JP2000173764A - Organic el element and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain generation and growth of dark spots, improve the conservation stability of an element and improve a lighting service life. SOLUTION: In this organic El element, a peripheral part between a board 2, on which the element is formed by laminating an organic layer including a luminescent layer between a pair of electrodes (a positive electrode and a negative electrode), and a sealing board 10 arranged facing opposite to the board 2 and spaced at a predetermined distance from the element is fixed and sealed in a dry atmosphere by a sealing film 9 formed of an organic adhesive. A recessed part 15 filled with the sealing film 9 is so formed in a region of the sealed part by the sealing film 9 on the surface side opposite to the element of the sealing board 10 to surround the element. The cross-linking density of the sealing film 9a filled in the recessed part 15 is slightly smaller than that of the sealing film 9b which abuts on the board 2 other than the recessed part 15, so that water molecules and the like passing through the sealing film 9 and intruding from the outside are caught.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic compound composed of a thin film of an organic compound material utilizing electroluminescence (hereinafter referred to as EL) of an organic compound material which emits light by injection and recombination of holes and electrons. The present invention relates to an EL device and a manufacturing method thereof.

[0002]

2. Description of the Related Art An organic EL device has a laminated structure in which a thin film containing a fluorescent organic compound is sandwiched between an anode and a cathode, and is excited by injecting holes and electrons into the thin film and recombining them. This is a display element that generates a photon (exciton) and performs display using light emission (fluorescence / phosphorescence) when the exciton is deactivated.

FIG. 6 is an exploded perspective view showing the structure of a conventional organic EL device of this type, and FIGS. 7 (a) to 7 (g) show the organic EL device of FIG.
It is a sectional side view which shows the manufacturing process of an L element.

An organic EL element 51 is formed on a glass substrate 52 having an insulating property and a transparent property by ITO (Indium Tin Oxid).
e), a transparent conductive film 53 is formed.
(A)). The transparent conductive film 53 is formed on the glass substrate 52 by a sputtering method, and is further etched by a photoresist pattern to form an anode 54 having a predetermined pattern shape (FIG. 7B).

An organic layer 55 made of a thin film of an organic compound material is formed on the anode 54 by a molecular beam evaporation method or a resistance heating method. The organic layer 55 in the example shown in FIG.
A copper phthalocyanine (CuPc) organic film 55a as a hole injection layer formed on the anode 54 shown in FIG. 7C and a hole formed on the CuPc organic film 55a shown in FIG. Α-NPD (Bis (N- (1-na
phtyl-N-phneyl) benzidine) tris (8-quinolinolato) aluminum (Alq) as an emission layer and an electron transport layer formed on the organic film 55b and the α-NPD organic film 55b shown in FIG. ₃ ) It is formed in a three-layer structure with the organic film 55c.

As shown in FIG. 7F, a cathode 56 made of a metal thin film of, for example, Al--Li is formed on the organic layer 55.
Is formed in a predetermined pattern shape by a molecular beam evaporation method or a resistance heating method.

[0007] As shown in FIG.
A sealing substrate 57, such as a glass substrate, is bonded and fixed to an outer peripheral portion of the sealing substrate 57 with an organic adhesive made of an ultraviolet curable resin in a dry atmosphere using an inert gas (eg, dry nitrogen) or dry air from which water is removed as much as possible. ing. The seal film 58 made of the adhesive is formed as thin as the film thickness does not affect the adhesive strength.
Further, the seal width of the seal film 58 on each side is set as wide as possible within the range allowed by the margin.

The organic EL element 51 constructed as described above
In this case, when a voltage is applied between the anode 54 and the cathode 56 to flow a constant current, holes are injected from the anode 54 into the organic layer 55 and electrons are injected from the cathode 56. Then, the injected holes and electrons are recombined to generate excitons, and a desired display is performed by emission of light when the excitons are deactivated. Light emission at that time is observed from the outside of the glass substrate 52 via the anode 54 which is a transparent electrode.

[0009]

The above-mentioned organic E
In the case where the L element 51 is used as a display element, the biggest problem is how to improve the durability. Above all, the generation and growth of a non-light-emitting portion called a dark spot are the most important problem. The cause of the formation of the dark spot is considered to be a large influence of moisture and oxygen. Particularly, it is considered that even a very small amount of water has a large influence.

Therefore, the organic EL element is manufactured by a dry process by devising as much as possible water, such as purification of the organic material to be used, quality of vacuum at the time of film formation, sealing of the element, and the like. However, at present, sufficient characteristics have not yet been obtained.

As described above, the biggest problem of the organic EL element is to eradicate dark spots and extend the life.
Improvement is achieved by sealing the element as shown in FIGS.

However, in the above-mentioned conventional organic EL element 51, since the element is sealed by forming the seal film 58 with an organic adhesive, its atoms (molecules) are compared with an adhesive such as metal and ceramics. ) The distance between them is large.

For this reason, especially in a high-temperature and high-humidity environment, the seal film 58 itself made of an organic adhesive swells, and gas such as moisture and oxygen in the air easily permeates.

Therefore, in order to minimize the contact area between the seal film 58 and gas molecules in the air, it is preferable to reduce the thickness of the seal film 58.

Further, when gas molecules come into contact with the seal film 58 and enter the seal film 58, it is preferable to pattern the seal film 58 with a wide width in order to save diffusion time.

However, increasing the width of the seal film 58 increases the margin area with respect to the display area of the device, and therefore, there is a limit in increasing the width of the seal film 58.

Even when the width of the sealing film 58 is reduced, it is very difficult to maintain the stability of the sealing process and the reproducibility of repetition. This causes a problem that the characteristics fluctuate greatly due to the variation.

The thickness of the seal film 58 will be described as an example. In the conventional organic EL element 51, a glass substrate 52
The element is sealed by fixing the outer peripheral portion between the substrate and the sealing substrate 57 with a seal film 58 made of an organic adhesive, but the film thickness of the seal film 58 in this sealed portion varies.
For this reason, especially in a portion where the thickness of the seal film is large, gas in the air such as moisture and oxygen easily permeates and enters the inside,
The generation and growth of dark spots are promoted, which causes deterioration of the device.

In view of the above, the present invention has been made in view of the above problems, and it is possible to suppress the generation and growth of dark spots, improve the storage stability of an element, and improve the lighting life. It is intended to provide an EL element.

It is another object of the present invention to provide a method of manufacturing an organic EL device capable of increasing the robustness against process variations during the encapsulation process and manufacturing a stable and reproducible device.

[0021]

In order to achieve the above object, according to the present invention, a substrate having an element formed by laminating an organic layer including a light emitting layer between a pair of electrodes is provided. In an organic EL element in which an outer peripheral portion of a sealing member arranged opposite to the substrate at an interval is fixed and sealed by a sealing film made of an adhesive in a dry atmosphere, A concave portion filled with the seal film is formed so as to surround the element in a region of a portion sealed by the seal film on a surface side facing the element.

According to a second aspect of the present invention, there is provided a substrate having an element formed by laminating an organic layer including a light emitting layer between a pair of electrodes, and a substrate facing the substrate at a predetermined distance from the element. In an organic EL device in which an outer peripheral portion with a sealing member is fixed and sealed by a sealing film made of an adhesive in a dry atmosphere, sealing with the sealing film is performed on a surface of the sealing member facing the element. In the partial region, a water-absorbing agent is filled, and a concave portion in which the sealing film is filled on the water-absorbing agent is formed so as to surround the element.

According to a third aspect of the present invention, in the organic EL device according to the first or second aspect, a plurality of the concave portions are formed so as to communicate with each other in the region of the sealing portion toward the element. And

According to a fourth aspect of the present invention, in the organic EL device according to the first or second aspect, beads having a predetermined particle size are mixed in the seal film filled in the concave portion. I do.

According to a fifth aspect of the present invention, in the organic EL device according to any one of the first to fourth aspects, the sealing film filled in the recess has a lower crosslinking density than the sealing film in contact with the substrate. It is characterized by.

According to a sixth aspect of the present invention, in the organic EL device according to any one of the first to fifth aspects, a water catching agent is provided on the sealing substrate at a position facing the element.

According to a seventh aspect of the present invention, there is provided a substrate having an element formed by laminating an organic layer including a light emitting layer between a pair of electrodes, and a substrate facing the substrate at a predetermined distance from the element. In a method of manufacturing an organic EL device in which an outer peripheral portion with a sealing member is fixed and sealed by a seal film made of an adhesive in a dry atmosphere, a sealing portion formed by the seal film on a surface facing the device is formed. Using a sealing member having a recess formed in the region, bonding the sealing member to the substrate, applying a predetermined load, filling the sealing film into the recess, and then curing the sealing film. It is characterized by including a step.

The invention according to claim 8 is that a substrate on which an element is formed by laminating an organic layer including a light emitting layer between a pair of electrodes is provided, and the element is disposed to face the substrate at a predetermined distance from the element. In a method of manufacturing an organic EL device in which an outer peripheral portion with a sealing member is fixed and sealed by a seal film made of an adhesive in a dry atmosphere, a sealing portion formed by the seal film on a surface facing the device is formed. Using a sealing member having a recess formed in the region, filling the inside of the recess with a water catching agent, bonding the sealing member and the substrate, and applying a predetermined load to seal the sealing film in the recess. And then curing the sealing film.

According to a ninth aspect of the present invention, in the method for manufacturing an organic EL device according to the seventh or eighth aspect, the seal film is made of an ultraviolet curable resin, and the seal film is cured by irradiating ultraviolet rays from outside the substrate. It is characterized by the following.

According to a tenth aspect of the present invention, in the method for manufacturing an organic EL device according to the seventh to ninth aspects, beads are mixed in the seal film.

[0031]

FIG. 1 is an exploded perspective view showing a first embodiment of an organic EL device according to the present invention, and FIGS.
FIG. 3G is a side sectional view showing a manufacturing process of the organic EL device of FIG. 1, and FIG. 3 is a partially enlarged sectional view of the organic EL device of FIG. Note that, in FIG. 3, an organic layer constituting a part of the element is omitted.

Hereinafter, a first embodiment of the organic EL device according to the present invention will be described with reference to FIGS.

As shown in FIGS. 1 to 3, the organic EL element 1 (1A) according to the first embodiment is based on a rectangular substrate 2 made of glass or the like having insulation and transparency. As shown in FIG. 2, a transparent conductive film 3 such as ITO
Is formed. The transparent conductive film 3 is made of, for example, PVD (Physical Vapor Depositio) such as a vacuum evaporation method and a sputtering method.
The film is formed to a thickness of about 100 nm (for example, 150 nm) by the method n). The transparent conductive film 3 is further patterned into a predetermined pattern by etching with a photoresist pattern to form an anode 4 (transparent electrode) as a first electrode.

Specifically, the anodes 4 are formed in stripes at predetermined intervals as shown in FIG. A part of the anode 4 is drawn out to the end of the substrate 2 and connected to a drive circuit (not shown).

As shown in FIG. 2, an organic layer 5 including a light emitting layer of a thin film of an organic compound material is formed on the anode 4. This organic layer 5 is formed, for example, by a molecular beam evaporation method.
The film is formed by a PVD method such as a resistance heating method.

The organic layer 5 in the example of FIG. 2 includes a CuPc organic film 5a as a hole injection layer formed on the anode 4 to a thickness of several nm to several hundreds nm (for example, 40 nm),
Several tens of nm (for example, 20 nm) on the uPc organic film 5a
Α-NPD organic film 5b as a hole transport layer formed with a thickness of 3 nm, and a light emitting layer and electron transport formed with a thickness of several tens nm (for example, 50 nm) on α-NPD organic film 5b. It is formed in a three-layer structure of the Alq ₃ organic film 5c as a layer.

The organic layer 5 is composed of a combination of a light emitting layer and a charge transport layer (a hole transport layer, a hole injection / transport layer, an electron injection layer, an electron injection / transport layer, etc.) in addition to the above. be able to. For example, a structure having only one light-emitting layer, a two-layer structure including a light-emitting layer and a hole transport layer, a two-layer structure including a light-emitting layer and an electron injection layer, and a three-layer structure including a hole transport layer, a light-emitting layer, and an electron injection layer. is there.

As the light emitting material of the light emitting layer, when the light emitting layer itself emits light, for example, Alq ₃ or a distyrylene-based compound is used. When light is emitted by doping a small amount of another light emitting material (dopant) into the light emitting layer, quinacridone (Qd), a dye for laser, or the like is used as the dopant.

The electron injecting layer may be made of, for example, a metal material having a small work function, such as Li, Na, Mg, Ca, etc., Al: Li, Mg:
An alloy having a small work function such as In, Mg: Ag, and LiF is used.

As shown in FIG. 2, a cathode 6 as a second electrode made of a metal thin film is formed on the organic layer 5. The cathode 6 is made of a single metal material having a small work function such as Al, Li, Mg, Ag, In, or the like, or Al-Li, Mg-
It is made of an alloy having a small work function such as Ag. The cathode 6 is formed in a predetermined pattern shape with a film thickness of, for example, several tens nm to several hundreds nm (for example, 100 nm) by a PVD method such as a molecular beam evaporation method and a resistance heating method.

More specifically, as shown in FIG.
It is formed in a stripe shape at predetermined intervals at right angles to the anode 4 and forms a matrix with the anode 4. The element 7 having a thickness of 1 μm to several hundreds of μm (specifically, 0.2 to 0.3 μm) is formed by the above-described anode 4, organic layer 5 and cathode 6.
Is formed, and the organic layer 5 is located at a position where the anode 4 and the cathode 6 overlap.
Is a rectangular light emitting section 8. Part of the cathode 6 is drawn out to the end of the substrate 2 and connected to a drive circuit (not shown).

As shown in FIG. 3, an outer peripheral portion of the substrate 2 on which the element 7 is formed is provided with an inert gas (eg, dry nitrogen) from which moisture is removed as much as possible or a dry atmosphere with dry air, such as an ultraviolet curable resin or epoxy. A rectangular sealing substrate 10 is fixed via a sealing film 9 made of an organic adhesive such as a thermosetting resin. Thus, the pair of electrodes 4 and 6 and the organic layer 5 are protected.

As shown in FIG. 3, beads 11 made of, for example, glass, ceramics, resin or the like are mixed in the seal film 9. The beads 11 are mixed at 1% by weight with respect to the adhesive forming the seal film 9 and have a thickness of 1 μm.
Particles having a particle size of about to several hundred μm (preferably around 10 μm) are used. The beads 11 are formed on the substrate 2 and the sealing substrate 10.
When the substrate is fixed and sealed, the distance between the substrate 2 and the sealing substrate 10 is kept constant by the particle size.

The sealing substrate 10 is made of, for example, metal, glass, ceramics, resin, enamel and the like. Specifically, a 0.3 mm thick stainless steel substrate (SUS304)
Can be used as the sealing substrate 10.

As shown in FIG. 2, a water collecting agent accommodating portion 12 formed of a rectangular concave portion facing the element 7 of the substrate 2 is formed at a central portion on the inner surface side of the sealing substrate 10. The water-absorbing agent accommodating section 12 contains a material having a water-capturing effect, for example, calcium oxide (CaO), barium oxide (BaO), calcium chloride (CaCl ₂ ), and magnesium oxide (MgO).
And a water catching agent 13 formed of a powder or a sheet. As shown in FIG. 2, the water-trapping agent storage unit 12
In a state where 3 is accommodated, it is covered with a sheet member 14 that allows moisture such as Teflon to pass through.

The water trapping agent 13 in the water trapping agent accommodating section 12 retains the water entering through the seal member 14, the internal residual water and the like by chemisorption.

To further explain, taking as an example the case where the water catching material 13 is composed of calcium oxide,
There was water and chemical reaction to produce a Ca (OH) _2, is adsorbed by chemical bonding water by holding the generated Ca (OH) _2.

As shown in FIGS. 2 and 3, the sealing substrate 10
In the area of the portion sealed by the seal film 9 on the surface side facing the element 7, that is, in the outer peripheral portion located a predetermined width inside from the outer edge portion of the sealing substrate 10, a frame is formed so as to surround the light emitting portion 8. A concave portion 15 is formed. The recess 15
It has a rectangular cross section, and the width H1 in the direction toward the element 7 is set to be smaller than the width H2 of the seal film 9 in the direction toward the element 7, so that the sealing film 9 seals between the substrate 2 and the sealing substrate 10. It is formed on the part. The sealing film 9 is filled in the recess 15 when a predetermined load is applied by bonding the substrate 2 and the sealing substrate 10 together. Thereby, the film thickness of the sealing film 9 at the concave portion 15 in the sealing portion is
It becomes thicker than film thicknesses other than 5.

The seal film 9 is cured by irradiating ultraviolet rays from the substrate 2 side. At this time, the seal film 9a filled in the concave portion 15 has a slightly lower crosslink density because the integrated ultraviolet light amount is less than that of the seal film 9b in contact with the substrate 2 other than the concave portion 15. Seal film 9 in recess 15
The cross-link density of “a” decreases toward the bottom 15 a. As a result, the organic EL that has completed the sealing process
When water molecules and the like enter the inside of the element 1A from the outside through the seal film 9, the seal film 9a having a low cross-linking density in the concave portion 15 functions as a trap layer for capturing water molecules and the like.

The organic EL device 1A configured as described above
As in the organic EL element 51 shown in FIGS. 6 and 7, when a drive voltage is applied from a drive circuit (not shown) between the anode 4 and the cathode 6 to flow a constant current, the anode Holes are injected from 4, and electrons are injected from the cathode 6. Then, the injected holes and electrons are recombined in the organic layer to generate excitons, and a desired display is performed by emission of light when the excitons are deactivated. Light emission at that time is observed from outside the substrate 2 through the anode 4 which is a transparent electrode.

In manufacturing the organic EL element 1A, the water trapping agent 1 is previously placed on the substrate 2 at a position facing the element 7.
A sealing substrate 10 having the water-trapping agent accommodating portion 12 in which the substrate 3 is accommodated and covered by the sheet member 14 and having a concave portion 15 in a portion where the substrate 2 is sealed is produced. The recess 15 filled with the seal film 9 has a width of, for example, 1.0 mm,
It is fabricated in a rectangular section with a depth of 0.4 mm.

Then, the substrate 2 is set in a chamber (not shown), and the transparent conductive film 3 is coated on the surface of the substrate 2 by, for example, 150 mm.
A film having a thickness of nm is formed (FIG. 2A). Subsequently, the transparent conductive film 3 is etched by a photoresist pattern to form the anodes 4 in a stripe shape (FIG. 2B).

The transparent conductive film 3 can be formed by a normal sputtering method. However, in the case of the film formation by the sputtering method, the transparent conductive film 3 is polycrystallized, and flake-like irregularities caused by crystal grain boundaries are formed on the surface. Therefore, it is preferable to form the film in an amorphous state. For example, if the transparent conductive film 3 is formed of an amorphous transparent conductive film made of IDIXO (trade name: Idemitsu Indium X-Metal Oxide, manufactured by Idemitsu Kosan Co., Ltd.), dense and excellent surface smoothness can be obtained. A film can be formed.

At the time of forming a transparent conductive film made of an amorphous material (such as a transparent conductive film made of IDIXO), mask deposition may be performed in order to perform desired patterning. In some cases, after the formation of the transparent conductive film, the transparent conductive film may be patterned using a normal photolithography method.

After the anode 4 is formed by the transparent conductive film 3, an organic layer 5 is formed on the anode 4 by a PVD method such as a molecular beam evaporation method or a resistance heating method. In forming the organic layer 5, first, a CuPc organic film 5a is formed on the anode 4 with a thickness of, for example, 40 nm (FIG. 2C). Then, C
An α-NPD organic film 5b is formed on the uPc organic film 5a to a thickness of, for example, 20 nm (FIG. 2D). Furthermore, α-
An Alq ₃ organic film 5c is formed on the NPD organic film 5b by, for example,
The film is formed with a thickness of 0 nm.

When the organic layer 5 is formed on the anode 4, P
A cathode 6 of a metal thin film of Al-Li is formed in a stripe shape orthogonal to the anode 4 on the organic layer 5 by, for example, a 100 nm-thickness by the VD method. Thus, an element 7 in which the organic layer 5 is stacked between the pair of electrodes 4 and 6 in a matrix is formed on the substrate 2.

When the element 7 is formed on the substrate 2, the beads 1 are placed at a predetermined position (near the recess 15) on the sealing substrate 10.
An adhesive mixed with 1 is applied to form a seal film 9,
The substrate 2 is placed on the sealing substrate 10 with the surface of the element 7 facing the surface of the sealing substrate 10 on which the sealing film 9 is formed. afterwards,
Using a load means such as a spring clip prepared in advance, the substrate 2
And a predetermined load is applied to the sealing substrate 10. Due to this load, the seal film 9 made of an adhesive is formed in the recess 15 of the sealing substrate 10.
Is filled, and the film thickness at the concave portion 15 in the sealed portion is more than the film thickness other than the concave portion 15 by the depth of the concave portion 15 (0.4 mm).
Only thicker.

In this state, when an ultraviolet irradiation process is performed from the outside of the substrate 2, the sealing film 9 in the sealing portion is cured, and the distance between the substrate 2 and the sealing substrate 10 is reduced by the beads 11 mixed in the sealing film 9. It is kept constant by the particle size. This allows
The organic EL element 1A is completed.

In curing the seal film 9,
A sufficient photopolymerization reaction acts on the seal film 9a in contact with the substrate 2 to increase the crosslink density. In contrast, recess 1
In the seal film 9b in 5, the crosslink density is slightly reduced because the integrated amount of ultraviolet light is not sufficient.

As a result, in the organic EL device 1A completed after the above sealing process, water molecules and the like that penetrate through the seal film 9 from the outside and enter through the seal film 9 are formed by the seal film 9b having a low crosslinking density in the concave portion 15. Can be caught.

Next, FIG. 4 is a partially enlarged sectional view showing a second embodiment of the organic EL device according to the present invention. The same components as those in the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the description of the configuration will be omitted.

The organic EL element 1B of the second embodiment is the same as the organic EL element 1A of the first embodiment except for the structure of the sealing portion.

As shown in FIG. 4, the concave portion 1 of the sealing substrate 10
5 is filled with a material having a water-trapping effect, for example, a water-trapping agent 16 made of a powder or a sheet of calcium oxide (CaO), barium oxide (BaO), calcium chloride (CaCl ₂ ), magnesium oxide (MgO) or the like. ing. The depth of the recess 15 is set to, for example, 10 μm or more because the inside of the recess 15 is filled with the water catching agent 16. Water collecting agent 16
May be sufficient to completely fill the recess 15 or less. The recess 15 filled with the water catching agent 16 is covered with the seal film 9 into which the beads 11 are mixed when the space between the substrate 2 and the sealing substrate 10 is fixed and sealed.

In manufacturing the organic EL element 1B having the above-described sealing structure, the water trapping agent 13 is stored in advance at a position facing the element 7 on the substrate 2 and the sheet member 14 is formed in the same manner as in the first embodiment. The sealing substrate 10 having the water trapping agent accommodating portion 12 covered with the substrate 2 and having the concave portion 15 in the sealing portion with the substrate 2 is prepared.

Hereinafter, processing for forming the element 7 on the substrate 2 is performed. The formation of the element 7 is performed by the same method as in the first embodiment. When the element 7 is formed on the substrate 2, the water trapping agent 16 is placed in the recess 15 of the sealing substrate 10.
Fill. At this time, the filling amount of the water catching agent 16 is
May be completely filled, or less.

Then, an adhesive mixed with the beads 11 is applied to a predetermined position (near the concave portion 15) on the sealing substrate 10 to form a sealing film 9, and the sealing substrate on which the sealing film 9 is formed is formed. The substrate 2 is sealed with the sealing substrate 1 with the surface of the element 7 facing the surface of the substrate 10.
Place on top of 0. Thereafter, a predetermined load is applied to the substrate 2 and the sealing substrate 10 using a load means such as a spring clip prepared in advance. In this state, when an ultraviolet irradiation process is performed from the outside of the substrate 2, the sealing film 9 in the sealing portion is hardened,
The distance between the sealing substrate 9 and the sealing substrate 9 is kept constant by the particle size of the beads 11 mixed in the sealing film 9.

As a result, in the organic EL device 1B completed after the above sealing process, the water trapping agent 16 in the concave portion 15 can catch water molecules and the like penetrating through the seal film 9 from the outside and entering. it can.

Next, FIG. 5 is a partially enlarged sectional view showing a third embodiment of the organic EL device according to the present invention. The same components as those in the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted.

The organic EL element 1C according to the third embodiment has the same configuration as the organic EL element 1A according to the first embodiment except for the configuration of the sealing portion.

As shown in FIG. 5, a frame-shaped concave portion 17 is formed on the outer peripheral portion located at a predetermined width inside from the outer edge portion of the sealing substrate 10 so as to surround the light emitting portion 8. As shown in FIG. 5, the concave portion 17 has a mountain-shaped cross section, and three concave portions 17A, 17B,
17C are mutually connected. The width H1 of the recess 17 in the direction toward the element 7 is set to be smaller than the width H2 of the seal film 9 in the direction toward the element 7, so that the sealing film 9 seals the portion between the substrate 2 and the sealing substrate 10 with each other. It is located and formed.

Each of the recesses 17A, 17B, and 17C is filled with the sealing film 9 when the substrate 2 and the sealing substrate 10 are bonded to each other and a predetermined load is applied. As a result, the sealing film 9 is provided with the concave portions 17A, 17B, 17 in the sealing portion.
The film thickness at C becomes larger than the film thickness other than the concave portions 17.

The seal film 9 is cured by irradiating ultraviolet rays from the substrate 2 side. At this time, the recesses 17A, 17B, 1
The sealing film 9a filled in 7C has a slightly lower cross-linking density because the integrated ultraviolet light amount is less than that of the sealing film 9b in contact with the substrate 2 other than the concave portion 17. The seal film 9a in the recesses 17A, 17B, 17C is
The crosslink density becomes smaller toward a.
Thereby, when water molecules or the like enter the organic EL element 1C after the sealing process from the outside through the seal film 9 and enter, the seal film 9a having a small cross-link density in the concave portions 17A, 17B, and 17C becomes water. It functions as a trap layer for capturing molecules and the like.

In manufacturing the organic EL element 1C having the above-mentioned sealing structure, the water-absorbing agent 13 is housed in a position facing the element 7 on the substrate 2 in advance, and the water-absorbing agent accommodating portion is covered by the sheet member 14. 12A and concave portions 17A, 17B, 17C mutually communicating with a sealing portion with the substrate 2
Is prepared in advance.

Hereinafter, processing for forming the element 7 on the substrate 2 is performed. The formation of the element 7 is performed by the same method as in the first embodiment. When the element 7 is formed on the substrate 2, a predetermined position (the concave portion 17) on the sealing substrate 10 is formed.
(In the vicinity of), an adhesive mixed with beads 11 is applied to form a sealing film 9, and the sealing substrate 1 on which the sealing film 9 is formed.
The substrate 2 is placed on the sealing substrate 10 with the surface of the element 7 facing the 0 surface. Thereafter, a predetermined load is applied to the substrate 2 and the sealing substrate 10 using a load means such as a spring clip prepared in advance. Due to this load, the concave portions 17A, 17A of the sealing substrate 10 are formed.
B and 17C are filled with the seal film 9 by the adhesive, and the film thickness at the concave portion 17 in the sealing portion becomes larger than the film thickness other than the concave portion 17 by the depth of the concave portion 17. In this state, when an ultraviolet irradiation process is performed from the outside of the substrate 2, the sealing film 9 in the sealing portion is cured, and the distance between the substrate 2 and the sealing substrate 10 is determined by the particle size of the beads 11 mixed in the sealing film 9. It is kept constant.

In curing the seal film 9,
A sufficient photopolymerization reaction acts on the seal film 9a in contact with the substrate 2 to increase the crosslink density. In contrast, recess 1
The seal films 9b in 7A, 17B, and 17C have a slightly lower crosslinking density because the integrated amount of ultraviolet light is not sufficient.

As a result, in the organic EL element 1B completed after the sealing process, the seal film 9a having a low cross-link density in the three concave portions 17A, 17B, and 17C communicating with each other causes the seal film 9 to be externally formed. Water molecules and the like that penetrate through the water can be captured.

In the third embodiment shown in FIG. 5, at least one of the concave portions 17A, 17B and 17C formed so as to communicate with the sealing substrate 10 may be filled with a water catching agent. Good. Further, the number of recesses 17 communicating with each other is not limited to the three structures shown in FIG. Further, the cross-sectional shape of the concave portion 15 in the first and second embodiments and the concave portion 17 in the third embodiment is not limited to the rectangular shape or the chevron shape shown in the drawings, and may be other shapes. Good.

As described above, the seal film 9 for fixing the outer peripheral portion between the substrate 2 and the sealing substrate 10 has a desired width H 1 smaller than the width H 2 in the direction toward the element 7. Since a thick portion is provided in the region of the sealing portion, the gas permeation characteristics of the sealing film 9 at the sealing portion can be improved as compared with the conventional case, and generation and growth of a dark spot can be suppressed. As a result, the storage stability of the organic EL element can be increased several times as compared with the conventional one, and the normal lighting life and the like can be improved.

Further, the robustness against the process variation during the sealing process can be increased, and an organic EL device having stable and reproducibility can be manufactured.

In each embodiment, since the beads 11 are mixed in the seal film 9, the substrate 2 and the sealing substrate 10
When the gap between the substrate 2 and the sealing substrate 10 is sealed, the distance between the substrate 2 and the sealing substrate 10 is kept constant by the particle diameter of the beads 11, thereby making it possible to eliminate variations in the thickness of the sealing film 9.

According to the first embodiment and the third embodiment, the recess 1 is formed in the direction of the element 7 in the region of the sealing portion.
5 and 17 are formed, and the recesses 15 and 17 are filled with a seal film 9a having a smaller cross-linking density than the seal film 9b in contact with the substrate 2, so that the seal films 9 penetrate from the outside and enter. Seal film 9 with low crosslinking density for water molecules and the like
a can be efficiently captured.

In particular, according to the third embodiment, the three concave portions 17A, 17A,
17B and 17C are formed so as to communicate with each other in the direction toward the element 7, so that each recess 17A, 17B, 1
Water molecules and the like can be more efficiently captured by the seal film 9a having a small cross-linking density of 7C.

According to the second embodiment, the recess 15 formed in the region of the sealing portion of the sealing substrate 10 so as to surround the element 7 is provided with a water trapping agent made of a material having a water trapping effect. Since the structure is filled with water 16, water molecules penetrating from the outside and penetrating through the seal film 9 can be captured by the water capturing agent 16.

According to each embodiment, the water-absorbing agent 13 is accommodated in the water-absorbing agent accommodating portion 12 formed at a position facing the element 7 of the sealing substrate 10 and covered with the sheet member 14. Therefore, together with the sealing film 9a and the water-absorbing agent 16 having a low cross-linking density in the concave portion 15 (or 17), water molecules penetrating from the outside and penetrating through the sealing film 9 are captured.
The residual moisture inside can also be efficiently caught.

In each of the above embodiments, the anode 4 made of the transparent conductive film 3 and the cathode 6 made of a metal thin film may be reversed. In this case, the CuPc organic film 5a, the α-NPD organic film 5b,
The lq ₃ organic film 5c is also stacked upside down. In this case, the substrate 2 used does not necessarily have to have a light-transmitting property, and a colored substrate having an insulating property can be used.

The pair of electrodes (anode 4 and cathode 6)
At least one of them may be formed of a conductive material having transparency. At this time, when both electrodes are made of a transparent conductive material, one of the electrodes (anode 4) is made of a transparent conductive material having a large work function (for example, ITO).
For the other electrode (cathode 6), a transparent conductive material having a small work function is used.

[0087]

As is apparent from the above description, according to the present invention, the gas permeation characteristics of the sealing film at the sealing portion can be improved as compared with the prior art, and the generation and growth of dark spots can be suppressed. . As a result, the storage stability of the organic EL element can be several times higher than before, and the normal lighting life and the like can be improved. In addition, robustness can be increased with respect to process variations during the sealing process, and a stable and reproducible organic EL device can be manufactured.

The sealing film filled in the recess formed in the region of the sealing portion of the sealing member has a lower crosslinking density than the sealing film in contact with the substrate. Water molecules and the like that enter can be efficiently caught by a seal film having a small crosslink density.

In particular, according to the configuration in which a plurality of concave portions filled with a seal film having a low cross-linking density are formed so as to communicate with each other toward the element in the region of the sealing portion of the sealing member, Water molecules and the like can be trapped more efficiently with a low-density seal film.

According to the configuration in which the water trapping agent is filled in the concave portion formed in the region of the sealing portion of the sealing substrate, the water trapping agent traps water molecules penetrating from the outside and entering through the seal film. be able to.

According to the structure in which the water catching agent is provided at a position facing the element on the sealing substrate, the water is allowed to pass through the seal film from the outside together with the sealing film or the water catching agent having a low crosslinking density in the concave portion. In addition to capturing water molecules that enter, it is also possible to efficiently capture residual moisture inside.

According to the structure in which the beads are mixed in the sealing film, when the space between the substrate and the sealing substrate is sealed, the distance between the substrate and the sealing substrate is kept constant by the particle diameter of the beads, and the sealing is performed. Variations in film thickness can be eliminated.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of an organic EL device according to the present invention.

2 (a) to 2 (g) are side sectional views showing manufacturing steps of the organic EL device of FIG. 1;

FIG. 3 is a partially enlarged cross-sectional view of the organic EL element of FIG.

FIG. 4 is a partially enlarged cross-sectional view showing a second embodiment of the organic EL device according to the present invention.

FIG. 5 is a partially enlarged sectional view showing a third embodiment of the organic EL device according to the present invention.

FIG. 6 is an exploded perspective view showing a configuration of a conventional organic EL element.

FIGS. 7A to 7G are side sectional views showing manufacturing steps of the organic EL device shown in FIGS.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Organic EL element, 2 ... Substrate, 4 ... Anode, 5 ... Organic layer,
6 Cathode, 7 Element, 9 Seal film, 10 Sealing substrate (sealing member), 11 Bead, 15, 17 (17A, 1
7B, 17C)... Recesses, 13, 16.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahisa Tsuruoka 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd. F-term (reference) 3K007 AB06 AB11 AB13 BA06 BB01 BB05 CA01 CB01 DA01 DB03 EB00 FA01 FA02

Claims (10)

[Claims] 1. A substrate on which an element is formed by stacking an organic layer including a light emitting layer between a pair of electrodes, and a sealing member disposed to face the substrate at a predetermined distance from the element. In an organic EL element in which an outer peripheral portion is fixed and sealed by a seal film made of an adhesive in a dry atmosphere, the organic EL device is provided in a region of a sealing portion formed by the seal film on a surface side of the sealing member facing the element. Wherein the recess filled with the seal film is formed so as to surround the element. 2. A substrate having an element formed by stacking an organic layer including a light-emitting layer between a pair of electrodes, and a sealing member disposed to face the substrate at a predetermined distance from the element. In an organic EL element in which an outer peripheral portion is fixed and sealed by a seal film made of an adhesive in a dry atmosphere, the organic EL device is provided in a region of a sealing portion formed by the seal film on a surface side of the sealing member facing the element. Is an organic EL device characterized in that a water-absorbing agent is filled, and a concave portion filled with the sealing film is formed on the water-absorbing agent so as to surround the device. 3. The organic EL device according to claim 1, wherein a plurality of the concave portions are formed so as to communicate with each other toward the device in a region of the sealing portion. 4. The organic EL device according to claim 1, wherein beads having a predetermined particle size are mixed in the seal film filled in the concave portion. 5. The organic EL device according to claim 1, wherein the seal film filled in the concave portion has a lower crosslinking density than a seal film that contacts the substrate. 6. The organic EL device according to claim 1, wherein a water catching agent is provided on the sealing substrate at a position facing the device. 7. A substrate having an element formed by stacking an organic layer including a light-emitting layer between a pair of electrodes, and a sealing member arranged to face the substrate at a predetermined distance from the element. In a method of manufacturing an organic EL device in which an outer peripheral portion is fixed and sealed by a seal film made of an adhesive in a dry atmosphere, a concave portion is formed in a region of the sealing portion by the seal film on a surface side facing the device. Using the formed sealing member, bonding the sealing member and the substrate, applying a predetermined load, filling the recess with the seal film, and then curing the seal film. A method for producing an organic EL device, characterized by: 8. A substrate having an element formed by stacking an organic layer including a light-emitting layer between a pair of electrodes, and a sealing member disposed to face the substrate at a predetermined distance from the element. In a method of manufacturing an organic EL device in which an outer peripheral portion is fixed and sealed by a seal film made of an adhesive in a dry atmosphere, a concave portion is formed in a region of the sealing portion by the seal film on a surface side facing the device. After using the formed sealing member and filling the concave portion with the water catching agent, bonding the sealing member and the substrate together and applying a predetermined load to fill the seal film into the concave portion And a step of curing the seal film. 9. The method for manufacturing an organic EL device according to claim 7, wherein the seal film is made of an ultraviolet curable resin, and the seal film is cured by irradiating ultraviolet rays from outside the substrate. 10. The method according to claim 7, wherein beads are mixed in the seal film.