JP2013222599A - Organic el display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL display device which has high reliability in display performance while making use of hygroscopic capability of a silicon-containing polymer having water absorption such as polysilazane.SOLUTION: An organic EL display device comprises a substrate 10, an organic EL element 20 provided on the substrate 10, an encapsulation substrate 50 provided on the organic EL element 20, a moisture absorption layer 30 provided between the substrate 10 and the encapsulation substrate 50, and an adhesion layer provided between the substrate 10 and the encapsulation substrate 50 for joining the substrate 10 and the encapsulation substrate 50. In the organic EL display device, the moisture absorption layer 30 is a layer made of a silicon-containing polymer having water absorption, an end of the moisture absorption layer 30 is exposed to the open air, and a stress relaxation member 41 is provided between the substrate 10 and the encapsulation substrate 50 so as to come into contact with at least the moisture absorption layer 30.

Description

  The present invention relates to an organic EL display device.

  The organic EL display device is a display device having a plurality of organic EL elements each composed of an anode, a cathode, and an organic compound layer disposed between the cathode and the anode. Here, the organic EL element is an electronic element in which an organic compound layer located between both electrodes emits light when a current is applied between the cathode and the anode. Here, since the organic EL element included in the organic EL display device is self-luminous, the organic EL element has a feature that it is highly visible and can be made thinner and lighter than a liquid crystal display device. For this reason, organic EL display devices are being developed for mobile applications, and have been put into practical use as display devices for mobile phones and the like.

  However, in an organic EL display device, an organic light-emitting material that is one of constituent materials is deteriorated due to a very small amount of moisture, oxygen, or the like, or peeling or the like occurs between the light-emitting layer and the electrode. As a result, there is a problem in that the display performance deteriorates such as a decrease in light emission efficiency and an increase in a non-light emitting region (dark spot).

  As a specific countermeasure against such a problem, there is a sealing method using a polysilazane film disclosed in Patent Document 1. According to this method, since the polysilazane film suppresses the intrusion of moisture from the outside as much as possible, it is possible to further improve moisture resistance.

JP 2009-259788 A

  Polysilazane has a repeating structural unit represented by the following general formula (A).

(In the formula (A), R ^{1 to} R ³ each represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkylsilyl group, an alkylamino group, an alkoxy group, or a metal atom, provided that R ^{1 to} R ^At least one of ³ is a hydrogen atom.)

In the formula (A), for example, polysilazane in which R ^{1 to} R ³ are all hydrogen atoms absorbs moisture in the atmosphere and becomes silica (SiO ₂ ) having excellent moisture resistance as shown in the following reaction formula. Convert.

  For this reason, polysilazane has a function as a hygroscopic material that absorbs moisture in the atmosphere, and also has a function as a moisture-proof material when it absorbs moisture in the atmosphere. Therefore, it can be said that polysilazane is a useful material in an organic EL display device that causes deterioration in display performance such as a decrease in luminous efficiency and an increase in dark spots due to a very small amount of moisture, oxygen, and the like.

  However, as shown in the above reaction formula, polysilazane reacts with water to release gas (ammonia gas, hydrogen gas). Here, when the polysilazane film is provided between the protective film and the protective film as in Patent Document 1, bubbles are generated and grow inside the protective film in the vicinity of the pinhole defect, which impairs the appearance during light emission. There was a problem.

In addition, since the structure of a polysilazane film changes into a dense silica-based inorganic film by reacting with water, volume shrinkage occurs due to the change in the structure of the film. For example, in the case of using polysilazane to which an amine-based catalyst that can be converted to silica at a low temperature is used, a thin film obtained by coating and baking at 100 ° C. has a density of 1 by reacting with water. Increase from ³ g / cm ³ to 1.6 g / cm ³ . This has been found to reduce the volume of the thin film by approximately 10%. As a result, in the configuration in which both surfaces of the moisture absorption layer are sandwiched between the protective layers as in Patent Document 1, film peeling occurs at the interface between the polysilazane and the moisture proof film, or film defects of the protective film that is the moisture proof member occur. Problems arise.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an organic EL display device having high display performance reliability while taking advantage of the moisture absorption capability of a water-containing silicon-containing polymer such as polysilazane. Is to provide.

The organic EL display device of the present invention includes a substrate,
An organic EL element provided on the substrate;
A sealing substrate provided on the organic EL element;
A moisture absorption layer provided between the substrate and the sealing substrate;
In an organic EL display device comprising: an adhesive layer provided between the substrate and the sealing substrate and joining the substrate and the sealing substrate;
The moisture absorption layer is a layer made of a silicon-containing polymer having water absorption,
The end of the moisture absorbing layer is exposed to the outside air,
A stress relaxation member is provided between the substrate and the sealing substrate, and at least in contact with the moisture absorption layer.

  ADVANTAGE OF THE INVENTION According to this invention, the organic EL display apparatus with high reliability of display performance can be provided, making use of the moisture absorption capability which the silicon-containing polymer which has water absorption, such as a polysilazane, has.

  That is, in the organic EL display device of the present invention, since the end of the hygroscopic layer is exposed to the outside air, the gas generated from the hygroscopic layer (outgas) is released from the end and generation of bubbles that can be generated from the hygroscopic layer is generated.・ Suppress growth. In addition, when a silica moisture-proof film is formed by incorporating water into the moisture-absorbing layer, the stress relaxation member is provided so as to be in contact with the moisture-absorbing layer, thereby preventing peeling of the adhesive layer due to volume shrinkage. An organic EL display device with high reliability is provided.

It is a cross-sectional schematic diagram which shows 1st embodiment in the organic electroluminescence display of this invention. It is a cross-sectional schematic diagram which shows 2nd embodiment in the organic electroluminescence display of this invention. It is a cross-sectional schematic diagram which shows 3rd embodiment in the organic electroluminescence display of this invention. It is a cross-sectional schematic diagram which shows 4th embodiment in the organic electroluminescence display of this invention. It is a cross-sectional schematic diagram which shows 5th embodiment in the organic electroluminescence display of this invention.

  The organic EL display device of the present invention includes a substrate, an organic EL element, a sealing substrate, a hygroscopic layer, and an adhesive layer. In the present invention, the organic EL element is an electronic element provided on a substrate. In the present invention, the sealing substrate is a substrate provided on the organic EL element. The sealing substrate is arranged so as to face the substrate and sandwich the organic EL element. In the present invention, the hygroscopic layer is a member provided between the substrate and the sealing substrate. In addition, the installation aspect of a moisture absorption layer is mentioned later. In the present invention, the adhesive layer is a member provided between the substrate and the sealing substrate, and is a member for joining the substrate and the sealing substrate.

  In the organic EL display device of the present invention, the moisture absorption layer is a layer made of a silicon-containing polymer having water absorption. In the organic EL display device of the present invention, the end of the moisture absorption layer is exposed to the outside air. That is, the end of the moisture absorption layer is not covered with other members constituting the organic EL display device. In the organic EL display device of the present invention, a stress relaxation member is provided between the substrate and the sealing substrate so as to be in contact with at least the moisture absorption layer.

  Hereinafter, the present invention will be described with reference to the drawings. In the following description, a well-known technique or a well-known technique in the technical field can be applied to a part that is not particularly illustrated or described. The items described below are only one embodiment of the present invention, and the present invention is not limited to these embodiments.

[First embodiment]
FIG. 1 is a schematic cross-sectional view showing a first embodiment of the organic EL display device of the present invention.

  The organic EL display device 1 of FIG. 1 includes an organic EL element 20 in which a first electrode 21, an organic compound layer 22, and a second electrode 23 are stacked in this order on a predetermined region on a substrate 10. It has been. Note that the predetermined area here is an area called a display area, and an area on the substrate 10 outside the display area (for example, an area corresponding to the outer periphery of the display area) is an area called a non-display area. is there. Incidentally, in the organic EL display device 1 of FIG. 1, one organic light emitting element 20 is provided in the display region. However, the present invention is not limited to the mode of FIG. A plurality of elements 20 may be provided. In the organic EL display device 1 of FIG. 1, the organic EL element 20 is covered with a moisture absorption layer 30. In the organic EL display device 1 of FIG. 1, the moisture absorption layer 30 is provided so as to cover the entire surface of the substrate 10, that is, the display area and the non-display area where the organic EL element 20 is provided. In the organic EL display device 1 of FIG. 1, the stress relaxation member 41 and the adhesive layer 42 are provided in this order on the moisture absorption layer 30 provided in the non-display area. In the organic EL display device 1 of FIG. 1, a sealing substrate 50 is provided on the adhesive layer 42.

  Next, components of the organic EL display device 1 shown in FIG. 1 will be described.

  The substrate 10 which is a constituent member of the organic EL display device 1 is, for example, a glass substrate, an insulating substrate made of synthetic resin, a conductive substrate having an insulating layer such as silicon oxide or silicon nitride formed on the surface, a semiconductor substrate, or the like. Can be mentioned. The substrate 10 itself may be transparent or opaque.

The first electrode 21 is an electrode provided on the substrate 10 and is a conductive thin film also called a lower electrode. The first electrode 21 may be a transparent electrode or a reflective electrode. If the first electrode 21 is a transparent electrode, as its constituent material, ITO, a transparent conductive material such as In ₂ O ₃ and the like. On the other hand, when the first electrode 21 is a reflective electrode, the constituent materials include simple metals such as Au, Ag, Al, Pt, Cr, Pd, Se, and Ir, alloys obtained by combining a plurality of these metals, and iodide. Examples thereof include metal compounds such as copper. The film thickness of the first electrode 21 is preferably 0.1 μm to 1 μm.

  The organic compound layer 22 provided on the first electrode 21 is a laminate composed of one or more layers having at least a light emitting layer. When the organic compound layer 22 is composed of a plurality of layers, the layer constituting the organic compound layer 22 can be appropriately selected in consideration of the light emitting function of the organic EL element. Specific examples of the layer constituting the organic compound layer 22 other than the light emitting layer include a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. Moreover, as a constituent material of the organic compound layer 22, a known compound can be used. Further, the organic compound layer 22 can be formed by a known thin film forming method such as a vacuum vapor deposition method or an ink jet method.

  The second electrode 23 formed on the organic compound layer 22 is a conductive thin film also called an upper electrode. The second electrode 23 may be a transparent electrode or a reflective electrode, and is appropriately selected according to the properties of the first electrode 21. Moreover, the material similar to the 1st electrode 21 mentioned above can be used for the constituent material of the 2nd electrode 23. FIG.

  The moisture absorption layer 30 provided on the organic EL element 20 and the substrate 10 in the non-display area is a silicon-containing polymer having water absorption. In particular, polysilazane represented by the following formula (A) is preferable.

(In the formula (A), R ^{1 to} R ³ each represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkylsilyl group, an alkylamino group, an alkoxy group, or a metal atom, provided that R ^{1 to} R ^At least one of ³ is a hydrogen atom.)

  As a method of forming the moisture absorption layer 30, for example, a thin film is formed by using a coating method such as spin coating using a coating liquid obtained by mixing a silicon-containing polymer having water absorption and an organic solvent. A method is mentioned. The film thickness of the moisture absorption layer 30 is preferably 100 nm to 2000 nm.

In addition, when there is a possibility that the organic EL element 20 may be damaged by the coating liquid used when the moisture absorption layer 30 is provided, a protective layer (not shown) may be provided for the purpose of preventing this. The constituent material of the protective layer is preferably an inorganic insulating material such as SiN, SiON, or SiO ₂ .

  In the organic EL display device 1 of FIG. 1, the stress relaxation member 41 provided on the hygroscopic layer 30 has a hygroscopic layer 30 when the hygroscopic layer 30 absorbs moisture in the atmosphere and a volume change of the hygroscopic layer 30 occurs. This is a member that prevents the adhesive layer 42 from being peeled off. That is, the stress relaxation member 41 relaxes the stress generated between the moisture absorption layer 30 and the adhesive layer 42 due to the volume change of the moisture absorption layer 30, and the substrate 10, the sealing substrate 50, the substrate 10, and the sealing substrate 50 And an adhesive layer 42 for joining the two layers to maintain the sealed state provided by the adhesive layer 42. The constituent material of the stress relaxation member 41 is preferably a resin material, and more preferably an ultraviolet curable resin, a thermosetting resin, or a thermoplastic resin. The stress relaxation member 41 is formed by a dispensing method or the like. The stress relaxation member 41 may be formed by appropriately processing a resin sheet made of an ultraviolet curable resin, a thermosetting resin, or a thermoplastic resin and placing the resin sheet on the moisture absorption layer 30. In the case where the stress relaxation member 41 is used as one of the sealing members, the stress relaxation member 41 is preferably provided so as to surround the outer periphery of the display region.

  In the organic EL display device 1 of FIG. 1, an adhesive layer 42 is formed between the stress relaxation member 41 and the sealing substrate 50 in order to bond the substrate 10 and the sealing substrate 50. The constituent material of the adhesive layer 42 is not particularly limited as long as it is a member having adhesiveness. For example, it is possible to use a low melting point metal that can be bonded at a low temperature that does not damage the stress relaxation member 41 made of a resin material, but a resin material is preferable. When the constituent material of the adhesive layer 42 is a resin material, specifically, an ultraviolet curable resin, a thermosetting resin, or a thermoplastic resin is preferable similarly to the stress relaxation member 41. The adhesive layer 42 is formed by a dispensing method or the like. The adhesive layer 42 may be placed on the stress relaxation member 41 by appropriately processing a resin sheet made of an ultraviolet curable resin, a thermosetting resin, or a thermoplastic resin.

  In the organic EL display device 1 of FIG. 1, examples of the sealing substrate 50 include a glass substrate, an insulating substrate made of synthetic resin, and a conductive substrate having an insulating layer such as silicon oxide or silicon nitride formed on the surface. . Further, the sealing substrate 50 may be transparent or opaque. However, when the substrate 10 is an opaque substrate, a transparent substrate is used as the sealing substrate 50.

  In the organic EL display device 1 of FIG. 1, the end of the hygroscopic layer 30 is not covered with the stress relaxation member 41 provided on the hygroscopic layer 30, so that the gas generated from the hygroscopic layer 30 is absorbed by the hygroscopic layer 30. Can be released from the end of the tube.

[Second Embodiment]
FIG. 2 is a schematic cross-sectional view showing a second embodiment of the organic EL display device of the present invention. Hereinafter, a description will be given focusing on differences from the first embodiment.

  The organic EL display device 2 of FIG. 2 is provided between the moisture absorption layer 30 and the sealing substrate 50, and a member for sealing the organic EL display device 2 functions as an adhesive layer (such as the moisture absorption layer 30). Only the stress relaxation member 43 having a function of bonding) is used. Except for this, the configuration is the same as that of the first embodiment. The stress relaxation member 43 in FIG. 2 is a member obtained by combining the stress relaxation member 41 and the adhesive layer 42 in FIG. 1 and is obtained by forming the combined member with the same material. .

  By using only the stress relaxation member 43 as the member provided between the moisture absorption layer 30 and the sealing substrate 50 as in the present embodiment, the manufacturing process can be simplified compared to the first embodiment. it can.

  The stress relaxation member 43 used in the present embodiment can be formed of a resin material as in the first embodiment. However, among the resin materials, the adhesive force with respect to the moisture absorption layer 30 and the sealing substrate 50 is also possible. It is preferable to use a material having

[Third embodiment]
FIG. 3 is a schematic cross-sectional view showing a third embodiment of the organic EL display device of the present invention. Hereinafter, a description will be given focusing on differences from the first embodiment.

  Similar to the organic EL display device 2 of FIG. 2, the organic EL display device 3 of FIG. 3 is provided between the moisture absorption layer 30 and the sealing substrate 50 and is a member for sealing the organic EL display device 3. Is the stress relaxation member 43 having the function of the adhesive layer. In the organic EL display device 3 of FIG. 3, the moisture absorption layer 30 is provided over the entire surface of the sealing substrate 50 on the organic EL element 20 side. Except for these, the configuration is the same as that of the first embodiment.

  By using only the stress relaxation member 43 as the member provided between the moisture absorption layer 30 and the sealing substrate 50 as in the present embodiment, the manufacturing process can be simplified compared to the first embodiment. it can.

  In the organic EL display device 3 of FIG. 3, the stress relaxation member 43 is provided so as to be in contact with the moisture absorption layer 30 and does not cover the end of the moisture absorption layer 30. Therefore, as in the first embodiment, the gas generated from the hygroscopic layer 30 can be released from the end of the hygroscopic layer 30, and the hygroscopic layer 30 and the stress relaxation member are changed by the volume change of the hygroscopic layer 30 due to moisture absorption. The effect which relieves the stress which arises between 43 is produced.

[Fourth embodiment]
FIG. 4 is a schematic cross-sectional view showing a fourth embodiment of the organic EL display device of the present invention. Hereinafter, a description will be given focusing on differences from the first embodiment.

  The organic EL display device 4 in FIG. 4 is not only provided with the hygroscopic layer 30 on the organic EL element 20 (the hygroscopic layer 30a) in the organic EL display device 1 in FIG. 1, but also on the organic EL element 20 side of the sealing substrate 50. A hygroscopic layer 30 (30b) is provided over the entire surface. As shown in the organic EL display device 4 of FIG. 4, an organic EL display device with higher moisture resistance can be obtained by increasing the number of places / areas where the moisture absorption layer is provided.

  The organic EL display device 4 of FIG. 4 is provided between the moisture absorption layer 30a and the moisture absorption layer 30b, and a member for sealing the organic EL display device 4 is a stress relaxation member 43 having a function of an adhesive layer. Only to. As in the first embodiment, the member provided between the moisture absorption layer 30a and the moisture absorption layer 30b can be a composite member composed of the stress relaxation member 41 and the adhesive layer 42 in FIG. is there. However, the manufacturing process can be simplified by using only the stress relaxation member 43 as a member provided between the moisture absorption layer 30a and the moisture absorption layer 30b as in the present embodiment.

  Further, in the organic EL display device 4 of FIG. 4, the stress relaxation member 43 is provided so as to be in contact with the two moisture absorption layers (30a, 30b), and the end portions of the two moisture absorption layers (30a, 30b) are not formed anyway. Is also not coated. For this reason, as in the first embodiment, the gas generated from the hygroscopic layer 30 can be released from the end of the hygroscopic layer 30, and the hygroscopic layers (30a, 30b) are changed by the volume change of the hygroscopic layer 30 due to moisture absorption. And the stress relaxation member 43 have an effect of relaxing the stress generated.

[Fifth embodiment]
FIG. 5 is a schematic cross-sectional view showing a fifth embodiment of the organic EL display device of the present invention. Hereinafter, a description will be given focusing on differences from the first embodiment.

  The organic EL display device 5 of FIG. 5 is sandwiched between the moisture absorption layer 30 and the sealing substrate 50 in a region where the display region in which the organic EL element 20 is provided and the peripheral region of the display region are combined. A stress relaxation member 43 having a function of an adhesive layer is provided so as to fill the remaining space. That is, the stress relaxation member 43 is provided so as to be in contact with the moisture absorption layer 30 and the sealing substrate 50.

  In the organic EL display device 5 of FIG. 5, the organic EL element 20 is covered with the moisture absorption layer 30 and the stress relaxation member 43, so that the moisture resistance is improved as compared with other embodiments. Moreover, since the contact area of the moisture absorption layer 30 and the stress relaxation member 43 is large compared with other embodiment, it becomes the structure by which the stress relaxation member 43 is more difficult to peel from the moisture absorption layer 30 with respect to the volume change of the moisture absorption layer 30. Yes.

  On the other hand, also in the present embodiment, the stress relaxation member 43 does not cover the end portion of the moisture absorption layer 30. For this reason, as in the first embodiment, the gas generated from the hygroscopic layer 30 can be released from the end of the hygroscopic layer 30, so that bubbles are generated due to outgas and the display performance is poor due to the generation of the bubbles. Is suppressed.

[Example 1]
The organic EL display device 1 of FIG. 1 was produced by the method described below.

(1) Manufacturing process of substrate with electrode A pixel circuit including a low-temperature polysilicon TFT was formed on a glass substrate. Next, the substrate 10 was fabricated by sequentially depositing SiN and polyimide resin on the formed pixel circuit. The film made of SiN functions as a semiconductor protective layer, and the film made of polyimide resin functions as a planarizing film.

  Next, AlNd and ITO were formed in this order on the substrate 10 by sputtering to form a laminated electrode film composed of an AlNd film and an ITO film. The thickness of the AlNd film was 100 nm and the thickness of the ITO film was 38 nm. Next, the first electrode 21 was formed by patterning the formed laminated electrode film for each pixel using a photolithography process.

  Next, a polyimide resin is spin-coated on the first electrode 21 and the substrate 10, and an opening (this opening corresponds to a pixel) is formed in a portion where the first electrode 21 is formed by using a photolithography process. The pixel separation layer (not shown) was formed by patterning as described above. At this time, the pitch (opening pitch) of each pixel was 30 μm, and the size of the opening (exposed portion of the first electrode 21) was 10 μm. Next, the substrate formed up to the pixel separation film was subjected to ultrasonic cleaning with isopropyl alcohol (IPA), and then dried after boiling and drying. Furthermore, the substrate with an electrode provided with the 1st electrode 21 in the display area was obtained by UV / ozone cleaning.

(2) Formation Step of Organic Compound Layer Next, the organic compound layer 22 was formed on the first electrode 21 by vacuum vapor deposition. The specific method will be described below.

  First, HT-1 (FL03) represented by the following formula was formed to form a hole transport layer. At this time, the thickness of the hole transport layer was set to 87 nm.

Next, CBP (host, carbazole compound) and Ir (piq) ₃ (added 9% by weight to the guest and host) are co-evaporated using a shadow mask having an opening in the region corresponding to the red pixel. A red light emitting layer was formed. At this time, the thickness of the red light emitting layer was set to 30 nm.

Next, using a shadow mask having an opening in the area corresponding to the green pixel, Alq ₃ (host, aluminum chelate complex) and coumarin 6 (added 1% by weight to the guest, host) are co-evaporated and green. A light emitting layer was formed. At this time, the thickness of the green light emitting layer was 40 nm.

  Next, using a shadow mask having an opening in a region corresponding to a blue pixel, BAlq (host, aluminum chelate complex) and perylene (added 3% by weight to the guest, host) are co-evaporated to form a blue light emitting layer. Formed. At this time, the thickness of the blue light emitting layer was set to 25 nm.

  Next, Bphen (phenanthroline compound) was formed on the light emitting layer to form an electron transport layer. At this time, the thickness of the electron transport layer was 10 nm.

Next, Bphen (host) and cesium carbonate (Cs ₂ CO ₃ , guest) were co-deposited on the electron transport layer (weight ratio: host: guest = 90: 10) to form an electron injection layer. At this time, the thickness of the electron injection layer was 40 nm. The organic compound layer 22 was formed as described above.

(3) Second Electrode Formation Step Next, the substrate 10 formed up to the organic compound layer 22 was moved to the sputtering apparatus without breaking the vacuum. Next, Ag and indium zinc oxide were formed in this order by sputtering, and the second electrode 23 was formed as a laminated electrode composed of an Ag film and a transparent conductive electrode film. At this time, the film thickness of the Ag film was 10 nm, and the film thickness of the transparent conductive electrode film was 50 nm.

  The organic EL element 20 was produced in the display area on the substrate 10 through the above steps.

(4) Formation process of a protective layer Next, the board | substrate 10 currently formed to the organic EL element 20 was conveyed to the CVD apparatus, without breaking a vacuum. Next, a protective layer (not shown) is formed by depositing SiN on the organic EL element 20 and a region corresponding to the outer periphery of the organic EL element 20 by plasma CVD using SiH ₄ gas, N ₂ gas, and H ₂ gas. ) Was formed. At this time, the thickness of the protective layer was 0.2 μm.

(5) Formation process of moisture absorption layer Next, the board | substrate 10 formed even to the protective layer was conveyed, and it was made to move to the glove box in nitrogen atmosphere. Next, a dibutyl ether solution prepared by mixing polysilazane (manufactured by AZ Electronic Materials Co., Ltd., Aquamica NAX120-20) and dibutyl ether was dropped on a protective layer (not shown) and then spin-coated. As a result, a coating film was formed over the entire surface of the substrate 10. Next, after transporting the substrate 10 to the vacuum drying furnace, the moisture absorption layer 30 was formed on the entire surface of the substrate 10 by maintaining the inside of the vacuum drying furnace at 60 ° C. to completely evaporate dibutyl ether. At this time, the film thickness of the moisture absorption layer 30 was 500 nm.

(6) Step of forming stress relaxation member Next, after the substrate 10 formed up to the moisture absorption layer 30 is returned into the glove box under a nitrogen atmosphere, the stress relaxation member 41 is placed on the moisture absorption layer 30 and is organic. It was formed on the outer periphery of the substrate 10 so as to surround the EL element 20. Specifically, by forming a thermosetting resin in the non-display area and surrounding the periphery of the organic EL element 20 by a dispensing method, the thermosetting resin is cured on a hot plate at 100 ° C. for 1 hour, The stress relaxation member 41 was formed. At this time, the line width of the stress relaxation member 41 was 2.5 mm, and the height was 20 μm.

(7) Sealing Step Next, the adhesive layer 42 made of an ultraviolet curable resin so that the organic EL element 20 is surrounded on the outer periphery of the glass sealing substrate (sealing substrate 50) in the previous glove box under a nitrogen atmosphere. Arranged. At this time, the line width of the adhesive layer 42 was 2 mm, and the height was 20 μm. Next, after the substrate 10 and the sealing substrate 50 are installed so that the stress relaxation member 41 and the adhesive layer 42 overlap each other, the adhesive layer 42 is irradiated with ultraviolet rays to cure the adhesive layer 42. A sealed organic EL display device 1 was obtained.

  In the obtained organic EL display device 1, since the stress relaxation member 41 is disposed so as to be in contact with the hygroscopic layer 30, the adhesive layer 42 is peeled off even when placed in an environment of 85 ° C. and 85% humidity for 500 hours. Was not recognized.

[Example 2]
The organic EL display device 2 of FIG. 2 was produced by the method described below.

(1) Manufacturing process of substrate with electrode By the same method as (1) of Example 1, the substrate with an electrode having the first electrode 21 was manufactured.

(2) Formation Step of Organic Compound Layer An organic compound layer 22 was formed by the same method as (2) of Example 1.

(3) Second Electrode Formation Step A second electrode 23 was formed by the same method as in Example 1 (3).

(4) Formation process of a protective layer The protective layer (not shown) was formed by the method similar to (4) of Example 1. FIG.

(5) Formation process of moisture absorption layer The moisture absorption layer 30 was formed by the method similar to (5) of Example 1. FIG.

(6) Step of forming stress relaxation member, sealing step Next, an ultraviolet curable resin is used so that the organic EL element 20 is surrounded by the outer periphery of the glass sealing substrate (sealing substrate 50) in a glove box under a nitrogen atmosphere. A stress relaxation member 43 made of At this time, the line width of the stress relaxation member 43 was 2 mm, and the height was 20 μm. Next, the substrate 10 formed up to the moisture absorption layer 30 and the sealing substrate 50 are overlapped, and the stress relaxation member 43 is irradiated with ultraviolet rays to cure the ultraviolet curable resin, thereby sealing the organic EL display device. 2 was obtained.

  Since the obtained organic EL display device 2 is provided with the stress relaxation member 43 that also serves as an adhesive layer so as to be in contact with the moisture absorption layer 30, even when it is placed in an environment of 85 ° C. and 85% humidity for 500 hours. Peeling of the stress relaxation member 43 corresponding to the adhesive layer was not recognized.

[Example 3]
The organic EL display device 3 of FIG. 3 was produced by the method described below.

(1) Manufacturing process of substrate with electrode By the same method as (1) of Example 1, the substrate with an electrode having the first electrode 21 was manufactured.

(2) Formation Step of Organic Compound Layer An organic compound layer 22 was formed by the same method as (2) of Example 1.

(3) Second Electrode Formation Step A second electrode 23 was formed by the same method as in Example 1 (3).

(4) Step of forming moisture absorbing layer Next, the glass sealing substrate (sealing substrate 50) was moved into a glove box under a nitrogen atmosphere. Next, a dibutyl ether solution prepared by mixing polysilazane (manufactured by AZ Electronic Materials Co., Ltd., Aquamica NAX120-20) and dibutyl ether was dropped on the sealing substrate 50 and then spin-coated. As a result, a coating film was formed over the entire surface of the sealing substrate 50. Next, after the sealing substrate 50 was conveyed to a vacuum drying furnace, the moisture absorption layer 30 was formed by keeping the inside of the vacuum drying furnace at 60 ° C. and completely evaporating dibutyl ether. At this time, the film thickness of the moisture absorption layer 30 was 500 nm.

(5) Stress Relaxation Member Formation Step and Sealing Step Next, a stress made of an ultraviolet curable resin so that the organic EL element 20 is surrounded in a non-display region on the substrate 10 in a glove box under a nitrogen atmosphere. A relaxation member 43 is arranged. At this time, the line width of the stress relaxation member 43 was 2 mm, and the height was 20 μm. Next, the moisture absorption layer 30 and the stress relaxation member 43 are brought into contact with the substrate 10 provided with the organic EL element 20 and the stress relaxation member 43 and the sealing substrate 50 provided with the moisture absorption layer 30. Superimposed. Next, the sealed organic EL display device 3 was obtained by irradiating the stress relaxation member 43 with ultraviolet rays to cure the ultraviolet curable resin.

  Since the obtained organic EL display device 3 is provided with the stress relaxation member 43 that also serves as an adhesive layer so as to be in contact with the hygroscopic layer 30, even when it is placed in an environment of 85 ° C. and 85% humidity for 500 hours. Peeling of the stress relaxation member 43 corresponding to the adhesive layer was not recognized.

[Example 4]
The organic EL display device 4 of FIG. 4 was produced by the method described below.

(1) Manufacturing process of substrate with electrode By the same method as (1) of Example 1, the substrate with an electrode having the first electrode 21 was manufactured.

(2) Formation Step of Organic Compound Layer An organic compound layer 22 was formed by the same method as (2) of Example 1.

(3) Second Electrode Formation Step A second electrode 23 was formed by the same method as in Example 1 (3).

(4) Formation process of a protective layer The protective layer (not shown) was formed by the method similar to (4) of Example 1. FIG.

(5) Formation process of moisture absorption layer The moisture absorption layer 30a was formed on the protective layer by the method similar to (5) of Example 1. FIG. Moreover, the moisture absorption layer 30b was formed over the whole surface of the sealing substrate 50 by the same method as Example 3 (4).

(6) Stress relaxation member forming step and sealing step Next, in the glove box under a nitrogen atmosphere, ultraviolet rays are formed so that the organic EL element 20 is surrounded on the moisture absorption layer 30a provided in the non-display region. A stress relaxation member 43 made of a cured resin was disposed. At this time, the line width of the stress relaxation member 43 was 2 mm, and the height was 20 μm. Next, the substrate 10 provided with the organic EL element 20, the moisture absorption layer 30a, and the stress relaxation member 43, and the sealing substrate 50 provided with the moisture absorption layer 30b are combined with the moisture absorption layer 30b, the stress relaxation member 43, and the like. Are stacked so that they touch each other. Next, the sealed organic EL display device 4 was obtained by irradiating the stress relaxation member 43 with ultraviolet rays to cure the ultraviolet curable resin.

  In the obtained organic EL display device 4, a stress relaxation member 43 that also serves as an adhesive layer is disposed so as to be in contact with either of the two moisture absorption layers (30a, 30b). For this reason, even when left in an environment of a temperature of 85 ° C. and a humidity of 85% for 500 hours, the stress relaxation member 43 corresponding to the adhesive layer was not peeled off.

[Example 5]
The organic EL display device 5 of FIG. 5 was produced by the method described below.

(1) Manufacturing process of substrate with electrode By the same method as (1) of Example 1, the substrate with an electrode having the first electrode 21 was manufactured.

(2) Formation Step of Organic Compound Layer An organic compound layer 22 was formed by the same method as (2) of Example 1.

(3) Second Electrode Formation Step A second electrode 23 was formed by the same method as in Example 1 (3).

(4) Formation process of a protective layer The protective layer (not shown) was formed by the method similar to (4) of Example 1. FIG.

(5) Formation process of moisture absorption layer The moisture absorption layer 30 was formed on the protective layer by the method similar to (5) of Example 1. FIG.

(6) Step of forming stress relaxation member Next, the stress relaxation member 43 made of a thermosetting resin was disposed on the sealing substrate 50 in the glove box under a nitrogen atmosphere. At this time, the height of the stress relaxation member 43 was 20 μm. In this example (Example 5), the stress relaxation member 43 provided on the sealing substrate 50 is provided in a display region and a region corresponding to the outer periphery thereof.

(7) Sealing Step Next, the substrate 10 provided with the organic EL element 20 and the moisture absorption layer 30a and the sealing substrate 50 provided with the stress relaxation member 43 are combined with the moisture absorption layer 30 and the stress relaxation member. After overlapping so as to come into contact with 43, the film was temporarily bonded by heating to 80 ° C. Next, the superposed substrate was placed on a hot plate at 100 ° C. and heated at this temperature for 2 hours. Thereby, the sealed organic EL display device 5 was obtained by curing the thermosetting resin.

  In the obtained organic EL display device 5, a stress relaxation member 43 that also serves as an adhesive layer is disposed so as to be in contact with the moisture absorption layer 30. For this reason, even when left in an environment of a temperature of 85 ° C. and a humidity of 85% for 500 hours, the stress relaxation member 43 corresponding to the adhesive layer was not peeled off.

  1 (2, 3, 4, 5) organic EL display device, 10: substrate, 20: organic EL element, 21: first electrode, 22: organic compound layer, 23: second electrode, 30: hygroscopic layer, 41 ( 43): Stress relaxation member, 42: adhesive layer, 50: sealing substrate

Claims (4)

A substrate,
An organic EL element provided on the substrate;
A sealing substrate provided on the organic EL element;
A moisture absorption layer provided between the substrate and the sealing substrate;
In an organic EL display device comprising: an adhesive layer provided between the substrate and the sealing substrate and joining the substrate and the sealing substrate;
The moisture absorption layer is a layer made of a silicon-containing polymer having water absorption,
The end of the moisture absorbing layer is exposed to the outside air,
An organic EL display device comprising a stress relaxation member provided between the substrate and the sealing substrate and in contact with at least a moisture absorption layer.   The organic EL display device according to claim 1, wherein the silicon-containing polymer is polysilazane.   The organic EL display device according to claim 1, wherein the stress relaxation member is a layer made of an ultraviolet curable resin, a thermosetting resin, or a thermoplastic resin.   The organic EL display device according to claim 1, wherein the stress relaxation member has a function of the adhesive layer.

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