Electroluminescent indicator device and method for its manufacture

Abstract

An electroluminescent display device comprising: a display panel (100) having a display area (AA) and a non-display area (NA); a planarization layer (105) over the non-display area (NA); a dam (106) on the planarization layer (105); an organic layer (152) on the dam (106); a cathode (153) on the dam (106), and which extends to the non-display area (NA) of the display panel (100); a cover layer (120) arranged on the cathode (153); a trench structure (180, 280, 380, 480, 580, 680) located in the non-display area (NA) and in a position where the cathode (153) and the organic layer (152) are removed, the trench structure (180, 280, 380, 480, 680) extending through the cover layer (120); an adhesion layer (130) over the cathode (153) and the trench structure (180, 280, 380, 480, 580, 680); and an encapsulation substrate (140) over the cathode (153) and the adhesion layer (130).

Description

BACKGROUNDTechnical field

[0001] The present disclosure relates to an electroluminescent display device, and more particularly relates to an electroluminescent display device having a narrow bezel. Description of the technology used

[0002] Recently, as our society evolves toward an information-oriented society, the field of display devices for visually representing an electrical information signal has undergone rapid development. Various display devices with outstanding performance in terms of thinness, light weight, and low power consumption are being developed accordingly.

[0003] Typical display devices include a liquid crystal display (LCD), an electrowetting display (EWD), an organic light emitting display (OLED), and the like.

[0004] Among these various display devices, an electroluminescent display device comprising an organic light-emitting display device is a self-emitting display device and can be manufactured to be lightweight and thin because it does not require a separate light source, unlike a liquid crystal display device that requires a separate light source. Furthermore, the electroluminescent display device has advantages in power consumption due to low-voltage driving and is excellent in color reproduction, response speed, viewing angle, and contrast ratio (CR). Therefore, electroluminescent display devices are expected to be used in various fields.

[0005] The electroluminescent display device is constructed by disposing a light-emitting layer made of an organic material between two electrodes called an anode and a cathode. Then, when holes are injected from the anode into the light-emitting layer and electrons are injected from the cathode into the light-emitting layer, the injected electrons and holes recombine to form excitons in the light-emitting layer and emit light.

[0006] The light-emitting layer contains a host material and a dopant, allowing the two materials to interact. A host generates excitons from electrons and holes and serves to transfer energy to a dopant. The dopant, a dye-based organic material added in a small amount, serves to receive energy from the host and convert it into light.

[0007] US 2020 / 0 212 140 A1 describes an electroluminescent display device comprising a substrate having a display region and a non-display region disposed near the display region; a light-emitting diode in the display region; an encapsulation layer on the light-emitting diode; a through-hole disposed within the display region so as to penetrate the substrate; an inner dam surrounding the through-hole; a trench disposed between the inner dam and the through-hole; and an etching stopper disposed between the trench and the through-hole on the insulating layer.

[0008] US 2015 / 0 207 100 A1 describes a display unit comprising a first substrate and a second substrate arranged opposite each other, a first insulating layer on the first substrate, a plurality of light-emitting elements arranged in a display region, the display region being on the first insulating layer and facing the second substrate, and a first moisture-resistant layer covering the first insulating layer in a peripheral region, the peripheral region being provided on the first substrate and surrounding the display region. BRIEF OVERVIEW

[0009] In current electroluminescent display devices, a reduced bezel spacing is beneficial for reliability, for example, by preventing moisture ingress. A "reliable bezel" may be a bezel spacing small enough to achieve a favorable level of moisture ingress prevention. The reliable bezel may be a distance from one end of a top substrate (e.g., an encapsulation substrate) to one end of a cathode.

[0010] In response to the demand for thinning display devices, there is also an increasing demand for thinning the non-display area of ​​the display device, generally outside the display area where an image is displayed. When the cathode and an organic layer are deposited, a shadow area is created due to a gap between a mask and a substrate. This shadow area can increase the difficulty in reducing the bezel size. The position and length of the shadow area are not uniform due to process variation, and uniform quality may be deteriorated due to differences in a reliable bezel pitch for each product.

[0011] Accordingly, a technical feature of the present disclosure provides an electroluminescent display device that can reduce a bezel width by converting an existing shadow area into a reliable bezel area.

[0012] Technical features of the present disclosure are not limited to the technical feature described above, and other technical features not mentioned above will be clearly apparent to those skilled in the art from the following description.

[0013] Various embodiments of the present disclosure provide an electroluminescent display device according to claim 1, an electroluminescent display device according to claim 17, and a method according to claim 18. Further embodiments are described in the dependent claims.An electroluminescent display device according to an embodiment of the present disclosure may include a display panel divided into a display region and a non-display region, a planarization layer and a dam extending to a non-display region of the display panel, an organic layer and a cathode disposed on the dam and extending to the non-display region of the display panel, a cap layer disposed on the cathode, a trench structure disposed in the non-display region outside the display region and in which the cathode and the organic layer are removed, the trench structure extending through the cap layer, and an adhesion layer and an encapsulation substrate disposed over the cathode, the adhesion layer covering the trench structure.

[0014] An electroluminescent display device according to another embodiment of the present disclosure may include a substrate divided into a display region and a non-display region, a planarization layer disposed on the substrate, a dam disposed over the planarization layer, an organic layer, a cathode, and a cap layer disposed on the dam and extending to the non-display region of the substrate, at least one trench structure disposed in the non-display region outside the display region and in which the cap layer, the cathode, the organic layer, the dam, and the planarization layer are removed, a passivation layer disposed on a bottom inside the trench structure, an adhesion layer filling an inside of the trench structure and disposed over the substrate, and an encapsulation substrate disposed on the adhesion layer.

[0015] Other detailed aspects of the embodiments are included in the detailed description and drawings.

[0016] In the present disclosure, a portion of the cathode and the organic layer is removed by forming the trench structure in an unnecessary shadow region generated due to using a deposition mask, so that it is possible to delay an amount of moisture penetration to a side surface of the non-display region, thereby enabling improvements in reliability and a reduction in the bezel width.

[0017] The effects according to the present disclosure are not limited to the contents set forth above, and other various effects are included in the present application. BRIEF DESCRIPTION OF THE DIFFERENT VIEWS OF THE DRAWINGS Fig. 1 is a plan view of an electroluminescent display device according to a first embodiment of the present disclosure. Fig. 2 is a cross-sectional view of a subpixel of the electroluminescent display according to the first embodiment of the present disclosure. Fig. 3 is a cross-sectional view along line II' of Fig. 1. Fig. 4 is a partial cross-sectional view of an electroluminescent display device according to a comparative example. Fig. 5a to Fig. 5e are cross-sectional views of a manufacturing process of the electroluminescent display device of the Fig. 3. Fig. 6 is a cross-sectional view of an electroluminescent display device according to a second embodiment of the present disclosure. Fig. 7 is a cross-sectional view of an electroluminescent display device according to a third embodiment of the present disclosure. Fig. 8 is a cross-sectional view of an electroluminescent display device according to a fourth embodiment of the present disclosure. Fig. 9 is a plan view of an electroluminescent display device according to a fifth embodiment of the present disclosure. Fig. 10 is a plan view of an electroluminescent display device according to a sixth embodiment of the present disclosure. Fig. 11 is a cross-sectional view taken along a line XX' of the Fig. 10. DETAILED DESCRIPTION

[0018] Advantages and features of the present disclosure and a method for achieving the advantages and features will be made known by reference to embodiments which will be described in detail below together with the accompanying drawings.

[0019] Shapes, sizes, ratios, angles, numbers, and the like illustrated in the accompanying drawings for describing embodiments of the present disclosure are examples, and the embodiments are not limited thereto. Such shapes, sizes, ratios, angles, numbers, and the like should be understood to have reasonable ranges that can be easily recognized by those skilled in the art. Like reference numerals generally refer to like elements throughout the application. In the following description of the present disclosure, detailed explanation of known related technologies may be omitted to avoid distracting from the technical features and advantages described with reference to embodiments of the present disclosure.Terms used herein, such as "comprise," "have," and "consist of," are generally intended to be open-ended, allowing additional components to be added, except when used with the term "only." Any singular designations may include the plural, unless expressly stated otherwise.

[0020] Components and dimensions thereof have a tolerance range, error, variation or the like, even if this is not expressly mentioned.

[0021] When a spatial relationship between two parts is described using terms such as "on," "above," "over," "below," "below," "beneath," and "beside," one or more parts may be located between the two parts, except when the terms are used with the term "immediate" or "direct." The spatial terms just listed above should include above, below, right of, left of, in front of, and behind, which will be understandable based on an orientation of a structure containing the two parts.

[0022] When an element or layer is described as being "on top of" another element or layer, another layer or element may be directly on top of the other element or inserted between them.

[0023] Although the terms "first," "second," and the like are used to describe various elements, these elements are not limited by these terms, for example, in their order, priority, physical dimension, or otherwise. These terms are used merely to distinguish one component from other components. Therefore, a first component mentioned below may be a second component in a technical concept (e.g., an order) of the present disclosure.

[0024] The size and thickness of each component illustrated in the drawings are shown for convenience of description, and such sizes and thicknesses are not drawn to scale. As such, the size and thickness of each illustrated component should be allowed a range as described in the various embodiments or as would be understood by one of ordinary skill in the art.

[0025] Features, structures, or properties may be described in the context of a single embodiment or of various embodiments. Features, structures, or properties may be omitted from one or more embodiments. Features, structures, or properties described in the context of one or more embodiments may be combined with each other in any suitable manner and may be structurally arranged and / or connected and operated in a variety of ways. The various embodiments may be practiced independently of one another or in conjunction with one another.

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

[0027] Fig. 1 is a plan view of an electroluminescent display device according to a first embodiment of the present disclosure.

[0028] Referring to Fig. 1, the electroluminescent display device according to the first embodiment of the present disclosure may include a display panel 100, flexible films 160, and a circuit board 170.

[0029] The display panel 100 is a panel for displaying an image to a user.

[0030] The display panel 100 may include display elements for displaying an image, a drive element for driving the display elements, and lines for transmitting various signals to the display elements and the drive element. The display element may have different materials and / or structures depending on a type of the display panel 100. For example, if the display panel 100 is an organic light-emitting display panel, the display element is an organic light-emitting element that includes an anode, an organic light-emitting layer, and a cathode. For example, if the display panel 100 is a liquid crystal display panel, the display element may be a liquid crystal display element.In the following, a description of the display panel 100 is provided in the context of an organic light emitting display panel, however, the display panel 100 is not limited to the organic light emitting display panel.

[0031] The display panel 100 may have a display area AA and a non-display area NA.

[0032] The display area AA is an area in which an image is displayed on the display panel 100.

[0033] A plurality of subpixels constituting a plurality of pixels and a circuit for driving the plurality of subpixels may be arranged in the display area AA. The plurality of subpixels are units constituting the display area AA, and the display element may be arranged in each of the plurality of subpixels, and the plurality of subpixels may constitute one pixel. For example, an organic light-emitting element including an anode, an organic light-emitting layer, and a cathode may be arranged in each of the plurality of subpixels, but is not limited thereto. In addition, a circuit for driving the plurality of subpixels may include a driving element, wiring, and the like. For example, the circuit may include a thin-film transistor, a capacitor, a gate line, a data line, and the like, but is not limited thereto.

[0034] The non-display area NA is an area in which an image is not displayed.

[0035] Fig. 1 illustrates that the non-display area NA surrounds the display area AA, which has a rectangular shape, but shapes and arrangements of the display area AA and the non-display area NA are not limited to the Fig. 1 example shown.

[0036] In other words, the shapes of the display area AA and the non-display area NA may be suitable for a configuration of an electronic device on which the electroluminescent display device is mounted. For example, a shape of the display area AA may be a pentagon, a hexagon, a circle, an oval, or the like.

[0037] Various lines and circuits for driving organic light-emitting elements of the display area AA may be arranged in the non-display area NA. For example, connecting lines for transmitting signals to the plurality of subpixels and circuits of the display area AA or driver ICs, such as a gate driver IC and a data driver IC, may be arranged in the non-display area NA, but are not limited thereto.

[0038] The electroluminescent display device may include various additional elements for generating various signals or driving pixels in the display area AA. The additional elements for driving the pixels may include an inverter circuit, a multiplexer, an electrostatic discharge (ESD) circuit, and the like. The electroluminescent display device may also include additional elements associated with functions other than driving pixels. For example, the electroluminescent display device may include additional elements that include a touch detection function, a user authentication function (e.g., fingerprint recognition), a multilevel pressure detection function, a tactile feedback function, and the like. The above-mentioned additional elements may be arranged in the non-display area NA and / or in an external circuit coupled to a connection interface.

[0039] The flexible film 160 is a film in which various components are arranged on a flexible base film. In particular, the flexible films 160 are films for supplying signals to the plurality of subpixels and circuits of the display area AA and can be electrically connected to the display panel 100. The flexible films 160 can be arranged at one end of the non-display area NA of the display panel 100 and supply a power voltage, a data voltage, and the like to the plurality of subpixels and circuits of the display area AA. The number of flexible films 100 can be changed variously according to the embodiment, but is not limited to the Fig. 1 shown design.

[0040] Here, driver ICs, such as a gate driver IC and a data driver IC, can be arranged on the flexible films 160. The driver IC is a component that processes data for displaying an image and a drive signal for further processing. The driver IC can be arranged according to a mounting method using a chip-on-glass (COG) process, a chip-on-film (COF) process, or a tape-on-carrier (TCP) process.

[0041] The circuit board 170 can be arranged at first ends of the flexible films 160 and coupled to the flexible films 160. Opposite ends of the flexible films 160 can be coupled to the display panel 100. The circuit board 170 is a component that supplies signals to the driver ICs. The circuit board 170 can supply various signals, such as a drive signal and a data signal, to the driver ICs. For example, a data driver that generates data signals can be mounted on the circuit board 170, and the generated data signals can be supplied through the flexible films 160 to the plurality of subpixels and circuits of the display panel 100. Fig. 1, a single circuit board 170 is shown. In one embodiment, two or more circuit boards 170 may be coupled to the display panel 100 and / or to each other.

[0042] In electroluminescent display devices, a reduced bezel pitch is advantageous for ensuring reliability, such as preventing moisture penetration. Demand for thinning the non-display region NA is also increasing in line with the demand for thinning display devices. In this case, when depositing a cathode and an organic layer, a shadow region is generated due to a gap between a mask and a substrate, thus limiting the bezel reduction.

[0043] Accordingly, the first embodiment of the present disclosure is characterized in that portions of the cathode and the organic layer are removed by forming trench structures 180 in the shadow region in the non-display region NA, thereby slowing the rate of moisture penetration on a side surface of the non-display region NA. In this way, a bezel width can be reduced by converting an existing shadow region into a reliable bezel region.

[0044] The trench structures 180 according to the first embodiment of the present disclosure may be formed over three surfaces (or "end portions") of the non-display area NA except for a lower end portion of the display panel 100 to which the flexible films 160 are coupled, but are not limited thereto. The trench structures 180 may not be formed in the lower end portion of the display panel 100 due to a risk of damage by laser light due to the arrangement of the driver ICs and the application of a voltage, but the present disclosure is not limited thereto. As shown in Fig. As shown in Figure 1, the end portions include an upper end portion opposite the lower end portion, and a left-side end portion and a right-side end portion extending from the upper end portion to the lower end portion. The trench structures 180 are located above the upper end portion and the left-side end portion and the right-side end portion. The lower end portion is substantially free of the trench structures 180.

[0045] The trench structures 180 can be formed, for example, by removing the cathode and the organic layer of the shadow region outside the display region AA by laser ablation. Accordingly, a reliable bezel region can be expanded, and the bezel width can be reduced by an amount equal to a length of the reliable bezel region that is added.

[0046] A planarization layer and a dam region are lower moisture-permeable paths. In one embodiment, the trench structures 180 may extend into the planarization layer and the dam region through a photolithography process, but the present disclosure is not limited thereto.

[0047] A passivation layer for protecting a gate-in-panel (GIP) circuit from laser ablation may be formed in the trench structures 180, but is not limited thereto. Various components forming the electroluminescent display device, including the trench structures 180, are described with reference to Fig. 2 and Fig. 3 will be described in detail.

[0048] Fig. 2 is a cross-sectional view of a subpixel of the electroluminescent display device according to the first embodiment of the present disclosure.

[0049] Fig. 3 is a cross-sectional view along line II' of Fig. 1.

[0050] Fig. For example, Fig. 3 shows a cross-section of a portion of a right side of the display panel 100 in which the trench structure 180 is formed. In Fig. 3, a pixel unit 115 in the display area AA is schematically illustrated for convenience of description. The pixel unit 115 may include various components beneath an organic layer 152. In addition, a gate-in-panel (GIP) unit 125 in the non-display area NA may also include various components and is schematically illustrated. The pixel unit 115 may be or include one or more of a pixel structure and a pixel circuit and may be referred to as a pixel structure 115 or a pixel circuit 115. The GIP unit 125 may be a GIP circuit 125 and may be referred to as a GIP circuit 125.

[0051] Referring to Fig. 2 and Fig. 3, in the electroluminescent display device according to the first embodiment of the present disclosure, a driving element 110 may be arranged on a substrate 101.

[0052] A planarization layer 105 may be arranged on the control element 110.

[0053] An organic light-emitting element 150 electrically coupled to the driving element 110 is disposed on the planarization layer 105, and a cap layer 120 is disposed on the organic light-emitting element 150 to thereby minimize or reduce penetration of oxygen and moisture to the organic light-emitting element 150.

[0054] An adhesion layer 130 and an encapsulation substrate 140 are sequentially disposed on the cover layer 120. However, the present disclosure is not limited to such a stacked structure.

[0055] The substrate 101 can be a glass substrate or a plastic substrate. In the case of a plastic substrate, a polyimide-based or polycarbonate-based material can be used to provide flexibility. In particular, polyimide is widely used as a plastic substrate because it can be used in high-temperature processes and can be coated.

[0056] A buffer layer 102 may be disposed on the substrate 101.

[0057] Buffer layer 102, which is a functional layer for protecting various electrodes and wiring from impurities such as alkali ions released from the substrate or underlying layers thereof, may have a multilayer structure formed from, but is not limited to, a first buffer layer 102a and a second buffer layer 102b. Buffer layer 102 may be formed from silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof.

[0058] Buffer layer 102 can delay the diffusion of moisture and / or oxygen penetrating into substrate 101. Buffer layer 102 can also comprise a multi-buffer and / or an active buffer. The active buffer can protect an active layer 111 composed of a semiconductor of the control element and block various types of impurities migrating from substrate 101. The active buffer can be formed, for example, from amorphous silicon (a-Si).

[0059] The driving element 110 may have a shape in which the active layer 111, an insulating layer 103, a gate electrode 113, a gate insulating layer 104, a source electrode, and a drain electrode 112 are arranged sequentially, and may be electrically coupled to the organic light-emitting element 150 through a connection electrode 114 to thereby transmit a current or a signal to the light-emitting element 150.

[0060] The active layer 111 may be disposed on the buffer layer 102. The active layer 111 may be formed of polysilicon (p-Si), in which case a predetermined region or a selected region thereof may be doped with impurities. The active layer 111 may be formed of amorphous silicon (a-Si) or various organic semiconductor materials, such as pentacene and the like. The active layer 111 may be formed of an oxide.

[0061] The insulating layer 103 may be disposed on the active layer 111. The insulating layer 103 may be formed of an insulating inorganic material, such as silicon oxide (SiOx) or silicon nitride (SiNx), and may also be formed of an insulating organic material or the like.

[0062] The gate electrode 113 may be disposed on the insulating layer 103. The gate electrode 113 may be formed from various conductive materials, for example, magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), gold (Au), or alloys thereof.

[0063] The gate insulating layer 104 may be disposed on the gate electrode 113. The gate insulating layer 104 may be formed from an insulating material, such as silicon oxide (SiOx) or silicon nitride (SiNx), and may also be formed from an insulating organic material.

[0064] By selectively removing the insulating layer 103 and the gate insulating layer 104, contact holes can be formed through which a source region and a drain region are exposed. The source electrode and the drain electrode 112 can be electrode materials on the gate insulating layer 104 and can be formed in a single-layer structure or a multi-layer structure. In one embodiment, an additional passivation layer made of an inorganic insulating material can be formed such that the source electrode and the drain electrode 112 are covered.

[0065] The planarization layer 105 may be arranged on the drive element 110 configured as described above.

[0066] The planarization layer 105 may have a multilayer structure composed of at least two layers and may, with reference to Fig. 2, a first planarization layer 105a and a second planarization layer 105b. The first planarization layer 105a may be arranged to cover the drive element 110 and may be arranged to expose portions of the source electrode and the drain electrode 112 of the drive element 110.

[0067] The planarization layer 105 may extend to the non-display area NA such that the GIP unit 125 is covered, as shown in Fig. 3 shown.

[0068] The planarization layer 105 may have a thickness in a range of about 1 micrometer (µm) to about 5 µm, such as, but not limited to, 1 µm, 2 µm, 3 µm, 4 µm, 5 µm, or any thickness therebetween.

[0069] The planarization layer 105 may be, but is not limited to, an overlay layer.

[0070] The planarization layer 105 may be arranged to determine a position that is offset by a predetermined distance or a selected distance that is Fig. 3 is designated “Dps”, is arranged away from one end of the substrate 101, but is not limited thereto.

[0071] The connection electrode 114 for electrically connecting the driving element 110 and the organic light-emitting element 150 may be arranged on the first planarization layer 105a. In addition, although Fig. 2, various metallic layers serving as lines / electrodes, such as data lines and signal lines, may be arranged on the first planarization layer 105a.

[0072] The second planarization layer 105b may be arranged on the first planarization layer 105a and the connection electrode 114. The planarization layer 105 according to the first embodiment of the present disclosure may be formed from two planarization layers 105a, 105b due to an increase in the number of different signal lines, as the electroluminescent display device has a higher resolution. Therefore, to support the routing of lines on one layer, an additional planarization layer 105b is provided while ensuring a minimal or reduced distance between the lines. Including such an additional layer (e.g., the second planarization layer 105b) provides space for routing lines, so that a line / electrode routing design can be further improved.In one embodiment, a dielectric material is used as the planarization layer 105 having multiple layers, enabling the formation of capacitors between metallic layers embedded in the planarization layer 105.

[0073] The second planarization layer 105b may be formed such that a portion of the connection electrode 114 is exposed, and the drain electrode 112 of the driving element 110 and the anode of the organic light-emitting element 150 may be electrically coupled to each other via the connection electrode 114.

[0074] The organic light-emitting element 150 may be formed by sequentially disposing an anode 151, a plurality of organic layers 152, and a cathode 153. That is, the organic light-emitting element 150 may include the anode 151 formed on the planarization layer 105, the organic layer 152 formed on the anode 151, and the cathode 153 disposed on the organic layer 152.

[0075] The electroluminescent display device can be implemented using a top-emission method or a bottom-emission method. In the top-emission method, a reflective layer formed 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 added under the anode 151 so that light emitted from the organic layer 152 is reflected by the anode 151 and directed upward, that is, in a direction toward the cathode 153 and away from the substrate 101. In the case of the bottom-emission method, the anode 151 can be formed of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), or the like.In the following, a description is provided in the context that the electroluminescent display device has the configuration of the bottom emission method. However, it should be noted that the description can be similarly applied to embodiments having the configuration of the top emission method.

[0076] A dam 106 may be formed on the planarization layer 105 in regions different from light-emitting regions. The dam 106 may have a dam hole exposing the anode 151. A position of the dam hole corresponds to the light-emitting region, as shown in Fig. 2. The dam 106 may be formed from an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx), or an organic insulating material such as BCB, acrylic resin, or imide resin.

[0077] The dam 106 may extend to the non-display area NA, as shown in Fig. 3 shown.

[0078] The dam 106 may have a thickness ranging from approximately 0.1 µm to approximately 10 µm, such as, but is not limited to, 1 µm, 2 µm, or 3 µm. It should be noted that any value between approximately 0.1 µm and approximately 10 µm, such as 4.501 µm or 6.356 µm, is included in the thickness range of the dam 106.

[0079] The dam 106 may, but is not limited to, covering an upper portion of the GIP unit 125. In one embodiment, the dam 106 partially covers an upper surface of the GIP unit 125 and exposes one or more areas of the upper surface, as shown in Fig. 3 shown.

[0080] The organic layer 152 may be disposed on the anode 151 exposed by the dam 106. The organic layer 152 may include one or more of a light-emitting layer, an electron-injection layer, an electron-transport layer, a hole-transport layer, a hole-injection layer, or the like.

[0081] The organic layer 152 may extend to the non-display region NA, as shown in Fig. 3 shown.

[0082] In the non-display region NA, the organic layer 152 may be disposed on the dam 106.

[0083] The cathode 153 may be arranged on the organic layer 152.

[0084] In the case of the top-emission process, the cathode 153 may comprise a light-transmitting conductive material. For example, the cathode 153 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), or the like. In the case of the bottom-emission process, the cathode 153 may comprise any of metallic materials such as gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), palladium (Pd), copper (Cu), or the like, or groups consisting of alloys thereof.Alternatively, the cathode 153 may be configured by stacking a layer formed of a light-transmitting conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), or indium gallium zinc oxide (IGZO), and a layer formed of a metallic material such as, but not limited to, gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), palladium (Pd), copper (Cu), or the like, or alloys thereof.

[0085] The cathode 153 may extend to the non-display area NA, as shown in Fig. 3 shown.

[0086] In the non-display region NA, the cathode 153 may be arranged to cover the organic layer 152. In one embodiment, the cathode 153 covers a top surface of the organic layer 152 and one or more sidewalls of the organic layer 152, as shown in Fig. 3. In one embodiment, the cathode 153 may have an end portion that contacts the dam 106.

[0087] The organic layer 152 may be arranged such that it is offset by a predetermined distance or a selected distance which is Fig. 3 marked “Doc”, is located away from one end of the cathode 153, but is not limited thereto.

[0088] The cathode 153 may be arranged to be displaced by a predetermined distance or a selected distance which is Fig. 3 with “D CB “, is located away from one end of the dam 106, but is not limited thereto.

[0089] In order to reduce diffuse reflection of external light, the cover layer 120 formed of a material having a high refractive index and light absorption may be disposed on the organic light-emitting element 150.

[0090] The cap layer 120 may be an organic layer formed from an organic material and may be omitted in some embodiments.

[0091] The cover layer 120 may extend to the non-display area NA, as shown in Fig. 3 shown.

[0092] In the non-display area NA, the cover layer 120 is arranged on the cathode 153.

[0093] The cathode 153 and the organic layer 152 may collectively be referred to as “a plurality of functional layers.”

[0094] The adhesion layer 130 and the encapsulation substrate 140 may be arranged on the cover layer 120.

[0095] The adhesion layer 130 and the encapsulation substrate 140 may extend to the non-display region NA so as to cover a portion of the polarization layer 105 and the dam 106, as shown in Fig. 3. In one embodiment, the adhesion layer 130 may contact the cover layer 120, the dam 106, and the planarization layer 105.

[0096] The adhesion layer 130 can be arranged to surround the cover layer 120 and the pixel unit 115. The adhesion layer 130, together with the cover layer 120 and the encapsulation substrate 140, can protect the organic light-emitting element 150 of the pixel unit from external moisture, oxygen, shock, and the like. The adhesion layer 130 can further comprise a moisture-absorbing material. The moisture-absorbing material can be or comprise particles that have hygroscopicity and can absorb moisture and oxygen from the outside, thereby minimizing or reducing the penetration of moisture and oxygen into the pixel unit 115.

[0097] The encapsulation substrate 140 may be disposed on the adhesion layer 130. The encapsulation substrate 140, together with the adhesion layer 130, may protect the organic light-emitting element 150 of the pixel unit 115. The encapsulation substrate 140 may protect the organic light-emitting element 150 from external moisture, oxygen, shock, and the like.

[0098] The adhesion layer 130 may be arranged such that it is spaced apart from an end of the encapsulation substrate 140 by a predetermined distance or a selected distance, but is not limited thereto. In one embodiment, the adhesion layer 130 ends at a position spaced apart from the end of the encapsulation substrate 140 by a distance that is Fig. 3 with “D AE “ is shifted sideways.

[0099] As described above, in the electroluminescent display device, a minimized or reduced bezel distance, that is, a reliable bezel L (see Fig. 3), advantageous for ensuring reliability, for example in terms of preventing the ingress of moisture.

[0100] The reliable enclosure L may have a distance measured from the end of the encapsulation substrate 140 to the end of the cathode 153.

[0101] In the non-display region NA, an outer region of the display region AA excluding the reliable bezel L may be referred to as the shadow region, which may include the gap between the mask and the substrate 101 when depositing the cathode 153 and the organic layer 152.

[0102] In one embodiment, the trench structures 180 are formed in the shadow region and extend through the cap layer 120, the cathode 153, the organic layer 152, the dam, and the planarization layer 105.

[0103] Fig. 3 illustrates two trench structures 180 as an example, but the present disclosure is not limited thereto. The trench structure 180 may include a single trench structure or a plurality of two or more trench structures, but the present disclosure is not limited to the number of trench structures 180.

[0104] The trench structures 180 can be formed, for example, by removing the cap layer 120, the cathode 153 and the organic layer 152 in the shadow area outside the display area AA by means of laser ablation.

[0105] In the case of the planarization layer 105 and the dam 106, the trench structures 180 may be extended by one or more photolithography processes, but are not limited thereto.

[0106] The trench structure 180 may have a width of approximately 70 µm when a laser width is 50 µm, but is not limited thereto. This takes into account a width (for example, approximately 20 µm) of a region affected by laser heat.

[0107] An inner surface of the trench structure 180 may be filled with the adhesion layer 130, but the present disclosure is not limited thereto. A material to be filled into the trench structure may be any material as long as it can prevent moisture penetration.

[0108] A passivation layer 185 for protecting the GIP device 125 from laser ablation may be disposed on a bottom portion of the trench structure 180 formed prior to deposition of the organic layer 152, the cathode 153, and the cap layer 120, but is not limited thereto.

[0109] The passivation layer 185 may be formed of a transparent conductive material that forms the anode 151 to absorb 100% of the laser energy when using a laser with an ultraviolet spectrum having a wavelength band of approximately 266 nm. The transparent conductive material may comprise indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), or the like.

[0110] As described above, according to the first embodiment of the present disclosure, portions of the cap layer 120, the cathode 153, the organic layer 152, the planarization layer 105, and the dam 106 are removed by forming the trench structure 180 in an inactive shadow region, so that it is possible to slow down the rate of moisture penetration on the side surface of the non-display region NA. This means that the bezel width can be reduced by converting the shadow region into a reliable bezel region L.

[0111] Fig. 4 is a partial cross-sectional view of an electroluminescent display device according to a comparative example.

[0112] The Fig. The electroluminescent display device shown in Fig. 4 has substantially the same configuration as the electroluminescent display device according to the first embodiment of the present disclosure of Fig. 3, except that the trench structures 180 are not present.

[0113] Referring to Fig. 4, in the electroluminescence display device according to the comparative example, since the trench structures 180 according to the first embodiment of the present disclosure are not provided, it can be seen that a length of the reliable bezel L' is longer than that of the reliable bezel L in the electroluminescence display device according to the first embodiment of the present disclosure of the Fig. 3. Due to the presence of the trench structures 180, the reliable enclosure L can have a reduced length, as shown in Fig. 3, which allows for thinning of the non-display area NA.

[0114] Fig. 5A to Fig. 5E are cross-sectional views sequentially showing parts of a manufacturing process of the electroluminescent display device of the Fig. 3 represent.

[0115] Referring to Fig. 5A, various components of the pixel unit 115 are formed on the substrate 101.

[0116] As described above, the pixel unit 115 is formed in the display area AA of the substrate 101 and may include various components under the organic layer.

[0117] The GIP unit 125 having various components may be formed in the non-display region NA of the substrate 101.

[0118] The planarization layer 105 may be formed to extend to the non-display area NA so as to cover the GIP unit 125.

[0119] The planarization layer 105 may be formed such that it is spaced from the end of the substrate 101 by a predetermined distance or a selected distance (in Fig. 3) is located remotely, but is not limited to this.

[0120] The dam 106 may be formed on the planarization layer 105 in a region different from the light-emitting region.

[0121] The dam 106 may be formed to extend to the non-display area NA.

[0122] The dam 106 may cover the upper portion of the GIP unit 125, but is not limited thereto.

[0123] The planarization layer 105 and the dam 106 of the non-display region NA outside the display region AA may be selectively removed by a predetermined photolithography process or selected photolithography processes, such as a coating process, a soft-bake process, an exposure process, a development process, and a curing process, so that primary trench structures 180' may be formed.

[0124] In one embodiment, the primary trench structures 180' may be formed over three surfaces of the non-display area NA, except for the lower end portion of the display panel (see Fig. 1), but are not limited to this.

[0125] The primary trench structures 180' may serve to block the penetration of moisture at the side surfaces of the non-display region NA through the planarization layer 105 and the dam 106 of the non-display region NA.

[0126] After forming the primary trench structures 180', referring to Fig. 5B, a predetermined passivation layer 185 or a selected passivation layer 185 may be formed in a bottom portion of the primary trench structure 180'. In one embodiment, the passivation layer 185 is formed on portions of the top surface of the GIP device 125 exposed by the primary trench structures 180'.

[0127] The passivation layer 185 may be formed of a light-transmitting conductive material to absorb 100% of the laser light when a laser is used in an ultraviolet range having a wavelength band of approximately 266 nm.

[0128] The translucent conductive material may comprise indium tin oxide (ITO), indium zinc oxide (IZO), or indium gallium zinc oxide (IGZO).

[0129] In one embodiment, the thickness of the passivation layer 185 is less than that of the planarization layer 105.

[0130] Fig. 5A and Fig. 5B illustrates, as an example, a case where the passivation layer 185 is formed after the planarization layer 105 and the dam 106 are formed, but the present disclosure is not limited thereto.

[0131] In one embodiment, in the case of a light-transmitting conductive material, such as ITO, as used to form the anode 151, an absorption rate of ITO in the ultraviolet spectrum is 100%. Thus, the passivation layer 185 can be formed in the same process step as the anode 151, avoiding the use of a separate process step for forming the passivation layer 185. When the anode is formed in the pixel unit 115, the passivation layer 185 can be formed on the bottom portion of the primary trench structure 180'. In one embodiment, when the anode is formed in the pixel unit 115, after forming the planarization layer 105 comprising the primary trench structure 180', the passivation layer 185 can be formed on the bottom portion of the primary trench structure 180' in the same process.Thereafter, the dam 106 having the primary trench structure 180' may be formed on the planarization layer 105.

[0132] Thereafter, with reference to Fig. 5C, the organic layer 152, the cathode 153 and the cap layer 120 are formed sequentially on the substrate 101 on which the primary trench structures 180' are formed.

[0133] The organic layer 152 may include the light-emitting layer, the electron-injection layer, the electron-transport layer, the hole-transport layer, the hole-injection layer, and the like.

[0134] The organic layer 152 may be formed to extend to the non-display region NA.

[0135] In the non-display area NA, the organic layer 152 may be arranged on the dam 106.

[0136] An inner side of the primary trench structure 180' may be filled with an organic material forming the organic layer 152.

[0137] The cathode 153 can be arranged on the organic layer 152.

[0138] The cathode 153 may be formed to extend to the non-display area NA.

[0139] In the non-display region NA, the cathode may be formed so as to cover the organic layer 152.

[0140] The organic layer 152 may be formed such that it is offset by a predetermined distance or a selected distance (indicated in Fig. 3) is located away from the end of the cathode 153, but is not limited thereto.

[0141] The cathode 153 may be formed such that it is offset by a predetermined distance or a selected distance (indicated in Fig. 3) is located away from the end of the dam layer 106, but is not limited thereto.

[0142] In order to reduce diffuse reflection of external light, the cover layer 120 formed of a material having a high refractive index and light absorption may be formed on the cathode 513.

[0143] The cap layer 120 may be an organic layer formed from an organic material and may be omitted in some embodiments.

[0144] The cover layer 120 may be formed to extend to the non-display area NA.

[0145] Then, with reference to Fig. 5D, portions of the cap layer 120, the cathode 153, the organic layer 152, the dam 106, and the planarization layer 105 on the passivation layer 185 are sequentially removed by a laser ablation process using a predetermined or selected laser light, so that the trench structures 180 can be formed. The portion of the trench structures 180 that extends through the cap layer 120, the cathode 153, and the organic layer 152 may be referred to as a "secondary trench structure."

[0146] The trench structures 180 may serve to block moisture penetration to the side surface of the non-display area NA.

[0147] In the first embodiment of the present disclosure, since the trench structures 180 are also formed in the dam 106 and the planarization layer 105, intrusion of moisture at the side surface of the non-display region NA can be effectively blocked by the dam 106 and the planarization layer 105.

[0148] Since the passivation layer 185, which can absorb 100% of the laser light, is disposed in the bottom portion of the trench structure 180, the GIP unit 125 located thereunder can be protected from laser ablation. Thus, laser ablation can be performed uninterrupted through a region including the GIP unit 125, allowing a high degree of freedom in the laser ablation process.

[0149] Thereafter, with reference to Fig. 5E, the adhesion layer 130 and the encapsulation substrate 140 are formed sequentially on the substrate 101 on which the cover layer 120 is formed.

[0150] The adhesion layer 130, together with the cover layer 120 and the encapsulation substrate 140, can protect the organic light-emitting element of the pixel unit 115 from external moisture, oxygen, shock, and the like. The adhesion layer 130 can further comprise a moisture-absorbing material.

[0151] The inside of the trench structure 180 can be filled with an organic material of the adhesion layer 130.

[0152] The encapsulation substrate 140 can be arranged on the adhesion layer 130.

[0153] The adhesion layer 130 may be formed such that it is spaced apart by a predetermined distance or a selected distance (indicated in Fig. 3) is located away from the end of the encapsulation substrate 140, but is not limited thereto.

[0154] In the case of the first embodiment of the present disclosure, since the trench structures 180 are formed in the shadow region outside the display region AA, it is possible to slow down the rate of water penetration at the side surface of the non-display region NA. This means that by converting the shadow region into the reliable bezel region, the bezel width can be reduced by an amount equal to the length of the reliable bezel.

[0155] In one embodiment, trench structures 280 may not extend into the planarization layer 105 and the dam 106, which may be described with reference to Fig. 6 is described below.

[0156] Fig. 6 is a cross-sectional view of an electroluminescent display device according to a second embodiment of the present disclosure.

[0157] In the second embodiment of the present disclosure, which is Fig. 6, configurations of the trench structures 280 differ from those of the trench structures 180 described with reference to Fig. 1 to Fig. 5E above, and other configurations are substantially the same as those of the electroluminescent display device according to the first embodiment of the present disclosure in Fig. 3. Therefore, for the sake of brevity, repeated descriptions will be omitted. Like reference numerals are used for like components.

[0158] Referring to Fig. 6, in the electroluminescent display device according to the second embodiment of the present disclosure, the trench structures 280 are formed such that regions from the cap layer 120 to the organic layer 152 on the outer side of the display region AA are removed therefrom.

[0159] This means that the trench structures 280 according to the second embodiment of the present disclosure may not be formed in the planarization layer 105 and the dam 106. Thus, the GIP device 125 may be protected from laser ablation by means of the dam 106 and the planarization layer 105, and the passivation layer 185 is not present.

[0160] The trench structures 280 can be removed, for example, by removing the cap layer 120, the cathode 153 and the organic layer 152 in the shadow area outside the display area AA by laser ablation.

[0161] An inner side of the trench structures 280 may be filled with the adhesion layer 130, but the present disclosure is not limited thereto.

[0162] In one embodiment, the trench structures are formed down to the planarization layer below, however, the passivation layer may not be formed on the bottom within the trench structure, which may be described with reference to Fig. 7 will be described below.

[0163] Fig. 7 is a cross-sectional view of an electroluminescent display device according to a third embodiment of the present disclosure.

[0164] In the third embodiment of the present disclosure of the Fig. 7, designs of the trench structures 380 differ from those described with reference to Fig. 1 to Fig. 6, and further embodiments are essentially the same as those described in Fig. 6. Thus, for the sake of brevity, a repeated description will be omitted. Like reference numerals are used for like components.

[0165] With reference to Fig. 7, the electroluminescent display device according to the third embodiment of the present disclosure comprises trench structures 380 extending through the cap layer 120 into the planarization layer 105 in the region outside the display region AA.

[0166] The passivation layer 185 is not formed on the bottom portion of the trench structure 380. In this case, a laser path can be modified during the laser ablation process to avoid sweeping over the GIP unit 125.

[0167] An inner side of the trench structure 380 may be filled with the adhesion layer 130, but the present disclosure is not limited thereto.

[0168] According to the present disclosure, an additional inorganic layer may be formed on the cover layer, which may be described with reference to Fig. 8 will be described below.

[0169] Fig. 8 is a cross-sectional view of an electroluminescent display device according to a fourth embodiment of the present disclosure.

[0170] In the Fig. 8, configurations of the trench structures 480 and an inorganic layer 486 differ from those described above with reference to Fig. 1 to Fig. 7, and other configurations are substantially the same as those described with reference to the first embodiment of the present disclosure of Fig. 2. Therefore, for the sake of brevity, repeated descriptions will be omitted. The same reference numerals are used for the same components.

[0171] Referring to Fig. 8, the electroluminescent display device according to the fourth embodiment of the present disclosure includes the trench structures 480 formed to extend outside the display area AA through the cap layer and into the planarization layer 105 thereunder.

[0172] The passivation layer 185 may be disposed on a bottom portion of the trench structure 480, but is not limited thereto.

[0173] The inorganic layer 486, formed of an inorganic insulating material, may be disposed on the cap layer 120. The inorganic layer 486 may be formed of silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof.

[0174] The inorganic layer 486 may be formed to cover the upper portion of the cap layer 120 and side surfaces of the cap layer 120, the cathode 153, and the organic layer 152.

[0175] An inner side of the trench structure 486 may be filled with the inorganic layer 486, but the present disclosure is not limited thereto.

[0176] In the fourth embodiment of the present disclosure, by forming the inorganic layer 486 on the cover layer 120, penetration of moisture into an upper portion of the organic layer 152 can be slowed down, and damage caused by notches or foreign substances can be reduced.

[0177] In one embodiment, the trench structure of the present disclosure may be divided into a plurality of structures other than a continuous single structure, which may be described with reference to Fig. 9 will be described below.

[0178] Fig. 9 is a plan view of an electroluminescent display device according to a fifth embodiment of the present disclosure.

[0179] In the Fig. In the fifth embodiment of the present disclosure illustrated in Figure 9, configurations of the trench structures 580 differ from those described above with reference to Fig. 1 to Fig. 8, and other configurations are substantially the same as those of the electroluminescent display device according to the first embodiment of the present disclosure in Fig. 1. For the sake of brevity, repeated descriptions will be omitted. Like reference numerals are used for like components.

[0180] Referring to Fig. 9, the electroluminescent display device according to the fifth embodiment of the present disclosure may include the display panel 100, the flexible films 160, and the circuit boards 170.

[0181] In the fifth embodiment of the present disclosure, the trench structure 580 is formed in a portion of the non-display region NA outside the display region AA.

[0182] The trench structure 580 may be formed such that a region from the cap layer 120 to the planarization layer 105 is removed therefrom, but is not limited thereto.

[0183] The trench structure 580 according to the fifth embodiment of the present disclosure may be formed over three surfaces of the non-display region NA except for the lower end portion of the display panel 100 to which the flexible films 160 are coupled, but the present disclosure is not limited thereto.

[0184] In Fig. 9 illustrates, as an example, a case where the trench structure 580 is divided into a plurality of columns to form two columns, but the present disclosure is not limited to this. The trench structure 580 may be divided into a plurality of columns to form one column or a plurality of two or more columns, but the present disclosure is not limited to the number of columns of the trench structures 580.

[0185] Here, the trench structure of the present disclosure may be provided in a plurality of three or more trench structures, which may be described with reference to Fig. 10 and Fig. 11 will be described below.

[0186] In one embodiment, forming the trench structures 580 comprises one or more laser ablation processes. In each laser ablation process, the laser light may be pulsed as the laser moves along the path of each trench structure 580, forming two or more trench segments 580S.

[0187] Fig. 10 is a plan view of an electroluminescent display device according to a sixth embodiment of the present disclosure.

[0188] Fig. 11 is a cross-sectional view taken along a line XX' of the Fig. 10.

[0189] Fig. For example, FIG. 11 illustrates a cross-section of a portion of a right side of the display panel 100 in which trench structures 680 are formed.

[0190] In the Fig. 10 and Fig. 11, configurations of the trench structures 680 are different from the previous description, and other configurations are substantially the same as those of the electroluminescent display device according to the first embodiment of the present disclosure described with reference to Fig. 1 to Fig. 3. Therefore, for the sake of brevity, repeated descriptions will be omitted. Like reference numerals are used for like components.

[0191] Referring to Fig. 10 and Fig. 11, the electroluminescent display device according to the sixth embodiment of the present disclosure may include the display panel 100, the flexible films 160, and the circuit board 170.

[0192] In the sixth embodiment of the present disclosure, the trench structure 680 is formed in a portion of the non-display region NA outside the display region AA.

[0193] The trench structure 680 according to the sixth embodiment of the present disclosure may be formed over three surfaces of the non-display area NA, except for the lower end portion of the display panel 100 to which the flexible films 160 are coupled, but is not limited thereto.

[0194] In Fig. 10 illustrates, as an example, a case where three trench structures 680 are provided, but the present disclosure is not limited thereto.

[0195] The trench structure 680 according to the sixth embodiment of the present disclosure may include at least one first trench structure 680a, from which a region from the cap layer 120 to the planarization layer 105 thereunder is removed, and at least one second trench structure 680b, from which a region from the cap layer 120 to the organic layer 152 is removed, but the present disclosure is not limited thereto. In one embodiment, the second trench structure 680b is based on the dam 106. In one embodiment, the first trench structures 680a are based on the GIP device 125.

[0196] Fig. 10 and Fig.11 illustrates a case where, as an example, two first trench structures 680a are provided and a first trench structure 680b is provided between the two first trench structures 680a, but the present disclosure is not limited thereto. In this case, the passivation layer 185 may be additionally disposed on a bottom portion of the first trench structure 680a, but is not limited thereto.

[0197] The first trench structure 680a and the second trench structure 680b may be arranged alternately.

[0198] The second trench structure 680b may be arranged between the first trench structures 680a. In one embodiment, two or more second trench structures 680b may be arranged between an adjacent pair of first trench structures 680a.

[0199] In addition, as long as the first trench structure 680a and the second trench structure 680b according to the sixth embodiment of the present disclosure have different shapes, they can be configured by applying various shapes of the above-described first embodiment to fifth embodiment of the present disclosure thereto.

[0200] Inner sides of the first trench structure 680a and the second trench structure 680b may be filled with the adhesion layer 130, but the present disclosure is not limited thereto.

[0201] Embodiments of the present disclosure may also be described as follows.

[0202] According to one embodiment of the present disclosure, an electroluminescent display device is provided. The electroluminescent display device includes a display panel having a display region and a non-display region, a planarization layer and a dam extending to a non-display region of the display panel, an organic layer and a cathode disposed on the dam and extending to the non-display region of the display panel, a cap layer disposed on the cathode, a trench structure disposed in the non-display region outside the display region and in which the cap layer, the cathode, and the organic layer are removed, and an adhesion layer and an encapsulation substrate disposed over the cathode, wherein the adhesion layer covers the trench structure.

[0203] The trench structure may be arranged over three surfaces of the non-display area except for a lower end portion of the display panel to which a flexible film may be coupled.

[0204] The electroluminescent display device may further comprise a gate-in-panel (GIP) unit disposed in the non-display region, wherein the planarization layer may extend to the non-display region so as to cover the GIP unit.

[0205] The dam may be disposed in a remaining region other than a light-emitting region on the planarization layer and may extend to the non-display region so as to cover an upper portion of the GIP unit.

[0206] The adhesion layer and the encapsulation substrate may extend to the non-display area such that they cover a portion of the planarization layer and the dam.

[0207] The trench structure may be provided as one trench structure or a plurality of two or more trench structures.

[0208] The cap layer, the cathode, the organic layer, the dam and the planarization layer may be removed in the trench structure.

[0209] The trench structure may be arranged above the GIP device, wherein a passivation layer may be arranged on a floor within the trench structure.

[0210] The passivation layer may be formed of a light-transmitting conductive material that establishes an anode of the display area.

[0211] The translucent conductive material may comprise indium tin oxide (ITO), indium zinc oxide (IZO), or indium gallium zinc oxide (IGZO).

[0212] An inner side of the trench structure can be filled with the adhesion layer.

[0213] The electroluminescent display device may further comprise an inorganic layer arranged on the cover layer, wherein an inner side of the trench structure may be filled with the inorganic layer.

[0214] The inorganic layer may be formed of silicon oxide (SiOx), silicon nitride (SiNx) or a multilayer thereof.

[0215] The inorganic layer may be arranged to cover an upper portion of the cover layer and side surfaces of the cover layer, the cathode and the organic layer.

[0216] The trench structure may be divided into a plurality of trench structures.

[0217] The trench structure may include at least a first trench structure in which a region may be removed downwards from the capping layer to the planarization layer, and at least a second trench structure in which a region may be removed downwards from the capping layer to the organic layer.

[0218] The first trench structure and the second trench structure may be arranged alternately.

[0219] The second trench structure may be arranged between the first trench structures.

[0220] According to another embodiment of the present disclosure, an electroluminescent display device is provided.The electroluminescent display device comprises a substrate having a display region and a non-display region, a planarization layer disposed on the substrate, a dam disposed over the planarization layer, an organic layer, a cathode, and a cap layer disposed on the dam and extending to the non-display region of the substrate, at least one trench structure disposed in the non-display region outside the display region and in which the cap layer, the cathode, the organic layer, the dam, and the planarization layer are removed, a passivation layer disposed on a bottom within the trench structure, an adhesion layer filling an inside of the trench structure and disposed over the substrate, and an encapsulation substrate disposed on the adhesion layer.

[0221] The various embodiments described above may be combined to provide further embodiments.

Claims

[1] An electroluminescent display device comprising: a display panel (100) having a display area (AA) and a non-display area (NA); a planarization layer (105) over the non-display area (NA); a dam (106) on the planarization layer (105); an organic layer (152) on the dam (106); a cathode (153) on the dam (106) and extending to the non-display area (NA) of the display panel (100); a cover layer (120) disposed on the cathode (153); a trench structure (180, 280, 380, 480, 580, 680) arranged in the non-display region (NA) and in a position where the cathode (153) and the organic layer (152) are removed, the trench structure (180, 280, 380, 480, 680) extending through the cap layer (120); an adhesion layer (130) over the cathode (153) and the trench structure (180, 280, 380, 480, 580, 680); and an encapsulation substrate (140) over the cathode (153) and the adhesion layer (130). [2] The electroluminescent display device according to claim 1, wherein the display panel (100) has a plurality of end portions, one of the plurality of end portions having a flexible film (160) connected thereto and being substantially free of the trench structure (180); wherein the trench structure (180, 280, 380, 480, 580, 680) is disposed over others of the plurality of end portions. [3] The electroluminescent display device according to claim 1 or 2, wherein the trench structure (180, 380, 480, 680) extends through the dam (106) and the planarization layer (105). [4] The electroluminescent display device according to any one of claims 1 to 3, further comprising: an inorganic layer (486) arranged on the cover layer (120), wherein the trench structure (480) is filled with the inorganic layer (486). [5] The electroluminescent display device according to claim 4, wherein the inorganic layer (486) is formed of silicon oxide, silicon nitride, or a multilayer film thereof. [6] The electroluminescent display device according to claim 4 or 5, wherein the inorganic layer (486) is arranged to cover an upper portion of the cover layer (120) and side surfaces of the cover layer (120), the cathode (153) and the organic layer (152). [7] The electroluminescent display device according to any one of claims 1 to 6, wherein the trench structure (680) comprises: at least one first trench structure (680a) extending through the planarization layer (105); and at least a second ditch structure (680b) based on the dam (106). [8] The electroluminescent display device according to claim 7, wherein at least one second trench structure (680b) is arranged between a pair of first trench structures (680a) that are adjacent to each other. [9] The electroluminescent display device according to any one of claims 1 to 8, further comprising: a gate-in-panel unit (125) arranged in the non-display region (NA), wherein the planarization layer (105) extends to the non-display region (NA) so as to cover the gate-in-panel unit (125). [10] The electroluminescent display device according to claim 9, wherein the dam (106) has an opening exposing a light-emitting region and covers an upper portion of the gate-in-panel unit (125). [11] The electroluminescent display device according to claim 9 or 10, wherein the trench structure (180) is arranged above the gate-in-panel unit (125), and wherein a passivation layer (185) is arranged in a bottom portion of the trench structure (180). [12] The electroluminescent display device according to claim 11, wherein the passivation layer (185) comprises a light-transmitting conductive material, the light-transmitting conductive material having substantially the same composition as that of an anode of the display region (AA). [13] The electroluminescent display device according to claim 12, wherein the light-transmitting conductive material comprises indium tin oxide, indium zinc oxide or indium gallium zinc oxide. [14] The electroluminescent display device according to any one of claims 1 to 13, wherein the adhesion layer (130) and the encapsulation substrate (140) cover a portion of the planarization layer (105) and the dam (106). [15] The electroluminescent display device according to any one of claims 1 to 14, wherein the trench structure (580) comprises two or more trench segments (580S). [16] The electroluminescent display device according to any one of claims 1 to 3 and 7 to 15, unless they refer back to any one of claims 4 to 6, wherein the trench structure (180, 280, 380, 680) is filled with the adhesion layer (130). [17] An electroluminescent display device comprising: a substrate (101) having a display area (AA) and a non-display area (NA); a planarization layer (105) disposed on the substrate (101); a dam (106) disposed over the planarization layer (105); a plurality of functional layers (152, 153) arranged on the dam (106) on the non-display area (NA) of the substrate (101); a cover layer (120) arranged on the plurality of functional layers (152, 153); at least one trench structure (680) in the non-display region (NA), wherein the at least one trench structure (680) extends through the cap layer (120), the plurality of functional layers (152, 153), the dam (106) and the planarization layer (105); a passivation layer (185) arranged in the at least one trench structure (680); an adhesion layer (130) on the passivation layer (185), wherein the adhesion layer (130) fills the at least one trench structure (680); and an encapsulation substrate (140) arranged on the adhesion layer (130). [18] A method comprising: Forming a planarization layer (105) on a non-display area (NA) of a substrate (101); Forming a dam (106) on the planarization layer (105); Forming a plurality of functional layers (152, 153) on the dam (106); Forming a cover layer (120) on the plurality of functional layers (152, 153); Forming a trench extending through the cover layer (120) and the plurality of functional layers (152, 153); depositing an adhesion layer (130) into the trench; and Attaching an encapsulation substrate (140) to the adhesion layer (130) over the trench. [19] The method of claim 18, wherein forming a trench comprises: Forming a primary trench structure (180') of the trench through the dam (106) and the planarization layer (105) by means of at least one photolithography process; and Forming a secondary trench structure of the trench through the cover layer (120) and the plurality of functional layers (152, 153) by means of at least one laser ablation process.

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