KR102735982B1 - Organic light emitting display device - Google Patents

Abstract

The present invention relates to an organic light-emitting display device and a manufacturing method thereof. The organic light-emitting display device according to the present invention includes a first bank provided on one side and the other side of an anode electrode, a second bank provided to expose an edge of the first bank, and an organic light-emitting layer provided on an upper surface of the anode electrode and an upper surface of the first bank, wherein the first bank and the second bank are formed of an organic material. In addition, the manufacturing method of the organic light-emitting display device according to the present invention includes a process of forming a first bank on one side and the other side of an anode electrode and forming a second bank on the first bank to expose an edge of the first bank, and is characterized by forming an organic light-emitting layer up to an upper surface of the exposed first bank. Through this, the anode electrode can be prevented from being damaged during the process of forming the banks, and the organic light-emitting layer can be formed flatly on the upper surface of the anode electrode to realize uniform brightness.

Description

ORGANIC LIGHT EMITTING DISPLAY DEVICE

The present invention relates to a display device, and more specifically, to an organic light emitting display device and a method for manufacturing the same.

Flat panel displays include liquid crystal display devices (LCDs), plasma display panel devices (PDPs), and organic light emitting display devices (OLEDs). Recently, electrophoretic display devices (EPDs) have also been widely used.

Among these, organic light-emitting display devices are attracting attention as next-generation flat panel display devices because they are self-luminous elements and have low power consumption, high-speed response speed, high luminance efficiency, high brightness, and wide viewing angle.

In particular, in order to increase the convenience and efficiency of the manufacturing process of organic light-emitting display devices, organic light-emitting display devices are being developed in which an organic light-emitting layer is formed using a material having soluble characteristics.

Figure 1 is a schematic cross-sectional view of a conventional available organic light emitting display device.

As can be seen in Fig. 1, a planarization layer (1), an anode electrode (2), a first bank (3), a second bank (4), an organic light-emitting layer (5), and a cathode electrode (6) are formed in sequence on a substrate (not shown).

The above-mentioned planarization layer (1) serves to planarize a thin film transistor layer (not shown) provided on the substrate, and the anode electrode (2) is formed on the above-mentioned planarization layer (1).

The first bank (3) and the second bank (4) are formed on the anode electrode (2) to define a pixel area. The first bank (3) and the second bank (4) are formed on one side and the other side of the anode electrode (2) while exposing the upper surface of the anode electrode (2). At this time, the first bank (3) is formed of an inorganic material.

The above organic light-emitting layer (5) is formed within the pixel area defined by the first bank (3) and the second bank (4), and the cathode electrode (6) is formed on the organic light-emitting layer (5).

Specifically, in the available organic light-emitting display device, in order to increase the convenience and efficiency of the manufacturing process, an organic light-emitting material having the property of availability is sprayed or dropped onto the pixel area defined by the first bank (3) and the second bank (4) using an inkjet printing method and then cured to form the organic light-emitting layer (5).

In particular, the conventional available organic light emitting display device forms the bank as a multi-layer of the first bank (3) and the second bank (4) as described above so as to prevent the pile up phenomenon of the organic light emitting layer (5).

The pile-up phenomenon means that when spraying organic light-emitting material using an inkjet printing method, the organic light-emitting layer (5) is formed thicker at the edge adjacent to the bank than at the center between the spaced banks. When the organic light-emitting layer (5) is formed unevenly like this, brightness unevenness occurs in the pixel area. Therefore, in order to prevent the pile-up phenomenon, banks are formed in multiple layers and organic light-emitting material is sprayed on the upper surface of the first bank (3) as well, so that the organic light-emitting layer (5) is formed flat on the upper surface of the anode electrode (2).

Conventional available organic light emitting display devices have the following problems:

As described above, after the planarization layer (1) and the thin film transistor layer, etc. are formed, the first bank (3) of the inorganic material must be deposited. However, if CVD (Chemical Vapor Deposition) is performed at a high temperature, the performance of the layers formed underneath may deteriorate, so in the past, CVD was performed at a low temperature of about 210°C to form the first bank (3).

And as the CVD was conducted in a low-temperature state, the film quality and adhesive strength of the first bank (3) were lowered compared to when it was formed in a high-temperature state, and as a result, a problem of peeling of the first bank (3) occurred in the finished product.

In addition, in the process of forming the first bank (3) by performing CVD, the first bank (3) must be patterned through a dry etching or wet etching process, so there was a problem of the anode electrode (2) being damaged during the etching process.

In addition, since the bank is formed in multiple layers as in the conventional method, the luminance unevenness in the light-emitting area can be resolved to some extent compared to the case where the bank is formed in a single layer, but there is still a problem that the organic light-emitting layer (5) formed in the light-emitting area is not formed flat.

The present invention has been designed to solve the above-mentioned conventional problems, and an object of the present invention is to provide an organic light-emitting display device and a manufacturing method thereof capable of preventing damage to an anode electrode during the process of forming a bank formed on an anode electrode and preventing peeling of the bank in a finished product.

In addition, the present invention aims to provide an organic light-emitting display device and a manufacturing method thereof in which an organic light-emitting layer is provided flatly on an anode electrode so as to realize uniform brightness.

To achieve the above object, an organic light-emitting display device according to one embodiment of the present invention includes a first bank provided on one side and the other side of an anode electrode, a second bank provided to expose an edge of the first bank, and an organic light-emitting layer provided on an upper surface of the anode electrode and an upper surface of the first bank, wherein the first bank and the second bank are provided with an organic material.

In addition, a method for manufacturing an organic light-emitting display device according to an embodiment of the present invention includes a process for forming banks on one side and the other side of an anode electrode, and a process for forming an organic light-emitting layer on an upper surface of the anode electrode, and in the process for forming the banks, a first bank is formed on one side and the other side of the anode electrode using a halftone mask, and a second bank is formed on the first bank so as to expose an edge of the first bank, and in the process for forming the organic light-emitting layer, the organic light-emitting layer is formed on an upper surface of the exposed first bank.

In addition, a method for manufacturing an organic light-emitting display device according to another embodiment of the present invention includes a process of forming a first bank provided with an organic material on one side and the other side of an anode electrode, a process of forming a second bank provided with an organic material on the first bank so as to expose an edge of the first bank, and a process of forming an organic light-emitting layer on an upper surface of the anode electrode and an upper surface of the exposed first bank.

According to the present invention as described above, the following effects are achieved.

According to an embodiment of the present invention, by forming a bank patterned on the upper surface of an anode electrode with an organic material, the anode electrode can be prevented from being damaged during the process of forming the bank, and peeling of the bank can be prevented.

In addition, according to an embodiment of the present invention, the upper part of the bank having a step structure is provided with a hydrophobic material and the lower part of the bank is provided with a hydrophilic material, so that an organic light-emitting layer can be formed flatly on the upper surface of the anode electrode and uniform brightness can be implemented.

In addition, according to an embodiment of the present invention, the side of the second bank formed to expose the edge of the first bank is inclined with respect to the surface of the substrate, thereby forming the organic light-emitting layer more flatly on the upper surface of the anode electrode, thereby realizing uniform brightness.

Figure 1 is a schematic cross-sectional view of a conventional available organic light emitting display device.
FIG. 2 is a cross-sectional view of an organic light emitting display device according to one embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view of an organic light emitting display device according to one embodiment of the present invention, showing area A illustrated in FIG. 2.
FIG. 4 is a schematic cross-sectional view of an organic light emitting display device according to another embodiment of the present invention, showing area A illustrated in FIG. 2.
FIG. 5 is a schematic cross-sectional view of an organic light emitting display device according to another embodiment of the present invention.
FIGS. 6A to 6J are process cross-sectional views showing a method for manufacturing an organic light-emitting display device according to one embodiment of the present invention.
FIGS. 7A to 7G are process cross-sectional views showing a manufacturing method for forming a bank of an organic light-emitting display device according to another embodiment of the present invention.

The advantages and features of the present invention, and the methods for achieving them, will become clear with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present invention complete and to fully inform a person having ordinary skill in the art to which the present invention belongs of the scope of the invention, and the present invention is defined only by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the matters illustrated. Like reference numerals refer to like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When the terms “includes,” “has,” “consists of,” etc. are used in this specification, other parts may be added unless “only” is used. When a component is expressed in the singular, it includes a case where the plural is included unless there is a specifically explicit description.

When interpreting a component, it is interpreted as including the error range even if there is no separate explicit description.

When describing a positional relationship, for example, when the positional relationship between two parts is described as 'on ~', 'upper ~', 'lower ~', 'next to ~', etc., one or more other parts may be located between the two parts, unless 'right' or 'directly' is used.

When describing a temporal relationship, for example, when describing a temporal relationship using phrases such as 'after', 'following', 'next to', or 'before', it can also include cases where there is no continuity, as long as 'right away' or 'directly' is not used.

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

The individual features of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and may be technically linked and driven in various ways, and each embodiment may be implemented independently of each other or may be implemented together in a related relationship.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a cross-sectional view of an organic light emitting display device according to one embodiment of the present invention.

As illustrated in FIG. 2, an organic light-emitting display device according to one embodiment of the present invention includes a thin film transistor layer (T), a passivation layer (165), a planarization layer (170), a first anode electrode (180), a second anode electrode (190), a bank (200), an organic light-emitting layer (210), and a cathode electrode (220) formed on a substrate (100).

The above thin film transistor layer (T) is composed of an active layer (110), a gate insulating film (120), a gate electrode (130), an interlayer insulating film (140), a source electrode (150), and a drain electrode (160).

The active layer (110) is formed on the substrate (100) so as to overlap the gate electrode (130). The active layer (110) may be formed of a silicon-based semiconductor material or an oxide-based semiconductor material. Although not shown, a light-shielding film may be additionally formed between the substrate (100) and the active layer (110). In this case, external light incident through the lower surface of the substrate (100) is blocked by the light-shielding film, thereby preventing the active layer (110) from being damaged by external light.

The gate insulating film (120) is formed on the active layer (110). The gate insulating film (120) performs a function of insulating the active layer (110) and the gate electrode (130). The gate insulating film (120) may be formed of an inorganic insulating material, for example, a silicon oxide film (SiOX), a silicon nitride film (SiNX), or a multi-film thereof, but is not necessarily limited thereto.

The gate electrode (130) is formed on the gate insulating film (120). The gate electrode (130) is formed to overlap the active layer (110) with the gate insulating film (120) therebetween. The gate electrode (130) may be a single layer or multiple layers made of one or an alloy of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), but is not necessarily limited thereto.

The interlayer insulating film (140) is formed on the gate electrode (130). The interlayer insulating film (140) may be formed of the same inorganic insulating material as the gate insulating film (120), for example, a silicon oxide film (SiOX), a silicon nitride film (SiNX), or a multi-film thereof, but is not necessarily limited thereto.

The source electrode (150) and the drain electrode (160) are formed to face each other on the interlayer insulating film (140). The gate insulating film (120) and the interlayer insulating film (140) described above are provided with a first contact hole (CH1) exposing one end region of the active layer (110) and a second contact hole (CH2) exposing the other end region of the active layer (110), and the source electrode (150) is connected to the other end region of the active layer (110) through the second contact hole (CH2), and the drain electrode (160) is connected to one end region of the active layer (110) through the first contact hole (CH1).

The above source electrode (150) may be formed of a multi-layer including a lower source electrode (151) and an upper source electrode (152).

The lower source electrode (151) may be formed between the interlayer insulating film (140) and the upper source electrode (152) to enhance the adhesive strength between the interlayer insulating film (140) and the upper source electrode (152). In addition, the lower source electrode (151) may protect the lower surface of the upper source electrode (152), thereby preventing the lower surface of the upper source electrode (152) from being corroded. Therefore, the oxidation degree of the lower source electrode (151) may be lower than that of the upper source electrode (152). That is, the material forming the lower source electrode (151) may be formed of a material having stronger corrosion resistance than the material forming the upper source electrode (152). In this way, the lower source electrode (151) functions as an adhesive strength enhancing layer or a corrosion preventing layer, and may be formed of an alloy of molybdenum and titanium (MoTi), but is not necessarily limited thereto.

The upper source electrode (152) is formed on the upper surface of the lower source electrode (151). The upper source electrode (152) may be formed of copper (Cu), which is a metal having low resistance, but is not necessarily limited thereto. The upper source electrode (152) may be formed of a metal having relatively low resistance compared to the lower source electrode (151). In order to reduce the overall resistance of the source electrode (150), it may be preferable that the thickness of the upper source electrode (152) be formed thicker than the thickness of the lower source electrode (151).

The above drain electrode (160) may be formed of a multilayer including a lower drain electrode (161) and an upper drain electrode (162), similar to the above-described source electrode (150).

The lower drain electrode (161) is formed between the interlayer insulating film (140) and the upper drain electrode (162) to enhance the adhesion between the interlayer insulating film (140) and the upper drain electrode (162) and also prevent the lower surface of the upper drain electrode (162) from being corroded. Therefore, the oxidation degree of the lower drain electrode (161) may be lower than that of the upper drain electrode (162). That is, the material forming the lower drain electrode (161) may be formed of a material having stronger corrosion resistance than the material forming the upper drain electrode (162). As such, the lower drain electrode (161) may be formed of an alloy of molybdenum and titanium (MoTi) which is the same as the lower source electrode (151) described above, but is not necessarily limited thereto.

The upper drain electrode (162) is formed on the upper surface of the lower drain electrode (161), and may be made of the same copper (Cu) as the upper source electrode (152) described above, but is not necessarily limited thereto. It may be desirable for the thickness of the upper drain electrode (162) to be formed thicker than the thickness of the lower drain electrode (161) to reduce the overall resistance of the drain electrode (160).

The upper drain electrode (162) can be formed of the same material and the same thickness as the upper source electrode (152), and the lower drain electrode (161) can be formed of the same material and the same thickness as the lower source electrode (151). In this case, there is an advantage in that the drain electrode (160) and the source electrode (150) can be formed simultaneously through the same process.

The configuration of the thin film transistor layer (T) as described above is not limited to the structure shown, and can be modified in various ways to a configuration known to those skilled in the art. For example, although the drawing shows a top gate structure in which the gate electrode (130) is formed on top of the active layer (110), it may also be formed as a bottom gate structure in which the gate electrode (130) is formed below the active layer (110).

The passivation layer (165) is formed on the thin film transistor layer (T), more specifically, on the upper surface of the source electrode (150) and the drain electrode (160). The passivation layer (165) functions to protect the thin film transistor layer (T), and the passivation layer (165) may be formed of an inorganic insulating material, for example, a silicon oxide film (SiOX) or a silicon nitride film (SiNX), but is not necessarily limited thereto.

The above-mentioned planarization layer (170) is formed on the above-mentioned passivation layer (165). The above-mentioned planarization layer (170) performs the function of planarizing the upper portion of the substrate (100) on which the thin film transistor (T) is provided. The above-mentioned planarization layer (170) may be made of an organic insulating material such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, etc., but is not necessarily limited thereto.

The above first anode electrode (180) is formed on the planarization layer (170). The above-described passivation layer (165) and the planarization layer (170) are provided with a third contact hole (CH3) that exposes the source electrode (150), and the source electrode (150) and the first anode electrode (180) are connected through the third contact hole (CH3).

The above first anode electrode (180) may include a first lower anode electrode (181) and a first upper anode electrode (182).

The first lower anode electrode (181) may be formed between the planarization layer (170) and the first upper anode electrode (182) to enhance the adhesive strength between the planarization layer (170) and the first upper anode electrode (182). In addition, the first lower anode electrode (181) may protect the lower surface of the first upper anode electrode (182), thereby preventing the lower surface of the first upper anode electrode (182) from being corroded. Accordingly, the oxidation degree of the first lower anode electrode (181) may be lower than the oxidation degree of the first upper anode electrode (182). That is, the material forming the first lower anode electrode (181) may be formed of a material having stronger corrosion resistance than the material forming the first upper anode electrode (182).

In addition, the first lower anode electrode (181) can prevent the upper surface of the upper source electrode (152) from being corroded by protecting the upper surface of the upper source electrode (152). Therefore, the oxidation degree of the first lower anode electrode (181) can be lower than the oxidation degree of the upper source electrode (152). That is, the material forming the first lower anode electrode (181) can be made of a material having stronger corrosion resistance than the material forming the upper source electrode (152).

In this way, since the first lower anode electrode (181) can prevent corrosion of the upper surface of the upper source electrode (152), it is possible to form the source electrode (150) in the two-layer structure described above. The first lower anode electrode (181) serves as an adhesion promoting layer or a corrosion preventing layer, and may be formed of an alloy of molybdenum and titanium (MoTi), but is not necessarily limited thereto.

The first upper anode electrode (182) is formed on the upper surface of the first lower anode electrode (181). The first upper anode electrode (182) may be formed of copper (Cu), which is a metal having a low resistance, but is not necessarily limited thereto. The first upper anode electrode (182) may be formed of a metal having a relatively low resistance compared to the first lower anode electrode (181). In order to reduce the overall resistance of the first anode electrode (180), it may be preferable that the thickness of the first upper anode electrode (182) be formed thicker than the thickness of the first lower anode electrode (181).

The second anode electrode (190) is formed on the upper surface of the first anode electrode (180). The second anode electrode (190) is formed so as to come into contact with the entire upper surface and side surface of the first anode electrode (180). That is, a separate insulating layer is not formed between the second anode electrode (190) and the first anode electrode (180), and thus, there is an advantage in that the insulating layer and contact hole formation process can be omitted. The second anode electrode (190) serves to reflect light emitted from the organic light-emitting layer (210) upward, and therefore, is formed by including a material having excellent reflectivity. In addition, the second anode electrode (190) is formed so as to cover the upper surface and side surface of the first anode electrode (180), and thus also serves to prevent the upper surface and side surface of the first anode electrode (180) from being corroded.

Such a second anode electrode (190) may include a second lower anode electrode (191), a second central anode electrode (192), and a second upper anode electrode (193).

The second lower anode electrode (191) is formed between the first anode electrode (180) and the second central anode electrode (192). The second lower anode electrode (191) is formed to cover the upper surface and the side surface of the first anode electrode (180), thereby preventing the first anode electrode (180) from being corroded. Therefore, the oxidation degree of the second lower anode electrode (191) may be lower than the oxidation degrees of the first lower anode electrode (181) and the first upper anode electrode (182) constituting the first anode electrode (180). That is, the material constituting the second lower anode electrode (191) may be formed of a material having stronger corrosion resistance than the material constituting the first lower anode electrode (181) and the first upper anode electrode (182).

In addition, the second lower anode electrode (191) protects the lower surface of the second central anode electrode (192), thereby preventing the lower surface of the second central anode electrode (192) from being corroded. Therefore, the oxidation degree of the second lower anode electrode (191) may be lower than the oxidation degree of the second central anode electrode (192). That is, the material forming the second lower anode electrode (191) may be made of a material having stronger corrosion resistance than the material forming the second central anode electrode (192). The second lower anode electrode (191) may be made of a transparent conductive material such as ITO, but is not necessarily limited thereto.

The second central anode electrode (192) is formed between the second lower anode electrode (191) and the second upper anode electrode (193). The second central anode electrode (192) is made of a material having lower resistance and better reflectivity than the second lower anode electrode (191) and the second upper anode electrode (193), and may be made of silver (Ag) as an example, but is not necessarily limited thereto. The thickness of the second central anode electrode (192), which has relatively low resistance, may be preferably formed thicker than the thickness of each of the second lower anode electrode (191) and the second upper anode electrode (193), which have relatively high resistance, so that the overall resistance of the second anode electrode (190) can be reduced.

The second upper anode electrode (193) is formed on the upper surface of the second central anode electrode (192), and can prevent the upper surface of the second central anode electrode (192) from being corroded. Therefore, the oxidation degree of the second upper anode electrode (193) may be lower than the oxidation degree of the second central anode electrode (192). That is, the material forming the second upper anode electrode (193) may be formed of a material having stronger corrosion resistance than the material forming the second central anode electrode (192). The second upper anode electrode (193) may be formed of a transparent conductive material such as ITO, but is not necessarily limited thereto.

In the above, the anode electrode is formed of multiple layers, such as the first anode electrode (180) and the second anode electrode (190), and each is formed as a double layer or triple layer. However, the present invention is not limited thereto, and it is also possible to form it as a single layer.

The above bank (200) is formed on the second anode electrode (190).

The above bank (200) is formed on one side and the other side of the second anode electrode (190) while exposing the upper surface of the second anode electrode (190). Since the bank (200) is formed to expose the upper surface of the second anode electrode (190), an area where an image is displayed can be secured. In addition, since the bank (200) is formed on one side and the other side of the second anode electrode (190), the side surface of the second anode electrode (190), which is vulnerable to corrosion, is prevented from being exposed to the outside, thereby preventing the side surface of the second anode electrode (190) from being corroded. At this time, the organic light-emitting layer (210) and the cathode electrode (220) are formed on the upper surface of the second anode electrode (190), and the exposed area of the second anode electrode (190) for forming the organic light-emitting layer (210) and the cathode electrode (220) corresponds to the light-emitting area (EA).

A bank (200) like this may be made of an organic insulating material such as polyimide resin, acrylic resin, benzocyclobutene (BCB), etc., but is not necessarily limited thereto.

In particular, the bank (200) according to the embodiment of the present invention includes, as illustrated in FIG. 2, a first bank (201) provided on one side and the other side of the first anode electrode (180) and the second anode electrode (190) so as to expose the upper surface of the second anode electrode (190), and a second bank (202) provided on the first bank (201) so as to expose the upper surface of the first bank (201). In particular, the second bank (202) is provided so as to expose the upper surface of the edge of the first bank (201).

In this way, in the embodiment of the present invention, the second bank (202) is provided on the first bank (201) while exposing the edge of the first bank (201), so that the bank (200) is provided in a shape having a step on the first anode electrode (180) and the second anode electrode (190) as shown in FIG. 2.

In an embodiment of the present invention, the second bank (202) is provided on the first bank (201) while exposing the edge of the first bank (201) to prevent a pile up phenomenon of the organic light-emitting layer (210).

The pile-up phenomenon means that when forming the organic light-emitting layer (210) by an inkjet printing method, the organic light-emitting material constituting the organic light-emitting layer (210) is sprayed or dropped onto the second anode electrode (190) and then dried. After the organic light-emitting material is dried and hardened, the thickness of the organic light-emitting layer (210) formed in the area in contact with the bank (200) is formed thicker than that of the organic light-emitting layer (210) formed on the upper surface of the second anode electrode (190), resulting in a thickness deviation.

As a result, the organic light-emitting layer (210) has a cross-section that is formed flat in the center of the light-emitting area (EA) and gradually increases in thickness as it approaches the portion adjacent to the bank (200). In addition, if the organic light-emitting layer (210) is formed unevenly on the second anode electrode (190) in this way, there is a problem of luminance unevenness occurring.

Therefore, in the embodiment of the present invention, the first bank (201) and the second bank (202) are included so that the banks (200) provided on one side and the other side of the first anode electrode (180) and the second anode electrode (190) have step-shaped steps, thereby preventing the pile-up phenomenon as described above.

In this way, when the first bank (201) and the second bank (202) are provided with step-shaped differences, the organic light-emitting material is sprayed onto the upper surface of the second anode electrode (190) exposed by the first bank (201) and the upper surface of the first bank (201) exposed by the second bank (202), so that the organic light-emitting layer (210) can be formed flat on the second anode electrode (190) corresponding to the light-emitting area (EA). That is, in the embodiment of the present invention, the organic light-emitting layer (210) can be formed flat in the light-emitting area (EA) by forming the organic light-emitting layer (210) on the upper surface of the edge of the first bank (201).

To this end, the first bank (201) may be formed to have hydrophilic characteristics overall, and the second bank (202) may be formed to have hydrophobic characteristics overall or to have hydrophobic characteristics only in the upper portion. That is, as described above, in the embodiment of the present invention, the organic light-emitting layer (210) must be formed up to the upper surface of the first bank (201) so that a pile-up phenomenon does not occur in the area where the second anode electrode (190) corresponding to the light-emitting area (EA) is exposed.

Accordingly, the first bank (201) is formed of a hydrophilic material so that the organic light-emitting layer (210) can be formed on the upper surface, and the second bank (202) is formed of a hydrophobic material so that the area where the organic light-emitting layer (210) is formed can be limited so as to define a pixel area. However, since the pixel area can be defined even if the organic light-emitting layer (210) is not formed only on the upper portion of the second bank (202), the second bank (202) may be formed of a hydrophobic material only on the upper portion, but the present invention is not limited thereto, and thus the entire bank may be formed of a hydrophobic material.

In addition, the first bank (201) and the second bank (202) are formed of an organic material. That is, in the past, the first bank (201) formed on the second anode electrode (190) was formed of an inorganic material. In this case, in order to prevent performance degradation of the planarization layer (170) and the thin film transistor layer (T) formed in the lower layer, CVD had to be performed at a low temperature, so there was a problem that the first bank (201) was peeled off in the finished product. In addition, there was a problem that the second anode electrode (190) was damaged by the etchant during the process of patterning the first bank (201) through an etching process.

Therefore, in order to prevent such quality deterioration and damage to the second anode electrode (190), in the embodiment of the present invention, the first bank (201) and the second bank (202) are both made of organic materials, thereby simplifying the process and improving productivity. A more specific manufacturing process of the first bank (201) and the second bank (202) will be described later.

The organic light-emitting layer (210) is formed on the second anode electrode (190). The organic light-emitting layer (210) may include a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, and an electron injection layer. The structure of the organic light-emitting layer (210) may be changed into various forms known in the art.

In particular, at least one layer among the hole injection layer, the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer constituting the organic light emitting layer (210) may be formed through a soluble process. For example, the hole injection layer, the hole transport layer, and the light emitting layer may be formed through a soluble process, and the electron transport layer and the electron injection layer may be formed by a vapor deposition method, but the present invention is not limited thereto.

The availability process is a process of forming the organic light-emitting layer (210) by spraying the available organic light-emitting material onto the second anode electrode (190) using an inkjet printing method as described above and curing it, and is used to increase the convenience and efficiency of the manufacturing process of an organic light-emitting display device.

In particular, the organic light-emitting layer (210) may extend to the upper surface of the first bank (201) exposed by the second bank (202). However, the organic light-emitting layer (210) does not extend to the upper surface of the second bank (202) while covering the upper surface of the second bank (202).

To this end, as described above, the first bank (201) may be formed entirely of a hydrophilic material, and the second bank (202) may be formed entirely of a hydrophobic material or only the upper portion may be formed of a hydrophobic material.

The above cathode electrode (220) is formed on the organic light-emitting layer (210). Since the cathode electrode (220) is formed on the surface from which light is emitted, it is made of a transparent conductive material.

Although not shown in the drawing, an encapsulation layer may be additionally formed on the cathode electrode (220) to prevent moisture penetration. Various materials known in the art may be used for the encapsulation layer. In addition, although not shown, a color filter may be additionally formed for each pixel on the cathode electrode (220), and in this case, white light may be emitted from the organic light-emitting layer (210).

In the embodiment of the present invention, a top emission type structure in which light generated from an organic light-emitting layer (210) is emitted to the outside through the cathode electrode (220) was taken as an example, but the present invention is not limited thereto, and may be configured in a bottom emission type in which light generated from an organic light-emitting layer (201) is emitted to the outside through the first anode electrode (180) and the second anode electrode (190).

FIG. 3 is a schematic cross-sectional view of an organic light emitting display device according to one embodiment of the present invention, showing area A illustrated in FIG. 2.

As illustrated in FIG. 3, a second anode electrode (190), a bank (200), an organic light-emitting layer (210), and a cathode electrode (220) are formed on a substrate of an organic light-emitting display device according to one embodiment of the present invention.

Since the above second anode electrode (190), bank (200), organic light-emitting layer (210), and cathode electrode (220) are laminated in the same manner as in the organic light-emitting display device according to FIG. 2, the same drawing reference numerals are given to the same configurations, and only configurations laminated in different structures will be described below.

The above bank (200) includes a first bank (201) provided on one side and the other side of the second anode electrode (190) so as to expose the upper surface of the second anode electrode (190), and a second bank (202) provided on the first bank (201) so as to expose the edge of the first bank (201). The first bank (201) may be provided with a thickness of 1.5 ㎛ or less, and the second bank (202) may be provided with a thickness of 2.0 ㎛ or less, so that the second bank (202) may be provided thicker than the first bank (201). That is, as illustrated in FIG. 3, the first bank (201) can be formed with a relatively thin thickness because the organic light-emitting layer (190) only needs to be formed on the upper surface so that the organic light-emitting layer (190) can be formed flatly on the second anode electrode (190), but the second bank (202) should be formed with a relatively thick thickness compared to the first bank (201) because it must be able to define a pixel area while limiting the area where the organic light-emitting layer (210) is formed.

That is, as illustrated in FIG. 3, since the second bank (202) is provided so as to expose the upper surface of the edge of the first bank (201), as illustrated in FIG. 3, the organic light-emitting layer (210) can be formed not only on the upper surface of the second anode electrode (190) but also on the upper surface of the first bank (201).

Accordingly, even if the organic light-emitting material is sprayed using an inkjet printing method, the organic light-emitting layer (210) can be formed flat on the upper surface of the second anode electrode (190) because the organic light-emitting material is additionally formed on the upper surface of the edge of the first bank (201). Accordingly, in the embodiment of the present invention, uniform light emission is possible in all areas of the pixel.

In addition, the second bank (202) may be provided such that the side surface (202a) is inclined at a predetermined angle with respect to the surface of the substrate. Specifically, as illustrated in FIG. 3, the angle (α) between the side surface (202a) of the second bank (202) and the surface of the substrate may be provided to be 45° or less.

That is, when the organic light-emitting layer (210) is formed on the side surface (202a) of the second bank (202) having a gentle slope, the variation in the thickness of the organic light-emitting layer (210) is reduced, and when the organic light-emitting layer (210) is formed on the side surface (202a) of the second bank (202) having a steep slope, the variation in the thickness of the organic light-emitting layer (210) is increased. Therefore, in the embodiment of the present invention, by forming the side surface (202a) of the second bank (202) at a gentle angle, the organic light-emitting layer (210) formed on the second anode electrode (190) can be formed flat. At this time, the angle (α) is not limited to the angle described above, and may be formed differently depending on the viscosity of the organic light-emitting material or the area of the upper surface of the first bank (201) exposed by the second bank (202). And, since the organic light-emitting layer (210) is formed on the upper surface of the edge of the first bank (201), the angle formed between the side surface (201a) of the first bank (201) and the surface of the substrate is not limited to a specific value.

In addition, according to one embodiment of the present invention, the first bank (201) is formed to have hydrophilic characteristics overall, and the second bank (202) is formed to have hydrophobic characteristics overall. That is, in the embodiment of the present invention, the organic light-emitting layer (210) must be formed up to the upper surface of the first bank (201) exposed by the second bank (202) so that the thickness of the organic light-emitting layer (210) can be formed uniformly in the light-emitting region.

Accordingly, the first bank (201) is formed of a hydrophilic material so that the organic light-emitting layer (210) can be formed on the upper surface, and the second bank (202) is formed of a hydrophobic material to limit the area where the organic light-emitting layer (210) is formed so as to define a pixel area.

In addition, the first bank (201) and the second bank (202) are formed of an organic material. That is, in the past, the first bank (201) formed on the second anode electrode (190) was formed of an inorganic material. In this case, in order to prevent performance degradation of the planarization layer (170) and the thin film transistor layer (T) formed in the lower layer, CVD had to be performed at a low temperature, so there was a problem that the first bank (201) was peeled off in the finished product. In addition, there was a problem that the second anode electrode (190) was damaged by the etchant during the process of patterning the first bank (201) through an etching process.

Therefore, in the embodiment of the present invention, in order to prevent such quality deterioration and damage to the second anode electrode (190), the first bank (201) formed of an organic material is patterned through a first mask process, and the second bank (202) formed of an organic material is patterned through a second mask process, thereby simplifying the process and improving productivity compared to the process of depositing an inorganic material. A more specific manufacturing process of the first bank (201) and the second bank (202) will be described later.

As such, in one embodiment of the present invention, the bank (200) including the first bank (201) formed of a hydrophilic material and the second bank (202) formed of a hydrophobic material is provided to have a step-like shape overall, thereby forming a flat organic light-emitting layer (210) on the second anode electrode (190), thereby realizing uniform brightness, and by forming the first bank (201) and the second bank (202) of an organic material, damage and quality deterioration of the second anode electrode (190) due to CVD performed at a low temperature can be prevented.

FIG. 4 is a schematic cross-sectional view of an organic light emitting display device according to another embodiment of the present invention, showing area A illustrated in FIG. 2, which is identical to the organic light emitting display device according to FIG. 3 described above, except that the configuration of the bank (200) is changed. Accordingly, the same reference numerals are given to the same configurations, and only different configurations will be described below.

In particular, in an organic light-emitting display device according to another embodiment of the present invention, the first bank (201) is formed to have hydrophilic characteristics overall, and the second bank (202) is formed to have hydrophobic characteristics only in the upper portion.

That is, as described above, in the embodiment of the present invention, the organic light-emitting layer (210) must be formed up to the upper surface of the first bank (201) exposed by the second bank (202) so that the thickness of the organic light-emitting layer (210) can be formed uniformly in the light-emitting region.

Accordingly, the first bank (201) must be formed entirely of a hydrophilic material since the organic light-emitting layer (210) must be formed on the upper surface thereof, but the second bank (202) may be formed with the organic light-emitting layer (210) up to the side surface (202a) since the second bank (202) is intended to define a pixel area. Accordingly, according to another embodiment of the present invention, only the upper portion, not the entire second bank (202), may be formed of a hydrophobic material. Specifically, in another embodiment of the present invention, during the process of patterning the first bank (201) and the second bank (202), only the upper portion of the second bank (202) may be formed hydrophobic, and the specific process will be described later.

In addition, according to another embodiment of the present invention, the first bank (201) and the second bank (202) can be pattern-formed through the same mask process using the same organic material. That is, in one embodiment of the present invention according to FIG. 3, the first bank (201) and the second bank (202) are formed through two mask processes, in which the first bank (201) is formed through a first mask process and the second bank (202) is formed through a second mask process. However, in another embodiment of the present invention, the first bank (201) and the second bank (202) can be formed through one mask process, and therefore the number of mask processes can be reduced.

In this way, in another embodiment of the present invention, the bank (200) including the first bank (201) formed of a hydrophilic material and the second bank (202) formed of a hydrophobic material is provided to have an overall step-like shape so that a flat organic light-emitting layer (210) is formed on the second anode electrode (190), thereby realizing uniform brightness, and by forming the first bank (201) and the second bank (202) of an organic material, damage and quality deterioration of the second anode electrode (190) due to CVD performed at a low temperature can be prevented, and by forming the first bank (201) and the second bank (202) having the above-described characteristics through a single mask process, the number of mask processes can be reduced.

FIG. 5 is a schematic cross-sectional view of an organic light emitting display device according to another embodiment of the present invention, which is the same as the organic light emitting display device according to FIG. 4 described above, except that the configuration of the bank (200) is changed. Therefore, the same reference numerals are given to the same configurations, and only different configurations will be described below.

In an organic light emitting display device according to another embodiment of the present invention, the bank (200) may include a first bank (201), a second bank (202), and a third bank (203). That is, as illustrated in FIG. 4, the bank (200) may be formed to have a two-step-shaped step, and as illustrated in FIG. 5, it may also be formed to have a three-step-shaped step. In addition, the step structure of the bank (200) is not limited to that illustrated, and may be formed to have a four or more-step-shaped step.

For example, when the bank (200) includes a first bank (201), a second bank (202), and a third bank (203), the third bank (203) may be provided on the second bank (202) so as to expose an edge of the second bank (202), and the organic light-emitting layer (210) may be formed to extend not only to the upper surface of the first bank (201) exposed by the second bank (202), but also to the upper surface of the second bank (202) exposed by the third bank (203). That is, when the organic light-emitting layer (210) is formed up to the upper surface of the exposed second bank (202), the organic light-emitting layer (210) can be gently formed along the upper surfaces of the first bank (201) and the second bank (202), and as a result, the thickness of the organic light-emitting layer (210) in the light-emitting area is provided more consistently.

In addition, when the bank (200) includes the first bank (201), the second bank (202), and the third bank (203), the first bank (201) and the second bank (202) are formed to have hydrophilic characteristics overall, and the third bank (203) is formed to have hydrophobic characteristics overall or to have hydrophobic characteristics only on the upper portion. That is, as described above, in order for the thickness of the organic light-emitting layer (210) to be formed uniformly in the light-emitting region, the organic light-emitting layer (210) must be formed up to the upper surface of the second bank (202) exposed by the third bank (203), so that the second bank (202) is formed of a hydrophilic material, and the third bank (203) can be formed of at least a hydrophobic material on the upper portion so as to limit the region where the organic light-emitting layer (210) is formed and define a pixel region.

In this way, when the bank (200) is provided to have a step-shaped difference of three or more steps, only the bank provided at the top is provided with a hydrophobic material to define a pixel area, and the remaining banks provided at the bottom are provided with a hydrophilic material to allow the organic light-emitting layer (210) to be formed smoothly, thereby reducing the thickness deviation of the organic light-emitting layer (210) in the light-emitting area.

In addition, as described above, the angle between the side surface (202a) of the second bank (202) and the side surface (203a) of the third bank (203) and the surface of the substrate is provided at a gentle angle of 45° or less, so that the organic light-emitting layer (210) can be formed flat in the light-emitting area.

FIGS. 6A to 6J are process cross-sectional views showing a method for manufacturing an organic light-emitting display device according to one embodiment of the present invention, which relate to the method for manufacturing an organic light-emitting display device according to FIG. 3 described above.

First, as can be seen in Fig. 6a, an active layer (110), a gate insulating film (120), a gate electrode (130), an interlayer insulating film (140), a source electrode (150), and a drain electrode (160) are sequentially formed on a substrate (100).

To explain more specifically, the active layer (110) is formed on the substrate (100), the gate insulating film (120) is formed on the active layer (110), the gate electrode (130) is formed on the gate insulating film (120), the interlayer insulating film (140) is formed on the gate electrode (130), a first contact hole (CH1) and a second contact hole (CH2) are formed in the gate insulating film (120) and the interlayer insulating film (140), and then the drain electrode (160) connected to one end region of the active layer (110) through the first contact hole (CH1) and the source electrode (150) connected to the other end region of the active layer (110) through the second contact hole (CH2) are formed.

The above source electrode (150) is composed of a lower source electrode (151) and an upper source electrode (152), and the above drain electrode (160) is composed of a lower drain electrode (161) and an upper drain electrode (162). The source electrode (150) and the drain electrode (160) can be formed simultaneously using the same material and through the same patterning process.

Next, as can be seen in Fig. 6b, a passivation layer (165) is formed on the source electrode (150) and the drain electrode (160), and a planarization layer (170) is formed on the passivation layer (165).

The above passivation layer (165) and the above planarization layer (170) are formed to have a third contact hole (CH3), so that the source electrode (150) is exposed to the outside through the third contact hole (CH3).

Next, as can be seen in Fig. 6c, a first anode electrode (180) and a second anode electrode (190) are sequentially formed on the flattening layer (170).

The above first anode electrode (180) is formed to be connected to the source electrode (150) through the third contact hole (CH3).

The first anode electrode (180) is composed of a first lower anode electrode (181) and a first upper anode electrode (182), and the second anode electrode (190) is composed of a second lower anode electrode (191), a second central anode electrode (192), and a second upper anode electrode (193).

Next, as can be seen in FIG. 6d, a first bank layer (BK1) made of a hydrophilic organic material is formed on the second anode electrode (190). More specifically, the first bank layer (BK1) is formed on the entire surface of the active area including the second anode electrode (190). In particular, the first bank layer (BK1) according to an embodiment of the present invention may be made of a negative type photosensitive material.

That is, since the first bank layer (BK1) is made of a negative type photosensitive material, the area irradiated with ultraviolet rays during exposure remains after the development process, and the area blocked from light during exposure has the characteristic of being removed after the development process.

Next, as can be seen in FIG. 6e, a first photoresist pattern (M1) is formed and aligned on the first bank layer (BK1). In particular, the first photoresist pattern (M1) may include a first transmitting pattern (M1-1) that transmits all light during exposure and a second blocking pattern (M1-2) that blocks all light during exposure.

After aligning the first photo resist pattern (M1) in this manner, an exposure and development process is performed on the first bank layer (BK1) using the first photo resist pattern (M1) as a mask.

Since the first photoresist pattern (M1) includes the first transparent pattern (M1-1) and the second blocking pattern (M1-2), ultraviolet rays are completely irradiated to the first bank layer (BK1) located below the first transparent pattern (M1-1), and ultraviolet rays are not irradiated to the first bank layer (BK1) located below the second blocking pattern (M1-2).

Next, as can be seen in FIG. 6f, the first photoresist pattern (M1) is removed through a strip process to obtain a substrate (100) in which the first bank (201) and the second anode electrode (190) are exposed to the outside. More specifically, the first bank (201) is patterned on one side and the other side of the second anode electrode (190), and the second anode electrode (190) is exposed to the outside in an area where the first bank (201) is not formed.

That is, as described above, since the first bank layer (BK1) is made of a negative type photosensitive material, the first bank layer (BK1) that is fully irradiated with ultraviolet rays corresponding to the first transmitting pattern (M1-1) remains to form the first bank (201), and the first bank layer (BK1) that is not irradiated with ultraviolet rays corresponding to the second blocking pattern (M1-2) is completely removed.

Next, as can be seen in FIG. 6g, a second bank layer (BK2) made of a hydrophobic organic material is formed on the first bank (201). More specifically, the second bank layer (BK2) is formed on the entire surface of the active area including the second anode electrode (190) and the first bank (201). In particular, the second bank layer (BK2) according to an embodiment of the present invention may be made of a negative-type photosensitive material.

That is, since the second bank layer (BK2) is made of a negative type photosensitive material, the area irradiated with ultraviolet rays during exposure remains after the development process, and the area blocked from light during exposure has the characteristic of being removed after the development process.

Next, as can be seen in FIG. 6h, a second photoresist pattern (M2) is formed and aligned on the second bank layer (BK2). In particular, the second photoresist pattern (M2) may include a second transmitting pattern (M2-1) that transmits all light during exposure and a second blocking pattern (M2-2) that blocks all light during exposure.

After aligning the second photo resist pattern (M2) in this manner, an exposure and development process is performed on the second bank layer (BK2) using the second photo resist pattern (M2) as a mask.

Since the second photoresist pattern (M2) includes the second transparent pattern (M2-1) and the second blocking pattern (M2-2), ultraviolet rays are completely irradiated to the second bank layer (BK2) located below the second transparent pattern (M2-1), and ultraviolet rays are not irradiated to the second bank layer (BK2) corresponding to the second blocking pattern (M2-2).

Next, as can be seen in FIG. 6i, the second photoresist pattern (M2) is removed through a strip process to obtain a substrate (100) in which the first bank (201), the second bank (202), and the second anode electrode (190) are exposed to the outside. More specifically, the first bank (201) and the second bank (202) are patterned on one side and the other side of the second anode electrode (190), and the edge of the first bank (201) and the second anode electrode (190) are exposed to the outside by the second bank (202).

That is, as described above, since the second bank layer (BK2) is made of a negative type photosensitive material, the second bank layer (BK2) that is fully irradiated with ultraviolet rays corresponding to the second transmitting pattern (M2-1) remains to form the second bank (202), and the second bank layer (BK2) that is not irradiated with ultraviolet rays corresponding to the second blocking pattern (M2-2) is completely removed.

In particular, in the embodiment of the present invention, the second bank (202) must be formed to expose the edge of the first bank (201), so that the second light-shielding pattern (M2-2) included in the second photoresist pattern (M2) is provided to have a wider width than the first light-shielding pattern (M1-2) included in the first photoresist pattern (M1).

Next, as can be seen in FIG. 6j, an organic light-emitting layer (210) and a cathode electrode (220) are sequentially formed on the second anode electrode (190). The organic light-emitting layer (210) is formed by spraying a soluble organic light-emitting material using an inkjet printing method, and as described above, the first bank (201) is made of a hydrophilic material and the second bank (202) is made of a hydrophobic material, so the organic light-emitting layer (210) can be deposited on the upper surface of the second anode electrode (190) and the upper surface of the edge of the first bank (201) exposed by the second bank (202), but is not deposited on the upper surface of the second bank (202).

That is, in the embodiment of the present invention, by forming the first bank (201) and the second bank (202) using the first bank layer (BK1) made of a hydrophilic material and the second bank layer (BK2) made of a hydrophobic material as described above, the organic light-emitting layer (210) can be formed not only on the upper surface of the second anode electrode (190) exposed by the first bank (201) but also on the upper surface of the first bank (201) exposed by the second bank (202). As a result, the organic light-emitting layer (210) can be formed flat in the area where the second anode electrode (190) is exposed, which corresponds to the light-emitting area.

In addition, in the embodiment of the present invention, by forming the first bank (201) and the second bank (202) using the first bank layer (BK1) and the second bank layer (BK2) made of organic materials as described above, the process can be simplified and productivity can be improved compared to the case where the bank is formed using an inorganic material, and the second anode electrode (190) can be prevented from being damaged by the etchant during the process of patterning the bank.

In the above, it has been described that the first bank (201) and the second bank (202) are formed through the first bank layer (BK1) and the second bank layer (BK2) made of a negative type photosensitive material, but the present invention is not limited thereto, and it will be possible to form the first bank (201) and the second bank (202) using a bank layer made of a positive type photosensitive material.

In addition, although not illustrated, after the process of forming the second bank (202) described above (FIG. 6i), a process of forming a third bank may be added to expose the edge of the second bank (202). In this case, during the process of forming the organic light-emitting layer (210) (FIG. 6j), the organic light-emitting layer (210) is formed up to the upper surface of the second bank (202) exposed by the third bank. Accordingly, the organic light-emitting layer (210) can be gently formed along the upper surfaces of the first bank (201) and the second bank (202), and as a result, the thickness of the organic light-emitting layer (210) in the light-emitting region becomes more constant. In this way, when the third bank is additionally formed on the second bank (202), the first bank (201) and the second bank (202) are formed using a hydrophilic material, and the third bank is formed using a hydrophobic material.

FIGS. 7A to 7G are process cross-sectional views showing a manufacturing method for forming a bank of an organic light-emitting display device according to another embodiment of the present invention. This relates to the manufacturing method of the organic light-emitting display device according to FIG. 4 described above. Therefore, the same reference numerals are assigned to the same components, and redundant descriptions of repetitive parts in materials and structures of each component are omitted.

First, as can be seen in Fig. 7a, an active layer (110), a gate insulating film (120), a gate electrode (130), an interlayer insulating film (140), a source electrode (150), and a drain electrode (160) are sequentially formed on a substrate (100).

To explain more specifically, the active layer (110) is formed on the substrate (100), the gate insulating film (120) is formed on the active layer (110), the gate electrode (130) is formed on the gate insulating film (120), the interlayer insulating film (140) is formed on the gate electrode (130), a first contact hole (CH1) and a second contact hole (CH2) are formed in the gate insulating film (120) and the interlayer insulating film (140), and then the drain electrode (160) connected to one end region of the active layer (110) through the first contact hole (CH1) and the source electrode (150) connected to the other end region of the active layer (110) through the second contact hole (CH2) are formed.

The above source electrode (150) is composed of a lower source electrode (151) and an upper source electrode (152), and the above drain electrode (160) is composed of a lower drain electrode (161) and an upper drain electrode (162). The source electrode (150) and the drain electrode (160) can be formed simultaneously using the same material and through the same patterning process.

Next, as can be seen in Fig. 7b, a passivation layer (165) is formed on the source electrode (150) and the drain electrode (160), and a planarization layer (170) is formed on the passivation layer (165).

The above passivation layer (165) and the above planarization layer (170) are formed to have a third contact hole (CH3), so that the source electrode (150) is exposed to the outside through the third contact hole (CH3).

Next, as can be seen in Fig. 7c, a first anode electrode (180) and a second anode electrode (190) are sequentially formed on the flattening layer (170).

The above first anode electrode (180) is formed to be connected to the source electrode (150) through the third contact hole (CH3).

The first anode electrode (180) is composed of a first lower anode electrode (181) and a first upper anode electrode (182), and the second anode electrode (190) is composed of a second lower anode electrode (191), a second central anode electrode (192), and a second upper anode electrode (193).

Next, as can be seen in FIG. 7d, a bank layer (BK) made of an organic material is formed on the second anode electrode (190). More specifically, the bank layer (BK) is formed on the entire surface of the active region including the second anode electrode (190). In particular, the bank layer (BK) according to an embodiment of the present invention may be made of a negative type photosensitive material.

That is, since the above bank layer (BK) is made of a negative type photosensitive material, the area irradiated with ultraviolet rays during exposure remains after the development process, and the area blocked from light during exposure has the characteristic of being removed after the development process.

In addition, the bank layer (BK) according to an embodiment of the present invention is formed by including a material to which a hydrophobic agent can be bound by cross linking in a region where ultraviolet (UV) rays are irradiated during exposure. For example, the bank layer (BK) may be a material in which fluorine, which is a hydrophobic agent, is mixed with an organic material such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin, but is not limited thereto. Hereinafter, a case in which the bank layer (BK) is an organic material including fluorine will be described as an example.

Next, as can be seen in Fig. 7e, a photoresist pattern (M) is formed and aligned on the bank layer (BK). Then, the solvent of the photoresist pattern (M) is removed through a soft baking process, and in this process, fluorine included in the bank layer (BK) moves to the surface.

In particular, the photoresist pattern (M) may include a transparent pattern (M1) through which all light is transmitted during exposure, a light-blocking pattern (M2) through which all light is blocked during exposure, and a semi-transparent pattern (M3) through which only half of the light is transmitted during exposure. After aligning the photoresist pattern (M) in this manner, an exposure and development process is performed on the bank layer (BK) using the photoresist pattern (M) as a mask.

Since the above photoresist pattern (M) includes the transparent pattern (M1), the shielding pattern (M2), and the semi-transparent pattern (M3), the bank layer (BK) located under the transparent pattern (M1) is completely irradiated with ultraviolet rays, the bank layer (BK) located under the shielding pattern (M2) is not irradiated with ultraviolet rays, and only a portion of the bank layer (BK) located under the semi-transparent pattern (M3) is irradiated with ultraviolet rays. In addition, the bank layer (BK) forms cross linking during exposure, and the fluorine that has moved to the surface during the above-described soft baking process is fixed to the surface by cross linking.

Accordingly, in the bank layer (BK) located below the transparent pattern (M1), cross-linking is formed to fix the hydrophobic agent, so that the upper part becomes hydrophobic, and since the hydrophobic agent does not exist in the bank layer (BK) located below the shading pattern (M2), it becomes hydrophilic. In addition, since only a portion of the bank layer (BK) located below the semi-transparent pattern (M3) is irradiated with ultraviolet rays, cross-linking is not properly formed, and thus the hydrophobic agent is not fixed, so the bank layer (BK) in the corresponding region becomes hydrophilic. Accordingly, when the exposure and development processes are performed, the upper part of the bank layer (BK) located below the transparent pattern (M1) is formed of a hydrophobic material, and the bank layer (BK) located below the shading pattern (M2) and the semi-transparent pattern (M3) is formed of a hydrophilic material. In this way, in an embodiment of the present invention, by using a bank layer including a hydrophobic agent, a bank having steps can be formed through a single mask process while making only the upper part hydrophobic.

Next, as can be seen in FIG. 7f, the photoresist pattern (M) is removed through a strip process to obtain a substrate (100) in which the edge of the first bank (201), the second bank (202), and the second anode electrode (190) are exposed to the outside. More specifically, the first bank (201) is patterned on one side and the other side of the second anode electrode (190), and the second anode electrode (190) is exposed to the outside in an area where the first bank (201) is not formed, and the second bank (202) is formed on the first bank (201) so as to expose the upper surface of the edge of the first bank (201).

That is, as described above, since the bank layer (BK) is made of a negative type photosensitive material, the bank layer (BK) that is fully irradiated with ultraviolet rays corresponding to the transparent pattern (M1) remains entirely, the bank layer (BK) that is not irradiated with ultraviolet rays corresponding to the light-shielding pattern (M2) is entirely removed, and the bank layer (BK) that is only partially irradiated with ultraviolet rays corresponding to the semi-transparent pattern (M3) remains only half. Accordingly, as finally illustrated in FIG. 7f, the first bank (201) and the second bank (202) having a step structure in the shape of a staircase are formed. In this way, in another embodiment of the present invention, the number of mask processes can be reduced by forming the first bank (201) and the second bank (202) through one slit mask or halftone mask.

Next, as can be seen in FIG. 7g, an organic light-emitting layer (210) and a cathode electrode (220) are sequentially formed on the second anode electrode (190). The organic light-emitting layer (210) is formed by spraying a soluble organic light-emitting material using an inkjet printing method, and as described above, the first bank (201) is formed of a hydrophilic material and the second bank (202) is formed of a hydrophobic material only in the upper part by the exposure process of forming the first bank (201) and the second bank (202). Therefore, the organic light-emitting layer (210) can be deposited on the upper surface of the second anode electrode (190) and the upper surface of the edge of the first bank (201) exposed by the second bank (202), but is not deposited on the upper surface of the second bank (202).

In particular, in the embodiment of the present invention, by using a bank layer (BK) made of a negative type photosensitive material as described above, the first bank (201) can be provided with a hydrophilic material and the second bank (202) can be provided with a hydrophobic material only on the upper part. This will be described in more detail as follows.

If the bank layer (BK) made of a positive type photosensitive material is used to carry out the above-described process, the area of the bank layer (BK) that has been irradiated with ultraviolet rays during exposure is removed after the development process, and the area that has been blocked from light during exposure remains after the development process. That is, the area that has been irradiated with ultraviolet rays changes into a state that can be removed by a developer through a photochemical reaction, and the area that has not been irradiated with ultraviolet rays remains as it is, so the hydrophobic agent cannot be bound to the surface by cross-linking as in the exposure process using a negative type photosensitive material. In this way, since it is impossible to form only the upper part of a specific bank hydrophobic by using the bank layer (BK) made of a positive type photosensitive material, in the embodiment of the present invention, the first bank (201) and the second bank (202) having the above-described characteristics can be formed by using the bank layer (BK) made of a negative type photosensitive material.

In addition, although not shown, during the process of forming the first bank (201) and the second bank (202) described above (FIG. 7f), the third bank may be formed together to expose the edge of the second bank (202). In this case, during the process of forming the organic light-emitting layer (210) (FIG. 7g), the organic light-emitting layer (210) is formed up to the upper surface of the second bank (202) exposed by the third bank. Accordingly, the organic light-emitting layer (210) may be gently formed along the upper surfaces of the first bank (201) and the second bank (202), and as a result, the thickness of the organic light-emitting layer (210) in the light-emitting region is provided more consistently. In particular, since the first bank (201) to the third bank are formed using a bank layer (BK) including a material to which a hydrophobic agent can be bound by cross-linking in an area where ultraviolet rays are irradiated during exposure as described above, the first bank (201) and the second bank (202) can be formed of a hydrophilic material, and only the upper part of the third bank can be formed of a hydrophobic material.

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

100: Substrate T: Thin film transistor layer
165: Passivation layer 170: Flattening layer
180: 1st anode electrode 190: 2nd anode electrode
201: First Bank 202: Second Bank
210: Organic light-emitting layer 220: Cathode electrode

Claims (12)

An insulating layer covering a thin film transistor provided on a substrate;
An anode electrode provided on the insulating layer and connected to the thin film transistor through a contact hole provided on the insulating layer;
A first bank provided on the insulating layer and covering the edge of the anode electrode;
A second bank provided on the first bank so as to expose an edge of the first bank;
An organic light-emitting layer provided on the upper surface of the anode electrode exposed by the first bank and on the upper surface of the exposed first bank; and
Including a cathode electrode provided on the organic light-emitting layer,
The above first bank and second bank are made of organic material,
The above anode electrode is
A first anode electrode having a multi-layer structure connected to the above thin film transistor and provided on the above insulating layer; and
A second anode electrode having a double-layer structure that is in contact with the first anode electrode and covers the entire upper surface and side surface of the first anode electrode,
In the light-emitting region provided by the first bank covering the edge of the first anode electrode and the edge of the second anode electrode, the organic light-emitting layer is in contact with the overlapping portion of the first and second anode electrodes,
The side surfaces of the first bank and the second bank are provided to be inclined at a predetermined angle with respect to the surface of the substrate, and the second angle formed between the side surface of the second bank and the surface of the substrate is smaller than the first angle formed between the side surface of the first bank and the surface of the substrate, and the second angle is larger than 0 degrees and smaller than 45 degrees.
The first anode electrode of the above-mentioned double-layer structure is,
A first lower anode electrode is included, and a first upper anode electrode is disposed on the first lower anode electrode and has lower resistance and thicker thickness than the first lower anode electrode.
The second anode electrode of the above-mentioned double-layer structure is,
An organic light emitting display device comprising a second lower anode electrode and a second upper anode electrode, and a second central anode electrode disposed between the second lower anode electrode and the second upper anode electrode and having lower resistance and thicker thickness than each of the second lower anode electrode and the second upper anode electrode. In the first paragraph,
An organic light-emitting display device, wherein the first bank is formed of a hydrophilic material, and the second bank is formed of a hydrophobic material. In the first paragraph,
An organic light-emitting display device further comprising a third bank provided on the second bank so as to expose an edge of the second bank, wherein the organic light-emitting layer is provided up to an upper surface of the exposed second bank. In the third paragraph,
An organic light-emitting display device, wherein the first bank and the second bank are formed of a hydrophilic material, and the third bank is formed of a hydrophobic material. In the third paragraph,
An organic light-emitting display device, wherein the side of the third bank is inclined at a predetermined angle with respect to the surface of the substrate. delete delete delete delete delete delete delete

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