KR102135920B1 - Organic Emitting Display Device and Manufacturing Method of the Same - Google Patents

Abstract

In the present invention, when sealing using a metal thin film, by treating the surface of the metal thin film on the substrate including the organic light emitting element array to increase the hardness of the metal film, it is possible to prevent defects due to foreign substances. An organic light emitting display device and a method of manufacturing the same, wherein the method of manufacturing the organic light emitting display device of the present invention comprises: preparing a substrate including an array of organic light emitting elements; and reacting nitrogen or carbon with the surface of the metal thin film , By heat-treating the metal thin film at a high temperature, the metal thin film is layered to a high hardness surface layer and a back layer; And it characterized in that it comprises a step of sealing, including an adhesive layer between the back layer of the metal thin film and the substrate including the organic light emitting device array.

Description

Organic light emitting display device and manufacturing method thereof {Organic Emitting Display Device and Manufacturing Method of the Same}

The present invention relates to an organic light emitting display device, and in particular, when sealing using a metal thin film, the surface of the metal thin film is processed on the substrate including the organic light emitting element array to increase the hardness thereof to external foreign matter. The present invention relates to an organic light emitting display device capable of preventing defects and a method for manufacturing the same.

With the advent of the full-fledged information age, the display field for visually displaying electrical information signals is rapidly developing. Accordingly, research is being conducted to develop performance of thinning, lightening, and low power consumption for various flat display devices.

Typical examples of such a flat panel display device are a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electroluminescent display device. (Electro Luminescence Display device: ELD), Electro-Wetting Display device (EWD), and organic light emitting display device (OLED).

These flat panel display devices in common, essentially include a flat panel display panel for realizing an image. The flat panel display panel is a structure in which a pair of substrates with unique light emitting materials or polarizing materials interposed therebetween.

Among them, the organic light emitting display device is a device that displays an image by using an organic light emitting diode, which is a self-emission type element.

Hereinafter, a general organic light emitting device will be described.

A typical organic light emitting device includes, on a substrate, first and second electrodes that face each other, and a light emitting layer formed therebetween as a basic configuration, and emits light based on a driving current flowing between the first electrode and the second electrode. . Here, in the light emitting layer, holes and electrons recombine to generate light.

In addition, a hole transport layer between the first electrode and the light emitting layer for easy hole transport from the first electrode to the light emitting layer, and an electron transport layer between the second electrode and the light emitting layer for easy electron transport from the second electrode to the light emitting layer. Can be formed.

In some cases, the hole transport layer may further include a hole injection layer adjacent to the first electrode, and the electron transport layer may further include an electron injection layer adjacent to the second electrode. Each hole injection layer may be formed integrally with the hole transport layer or may be formed with another layer, and the electron injection layer may also be formed integrally with the electron transport layer or as a separate layer.

Here, the components of the layers included between the first electrode and the second electrode are organic substances, and these organic substance layers are formed by vaporizing the components of the layer and sequentially depositing them on a substrate.

In addition, the organic light emitting display device using the above-described organic light emitting device has an advantage that it can be thinned.

The organic light emitting display device includes an organic material layer that is vulnerable to moisture or outside air, and thus encapsulation is required to block it from the outside.

As a method of encapsulation, a substrate on which an organic light emitting layer is formed and a counter substrate are placed and sealed with a sealant at the edge, and a method in which an organic or inorganic film of a thin film is alternately laminated and sealed on a substrate on which an organic light emitting layer is formed, and a metal foil ).

Recently, a bag using a metal thin film has been preferred because of its convenience, flexibility, and excellent external barrier.

However, the conventional organic light emitting display device as described above has the following problems.

The metal thin film has good flexibility in material, but when foreign matters correspond to the surface, there may be defects or scratches, which may deteriorate the image display.

The present invention has been devised to solve the above problems, and when sealing using a metal thin film, the surface of the metal thin film is processed on the substrate including the organic light emitting element array to increase its hardness. , An object of the present invention is to provide an organic light emitting display device and a method of manufacturing the same, which can prevent defects caused by foreign substances.

An organic light emitting display device of the present invention for achieving the above object is a substrate including an organic light emitting element array; And a metal thin film made of a double layer having a hardness of a surface layer higher than that of a back surface layer by sealing the organic light emitting element array through an adhesive layer between the substrate and the surface. It has its features.

The surface treatment is to react nitrogen or carbon with the surface layer of the metal thin film by heat treatment at a high temperature. In this case, the high-temperature heat treatment may be performed at a temperature of 400°C to 850°C.

In addition, the surface treatment may be to increase the hardness of the surface layer by penetrating the activated carbon using a carburizing agent into the surface layer of the metal thin film. In this case, the carburizing agent is a hydrocarbon-based gas, carbon dioxide (CO ₂ ), potassium cyanide (KCN), sodium cyanide (NaCN), potassium ferrocyanide (K ₄ Fe(CN) ₆ , 3H ₂ O) and carbon powder It can be either.

In addition, the carburizing agent may further include a carburizing accelerator when chemically changing the carburizing agent to activated carbon by heat treatment at a high temperature. In this case, the carburizing accelerator may be any one of barium carbonate (BaCO ₃ ), soda carbonate (Na ₂ CO ₃ ), calcium carbonate (CaCO ₃ ), and sodium chloride (NaCl).

Alternatively, the surface treatment may be to heat the raw material of the metal thin film with a nitriding agent to form a surface layer having a hardness higher than that of the back layer. In this case, the nitrating agent may include NH ₃ gas or cyan gas.

In addition, the metal thin film may be chromium, molybdenum, aluminum, nickel, or alloys thereof.

In addition, a method of manufacturing an organic light emitting display device of the present invention for achieving the same object comprises the steps of preparing a substrate including an array of organic light emitting elements; and reacting nitrogen or carbon on the surface of the metal thin film to form a metal thin film. Performing a heat treatment at a high temperature, so that the metal thin film is layered between a high hardness surface layer and a back layer; And a step of encapsulating and including an adhesive layer between the back layer of the metal thin film and the substrate including the organic light emitting diode array.

The organic light emitting display device of the present invention as described above and a method of manufacturing the same have the following effects.

The metal thin film itself has the advantage of being able to lower the flexibility and thickness in terms of material, but it is easy to be scratched or scratched by an external environment (foreign material, etc.). When scratches or scratches occur, image defects may occur due to damage to the organic light emitting device. In order to remove such defects, the surface treatment of the metal thin film of the present invention increases the surface hardness by injecting carbon or cyan gas to the surface of the metal thin film exposed to the outside by using a carburizing method, or the nitriding agent of cyan gas or ammonia gas. It is to increase the hardness by curing the surface layer by reacting the metal surface.

As a result, only the surface exposed by the metal thin film is reinforced with carbon or nitrogen to form an original soft metal material and a surface-hardened metal film material, which is resistant to scratches and scratches, and can prevent image defects. have.

In addition, the outer surface of the metal thin film used as an encapsulation material for the large-area organic light emitting display device of the present invention may be strengthened to prevent image defects caused by external scratches or scratches, thereby improving yield.

1 is a cross-sectional view showing an organic light emitting display device of the present invention
2A and 2B are perspective views illustrating surface treatment and post-treatment of a metal thin film applied to the organic light emitting display device of the present invention.
Figure 3 is a cross-sectional view showing the metal thin film of Figure 2b and an enlarged view thereof
4 is a view showing a method of surface-treating a metal thin film according to a first embodiment of the present invention
5 is a view showing a method of surface-treating a metal thin film according to a second embodiment of the present invention
6A and 6B are cross-sectional views showing a principle in which a foreign substance corresponds and a defect appears in an organic light emitting display device having a metal thin film without surface treatment.
FIG. 7 is a photograph showing the defect in FIG. 6B from the top surface of the organic light emitting diode display.
8 is a graph showing hardness before and after display processing

Hereinafter, an organic light emitting display device of the present invention and a manufacturing method thereof will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing an organic light emitting display device of the present invention.

As shown in FIG. 1, the organic light emitting display device of the present invention, in turn, on the substrate 100, the thin film transistor array 110, the organic light emitting device array 120, the adhesive layer 130 and the metal thin film (metal foil) ( 200) is formed.

Here, the thin film transistor array 110 includes a thin film transistor (not shown) formed in each pixel in a pixel on a matrix defined on the substrate 100.

Meanwhile, the substrate 100 may be a glass substrate or an insulating plastic film having a thickness of several tens of μm. In the case of a glass substrate, the thickness of the glass substrate may be etched to make the device flexible. In addition, in the array process, since a thin substrate is difficult to maintain flatness and may impair the stability of the process, in the array process (thin film transistor array formation and organic light emitting device array formation), the array process (with the buffer layer on the glass substrate) After forming the thin film transistor array and forming the organic light emitting device array) and completing the array process, the glass substrate may be removed by a method such as laser irradiation or etching. In this case, the buffer layer may be the above-described substrate 100 or a separate plastic film may be attached to the surface from which the glass substrate has been removed to protect the array.

In addition, the organic light emitting diode array 120 includes an organic light emitting diode connected to a corresponding thin film transistor for each pixel.

In addition, the adhesive layer 130 is a layer in which the metal thin film 200 is sandwiched to seal the surface of the substrate 100 on which the organic light emitting device array 120 is formed. In this case, the metal thin film 200 is an organic light emitting device array ( It is formed to have a larger area than the area of 120), so that the organic light emitting device array 120 is sufficiently blocked from outside air or moisture.

In addition, the metal thin film 200 is divided into a back surface layer 150 contacting the adhesive layer 130 and a surface layer 155 positioned thereon. In this case, the back layer 150 has the properties of the intrinsic material of the metal thin film 200, and the surface layer 155 is surface treated, and its hardness is significantly higher than that of the back layer 150.

Here, the intrinsic material of the metal thin film 200 may be a single material of chromium (Cr), molybdenum (Mo), aluminum (Al), and nickel (Ni) or an alloy thereof.

Hereinafter, a method of treating the surface of the metal thin film 200 will be described. The surface treatment is performed before the metal thin film 200 encapsulates the organic light emitting device array 120. Before the encapsulation process, the metal thin film 200 is prepared in a state where the surface hardness is already high by the following process. do.

2A and 2B are perspective views illustrating the surface treatment and post-treatment of the metal thin film applied to the organic light emitting display device of the present invention, and FIG. 3 is a cross-sectional view showing the metal thin film of FIG. 2B and an enlarged view thereof.

As shown in FIG. 2A, after preparing a metal thin film 1500 made of a single material or an alloy of chromium (Cr), molybdenum (Mo), aluminum (Al), and nickel (Ni) having a thickness within about 100 μm, High-temperature heat treatment is performed so that the carbon (C) or nitrogen (N) component reacts on the surface.

In this case, the high-temperature heat treatment is performed at a temperature of 400°C to 850°C.

After a predetermined time, when carbon or nitrogen reacts to the surface layer 155 of the metal thin film, as shown in FIG. 3, the particles have crystal grains, and the hardness of the lower back layer 150 is increased. At this time, the metal inner structure of the lower back surface layer 150 has a grainy state with no intergranular bonding or has a softer property than the surface layer 155.

That is, as shown in FIG. 2B, the metal thin film 200 that has undergone the high-temperature heat treatment described above is denatured by the surface layer 155 to be layered into the surface layer 155 and the back layer 150, and the surface layer is resistant to external stimuli. Will have.

On the other hand, high-temperature heat treatment is classified into a carburizing method and a nitriding method according to the material of the component reacting to the surface layer 155.

4 is a view showing a method of surface-treating a metal thin film according to a first embodiment of the present invention.

Fig. 4 shows a first embodiment of the present invention using a carburizing method using a powder containing carbon or gas containing carbon.

As shown in Fig. 4, the method for surface treatment of a metal thin film according to the first embodiment of the present invention is to increase the hardness of the surface layer by penetrating activated carbon using a carburizing agent into the surface layer 155 of the metal thin film. In this case, the carburizing agent is a hydrocarbon-based gas, carbon dioxide (CO ₂ ), potassium cyanide (KCN), sodium cyanide (NaCN), potassium ferrocyanide (K ₄ Fe(CN) ₆ , 3H ₂ O) and carbon powder It can be either.

For example, when the carburizing agent containing carbon is heated at a high temperature, it is divided into an active carbon (C) component and carbon dioxide (CO ₂ ), and at this time, the activated carbon penetrates from the surface of the metal thin film and causes diffusion to cause metal The thin film on the surface of the thin film 1500 forms the surface layer 155 with high hardness.

Depending on the carburizing agent component, it can be divided into solid carburizing, liquid carburizing and gas carburizing.

For example, the solid carburization method is a carbon powder of charcoal, coke, and bone charcoal as a coaling agent, and barium carbonate (BaCO ₃ ), soda (Na ₂ CO ₃ ), calcium carbonate (CaCO ₃ ), and sodium chloride (Carbonate) as carburizing accelerator NaCl), the metal thin film 1500 is put in a furnace and heated for a certain period of time to react the surface layer of the metal thin film 1500 with activated carbon to increase hardness.

The liquid carburization method uses potassium cyanide, sodium cyanide, and ferrocyanide as carburizing agents, and potassium carbonate, sodium carbonate, potassium chloride, and sodium chloride are used as accelerators to make a molten salt bath by heat treatment at high temperature, and the molten salt bath The metal thin film 1500 is put inside. At this time, the metal thin film 100 may be formed with a surface layer on both sides, a carburizing agent component may include a cyan (CN) component, and both carbon and nitrogen may penetrate the surface layer. For this reason, it can also be called carburizing nitriding method or cyan cyanide method.

In addition, the gas carburization method is a carbonaceous agent, and is a hydrocarbon-based natural gas, for example, methane, ethylene, propane gas or carbon monoxide (CO), carbon dioxide (CO ₂ ) gas penetrates the surface of the metal thin film 1500 To react with the activated carbon and the surface layer of the metal thin film 1500.

Looking at the chemical change of the carburizing method, when a carburizing accelerator is added to the reaction of "C (carbon powder) + CO2", it changes to 2CO, which reacts again with "C (active carbon) + CO2". In this case, when C (active carbon) penetrates into a metal thin film, it reacts like "γ iron + C", and it can be expected that the hardness increases due to such chemical change.

5 is a view showing a method of surface-treating a metal thin film according to a second embodiment of the present invention.

On the other hand, the method of processing the metal thin film according to the second embodiment of the present invention, as shown in Figure 5, by supplying NH ₃ gas or cyan gas to the surface of the metal thin film 1500 to produce a compound layer and harden mainly nitrogen It can be called a nitriding method by reacting with the surface of a metal thin film.

In the case of such a nitriding method, in order to increase reactivity with a nitrating agent when forming the compound layer of the surface layer 255, the raw material of the metal thin film 1500 is nickel or an alloy thereof, a small amount of chromium (Cr), or molybdenum (Mo ) Or aluminum (Al). It is preferable that the content of chromium, molybdenum, and aluminum in a range effective for nitriding is less than 2% of the total content of the metal thin film.

Further, the nitriding method may be divided into ion nitriding, gas nitriding, salt bath nitriding, and gas soft nitriding depending on the state of the nitriding agent to be supplied.

For example, the ion nitriding method diffuses and infiltrates nitrogen (N) to the surface of a metal thin film in a vacuum or a gas alone or mixed gas atmosphere by generating a tube discharge in a vacuum furnace.

In addition, the gas nitriding method diffuses nitrogen in an ammonia (NH ₃ ) gas atmosphere to produce a nitrogen element compound. That is, the ammonia component is divided into a nitrogen element and a hydrogen component in external electric heating, and nitrogen penetrates into the surface layer of the metal thin film.

The salt bath nitriding method diffuses nitrogen (N) and carbon (N) into the surface layer of the metal thin film by reaction in a salt bath such as XCN, XCNO, and X ₂ O ₃ (where X is an alkali metal).

At this time, the reaction is performed in the following order. That is, after the primary reaction with 2XCN+O ₂ (air)->2XCNO, 4XCNO->X ₂ O ₃ +2XCN+CO+2[N]2CO->[C]+CO ₂ .

Here, [C] is an active carbon, [N] is a component that penetrates into the metal thin film with active nitrogen.

On the other hand, gas softening is to diffusely penetrate nitrogen and carbon into the metal thin film in a mixed atmosphere of 50% RX gas and 50% fmf of NH3 gas. The reaction at this time consists of 2NH ₃ ->2[N]+3[H] _2, 2(CO)->[C]+CO ₂ .

In addition, the carburizing agent may further include a carburizing accelerator when chemically changing the carburizing agent to activated carbon by heat treatment at a high temperature. In this case, the carburizing accelerator may be any one of barium carbonate (BaCO ₃ ), soda carbonate (Na ₂ CO ₃ ), calcium carbonate (CaCO ₃ ), and sodium chloride (NaCl).

On the other hand, in the organic light emitting display device of the present invention and its manufacturing method, the reason for the surface treatment using nitrogen or carbon on the surface of the metal thin film is to increase the hardness of the surface layer so as not to cause surface changes due to external stimuli or foreign matter. to be.

When applying a general metal thin film, we examine the defects caused by foreign substances.

6A and 6B are cross-sectional views illustrating a principle in which a foreign substance corresponds and a defect appears in an organic light emitting display device having a metal thin film that is not surface treated. In addition, FIG. 7 is a photograph showing the defective phenomenon of FIG. 6B on the top surface of the organic light emitting diode display.

As shown in FIG. 6A, when sealing the substrate 10 including the array of organic light-emitting elements through the adhesive layer 20 as a raw material of the general metal thin film 30, the foreign material 40 corresponds to the surface of the metal thin film 30 6B, the foreign material 40 acts as a kind of pressure, so that the surface of the metal thin film 30 to which the foreign material corresponds is pressed, and the other area is not flat and rises upward due to a pressure difference with the other area. The coming problem arises.

In this case, as shown in FIG. 7, when observed from the substrate 10 side where the metal thin film 30 is not formed, it can be seen that the area where the foreign matter has been generated is black and pixel deterioration occurs.

In the case of the surface treatment of the metal thin film of the present invention, the surface layer of the metal thin film is relatively higher in hardness than the foreign material, and there is an advantage that defects or scratches caused by the foreign material are not generated. Among them, there is an advantage of maintaining flatness without distortion, and as a result, it has an effect of preventing pixel defects.

8 is a graph showing hardness before and after display processing.

Table 1 shows the hardness of the average value when the raw material of the metal thin film and the metal thin film subjected to surface treatment (high-temperature heat treatment at a temperature of about 480° C.) were subjected to a test force of 0.1 to 1960 mN (0.01 to 200 g) over 10 times. It shows that it was measured. As shown in Table 1, in each experiment, it was confirmed that the hardness of the surface-treated metal thin film is higher than that of the raw material of the metal thin film. Referring to the graph of FIG. 8, the hardness of the surface-treated metal thin film compared to the raw material of the metal thin film It can be seen that the increase from 200 (AU) to 350 (AU). That is, it was confirmed that the hardness of the metal thin film to which the surface treatment was applied was improved.

turn Raw material of metal thin film Surface-treated metal thin film One 206.94 331.90 2 179.71 380.24 3 190.56 299.91 4 202.32 340.73 5 202.52 350.48 6 187.11 360.36 7 216.25 332.02 8 202.49 298.66 9 210.90 323.01 10 215.66 349.92 Average 201.45 336.82

As described above, the metal thin film itself has the advantage of lowering the flexibility and thickness in terms of material, but it may easily cause scratching or scratching due to an external environment (foreign material, etc.). When scratches or scratches occur, image defects may occur due to damage to the organic light emitting device. In order to remove such defects, the surface treatment of the metal thin film of the present invention increases the surface hardness by injecting carbon or cyan gas to the surface of the metal thin film exposed to the outside by using a carburizing method, or a nitriding agent of cyan gas or ammonia gas. It is to increase the hardness by curing the surface layer by reacting the metal surface.

By doing so, only the surface exposed to the outside of the metal thin film is reinforced with carbon or nitrogen to form the original soft metal material and the surface-treated metal film material with high hardness to resist scratches and scratches, and to prevent burn defects. have.

On the other hand, the present invention described above is not limited to the above-described embodiments and accompanying drawings, and various substitutions, modifications and changes are possible within the scope of the technical spirit of the present invention. It will be obvious to those with ordinary knowledge.

100: substrate 110: thin film transistor array
120: organic light emitting element array 130: adhesive layer
150: back layer 155: surface layer
200: metal thin film (after surface treatment) 1500: metal thin film (raw material)

Claims (19)

A substrate including an organic light emitting diode array; And
The organic light emitting device array is sealed by interposing an adhesive layer with the substrate, and the surface is treated to include a metal thin film made of a double layer having a hardness of a surface layer higher than that of a back surface layer.
The metal thin film comprises at least one of chromium, molybdenum, aluminum and nickel. According to claim 1,
The surface treatment is an organic light emitting display device, characterized in that nitrogen or carbon is reacted with the surface layer of the metal thin film by heat treatment at a high temperature. According to claim 2,
The high-temperature heat treatment is performed at a temperature of 400 ℃ to 850 ℃ organic light emitting display device, characterized in that. According to claim 3,
The surface treatment is an organic light emitting display device, characterized in that by using a carburizing agent, activated carbon is penetrated into the surface layer of the metal thin film to increase the hardness of the surface layer. The method of claim 4,
The carburizing agent is any one of a hydrocarbon-based gas, carbon dioxide (CO ₂ ), potassium cyanide (KCN), sodium cyanide (NaCN), potassium ferrocyanide (K ₄ Fe(CN) ₆ , 3H ₂ O) and carbon powder An organic light emitting display device, characterized in that. The method of claim 4,
An organic light emitting display device further comprising a carburizing accelerator when chemically changing the carburizing agent to activated carbon by heat treatment at a high temperature. The method of claim 6,
The carburizing accelerator is any one of barium carbonate (BaCO ₃ ), soda carbonate (Na ₂ CO ₃ ), calcium carbonate (CaCO ₃ ), and sodium chloride (NaCl). According to claim 3,
In the surface treatment, the raw material of the metal thin film is heated with a nitriding agent to form a surface layer having a hardness higher than that of the back layer. The method of claim 8,
The nitriding agent comprises an NH ₃ gas or a cyan gas, the organic light emitting display device. delete Preparing a substrate including an organic light emitting diode array;
A metal thin film containing at least one of chromium, molybdenum, aluminum, and nickel is prepared, and nitrogen or carbon is reacted on the surface of the metal thin film and subjected to high temperature heat treatment, so that the metal thin film is layered into a high hardness surface layer and a back layer. To do; And
And a step of encapsulating and sealing an adhesive layer between the back layer of the metal thin film and the substrate including the organic light emitting element array. The method of claim 11,
The high-temperature heat treatment is performed at a temperature of 400 °C to 850 °C. The method of claim 12,
The surface layer is a method of manufacturing an organic light emitting display device, characterized in that by using a carburizing agent, activated carbon is penetrated into a surface layer of the metal thin film to increase hardness of the surface layer. The method of claim 13,
The carburizing agent is any one of a hydrocarbon-based gas, carbon dioxide (CO ₂ ), potassium cyanide (KCN), sodium cyanide (NaCN), potassium ferrocyanide (K ₄ Fe(CN) ₆ , 3H ₂ O) and carbon powder A method of manufacturing an organic light emitting display device, characterized in that. The method of claim 14,
A method of manufacturing an organic light emitting display device further comprising a carburizing accelerator when chemically changing the carburizing agent to activated carbon by heat treatment at a high temperature. The method of claim 15,
The carburization accelerator is a method of manufacturing an organic light emitting display device, characterized in that any one of barium carbonate (BaCO ₃ ), soda carbonate (Na ₂ CO ₃ ), calcium carbonate (CaCO ₃ ), and sodium chloride (NaCl). The method of claim 12,
The surface layer is a method of manufacturing an organic light emitting display device characterized in that the raw material of the metal thin film is heated by a high temperature heat treatment including a nitriding agent to form a surface layer having a hardness higher than that of the back layer. The method of claim 17,
The method of manufacturing an organic light emitting display device, wherein the nitriding agent comprises NH ₃ gas or cyan gas. delete

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