JP2002280169A - Organic el device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive organic EL device having a high-reliability sealing structure. SOLUTION: This organic EL device 1 has an element board 2 having an organic EL element 3 formed on its inside surface, and a sealing board 7 facing to the organic EL element with a predetermined clearance and is provided with an adhesive 11 between the circumferential parts of both the boards. A frame-like inside barrier rib 8 is disposed between the element board 2 and the sealing board 7 and circularly surrounds the EL element 3, and in the inside thereof, a water catching part 10 is formed on the inside surface side of the sealing board 7. An outside barrier rib 9 surrounding the inside barrier rib in a frame-like form is formed between the circumferential parts of the element board 2 and the sealing board 7, the adhesive 11 is filled between the inside barrier rib 8 and the outside barrier rib 9 to bond both the boards to each other. The need of a metal cap for covering the organic EL element is obviated. The barrier ribs can be formed of low-melting point glass, and moisture permeability of the bonded surfaces thereof is small so that the reliability thereof is high. Since the water catching part and the sealant are partitioned by the inside barrier rib, the application region of a water catching agent dissolved in a solvent can be limited and the reliability of the sealing is never deteriorated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence (hereinafter, referred to as "organic EL") device which uses light emitted from an organic electroluminescence (hereinafter, referred to as "organic EL") device as a light source and a display.

[0002]

2. Description of the Related Art An organic EL device has a structure in which a thin organic layer containing a fluorescent organic compound is sandwiched between a cathode serving as an electron injection electrode and an anode serving as a hole injection electrode. A display element that generates excitons (excitons) by injecting and recombining holes and injects light to emit light (fluorescence / phosphorescence) when the excitons are deactivated.

Since the organic EL element is very weak to moisture, when it is actually used as a light-emitting portion of a light-emitting / display device, a sealing structure in which the organic EL element itself is not exposed to the outside air is adopted. For example, FIG. 4 is a cross-sectional view showing an example of an organic EL element sealing structure using a metal sealing cap. On the inner surface of the glass substrate 100, a light-transmitting anode 101, an organic layer 102, and a cathode 103 are laminated to form an organic EL element 104. A metal sealing cap 105 is adhered to the upper surface of the glass substrate 100 with an adhesive 106 so as to cover the organic EL element 104. Sealing cap 10 facing organic EL element 104
A concave portion 107 is provided in a part of 5, and the concave portion 107 is filled with a water catching agent 109 and held by a water-permeable holding sheet. As the water catching agent 109, barium oxide, calcium oxide, or the like is used. The water catching agent 109 adsorbs moisture adhering to the organic EL element 104, moisture contained in the atmosphere inside the sealing cap, and moisture entering the sealing cap from the outside.

[0004]

However, the conventional organic EL device using a metal sealing cap as described above has the following problems.

That is, the metal sealing cap 105 needs to be processed in accordance with the size of the glass substrate 100 on which the organic EL element 104 is formed. No. For this reason, a mold for shaping the metal is required for each type, and there is a problem in workability and cost. If the precision of the mold is not controlled and manufactured, the obtained sealing cap 105
Since the flatness of the sealing surface cannot be kept good and the unevenness becomes large, the moisture permeability on the bonding surface with the glass substrate 100 is increased, and the reliability of the organic EL element 104 may be significantly reduced. Further, the adhesive 106 must adhere to both metal and glass with sufficient reliability, and it is difficult to select a material.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an organic EL device capable of obtaining an inexpensive and highly reliable sealing structure without using a metal cap and a method of manufacturing the same. It is an object.

[0007]

An organic EL device according to a first aspect of the present invention comprises an element substrate (2) having an organic EL element (3) formed on an inner surface thereof and a predetermined distance from the organic EL element on the element substrate. An organic EL device having an encapsulation substrate (7), which faces the substrate, and a sealant (adhesive 11) provided between the element substrate and an outer peripheral portion of the encapsulation substrate to seal both substrates ( In 1), a water catching portion (10) is provided between the element substrate and an outer peripheral portion of the sealing substrate to surround the organic EL element in a circumferential shape and on the inner side of the element substrate inside the organic EL element. An inner partition (8) defining an area, provided between the element substrate and an outer peripheral portion of the sealing substrate, surrounding the inner partition in a circumferential shape, and filling the inner partition with the sealant. And an outer partition (9) defining a sealed area to be formed. .

According to a second aspect of the present invention, in the organic EL device according to the first aspect, the inner partition wall and the outer partition wall are made of an inorganic material as a water-impermeable material. It is characterized by consisting of.

An organic EL device according to a third aspect is characterized in that, in the organic EL device according to the second aspect, the inorganic material is a low-melting glass that has undergone a firing step.

According to a fourth aspect of the present invention, there is provided the organic EL device according to the first aspect, wherein the water trapping portion is provided on the inner surface of the element substrate inside the inner partition wall. 10) is formed.

According to a fifth aspect of the present invention, there is provided a method of manufacturing an organic EL device, comprising: forming an organic EL element (3) on an inner surface of an element substrate (2); Forming an inner partition wall (8) and a peripheral outer partition wall (9) surrounding the inner partition wall from an inorganic material; and forming a water catching section (10) on the inner surface of the sealing substrate inside the inner partition wall. Performing a step of providing a sealant (adhesive) between the inner partition and the outer partition; and attaching the element substrate to the sealing substrate such that the organic EL element is disposed inside the inner partition. Facing and bonding.

According to a sixth aspect of the present invention, there is provided a method of manufacturing an organic EL device, comprising: forming an organic EL element (3) on an inner surface of an element substrate (2); Printing and baking an inner partition (8) and a peripheral outer partition (9) surrounding the inner partition with a glass paste, and applying a water catching agent to the inner surface of the sealing substrate inside the inner partition. Forming a water catching section (10) by drying; and applying an ultraviolet curable adhesive (11) as a sealant between the inner partition and the outer partition;
A step of bonding the element substrate to the sealing substrate so that the organic EL element is disposed inside the inner partition wall, and a step of curing the adhesive (11) by irradiation of ultraviolet rays. are doing.

A method of manufacturing an organic EL device according to a seventh aspect of the present invention includes a step of forming a plurality of organic EL elements (3) on an inner surface of one element substrate (element original plate 22) at appropriate intervals. On the inner surface of one sealing substrate (the original sealing plate 27),
At a plurality of positions corresponding to a plurality of organic EL elements formed on the element substrate, a circumferential inner partition (8) and a circumferential outer partition (9) surrounding the inner partition are printed by glass paste, respectively. Baking, and applying a water-absorbing agent to the inner surface of the sealing substrate inside each of the inner partition walls, followed by drying to form a water catching section (10). An ultraviolet-curing adhesive (1) is used as a sealant between the outer partition walls.
1) applying, bonding the element substrate to the sealing substrate such that the organic EL elements are disposed inside the inner partition walls, and irradiating the adhesive with ultraviolet rays. Curing the (11) and cutting the element substrate (22) and the sealing substrate (27) along the outer periphery of the outer partition wall to obtain a plurality of organic EL elements (1). ing.

[0014]

FIG. 1A is a vertical sectional view of an organic EL device 1 according to an embodiment of the present invention, and FIG.
FIG. 2 is a plan sectional view taken along a cutting line in FIG. The element substrate 2 is obtained by cutting a plate glass as a light-transmitting and insulating substrate such as soda lime glass into a predetermined rectangular shape. An organic EL element is formed at the center on the inner surface side of the element substrate 2. The organic EL element 3 has a translucent anode 4 formed on the inner surface of the element substrate 2, an organic layer 5 formed thereon, and a cathode 6 formed thereon.

A sealing substrate 7 is provided so as to face the organic EL element 3 at a predetermined interval. The sealing substrate 7 is a glass plate having substantially the same outer shape and material as the element substrate 2.

An inner partition 8 and an outer partition 9 are provided between the element substrate 2 and the sealing substrate 7. The inner partition wall 8 and the outer partition wall 9 are made of an inorganic material such as low melting point frit glass and have high water impermeability. The internal partition 8 has a rectangular frame structure in plan view surrounding the periphery of the organic EL element 3, and the external partition 9 has a rectangular frame structure in plan view surrounding the internal partition 8 at a predetermined interval. The outer surface of the outer partition wall 9 substantially coincides with the end surfaces of the outer peripheral portions of the element substrate 2 and the sealing substrate 7, thereby forming a thin panel-shaped container as a whole.

The inner partition wall 8 and the outer partition wall 9 serve not only as spacers for keeping the distance between the element substrate 2 and the sealing substrate 7 constant, but also have the following functions. That is, the sealing substrate 7 facing the organic EL element 3 is provided inside the inner partition 8.
A rectangular area is defined on the inner surface of the section, and a water catching section 10 is formed in this area. The water catching section 10 of this embodiment is a layer made of a water catching substance, and the water catching substance is the same as the conventional one. An adhesive 11 as a sealant is filled in a frame-shaped space between the inner partition wall 8 and the outer partition wall 9 to bond the element substrate 2 and the sealing substrate 7 together.

Next, a manufacturing process of the organic EL device 1 will be described with reference to FIG. FIG. 2A shows the sealing substrate 7.
Is shown. The shape and the like of the element substrate 2 are substantially the same. When soda lime glass is used as the material of the sealing substrate 7, at least a protective film such as SiO ₂ is brought into contact with an adhesive (sealant) in order to prevent interface peeling with an epoxy sealant due to leaching of an alkali component. It is preferable to form it on the surface to be formed.

As shown in FIG. 2B, an inner partition 8 and an outer partition 9 are formed on the inner surface of the sealing substrate 7. As a forming method, a printing method, a photolithography method, or the like can be used. In the present embodiment, the above-mentioned double frame-shaped pattern is formed using low melting point frit glass powder as an inorganic substance,
After that, unnecessary components were removed by baking and hardened to form inner partition walls 8 and outer partition walls 9 having predetermined dimensions. Specifically, a predetermined pattern was formed by a printing method using a paste containing low melting point frit glass powder, and the dimensions of the partition walls obtained after firing were 0.2 mm in width and 0.1 mm in height. After the partition walls are formed, they are washed.

As described above, in the present embodiment, the partitions 8 and 9 are formed on the sealing substrate 7 side separate from the element substrate 2 on which the organic EL elements 3 are formed. Can be used. That is, the water-impermeable barrier ribs 8 and 9 made of an inorganic material such as glass which require a firing step are formed in an organic EL device which is weak against heat, and are used as spacers or as a means for partitioning a region to which a water catching agent or a sealant is applied. be able to.

As shown in FIG. 2 (c), a liquid water-absorbing agent is applied to the inside of the inner partition wall 8 and dried to form a water-absorbing section 10.

As shown in FIG. 2D, a UV-curable epoxy-based adhesive 11 is applied between the inner partition 8 and the outer partition 9 as a sealant.

As shown in FIG. 2 (e), the element substrate 2 on which the organic EL element 3 has been formed in advance is placed on the partition wall of the sealing substrate 7 in an atmosphere of dry nitrogen.
The elements 3 are combined so as to enter the inside of the inner partition 8.

Then, the adhesive 11 is cured by irradiation of ultraviolet rays, and the both substrates are sealed.

The organic EL device formed as described above is driven to actually emit light from the organic EL element 3. The state of light emission is observed using a microscope, and then put into a high temperature and high humidity atmosphere of 85 ° C. and 85%. To confirm the water catching effect. After 100 hours, the organic EL element 3 was taken out, emitted under the same light emitting conditions, and observed with a microscope. As a result, no growth of a non-light emitting portion (dark spot) was observed, and the sealing substrate 7 was made of organic E.
It was confirmed that the device sufficiently functions as a sealing cap for sealing the L element 3.

Next, a manufacturing process of an organic EL device according to another embodiment of the present invention will be described with reference to FIG. The present embodiment is characterized in that a plurality of organic EL devices are simultaneously manufactured using a glass plate relatively larger than the organic EL device to be manufactured. First, as shown in FIG. 3, an element base plate 22 having a shape and dimensions enough to take out a plurality of element substrates is prepared, and a plurality of organic ELs are arranged in a predetermined arrangement.
The element 3 is manufactured. On the other hand, a sealing base plate 27 having a shape and dimensions corresponding to the element base plate 22 is prepared, and the above-described inner partition walls 8 and outer partition walls 9 are formed thereon at locations and arrangements corresponding to the number and arrangement of the organic EL elements 3. I do. As described above, the water catching section 10 is provided on the inner bulkhead 8 and the outer bulkhead 9 at each position.
And an adhesive 11 as a sealing agent.

The sealing original plate 27 and the element original plate 22 are overlapped and combined so that each organic EL element 3 enters the inside of each inner partition 8. Then, ultraviolet rays are irradiated to the sealant, and the two original plates 2
The adhesion of 2,27 is fixed.

Then, as shown by arrows in FIG. 3, each original plate 2 is adjusted to the outer shape of each organic EL device 1 to be manufactured.
2 and 27 are cut with a cutter, and the original plates 22 and 27 are cut with the grooves.
To obtain a plurality of organic EL devices 1. In this example,
The element base plate 22 is split so that a plate portion 2a protruding from the panel-like outer shape is formed on the element base plate 22 side (organic EL element side) of each organic EL device. The protruding plate portion 2a can be used as a space for forming an external terminal portion and the like connected to internal electrodes.

In the present embodiment, the adhesive 11 for bonding the element substrate 2 and the sealing substrate 7 is blocked by the outer partition wall 9 so as not to flow out, so that a large set of The organic EL device 1 can be manufactured by arranging the plurality of organic EL devices 1 on the original plates 22 and 27 and then folding the original plates 22 and 27. That is, if the outer partition wall 9 is not provided, the adhesive 11 drips outward, and the adhesive 11 hardens in a state where the adhesive 11 traverses a portion to be the outer shape of the organic EL device 1. It doesn't work even if you try to fold it neatly. However, according to this example, since there is no such a problem, a large number of organic EL devices 1 can be manufactured at a time by using the large original plates 22 and 27 as described above. Although only two organic EL devices 1 are shown in FIG. 3 for the sake of illustration, more organic EL devices 1 can be manufactured simultaneously by appropriately selecting the sizes of the original plates 22 and 27. In that case, the rectangular organic E
The L device 1 is configured to be regularly arranged at predetermined intervals vertically and horizontally with respect to the original plates 22 and 27, and the original plate is cut by one cutting operation along each of the vertical and horizontal sides of each organic EL device 1. It is efficient to be able to do so.

[0030]

According to the present invention, since a partition is formed on a substrate material such as a sheet glass by a printing method or a photolithography method, a mold processing is not required unlike a conventionally used metal cap. It can be applied regardless of the quantity or type of the organic EL device to be manufactured, and is advantageous in terms of workability and cost as compared with the related art. Further, since the substrate material is used as it is, the flatness of the sealing surface is good, the moisture permeability at the bonding surface between the substrate and the partition wall is small, and the reliability as an organic EL device is high. Further, when a glass plate is used as a substrate, a sealant suitable for only glass may be selected.

Since the water catching section and the sealant are partitioned by the inner partition, when the step of dissolving the water catching agent constituting the water catching section in a solvent and applying is adopted, the water catching agent is applied to the water catching section. In addition to the problem that the region where the water is formed can be limited, the problem that the water catching agent spreads to the seal portion and lowers the reliability of the seal does not occur.

Since the outer partition is provided outside the seal application area, the adhesive (seat) does not spread outside the substrate. For this reason, the problem that the electrical terminals drawn out from the inside of the device via the substrate surface and covered with the sealing agent protruding outside the device along the substrate surface hardly causes a problem that the connection reliability is reduced is caused. Also, when a plurality of organic EL devices manufactured at a time on a large common base plate are divided and taken out, the sealant does not protrude onto the base plate. There is no inconvenience that the image cannot be divided (folded) because of the existence of.

Conventionally, a spacer material such as beads is mixed in a sealant to determine a distance between the two substrates.
In the present invention, since the partition also has a function as a spacer for determining a distance between the element substrate and the sealing substrate, it is not necessary to provide a dedicated spacer material such as beads.

Since the partition can be manufactured on a substrate on a side different from the substrate on which the heat-sensitive organic EL element is formed, it is necessary to manufacture the partition using an inorganic material such as glass which requires a heating step. Can be. Since an inorganic material such as glass has a higher moisture resistance than an epoxy resin or the like which has been conventionally used as a sealant, the present invention was able to obtain a higher moisture resistance as a whole of the organic EL device than before.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of an organic EL device according to a first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along a cutting line of FIG.

FIG. 2 shows an organic EL according to a first embodiment of the present invention.
It is a manufacturing process figure of an apparatus.

FIG. 3 shows an organic EL according to a second embodiment of the present invention.
It is a figure showing one process in manufacture of a device.

FIG. 4 is a cross-sectional view of a conventional organic EL device having a metal cap.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 organic EL device 2 element substrate 3 organic EL element 7 sealing substrate 8 inner partition 9 outer partition 10 water catching part 11 adhesive as sealant

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Yuji Saito 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd. F-term (reference) 3K007 AB13 AB18 BB00 BB05 CA01 CB01 DA01 DB03 EA01 EB00 FA02

Claims (7)

[Claims] An element substrate having an organic EL element formed on an inner surface thereof; a sealing substrate facing the organic EL element of the element substrate at a predetermined interval; and an outer peripheral portion of the element substrate and the sealing substrate. In an organic EL device having a sealant provided between the element substrate and the sealing substrate, the organic EL device is provided between the element substrate and an outer peripheral portion of the sealing substrate so as to surround the organic EL element in a peripheral shape. On the inner side, an inner partition partitioning a formation region of a water catching portion on the inner surface side of the element substrate, and provided between the outer peripheral portion of the element substrate and the sealing substrate to surround the inner partition circumferentially, And an outer partition partitioning a seal region filled with the sealant between the inner partition and the inner partition. 2. The organic EL according to claim 1, wherein the inner partition and the outer partition are made of an inorganic material as a water-impermeable material.
apparatus. 3. The organic EL device according to claim 2, wherein the inorganic material is a low-melting glass that has undergone a firing step. 4. The organic EL according to claim 1, wherein a water catching portion is formed on an inner surface of the element substrate inside the inner partition wall.
apparatus. 5. A step of forming an organic EL element on an inner surface of an element substrate; and a step of forming a circumferential inner partition and a circumferential outer partition surrounding the inner partition on an inner surface of a sealing substrate using an inorganic material; Forming a water catching portion on the inner surface of the sealing substrate inside the inner partition; providing a sealant between the inner partition and the outer partition; And bonding the device substrate to the sealing substrate so as to face the sealing substrate. 6. A step of forming an organic EL element on an inner surface of an element substrate, and a step of printing and firing a peripheral inner partition wall and a peripheral outer partition wall surrounding the inner partition wall with a glass paste on an inner surface of a sealing substrate. Forming a water catching portion by applying and drying a water catching agent on the inner surface of the sealing substrate inside the inner partition, and curing ultraviolet rays as a sealant between the inner partition and the outer partition. A step of applying a mold adhesive; a step of bonding the element substrate so as to face the sealing substrate so that the organic EL element is arranged inside the inner partition; and Curing the organic EL device. 7. A plurality of organic E layers are formed on the inner surface of one element substrate.
Forming L elements at appropriate intervals; and forming a circumferential inner partition wall at a plurality of positions on the inner surface of one sealing substrate corresponding to the plurality of organic EL elements formed on the element substrate. Printing the outer peripheral partition walls surrounding the inner partition walls with a glass paste, respectively, and baking the coated outer partition walls; applying a water collecting agent to the inner surface of the sealing substrate inside each of the inner partition walls, followed by drying to collect the water; A step of forming a water portion; a step of applying an ultraviolet-curable adhesive as a sealant between each of the inner partition walls and the outer partition walls; and disposing the organic EL elements inside the inner partition walls. Bonding the device substrate to the sealing substrate so that the device substrate faces the sealing substrate; curing the adhesive by irradiating ultraviolet rays; and sealing the device substrate along the outer periphery of the outer partition wall. A method of manufacturing an organic EL device having a step of cutting the substrate to obtain a plurality of organic EL elements.