130 is interposed between the channel region and the gate GE. The source / drain regions of the active layer ACT can be formed parallel to each other, wherein a channel region is interposed between them. Additionally, the gate insulating layer 130 can be disposed between the channel region of the active layer ACT and the gate GE. The gate insulating layer 130 insulates the active layer ACT from the gate GE. The active layer ACT can be formed of a silicon-based semiconductor material or an oxide-based semiconductor material.

[0055] The gate insulating layer 130 can be disposed above the active layer ACT and can also be disposed above the buffer layer 120. Furthermore, the gate insulating layer 130 can insulate the active layer ACT from the gate GE. The gate insulating layer 130 can be formed as a single layer or multiple layers including at least one of silicon nitride (SiNx) and silicon oxide (SiO2). The material of the gate insulating layer 130 is not limited thereto.

[0056] The gate GE can be disposed above the gate insulating layer 130. The gate GE can be formed as a single layer or multiple layers of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), silver (Ag), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), or alloys of the aforementioned metals.

[0057] An interlayer insulating layer 140 may be disposed above the gate GE and the gate insulating layer 130. The interlayer insulating layer 140 may be used to protect the driving TFT T. A corresponding region of the interlayer insulating layer 140 may be removed to allow the active layer ACT to contact the source SE or drain DE. For example, the interlayer insulating layer 140 may include contact holes that allow the source SE and the source region of the active layer ACT to contact each other, and contact holes that allow the drain DE and the drain region of the active layer ACT to contact each other. Additionally, the interlayer insulating layer 140 may be formed above the gate insulating layer 130. According to one example, the interlayer insulating layer 140 may include a silicon oxide layer (SiO2) or a silicon nitride layer (SiN), or may include multiple layers comprising a silicon oxide layer (SiO2) and a silicon nitride layer (SiN).

[0058] According to embodiments of this disclosure, the source (SE) and drain (DE) can be formed as a single layer or multiple layers of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), silver (Ag), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), or alloys of the aforementioned metals. In this disclosure, materials that satisfy the specific electrical properties required to drive the TFT T can be used as the selected materials for the source (SE) and drain (DE).

[0059] Additionally, a light-blocking layer LS may be further included, disposed below the active layer ACT of the driving TFT T. The light-blocking layer LS may be disposed above the substrate 110 to overlap with the driving TFT T. For example, the light-blocking layer LS can be formed by depositing a metal layer above the substrate 110 and then patterning it. The light-blocking layer LS may be a single layer or multiple layers formed of metals such as molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), silver (Ag), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or alloys of the aforementioned metals, but is not limited thereto, and can be implemented using various materials known in the art. Furthermore, the light-blocking layer LS may include a lower light-blocking layer and an upper light-blocking layer.

[0060] A protective layer 150 may be disposed above the interlayer insulating layer 140, the source electrode SE, and the drain electrode DE. The protective layer 150 may be used to protect the source electrode SE and the drain electrode DE. The protective layer 150 may include contact holes that allow the pixel electrode 210 and the source electrode SE to contact each other. Here, the contact holes of the protective layer 150 may overlap and connect with the contact holes of the planarization layer 160 (which are formed to allow the pixel electrode 210 and the source electrode SE to contact each other). According to one example, the protective layer 150 may be a single layer comprising a silicon oxide layer (SiO2) or a silicon nitride layer (SiN). Alternatively, the protective layer 150 may comprise multiple layers comprising a silicon oxide layer (SiO2) and a silicon nitride layer (SiN).

[0061] The protective layer 150 may include a first contact hole CH1 for a contact structure between the cathode contact electrode 270 and the auxiliary electrode AE ​​in the cathode contact region CCA or the sub-pixel region SPA. The first contact hole CH1 may be formed to overlap at least a portion of the non-light-emitting region NEA of the sub-pixel region SPA. In this case, the first contact hole CH1 can be provided by removing the entire protective layer 150 in the thickness direction. Therefore, a stable contact structure between the cathode contact electrode 270 and the auxiliary electrode AE ​​can be provided by the first contact hole CH1 formed in the protective layer 150.

[0062] The planarization layer 160 can be disposed above the substrate 110 to overlap with the sub-pixel regions including the first sub-pixel region SPA1 and the second sub-pixel region SPA2. Additionally, the planarization layer 160 can be formed to overlap with the cathode contact region CCA. Specifically, the planarization layer 160 can overlap with the light-emitting region EA of the active region AA, such that the light-emitting region EA defined by the light-emitting device 200 and the embankment 180 is formed substantially flat. Furthermore, the planarization layer 160 can overlap with the cathode contact region CCA. Additionally, as described above, in the planarization layer 160, since the first contact hole CH1 for the contact structure of the auxiliary electrode AE ​​is formed in the non-light-emitting region NEA adjacent to the cathode contact region CCA, the planarization layer 160 can be configured such that at least a portion of it is removed in the non-light-emitting region NEA adjacent to the cathode contact region CCA.

[0063] The planarization layer 160 can be formed from organic materials such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, etc.

[0064] The light-emitting device 200 can be disposed above the planarization layer 160 and can be electrically connected to the driving TFT T. The pixel electrode 210 of the light-emitting device 200 can contact the source electrode SE of the driving TFT T through contact holes formed in at least a portion of the planarization layer 160 and the protective layer 150.

[0065] According to embodiments of this disclosure, the light-emitting device 200 may include a pixel electrode 210 formed over the planarization layer 160 and in at least a portion of the active region AA in the substrate 110, a cathode 250 formed facing the pixel electrode 210 and overlapping the entire active region AA, and a light-emitting layer 230 formed between the pixel electrode 210 and the cathode 250 and corresponding to the pixel. Furthermore, according to the method of fabricating the respective layers, the light-emitting layer 230 and the cathode 250 may be formed to overlap at least a portion of the non-active region IA adjacent to the active region AA, but are not limited thereto.

[0066] The pixel electrode 210 can be disposed above the planarization layer 160 and can be electrically connected to the source SE of the driving TFT T. The pixel electrode 210 can contact the source SE of the driving TFT T through contact holes disposed in the planarization layer 160.

[0067] The pixel electrode 210 may include a first pixel electrode 211 disposed above the planarization layer 160 and a second pixel electrode 213 disposed above the first pixel electrode 211.

[0068] The first pixel electrode 211 can be disposed above the planarization layer 160, and the second pixel electrode 213 can be disposed to overlap with the first pixel electrode 211.

[0069] In this case, the second pixel electrode 213 can be formed to have a width substantially the same as that of the first pixel electrode 211. After the pixel electrode 210, including the first pixel electrode 211 and the second pixel electrode 213, is formed over the planarization layer 160, the pixel electrode 210 can be patterned to be formed using a specific mask pattern and by performing an etching process.

[0070] Here, the etching process used for patterning the pixel electrode 210 can be a dry etching process. Therefore, as... Figure 2 and Figure 3 As shown, the pixel electrode 210, including the first pixel electrode 211 and the second pixel electrode 213, can be formed by a dry etching process to have a certain tilt angle on one side and the other side of the pixel electrode 210, and the tilt angle can be close to 90 degrees. Therefore, the first pixel electrode 211 and the second pixel electrode 213 can be formed to have substantially the same width.

[0071] One side and the other side of the pixel electrode 210, including the first pixel electrode 211 and the second pixel electrode 213, can be covered by the embankment 180.

[0072] Each of the first pixel electrode 211 and the second pixel electrode 213 may include a metallic material.

[0073] For example, the first pixel electrode 211 may include at least one of copper (Cu), silver (Ag), palladium (Pd) and aluminum (Al), but is not limited thereto.

[0074] For example, the second pixel electrode 213 may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), titanium (Ti), molybdenum (Mo), and titanium-molybdenum (MoTi) alloys, but is not limited thereto.

[0075] Additionally, the first pixel electrode 211 may include the same material as the first cathode contact electrode 271 described later, and the second pixel electrode 213 may include the same material as the second cathode contact electrode 273 described later.

[0076] Furthermore, the pixel electrode 210 according to embodiments of the present disclosure may further include transparent conductive oxides disposed below the first pixel electrode 211 and above the second pixel electrode 213. Therefore, when transparent conductive oxides are included, the pixel electrode 210 according to embodiments of the present disclosure may be a pixel electrode with a four-layer structure.

[0077] The dam 180 can define a light-emitting region EA for each sub-pixel region. In the light-emitting region EA of each sub-pixel region, the pixel electrode 210, the light-emitting layer 230, and the cathode 250 are sequentially stacked to form the light-emitting region. Holes from the pixel electrode 210 and electrons from the cathode 250 combine with each other in this light-emitting region to emit light. In this case, the area where the dam 180 forms does not emit light and is therefore a non-light-emitting region NEA, while the area where the dam 180 is not formed and the pixel electrode 210 is exposed can become the light-emitting region EA. Furthermore, the dam 180 can be formed to cover the edge of the pixel electrode 210 and expose a portion of the pixel electrode 210. Therefore, the dam 180 can prevent the problem of reduced luminous efficiency due to current concentration at the end of the pixel electrode 210.

[0078] The embankment 180 is formed of organic materials such as acrylic resin, epoxy resin, phenolic resin, polyamide resin and polyimide resin.

[0079] The embankment 180 can be configured to cover the cathode contact electrode 270 (described later) and can be formed to protrude more than the side of the cathode contact electrode 270 facing the cathode contact region CCA. Additionally, within the embankment 180, the cathode contact electrode 270, including the first cathode contact electrode 271 and the second cathode contact electrode 273, can be used as a mask pattern in an etching process to form a reverse step structure. Reference Figure 2 and Figure 3The embankment 180 can be configured to overlap with the first contact hole CH1. Therefore, the first contact hole CH1 can be filled by the embankment or the embankment 180 can fill the space within the first contact hole CH1.

[0080] Additionally, the embankment 180 can be disposed between a plurality of pixel electrodes 210 and cathode contact electrodes 270 to electrically insulate adjacent pixel electrodes 210 and cathode contact electrodes 270 from each other.

[0081] The light-emitting layer 230 can be configured to overlap at least a portion of the pixel electrode 210 of the light-emitting region EA in the first sub-pixel region SPA1, and can be configured to cover the embankment of the non-light-emitting region NEA. Similarly, as with the first sub-pixel region SPA1, the light-emitting layer 230 can be configured to overlap at least a portion of the pixel electrode 210 of the light-emitting region EA in the second sub-pixel region SPA2, and can be configured to cover the embankment of the non-light-emitting region NEA, and can be disposed above the planarization layer 160 to at least partially overlap with the cathode contact region CCA.

[0082] According to another embodiment of this disclosure, the light-emitting layer 230 can be formed by a deposition process on a region corresponding to each sub-pixel using a specific mask pattern, and when formed in this way, the light-emitting layer 230 can be formed so as not to overlap with the cathode contact region CCA. In this disclosure, the light-emitting layer 230 will be described as being formed without using a separate mask pattern in the active region AA.

[0083] like Figure 2 and Figure 3 As shown, in the non-light-emitting region NEA adjacent to the cathode contact region CCA, the light-emitting layer 230 overlapping the first sub-pixel region SPA1 can be formed with a tail shape having a gradually decreasing thickness. For example, the thickness of the light-emitting layer 230 can have a tail shape where the non-light-emitting region NEA thins out in the region adjacent to the cathode contact region CCA. Therefore, the thickness of the light-emitting layer 230 disposed above the embankment in the non-light-emitting region NEA can have a tail shape where it gradually thins out in the portion adjacent to the cathode contact region CCA. The light-emitting layer 230' overlapping the second sub-pixel region SPA2 can be formed flat on the side adjacent to the second sub-pixel region SPA2, and can have a tail shape where the thickness gradually decreases in the direction toward the first sub-pixel region SPA1. Reference Figure 2 and Figure 3 The light-emitting layer 230 disposed in the first sub-pixel region SPA1 and the light-emitting layer 230' disposed in the second sub-pixel region SPA2 can have a thin tail shape with a gradually decreasing thickness in the undercut (UC) region.

[0084] According to one example, the light-emitting layer 230 may include a hole transport layer, a light-emitting layer, and an electron transport layer. In this case, when a voltage is applied to the pixel electrode 210 and the cathode 250, holes and electrons move to the light-emitting layer through the hole transport layer and the electron transport layer, respectively, and combine with each other in the light-emitting layer to emit light. According to one example, the light-emitting layer 230 may also include at least one functional layer to improve the luminous efficiency and lifetime of the light-emitting layer 230.

[0085] The cathode 250 can be disposed above the light-emitting layer 230, and the cathode 250 can be implemented as an electrode shared with the active region AA. Figure 2 and Figure 3 In the diagram, the cathode 250 of the first sub-pixel region SPA1 and the cathode 250' of the second sub-pixel region SPA2 are shown as physically disconnected, but this is only... Figure 1 An example diagram of the cutting line I-I'. In the active region AA where the cathode contact area CCA is not formed, the cathodes of multiple sub-pixel regions can be configured to be connected together.

[0086] Therefore, the cathode 250 can be a common layer formed together in the sub-pixel region to apply the same voltage. The cathode 250 can be formed of a transparent conductive material (TCO) such as ITO and IZO that can transmit light, or a semi-transmissive conductive material such as magnesium (Mg), silver (Ag), or an alloy of magnesium (Mg) and silver (Ag), but is not limited thereto.

[0087] The cathode 250 is formed using a deposition process similar to that of the light-emitting layer 230, but due to the nature of the inorganic layer, it exhibits higher step coverage characteristics than the light-emitting layer 230. Furthermore, the cathode 250 can be formed in all regions of the active region AA that overlap with the organic light-emitting layer 230, and can also be formed to overlap with at least a portion of the undercut UC region described later. Therefore, the cathode 250' of the second sub-pixel region SPA2 can be formed to overlap with at least a portion of the undercut UC region and can contact one side surface of the first cathode contact electrode 271 described later.

[0088] The cathode contact electrode 270 may be adjacent to the cathode contact region CCA and may be formed to overlap at least a portion of the non-light-emitting region NEA surrounding the light-emitting region EA. The cathode contact electrode 270 may be formed to overlap with the two sidewalls of the first contact hole CH1 formed in the protective layer 150 and the planarization layer 160. For example, at least a portion of the cathode contact electrode 270 may extend along the sidewalls of the first contact hole CH1 toward the upper surface of the planarization layer 160. Additionally, the cathode contact electrode 270 may be formed to at least partially overlap the upper surface of the planarization layer 160 surrounding the first contact hole CH1. Furthermore, the cathode contact electrode 270 may extend above the planarization layer 160 and protrude into the cathode contact region CCA to contact the cathode 250' of the second sub-pixel region SPA2. The cathode 250' may contact the side surface of the cathode contact electrode 270.

[0089] The cathode contact electrode 270 may include a first cathode contact electrode 271 and a second cathode contact electrode 273.

[0090] In this configuration, the second cathode contact electrode 273 can be disposed above the upper surface of the first cathode contact electrode 271 and can be configured to overlap with the first cathode contact electrode 271. At least a portion of the first cathode contact electrode 271 can extend from the sidewall of the region where the contact hole CH1 is formed in the protective layer 150 and the planarization layer 160 toward the upper surface of the planarization layer 160, such that the side surface of the first cathode contact electrode 271 is disposed on the upper surface of the planarization layer 160. Furthermore, although Figure 2 and Figure 3 An example is shown where the first cathode contact electrode 271 and the second cathode contact electrode 273 are formed to extend to the upper surface of the planarization layer 160. However, it should be understood that in other embodiments, the first cathode contact electrode 271 and the second cathode contact electrode 273 are formed to extend along the sidewall of the first contact hole CH1, such that the side surface of the first cathode contact electrode 271 or the second cathode contact electrode 273 is disposed on the sidewall of the first contact hole CH1. Furthermore, the width of the second cathode contact electrode 273 may be greater than the width of the first cathode contact electrode 271, and may protrude toward, for example, the cathode contact region. Therefore, due to the first cathode contact electrode 271 and the second cathode contact electrode 273, a reverse step structure can be provided such that, in the area where the side surface of the cathode contact electrode 270 is exposed, the second cathode contact electrode 273, located above the first cathode contact electrode 271, protrudes more. According to the design of the electroluminescent display device, in the area where the side surface of the cathode contact electrode 270 is exposed, the embankment 180 and the cathode contact electrode 270 further extend toward the cathode contact region CCA to at least partially overlap with the cathode contact region CCA, or may be as follows: Figure 2The area shown overlaps with at least a portion of the non-light-emitting region NEA of the sub-pixel region.

[0091] like Figure 3 As shown, the second cathode contact electrode 273 can be configured to form an undercut UC region with a first width W1 toward the light-emitting region EA relative to the end of the embankment 180 facing the cathode contact region CCA, and the first cathode contact electrode 271 can be configured to form an undercut UC region with a second width W2 toward the light-emitting region EA relative to the end of the second cathode contact electrode 273 facing the cathode contact region CCA.

[0092] In this case, the first width W1 can be greater than the thickness of the second cathode contact electrode 273, and the second width W2 can be greater than the thickness of the first cathode contact electrode 271. Therefore, the sum of the first width W1 and the second width W2 can be greater than the sum of the thickness of the second cathode contact electrode 273 and the thickness of the first cathode contact electrode 271.

[0093] The undercut UC region can be defined as having a cathode contact electrode 270, including a first cathode contact electrode 271 and a second cathode contact electrode 273, whose end of the embankment 180 facing the cathode contact region CCA is further etched inward, and one side of the first cathode contact electrode 271, located below the second cathode contact electrode 273, is formed further inward than one side of the second cathode contact electrode 273. Specifically, a portion of the embankment 180 may protrude beyond the side surface of the first cathode contact electrode 271. The second cathode contact electrode 273 may be disposed on the first cathode contact electrode 271 such that the side surface of the second cathode contact electrode 273 protrudes beyond the side surface of the first cathode contact electrode 271, and the lower surface of the second cathode contact electrode 273 is exposed. The embankment 180 may also extend beyond the side surface of the second cathode contact electrode 273 to expose the lower surface of the embankment 180.

[0094] Therefore, the stacked structure in which the first cathode contact electrode 271, the second cathode contact electrode 273, and the embankment 180 are sequentially stacked in the undercut UC region can have a multi-level reverse step structure. Furthermore, in Figure 2 and Figure 3 In the diagram, the first cathode contact electrode 271 and the second cathode contact electrode 273 are shown in an angled form, but the structure of the cathode contact electrode 270 having the contours of the first cathode contact electrode 271 and the second cathode contact electrode 273 (which have a certain roughness and have a concave or convex tilt angle) can also be considered to be included within the scope of this disclosure.

[0095] According to embodiments of this disclosure, for a stacked structure in which the first cathode contact electrode 271, the second cathode contact electrode 273, and the embankment 180 are sequentially stacked in the undercut UC region, in an etching process that forms a multi-level reverse step structure, when the etching process is executed as a single process, the etching rate of the etching process of the first cathode contact electrode 271 can be higher than the etching rate of the etching process of the second cathode contact electrode 273.

[0096] Alternatively, for the stacked structure in which the first cathode contact electrode 271, the second cathode contact electrode 273, and the embankment 180 are sequentially stacked in the undercut UC region, in the etching process that forms a multi-level reverse step structure, when the etching process is performed as multiple etching processes (e.g., two etching processes), the first cathode contact electrode 271 and the second cathode contact electrode 273 can be etched simultaneously in the first etching process, and as described above, the etching rate of the etching process of the first cathode contact electrode 271 can be greater than the etching rate of the etching process of the second cathode contact electrode 273, and the first cathode contact electrode 271 can be etched at a relatively high etching rate in the second etching process.

[0097] Therefore, as will be referred to later Figures 4A to 4D As described, when the exposed side surface of the cathode contact electrode 270 is formed using the embankment 180 as a mask pattern, a reverse step structure including the cathode contact electrode 270 having a first cathode contact electrode 271 and a second cathode contact electrode 273 and the embankment 180 can be prepared by performing a single etching process or multiple etching processes.

[0098] refer to Figure 2 and Figure 3 The cathode 250' disposed in the second sub-pixel region SPA2 can contact and be electrically connected to one side surface of the first cathode contact electrode 271 of the cathode contact electrode 270. Therefore, at least a portion of the cathode can contact the side surface of the cathode contact electrode 270 in the region below the embankment 180 (more specifically, in the region below the protrusion of the embankment 180). The cathode may include a first cathode (e.g., 250) disposed at least in the first sub-pixel region SPA1 and a second cathode (e.g., 250') disposed at least in the second sub-pixel region SPA2 and the cathode contact region, and the second cathode can contact the side surface of the first cathode contact electrode 271. In one example, the first cathode may be physically disconnected from the second cathode. In another example, the first cathode and the second cathode are integrally formed. Additionally, the upper surface of the cathode 250' contacting one side surface of the first cathode contact electrode 271 can be spaced apart from the lower surface of the second cathode contact electrode 273. Therefore, the thickness of the cathode 250' contacting one side surface of the first cathode contact electrode 272 can be less than the thickness of the first cathode contact electrode 271.

[0099] For example, the first cathode contact electrode 271 may include at least one of copper (Cu), silver (Ag), palladium (Pd) and aluminum (Al), but is not limited thereto.

[0100] For example, the second cathode contact electrode 273 may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), titanium (Ti), molybdenum (Mo), and titanium-molybdenum (MoTi) alloys, but is not limited thereto.

[0101] Therefore, the cathode contact electrode 270 may include the same material as the pixel electrode 210 and may have the same stacked structure. Specifically, the first cathode contact electrode 271 may include the same material as the first pixel electrode 211, and the second cathode contact electrode 273 may include the same material as the second pixel electrode 213.

[0102] In addition, according to the embodiments of the present disclosure, the cathode contact electrode 270 can be configured to be spaced apart from the pixel electrode 210 on one side, and the cathode contact electrode 270 and the pixel electrode 210 are electrically insulated from each other through the aforementioned dam 180.

[0103] Please refer to later Figures 4A to 4D A method for manufacturing a reverse step structure in a structure having a first cathode contact electrode 271, a second cathode contact electrode 273, and a dam 180 stacked, according to an embodiment of the present disclosure, is described.

[0104] The side surface of the first cathode contact electrode 271 exposed in the cathode contact region CCA can contact the cathode 250' of the second sub-pixel region SPA2.

[0105] Therefore, in the electroluminescent display according to embodiments of the present disclosure, in the cathode contact region CCA, the cathode contact electrode 270 does not contact the surfaces of the cathodes 250 and 250', but in the non-light-emitting region NEA located on the side of the first sub-pixel region SPA1, it makes surface contact with one exposed side surface of the cathode contact electrode 270. Therefore, in the electroluminescent display device according to embodiments of the present disclosure, since the cathode contact electrode 270 does not need to contact the surfaces of the cathodes 250 and 250' in the cathode contact region CCA, the cathode contact region CCA can be designed to have a small area, which is advantageous in terms of design rules. Here, surface contact can be defined as the contact between the upper surface of the cathode contact electrode 270 and the lower surface of the cathodes 250 and 250'.

[0106] The auxiliary electrode AE ​​can be disposed above the interlayer insulation layer and can contact the auxiliary power line EVSS, which will be described later. The auxiliary electrode AE ​​can contact the cathode contact electrode 270 through the first contact hole CH1 described above. Here, the cathode contact electrode 270 and the auxiliary electrode AE ​​can contact each other through the contact hole CH1 formed in at least a portion of the protective layer 150 adjacent to the cathode contact region CCA.

[0107] The auxiliary power line EVSS can be electrically connected to the auxiliary electrode AE ​​and can comprise the same material as the light-blocking layer LS. The auxiliary power line EVSS can be disposed above the substrate 110. Therefore, the auxiliary power line EVSS can be formed of a single layer or multiple layers of metals (e.g., copper (Cu), titanium (Ti), molybdenum (Mo), aluminum (Al), chromium (Cr), and silver (Ag) or alloys of the aforementioned materials), but is not limited thereto, and can be implemented with various materials known in the art.

[0108] The above is for reference only. Figure 1 The first power connection line 62 described can have the same configuration as the auxiliary power line EVSS and the auxiliary electrode AE. Figure 1 In the diagram, due to display limitations, the first power connection line 62 is shown as a single line, but it may include an auxiliary power line EVSS and an auxiliary electrode AE, and may improve the resistance uniformity of the cathode.

[0109] The auxiliary electrode AE ​​can contact the auxiliary power line EVSS through a second contact hole CH2 formed in at least a portion of the interlayer insulating layer 140. Here, if necessary, the second contact hole CH2 can be formed by removing at least a portion of the buffer layer 120 and the interlayer insulating layer 140.

[0110] The auxiliary electrode AE ​​can be positioned above the interlayer insulating layer 140, spaced apart from the source electrode SE and the drain electrode DE, and can be formed of the same material as the source electrode SE and the drain electrode DE and fabricated in the same process. The auxiliary electrode AE ​​can have the same stacked structure as the source electrode SE and the drain electrode DE. Therefore, the auxiliary electrode AE ​​can be formed as a single layer or multiple layers of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), silver (Ag), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), or alloys of the aforementioned metals.

[0111] According to embodiments of this disclosure, in the light-emitting region EA, the planarization layer 160 may include contact holes through which the pixel electrode 210 passes. Here, the contact holes of the planarization layer 160 may be connected to the contact holes of the protective layer 150 to allow the pixel electrode 210 to pass through. For example, the planarization layer 160 may include organic materials such as photoacrylic acid and polyimide.

[0112] The encapsulation portion 170 can cover sub-pixel regions SPA1 and SPA2 and the cathode contact region CCA, and can cover at least a portion of the non-active region IA. According to embodiments of this disclosure, the encapsulation portion 170 may include at least one inorganic layer and at least one organic layer. Furthermore, the encapsulation portion 170 may have a thin-film encapsulation structure with alternating inorganic and organic layers, and can prevent moisture or oxygen from penetrating into the light-emitting device 200. For example, the encapsulation portion 170 may include a first encapsulation portion 171, a second encapsulation portion 172, and a third encapsulation portion 173 stacked sequentially. Additionally, the first encapsulation portion 171 and the third encapsulation portion 173 of the encapsulation portion 170 may be inorganic layers, and the second encapsulation portion 172 may be an organic layer, but the method is not limited thereto.

[0113] In addition, such as Figure 2 and Figure 3 As shown, the first encapsulation portion 171 can be configured to cover the first sub-pixel region SPA1, the second sub-pixel region SPA2, and the cathode contact region CCA.

[0114] The electroluminescent display device according to embodiments of the present disclosure can be configured to include a planarization layer 160 in a region that overlaps with at least a portion of the cathode contact region CCA. Furthermore, the step height d between the upper surface of the first encapsulation portion 171 located in the non-light-emitting region NEA of the first sub-pixel region SPA1 and the upper surface of the first encapsulation portion 171 located in the cathode contact region CCA can be set to a height equal to the sum of the thicknesses of the embankment 180 and the cathode contact electrode 270. Therefore, the step height d between the non-light-emitting portion NEA of the first sub-pixel region SPA1 and the cathode contact region CCA can be reduced or minimized, and during the formation of the first encapsulation portion 171, the first encapsulation portion 171 can be formed to cover both the non-light-emitting region NEA and the cathode contact region CCA of the first sub-pixel region SPA1 without being disconnected.

[0115] The first package portion 171 and the third package portion 173 may include, but are not limited to, a silicon oxide layer (SiOx) or a silicon nitride layer (SiNx). The first package portion 171 and the third package portion 173 may be a multilayer comprising a silicon oxide layer (SiOx) and a silicon nitride layer (SiNx). The second package portion 172 may be formed of an organic material, but is not limited to that.

[0116] The step height d can be equal to the sum of the thicknesses of the embankment and the cathode contact electrode. In this case, the thickness of the cathode contact electrode 270 can be defined as the sum of the thicknesses of the first cathode contact electrode 271 and the second cathode contact electrode 273 formed above the planarization layer 160. Additionally, the thickness of the embankment 180 can be defined as the thickness of the embankment 180 from the upper surface of the cathode contact electrode 270 above the planarization layer 160.

[0117] In existing electroluminescent display devices, a step height greater than or equal to the thickness of the planarization layer is formed in the non-light-emitting portion of the sub-pixel region and the cathode contact region. This can lead to recesses or seams during the formation of the first encapsulation portion due to unfilled areas. Furthermore, such recesses or seams caused by unfilled areas may act as moisture penetration paths or cause reliability issues due to structural instability.

[0118] Figures 4A to 4D The process of manufacturing a method for an electroluminescent display device according to an embodiment of the present disclosure is shown in sequence.

[0119] refer to Figures 4A to 4D A pixel electrode 210, including a first pixel electrode 211 and a second pixel electrode 213, and a cathode contact electrode 270, including a first cathode contact electrode 271 and a second cathode contact electrode 273, can be fabricated by a deposition process.

[0120] The pixel electrode 210 and the cathode contact electrode 270 can be patterned in predetermined areas using a mask pattern. Here, for the pixel electrode 210, the predetermined area may correspond to the light-emitting area EA, and for the cathode contact electrode 270, the predetermined area may correspond to the non-light-emitting area NEA adjacent to the cathode contact area CCA. Furthermore, the first cathode contact electrode 271 and the second cathode contact electrode 273 can be formed from the same material as the first pixel electrode 211 and the second pixel electrode 213. Therefore, the pixel electrode 210 and the cathode contact electrode 270 can be formed in a single process.

[0121] Therefore, at this time, one side surface and the other side surface of the cathode contact electrode 270 can be formed to have a certain degree of inclination by an etching process with a normal tapered angle similar to that of one side surface and the other side surface of the pixel electrode 210.

[0122] Next, a dam 180 is formed to separate the light-emitting region EA and insulate the pixel electrode 210 and the cathode contact electrode 270. In this case, the dam 180 may be configured to cover the entire cathode contact electrode 270 adjacent to the pixel electrode 210 and may be configured to expose the cathode contact electrode 270 adjacent to the cathode contact region CCA or overlap with at least a portion of the cathode contact region CCA.

[0123] Next, in order to form a reverse step structure including a cathode contact electrode 270 having a first cathode contact electrode 271 and a second cathode contact electrode 273 and a dam 180, a specific mask pattern MP can be formed in the area other than the cathode contact region CCA, and an etching process for the cathode contact electrode 270 can be performed. Additionally, the dam 180 can also be used as a mask for etching the cathode contact electrode 270.

[0124] The cathode contact electrode 270 can be formed using materials with different etching rates for the etching process used in the patterning process. In this case, when the etching process is performed as a single process, the etching rate of the etching process for the first cathode contact electrode 271 can be set to a value having a higher etching rate than that of the etching process for the second cathode contact electrode 273. Here, the etching process can be wet etching. Therefore, the etching rate of the etchant used in the wet etching process can be greater for the first cathode contact electrode 271 than for the second cathode contact electrode 273. Here, known wet etchants for metal etching can be used as the etchant. Furthermore, the above-described etching process is not limited to wet etching; a dry etching process can be used when the etching rate of the first cathode contact electrode 271 in the dry etching process and the etching rate of the second cathode contact electrode 273 in the dry etching process are set differently.

[0125] Furthermore, according to another embodiment of this disclosure, in order to form a reverse step structure including a cathode contact electrode 270 having a first cathode contact electrode 271 and a second cathode contact electrode 273 and a dam portion 180, if the etching process is performed through multiple processes, for example, through two etching processes, the first cathode contact electrode 271 and the second cathode contact electrode 273 can be etched simultaneously in the first etching process. As described above, the etching rate of the etching process for the first cathode contact electrode 271 can be greater than the etching rate of the etching process for the second cathode contact electrode 273, and in the second etching process, the first cathode contact electrode 271 can be etched at a relatively high etching rate. Therefore, in the case of a cathode contact electrode 270 including a first cathode contact electrode 271 and a second cathode contact electrode 273, when using the aforementioned etching process, a single process can be used to set the second cathode contact electrode 273 to overlap with the first cathode contact electrode 271, and the width of the second cathode contact electrode 273 can be greater than the width of the first cathode contact electrode 271.

[0126] Next, the light-emitting layer 230 and the cathode 250 of the light-emitting device 200 are formed. In this case, the cathode 250' of the second sub-pixel region SPA2 can contact one side surface of the cathode contact electrode 270 in the non-light-emitting region NEA adjacent to the cathode contact region CCA, specifically, one side surface of the first cathode contact electrode 271.

[0127] Therefore, as described above, the cathode contact electrode 270, including the first cathode contact electrode 271 and the second cathode contact electrode 273, can have a reverse step structure in the portion of its side surface that is exposed. Additionally, as... Figure 2 and Figure 3 As shown, the reverse step structure formed on one side of the cathode contact electrode 270 including the first cathode contact electrode 271 and the second cathode contact electrode 273 is covered by the embankment 180, and the reverse step structure formed on the other side surface of the cathode contact electrode 270 including the first cathode contact electrode 271 and the second cathode contact electrode 273 can be provided in a form that is exposed in the cathode contact area without being covered by the embankment 180.

[0128] Here, the side surface of the cathode contact electrode 270 exposed in the cathode contact region can contact the cathode 250' of the light-emitting device of the second sub-pixel region SPA2.

[0129] According to embodiments of this disclosure, it has the effect of providing uniform cathode resistance over the entire active area of ​​the electroluminescent display device.

[0130] Furthermore, according to embodiments of this disclosure, it has the effect of blocking the path of moisture penetration in the cathode contact area of ​​the electroluminescent display device.

[0131] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand other effects not mentioned herein through the following description.

[0132] The features, structures, and effects described above are included in at least one embodiment of this disclosure, but are not limited to one embodiment. Furthermore, those skilled in the art can implement the features, structures, and effects described in at least one embodiment of this disclosure through combinations or modifications of other embodiments. Therefore, the content relating to such combinations and modifications should be understood as being within the scope of this disclosure.

[0133] It will be apparent to those skilled in the art that various modifications and variations can be made to this disclosure without departing from its spirit or scope. Therefore, this disclosure is intended to cover such modifications and variations as long as they fall within the scope of the appended claims and their equivalents.

Claims

1. An electroluminescent display device, comprising: A substrate, the substrate including a plurality of sub-pixel regions and a cathode contact region, each sub-pixel region including a light-emitting region and a non-light-emitting region surrounding the light-emitting region, the cathode contact region being located on at least one side between the plurality of sub-pixel regions; A planarization layer is disposed above the substrate and configured to overlap at least a portion of each of the light-emitting region and the cathode contact region; A light-emitting device disposed above the planarization layer and configured to overlap at least a portion of the light-emitting region, and comprising a pixel electrode and a cathode facing the pixel electrode; as well as A cathode contact electrode is formed above the planarization layer and is configured to overlap at least a portion of the non-light-emitting region. The cathode contact electrode includes a side surface exposed toward the cathode contact region, and the cathode is in contact with the side surface of the cathode contact electrode. The pixel electrode includes a first pixel electrode and a second pixel electrode configured to overlap with the first pixel electrode. The cathode contact electrode includes a first cathode contact electrode and a second cathode contact electrode configured to overlap with the first cathode contact electrode and protrude further into the cathode contact region than the first cathode contact electrode, thereby exposing the lower surface of the second cathode contact electrode. The plurality of sub-pixel regions include: A first sub-pixel region, the first sub-pixel region being disposed above the substrate; and The second sub-pixel region is configured to be adjacent to the first sub-pixel region. Wherein, the cathode contact area is located in at least a portion between the first sub-pixel area and the second sub-pixel area, and The side surface of the first cathode contact electrode is in contact with the cathode disposed in the second sub-pixel region.

2. The electroluminescent display device according to claim 1, further comprising: A dam, which is disposed above the pixel electrode and configured to separate the light-emitting area; as well as An undercut structure, wherein the cathode contact electrode is formed further inward than one end of the embankment adjacent to the cathode contact area.

3. The electroluminescent display device according to claim 2, further comprising: A first encapsulation portion is configured to cover the plurality of sub-pixel regions and the cathode contact region. The first encapsulation portion is formed to have steps in the non-light-emitting area and the cathode contact area, and The height of the step is equal to the sum of the thickness of the embankment and the cathode contact electrode.

4. The electroluminescent display device according to claim 1, further comprising: A driving thin-film transistor, i.e., a driving TFT, wherein the driving TFT is disposed in a sub-pixel region and includes an active layer, a gate, a source, and a drain; A protective layer disposed beneath the planarization layer and configured to cover the driving TFT; An interlayer insulating layer is disposed between the protective layer and the substrate; as well as A light-blocking layer is disposed below the driving TFT.

5. The electroluminescent display device according to claim 4, further comprising: An auxiliary electrode is disposed on the interlayer insulating layer and contacts the cathode contact electrode through a first contact hole formed in at least a portion of the planarization layer.

6. The electroluminescent display device according to claim 5, wherein, The auxiliary electrode comprises the same material as the source and drain of the driving TFT.

7. The electroluminescent display device according to claim 5, further comprising: An auxiliary power line is disposed above the substrate at a distance from the light-blocking layer and is configured to overlap at least a portion of the plurality of sub-pixel regions. The auxiliary power line is made of the same material as the light-blocking layer.

8. The electroluminescent display device according to claim 7, wherein, The auxiliary electrode contacts the auxiliary power line through a second contact hole formed in at least a portion of the interlayer insulation layer.

9. A display device, comprising: A substrate, the substrate including a plurality of sub-pixel regions and a contact region, the plurality of sub-pixel regions including a first sub-pixel region and a second sub-pixel region, the contact region being located between the first sub-pixel region and the second sub-pixel region; A light-emitting device, wherein the light-emitting device is disposed on an insulating layer and located in the first sub-pixel region, the light-emitting device comprising at least a first electrode, a light-emitting layer, and a second electrode; A first contact electrode is configured to receive a voltage from a first power line on the substrate, wherein at least a portion of the first contact electrode extends from a region within a contact hole formed in the insulating layer to the upper surface of the insulating layer. The second contact electrode on the first contact electrode; and A dam portion, the dam portion being at least on the first electrode and the first contact electrode of the light-emitting device, A portion of the embankment protrudes beyond the side surface of the first contact electrode. Wherein, at least a portion of the second electrode is in contact with the side surface of the first contact electrode in the region below the embankment. Wherein, the side surface of the second contact electrode protrudes beyond the side surface of the first contact electrode to expose the lower surface of the second contact electrode, and Wherein, the portion of the second electrode that contacts the side surface of the first contact electrode is spaced apart from the lower surface of the second contact electrode.

10. The display device according to claim 9, wherein, The protrusion of the embankment extends beyond the side surface of the second contact electrode to expose the lower surface of the embankment.

11. The display device according to claim 9, wherein, The portion of the second electrode does not contact the upper surface of the first contact electrode.

12. The display device according to claim 9, wherein, A portion of the embankment is configured to fill the space within the contact hole.

13. The display device according to claim 9, wherein, The second electrode includes a first cathode in the first sub-pixel region and a second cathode disposed along the second sub-pixel region and the contact region, and The second cathode is in contact with the side surface of the first contact electrode, and the first cathode is disconnected from the second cathode.

14. The display device according to claim 9, further comprising an auxiliary electrode on the substrate, the auxiliary electrode being electrically connected to the first power line, wherein, The contact hole exposes a portion of the auxiliary electrode, and the first contact electrode contacts the exposed portion of the auxiliary electrode.

15. The display device according to claim 14, further comprising: A driving thin-film transistor, i.e., a driving TFT, wherein the driving TFT is disposed in the first sub-pixel region and includes a source and a drain; The auxiliary electrode is made of the same material as the source and the drain.

16. The display device according to claim 15, further comprising a light-blocking layer beneath the driving TFT. in, The first power line comprises the same material as the light-blocking layer.

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