Electroluminescent display device

Abstract

An electroluminescent display device according to an exemplary embodiment of the present disclosure includes a display panel divided into a display area and a non-display area; a planarization layer and a bank extending to the non-display area of the display panel; an organic layer and a cathode disposed on the bank and extending to the non-display area of the display panel; a trench disposed in the non-display area outside the display area, and the cathode, the organic layer, the bank, and the planarization layer are removed from the trench; an undercut structure disposed within the trench and mainly composed of the bank and the planarization layer, in which the planarization layer is indented inward from an end of the bank to create an undercut portion; and an adhesive layer and an encapsulation substrate disposed on the cathode. Thus, reliability can be improved and a bezel width can be reduced.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 202210685092.6, filed on June 14, 2022, entitled "Electronic Light Emitting Display Device". Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0079413, filed on June 18, 2021, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to an electroluminescent display device, and more specifically, to an electroluminescent display device with a narrow bezel. Background Technology

[0004] With the advent of the information age, display technologies for visually displaying electrical information signals are developing rapidly. Therefore, various efforts have been made to reduce the size, weight, and power consumption of various display devices.

[0005] Representative display devices may include liquid crystal displays (LCDs), electrowetting displays (EWDs), and organic light-emitting diode displays (OLEDs).

[0006] Electroluminescent displays, including organic light-emitting diodes (OLEDs), are self-emissive devices that do not require a separate light source, unlike liquid crystal displays (LCDs). Therefore, electroluminescent displays can be manufactured to be thin and lightweight. Furthermore, due to their lower driving voltage, electroluminescent displays offer advantages not only in power consumption but also in color reproduction, response speed, viewing angle, and contrast ratio (CR). Therefore, they hold promise for applications in various fields.

[0007] In an electroluminescent display device, an emitting layer (light-emitting layer) made of organic material is disposed between two electrodes consisting of an anode and a cathode. Furthermore, when holes in the anode are injected into the emitting layer and electrons in the cathode are injected into the emitting layer, the injected holes and electrons recombine and form excitons in the emitting layer to emit light. Summary of the Invention

[0008] Currently, in electroluminescent display devices, a minimum bezel distance is required to ensure reliability, such as resistance to moisture penetration. This minimum bezel distance can be referred to as the "reliable bezel." The reliable bezel can be defined as the distance from the end of the upper substrate (encapsulation substrate) to the end of the cathode.

[0009] Simultaneously, with the increasing demand for thinner display devices, the demand for thinner non-display areas beyond the display area for displaying images is also increasing. However, a cathode needs to be formed to cover the organic layer in order to suppress mass production failures caused by the exposure of the organic layer. Therefore, there are limitations in ensuring a reliable bezel.

[0010] One or more embodiments of this disclosure provide an electroluminescent display device that employs an undercut structure to block lateral moisture penetration paths. In this electroluminescent display device, the end (one end) of the cathode can be recessed (retracted) toward the display area to increase the reliable bezel and thereby reduce the bezel width.

[0011] The technical advantages of this disclosure are not limited to those described above, and other advantages not mentioned above can be clearly understood by those skilled in the art through the following description.

[0012] According to one embodiment of this disclosure, an electroluminescent display device includes a display panel divided into a display area and a non-display area. Furthermore, the electroluminescent display device includes a planarization layer and a dam extending into the non-display area of ​​the display panel. Additionally, the electroluminescent display device includes an organic layer disposed on the dam and extending into the non-display area of ​​the display panel, and a cathode. Furthermore, the electroluminescent display device includes a trench disposed in the non-display area outside the display area, and the cathode, the organic layer, the dam, and the planarization layer are removed from the trench. Furthermore, the electroluminescent display device may include an undercut structure disposed within the trench and primarily composed of the dam and the planarization layer, wherein the planarization layer is recessed inward from one end of the dam to create an undercut. Furthermore, the electroluminescent display device may include an adhesive layer and an encapsulation substrate disposed on the cathode.

[0013] Further details of the exemplary embodiments are included in the detailed description and accompanying drawings.

[0014] According to this disclosure, an undercut structure is applied between the display area and the non-display area to block lateral moisture penetration paths and suppress exposure of the side surface of the organic layer caused by the step-like coverage between the cathode and the organic layer. Therefore, reliability can be improved and bezel width can be reduced.

[0015] According to this disclosure, the end of the cathode can be recessed from the bezel area toward the display area to increase the reliable bezel. Therefore, the bezel width can be reduced.

[0016] The effects of this disclosure are not limited to those illustrated above, and many more effects are included in this specification. Attached Figure Description

[0017] The above and other aspects, features, and other advantages of this disclosure will become clearer from the following detailed description taken in conjunction with the accompanying drawings, in which: Figure 1 This is a plan view illustrating an electroluminescent display device according to a first exemplary embodiment of the present disclosure; Figure 2 This is a cross-sectional view of a sub-pixel of an electroluminescent display device according to a first exemplary embodiment of the present disclosure; Figure 3 It is along Figure 1 A cross-sectional view taken from line II′; Figure 4 This is a cross-sectional view showing a portion of an electroluminescent display device according to a comparative embodiment; Figures 5A to 5E It is shown in sequence. Figure 3 A cross-sectional view of a portion of the manufacturing process of the electroluminescent display device shown.

[0018] Figures 6A to 6G To show in more detail Figure 3 A cross-sectional view of a portion of the manufacturing process of the non-display area in the electroluminescent display device shown.

[0019] Figure 7 This is a cross-sectional view showing an electroluminescent display device according to a second exemplary embodiment of the present disclosure; Figure 8 This is a plan view illustrating an electroluminescent display device according to a third exemplary embodiment of the present disclosure; Figure 9A and Figure 9B It is along Figure 8 A cross-sectional view taken from line VIII-VIII′; Figures 10A to 10D This is a cross-sectional view showing a portion of the manufacturing process of an electroluminescent display device according to a third exemplary embodiment of the present disclosure; Figures 11A to 11D These are additional cross-sectional views showing a portion of the manufacturing process of the electroluminescent display device according to a third embodiment of the present disclosure; Figure 12 This is a plan view illustrating an electroluminescent display device according to a fourth exemplary embodiment of the present disclosure; and Figure 13 This is a plan view illustrating an electroluminescent display device according to a fifth exemplary embodiment of the present disclosure. Detailed Implementation

[0020] The advantages and features of this disclosure, as well as the methods for achieving these advantages and features, will become clear from the exemplary embodiments described in detail below with reference to the accompanying drawings. However, this disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. These exemplary embodiments are provided by way of example only to enable those skilled in the art to fully understand the disclosure and scope of this disclosure. Therefore, this disclosure will be limited only by the scope of the appended claims.

[0021] The shapes, dimensions, scales, angles, quantities, etc., shown in the accompanying drawings to describe exemplary embodiments of this disclosure are merely examples, and this disclosure is not limited thereto. Furthermore, in the following description of this disclosure, detailed explanations of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of this disclosure. Terms such as “comprising,” “having,” and “consisting of” as used herein are generally intended to allow for the addition of additional components, unless these terms are used in conjunction with the term “only.” Unless otherwise expressly stated, any reference to the singular may include the plural.

[0022] Even if not explicitly stated, components are interpreted as including (containing) the general tolerance range.

[0023] When terms such as “above,” “over,” “below,” and “next” are used to describe the positional relationship between two parts, one or more parts may be positioned between the two parts, unless these terms are used with the terms “immediately following” or “directly.”

[0024] When one element or layer is placed "on" another element or layer, yet another element or layer can be directly inserted on or between the other element or layer.

[0025] Although the terms "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from other components. Therefore, the first component referred to below may be the second component in the technical concept of this disclosure.

[0026] Throughout the specification, similar reference numerals generally denote similar elements.

[0027] The dimensions and thicknesses of the components shown in the accompanying drawings are illustrated for ease of description, and this disclosure is not limited to the dimensions and thicknesses of the components shown.

[0028] The features of the various embodiments of this disclosure may be partially or wholly attached to or combined with each other, and may be technically interlocked and operated in various ways, and the embodiments may be implemented independently or in association with each other.

[0029] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0030] Figure 1 This is a plan view illustrating an electroluminescent display device according to a first exemplary embodiment of the present disclosure.

[0031] Reference Figure 1 An electroluminescent display device according to a first exemplary embodiment of the present disclosure may include a display panel 100, a flexible film 160, and a printed circuit board 170.

[0032] Display panel 100 is a panel used to display images to the user.

[0033] The display panel 100 may include display elements for displaying images, driving elements for driving the display elements, and lines for transmitting various signals to the display elements and driving elements. The display elements may be defined in different ways depending on the type of the display panel 100. For example, if the display panel 100 is an organic light-emitting display panel, the display element may be an organic light-emitting diode (OLED) comprising an anode, an organic emitting layer, and a cathode.

[0034] In the following text, although the display panel 100 is assumed to be an organic light-emitting display panel, the display panel 100 is not limited to an organic light-emitting display panel.

[0035] Display panel 100 may include a display area AA and a non-display area NA.

[0036] Display area AA is the area in display panel 100 where images are displayed.

[0037] In the display area AA, multiple sub-pixels forming multiple pixels and circuitry for driving the multiple sub-pixels can be provided. The multiple sub-pixels are the smallest units for forming the display area AA, and a display element can be disposed in each of the multiple sub-pixels. Furthermore, the multiple sub-pixels can form pixels. For example, an organic light-emitting diode (OLED) including an anode, an organic emitting layer, and a cathode can be disposed in each of the multiple sub-pixels, but this disclosure is not limited thereto. Furthermore, the circuitry for driving the multiple sub-pixels can include driving elements, lines, etc. For example, the circuitry can be constructed from thin-film transistors, storage capacitors, gate lines, data lines, etc., but is not limited thereto.

[0038] The non-display area (NA) is the area where no image is displayed.

[0039] Figure 1 The diagram shows a non-display area NA surrounding a rectangular display area AA. However, the shape and layout of the display area AA and the non-display area NA are not limited to... Figure 1 The example shown.

[0040] In other words, the display area AA and the non-display area NA can have shapes suitable for the design of electronic devices equipped with electroluminescent display devices. Another exemplary shape of the display area AA can be, for example, a pentagon, a hexagon, a circle, an ellipse, etc.

[0041] In the non-display area NA, various lines and circuits can be provided for driving the organic light-emitting diodes in the display area AA. For example, in the non-display area NA, link lines or driver ICs such as gate driver ICs or data driver ICs can be provided for transmitting signals to multiple sub-pixels and circuits in the display area AA. However, this disclosure is not limited thereto.

[0042] at the same time, Figure 1 The left and right sides can be defined as the gate pad areas for setting the gate driver IC. Figure 1 The bottom side can be defined as a data pad area connected to the flexible film 160. However, this disclosure is not limited thereto.

[0043] Electroluminescent display devices may include various additional components configured to generate various signals or drive pixels in a display area AA. Additional components for driving pixels may include inverter circuits, multiplexers, electrostatic discharge (ESD) circuits, etc. Electroluminescent display devices may also include additional components associated with functions other than driving pixels. For example, an electroluminescent display device may include additional components providing touch sensing functions, user authorization functions (e.g., fingerprint recognition), multi-level pressure sensing functions, haptic feedback functions, etc. These additional components may be located in the non-display area NA and / or connected to external circuitry of a connection interface.

[0044] The flexible film 160 is a film in which various components are disposed on a base film with elasticity. More specifically, the flexible film 160 is configured to provide signals to the plurality of sub-pixels and circuits in the display area AA, and can be electrically connected to the display panel 100. The flexible film 160 can be disposed at one end of the non-display area NA of the display panel 100, and can provide power supply voltage, data voltage, etc. to the plurality of sub-pixels and circuits in the display area AA. Furthermore, the number of flexible films 160 can vary depending on the design and is not limited thereto.

[0045] Driver ICs, such as data driver ICs, can be mounted on the flexible film 160. The driver IC is a component that processes data signals used for displaying images and drive signals used for processing these data signals. Depending on the mounting method, the driver IC can be mounted using chip-on-glass (COG), chip-on-film (COF), or tape-on-cable (TCP) technology.

[0046] A printed circuit board 170 may be disposed at one end of the flexible film 160 and connected to the flexible film 160. The printed circuit board 170 is a component for providing signals to a driver IC. The printed circuit board 170 may provide various signals to the driver IC, such as drive signals or data signals. For example, a data driver that generates data signals may be mounted on the printed circuit board 170. The generated data signals can be provided to the plurality of sub-pixels and circuits in the display panel 100 through the flexible film 160. The number of printed circuit boards 170 may vary depending on the design and is not limited thereto.

[0047] Meanwhile, electroluminescent display devices require a minimum bezel distance to ensure reliability, such as resistance to moisture penetration. Furthermore, with the increasing demand for thinner display devices, the need for an even thinner non-display area NA, in addition to the display area AA that displays the image, is also increasing. However, a cathode needs to be formed to cover the side surfaces of the organic layer in order to suppress mass production failures caused by exposed organic layers. Therefore, there are limitations in ensuring a reliable bezel L.

[0048] In a first exemplary embodiment of this disclosure, a trench 180 including an undercut structure UC is formed in a shaded (masking) area within the non-display area NA. Therefore, moisture penetration through the side surface can be suppressed. Since moisture penetration through the side surface can be suppressed, one end of the cathode is recessed toward the display area AA. Therefore, a reliable bezel L can be increased, and thereby the bezel width can be reduced. The reliable bezel L can be defined as extending from one end of the upper substrate (packaging substrate) to said end of the cathode. In a first exemplary embodiment of this disclosure, the reliable bezel L can be spaced apart from the trench 180 by a predetermined distance.

[0049] For reference, the shadow area refers to a portion of the non-display area (NA) formed by the gap between the mask and the substrate during the deposition of the cathode and organic layer.

[0050] In a first exemplary embodiment of this disclosure, the undercut structure UC and the trench 180 can be formed on the three sides of the non-display area NA, excluding the lower side of the display panel 100 connected to the flexible film 160 (i.e., the data pad area). However, this disclosure is not limited to this. That is, the data pad area includes a wide line area, and therefore it is difficult to form the undercut structure UC. Therefore, the undercut structure UC and the trench 180 are not formed in the data pad area. However, this disclosure is not limited to this. Meanwhile, in the three sides of the non-display area NA, the gate line, etc., does not pass through the upper side of the non-display area NA. Therefore, the undercut structure UC and the trench 180 on the upper side of the non-display area NA are formed as a single unit. However, the gate line, etc., passes through the left and right sides (left and right sides) of the non-display area NA, and therefore, the undercut structure UC and the trench 180 on the left and right sides of the non-display area NA can be divided into multiple undercut structures and trenches (in other words, multiple parts) by the gate line. However, this disclosure is not limited to this.

[0051] For example, the trench 180 including the undercut structure UC can be formed by patterning a dam and a planarization layer in the shadow area outside the display area AA via a photolithography process. That is, a porous planarization layer and a dam can be used to form the trench 180 including the undercut structure UC, and thus block lateral moisture penetration paths. In addition, the end of the cathode can be recessed toward the display area AA to increase the reliable bezel L and thereby reduce the bezel width.

[0052] Reference Figure 2 and Figure 3 The present disclosure describes in detail various components of an electroluminescent display device including an undercut structure UC and a groove 180 according to a first exemplary embodiment.

[0053] Figure 2 This is a cross-sectional view of a sub-pixel of an electroluminescent display device according to a first exemplary embodiment of the present disclosure.

[0054] Figure 3 It is along Figure 1 The cross-sectional view taken from line II′.

[0055] Figure 3 A cross-sectional view of the left side (i.e., a portion of the gate pad area) of the display panel 100 is shown as an example, where an undercut structure UC and a trench 180 are formed on this left side. For ease of description, Figure 3 The pixel portion 115 within the display area AA is shown schematically. The pixel portion 115 may include various components located beneath the organic layer 152.

[0056] Reference Figure 2 and Figure 3In the electroluminescent display device according to the first exemplary embodiment of the present disclosure, the driving element 110 may be disposed on the substrate 101.

[0057] In addition, the planarization layer 105 can be disposed on the drive element 110.

[0058] Additionally, an organic light-emitting diode (OLED) 150 electrically connected to the driving element 110 can be disposed on the planarization layer 105. A masking layer 120 can be disposed on the OLED 150. Therefore, the penetration of oxygen and moisture into the OLED 150 can be minimized.

[0059] The adhesive layer 130 and the encapsulation substrate 140 may be sequentially disposed on the cover layer 120. However, this disclosure is not limited to this stacked structure.

[0060] The substrate 101 can be a glass or plastic substrate. If the substrate 101 is a plastic substrate, it can be made of a polyimide-based material or a polycarbonate-based material, and therefore can be flexible. In particular, polyimide can be used in high-temperature processes and can be used for coating. Therefore, polyimide has been widely used in plastic substrates.

[0061] The buffer layer 102 can be disposed on the substrate 101.

[0062] Buffer layer 102 is a functional layer configured to protect various electrodes and lines (wiring) from impurities such as alkali ions flowing from substrate 101 or its underlying layers. Buffer layer 102 may have a multilayer structure including a first buffer layer and a second buffer layer, but is not limited thereto. Buffer layer 102 may be made of silicon oxide (SiOx) or silicon nitride (SiNx), or may be formed in multiple layers thereof.

[0063] The buffer layer 102 can delay the diffusion of moisture and / or oxygen that permeates into the substrate 101. Furthermore, the buffer layer 102 may include multiple buffers and / or active buffers. Active buffers can be used to protect the active layer 111, made of semiconductors from the driving element 110, and to block various types of defects flowing in from the substrate 101. Active buffers may be made of amorphous silicon (a-Si).

[0064] The light-shielding layer 116 can be disposed between the substrate 101 and the buffer layer 102.

[0065] The light-shielding layer 116 can be disposed on the substrate 101 at the location where the active layer 111 is formed. In particular, the light-shielding layer 116 can be formed to be slightly larger than the active layer 111 to completely cover the active layer 111. However, this disclosure is not limited thereto.

[0066] The buffer layer 102 can be disposed on the entire surface of the substrate 101 on which the light-shielding layer 116 has been formed.

[0067] The drive element 110 can be disposed on the buffer layer 102.

[0068] The driving element 110 may have a structure in which an active layer 111, an interlayer insulating layer 103, a gate electrode 113, a source electrode 114, and a drain electrode 112 are sequentially disposed. The driving element 110 may be electrically connected to an organic light-emitting diode 150 via a connecting electrode 104 to transmit current or a signal to the organic light-emitting diode 150.

[0069] The active layer 111 can be positioned on the buffer layer 102. The active layer 111 can be made of polycrystalline silicon (p-Si), and in this case, a predetermined region can be doped with impurities. Alternatively, the active layer 111 can be made of amorphous silicon (a-Si), or it can be made of various organic semiconductor materials such as pentacene. The active layer 111 can also be made of oxide.

[0070] The interlayer insulation layer 103 can be located on the active layer 111.

[0071] The interlayer insulation layer 103 can be made of insulating inorganic materials such as silicon oxide (SiOx) or silicon nitride (SiNx), or it can be made of insulating organic materials.

[0072] The gate electrode 113 may be located on the interlayer insulating layer 103. The gate electrode 113 may be made of various conductive materials such as magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), gold (Au) or their alloys.

[0073] The source electrode 114 and the drain electrode 112 can be formed on the interlayer insulating layer 103 as a single layer or multiple layers of electrode material. The source electrode 114 and the drain electrode 112 can be made of various conductive materials or alloys thereof, such as magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), gold (Au).

[0074] A passivation layer made of inorganic insulating material can be further formed to cover the gate electrode 113, the source electrode 114, and the drain electrode 112.

[0075] The planarization layer 105 can be disposed on the drive element 110 configured as described above.

[0076] The planarization layer 105 may have a multilayer structure consisting of at least two layers. For example, the planarization layer 105 may include a first planarization layer 105a and a second planarization layer 105b. In this case, the first planarization layer 105a may be configured to cover a portion of the drive element 110 and expose a portion of the drain electrode 112 of the drive element 110.

[0077] The planarization layer 105 can be extended to the non-display area NA.

[0078] The planarization layer 105 may have a thickness of about 2 μm, but is not limited to this.

[0079] The planarization layer 105 may include, but is not limited to, an outer coating layer.

[0080] The second planarization layer 105b may be configured to be spaced apart from the end of the substrate 101 by a predetermined distance, but is not limited thereto.

[0081] The connection electrode 104 for electrically connecting the driving element 110 and the organic light-emitting diode 150 can be disposed on the first planarization layer 105a. Furthermore, in Figure 2 As not shown, various metal layers used as wiring or electrodes, such as data lines or signal lines, may also be disposed on the first planarization layer 105a.

[0082] Furthermore, a second planarization layer 105b can be disposed on the first planarization layer 105a and the connecting electrode 104. In a first exemplary embodiment of this disclosure, the planarization layer 105 consists of two layers because the number of various signal lines increases with the resolution of the electroluminescent display device. Therefore, it is difficult to arrange all the lines in a single layer so that they are spaced apart from each other with minimal distance, and thus, an additional layer is formed. Due to this additional layer (the second planarization layer 105b), spare space can be provided for the lines. Therefore, it is easier to design the layout of wiring or electrodes. Furthermore, if a dielectric material is used in the planarization layer 105 having a multilayer structure, the planarization layer 105 can be used to form capacitors between metal layers. However, this disclosure is not limited to this.

[0083] The second planarization layer 105b can be formed as part of the exposed connection electrode 104. The drain electrode 112 of the drive element 110 and the anode 151 of the organic light-emitting diode 150 can be electrically connected to each other through the connection electrode 104.

[0084] The organic light-emitting diode 150 may have a structure in which an anode 151, a plurality of organic layers 152 and a cathode 153 are sequentially disposed. That is, the organic light-emitting diode 150 may be composed of an anode 151 formed on a planarization layer 105, an organic layer 152 formed on the anode 151 and a cathode 153 formed on the organic layer 152.

[0085] The electroluminescent display device can be a top-emitting electroluminescent display device or a bottom-emitting electroluminescent display device. For a top-emitting electroluminescent display device, light emitted from the organic layer 152 can be reflected upwards from the anode 151, i.e., reflected towards the cathode 153 above it. For this purpose, a reflective layer made of an opaque conductive material with high reflectivity, such as silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), tungsten (W), or chromium (Cr), or an alloy thereof, can be further disposed below the anode 151. In contrast, for a bottom-emitting electroluminescent display device, the anode 151 can be made solely of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), or indium gallium zinc oxide (IGZO). Hereinafter, the electroluminescent display device of this disclosure will be assumed to be a bottom-emitting electroluminescent display device.

[0086] In addition to the emitter region, a dam 106 can be formed on the planarization layer 105. That is, the dam 106 has a dam hole through which the anode 151 corresponding to the emitter region is exposed. The dam 106 can be made of an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx) or an organic insulating material such as benzocyclobutene (BCB), acrylic resin or imide resin.

[0087] The embankment 106 can be extended to the non-display area NA.

[0088] The embankment 106 may have a thickness of about 1 μm, but is not limited to this.

[0089] The organic layer 152 can be disposed on the anode 151 exposed by the embankment 106. The organic layer 152 may include an emitter layer, an electron injection layer, an electron transport layer, a hole transport layer, a hole injection layer, etc.

[0090] The organic layer 152 can be extended into the non-display area NA.

[0091] The organic layer 152 can be disposed on the embankment 106 in the non-display area NA.

[0092] In the non-display area NA, the organic layer 152 can be configured to be spaced apart from the end (one end) of the embankment 106 by a predetermined distance.

[0093] The cathode 153 can be disposed on the organic layer 152.

[0094] For top-emitting electroluminescent display devices, the cathode 153 may comprise a transparent conductive material. For example, the cathode 153 may be made of indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), etc. For bottom-emitting electroluminescent display devices, the cathode 153 may comprise any one of the group consisting of metallic materials such as gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), palladium (Pd), and copper (Cu), or an alloy thereof. Alternatively, the cathode 153 may have a stacked structure comprising a layer made of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), or indium gallium zinc oxide (IGZO) and a layer made of metallic materials such as gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), palladium (Pd), and copper (Cu), or an alloy thereof. However, this disclosure is not limited thereto.

[0095] The cathode 153 can be extended to the non-display area NA.

[0096] In the non-display area NA, the cathode 153 can be configured to cover a portion of the organic layer 152. In this case, in the non-display area NA, the cathode 153 can be configured to be spaced apart from the end of the organic layer 152 by a predetermined distance. However, this disclosure is not limited thereto. Because the cathode 153 is configured to be spaced apart from the end of the organic layer 152 by a predetermined distance, the reliable bezel L is increased compared to the prior art. Therefore, the bezel width W can be reduced.

[0097] A cover layer 120 made of a material with high refractive index and light absorption can be disposed on the organic light-emitting diode 150 to reduce diffuse reflection of external light.

[0098] The covering layer 120 can be an organic layer made of organic material, and can be omitted if necessary.

[0099] The overlay layer 120 can be extended to the non-display area NA.

[0100] In the non-display area NA, the cover layer 120 can be disposed on the cathode 153. For example, the cover layer 120 and the cathode 153 can be disposed at a predetermined distance from the end of the organic layer 152. However, this disclosure is not limited thereto. Figure 3 An example is shown in which one end of the cathode 153 and one end of the cover layer 120 are matched (in other words, aligned) with each other. However, this disclosure is not limited thereto.

[0101] The adhesive layer 130 and the encapsulation substrate 140 can be disposed on the cover layer 120.

[0102] The adhesive layer 130 and the encapsulation substrate 140 may extend into the non-display area NA to cover a portion of the embankment 106 and the planarization layer 105. The adhesive layer 130 and the encapsulation substrate 140 may expose another portion of the planarization layer 105. However, this disclosure is not limited thereto.

[0103] The adhesive layer 130 can be configured to cover the cover layer 120 and the pixel portion 115. Together with the cover layer 120 and the encapsulation substrate 140, the adhesive layer 130 protects the organic light-emitting diode 150 of the pixel portion 115 from external moisture, oxygen, and impact. The adhesive layer 130 may also contain a getter. This getter may be hygroscopic particles capable of absorbing moisture and oxygen from the outside. Therefore, the penetration of moisture and oxygen into the pixel portion 115 can be minimized.

[0104] The encapsulation substrate 140 can be disposed on the adhesive layer 130. The encapsulation substrate 140 and the adhesive layer 130 can protect the organic light-emitting diode 150 of the pixel portion 115. The encapsulation substrate 140 can protect the organic light-emitting diode 150 from the effects of external moisture, oxygen and impact.

[0105] At the same time, as mentioned above, electroluminescent display devices require a minimum bezel distance, i.e., a reliable bezel L, to ensure reliability such as resistance to moisture penetration.

[0106] The reliable border L can be defined as the distance from the end of the package substrate 140 to the end of the cathode 153.

[0107] The area outside the display area AA in the non-display area NA, excluding the reliable border L, can be referred to as the shadow area. This shadow area can be defined by the gap between the mask and the substrate 101 during the deposition of the cathode 153 and the organic layer 152.

[0108] In a first exemplary embodiment of this disclosure, a groove 180 including an undercut structure UC is formed in the shaded area.

[0109] Figure 3 An example is shown in which each of the undercut structure UC and the groove 180 is formed in one column (or formed as one column). However, this disclosure is not limited thereto. Each of the undercut structure UC and the groove 180 may be formed in two or more columns (or formed as two or more columns). This disclosure is not limited to the number of columns of the undercut structure UC and the groove 180.

[0110] In this case, for example, the trench 180 can be formed by removing the masking layer 120, cathode 153, organic layer 152, embankment 106 and planarization layer 105 in the shadow area outside the display area AA.

[0111] Within the trench 180, an undercut structure UC can be provided, which consists of a embankment pattern 106′, an anode pattern 151′, and a first planarization layer pattern 105a′. The embankment pattern 106′, the anode pattern 151′, and the first planarization layer pattern 105a′ are made of the same material as the embankment 106, the anode 151, and the first planarization layer 105a.

[0112] When the anode 151 is formed on the pixel portion 115 of the display area AA, the anode pattern 151' can be simultaneously formed on the first planarization layer pattern 105a'. The anode pattern 151' can be used to enhance the adhesion between the embankment pattern 106' and the first planarization layer pattern 105a'. The embankment pattern 106' can be disposed on the anode pattern 151' to cover the anode pattern 151'. However, this disclosure is not limited thereto.

[0113] Organic layer pattern 152', cathode pattern 153' and cover layer pattern 120' can be set on the undercut structure UC. Organic layer pattern 152', cathode pattern 153' and cover layer pattern 120' are separated (disconnected) from organic layer 152, cathode 153 and cover layer 120 on the left and right sides (left and right sides) of trench 180, respectively.

[0114] The side surfaces of the embankment 106 and the planarization layer 105 can be exposed to the left and right side walls of the trench 180. The organic layer 152, the cathode 153, and the cover layer 120 can be configured to cover the exposed side surfaces of the embankment 106 and the planarization layer 105. Simultaneously, the cathode 153 can be configured to cover the side surface of the organic layer 152 within the trench 180.

[0115] Here, for the undercut structure UC, the porous first planarization layer pattern 105a′ can be etched and recessed inward from the end of the dam pattern 106′ to form an eaves structure, i.e., the undercut. Therefore, the organic layer pattern 152′, cathode pattern 153′, and cover layer pattern 120′ on the undercut structure UC can be separated (disconnected) from the organic layer 152, cathode 153, and cover layer 120 on the left and right sides of the trench 180, respectively.

[0116] The interior of the trench 180, excluding the undercut structure UC, may be filled with an adhesive layer 130. However, this disclosure is not limited thereto. The interior of the trench 180 may be filled with any material that can inhibit moisture penetration. For example, an inorganic layer made of an inorganic insulating material may be further disposed on a cover layer 120 in the region including the interior of the trench 180. The inorganic layer may be made of silicon oxide (SiOx) or silicon nitride (SiNx), or may be formed in multiple layers thereof. In this case, the moisture penetration delay effect can be increased, and thereby the reliable border can be further increased.

[0117] As described above, according to the first exemplary embodiment of this disclosure, the groove 180 including the undercut structure UC is formed in an unnecessarily shaded area. Therefore, moisture penetration through the side surface can be suppressed. Thus, the border width W can be reduced by transforming the shaded area into a reliable border L. This will be described in detail with reference to comparative embodiments.

[0118] Figure 4 This is a cross-sectional view showing a portion of an electroluminescent display device according to a comparative embodiment.

[0119] Except that, due to the absence of undercut structures and trenches, the cathode 153 is formed to completely cover the organic layer 152, according to Figure 4 The electroluminescent display device of the comparative embodiment shown is different from that according to... Figure 3 The electroluminescent display device shown in the first exemplary embodiment of this disclosure is substantially the same.

[0120] refer to Figure 4 The electroluminescent display device according to the comparative embodiment does not include the undercut structure and trenches of the first exemplary embodiment of the present disclosure. Therefore, in the electroluminescent display device according to the comparative embodiment, unlike the electroluminescent display device according to the first exemplary embodiment of the present disclosure, the cathode 153 needs to be formed to completely cover the organic layer 152. Therefore, it can be seen that a reliable border L′ cannot be sufficiently ensured. As a result, it can be seen that, compared with the device according to… Figure 3 Compared to the electroluminescent display device of the first exemplary embodiment of this disclosure, the bezel width W′ may be increased.

[0121] Figures 5A to 5E It is shown in sequence. Figure 3 A cross-sectional view of a portion of the manufacturing process of the electroluminescent display device shown.

[0122] Figures 6A to 6G To show in more detail Figure 3 A cross-sectional view of a portion of the manufacturing process of the non-display area in the electroluminescent display device shown.

[0123] As an example, the manufacturing process of a portion of the non-display area NA is... Figures 5A to 5E The left side is shown in the image. Additionally, as an example, the manufacturing process of a portion of the display area AA is shown in... Figures 5A to 5E It is shown on the right side.

[0124] exist Figures 6A to 6G For ease of description, the illustration of the substrate 101 below the buffer layer 102 is omitted.

[0125] Reference Figure 5A and Figure 6A Various components of the pixel portion are formed on the substrate 101.

[0126] As described above, the pixel portion is formed on the display area of ​​the substrate 101 and may include various components beneath the organic layer.

[0127] That is, for example, a buffer layer 102 can be formed on a substrate 101.

[0128] Buffer layer 102 is a functional layer configured to protect various electrodes and circuits from impurities such as alkali ions flowing from substrate 101 or its underlying layers. Buffer layer 102 may have a multilayer structure including a first buffer layer and a second buffer layer, but is not limited thereto. Buffer layer 102 may be made of silicon oxide (SiOx) or silicon nitride (SiNx), or may be formed in multiple layers thereof.

[0129] The light-shielding layer 116 can be disposed between the substrate 101 and the buffer layer 102.

[0130] The light-shielding layer 116 can be disposed on the substrate 101 at the location where the active layer 111 is formed. The light-shielding layer 116 can also be formed below the second storage electrode 117, but is not limited thereto. The light-shielding layer 116 disposed below the second storage electrode 117 can also be referred to as the first storage electrode.

[0131] The buffer layer 102 can be disposed on the entire surface of the substrate 101 on which the light-shielding layer 116 has been formed. That is, the buffer layer 102 can be formed to extend into the non-display area.

[0132] The drive element 110 can be formed on the buffer layer 102.

[0133] The active layer 111 can be formed on the buffer layer 102. The active layer 111 can be made of polycrystalline silicon (p-Si), and in this case, predetermined regions can be doped with impurities. Alternatively, the active layer 111 can be made of amorphous silicon (a-Si), or it can be made of various organic semiconductor materials such as pentacene. The active layer 111 can also be made of oxide.

[0134] Furthermore, the second storage electrode 117 may be formed on the buffer layer 102, but is not limited thereto.

[0135] Interlayer insulation layer 103 can be formed on active layer 111.

[0136] The interlayer insulation layer 103 can be made of insulating inorganic materials such as silicon oxide (SiOx) or silicon nitride (SiNx), or it can be made of insulating organic materials.

[0137] The gate electrode 113 can be formed on the interlayer insulating layer 103. Furthermore, the source electrode 114 and the drain electrode 112 can be formed on the interlayer insulating layer 103. However, this disclosure is not limited thereto. After the gate electrode 113 is formed, the source electrode 114 and the drain electrode 112 can also be formed on a layer different from the interlayer insulating layer 103.

[0138] The gate electrode 113, source electrode 114, and drain electrode 112 can be formed as a single layer or multiple layers. The gate electrode 113, source electrode 114, and drain electrode 112 can be made of various conductive materials or alloys thereof, such as magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), and gold (Au).

[0139] A passivation layer made of inorganic insulating material can be further formed to cover the gate electrode 113, the source electrode 114, and the drain electrode 112.

[0140] The first planarization layer 105a can be disposed on the drive element 110 configured as described above.

[0141] The first planarization layer 105a can be extended to the non-display area.

[0142] Meanwhile, for bottom-emitting electroluminescent display devices, a predetermined color filter layer can be formed on the first planarization layer 105a in the display area. However, this disclosure is not limited thereto.

[0143] Then, an insulating layer 105b″ can be formed on the first planarization layer 105a.

[0144] The insulating layer 105b″ may include, but is not limited to, an outer coating.

[0145] The insulating layer 105b″ may have a first thickness.

[0146] Meanwhile, the upper part of the drain electrode 112 and the upper part of the second storage electrode 117 can be removed from the insulating layer 105b″ in the display area.

[0147] Furthermore, for the insulating layer 105b″ in the non-display area, a portion of the shaded area can be removed to form a trench 180. In this case, an insulating layer pattern 105b′ formed by the insulating layer can be formed within the trench 180.

[0148] The insulating layer 105b″ in the non-display area can be formed to be spaced apart from the end of the substrate 101 by a predetermined distance, but is not limited thereto.

[0149] The insulating layer pattern 105b′ can have a second thickness that is less than the first thickness.

[0150] The insulating layer 105b″ and the insulating layer pattern 105b′ can be formed using the same masking process. For example, the insulating layer 105b″ and the insulating layer pattern 105b′ can be formed by coating an organic insulating material onto the substrate 101 and then performing a single-mask process using a halftone mask. However, this disclosure is not limited thereto. For example, the insulating layer 105b″ can be formed using the full tone of a halftone mask, and the insulating layer pattern 105b′ can be formed using the halftone of a halftone mask. However, this disclosure is not limited thereto.

[0151] Then, refer to Figure 5B and Figure 6B A first contact hole 140a can be formed by selectively removing the first planarization layer 105a using the insulating layer 105b″ and the insulating layer pattern 105b′ as a mask, through which a portion of the drain electrode 112 is exposed in the display area. The first planarization layer 105a is disposed below the insulating layer 105b″ and the insulating layer pattern 105b′. Furthermore, a second contact hole 140b can be formed within the trench 180, through which the buffer layers 102 on the left and right sides of the insulating layer pattern 105b′ are exposed.

[0152] In this case, the first planarization layer pre-pattern 105a″ formed by the first planarization layer 105a can be formed below the insulating layer pattern 105b′.

[0153] The first planarization layer 105a can be removed using wet etching. However, this disclosure is not limited thereto.

[0154] Then, refer to Figure 5C and Figure 6C The insulating layer pattern 105b′ is removed by ashing a portion of the insulating layer 105b″ and a portion of the insulating layer pattern 105b′ along the thickness direction.

[0155] Simultaneously, a portion of the insulating layer 105b″ can be removed along the thickness direction. Therefore, a second planarization layer 105b having a third thickness less than the first thickness can be formed.

[0156] Then, refer to Figure 5D , Figure 6D and Figure 6E The anode 151 can be formed on the second planarization layer 105b in the display area using a predetermined conductive material. In addition, the anode pattern 151′ can be formed on the first planarization layer pre-pattern 105a″ within the trench 180.

[0157] For example, the anode 151 and the anode pattern 151′ can be formed by depositing conductive materials, masking processes, wet etching, and stripping processes, but are not limited thereto.

[0158] As described above, the electroluminescent display device can be a top-emitting electroluminescent display device or a bottom-emitting electroluminescent display device. For a top-emitting electroluminescent display device, a reflective layer made of an opaque conductive material with high reflectivity, such as silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), tungsten (W), chromium (Cr), or an alloy thereof, can be further disposed below the anode 151 and the anode pattern 151'.

[0159] Meanwhile, for bottom-emitting electroluminescent display devices, the anode 151 and the anode pattern 151' can be made solely of transparent conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), and indium gallium zinc oxide (IGZO).

[0160] The anode pattern 151′ can be patterned to have a width smaller than that of the first planarization layer prepattern 105a″.

[0161] Then, a dam 106 can be formed on the second planarization layer 105b, excluding the emitting region, by coating with a predetermined insulating material. That is, the dam 106 may have a dam hole through which the anode 151 corresponding to the emitting region is exposed. The dam 106 may be made of an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx) or an organic insulating material such as benzocyclobutene (BCB), acrylic resin, or imide resin.

[0162] The embankment 106 can be extended to the non-display area NA.

[0163] Furthermore, the embankment pattern 106′ made of insulating material used to form the embankment 106 can be formed on the first planarization layer pre-pattern 105a″ and the anode pattern 151′.

[0164] The anode pattern 151' can be used to enhance the adhesion between the first planarization layer pre-pattern 105a″ and the embankment pattern 106'. The embankment pattern 106' can be formed on the anode pattern 151' to cover the anode pattern 151'. However, this disclosure is not limited thereto.

[0165] Afterwards, refer to Figure 5E , Figure 6F and Figure 6G A photosensitive film pattern PR can be formed on the embankment 106 to cover the embankment 106 in order to form an undercut structure. For example, the photosensitive film pattern PR can be formed to cover not only the upper surface and side surface of the embankment 106, but also the side surfaces of the first planarization layer 105a and the second planarization layer 105b below the embankment 106.

[0166] Meanwhile, since the photosensitive film pattern PR is not formed on the upper and side surfaces of the embankment pattern 106′, the embankment pattern 106′ can be exposed. In this case, the side surface of the first planarization layer pre-pattern 105a″ below the embankment pattern 106′ can also be exposed.

[0167] Then, the photosensitive film pattern PR can be used as a mask to wet etch the first planarization layer pre-pattern 105a″ below the embankment pattern 106′ to form an undercut structure UC within the trench 180.

[0168] That is, the porous first planarization layer pre-pattern 105a″ is etched to form a first planarization layer pattern 105a′ with a smaller width. In this case, the first planarization layer pattern 105a′ can be recessed inward from the end of the embankment pattern 106′ to form an eaves structure, i.e., an undercut structure UC.

[0169] Within the trench 180, an undercut structure UC consisting of a dam pattern 106′, an anode pattern 151′, and a first planarization layer pattern 105a′ can be formed. The dam pattern 106′, the anode pattern 151′, and the first planarization layer pattern 105a′ are made of the same material as the dam 106, the anode 151, and the first planarization layer 105a.

[0170] Afterwards, the photosensitive film pattern (PR) can be removed by peeling.

[0171] Then, although not shown in the figure, an organic layer, a cathode, and a masking layer can be sequentially formed on the substrate 101 on which the undercut structure UC has already been formed.

[0172] The organic layer may include an emitter layer, an electron injection layer, an electron transport layer, a hole transport layer, a hole injection layer, etc. However, this disclosure is not limited thereto.

[0173] The organic layer can be extended into the non-display area.

[0174] An organic layer can be formed on the embankment 106 in the non-display area.

[0175] The cathode can be formed on an organic layer.

[0176] The cathode can be extended into the non-display area.

[0177] In the non-display area, the cathode can be configured to cover a portion of the organic layer. That is, in the non-display area, the cathode can be configured to be spaced apart from the end of the organic layer by a predetermined distance. However, this disclosure is not limited to this. Because the cathode is configured to be spaced apart from the end of the organic layer by a predetermined distance, the reliable bezel is increased compared to the prior art. Therefore, the bezel width can be reduced.

[0178] A shielding layer made of a material with high refractive index and light absorption can be formed on the cathode to reduce diffuse reflection of external light.

[0179] The covering layer can be an organic layer made of organic materials, and it can be omitted if needed.

[0180] The overlay can be extended into non-display areas.

[0181] Meanwhile, an organic layer pattern, a cathode pattern, and a cover layer pattern can be sequentially formed on the undercut structure UC. The organic layer pattern, cathode pattern, and cover layer pattern are made of the same material as the organic layer, cathode, and cover layer, respectively.

[0182] In this case, the organic layer pattern, cathode pattern, and capping layer pattern on the undercut structure can be separated (disconnected) from the organic layer, cathode, and capping layer on the left and right sides of the trench 180, respectively.

[0183] When the undercut structure UC is applied, the second planarization layer 105b, the embankment 106, and the organic layer can be separated (disconnected) between the non-display area and the display area through the undercut structure UC. Therefore, it is possible to suppress moisture penetration through the side surface.

[0184] Furthermore, the cathode can be recessed toward the display area, thus further ensuring a reliable bezel.

[0185] Then, an adhesive layer and an encapsulation substrate can be sequentially formed on the substrate 101 on which the cover layer has already been formed.

[0186] The adhesive layer, together with the masking layer and the encapsulation substrate, protects the organic light-emitting diodes (OLEDs) in the pixel portion from external moisture, oxygen, and shock. The adhesive layer may also contain a getter.

[0187] The interior of the trench 180, excluding the undercut structure UC, may be filled with an adhesive layer. However, this disclosure is not limited thereto. The interior of the trench 180 may be filled with any material that can inhibit moisture penetration. For example, an inorganic layer made of an inorganic insulating material may be further provided on the covering layer in the region including the interior of the trench 180. The inorganic layer may be made of silicon oxide (SiOx) or silicon nitride (SiNx), or may be formed in multiple layers thereof. In this case, the moisture penetration delay effect can be enhanced, and thereby the reliable border can be further increased. This will be described in detail with reference to a second exemplary embodiment of this disclosure.

[0188] Figure 7 This is a cross-sectional view showing an electroluminescent display device according to a second exemplary embodiment of the present disclosure.

[0189] In addition to forming an inorganic layer 207 made of inorganic insulating material on the covering layer 120, Figure 7 The second exemplary embodiment of this disclosure shown is related to Figure 3 The electroluminescent display device shown according to the first exemplary embodiment of this disclosure is substantially the same. Therefore, redundant descriptions thereof will be omitted. Identical components will be indicated by the same reference numerals.

[0190] Reference Figure 7 In the electroluminescent display device according to the second exemplary embodiment of the present disclosure, the trench 280 including the undercut structure UC is formed in the shadow area within the non-display area NA in the same manner as in the first exemplary embodiment of the present disclosure. Therefore, moisture penetration through the side surface can be suppressed. Furthermore, the end of the cathode 153 can be recessed toward the display area AA, and an inorganic layer 207 made of inorganic insulating material is further formed within the trench 280. Therefore, the reliable bezel L″ can be increased, and thus, the bezel width can be reduced.

[0191] In a second exemplary embodiment of this disclosure, the undercut structure UC and the groove 280 can be formed on three sides of the non-display area NA, excluding the lower side of the display panel connected to the flexible film (i.e., the data pad area). However, this disclosure is not limited thereto. Furthermore, on the upper side of the non-display area NA, one of the three sides, the undercut structure UC and the groove 280 are formed as a single unit. Simultaneously, on the left and right sides of the non-display area NA, the undercut structure UC and the groove 280 can be divided into multiple undercut structures and grooves. However, this disclosure is not limited thereto.

[0192] For example, the trench 280 including the undercut structure UC can be formed by patterning the embankment 106 and the planarization layer 105 in the shadow area outside the display area AA via a photolithography process.

[0193] In a second exemplary embodiment of this disclosure, an inorganic layer 207 made of an inorganic insulating material is further disposed on a cover layer 120 in a region including the interior of the trench 280. In this case, the moisture penetration delay effect can be enhanced by the inorganic layer 207. Therefore, the reliable border L″ can be increased compared to the first exemplary embodiment of this disclosure. That is, in the first exemplary embodiment of this disclosure, the reliable border L is defined as extending from the end of the encapsulation substrate 140 to the end of the cathode 153, but in the second exemplary embodiment of this disclosure, the reliable border L″ can be defined as extending from the end of the encapsulation substrate 140 to the side surface of the inorganic layer 207 filled in the trench 280, and the reliable border L″ can be further increased due to the inorganic layer 207. The inorganic layer 207, made of an inorganic insulating material capable of delaying moisture penetration, is formed in the trench 280.

[0194] The inorganic layer 207 can be made of silicon oxide (SiOx) or silicon nitride (SiNx), or it can be formed in multiple layers.

[0195] Figure 7 An example is shown in which an inorganic layer 207 is disposed on a cover layer 120 in a display area AA and on a cover layer 120 in a non-display area NA including the interior of a groove 280. However, this disclosure is not limited thereto. The inorganic layer 207 according to a second exemplary embodiment of this disclosure may be disposed on the display area AA and the cover layer 120 in the non-display area NA including the interior of a groove 280. Furthermore, the inorganic layer 207 according to a second exemplary embodiment of this disclosure may be extended to cover the upper surface of the cover layer 120 in the display area AA and the non-display area NA including the interior of a groove 280, and the side surface of the embankment 106 in the non-display area NA.

[0196] Meanwhile, in the first and second exemplary embodiments of this disclosure, an example is described in which the gate line passes through the left and right sides of the non-display area, one of the three sides of the non-display area, and thus, the undercut structure and trench are divided into a plurality of undercut structures and trenches by the gate line. However, this disclosure is not limited thereto. According to this disclosure, if the gate line has a bypass structure, the undercut structure and trench can be formed as a single unit (i.e., integral with each other) on the three sides of the non-display area other than the lower side. This will be described in detail with reference to the third exemplary embodiment of this disclosure.

[0197] Figure 8 This is a plan view illustrating an electroluminescent display device according to a third exemplary embodiment of the present disclosure.

[0198] Figure 9A and Figure 9B It is along Figure 8 A cross-sectional view taken from line VIII-VIII′.

[0199] Except that gate lines 309a and 309b have bypass structures and the undercut structure UC and trench 380 are formed as a single unit (i.e., integrated with each other) on the three sides of the non-display area NA excluding the bottom side, Figure 8 , Figure 9A and Figure 9B The third exemplary embodiment of this disclosure shown is in conjunction with Figures 1 to 3 The electroluminescent display device shown according to the first exemplary embodiment of this disclosure is substantially the same. Therefore, redundant descriptions thereof will be omitted. Identical components will be indicated by the same reference numerals.

[0200] also, Figure 9AA cross-sectional view of a portion of the non-display area NA, through which gate lines 309a and 309b do not pass, is shown as an example. Figure 9B A cross-sectional view of a portion of the non-display area NA through which gate lines 309a and 309b pass is shown as an example.

[0201] Reference Figure 8 , Figure 9A and Figure 9B An electroluminescent display device according to a third exemplary embodiment of the present disclosure may include a display panel 100, a flexible film 160, and a printed circuit board 170.

[0202] In the third exemplary embodiment of this disclosure, the trench 380 of the undercut structure UC, comprising the embankment pattern 351', the anode pattern 306', and the first planarization layer pattern 305a', is formed in the shadow area within the non-display area NA in the same manner as in the first and second exemplary embodiments. Therefore, moisture penetration through the side surfaces can be suppressed. Furthermore, since moisture penetration through the side surfaces can be suppressed, the end of the cathode 153 can be recessed toward the display area AA. Therefore, the reliable bezel can be increased, and thereby the bezel width can be reduced.

[0203] Furthermore, in the third exemplary embodiment of this disclosure, gate lines 309a and 309b have bypass structures. Therefore, the undercut structure UC and the trench 380 are formed as a single unit (i.e., integrated with each other) on the three sides of the non-display area NA, excluding the underside of the display panel 100. This allows for more effective blocking of lateral moisture penetration paths, thereby improving reliability.

[0204] Specifically, refer to Figure 9B A connection line 308 is provided below the buffer layer 102, and the left gate line 309a and the right gate line 309b, which are divided by the trench 380, can be electrically connected to each other through the connection line 308.

[0205] Simultaneously, the side surfaces of the embankment 106 and the first planarization layer 105a and the second planarization layer 105b can be exposed to the left and right side walls of the trench 380. The organic layer 152, the cathode 153, and the cover layer 120 can be configured to cover the exposed side surfaces of the embankment 106 and the first planarization layer 105a and the second planarization layer 105b. The cathode 153 can be configured to cover the side surface of the organic layer 152 within the trench 380.

[0206] Figure 8 An example is shown in which each of the undercut structure UC and the groove 380 is formed in a single column. However, this disclosure is not limited thereto. Each of the undercut structure UC and the groove 380 may be formed in two or more columns. This disclosure is not limited to the number of columns of the undercut structure UC and the groove 380.

[0207] Figures 10A to 10D This is a cross-sectional view showing a portion of the manufacturing process of an electroluminescent display device according to a third exemplary embodiment of the present disclosure.

[0208] Figures 11A to 11D These are additional cross-sectional views showing a portion of the manufacturing process of an electroluminescent display device according to a third exemplary embodiment of the present disclosure.

[0209] Figures 10A to 10D A portion of the manufacturing process of a display panel, including the areas through which gate lines 309a and 309b do not pass, is shown in sequence. Figures 11A to 11D A portion of the manufacturing process of the display panel, including the area through which gate lines 309a and 309b pass, is shown in sequence.

[0210] Figures 10A to 10D and Figures 11A to 11D The left side of the image shows the manufacturing process of a portion of the non-display area NA. Furthermore, Figures 10A to 10D and Figures 11A to 11D The right side shows the manufacturing process of a portion of the display area AA.

[0211] Reference Figure 10A and Figure 11A The light-shielding layer 116 can be formed on the substrate 101.

[0212] The light-shielding layer 116 can be formed below the active layer on the substrate 101 in the display area AA. The light-shielding layer 116 can also be formed below the second storage electrode on the substrate 101 in the display area AA, but is not limited thereto. The light-shielding layer 116 disposed below the second storage electrode can also be referred to as the first storage electrode.

[0213] In addition, the connecting line 308 can be formed below a trench on the substrate in the non-display area NA.

[0214] The light-shielding layer 116 and the connecting line 308 can be made of opaque conductive material using the same masking process.

[0215] The buffer layer 102 can be formed on the substrate 101 on which the light-shielding layer 116 and the connecting line 308 have already been formed.

[0216] Buffer layer 102 is a functional layer configured to protect various electrodes and circuits from impurities such as alkali ions flowing from substrate 101 or its underlying layers. Buffer layer 102 may have a multilayer structure including a first buffer layer and a second buffer layer, but is not limited thereto. Buffer layer 102 may be made of silicon oxide (SiOx) or silicon nitride (SiNx), or may be formed as multiple layers thereof.

[0217] The buffer layer 102 can be extended to the non-display area NA.

[0218] Then, refer to Figure 10B and Figure 11B The active layer 111 can be formed on the buffer layer 102. The active layer 111 can be made of polycrystalline silicon (p-Si), in which case the predetermined region can be doped with impurities. Alternatively, the active layer 111 can be made of amorphous silicon (a-Si), or it can be made of various organic semiconductor materials such as pentacene. The active layer 111 can also be made of oxide.

[0219] Furthermore, the second storage electrode 117 may be formed on the buffer layer 102, but is not limited thereto.

[0220] Then, refer to Figure 10C and Figure 11C An insulating layer 103' can be formed on a substrate 101 on which an active layer 111 has already been formed.

[0221] The insulating layer 103′ can be made of insulating inorganic materials such as silicon oxide (SiOx) or silicon nitride (SiNx) to form an interlayer insulating layer, or it can be made of insulating organic materials.

[0222] Then, a pair (or pairs) of third contact holes 140c can be formed by selectively removing a portion of the insulating layer 103′, through which the source and drain regions of the active layer 111 are exposed.

[0223] In addition, a pair (or pairs) of fourth contact holes 140d can be formed by selectively removing some portions of the insulating layer 103′ and the buffer layer 102, through which a portion of the connecting wire 308 is exposed.

[0224] The pair of fourth contact holes 140d can expose some portions of the left and right sides of the connecting line 308.

[0225] In addition, a fifth contact hole 140e can be formed by selectively removing some portions of the insulating layer 103' and the buffer layer 102, through which a portion of the light-shielding layer 116 is exposed.

[0226] Subsequently, refer to Figure 10D and Figure 11D A gate electrode 113 can be formed on the active layer 111, with an interlayer insulating layer 103 inserted therebetween. In addition, a source electrode 114 and a drain electrode 112, which are electrically connected to the source region and drain region of the active layer 111 respectively through a third contact hole 140c, can be formed on the interlayer insulating layer 103.

[0227] However, this disclosure is not limited thereto. After the gate electrode 113 is formed, the source electrode 114 and the drain electrode 112 may also be formed on a layer other than the interlayer insulating layer 103.

[0228] Then, by selectively removing the insulating layer 103′, the interlayer insulating layer 103 can be formed below the gate electrode 113, the source electrode 114, and the drain electrode 112.

[0229] In this configuration, the drain electrode 112 can be electrically connected to the light-shielding layer 116 below it via the fifth contact hole 140e. However, this disclosure is not limited thereto.

[0230] Furthermore, gate lines 309a and 309b, electrically connected to connection line 308 via fourth contact hole 140d, can be formed on substrate 101 in non-display area NA. Due to the bypass structure of gate lines 309a and 309b, gate line 309b in display area AA can be connected to gate line 309a in non-display area NA without exposing gate lines 309a and 309b through trenches.

[0231] Each of the gate electrode 113, gate lines 309a and 309b, source electrode 114, and drain electrode 112 can be formed as a single-layer or multi-layer structure. Each of the gate electrode 113, gate lines 309a and 309b, source electrode 114, and drain electrode 112 can be made of various conductive materials or alloys thereof, such as magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), and gold (Au).

[0232] Subsequent processes and Figures 5A to 5E and Figures 6A to 6G The manufacturing process shown according to the first exemplary embodiment is substantially the same. Therefore, redundant descriptions thereof will be omitted.

[0233] Furthermore, the undercut structure and trenches of this disclosure can extend toward the data pad area and can be formed in two or more columns rather than in one column. This will be described in detail with reference to the fourth and fifth exemplary embodiments of this disclosure.

[0234] Figure 12 This is a plan view illustrating an electroluminescent display device according to a fourth exemplary embodiment of the present disclosure.

[0235] In addition to the undercut structure UC and trench 480 being extended toward the data pad area, Figure 12 The fourth exemplary embodiment of this disclosure shown is in conjunction with Figure 8 The electroluminescent display device shown according to the third exemplary embodiment of this disclosure is substantially the same. Therefore, redundant descriptions thereof will be omitted. Identical components will be indicated by the same reference numerals.

[0236] Reference Figure 12 An electroluminescent display device according to a fourth exemplary embodiment of the present disclosure may include a display panel 100, a flexible film 160, and a printed circuit board 170.

[0237] In the fourth exemplary embodiment of this disclosure, the groove 480 including the undercut structure UC is formed in the shadow area within the non-display area NA in the same manner as in the first to third exemplary embodiments. Therefore, moisture penetration through the side surface can be suppressed. Furthermore, since moisture penetration through the side surface can be suppressed, the end of the cathode can be recessed toward the display area AA. Therefore, a reliable bezel can be increased, and thereby the bezel width can be reduced.

[0238] Furthermore, in the fourth exemplary embodiment of this disclosure, the gate line has a bypass structure in the same manner as in the third exemplary embodiment. Therefore, the undercut structure UC and the trench 480 are formed as a single unit (i.e., integrated with each other) on the three sides of the non-display area NA, excluding the underside of the display panel 100. This allows for more effective blocking of lateral moisture penetration paths, thereby improving reliability.

[0239] Meanwhile, the undercut structure UC and the trench 480 according to the fourth exemplary embodiment of this disclosure are extended toward the data pad area by a predetermined length. That is, the undercut structure UC and the trench 480, which are formed as a single unit (i.e., integrated with each other), can be extended toward the flexible membrane 160 in the data pad area by a predetermined length. Therefore, it is possible to more effectively block the lateral moisture penetration path at the corner area.

[0240] In this configuration, the trench 480 may include a first trench 480a disposed on the upper side of the non-display area NA, one of the four sides of the non-display area NA. Furthermore, the trench 480 may include a second trench 480b disposed on the left and right sides of the non-display area NA, and a third trench 480c disposed on the lower side of the non-display area NA. The undercut structure UC has a similar structure.

[0241] The first groove 480a, the second groove 480b and the third groove 480c can be formed as a single unit (i.e., become one with each other).

[0242] Figure 12 An example is shown where each of the undercut structure UC and the groove 480 is formed in one column. However, this disclosure is not limited thereto. Each of the undercut structure UC and the groove 480 may be formed in two or more columns. This disclosure is not limited to the number of columns of the undercut structure UC and the groove 480.

[0243] Figure 13This is a plan view illustrating an electroluminescent display device according to a fifth exemplary embodiment of the present disclosure.

[0244] Except that the undercut structure UC and the groove 580 are not formed in one row, but in two or more rows. Figure 13 The fifth exemplary embodiment of this disclosure shown is in conjunction with Figure 8 The electroluminescent display device shown according to the third exemplary embodiment of this disclosure is substantially the same. Therefore, redundant descriptions thereof will be omitted. Identical components will be indicated by the same reference numerals.

[0245] Reference Figure 13 An electroluminescent display device according to a fifth exemplary embodiment of the present disclosure may include a display panel 100, a flexible film 160, and a printed circuit board 170.

[0246] In the fifth exemplary embodiment of this disclosure, the groove 580 including the undercut structure UC is formed in the shadow area within the non-display area NA in the same manner as in the first to fourth exemplary embodiments. Therefore, moisture penetration through the side surface can be suppressed. Furthermore, since moisture penetration through the side surface can be suppressed, the end of the cathode can be recessed toward the display area AA. Therefore, the reliable bezel L′″ can be increased, and thereby the bezel width can be reduced.

[0247] Furthermore, in the fifth exemplary embodiment of this disclosure, the gate line has a bypass structure in the same manner as in the third and fourth exemplary embodiments. Therefore, the undercut structure UC and the trench 580 are formed as a single unit (i.e., integrated with each other) on the three sides of the non-display area NA, excluding the underside of the display panel 100. This allows for more effective blocking of lateral moisture penetration paths, thereby improving reliability.

[0248] Furthermore, each of the undercut structure UC and the groove 580 according to the fifth exemplary embodiment of this disclosure may be formed in two or more columns. This disclosure is not limited to the number of columns of the undercut structure UC and the groove 580.

[0249] The groove 580 may include a first groove 580a positioned relatively on the inner side and a second groove 580b positioned relatively on the outer side. The undercut structure UC has a similar structure.

[0250] Specifically, in the fifth exemplary embodiment of this disclosure, the undercut structure UC and the trench 580 are formed in two or more columns. Therefore, a reliable border L′″ extends from the end of the upper substrate (packaging substrate) to the first trench 580a positioned relatively inward. This allows for more effective blocking of lateral moisture penetration paths, thereby improving reliability.

[0251] Exemplary embodiments of the present invention can also be described as follows: According to one aspect of this disclosure, an electroluminescent display device is provided. The electroluminescent display device includes: a display panel divided into a display area and a non-display area; a planarization layer and a dam extending into the non-display area of ​​the display panel; an organic layer and a cathode disposed on the dam and extending into the non-display area of ​​the display panel; a trench disposed in the non-display area outside the display area, wherein the cathode, the organic layer, the dam, and the planarization layer are removed from the trench; an undercut structure disposed within the trench, the undercut structure primarily comprising the dam and the planarization layer, such that the planarization layer is recessed inward from an end of the dam to create an undercut; and an adhesive layer and an encapsulation substrate disposed on the cathode.

[0252] The undercut structure and grooves can be set on the three sides of the non-display area, excluding the side of the display panel that is connected to the flexible film.

[0253] The undercut structure may include a embankment pattern, an anode pattern, and a planarization layer pattern made of the same material as the embankment, the anode formed on the planarization layer, and the planarization layer, respectively, within the trench.

[0254] A levee pattern can be set on the anode pattern to cover the anode pattern.

[0255] The organic layer can extend into the non-display area and can be set on the embankment in the non-display area.

[0256] The organic layer can be spaced apart from the end of the dike in the non-display area by a predetermined distance.

[0257] The cathode can extend into the non-display area and can cover a portion of the organic layer in the non-display area.

[0258] The cathode can be spaced apart from the end of the organic layer in the non-display area by a predetermined distance.

[0259] Each of the undercut structures and grooves can be formed in a row.

[0260] Each of the undercut structures and grooves can be formed in two or more columns.

[0261] The electroluminescent display device may further include a cover layer disposed on the cathode, wherein an organic layer pattern, a cathode pattern, and a cover layer pattern may be disposed on the undercut structure, wherein the organic layer pattern, the cathode pattern, and the cover layer pattern are separated (disconnected) from the organic layer, cathode, and cover layer disposed on the left and right sides of the trench, respectively.

[0262] The side surfaces of the embankment and the leveling layer can be exposed to the left and right walls of the trench, and the organic layer, cathode, and cover layer can cover the exposed side surfaces of the embankment and the leveling layer.

[0263] The cathode can be positioned on the left and right walls of the trench to cover the side surfaces of the organic layer.

[0264] The interior of the trench, excluding the undercut structure, may be filled with the adhesive layer (by the adhesive layer).

[0265] The electroluminescent display device may also include a cover layer and an inorganic layer, the cover layer being disposed on the cathode, and the inorganic layer being made of an inorganic insulating material and disposed on the cover layer in a region including the interior of the trench.

[0266] The undercut structure and grooves can extend toward the flexible film located on one side of the display panel.

[0267] The electroluminescent display device may further include connecting lines disposed on a substrate in a non-display area, a buffer layer disposed on a substrate on which the connecting lines can be disposed, and gate lines disposed on the buffer layer, wherein the gate lines can be electrically connected to the connecting lines.

[0268] The connecting wire can pass under the trench.

[0269] Although exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto and may be implemented in many different forms without departing from the technical concept of the present disclosure. Therefore, exemplary embodiments of the present disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are illustrative in all respects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the appended claims, and all technical concepts within the equivalent scope thereof should be understood to fall within the scope of the present disclosure.

Claims

1. An electroluminescent display device, comprising: A display panel, wherein the display panel is divided into a display area and a non-display area; A planarization layer and a levee extending into the non-display area of ​​the display panel; An organic layer and a cathode are disposed above the embankment, the organic layer and the cathode extending into the non-display area of ​​the display panel; A trench is provided in the non-display area outside the display area, and the organic layer, the embankment, and the planarization layer are removed from the trench; as well as An adhesive layer and a packaging substrate are disposed above the cathode.

2. The electroluminescent display device according to claim 1, wherein, The electroluminescent display device further includes: An undercut structure disposed within the trench, the undercut structure comprising the embankment and the planarization layer, wherein the planarization layer is recessed inward from the end of the embankment to define the undercut.

3. The electroluminescent display device according to claim 2, wherein, The undercut structure and the groove are arranged along multiple sides of the non-display area, excluding the side of the display panel that is connected to the flexible film.

4. The electroluminescent display device according to claim 2, wherein, The undercut structure includes a embankment pattern, an anode pattern, and a planarization layer pattern made of the same material as the embankment, the anode, and the planarization layer, respectively, within the trench.

5. The electroluminescent display device according to claim 4, wherein, The embankment pattern is set on the anode pattern to cover the anode pattern.

6. The electroluminescent display device according to claim 1, wherein, The organic layer extends into the non-display area and is disposed on the embankment in the non-display area.

7. The electroluminescent display device according to claim 6, wherein, The organic layer is spaced apart from the end of the embankment in the non-display area by a predetermined distance.

8. The electroluminescent display device according to claim 1, wherein, The cathode extends into the non-display area and covers a portion of the organic layer in the non-display area.

9. The electroluminescent display device according to claim 8, wherein, The cathode is spaced apart from the end of the organic layer in the non-display area by a predetermined distance.

10. The electroluminescent display device according to claim 2, wherein, Each of the undercut structures and the grooves is formed in a row.

11. The electroluminescent display device according to claim 2, wherein, Each of the undercut structures and the grooves is formed in two or more columns.

12. The electroluminescent display device according to claim 2, wherein, The electroluminescent display device further includes: A shielding layer disposed on the cathode The organic layer pattern, cathode pattern, and masking layer pattern, which are separate from the organic layer, the cathode, and the masking layer, are respectively disposed on the undercut structure on both sides of the trench.

13. The electroluminescent display device according to claim 12, wherein, The side surfaces of the embankment and the planarization layer are exposed to the left and right walls of the trench, and the organic layer, the cathode, and the shielding layer cover the exposed side surfaces of the embankment and the planarization layer.

14. The electroluminescent display device according to claim 13, wherein, The cathode is disposed on the left and right walls of the trench and covers the side surface of the organic layer.

15. The electroluminescent display device according to claim 11, wherein, The inner side of the groove, excluding the undercut structure, is filled with the adhesive layer.

16. The electroluminescent display device according to claim 15, wherein, The electroluminescent display device further includes: An inorganic layer made of inorganic insulating material is disposed on the inner side of the cover layer and the trench.

17. The electroluminescent display device according to claim 3, wherein, The undercut structure and the groove extend toward the flexible film located on one side of the display panel.

18. The electroluminescent display device according to claim 1, wherein, The electroluminescent display device further includes: Connection lines disposed above the substrate in the non-display area; A buffer layer is disposed above the substrate on which the connecting lines are provided; and Gate lines disposed on the buffer layer The gate line is electrically connected to the connection line.

19. The electroluminescent display device according to claim 18, wherein, The connecting line passes beneath the trench.

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