KR20210082605A - Organic light emitting display apparatus - Google Patents

Abstract

According to various examples of the present specification, an organic light emitting display device comprises: a substrate; a pixel area on the substrate; a bank disposed on the substrate and defining an opening in the pixel area; a first electrode disposed in the opening of the pixel area; an organic light emitting layer disposed on the first electrode; a second electrode disposed on the organic light emitting layer; and a conductive layer disposed under the first electrode. The organic light emitting layer can be electrically connected to the conductive layer through the bank. Therefore, the organic light emitting display device can increase display quality.

Description

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

This specification relates to an organic light emitting display device.

An organic light emitting display (OLED) is a self-luminance display device, and is formed from an electrode for hole injection and a cathode for electron injection, respectively. This is a display device using an organic light emitting diode that emits light when holes and electrons are injected into the light emitting layer, and excitons in which the injected holes and electrons are combined fall from an excited state to a ground state.

The organic light emitting diode display is divided into a top emission method, a bottom emission method, a dual emission method, etc. according to a direction in which light is emitted, and a passive matrix type according to a driving method. matrix) and an active matrix type.

Unlike a liquid crystal display (LCD), an organic light emitting display device does not require a separate light source, so it can be manufactured in a lightweight and thin form. In addition, the organic light emitting display device is not only advantageous in terms of power consumption due to low voltage driving, but also has excellent color realization, response speed, viewing angle, and contrast ratio (CR), and is being studied as a next-generation display device.

The content of the background art described above is technical information possessed by the inventor of the present specification for the purpose of derivation of the present specification or acquired in the process of derivation of the present specification, and must be referred to as known technology disclosed to the general public before the specification of the present specification. can't

An organic light emitting diode display includes a plurality of organic light emitting layers emitting different colors between two electrodes, for example, a red light emitting layer for emitting red light, a green light emitting layer for emitting green light, and a blue light emitting layer for emitting blue light. Each of the red sub-pixels, the green sub-pixels and the blue sub-pixels may be configured separately. Each of the emission layers may be pattern-deposited using a mask opened for each sub-pixel, for example, a fine metal mask (FMM).

In addition, between the two electrodes, a hole injecting layer, a hole transporting layer, an electron in order to improve characteristics of the organic light emitting device, for example, driving voltage or luminous efficiency, in addition to the organic light emitting layer. A plurality of organic material layers such as an electron injecting layer and an electron transporting layer may be disposed.

In the organic light emitting diode display, at least some of the organic material layers other than the emission layer among the organic material layers present between the two electrodes may have a common layer structure.

Such a common layer structure may be formed using a common mask in which all pixels are opened, and may be stacked in the same structure on all sub-pixels without a pattern for each sub-pixel. That is, since the organic material layer having a common layer structure is disposed to be connected or extended from one sub-pixel to an adjacent sub-pixel without a break, it is shared by a plurality of sub-pixels.

As such, when the organic material layer is formed as a common layer so as to correspond in common to a plurality of sub-pixels, a lateral leakage current may occur to adjacent sub-pixels through the organic material layer.

That is, when the organic light emitting diode display is driven, some current leaks through the organic material layer having a common layer structure, and thus not only the driven sub-pixel but also the sub-pixel adjacent to the driven sub-pixel may be unnecessarily emitting light.

In particular, when a low current flows through the organic light emitting diode display to express a low gray level of 30 gray or less, the common layer is not applied to sub-pixels other than the sub-pixels to emit light. As a leakage current flows through the organic layer of the structure to sub-pixels other than those intended to emit light, light is emitted from adjacent sub-pixels other than those intended to emit light.

For example, when green or blue light is emitted, a different color light emission phenomenon occurs in which red light is emitted from adjacent red sub-pixels due to leakage current, and unnecessary light is emitted from the red sub-pixel which is an unwanted pixel. This light emission causes color mixture between the green sub-pixel and the red sub-pixel or color mixture between the blue sub-pixel and the red sub-pixel, thereby deteriorating the display quality and reliability of the organic light emitting diode display.

Accordingly, the inventor of the present specification has invented an organic light emitting display device in which unwanted sub-pixel light emission can be minimized and reliability can be improved.

In the present specification, a conductive layer is formed under the pixel electrode, and the conductive layer and the organic material layer having a common layer structure are electrically connected in the bank region so that a horizontal leakage current flows to the outside through the conductive layer, thereby emitting light as an unwanted sub-pixel. It is an object of the present invention to provide an organic light emitting diode display capable of improving high resolution and reliability by minimizing the phenomenon of the display and the process margin between sub-pixels being minimized.

In addition to the tasks of the present specification mentioned above, other features and advantages of the present specification may be described below or clearly understood by those of ordinary skill in the art to which the technical spirit of the present specification belongs from such descriptions and descriptions. will be.

The organic light emitting diode display according to various examples of the present specification may include a substrate, a pixel region on the substrate, a bank disposed on the substrate and defining an opening of the pixel region, a first electrode disposed in the opening of the pixel region, and the an organic light-emitting layer disposed on the first electrode, a second electrode disposed on the organic light-emitting layer, and a conductive layer disposed under the first electrode, wherein the organic light-emitting layer is coupled to the conductive layer through the bank can be electrically connected.

In the organic light emitting display device according to the present specification, a conductive layer is formed under the pixel electrode, and the conductive layer and the organic material layer having a common layer structure are electrically connected in the bank region so that a horizontal leakage current flows to the outside through the conductive layer, A phenomenon in which unwanted sub-pixels emit light due to the horizontal leakage current can be minimized. Accordingly, the display quality of the organic light emitting diode display can be improved by reducing color mixture between adjacent sub-pixels, and reliability of the organic light emitting display can be improved at low grayscale.

In the organic light emitting diode display according to the present specification, the conductive layer formed under the pixel electrode functions as a reflective layer and suppresses horizontal leakage current at the same time, thereby improving luminous efficiency by the reflective layer and minimizing a process margin between sub-pixels. Therefore, there is an advantageous effect in realizing a high-resolution organic light emitting display device.

In addition to the effects of the present specification mentioned above, other features and advantages of the present specification will be described below or will be clearly understood by those skilled in the art from such description and description.

1 is a diagram schematically illustrating an organic light emitting diode display according to various examples of the present specification.
FIG. 2 is a diagram schematically illustrating a pixel illustrated in FIG. 1 .
3 is a cross-sectional view illustrating a cross-sectional structure of an organic light emitting diode display according to various examples of the present specification.
4 is a plan view illustrating a planar structure of an organic light emitting diode display according to various examples of the present specification.
5 is a cross-sectional view illustrating a cross-sectional structure of an organic light emitting diode display according to various examples of the present specification illustrated in FIG. 4 .
6 to 8 are plan views illustrating a device arrangement structure of an organic light emitting diode display according to various examples of the present specification illustrated in FIG. 4 .

Advantages and features of the present specification, and methods of achieving them, will become apparent with reference to the various examples described below in detail in conjunction with the accompanying drawings. However, the present specification is not limited to the various examples disclosed below, but will be implemented in various different forms, and only the various examples of the present specification allow the disclosure of the present specification to be complete, and in the technical field to which the technical spirit of the present specification belongs It is provided to fully inform those of ordinary skill in the scope of the technical idea of the present specification, and examples of the present specification are only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining various examples of the present specification are exemplary and are not limited to the matters illustrated in the drawings of the present specification. Like reference numerals refer to like elements throughout. In addition, in describing an example of the present specification, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present specification, the detailed description thereof will be omitted.

When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.

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

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

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal relationship is described with 'after', 'following', 'after', 'before', etc. It may include cases that are not continuous unless this is used.

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

"First horizontal axis direction", "second horizontal axis direction" and "vertical axis direction" should not be construed only as a geometric relationship in which the relationship between each other is vertical, and the range in which the configuration of the present specification can function functionally It may mean to have a broader direction than within.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, the meaning of "at least one of the first, second, and third items" means 2 of the first, second, and third items as well as each of the first, second, or third items. It may mean a combination of all items that can be presented from more than one.

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

Hereinafter, a preferred example of a flexible display device and an electronic device including the same according to the present specification will be described in detail with reference to the accompanying drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. And, since the scales of the components shown in the accompanying drawings have different scales from the actual for convenience of explanation, the scales shown in the drawings are not limited thereto.

1 is a diagram schematically illustrating an organic light emitting diode display according to various examples of the present specification. FIG. 2 is a diagram schematically illustrating a pixel illustrated in FIG. 1 .

Referring to FIG. 1 , an organic light emitting diode display 100 according to various examples of the present specification may include a display driving circuit and a display panel DIS.

The display driving circuit may include the data driving circuit 12 , the gate driving circuit 14 , and the timing controller 16 to write the video data voltage of the input image to the pixels PXL of the display panel DIS. The data driving circuit 12 may convert digital video data RGB input from the timing controller 16 into an analog gamma compensation voltage to generate a data voltage. The data voltage output from the data driving circuit 12 may be supplied to the data lines D1 to Dm. The gate driving circuit 14 may sequentially supply a gate signal synchronized with the data voltage to the gate lines G1 to Gn to select the pixels PXL of the display panel DIS to which the data voltage is written.

The timing controller 16 inputs timing signals such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, and a main clock MCLK input from the host system 19 . In response, the operation timings of the data driving circuit 12 and the gate driving circuit 14 can be synchronized. The data timing control signal for controlling the data driving circuit 12 may include a source sampling clock (SSC), a source output enable signal (SOE), and the like. The gate timing control signal for controlling the gate driving circuit 14 includes a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal (GOE), and the like. may include.

The host system 19 may be implemented as any one of a television system, a set-top box, a navigation system, a DVD player, a Blu-ray player, a personal computer (PC), a home theater system, and a phone system. The host system 19 may include a system on chip (SoC) having a built-in scaler to convert digital video data RGB of an input image into a format suitable for display on the display panel DIS. The host system 19 may transmit the timing signals Vsync, Hsync, DE, and MCLK together with the digital video data to the timing controller 16 .

The display panel DIS may have various planar shapes. That is, the display panel DIS may have a rectangular shape or a square shape, as well as various free form planar shapes such as a circular shape, an oval shape, and a polygonal shape.

The display panel DIS may include an active area having a plurality of pixels PXL. Each of the pixels PXL may be defined by an intersecting structure of data lines D1 to Dm, m is a positive integer, and gate lines G1 to Gn, n is a positive integer, but is limited thereto. no. Each of the pixels PXL may include an organic light emitting diode that is a self-emission device. The display panel DIS may include red, green, and blue pixels PXL that emit red, green, and blue light. The arrangement structure of the plurality of pixels PXL in FIG. 1 is a pentile matrix capable of realizing high resolution with a small number of pixels by applying a rendering driving that expresses colors by sharing adjacent pixels. Examples, but are not limited thereto.

2 , a plurality of data lines D and a plurality of gate lines G cross each other in the display panel DIS, and pixels PXL may be arranged in a matrix form in each crossed area. have. Each of the pixels PXL includes an organic light emitting diode (OLED), a driving thin film transistor (DT) controlling the amount of current flowing through the organic light emitting diode (OLED), and a gate-source voltage of the driving thin film transistor (DT). It may include a programming unit SC for setting.

The programming unit SC may include at least one switched thin film transistor and at least one storage capacitor. The switched thin film transistor may be turned on in response to a gate signal from the gate line G to apply a data voltage from the data line D to one electrode of the storage capacitor. The driving thin film transistor DT may control the amount of light emitted by the organic light emitting diode OLED by controlling the amount of current supplied to the organic light emitting diode OLED according to the level of the voltage charged in the storage capacitor. The amount of light emitted from the organic light emitting diode OLED may be proportional to the amount of current supplied from the driving thin film transistor DT. The pixel PXL is connected to the high potential voltage source Evdd and the low potential voltage source Evss, and receives a high potential power supply voltage and a low potential power supply voltage from a power generator (not shown), respectively. The thin film transistors constituting the pixel PXL may be implemented as p-type or n-type. In addition, the semiconductor layer of the thin film transistors constituting the pixel PXL may include amorphous silicon, polysilicon, or oxide. The organic light emitting diode OLED may include an anode electrode ANO, a cathode electrode CAT, and an organic light emitting layer OL interposed between the anode electrode ANO and the cathode electrode CAT. The anode electrode ANO may be connected to the driving thin film transistor DT. The organic light emitting layer OL includes an emission layer (EML), a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer. It may further include any one or more of an electron injection layer (EIL).

3 is a cross-sectional view illustrating a cross-sectional structure of an organic light emitting diode display according to various examples of the present specification. FIG. 3 illustrates a cross-sectional structure of the organic light emitting diode display in a region where the thin film transistors do not overlap under the pixels as a cross-section of portion I-I' of FIG. 1 .

Referring to FIG. 3 , an organic light emitting diode display according to various examples of the present specification includes a substrate 110 , a planarization layer 130 , a conductive layer 145 , an insulating layer 135 , a first electrode 140 , and an organic light emitting layer. 150 , a second electrode 160 , and a bank 170 may be included.

The organic light emitting diode display may include a plurality of sub pixel regions SP1 , SP2 , and SP3 . The sub-pixel areas SP1 , SP2 , and SP3 refer to pixel areas of a minimum unit in which actual light is emitted. In addition, the plurality of sub-pixel areas SP1 , SP2 , and SP3 may be gathered to form a minimum group capable of expressing white light. For example, three sub-pixel areas are one group, and a red sub-pixel area may be formed. , the green sub-pixel area and the blue sub-pixel area may form one group. However, the present invention is not limited thereto, and various sub-pixel area designs may be possible.

The substrate 110 is for supporting various components of the organic light emitting diode display and may be made of an insulating material, for example, glass or polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polyimide-based material. It may be made of a plastic substrate or the like. When the organic light emitting display device is a flexible organic light emitting display device, it may be made of a flexible plastic material. A passivation layer may be formed on the substrate 110 to block penetration of impurity elements from the substrate 110 and external elements and to protect various components of the organic light emitting diode display, and a thin film transistor may be formed on the passivation layer. have. In addition, a planarization layer 130 for protecting the thin film transistor and planarizing the upper portion of the substrate 110 may be formed on the substrate 110 .

A conductive layer 145 may be formed on the planarization layer 130 . The conductive layer 145 may be formed in a flat plate shape over the entire surface of the planarization layer 130 . The conductive layer 145 may include a reflective conductive material having excellent reflection efficiency so that light emitted from the organic light emitting layer 150 is emitted upward when the organic light emitting display device is driven in a top emission method; For example, it may be made of aluminum (Al), silver (Ag), copper (Cu), nickel (Ni), or an alloy thereof, preferably APC (Ag/Pd/Cu).

In the organic light emitting diode display according to various examples of the present specification, the first electrode 140 may be formed on the conductive layer 145 with the insulating layer 135 interposed therebetween. That is, the conductive layer 145 and the first electrode 140 are formed of a first electrode 140 made of a transparent conductive material and a reflective conductive material in a conventional first electrode having a multilayer structure in which a transparent conductive layer and a reflective layer are sequentially stacked. The conductive layer 145 may be disposed to be separated with the insulating layer 135 interposed therebetween. For example, the first electrode 140 may be formed of a transparent conductive material, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or the like. have. In addition, the insulating layer 135 may be formed in a single-layer or multi-layer structure made of an inorganic insulating material such as a silicon oxide layer (SiOx) or a silicon nitride layer (SiNx). In addition, the conductive layer 145 is formed of a reflective conductive material, and may be made of, for example, aluminum (Al), silver (Ag), copper (Cu), nickel (Ni), or an alloy thereof, preferably It may be made of APC (Ag/Pd/Cu). However, the present invention is not limited thereto, and when the organic light emitting diode display is driven by a bottom emission method, the conductive layer 145 may be formed of a transparent conductive material in the same manner as the first electrode 140 .

In the organic light emitting diode display according to various examples of the present specification, the conductive layer 145 is positioned under the first electrode 140 and the bank 170 and is not divided into areas corresponding to each sub-pixel area; It may be formed in the form of one common layer having an area covering a plurality of sub-pixel areas. The conductive layer 145 may be connected to the organic light emitting layer 150 in direct contact with the bank 170 and the through portion 171 penetrating the insulating layer 135 . That is, the conductive layer 145 and the organic light emitting layer 150 may be configured to be electrically connected. The organic light emitting layer 150 may include a plurality of organic material layers 151 and 153 and a light emitting layer 152 having a common layer structure. The organic material layer 151 between the first electrode 140 and the emission layer 152 may include a hole injection layer or a hole transport layer, and the organic material layer 153 between the second electrode 160 and the emission layer 152 is an electron injection layer. layer or an electron transport layer. In addition, the light-emitting layer 152 may include a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer, each of which may be formed of a red light-emitting material, a green light-emitting material, and a blue light-emitting material, The light emitting material may be formed using a phosphorescent material.

In addition, in the organic light emitting display device according to various examples of the present specification, the conductive layer 145 may be implemented such that a voltage lower than the voltage of the second electrode 160 or the turn-on voltage of the organic light emitting layer 150 is applied.

For example, the conductive layer 145 may be electrically connected to a terminal to which a voltage of the second electrode 160 is applied among various power supply lines disposed under the display area. Alternatively, the organic light emitting layer 150 may be electrically connected to a terminal to which a voltage lower than the turn-on voltage for emitting light is applied. Alternatively, the conductive layer 145 may be electrically connected to an external power supply line disposed outside the display area. For example, the power supply line in the display area may be a line for supplying the initialization voltage Vint or a line connected to a ground terminal. In addition, the external power supply line outside the display area may be a line for supplying a voltage to the second electrode 160 or a line connected to a separate DC power terminal.

As described above, the conductive layer 145 is formed to directly contact the organic emission layer 150 , and a voltage lower than the voltage of the second electrode 160 or the turn-on voltage of the organic emission layer 150 is applied to the conductive layer 145 . , horizontal leakage current generated in the organic light emitting layer 150 of the specific pixel area SP2 flows into the conductive layer 145 without flowing into the adjacent sub pixel areas SP1 and SP3 to the adjacent sub pixel area. It is possible to minimize the occurrence of leakage current.

The first electrode 140 may be formed on the insulating layer 135 . The first electrode 140 may be an anode electrode, may be formed of a conductive material having a relatively large work function value, and may serve to supply holes to the organic light emitting layer 150 .

A bank 170 may be formed on the first electrode 140 . The bank 170 may define an opening in the pixel area. The opening of the bank 170 covers the edge of the first electrode 140 and exposes a portion of the top surface of the first electrode 140 . Also, the bank 170 may divide a pixel area divided into a plurality of sub-pixel areas SP1 , SP2 , and SP3 . In the bank 170 , the conductive layer 145 is disposed under the first electrode 140 in the non-emission area NEA between the adjacent sub-pixel areas SP1 , SP2 , and SP3 with the insulating layer 135 interposed therebetween. A through portion 171 exposing a portion of the upper surface may be formed. The through portion 171 may be formed by etching the bank 170 and the insulating layer 135 . Also, the bank 170 may contact the organic light emitting layer 150 , and more specifically, may directly contact the organic material layer 151 of the organic light emitting layer 150 . The bank 170 may be made of an organic material. For example, the bank 170 may be made of polyimide, acryl, or benzocyclobutene (BCB)-based resin, but is not limited thereto.

The second electrode 160 may be formed on the organic emission layer 150 . The second electrode 160 may be a cathode electrode, and since electrons must be supplied to the organic light emitting layer 150 , it may be formed of a conductive material having a low work function. For example, the second electrode 160 may be a metal material such as magnesium (Mg) or silver-magnesium (Ag:Mg), but is not limited thereto. In addition, when the organic light emitting diode display according to various examples of the present specification is driven by a top emission method, the second electrode 160 may be formed of indium tin oxide (ITO) or indium zinc oxide (Indium). Zin Oxide (IZO), Indium Tin Zinc Oxide (ITZO), Zinc Oxide (ZnO), or Tin Oxide (TiO) series of transparent conductive oxides, but is not limited thereto. .

The organic light emitting part 150 may be formed between the first electrode 140 and the second electrode 160 . The organic light emitting unit 150 may include various organic material layers 151 and 153 as necessary, and may also include the light emitting layer 152 . The organic material layer 151 between the first electrode 140 and the emission layer 152 may include a hole injection layer or a hole transport layer, and the organic material layer 153 between the second electrode 160 and the emission layer 152 is an electron injection layer. layer or an electron transport layer. The plurality of organic material layers 151 and 153 may have a common layer structure to correspond to all of the plurality of sub-pixel areas SP1 , SP2 , and SP3 .

Hereinafter, a structure of an organic light emitting diode display according to various examples of the present specification will be described in detail with further reference to FIGS. 4 to 8 . 4 is a plan view illustrating a planar structure of an organic light emitting diode display according to various examples of the present specification. 5 is a cross-sectional view illustrating a cross-sectional structure of an organic light emitting diode display according to various examples of the present specification illustrated in FIG. 4 . 6 to 8 are plan views illustrating a device arrangement structure of an organic light emitting diode display according to various examples of the present specification illustrated in FIG. 4 . 4 illustrates the planar structure of the organic light emitting display device before the organic light emitting layer and the second electrode are disposed on the first electrode and the bank. The cross-sectional structure of the organic light emitting diode display is shown in the region where the thin film transistors are overlapped under each other. The components described in this specification are not limited to the arrangement of the components shown in FIGS. 4 to 8 and may be formed in various ways.

Referring to FIG. 4 , an organic light emitting diode display according to various examples of the present specification may include a plurality of pixel regions including a first electrode 140 forming region and a bank 170 forming region. In the drawings, a case in which the pixel area has a substantially polygonal shape and is arranged in a pentile matrix is illustrated as an example, but the present invention is not limited thereto. That is, the pixel area may have various shapes and various arrangements. For example, the pixel area may have various planar shapes such as a rectangle, a circle, an ellipse, and a polygon. In addition, any one of the pixel areas may have a size different from that of the other one, and may have a different planar shape. The planar shape of the pixel area may be determined by the planar shape of the bank.

A bank 170 is formed to overlap one side of the first electrode 140 to surround the first electrode 140 , and the bank 170 defines a pixel area of the organic light emitting diode display. That is, an organic light emitting layer is formed on the first electrode 140 exposed by the bank 170 , and light can be emitted in the corresponding region.

A conductive layer 145 separated and disposed with an insulating layer 135 interposed therebetween may be formed under the first electrode 140 , and disposed under the first electrode 140 in the bank 170 between the pixel regions. A through portion 171 exposing a portion of the upper surface of the conductive layer 145 may be formed.

The first electrode 140 has a contact hole 141 penetrating through the planarization layer 130 and the insulating layer 135 positioned between the thin film transistor and the thin film transistor, and the first electrode 140 forms the contact hole 141 through the first electrode 140 . may be electrically connected to the thin film transistor through the

In the conductive layer 145 , a contact hole 146 passing through the planarization layer 130 is formed, and the conductive layer 145 is disposed on the same layer or a different layer from the thin film transistor in the display area through the contact hole 146 . It can be electrically connected to the specified power supply line.

Referring to FIG. 5 , an organic light emitting diode display according to various examples of the present specification includes a substrate 110 , a buffer layer 111 , a thin film transistor 120 , a gate insulating layer 112 , an interlayer insulating layer 113 , and a planarization layer ( 130 , a conductive layer 145 , an insulating layer 135 , a first electrode 140 , and a bank 170 .

The substrate 110 serves to support and protect various components of the organic light emitting diode display. The substrate 110 may be made of an insulating material, and may be made of, for example, glass, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or a polyimide-based plastic substrate. When the organic light emitting display device is a flexible organic light emitting display device, it may be made of a flexible plastic material.

A buffer layer 111 may be formed on the substrate 110 to block penetration of the substrate 110 and impurity elements from the outside and to protect various components of the organic light emitting diode display. The buffer layer 111 may be formed of, for example, a single layer or a multilayer structure of a silicon oxide layer (SiOx) or a silicon nitride layer (SiNx). The buffer layer 111 may be omitted depending on the structure or characteristics of the organic light emitting diode display.

The thin film transistor 120 may be formed on the buffer layer 111 . The thin film transistor 120 may supply a signal to the organic light emitting layer. The thin film transistor 120 may include an active layer 121 , a gate electrode 122 , a source electrode 123 , and a drain electrode 124 . Specifically, the active layer 121 may be formed on the buffer layer 111 , and a gate insulating layer 112 for insulating the active layer 121 and the gate electrode 122 may be formed on the active layer 121 . . In addition, the gate electrode 122 may be formed on the gate insulating layer 112 to overlap the active layer 121 , and an interlayer insulating layer 113 may be formed on the gate electrode 122 and the gate insulating layer 112 . A source electrode 123 and a drain electrode 124 may be formed on the interlayer insulating layer 113 . The source electrode 123 and the drain electrode 124 may be electrically connected to the active layer 121 .

The active layer 121 may be formed of amorphous silicon (a-Si), polycrystalline silicon (poly-Si), an oxide semiconductor, or an organic semiconductor. When the active layer 121 is made of an oxide semiconductor, any one of Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Zinc Tin Oxide (ZTO), Indium Gallium Zinc Oxide (IGZO), or Indium Tin Zinc Oxide (ITZO) It may be made of a single material, but is not limited thereto.

The gate insulating layer 112 may be formed in a single-layer or multi-layer structure made of an inorganic insulating material such as a silicon oxide layer (SiOx) or a silicon nitride layer (SiNx).

The gate electrode 122 transmits a gate signal to the thin film transistor 120 and is made of at least one metal or alloy of aluminum (Al), molybdenum (Mo), titanium (Ti), and copper (Cu). and may be formed in a single-layer or multi-layer structure of the metal or material, but is not limited thereto.

The source electrode 123 and the drain electrode 124 may serve to transmit an external electrical signal from the thin film transistor 120 to the organic light emitting layer. The source electrode 123 and the drain electrode 124 may be made of at least one metal or alloy of aluminum (Al), molybdenum (Mo), titanium (Ti), and copper (Cu), and may be formed of a single metal or material. It may be formed in a layered or multi-layered structure, but is not limited thereto.

In this specification, only the driving thin film transistor 120 connected to the first electrode 140 is illustrated among various thin film transistors 120 that may be included in the organic light emitting diode display for convenience of description. Each pixel area may further include a switching thin film transistor or a capacitor. In addition, although the thin film transistor 120 is described as having a coplanar structure in this specification, the thin film transistor 120 having an inverted staggered structure may also be used. In addition, although a structure in which the first electrode 140 is connected to the source electrode 123 of the thin film transistor 120 is illustrated in the drawing, the first electrode 140 is the drain electrode 124 of the thin film transistor 120 according to the design. may be connected with

Various power supply lines 125 may be formed on the buffer layer 111 to be electrically separated from the thin film transistor 120 . For example, the power supply line 125 may be a line for supplying the initialization voltage Vint to the organic light emitting diode or a line connected to a ground terminal. Alternatively, the power supply line 125 may be a line that is disposed outside the display area and is electrically connected to a power supply pad that supplies a voltage to the second electrode. For example, a voltage lower than the voltage of the second electrode or the turn-on voltage of the organic light emitting layer may be applied to the power supply line 125 . As another example, it may be a line connected to a separate DC power terminal.

A planarization layer 130 may be formed on the thin film transistor 120 . The planarization layer 130 is a layer that planarizes the upper portion of the substrate 110 , and may function as a planarization layer. The planarization layer 130 includes a contact hole 141 for electrically connecting the first electrode 140 and the source electrode 123 of the thin film transistor 120 , the conductive layer 145 and the power supply line 125 . A contact hole 146 for electrically connecting may be included.

A conductive layer 145 may be formed on the planarization layer 130 . As shown in FIG. 6 , the conductive layer 145 may be formed in a flat plate shape over the entire surface of the planarization layer 130 . Also, the conductive layer 145 may include a plurality of opening patterns 147 . The plurality of opening patterns 147 of the conductive layer 145 may be located in a region where the first electrode 140 and the thin film transistor 120 overlap each other. That is, the first electrode 140 may be electrically connected to the thin film transistor 120 through the contact holes 141 formed at positions corresponding to the plurality of opening patterns 147 of the conductive layer 145 .

An insulating layer 135 may be formed on the conductive layer 145 , and the first electrode 140 may be formed with the insulating layer 135 interposed therebetween. As shown in FIG. 7 , the first electrode 140 may be formed on the insulating layer 135 in an island pattern corresponding to the pixel area. Since the first electrodes 140 are disposed separately from each other, they may be referred to as a patterned electrode or an electrode having a patterned structure.

The first electrode 140 may be formed using a mask, for example, a fine metal mask (FMM), opened for each pixel region, and has a separate structure for each pixel region. That is, the pattern structure of the first electrode 140 has a structure in which one pixel area is not connected to an adjacent pixel area and is disconnected.

In the organic light emitting diode display according to various examples of the present specification, the conductive layer 145 and the first electrode 140 are formed of a transparent conductive material in the first electrode having a conventional multilayer structure in which a transparent conductive layer and a reflective layer are sequentially stacked. The first electrode 140 and the conductive layer 145 made of a reflective conductive material may be disposed to be separated with the insulating layer 135 interposed therebetween. For example, the first electrode 140 may be formed of a transparent conductive material, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or the like. have. In addition, the insulating layer 135 may be formed in a single-layer or multi-layer structure made of an inorganic insulating material such as a silicon oxide layer (SiOx) or a silicon nitride layer (SiNx). In addition, the conductive layer 145 is formed of a reflective conductive material, and may be made of, for example, aluminum (Al), silver (Ag), copper (Cu), nickel (Ni), or an alloy thereof, preferably It may be made of APC (Ag/Pd/Cu). However, the present invention is not limited thereto, and when the organic light emitting diode display is driven by a bottom emission method, the conductive layer 145 may be formed of a transparent conductive material in the same manner as the first electrode 140 .

A bank 170 may be formed on the first electrode 140 . The bank 170 may define an opening in the pixel area. The opening of the bank 170 covers the edge of the first electrode 140 and exposes a portion of the top surface of the first electrode 140 . Also, the bank 170 may divide pixel areas. As shown in FIG. 8 , the bank 170 is formed on the insulating layer 135 and the first electrode 140 formed by patterning on the insulating layer 135 , and is formed on the first electrode 140 through an etching process. An opening exposing a portion of the upper surface and a through portion 171 exposing a portion of the upper surface of the conductive layer 145 disposed below the first electrode 140 with the insulating layer 135 interposed therebetween may be formed. That is, the bank 170 defines a pixel region through an opening exposing a portion of the upper surface of the first electrode 140 , and a through-portion (exposing a portion of the upper surface of the conductive layer 145 ) between adjacent pixel regions. 171), a boundary between pixel areas may be defined.

Referring back to FIG. 5 , in the organic light emitting diode display according to various examples of the present specification, the conductive layer 145 is positioned under the first electrode 140 and the bank 170 , and corresponds to each sub-pixel area. The first electrode 140 on the conductive layer 145 is formed in the form of a single common layer having an area that can encompass a plurality of sub-pixel regions, as shown in FIG. 6 , ) and the thin film transistor 120 may be electrically connected to each other, and a plurality of opening patterns 147 may be formed. A portion of the upper surface of the conductive layer 145 may be exposed to the outside through the through portion 171 penetrating the bank 170 and the insulating layer 135 . This may be connected by direct contact with the organic emission layer formed on the first electrode 140 and the bank 170 .

The conductive layer 145 may include a contact hole 146 penetrating the planarization layer 130 , and various power supply lines 125 and contact holes 146 that are electrically separated from the thin film transistor 120 . can be electrically connected through For example, the power supply line 125 may be a line for supplying the initialization voltage Vint to the organic light emitting diode or a line connected to a ground terminal. Alternatively, the power supply line 125 may be a line that is disposed outside the display area and is electrically connected to a power supply pad that supplies a voltage to the second electrode. For example, a voltage lower than the voltage of the second electrode or the turn-on voltage of the organic light emitting layer may be applied to the power supply line 125 . As another example, it may be a line connected to a separate DC power terminal.

In the first electrode 140 , a contact hole 141 passing through the insulating layer 135 and the planarization layer 130 is formed at a position corresponding to the plurality of opening patterns 147 of the conductive layer 140 , and the thin film transistor ( It may be electrically connected to the source electrode 123 of the 120 .

In the case of the conventional organic light emitting diode display, it is difficult to improve the horizontal leakage current because an area in which an electrode or a wiring can be formed is insufficient as the resolution increases. However, in the case of the organic light emitting display device according to various examples of the present specification, the first electrode 140 made of a transparent conductive material and a reflective conductive material are used in the conventional first electrode having a multilayer structure in which a transparent conductive layer and a reflective layer are sequentially stacked. The conductive layer 145 made of the insulating film 135 is disposed therebetween, and the bank 170 is formed so that the conductive layer 145 under the first electrode 140 directly contacts the organic light emitting layer, thereby horizontal leakage. By allowing the current to flow through the conductive layer 145 instead of flowing into the adjacent pixel area, unwanted adjacent pixels due to horizontal leakage current emit light even if the distance between the pixel areas becomes narrow as the resolution of the organic light emitting diode display increases. phenomenon can be minimized. Through this, the display quality of the organic light emitting diode display may be improved by reducing color mixture between adjacent sub-pixels, and reliability of the organic light emitting display may be improved in low grayscale. In addition, since the conductive layer 145 of the organic light emitting diode display simultaneously functions as a reflective layer and suppresses horizontal leakage current, luminous efficiency by the reflective layer is improved and a process margin between sub-pixels can be minimized. It may be advantageous for realizing an organic light emitting diode display.

An organic light emitting diode display according to an example of the present specification may be described as follows.

The organic light emitting diode display according to various examples of the present specification may include a substrate, a pixel region on the substrate, a bank disposed on the substrate and defining an opening of the pixel region, a first electrode disposed in the opening of the pixel region, and the an organic light-emitting layer disposed on the first electrode, a second electrode disposed on the organic light-emitting layer, and a conductive layer disposed under the first electrode, wherein the organic light-emitting layer is coupled to the conductive layer through the bank can be electrically connected.

In the organic light emitting diode display according to various examples of the present specification, the conductive layer may be disposed to be separated from the first electrode with an insulating layer interposed therebetween.

In the organic light emitting display device according to various examples of the present specification, the conductive layer and the organic light emitting layer may be connected to each other through a penetrating portion penetrating the bank and the insulating layer.

In the organic light emitting diode display according to various examples of the present specification, the first electrode may be formed of a transparent conductive material.

In the organic light emitting diode display according to various examples of the present specification, the conductive layer may be formed of a reflective conductive material.

The organic light emitting diode display according to various examples of the present specification may be implemented such that a voltage lower than a voltage of the second electrode or a turn-on voltage of the organic light emitting layer is applied to the conductive layer.

In the organic light emitting diode display according to various examples of the present specification, the conductive layer may overlap the first electrode and the bank.

The organic light emitting diode display according to various examples of the present specification may further include a planarization layer and a thin film transistor under the conductive layer, and the conductive layer may be formed on the planarization layer in the form of a flat plate having a plurality of opening patterns. have.

In the organic light emitting diode display according to various examples of the present specification, the plurality of opening patterns may be located in a region where the first electrode and the thin film transistor overlap each other.

In the organic light emitting diode display according to various examples of the present specification, the first electrode may be electrically connected to the thin film transistor through contact holes formed at positions corresponding to the plurality of opening patterns.

The organic light emitting diode display according to various examples of the present specification further includes a power supply line disposed under the conductive layer while overlapping the bank, wherein the conductive layer includes a contact hole formed at a position corresponding to the power supply line. may be electrically connected to the power supply line through the

In the organic light emitting display device according to various examples of the present specification, the power supply line may be implemented to apply a voltage lower than a voltage of the second electrode or a turn-on voltage of the organic light emitting layer.

In the organic light emitting diode display according to various examples of the present specification, the first electrode may be formed in an island pattern corresponding to the pixel area.

The organic light emitting display device according to various examples of the present specification further includes at least one organic material layer formed between the organic light emitting layer and the first electrode or the second electrode, wherein the organic material layer includes at least one of a hole injection layer and a hole transport layer. may include

In the organic light emitting diode display according to various examples of the present specification, the organic material layer may be directly connected to the conductive layer through the bank.

In the organic light emitting display device according to various examples of the present specification, the organic light emitting layer includes a red light emitting layer, a green light emitting layer, and a blue light emitting layer, and the red light emitting layer, the green light emitting layer, and the blue light emitting layer may comprise at least one phosphorescent material.

Features, structures, effects, etc. described in various examples of the present specification are included in at least one example of the present specification, and are not necessarily limited to only one example. Furthermore, features, structures, effects, etc. illustrated in at least one example of the present specification may be combined or modified with respect to other examples by those of ordinary skill in the art to which this specification belongs. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present specification.

The present specification described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the technical field to which this specification belongs that various substitutions, modifications and changes are possible within the scope without departing from the technical details of the present specification. It will be clear to those who have the knowledge of Therefore, the scope of the present specification is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present specification.

100: organic light emitting display device
110: substrate
120: thin film transistor
130: planarization layer
145: conductive layer
140: first electrode
150: organic light emitting layer
160: second electrode
170: bank

Claims (16)

Board;
a pixel area on the substrate;
a bank disposed on the substrate and defining an opening of the pixel area;
a first electrode disposed in the opening of the pixel area;
an organic light emitting layer disposed on the first electrode;
a second electrode disposed on the organic light-emitting layer; and
a conductive layer disposed under the first electrode;
and the organic light emitting layer is electrically connected to the conductive layer through the bank. According to claim 1,
and the conductive layer is disposed to be separated from the first electrode with an insulating layer interposed therebetween. 3. The method of claim 2,
and the conductive layer and the organic light emitting layer are connected through a through portion penetrating the bank and the insulating layer. According to claim 1,
and the first electrode is made of a transparent conductive material. According to claim 1,
and the conductive layer is made of a reflective conductive material. According to claim 1,
and a voltage lower than a voltage of the second electrode or a turn-on voltage of the organic light emitting layer is applied to the conductive layer. According to claim 1,
and the conductive layer overlaps the first electrode and the bank. According to claim 1,
A planarization layer and a thin film transistor are further included under the conductive layer,
The conductive layer is formed in a flat panel shape having a plurality of opening patterns on the planarization layer. 9. The method of claim 8,
and the plurality of opening patterns are located in a region where the first electrode and the thin film transistor overlap each other. 10. The method of claim 9,
and the first electrode is electrically connected to the thin film transistor through contact holes formed at positions corresponding to the plurality of opening patterns. 9. The method of claim 8,
Further comprising a power supply line disposed under the conductive layer while overlapping the bank,
and the conductive layer is electrically connected to the power supply line through a contact hole formed at a position corresponding to the power supply line. 12. The method of claim 11,
The power supply line is configured to apply a voltage lower than a voltage of the second electrode or a turn-on voltage of the organic light emitting layer. According to claim 1,
and the first electrode is formed in an island pattern corresponding to the pixel area. According to claim 1,
At least one organic material layer formed between the organic light emitting layer and the first electrode or the second electrode,
The organic material layer includes at least one of a hole injection layer and a hole transport layer. 14. The method of claim 13,
and the organic layer is directly connected to the conductive layer through the bank. According to claim 1,
The organic light emitting layer includes a red light emitting layer, a green light emitting layer and a blue light emitting layer,
The red light emitting layer, the green light emitting layer, and the blue light emitting layer include at least one phosphorescent material.

Images