KR20220165717A - Flexible electroluminescent display device - Google Patents

Abstract

A flexible electroluminescent display device according to an embodiment of the present specification may include: a shield layer on a flexible substrate; a buffer layer on the shield layer; a thin film transistor on the buffer layer; and an electroluminescent element on the thin film transistor. The shield layer and the thin film transistor have an overlapping region, and the thin film transistor and the shield layer are connected in the overlapping region, thereby improving a process.

Description

Flexible electroluminescent display device and its manufacturing method {FLEXIBLE ELECTROLUMINESCENT DISPLAY DEVICE}

The present specification relates to a flexible electroluminescence display device and a manufacturing method thereof, and more particularly, to a flexible electroluminescence display device capable of improving a process of the flexible electroluminescence display device and a manufacturing method thereof.

As we enter the full-fledged information age, the field of display devices that visually display electrical information signals is developing rapidly, and research is continuing to develop performance such as thinning, lightening, and low power consumption for various display devices.

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

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

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

In addition, the light emitting layer includes a host material and a dopant material, and interaction between the two materials occurs. The host serves to generate excitons from electrons and holes and transfers energy to the dopant, and the dopant is a dye organic material added in a small amount and serves to receive energy from the host and convert it into light.

An electroluminescent display device including a light emitting layer made of organic materials encapsulates the electroluminescent display device with glass, metal, or film so that moisture or oxygen is not released from the outside into the electroluminescent display device. By blocking the inflow, oxidation of the light emitting layer and the electrode is prevented, and it is protected from mechanical or physical impact applied from the outside.

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

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

In a flexible electroluminescent display device that can maintain display performance even when bent by applying a flexible substrate of a flexible material such as plastic, which is being developed recently, the bezel area is reduced while securing the area for wiring and driving circuits. In order to reduce the size, the non-display area of the flexible substrate may be bent.

However, the flexible substrate included in the electroluminescent display device may deteriorate the performance of the thin film transistor disposed thereon due to charged charges generated on the substrate when the electroluminescent display device is operated for a long period of time.

A thin film transistor included in a flexible electroluminescent display device includes a large number of contact holes and requires several stages of processing, resulting in difficulties in production.

Accordingly, the inventors of the present specification recognized the above-mentioned problems and invented a flexible electroluminescent display device including a thin film transistor having a new structure.

In addition, the inventors of the present specification recognize that as the resolution of the electroluminescent display device gradually increases, there is a shortage of space for arranging wires, and an electroluminescent display device having a new structure capable of more freely arranging wires within a limited space. Invented.

An object to be solved according to an embodiment of the present specification is to provide an electroluminescent display device capable of reducing the influence of a thin film transistor on a semiconductor layer by forming a shield layer.

An object to be solved according to embodiments of the present specification is to provide a method of manufacturing an electroluminescent display device in which a process of connecting a shield layer and an electrode can be simplified.

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

A flexible electroluminescent display device according to an embodiment of the present specification includes a shield layer on a flexible substrate, a buffer layer on the shield layer, a thin film transistor on the buffer layer, and an electroluminescent device on the thin film transistor. The thin film transistor and the thin film transistor have an overlapping region, and the thin film transistor and the shield layer are connected in the overlapping region.

A flexible electroluminescent display device according to an embodiment of the present specification includes forming a shield layer on a flexible substrate, forming a buffer layer on the shield layer, and forming a semiconductor layer, a gate electrode, a source electrode, and a drain electrode on the buffer layer. Forming a thin film transistor comprising a thin film transistor, forming an electroluminescent device on the thin film transistor, and the shield layer and the thin film transistor have an overlapping area, and the thin film transistor and the shield layer are connected in the overlapping area. .

The electroluminescent display device according to the exemplary embodiment of the present specification has an effect of improving the performance of the thin film transistor by configuring a shield layer to reduce the influence of charges on the flexible substrate to the semiconductor layer of the thin film transistor.

The electroluminescent display device according to the exemplary embodiment of the present specification has an effect of forming a contact hole connecting the shield layer and the electrode without an additional process.

The electroluminescent display device according to the exemplary embodiment of the present specification has an effect of more freely arranging wires used in the flexible electroluminescent display device within a limited space.

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

Since the content of the specification described in the problem to be solved, the problem solution, and the effect above does not specify the essential features of the claim, the scope of the claim is not limited by the matters described in the content 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 exemplary embodiment of the present specification.
3 is a plan view of an electroluminescent display device according to an exemplary embodiment of the present specification.
4A and 4B are cross-sectional views of detailed structures of a display area and a bending area of an electroluminescent display device according to an embodiment of the present specification.
5A and 5B are cross-sectional views of the shield layer connection structure included in the electroluminescent display device according to the first and second embodiments of the present specification.
6A to 6D are manufacturing processes of a shield layer connection structure included in an electroluminescent display device according to a second embodiment of the present specification.
7 is a cross-sectional view of a bending area of a flexible electroluminescent display device according to an exemplary embodiment of the present specification.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

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

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

Although 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. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can 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 processor 110 , a timing controller 120 , a data driver 130 , a gate driver 140 and a display panel 150 .

The image processor 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 a data signal DATA along with a data enable signal DE or a drive signal including a vertical sync signal, a horizontal sync signal, and a clock signal from the image processor 110 . The timing controller 120 generates 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. outputs

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, converts it into a gamma reference voltage, and outputs the result. . 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 pixels 160 emit light in response to the data signal DATA and the gate signal supplied from the data driver 130 and the gate driver 140 . The structure of the pixel 160 is 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 exemplary embodiment of the present specification.

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

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

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

The driving transistor 250 operates to allow a constant driving current to flow 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 for the threshold voltage of the driving transistor 250, and the compensation circuit 260 includes one or more thin film transistors and capacitors. The configuration of the compensation circuit may vary according to the compensation method.

In addition, the pixel of the electroluminescent display device 200 is composed of a 2T (Transistor) 1C (Capacitor) structure including a switching transistor 240, a driving transistor 250, a capacitor, and a light emitting element 270, but a compensation circuit ( 260) can be formed in various ways such as 3T1C, 4T2C, 5T2C, 6T1C, 6T2C, 7T1C, and 7T2C.

3 is a plan view of an electroluminescent display device according to an exemplary embodiment of the present specification. In detail, the flexible substrate 310 of the flexible electroluminescence display 300 is in an unbent state.

Referring to FIG. 3 , the flexible electroluminescent display device 300 includes an active area (A/A) in which pixels that actually emit light through thin film transistors and light emitting elements are disposed on a flexible substrate 310 and a display area (A/A). A non-active area (N/A) surrounding the edge of the area A/A is included.

In the non-display area N/A of the flexible substrate 310, circuits such as the gate driver 390 for driving the flexible electroluminescence display 300 and various signals such as scan lines (S/L) Wiring can be placed. In addition, the circuit for driving the flexible electroluminescent display device 300 is disposed on the substrate 310 as a gate in panel (GIP), or a flexible substrate (tape carrier package (TCP) or chip on film (COF) method). 310) may be connected.

A pad 395 is disposed on one side of the substrate 505 in the non-display area N/A. The pad 395 is a metal pattern bonded to an external module.

A portion of the non-display area N/A of the flexible substrate 310 may be bent in a bending direction as indicated by an arrow to form the bending area B/A. Since the non-display area (N/A) of the flexible substrate 310 is an area where wires and driving circuits for driving a screen are disposed and an image is not displayed, it does not need to be visually recognized from the upper surface of the flexible substrate 310. . Therefore, by bending a partial area of the non-display area N/A of the flexible substrate 310, the bezel area can be reduced while securing an area for wiring and a driving circuit.

Various wires are formed on the flexible substrate 310 . The wiring may be formed in the display area A/A of the substrate 310 . Alternatively, the circuit wiring 370 formed in the non-display area N/A may transmit a signal by connecting a driving circuit, a gate driver, and a data driver.

The circuit wiring 370 is formed of a conductive material, and may be formed of a conductive material having excellent ductility in order to reduce the occurrence of cracks when the substrate 310 is bent. For example, the circuit wiring 370 may be formed of a conductive material having excellent ductility, such as gold (Au), silver (Ag), or aluminum (Al), and various conductive materials used in the display area A/A. It may be formed of one of molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and an alloy of silver (Ag) and magnesium (Mg), etc. It may also consist of Further, the circuit wiring 370 may be composed of a multi-layer structure including various conductive materials, for example, a titanium (Ti)/aluminum (Al)/titanium (Ti) three-layer structure. Not limited.

When the circuit wiring 370 formed in the bending area B/A is bent, it receives a tensile force. For example, the circuit wiring 370 extending in the same direction as the bending direction (indicated by an arrow) on the flexible substrate 310 receives the greatest tensile force, and cracks may occur. If the crack is severe, disconnection may occur. there is. Therefore, instead of forming the circuit wiring 370 to extend in the bending direction, at least a portion of the circuit wiring 370 disposed including the bending area B/A extends in an oblique direction that is different from the bending direction. By forming, it is possible to minimize cracking by minimizing tensile force.

The circuit wiring 370 disposed including the bending area B/A may be formed in various shapes, for example, a trapezoidal wave shape, a triangular wave shape, a sawtooth wave shape, a sinusoidal wave shape, an omega (Ω) shape, and a diamond shape. It can be formed in various shapes such as shape.

4A and 4B are cross-sectional views of detailed structures of a display area and a bending area of an electroluminescent display device according to an embodiment of the present specification.

FIG. 4A is a cross-sectional view of the display area A/A described in FIG. 3 .

Referring to FIG. 4A , the substrate 405 serves to support and protect the components of the electroluminescent display device 400 disposed thereon, and recently may be made of a flexible material having a flexible property. , the substrate 405 may be a flexible substrate. For example, the flexible substrate may be in the form of a film containing one of the group consisting of polyester-based polymers, silicone-based polymers, acrylic-based polymers, polyolefin-based polymers, and copolymers thereof.

For example, the substrate 405 may be formed of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polysilane, polysiloxane, polysilazane, polycarbosilane, polyacrylate, polymethacrylate, polymethylacrylate, polymethylmethacrylate, polyethylacrylate, polyethylmethacrylate, Click Olefin Copolymer (COC), Cyclic Olefin Polymer (COP), Polyethylene (PE), Polypropylene (PP), Polyimide (PI), Polymethylmethacrylate (PMMA), Polystyrene (PS), Polyacetal ( POM), polyetheretherketone (PEEK), polyestersulfone (PES), polytetrafluoroethylene (PTFE), polyvinylchloride (PVC), polycarbonate (PC), polyvinylidene fluoride (PVDF), purple It may be composed of at least one of fluoroalkyl polymer (PFA), styrene acrylonitrile copolymer (SAN), and combinations thereof.

Then, a first buffer layer 412 and a second buffer layer 414 are disposed on the substrate 405 . The first and second buffer layers 412 and 414 composed of a single layer or a plurality of layers of silicon oxide (SiOx) or silicon nitride (SiNx) prevent penetration of moisture or other impurities through the substrate 405, and the substrate ( 405) can be planarized. The first and second buffer layers 412 and 414 are not necessarily required and may be omitted depending on the type of substrate 405 or the type of thin film transistor 420 disposed on the substrate 405 .

A shield layer 410 is disposed on the first buffer layer 412 . The shield layer 410 is made of conductive metals such as copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), and neodymium (Nd). It can be composed of a metal material or an alloy thereof, a single layer or a multi-layer, and is disposed to overlap the semiconductor layer 428 between the substrate 405 and the semiconductor layer 428.

Electrical characteristics of the thin film transistor may be prevented from being changed by applying power to the shield layer 410 . When power is applied to the shield layer 410 , an electric field formed by the flexible substrate 405 is shielded under the semiconductor layer 428 , thereby preventing the characteristics of the thin film transistor 420 from being changed. At this time, as a method of applying power, source power may be applied to the shield layer 410 by connecting the source electrode 424 of the thin film transistor 420 and the shield layer 410 in each pixel. A connection structure between the source electrode 424 and the shield layer 410 will be described in detail with reference to FIGS. 5A and 5B.

A second buffer layer 414 is disposed on the shield layer 410, and the thin film transistor 420 disposed on the second buffer layer 414 includes a gate electrode 422, a source electrode 424, and a drain electrode 426 and a semiconductor layer 428 .

The semiconductor layer 428 is amorphous silicon or polycrystalline silicon, which has better mobility than amorphous silicon, low energy consumption and excellent reliability, and can be applied to a driving thin film transistor in a pixel. ), but is not limited thereto.

The semiconductor layer 428 may be formed of an oxide semiconductor, and the oxide semiconductor has 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 which is a 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 The semiconductor layer 428 may be formed of 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 limited.

The semiconductor layer 428 may include a source region including p-type or n-type impurities, a drain region, and a channel between the source region and the drain region. A lightly doped region may be included between adjacent source and drain regions.

The source region and the drain region are regions doped with impurities at a high concentration, and are regions where the source electrode 424 and the drain electrode 426 of the thin film transistor 420 are respectively connected. As the impurity ion, a p-type impurity or an n-type impurity may be used. The p-type impurity may be one of boron (B), aluminum (Al), gallium (Ga), and indium (In), and the n-type impurity may be phosphorus ( P), arsenic (As), and antimony (Sb).

Depending on the NMOS or PMOS thin film transistor structure of the semiconductor layer 428, the channel region may be doped with an n-type impurity or a p-type impurity. Alternatively, a thin film transistor of PMOS is applicable.

The first insulating layer 431 is an insulating layer composed of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx), and current flowing through the semiconductor layer 428 does not flow to the gate electrode 422. placed so as not to In addition, silicon oxide has lower ductility than metal, but is superior in ductility to silicon nitride, and can be selectively formed into a single layer or multiple layers according to its characteristics.

The gate electrode 422 serves as a switch to turn on or turn off the thin film transistor 420 based on an electrical signal transmitted from the outside through a gate line, and is made of a conductive metal. Phosphorus copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), and neodymium (Nd), etc., or a single layer of an alloy thereof Or it may be composed of multiple layers, but is not limited thereto.

The source electrode 424 and the drain electrode 426 are connected to the data line and allow electrical signals transferred from the outside to be transferred from the thin film transistor 420 to the light emitting element 440 . The source electrode 424 and the drain electrode 426 are made of conductive metal such as copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), and neodymium (Nd), or a metal material or an alloy thereof, which may be configured as a single layer or multiple layers, but is not limited thereto.

In order to insulate the gate electrode 422, the source electrode 424, and the drain electrode 426 from each other, a second insulating layer 433 composed of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx) is provided as a gate. It may be disposed between the electrode 422 and the source electrode 424 and the drain electrode 426 .

A passivation layer composed of an inorganic insulating layer such as silicon oxide (SiOx) or silicon nitride (SiNx) may be further disposed on the thin film transistor 420 . The passivation layer may serve to prevent unnecessary electrical connection between passivation layer components and to prevent contamination or damage from the outside, and may be omitted depending on the configuration and characteristics of the thin film transistor 420 and the light emitting element 440. You may.

The thin film transistor 420 may be classified into an inverted staggered structure and a coplanar structure according to positions of components constituting the thin film transistor 420 . In the thin film transistor of the inverted staggered structure, the gate electrode is located on opposite sides of the source electrode and the drain electrode with respect to the semiconductor layer. As shown in FIG. 4A , in the thin film transistor 420 having a coplanar structure, the gate electrode 422 is located on the same side as the source electrode 424 and the drain electrode 426 with respect to the semiconductor layer 428 .

Although the thin film transistor 420 of a coplanar structure is shown in FIG. 4A , the electroluminescent display device 400 may include a thin film transistor of an inverted staggered structure.

For convenience of explanation, only a driving thin film transistor is shown among various thin film transistors that may be included in the electroluminescent display device 400, but switching thin film transistors and capacitors may also be included in the electroluminescent display device 400. At this time, when a signal is applied from the gate wiring, the switching thin film transistor transfers the signal from the data wiring to the gate electrode of the driving thin film transistor. The driving thin film transistor transfers the current transmitted through the power wiring to the anode 442 by the signal received from the switching thin film transistor, and controls light emission by the current transmitted to the anode 442 .

It protects the thin film transistor 420, alleviates the level difference caused by the thin film transistor 420, and parasitic capacitance generated between the thin film transistor 420, the gate line and data line, and the light emitting element 440 (parasitic capacitance) In order to reduce capacitance, planarization layers 435 and 437 are disposed on the thin film transistor 420 .

The planarization layers 435 and 437 include acrylic resin, epoxy resin, phenolic resin, polyamides resin, polyimide resin, and unsaturated polyester. It may be formed of one or more of unsaturated polyesters resin, polyphenylene resin, polyphenylenesulfides resin, and benzocyclobutene, but is not limited thereto.

The electroluminescent display device 400 according to the exemplary embodiment of the present specification may include a first planarization layer 435 and a second planarization layer 437, which are a plurality of planarization layers 435 and 437 sequentially stacked.

For example, a first planarization layer 435 may be stacked and disposed on the thin film transistor 420 , and a second planarization layer 437 may be sequentially stacked and disposed on the first planarization layer 435 .

Also, a buffer layer may be disposed on the first planarization layer 435 . The buffer layer is disposed to protect components disposed on the first planarization layer 435, and is a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multiple layer of silicon nitride (SiNx) or silicon oxide (SiOx). It may be composed of layers, and may be omitted depending on the configuration and characteristics of the thin film transistor 420 and the light emitting element 440 .

The intermediate electrode 430 is connected to the thin film transistor 420 through a contact hole formed in the first planarization layer 435 . The intermediate electrode 430 may be formed to be connected to the thin film transistor 420 .

Also, since the data line may be formed in a structure in which a lower layer made of the same material as the source electrode 424 and the drain electrode 426 and a layer made of the same material as the intermediate electrode 430 are connected, the two layers are parallel to each other. Since the data line can be implemented in a connected structure, wiring resistance of the data line can be reduced.

A passivation layer composed of an inorganic insulating layer such as silicon oxide (SiOx) or silicon nitride (SiNx) may be further disposed on the first planarization layer 435 and the intermediate electrode 430 . The passivation layer may serve to prevent unnecessary electrical connection between components and prevent contamination or damage from the outside, and may be omitted depending on the configuration and characteristics of the thin film transistor 420 and the light emitting device 440 .

The light emitting device 440 disposed on the second planarization layer 437 includes an anode 442 , a light emitting part 444 and a cathode 446 .

The anode 442 may be disposed on the second planarization layer 437 . The anode 442 is an electrode serving to supply holes to the light emitting unit 444, and is connected to the intermediate electrode 430 through a contact hole in the second planarization layer 437 and electrically connected to the thin film transistor 420. connected to

The anode 442 may be made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO), but is not limited thereto.

When the electroluminescent display device 400 is a top emission type that emits light toward the upper portion where the cathode 446 is disposed, the emitted light is reflected from the anode 442 and more smoothly passes through the cathode 446. A reflective layer may be further included so that is emitted in an upper direction where is disposed.

For example, the anode 442 may have a two-layer structure in which a transparent conductive layer made of a transparent conductive material and a reflective layer 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. It may be silver (Ag) or an alloy containing silver.

The bank 450 disposed on the anode 442 and the second planarization layer 437 may define a pixel by partitioning a region that actually emits light. After forming a photoresist on the anode 442, the bank 450 is formed by photolithography. A photoresist refers to a photosensitive resin whose solubility in a developing solution is changed by the action of light, and a specific pattern can be obtained by exposing and developing the photoresist. Photoresists can be classified into positive photoresists and negative photoresists. A positive photoresist refers to a photoresist in which the solubility of an exposed portion in a developing solution is increased by exposure, and a pattern in which the exposed portion is removed is obtained when the positive photoresist is developed. And, the negative photoresist refers to a photoresist in which the solubility of the exposed portion in the developing solution 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 444 of the light emitting element 440, a fine metal mask (FMM), which is a deposition mask, may be used. In addition, in order to prevent damage that may occur due to contact with the deposition mask disposed on the bank 450 and to maintain a constant distance between the bank 450 and the deposition mask, poly, a transparent organic material, is placed on the top of the bank 450. A spacer 452 composed of one of mead, photoacrylic and benzocyclobutene (BCB) may be disposed.

A light emitting unit 444 is disposed between the anode 442 and the cathode 446 . The light emitting unit 444 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), and some components of the light emitting unit 444 may be omitted depending on the structure or characteristics of the electroluminescent display device 400 . Here, as the light emitting layer, it is also possible to apply an electroluminescent layer and an inorganic light emitting layer.

The hole injection layer is disposed on the anode 442 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 consist of any one or more of NPD (N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine).

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) may be made of any one or more.

The light emitting layer is disposed on the hole transport layer and may emit light of a specific color by including a material capable of emitting 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), PIQIr(acac)(bis(1-phenylisoquinoline)(acetylacetonate) iridium), PQIr(acac)(bis(1-phenylquinoline)(acetylacetonate) ) iridium), tris(1-phenylquinoline) iridium (PQIr), and octaethylporphyrin platinum (PtOEP). Alternatively, it may be made of a fluorescent material including PBD:Eu(DBM)3(Phen) or Perylene.

Here, the peak wavelength (λ) refers to the maximum wavelength of EL (ElectroLuminescence). The wavelength at which the light emitting layers constituting the light emitting part emits its own light is called PL (PhotoLuminescence), and the influence of the thickness or optical characteristics of the layers constituting the light emitting layers is The received light is called emittance At this time, EL (ElectroLuminescence) refers to light finally emitted by the electroluminescence display and can be expressed as a product of PL (PhotoLuminescence) and emittance.

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

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

An 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 electron injection from the cathode 446 and may be omitted depending on the structure and characteristics of the electroluminescent display device 400 . The electron injection layer may be a metal inorganic compound such as BaF 2 , LiF , NaCl, CsF, Li ₂ O and BaO, and 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 hole blocking layer to block the flow of holes or electrons 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. When holes are injected into the light emitting layer, it is possible to improve light emitting efficiency by preventing a phenomenon in which holes move from the light emitting layer and pass through an adjacent electron transport layer.

The cathode 446 is disposed on the light emitting part 444 and serves to supply electrons to the light emitting part 444 . Since the cathode 446 needs to supply electrons, it may be made of a metal material such as magnesium (Mg) or silver-magnesium (Ag:Mg), which is a conductive material having a low work function, but is not limited thereto.

When the electroluminescent display device 400 is a top emission type, the cathode 446 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide ( It may be a transparent conductive oxide based on Zinc Oxide (ZnO) and Tin Oxide (TiO).

On the light emitting element 440, there is a seal to prevent the thin film transistor 420 and the light emitting element 440, which are components of the electroluminescent display device 400, from being oxidized or damaged due to moisture, oxygen, or impurities introduced from the outside. The unit 460 may be disposed, and may be formed by stacking a plurality of encapsulation layers, a foreign material compensation layer, and a plurality of barrier films.

The encapsulation layer is disposed on the entire upper surface of the thin film transistor 420 and the light emitting element 440, and may be made of one of inorganic materials such as silicon nitride (SiNx) or aluminum oxide (AlyOz), but is not limited thereto.

An encapsulation layer may be further disposed on the foreign material compensation layer disposed on the encapsulation layer.

The foreign material compensation layer is disposed on the encapsulation layer, and organic silicon oxycarbon (SiOCz), acrylic, or epoxy-based resin may be used, but is not limited thereto, and may occur during the process. When a defect occurs due to a crack caused by a foreign substance or particle, the foreign matter compensation layer can compensate for the defect by covering the bend and foreign matter.

By disposing a barrier film on the encapsulation layer and the foreign matter compensation layer, the electroluminescent display device 400 can delay penetration of oxygen and moisture from the outside. The barrier film is composed of a light-transmitting and double-sided adhesive film type, and may be composed of any one of olefin-based, acrylic-based, and silicon-based insulating materials, or COP (Cyclolefin Polymer), a barrier film made of any one of COC (Cycloolefin Copolymer) and PC (Polycarbonate) may be further laminated, but is not limited thereto.

FIG. 4B is a cross-sectional view of the bending area B/A described in FIG. 3 .

Some components of FIG. 4B are substantially the same as/similar to the components described in FIG. 4A , and detailed description thereof will be omitted.

The gate signals and data signals described in FIGS. 1 to 3 pass through circuit wires disposed in the non-display area N/A of the electroluminescent display device 400 from the outside, and then pixels disposed in the display area A/A. to be transmitted to emit light.

When the wiring disposed in the non-display area N/A including the bending area B/A of the electroluminescent display device 400 is formed in a single-layer structure, a lot of space is required to arrange the wiring. After the conductive material is deposited, the conductive material is patterned in a process such as etching in the shape of a wire to be formed. Since there is a limit to the detail of the etching process, a lot of space is required due to the limitation to narrow the gap between the wires. Since the area of the non-display area N/A increases, difficulties may arise in implementing a narrow bezel.

In addition, when one 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 substrate 405, a crack may be generated in the wiring itself or a crack may be generated in another layer, and the crack may propagate to the wiring. In this way, when a crack occurs in the wiring, a signal to be transmitted may not be transmitted.

Accordingly, the wiring disposed in the bending area B/A of the electroluminescent display device 400 according to the embodiment of the present specification is disposed in a double wiring form of the first wiring 462 and the second wiring 464. .

The first wiring 462 and the second wiring 464 are formed of a conductive material, and may be formed of a conductive material having excellent ductility in order to reduce the occurrence of cracks when the flexible substrate 405 is bent. The first wire 462 and the second wire 464 may be formed of a conductive material having excellent ductility, such as gold (Au), silver (Ag), or aluminum (Al), and may be formed in the display area (A/A). It can be formed of one of the various conductive materials used in A), molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and silver (Ag) It may also be composed of an alloy of and magnesium (Mg). Also, the first wiring 462 and the second wiring 464 may have a multilayer structure including various conductive materials, for example, titanium (Ti)/aluminum (Al)/titanium (Ti) 3 It may be composed of a layer structure, but is not limited thereto.

In order to protect the first wiring 462 and the second wiring 464, a buffer layer made of an inorganic insulating layer may be disposed under the first wiring 462 and the second wiring 464, and the first wiring 462 ) And a passivation layer made of an inorganic insulating layer is formed to surround the upper and side portions of the second wiring 464 to prevent the first wiring 462 and the second wiring 464 from being corroded by reaction with moisture or the like. It could be.

When the first wiring 462 and the second wiring 464 formed in the bending area B/A are bent, they receive a tensile force. As described with reference to FIG. 3 , wires extending in the same direction as the bending direction on the substrate 405 receive the greatest tensile force, and cracks may occur. If the cracks are severe, disconnection may occur. Therefore, instead of forming the wires to extend in the bending direction, at least a portion of the wires disposed including the bending area B/A is formed to extend in an oblique direction, which is a direction different from the bending direction, thereby minimizing cracking force. occurrence can be reduced. The shape of the wiring may be configured in a diamond shape, a triangular wave shape, a sinusoidal wave shape, a trapezoidal shape, or the like, but is not limited thereto.

A first wiring 462 is disposed on the substrate 405 and a first planarization layer 435 is disposed on the first wiring 462 . A second wiring 464 is disposed on the first planarization layer 435 , and a second planarization layer 437 is disposed on the second wiring 464 .

The first planarization layer 435 and the second planarization layer 437 may include acrylic resin, epoxy resin, phenolic resin, polyamides resin, or polyimide resin. (Polyimides Resin), Unsaturated Polyesters Resin, Polyphenylene Resin, Polyphenylenesulfides Resin, and Benzocyclobutene. may be, but is not limited thereto.

A micro coating layer 466 is disposed on the second planarization layer 437 . When the micro-coating layer 466 is bent, a tensile force acts on the wiring part disposed on the substrate 405, which may cause micro cracks. can play a role in

5A and 5B are cross-sectional views of the shield layer connection structure included in the electroluminescent display device according to the first and second embodiments of the present specification.

5A is a structure in which the shield layer 510 and the source electrode 524 are electrically connected via a gate bridge 522, and FIG. 5B is a structure in which the shield layer 510 is directly connected to the source electrode 524. Depending on the structure or characteristics of the electroluminescent display device, one of the two structures may be selectively disposed.

The main components of the electroluminescent display shown in FIGS. 5A and 5B are substantially the same as or similar to the main components described in FIGS. 1 to 4B , and overlapping structures are omitted.

Referring to FIG. 5A, a substrate 505 having a flexible property such as polyimide is composed of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx) to prevent penetration of moisture or the like from the outside. The first buffer layer 512 and the second buffer layer 514 are sequentially stacked and disposed.

A shield layer 510 is disposed on the first buffer layer 512 to minimize an effect on the semiconductor layer 528 from charges generated from the flexible substrate 505 . The shield layer 510 is made of conductive metals such as copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), and neodymium (Nd). It can be composed of a metal material or an alloy thereof, single layer or multilayer. The shield layer 510 is disposed between the substrate 505 and the semiconductor layer 528 to overlap the semiconductor layer 528 .

A second buffer layer 514 and a semiconductor layer 528 are sequentially stacked and disposed on the shield layer 510 .

The semiconductor layer 528 may be formed of amorphous silicon, polycrystalline silicon having better mobility than amorphous silicon, or an oxide semiconductor such as ZnO or IGZO having better mobility and uniformity.

The semiconductor layer 528 includes a source region and a drain region including p-type or n-type impurities, and a channel between them, and may further include a lightly doped region between the source region and the drain region adjacent to the channel. .

A first insulating layer 531 composed of a single layer or a plurality of layers of silicon oxide (SiOx) or silicon nitride (SiNx) is disposed on the semiconductor layer 528 .

A gate bridge 522 formed of the same layer as the gate electrode of the thin film transistor is disposed on the first insulating layer 531 and overlapping the shield layer 522 . The gate bridge 522 is spaced apart from the gate electrode and directly connected to the shield layer 510 through contact holes formed in the second buffer layer 514 and the first insulating layer 531 . The gate bridge 522 may be a connection electrode.

A second insulating layer 533 may be disposed on the gate electrode and the gate bridge 522 to insulate the source electrode 524 .

A source electrode 524 connected to the semiconductor layer 528 is disposed on the second insulating layer 533 .

The source electrode 524 serves to transfer electrical signals transmitted from the outside from the thin film transistor to the electroluminescent device, and is a conductive metal such as copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), etc., or an alloy thereof, may be composed of a single layer or multiple layers.

The source electrode 524 is directly connected to the gate bridge 522 through a contact hole formed in the second insulating layer 533 . Through this, since the source electrode 524 and the shield layer 510 are electrically connected to each other, the influence of the semiconductor layer 528 disposed on the shield layer 510 from the flexible substrate 505 can be minimized.

A planarization layer 535 is formed on the source electrode 524, and other main components of the electroluminescent display on the planarization layer 535 are substantially the same as or similar to the main components described in FIGS. 4A to 4B. .

Referring to FIG. 5B, a substrate 505 having a flexible property such as polyimide is composed of a single layer or multiple layers of silicon oxide (SiOx) or silicon nitride (SiNx) to prevent penetration of moisture or the like from the outside. A first buffer layer 512 and a second buffer layer 514 which may be may be sequentially stacked and disposed. Also, the buffer layer may be omitted depending on the structure or characteristics of the electroluminescent display device.

A shield layer 510 is disposed on the first buffer layer 512 to minimize an effect on the semiconductor layer 528 from charges generated from the flexible substrate 505 . The shield layer 510 is made of conductive metal such as copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), etc. It can be composed of a metal material or an alloy thereof, single layer or multilayer. The shield layer 510 is disposed to overlap the semiconductor layer 528 between the substrate 505 and the semiconductor layer 528 .

On the shield layer 510, the second buffer layer 514 and a semiconductor layer (528) that can be composed of amorphous silicon or polysilicon having better mobility than amorphous silicon or an oxide semiconductor such as ZnO or IGZO having excellent mobility and uniformity characteristics. ) are sequentially stacked and arranged.

The semiconductor layer 528 includes a source region and a drain region containing p-type or n-type impurities and includes a channel between them, and may further include a lightly doped region between the source region and the drain region adjacent to the channel. there is.

A first insulating layer 531 and a second insulating layer 533 composed of a single layer or a plurality of layers of silicon oxide (SiOx) or silicon nitride (SiNx) are sequentially disposed on the semiconductor layer 528 .

On the second insulating layer 533, a source electrode 524 connected to the semiconductor layer 528 and serving to transfer electrical signals from the thin film transistor to the light emitting device is disposed.

The source electrode 524 is connected to the semiconductor layer 528 through a contact hole passing through the second buffer layer 514, the semiconductor layer 528, the first insulating layer 531, and the second insulating layer 533 collectively. while being connected to the shield layer 510 at the same time. Through this, since the source electrode 324 and the shield layer 510 are electrically connected to each other, the influence of the semiconductor layer 528 disposed on the shield layer 510 from the flexible substrate 505 can be minimized.

A planarization layer 535 is formed on the source electrode 524, and other main components of the electroluminescent display on the planarization layer 535 are substantially the same as or similar to the main components described in FIGS. 4A to 4B. .

6A to 6D are manufacturing processes of a shield layer connection structure included in an electroluminescent display device according to a second embodiment of the present specification.

The main components of the flexible electroluminescent display shown in FIGS. 6A to 6C are substantially the same as or similar to the main components described in FIGS. 1 to 5B , and overlapping components are omitted.

Referring to FIG. 6A , a first buffer layer 612 is deposited as a single layer or a plurality of layers of silicon oxide (SiOx) or silicon nitride (SiNx) on a substrate 605 and a metal layer is deposited. A mask is placed on the deposited metal layer and patterned to form the shield layer 610 . And, the shield layer 610 is overlapped with the semiconductor layer 528 disposed thereon.

Referring to FIG. 6B , a second buffer layer 614 is deposited on the shield layer 610 , a semiconductor material is deposited on the second buffer layer 614 , and patterned using a mask to form a semiconductor layer 628 .

Referring to FIG. 6C , a first insulating layer 631 is deposited on the semiconductor layer 628 . As described in FIGS. 5A and 5B , in the electroluminescent display device according to the first embodiment of the present specification, a separate layer penetrating the second buffer layer 614 and the first insulating layer 631 is provided to connect the gate bridge and the shield layer. Although contact holes are formed, in the electroluminescent display device according to the second embodiment of the present specification, since separate contact holes penetrating the second buffer layer 614 and the first insulating layer 631 are not formed, the manufacturing process is reduced. There is a simplification effect.

A second insulating layer 633 is deposited on the first insulating layer 631, and the first insulating layer 631, the second insulating layer 633, the semiconductor layer 628 and the second insulating layer 633 are deposited using a mask. A contact hole through which an upper portion of the shield layer 610 is exposed is formed through the buffer layer 614 .

Referring to FIG. 6D, a conductive metal layer is deposited on the second insulating layer 633 and patterned with a mask to form a source electrode 624, and is connected to the semiconductor layer 628 through a contact hole while simultaneously shielding the shield layer 610. ), the influence of the semiconductor layer 618 disposed on the shield layer 610 from the charge of the substrate 605 can be minimized.

Manufacturing processes for other main components of the electroluminescent display on the source electrode 624 are substantially the same as or similar to those of the main components described in FIGS. 4A to 5B and are omitted.

7 is a cross-sectional view of a bending area of a flexible electroluminescent display device according to an embodiment of the present specification.

Referring to FIG. 7 , a barrier film 720 is disposed on a flexible substrate 710 . The barrier film 720 is a component for protecting various components of the flexible electroluminescent display device 700 and may be disposed to correspond to at least the display area A/A of the flexible electroluminescent display device 700 .

For example, the barrier film 720 may include a material having adhesiveness, and the material having adhesiveness may be a heat curing type or a natural curing type adhesive, and may be made of a material such as PSA (Pressure Sensitive Aadhesive). It can be configured so that it can serve to fix the polarizer 730 on the barrier film 720 .

The polarizer 730 disposed on the barrier film 720 suppresses reflection of external light on the display area A/A. When the display device 700 is used outside, external natural light may be introduced and reflected by a reflector included in an anode of the electroluminescent device or reflected by a metal electrode disposed under the organic light emitting device. The image of the display device 700 may not be well recognized due to the reflected light. The polarizer 730 polarizes light introduced from the outside in a specific direction and prevents the reflected light from being emitted to the outside of the display device 700 again. The polarizer 730 may be disposed on the display area A/A, but is not limited thereto.

The polarizing plate 730 may be a polarizing plate composed of a polarizer and a protective film protecting the polarizer, or may be formed by coating a polarizing material for flexibility.

An adhesive layer may be disposed on the polarizer 730 to protect the appearance of the display device 700 by bonding a cover glass (CG).

A back plate 740 is disposed below the flexible substrate 710 . When the flexible substrate 710 is made of a plastic material such as polyimide, the manufacturing process of the flexible electroluminescent display device 700 proceeds in a situation where a support substrate made of glass is disposed under the flexible substrate 710, and the manufacturing process After completion, the support substrate can be separated and released.

Since a component for supporting the flexible substrate 710 is required even after the support substrate is released, a back plate 740 for supporting the flexible substrate 505 may be disposed under the flexible substrate 710 . The back plate 740 may be disposed adjacent to the bending area B/A in other areas of the flexible substrate 505 excluding the bending area B/A.

The back plate 740 may be formed of a plastic thin film formed of polyimide, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polymers, combinations of these polymers, or the like.

A support member 770 may be disposed between the two back plates 740 , and the support member 770 may be adhered to the back plate 740 by an adhesive layer 760 . The support member 570 may be formed of a plastic material such as polycarbonate (PC), polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polymers, combinations of these polymers, and the like. The strength of the support member 770 formed of these plastic materials may be controlled by adding additives to increase the thickness and strength of the support member 770 . Also, the support member 770 may be formed of glass, ceramic, metal, or other rigid materials or combinations of the foregoing materials.

A micro coating layer 750 is disposed on the bending area B/A of the flexible substrate 710 . The micro-coating layer 750 may be formed to cover one side of the barrier film 720 .

When the micro-coating layer 750 is bent, a tensile force acts on the wiring part disposed on the flexible substrate 710 and micro-cracks may occur. can play a protective role.

The micro-coating layer 750 may adjust the neutral plane of the bending area B/A. The neutral plane means a virtual plane that does not receive stress because compressive force and tensile force applied to the structure cancel each other when the structure is bent. When two or more structures are stacked, a virtual neutral plane may be formed between the structures. When the entire structure is bent in one direction, the structures disposed in the bending direction based on the neutral plane are compressed by the bending and thus receive a compressive force. Conversely, structures arranged in the direction opposite to the bending direction based on the neutral plane are elongated by bending and thus receive a tensile force. At this time, since structures are generally more vulnerable when subjected to tensile force among the same compressive force and tensile force, cracks are more likely to occur when subjected to tensile force.

Since the flexible substrate 710 disposed below the neutral plane is compressed, it may receive a compressive force, and wires disposed above may receive a tensile force, and thus cracks may occur due to the tensile force. Therefore, in order to minimize the tensile force applied to the wiring, it can be located on the neutral plane.

By disposing the micro-coating layer 750 on the bending area B/A, the neutral plane can be raised upward, and the neutral plane is formed at the same position as the wiring or located higher than the neutral plane to reduce stress during bending. Crack generation can be suppressed by being subjected to compressive force.

The micro-coating layer 750 may be made of resin, but may be made of acrylic material or urethane acrylate, but is not limited thereto.

An insulating film 780 is connected to an end of the flexible substrate 710 . Various wires are formed on the insulating film 780 to transmit signals to pixels disposed in the display area A/A. The insulating film 780 is formed of a material having flexibility so as to be bendable. A driving element may be mounted on the insulating film 780, and together with the insulating film 780, a driving package such as a chip on film (COF) is formed and formed on the insulating film 780. It is connected to the wire to provide driving signals and data to the pixels disposed in the display area A/A.

The circuit board connected to the insulating film 780 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. .

A flexible electroluminescent display device according to an embodiment of the present specification includes a shield layer on a flexible substrate, a buffer layer on the shield layer, a thin film transistor on the buffer layer, and an electroluminescent device on the thin film transistor. The thin film transistor and the thin film transistor have an overlapping region, and the thin film transistor and the shield layer are connected in the overlapping region.

The thin film transistor of the flexible electroluminescent display device according to the exemplary embodiment of the present specification is connected to the shield layer through a contact hole.

A thin film transistor of a flexible electroluminescent display device according to an embodiment of the present specification includes a semiconductor layer on a substrate, a first insulating layer on the semiconductor layer, a gate electrode on the first insulating layer, and a second insulating layer on the gate electrode. It includes an insulating layer, a drain electrode and a source electrode on the second insulating layer.

The contact hole of the flexible electroluminescent display device according to the exemplary embodiment of the present specification passes through the buffer layer, the first insulating layer, the second insulating layer, and the semiconductor layer, and the source electrode and the shield layer are connected.

The contact hole of the flexible electroluminescent display device according to the exemplary embodiment of the present specification passes through the buffer layer and the first insulating layer, and the connection electrode on the same layer as the gate electrode is connected to the shield layer.

The connection electrode of the flexible electroluminescent display device according to the embodiment of the present specification is directly connected to the source electrode.

A semiconductor layer of a flexible electroluminescent display device according to an embodiment of the present specification includes a region doped with impurities.

The impurity of the flexible electroluminescent display device according to the exemplary embodiment of the present specification is one of boron (B), aluminum (Al), gallium (Ga), and indium (In).

The impurity of the flexible electroluminescent display device according to the exemplary embodiment of the present specification is one of phosphorus (P), arsenic (As), and antimony (Sb).

A semiconductor layer of a flexible electroluminescent display device according to an embodiment of the present specification is one of an oxide semiconductor layer and a polysilicon semiconductor layer.

At least one of the source electrode, the drain electrode, and the gate electrode of the flexible electroluminescent display device according to the exemplary embodiment of the present specification is composed of a plurality of metal layers.

A flexible electroluminescent display device according to an embodiment of the present specification includes forming a shield layer on a flexible substrate, forming a buffer layer on the shield layer, and forming a semiconductor layer, a gate electrode, a source electrode, and a drain electrode on the buffer layer. Forming a thin film transistor comprising a thin film transistor, forming an electroluminescent device on the thin film transistor, and the shield layer and the thin film transistor have an overlapping area, and the thin film transistor and the shield layer are connected in the overlapping area. .

The thin film transistor of the flexible electroluminescent display device according to an embodiment of the present specification includes forming a semiconductor layer on a buffer layer, forming a first insulating layer on the semiconductor layer, and forming a gate electrode on the first insulating layer. It is manufactured by including steps of forming a second insulating layer on the gate electrode, and forming a drain electrode and a source electrode on the second insulating layer.

A flexible electroluminescent display device according to an embodiment of the present specification includes forming contact holes passing through a buffer layer, a semiconductor layer, a first insulating layer, and a second insulating layer at once, and connecting a source electrode and a contact hole through the contact hole. The shield layer is prepared to be directly connected.

A flexible electroluminescent display device according to an embodiment of the present specification includes forming a contact hole passing through a buffer layer and a first insulating layer, and forming a connection electrode on the same layer as a gate electrode. It is manufactured so that the connection electrode and the shield layer are connected through the hole.

A step of forming a contact hole penetrating the second insulating layer of the flexible electroluminescent display device according to the embodiment of the present specification is prepared so that the connection electrode and the source electrode are connected through the contact hole.

A step of doping impurity into the semiconductor layer of the flexible electroluminescent display device according to the embodiment of the present specification is further included.

The impurity of the flexible electroluminescent display device according to the exemplary embodiment of the present specification is made of one of boron (B), aluminum (Al), gallium (Ga), and indium (In).

The impurity of the flexible electroluminescent display device according to the exemplary embodiment of the present specification is made of one of phosphorus (P), arsenic (As), and antimony (Sb).

At least one of the source electrode, the drain electrode, and the gate electrode of the flexible electroluminescent display device according to the exemplary embodiment of the present specification is manufactured to include a plurality of metal layers.

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 may be variously modified and implemented without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea 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 according to the claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100, 200, 300, 400, 700: electroluminescence display
110: image processing unit
120: timing controller
130: data driver
140: gate driver
150: display panel
160: pixels
220: gate line
230: data line
240: switching transistor
250: drive transistor
260: compensation circuit
270, 440: light emitting element
310, 405, 505, 605, 710: substrate
370: circuit wiring
390: gate driving unit 395: pad
410, 510, 610: shield layer
412, 512, 612: first buffer layer
414, 514, 614: second buffer layer
420: thin film transistor
422: gate electrode
424, 524, 624: source electrode
426: drain electrode
428, 528, 628: semiconductor layer
431, 531, 631: first insulating layer
433, 533, 633: second insulating layer
435: first planarization layer
437: second planarization layer
442 anode
444: light emitting part
446 cathode
450: bank
452 spacer
460: encapsulation
462 first wiring
464 second wire
466, 750: micro coating layer
522: gate bridge
535: planarization layer
720: barrier film
730: polarizer
740: back plate
760: adhesive layer
770: support member
780: circuit board
A/A: display area
N/A: non-display area
B/A: bending area
S/L: scanline
C/H: contact hole

Claims (13)

a flexible substrate including a display area and a non-display area, and forming a bending area by bending a portion of the non-display area in a bending direction;
a shield layer on the flexible substrate;
a buffer layer on the shield layer;
a thin film transistor disposed on the buffer layer;
a first planarization layer on the thin film transistor;
an intermediate electrode disposed on the first planarization layer and electrically connected to the thin film transistor;
a second planarization layer on the intermediate electrode;
an electroluminescent device disposed on the second planarization layer; and
a circuit wiring on the buffer layer in the bending region;
The flexible electroluminescent display device, wherein the first planarization layer and the second planarization layer are disposed in the bending region. According to claim 1,
wherein the circuit wiring further includes a second wiring on the second planarization layer. According to claim 2,
The second wire is formed of the same material on the same layer as the intermediate electrode. According to claim 2,
The circuit wiring further includes a first wiring,
The first wire is disposed under the second wire,
The first wire is disposed so as not to overlap with the second wire, the flexible electroluminescent display device. According to claim 1,
A flexible electroluminescent display device further comprising a back plate, a support member, and an adhesive layer disposed under the flexible substrate. According to claim 5,
The flexible electroluminescent display device of claim 1 , wherein ends of the back plate, the support member, and the adhesive layer on the side of the bending area coincide with each other. According to claim 1,
a barrier film disposed on the flexible substrate; and
Further comprising a micro coating layer disposed on the bending area,
The micro-coating layer extends to a part of the non-display area and is disposed to cover one side of the barrier film. According to claim 7,
Further comprising an insulating film connected to an end of the flexible substrate bent in the bending direction,
The micro-coating layer is disposed to cover one side of the insulating film, the flexible electroluminescent display device. According to claim 1,
The thin film transistor is electrically connected to the shield layer through a contact hole. According to claim 1,
A portion of the circuit wiring disposed in the bending area extends in an oblique direction different from the bending direction. According to claim 1,
The flexible electroluminescent display device further comprises a semiconductor layer disposed on the shield layer to overlap the shield layer. According to claim 11,
and a source electrode disposed on the semiconductor layer and electrically connected to the shield layer through the semiconductor layer, and a drain electrode electrically connected to the anode of the electroluminescent device. According to claim 11,
wherein the semiconductor layer is composed of either an oxide semiconductor layer or a polysilicon semiconductor layer.

Images