JPWO2012161151A1 - ORGANIC EL ELEMENT AND METHOD FOR PRODUCING ORGANIC EL ELEMENT - Google Patents

Abstract

The organic EL element 1 includes a first substrate 10 having an organic EL layer 11 on the upper surface, a second substrate 20 disposed so as to face the upper surface of the first substrate 10, and a first so as to surround the organic EL layer 11. A frit 30 disposed between the substrate 10 and the second substrate 20 and sealing the space where the organic EL layer 11 is provided as the sealing region S while bonding the first substrate 10 and the second substrate 20; A protective member 40 formed inside the sealing region S so as to cover the organic EL layer 11 with a gap G1 interposed between the frit 30 and the frit 30.

Description

  The present invention relates to an organic EL element and a method for manufacturing the organic EL element.

  In an organic EL (Electro-Luminescence) element, an organic material such as an organic light emitting material used for an organic EL layer is weak against moisture, oxygen, and the like. In addition, since the characteristics of the electrodes included in the organic EL layer are rapidly deteriorated in the atmosphere due to oxidation, it is general to protect the organic EL layer from oxygen, moisture, and the like.

As a method for sealing an organic EL layer for protecting an organic EL element, many studies have been made so far. For example, a casing type sealing method, a close contact type sealing method, and a frit type sealing method. Etc.
The casing-type sealing method is to seal an organic EL layer by putting it inside the case and blocking the outside, and filling the case with a predetermined sealing gas or fluid together with the organic EL layer. Is the method.
The close-contact type sealing method is a method in which a substrate such as a glass plate is bonded to the surface of an organic EL layer formed on the substrate with a sealing adhesive between the substrate and the sealing substrate. This is a method for sealing an EL layer.
In the frit type sealing method, the sealing substrate is disposed so as to face the supporting substrate on which the organic EL layer is formed, and the supporting substrate and the sealing substrate are interposed through the frit provided so as to surround the organic EL layer. Are joined and sealed.
The casing type sealing method has various problems such as being unable to be made thin because the case is filled with a sealing gas or fluid, the process being complicated, and unsuitable for mass production. It was.
The close-contact type sealing method is capable of being thin and is relatively easy to mass-produce, but has a problem in terms of protecting the organic EL layer from oxygen and moisture.
In light of these problems, the frit type sealing method can be thinned and has an advantage in terms of sealing the organic EL layer because it is sealed with frit glass. A stopping method is considered.
For example, as described above, in the organic EL element using the conventional frit type sealing method, as shown in FIG. 4, the support substrate 91 having the organic EL layer 90 formed on the upper surface, and the upper surface of the support substrate 91. The space in which the organic EL layer 90 is provided is sealed as a sealing region 94 by joining the sealing substrate 92 opposed to the substrate through a frit 93 provided so as to surround the organic EL layer 90. Yes.

  The frit 93 is generally made of glass, and is individually bonded to the support substrate 91 and the sealing substrate 92 by laser welding. Although the frit 93 has good characteristics with respect to permeation of oxygen, moisture, and the like, it has poor mechanical strength and cannot firmly support the sealing substrate 92. Therefore, when an external force is applied to the sealing substrate 92, the sealing substrate 92 may bend and damage the organic EL layer 90.

  Therefore, in order to solve the problems of the conventional frit type sealing method, for example, in the techniques described in Patent Documents 1 to 3, the sealing region 94 is filled with a filler made of an inert liquid or resin. Thus, the organic EL layer 90 is protected while improving the breakdown voltage characteristics.

JP 2010-108905 A JP 2010-103112 A JP 2010-225569 A

  However, in the techniques described in Patent Documents 1 to 3, since each joint between the support substrate 91 and the sealing substrate 92 and the frit 93 is in contact with a filler made of an inert liquid or resin, the joint When the laser is welded, the filler material melts to cause poor welding, and there is a possibility that sufficient bonding strength cannot be ensured. If sufficient bonding strength cannot be ensured, the organic EL layer cannot be sufficiently sealed against intruders such as oxygen and moisture from the outside, or sufficient mechanical strength cannot be obtained, and a sealing substrate, etc. Cannot be firmly supported.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the organic EL element which can prevent the laser welding defect of a frit, and its manufacturing method, protecting an organic EL layer.

In order to solve the above problem, the invention according to claim 1 is an organic EL element,
A first substrate having an organic EL layer on the upper surface;
A second substrate disposed to face the upper surface of the first substrate;
It is disposed between the first substrate and the second substrate so as to surround the organic EL layer, and seals the space in which the organic EL layer is provided while bonding the first substrate and the second substrate. A frit for sealing as a stop region;
A protective member formed inside the sealing region so as to cover the organic EL layer while interposing a gap with the frit;
It is characterized by providing.

The invention according to claim 2 is the organic EL element according to claim 1,
A gap between the protective member and the frit is 0.2 mm or more.

The invention according to claim 3 is the organic EL element according to claim 1 or 2,
The protective member is characterized in that a gap is interposed between the protective member and the second substrate.

The invention according to claim 4 is the organic EL element according to claim 3,
The height of the protective member is in the range of 30 to 90% of the height of the frit.

The invention according to claim 5 is the organic EL element according to any one of claims 1 to 4,
The protective member is a UV curable resin or a thermosetting resin.

The invention according to claim 6 is the organic EL element according to claim 5,
The protective member is an epoxy resin, an acrylate resin, or a urethane acrylate resin.

The invention according to claim 7 is the organic EL element according to any one of claims 1 to 6,
An extraction electrode formed on the upper surface of the first substrate such that one end is connected to the organic EL layer inside the sealing region and the other end is exposed to the outside of the sealing region;
A sealing member disposed between the first substrate and the second substrate so as to surround the outer periphery of the frit while covering the outer periphery of the frit while covering the periphery of the extraction electrode at the lower part and covering the periphery of the second substrate at the upper part When,
It is characterized by providing.

The invention according to claim 8 is the organic EL element according to claim 7,
The sealing member is an epoxy resin, an acrylate resin, or a urethane acrylate resin.

Invention of Claim 9 is in the manufacturing method of an organic EL element,
A first step of forming an organic EL layer on the upper surface of the first substrate;
A second step of covering the organic EL layer with a protective member and disposing a frit on the upper surface of the first substrate so as to surround the organic EL layer while interposing a gap between the organic EL layer and the protective member;
A second substrate is disposed so as to face the upper surface of the first substrate, the first substrate, the second substrate, and the frit are laser-welded, and the space provided with the organic EL layer is sealed as a sealing region And a third step of sealing as
It is characterized by providing.

Invention of Claim 10 is the manufacturing method of the organic EL element of Claim 9,
A gap between the protective member and the frit is 0.2 mm or more.

Invention of Claim 11 is the manufacturing method of the organic EL element of Claim 9 or 10,
In the second step, the frit is formed higher than the protective member so that a gap is interposed between the protective member and the second substrate in the third step.

Invention of Claim 12 in the manufacturing method of the organic EL element of Claim 11,
The height of the protective member is in the range of 30 to 90% of the height of the frit.

Invention of Claim 13 in the manufacturing method of the organic EL element as described in any one of Claims 9-12,
The protective member is a UV curable resin or a thermosetting resin.

Invention of Claim 14 in the manufacturing method of the organic EL element of Claim 13,
The protective member is an epoxy resin, an acrylate resin, or a urethane acrylate resin.

Invention of Claim 15 in the manufacturing method of the organic EL element as described in any one of Claims 9-14,
In the first step, an extraction electrode is disposed on the upper surface of the first substrate, and one end thereof is connected to the organic EL layer,
In the second step, the frit is disposed so that one end of the extraction electrode is located inside the sealing region and the other end of the extraction electrode is exposed to the outside of the sealing region,
After the third step, the first substrate and the second substrate are covered so as to surround the outer periphery of the frit while covering the periphery of the second substrate at the top and the periphery on the extraction electrode at the bottom. A fourth step of disposing a sealing member therebetween is provided.

The invention according to claim 16 is the method for producing an organic EL element according to claim 15,
The sealing member is an epoxy resin, an acrylate resin, or a urethane acrylate resin.

  According to the present invention, since the organic EL layer is covered with the protective member and the gap is interposed between the protective member and the frit, the first substrate and the second substrate are protected while the organic EL layer is protected by the protective member. At the time of laser welding of the substrate and the frit, it is possible to prevent the protective member from being melted into the joint portion. Therefore, it is possible to prevent frit laser welding defects while protecting the organic EL layer.

It is a sectional side view of the organic EL element in an embodiment. It is sectional drawing in the II-II line of FIG. It is a figure for demonstrating each manufacturing process of the organic EL element in embodiment. It is a figure for demonstrating each manufacturing process of the organic EL element in embodiment. It is a figure for demonstrating each manufacturing process of the organic EL element in embodiment. It is a figure for demonstrating each manufacturing process of the organic EL element in embodiment. It is a sectional side view of the conventional organic EL element.

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

  FIG. 1 is a side sectional view of an organic EL (Electro-Luminescence) element 1 in the present embodiment, and FIG. 2 is a sectional view taken along line II-II in FIG.

  As shown in these drawings, the organic EL element 1 includes a first substrate 10 made of glass, and an organic EL layer 11 is formed at the center of the upper surface of the first substrate 10. Although not shown, the organic EL layer 11 has a laminated structure in which organic functional layers (for example, light emitting layers) are laminated so as to be sandwiched between counter electrodes (anode and cathode). A pair of extraction electrodes 12 a and 12 b are formed on the upper surface of the first substrate 10 so as to sandwich both sides of the organic EL layer 11. The pair of extraction electrodes 12 a and 12 b are an anode extraction electrode 12 a and a cathode extraction electrode 12 b, and the inner ends are individually connected to the anode and cathode of the organic EL layer 11.

  A glass-made second substrate 20 is disposed above the first substrate 10 so as to face the upper surface of the first substrate 10. The first substrate 10 and the second substrate 20 are joined by a frit 30 having glass. The frit 30 is disposed between the first substrate 10 and the second substrate 20 so as to surround the periphery of the organic EL layer 11, and the organic EL layer is bonded to the first substrate 10 and the second substrate 20. 11 is sealed as a sealing region S. Further, the frit 30 has the extraction electrode 12a, 12b such that the inner end is located inside the sealing region S and the outer end is exposed outside the sealing region S. , 12b.

  Inside the sealing region S, a protection member 40 for protecting the organic EL layer 11 is provided so as to cover the organic EL layer 11. The protective member 40 has a gap G1 interposed between the frit 30 and the entire circumference and a gap G2 interposed between the protective member 40 and the second substrate 20. As the protective member 40, it is preferable to use a UV curable resin or a thermosetting resin. Specifically, for example, an epoxy resin, an acrylate resin, or a urethane acrylate resin can be used.

  Outside the sealing region S, a sealing member 50 that seals the space between the first substrate 10 and the second substrate 20 outside the frit 30 is provided. The sealing member 50 is disposed between the first substrate 10 and the second substrate 20 so as to surround the outer periphery of the frit 30, and is bonded to the first substrate 10 and the second substrate 20, respectively. Further, the sealing member 50 is formed so as to cover a part of the periphery on the extraction electrodes 12a and 12b in the lower part while covering the periphery of the second substrate 20 in the upper part. As such a sealing member 50, it is preferable to use UV curable resin or thermosetting resin, and specifically, for example, epoxy resin, acrylate resin, or urethane acrylate resin can be used.

Then, the manufacturing method of the organic EL element 1 is demonstrated with reference to FIG. 3A-FIG. 3D.
3A to 3D are diagrams for explaining each manufacturing process of the organic EL element 1.

  First, as shown in FIG. 3A, the organic EL layer 11 is formed at the center of the upper surface of the first substrate 10. Then, a pair of extraction electrodes 12a and 12b are arranged on the upper surface of the first substrate 10 so as to sandwich both sides of the organic EL layer 11, and the inner ends thereof are individually connected to the anode and the cathode of the organic EL layer 11. Connect to.

  Next, as shown in FIG. 3B, the upper surface of the organic EL layer 11 is covered with an uncured protective member 40. Then, a paste-like frit 30 is applied to the upper surface of the first substrate 10 so as to surround the organic EL layer 11 with a gap G1 interposed between the protective member 40 and the protective member 40. At this time, the frit 30 is formed higher than the protection member 40 so that the height difference from the protection member 40 corresponds to the gap G2. The height of the protective member 40 is a value measured from the first substrate 10 on which the organic EL layer 11 and the extraction electrodes 12a and 12b are not formed. At this time, the frit is so that the inner ends of the extraction electrodes 12a and 12b are located inside the sealing region S and the outer ends of the extraction electrodes 12a and 12b are exposed to the outside of the sealing region S. 30 is taken out and arranged on the electrodes 12a and 12b.

  Next, as shown in FIG. 3C, the second substrate 20 is disposed so as to face the upper surface of the first substrate 10, and the first substrate 10 and the frit 30 and the second substrate 20 and the frit 30 are respectively bonded by laser welding. Join. Specifically, the first substrate 10 and the frit 30 and the second substrate 20 and the frit 30 are welded by irradiating the frit 30 with laser light from above or below via the first substrate 10 or the second substrate 20, respectively. Let Thereby, the space in which the organic EL layer 11 is provided is sealed as the sealing region S. Further, as described above, since the frit 30 is formed higher than the protection member 40, a gap G2 is formed between the protection member 40 and the second substrate 20.

  Then, the protective member 40 is irradiated with ultraviolet rays through the second substrate 20 or the protective member 40 is heated with a heater to cure the protective member 40. However, the protection member 40 may be cured before the laser welding of the first substrate 10 and the second substrate 20 and the frit 30.

  Next, as shown in FIG. 3D, an uncured sealing member 50 is placed between the first substrate 10 and the second substrate 20 so as to surround the outer periphery of the frit 30 at a position slightly separated from the frit 30. Deploy. At this time, the sealing member 50 is arranged so that the upper part of the sealing member 50 covers the periphery of the second substrate 20 and the lower part covers a part of the periphery of the extraction electrodes 12a and 12b. Then, the sealing member 50 is irradiated with ultraviolet rays, or the sealing member 50 is heated with a heater to cure the sealing member 50.

  As described above, according to the present embodiment, the organic EL layer 11 is covered with the protective member 40, and the gap G <b> 1 is interposed between the protective member 40 and the frit 30. While protecting the layer 11, it is possible to prevent the protective member 40 from being melted into the joint portion at the time of laser welding of the first substrate 10 and the second substrate 20 and the frit 30. Therefore, it is possible to prevent the defective fusing of the frit 30 while protecting the organic EL layer 11.

  Further, since the gap G2 is interposed between the protective member 40 and the second substrate 20, unlike the conventional case where the filler is filled in the sealing region, the second substrate 20 is bent. Even if it exists, a load is not added to the organic EL layer 11 through the filler, and the organic EL layer 11 can be more suitably protected.

Further, a sealing member 50 is provided between the first substrate 10 and the second substrate 20, and the upper portion covers the periphery of the second substrate 20 and the lower portion covers a part of the periphery on the extraction electrodes 12 a and 12 b. Therefore, it is possible to protect the peripheral edge (edge) of the second substrate 20 and the extraction electrodes 12a and 12b that are particularly fragile, and to reinforce the frit 30.
Furthermore, since the sealing member 50 is provided so as to surround the outer periphery of the frit 30, even when the frit 30 is damaged, the sealed state of the space in which the organic EL layer 11 is provided can be maintained. it can.

  The embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to this example.

  In Example 1, using the gap G1 between the protective member 40 and the frit 30 as a parameter, the bonding state of the bonding portion when the second substrate 20 and the frit 30 were laser welded was evaluated by simulation.

<Simulation conditions>
The joint between the second substrate 20 and the frit 30 was irradiated with laser light while spraying nitrogen gas in the atmosphere, and the joint was heated to about 600 ° C. for welding. Various conditions of the irradiated laser light are as follows. Here, the “moving speed” is a speed at which the laser light is moved along the longitudinal direction of the frit 30.
Output: 5w
Spot diameter: 0.5mm
Wavelength: 980nm
Movement speed: 10mm / sec

<Other conditions>
Conditions such as the shape of each part other than the above are as follows.
Width of frit 30: 0.2 mm
The thickness of the second substrate 20: 0.7 mm
Material of protective member 40: Epoxy resin Heat resistant temperature of protective member 40: 300-600 ° C

<Result>
The results are shown in Table 1. The symbols in the “Evaluation result” column in the table indicate the following contents, respectively.

A: The strength of the joint was very good and there was no variation.
Further, the protective member 40 and the organic EL layer 11 were not damaged.
○: The strength of the joint was good and there was almost no variation.
Further, the protective member 40 and the organic EL layer 11 were not damaged.
Δ: The joint strength was good, but there was some variation.
Although the protective member 40 was slightly damaged,
The organic EL layer 11 was not damaged.
X: The strength of the joint was poor and there was variation.
Further, the protective member 40 and the organic EL layer 11 were damaged.
“Variation” refers to variation in bonding strength across all bonding surfaces on the first substrate 10.

<Summary>
From the results shown in Table 1, it can be seen that the gap G1 between the protective member 40 and the frit 30 is preferably 0.05 mm or more, more preferably 0.2 mm or more, and even more preferably 0.75 mm or more.

  In Example 2, the height of the protective member 40 was used as a parameter, and the influence on the organic EL layer 11 when a load was applied to the upper surface of the second substrate 20 and the difficulty in forming the protective member 40 were evaluated. .

<Test conditions>
The height of the frit 30 from the first substrate 10 to the second substrate 20 was 10 μm. The thickness of the second substrate 20 was 0.7 mm.

<Result>
The results are shown in Table 2. In the table, the symbols in the respective columns of “Effect of pressure on organic EL layer” and “Difficulty in manufacturing” indicate the following contents, respectively.

"Influence of pressure on organic EL layer"
A: The organic EL layer 11 was not damaged at all.
○: The organic EL layer 11 was hardly damaged.
Δ: The organic EL layer 11 was slightly damaged.

"Manufacturing difficulties"
(Double-circle): The protection member 40 can be formed without a problem.
(Triangle | delta): Some difficulty accompanies formation of the protection member 40.

<Summary>
From the results shown in Table 2, the ratio of the height of the protective member 40 to the height of the frit 30 is preferably 30% or more from the viewpoint of manufacturing difficulty, and 90% from the viewpoint of protecting the organic EL layer 11. % Or less is preferable.

  As described above, the organic EL element and the manufacturing method thereof according to the present invention are useful for preventing the frit laser welding failure while protecting the organic EL layer.

DESCRIPTION OF SYMBOLS 1 Organic EL element 10 1st board | substrate 11 Organic EL layer 12a, 12b Extraction electrode 20 2nd board | substrate 30 Frit 40 Protection member 50 Sealing member G1 Gap (gap between a protection member and a frit)
G2 gap (gap between the protective member and the second substrate)
S Sealing area

Claims (16)

A first substrate having an organic EL layer on the upper surface;
A second substrate disposed to face the upper surface of the first substrate;
It is disposed between the first substrate and the second substrate so as to surround the organic EL layer, and seals the space in which the organic EL layer is provided while bonding the first substrate and the second substrate. A frit for sealing as a stop region;
A protective member formed inside the sealing region so as to cover the organic EL layer while interposing a gap with the frit;
An organic EL device comprising:   The organic EL element according to claim 1, wherein a gap between the protective member and the frit is 0.2 mm or more.   The organic EL element according to claim 1, wherein a gap is interposed between the protective member and the second substrate.   4. The organic EL element according to claim 3, wherein the height of the protective member is within a range of 30 to 90% of the height of the frit.   The organic EL device according to claim 1, wherein the protective member is a UV curable resin or a thermosetting resin.   The organic EL element according to claim 5, wherein the protective member is an epoxy resin, an acrylate resin, or a urethane acrylate resin. An extraction electrode formed on the upper surface of the first substrate such that one end is connected to the organic EL layer inside the sealing region and the other end is exposed to the outside of the sealing region;
A sealing member disposed between the first substrate and the second substrate so as to surround the outer periphery of the frit while covering the outer periphery of the frit while covering the periphery of the extraction electrode at the lower part and covering the periphery of the second substrate at the upper part When,
The organic EL element according to any one of claims 1 to 6, further comprising:   The organic EL element according to claim 7, wherein the sealing member is an epoxy resin, an acrylate resin, or a urethane acrylate resin. A first step of forming an organic EL layer on the upper surface of the first substrate;
A second step of covering the organic EL layer with a protective member and disposing a frit on the upper surface of the first substrate so as to surround the organic EL layer while interposing a gap between the organic EL layer and the protective member;
A second substrate is disposed so as to face the upper surface of the first substrate, the first substrate, the second substrate, and the frit are laser-welded, and the space provided with the organic EL layer is sealed as a sealing region And a third step of sealing as
A method for producing an organic EL element, comprising:   The method for producing an organic EL element according to claim 9, wherein a gap between the protective member and the frit is 0.2 mm or more.   In the second step, the frit is formed higher than the protective member so that a gap is interposed between the protective member and the second substrate in the third step. The manufacturing method of the organic EL element of 9 or 10.   12. The method of manufacturing an organic EL element according to claim 11, wherein the height of the protective member is within a range of 30 to 90% of the height of the frit.   The method for producing an organic EL element according to claim 9, wherein the protective member is a UV curable resin or a thermosetting resin.   The method for producing an organic EL element according to claim 13, wherein the protective member is an epoxy resin, an acrylate resin, or a urethane acrylate resin. In the first step, an extraction electrode is disposed on the upper surface of the first substrate, and one end thereof is connected to the organic EL layer,
In the second step, the frit is disposed so that one end of the extraction electrode is located inside the sealing region and the other end of the extraction electrode is exposed to the outside of the sealing region,
After the third step, the first substrate and the second substrate are covered so as to surround the outer periphery of the frit while covering the periphery of the second substrate at the top and the periphery on the extraction electrode at the bottom. The method for producing an organic EL element according to any one of claims 9 to 14, further comprising a fourth step of disposing a sealing member therebetween.   The method for producing an organic EL element according to claim 15, wherein the sealing member is an epoxy resin, an acrylate resin, or a urethane acrylate resin.

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