KR102328104B1 - Flexible Electroluminescent Display Device - Google Patents

Abstract

A flexible electroluminescent display device according to an embodiment of the present specification includes a flexible substrate including a display area and a bent area extending from one side of the display area, a light emitting device and a thin film transistor on the display area, a display area and a bending area A first planarization layer including a first planarization layer and a second planarization layer on a flexible substrate, including a display area and a bending area, and on a first planarization layer including a first wiring, a display area and a bending area on the flexible substrate and a compensation pattern on the second wiring and the second planarization layer, wherein a partial region of the first wiring and the second wiring in the bending region overlaps each other, and the compensation pattern includes the overlapping of the first wiring and the second wiring. is in the area

Description

Flexible Electroluminescent Display Device

The present specification relates to a flexible electroluminescent display, and more particularly, to a flexible electroluminescent display capable of minimizing defects in the flexible electroluminescent display.

As we enter the information age in earnest, the field of display devices that visually display electrical information signals is developing rapidly, and research to develop performance such as thinness, weight reduction, and low power consumption for various display devices is continuing.

Representative display devices include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electro-wetting display device (Electro-Wetting). Display device (EWD) and organic light emitting display device (Organic Light Emitting Display Device; OLED), and the like.

An electroluminescent display device, which is an organic light emitting display device, is a self-luminous display device, and unlike a liquid crystal display device, it does not require a separate light source, so it can be manufactured in a lightweight and thin form. In addition, the organic light emitting display device is not only advantageous in terms of power consumption due to low voltage driving, but also has excellent color realization, response speed, viewing angle, and contrast ratio (CR), and is expected to be utilized in various fields.

In the organic light emitting diode display, an organic light emitting layer (EML) is disposed between two electrodes of an anode and a cathode. When holes from the anode are injected into the emission layer and electrons from the cathode are injected into the emission layer, the injected electrons and holes recombine with each other to form excitons in the emission layer and emit light.

In this case, the light emitting layer contains a host material and a dopant material, so that the two materials interact. The host generates excitons from electrons and holes and serves to transfer energy to the dopant, and the dopant is a dye-type organic material added in a small amount, and serves to receive energy from the host and convert it into light.

An organic light emitting display device including a light emitting layer made of an organic material encapsulates the organic light emitting display device with glass, metal, or film, thereby allowing moisture or oxygen to enter the organic light emitting display device from the outside. It blocks the inflow to prevent oxidation of the light emitting layer and electrode, and protects it from mechanical or physical impact applied from the outside.

As the display device becomes smaller, efforts are being made to reduce the bezel area, which is the outer portion of the active area (A/A), in order to increase the effective display screen size in the same area of the display device.

In general, since wiring and a driving circuit for driving a screen are disposed in a bezel area corresponding to a non-active area (N/A), there is a limit in reducing the bezel area.

In a flexible electroluminescent display device that can maintain display performance even when bent by applying a flexible substrate made of a flexible material such as plastic, which has been recently developed, the bezel area is reduced while securing the area for wiring and driving circuits. In order to do this, a technology for reducing the bezel area by bending the non-display area of the flexible substrate has been developed and applied.

In addition, in an electroluminescent display device using a flexible substrate such as plastic, it is necessary to secure flexibility such as a substrate, various insulating layers disposed on the substrate, and wiring formed of a metal material.

In the case of wiring, when a substrate on which wiring is formed is bent, cracks may be generated in the wiring due to tensile force caused by bending. When a crack is generated in the wiring, normal signal transmission is not performed, so that the thin film transistor or the organic light emitting diode cannot operate normally, leading to a defect in the electroluminescent display device.

In the case of the insulating layer, since the inorganic or organic material itself constituting the insulating layer has a characteristic of brittleness, the insulating layer has considerably lower flexibility than a wiring formed of a metal. Accordingly, when the substrate on which the insulating layer is formed is bent, cracks may also occur in the insulating layer due to the tensile force caused by bending.

A neutral plane (N/P) refers to a virtual plane that is not subjected to stress because compressive and tensile forces applied to the structure cancel each other when a structure is bent. When bending, the layer disposed on the upper surface with respect to the neutral plane is stretched to receive a tensile force, and the layer disposed on the lower surface is compressed and thus receives a compressive force. At this time, since the wiring or insulating layer is more vulnerable when subjected to tensile force among compressive and tensile forces of the same magnitude, it is very important to optimize the neutral plane in order to minimize the magnitude of the force even if it does not receive tensile force or receives tensile force. .

In addition, when the neutral plane is abruptly changed due to structures disposed adjacent to the neutral plane, compressive force and tensile force may simultaneously act in a region where the neutral plane is abruptly changed. For this reason, cracks occur in the insulating layer in the region where the neutral plane changes rapidly, and it is also very important to maintain the neutral plane as little as possible.

Accordingly, the inventors of the present specification have invented an electroluminescent display device having a novel structure capable of minimizing defects caused by cracks in wiring formed in a bent region of the electroluminescent display device.

In addition, the inventors of the present specification have recognized that the space to arrange wiring is insufficient as the resolution of the electroluminescent display device is gradually increased, and developed a new structure of the electroluminescent display device in which wiring can be more freely arranged in a limited space. invented.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

A flexible electroluminescent display device according to an embodiment of the present specification includes a flexible substrate including a display area and a bent area extending from one side of the display area, a light emitting device and a thin film transistor on the display area, a display area and a bending area A first planarization layer including a first planarization layer and a second planarization layer on a flexible substrate, including a display area and a bending area, and on a first planarization layer including a first wiring, a display area and a bending area on the flexible substrate and a compensation pattern on the second wiring and the second planarization layer, wherein a partial region of the first wiring and the second wiring in the bending region overlaps each other, and the compensation pattern includes the overlapping of the first wiring and the second wiring. is in the area

A flexible electroluminescent display device according to another embodiment of the present specification includes a flexible substrate including a display area and a non-display area surrounding the display area, a light emitting device and a thin film transistor on the display area, and a flexible substrate in the non-display area. The first planarization layer and the second planarization layer on the bending area including the bent area, the display area, and the non-display area including the bending area, the wiring and the bending area on the substrate and the first planarization layer, respectively It is disposed on an overlapping region in which a partial region of the interconnection and a part region of the interconnection on the first planarization layer overlap, and includes a compensation pattern that moves the neutral plane of the bending region away from the flexible substrate to prevent damage to the bending region. do.

The present specification has an effect of minimizing defects caused by cracks formed in the bending region by optimizing the neutral plane of the bending region by configuring the compensation pattern in the bending region.

The present specification has an effect that wiring used in a flexible electroluminescent display can be more freely arranged in a limited space.

In the present specification, by configuring a region connecting two wirings in the bending region, the resistance of the wiring to stress is strengthened even in stress concentrated during bending, thereby preventing the occurrence of cracks.

In the present specification, by forming at least a portion of the wiring including the bending region to extend in an oblique direction that is different from the bending direction, it is possible to minimize the tensile force to reduce the occurrence of cracks.

Effects according to the present specification are not limited by the contents exemplified above, and more various effects are included in the present specification.

Since the contents of the specification described in the problems to be solved above, the means for solving the problems, and the effects do not specify the essential characteristics of the claims, the scope of the claims is not limited by the matters described in the contents of the specification.

1 is a block diagram of an electroluminescent display device according to an embodiment of the present specification.
2 is a circuit diagram of a pixel included in an electroluminescent display device according to an embodiment of the present specification.
3 is a cross-sectional view of a pixel included in an electroluminescent display device according to an exemplary embodiment of the present specification.
4 is a plan view of an electroluminescent display device according to an embodiment of the present specification.
5 is a cross-sectional view of a bending region B/A of a flexible electroluminescent display according to an embodiment of the present specification.
6A and 6B are cross-sectional views and enlarged views of a portion of a bending region B/A of a flexible electroluminescent display device according to an embodiment of the present specification.
7 is a cross-sectional view of a first area of a bending area B/A of a flexible electroluminescent display according to an exemplary embodiment of the present specification.
8A and 8B are cross-sectional views of a second area of a bending area B/A of a flexible electroluminescent display according to an exemplary embodiment of the present specification.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between the two parts unless 'directly' is used.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be implemented independently of each other or may be implemented together in a related relationship. may be

1 is a block diagram of an electroluminescent display device 100 according to an embodiment of the present specification.

Referring to FIG. 1 , the electroluminescent display device 100 includes an image processing unit 110 , a timing controller 120 , a data driver 130 , a gate driver 140 , and a display panel 150 .

The image processing unit 110 outputs a data enable signal DE along with the data signal DATA supplied from the outside. The image processing unit 110 may output one or more of a vertical synchronization signal, a horizontal synchronization signal, and a clock signal in addition to the data enable signal DE.

The timing controller 120 receives the data signal DATA from the image processing unit 110 as well as a driving signal including a data enable signal DE or a vertical synchronization signal, a horizontal synchronization signal, and a clock signal. The timing controller 120 includes a gate timing control signal GDC for controlling the operation timing of the gate driver 140 and a data timing control signal DDC for controlling the operation timing of the data driver 130 based on the driving signal. to output

The data driver 130 samples and latches the data signal DATA supplied from the timing controller 120 in response to the data timing control signal DDC supplied from the timing controller 120 , and converts it into a gamma reference voltage and outputs it. . The data driver 130 outputs the data signal DATA through the data lines DL1 to DLn.

The gate driver 140 outputs a gate signal while shifting the level of the gate voltage in response to the gate timing control signal GDC supplied from the timing controller 120 . The gate driver 140 outputs a gate signal through the gate lines GL1 to GLm.

The display panel 150 displays an image while the pixel 160 emits light in response to the data signal DATA and the gate signal supplied from the data driver 130 and the gate driver 140 . The detailed structure of the pixel 160 will be described with reference to FIGS. 2 and 3 .

2 is a circuit diagram of a pixel included in an electroluminescent display device according to an embodiment of the present specification.

Referring to FIG. 2 , a pixel of the electroluminescent display device 200 includes a switching transistor 240 , a driving transistor 250 , a compensation circuit 260 , and an organic light emitting device 270 .

The organic light emitting device 270 operates to emit light according to a driving current formed by the driving transistor 250 .

The switching transistor 240 performs a switching operation such that the data signal supplied through the data line 230 is stored as a data voltage in the capacitor in response to the gate signal supplied through the gate line 220 .

The driving transistor 250 operates so that a constant driving current flows between the high potential power line VDD and the low potential power line GND in response to the data voltage stored in the capacitor.

The compensation circuit 260 is a circuit for compensating the threshold voltage of the driving transistor 350 , and the compensation circuit 260 includes one or more thin film transistors and a capacitor. The configuration of the compensation circuit may vary greatly depending on the compensation method.

In addition, the pixel of the electroluminescent display device 200 has a 2T (Transistor) 1C (Capacitor) structure including a switching transistor 240 , a driving transistor 250 , a capacitor and an organic light emitting device 270 , but a compensation circuit When 260 is added, it can be variously formed as 3T1C, 4T2C, 5T2C, 6T1C, 6T2C, 7T1C, 7T2C, and the like.

3 is a cross-sectional view of a pixel included in an electroluminescent display device according to an exemplary embodiment of the present specification.

The substrate 310 serves to support and protect the components of the electroluminescent display 300 disposed thereon. Recently, since the substrate 310 may be made of a flexible material having a flexible characteristic, the substrate 310 may be It may be a flexible substrate.

In addition, the flexible substrate may be in the form of a film including one selected from the group consisting of a polyester-based polymer, a silicone-based polymer, an acrylic polymer, a polyolefin-based polymer, and a copolymer thereof.

For example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polysilane (polysilane), polysiloxane (polysiloxane), polysilazane (polysilazane), polycarbosilane (polycarbosilane), polyacrylate (polyacrylate) ), polymethacrylate, polymethylacrylate, polymethylmethacrylate, polyethylacrylate, polyethylmethacrylate, cyclic olefin copolymer ( COC), cyclic olefin polymer (COP), polyethylene (PE), polypropylene (PP), polyimide (PI), polymethylmethacrylate (PMMA), polystyrene (PS), polyacetal (POM), polyether Etherketone (PEEK), polyester sulfone (PES), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polycarbonate (PC), polyvinylidene fluoride (PVDF), perfluoroalkyl polymers ( PFA), styrene-acrylnitrile copolymer (SAN), and a combination thereof may be composed of at least one.

A buffer layer may be further disposed on the substrate 310 . The buffer layer prevents penetration of moisture or other impurities through the substrate 310 and may planarize the surface of the substrate 310 . The buffer layer is not a necessary configuration, and may not be disposed depending on the type of the substrate 310 or the type of the thin film transistor 320 disposed on the substrate.

The thin film transistor 320 disposed on the substrate 310 includes a gate electrode 322 , a source electrode 324 , a drain electrode 326 , and a semiconductor layer 328 .

The semiconductor layer 328 has better mobility than amorphous silicon or amorphous silicon, so it has low energy consumption and excellent reliability. Polycrystalline silicon that can be applied to a driving thin film transistor in a pixel ), but is not limited thereto.

Recently, oxide semiconductors have been spotlighted for their excellent mobility and uniformity. The oxide semiconductor is a quaternary metal oxide indium tin gallium zinc oxide (InSnGaZnO)-based material, a ternary metal oxide indium gallium zinc oxide (InGaZnO)-based material, indium tin zinc oxide (InSnZnO)-based material, indium aluminum zinc oxide (InAlZnO) ) based material, tin gallium zinc oxide (SnGaZnO) based material, aluminum gallium zinc oxide (AlGaZnO) based material, tin aluminum zinc oxide (SnAlZnO) based material, indium zinc oxide (InZnO) based material as binary metal oxide, tin zinc Oxide (SnZnO)-based material, aluminum zinc oxide (AlZnO)-based material, zinc magnesium oxide (ZnMgO)-based material, tin magnesium oxide (SnMgO)-based material, indium magnesium oxide (InMgO)-based material, indium gallium oxide (InGaO)-based material material, an indium oxide (InO)-based material, a tin oxide (SnO)-based material, a zinc oxide (ZnO)-based material, or the like, and the composition ratio of each element is not particularly limited.

The semiconductor layer 328 may include a source region and a drain region including p-type or n-type impurities, and a channel between the source region and the drain region. A lightly doped region may be included between the adjacent source and drain regions.

The gate insulating layer 331 is an insulating film composed of a single layer of silicon oxide (SiOx) or silicon nitride (SiNx) or multiple layers thereof, and is disposed so that the current flowing through the semiconductor layer 328 does not flow to the gate electrode 322 . do. In addition, silicon oxide has lower ductility than metal, but has superior ductility compared to silicon nitride, and may be selectively formed as a single layer or a plurality of layers according to its characteristics.

The gate electrode 322 serves as a switch for turning on or off the thin film transistor 320 based on an electric signal transmitted from the outside through the gate line, and a conductive metal Phosphorus copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), etc. Or it may be composed of multiple layers, but is not limited thereto.

The source electrode 324 and the drain electrode 326 are connected to the data line so that an electric signal transmitted from the outside is transmitted from the thin film transistor 320 to the organic light emitting diode 340 . The source electrode 324 and the drain electrode 326 are conductive metals copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), and a metal material such as neodymium (Nd) or an alloy thereof may be configured as a single layer or multiple layers, but is not limited thereto.

In order to insulate the gate electrode 322, the source electrode 324, and the drain electrode 326 from each other, an interlayer insulating layer 333 composed of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx) is formed as a gate electrode. It may be disposed between the 322 and the source electrode 324 and the drain electrode 326 .

A passivation layer 335 made of an inorganic insulating layer such as silicon oxide (SiOx) or silicon nitride (SiNx) is disposed on the thin film transistor 320 . The passivation layer 335 may prevent unnecessary electrical connections between components of the thin film transistor 320 and may prevent external contamination or damage. The passivation layer 335 may be omitted depending on the configuration and characteristics of the thin film transistor 320 and the organic light emitting device 340 .

The thin film transistor 320 may be classified into an inverted staggered structure and a coplanar structure according to positions of components constituting the thin film transistor 320 . In the thin film transistor of the inverted staggered structure, the gate electrode is positioned opposite the source electrode and the drain electrode with respect to the semiconductor layer. As shown in FIG. 3 , in the thin film transistor 320 having a coplanar structure, the gate electrode 322 is positioned on the same side as the source electrode 324 and the drain electrode 326 with respect to the semiconductor layer 328 .

Although the thin film transistor 320 having a coplanar structure is illustrated in FIG. 3 , the electroluminescent display device may include a thin film transistor having an inverted staggered structure.

For convenience of description, only the driving thin film transistor is illustrated among various thin film transistors that may be included in the electroluminescent display, but a switching thin film transistor, a capacitor, and the like may also be included in the electroluminescent display. At this time, when a signal is applied from the gate line to the switching thin film transistor, the signal from the data line is transferred to the gate electrode of the driving thin film transistor. The driving thin film transistor transmits a current transmitted through the power wiring to the anode according to a signal received from the switching thin film transistor, and controls light emission by the current transmitted to the anode.

The thin film transistor 320 is protected and the step difference generated by the thin film transistor 320 is alleviated, and the parasitic capacitance ( A planarization layer 337 is disposed on the thin film transistor 320 to reduce parasitic-capacitance.

The planarization layer 337 is an acrylic resin, an epoxy resin, a phenolic resin, a polyamides resin, a polyimides resin, an unsaturated polyester resin (Unsaturated Polyesters Resin), polyphenylene-based resin (Polyphenylene Resin), polyphenylenesulfide-based resin (Polyphenylenesulfides Resin), and benzocyclobutene (Benzocyclobutene) may be formed of at least one material, but is not limited thereto.

Also, the planarization layer 337 may be disposed in a plurality of layers, which will be described with reference to FIG. 6 .

The organic light emitting diode 340 disposed on the planarization layer 337 includes an anode 342 , a light emitting unit 344 , and a cathode 346 .

The anode 342 may be disposed on the planarization layer 337 . The anode 342 is an electrode serving to supply holes to the light emitting unit 344 , and may be electrically connected to the thin film transistor 320 through a contact hole in the planarization layer 337 .

The anode 342 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), or the like, which are transparent conductive materials, but is not limited thereto.

In addition, when the electroluminescent display device 300 is a top emission that emits light to an upper portion where the cathode 346 is disposed, the emitted light is reflected from the anode 342 to more smoothly the cathode 346 . It may further include a reflective layer so that it can be emitted in the upper direction in which it is disposed. In addition, the anode 342 may have a two-layer structure in which a transparent conductive layer and a reflective layer made of a transparent conductive material are sequentially stacked, or a three-layer structure in which a transparent conductive layer, a reflective layer, and a transparent conductive layer are sequentially stacked, and the reflective layer is silver ( Ag) or an alloy containing silver.

The bank 350 disposed on the anode 342 and the planarization layer 337 may define a pixel capable of partitioning a region that actually emits light. After photoresist is formed on the anode 342 , the bank 350 is formed by photolithography. The photoresist refers to a photosensitive resin whose solubility in a developer is changed by the action of light, and a specific pattern can be obtained by exposing and developing the photoresist. The photoresist may be classified into a positive photoresist and a negative photoresist. The positive photoresist refers to a photoresist in which the solubility of the exposed portion in the developer is increased by exposure, and when the positive photoresist is developed, a pattern in which the exposed portion is removed is obtained. In addition, the negative photoresist refers to a photoresist whose solubility in the developer of the exposed portion is greatly reduced by exposure, and when the negative photoresist is developed, a pattern in which the unexposed portion is removed is obtained.

In order to form the light emitting part 344 of the organic light emitting device 340, a deposition mask, FMM (Fine Metal Mask) may be used. In addition, in order to prevent damage that may be caused by contact with the deposition mask disposed on the bank 350 and to maintain a constant distance between the bank 350 and the deposition mask, a transparent organic material polyi is placed on the bank 350 . A spacer 352 composed of one of mid, photoacryl and benzocyclobutene (BCB) may be disposed.

A light emitting part 344 is disposed between the anode 342 and the cathode 346 . The light emitting unit 344 serves to emit light, and includes a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer, an electron transport layer (ETL), and an electron injection layer. (Electron Injection Layer; EIL) may include at least one layer, and some components of the light emitting unit 444 may be omitted depending on the structure or characteristics of the electroluminescent display device 300 . Here, as the light emitting layer, it is also possible to apply an organic light emitting layer and an inorganic light emitting layer.

The hole injection layer is disposed on the anode 342 to facilitate hole injection. The hole injection layer is, for example, HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10.11-hexacarbonitrile), CuPc (phthalocyanine), and It may be formed of at least one of N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine (NPD).

The hole transport layer is disposed on the hole injection layer to smoothly transfer holes to the light emitting layer. The hole transport layer is, for example, NPD (N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine), TPD (N,N'-bis) -(3-methylphenyl)-N,N'-bis-(phenyl)-benzidine), s-TAD(2,2',7,7'-tetrakis(N,N-dimethylamino)-9,9-spirofluorene) , and MTDATA (4,4',4"-Tris(N-3-methylphenyl-N-phenyl-amino)-triphenylamine).

The light emitting layer is disposed on the hole transport layer and includes a material capable of emitting light of a specific color to emit light of a specific color. In addition, the light emitting material may be formed using a phosphorescent material or a fluorescent material.

When the emission layer emits red light, the emission peak wavelength may be in the range of 600 nm to 650 nm, and CBP (4,4'-bis (carbazol-9-yl) biphenyl) or mCP (1,3) -bis(carbazol-9-yl)benzene) containing host material, PIQIr(acac)(bis(1-phenylisoquinoline)(acetylacetonate) iridium), PQIr(acac)(bis(1-phenylquinoline)(acetylacetonate) ) iridium), PQIr (tris(1-phenylquinoline) iridium) and PtOEP (octaethylporphyrin platinum). Alternatively, it may be made of a fluorescent material including PBD:Eu(DBM)3(Phen) or Perylene.

Here, the peak wavelength λmax refers to the maximum wavelength of EL (ElectroLuminescence). The wavelength at which the light emitting layers constituting the light emitting unit emits unique light is called PL (PhotoLuminescence), and the light emitted by the thickness or optical characteristics of the layers constituting the light emitting layers is called the emittance. In this case, EL (ElectroLuminescence) refers to light finally emitted by the electroluminescent display device, and may be expressed as a product of PL (PhotoLuminescence) and an emittance (Emittance).

When the emission layer emits green light, the emission peak wavelength may be in the range of 520 nm to 540 nm, and includes a host material including CBP or mCP, and Ir(ppy) ₃ (tris(2-phenylpyridine)iridium ) may be made of a phosphorescent material including a dopant material such as an Ir complex containing. In addition, _{it may be formed of a fluorescent material including Alq 3} (tris(8-hydroxyquinolino)aluminum).

When the emission layer emits blue light, the emission peak wavelength may be in the range of 440 nm to 480 nm, and includes a host material including CBP or mCP, and FIrPic(bis(3,5-difluoro-2) -(2-pyridyl)phenyl-(2-carboxypyridyl)iridium) may be formed of a phosphorescent material including a dopant material, and spiro-DPVBi(4,4'-Bis(2,2-diphenyl-ethen) Any of -1-yl)biphenyl), DSA (1-4-di-[4-(N,N-di-phenyl)amino]styryl-benzene), PFO (polyfluorene)-based polymer, and PPV (polyphenylenevinylene)-based polymer It may be made of a fluorescent material including one.

The electron transport layer is disposed on the light emitting layer to facilitate the movement of electrons to the light emitting layer. The electron transport layer is, for example, Liq (8-hydroxyquinolinolato-lithium), PBD (2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole), TAZ (3- (4-biphenyl)4-phenyl-5-tert-butylphenyl-1,2,4-triazole), spiro-PBD, BCP (2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline) and BAlq (bis(2-methyl-8-quinolinolate)-4-(phenylphenolato)aluminum).

An electron injection layer may be further disposed on the electron transport layer. The electron injection layer is an organic layer that facilitates injection of electrons from the cathode 346 , and may be omitted depending on the structure and characteristics of the electroluminescent display 300 . The electron injection layer is BaF2, LiF, NaCl, CsF, Li 2 O , and may be a metallic inorganic compound such as BaO, HAT-CN (dipyrazino [ 2,3-f: 2 ', 3'-h] quinoxaline-2, 3,6,7,10.11-hexacarbonitrile), CuPc (phthalocyanine), and NPD (N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine) It may be any one or more organic compounds.

By further disposing an electron blocking layer or a hole blocking layer that blocks the flow of holes or electrons at a position adjacent to the light emitting layer, when electrons are injected into the light emitting layer, they move from the light emitting layer and pass through the adjacent hole transport layer or When a hole is injected into the light emitting layer, it is possible to prevent a phenomenon that the hole moves from the light emitting layer and passes to the adjacent electron transport layer, thereby improving the luminous efficiency.

The cathode 346 is disposed on the light emitting unit 344 and serves to supply electrons to the light emitting unit 344 . Since the cathode 346 must supply electrons, it may be formed of a metal material such as magnesium (Mg), silver-magnesium (Ag:Mg), which is a conductive material having a low work function, but is not limited thereto. And, when the electroluminescent display device 300 is a top emission type, the cathode 346 is indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (Indium Tin Zinc Oxide, ITZO), zinc It may be a transparent conductive oxide based on oxide (ZnO) and tin oxide (TiO).

On the organic light emitting device 340, the thin film transistor 320 and the organic light emitting device 340, which are components of the electroluminescent display device 300, are prevented from being oxidized or damaged due to moisture, oxygen, or impurities introduced from the outside. An encapsulation unit 360 may be disposed for the purpose, and a plurality of encapsulation layers, a foreign material compensation layer, and a plurality of barrier films may be laminated to form.

The encapsulation layer is disposed on the upper front surface of the thin film transistor 320 and the organic light emitting device 340 , and may be composed of one of inorganic silicon nitride (SiNx) or aluminum oxide (AlyOz), but is not limited thereto. An encapsulation layer may be further stacked on the foreign material compensation layer disposed on the encapsulation layer.

The foreign material compensation layer is disposed on the encapsulation layer, and an organic material such as silicon oxycarbon (SiOCz), acryl or epoxy resin may be used, but is not limited thereto. When a defect occurs due to a crack generated by a foreign material or particles that may be generated during the process, it can be compensated for by being covered by the foreign material compensation layer and bending.

By disposing a barrier film on the encapsulation layer and the foreign material compensation layer, the electroluminescent display device 300 may delay penetration of oxygen and moisture from the outside. The barrier film is configured in the form of a film having light-transmitting and double-sided adhesiveness, and may be composed of any one insulating material among olefin-based, acrylic-based, and silicone-based insulating materials, or COP (Cyclolefin). Polymer), COC (Cycloolefin Copolymer), and PC (Polycarbonate) may be further laminated with a barrier film made of any one material, but is not limited thereto.

4 is a plan view of an electroluminescent display device according to an embodiment of the present specification.

Referring to FIG. 4 , the flexible electroluminescent display 400 includes an active area (A/A) in which pixels that actually emit light through a thin film transistor and an organic light emitting device are disposed on a flexible substrate 410 , and and a non-active area (N/A) surrounding the edge of the display area A/A.

And, FIG. 4 is a plan view of the flexible substrate 410 of the flexible electroluminescent display 400 according to the embodiment of the present specification in a state in which it is not bent.

A circuit and wiring for driving the flexible electroluminescent display 400 may be disposed in the non-display area N/A of the flexible substrate 410 . In addition, it may be disposed on the substrate 410 as a gate in panel (GIP), or may be connected to the flexible substrate 410 using a tape carrier package (TCP) or a chip on film (COF) method.

A portion of the non-display area N/A of the flexible substrate 410 may be bent in a bending direction as indicated by an arrow to form the bending area B/A. In the non-display area N/A of the flexible substrate 410 , wiring and a driving circuit for driving the screen are disposed, and since an image is not displayed, there is no need to be visually recognized from the upper surface of the flexible substrate 410 . , a portion of the non-display area N/A of the flexible substrate 410 may be bent to secure an area for the wiring and the driving circuit while reducing the bezel area.

The bending region B/A of the flexible substrate 410 will be described with reference to FIGS. 5 to 6 .

Various wirings are formed on the flexible substrate 410 . The wiring may be formed in the display area A/A of the substrate 410 or the circuit wiring 420 formed in the non-display area N/A may be connected to a driving circuit, a gate driver, a data driver, etc. signal can be transmitted.

The circuit wiring 420 may be formed of a conductive material, and may be formed of a conductive material having excellent ductility to minimize cracks from occurring when the flexible substrate 410 is bent. For example, it may be formed of a conductive material having excellent ductility, such as gold (Au), silver (Ag), aluminum (Al), etc., and may be formed of one of various conductive materials used in the display area A/A. , molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and an alloy of silver (Ag) and magnesium (Mg). . In addition, it may be configured as a multi-layer structure including various conductive materials, for example, it may be configured as a three-layer structure of titanium (Ti)/aluminum (Al)/titanium (Ti), but is not limited thereto.

The circuit wiring 420 formed in the bending area B/A receives a tensile force when bent. For example, the circuit wiring 420 extending in the same direction as the bending direction (indicated by the arrow) on the flexible substrate 410 receives the greatest tensile force, and cracks may occur, and if the cracks are severe, disconnection may occur. have. Accordingly, rather than forming the circuit wiring 420 to extend in the bending direction, at least a portion of the circuit wiring 420 disposed including the bending region B/A extends in an oblique direction that is different from the bending direction. By forming, it is possible to minimize the tensile force to minimize the occurrence of cracks.

The circuit wiring 420 disposed including the bending region B/A may be formed in various shapes, for example, a trapezoidal wave shape, a triangular wave shape, a sawtooth wave shape, a sine wave shape, an omega (Ω) shape, a rhombus. It may be formed in various shapes, such as a shape.

The structure of the circuit wiring 420 disposed including the bending region B/A of the flexible substrate 410 will be described with reference to FIGS. 6A to 8B .

The gate signal and data signal described in FIG. 1 are disposed in the display area A/A through the circuit wiring 420 disposed in the non-display area N/A of the flexible electroluminescent display device 400 from the outside. It is transmitted to the pixel so that it emits light.

5 is a cross-sectional view of a bending region B/A of a flexible electroluminescent display according to an embodiment of the present specification.

Referring to FIG. 5 , a barrier film 520 is disposed on the flexible substrate 510 . The barrier film 520 is a component for protecting various components of the flexible electroluminescent display device 500 , and may be disposed to correspond to at least the display area A/A of the flexible electroluminescent display device 500 . In addition, the barrier film 520 may be made of a material having an adhesive property, and may serve to fix the polarizing plate 530 on the barrier film 520 .

A back plate 540 is disposed under the flexible substrate 510 . When the flexible substrate 510 is made of a plastic material such as polyimide, the flexible electroluminescent display device 500 manufacturing process proceeds in a situation where a support substrate made of glass is disposed under the flexible substrate 510, and the manufacturing process is After completion, the support substrate may be separated and released.

Since components for supporting the flexible substrate 510 are required even after the supporting substrate is released, a back plate 540 for supporting the flexible substrate 510 may be disposed under the flexible substrate 510 . The back plate 540 may be disposed adjacent to the bending area B/A in another area of the flexible substrate 510 except for the bending area B/A.

Backplate 540 may be made of a thin plastic film formed of polyimide, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), other suitable polymers, combinations of these polymers, or the like.

A support member 570 is disposed between the two backplates 540 , and the support member 570 may be adhered to the backplate 540 by an adhesive layer 560 . Support member 570 may be formed of a plastic material such as polycarbonate (PC), polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), other suitable polymers, combinations of these polymers, or the like. . The strength of the support member 570 formed of these plastic materials may be controlled by providing additives to increase the thickness and strength of the support member 570 . In addition, the support member 570 may be formed of glass, ceramic, metal, or other rigid materials or combinations of the aforementioned materials.

A micro coating layer 550 is disposed on the bending area B/A of the flexible substrate 510 . The micro coating layer 550 may be formed to cover one side of the barrier film 520 . In addition, since the micro-coating layer 550 may generate micro-cracks due to tensile force acting on the wiring portion disposed on the flexible substrate 510 during bending, a thin layer of resin is coated at the bending position for wiring. can play a role in protecting

An insulating film 580 is connected to an end of the flexible substrate 510 . Various wirings for transmitting signals to pixels disposed in the display area A/A are formed on the insulating film 580 . The insulating film 580 is formed of a material having flexibility so that it can be bent. A driving device may be mounted on the insulating film 580 , and a driving package such as a chip on film (COF) is formed together with the insulating film 650 , and formed on the insulating film 580 . It is connected to the wiring to provide a driving signal and data to the pixels disposed in the display area A/A.

The circuit board connected to the insulating film 580 may receive an image signal from the outside and apply various signals to the pixels disposed in the display area A/A, and may be a printed circuit board. .

6A and 6B are cross-sectional views and enlarged views of a portion of a bending area B/A of a flexible electroluminescent display device according to an embodiment of the present specification.

6A and 6B are enlarged plan views of the wiring of the bending area B/A in the flexible electroluminescent display 500 described with reference to FIG. 5 for convenience of explanation. FIG. 6 illustrates a portion of the bending area B/A in the flexible electroluminescent display device described with reference to FIGS. 1 to 5 for convenience of explanation. The main components are substantially the same as or similar to the main components described in FIGS. 1 to 5 .

6A and 6B , the first wiring 620 and the second wiring 630 are sequentially disposed in the bending area B/A of the flexible substrate 610 .

When the wiring disposed in the non-display area N/A including the bending area B/A of the flexible electroluminescent display device 600 is formed in a single-layer structure, a large amount of space for disposing the wiring is required. After depositing the conductive material, the conductive material is patterned in the shape of the wiring to be formed by an etching process, etc. Since the precision of the etching process is limited, a lot of space is required due to the limitation to narrow the gap between the wirings, Since the area of the non-display area N/A is increased, it may be difficult to implement a narrow bezel.

In addition, when a single wire is used to transmit one signal, the corresponding signal may not be transmitted when a crack occurs in the corresponding wire. In the process of bending the flexible substrate 610 , cracks may be generated in the wiring itself or cracks in other layers may be generated and the cracks may propagate to the wiring. As such, when a crack occurs in the wiring, the transmitted signal may not be transmitted.

Accordingly, the wirings disposed in the non-display area N/A including the bending area B/A of the flexible electroluminescent display device 600 according to the embodiment of the present specification are the first wiring 620 and the second wiring. The wiring 630 is disposed in the form of a double wiring.

The first wiring 620 and the second wiring 630 may be formed of a conductive material, and may be formed of a conductive material having excellent ductility in order to reduce cracking when the flexible substrate 610 is bent. For example, it may be formed of a conductive material having excellent ductility, such as gold (Au), silver (Ag), aluminum (Al), etc., and may be formed of one of various conductive materials used in the display area A/A. , molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and an alloy of silver (Ag) and magnesium (Mg). . In addition, it may be composed of a multi-layer structure including various conductive materials, for example, it may be composed of a titanium (Ti)/aluminum (Al)/titanium (Ti) three-layer structure, but is not limited thereto.

The first wiring 620 and the second wiring 630 may be surrounded by an insulating material for protecting the first wiring 620 and the second wiring 630 . For example, the first wiring 620 and the second wiring 630 may be surrounded by an inorganic layer for protecting the first wiring 620 and the second wiring 630 . For example, a buffer layer made of an inorganic material may be disposed on the lower portion, and a passivation layer made of an inorganic material may be formed to surround upper portions and sides of the first wiring 620 and the second wiring 630 . Accordingly, a phenomenon in which the first wiring 620 and the second wiring 630 react with moisture and corrode may be prevented.

When bent, the first wiring 620 and the second wiring 630 formed in the bending region B/A receive a tensile force. As described in FIG. 4 , the wiring extending in the same direction as the bending direction on the flexible substrate 610 receives the greatest tensile force, and cracks may occur. If the cracks are severe, disconnection may occur. Accordingly, rather than forming the wiring to extend in the bending direction, at least a portion of the wiring disposed including the bending region B/A is formed to extend in an oblique direction that is different from the bending direction, thereby minimizing the tensile force and thus cracking. occurrence can be reduced.

The first wiring 620 and the second wiring 630 of the flexible electroluminescent display device 600 according to the embodiment of the present specification are formed in a zigzag (Zig-Zag) shape along the bending direction, and the flexible electroluminescent display device According to (600), the shape of the wiring may be configured in a rhombus shape, a triangular wave shape, a sinusoidal wave shape, a trapezoidal shape, or the like, but is not limited thereto.

The first wiring 620 and the second wiring 630 include first regions 620a and 630a formed in a zigzag shape along the bending direction, respectively, and the same layer of the first wiring 620 and the second wiring 630 . and second regions 620b and 630b that are connection patterns connecting two wires adjacent to each other. In addition, the second regions 620b and 630b of the first wiring 620 and the second wiring 630 are formed along a direction perpendicular to the bending direction, and the second regions 620b and 630b of the first wiring 620 and the second wiring 630 . 1 is formed at the inflection point in the zigzag shape of the regions 620a and 630a. In addition, some regions of the second regions 620b and 630b of the first wiring 620 and the second wiring 630 are formed to overlap each other.

The first wiring 620 and the second wiring 630 are formed to include both the first regions 620a and 630a and the second regions 620b and 630b, respectively, so that two adjacent wirings receive one signal. Even if a crack occurs in one of the two wires, there is an additional wire, so that the signal can be transmitted normally.

When the first wiring 620 and the second wiring 630 have a zigzag shape, a crack may occur in this region as stress during bending is applied to an inflection point of the zigzag shape. In order to prevent this, the inflection points of the first regions 620a and 630a of the first wiring 620 and the second wiring 630 are formed along the bending direction and the vertical direction of the first wiring 620 and the second wiring 630 . Even when the second regions 620b and 630b are connected to stress concentrated during bending, the resistance to stress of the first wiring 620 and the second wiring 630 is strengthened, thereby preventing cracks from occurring.

A first wiring 620 is disposed on the flexible substrate 610 , and a first planarization layer 650 is disposed on the first wiring 620 . A second wire 630 is disposed on the first planarization layer 650 , and a second planarization layer 660 is disposed on the second wire 630 . The first planarization layer 650 and the second planarization layer 660 include an acrylic resin, an epoxy resin, a phenolic resin, a polyamides resin, and a polyimide-based resin. (Polyimides Resin), Unsaturated Polyesters Resin, Polyphenylene Resin, Polyphenylenesulfides Resin, and Benzocyclobutene may, but is not limited thereto.

A compensation pattern 640 is formed on the second planarization layer 650 in a region where the second regions 620b and 630b of the first wiring 620 and the second wiring 630 overlap each other. In this case, the compensation pattern 640 may be formed of the same layer and the same material as the bank 350 or the spacer 352 described with reference to FIG. 3 . Depending on the height of the compensation pattern 640 , the bank 350 or the spacer 352 , the bank 350 and the spacer 352 may be formed including both, or may be formed at the same time, but is not limited thereto.

The neutral plane N/P formed in the bending region has a close relationship with the crack formation of the wiring and the insulating layer of the bending region B/A, and it is very important to optimize the neutral plane. In the second regions 620b and 630b of the first wiring 620 and the second wiring 630 , the neutral plane N/P changes rapidly while some regions overlap each other, and accordingly, the compressive and tensile forces are simultaneously applied. In some cases, cracks may occur more easily in the insulating layer in the region where the neutral plane changes rapidly.

The compensation pattern 640 is formed on the overlapping region of the second regions 620b and 630b of the first wiring 620 and the second wiring 630 to prevent a sudden change in the neutral plane, thereby preventing cracks. .

The width of the compensation pattern 640 is at least 1.5 μm apart from the overlapping regions of the second regions 620b and 630b of the first wiring 620 and the second wiring 630 to secure a process margin. have.

The cross-sectional structure of the bending region B/A of the flexible substrate 610 will be described with reference to FIGS. 7, 8A, and 8B.

7 is a cross-sectional view of a first area of a bending area B/A of a flexible electroluminescent display according to an exemplary embodiment of the present specification.

FIG. 7 is a cross-sectional view of region II′ in FIG. 6A , showing first regions 620a and 630a of the first interconnection 620 and the second interconnection 630 . FIG. 7 illustrates a portion of the bending area B/A in the flexible electroluminescent display device described with reference to FIGS. 1 to 6 for convenience of explanation. The main components are substantially the same as or similar to the main components described in FIGS. 1 to 6 .

Referring to FIG. 7 , a first wiring 620 including a first region 620a is disposed on a flexible substrate 610 , and a first planarization layer 650 is disposed on the first wiring 620 . The second wiring 630 including the first region 630a is disposed on the first planarization layer 650 , and the second planarization layer 660 is disposed on the second wiring 630 .

The first wiring 620 and the second wiring 630 may be formed of a conductive material, and may be formed of a conductive material having excellent ductility in order to reduce cracking when the flexible substrate 610 is bent. For example, it may be formed of a conductive material having excellent ductility, such as gold (Au), silver (Ag), aluminum (Al), etc., and may be formed of one of various conductive materials used in the display area A/A. , molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and an alloy of silver (Ag) and magnesium (Mg). . In addition, it may be composed of a multi-layer structure including various conductive materials, for example, it may be composed of a titanium (Ti)/aluminum (Al)/titanium (Ti) three-layer structure, but is not limited thereto.

The first wiring 620 and the second wiring 630 may be surrounded by an insulating material for protecting the first wiring 620 and the second wiring 630 . For example, the first wiring 620 and the second wiring 630 may be surrounded by an inorganic layer for protecting the first wiring 620 and the second wiring 630 . For example, a buffer layer made of an inorganic material may be disposed on the lower portion, and a passivation layer made of an inorganic material may be formed to surround upper portions and sides of the first wiring 620 and the second wiring 630 . Accordingly, a phenomenon in which the first wiring 620 and the second wiring 630 react with moisture and corrode may be prevented.

A first planarization layer 650 is deposited and formed on the first wiring 620 to planarize the upper portion. The first planarization layer 650 is substantially the same as or similar to the planarization layer 337 described with reference to FIG. 3 . And, the first planarization layer 650 is an acrylic resin (Acrylic Resin), an epoxy resin (Epoxy Resin), a phenol resin (Phenolic Resin), a polyamide-based resin (Polyamides Resin), a polyimide-based resin (Polyimides Resin), unsaturated Polyester-based resin (Unsaturated Polyesters Resin), polyphenylene-based resin (Polyphenylene Resin), polyphenylene sulfide-based resin (Polyphenylenesulfides Resin), and benzocyclobutene (Benzocyclobutene) may be formed of at least one material, but is not limited thereto. does not

A second wiring 630 is disposed on the first planarization layer 660 . As the second wiring 630 is disposed on the first planarization layer 660 , the number of wirings for transmitting a signal in the display area A/A may be more comfortably secured.

A second planarization layer 660 is deposited on the second wiring 630 to planarize an upper portion thereof. The second planarization layer 660 is substantially the same as or similar to the planarization layer 337 described with reference to FIG. 3 . And, the second planarization layer 660 is an acrylic resin (Acrylic Resin), an epoxy resin (Epoxy Resin), a phenol resin (Phenolic Resin), a polyamide-based resin (Polyamides Resin), a polyimide-based resin (Polyimides Resin), unsaturated Polyester-based resin (Unsaturated Polyesters Resin), polyphenylene-based resin (Polyphenylene Resin), polyphenylene sulfide-based resin (Polyphenylenesulfides Resin), and benzocyclobutene (Benzocyclobutene) may be formed of at least one material, but is not limited thereto. does not

On the second planarization layer 660 , when bending in the bending region B/A of the flexible substrate 610 , a tensile force is applied to the first wiring 620 and the second wiring 630 disposed on the flexible substrate 610 . Since micro-cracks may occur due to the action, the micro-coating layer 670 made of resin may be formed thereon to protect the wiring. In addition, the micro-coating layer 670 may be formed by coating with a thin thickness.

The neutral plane (N/P) refers to an imaginary plane that is not subjected to stress because compressive and tensile forces applied to the structure cancel each other when a structure is bent. When bending, the layer disposed on the upper surface with respect to the neutral plane (N/P) is stretched to receive a tensile force, and the layer disposed on the lower surface is compressed and thus receives a compressive force.

Since the wirings such as the first wiring 620 and the second wiring 630 are more vulnerable when receiving a tensile force among compression and tensile forces of the same magnitude, the neutral plane is not subjected to the tensile force or to minimize the magnitude of the tensile force even when receiving the tensile force. It is disposed under (N/P) and controls the thickness of the micro-coating layer 670 formed on the second planarization layer 660 . In addition, since the neutral plane N/P of the region where the first wiring 620 and the second wiring 630 are disposed should not be subjected to stress by canceling each other with the tensile force of the micro-coating layer 670 formed thereon, the wiring It is formed closer to the substrate than the neutral plane (N/P) of this non-formed region.

8A and 8B are cross-sectional views of a second area of a bending area B/A of a flexible electroluminescent display according to an embodiment of the present specification.

8A and 8B are cross-sectional views taken along region II-II′ in FIG. 6A , showing the first and second regions 620b and 630b of the second interconnection 630 . 8A and 8B illustrate a portion of the bending area B/A in the flexible electroluminescent display device described with reference to FIGS. 1 to 6 for convenience of explanation. The main components are substantially the same as or similar to the main components described in FIGS. 1 to 6 .

8A and 8B , a first wiring 620 including a second region 620b is disposed on a flexible substrate 610 , and a first planarization layer 650 is disposed on the first wiring 620 . do. A second wiring 630 including a second region 630b is disposed on the first planarization layer 650 , and a second planarization layer 660 is disposed on the second wiring 630 .

The first wiring 620 and the second wiring 630 may be formed of a conductive material, and may be formed of a conductive material having excellent ductility in order to reduce cracking when the flexible substrate 610 is bent. For example, it may be formed of a conductive material having excellent ductility, such as gold (Au), silver (Ag), aluminum (Al), etc., and may be formed of one of various conductive materials used in the display area A/A. , molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and an alloy of silver (Ag) and magnesium (Mg). . In addition, it may be configured as a multi-layer structure including various conductive materials, for example, it may be configured as a three-layer structure of titanium (Ti)/aluminum (Al)/titanium (Ti), but is not limited thereto.

The first wiring 620 and the second wiring 630 may be surrounded by an insulating material for protecting the first wiring 620 and the second wiring 630 . For example, the first wiring 620 and the second wiring 630 may be surrounded by an inorganic layer for protecting the first wiring 620 and the second wiring 630 . For example, a buffer layer made of an inorganic material may be disposed on the lower portion, and a passivation layer made of an inorganic material may be formed to surround upper portions and sides of the first wiring 620 and the second wiring 630 . Accordingly, a phenomenon in which the first wiring 620 and the second wiring 630 react with moisture and corrode may be prevented.

The first planarization layer 650 and the second planarization layer 660 are substantially the same as or similar to the planarization layer 337 described with reference to FIG. 3 . In addition, the first planarization layer 650 and the second planarization layer 660 include an acrylic resin, an epoxy resin, a phenolic resin, a polyamides resin, and a polyimide. At least one material of Polyimides Resin, Unsaturated Polyesters Resin, Polyphenylene Resin, Polyphenylenesulfides Resin, and Benzocyclobutene may be formed, but is not limited thereto.

On the second planarization layer 660 , when bending in the bending region B/A of the flexible substrate 610 , a tensile force is applied to the first wiring 620 and the second wiring 630 disposed on the flexible substrate 610 . Since micro-cracks may occur due to the action, the micro-coating layer 670 made of resin may be formed thereon to protect the wiring. In addition, the micro-coating layer 670 may be formed by coating with a thin thickness.

The neutral plane (N/P) refers to an imaginary plane that is not subjected to stress because compressive and tensile forces applied to the structure cancel each other when a structure is bent. When bending, the layer disposed on the upper surface with respect to the neutral plane (N/P) is stretched to receive a tensile force, and the layer disposed on the lower surface is compressed and thus receives a compressive force.

Since the wirings such as the first wiring 620 and the second wiring 630 are more vulnerable when receiving a tensile force among compression and tensile forces of the same magnitude, the neutral plane is not subjected to the tensile force or to minimize the magnitude of the tensile force even when receiving the tensile force. It is disposed under (N/P), and the thickness of the micro-coating layer 670 formed on the second planarization layer 660 can be adjusted. In addition, since the neutral plane N/P of the region where the first wiring 620 and the second wiring 630 are disposed should not be subjected to stress by canceling each other with the tensile force of the micro-coating layer 670 formed thereon, the wiring It is formed closer to the substrate than the neutral plane (N/P) of the non-formed region.

Referring to FIG. 8A , a second region ( Some regions of 620b and 630b are formed to overlap each other.

A partial region of the second region of the second wiring 630 is formed to overlap with each other in a partial region above the second region of the first wiring 620 . In addition, the second region 620b and the second wiring 630 of the first wiring 620 are less than the neutral plane N/P of the region in which the first wiring 620 or the second wiring 630 is arranged alone. Since the neutral plane (N/P) of the region where the second region 630b of the overlapping region overlaps with each other should not be subjected to stress by canceling each other with the tensile force of the micro-coating layer 670, the neutral plane (N/P) of the region in which the wiring is not formed. P) and the first wiring 620 or the second wiring 630 are formed closer to the substrate than the neutral plane N/P of the region in which the first wiring 620 or the second wiring 630 is arranged alone.

In the region where the neutral plane N/P fluctuates more rapidly than the surrounding region, compressive force and tensile force may act simultaneously in some cases, and the second region 620b of the first wiring 620 and the second wiring 630 . The region in which the second regions 630b of the overlapping regions are overlapped with each other is a region in which the neutral plane N/P is more abruptly changed than that of the surrounding region, and the insulating layer may be more easily cracked.

Referring to FIG. 8B , a compensation pattern 640 is formed on the second planarization layer 660 in a region where the second region of the first interconnection 620 and the second region of the second interconnection 630 overlap each other. There is an effect of preventing a crack from occurring in the insulating layer by preventing a sudden change of the neutral plane (N/P).

The second region 620b of the first wiring 620 and the second wiring 630 are formed on the second planarization layer 660 that is an upper portion of the neutral plane N/P formed in the bending region B/A. The compensation pattern 640 formed in the region where the second region 630b of the overlapped with each other moves the neutral plane N/P formed closer to the substrate than the peripheral region away from the substrate, so that the neutral plane ( N/P) to keep the fluctuation range within a certain value.

The compensation pattern 640 may be formed of the same layer and the same material as the bank 350 or the spacer 352 described with reference to FIG. 3 . Depending on the height of the compensation pattern 640 , the bank 350 or the spacer 352 , the bank 350 and the spacer 352 may be formed including both, or may be formed at the same time, but is not limited thereto.

The height of the compensation pattern 640 is maintained within a predetermined range with the neutral plane N/P of the adjacent region of the region where the compensation pattern 640 is disposed, and is 1 μm or less in the direction of the substrate from the top surface of the second planarization layer 660 . It is possible to adjust the height to be located in, but is not limited thereto.

A flexible electroluminescent display device according to an embodiment of the present specification includes a flexible substrate including a display area and a bent area extending from one side of the display area, a light emitting device and a thin film transistor on the display area, a display area and a bending area A first planarization layer including a first planarization layer and a second planarization layer on a flexible substrate, including a display area and a bending area, and on a first planarization layer including a first wiring, a display area and a bending area on the flexible substrate and a compensation pattern on the second wiring and the second planarization layer, wherein a partial region of the first wiring and the second wiring in the bending region overlaps each other, and the compensation pattern includes the overlapping of the first wiring and the second wiring. is in the area

The first wiring and the second wiring in the bending region may have a zigzag shape.

Each of the first wiring and the second wiring in the bending region may include a further connection pattern connecting two wirings adjacent to the same layer.

The overlapping region of the first wiring and the second wiring may be a partial region of the connection pattern.

A buffer layer may be further included between the first wiring and the substrate.

The first planarization layer and the second planarization layer may be formed of an organic material.

The width of the compensation pattern may be wider than the overlapping area of the first wiring and the second wiring.

The organic light emitting device may include a bank and a spacer made of an organic material.

The compensation pattern may be formed on the same layer as the bank or spacer.

An insulating film connected to the flexible substrate may be further included, and a driving element may be disposed on the insulating film.

Each of the first wiring and the second wiring may be formed of a plurality of metal layers.

A micro cover layer on the second planarization layer of the bending region may be further included.

The height of the compensation pattern may be 1 μm or less in the direction of the substrate from the upper surface of the second planarization layer to the neutral plane in the overlapping region of the first wiring and the second wiring in the bending region.

A flexible electroluminescent display device according to another embodiment of the present specification includes a flexible substrate including a display area and a non-display area surrounding the display area, a light emitting device and a thin film transistor on the display area, and a flexible substrate in the non-display area. The first planarization layer and the second planarization layer on the bending area including the bent area, the display area, and the non-display area including the bending area, the wiring and the bending area on the substrate and the first planarization layer, respectively It is disposed on an overlapping region in which a partial region of the interconnection and a part region of the interconnection on the first planarization layer overlap, and includes a compensation pattern that moves the neutral plane of the bending region away from the flexible substrate to prevent damage to the bending region. do.

The wiring in the bending region may have a zigzag shape.

The wiring in the bending area may include a connection pattern connecting two wirings adjacent to the same layer.

The overlapping region between wirings may be a partial region of the connection pattern.

The width of the compensation pattern may be wider than a region overlapping the interconnections.

A micro cover layer on the second planarization layer in the bending region may be further included.

The height of the compensation pattern may be a height at which the neutral plane of the region overlapping the interconnections in the bending region is located 1 μm or less from the upper surface of the second planarization layer in the direction of the flexible substrate.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100, 200, 300, 400, 500, 600: electroluminescent display device
110: image processing unit 120: timing controller
130: data driver 140: gate driver
150: display panel
160: pixel
220: gate line
230: data line
240: switching transistor 250: driving transistor
260: compensation circuit
270, 340: organic light emitting device
310, 410, 510, 610: substrate
320: thin film transistor 322: gate electrode
324: source electrode 326: drain electrode
328: semiconductor layer 331: gate insulating layer
333: interlayer insulating layer 335: passivation layer
337: planarization layer 342: anode
344: light emitting part 346: cathode
350: bank 352: spacer
360: encapsulation unit 420: circuit wiring
520: barrier film 530: polarizing plate
540: back plate
550, 670: micro coating layer
560: adhesive layer 570: support member
580: circuit board
620: first wiring
620a: first area of first wiring 620b: second area of first wiring
630: second wiring
630a: first region of second wiring 630b: second region of second wiring
640: reward pattern
650: first planarization layer 660: second planarization layer
A/A: Display area N/A: Non-display area
B/A: bending area N/P: neutral plane
I-I': cross section of the first region
II-II: Section 2 of the second region

Claims (20)

a flexible substrate including a display area and a bending area extending from one side of the display area and bent;
a light emitting device and a thin film transistor on the display area;
a first planarization layer and a second planarization layer on the flexible substrate including the display area and the bending area;
a first wiring on the flexible substrate including the display area and the bending area;
a second wiring on the first planarization layer including the display area and the bending area; and
a compensation pattern on the second planarization layer, a partial region of the first wiring and the second wiring in the bending region overlaps with each other, and the compensation pattern includes a portion of the first wiring and the second wiring. A flexible electroluminescent display in an overlapping area. According to claim 1,
The first wiring and the second wiring in the bending region include a zigzag shape. 3. The method of claim 2,
Each of the first wiring and the second wiring in the bending region further includes a connection pattern connecting two wirings adjacent to the same layer. 4. The method of claim 3,
An overlapping region of the first wiring and the second wiring is a partial region of the connection pattern. According to claim 1,
The flexible electroluminescent display device further comprising a buffer layer between the first wiring and the substrate. According to claim 1,
The first planarization layer and the second planarization layer are made of an organic material. According to claim 1,
and an area of the compensation pattern is wider than an overlapping area of the first wiring and the second wiring. According to claim 1,
The light emitting device comprises a bank and a spacer made of an organic material, a flexible electroluminescent display. 9. The method of claim 8,
The compensation pattern is composed of the same layer as the bank or the spacer, a flexible electroluminescent display device. According to claim 1,
Further comprising an insulating film connected to the flexible substrate,
A driving element is disposed on the insulating film, a flexible electroluminescent display device. According to claim 1,
The first wiring and the second wiring are each composed of a plurality of metal layers, a flexible electroluminescent display device. According to claim 1,
The flexible electroluminescent display device further comprising a micro cover layer on the second planarization layer in the bending region. 13. The method of claim 12,
The height of the compensation pattern is 1 μm or less in the direction of the flexible substrate from the upper surface of the second planarization layer to the neutral plane of the bending region in the overlapping region of the first wiring and the second wiring. a flexible substrate including a display area and a non-display area surrounding the display area;
a light emitting device and a thin film transistor on the display area;
a bending area in the non-display area and including an area in which the flexible substrate is bent;
a first planarization layer and a second planarization layer on the display area and the non-display area including the bending area;
wirings respectively on the substrate and the first planarization layer; and
It is disposed on an overlapping region in which a partial region of the wiring in the bending region and a partial region of the wiring in the first planarization layer overlap, and a neutral plane of the bending region is formed to prevent damage to the bending region. A flexible electroluminescent display device comprising a compensation pattern moving away from the flexible substrate. 15. The method of claim 14,
The wiring in the bending region includes a zigzag shape. 16. The method of claim 15,
The wiring in the bending region includes a connection pattern connecting two wirings adjacent to the same layer. 17. The method of claim 16,
The overlapping region is a portion of the connection pattern, the flexible electroluminescent display device. 15. The method of claim 14,
and an area of the compensation pattern is wider than that of the overlapping area. 15. The method of claim 14,
The flexible electroluminescent display device further comprising a micro cover layer on the second planarization layer in the bending region. 20. The method of claim 19,
The height of the compensation pattern is a height at which the neutral plane of the overlapping region in the bending region is located 1 μm or less from the upper surface of the second planarization layer in the direction of the flexible substrate.

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