Display device

Abstract

To provide a display device capable of accurately measuring the location and amount of moisture penetration.SOLUTION: A display device according to the present invention includes a substrate including a display area AA containing a plurality of sub-pixels SP and a non-display area NA outside the display area AA, transistors and light-emitting elements arranged in the sub-pixels SP of the display area AA, a sealing layer that seals the light-emitting elements, and a plurality of moisture detection units WSP arranged in the non-display area NA that detect moisture penetrating from the outside, and the amount of current output by the moisture detection units WSP changes depending on the amount of moisture that penetrates.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a display device, and more particularly to a display device that can easily detect the penetration of moisture. [Background technology]

[0002] With the development of information technology, various types of small and thin display devices have been proposed, such as liquid crystal display devices, organic light emitting display devices, plasma display devices, micro LED display devices, etc. Furthermore, such display devices are used in various electronic devices such as smartphones and tablet PCs.

[0003] A display device not only has various electrodes formed therein, but also includes various layers and elements such as a display unit that actually displays images, etc. Such a display device has a problem in that when moisture or hydrogen from the outside penetrates into the display device, the electrodes corrode or the organic light-emitting layer deteriorates. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a display device that can accurately measure the location and amount of moisture penetration. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, the display device of the present invention comprises a substrate including a display area including a plurality of sub-pixels and a non-display area outside the display area, transistors and light-emitting elements arranged in the sub-pixels of the display area, a sealing layer that seals the light-emitting elements, and a plurality of moisture detection units arranged in the non-display area that detect moisture penetrating from the outside, and the moisture detection units output a current that changes depending on the amount of moisture that penetrates.

[0006] The plurality of moisture detectors may be arranged along the outer edge of the display area, or may be arranged in an area of ​​the display area where stress is applied.

[0007] The moisture detector can be disposed so as to overlap at least one of the first dam and the second dam disposed in the non-display area.

[0008] The moisture detection unit can include a first electrode layer arranged on the interlayer insulating layer below the first dam, an intermediate layer formed on the first layer of the first dam and electrically connected to the first electrode layer via a contact hole formed in the first layer, and a second electrode layer arranged on the intermediate layer.

[0009] The first electrode layer is made of the same material as the connecting electrode, the second electrode layer is made of the same material as the first electrode of the light-emitting element, and the intermediate layer can be made of a metal oxide such as IGZO (Indium Gallium Zinc Oxide), IZO (Indium Zinc Oxide), IGTO (Indium Gallium Tin Oxide), or IGO (Indium Gallium Oxide), whose electrical conductivity increases when bonded with hydrogen atom radicals.

[0010] The moisture detection unit also includes a first electrode layer arranged on the interlayer insulating layer below the second dam, an intermediate layer formed on the fourth layer of the second dam and electrically connected to the first electrode layer via a contact hole formed in the fourth layer, and a second electrode layer arranged on the intermediate layer.

[0011] The intermediate layer may be composed of a material selected from the group consisting of IGZO, IZO, IGTO, and IGO.

[0012] A plurality of moisture detection wirings connected to a plurality of moisture detection units are arranged in the display area, and the moisture detection units are electrically connected to the moisture detection wirings and can detect moisture penetration based on the current input from the moisture detection units.

[0013] The present invention is provided with a moisture detector whose electrical conductivity increases as moisture penetrates, and can accurately detect the location of moisture penetration, allowing measures to be taken quickly and accurately according to the location.

[0014] Furthermore, since the present invention can accurately detect the amount of moisture penetration, it is possible to determine as defective only those display devices that have experienced moisture penetration to an extent that actually affects the display device, and to determine as normal those display devices that have only a small amount of moisture penetration, thereby reducing or minimizing the number of display devices that are discarded as defective.

[0015] In this way, the number of display devices that are discarded due to defects can be reduced or minimized, thereby reducing harmful substances and achieving a recycling effect. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a block diagram schematically illustrating a display device according to the present invention. [Figure 2] FIG. 1 is a block diagram illustrating a sub-pixel of a display device according to the present invention. [Figure 3] FIG. 1 is a circuit diagram conceptually showing a sub-pixel of a display device according to the present invention. [Figure 4] 1 is a plan view schematically showing a display device according to the present invention. [Figure 5] FIG. 2 is a block diagram showing a moisture detection unit according to the present invention. [Figure 6] 1 is a cross-sectional view showing the structure of a display device according to a first embodiment of the present invention. [Figure 7]FIG. 7 is an enlarged cross-sectional view of region A in FIG. 6. [Figure 8] 10 is a graph showing a current versus voltage detected by a moisture detector. [Figure 9] FIG. 10 is a cross-sectional view showing the structure of a display device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The advantages and features of the present invention, as well as methods for achieving them, will become clearer with reference to the following detailed description of the embodiments in conjunction with the drawings. However, the present invention is not limited to the embodiments disclosed below, and can be embodied in various different forms. However, the embodiments are provided so that the disclosure of the present invention will be complete and so that those skilled in the art will be able to fully understand the scope of the invention, and the present invention is defined by the scope of the claims.

[0018] The shapes, sizes, dimensions (e.g., length, width, height, thickness, radius, diameter, area, etc.), ratios, angles, and numbers of components disclosed in the drawings for illustrating embodiments of the present invention are illustrative only and are not intended to limit the scope of the present invention. The dimensions, such as the size and thickness, of each component shown in the drawings are shown for convenience of explanation, and the present invention is not limited to the size and thickness of the components shown. However, it should be noted that the relative dimensions, such as the relative size, position, and thickness of the components shown in the various drawings submitted herein are part of the present invention. The same reference numerals refer to the same components throughout the specification. Furthermore, when describing the present invention, if a detailed description of related prior art is deemed to obscure the gist of the present invention, such a detailed description will be omitted. When the terms "comprise," "include," "have," "have," "become," etc. are used in this specification, other parts may be added unless "only" is also used. Furthermore, when a component is referred to in the singular, it may be interpreted as being plural unless otherwise expressly stated.

[0019] Furthermore, when interpreting elements, a margin of error is included even if not explicitly stated.

[0020] For example, when describing the positional relationship between two elements using terms such as "above," "on top," "below," or "beside," one or more other elements may be located between the two elements unless the term "directly" or "directly" is used.

[0021] Furthermore, when describing temporal relationships, for example, using "after," "following," "next," or "before," non-sequential cases can be included unless "directly" or "immediately" is used.

[0022] Furthermore, terms such as "first" and "second" are used to distinguish between components, but the components are not limited to such terms. Therefore, a first component referred to below may also be a second component within the technical concept of the present invention.

[0023] In describing components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used, but these terms are only used to distinguish the components and do not limit the nature, order, sequence, number, etc. of the components. When a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that both components may be directly coupled, coupled, or connected, but that there may also be another component between the components, and each component may be "coupled," "coupled," or "connected" via another component.

[0024] The term "apparatus" in the present invention may include a display device in the narrow sense, such as a display module including a display panel and a driver for driving the display panel. The term "apparatus" may also include a complete product (final product) including a display module, such as a laptop computer, television, or computer monitor, or an equipment display including an automotive display, vehicle display, or other display, or a set electronic device or set apparatus, such as a mobile electronic device, such as a smartphone or electronic pad.

[0025] Therefore, the display device in the present invention can include a display device itself in the narrow sense, such as a display module, an applied product including a display module, or even a set device that is a final product.

[0026] The present invention will be described in detail below with reference to the drawings.

[0027] FIG. 1 is a block diagram that schematically shows a display device 100 according to the present invention, and FIG. 2 is a block diagram that schematically shows a sub-pixel SP shown in FIG.

[0028] As shown in FIG. 1 , the display device 100 includes a video processor 102, a timing controller 104, a gate driver 106, a data driver 107, a power supply 108, and a display panel 109. As used herein, the term “unit” or “module” includes any electrical circuit, function, component, assembly of electronic components, etc. That is, a “unit” or “module” includes any processor-based system, including systems using microcontrollers, integrated circuits, chips, microchips, reduced instruction set computers (RSICs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), graphical processing units (GPUs), logic circuits, and other circuits or processors capable of performing the various operations and functions described herein. The above examples are merely examples and are not intended to limit the definition or meaning of the terms “unit” or “module.” In some embodiments, the various units or modules described herein may be included in or implemented by processing circuitry, such as a microprocessor or microcontroller.

[0029] The image processor 102 outputs drive signals for driving various devices together with external image data. For example, the drive signals output from the image processor 102 may include a data enable signal, a vertical synchronization signal, a horizontal synchronization signal, and a clock signal.

[0030] The timing control unit 104 receives drive signals and the like together with video data from the video processing unit 102. Based on the drive signals input from the video processing unit 102, the timing control unit 104 generates and outputs a gate timing control signal GDC for controlling the operation timing of the gate driver 106 and a data timing control signal DDC for controlling the operation timing of the data driver 107.

[0031] The gate driver 106 outputs a scan signal to the display panel 109 in response to a gate timing control signal GDC from the timing control unit 104. The gate driver 106 outputs the scan signal through a plurality of gate lines GL1 to GLm. In this case, the gate driver 106 may be in the form of an IC (Integrated Circuit), but is not limited to this. The gate driver 106 includes various gate drive circuits, and the gate drive circuits may be formed directly on the substrate of the display panel 109. In this case, the gate driver 106 may be a GIP (Gate-In-Panel).

[0032] The data driver 107 outputs a data voltage to the display panel 109 in response to a data timing control signal DDC input from the timing controller 104. The data driver 107 samples and latches the digital data signal DATA from the timing controller 104 and converts it into an analog data voltage based on the gamma voltage. The data driver 107 outputs the data voltage through a plurality of data lines DL1 to DLn. In this case, the data driver 107 may be in the form of an IC, but is not limited thereto.

[0033] The power supply 108 outputs a high voltage VDD and a low voltage VSS to the display panel 109. The high voltage VDD is supplied to the display panel 109 through a first power line EVDD, and the low voltage VSS is supplied to the display panel 109 through a second power line EVSS. At this time, the voltages output from the power supply 108 may be output to the gate driver 106 and the data driver 107 and used to drive them.

[0034] The display panel 109 displays an image in response to a data voltage and a scan signal supplied from the gate driver 106 and the data driver 107, and a voltage supplied from the power supply .

[0035] The display panel 109 is composed of a plurality of sub-pixels SP, which actually display an image. The sub-pixels SP may include red, green, and blue sub-pixels, or may include white (W), red, green, and blue sub-pixels. The white (W), red, green, and blue sub-pixels SP may all have the same area, or may have different areas.

[0036] As shown in Figure 2, one subpixel SP can be connected to a gate line GL1, a data line DL1, a first power supply line EVDD, and a second power supply line EVSS. The subpixel SP can include multiple thin film transistors and storage capacitors depending on the pixel circuit configuration. For example, the subpixel SP can be configured with two transistors and one capacitor (2T1C), but is not limited to this. It can also be configured with other configurations, such as 3T1C, 4T1C, 5T1C, 6T1C, 7T1C, 3T2C, 4T2C, 5T2C, 6T2C, 7T2C, and 8T2C.

[0037] FIG. 3 is a circuit diagram that schematically shows a sub-pixel SP of the display device 100 according to the present invention.

[0038] As shown in FIG. 3, the display device of the present invention includes gate lines GL, data lines DL, and power lines PL that intersect with each other to define sub-pixels SP, and the sub-pixels SP include a switching transistor Ts, a driving transistor Td, a storage capacitor Cst, and a light-emitting element D.

[0039] The switching transistor Ts is connected to the gate line GL and the data line DL, the drive transistor Td and the storage capacitor Cst are connected between the switching transistor Ts and the power line PL, and the light emitting element D is connected to the drive transistor Td.

[0040] In a display device having such a structure, when the switching transistor Ts is turned on by a gate signal applied to the gate line GL, the data signal applied to the data line DL is applied to the gate electrode of the driving transistor Td and one electrode of the storage capacitor Cst via the switching transistor Ts.

[0041] The drive transistor Td is turned on by a data signal applied to its gate electrode, causing a current proportional to the data signal to flow from the power supply line PL through the drive transistor Td to the light-emitting element D, causing the light-emitting element D to emit light with a brightness proportional to the current flowing through the drive transistor Td.

[0042] At this time, the storage capacitor Cst is charged with a voltage proportional to the data signal, so that the voltage of the gate electrode of the driving transistor Td is kept constant during one frame.

[0043] Although only two transistors Td and Ts and one capacitor Cst are shown in FIG. 3, the present invention is not limited to this and three or more transistors and two or more capacitors may be provided.

[0044] FIG. 4 is a plan view schematically showing the structure of a display device 100 according to the present invention.

[0045] 4, the display device 100 according to the present invention includes a display panel PNL on which an image is displayed and a detection circuit WSU (also referred to as a moisture detection unit WSU) arranged outside the display panel PNL. The display panel PNL includes a display area AA on which an image is actually displayed and a non-display area NA arranged outside the display area AA.

[0046] A plurality of sub-pixels SP are arranged in the display area AA. The sub-pixels SP may include a red R sub-pixel, a green G sub-pixel, and a blue B sub-pixel. The sub-pixels SP may further include a white W sub-pixel.

[0047] Although not shown in Fig. 4, a plurality of gate lines and data lines are arranged in the display area AA, and sub-pixels SP are arranged at the intersections of the gate lines and the data lines. Each sub-pixel SP includes a thin film transistor, which is a switching element, and a display element for actually displaying an image.

[0048] The display element can include various display elements, such as an organic electroluminescent display element, a liquid crystal display element, a quantum dot display element, a micro LED display element, or a mini LED display element.

[0049] The non-display area NA may include a gate driver and a data driver for applying various signals to the sub-pixels SP. The gate driver applies scanning signals to the sub-pixels SP through gate lines, and the data driver applies video signals to the sub-pixels SP through data lines.

[0050] A dam DMA is formed in the non-display area NA, surrounding the display area AA. If the thin film transistors and organic light-emitting layers of the display device 100 are exposed to external impurities such as air or moisture, the thin film transistors and organic light-emitting layers may deteriorate, causing malfunctions in the display device 100. For this reason, an encapsulation layer (not shown) should be formed in the display device 100 to seal the display device 100 from the external environment. As will be described later, the dam DMA is formed in the non-display area NA and blocks the flow of encapsulation material when the encapsulation material is applied to form the encapsulation layer, thereby preventing the encapsulation material from leaking out of the display device 100.

[0051] Although the figure shows one dam DAM in the non-display area NA, in reality, multiple dams DAM are placed in the non-display area NA, surrounding the outside of the display area AA. The reason for forming multiple dams DAM is as follows.

[0052] If the encapsulation layer is not formed with a uniform thickness over the entire display device 100, poor image quality will occur due to optical refraction at the interface of the encapsulation layer. The reason for the uneven formation of the encapsulation layer is that the speed at which the dropped encapsulation material spreads over the entire display device 100 is uneven. That is, when the encapsulation material spreads in all directions of the display device 100, the speed differs depending on the direction, so that more than the set amount is applied to certain areas and less than the set amount is applied to other areas, resulting in an uneven thickness of the hardened encapsulation layer.

[0053] The deterioration of image quality occurs mainly when the encapsulation layer falls below a set thickness. Therefore, in a typical display device, in order to make the entire encapsulation layer thicker than the set thickness, a larger amount of encapsulation material is dropped taking into account the difference in spreading speed, and multiple dams (DAM) are formed to reliably block any encapsulation material that exceeds the set amount from spreading to the outside.

[0054] In addition, a detection unit WSP (also called a moisture detection unit WSP) that detects moisture and hydrogen penetrating from the outside is arranged in the non-display area NA. Since moisture and hydrogen penetrate from the entire area of ​​the display area 100, the detection units WSP can be arranged at regular intervals along the entire edge of the display area AA. Although not shown in the figure, the moisture detection unit WSP can be arranged only in a specific area. The moisture detection unit WSP can also be arranged only in an area where cracks are likely to occur due to the application of cyclic stress, such as the folding area of ​​a foldable display device or the curved area of ​​a flexible display device.

[0055] 4, multiple moisture detection units WSP are arranged at regular intervals along the entire edge of the display area AA, but this is not limited to this. For example, in areas where cracks occur, the intervals between the moisture detection units WSP can be made smaller and a relatively large number of moisture detection units WSP can be arranged, and in areas where cracks do not occur, the intervals between the moisture detection units WSP can be made larger and a relatively small number of moisture detection units WSP can be arranged.

[0056] As shown in FIG. 4, the moisture detection unit WSP can be arranged so as to overlap with the dam DAM, but it can also be arranged in a different area from the dam DAM.

[0057] A plurality of detection wirings WSL (also referred to as a plurality of moisture detection wirings WSL) are arranged in the non-display area NA. The plurality of moisture detection wirings WSL are each connected to a moisture detection unit WSP, and measure and detect current when a voltage is applied to the moisture detection unit WSP.

[0058] The moisture detection wiring WSL is connected to the moisture detection unit WSU, which detects the current from the moisture detection part WSP and determines whether moisture or hydrogen has penetrated.

[0059] 4, the moisture detection unit WSU is disposed outside the display panel PNL, but the moisture detection unit WSU may be formed below the non-display area NA of the display panel PNL. The moisture detection unit WSU may also be connected to an external system of the display device 100 to determine whether moisture has penetrated during the manufacturing process of the display device 100.

[0060] FIG. 5 is a block diagram showing a moisture sensing unit WSU according to the present invention.

[0061] As shown in Figure 5, the moisture detection unit WSU includes a current detection unit IDU to which the moisture detection wiring WSL is connected and which detects the current from the moisture detection section WSP, a comparison unit COU which compares the current detected by the current detection unit IDU with a stored reference value, a moisture permeation position determination unit WPU which determines the area where moisture is detected, i.e., the moisture penetration area, based on the value compared by the comparison unit COU, and a moisture permeation amount determination unit WAU which determines the amount of moisture that has penetrated based on the value compared by the comparison unit COU.

[0062] The reference value stored in the comparison unit COU may be a moisture penetration tolerance. That is, a value that causes the display device 100 to malfunction when moisture penetrates into the display device 100 is stored as the reference value. The moisture permeation position determination unit WPU detects a current that exceeds the reference value stored in the comparison unit COU from among a plurality of currents input from a plurality of moisture detection units WSP, and determines a moisture permeation position.

[0063] If each measured current value is smaller than the set reference value, the moisture permeability determination unit WAU determines that the moisture permeability does not affect the display device 100, and does not determine the moisture permeation position or moisture permeation amount, and can determine the measured moisture permeability only if the measured current value is larger than the set reference value.

[0064] However, the present invention is not limited to this. The moisture permeation amount determination unit WAU can detect the position and amount of moisture permeation every time moisture permeation is detected, regardless of the moisture permeation amount, and determine the risk of moisture permeation using a separate method.

[0065] The moisture permeation amount can be determined based on a table of current versus moisture permeation amount set in the moisture permeation amount determination unit WAU, but is not limited to this.

[0066] The moisture detection unit WSU also includes a voltage source P, which can apply a voltage to the multiple moisture detection wirings WSL.

[0067] As described above, the present invention is equipped with a moisture detection unit WSP, which can quickly and easily check whether moisture or hydrogen has penetrated, making it easy to detect defects in the display device 100 caused by moisture or hydrogen penetration.

[0068] In particular, since the present invention can accurately detect the location of moisture penetration, measures can be taken quickly and accurately according to the location of moisture penetration. Furthermore, since the amount of moisture penetration can be accurately detected, only display devices 100 that have experienced moisture penetration to an extent that actually affects the display device 100 are judged as defective, and display devices 100 that have experienced only a slight amount of moisture penetration are judged as normal, thereby reducing or minimizing the number of display devices 100 that are discarded due to being defective.

[0069] Hereinafter, a specific structure of a display device 100 according to an embodiment of the present invention will be described with reference to the drawings.

[0070] Fig. 6 is a cross-sectional view showing the structure of a display device 100 according to a first embodiment of the present invention, and Fig. 7 is an enlarged cross-sectional view of region A in Fig. 6. For ease of explanation, the figure shows a display region AA and a non-display region NA. In reality, multiple thin film transistors and various wirings are arranged in the display region AA and the non-display region NA, but for ease of explanation, only the thin film transistors arranged in the display region AA are shown.

[0071] 6 and 7, the substrate 140 includes a display area AA and a non-display area NA. The substrate 140 may be made of a hard material such as glass, or may be made of a flexible plastic material.

[0072] When the substrate 140 is made of a plastic material, the substrate 140 may be made of at least one of polyimide, polymethyl methacrylate, polyethylene terephthalate, polyethersulfone, and polycarbonate, but is not limited thereto.

[0073] For example, when the substrate 140 is made of polyimide, it may be made of a plurality of polyimides, and an inorganic layer may be further disposed between the polyimides, but is not limited thereto.

[0074] A buffer layer 142 is formed on the substrate 140. The buffer layer 142 is formed over the entire substrate 140 and can improve the adhesive strength between the substrate 140 and a layer formed on the substrate 140, and can block alkaline components from flowing out from the substrate 140. The buffer layer 142 can also slow the diffusion of moisture or oxygen that has penetrated into the substrate 140.

[0075] The buffer layer 142 may be a single layer or multiple layers made of SiNx or SiOx. When the buffer layer 142 is a multiple layer, SiNx and SiOx may be alternately formed. The buffer layer 142 may be omitted depending on the type and material of the substrate 140, the structure and type of the thin film transistor, etc.

[0076] A thin film transistor T is formed on the buffer layer 142 in the display area AA. For convenience of explanation, only a driving thin film transistor is shown among various thin film transistors that may be arranged in the display area AA, but other thin film transistors such as a switching thin film transistor may also be included. Also, although a thin film transistor having a top gate structure is shown, the present invention is not limited to this, and the thin film transistor may have other structures such as a bottom gate structure.

[0077] The thin film transistor T includes a semiconductor layer 112 disposed on a buffer layer 142, a gate insulating layer 144 formed on the semiconductor layer 112, a gate electrode 114 disposed on the gate insulating layer 144, an interlayer insulating layer 146 formed on the gate electrode 114, and a source electrode 115 and a drain electrode 116 disposed on the interlayer insulating layer 146.

[0078] The semiconductor layer 112 may be made of a polycrystalline semiconductor, for example, but not limited to, low temperature polysilicon (LTPS) having high mobility.

[0079] The semiconductor layer 112 may be made of an oxide semiconductor, such as, but not limited to, IGZO (indium gallium zinc oxide), IZO (indium zinc oxide), IGTO (indium gallium tin oxide), or IGO (indium gallium oxide). The semiconductor layer 112 includes a channel region 112a in its central region and a source region 112b and a drain region 112c, which are doped layers on either side of the channel region 112a.

[0080] The gate insulating layer 144 may be formed in both the display area AA and the non-display area NA, or may be formed only in the display area AA. The gate insulating layer 144 may be a single layer or multiple layers made of an inorganic material such as SiNx or SiOx, but is not limited thereto.

[0081] The interlayer insulating layer 146 may be formed in both the display area AA and the non-display area NA, or may be formed only in the display area AA. The interlayer insulating layer 146 may be a single layer or multiple layers made of an organic material such as photoacrylic or an inorganic material such as SiNx or SiOx. The interlayer insulating layer 146 may also be a multilayer made of an organic material layer and an inorganic material layer, but is not limited to this.

[0082] The source electrode 115 and the drain electrode 116 may be a single layer or a multilayer made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof, but are not limited thereto. The source electrode 115 and the drain electrode 116 can be in contact with the source region 112b and the drain region 112c of the semiconductor layer 112 through contact holes formed in the gate insulating layer 144 and the interlayer insulating layer 146, respectively.

[0083] Although not shown, a bottom shield metal layer may be disposed on the substrate 140 below the semiconductor layer 112. The bottom shield metal layer is intended to reduce or minimize the back channel effect caused by charges trapped in the substrate 140 and prevent image retention and degradation of transistor performance, and may be a single layer or multiple layers made of molybdenum (Mo), titanium (Ti), or an alloy thereof, but is not limited thereto.

[0084] A first planarization layer 148 is formed on the substrate 140 on which the thin film transistor T is disposed. The first planarization layer 148 may be made of an organic material such as photoacrylic, but is not limited thereto, and may also be a multi-layer structure made up of an inorganic layer and an organic layer.

[0085] A connection electrode 154 is disposed on the first planarization layer 148 and is electrically connected to the drain electrode 116 of the thin film transistor T via a contact hole formed in the first planarization layer 148 .

[0086] A second planarization layer 150 is formed on the first planarization layer 148 on which the connection electrode 154 is formed. The second planarization layer 150 may be made of an organic material such as photoacrylic, but is not limited thereto, and may also be a multi-layer structure made up of an inorganic layer and an organic layer. The second planarization layer 150 may be made of the same material as the first planarization layer 148, or may be made of a different material.

[0087] In this way, in the present invention, by using a two-layer structure 148, 150 for the planarization layer, it is possible to form all electrodes and wiring between the first planarization layer 148 and the second planarization layer 150. This allows the electrodes to be arranged vertically, and the area of ​​the electrodes and wiring in the subpixels can be reduced. As a result, the area of ​​the subpixels can be reduced, and a display device 100 with high resolution can be manufactured.

[0088] A light-emitting element D is disposed in the display area AA on the second planarization layer 150. The light-emitting element D is composed of a first electrode 132, a light-emitting layer 134, and a second electrode 136.

[0089] The first electrode 132 is disposed on the second planarization layer 150 and is electrically connected to the connection electrode 154 through a contact hole formed in the second planarization layer 150. The first electrode 132 is electrically connected to the drain electrode 116 of the thin film transistor T through the connection electrode 154. The first electrode 132 may be made of at least one of silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), tungsten (W), chromium (Cr), or an alloy thereof. The first electrode 132 may also be a transparent metal oxide material layer such as ITO or IZO.

[0090] If the display device 100 is a top emission type, the first electrode 132 may further include an opaque conductive material to function as a reflective electrode that reflects light. If the display device 100 is a bottom emission type, the first electrode 132 may use a transparent conductive material that transmits light, such as ITO or IZO.

[0091] A bank layer BNK is formed on the second planarization layer 150 at the boundary between each sub-pixel. The bank layer BNK can be a partition wall that separates the sub-pixels. The bank layer BNK separates each sub-pixel and can prevent light of a specific color emitted from adjacent pixels from being mixed and emitted.

[0092] The bank layer BNK may be made of at least one of inorganic insulating materials such as SiNx or SiOx, or organic insulating materials such as BCB (benzocyclobutene), acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin, or a photosensitive agent containing black (or black color) pigment, but is not limited to these.

[0093] The light-emitting layer 134 is formed on the upper surface of the first electrode 132 in the display area AA and on a part of the slope and upper surface of the bank layer BNK, and can extend into the non-display area NA.

[0094] The light-emitting layer 134 may be formed in R, G, and B sub-pixels and may include an R-light-emitting layer that emits red light, a G-light-emitting layer that emits green light, and a B-light-emitting layer that emits blue light. For example, the light-emitting layer 134 may include, but is not limited to, an organic light-emitting layer or an inorganic light-emitting layer, such as a nano-sized material layer, quantum dots, a micro LED light-emitting layer, or a mini LED light-emitting layer.

[0095] The light-emitting layer 134 may include, but is not limited to, an electron injection layer and a hole injection layer that inject electrons and holes into the light-emitting layer, respectively, and an electron transport layer, a hole blocking layer, an electron blocking layer, a hole transport layer, etc. that transport the injected electrons and holes to the light-emitting layer, respectively.

[0096] The second electrode 136 is disposed on the light-emitting layer 134 and may be a single layer or multiple layers made of a metal or metal alloy. The second electrode 136 may be made of a transparent metal oxide such as ITO or IZO, but is not limited to these.

[0097] When the display device 100 is a top-emission type, a translucent conductive material that transmits light can be used for the second electrode 136. For example, the second electrode 136 can be made of at least one of alloys such as LiF / Al, CsF / Al, Mg:Ag, Ca / Ag, Ca:Ag, LiF / Mg:Ag, LiF / Ca / Ag, and LiF / Ca:Ag.

[0098] When the display device 100 is a bottom emission type, the second electrode 136 is a reflective electrode that reflects light and may be made of an opaque conductive material. For example, the second electrode 136 may be made of at least one of silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), tungsten (W), chromium (Cr), or an alloy thereof.

[0099] The light-emitting element D may also have a tandem structure. The tandem structure may include multiple light-emitting layers, with a charge-generating layer between the light-emitting layers. The charge-generating layer adjusts the charge balance between the multiple organic layers and may be a multi-layer structure including a first charge-generating layer and a second charge-generating layer. The charge-generating layer may include an N-type charge-generating layer and a P-type charge-generating layer, and may be composed of a light-emitting layer doped with an alkali metal such as Li, Na, K, or Cs, or an alkaline earth metal such as Mg, Sr, Ba, or Ra, but is not limited thereto.

[0100] A sealing layer 180 is formed in the display area AA and the non-display area NA to seal the light-emitting element D. If the light-emitting element D is exposed to moisture or oxygen, pixel shrinkage, in which the light-emitting area shrinks, or defects such as black spots may occur within the light-emitting area. Moisture and oxygen also oxidize metal electrodes. The sealing layer 180 blocks the penetration of moisture and oxygen from the outside, preventing defects in the light-emitting element D and all electrodes.

[0101] The sealing layer 180 may be composed of a first sealing layer 182, a second sealing layer 184, and a third sealing layer 186, but is not limited to this and may also be composed of two layers, or four or more layers.

[0102] The first and third sealing layers 182 and 186 may be single or multi-layered, each made of an inorganic material such as SiOx, SiON, or SiNx, and may further contain an organic material between the inorganic materials such as SiOx, SiON, or SiNx, but are not limited thereto. The second sealing layer 184 may be made of an epoxy resin.

[0103] Although not shown in the figure, a touch element may be provided in the display area. The touch element is provided in the display area and can detect touch input. The touch element can detect external touch information using a user's finger, a touch pen, or the like.

[0104] In the non-display area NA, a first dam DAM1 and a second dam DAM2 are formed, which are arranged at a predetermined distance outside the first dam DAM1. Because the organic material forming the second sealing layer 184 has fluidity, when the second sealing layer 184 is formed, the organic material may flow out of the substrate 140 via the outside of the non-display area NA. The dams DAM1 and DAM2 are formed to surround the display area AA, and contain the organic material that flows out of the substrate 140 when the second sealing layer 184 is formed, preventing the organic material from flowing out of the substrate 140.

[0105] The reason why a plurality of dams DAM1 and DAM2 are formed in this embodiment is as follows.

[0106] If the encapsulation layer is not formed with a uniform thickness across the entire display device 100, poor image quality occurs due to light refraction at the interface of the encapsulation layer. The reason for the uneven formation of the encapsulation layer is that the speed at which the dropped encapsulation material spreads across the entire display device 100 is uneven. That is, when the encapsulation material spreads in all directions of the display device 100, the speed varies depending on the direction, so that a much smaller amount than the set amount may be applied to certain areas, and even areas may not be coated at all. Areas where the encapsulation layer is formed with a thickness less than the set thickness or areas where the encapsulation layer is not formed may cause defects such as unevenness due to refraction of transmitted light, which is a major cause of display device defects.

[0107] Therefore, in the display device 100 of the present invention, in order to make the entire sealing layer thicker than the set thickness, the difference in spreading speed is taken into account and a larger amount of sealing material than the set amount is dropped to form multiple dams DAM1 and DAM2, thereby reliably preventing the sealing material exceeding the set amount from spreading out to the outside.

[0108] The first dam DAM1 may include a first layer 156a, a second layer 156b, and a third layer 156c. The first layer 156a is disposed on the interlayer insulating layer 146 and may be made of the same material as the second planarization layer 150, but is not limited to this. The second layer 156b is disposed on the first layer 156a and may be made of the same material as the bank layer BNK, but is not limited to this. The third layer 156c is disposed on the second layer 156b and may be made of an organic material. The third layer 156c may be, but is not limited to, a spacer on which a metal mask for emitting material deposition is placed and supported when forming the light-emitting layer 134.

[0109] The second dam DAM2 may include a fourth layer 158a and a fifth layer 158b. The fourth layer 158a is disposed on the interlayer insulating layer 146 and may be made of, but is not limited to, the same material as the second planarization layer 150. The fifth layer 158b is disposed on the fourth layer 158a and may be made of, but is not limited to, the same material as the bank layer BNK.

[0110] The moisture detector WSP is disposed in the second dam DAM2. The moisture detector WSP includes a first electrode layer 162, a second electrode layer 166, and an intermediate layer 164 disposed between the first electrode layer 162 and the second electrode layer 166, the conductivity of which changes depending on the concentration of hydrogen.

[0111] The first electrode layer 162 may be formed of the same material and in the same process as the connection electrode 154, but is not limited to this.

[0112] The intermediate layer 164 can be composed of metal oxides such as IGZO, IZO, IGTO, and IGO.

[0113] The intermediate layer 164 is formed on the fourth layer 158a of the second dam DAM2, and is electrically connected to the first electrode layer 162 via a contact hole formed in the fourth layer 158a.

[0114] The second electrode layer 166 may be formed of the same material and through the same process as the first electrode 132 of the light emitting device D, but is not limited thereto.

[0115] A moisture detection wiring WSL connected to an external moisture detection unit WSU is arranged on the interlayer insulating layer 146 in the non-display area NA, and the moisture detection wiring WSL is electrically connected to the first electrode layer 162 via a connection wiring 159.

[0116] The moisture detection wiring WSL may be formed using the same material and process as the source electrode 115 of the thin film transistor T. Alternatively, the moisture detection wiring WSL may be formed using the same material and process as the first electrode layer 162, but is not limited to this. Furthermore, the connection wiring 159 may be formed using the same material and process as the first electrode layer 162, or may be formed using the same material and process as the source electrode 115 of the thin film transistor T.

[0117] An external voltage is applied to the first electrode layer 162 of the moisture detection part WSP via the moisture detection wiring WSL and the connection wiring 159, and a reference voltage, for example, a ground voltage, can be applied to the second electrode layer 166. A voltage difference between the first electrode layer 162 and the second electrode layer 166 generates a current between the two electrode layers, and the current is input to the moisture detection unit WSU via the connection wiring 159 and the moisture detection wiring WSL.

[0118] The conductivity of the intermediate layer 164 between the first electrode layer 162 and the second electrode layer 166 changes due to the penetration of moisture, which causes a change in the amount of current in the first electrode layer 162 and the second electrode layer 166, and the moisture detection unit WSU detects the moisture penetration based on the amount of change in the current.

[0119] For example, when a metal oxide such as IGZO is used for the intermediate layer 164, when moisture penetrates and reaches the intermediate layer 164, hydrogen atom radicals of the moisture penetrate the surface of the intermediate layer 164 and form a complex layer of metal and hydroxyl groups (OH). That is, the hydrogen atom radicals form oxygen ions (O2- ) and reacts with hydroxide ions (OH - ) and electrons (e - Therefore, the electron density in the complex layer of metal and hydroxyl (OH) groups formed on the surface of the intermediate layer 164 increases, resulting in increased electrical conductivity.

[0120] Such an increase in electrical conductivity causes an increase in the current generated in the moisture detector WSP, and the moisture detector WSP can detect this increase in current and detect the moisture penetration area and the moisture permeation amount.

[0121] FIG. 8 is a graph showing the current detected by the moisture detector WSP, and is a graph showing the relationship between voltage and current.

[0122] As shown in FIG. 8, when moisture permeation does not occur in the display device 100, the amount of current generated in the moisture detection unit WSP is approximately 5×10 -13 A, and approximately 2 × 10 at 20 V and -20 V. -9 It's A.

[0123] When the degree of moisture permeability in the display device 100 is small, the amount of current generated in the moisture detection unit WSP is approximately 0.5×10 at 0 V. -11 A, and approximately 2 × 10 at 20 V and -20 V. -8 A. Therefore, when moisture permeation occurs, the amount of current generated in the moisture detection unit WSP increases.

[0124] When the degree of moisture permeability in the display device 100 is high, the amount of current generated in the moisture detection unit WSP is approximately 2×10 -7 A, and approximately 3 × 10 at 20 V and -20 V. -2 A. Therefore, as the moisture permeation intensity (i.e., the amount of moisture permeation) increases, the amount of current generated in the moisture detection unit WSP further increases.

[0125] In this way, in the present invention, the amount of current generated in the moisture detection unit WSP changes depending on the degree of moisture penetration, i.e., the moisture permeability strength, so by detecting this current, the moisture permeability strength can be accurately detected.

[0126] 6, second sealing layer 184 is formed inside first dam DAM1, while first sealing layer 182 and third sealing layer 186 extend to the end side via first dam DAM1 and second dam DAM2. Therefore, first sealing layer 182 and third sealing layer 186 exist above moisture detection unit WSP.

[0127] As described above, in the present invention, the moisture detection unit WSP is provided below the second dam DAM2 in the non-display area NA, and when moisture penetrates, the moisture penetration position and moisture penetration amount can be measured, thereby quickly and easily determining whether the display device 100 is defective due to moisture penetration. Furthermore, even when moisture penetration occurs, only display devices 100 that have experienced moisture penetration to an extent that actually affects the display device 100 are determined to be defective, and display devices 100 with only a slight amount of moisture penetration are determined to be normal, thereby reducing or minimizing the number of display devices 100 that are discarded due to being defective.

[0128] Meanwhile, in FIG. 6, the moisture detection unit WSP is formed so as to overlap the second dam DAM2, but the moisture detection unit WSP may be formed in various positions.

[0129] Figure 9 is a cross-sectional view showing a display device 200 according to a second embodiment of the present invention. Explanation of the same structure as in the first embodiment of Figure 4 will be omitted or simplified, and only the different structure will be described in detail. Here, explanation of the same parts as in the first embodiment of Figures 4 to 6 will be omitted or simplified, and only the configuration different from the first embodiment will be described in detail.

[0130] As shown in FIG. 9, in a display area AA of a substrate 240, a thin film transistor T and a light emitting element D are arranged.

[0131] The thin film transistor T includes a semiconductor layer 212 disposed on a buffer layer 242 , a gate electrode 214 disposed on a gate insulating layer 244 , and a source electrode 215 and a drain electrode 216 disposed on an interlayer insulating layer 246 .

[0132] The light-emitting element D includes a first electrode 232 , a light-emitting layer 234 , and a second electrode 236 .

[0133] A sealing layer 280 is formed on the light-emitting element D in the display area AA to seal the light-emitting element D. The sealing layer 280 includes a first sealing layer 282 made of an inorganic material, a second sealing layer 284 made of an organic material, and a third sealing layer 286 made of an inorganic material.

[0134] A plurality of dams DAM1 and DAM2 are arranged in the non-display area NA to prevent the fluid second sealing layer 284 from flowing out of the non-display area NA to the outside of the substrate 240. The second sealing layer 284 is formed only within the first dam DAM1, but the first sealing layer 282 and the third sealing layer 286 extend past the first dam DAM1 and the second dam DAM2 to the edge of the substrate 240.

[0135] The first dam DAM1 may include a first layer 256a, a second layer 256b, and a third layer 256c. The first layer 256a is disposed on the interlayer insulating layer 246 and may be made of the same material as the second planarization layer 250, but is not limited to this. The second layer 256b is disposed on the first layer 256a and may be made of the same material as the bank layer BNK, but is not limited to this. The third layer 256c is disposed on the second layer 256b and may be made of an organic material. The third layer 256c may be, but is not limited to, a spacer on which a metal mask for emitting material deposition is placed and supported when forming the emitting layer 234.

[0136] The second dam DAM2 may include a fourth layer 258a and a fifth layer 258b. The fourth layer 258a is disposed on the interlayer insulating layer 246 and may be made of, but is not limited to, the same material as the second planarization layer 250. The fifth layer 258b is disposed on the fourth layer 258a and may be made of, but is not limited to, the same material as the bank layer BNK.

[0137] The moisture detector WSP is disposed in the region where the first dam DAM1 is disposed. The moisture detector WSP includes a first electrode layer 262, an intermediate layer 264, and a second electrode layer 266.

[0138] The first electrode layer 262 is disposed on the interlayer insulating layer 246 and can be formed of the same material and in the same process as the connection electrode 254, but is not limited to this.

[0139] The intermediate layer 264 is formed on the first layer 256a of the first dam DAM1 and is electrically connected to the first electrode layer 262 through a contact hole formed in the first layer 256a. The intermediate layer 264 can be made of a metal oxide such as IGZO, IZO, IGTO, or IGO.

[0140] The second electrode layer 266 is disposed on the intermediate layer 264 and can be formed of the same material and through the same process as the first electrode 232 of the light emitting element D, but is not limited thereto.

[0141] Meanwhile, in the display device 100 of the first embodiment shown in Fig. 6, the moisture detection unit WSP is arranged so as to overlap with the second dam DAM2, and in the display device 200 of the second embodiment shown in Fig. 9, the moisture detection unit WSP is arranged so as to overlap with the first dam DAM1, but the present invention is not limited to such a configuration. Two moisture detection units WSP may be arranged along the outer direction of the non-display area NA so as to overlap with the first dam DAM1 and the second dam DAM2, or may be arranged so as not to overlap with the dams DAM1 and DAM2.

[0142] Although the embodiments of the present invention have been described in more detail above with reference to the drawings, the present invention is not necessarily limited to these embodiments. The present invention can be modified in various ways without departing from the technical concept of the present invention. Therefore, the embodiments disclosed herein are for illustrative purposes, not for limiting the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these embodiments. Therefore, all of the above-described embodiments should be understood as illustrative and not limiting. [Explanation of symbols]

[0143] 112...semiconductor layer, 114...gate electrode, 115...source electrode, 116...drain electrode, 132...first electrode, 134...light-emitting layer, 136...second electrode, 140...substrate, 146...interlayer insulating layer, 148...planarization layer, 180...sealing layer, DAM1, DAM2...dam, BNK...bank layer, D...light-emitting element, WSU...moisture detection unit, WSP...moisture detection section, WSL...moisture detection wiring

Claims

1. a substrate including a display area including a plurality of sub-pixels and a non-display area adjacent to the display area; a thin film transistor and a light emitting element disposed in each sub-pixel of the display area; a sealing layer on the upper part of the light-emitting element; a detection unit disposed in the non-display area and configured to detect moisture penetrating from the outside, The detection unit outputs a current whose amount changes depending on the amount of water that penetrates.

2. a first planarization layer on the thin film transistor; a connection electrode on the first planarization layer, the connection electrode electrically connecting the drain electrode of the thin film transistor and the first electrode of the light-emitting element; a second planarization layer on the connection electrode and the first planarization layer; a bank layer on the second planarization layer, the bank layer surrounding the sub-pixels in a plan view; The display device of claim 1 further comprising:

3. The display device according to claim 2 , wherein the detection unit is arranged along an outer edge of the display area.

4. The display device according to claim 2 , wherein the detection unit is disposed in a region of the display area where stress is applied.

5. The display device according to claim 3 , wherein the detection unit is disposed in a folding region or a curved region of the substrate.

6. an interlayer insulating layer between the substrate and the first planarization layer; a first dam disposed in the non-display area; a second dam adjacent to the first dam; The display device according to claim 2 , wherein the detection unit is superimposed on at least one of the first dam and the second dam.

7. The first dam is a first layer on the interlayer insulating layer; a second layer on the first layer; and a third layer on the second layer; the first layer is made of the same material as the second planarization layer; the second layer is made of the same material as the bank layer, The display device according to claim 6 , wherein the third layer is a spacer.

8. The detection unit a first electrode layer on the interlayer insulating layer below the first dam; an intermediate layer on the first layer of the first dam, the intermediate layer being electrically connected to the first electrode layer through a contact hole formed in the first layer; The display device according to claim 7 , further comprising: a second electrode layer on the intermediate layer.

9. the first electrode layer is made of the same material as the connection electrode, The display device according to claim 8 , wherein the second electrode layer is made of the same material as the first electrode of the light-emitting element.

10. The display device according to claim 9 , wherein the intermediate layer is made of a metal oxide whose electrical conductivity increases when bonded with hydrogen atom radicals.

11. 11. The display device according to claim 10, wherein the metal oxide is selected from the group consisting of indium gallium zinc oxide (IGZO), indium zinc oxide (IZO), indium gallium tin oxide (IGTO), and indium gallium oxide (IGO).

12. The second dam is a fourth layer on the interlayer insulating layer; a fifth layer on the fourth layer; The display device according to claim 6 , wherein the fourth layer is made of the same material as the second planarization layer, and the fifth layer is made of the same material as the bank layer.

13. The detection unit a first electrode layer on the interlayer insulating layer below the second dam; an intermediate layer on the fourth layer of the second dam, the intermediate layer being electrically connected to the first electrode layer through a contact hole formed in the fourth layer; The display device according to claim 12 , further comprising: a second electrode layer on the intermediate layer.

14. The display device of claim 13 , wherein the intermediate layer is made of a material selected from the group consisting of IGZO, IZO, IGTO, and IGO.

15. a detection wiring that is disposed in the non-display area and connected to the detection unit; The display device according to claim 1 , further comprising a detection circuit electrically connected to the detection wiring, which detects penetration of moisture based on a current input from the detection unit.

16. the detection circuit includes a current detection unit that detects a current input from the detection unit via the detection wiring; 16. The display device according to claim 15, further comprising: a comparison unit that compares the current detected by the current detection unit with a stored reference value.

17. The display device according to claim 16, wherein the detection circuit further includes a moisture permeation position determination unit that determines a moisture permeation region based on the value compared by the comparison unit.

18. 18. The display device according to claim 17, wherein the detection circuit includes a moisture permeation amount determination unit that determines the amount of moisture penetration based on the value compared by the comparison unit.

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