Display device

Abstract

A display device according to an example of the present disclosure includes a substrate in which a light emitting region and a non-light emitting region are divided and a plurality of sub-pixels are defined, an insulating layer disposed above the substrate, a first electrode disposed in each of the plurality of sub-pixels, a bank disposed on the insulating layer and exposing the first electrode through an opening thereof, an organic layer disposed on the first electrode, and a second electrode disposed on the organic layer. The bank includes an exposed side obtained by removing one region between the plurality of sub-pixels and an undercut structure inward from a lower end of the exposed side. The bank further includes an exposed side obtained by removing one region between the plurality of sub-pixels and a trench structure obtained by removing a portion of a thickness of the insulating layer.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2020-0117650, filed in Korea on September 14, 2020, the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] This disclosure relates to a display device, and more specifically, to a display device capable of minimizing light emission caused by leakage current. Background Technology

[0004] Recently, as our society moves towards an information society, the field of display devices for visually representing electrical information signals has developed rapidly. Various display devices with excellent performance in terms of thinness, lightness, and low power consumption are also continuously evolving accordingly.

[0005] Among these various display devices, unlike liquid crystal displays (LCDs) which have a separate light source, organic light-emitting diode (OLED) displays are self-emissive. Because OLEDs do not require a separate light source, they can be manufactured in a thinner and lighter form factor. Furthermore, OLEDs offer advantages in power consumption due to their low driving voltage, and excel in color reproduction, response speed, viewing angle, and contrast ratio (CR). Therefore, OLEDs are being researched as the next generation of displays. Summary of the Invention

[0006] One aspect of this disclosure is to provide a display device that employs a multi-stack structure using multiple light-emitting units to achieve improved efficiency and lifespan characteristics.

[0007] Another aspect of this disclosure is to provide a display device that minimizes the phenomenon that a portion of a plurality of light-emitting elements having a common layer emits light due to leakage current.

[0008] Another aspect of this disclosure is to provide a display device that can prevent leakage current and at the same time prevent a bluish tint.

[0009] The purpose of this disclosure is not limited to the above-mentioned purposes, and other purposes not mentioned above will be clearly understood by those skilled in the art through the following description.

[0010] A display device according to an exemplary embodiment of the present disclosure includes: a substrate in which a light-emitting region and a non-light-emitting region are divided and a plurality of sub-pixels are defined; an insulating layer disposed above the substrate; a first electrode disposed in each of the plurality of sub-pixels; a dam disposed on the insulating layer and exposing the first electrode through an opening therein; an organic layer disposed on the first electrode; and a second electrode disposed on the organic layer, wherein the dam has exposed sides by removing a region between the plurality of sub-pixels and has an undercut structure extending inward from the lower end of the exposed sides, wherein the dam has other exposed sides by removing another region between the plurality of sub-pixels and has a trench structure by removing a portion of the thickness of the insulating layer.

[0011] Further details of the exemplary embodiments are included in the detailed description and accompanying drawings.

[0012] According to this disclosure, high efficiency can be achieved by applying organic light-emitting elements with multi-stacked structures, and low drive current can be allowed, thereby improving the lifetime of organic light-emitting elements.

[0013] According to this disclosure, current leakage through a common layer of multiple light-emitting elements can be prevented or minimized.

[0014] According to this disclosure, accidental luminescence of the light-emitting element can be minimized and blue tint can be prevented, thereby improving color reproduction.

[0015] The effects of this disclosure are not limited to the examples above and below, and include many more effects in this specification. Attached Figure Description

[0016] Figure 1 This is an enlarged plan view of a sub-pixel of a display device according to a first exemplary embodiment of the present disclosure.

[0017] Figure 2 It is along Figure 1 The cross-sectional view taken from line I-I'.

[0018] Figure 3A and Figure 3B These are TEM (transmission electron microscopy) images of the embankment according to the comparative example, shown as examples.

[0019] Figure 4 This is a cross-sectional view of the angle of inclination of the exposed side of the embankment according to this disclosure, shown as an example.

[0020] Figure 5 The image shown is a TEM image of a embankment according to this disclosure, presented as an example.

[0021] Figure 6It is an image showing the small potential voltage difference based on the resistance of the thin film.

[0022] Figure 7 This is an enlarged plan view of a sub-pixel of a display device according to a second exemplary embodiment of the present disclosure.

[0023] Figure 8 It is along Figure 7 The cross-sectional view taken from line VII-VII'.

[0024] Figure 9 This is an enlarged plan view of a sub-pixel of a display device according to a third exemplary embodiment of the present disclosure.

[0025] Figure 10 It is along Figure 9 The cross-sectional view taken from line IX-IX'.

[0026] Figure 11 This is an enlarged plan view of a sub-pixel of a display device according to a fourth exemplary embodiment of the present disclosure.

[0027] Figure 12 It is along Figure 11 The cross-sectional view taken from line XIA-XIa'.

[0028] Figure 13 It is along Figure 11 The cross-sectional view taken from line XIb-XIb'.

[0029] Figure 14A It is a TEM image of subpixels according to a fourth exemplary embodiment of the present disclosure.

[0030] Figure 14B It is along Figure 14A The cross-sectional image captured by line A-A'.

[0031] Figure 14C It is along Figure 14A The cross-sectional image captured by line B-B'. Detailed Implementation

[0032] The advantages and features of this disclosure and its implementation methods will become clear from the following detailed description of exemplary embodiments and the accompanying drawings. However, this disclosure is not limited to the exemplary embodiments disclosed herein, but is implemented in various forms. Exemplary embodiments are provided by way of example only so that those skilled in the art can fully understand the disclosure and scope of this disclosure. Therefore, this disclosure is limited only by the scope of the appended claims.

[0033] The shapes, dimensions, ratios, angles, quantities, etc., shown in the accompanying drawings to describe exemplary embodiments of this disclosure are merely examples, and this disclosure is not limited thereto. Throughout the specification, similar reference numerals generally denote similar elements. Furthermore, in the following description of this disclosure, detailed descriptions of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of this disclosure. Terms such as “comprising,” “having,” and “consisting of” as used herein are generally intended to allow for the addition of additional components, unless used in conjunction with the term “only.” Unless otherwise expressly stated, any reference to the singular may include the plural.

[0034] Even if not explicitly stated, the component is to be interpreted as including a general tolerance range.

[0035] When using terms such as “above,” “over,” “below,” and “near” to describe the positional relationship between two parts, one or more parts may be located between the two parts unless the term is used with the terms “exactly” or “directly.”

[0036] When an element or layer is placed "on" another element or layer, the other layer or element may be placed directly on top of the other element or between them.

[0037] Although the terms "first," "second," etc., are used to describe various components, these components are not limited to these terms. These terms are only used to distinguish one component from other components. Therefore, in the technical concept of this disclosure, the first component referred to below can be the second component.

[0038] Throughout the specification, similar reference numerals generally denote similar elements.

[0039] The dimensions and thicknesses of each component shown in the figures are for ease of description and this disclosure is not limited to the dimensions and thicknesses of the components shown.

[0040] The features of the various embodiments of this disclosure may be combined or integrated with each other in part or in whole, and may be interlocked and operated in various technical ways, and the embodiments may be implemented independently of each other or in relation to each other.

[0041] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0042] Figure 1 This is an enlarged plan view of a sub-pixel of a display device according to a first exemplary embodiment of the present disclosure.

[0043] Figure 2 It is along Figure 1 The cross-sectional view taken from line I-I'.

[0044] Figure 1The example shown illustrates the case where the shapes of subpixels R, G, and B are rectangles, but this disclosure is not limited thereto. Figure 2 It shows in Figure 1 The cross-sectional structure includes any one transistor 120. For example, in Figure 2 For ease of description, only one transistor 120 of the pixel circuitry for a single sub-pixel R, G, or B is shown. Additionally, Figure 2 Together, we show the cross-sections of any two sub-pixels G and B taken along the horizontal direction, and the cross-sections of any two sub-pixels R and G taken along the vertical direction.

[0045] In one or more embodiments of this disclosure, the display device may include: a display panel PN including a plurality of sub-pixels R, G, and B; a gate driver and a data driver that provide various signals to the display panel PN; and a timing controller that controls the gate driver and the data driver. The sub-pixels may also be combinations of different sub-pixels (e.g., R (red), G (green), B (blue), and W (white)).

[0046] refer to Figure 1 and Figure 2 As an example, the display panel PN according to the first exemplary embodiment of this disclosure may include a substrate 110, a transistor 120, a light-emitting element 130, a dam 114, and a package 150. The display device may be implemented as a top-emitting display device, but is not limited thereto.

[0047] The display panel PN is a component used to display images to a user and may include multiple sub-pixels R, G, and B. In the display panel PN, multiple scan lines and multiple data lines intersect each other, and each of the multiple sub-pixels R, G, and B can be connected to both scan lines and data lines. Additionally, each of the multiple sub-pixels R, G, and B can be connected to high-potential power lines, low-potential power lines, initialization signal lines, light emission control signal lines, etc.

[0048] Subpixels R, G, or B are the smallest units of the screen that constitute the display panel PN, and each of the plurality of subpixels R, G, and B may include a light-emitting element 130 and pixel circuitry for driving the light-emitting element 130. The plurality of light-emitting elements 130 may be defined differently depending on the type of the display panel PN. For example, when the display panel PN is an organic light-emitting display panel, the light-emitting element 130 may be an organic light-emitting element including a first electrode 131, an organic layer 132, and a second electrode 133. In the following description, it is assumed that the light-emitting element 130 is an organic light-emitting element, but this disclosure is not limited thereto.

[0049] The pixel circuit is a circuit used to control the driving of the light-emitting element 130. The pixel circuit may include, for example, multiple transistors 120 and capacitors, but is not limited thereto.

[0050] The plurality of subpixels R, G, and B are independent light-emitting units, and the light-emitting element 130 can be disposed in each of the plurality of subpixels R, G, and B. The plurality of subpixels R, G, and B may include a first subpixel R, a second subpixel G, and a third subpixel B that emit light of different colors, but are not limited thereto. For example, the first subpixel R may be a blue subpixel, the second subpixel G may be a green subpixel, and the third subpixel B may be a red subpixel, but this disclosure is not limited thereto.

[0051] The regions of multiple sub-pixels R, G, and B can be defined by the dam 114. For example, the dam 114 can be configured to partially cover the planarization layer 113 and the first electrode 131 of the light-emitting element 130 in the multiple sub-pixels R, G, and B. The substrate 110 can be divided into light-emitting regions and non-light-emitting regions. For example, in the non-light-emitting regions, the dam 114 can be disposed on the first electrode 131 to prevent light generation in the non-light-emitting regions. On the other hand, the dam 114 is not disposed in the light-emitting regions, and the organic layer 132 can be directly located on the first electrode 131, thereby allowing light to be generated from the organic layer 132.

[0052] Furthermore, this disclosure is characterized in that the undercut UC structure and the trench T structure are disposed together between multiple sub-pixels R, G, and B. For example, the undercut UC structure can be provided to prevent the light-emitting element 130 from emitting light due to leakage current, and the trench T structure can be provided to prevent the color from turning bluish due to reduced brightness.

[0053] In the undercut UC structure, the embankment 114 is removed to expose the side of the embankment 114, and the embankment 114 is further removed inward from the lower end of the exposed side of the embankment 114 at a predetermined distance, thereby forming the undercut UC.

[0054] In a first exemplary embodiment of this disclosure, the conductive pattern 131b formed by the conductive layer of the first electrode 131 is retained inside the undercut UC, but this disclosure is not limited thereto.

[0055] In the undercut UC structure, due to the steep inclination angle of the exposed side of the embankment 114 and the undercut UC structure, the organic layer 132 and the second electrode 133 of the light-emitting element 130 to be formed later are disconnected. At this time, within the undercut UC structure, the organic layer pattern 132a and the second electrode pattern 133a are stacked on top of each other, and each of the organic layer pattern 132a and the second electrode pattern 133a is not connected to the organic layer 132 and the second electrode 133, and is disconnected from the organic layer 132 and the second electrode 133.

[0056] On the other hand, in the trench T structure, a trench T can be formed in the planarization layer 113 by removing a portion of the thickness of the lower planarization layer 113 and removing the embankment 114.

[0057] In the trench T structure, there is no undercut UC, so each of the organic layer 132 and the second electrode 133 of the light-emitting element 130 can be connected without interruption. However, due to the patterning of the embankment 114 and the trench T formed in the planarization layer 113, the leakage current path is extended, thereby reducing the impact of leakage current.

[0058] refer to Figure 1 For example, multiple third sub-pixels B can be set in the same column, and multiple first sub-pixels R and second sub-pixels G can be alternately set in the same column.

[0059] More specifically, multiple third sub-pixels B can be arranged in the first and third columns, and multiple first sub-pixels R and second sub-pixels G can be alternately arranged in the second and fourth columns. However, this disclosure is not limited thereto.

[0060] Additionally, for example, the first sub-pixel R and the second sub-pixel G can be set to the left and right of the third sub-pixel B, but are not limited to this.

[0061] Therefore, multiple third sub-pixels B and multiple first sub-pixels R and second sub-pixels G can be alternately arranged horizontally, and multiple third sub-pixels B can be repeatedly arranged vertically, or multiple first sub-pixels R and multiple second sub-pixels G can be alternately arranged vertically. In this case, the undercut UC structure can be arranged vertically among multiple sub-pixels R, G and B, while the trench T structure can be arranged horizontally among multiple sub-pixels R, G and B. For example, the undercut UC structure can be arranged vertically among multiple third sub-pixels B and multiple first sub-pixels R and second sub-pixels G (see reference). Figure 3A Furthermore, the trench T structure can be horizontally positioned between multiple first sub-pixels R and multiple second sub-pixels G (see reference). Figure 3B However, this disclosure is not limited thereto.

[0062] For example, the groove T-structure can be formed to extend laterally from the undercut UC structure set in the longitudinal direction, but is not limited to this.

[0063] Undercut UC structures can be divided into multiple undercut structures, but are not limited to this.

[0064] The groove T-structure can be formed longitudinally between multiple separate undercut UC structures, but is not limited to this.

[0065] For example, the undercut UC structure of this disclosure can effectively prevent lateral leakage current generated in multi-stacked structures. For example, due to the undercut UC structure of this disclosure, the organic layer 132 and the second electrode 133 between adjacent sub-pixels R, G, and B can be disconnected from each other. However, this disclosure is not limited to multi-stacked structures and can be effectively applied to situations where lateral leakage current is generated in conventional organic light-emitting display devices.

[0066] In this case, the organic layer 132 and the second electrode 133 being disconnected from each other between adjacent sub-pixels R, G, and B means that they are only disconnected from each other in the region where the undercut UC structure is provided. In regions other than this region, the organic layer 132 and the second electrode 133 are connected to each other.

[0067] In addition, this disclosure is more effective in preventing leakage current that may occur due to the use of a common layer as a result of the process characteristics of organic light-emitting display devices, and in particular, more effective in preventing leakage current that occurs through strong current paths formed primarily in low grayscale regions.

[0068] Furthermore, this disclosure can solve or address the problem of bluish color shift caused by reduced brightness and can prevent leakage current. For example, when connecting the second electrode 133, this disclosure prevents lateral leakage current between the plurality of third sub-pixels B and the plurality of first sub-pixels R and second sub-pixels G through an undercut UC structure, and simultaneously extends the current path between the plurality of first sub-pixels R and the plurality of second sub-pixels G, thereby compensating for the bluish color shift. For example, since the low potential voltage of the second electrode 133 is more affected by the lateral thin-film resistance than the vertical thin-film resistance, a trench T structure can be formed, which extends the current path between the first sub-pixels R and the second sub-pixels G, while the second electrode 133 remains connected. This will be described in detail later.

[0069] The groove T-structure can be patterned together with the undercut UC structure.

[0070] refer to Figure 2 The substrate 110 (a support member for supporting other components of the display device) may be formed of an insulating material.

[0071] For example, substrate 110 can be formed of glass or resin. Alternatively, substrate 110 can be formed of a polymer such as polyimide (PI) or a plastic, or it can be formed of a flexible material.

[0072] A buffer layer 111 may be disposed above the substrate 110. The buffer layer 111 can reduce the penetration of moisture or impurities through the substrate 110. For example, the buffer layer 111 may be made of silicon oxide (SiO2). x ) or silicon nitride (SiN) xThe buffer layer 111 may be formed in one or more layers, but is not limited thereto. However, depending on the type of substrate 110 or the type of transistor, the buffer layer 111 may be omitted, but is not limited thereto.

[0073] Transistor 120 may be disposed above buffer layer 111. Transistor 120 may include gate electrode 121, active layer 122, source electrode 123 and drain electrode 124.

[0074] Figure 2 The transistor 120 shown is a transistor with a bottom gate structure, wherein the active layer 122 is disposed above the gate electrode 121 and the source electrode 123 and the drain electrode 124 are disposed above the active layer 122, but this disclosure is not limited thereto.

[0075] The gate electrode 121 can be disposed above the buffer layer 111.

[0076] The gate electrode 121 may be formed of a conductive material, such as copper (Cu), aluminum (Al), molybdenum (Mo), nickel (Ni), titanium (Ti), chromium (Cr), or alloys thereof, but is not limited thereto.

[0077] The gate insulating layer 112 can be disposed above the gate electrode 121.

[0078] Gate insulating layer 112 is an insulating layer used to insulate the active layer 122 and the gate electrode 121, and can be made of silicon oxide (SiO2). x ) or silicon nitride (SiN) x It consists of a single layer or multiple layers, but is not limited to this.

[0079] The active layer 122 can be disposed above the gate insulating layer 112.

[0080] The active layer 122 may be formed of a semiconductor material such as oxide semiconductor, amorphous silicon, or polycrystalline silicon, but is not limited thereto. For example, when the active layer 122 is formed of oxide semiconductor, the active layer 122 may be formed of a trench region, a source region, and a drain region, and the source region and drain region may be conductive regions, but are not limited thereto.

[0081] An etch barrier layer 117 may be disposed on the active layer 122. When the source electrode 123 and drain electrode 124 are patterned by an etching method, the etch barrier layer 117 may be additionally formed to prevent plasma from damaging the surface of the active layer 122. A portion of one end of the etch barrier layer 117 may overlap with the source electrode 123, and a portion of the other end of the etch barrier layer 117 may overlap with the drain electrode 124. However, the etch barrier layer 117 may be omitted.

[0082] Source electrode 123 and drain electrode 124 may be disposed above active layer 122 and etch barrier layer 117. Source electrode 123 and drain electrode 124, which are disposed spaced apart from each other, may be electrically connected to active layer 122. Source electrode 123 and drain electrode 124 may be formed of conductive material, such as copper (Cu), aluminum (Al), molybdenum (Mo), nickel (Ni), titanium (Ti), chromium (Cr), or alloys thereof, but are not limited thereto.

[0083] Planarization layer 113 may be disposed above transistor 120. Planarization layer 113 is an insulating layer that planarizes the upper part of substrate 110. Planarization layer 113 may be formed of organic material and may be composed of a single layer or multiple layers of, for example, polyimide or photoacrylic acid, but is not limited thereto.

[0084] The light-emitting element 130 can be disposed in each of the plurality of sub-pixels R, G, and B above the planarization layer 113. The light-emitting element 130 may include a first electrode 131, an organic layer 132, and a second electrode 133. However, the organic layer 132 may be composed of a light-emitting layer disposed in the light-emitting region and a common layer disposed above the entire surface of the substrate 110 (including the light-emitting region and the non-light-emitting region), but is not limited thereto.

[0085] The first electrode 131 can be disposed on the planarization layer 113.

[0086] The first electrode 131 can be electrically connected to the transistor 120 and receive the drive current of the pixel circuit. Since the first electrode 131 supplies holes to the light-emitting layer, it can be formed of a conductive material with a high work function. For example, the first electrode 131 can be formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO), but is not limited thereto.

[0087] The display device can be implemented using either a top-emitting or bottom-emitting method. In the case of a top-emitting method, a metallic material with excellent reflectivity (e.g., a reflective layer formed of a material such as aluminum (Al) or silver (Ag)) can be added below the first electrode 131, such that light emitted from the light-emitting layer is reflected onto the first electrode 131 and directed upwards, for example, toward the second electrode 133. On the other hand, when the display device is bottom-emitting, the first electrode 131 can be formed solely of a transparent conductive material. In the following description, it will be assumed that the display device according to the exemplary embodiments is a top-emitting type, but this disclosure is not limited thereto.

[0088] The first electrode 131 may be formed in a stacked structure including, for example, a reflective layer, two or more layers.

[0089] The organic layer 132 can be disposed between the first electrode 131 and the second electrode 133.

[0090] The organic layer 132 is the region in which light is emitted by the combination of electrons and holes supplied from the first electrode 131 and the second electrode 133.

[0091] Meanwhile, in order to improve the quality and productivity of organic light-emitting display devices, various organic light-emitting element structures have been proposed to improve the efficiency and lifespan of organic light-emitting elements and reduce their power consumption.

[0092] Therefore, in addition to organic light-emitting elements employing a single stack (e.g., a single electroluminescent (EL) unit), organic light-emitting elements 130 with a tandem structure (where multiple stacks, e.g., a stack of multiple light-emitting units) have been proposed to achieve improved efficiency and lifetime characteristics. Although this disclosure is not limited to tandem structures, tandem structures will be described below as examples for convenience.

[0093] In an organic light-emitting element 130 with a series structure (e.g., a two-stack structure using a stack of first and second light-emitting units), the light-emitting region that emits light through the recombination of electrons and holes is located in each of the first and second light-emitting units, and the light emitted from the first light-emitting layer of the first light-emitting unit and the light emitted from the second light-emitting layer of the second light-emitting unit may respectively cause constructive interference. Therefore, compared with a single-stack organic light-emitting element 130, a two-stack organic light-emitting element 130 can provide higher brightness.

[0094] The stacked structure may include, for example, a charge-generating layer disposed between the first electrode 131 and the second electrode 133, a first stack disposed between the charge-generating layer and the first electrode 131, and a second stack disposed between the second electrode 133 and the charge-generating layer. The charge-generating layer may be disposed between the first stack and the second stack to generate charge. The charge-generating layer may be formed as a structure of a stack of p-type and n-type charge-generating layers. For example, the charge-generating layer may consist of a p-type charge-generating layer and an n-type charge-generating layer that generate positive and negative charges in two directions, and may generally function as electrodes.

[0095] Each of the first stack and the second stack includes at least one light-emitting layer and may include common layers above and below the light-emitting layers, with each light-emitting layer located between the common layers.

[0096] Furthermore, as the resolution of organic light-emitting display devices increases, the distance between the multiple sub-pixels R, G, and B constituting a pixel in the organic light-emitting element 130 decreases. Auxiliary organic layers (e.g., hole injection layer EIL, hole transport layer HTL, charge generation layer CGL, electron injection layer EIL, electron transport layer ETL, etc.) other than the emissive layer EML are deposited using a common mask to correspond to all of the multiple sub-pixels R, G, and B and form a common layer. Alternatively, fine masks can be used to deposit emissive layers that generate light of different wavelengths in each of the multiple sub-pixels R, G, and B, forming layers corresponding to each sub-pixel R, G, and B.

[0097] In the case of the organic light-emitting element 130 as described above, when a voltage is applied between the first electrode 131 and the second electrode 133, a lateral leakage current is generated in the lateral direction of the organic light-emitting element 130 through the common layer formed in the organic light-emitting element 130. Therefore, color mixing defects occur because not only do the required light-emitting sub-pixels R, G, and B emit light, but also the adjacent unwanted sub-pixels R, G, and B emit light. Compared to a single-stack organic light-emitting element, the aforementioned color mixing defects may be more severe in a double-stack organic light-emitting element 130 that utilizes the constructive interference of light by stacking the first and second light-emitting units.

[0098] Therefore, in this disclosure, an undercut UC structure is formed between multiple sub-pixels R, G, and B, such that the organic layer 132 and the second electrode 133 between adjacent sub-pixels R, G, and B are partially disconnected, and the current path is increased through the trench T structure (especially when driving a display device with a multi-stack structure), thereby minimizing leakage current. In this disclosure, for example, an undercut UC structure is formed between multiple third sub-pixels B and multiple first sub-pixels R and second sub-pixels G, and a trench T structure is formed between the first sub-pixels R and the second sub-pixels G.

[0099] In the undercut UC structure, the embankment 114 is removed to expose the side of the embankment 114, and the embankment 114 is further removed inward from the lower end of the exposed side of the embankment 114 at a predetermined distance, thereby forming the undercut UC.

[0100] In a first exemplary embodiment of this disclosure, the conductive pattern 131b formed by the conductive layer of the first electrode 131 is retained inside the undercut UC, but this disclosure is not limited thereto.

[0101] Within the undercut UC structure, the organic layer pattern 132a and the second electrode pattern 133a are stacked on top of each other, and each of the organic layer pattern 132a and the second electrode pattern 133a is not connected to the organic layer 132 and the second electrode 133, and is disconnected from the organic layer 132 and the second electrode 133.

[0102] Furthermore, at high brightness, a bluish color difference (27%) may occur due to the reduced brightness of red and green compared to blue. Compared to the case without an undercut UC structure, the brightness decreases with an undercut UC structure due to the increased resistance of the second electrode 133. Specifically, a bluish color difference may occur because red and green are less bright than blue. Therefore, a trench T structure can be formed between the first sub-pixel R and the second sub-pixel G instead of an undercut UC structure, ensuring that the second electrode 133 remains connected. For example, if the connection of the second electrode 133 between the red first sub-pixel R and the green second sub-pixel G is completely blocked, a bluish color difference may occur. When a trench T structure is provided laterally instead of an undercut UC structure, the connection of the second electrode 133 can prevent the rise of low-potential voltage. For reference, the low-potential voltage deviation (max-Min) of the second electrode 133 due to changes in sheet resistance is more significantly affected by the lateral sheet resistance than by the vertical sheet resistance.

[0103] In this case, in the trench T structure, the trench T can be formed in the planarization layer 113 by removing a portion of the thickness of the lower planarization layer 113 and removing the embankment 114.

[0104] The groove T-structure can be patterned together with the undercut UC structure.

[0105] For example, when the first electrode 131 is patterned, a conductive layer pattern is additionally formed between a plurality of third sub-pixels B and a plurality of first sub-pixels R and second sub-pixels G.

[0106] Subsequently, a dam 114 is formed above the first electrode 131 and the planarization layer 113.

[0107] Next, when the embankment 114 on the conductive layer pattern is removed, the surface of the conductive layer pattern is exposed.

[0108] At the same time, the embankment 114 between the first sub-pixel R and the second sub-pixel G was removed to expose the surface of the planarization layer 113.

[0109] Dry etching can be used to remove the embankment 114, but this disclosure is not limited thereto.

[0110] Next, wet etching is performed to remove the conductive layer pattern, thereby forming an undercut UC in the lower part of the exposed side of the embankment 114. At the same time, since a portion of the thickness of the planarization layer 113 exposed between the first sub-pixel R and the second sub-pixel G is removed, a trench T is formed in the planarization layer 113.

[0111] At this time, the conductive pattern 131b formed by the conductive layer of the first electrode 131 remains inside the undercut UC, but this disclosure is not limited thereto.

[0112] See again Figure 2 The dam 114 can be disposed above the first electrode 131 and the planarization layer 113. The dam 114 is an insulating layer disposed between multiple sub-pixels R, G and B to distinguish the multiple sub-pixels R, G and B.

[0113] The dam 114 may include an opening OP that exposes a portion of the first electrode 131. The dam 114 may be formed of an organic insulating material configured to cover the edge or corner portions of the first electrode 131. The dam 114 may be formed of, for example, polyimide, acrylic, or a benzocyclobutene (BCB)-based resin, but is not limited thereto.

[0114] Multiple spacers can be disposed above the embankment 114 in the non-light-emitting area. For example, when forming the light-emitting element 130, the spacers can be disposed above the embankment 114 in the non-light-emitting area to maintain a predetermined distance from the deposition mask. The spacers ensure that the embankment 114 below the spacers and the first electrode 131 maintain a predetermined distance from the deposition mask and prevent damage caused by contact between the deposition mask and the embankment 114. In this case, the multiple spacers can be formed in a form where their width decreases upwards, for example, formed in a conical shape, to minimize the contact area with the deposition mask, but this disclosure is not limited thereto.

[0115] Organic layer 132 may be disposed on first electrode 131. Organic layer 132 may include a light-emitting layer disposed in each of the plurality of sub-pixels R, G, and B, and a common layer disposed together in the plurality of sub-pixels R, G, and B, but this disclosure is not limited thereto. The light-emitting layer is an organic layer for emitting light of a specific color, and different light-emitting layers may be disposed in each of the first sub-pixel R, the second sub-pixel G, and the third sub-pixel B. However, this disclosure is not limited thereto, and multiple light-emitting layers may be disposed in each of the sub-pixels R, G, and B to emit white light.

[0116] The common layer is an organic layer designed to improve the luminous efficiency of the light-emitting layer. The common layer can be formed as a single layer covering multiple sub-pixels R, G, and B. For example, the common layers of multiple sub-pixels R, G, and B can be interconnected and integrally formed. The common layer may include, but is not limited to, hole injection layers, hole transport layers, electron transport layers, electron injection layers, charge generation layers, etc.

[0117] The second electrode 133 can be disposed on the organic layer 132.

[0118] The second electrode 133 is an electrode that supplies electrons to the organic light-emitting element 130 according to a first exemplary embodiment of the present disclosure. The second electrode 133 may be formed of a material having a low work function. The second electrode 133 may include a transparent conductive material. For example, the second electrode 133 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), etc. Alternatively, the second electrode 133 may include any of the group consisting of metallic materials such as gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), palladium (Pd), copper (Cu), etc., or alloys thereof. For example, the second electrode 133 may be formed of an alloy of magnesium (Mg) and silver (Ag). Alternatively, the second electrode 133 may be constructed by stacking layers of transparent conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO) or indium gallium zinc oxide (IGZO) and layers of metallic materials such as gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), palladium (Pd), copper (Cu) or alloys thereof, but is not limited thereto.

[0119] The second electrode 133 can be electrically connected to a low-potential power line and receive a low-potential power signal.

[0120] The encapsulation part 150 can be disposed above the second electrode 133.

[0121] The encapsulation portion 150 can be disposed above the embankment portion 114 and the light-emitting element 130.

[0122] The encapsulation portion 150 can prevent oxygen and moisture from penetrating into the display device from the outside. For example, when the display device is exposed to moisture or oxygen, pixel shrinkage may occur, resulting in a reduction in the light-emitting area, or black spots may appear in the light-emitting area. Therefore, the encapsulation portion 150 can protect the display device by preventing oxygen and moisture from penetrating into it.

[0123] The packaging section 150 may include a first packaging layer 150a, a second packaging layer 150b, and a third packaging layer 150c.

[0124] The first encapsulation layer 150a can be disposed above the second electrode 133 and suppress the penetration of moisture or oxygen. The first encapsulation layer 150a can be made of materials such as silicon nitride (SiN). x ), silicon oxynitride (SiN) x O y ), or aluminum oxide (Al y O z Inorganic materials are formed, but not limited to this.

[0125] The second encapsulation layer 150b can be disposed on the first encapsulation layer 150a and the surface of the first encapsulation layer 150a can be planarized. Additionally, the second encapsulation layer 150b can cover foreign matter or particles that may appear during the manufacturing process of the display device. The second encapsulation layer 150b can be formed of an organic material, such as silicon carbide (SiO2). x C z Acrylic or epoxy resins, but not limited to these.

[0126] The third encapsulation layer 150c can be disposed on the second encapsulation layer 150b and suppress the penetration of moisture or oxygen. The third encapsulation layer 150c can be made of materials such as silicon nitride (SiN). x ), silicon oxynitride (SiN) x O y ), silicon oxide (SiO) x ) or aluminum oxide (Al y O z Inorganic materials are formed, but not limited to this.

[0127] Meanwhile, as described above, the common layer of the multiple light-emitting elements 130 can be formed as a single layer covering the multiple sub-pixels R, G, and B. In this case, since the multiple light-emitting elements 130 of the multiple sub-pixels R, G, and B are formed in a structure where they share a common layer, the following phenomenon may occur: when the light-emitting element 130 of a specific sub-pixel R, G, or B emits light, current flows to the light-emitting elements 130 of the sub-pixels R, G, and B adjacent to that specific sub-pixel R, G, or B, for example, current leakage. Current leakage causes the light-emitting elements 130 of other undesirable sub-pixels to emit light, which may lead to color mixing among the multiple sub-pixels R, G, and B, and increase power consumption. Furthermore, due to leakage current, color anomalies and unevenness may be visually identifiable, thereby reducing display quality. For example, when only the first sub-pixel R of the multiple sub-pixels R, G, and B emits light, a portion of the current supplied to drive the light-emitting element 130 of the first sub-pixel R may leak through the common layer to the second sub-pixel G and / or the third sub-pixel B adjacent to the first sub-pixel R.

[0128] Therefore, the display device of this disclosure is characterized by minimizing leakage current through the common layer of the light-emitting element 130 by forming an undercut UC structure and a trench T structure between a plurality of sub-pixels R, G and B as described above.

[0129] Furthermore, in the display device of this disclosure, the tilt angle of the side of the dam 114 above the undercut UC structure is relatively larger than the tilt angle of the side of the dam 114 in areas other than above the undercut UC structure (e.g., in the light-emitting area), thereby enabling more effective disconnection of the organic layer 132 and the second electrode 133 between adjacent sub-pixels R, G, and B. (Refer to...) Figure 3A and Figures 3B to 5 This will be described in detail.

[0130] Figure 3A and Figure 3B These are TEM images of the embankment according to the comparative example, shown as examples.

[0131] Figure 4 This is a cross-sectional view of the angle of inclination of the exposed side of the embankment according to this disclosure, shown as an example.

[0132] Figure 5 The image shown is a TEM image of a embankment according to this disclosure, presented as an example.

[0133] Figure 3A and Figure 3B A TEM (transmission electron microscope) image of the embankment 14 above the undercut is shown according to a comparative example, in which the tilt angle of the side of the embankment 14 is relatively small. Figure 4 and Figure 5 A TEM image of a dam 114 above the undercut UC according to an example of the present disclosure is shown, in which the tilt angle α of the side of the dam 114 is relatively large, for example, greater than 75°. Here, the taper angle α can vary depending on various process conditions, and the present disclosure can be applied to situations where the tilt angle α of the side of the dam 114 above the undercut UC has a relatively large angle compared to the tilt angle β of the side of the dam 114 in the light-emitting region. For reference, typically the tilt angle β of the side of the dam 114 in the light-emitting region is less than 40°.

[0134] Figure 3A and Figure 3B In a comparative example, the tilt angle of the side of the embankment 14 above the undercut has the same or similar value as the tilt angle of the side of the embankment 14 in the light-emitting area.

[0135] In this situation, as the inclination angle of the side of the embankment 14 decreases, the following may occur: Figure 3A As shown, its end is raised or as Figure 3B This illustrates the problem of its drooping ends.

[0136] On the other hand, reference Figure 4 and Figure 5 According to the examples of this disclosure, when the inclination angle α of the side of the embankment 14 above the undercut UC is relatively large, for example, above 75°, it can be confirmed that the undercut UC structure is formed stably without the problem of end lifting or sagging.

[0137] For example, when the width of the conductive layer pattern used for the undercut UC structure is approximately 6 μm and the width of the conductive layer pattern exposed by etching of the embankment 114 is approximately 2.5 μm, the undercut UC structure on one side can be formed within approximately 1 μm, and a portion of the conductive pattern can remain within the undercut UC. However, this disclosure is not limited thereto, and the conductive pattern may not be retained depending on the process conditions.

[0138] Figure 6 It is an image showing the small potential voltage difference based on the resistance of the thin film.

[0139] Figure 6 The horizontal axis represents the value of the lateral thin-film resistance, while Figure 6 The longitudinal axis represents the value of the longitudinal sheet resistance. Figure 6 The low potential voltage deviation (max-Min) of the thin film resistance is shown to decrease from red towards blue.

[0140] refer to Figure 6 As the sheet resistance increases, the low-potential voltage deviation (max-Min) increases. In particular, in the case of sheet resistance in the lateral direction, it can be confirmed that as the sheet resistance increases, the low-potential voltage deviation (max-Min) increases very significantly.

[0141] For example, it can be confirmed that the low potential voltage deviation (max-Min) of the second electrode based on the sheet resistance is more affected by the sheet resistance in the transverse direction than the sheet resistance in the longitudinal direction.

[0142] Figure 7 This is an enlarged plan view of a sub-pixel of a display device according to a second exemplary embodiment of the present disclosure.

[0143] Figure 8 It is along Figure 7 The cross-sectional view taken from line VII-VII'.

[0144] Aside from the fact that no conductive pattern is retained within the undercut UC, Figure 7 and Figure 8 The second exemplary embodiment of this disclosure shown has a configuration substantially the same as the first exemplary embodiment of this disclosure. Therefore, redundant descriptions of the same configuration will be omitted or can be briefly described.

[0145] Figure 7 An example is shown in which the shapes of subpixels R, G, and B are rectangular, but this disclosure is not limited to the shapes of subpixels R, G, and B. Figure 8 It shows including Figure 7 Any one of the transistors 120 in the cross-sectional structure. Additionally, Figure 8The diagram shows cross-sections of any two sub-pixels G and B taken horizontally and cross-sections of any two sub-pixels R and G taken vertically.

[0146] refer to Figure 7 and Figure 8 The display panel PN according to the second exemplary embodiment of the present disclosure is characterized in that the undercut UC structure and the groove T structure are disposed together between a plurality of sub-pixels R, G and B in the same manner as the aforementioned first exemplary embodiment of the present disclosure.

[0147] In the undercut UC structure, the embankment 214 is removed to expose the side of the embankment 214, and the embankment 214 is further removed inward from the lower end of the exposed side of the embankment 214 at a predetermined distance, thereby forming the undercut UC.

[0148] In a second exemplary embodiment of this disclosure, the conductive pattern formed by the conductive layer of the first electrode 231 is not retained within the undercut UC. In this case, whether the conductive pattern is retained within the undercut UC or not can be determined by the difference in wet etching. For example, when using a high-viscosity phosphoric acid / nitric acid / acetic acid etching solution, silver (Ag) can be easily removed, thereby removing the entire conductive pattern including silver (Ag).

[0149] If the conductive pattern is not retained within the undercut UC, its advantage is that it prevents accidental short circuits caused by the conductive pattern.

[0150] In the undercut UC structure, due to the steep inclination angle of the exposed side of the embankment 214 and the undercut UC structure, the organic layer pattern 232a and the second electrode pattern 233a are stacked on top of each other within the undercut UC structure, and each of the organic layer pattern 232a and the second electrode pattern 233a is not connected to the organic layer 232 and the second electrode 233, and is disconnected from the organic layer 232 and the second electrode 233.

[0151] On the other hand, in the trench T structure, the trench T can be formed in the planarization layer 113 by removing a portion of the thickness of the lower planarization layer 113 and removing the embankment 214.

[0152] In the trench T structure, there is no undercut UC, so each of the organic layer 232 and the second electrode 233 of the light-emitting element 230 can be connected without interruption.

[0153] In the same manner as the first exemplary embodiment of this disclosure described above, the undercut UC structure can be arranged vertically among multiple sub-pixels R, G, and B, and the trench T structure can be arranged horizontally among multiple sub-pixels R, G, and B. For example, the undercut UC structure can be arranged vertically between multiple third sub-pixels B and multiple first sub-pixels R and second sub-pixels G (see reference). Figure 7 (A) and simultaneously, the trench T structure can be arranged laterally between multiple first sub-pixels R and multiple second sub-pixels G (see reference). Figure 7 (B). However, this disclosure is not limited thereto.

[0154] For example, the groove T-structure can be formed to extend laterally from the undercut UC structure located in the longitudinal direction, but is not limited thereto.

[0155] Undercut UC structures can be divided into multiple undercut structures, but are not limited to this.

[0156] The groove T-structure can be formed longitudinally between multiple separate undercut UC structures, but is not limited to this.

[0157] The groove T-structure can be patterned together with the undercut UC structure.

[0158] Figure 9 This is an enlarged plan view of a sub-pixel of a display device according to a third exemplary embodiment of the present disclosure.

[0159] Figure 10 It is along Figure 9 The cross-sectional view taken from line IX-IX'.

[0160] In addition to the shapes of the sub-pixels R, G, and B Figure 9 and Figure 10 The third exemplary embodiment of this disclosure shown has a configuration substantially the same as the first exemplary embodiment of this disclosure. Therefore, redundant descriptions of the same configuration will be omitted or can be briefly described.

[0161] For example, Figure 9 The illustration shows cases where the shapes of sub-pixels R, G, and B are octagonal or elliptical, but this disclosure is not limited to the shapes of sub-pixels R, G, and B.

[0162] in addition, Figure 10 It shows including Figure 9 Any one of the transistors 120 in the cross-sectional structure. And, Figure 10 The diagram shows the cross-sections of any two sub-pixels G and R taken along the diagonal direction, and the cross-sections of any two sub-pixels R and B taken along the horizontal direction.

[0163] refer to Figure 9 and Figure 10For example, multiple second sub-pixels G can be set in the same column, and multiple first sub-pixels R and third sub-pixels B can be alternately set in the same column.

[0164] More specifically, multiple second sub-pixels G can be arranged in the first, third, and fifth columns, and multiple first sub-pixels R and third sub-pixels B can be alternately arranged in the second and fourth columns. However, this disclosure is not limited thereto.

[0165] Furthermore, for example, multiple second sub-pixels G can be set in the same row, and multiple first sub-pixels R and third sub-pixels B can be alternately set in the same row.

[0166] More specifically, multiple second sub-pixels G can be arranged in the first, third, and fifth rows, and multiple first sub-pixels R and third sub-pixels B can be alternately arranged in the second and fourth rows. However, this disclosure is not limited thereto.

[0167] Additionally, for example, multiple second sub-pixels G and third sub-pixels B can be alternately arranged along a diagonal direction, and multiple first sub-pixels R and second sub-pixels G can be alternately arranged along adjacent diagonal directions. Furthermore, multiple second sub-pixels G and third sub-pixels B can be alternately arranged along another diagonal direction, and multiple first sub-pixels R and second sub-pixels G can be alternately arranged along another adjacent diagonal direction.

[0168] Meanwhile, in the third exemplary embodiment of this disclosure, in addition to the contact area CA of the first electrode 331, the undercut UC structure can be disposed along the lateral and diagonal directions between the plurality of sub-pixels R, G, and B, and the trench T structure can be disposed along the longitudinal direction between the plurality of sub-pixels R, G, and B. For example, in addition to the contact area CA of the first electrode 331, the undercut UC structure can be disposed along the lateral and diagonal directions between the plurality of first sub-pixels R and the plurality of second sub-pixels G or between the plurality of third sub-pixels B and the plurality of second sub-pixels G (see reference). Figure 9 (A and C), and simultaneously, the trench T structure can be arranged longitudinally among multiple second sub-pixels G (see reference). Figure 9 (B). However, this disclosure is not limited thereto.

[0169] Since the contact area CA of the first electrode 331 does not have space for forming a conductive layer pattern, an undercut UC structure or a trench T structure may not be formed.

[0170] For example, the trench T structure can be formed as extending longitudinally from the undercut UC structure set along the diagonal direction, but is not limited to this.

[0171] Undercut UC structures can be divided into multiple undercut structures, but are not limited to this.

[0172] The groove T-structure can be patterned together with the undercut UC structure.

[0173] In this manner, the display panel PN according to the third exemplary embodiment of the present disclosure is characterized in that the undercut UC structure and the groove T structure are disposed together between a plurality of sub-pixels R, G and B.

[0174] In the undercut UC structure, the embankment 314 is removed to expose the side of the embankment 314, and the embankment 314 is further removed inward from the lower end of the exposed side of the embankment 314 at a predetermined distance, thereby forming the undercut UC.

[0175] In a third exemplary embodiment of this disclosure, the conductive pattern 331b formed by the conductive layer of the first electrode 331 is retained inside the undercut UC, but is not limited thereto.

[0176] In the undercut UC structure, due to the steep inclination angle of the exposed side of the embankment 314 and the undercut UC structure, the organic layer pattern 332a and the second electrode pattern 333a are stacked on top of each other within the undercut UC structure, and each of the organic layer pattern 332a and the second electrode pattern 333a is not connected to the organic layer 332 and the second electrode 333, and is disconnected from the organic layer 332 and the second electrode 333.

[0177] On the other hand, in the trench T structure, a trench T can be formed in the planarization layer 113 by removing a portion of the thickness of the lower planarization layer 113 and removing the embankment 314.

[0178] In the trench T structure, there is no undercut UC, so each of the organic layer 332 and the second electrode 333 of the light-emitting element 330 can be connected without interruption.

[0179] Figure 11 This is an enlarged plan view of a sub-pixel of a display device according to a fourth exemplary embodiment of the present disclosure.

[0180] Figure 12 It is along Figure 11 The cross-sectional view taken from line XIA-XIa'.

[0181] Figure 13 It is along Figure 11 The cross-sectional view taken from line XIb-XIb'.

[0182] Figure 14A It is a TEM image of subpixels according to a fourth exemplary embodiment of the present disclosure.

[0183] Figure 14B It is along Figure 14A The cross-sectional image captured by line A-A'.

[0184] Figure 14C It is along Figure 14A The cross-sectional image captured by line B-B'.

[0185] In addition to the shapes of the sub-pixels R, G, and B Figures 11 to 13 The fourth exemplary embodiment of this disclosure shown has a configuration substantially the same as the first exemplary embodiment of this disclosure. Therefore, redundant descriptions of the same configuration will be omitted or can be briefly described. Furthermore, except for omitting the trench structure, the fourth exemplary embodiment of this disclosure has a configuration substantially the same as the third exemplary embodiment of this disclosure described above.

[0186] For example, Figure 11 The illustration shows cases where the shapes of sub-pixels R, G, and B are octagonal or elliptical, but this disclosure is not limited to the shapes of sub-pixels R, G, and B.

[0187] in addition, Figure 12 It shows including Figure 11 Any one of the transistors 120 in the cross-sectional structure. Further, Figure 12 The diagram shows a cross-section of any two sub-pixels G and B taken along the diagonal direction. Figure 13 It shows in Figure 11 The cross-section of the undercut end of UC is taken from the cross-sectional structure.

[0188] Figure 14A and Figure 14B TEM images of the undercut UC structure according to the fourth exemplary embodiment of this disclosure are shown as examples. Figure 14C A TEM image of a cross-section taken from the end of the undercut UC is shown.

[0189] refer to Figures 11 to 13 For example, multiple second sub-pixels G can be set in the same column, and multiple first sub-pixels R and third sub-pixels B can be alternately set in the same column.

[0190] More specifically, multiple second sub-pixels G can be arranged in the first, third, and fifth columns, and multiple first sub-pixels R and third sub-pixels B can be alternately arranged in the second and fourth columns. However, this disclosure is not limited thereto.

[0191] Furthermore, for example, multiple second sub-pixels G can be set in the same row, and multiple first sub-pixels R and third sub-pixels B can be alternately set in the same row.

[0192] More specifically, multiple second sub-pixels G can be arranged in the first, third, and fifth rows, and multiple first sub-pixels R and third sub-pixels B can be alternately arranged in the second and fourth rows. However, this disclosure is not limited thereto.

[0193] Additionally, for example, multiple second sub-pixels G and third sub-pixels B can be alternately arranged along a diagonal direction, and multiple first sub-pixels R and second sub-pixels G can be alternately arranged along adjacent diagonal directions. Furthermore, multiple second sub-pixels G and third sub-pixels B can be alternately arranged along another diagonal direction, and multiple first sub-pixels R and second sub-pixels G can be alternately arranged along another adjacent diagonal direction.

[0194] Furthermore, in the fourth exemplary embodiment of this disclosure, in addition to the contact area CA of the first electrode 431, the undercut UC structure can be arranged diagonally between multiple sub-pixels R, G, and B. For example, in addition to the contact area CA of the first electrode 431, the undercut UC structure can be arranged diagonally between multiple first sub-pixels R and multiple second sub-pixels G, or between multiple third sub-pixels B and multiple second sub-pixels G. However, this disclosure is not limited thereto.

[0195] For example, a portion of the undercut UC structure can extend longitudinally in the diagonal direction, but it is not limited to this.

[0196] Undercut UC structures can be divided into multiple undercut structures, but are not limited to this.

[0197] In this way, the display panel PN according to the fourth exemplary embodiment of the present disclosure is characterized in that the undercut UC structure is disposed between a plurality of sub-pixels R, G and B.

[0198] refer to Figure 12 as well as Figure 14A and Figure 14B In the undercut UC structure, the embankment 414 is removed to expose the side of the embankment 414, and the embankment 414 is further removed inward from the lower end of the exposed side of the embankment 414 at a predetermined distance, thereby forming the undercut UC.

[0199] In the fourth exemplary embodiment of this disclosure, the conductive pattern 431b formed by the conductive layer of the first electrode 431 is retained inside the undercut UC, but is not limited thereto.

[0200] In the undercut UC structure, due to the steep inclination angle of the exposed side of the embankment 414 and the undercut UC structure, the organic layer pattern 432a and the second electrode pattern 433a are stacked on top of each other within the undercut UC structure, and each of the organic layer pattern 432a and the second electrode pattern 433a is not connected to the organic layer 432 and the second electrode 433, and is disconnected from the organic layer 432 and the second electrode 433.

[0201] In the fourth exemplary embodiment of this disclosure, the trench T structure is omitted, but reference is made to... Figure 13 as well as Figure 14A and Figure 14C Due to the etching differences from other areas at the end of the undercut UC structure, a short trench T can be formed in the planarization layer 113 by removing a portion of the thickness of the planarization layer 113 from the side of the embankment 414.

[0202] However, in the trench T structure of the fourth exemplary embodiment of this disclosure, the organic layer 432 and the second electrode 433 of the light-emitting element 430 can be connected to the organic layer pattern 432a and the second electrode pattern 433a in the adjacent undercut UC structure. However, the present invention is not limited thereto.

[0203] For example, the thickness of the organic layer 432 and the second electrode 433 in the trench T structure may be 20% to 30% and 50% of the thickness of each of the organic layer pattern 432a and the second electrode pattern 433a in other regions (e.g., in the undercut UC structure), but this disclosure is not limited thereto.

[0204] In the fourth exemplary embodiment of this disclosure, compared with other embodiments, it has the advantage of simple process because the groove T structure is not intentionally formed.

[0205] Exemplary embodiments of this disclosure can also be described as follows:

[0206] According to one aspect of this disclosure, a display device is provided. The display device includes: a substrate, wherein a light-emitting region and a non-light-emitting region are divided therein and a plurality of sub-pixels are defined; an insulating layer disposed above the substrate; a first electrode disposed in each of the plurality of sub-pixels; a dam portion disposed on the insulating layer and exposing the first electrode through an opening therethrough; an organic layer disposed on the first electrode; and a second electrode disposed on the organic layer, wherein the dam portion has exposed sides by removing a region between the plurality of sub-pixels and has an undercut structure extending inward from the lower end of the exposed sides, wherein the dam portion has other exposed sides by removing another region between the plurality of sub-pixels and has a trench structure by removing a portion of the thickness of the insulating layer.

[0207] The multiple sub-pixels may include multiple first sub-pixels that emit light of a first color, multiple second sub-pixels that emit light of a second color, and multiple third sub-pixels that emit light of a third color.

[0208] The first color can be red, the second color can be green, and the third color can be blue.

[0209] The display device may further include a conductive pattern disposed inside the undercut structure and formed of a conductive material constituting the first electrode.

[0210] The display device may further include an organic layer pattern and a second electrode pattern, which are disposed in the undercut structure and formed by organic materials constituting the organic layer and the second electrode, respectively, wherein each of the organic layer pattern and the second electrode pattern may be disconnected from the organic layer and the second electrode.

[0211] In the trench structure, the organic layer and the second electrode can be connected.

[0212] Multiple third subpixels can be set in the same column, multiple first subpixels and multiple second subpixels can be set alternately in the same column, and the first and second subpixels can be set to the left and right of the third subpixels.

[0213] Multiple third sub-pixels and multiple first sub-pixels and second sub-pixels can be alternately set horizontally, and multiple third sub-pixels can be repeatedly set vertically, or multiple first sub-pixels and multiple second sub-pixels can be alternately set vertically.

[0214] Undercut structures can be set vertically between multiple subpixels, and trench structures can be set horizontally between multiple subpixels.

[0215] The undercut structure can be arranged vertically between multiple third sub-pixels and multiple first sub-pixels and multiple second sub-pixels, and the trench structure can be arranged horizontally between multiple first sub-pixels and multiple second sub-pixels.

[0216] The trench structure can be configured to extend laterally from the undercut structure located in the longitudinal direction.

[0217] The undercut structure can be divided into multiple undercut structures, wherein the display device may also include another groove structure disposed longitudinally between multiple separate undercut structures in the longitudinal direction.

[0218] The inclination angle of the side of the embankment above the undercut structure can be relatively larger than the inclination angle of the side of the embankment in the light-emitting area.

[0219] Multiple second subpixels can be set in the same column, and multiple first subpixels and multiple third subpixels can be alternately set in the same column, and multiple second subpixels can be set in the same row, and multiple first subpixels and multiple third subpixels can be alternately set in the same row.

[0220] Multiple second sub-pixels and multiple third sub-pixels can be alternately set in the diagonal direction, and multiple first sub-pixels and multiple second sub-pixels can be alternately set in adjacent diagonal directions.

[0221] Multiple second sub-pixels and multiple third sub-pixels can be alternately set in another diagonal direction, and multiple first sub-pixels and multiple second sub-pixels can be alternately set in an adjacent diagonal direction.

[0222] The undercut structure can be arranged in the horizontal and diagonal directions among multiple sub-pixels other than the contact area of ​​the first electrode, and the trench structure can be arranged in the vertical direction among multiple sub-pixels other than the contact area of ​​the first electrode.

[0223] The undercut structure can be arranged in the horizontal and diagonal directions between multiple first sub-pixels and multiple second sub-pixels, or between multiple third sub-pixels and second sub-pixels, excluding the contact area of ​​the first electrode, and the trench structure can be arranged in the vertical direction between multiple second sub-pixels, excluding the contact area of ​​the first electrode.

[0224] The trench structure can be configured to extend longitudinally from the undercut structure in the diagonal direction.

[0225] The display device may also include another groove structure disposed at the end of the undercut structure and disposed by removing a portion of the thickness of the insulating layer from the side of the embankment.

[0226] 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 spirit 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 spirit of the present disclosure. The scope of the technical spirit 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 ideas within their equivalents should be interpreted as falling within the scope of the present disclosure.

Claims

1. A display device comprising: a substrate in which a light-emitting region and a non-light-emitting region are divided and a plurality of subpixels are defined; an insulating layer provided over the substrate; a first electrode provided in each of the plurality of subpixels; a bank portion provided on the insulating layer and including an opening through which the first electrode is exposed; an organic layer provided on the first electrode; and a second electrode provided on the organic layer, wherein the bank portion includes an exposed side surface obtained by removing one region between the plurality of subpixels, and includes an undercut structure inward from a lower end of the exposed side surface, and wherein the bank portion further includes an exposed side surface obtained by removing one region between the plurality of subpixels, and includes a trench structure obtained by removing a portion of a thickness of the insulating layer, wherein the plurality of subpixels include: a plurality of first subpixels configured to emit light of a first color; a plurality of second subpixels configured to emit light of a second color; and a plurality of third subpixels configured to emit light of a third color, wherein the plurality of third subpixels are provided alternately with the plurality of first subpixels and the plurality of second subpixels in a lateral direction, and wherein the trench structure is provided between the plurality of first subpixels and the plurality of second subpixels in the lateral direction. The first color is red, the second color is green, and the third color is blue.

2. The display device according to claim 1, wherein 3. The display device according to claim 1, further comprising: a conductive pattern provided inside the undercut structure of the bank portion and formed of a conductive material constituting the first electrode.

4. The display device according to claim 1, further comprising: an organic layer pattern and a second electrode pattern provided in the undercut structure of the bank portion and formed of an organic material and a conductive material constituting the organic layer and the second electrode, respectively, wherein each of the organic layer pattern and the second electrode pattern is disconnected from the organic layer and the second electrode. The organic layer and the second electrode are connected in the trench structure of the bank portion.

5. The display device according to claim 1, wherein The plurality of third subpixels are provided in the same column, the plurality of first subpixels and the plurality of second subpixels are provided alternately in the same column, and 6. The display device according to claim 2, wherein one of the plurality of first subpixels and one of the plurality of second subpixels are provided on opposite sides of one of the plurality of third subpixels, respectively. The plurality of third subpixels are provided repeatedly in a longitudinal direction, or the plurality of first subpixels and the plurality of second subpixels are provided alternately in the longitudinal direction.

7. The display device of claim 6, wherein, The undercut structure of the bank portion is provided between the plurality of subpixels in the longitudinal direction, and 8. The display device of claim 7, wherein, the trench structure of the bank portion is provided between the plurality of subpixels in the lateral direction. The undercut structure is provided between the plurality of third subpixels and the plurality of first subpixels and the plurality of second subpixels in the longitudinal direction.

9. The display device of claim 8, wherein, The trench structure is provided between the plurality of first subpixels and the plurality of second subpixels in the lateral direction.

10. The display device of claim 9, wherein, The trench structure is disposed to extend from the undercut structure disposed in the longitudinal direction along the lateral direction.

11. The display device of claim 9, wherein, The undercut structure is divided into a plurality of undercut structures, and The display device further includes another trench structure disposed between the undercut structures in a plurality of separate longitudinal directions along the longitudinal direction.

12. The display device of claim 1, wherein, The inclination angle of the side surface of the bank portion above the undercut structure is relatively larger than the inclination angle of the side surface of the bank portion in the light emitting region.

13. The display device according to claim 2, wherein The plurality of second sub-pixels are disposed in the same column, and the plurality of first sub-pixels and the plurality of third sub-pixels are alternately disposed in the same column, and The plurality of second sub-pixels are disposed in the same row, and the plurality of first sub-pixels and the plurality of third sub-pixels are alternately disposed in the same row.

14. The display device of claim 13, wherein, The plurality of second sub-pixels and the plurality of third sub-pixels are alternately disposed in diagonal directions, and the plurality of first sub-pixels and the plurality of second sub-pixels are alternately disposed in adjacent diagonal directions.

15. The display device of claim 14, wherein, The plurality of second sub-pixels and the plurality of third sub-pixels are alternately disposed in another diagonal direction, and the plurality of first sub-pixels and the plurality of second sub-pixels are alternately disposed in adjacent another diagonal direction.

16. The display device of claim 15, wherein, The undercut structure of the bank portion is disposed between the plurality of sub-pixels other than the contact region of the first electrode along the lateral direction and the diagonal direction, and the trench structure of the bank portion is disposed between the plurality of sub-pixels other than the contact region of the first electrode along the longitudinal direction.

17. The display device of claim 16, wherein, The undercut structure is disposed between the plurality of first sub-pixels and the plurality of second sub-pixels or between the plurality of third sub-pixels and the plurality of second sub-pixels other than the contact region of the first electrode along the lateral direction and the diagonal direction, and The trench structure is disposed between the plurality of second sub-pixels other than the contact region of the first electrode along the longitudinal direction.

18. The display device of claim 17, wherein, The trench structure is disposed to extend from the undercut structure in the diagonal direction along the longitudinal direction.

19. The display device of claim 1, further comprising: Another trench structure of the bank portion is disposed at an end portion of the undercut structure and is disposed by removing a portion of a thickness of the insulating layer from the side surface of the bank portion.

Images