KR102632250B1 - Organic light emitting display device - Google Patents

Abstract

This specification discloses an organic light emitting display device. The organic light emitting display device includes a substrate on which a display area on which an image is displayed and a non-display area surrounding the display area are defined; a first wiring in a non-display area of the substrate; a first planarization layer that planarizes an upper portion of the first wiring; a second interconnection on the first planarization layer; and a second planarization layer that planarizes an upper portion of the second wiring.

Description

Organic light emitting display device {ORGANIC LIGHT EMITTING DISPLAY DEVICE}

This specification relates to an organic light emitting display device.

Video display devices, which display various information on a screen, are a core technology of the information and communication era and are developing to be thinner, lighter, more portable, and more high-performance. Accordingly, organic light emitting display devices that display images by controlling the amount of light emitted from organic light emitting devices are receiving attention.

Organic light-emitting devices are self-luminous devices that use a thin light-emitting layer between electrodes and have the advantage of being able to be made into thin films. A typical organic light emitting display device has a structure in which a pixel driving circuit and an organic light emitting element are formed on a substrate, and the light emitted from the organic light emitting element passes through the substrate or barrier layer to display an image.

Since the organic light emitting display device is implemented without a separate light source device, it is easy to be implemented as a flexible display device. At this time, flexible materials such as plastic and thin metal foil can be used as a substrate for the organic light emitting display device.

Recently, as organic light emitting display devices have progressed in miniaturization and higher resolution, the required wiring has increased, but the space to place the wiring has become scarce. In this situation, securing space for various elements, including electrical wiring, has become an important task. Furthermore, ways to streamline the arrangement of various parts and elements are also being studied.

The purpose of this specification is to propose an organic light emitting display device and a wiring arrangement structure applied to the organic light emitting display device. The tasks of this 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.

An organic light emitting display device is provided according to an embodiment of the present specification. The organic light emitting display device includes a substrate on which a display area on which an image is displayed and a non-display area surrounding the display area are defined; a first wiring in a non-display area of the substrate; a first planarization layer that planarizes an upper portion of the first wiring; a second interconnection on the first planarization layer; It may include a second planarization layer that planarizes an upper part of the second wiring.

Specific details of other embodiments are included in the detailed description and drawings.

Embodiments of the present specification can provide an organic light emitting display device in which the problem of conductor placement in a non-display area is improved. More specifically, embodiments of the present specification can provide an organic light emitting display device in which conductors are efficiently arranged in a limited space of the outer portion. Accordingly, the organic light emitting display device according to the embodiment of the present specification can implement a narrow bezel. The effects according to the embodiments of the present specification are not limited to the contents exemplified above, and further various effects are included in the present specification.

1 is a plan view showing an organic light emitting display device according to an embodiment of the present specification.
Figure 2 is a cross-sectional view showing a portion of the display area of an organic light emitting display device according to an embodiment of the present specification.
Figure 3 is a cross-sectional view showing a portion of the non-display area of an organic light emitting display device according to the prior art.
4A and 4B are diagrams showing a portion of a non-display area of an organic light emitting display device according to an embodiment of the present specification.

The advantages and features of the present specification and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. The present embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The shape, size, ratio, angle, number, etc. disclosed in the drawings for explaining the embodiments of the present specification are illustrative, and the present specification is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', 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 plural is included unless specifically stated otherwise. When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship between two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'immediately' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used. When an element or layer is referred to as “on” another element or layer, it includes all cases where the other layer or other element is interposed or directly on top of the other element. When a component is described as being “connected,” “coupled,” or “connected” to another component, that component may be directly connected or connected to that other component, but there are no other components between each component. It should be understood that may be “interposed” or that each component may be “connected,” “combined,” or “connected” through other components.

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

The size and thickness of each component shown in the drawings are shown for convenience of explanation, and the present invention is not necessarily limited to the size and thickness of the components shown. Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings.

1 is a plan view showing an organic light emitting display device according to an embodiment of the present specification.

Referring to FIG. 1, the organic light emitting display device 100 includes at least one display area (active area, A/A), and an array of pixels is disposed in the display area. One or more inactive areas (I/A) may be placed around the display area. That is, the non-display area may be adjacent to one or more sides of the display area. In Figure 1, the non-display area surrounds a rectangular display area. However, the shape of the display area and the shape/arrangement of the non-display area adjacent to the display area are not limited to the example shown in FIG. 1. The display area and the non-display area may have a shape suitable for the design of an electronic device equipped with the display device 100. Exemplary shapes of the display area include pentagon, hexagon, circle, oval, etc.

Each pixel within the display area (A/A) may be associated with a pixel driving circuit. The pixel driving circuit may include one or more switching transistors and one or more driving transistors. Each pixel driving circuit may be electrically connected to a signal line (gate line, data line, etc.) to communicate with a gate driver, data driver, etc. located in the non-display area.

The gate driver and data driver may be implemented as a thin film transistor (TFT) in the non-display area (I/A). These drivers may be referred to as gate-in-panel (GIP). Additionally, some components, such as data driver ICs, are mounted on separate printed circuit boards and circuit films such as FPCB (flexible printed circuit board), COF (chip-on-film), TCP (tape-carrier-package), etc. It can be combined with a connection interface (pad, bump, pin, etc.) disposed in the non-display area. The printed circuit (COF, PCB, etc.) may be located behind the display device 100.

The organic light emitting display device 100 may include various additional elements for generating various signals or driving pixels within the display area. Additional elements for driving the pixel may include an inverter circuit, a multiplexer, an electrostatic discharge (ESD) circuit, etc. The organic light emitting display device 100 may also include additional elements related to functions other than pixel driving. For example, the organic light emitting display device 100 may include additional elements that provide a touch detection function, a user authentication function (e.g., fingerprint recognition), a multi-level pressure detection function, a tactile feedback function, etc. there is. The above-mentioned additional elements may be located in the non-display area and/or in an external circuit connected to the connection interface.

The organic light emitting display device according to the present specification may include a substrate 101 on which thin film transistors and organic light emitting elements are arranged, an encapsulation layer 120, a barrier film 140, etc.

The substrate 101 supports various components of the organic light emitting display device 100. The substrate 101 may be formed of a transparent insulating material, such as glass or plastic. The substrate (array substrate) is also referred to as a concept that includes elements and functional layers formed thereon, such as a switching TFT, a driving TFT connected to the switching TFT, an organic light emitting device connected to the driving TFT, a protective film, etc.

The organic light emitting device is disposed on the substrate 101. The organic light emitting device includes an anode, an organic light emitting layer, and a cathode. The organic light-emitting device may be composed of a single light-emitting layer structure that emits a single light, or may be composed of a plurality of light-emitting layers that emit white light. When the organic light emitting device emits white light, a color filter may be further provided. The organic light emitting device may be formed in the central portion of the substrate 101 to correspond to the display area.

The encapsulation layer 120 may cover the organic light emitting device. The encapsulation layer protects the organic light emitting device from external moisture or oxygen. A barrier film is placed on the encapsulation layer.

The organic light emitting display device 100 is composed of a plurality of pixels, and one pixel may include a plurality of subpixels. At this time, a subpixel is the minimum unit for expressing one color.

One subpixel may include multiple transistors, capacitors, and multiple wiring lines. A subpixel may be composed of two transistors and a capacitor (2T1C), but is not limited to this and may be implemented as a subpixel using 4T1C, 7T1C, 6T2C, etc. Additionally, the subpixel may be implemented to be suitable for the top-emission organic light emitting display device 100.

Figure 2 is a cross-sectional view showing a portion of the display area of an organic light emitting display device according to an embodiment of the present specification.

The organic light emitting display device of FIG. 2 has an exemplary structure consisting of two planarization layers. In the organic light emitting display device 100, thin film transistors 102, 104, 106, 108, organic light emitting elements 112, 114, 116, and various functional layers are located on a substrate (or array substrate). .

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

The buffer layer 130 is a functional layer for protecting electrodes/wires from impurities such as alkaline ions leaking from the substrate 101 or lower layers. The buffer layer may be made of silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof. The buffer layer 130 may include a multi buffer (131) and/or an active buffer (132). The multi-buffer 131 may be formed by alternately stacking silicon nitride (SiNx) and silicon oxide (SiOx), and may delay the diffusion of moisture and/or oxygen penetrating into the substrate 101. The active buffer 132 protects the semiconductor layer 102 of the transistor and functions to block various types of defects flowing from the substrate 101. The active buffer 132 may be formed of amorphous silicon (a-Si).

The thin film transistor may have a semiconductor layer 102, a gate insulating film 103, a gate electrode 104, an interlayer insulating film 105, and source and drain electrodes 106 and 108 arranged sequentially. The semiconductor layer 102 is located on the buffer layer 130. The semiconductor layer 102 may be made of polysilicon (p-Si), in which case a predetermined region may be doped with impurities. Additionally, the semiconductor layer 102 may be made of amorphous silicon (a-Si), or may be made of various organic semiconductor materials such as pentacene. Furthermore, the semiconductor layer 102 may be made of oxide. The gate insulating film 103 may be formed of an insulating inorganic material such as silicon oxide (SiOx) or silicon nitride (SiNx), and may also be formed of an insulating organic material. The gate electrode 104 is made of various conductive materials, such as magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), gold (Au), or alloys thereof. etc. can be formed.

The interlayer insulating film 105 may be formed of an insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), and may also be formed of an insulating organic material. By selectively removing the interlayer insulating film 105 and the gate insulating film 103, a contact hole exposing the source and drain regions may be formed.

The source and drain electrodes 106 and 108 are formed of an electrode material on the interlayer insulating film 105 in a single-layer or multi-layer shape. If necessary, a passivation layer made of an inorganic insulating material may cover the source and drain electrodes 106 and 108.

The first planarization layer 107-1 may be located on the thin film transistor. The first planarization layer 107-1 protects the thin film transistor, etc. and planarizes the upper part thereof. The first planarization layer 107-1 may be composed of various forms, including acrylic resin, epoxy resin, phenol resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, and polyphenyl resin. It may be formed of one or more of rensulfide-based resins, but is not limited thereto.

Various metal layers that serve as wires/electrodes may be disposed on the first planarization layer 107-1.

The second planarization layer 107-2 is located on top of the first planarization layer 107-1. The reason that there are two planarization layers in this embodiment is because various signal wirings have increased as display devices have evolved into higher resolutions. Therefore, it was difficult to place all the wiring on one layer while ensuring the minimum spacing, so an additional layer was created. This additional layer (second planarization layer) allows room for wiring placement, making wire/electrode placement design easier. In addition, when a dielectric material is used as the planarization layer (107-1, 107-2), the planarization layer (107-1, 107-2) can be used to form capacitance between metal layers. It may be possible.

The organic light emitting device may have a first electrode 112, an organic light emitting layer 114, and a second electrode 116 arranged sequentially. That is, the organic light emitting device includes a first electrode 112 formed on the planarization layer 107, an organic light emitting layer 114 located on the first electrode 112, and a second electrode located on the organic light emitting layer 114 ( 116).

The first electrode 112 may be electrically connected to the drain electrode 108D of the driving thin film transistor through the connection electrode 108-2. When the organic light emitting display device 100 is a top emission type, the first electrode 112 may be made of an opaque conductive material with high reflectivity. For example, the first electrode 112 may be formed of silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), tungsten (W), chromium (Cr), or an alloy thereof. . The connection electrode 108-2 may be made of the same material as the source and drain electrodes 106 and 108.

The bank 110 is formed in the remaining area excluding the light emitting area. Accordingly, the bank 110 has a bank hole that exposes the first electrode 112 corresponding to the light emitting area. The bank 110 may be made of an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx), or an organic insulating material such as BCB, acrylic resin, or imide resin.

The organic light emitting layer 114 is located on the first electrode 112 exposed by the bank 110 . The organic light-emitting layer 114 may include a light-emitting layer, an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer.

The second electrode 116 is located on the organic light emitting layer 114. When the organic light emitting display device 100 is a top emission type, the second electrode 116 is a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). By being formed of a material, the light generated in the organic light emitting layer 114 is emitted to the upper part of the second electrode 116.

Encapsulation layer 120 is positioned on second electrode 116. The encapsulation layer 120 prevents oxygen and moisture from penetrating from the outside to prevent oxidation of the light emitting material and electrode material. When an organic light-emitting device is exposed to moisture or oxygen, pixel shrinkage, which reduces the light-emitting area, may occur, or dark spots may appear within the light-emitting area. The encapsulation layer may be composed of an inorganic layer made of glass, metal, aluminum oxide (AlOx), or silicon (Si)-based material, or may have a structure in which organic and inorganic layers are alternately stacked. The inorganic film serves to block the penetration of moisture or oxygen, and the organic film serves to flatten the surface of the inorganic film. The reason for forming the encapsulation layer with multiple thin film layers is to make the movement path of moisture or oxygen longer and more complicated than a single layer, making it difficult for moisture/oxygen to penetrate into the organic light emitting device.

The barrier film 140 is positioned on the encapsulation layer 120 to encapsulate the entire substrate 101 including the organic light emitting device. The barrier film 140 may be a retardation film or an optically isotropic film. If the barrier film has optical isotropic properties, the incident light passing through the barrier film is transmitted without phase delay. Additionally, an organic layer or an inorganic layer may be further positioned on the upper or lower surface of the barrier film. The organic or inorganic film formed on the upper or lower surface of the barrier film serves to block the penetration of external moisture or oxygen.

An adhesive layer 145 may be positioned between the barrier film 140 and the encapsulation layer 120. The adhesive layer 145 adheres the encapsulation layer 120 and the barrier film 140. The adhesive layer 145 may be a heat-curing or natural-curing type adhesive. For example, the adhesive layer 145 may be made of a material such as barrier pressure sensitive adhesive (B-PSA).

A touch panel (film), a polarizing film, a top cover, etc. may be further positioned on the barrier film 140.

Figure 3 is a cross-sectional view showing a portion of the non-display area of an organic light emitting display device according to the prior art.

The non-display area (I/A) may be located on the outside of the display area (A/A) as shown, and a driving circuit (eg, GIP), power wiring, etc. may be placed thereon.

The substrate 301 shown in FIG. 3 is the same as the substrate 101 described in FIGS. 1 and 2. In addition, the interlayer insulating film 305, buffer layer 330, bank 310, and organic light emitting elements 312, 314, and 316 are the interlayer insulating film 105, buffer layer 130, and bank 110 described in FIGS. 1 and 2. and organic light emitting devices (112, 114, 116).

Various driving circuits arranged in the non-display area and electrodes/wires connected thereto may be made of gate metal 304' and/or source/drain metal 308'. At this time, the gate metal 304' is formed from the same material as the gate electrode of the TFT in the same process, and the source/drain metal 308' is formed from the same material as the source/drain electrode of the TFT in the same process. Meanwhile, the cathode 316 can receive power through connection with the metal layer 312'. At this time, the metal layer 312' may be a metal made of the same material as the anode 312 of the organic light emitting diode.

A conventional organic light emitting display device includes the planarization layer 307 as a single layer in the display area (A/A) and/or the non-display area (I/A). In this single planarization layer structure, circuits (eg, GIP) and/or wiring are placed on the same plane on the outer bezel. That is, as shown in FIG. 3, various wires 308' are arranged on the same layer (eg, buffer layer 305). This arrangement occupies a significant left and right width, which limits the ability to create a narrower bezel.

Accordingly, the inventors of the present invention derived a new structure to implement a narrower bezel.

4A and 4B are diagrams showing a portion of a non-display area of an organic light emitting display device according to an embodiment of the present specification.

A structure for implementing a narrow bezel was applied to the organic light emitting display device shown in FIGS. 4A and 4B. Among the components in FIGS. 4A and 4B, the same components as those in FIGS. 1 and 2 are given the same reference numerals, and duplicate description thereof will be omitted.

In the illustrated embodiment, the planarization layer is provided in two layers 107-1 and 107-2. As explained earlier, this is to accommodate the increased wiring structure in line with the high-resolution screen.

The first planarization layer 107-1 flattens the top of various circuit elements (thin film transistors, capacitors, conductors, etc.) on the substrate. A protective layer 109-1 made of an inorganic material may be positioned between the first planarization layer 107-1 and the circuit element. Metal layers with various functions may be disposed on the first planarization layer 107-1. At this time, inorganic layers 109-2 and 109-3 for arranging the metal layers may be provided on the first planarization layer 107-1. As an example, the inorganic layer includes a buffer layer 109-2 and a protection layer 109-3. The metal layer may be disposed on the buffer layer 109-2 and covered with a protective layer 109-3.

Organic light emitting elements 112, 114, and 116 may be disposed on the second planarization layer 107-2. At this time, a metal layer 112' connected to the organic light emitting device may be placed on top of the second planarization layer 107-2. An encapsulation layer covers the top of the organic light emitting device. The encapsulation layer may be composed of an inorganic film made of glass, metal, aluminum oxide (AlOx), or silicon (Si)-based material, or may have a structure in which organic films and inorganic films are alternately stacked.

The outer wires 108-1 and 108-2 are arranged in two or more layers. The wires may be conductors that transmit signals and/or power to various driving circuits (gate driving circuit, data driving circuit, etc.). For example, the outer wires 108-1 and 108-2 may be disposed above and below the first planarization layer 107-1, respectively. That is, the first wiring 108-1 is disposed on the buffer layer 130 and/or the insulating layer 105 on the substrate 101, and the second wiring 108-2 is disposed on the first planarization layer 107-1. ) and the second planarization layer 107-2.

FIG. 4A is a plan view of an organic light emitting display device according to an embodiment of the present specification. Wires are arranged at the boundary between the display area and the non-display area of the organic light emitting display device, and are divided into two or more layers. Referring to FIG. 4B, the first wiring 108-1 and the second wiring 108-2 are arranged vertically with the first planarization layer 107-1 in between, and at least a portion of them overlap each other in the vertical direction. . The shape, size, and density of the illustrated wiring arrangement are illustrative only and the spirit of the present specification is not limited thereto. In another embodiment, the first wiring 108-1 and the second wiring 108-2 may be provided so as not to overlap each other in the vertical direction.

Referring to FIG. 4B, the substrate 101 is defined by a display area (A/A) in which an image is displayed and a non-display area (I/A) surrounding the display area, including a first wire 108-1 and The second wiring 108-2 is in the non-display area (I/A). The first wiring 108-1 may be made of the same material as the source and drain electrodes 106 and 108 of FIG. 2. Additionally, the second wiring 108-2 may be made of the same material as the connection electrode 108-2 or the source/drain electrodes of FIG. 2. As an example, the first wire 108-1 is a wire associated with a gate-in panel (GIP) circuit, and the second wire 108-2 transmits a control signal (e.g. clock) to the GIP circuit. It could be wiring. Meanwhile, the substrate 101 may be a flexible substrate with flexibility.

The first planarization layer 107-1 planarizes the top of the first wiring 108-1, and the second wiring 108-2 is located on the first planarization layer 107-1. And, the second planarization layer 107-2 planarizes the upper part of the second wiring 108-2.

A buffer layer 130, an insulating layer 105, etc. may be located between the substrate 101 and the first wiring 108-1. Additionally, an inorganic layer 109-1 covering the first wiring 108-1 may be located below the first planarization layer 107-1. Additionally, a buffer layer 109-2 covering the top of the first planarization layer 1047-1 may be located below the second wiring 108-2.

A metal layer 112' may be positioned on the second planarization layer 107-2. The cathode 116 may receive power through connection to the metal layer 112'. At this time, the metal layer 112' may be a metal made of the same material as the anode 112 of the organic light emitting diode. That is, the metal layer 112' may serve as a conductor that transmits the power voltage to the cathode 116. As shown in FIG. 4B, the metal layer 112' may contact the cathode at the top of the first and second wires 108-1 and 108-2.

Through the illustrated multi-layer structure, the first and second wires 108-1 and 108-2 can be arranged without shorting, and their occupied width can be reduced. Through experiments, it was confirmed that the bezel (non-display area) width was reduced by 15 to 20% through the wiring arrangement of this multi-layer structure.

Although embodiments of the present specification have been described in detail with reference to the attached drawings, the present specification is not necessarily limited to these embodiments, and various modifications may be made without departing from the technical spirit thereof. Accordingly, the embodiments disclosed in this specification are not intended to limit the technical idea of the present invention, but rather to explain it, and the scope of the technical idea of the present invention is not limited by these embodiments. Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, and can be technically linked and driven in various ways by those skilled in the art, and each embodiment can be performed independently of each other or together in a related relationship. It may be implemented.

The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

Claims (10)

a substrate on which a display area on which an image is displayed and a non-display area surrounding the display area are defined;
a transistor in the display area of the substrate;
a first wiring on the same layer as the source electrode of the transistor in the non-display area of the substrate;
a first planarization layer that planarizes an upper portion of the first wiring;
a second interconnection on the first planarization layer;
a second planarization layer that planarizes an upper part of the second wiring; and
An organic light emitting display device comprising an organic light emitting element on the second planarization layer in the display area. According to claim 1,
An organic light emitting display device further comprising a buffer layer between the substrate and the first wiring. According to claim 1,
The organic light emitting display device further includes an inorganic layer covering the first wiring and below the first planarization layer. According to claim 1,
The organic light emitting display device further includes a buffer layer covering an upper portion of the first planarization layer and below the second wiring. According to claim 1,
The organic light emitting display device wherein at least a portion of the first wire and the second wire overlap each other in a vertical direction. According to clause 5,
The organic light emitting display device further includes a metal layer on the second planarization layer, wherein the metal layer contacts a cathode on top of the first wiring and the second wiring. According to clause 6,
An organic light emitting display device in which the metal layer serves as a conductor that transmits a power voltage to the cathode. According to claim 1,
The first wiring is a wiring associated with a GIP circuit. According to clause 8,
The second wire is a wire that transmits a control signal to the GIP circuit. According to claim 1,
The substrate is an organic light emitting display device that is a flexible substrate.

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