JP2014067599A - Organic el display, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL display excellent in moisture-proof performance without spoiling optical characteristics of an EL element, and a method of manufacturing the same.SOLUTION: In a method of manufacturing an organic EL display formed by sticking a sealing substrate 10 to an organic EL element substrate including a pattern-shaped first electrode 4 provided on a substrate 1, a barrier plate 5 covering an end part of the first electrode 4, an organic luminescent medium layer 6 provided in a region located on the first electrode 4 and partitioned by the barrier plate 5, and a second electrode 7 facing the first electrode 4 with the organic luminescent medium layer 6 placed between them from the second electrode 7 side, at least an inorganic filler 12 and a sealant 11 are provided on one surface of the sealing substrate 10, and the organic EL substrate is stuck to the sealing substrate 10 in an inert gas atmosphere so as to hold the inorganic filler 12 and the sealant 11 between the organic EL substrate and the sealing substrate 10.

Description

  The present invention relates to an organic EL display manufacturing method and an organic EL display. In particular, the present invention relates to a method for manufacturing an organic EL display having improved moisture resistance and an organic EL display.

  2. Description of the Related Art Conventionally, EL devices such as inorganic EL (Electro-Luminescence) devices and organic EL devices can emit light and obtain a high-luminance screen. For example, as a display or lighting device for thin and light portable devices. Practical use is in progress. This EL device has a structure in which an EL element having a pair of electrode layers, at least one of which is a transparent electrode, and a light emitting layer sandwiched between them is formed on a substrate. In such an EL device, the light emitting layer and the electrode layer of the EL element are damaged by the intrusion of moisture, and there is a possibility that the image quality is deteriorated and the life is shortened. For this reason, it has been proposed to cover the surface of the EL element with a protective film in order to prevent moisture from entering from the outside.

  For example, Patent Document 1 discloses a technique in which polysilazane is applied to the surface of an EL element to form a silica film or a silica-based film, and this is used as a protective film. Further, in Patent Document 2, in an EL device in which an EL element having a first electrode layer, a light emitting layer, and a second electrode layer is formed, a dry method is used on the surface of the EL element so as to cover the EL element. EL device comprising: first protective film formed; and second protective film formed on the surface of first protective film by a wet method and filling a non-attached portion of first protective film Has been proposed.

JP 2002-222691 A JP 2005-056587 A

  However, as in Patent Document 1, if a silica film or the like is formed by directly applying polysilazane to the surface of an EL element, the applied polysilazane solvent may damage the electrode layer or the light emitting layer of the EL element. There is. In Patent Document 2, a protective film is formed on the surface of an EL element by a dry method, and a cured product layer made of a cured product of a polysilazane-containing composition is formed by a wet method, but the moisture resistance of the protective film is excellent. Otherwise, the polysilazane solvent may permeate the protective film layer and similarly damage the electrode layer and the light emitting layer of the EL element. In addition, a baking treatment is performed to remove the polysilazane solvent. However, there is a possibility that the optical characteristics of the EL element may be impaired by heat during baking.

  The present invention has been made to solve such a conventional problem, and an organic EL display that has a simple structure and can prevent deterioration due to ingress of moisture without damaging the EL element. For the purpose of providing. Another object of the present invention is to provide a method for producing an organic EL display capable of obtaining such an organic EL display.

  One embodiment of the present invention includes a patterned first electrode provided on a substrate, a partition covering an end of the first electrode, and a region on the first electrode and partitioned by the partition. A sealing substrate is bonded from the second electrode side to an organic EL element substrate comprising an organic light emitting medium layer provided and a second electrode facing the first electrode across the organic light emitting medium layer In the method for manufacturing an organic EL display, at least one surface of the sealing substrate is provided with an inorganic filler and a sealing agent, and the inorganic filler and the sealing agent are used as the organic EL element substrate and the An organic EL display manufacturing method, wherein the organic EL element substrate and the sealing substrate are bonded together in an inert gas atmosphere so as to be sandwiched between the sealing substrates.

In the method for manufacturing an organic EL display, the inorganic filler may be made of a material containing at least a polysilazane composition.
In the method for producing an organic EL display, the inorganic filler is a solution containing the polysilazane composition and a solvent for dissolving the polysilazane composition on the sealing substrate in an inert gas atmosphere. Coating may be performed and the coated solution may be baked.

Further, in the above-described organic EL display manufacturing method, the sealing agent is formed on the sealing substrate so as to surround the periphery of the organic EL light emitting region when the organic EL element substrate and the sealing substrate are disposed to face each other. It is good also as being formed.
In the method for manufacturing an organic EL display, the inorganic filler may be formed at least in an inner region of the sealant.

In the method for manufacturing an organic EL display, the sealing substrate may be at least a flat plate shape.
In the method for manufacturing an organic EL display, a protective film may be formed on the second electrode before the organic EL element substrate and the sealing substrate are bonded to each other in the inert gas atmosphere. Good.

Another aspect of the present invention is an organic EL display manufactured using the method for manufacturing an organic EL display described above.
Still another embodiment of the present invention is a pattern-shaped first electrode formed on a substrate, a partition formed to cover an end of the first electrode, and the first electrode, An organic light emitting medium layer formed in a region partitioned by the partition, a second electrode formed to face the first electrode so as to sandwich the organic light emitting medium layer, and the second electrode and the partition are covered An inorganic filler formed as described above, a sealing agent formed in an outer region of the inorganic filler, and a sealing material formed on the sealing agent and on the inorganic filler. It is an organic EL display.
In the organic EL display, a protective film may be provided between the second electrode and the inorganic filler.

  ADVANTAGE OF THE INVENTION According to this invention, the organic electroluminescent display excellent in moisture resistance and the manufacturing method can be provided, without impairing the optical characteristic of an organic electroluminescent element.

It is sectional drawing which shows the organic electroluminescent display which concerns on one Embodiment of this invention. It is sectional drawing which shows the organic electroluminescent display which concerns on one Embodiment of this invention. It is a figure which shows a mode that an organic EL element substrate and a sealing substrate are bonded together.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. Note that the drawings referred to in the following description of the embodiments are for explaining the configuration of the present invention, and the size, thickness, dimensions, and the like of each part illustrated are different from the actual ones. The present invention is not limited to these.
The organic EL display and the manufacturing method thereof according to the present embodiment will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view of an organic EL display according to an embodiment of the present invention. The organic EL display according to this embodiment includes a substrate 1, a thin film transistor (TFT) 2, a planarizing film layer 3, a first electrode 4, a partition wall 5, an organic light emitting medium layer 6, a second electrode 7, a sealing substrate 10, and a seal. An organic EL display including the agent 11 and the inorganic filler 12. More specifically, the organic EL display according to this embodiment includes a patterned first electrode 4 formed on the substrate 1, a partition wall 5 formed so as to cover an end of the first electrode 4, An organic light emitting medium layer 6 formed in a region on one electrode 4 and partitioned by a partition wall 5, and a second electrode 7 formed to face the first electrode 4 so as to sandwich the organic light emitting medium layer 6; The inorganic filler 12 formed so as to cover the second electrode 7 and the partition wall 5, the sealing agent 11 formed in the outer region of the inorganic filler 12, the sealing agent 11 and the inorganic filler 12 are formed. And an organic EL display.

  FIG. 2 is a cross-sectional view of an organic EL display according to another embodiment of the present invention. The organic EL display according to this embodiment is an organic EL display further including a protective film 13 in addition to the substrate shown in FIG. More specifically, the organic EL display according to this embodiment is an organic EL display including a protective film 13 between the second electrode 7 and the inorganic filler 12.

Hereinafter, the material of each part which comprises the organic EL display which concerns on this embodiment is demonstrated.
(1) Substrate 1
Examples of the material of the substrate 1 according to this embodiment include plastic films such as glass, quartz, polypropylene, polyethersulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethylmethacrylate, polyethylene terephthalate, and polyethylene naphthalate. Metal sheets such as silicon oxide and aluminum oxide, metal fluorides such as aluminum fluoride and magnesium fluoride, metal nitrides such as silicon nitride and aluminum nitride, silicon oxynitride Translucent substrates with single or laminated polymer resin films such as metal oxynitrides, acrylic resins, epoxy resins, silicone resins, polyester resins, metal foils such as aluminum and stainless steel, sheets, plates, etc. , Stick film or aluminum sheet may be copper, nickel, stainless steel and metal film non-translucent substrate as a laminate of such.

  In addition, the material of the board | substrate 1 which concerns on this embodiment is not limited to these materials. Moreover, what is necessary is just to select the translucency of the base material 1 according to which surface light extraction is performed from. The substrate 1 made of the above-mentioned material has been subjected to moisture-proofing treatment or hydrophobic treatment by forming an inorganic film or applying a fluororesin in order to avoid moisture intrusion into the organic EL element. It is preferable. In particular, it is preferable to reduce the moisture content and gas permeability coefficient of the substrate 1 in order to avoid the intrusion of moisture into the organic light emitting medium layer 6 described later.

(2) Thin film transistor 2 (TFT)
Further, as the substrate 1, a driving substrate on which a thin film transistor (TFT) 2 is formed may be used as necessary. In the case of an active drive type organic EL element, a planarizing film layer 3 is formed on the TFT 2, a first electrode 4 of the organic EL element is provided on the planarizing film layer 3, and It is preferable that the TFT 2 and the first electrode 4 are electrically connected through a contact hole provided in the planarizing film layer 3. By comprising in this way, the outstanding electroconductivity can be obtained between TFT2 and an organic EL element. A known thin film transistor can be used as the thin film transistor 2 provided on the substrate 1. Specifically, a thin film transistor mainly including an active layer in which a source / drain region and a channel region are formed, a gate insulating film, and a gate electrode can be given. The structure of the thin film transistor 2 is not particularly limited, and examples thereof include a stagger type, an inverted stagger type, a top gate type, and a coplanar type.

(3) Planarization film layer 3
Next, a planarizing film layer 3 is formed on the TFT 2. Examples of the material of the planarizing film layer 3 include inorganic materials such as SiO ₂ , spin-on glass, SiN (Si ₃ N ₄ ), and TaO (Ta ₂ O ₅ ), polyimide resin, acrylic resin, photoresist material, and black. An organic material such as a matrix material can be used. The formation method of the planarization film layer 3 can be selected from, for example, spin coating, CVD, vapor deposition, or the like according to the above-described materials. If necessary, a photosensitive resin is used as the material of the planarizing film layer 3 and the planarizing film layer 3 is once formed on the entire surface by a photolithography technique, and then dry-etched at a position corresponding to the lower-layer thin film transistor 2. Then, contact holes are formed by wet etching or the like. The formed contact hole is then filled with a conductive material. By doing so, electrical connection with the first electrode 4 (pixel electrode) formed on the upper layer of the planarizing film layer 3 can be achieved. The thickness of the planarizing film layer 3 is sufficient if it can cover the lower TFT 2, capacitor, wiring, and the like. Therefore, the thickness of the planarizing film layer 3 may be several μm, for example, about 3 μm.

(4) First electrode 4
Next, the first electrode 4 is formed on the planarizing film layer 3. The first electrode 4 is formed on the planarizing film layer 3, and is formed by patterning as necessary. In the present embodiment, the first electrode 4 is partitioned by a partition wall 5 and is a pixel electrode corresponding to each pixel. Examples of the material of the first electrode 4 include metal composite oxides such as ITO (indium tin composite oxide), indium zinc composite oxide, and zinc aluminum composite oxide, metal materials such as gold and platinum, and these metals. Either a single layer or a laminate of fine particle dispersion films in which fine particles of an oxide or a metal material are dispersed in an epoxy resin or an acrylic resin can be used. When the first electrode 4 is used as an anode, it is preferable to select a material having a high work function such as ITO. In the case of a so-called bottom emission structure in which light is extracted from below (the substrate 1 side in FIG. 1), it is necessary to select a light-transmitting material as the material of the first electrode 4. If necessary, a metal material such as copper or aluminum may be provided as an auxiliary electrode in order to reduce the wiring resistance of the first electrode 4. As a method for forming the first electrode 4, depending on the material, for example, a resistance heating evaporation method, an electron beam evaporation method, a reactive evaporation method, an ion plating method, a dry film forming method such as a sputtering method, a gravure printing method, A wet film formation method such as a screen printing method can be used. As a patterning method for the first electrode 4, an existing patterning method such as a mask vapor deposition method, a photolithography method, a wet etching method, or a dry etching method can be used depending on the material and the film forming method. In addition, when using the thing in which TFT2 was formed as the board | substrate 1, the 1st electrode 4 is formed so that conduction | electrical_connection can be aimed at corresponding to the pixel of a lower layer.

(5) Bulkhead 5
Next, partition walls 5 are formed on the planarizing film layer 3. The partition walls 5 are formed in a lattice shape so as to partition the light emitting regions corresponding to the pixels. Here, the partition wall 5 is preferably formed so as to cover an end portion of the first electrode 4 which is a pixel electrode. In general, in an active matrix drive type display device, a pixel electrode is formed for each pixel (sub-pixel), and each pixel tries to occupy as wide an area as possible. For this reason, the most preferable shape of the partition wall 5 formed so as to cover the end of the pixel electrode is basically a lattice shape that divides each pixel electrode by the shortest distance. As a method for forming the partition walls 5, as in the past, an inorganic film is uniformly formed on the first electrode 4, masked with a resist, and then dry etching is performed, or a photosensitive resin is applied on the first electrode 4. A method of laminating and forming a predetermined pattern by a photolithography method can be mentioned. If necessary, a water repellent can be added, or liquid or water repellency can be imparted to the partition walls 5 after formation by irradiation with plasma or UV. The preferable height of the partition wall 5 is in the range of 0.1 μm to 10 μm, and more preferably in the range of 0.5 μm to 3 μm.

(6) Organic light emitting medium layer 6
Next, the organic light emitting medium layer 6 is formed on the first electrode 4. In the present embodiment, the organic light emitting medium layer 6 can be formed of a single layer film or a multilayer film containing a light emitting substance. Examples of the configuration in the case where the organic light emitting medium layer 6 is formed of a multilayer film include a hole transport layer, an electron transport light emitting layer or a hole transport light emitting layer, a two-layer structure comprising an electron transport layer, a hole transport layer, A three-layer structure including a light emitting layer and an electron transport layer can be given. Further, if necessary, a multilayer may be formed by separating a hole (electron) injection function and a hole (electron) transport function, or by inserting a layer that blocks the transport of holes (electrons). . In addition, the organic light emitting layer in this embodiment refers to the layer containing an organic light emitting material, and a charge transport layer refers to the layer formed in order to improve luminous efficiency other than that, such as a positive hole transport layer.

Examples of the hole transport material used for the organic light emitting medium layer 6 include metal phthalocyanines and metal-free phthalocyanines such as copper phthalocyanine and tetra (t-butyl) copper phthalocyanine, quinacridone compounds, 1,1-bis (4-di -P-tolylaminophenyl) cyclohexane, N, N'-diphenyl-N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine, N, N'-di ( 1-naphthyl) -N, N′-diphenyl-1,1′-biphenyl-4,4′-diamine and other aromatic amine-based low-molecular hole injection / transport materials, polyaniline, polythiophene, polyvinylcarbazole, poly (3 , 4-ethylenedioxythiophene) and a mixture of polystyrene sulfonic acid and other polymer hole transport materials, polythiophene oligomer materials, Cu ₂ O, C _{r 2 O 3, Mn 2 O} 3, FeOx (x~0.1), NiO, CoO, Pr 2 O 3, Ag 2 O, MoO 2, Bi 2 O 3, ZnO, TiO 2, SnO 2, ThO 2 , V ₂ O ₅ , Nb ₂ O ₅ , Ta ₂ O ₅ , MoO ₃ , WO ₃ , MnO ₂ and other inorganic materials, and other existing hole transport materials.

  In the case where the light emitting material of the organic light emitting medium layer 6 is a polymer material, the hole transportability is increased between the light emitting layer and the hole transport layer or between the hole transport layer and the electron transport layer, It is preferable to form an interlayer layer having a function of blocking electrons from the cathode. Examples of the material used for this interlayer layer include polymers containing aromatic amines such as polyvinyl carbazole or derivatives thereof, polyarylene derivatives having aromatic amines in the side chain or main chain, arylamine derivatives, and triphenyldiamine derivatives. Etc. The interlayer layer can be formed by dissolving or dispersing these materials in a solvent and using various coating methods such as a spin coating method or a relief printing method.

  Examples of the light emitting material for the organic light emitting medium layer 6 include 9,10-diarylanthracene derivatives, pyrene, coronene, perylene, rubrene, 1,1,4,4-tetraphenylbutadiene, tris (8-quinolinolato) aluminum complex, Tris (4-methyl-8-quinolinolato) aluminum complex, bis (8-quinolinolato) zinc complex, tris (4-methyl-5-trifluoromethyl-8-quinolinolato) aluminum complex, tris (4-methyl-5-cyano) -8-quinolinolato) aluminum complex, bis (2-methyl-5-trifluoromethyl-8-quinolinolato) [4- (4-cyanophenyl) phenolate] aluminum complex, bis (2-methyl-5-cyano-8- Quinolinolato) [4- (4-cyanophenyl) phenoler ] Aluminum complex, tris (8-quinolinolato) scandium complex, bis [8- (para-tosyl) aminoquinoline] zinc complex and cadmium complex, 1,2,3,4-tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, poly -2,5-diheptyloxy-para-phenylene vinylene, coumarin phosphor, perylene phosphor, pyran phosphor, anthrone phosphor, porphyrin phosphor, quinacridone phosphor, N, N'-dialkyl Low molecular light emitting materials such as substituted quinacridone phosphors, naphthalimide phosphors, N, N′-diaryl substituted pyrrolopyrrole phosphors, phosphorescent emitters such as Ir complexes, polyfluorenes, polyparaphenylene vinylenes , Polythiophene, polyspiro and other polymer materials The materials and dispersed or copolymerization of low molecular weight material in the material, it is possible to use other conventional fluorescent light emitting material or phosphorescent material.

  Examples of the electron transport material of the organic light emitting medium layer 6 include 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole, 2,5-bis ( 1-naphthyl) -1,3,4-oxadiazole, oxadiazole derivatives, bis (10-hydroxybenzo [h] quinolinolato) beryllium complexes, triazole compounds, and the like can be used. Alternatively, these electron transport materials may be used as an electron injection layer by doping a small amount of alkali metal or alkaline earth metal having a low work function such as sodium, barium, or lithium.

  The thickness of the organic light emitting medium layer 6 is 1 μm or less, preferably about 0.02 to 0.2 μm, even when the organic light emitting medium layer 6 is formed as a single layer or a stacked layer. As a method for forming the organic light-emitting medium layer 6, depending on the material, for example, a vacuum deposition method, a slit coating, a spin coating, a spray coating, a nozzle coating, a flexo, a gravure, a micro gravure, an intaglio offset, or a coating method or a printing method Ink jet method can be used.

(7) Second electrode 7
Next, the second electrode 7 is formed on the organic light emitting medium layer 6. When the second electrode 7 is a cathode, a substance having a high electron injection efficiency into the organic light emitting medium layer 6 and a low work function is used as the second electrode 7. Specifically, a single metal such as Mg, Al, or Yb is used, or a compound such as Li, oxidized Li, or LiF is sandwiched by about 1 nm at the interface contacting the light emitting medium, and Al or Cu having high stability and conductivity is placed. You may laminate and use. Alternatively, in order to achieve both electron injection efficiency and stability, one or more metals such as Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Y, and Yb having a low work function and stable Ag, An alloy system with a metal element such as Al or Cu may be used. Specifically, alloys such as MgAg, AlLi, and CuLi can be used. In the case of a so-called top emission structure in which light is extracted from the second electrode 7 side, it is necessary to select a translucent material for the second electrode 7, and a metal composite such as ITO used for the first electrode 4. An oxide can be used as the second electrode 7. When ITO is used as the second electrode 7, a compound such as Li, oxidized Li, or LiF may be formed between the second electrode 7 and the organic light emitting medium layer 6. For example, a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method can be used as a method of forming the second electrode 7. Although there is no restriction | limiting in particular in the thickness of the 2nd electrode 7, 50 nm-about 1000 nm are desirable.
The patterned first electrode 4 provided on the substrate 1 formed as described above, the partition wall 5 covering the end of the first electrode 4, and the partition wall 5 on the first electrode 4. A substrate provided with the organic light emitting medium layer 6 provided in the partitioned area and the second electrode 7 facing the first electrode 4 with the organic light emitting medium layer 6 interposed therebetween is hereinafter referred to as an organic EL element substrate 20. .

(8) Sealing substrate 10
The sealing substrate 10 is not particularly limited as long as it maintains an airtight state and has a predetermined strength, but preferably has a flat plate shape. By using a translucent base material, it can also be used as a sealing structure of a top light emitting element that extracts light from the sealing base material 10 side. As a material of the sealing substrate 10, for example, glass, quartz, resin, or the like can be used. In addition, it can be set as an inexpensive and thin organic EL display by using a glass flat plate. As such a glass material, alkali glass is preferable from the viewpoint of cost, but glass materials such as soda lime glass, lead alkali glass, borosilicate glass, aluminosilicate glass, and silica glass are also preferable. As the sealing substrate 10, a moisture-resistant film can be used in addition to the glass plate. Examples of the moisture-resistant film include a film in which SiOx is formed on both surfaces of a plastic substrate by a CVD method, a film with low permeability, a water-absorbing film, or a polymer film coated with a water-absorbing agent. In addition, it is preferable that the water-vapor-permeation rate of this moisture resistant film is 10 < ^-6 > g / m < ² > / day or less.

(9) Sealant 11
The sealing agent 11 is formed on either the organic EL element substrate 20 or the sealing substrate 10 if the organic EL element substrate 20 and the sealing substrate 10 are disposed so as to surround the periphery of the organic EL light emitting region. However, in order to fill the inside of the sealing agent 11 with the inorganic filler 12 described later, the sealing substrate 10 side is preferable because it is simpler. As the sealant 11, an organic photocurable adhesive or a thermosetting adhesive can be used as appropriate. Specifically, for example, an acrylic acid oligomer, a photocuring and thermosetting sealing agent having a reactive vinyl group of a methacrylic acid oligomer, a moisture curable adhesive such as 2-cyanoacrylate, an epoxy type, etc. Heat- and chemical-curing type (two-component mixed) adhesives, cationic curing type ultraviolet curing epoxy resin adhesives, and the like can be used. However, when a solvent is used to form the inorganic filler 12 and heat is applied to the substrate 1 to remove the solvent, a thermosetting adhesive cannot be used. The sealing agent 11 is formed in an inert gas atmosphere, and for example, screen printing, dispensing method, or the like can be used.

(10) Inorganic filler 12
A material containing at least a polysilazane composition can be used for the inorganic filler 12. The polysilazane composition is, for example, the following formula:
- _(SiH 2 NH) -
The material formed from the polysilazane which has a repeating unit represented by these. Polysilazane reacts with water by the following reaction to produce silica (SiO ₂ ). By this reaction, the polysilazane composition exhibits the ability to absorb moisture.
_{- (SiH 2 NH) - +} 2H 2 O → SiO 2 + NH 3

In addition, the polysilazane which comprises a polysilazane composition is not restricted to what has the said repeating unit, As long as it has the function to absorb a water | moisture content, you may have another repeating unit. For example, — (SiH ₂ NH) —, — (SiRHNH) —, — (SiR ₂ NH) —, and — (SiBNH) — (wherein R represents a hydrocarbon such as a methyl group or an ethyl group). If the polysilazane has at least one repeating unit selected from.), The same effect is exhibited.

  The inorganic filler 12 is formed in the inner region of the sealing agent 11. The inorganic filler 12 may be formed on the sealing substrate 10 before the sealing agent 11 is formed, or may be formed on the sealing substrate 10 after the sealing agent 11 is formed. The inorganic filler 12 is formed in an inert gas atmosphere, and a layer of a solution containing a polysilazane composition and a solvent that dissolves the polysilazane composition is formed, for example, by screen printing, spray coating, nozzle printing, letterpress printing. And using a method such as dispensing. Next, the inorganic filler 12 can be formed by removing the solvent from the formed solution layer. As the solvent to be used, it is not preferable to use a solvent containing alcohol or water that easily reacts with the polysilazane composition. Specifically, for example, hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons and aromatic hydrocarbons, ethers such as halogenated hydrocarbon solvents, aliphatic ethers and alicyclic ethers may be used. it can. The thickness of the inorganic filler 12 is desirably 0.1 μm to 100 μm, and more preferably 1 μm to 50 μm.

The organic EL element substrate 20 and the sealing substrate 10 formed as described above are finally bonded together. The lamination of the organic EL element substrate 20 and the sealing substrate 10 is 10 to 1 × 10 in consideration of the bonding stability, the prevention of bubbles from being mixed into the bonding portion, the flatness of the flexible sealing substrate, and the like. It is preferable to carry out under a reduced pressure condition of ⁻⁵ Pa.
Moreover, it is preferable that bonding of the organic EL element substrate 20 and the sealing substrate 10 is performed in an inert gas atmosphere. By doing in this way, the inorganic filler 12 after bonding remains the polysilazane composition, and can have the ability to absorb moisture.

  Further, when the organic EL element substrate 20 and the sealing substrate 10 are bonded together, the inorganic filler 12 and the sealant 11 are sealed with the organic EL element substrate 20 as shown in FIGS. Bonding is performed so as to be sandwiched between the stop substrate 10. Here, FIG. 3A is a diagram showing a state before the organic EL element substrate 20 and the sealing substrate 10 are bonded together. FIG. 3B is a diagram illustrating a state after the organic EL element substrate 20 and the sealing substrate 10 are bonded together.

(11) Protective film 13
A protective film 13 is formed on the second electrode 7 (see FIG. 2). In other words, the protective film 13 is formed between the second electrode 7 and the inorganic filler 12. The protective film 13 is formed of a material having electrical insulation and barrier properties against moisture, oxygen, and low molecular components. As the material of the protective film 13, for example, at least one inorganic material selected from the group consisting of silicon oxide, aluminum oxide, magnesium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), and silicon nitride is used. it can. As a method for forming the protective film 13, for example, a sputtering method, a CVD method, a vacuum evaporation method, or the like can be used. By combining the hygroscopic ability of the inorganic filler 12 made of the polysilazane composition and the protective film 13, a more remarkable moisture-proof effect can be obtained. Further, the protective film 13 can prevent H ₂ and NH ₃ generated when the polysilazane composition reacts with moisture to become a silica film. The thickness of the protective film 13 is not limited because of the moisture resistance of the film, but is preferably 0.2 μm to 10 μm.
The protective film 13 is formed on the second electrode 7 before the organic EL element substrate 20 and the sealing substrate 10 are bonded together in an inert gas atmosphere.

<Effect of embodiment>
As described above, in the manufacturing method of the organic EL display according to the present embodiment, at least the sealing agent 11 and the inorganic filler 12 are formed on one surface of the sealing substrate 10. The inorganic filler 12 is made of a material containing a polysilazane composition. Furthermore, since the sealing substrate 10 on which the inorganic filler 12 is formed and the organic EL element substrate 20 are bonded in an inert gas atmosphere, the inorganic filler 12 after the bonding is a polysilazane composition. It has the ability to absorb moisture. The inorganic filler 12 reacts with moisture that has permeated the sealant 11 or the sealant 11 / substrate 1 interface to form a silica film.

In addition, in the method for manufacturing an organic EL display according to the present embodiment, coating or baking treatment of a solution containing a polysilazane composition and a solvent that dissolves the polysilazane composition is performed on the sealing substrate 10 side. For this reason, the organic EL element substrate 20 is not affected by the solvent or heat. Therefore, the optical characteristics are not deteriorated. When moisture permeates into the organic EL element substrate 20 from the outside, the organic EL element substrate 20 and the sealing substrate 10 are in close contact with each other through the silica film, so that the moisture resistance is very high. Further, when the second electrode 7 on the further a protective film 13, to obtain a more moisture-proof effect, preventing of H ₂ and NH ₃ generated when the polysilazane composition is a silica film reacts with moisture Can do.

Examples of the present invention and comparative examples will be described below.
Example 1
In this example, an active matrix substrate having a thickness of 0.7 mm provided with a thin film transistor 2 provided on the substrate 1 and a pixel electrode (first electrode 4) was used. The size of this active matrix substrate is 5 inches diagonal, and the number of pixels is 320 × 240. A partition wall 5 was formed so as to cover the end of the pixel electrode and partition the pixel. The partition wall 5 was formed by forming a positive resist represented by a trade name “ZWD6216-6” manufactured by Nippon Zeon Co., Ltd. on the entire surface of the active matrix substrate with a height (thickness) of 2 μm using a spin coater method. Thereafter, a partition wall 5 having a width of 40 μm was formed by photolithography. As a result, a pixel region having a sub-pixel number of 960 × 240 dots and a pitch of 0.12 mm × 0.36 mm was defined.

Next, a hole transport layer was formed on the pixel electrode. For the hole transport layer, molybdenum oxide having a thickness of 30 nm was formed by a sputtering method using a metal mask.
Next, an interlayer layer was printed by a relief printing method in line with the line pattern directly above the pixel electrode sandwiched between the partition walls 5. Printing was performed using an ink in which a polyvinyl carbazole derivative, which is a material of the interlayer layer, was dissolved in toluene to a concentration of 0.7%. The thickness of the interlayer layer after printing and drying was 20 nm.

Next, the organic light emitting layer was printed by a relief printing method in line with the line pattern, directly above the pixel electrode sandwiched between the partition walls 5. Printing was performed using an organic light-emitting ink in which a polyphenylene vinylene derivative, which is a material of the organic light-emitting layer, was dissolved in toluene to a concentration of 1%. The film thickness of the organic light emitting layer after printing and drying was 70 nm.
Next, as a counter electrode (second electrode 7), a 20-nm-thick calcium film was formed using a metal mask by a vacuum evaporation method, and subsequently, a 200-nm-thick aluminum film was formed using a metal mask.

  Next, in a globe BOX composed of a nitrogen atmosphere, a sealing glass (manufactured by Nippon Electric Glass Co., Ltd., OA10G glass, 0.7 mmt) and a UV curable resin (Nagase Sangyo Co., Ltd., XNR5516Z, containing 1% spacer) , Spacer diameter 10 μm) was applied by a dispensing method. The ultraviolet curable resin was applied so as to surround the periphery of the organic EL light emitting region when the organic EL element substrate and the sealing substrate 10 were disposed to face each other.

Next, under the same environment, a solution containing a polysilazane composition and a solvent for dissolving the polysilazane composition (Aurum Z, manufactured by Atpred Co.) was applied to the inner region of the ultraviolet curable adhesive by a dispensing method. Thereafter, the solvent was removed in a vacuum oven adjacent to the globe BOX to form an inorganic filler 12.
Finally, the organic EL element substrate formed up to the second electrode 7 and the sealing substrate 10 formed with the sealing agent 11 and the inorganic filler 12 were vacuum bonded without being exposed to the atmosphere. Bonding was performed at a vacuum degree of 1 × 10 ⁻² Pa, and ultraviolet light (365 nm wavelength measurement) was irradiated from the sealing substrate 10 side with 6000 mJ / cm ² in the bonded state to cure the ultraviolet curable resin.

(Example 2)
On the organic EL element substrate formed up to the second electrode 7 in the same manner as in Example 1, a 2 μm SiNx film was further formed by a CVD apparatus. The SiNx film was performed under the conditions of total pressure: 300 Pa, power: 1.2 kW, SiH ₄ gas: 100 sccm, NH ₃ gas: 0.02 sLm, N ₂ gas: 0.8 sLm. Except this, the procedure of Example 1 was repeated.

(Comparative Example 1)
Instead of forming the inorganic filler 12 in Example 1, the procedure of Example 1 was repeated except that an ultraviolet curable adhesive formed on the outer periphery was formed on the entire surface.
(Evaluation)
The organic EL displays obtained in Examples 1 and 2 and Comparative Example 1 were placed in a constant temperature and humidity chamber at 60 ° C. and 90% RH for 1000 h, and the progress of dark spots with respect to elapsed time was measured. The measurement results are shown in Table 1. In Table 1, “Initial” refers to the state before putting the organic EL display in a constant temperature and humidity chamber at 60 ° C. and 90% RH (that is, before leaving the constant temperature and humidity chamber).

  As can be seen from Table 1, Examples 1 and 2 have far less dark spot magnification than Comparative Example 1. In Example 2, the dark spot is enlarged by a measurement error and is not enlarged at all. Therefore, it can be seen that the organic EL display in which the deterioration phenomenon of the element is suppressed can be realized because the dark spot is hardly enlarged even if left in the thermostatic chamber.

DESCRIPTION OF SYMBOLS 1 ... Board | substrate 2 ... Thin-film transistor 3 ... Planarization film layer 4 ... 1st electrode 5 ... Partition 6 ... Organic luminescent medium layer 7 ... 2nd electrode 10 ... Sealing substrate 11 ... Sealing agent 12 ... Inorganic filler 13 ... Protective film 20 ... Organic EL element substrate

Claims (10)

A patterned first electrode provided on the substrate, a partition covering the end of the first electrode, and an organic light emitting medium layer provided on the first electrode and in a region partitioned by the partition And a second electrode opposed to the first electrode across the organic light emitting medium layer, and a method for producing an organic EL display comprising a sealing substrate bonded to the organic EL element substrate from the second electrode side In
On one side of the sealing substrate, at least an inorganic filler and a sealing agent are provided,
The organic EL element substrate and the sealing substrate are bonded together under an inert gas atmosphere so that the inorganic filler and the sealing agent are sandwiched between the organic EL element substrate and the sealing substrate. Manufacturing method of organic EL display.   The method for manufacturing an organic EL display according to claim 1, wherein the inorganic filler is made of a material containing at least a polysilazane composition.   The inorganic filler is formed by coating a solution containing the polysilazane composition and a solvent that dissolves the polysilazane composition on the sealing substrate in an inert gas atmosphere, and baking the coated solution. The method for producing an organic EL display according to claim 2, wherein:   The sealant is formed on the sealing substrate so as to surround the periphery of the organic EL light emitting region when the organic EL element substrate and the sealing substrate are disposed to face each other. The manufacturing method of the organic electroluminescent display as described in any one of Claims 1-3.   The method for manufacturing an organic EL display according to any one of claims 1 to 4, wherein the inorganic filler is formed at least in an inner region of the sealant.   The method for manufacturing an organic EL display according to claim 1, wherein the sealing substrate is at least a flat plate shape.   The protective film is formed on the second electrode before the organic EL element substrate and the sealing substrate are bonded to each other under the inert gas atmosphere. The manufacturing method of the organic electroluminescent display of one term.   An organic EL display manufactured using the method for manufacturing an organic EL display according to any one of claims 1 to 7. A patterned first electrode formed on the substrate;
A partition formed to cover an end of the first electrode;
An organic light emitting medium layer formed on the first electrode and in a region partitioned by the partition;
A second electrode formed to face the first electrode so as to sandwich the organic light emitting medium layer;
An inorganic filler formed to cover the second electrode and the partition;
A sealant formed in an outer region of the inorganic filler;
An organic EL display comprising: a sealing material formed on the sealing agent and the inorganic filler.   The organic EL display according to claim 9, further comprising a protective film between the second electrode and the inorganic filler.

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