KR20160140157A

KR20160140157A - Organic light emitting diode display and manufacturing method of the same

Info

Publication number: KR20160140157A
Application number: KR1020150076415A
Authority: KR
Inventors: 김태경; 최원열; 김병철; 허해리; 박희성
Original assignee: 엘지디스플레이 주식회사
Priority date: 2015-05-29
Filing date: 2015-05-29
Publication date: 2016-12-07

Abstract

According to an embodiment of the present invention, provided is an organic light emitting diode display device capable of minimizing the permeation of oxygen used for forming an oxide layer to an organic light emitting layer. Provided is a substrate where a plurality of organic light emitting elements and a plurality of driving elements are arranged and a display region is defined. An encapsulation layer is arranged on the substrate to protect the organic light emitting element. The encapsulation layer has a crack reduction section by a structure arranged on the outermost part of the substrate. In the organic light emitting diode display device according to an embodiment of the present invention, the reliability of the encapsulation layer is further improved by the structure arranged on the outermost part of the substrate and the crack reduction section.

Description

Technical Field [0001] The present invention relates to an organic light emitting diode (OLED) display device,

The present invention relates to an organic light emitting diode (OLED) display, and more particularly, to an organic light emitting diode (OLED) display capable of reducing cracks in an encapsulating layer protecting an organic light emitting layer from moisture and oxygen, and a method of manufacturing the same.

The organic light emitting diode (OLED) is a self-emissive type display device, and unlike a liquid crystal display (LCD), a separate light source is not required, so that it can be manufactured in a light and thin shape. Further, the organic light emitting display device is not only advantageous from the viewpoint of power consumption by low voltage driving, but also excellent in color implementation, response speed, viewing angle, and contrast ratio (CR), and is being studied as a next generation display.

The organic light emitting diode display includes a light emitting layer made of an organic material between an anode electrode and a cathode electrode. Here, the holes supplied from the anode electrode and the electrons supplied from the cathode electrode are combined in the light-emitting layer to form an excitation as a hole-electron pair, and the light-emitting layer emits light due to the energy generated when the excitons return to the ground state do.

However, organic light emitting display devices are extremely vulnerable to oxygen, moisture, and the like because organic materials are used as the light emitting layer. Accordingly, various techniques for sealing the organic light emitting device have been used to minimize penetration of oxygen, water, etc. from the outside into the organic light emitting layer.

BACKGROUND ART [0002] In recent years, a thin film encapsulation technique in which an inorganic material and an organic material are alternately stacked is widely used. What is the thin film seal layer using inorganic and organic materials? It is excellent in the ability to prevent penetration of oxygen and moisture while having a thickness.

Chemical vapor deposition (CVD) may be used to alternately deposit inorganic and organic materials, but active application studies of atomic deposition (ALD) have been conducted in recent years.

However, in a process of alternately depositing organic and inorganic materials on a substrate including an organic light emitting device, and then performing additional processes such as adhesion and cutting performed on a subsequent substrate, or in the process of using the organic light emitting display device, There is a possibility that oxygen and moisture permeate into the generated cracks and the reliability of the organic light emitting device is deteriorated.

[Related Technical Literature]

[Patent Literature]

1. Display (Patent Application No. 10-2011-0135824)

As described above, cracks may occur in a manufacturing process performed after forming a thin-film encapsulating layer in a thin-film encapsulating layer using an inorganic material and an organic material for encapsulating an organic light-emitting device and minimizing penetration of oxygen and moisture. A step of disposing a driving element, an organic light emitting element, and the like on a mother substrate on which a plurality of substrates are defined, disposing a thin film sealing layer, and cutting the substrate into a plurality of substrates can be performed. In addition, cracks may occur in the thin film encapsulation layer due to an impact that may occur in an environment where the user uses the organic light emitting display device.

Such cracks that can occur generally lead to progressive cracks that occur at the uppermost end of the substrate and proceed to the center of the OLED display.

Oxygen and moisture may penetrate into the cracks generated in the thin film encapsulation layer to shorten the lifetime of the organic light emitting device and thus the reliability of the organic light emitting display device may be deteriorated.

Accordingly, the inventors of the present invention have invented a new structure and method of an organic light emitting display device capable of reducing cracks in a thin film encapsulation layer.

SUMMARY OF THE INVENTION The present invention provides an OLED display capable of minimizing cracks and progressive cracks that may occur during a process performed on a substrate including a thin-film encapsulation layer, and a method of manufacturing the OLED display.

Another object of the present invention is to provide an organic light emitting display device and a method of manufacturing the same, which can reduce the manufacturing cost by improving the reliability of the thin film sealing layer and improving the process stability performed on the substrate.

The solutions according to one embodiment of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

There is provided an organic light emitting display device in which cracks in a sealing layer can be minimized by disposing a structure and a crack reduction section according to an embodiment of the present invention. An encapsulation layer is disposed on a substrate including a display region in which a plurality of organic light emitting elements and a plurality of driving elements are arranged to cover the organic light emitting element. The structure is disposed at the outermost portion of the substrate, and the sealing layer has a crack-reducing section that can facilitate the process performed on the substrate, so that the reliability of the sealing layer can be improved.

A method of manufacturing an organic light emitting display device according to an embodiment of the present invention is provided. A driving element and an organic light emitting element are formed on a mother substrate on which at least one substrate is defined. A structure is formed on the outermost part of the substrate defined on the mother substrate. An encapsulating layer is formed on the organic light emitting element. Separate the substrate from the mother board with respect to the structure. In the method of manufacturing an organic light emitting diode display according to an embodiment of the present invention, cracks that may occur in the sealing layer can be minimized during the process of separating the substrate from the mother substrate with reference to the structure, The reliability of the sealing layer can be improved.

According to the embodiment of the present invention, cracks that may occur in the sealing layer can be reduced by providing a crack-reducing section by the structure.

In addition, the crack reducing section minimizes crack generation and propagation in a subsequent process applied to a substrate, thereby enhancing process stability and reducing manufacturing cost.

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

The scope of the claims is not limited by the matters described in the contents of the invention, as the contents of the invention described in the problems, the solutions to the problems and the effects to be solved do not specify essential features of the claims.

FIG. 1A is a schematic cross-sectional view illustrating an OLED display including a structure and a crack reduction section according to an embodiment of the present invention. Referring to FIG.
FIG. 1B is a schematic cross-sectional view illustrating an organic light emitting display including an encapsulation layer and a crack reduction section according to an embodiment of the present invention. Referring to FIG.
FIG. 1C is a schematic cross-sectional view of an OLED display for explaining another structure of a crack encapsulation layer and a reduction section according to an embodiment of the present invention.
FIG. 2 is a schematic plan view of an organic light emitting display device for explaining a layout relationship of structures disposed on a substrate according to an embodiment of the present invention. Referring to FIG.
3 is a flowchart illustrating a method of manufacturing an organic light emitting display including a structure according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. Like reference numerals refer to like elements throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Where the terms "comprises", "having", "done", and the like are used in this specification, other portions may be added unless "only" is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Alternatively, one or more other parts may be located between the two parts, unless the direct? Is used.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other, partially or wholly, technically various interlocking and driving, and that the embodiments may be practiced independently of each other, It is possible.

Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1A is a schematic cross-sectional view illustrating an OLED display including a structure and a crack reduction section according to an embodiment of the present invention. Referring to FIG.

1A, a display region 120 is defined on a substrate 100, and a driving device 121, an organic light emitting device 122, an encapsulating layer 123, a planarizing layer 123, 124, a bank layer 125, a structure 130, and a crack reduction section 140.

A driving element 121 is disposed on a substrate 110, and a flat layer 124 is disposed. The planarizing layer 124 is a layer for arranging the organic light emitting elements, and is disposed so that the driving elements 121 and the organic light emitting elements 122 can be connected. The bank layer 125 is disposed between the organic light emitting elements 122 so that a plurality of pixels can be defined in the display region 120 and the sealing layer 123 is disposed on the organic light emitting element 122.

The substrate 110 may further include a barrier layer for further blocking oxygen and moisture. A plurality of pixels are defined in the display region 120 defined in the substrate 110, and a bank layer 125 The separate organic light emitting elements 122 and individual pixels correspond to each other. The driving element 121 and the organic light emitting element 122 are schematically illustrated. However, the substrate 110 may further include a plurality of wiring electrodes, and the driving element 121 may receive signals and currents from the wiring electrodes.

1A, a thin film transistor (TFT) and a capacitor CST are positioned as a driving element 121 on a substrate 110. [ The driving element 121 may further include a semiconductor layer, a gate electrode, and a source / drain electrode.

The organic light emitting device 122 includes a pixel electrode, an organic light emitting layer, and a common electrode, and injects electrons and holes from the pixel electrode and the common electrode into the organic light emitting layer, thereby emitting light.

The organic light emitting layer includes a hole injection layer, a hole transporting layer, an emitting material layer, an electron transporting layer, and an electron injection layer, As shown in FIG.

The organic luminescent layer is weak in structure due to oxygen and moisture, and the electrode included in the organic luminescent layer is oxidized by oxygen and moisture, resulting in deterioration of luminous efficiency or defects such as a dark spot.

An encapsulation layer 123 is disposed on the substrate 110 so as to cover the organic light emitting device 122. The sealing layer may be a multi-layer structure comprising at least one inorganic layer and at least one organic layer so as to lower the permeation rate through which oxygen is permeated and the moisture absorption rate through which moisture permeates.

The organic material layer included in the sealing layer 123 may be an organic material based on a polyethylene-based resin, and the inorganic material layer may be an aluminum, tin, zinc, or an alloy film based on at least one of them.

FIG. 1A schematically shows an organic light emitting display 100, and may include but is not limited to an upper substrate, a color filter, a touch electrode, and the like, which are opposite to the substrate 110.

A crack 130 is disposed at the outermost portion of the substrate 110 and adjacent to the structure 130.

An organic luminescent layer 122 and an encapsulating layer 123 are disposed from a driving element 121 on a mother substrate having a plurality of substrates 110 defined therein in various methods for manufacturing one substrate 110, A method of separating the substrate 110 through a scribing process can be used. The manufacturing method will be described again later.

The sealing layer 123 protecting the organic light emitting diode 122 may be cracked due to a physical impact in the above-described process, for example, a scribing process performed on the substrate 110, The cracks may progress into the display area 120 or oxygen and moisture may penetrate through the generated micro cracks.

The structure 130 is disposed outside the display area 120 and the crack reduction section 140 in which the sealing layer 123 is discontinuous can be disposed adjacent to the structure 130 or from the side of the structure 130 have.

A method of disposing the crack reduction section 140 will be described later.

The structure 130 may be disposed at the outermost portion of the substrate 110 and may be coincided with the left and right cut surfaces of the substrate 110 and one side of the structure 130. One side of the structure 130 may be a cut surface of the substrate 110, And the like.

The structure 130 may have an inverted tapered shape on the substrate 110 in the direction of the display region 120 and the structure 130 may have an undercut Pattern.

The structure 130 may be substantially the same material as the bank layer disposed on the substrate 110 and may include two layers that are responsive to different etchants or have different etch rates.

In recent years, organic light emitting display devices in which a region other than the display region 120 defined on the substrate 110 is minimized, and organic light emitting display devices such as Narrow-bezel or Bezelless organic light emitting display devices popular.

The minimum structure of the structure 130 for disposing the crack reduction section 140 in the outer portion of the display region 120 of the substrate 110 is arranged in a range of 20 to 100 μm considering a scribe alignment error and a screed damage region. do.

FIG. 1B is a schematic cross-sectional view for explaining an organic light emitting diode display including an encapsulation layer and a crack reduction section according to an embodiment of the present invention. FIG. 1C is a cross- Sectional view of an organic light emitting display device for explaining another structure of the organic light emitting display according to the present invention.

In describing the present embodiment, description of the same or corresponding elements to those of the previous embodiment will be omitted. Hereinafter, a structure disposed on the substrate according to the present embodiment will be described with reference to the drawings.

1B and 2C, the sealing layer 123 disposed in the OLED display 100 includes an inorganic layer 123a and an inorganic layer 123b. The crack layer 140 is disposed on the sealing layer 123 disposed on the upper side of the structure 130 by the structure 130.

The inorganic layer 123a of the inorganic layer 123a and the organic layer 123b is generally more susceptible to cracking than the organic material due to the nature of the inorganic substance and the crack generated once is propagated from the inorganic layer 123a to form the display region 120 ), Oxygen and moisture permeate into the surface.

1C, the organic material layer 123b extends to the upper end of the structure 130. As shown in FIG. 1C, the organic material layer 123b extends to the upper end of the structure 130, Can be arranged continuously.

That is, the crack reduction section 140 may include a discontinuous section of the inorganic material layer 123a, and the organic material layer 123b may not be discontinuous.

FIG. 2 is a schematic plan view of an organic light emitting display device for explaining a layout relationship of structures disposed on a substrate according to an embodiment of the present invention. Referring to FIG.

2, the OLED display 200 includes a display area 220 on a substrate 210 and a structure 230 on the outside of the display area 220.

The structure 230 may be disposed to coincide with the cut surface of the substrate 210 and may be disposed on the side of the substrate 210 on which the cutting process is performed, .

3 is a flowchart illustrating a method of manufacturing an organic light emitting display including a structure according to an embodiment of the present invention.

First, an organic light emitting element and a driving element are formed on a mother substrate (S310). At least one substrate is defined so that the mother substrate can be separated into a single substrate at a later time, a driving device is formed on the mother substrate, and a flat layer and an organic light emitting device are formed.

Then, a structure is formed (S320). A structure is formed on the substrate defined on the mother substrate, and then the structure is formed to correspond to the separation line separating the substrate from the mother substrate. The structure may be formed in an inverted tapered shape using a negative PR that does not dissolve in a specific solution in response to a wavelength such as UV. In order to form a structure having a reverse taper shape, a negative PR is applied to a substrate and then partially cured at a certain temperature and irradiated with UV light. When irradiated with UV light, UV is irradiated so that the structure has a reverse tapered shape When the angle is adjusted and the Developing process is used after curing, a reverse tapered structure can be formed.

Subsequently, an encapsulating layer is formed (S330). The sealing layer may be deposited as a single layer or a plurality of layers including an inorganic layer or an organic layer, and may be formed to cover the organic light emitting layer formed on the mother substrate using a CVD process or an ALD process. The inorganic layer is discontinued in some sections due to the structure disposed on the substrate in the forming step so that a crack reducing section is formed.

Thereafter, the mother substrate is scribed to separate the substrate (S340). The scribe line separating the substrate from the mother substrate can be made to coincide with the structure, and the crack can be cracked into the encapsulation layer by the crack reducing section formed by the structure. Thereby minimizing propagation.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

100, 200: organic light emitting display
110, 210: substrate
120, 220: display area
121: Driving element
122: Organic light emitting device
123: encapsulation layer
124: flat layer
125: bank layer
130, 230: Structure
140: Crack reduction section

Claims

A substrate including a display region in which a plurality of organic light emitting elements and a plurality of driving elements are arranged;
A sealing layer disposed on the substrate so as to cover the organic light emitting device; And
And a structure disposed on the substrate,
Wherein the structure is disposed at an outermost portion of the substrate,
Wherein the encapsulation layer has a crack-reducing period by the structure to facilitate a process performed on the substrate.

The method according to claim 1,
Wherein the sealing layer is a single layer structure or a multi-layer structure including at least two layers.

3. The method of claim 2,
Wherein the sealing layer comprises at least one organic material layer and at least one inorganic material layer.

The method of claim 3,
Wherein the crack reduction period is a period in which the inorganic material layer is broken.

3. The method of claim 2,
Wherein the crack reduction period is a period in which at least one layer included in the encapsulation layer is broken.

The method according to claim 1,
Further comprising a flat layer and a bank layer on the substrate,
Wherein the structure includes the same material as the flat layer or the bank layer.

The method according to claim 6,
Wherein the structure is a multi-layer structure including at least two layers having at least different etching rates or reacting with different etching solvents.

8. The method of claim 7,
Wherein the structure is a reverse tapered structure.

The method according to claim 6,
Wherein the sealing layer covers an upper end of the structure.

The method according to claim 6,
Wherein the structure is disposed at selected edges of upper, lower, left and right edges of the substrate.

11. The method of claim 10,
Wherein one side of the structure and one side of the substrate have the same cutting pattern.

Forming a driving element and an organic light emitting element on a mother substrate on which at least one substrate is defined;
Forming a structure on a substrate in an area including the outermost portion of the substrate;
Forming an encapsulation layer on the organic light emitting device; And
And separating the substrate from the mother substrate on the basis of the structure.

13. The method of claim 12,
Wherein the forming of the structure comprises forming a reverse tapered section in the structure.

13. The method of claim 12,
Wherein the step of separating the substrate from the mother substrate includes a scribing step, wherein the scribing step includes a laser scribing method and a wheel scribing method.

15. The method of claim 14,
Wherein the step of separating the substrate from the mother substrate comprises scribing the substrate on the structure to separate the substrate.

13. The method of claim 12,
Wherein the step of forming an encapsulation layer on the organic light emitting device includes forming an upper end of the structure, and forming a crack reduction section.