KR102469598B1 - Photoresist composition for organic light emitting display device and method of manufacturing organic light emitting display device using the same - Google Patents

Abstract

An organic light emitting display device according to an embodiment of the present specification includes an anode on a substrate, a bank layer on the anode, a cathode on the bank layer, and a light emitting portion between the anode and the cathode, and a photo for forming the bank layer. By configuring the resist with a photoresist composition containing black pigment and a solvent having a boiling point of 60°C to 120°C, reflection by external light can be minimized and lifespan can be improved.

Description

Photoresist composition for organic light emitting display device and manufacturing method of organic light emitting display device using the same

The present specification relates to a photoresist composition for an organic light emitting display device and a method for manufacturing an organic light emitting display device using the same, and more particularly, to a photoresist composition for an organic light emitting display device capable of minimizing reflection by external light and improving lifespan. It relates to a resist composition and a method for manufacturing an organic light emitting display device using the same.

Recently, as we enter the information age, the display field that visually expresses electrical information signals has developed rapidly. is being developed.

Specific examples of such a display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), an organic light emitting display device ( Organic Light Emitting Display Device: OLED) and the like.

In particular, the organic light emitting display device is a self-light emitting device and has received wide attention because it has a fast response speed and a large light emitting efficiency, luminance, and viewing angle compared to other display devices.

In addition, an Organic Light Emitting Diode (OLED) applied to an organic light emitting display device is a next-generation light source having self-luminance characteristics, and has a viewing angle, contrast, and It has excellent advantages in terms of response speed and power consumption. In addition, since the organic light emitting device has a surface light emitting structure, it is easy to implement a flexible form.

Recently, based on many advantages of the organic light emitting device, active research has been conducted to use the organic light emitting device as a light source for lighting or display devices.

An organic light emitting display device includes an organic light emitting device and includes a bank layer capable of defining a pixel area of the organic light emitting device. The bank layer is made of a transparent material, and light transmitted from the outside by the transparent bank layer is reflected from a metal under the bank layer, resulting in increased reflection of external light in the organic light emitting display device. In addition, a low level of reflection of external light is required in a vehicle display device that is easy to implement in a flexible form, but the required level has not yet been reached.

Therefore, the inventor of the present invention recognizes the above-mentioned problems and improves the composition of the photoresist for forming the bank layer of the organic light emitting display device to minimize reflection by external light and minimize the solvent remaining in the bank layer. , experiments were conducted to improve the lifespan of organic light emitting display devices.

Therefore, through various experiments, an organic light emitting display device capable of improving the composition of the photoresist for forming the bank layer to minimize reflection by external light, minimize the solvent remaining in the bank layer, and improve the lifetime Invented.

An object to be solved according to an embodiment of the present specification is to provide a photoresist composition capable of minimizing reflection by external light and minimizing the solvent remaining in the bank layer by improving the composition of the photoresist for forming the bank layer. is to do

An object to be solved according to embodiments of the present specification is to provide a method of manufacturing an organic light emitting display device capable of improving lifespan by using a photoresist composition in which solvents remaining in a bank layer are minimized.

Solved problems according to embodiments of the present invention are not limited to the above-mentioned problems, and other problems not mentioned above will be clearly understood by those skilled in the art from the description below.

A photoresist composition for an organic light emitting display device according to an embodiment of the present specification includes an anode on a substrate, a bank layer on the anode, a cathode on the bank layer, and a light emitting portion between the anode and the cathode, The photoresist to be formed is composed of black pigment and a solvent having a boiling point of 60°C to 120°C.

A method of manufacturing an organic light emitting display device according to an embodiment of the present specification includes forming an anode on a substrate, forming a photoresist including black pigment and a solvent having a boiling point of 60°C to 120°C on the anode. Step, firing the photoresist, forming a bank layer in a partial region of the anode by photo-etching the photoresist, forming a light emitting unit on a partial region of the anode and the bank layer, and forming a cathode on the light emitting unit It includes steps to

Other embodiment specifics are included in the detailed description and drawings.

In embodiments of the present specification, reflection of external light of an organic light emitting display device can be minimized by configuring the bank layer to include black pigment.

In addition, in embodiments of the present specification, reflection of external light of an organic light emitting display device can be minimized by configuring the bank layer and the spacer to include black pigment.

In addition, in the embodiments of the present specification, since the bank layer and the spacer are formed of the same material including black pigment, they can be simultaneously formed by photolithography, thereby simplifying the process.

In addition, when the organic light emitting display according to the exemplary embodiments of the present specification including a bank layer including black pigment is applied to a display device for a vehicle, a display device capable of minimizing reflection by external light may be provided.

In addition, in the embodiments of the present specification, the photoresist for forming the bank layer is composed of a photoresist composition including black pigment and a solvent having a boiling point of 120 ° C or less, so that the solvent included in the bank layer is evaporated by a firing process. Therefore, it is possible to provide an organic light emitting display device in which the density of the bank layer is improved.

In addition, the embodiments of the present specification are composed of a photoresist composition containing black pigment and a solvent having a boiling point of 120 ° C or less as a photoresist for forming a bank layer, so that damage to the light emitting part due to outgassing can be prevented. , it is possible to provide an organic light emitting display device capable of improving lifespan.

In addition, in the embodiments of the present specification, the photoresist for forming the bank layer is composed of a photoresist composition containing black pigment and a solvent having a boiling point of 120 ° C or less, so that the density of the bank layer is improved and the bank layer is outgassed. Since it can serve as a barrier for , it is possible to provide an organic light emitting display device capable of improving lifespan.

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

Since the contents of the specification described in the problems to be solved, the means for solving the problems, and the effects above do not specify essential features of the claims, the scope of rights of the claims is not limited by the matters described in the contents of the specification.

1 is a diagram illustrating an organic light emitting display device according to an exemplary embodiment of the present specification.
2 is a diagram illustrating a method for measuring reflected luminance according to an embodiment of the present specification.
3 is a diagram illustrating an organic light emitting display device according to another exemplary embodiment of the present specification.
4 is a flowchart illustrating a method of manufacturing an organic light emitting display device according to another exemplary embodiment of the present specification.
5A to 5F are views illustrating a method of manufacturing an organic light emitting display device according to another exemplary embodiment of the present specification.
6 is a flowchart illustrating a method of manufacturing an organic light emitting display device according to another exemplary embodiment of the present specification.
7A to 7D are diagrams illustrating a manufacturing method of an organic light emitting display device according to another exemplary embodiment of the present specification.

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

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

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

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

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal precedence relationship is described in terms of 'after', 'following', 'next to', 'before', etc. It can also include non-continuous cases unless is used.

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

Each feature of the various embodiments of the present specification can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in an association relationship. may be

Hereinafter, looking at the embodiments of the present specification in detail through the accompanying drawings and embodiments are as follows.

1 is a diagram illustrating an organic light emitting display device according to an exemplary embodiment of the present specification.

An organic light emitting display device 1000 according to an exemplary embodiment of the present specification shown in FIG. 1 includes a substrate 101, a thin film transistor 130, a bank layer 160, a spacer 170, and an organic light emitting element (light-emitting device). emitting device, ED).

The organic light emitting diode (ED) is disposed on the thin film transistor 130 and includes an anode 102 , a light emitting unit 180 , and a cathode 104 .

The thin film transistor 130 includes an active layer, a gate electrode, a source electrode, and a drain electrode.

The bank layer 160 may define a pixel area of the organic light emitting display device 1000 and exposes a portion of the top surface of the anode 102 . Specifically, as shown in FIG. 1 , the bank layer 160 may be disposed to cover a portion of the anode 102 . The bank layer 160 is made of a transparent organic insulating material such as polyimide.

In addition, a fine metal mask (FMM), which is a deposition mask, is used to form the light emitting unit 180 in the pixel region that can be defined as the bank layer 160 . When a deposition mask is placed on the bank layer 160 to form the light emitting part 180, the bank layer 160 may be damaged due to contact between the bank layer 160 and the deposition mask. To prevent damage to the bank layer 160 and to maintain a distance between the bank layer 160 and the deposition mask, a spacer 170 is formed in a portion of the bank layer 160 . Also, the spacer 170 is made of polyimide, which is a transparent organic insulating material.

Since the bank layer 160 is formed of a transparent material, light incident from the outside is transmitted by the transparent bank layer 160 and is located under the bank layer 160 and is located under the anode 102 including a layer made of a metal material. It is reflected. Therefore, the organic light emitting display device 1000 has a problem in that reflection occurs due to external light. Also, when the organic light emitting display device 1000 is applied to a vehicle display device, reflection by external light makes it difficult to apply the organic light emitting display device 1000 to the vehicle display device.

Reflection by external light may be expressed as reflected luminance, and a method of measuring the reflected luminance will be described with reference to FIG. 2 .

2 is a diagram illustrating a method for measuring reflected luminance according to an embodiment of the present specification.

Referring to FIG. 2 , the reflected luminance is measured at a reflection angle of 30 degrees among several reflected lights A when light of 400 Knit is incident at 45 degrees in the organic light emitting display device 1000 (the incident light is indicated as “B” in FIG. 2 ). It refers to the luminance of the reflected light. This reflected luminance is measured with a DMS803 instrument. Taking the reflected luminance of the organic light emitting display device 1000 of FIG. 1 measured using this equipment as an example, the reflected luminance becomes more than 300 nit at a reflection angle of 30 degrees when incident at 400 Knit and an incident angle of 45 degrees. When the reflected luminance is more than 300 nits, the left and right viewing characteristics of the organic light emitting display device 1000 deteriorate due to reflection by external light. Therefore, in order to minimize reflection of external light of the organic light emitting display device 1000, the bank layer 160 should be made of a material that does not reflect light transmitted from the outside. Accordingly, the inventors of the present specification conducted several experiments to improve the material of the bank layer 160 .

The inventors of the present specification configured a photoresist for forming a bank layer with a composition containing black pigment to minimize reflection of external light through various experiments. And, the composition of the photoresist includes a solvent. This solvent is removed by a firing process before the photolithography process for forming the bank layer. However, when the solvent remains without being removed by the firing process, the density of the bank layer decreases and the lifetime of the organic light emitting display device decreases. Accordingly, the inventors of the present specification have invented a photoresist composition for an organic light emitting display device capable of minimizing reflection of external light and improving lifespan. Other embodiments of the present specification applying this will be described with reference to FIGS. 3 and 4a to 4f.

3 is a diagram illustrating an organic light emitting display device according to another exemplary embodiment of the present specification.

An organic light emitting display device 2000 according to another embodiment of the present specification shown in FIG. 3 includes a substrate 201, a thin film transistor 230, a bank layer 260, a spacer 270, and an organic light emitting device (light-emitting device). emitting device, ED).

The substrate 201 serves to support and protect various components of the organic light emitting display device 2000 . The substrate 201 may be made of an insulating material, and may be made of, for example, a material having flexibility such as glass or a polyimide-based material. When the organic light emitting display device 2000 is a flexible organic light emitting display device, the substrate 201 may be made of a flexible material such as plastic. In addition, when an organic light emitting device, which is easy to implement flexible, is applied to a vehicle lighting device or a vehicle display device, various designs and degrees of freedom in design of the vehicle lighting device or vehicle display device are provided according to the structure or exterior shape of the vehicle. can be secured

In addition, the organic light emitting display device 2000 according to another embodiment of the present specification is a TV, a mobile device, a tablet PC, a monitor, a laptop computer, and a vehicle display device. It can be applied to display devices including Alternatively, it may be applied to a curved display device, a wearable display device, a foldable display device, a rollable display device, and the like.

The organic light emitting display device 2000 of FIG. 3 or the substrate 201 of the organic light emitting display device 2000 includes a plurality of sub-pixels adjacent to each other. A sub-pixel is an area for displaying one color, and refers to an area of a minimum unit in which light is emitted, and may also be referred to as a sub-pixel area. In addition, a plurality of sub-pixels may be gathered to form one pixel capable of expressing white light. For example, a red sub-pixel, a green sub-pixel, and a A blue sub-pixel may be configured as one pixel. However, it is not limited thereto, and various pixel designs are possible.

A thin film transistor 230 is disposed on the substrate 201, and the thin film transistor 230 supplies a signal to the organic light emitting device ED. The thin film transistor 230 includes an active layer, a gate electrode, a source electrode, and a drain electrode. The active layer may be formed of amorphous silicon (a-Si), polycrystalline silicon (poly-Si), an oxide semiconductor, or an organic semiconductor. When the active layer is formed of an oxide semiconductor, it may be formed of ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IGZO (Indium Gallium Zinc Oxide), ITZO (Indium Tin Zinc Oxide), etc., but is limited thereto. It is not. Also, the thin film transistor 230 may have a coplanar structure or an inverted staggered structure.

And, a buffer layer may be further formed on the substrate 201 . The buffer layer may prevent penetration of moisture or impurities through the substrate 201 . The buffer layer is not necessarily a necessary configuration. Whether or not the buffer layer is formed is determined based on the type of substrate 201 or the type of thin film transistor 230 applied to the organic light emitting display device 2000 .

Further, the thin film transistor 230 includes a driving thin film transistor connected to the anode 202 of the organic light emitting diode (ED), and each sub-pixel of the organic light emitting display device 2000 drives the organic light emitting diode (ED). A switching thin film transistor or capacitor may be further included.

A planarization layer may be disposed on the thin film transistor 230 . The planarization layer is a layer for planarizing the upper portion of the thin film transistor 230, and the organic light emitting diode (ED) may be disposed on the planarization layer. In addition, at least one of the source electrode and the drain electrode of the thin film transistor 230 may be connected to the anode 202 through a contact hole provided in the planarization layer.

The organic light emitting diode (ED) is disposed on the thin film transistor 230 and includes an anode 202 , a light emitting unit 280 , and a cathode 204 .

The anode 202 is an electrode supplying holes to the light emitting unit 280 and may be made of a transparent conductive material having a high work function. Here, the transparent conductive material includes indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and indium gallium zinc oxide (IGZO). Gallium Zinc Oxide), but is not limited thereto.

Also, when the organic light emitting display device 2000 is implemented in a top emission method, the anode 202 may further include a reflective layer made of a metal material. For example, the anode 202 may have a two-layer structure in which a transparent layer and a reflective layer are stacked, or a three-layer structure in which a transparent layer, a reflective layer, and a transparent layer are stacked. The transparent layer may be made of the above-mentioned transparent conductive material. In addition, the metal material constituting the reflective layer is copper (Cu), silver (Ag), palladium (Pd), aluminum (Al), platinum (At), gold (Au), chromium (Cr), tungsten (T), mole It may be made of ribdenium (Mo), titanium (Ti), iridium (Ir), etc., but is not limited thereto. Here, the anode 202 may also be referred to as a pixel electrode.

The cathode 204 is an electrode supplying electrons and may be made of a metallic material having a relatively low work function. For example, the cathode 204 is silver (Ag), titanium (Ti), aluminum (Al), molybdenum (Mo), an alloy of silver (Ag) and magnesium (Mg) (Ag:Mg), magnesium (Mg) and lithium fluoride alloy (Mg:LiF), but is not limited thereto. Here, the cathode 204 may also be referred to as a common electrode.

The light emitting unit 280 may include an organic light emitting layer. The organic light emitting display device 2000 may have a patterned emission layer structure according to design. An organic light emitting display device having a patterned light emitting layer structure has a structure in which light emitting layers emitting different colors are separated for each pixel. For example, a red organic light emitting layer for emitting red light, a green organic light emitting layer for emitting green light, and a blue organic light emitting layer for emitting blue light are respectively a red sub-pixel, a green sub-pixel, and a blue sub-pixel. It may be configured separately from the pixel. In each of the red organic light emitting layer, the green organic light emitting layer, and the blue organic light emitting layer, holes and electrons supplied through the anode 202 and the cathode 204 are combined with each other to emit light. Each organic emission layer may be pattern-deposited using a mask opened for each sub-pixel, for example, a fine metal mask (FMM).

Between the anode 202 and the cathode 204, in addition to the organic light emitting layer, at least one organic layer of an injection layer and a transporting layer for improving light emitting efficiency of the organic light emitting device may be further disposed. At least some of the organic layers may have a common structure that is commonly disposed in a plurality of sub-pixels in order to take advantage of a manufacturing process.

Here, the layer having a common structure can be formed using a common mask in which all sub-pixels have openings, and can be stacked with the same structure in all sub-pixels without a pattern for each sub-pixel. That is, since a layer having a common structure is connected or extended from one sub-pixel to a neighboring sub-pixel without being disconnected, it is shared by a plurality of sub-pixels. A layer having a common structure may be referred to as a common layer or a layer of a common structure.

For example, between the anode 202 and the cathode 204, in addition to the organic light emitting layer, a hole injection layer for more smooth movement of holes, a hole transporting layer, and a hole transporting layer p At least one of the p-type hole transport layers doped with a type dopant may be further disposed. The hole injection layer, the hole transport layer, and the p-type hole transport layer may have a common structure that is commonly disposed in a plurality of sub-pixels. Also, an electron injection layer or an electron transporting layer may be further disposed to facilitate electron movement. The electron injection layer or the electron transport layer may have a common structure that is commonly disposed in a plurality of sub-pixels.

Also, the bank layer 260 may define sub-pixels, and the bank layer 260 may be disposed to cover a partial area of the anode 302 .

The bank layer 260 is formed by photolithography. That is, in order to form the bank layer 260 , photoresist (PR) is formed on the anode 202 and then the bank layer 260 is formed by a photolithography process.

Photoresist refers to a photosensitive resin capable of obtaining a pattern by changing its solubility in a developing solution by the action of light. Photoresists can be classified into positive photoresists and negative photoresists. The positive photoresist increases the solubility of the exposed portion in the developing solution, so that the exposed portion is removed during the development process, thereby obtaining a pattern. In addition, since the solubility of the negative photoresist in the developing solution of the exposed portion is lowered, the unexposed portion is removed in the developing process, thereby obtaining a pattern.

In order to minimize reflection by external light of the organic light emitting display device 2000, the bank layer 260 should be made of a material that minimizes reflection of external light. Accordingly, the photoresist for forming the bank layer 260 may be made of a material containing black pigment. Black pigment may be composed of organic or inorganic materials. In addition, the black pigment may be composed of carbon-based or metal oxide. In addition, the photoresist may include photosensitive compounds including at least one of a polymer, a monomer, and a photoinitiator. And, the photoresist may include a solvent dispersing the photosensitive compound.

Looking at the reaction mechanism, before exposure, the photoresist has a form in which black pigment is dispersed in a photosensitive compound by a solvent. And, after exposure, the photoinitiator included in the photosensitive compound generates radicals by light. In addition, the monomer included in the photoresist has a double bond, and thus cross-links by reacting with radicals of the photoinitiator. Accordingly, since a photoresist having a high molecular weight is formed after exposure, it is not dissolved by a developing solution. After that, in the process of developing using a developer, the portion not dissolved by the developer becomes the bank layer 260, and the portion dissolved by the developer is removed. Accordingly, the photoresist forming the bank layer 260 may be referred to as a negative photoresist.

In addition, the photoinitiator included in the photoresist may include an imine-based photoinitiator in order to improve crosslinking after exposure. The imine-based photoinitiator may include, for example, at least one of oxime and oxime ester. An oxime or oxime ester is a long-wavelength photoinitiator that can enhance crosslinking. Here, the long wavelength refers to 365 nm or more. In addition, a light source used during exposure is a high-pressure mercury lamp and has several wavelengths. Several wavelengths may be 436 nm for G-line, 405 nm for H-line, and 365 nm for I-line. Among them, a photolithography process is performed using an I-line of 365 nm or more.

In addition, since oxime or oxime ester can minimize by-products generated after exposure, impurities generated when by-products react with other molecules in a baking process, which is a subsequent process after crosslinking, can be minimized. In addition, since oxime or oxime ester is used together with the black pigment, there is an effect of forming the bank layer 260 having high light blocking properties. Alternatively, acetophenone may be further included in the oxime or oxime ester as the photoinitiator.

For example, oxime may be represented by Formula 1 below.

[Formula 1]

Here, R and R' may be either an alkyl group having 1 to 15 carbon atoms or a phenyl group.

For example, the oxime ester may be represented by Formula 2 below.

[Formula 2]

Here, R is an aryl group, and R' may be either an alkyl group having 1 to 15 carbon atoms or a phenyl group.

The monomer may include a 6-functional group, and may include, for example, DPHA (DiPentaerythritol HexaAcrylate). This DPHA has a double bond and can be rapidly cured by light after crosslinking. Accordingly, the photoresist for forming the bank layer 260 can be formed as a hard film, and the developing resistance is improved so that the bank layer 260 is not lost even in a developing process with a high concentration of the developing solution.

And, the polymer of the photoresist includes a cardo-based polymer. Cardo-based polymers have excellent heat resistance, compatibility with pigments, and excellent solubility. In addition, the polymer of the photoresist may further include epoxy acrylate. Therefore, the polymer of the photoresist including cardo-based or epoxy acrylate serves to improve the dispersibility by allowing the black pigment to be dispersed in the polymer. Dispersibility refers to the uniformity of the photoresist, and as the dispersibility is improved, a more uniform bank layer 260 can be formed.

For example, a cardo-based polymer may be represented by [Formula 3] below.

[Formula 3]

And, the developer may be, for example, TMAH (TetraMethylAmmoniumHydroxide) or KOH (Potassium Hydroxide).

Accordingly, since the bank layer 260 includes the black pigment, optical density (OD) representing the degree of light blocking is increased. When the optical density is increased, reflection by external light can be minimized.

That is, since the bank layer 260 is made of a material containing black pigment, when the incident angle of incident light is 45 degrees, the reflected luminance at a reflection angle of 30 degrees can be configured to be 30 nit or less. Accordingly, the reflected luminance may be reduced by improving reflection by external light. The reflected luminance of the bank layer 260 is measured by DMS803. Here, the reflected luminance may include reflected luminance from left and right sides of the organic light emitting display device. That is, the left and right reflected luminance may be 30 nit or less at a reflection angle of 30 degrees when the incident angle of incident light is 45 degrees. In addition, when the organic light emitting display device is applied to a vehicle display device, a display device in which reflection by external light is minimized may be provided. In addition, since reflection of external light of the organic light emitting display device can be minimized, luminous characteristics of the organic light emitting display device in the left and right directions can be improved.

The solvent included in the photoresist may be removed in a vacuum drying process or a curing process prior to the photolithography process. As the solvent, at least one of PGMEA (Propylene Glycol Monomethyl Ether Acetate), MBA (3-Methoxy Butyl Acetate), and EP (Ethyl-3-ethoxy Propionate) is used. The boiling point of PGMEA is 146°C, that of MBA is 172°C, and that of EP is 166°C. In the case of a solvent with a high boiling point, the solvent remains without evaporation even after the firing process. The solvent remaining in the photoresist lowers cross-linking between the photoinitiator and the monomer during the exposure process. When the cross-linking is lowered, the film of the photoresist cannot be firmly formed, and the density of the photoresist is lowered. In addition, there is a problem in that the remaining solvent that is not evaporated in the firing process cannot be removed because it is not dissolved in water even in the developing process.

Also, when the bank layer 260 is not formed as a hard film, the bank layer 260 cannot serve as a barrier against outgassing occurring in the planarization layer of the thin film transistor. Therefore, since the organic light emitting device ED is damaged by outgassing, a problem in that the lifetime of the organic light emitting display device 2000 is reduced. Here, outgassing refers to the discharge of a gaseous compound having a negative charge from an organic material constituting the planarization layer. The gas compound reacts with the organic layer constituting the light emitting unit 280 . For example, when a gaseous compound reacts with the hole injection layer, the hole injection layer loses positive charge, making it impossible to inject holes into the light emitting layer. Accordingly, the light emitting unit 280 deteriorates, resulting in a decrease in lifespan of the organic light emitting display device 2000 . Also, outgassing may occur when the organic light emitting display device 2000 is exposed to external light such as UV for a long time.

Therefore, the solvent of the photoresist should be improved so that the solvent evaporated in the firing process and remaining in the photoresist is minimized. And, if the solvent remains without evaporation in the firing process, the remaining solvent must be removed in the developing process. That is, it is composed of a material with a boiling point of 120 ° C or less so that it can be evaporated in the firing process, and it is composed of a material with good solubility in water so that it can be removed in the developing process. By configuring the solvent with a material having a boiling point of 60°C to 120°C, the amount of solvent remaining in the photoresist that evaporates during the firing process can be minimized. In addition, by configuring the material with good solubility in water, even the remaining solvent that is not evaporated in the firing process can be removed in the developing process. Accordingly, the solvent of the photoresist may include at least one of methanol, ethanol, isopropyl alcohol, and glycol ethers (1,2-dimethoxy ethane). Glycol ethers may also be referred to as glymes. In addition, isopropyl alcohol is a solvent that evaporates easily without leaving stains. Methanol has a boiling point of 64.7°C, ethanol has a boiling point of 78.3°C, isopropyl alcohol has a boiling point of 82.6°C, and glycol ether has a boiling point of 85°C. That is, since the boiling point of the solvent is not high, it can evaporate even at room temperature.

Therefore, since the solvent of the photoresist has a boiling point of 120 ° C or less and is composed of a material with good solubility in water, the solvent can be almost evaporated in the firing process, so the solvent remaining in the anode 202 after forming the bank layer can be minimized. As a result, since crosslinking in the exposure process can be improved, the density of the bank layer 260 can be improved. Since the density of the bank layer 260 is improved, the bank layer 260 may serve as a barrier against outgassing. Therefore, since damage to the light emitting unit 280 due to outgassing can be reduced, the lifetime of the organic light emitting display device 2000 can be improved.

The photoresist composition for forming the bank layer 260 includes black pigment and a solvent having a boiling point of 120°C or less. The solvent may include at least one of methanol, ethanol, isopropyl alcohol, and glycol ethers (1,2-dimethoxy ethane). And, the photoresist may further include at least one of a polymer, a monomer, and a photoinitiator. The polymer of the photoresist may include at least one of cardo-based and epoxy acrylate. A monomer of the photoresist may include 6 functional groups. The photoinitiator of the photoresist may include at least one of an oxime and an oxime ester.

Also, the spacer 270 may be disposed in a partial region of the bank layer 260 and may be formed in an region other than a sub-pixel of the organic light emitting display device 2000 . That is, the spacer 270 may be disposed in the non-pixel area. The non-pixel area may be an area other than a light emitting area. The spacer 270 may be formed of one of transparent materials such as polyimide, photo acryl, and benzocyclobutene (BCB).

A method of manufacturing the organic light emitting display of FIG. 3 will be described below with reference to FIGS. 4 and 5A to 5F.

4 is a flowchart illustrating a method of manufacturing an organic light emitting display device according to another exemplary embodiment of the present specification. 5A to 5F are cross-sectional views of process steps for explaining a manufacturing method of an organic light emitting display device according to another exemplary embodiment of the present specification.

Referring to FIG. 4 , a method of manufacturing an organic light emitting display device 2000 according to another embodiment of the present invention includes forming an anode on a substrate (S410), black pigment on the anode, and a boiling point of 120°C or less. Forming a first photoresist containing a solvent (S420), firing the first photoresist (S430), photo-etching the first photoresist to form a bank layer in a partial region of the anode (S440) , Forming a second photoresist on the bank layer (S450), photo-etching the second photoresist to form a spacer on the bank layer (S460), forming a light emitting part on a partial region of the anode and on the spacer Step S470, and forming a cathode on the light emitting unit (S480).

First, referring to FIG. 5A , a thin film transistor 230 is formed on a substrate 201 . The thin film transistor 230 includes an active layer, a gate electrode, a source electrode, and a drain electrode. A planarization layer may be further disposed on the thin film transistor 230 . The planarization layer includes a contact hole for electrically connecting one of the source electrode and the drain electrode of the thin film transistor 230 and the anode 202 in each sub-pixel. Then, the anode 202 is formed on the substrate 201 including the thin film transistor 230 (S410).

And, as shown in Figure 5a, to form a first photoresist 291 containing black pigment and a solvent having a boiling point of 120 ° C or less on the anode 202 (S420). The first photoresist 291 may include at least one of a polymer, a monomer, and a photoinitiator. The polymer of the first photoresist 291 may include cardo-based acrylate and epoxy acrylate. Also, the monomer of the first photoresist 291 may include a hexafunctional group, for example, DPHA (DiPentaerythritol HexaAcrylate). Also, the photoinitiator of the first photoresist 291 may include one of oxime and oxime ester. The solvent of the first photoresist 291 may include at least one of methanol, ethanol, isopropyl alcohol, and glycol ethers (1,2-dimethoxy ethane). can The boiling point of the solvent of the first photoresist 291 may be 60°C to 120°C.

Then, the first photoresist 291 is fired (S430). In this firing process, the solvent of the first photoresist 291 evaporates. That is, the step of baking the first photoresist 291 includes the step of evaporating the solvent of the first photoresist 291 . The firing process may be carried out for about 1 hour at a temperature of 230 ° C, but is not limited thereto.

And, as shown in FIGS. 5A and 5B, after the step of baking the first photoresist 291, a mask is placed on the first photoresist 291, and then an exposure process and a development process, which are photolithography processes, are performed. do. The mask is composed of a transmission area M1 and a blocking area M2. The first photoresist 291 corresponding to the transmission region M1 forms the bank layer 260 in the first region (a). The blocking region M2 of the mask is a region blocked by light, and exposes the second region (b) through a developing process. A light emitting unit 280 may be formed in the second region (b). Specifically, the first photoresist 291 of the transmission area M1 exposed to light through a mask is made of a polymer crosslinked by light and does not react with a developer, and the blocking area not exposed to light. The first photoresist 291 of (M2) reacts with the developer and is removed. Accordingly, the first photoresist 291 may be a negative photoresist. After the developing process, a baking process, which is a heating process, is performed to form the bank layer 260 (S440).

Accordingly, the forming of the bank layer 260 includes disposing a mask including a transmission region M1 and a blocking region M2 on the first photoresist 291, and taking a photo of the first photoresist 291. The first photoresist 291 corresponding to the blocking region M2 by etching is removed to expose a partial region of the anode 202, and the first photoresist 291 corresponding to the transmission region M1 is the anode 202 ) may include forming the bank layer 260 in a partial region.

In addition, since the bank layer 260 includes black pigment, light is absorbed during an exposure process, and thus a process using a halftone mask may be difficult. In order to solve this problem, it can be improved by increasing the exposure amount during the exposure process. For example, the exposure amount may be in the range of 40 mJ to 100 mJ.

As shown in FIGS. 5C and 5D , a second photoresist 292 is formed on the bank layer 260 (S450). Then, after disposing a mask on the second photoresist 292, an exposure process and a development process, which are photolithography processes, are performed. The mask is composed of a transmission area M1 and a blocking area M2. The second photoresist 292 corresponding to the blocking region M2 forms spacers 270 in the third region (c). The transmission region M1 of the mask is a region that is transmitted by light, and exposes the fourth region (d) by a developing process. Specifically, the second photoresist 292 of the transmission region M1 exposed to light through the mask is removed by reacting with a developer, and the second photoresist 292 of the blocking region M2 that is not exposed to light ( 292) does not react with the developer. Accordingly, the second photoresist 292 may be a positive photoresist. After the developing process, a baking process, which is a heating process, is performed to form spacers 270 (S460).

Accordingly, the step of forming the spacer 270 includes forming the second photoresist 292 on the bank layer 260, and disposing a mask including a transmission region and a blocking region on the second photoresist 292. In the step of photo-etching the second photoresist 292, the second photoresist 292 corresponding to the transmission region M1 is removed, and the second photoresist 292 corresponding to the blocking region M2 is bank It may include forming spacers 270 on layer 260 . In addition, the spacer may be composed of one of polyimide, photo acryl, and benzocyclobutene (BCB).

Then, as shown in FIG. 5E, a light emitting unit 280 is formed on a partial region of the anode 202 and the spacer 270 (S470). The light emitting unit 280 may include an organic light emitting layer. The organic light emitting display device may have a patterned emission layer structure according to design. An organic light emitting display device having a patterned light emitting layer structure has a structure in which light emitting layers emitting different colors are separated for each pixel. For example, a red organic light emitting layer for emitting red light, a green organic light emitting layer for emitting green light, and a blue organic light emitting layer for emitting blue light are respectively a red sub-pixel, a green sub-pixel, and a blue sub-pixel. It can be configured separately in . In each of the red organic light emitting layer, the green organic light emitting layer, and the blue organic light emitting layer, holes and electrons supplied through the anode 202 and the cathode 204 are combined with each other to emit light. Each organic emission layer may be pattern-deposited using a mask opened for each sub-pixel, for example, a fine metal mask (FMM). Between the anode 202 and the cathode 204, in addition to the organic light emitting layer, at least one organic layer of an injection layer and a transporting layer for improving light emitting efficiency of the organic light emitting device may be further disposed.

As shown in FIG. 5F, a cathode 204 is formed on the light emitting part 280 (S480).

Also, even if the bank layer 260 is made of a material containing black pigment, if the spacer 270 is made of a transparent material, scattering of light occurs, so that the effect of suppressing the reflection of external light by the bank layer 260 can be reduced. have.

Accordingly, the spacer may be made of the same material as the bank layer in order to minimize reflection and scattering of external light of the organic light emitting display device 2000 and to simplify a process. That is, since the bank layer and the spacer can be simultaneously formed using the halftone process, the process can be simplified. This will be described with reference to FIGS. 6 and 7A to 7D.

6 is a flowchart illustrating a method of manufacturing an organic light emitting display device according to another exemplary embodiment of the present specification. 7A to 7D are cross-sectional views of process steps for explaining a manufacturing method of an organic light emitting display device according to another exemplary embodiment of the present specification.

Referring to FIG. 6 , a method of manufacturing an organic light emitting display device 2000 according to another embodiment of the present invention includes forming an anode on a substrate (S610), black pigment on the anode, and a boiling point of 120°C. Forming a photoresist containing the following solvent (S620), firing the photoresist (S630), photo-etching the photoresist to form a bank layer and a spacer (S640), on a portion of the anode and the spacer forming a light emitting unit (S650), and forming a cathode on the light emitting unit (S660).

First, referring to FIG. 7A , a thin film transistor 330 is formed on a substrate 301 . The thin film transistor 330 includes an active layer, a gate electrode, a source electrode, and a drain electrode. A planarization layer may be further disposed on the thin film transistor 330 . The planarization layer includes a contact hole for electrically connecting one of the source electrode and the drain electrode of the thin film transistor 330 and the anode 302 in each sub-pixel. Then, the anode 301 is formed on the substrate 301 including the thin film transistor 330 (S610).

As shown in FIG. 7A, a photoresist 390 including black pigment and a solvent having a boiling point of 120° C. or less is formed on the anode 301 (S620). The photoresist 390 may include at least one of a polymer, a monomer, and a photoinitiator. The polymer of the photoresist 390 may include cardo-based acrylate and epoxy acrylate. In addition, the monomer of the photoresist 390 may include a hexafunctional group, for example, DPHA (DiPentaerythritol HexaAcrylate). Also, the photoinitiator of the photoresist 390 may include one of oxime and oxime ester. Also, the solvent of the photoresist 390 may include at least one of methanol, ethanol, isopropyl alcohol, and glyme (1,2-dimethoxy ethane). The boiling point of the solvent of the photoresist 390 may be between 60°C and 120°C.

Then, the photoresist 390 is fired (S630). In this firing process, the solvent of the photoresist 390 evaporates. That is, the step of baking the photoresist 390 includes evaporating the solvent of the photoresist 390 . The firing process may be carried out for about 1 hour at a temperature of 230 ° C, but is not limited thereto.

And, as shown in FIGS. 7A and 7B, after the firing of the photoresist 390, a mask is placed on the photoresist 390, and then an exposure process and a development process, which are photolithography processes, are performed. The mask is a halftone mask, and is composed of masks having different transmittances of light. That is, the mask is composed of a transmissive area M1, a blocking area M2, and a semi-transmissive area M3. The photoresist 390 corresponding to the transflective region M3 forms the bank layer 360 in the third region (c). The photoresist 390 corresponding to the transmissive region M1 forms spacers 370 on the bank layer 360 in the first region (a). The blocking region M3 of the mask is a region blocked by light, and exposes the second region (b) through a developing process. A light emitting unit 380 may be formed in the second region (b). Specifically, the photoresist 390 in the transmissive region M1 and the semi-transmissive region M3 exposed to light through a mask is a polymer crosslinked by light, so that it does not react with a developer and does not react to light. The photoresist 390 in the unexposed blocking region M3 reacts with the developer and is removed. Thus, the photoresist 390 may be a negative photoresist. After the developing process, a baking process, which is a heating process, may be performed to form the bank layer 360 and the spacer 370 (S640).

Accordingly, forming the bank layer 360 may include forming the spacer 370 on the bank layer 360 . That is, the step of forming the bank layer 360 and the spacer 370 is a step of disposing a mask including a transmissive region, a semi-transmissive region, and a blocking region on the photoresist 390, and taking a photo of the photoresist 390. By etching, the photoresist 390 corresponding to the blocking area is removed to expose a partial area of the anode 302, and the photoresist 390 corresponding to the semi-transmissive area is partially exposed to the bank layer 360 of the anode 302. ), and the photoresist 390 corresponding to the transmissive region may include forming a spacer 370 in a partial region of the bank layer 360 .

Since the spacer 370 is made of the same material as the photoresist used to form the bank layer 360, the bank layer 360 and the spacer 370 may be simultaneously formed through a halftone process. Therefore, there is an effect of simplifying the process.

In addition, since the bank layer 360 and the spacer 370 contain black pigment, light is absorbed during an exposure process, making it difficult to apply a half-tone process. In order to solve this problem, an exposure amount may be increased during an exposure process. For example, the exposure amount may be in the range of 40 mJ to 100 mJ.

Then, as shown in FIG. 7C, a light emitting unit 380 is formed on a partial region of the anode 302 and the spacer 370 (S650). The light emitting unit 380 may include an organic light emitting layer. The organic light emitting display device may have a patterned emission layer structure according to design. An organic light emitting display device having a patterned light emitting layer structure has a structure in which light emitting layers emitting different colors are separated for each pixel. For example, a red organic light emitting layer for emitting red light, a green organic light emitting layer for emitting green light, and a blue organic light emitting layer for emitting blue light are respectively a red sub-pixel, a green sub-pixel, and a blue sub-pixel. It can be configured separately in . In each of the red organic light emitting layer, the green organic light emitting layer, and the blue organic light emitting layer, holes and electrons supplied through the anode 302 and the cathode 304 are combined with each other to emit light. Each organic emission layer may be pattern-deposited using a mask opened for each sub-pixel, for example, a fine metal mask (FMM). In addition to the organic light emitting layer, organic layers such as an injection layer and a transporting layer may be further disposed between the anode 302 and the cathode 304 to improve light emitting efficiency of the organic light emitting device.

As shown in FIG. 7D, a cathode 304 is formed on the light emitting part 380 (S660).

A photoresist composition for an organic light emitting display device and a method of manufacturing the organic light emitting display device using the photoresist composition according to an embodiment of the present specification can be described as follows.

A photoresist composition for an organic light emitting display device according to an embodiment of the present specification includes an anode on a substrate, a bank layer on the anode, a cathode on the bank layer, and a light emitting portion between the anode and the cathode, The photoresist to be formed is composed of black pigment and a solvent having a boiling point of 60°C to 120°C.

The solvent may include at least one of methanol, ethanol, isopropyl alcohol, and glycol ethers (1,2-dimethoxy ethane).

The photoresist may include at least one of a polymer, a monomer, and a photoinitiator.

The polymer may include at least one of a cardo-based polymer and an epoxy acrylate polymer, the monomer may include 6 functional groups, and the photoinitiator may include at least one of an oxime and an oxime ester.

A spacer may be further included on the bank layer, and the spacer may be made of the same material as a photoresist for forming the bank layer.

A method of manufacturing an organic light emitting display device according to an embodiment of the present specification includes forming an anode on a substrate, forming a first photoresist including black pigment and a solvent having a boiling point of 60°C to 120°C on the anode. Forming a step, firing a first photoresist, photo-etching the first photoresist to form a bank layer in a partial region of the anode, forming a light emitting portion on a partial region of the anode and the bank layer, and emitting light and forming a cathode on the side.

Baking the first photoresist may include evaporating the solvent.

The method may further include disposing a mask including a transmission region and a blocking region on the photoresist after the firing of the first photoresist.

In the forming of the bank layer, the first photoresist is photo-etched, the first photoresist corresponding to the blocking region is removed to expose a partial region of the anode, and the first photoresist corresponding to the transmission region is partially exposed to the anode. A step of forming a bank layer may be included.

After forming the bank layer, a step of forming spacers on the bank layer may be further included.

The forming of the spacer may include forming a second photoresist on the bank layer, disposing a mask including a transmission region and a blocking region on the second photoresist, and photo-etching the second photoresist to transmit light. The second photoresist corresponding to the region may be removed, and the second photoresist corresponding to the blocking region may include forming a spacer on the bank layer.

Forming the bank layer may include forming spacers on the bank layer.

The forming of the bank layer and the spacer may include disposing a mask including a transmissive region, a semi-transmissive region, and a blocking region on a first photoresist, and photo-etching the first photoresist to obtain a first photoresist corresponding to the blocking region. 1 The photoresist is removed to expose a partial region of the anode, the first photoresist corresponding to the transflective region forms a bank layer in the partial region of the anode, and the first photoresist corresponding to the transmissive region is formed on the bank layer It may include forming a spacer.

The solvent may include at least one of methanol, ethanol, isopropyl alcohol, and glycol ethers (1,2-dimethoxy ethane).

The photoresist may include at least one of a polymer, a monomer, and a photoinitiator.

The polymer may include at least one of a cardo-based polymer and an epoxy acrylate polymer, the monomer may include 6 functional groups, and the photoinitiator may include at least one of an oxime and an oxime ester.

When an incident angle of light incident on the organic light emitting display device is 45 degrees, the reflected luminance at a reflection angle of 30 degrees of the organic light emitting display device may be less than 30 nits.

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

However, the present invention is not necessarily limited to these embodiments, and may be variously modified and implemented without departing from the technical spirit of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. The protection scope of the present invention should be construed according to the scope of the claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

1000, 2000: organic light emitting display device
102, 202, 302: anode 104, 204, 304: cathode
160, 260, 360: bank layer
170, 270, 370: spacer 180, 280, 380: light emitting part
ED: organic light emitting device 130, 230, 330: thin film transistor
291, 292, 390: photoresist

Claims (17)

an anode on a substrate;
a bank layer on the anode;
a cathode on the bank layer; and
A light emitting unit between the anode and the cathode,
The photoresist composition for forming the bank layer includes a black pigment and a solvent having a boiling point of 60 ° C to 120 ° C, a photoresist composition for an organic light emitting display device. According to claim 1,
A photoresist composition for an organic light emitting display device, wherein the solvent includes at least one of methanol, ethanol, isopropyl alcohol, and glycol ethers (1,2-dimethoxy ethane) . According to claim 1,
The photoresist composition includes at least one of a polymer, a monomer, and a photoinitiator. According to claim 3,
The polymer includes at least one of a cardo-based polymer and an epoxy acrylate polymer, the monomer includes 6 functional groups, and the photoinitiator includes at least one of an oxime and an oxime ester. , A photoresist composition for an organic light emitting display device. According to claim 1,
A photoresist composition for an organic light emitting display device, further comprising a spacer on the bank layer, wherein the spacer is made of the same material as a photoresist for forming the bank layer. forming an anode on the substrate;
Forming a first photoresist containing black pigment and a solvent having a boiling point of 60 ° C to 120 ° C on the anode;
firing the first photoresist;
forming a bank layer in a partial region of the anode by photo-etching the first photoresist;
forming a light emitting unit on a portion of the anode and on the bank layer; and
A method of manufacturing an organic light emitting display device comprising forming a cathode on the light emitting part. According to claim 6,
Wherein the firing of the first photoresist comprises evaporating the solvent. According to claim 6,
The method of manufacturing the organic light emitting display device further comprising the step of disposing a mask including a transmission region and a blocking region on the first photoresist after the step of firing the first photoresist. According to claim 8,
In the forming of the bank layer, a first photoresist is photoetched to remove the first photoresist corresponding to the blocking region to expose a partial region of the anode, and the first photoresist corresponding to the transmission region and forming the bank layer on a partial region of the anode. According to claim 6,
The method of manufacturing the organic light emitting display device further comprising forming a spacer on the bank layer after the forming of the bank layer. According to claim 10,
Forming the spacer,
forming a second photoresist on the bank layer;
disposing a mask including a transmission area and a blocking area on the second photoresist; and
Photo-etching the second photoresist to remove the second photoresist corresponding to the transmission region, and forming the spacer on the bank layer from the second photoresist corresponding to the blocking region. , Method of manufacturing an organic light emitting display device. According to claim 6,
The method of claim 1 , wherein the forming of the bank layer includes forming spacers on the bank layer. According to claim 12,
Forming the bank layer and the spacer may include:
disposing a mask including a transmissive region, a semi-transmissive region, and a blocking region on the first photoresist; and
The first photoresist is photo-etched to remove the first photoresist corresponding to the blocking region to expose a partial region of the anode, and the first photoresist corresponding to the semi-transmissive region partially exposes the anode. and forming a bank layer on the first photoresist corresponding to the transmissive region and forming a spacer on the bank layer. According to claim 6,
The method of claim 1 , wherein the solvent includes at least one of methanol, ethanol, isopropyl alcohol, and glycol ethers (1,2-dimethoxy ethane). According to claim 6,
The method of claim 1 , wherein the photoresist includes at least one of a polymer, a monomer, and a photoinitiator. According to claim 15,
The polymer includes at least one of a cardo-based polymer and an epoxy acrylate polymer, the monomer includes 6 functional groups, and the photoinitiator includes at least one of an oxime and an oxime ester. , Method of manufacturing an organic light emitting display device. According to claim 6,
Wherein the organic light emitting display device has a reflected luminance of 30 nit or less at a reflection angle of 30 degrees when an incident angle of light incident on the organic light emitting display device is 45 degrees.

Images