JP3772752B2 - Organic EL display device and organic EL element sealing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic EL display device and a method for sealing an organic EL element used therein.
[0002]
[Prior art]
Conventionally, there is a light emitting display element (hereinafter referred to as an organic EL element) using an electroluminescence phenomenon of an organic thin film called an organic electroluminescence element, an organic electroluminescence element, an organic LED element or the like. And there exists an organic electroluminescent display apparatus (henceforth an organic EL display apparatus) using such an organic EL element. The organic EL element is usually formed by forming a light emitting part in a dot matrix form on a glass substrate in the order of an anode layer, an organic EL layer, and a cathode layer.
[0003]
In such an organic EL display device, the organic EL element is sealed off from the outside air, but the organic EL element is deteriorated by moisture, oxygen, or other substances remaining in the display device.
Further, even when the organic EL element is sealed as described above, a slight amount of moisture, oxygen, or the like passes into the display device through the sealing member or the lid member. These moisture, oxygen, and the like also cause deterioration of the organic EL element.
[0004]
In order to solve such a problem, Japanese Patent Application Laid-Open No. 2000-306664 provides a material that physically and / or chemically adsorbs moisture on at least one surface of a sealing member and a substrate. An organic EL display device is disclosed.
FIG. 5 is a side sectional view showing a conventional configuration in which such an organic EL element is sealed so as not to be exposed to the atmosphere. As shown in the figure, an organic EL element 5 including an anode layer 2, an organic EL layer 3, and a cathode layer 4 is formed on a glass substrate 1. The organic EL element 5 is covered with a counter substrate 6 and a sealing portion 7. The counter substrate 6 is fixed to the glass substrate 1 by a sealing portion 7 and blocks the inside from the outside as a whole.
Further, the substance 8 provided on the sealing member or the like can physically and / or chemically adsorb the internal moisture to eliminate the adverse effect of the internal residual moisture on the organic EL element 5 with a relatively simple configuration. It is said that the growth of dark spots can be suppressed.
[0005]
[Problems to be solved by the invention]
However, when all the substances that physically and / or chemically adsorb moisture react with water, it becomes impossible to adsorb more moisture, and moisture that has entered the display device reacts with the organic EL element, The organic EL element deteriorates.
[0006]
Accordingly, the larger the amount of the adsorbing substance provided in the display device, the better.
An object of the present invention is to solve the above-mentioned problems by increasing the amount of a member that adsorbs or absorbs a harmful substance to an organic EL element provided in a display device in view of the above-described conventional situation. An organic EL display device is provided.
[0007]
[Means for Solving the Problems]
Below, the structure of the organic EL display apparatus concerning this invention and the sealing method of the organic EL element used for it is described.
First, an organic EL display device according to claim 1 is formed on a transparent substrate and one surface of the transparent substrate, an organic layer is provided between the anode and the cathode, and current is injected between the electrodes. A cover member that covers the organic EL element on one surface of the transparent substrate to seal the organic EL element, and an edge bottom surface of the cover member. A sealing member that is interposed between and hardened on one surface of the transparent substrate, and the lid member has a rough surface with an uneven surface, and a part of the rough surface. Alternatively, it is formed by depositing aluminum on the entire surface.
[0008]
In this organic EL display device, for example, as described in claim 2, the lid member also has a side wall, an uneven surface is formed on the inner surface of the side wall, and the aluminum is also applied to the rough surface. It is formed by adhering .
[0009]
The cathode is, for example, aluminum as described in claim 3.
[0010]
Next, in the method for sealing an organic EL element according to the fourth aspect of the present invention, the organic EL element is covered on one surface of the transparent substrate with respect to the organic EL element formed on one surface of the transparent substrate. An adhering step of attaching aluminum to a part or the entire inner surface of the lid member thus formed, and a sealing member interposed between the edge of the lid member and one surface of the transparent substrate are arranged. An arrangement step includes an adhesion step for bonding the edge of the lid member and one surface of the transparent substrate via the sealing member, and a curing step for curing the sealing member. The
For example, as described in claim 5 , at least the bonding step and the curing step are preferably performed in a nitrogen atmosphere with a dew point set as low as possible.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a side sectional view schematically showing a configuration of an organic EL display device according to an embodiment.
[0012]
FIG. 2 is a process block diagram showing the manufacturing process of the organic EL display device, and is a diagram for explaining a method of sealing an organic EL element used in the organic EL display device.
As shown in FIG. 2, the organic EL display device and the organic EL element sealing method of the present invention are formed in an anode film forming step S <b> 1 using an appropriate film forming device 20, and the organic EL processed in the vacuum device 21. Layer film forming step S2, cathode film forming step S3, Al (aluminum) film forming step S4 as a lid member, UV as a sealing member processed in a low dew point nitrogen atmosphere 22 This is realized by the step S5 of applying a cured resin and the step S6 of adhering a sealing cap to the glass substrate.
[0013]
In the anode film forming step S1, the anode layer 11 is formed on the glass substrate 10 shown in FIG. The anode layer 11 is not particularly shown, but first, a transparent electrode layer is formed on the entire surface of the glass substrate 10 by, for example, sputtering, vacuum deposition, ion plating, etc. A thin film anode electrode is formed in a stripe shape. As the material for the transparent electrode layer, nickel, gold, platinum, palladium, alloys thereof, metals such as tin oxide and copper iodide, alloys and compounds thereof, and conductive polymers can be used. .
[0014]
Next, in the organic EL layer deposition step S2, a thin organic EL layer 12 is deposited on the anode layer 11 as shown in FIG. As materials for the organic EL layer 12, for example, low molecular weight materials such as tris (8-quinolinolato) aluminum (ALQ3) and high molecular weight materials such as polyparaphenylene vinylene (PPV) have been researched and developed and put into practical use. I'm starting.
[0015]
In the subsequent cathode film forming step S3, the cathode layer 13 is formed on the organic EL layer 12. Although this cathode layer 13 is not particularly shown, a thin film cathode is formed in a stripe shape. The striped cathode is formed so as to intersect with the striped anode in a grid pattern with the organic EL layer 12 interposed therebetween.
[0016]
In addition, as the material of the cathode layer, aluminum, magnesium, magnesium indium alloy, magnesium aluminum alloy, magnesium silver alloy, aluminum lithium alloy, and the like are usually considered, but it has good conductivity and is extremely inexpensive. Aluminum is often used because it is relatively easy to vacuum deposit.
[0017]
Through the above steps, as shown in FIG. 1, the above-described anode layer 11, organic EL layer 12, and cathode layer 13 are sequentially laminated on one surface (upper surface in the drawing) of the glass substrate 10. The organic EL element 14 is formed.
Subsequently, in step S4 of depositing Al (aluminum) on the sealing cap, aluminum is vacuum-deposited on the entire inner surface of the sealing cap 15 shown in FIG. A thin film 17 is formed.
[0018]
As shown in the figure, the sealing cap 15 has a ceiling surface and an inner wall surface that are rough and uneven. As a result, a larger inner area is formed for the same internal volume as that of the smooth surface.
The vacuum deposition of the aluminum thin film 17 is not limited to the entire surface, but may be partial deposition depending on the design.
[0019]
In any case, an aluminum thin film is deposited on the inner surface formed in a larger area by the uneven rough surface.
Next, the sealing cap 15 on which the aluminum thin film 17 is formed and the glass substrate 10 on which the organic EL element 14 is formed are transferred from a vacuum field to a nitrogen atmosphere without being exposed to the air. This is accomplished by using nitrogen rather than air when performing a vacuum break in the processing equipment. Further, the nitrogen atmosphere in the processing apparatus formed thereby is formed in a state where the dew point is controlled as low as possible in order to prevent moisture from remaining as water vapor as much as possible.
[0020]
Then, in the step S5 of applying the UV curable resin performed in such a nitrogen atmosphere, the UV curable resin as the sealing member is applied so as to be placed on the bottom surface of the edge of the sealing cap 15 or sealed. In this case, the glass substrate 10 is embedded in the groove 10-1 formed in advance corresponding to the bottom surface of the edge so as to rise slightly from the surface of the glass substrate 10. Of course, both an appropriate amount of application and an appropriate amount of embedding may be performed.
[0021]
Finally, in step S6 for adhering the sealing cap to the glass substrate, the sealing cap 15 on which the aluminum thin film 17 is formed is placed at a predetermined position so as to cover the organic EL element 14 on the glass substrate 10. That is, the edge bottom surface of the sealing cap 15 and the groove 10-1 of the glass substrate 10 are positioned and covered at corresponding positions.
[0022]
Thereby, as shown in FIG. 1, the previously applied or embedded UV curable resin 16 is interposed between the bottom surface of the edge of the sealing cap 15 and the groove 10-1 of the glass substrate 10.
Thereafter, the UV curable resin 16 is cured, and the bottom surface of the edge of the sealing cap 15 is fixed to the surface of the glass substrate 10 so as to be positioned at substantially the same height as the surface of the glass substrate 10. The inside of the cap 15 is sealed.
[0023]
As described above, the sealing cap 15 has a rough surface with an uneven surface on the ceiling surface and an inner wall surface. The sealing cap 15 has a larger area, and the aluminum thin film 17 is deposited on the larger area. Therefore, the amount of the aluminum thin film 17 deposited in this example is significantly increased compared to the case where the inner surface of the sealing cap 15 is flat. Originally, aluminum is easily oxidized and also has a moisture adsorbing action. Therefore, the increased amount of the aluminum thin film 17 gradually enters from the outside in addition to moisture and oxygen remaining inside the sealing cap 15. It reacts well with the water and oxygen coming and adsorbs.
[0024]
This not only prevents the deterioration and deterioration of the element due to residual moisture as in the conventional case, but also causes deterioration of the organic EL layer and the cathode layer 13 against newly entering moisture and oxygen. The progress of oxidation of the aluminum electrode is greatly suppressed. That is, the service life of the entire organic EL element 14 can be extended.
[0025]
In the description of the above process, it has been described that the film formation of the anode is performed by another apparatus independent of the vacuum apparatus. However, from the anode film formation process S1 to the Al film formation process S4 on the sealing cap, You may make it carry out continuously in a vacuum apparatus consistently.
FIG. 3 is a process block diagram in the case where such steps S1 to S4 are consistently processed in the vacuum apparatus. As shown in FIG. 2, the normal film forming apparatus 20 shown in FIG. 2 is not provided, and the anode film forming process S1 is performed in the vacuum apparatus 21, and the organic EL layer forming process S2 and the cathode are continuously performed as they are. A film forming step S3 and an aluminum film forming step S4 on the sealing cap are performed. The subsequent steps are the same as in FIG.
[0026]
【The invention's effect】
As described above in detail, according to the present invention, the inner wall of the sealing cap is formed in a rough rough surface to increase the inner area, and moisture and oxygen that are harmful to the organic EL element on this surface. By attaching a removal member (aluminum) that adsorbs or absorbs substances such as by vacuum deposition, harmful substances can be adsorbed or absorbed by a larger amount of removal member (aluminum) , reducing the deterioration of the organic EL element. Can be made.
[0027]
In addition, due to the large amount of removal member (aluminum) due to the uneven rough surface of the inner wall of the sealing cap, not only moisture and oxygen remaining after treatment in a nitrogen atmosphere, but also moisture and oxygen entering from the outside afterwards. Therefore, it is possible to prevent the deterioration of the organic EL element for a longer period of time, thereby suppressing the generation of dark spots and dark areas for a long period of time, thereby extending the life of the organic EL element. It can be improved even longer.
In addition, when “aluminum” of the same material as “aluminum formed by adhering to the rough surface of the lid member” is used for the cathode, the increase in facilities and processes for adhering “aluminum” is minimized. In addition, the material utilization efficiency of “aluminum” can be improved.
[Brief description of the drawings]
FIG. 1 is a side sectional view schematically showing a configuration of an organic EL display device according to an embodiment.
FIG. 2 is a process block diagram illustrating a manufacturing process of an organic EL display device and an organic EL element sealing method according to an embodiment.
FIG. 3 is a process block diagram showing an example in the case where manufacturing steps S1 to S4 are consistently processed in a vacuum apparatus.
FIG. 4 is a side sectional view showing a configuration in which a conventional organic EL element is sealed so as not to be exposed to the atmosphere.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Anode layer 3 Organic EL layer 4 Cathode layer 5 Organic EL element 6 Opposite substrate 7 Sealing part 8 Substance which adsorb | sucks moisture etc. physically and / or chemically 10 Glass substrate 11 Anode layer 12 Organic EL layer 13 Cathode layer 14 Organic EL element 15 Sealing cap 16 UV curable resin 17 Aluminum thin film 20 Film forming apparatus 21 Vacuum apparatus 22 Nitrogen atmosphere

Claims (5)

A transparent substrate, and an organic EL element that is formed on one surface of the transparent substrate, an organic layer is provided between the anode and the cathode, and light is emitted from the organic layer by injecting current between the electrodes;
A lid member that covers the organic EL element on one surface of the transparent substrate to seal the organic EL element, and is interposed between an edge bottom surface of the lid member and one surface of the transparent substrate. A cured sealing member,
The surface of the lid member facing the substrate is formed as an uneven rough surface, and aluminum is attached to a part or the entire surface of the rough surface.
An organic EL display device characterized by that. 2. The organic material according to claim 1, wherein the lid member also has a side wall, an uneven rough surface is formed on the inner surface of the side wall, and the aluminum is adhered to the rough surface. EL display device. The display device according to claim 1, wherein the cathode is aluminum. For the organic EL element formed on one surface of the transparent substrate,
An attaching step of attaching aluminum to a part or the entire inner surface of a lid member formed to cover the organic EL element on one surface of the transparent substrate;
An arrangement step of arranging a sealing member interposed between an edge portion of the lid member and one surface of the transparent substrate, and an edge portion of the lid member and one surface of the transparent substrate are sealed. An adhering step for adhering via a stop member;
A curing step for curing the sealing member;
The sealing method of the organic EL element characterized by including. 5. The organic EL element sealing method according to claim 4 , wherein at least the adhesion step and the curing step are performed in a nitrogen atmosphere with a dew point set as low as possible.

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