WO2013035143A1

WO2013035143A1 - Method for manufacturing organic electroluminescent panel

Info

Publication number: WO2013035143A1
Application number: PCT/JP2011/070151
Authority: WO
Inventors: 田中　洋平
Original assignee: パイオニア株式会社; 三菱化学株式会社
Priority date: 2011-09-05
Filing date: 2011-09-05
Publication date: 2013-03-14

Abstract

[Problem] To provide a method for manufacturing an organic electroluminescent panel in which occurrences of variations in drying of a finish organic layer during the manufacture of the organic electroluminescent panel are suppressed and manufacturing yields are improved. [Solution] The manufacturing method is a method for manufacturing an organic electroluminescent panel, which is provided with a plurality of organic electroluminescent elements disposed on a substrate and divided by banks and which has a plurality of organic layers laminated between a pair of a first electrode and a second electrode each faced by the plurality of organic electroluminescent element. The method for manufacturing the organic electroluminescent panel includes an organic layer forming step that coats a surface of a substrate having an electrode pattern on a main surface with at least one organic layer and a bank forming step that forms a bank pattern by ejecting a bank application fluid containing a bank pattern material as droplets on the organic layer using a droplet ejection nozzle and drying the same.

Description

Method for manufacturing organic electroluminescence panel

The present invention relates to a method of manufacturing an organic EL panel including a plurality of organic electroluminescence (EL) elements arranged on a substrate and separated by a bank.

Organic EL panels such as an organic EL display panel using a plurality of organic EL elements are widely known. Each of the organic EL elements includes a plurality of organic layers (charge transport layers) made of an organic compound having a charge transport property between an anode and a cathode, and includes at least one light emitting layer in the organic layer. . In the light emitting layer, holes and electrons increase the recombination probability, and the generated excitons emit light.

In the manufacturing method of the organic EL panel, the use of forming a film by wet coating is increasing for the purpose of establishing a production method at a lower cost and improving the maintainability. In addition to organic EL displays, in the fields of organic EL lighting of organic EL panels using an array of a plurality of organic EL elements, organic TFTs using organic layers, and organic solar cells, a resist solution or the like on a transparent substrate such as glass There is an increasing use of a coating process in which a coating liquid is applied and dried, and a desired pattern is formed by photolithography or the like. Examples of the wet application method of the organic coating liquid for the organic layer include a spin method, a dip method, a roll method, and an ink jet method.

In the manufacturing method of the coating type organic EL panel, a process of forming a bank for separating each organic EL element is adopted in order to coat the light emitting layer and the organic layer for each organic EL element on the substrate using the inkjet method. There are many cases. For example, it has been widely proposed that banks be formed by a photolithography technique or a printing technique (see Patent Documents 1 to 12).

JP 2010-56012 A JP 2010-33971 JP 2010-33972 A JP 2009-187957 A JP 2004-111166 A JP 2000-323276 A JP 2006-171365 A JP 2004-234901 A JP 2004-235128 A JP 2010-73598 A JP 2010-103105 A JP 2007-242272 A

In a conventional process for producing a general coating type organic EL panel, as shown in FIG. 1, an insulating property is obtained by photolithography on a substrate 1 such as glass on which an anode 2 such as ITO and a bus line BU are formed. The coating liquid containing various charge transporting organic compounds constituting the hole injection layer, the light emitting layer, and the like is applied to the openings defined by the bank BK, and dried and baked. The organic layer that fulfills the above functions is sequentially formed, and after the film formation, the cathode metal film 9 is formed by vapor deposition or the like, and then an organic EL panel is obtained through a sealing process.

In the manufacturing process of a coating type organic EL panel which is banked by a conventional photolithography process, for example, a hole transport layer, for example, a hole injection layer material is formed as a uniform thin film on the anode on the substrate. After forming the layer, a bank is formed. For example, the bank is coated with an alkali development type fluorine-containing photosensitive resin solution on the hole injection layer in a predetermined film thickness, and after drying the solvent, only the portion where the bank is formed is exposed through a photomask. It is formed by developing using an alkaline developer.

However, when a bank is formed on the charge transport layer by a photolithography process, the interface between the charge transport layer and the light emitting layer is eroded by the photolithography process, which causes a problem that the device performance is deteriorated. Furthermore, when a bank is formed on the anode of the substrate by an ink jet method which is a patterning method sensitive to substrate wettability and unevenness, SiO ₂ , ITO, and bus lines are formed on the substrate of the organic EL panel substrate in the region where the bank is to be formed. Since it is formed in a mixed manner, unevenness of the surface and wettability are different, and it is very difficult to form a good organic layer pattern by the ink jet method. There was also a problem.

This invention is made in view of such a situation, and provides the manufacturing method of the organic electroluminescent panel which can suppress the dry nonuniformity generation | occurrence | production of the finished organic layer during organic electroluminescent panel manufacture, and can improve a manufacture yield. With the goal.

The manufacturing method of the organic electroluminescent panel of Claim 1 is provided with the some organic electroluminescent element arrange | positioned on the board | substrate, and was divided | segmented by the bank, Each of these organic electroluminescent elements each faces a pair A method for producing an organic electroluminescence panel having a plurality of organic layers laminated between a first electrode and a second electrode,
An organic layer forming step of covering the surface of the substrate having an electrode pattern on the main surface with at least one organic layer;
And a bank forming step of forming a bank pattern by discharging a bank coating liquid containing a solid content of the bank pattern material as droplets by a droplet discharge nozzle onto the organic layer and drying it. .

According to the present invention, since the bank is formed on the charge transport layer by an ink jet method instead of the photolithography process, the interface between the charge transport layer and the light emitting layer is cleaned, and the charge transport layer is formed on the anode or bus line on the substrate. Therefore, it is possible to sufficiently suppress the occurrence of drying unevenness in the finished organic layer of the organic EL panel and to improve the production yield.

It is a schematic sectional drawing which shows the laminated structure of an organic electroluminescent panel. It is a schematic block diagram which shows the laminated structure of the organic EL element in an organic EL panel. It is a schematic sectional drawing which shows the board | substrate for demonstrating the manufacturing method of the organic electroluminescent panel of embodiment by this invention. It is a schematic sectional drawing which shows the board | substrate for demonstrating the manufacturing method of the organic electroluminescent panel of embodiment by this invention. It is a schematic sectional drawing which shows the board | substrate for demonstrating the manufacturing method of the organic electroluminescent panel of embodiment by this invention. It is a schematic sectional drawing which shows the board | substrate for demonstrating the manufacturing method of the organic electroluminescent panel of embodiment by this invention. It is a schematic sectional drawing which shows the board | substrate for demonstrating the manufacturing method of the organic electroluminescent panel of embodiment by this invention. It is a schematic sectional drawing which shows the board | substrate for demonstrating the manufacturing method of the organic electroluminescent panel of embodiment by this invention. It is a schematic sectional drawing which shows the board | substrate for demonstrating the manufacturing method of the organic electroluminescent panel of embodiment by this invention. It is a schematic sectional drawing which shows the board | substrate for demonstrating the manufacturing method of the organic electroluminescent panel of embodiment by this invention. It is a graph which shows the solid content density | concentration of the coating liquid for banks used for embodiment by this invention, and the film thickness of a coating liquid film.

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

[Organic EL device]
As an example of each organic EL element of the organic EL panel according to the present embodiment, as shown in FIG. 2, on a transparent substrate 1 such as glass, a transparent anode 2, a hole injection layer 3, and a hole transport are sequentially arranged. The layer 4, the light emitting layer 5, the hole blocking layer 6, the electron transport layer 7, the electron injection layer 8, and a cathode 9 made of a metal are stacked to obtain. The hole injection layer 3, the hole transport layer 4, the light emitting layer 5, the hole blocking layer 6, and the electron transport layer 7 are organic layers. That is, in an organic EL device, a plurality of organic layers stacked between a pair of opposing anodes and cathodes are a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron Includes an injection layer. Components such as the organic layer will be described later.

Other than the structure of anode 2 / hole injection layer 3 / hole transport layer 4 / light emitting layer 5 / hole blocking layer 6 / electron transport layer 7 / electron injection layer 8 / cathode 9 / shown in FIG. However, the anode 2 / hole injection layer 3 / light emitting layer 5 / electron transport layer 7 / electron injection layer 8 / cathode 9 / hole transport layer 4 and hole blocking layer 6 are omitted, although not shown, The anode 2 / hole transport layer 4 / light emitting layer 5 / electron transport layer 7 / electron injection layer 8 / cathode 9 / hole injection layer 3 and hole blocking layer 6 are omitted, and although not shown, the anode 2 A configuration in which the hole injection layer 3, the hole transport layer 4, and the hole blocking layer 6 of / light emitting layer 5 / electron transport layer 7 / electron injection layer 8 / cathode 9 / is omitted is also included in the present invention. Moreover, in the layer structure demonstrated above, it is also possible to laminate | stack components other than a board | substrate in reverse order. In any case, the present invention is not limited to these stacked structures, and includes a structure including at least a light-emitting layer or a charge transport layer that can also be used.

[substrate]
As the substrate 1, a quartz or glass plate, a metal plate or a metal foil, a resin substrate to be bent, a plastic film, a sheet, or the like is used. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferable. When using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the substrate is too small, the organic EL element may be deteriorated by the outside air that has passed through the substrate. For this reason, a method of providing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate is also a preferable method.

[Anode and cathode]
The anode 2 for supplying holes to the layers up to the light emitting layer is usually a metal such as aluminum, gold, silver, nickel, palladium, platinum, or a metal such as indium and / or tin or zinc oxide (ITO or IZO). It is composed of an oxide, a metal halide such as copper iodide, carbon black, or a conductive polymer such as poly (3-methylthiophene), polypyrrole, or polyaniline.

The anode is usually formed by a sputtering method, a vacuum deposition method, or the like. In addition, when forming an anode using fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, or conductive polymer fine powder, an appropriate binder resin solution is used. The anode can also be formed by dispersing and coating the substrate. Further, in the case of a conductive polymer, a thin film can be directly formed on the substrate by electrolytic polymerization, or the anode can be formed by applying a conductive polymer on the substrate.

The anode usually has a single-layer structure, but it can also have a laminated structure made of a plurality of materials if desired.

The thickness of the anode depends on the required transparency. When transparency is required, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and is usually 1000 nm or less, preferably about 500 nm or less. If it may be opaque, the thickness of the anode is arbitrary, and the anode may be integrated with the substrate 1. Furthermore, different conductive materials may be laminated.

For the purpose of removing impurities adhering to the anode and adjusting the ionization potential to improve the hole injection property, the anode surface is subjected to ultraviolet (UV) / ozone treatment or oxygen plasma or argon plasma surface treatment. That is preferred.

As a material of the cathode 9 for supplying electrons to the layers up to the light emitting layer, a material used for the anode can be used. However, in order to perform electron injection efficiently, a metal having a low work function is preferable. A suitable metal such as tin, magnesium, indium, calcium, aluminum, silver, or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

In addition, only 1 type may be used for the material of the

cathode

9, and 2 or more types may be used together by arbitrary combinations and a ratio. The thickness of the cathode is usually the same as that of the anode.

Further, for the purpose of protecting the cathode made of a low work function metal, it is preferable to further stack a metal layer having a high work function and stable to the atmosphere because the stability of the device is increased. For this purpose, for example, metals such as aluminum, silver, copper, nickel, chromium, gold, platinum are used. In addition, these materials may be used only by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

Further, when the anode and the cathode are on the light emission extraction side, the material and film thickness are selected so as to be transparent or translucent. In particular, it is preferable to select a material in which either or both of the anode and the cathode have a transmittance of at least 10% at the emission wavelength obtained from the organic light emitting material. These electrodes may be patterned as necessary.

[Organic layer]
(Hole injection layer)
The hole injection layer 3 is preferably a layer containing an electron accepting compound. The thickness of the hole injection layer is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. The hole injection layer is preferably formed by a wet film formation method from the viewpoint of reducing dark spots.

When a hole injection layer is formed by a wet film formation method, a composition for film formation (holes) is usually mixed with a solvent (hole injection layer solvent) suitable for the material constituting the hole injection layer. An injection layer forming composition) is prepared, and this hole injection layer forming composition is coated on the anode by an appropriate technique to form a film and dried to form a hole injection layer. The drying is preferably vacuum drying. Vacuum drying is a method in which a substrate coated with an organic layer is placed in a sealed container and evacuated with a vacuum pump to artificially increase the difference in vapor partial pressure, which is a drying condition. For example, vacuum drying is preferable because it can be dried in a shorter time than hot air drying. In vacuum drying, since the pressure is forcibly reduced to a narrow gap of solid content, the solvent in the gap evaporates more quickly, and uniform drying can be realized up to the inside of the layer.

The composition for forming a hole injection layer usually contains a hole transporting compound and a solvent as constituent materials of the hole injection layer. Examples of the solvent include, but are not limited to, ether solvents, ester solvents, aromatic hydrocarbon solvents, amide solvents, and the like.
Examples of ether solvents include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether acetate (PGMEA), 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2 -Aromatic toluene such as methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and the like.

Examples of the ester solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

Examples of the aromatic hydrocarbon solvent include toluene, xylene, cyclohexylbenzene, 3-isopropylpropylphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene. Can be mentioned.

Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, and the like. In addition, dimethyl sulfoxide and the like can also be used. These solvent may use only 1 type and may use 2 or more types by arbitrary combinations and a ratio.

As long as the hole transporting compound is a compound having a hole transporting property that is usually used in a hole injection layer of an organic EL element, a polymer or the like may be a monomer or the like. Although it may be a low molecular compound, it is preferably a low molecular compound.

The hole transporting compound is preferably a compound having an ionization potential of 4.5 eV to 6.0 eV from the viewpoint of a charge injection barrier from the anode to the hole injection layer. Examples of hole transporting compounds include aromatic amine derivatives, phthalocyanine derivatives typified by phthalocyanine copper (CuPc), porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, benzylphenyl derivatives, and tertiary amines linked by fluorene groups. Examples thereof include compounds, hydrazone derivatives, silazane derivatives, silanamine derivatives, phosphamine derivatives, quinacridone derivatives, polyaniline derivatives, polypyrrole derivatives, polyphenylene vinylene derivatives, polythienylene vinylene derivatives, polyquinoline derivatives, polyquinoxaline derivatives, and carbon.

Here, the derivative includes, for example, an aromatic amine derivative, and includes an aromatic amine itself and a compound having an aromatic amine as a main skeleton. It may be a body.

The hole transporting compound used as the material for the hole injection layer may contain any one of these compounds alone, or may contain two or more. When two or more hole transporting compounds are contained, the combination thereof is arbitrary, but one or more aromatic tertiary amine polymer compounds and one or two other hole transporting compounds are used. The above can also be used together. From the viewpoints of amorphousness and visible light transmittance, an aromatic amine compound is preferable for the hole injection layer, and an aromatic tertiary amine compound is particularly preferable. Here, the aromatic tertiary amine compound is a compound having an aromatic tertiary amine structure, and includes a compound having a group derived from an aromatic tertiary amine. Specific examples include those described in the pamphlet of International Publication No. 2005/089024.

As the hole transporting compound, a conductive polymer (PEDOT / PSS) obtained by polymerizing 3,4-ethylenedioxythiophene, which is a derivative of polythiophene, in high molecular weight polystyrene sulfonic acid is also preferable. Moreover, the end of this polymer may be capped with methacrylate or the like.

The concentration of the hole transporting compound in the composition for forming a hole injection layer is usually 0.01% by weight or more, preferably 0.1% by weight or more, and more preferably 0.00% by weight in terms of film thickness uniformity. 5% by weight or more, usually 70% by weight or less, preferably 60% by weight or less, more preferably 50% by weight or less. If this concentration is too high, film thickness unevenness may occur, and if it is too low, defects may occur in the formed hole injection layer.

The composition for forming a hole injection layer preferably further contains an electron-accepting compound, and may further contain other components in addition to the hole-transporting compound and the electron-accepting compound. Examples of other components include various light emitting materials, electron transporting compounds, binder resins, and coating property improving agents. In addition, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

(Hole transport layer)
The material of the hole transport layer 4 may be any material that has been conventionally used as a constituent material of the hole transport layer. For example, the hole transport layer is exemplified as the hole transport compound used in the above-described hole injection layer. Things. In addition, arylamine derivatives, fluorene derivatives, spiro derivatives, carbazole derivatives, pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, phthalocyanine derivatives, porphyrin derivatives, silole derivatives, oligothiophene derivatives, condensed polycyclic aromatics Group derivatives, metal complexes and the like. Also, for example, polyvinylcarbazole derivatives, polyarylamine derivatives, polyvinyltriphenylamine derivatives, polyfluorene derivatives, polyarylene derivatives, polyarylene ether sulfone derivatives containing tetraphenylbenzidine, polyarylene vinylene derivatives, polysiloxane derivatives, polythiophenes Derivatives, poly (p-phenylene vinylene) derivatives, and the like. These may be any of an alternating copolymer, a random polymer, a block polymer, or a graft copolymer. Further, it may be a polymer having a branched main chain and three or more terminal portions, or a so-called dendrimer.

Specific examples of the material for the hole transport layer 4 include polyarylene derivatives described in JP-A-2008-98619.

In the case of forming the hole transport layer by a wet film formation method, a composition for forming a hole transport layer is prepared in the same manner as the formation of the hole injection layer, and then heated and dried after the wet film formation.

The composition for forming a hole transport layer contains a solvent in addition to the hole transport compound. The solvent used is the same as that used for the composition for forming the hole injection layer. The film forming conditions, heat drying conditions, and the like are the same as in the case of forming the hole injection layer.

The hole transport layer may contain various light emitting materials, electron transport compounds, binder resins, coatability improvers and the like in addition to the hole transport compound.

The film thickness of the hole transport layer is usually 5 nm or more, preferably 10 nm or more, and usually 300 nm or less, preferably 100 nm or less.

The hole transport layer may be formed by a vacuum deposition method or a wet film formation method, but is preferably formed by a wet film formation method from the viewpoint of reducing dark spots.

The hole transport layer 4 may be a layer containing a polymer obtained by crosslinking an amine-based crosslinking compound.

(Light emitting layer)
The light emitting layer 5 contains at least a material having a light emitting property (light emitting material) as a constituent material, and preferably a compound having a hole transporting property (hole transporting compound) or an electron transport. A compound (electron transporting compound) having the following properties: A light emitting material may be used as a dopant material, and a hole transporting compound, an electron transporting compound, or the like may be used as a host material. There is no particular limitation on the light-emitting material, and a material that emits light at a desired light emission wavelength and has favorable light emission efficiency may be used. In addition, when forming a light emitting layer by wet film-forming methods, such as the inkjet method, it is preferable to use a low molecular weight material in any case.

Any known material can be applied as the light emitting material. For example, a fluorescent material or a phosphorescent material may be used, but a phosphorescent material is preferred from the viewpoint of internal quantum efficiency. Alternatively, blue may be used in combination, such as using a fluorescent material, and green and red using a phosphorescent material.

For the purpose of improving the solubility in a solvent, it is preferable to reduce the symmetry and rigidity of the molecule of the luminescent material or introduce a lipophilic substituent such as an alkyl group.

Examples of fluorescent light emitting materials (blue fluorescent dyes) that emit blue light include naphthalene, perylene, pyrene, chrysene, anthracene, coumarin, p-bis (2-phenylethenyl) benzene, and derivatives thereof.

Examples of the fluorescent light-emitting material (green fluorescent dye) that emits green light include aluminum complexes such as quinacridone derivatives, coumarin derivatives, and Alq3 (tris (8-hydroxy-quinoline) aluminum).

Examples of the fluorescent light emitting material (yellow fluorescent dye) that emits yellow light include rubrene and perimidone derivatives.

Examples of fluorescent materials that emit red light (red fluorescent dyes) include DCM (4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, Examples include benzothioxanthene derivatives and azabenzothioxanthene.

As the phosphorescent material, for example, a long-period type periodic table (hereinafter, unless otherwise specified, the term “periodic table” refers to a long-period type periodic table) selected from Group 7 to 11 And an organometallic complex containing a metal. Preferred examples of the metal selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. As the ligand of the complex, a ligand in which a (hetero) aryl group such as a (hetero) arylpyridine ligand or a (hetero) arylpyrazole ligand and a pyridine, pyrazole, phenanthroline, or the like is connected is preferable. A pyridine ligand and a phenylpyrazole ligand are preferable. Here, (hetero) aryl represents an aryl group or a heteroaryl group.

Specific examples of phosphorescent materials include tris (2-phenylpyridine) iridium (Ir (ppy) 3), tris (2-phenylpyridine) ruthenium, tris (2-phenylpyridine) palladium, and bis (2-phenylpyridine). ) Platinum, tris (2-phenylpyridine) osmium, tris (2-phenylpyridine) rhenium, octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladium porphyrin, octaphenylpalladium porphyrin, and the like.

The molecular weight of the compound used as the light emitting material is usually 10,000 or less, preferably 5000 or less, more preferably 4000 or less, still more preferably 3000 or less, and usually 100 or more, preferably 200 or more, more preferably 300 or more, still more preferably. The range is 400 or more. If the molecular weight of the light-emitting material is too small, the heat resistance is significantly reduced, gas is generated, the film quality is deteriorated when the film is formed, or the morphology of the organic EL element is changed due to migration or the like. There is a case to do. On the other hand, if the molecular weight of the luminescent material is too large, it tends to be difficult to purify the organic compound, or it may take time to dissolve in the solvent.

In addition, any 1 type may be used for a luminescent material, and 2 or more types may be used together by arbitrary combinations and a ratio. The ratio of the light emitting material in the light emitting layer is usually in the range of 0.05% by weight or more and usually 35% by weight or less. If the amount of the light emitting material is too small, uneven light emission may occur. If the amount is too large, the light emission efficiency may be reduced. In addition, when using together 2 or more types of luminescent material, it is made for the total content of these to be contained in the said range. The component having the highest content in the light emitting layer is called a host material, and the component having a smaller content is called a guest material. Therefore, at least two kinds of solid contents (host material and guest material) to be the light emitting layer can be prepared by being dispersed or dissolved in a solvent as a solute in the light emitting layer coating liquid.

The light emitting layer may contain a hole transporting compound as a constituent material. Here, among the hole transporting compounds, examples of the low molecular weight hole transporting compound include various compounds exemplified as the hole transporting compound in the hole injection layer 3 described above, for example, Two or more condensed aromatic rings containing two or more tertiary amines represented by 4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) are attached to the nitrogen atom. Aromatic amine compounds having a starburst structure (Journal ジアミン of ジアミン Luminescence, such as substituted aromatic diamines (Japanese Patent Laid-open No. Hei 5-234681), 4,4 ′, 4 ″ -tris (1-naphthylphenylamino) triphenylamine) 1997, Vol.72-74, pp.985), aromatic amine compounds consisting of tetramers of triphenylamine (Chemical Communications, 1996, pp.2175), 2,2 ′, 7,7′-tetrakis- ( Diphenylamino) Examples include spiro compounds such as -9,9'-spirobifluorene (Synthetic Metals, 1997, Vol. 91, pp. 209).

In the light emitting layer, only one type of hole transporting compound may be used, or two or more types may be used in any combination and ratio.
The ratio of the hole transporting compound in the light emitting layer is usually in the range of 0.1% by weight or more and usually 65% by weight or less. If the amount of the hole transporting compound is too small, it may be easily affected by a short circuit, and if it is too large, the film thickness may be uneven. In addition, when using together 2 or more types of hole transportable compounds, it is made for the total content of these to be contained in the said range.

The light emitting layer may contain an electron transporting compound as a constituent material. Here, among the electron transporting compounds, examples of low molecular weight electron transporting compounds include 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (BND), 2,5, -Bis (6 '-(2', 2 "-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), bathophenanthroline (BPhen), 2,9-dimethyl-4,7 Diphenyl-1,10-phenanthroline (BCP, bathocuproin), 2- (4-biphenylyl) -5- (p-tertiarybutylphenyl) -1,3,4-oxadiazole (tBu-PBD), 4 , 4′-bis (9H-carbazol-9-yl) biphenyl (CBP), etc. In the light emitting layer, only one kind of electron transporting compound may be used, or two or more kinds. It may be used together in any combination and ratio.

The ratio of the electron transporting compound in the light emitting layer is usually in the range of 0.1% by weight or more and usually 65% by weight or less. If the amount of the electron transporting compound is too small, it may be easily affected by a short circuit, and if it is too large, the film thickness may be uneven. In addition, when using together 2 or more types of electron transport compounds, it is made for the total content of these to be contained in the said range.

As the light-emitting layer solvent to be contained in the light-emitting layer forming composition for forming the light-emitting layer by a wet film forming method, any solvent can be used as long as the light-emitting layer can be formed. The suitable example of the solvent for light emitting layers is the same as that used for the composition for hole injection layer formation.

The ratio of the light emitting layer solvent to the light emitting layer forming composition for forming the light emitting layer is usually 0.01% by weight or more and usually 70% by weight or less. In addition, when mixing and using 2 or more types of solvents as a solvent for light emitting layers, it is made for the sum total of these solvents to satisfy | fill this range.

The solid content concentration of the light emitting material, hole transporting compound, electron transporting compound, etc. in the composition for forming a light emitting layer is usually 0.01% by weight or more and usually 70% by weight or less. If this concentration is too large, film thickness unevenness may occur, and if it is too small, defects may occur in the film.

After forming the light emitting layer forming composition by wet film formation such as an ink jet method, the obtained coating film is dried and the solvent is removed to form the light emitting layer. The light emitting layer is preferably formed by an inkjet method from the viewpoint of reducing dark spots.

The film thickness of the light emitting layer is usually 3 nm or more, preferably 5 nm or more, and usually 200 nm or less, preferably 100 nm or less. If the light emitting layer is too thin, defects may occur in the film, and if it is too thick, the driving voltage may increase.

(Hole blocking layer)
The hole blocking layer 6 is a layer laminated on the light emitting layer so as to be in contact with the cathode side interface of the light emitting layer. The hole blocking layer has a role of blocking holes moving from the anode from reaching the cathode and a role of efficiently transporting electrons injected from the cathode toward the light emitting layer.

The physical properties required for the material constituting the hole blocking layer include high electron mobility, low hole mobility, large energy gap (difference between HOMO and LUMO), and excited triplet level (T1). It is expensive. Examples of the material for the hole blocking layer satisfying such conditions include bis (2-methyl-8-quinolinolato) (phenolato) aluminum (PAlq) and bis (2-methyl-8-quinolinolato) (triphenylsilanol). Mixed ligand complexes such as lato) aluminum (SAlq), metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolinato) aluminum binuclear metal complexes Styryl compounds such as distyrylbiphenyl derivatives (Japanese Patent Laid-Open No. 11-242996), 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole, etc. Phenanthroline derivatives such as triazole derivatives of JP-A-7-41759 and bathocuproin (BCP) Like body (Japanese Unexamined Patent Publication No. 10-79297). Furthermore, compounds having at least one pyridine ring substituted at the 2,4,6-positions described in International Publication No. 2005-022962 are also preferable as the material for the hole blocking layer.

In addition, the material of a hole-blocking layer may use only 1 type, and may use 2 or more types together by arbitrary combinations and ratios. Although there is no restriction | limiting in the formation method of a hole-blocking layer, It is preferable to form by wet film-forming methods, such as an inkjet method, from a viewpoint of dark spot reduction.

The film thickness of the hole blocking layer is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

(Electron transport layer)
The electron transport layer 7 is provided for the purpose of further improving the light emission efficiency of the device, and can efficiently transport electrons injected from the cathode between the electrodes to which an electric field is applied in the direction of the light emitting layer. Formed from compounds.

As the electron transporting compound used for the electron transport layer, usually, the electron injection efficiency from the cathode 9 or the electron injection layer 8 is high, and the injected electrons having high electron mobility can be efficiently transported. Use possible compounds. Examples of the compound satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline such as Alq3 (Japanese Patent Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo [h] quinoline, oxadi Azole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxaline Compound (JP-A-6-207169), phenanthroline derivative (JP-A-5-331459), 2-t-butyl-9,10-N, N′-dicyanoanthraquinonediimine, n-type hydrogenated amorphous Silicon carbide, n-type sulfur Zinc, such as n-type zinc selenide.

In addition, only 1 type may be used for the material of an electron carrying layer, and 2 or more types may be used together by arbitrary combinations and a ratio.

The formation method of the electron transport layer is not limited, but it is preferably formed by a wet film formation method such as an inkjet method from the viewpoint of reducing dark spots.

The film thickness of the electron transport layer is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

(Electron injection layer)
The electron injection layer 8 plays a role of efficiently injecting electrons injected from the cathode into the light emitting layer. In order to perform electron injection efficiently, the material for forming the electron injection layer is preferably a metal having a low work function. Examples include alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and their compounds (CsF, Cs ₂ CO ₃ , Li ₂ O, LiF) and the like. .1 nm or more and 5 nm or less are preferable.

Furthermore, an organic electron transport compound typified by a metal complex such as a nitrogen-containing heterocyclic compound such as bathophenanthroline or an aluminum complex of 8-hydroxyquinoline is doped with an alkali metal such as sodium, potassium, cesium, lithium or rubidium ( As described in JP-A-10-270171, JP-A-2002-1000047, JP-A-2002-1000048, and the like, it is possible to improve the electron injection / transport property and achieve excellent film quality. preferable. In this case, the film thickness is usually 5 nm or more, preferably 10 nm or more, and is usually 200 nm or less, preferably 100 nm or less.

In addition, only 1 type may be used for the material of an electron injection layer, and 2 or more types may be used together by arbitrary combinations and a ratio. There is no restriction | limiting in the formation method of an electron injection layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods.

[Method for manufacturing organic EL panel]
An example of the manufacturing method of the organic EL panel according to the present embodiment will be summarized as follows. As shown in FIG. 3, the first electrode formation step (S1) sequentially performed as shown in FIG. A first organic layer forming step (S2) for forming a layer, and a bank forming step (S3) for patterning an insulating layer, that is, a bank pattern by an inkjet method in order to define a light emitting area of each organic EL element on the charge transport layer. ), A second organic layer forming step (S4) and a second electrode forming step (S5) for forming at least one organic layer for each bank section. In the organic layer forming step, coating, drying and baking are repeated for each organic layer to form a plurality of organic layers.

Hereinafter, the manufacturing method of the organic EL panel includes the first electrode formation step (S1), the first organic layer formation step (S2), the bank formation step (S3), the second organic layer formation step (S4), and the second electrode. Each forming step (S5) will be described.

(First electrode forming step)
As shown in FIG. 4, a transparent substrate 1 such as washed glass is prepared, and a transparent anode 2 made of ITO or the like having a larger area than the opening of the planned bank section is formed in a predetermined pattern. A bus line BU made of a metal such as aluminum is formed in advance in a predetermined pattern on a part of the anode 2 located under a predetermined bank.

(First organic layer forming step)
As shown in FIG. 5, for example, the hole injection layer 3 and the hole transport layer 4 are sequentially stacked by a wet film formation method. In this case, the materials constituting the hole injection layer and the hole transport layer are mixed with appropriate solvents (a solvent for the hole injection layer and a solvent for the hole transport layer), respectively, and a predetermined organic coating of the composition for film formation is performed. Liquids (a composition for forming a hole injection layer and a composition for a hole transport layer), and coating each of the coating liquids on the anode by, for example, a spin method, a dip method, a roll method, The hole transport layer 4 is formed by vacuum-drying and further coating on the vacuum-injected hole injection layer 3 to form a film, followed by drying. Moreover, as a drying and baking method after film formation, a method of drying using a hot plate, a clean oven, an IR oven, or a convection oven is preferable. As described above, in the first organic layer forming step (S2), at least one layer coated over the main surface of the substrate 1 and the electrode pattern thereon so as to cover and flatten the anode and the bus line on the substrate. The charge transport layer is formed. In order to planarize, it is preferable to form a two-layer structure of a hole injection layer and a hole transport layer in which at least a charge transport layer is sequentially formed.

(Bank formation step)
As shown in FIG. 6, on the hole transport layer 4 of the charge transport layer on the bus line BU pattern of the anode 32 of the substrate 1, a partition bank BK is formed by a wet film-forming ink jet method. That is, as a drawing step, a bank coating liquid containing a solid content of the bank pattern material is drawn and drawn as droplets by the droplet discharge nozzle NZ on the hole transport layer 4, and then vacuum dried and solidified. A bank pattern is formed.

As a bank coating liquid for bank film formation, an organic coating liquid is prepared by mixing a bank constituent material (solid content) such as a resin, a liquid repellent, and an additive with an appropriate bank solvent. As the bank solvent, for example, propylene glycol monomethyl ether acetate (PGMEA) having wettability to the hole transport layer 4 of the charge transport layer is used. Moreover, acrylic, epoxy, etc. are used for resin of bank coating liquid. As the liquid repellent component (liquid repellent), a fluorine-based monomer, a silicone-based monomer, or the like is used.

Due to the liquid repellent component, the contact angle of the bank coating solution with respect to the hole transport layer 4 may be 20 ° or more and less than 90 °, more preferably 20 ° or more and less than 50 °. If the contact angle of the bank coating solution is less than 20 °, the bank coating solution spreads out and the bank outline cannot be clearly formed. If the contact angle of the bank coating solution is 90 ° or more, the bank coating solution rolls. As a result, a bank cannot be formed. The reason why the upper limit contact angle of the bank coating liquid is less than 50 ° is that, for example, the use of the solvent PGMEA can clearly form the bank outline. In order to obtain film thickness stability, in the solvent PGMEA, the solid content concentration of the bank coating solution is preferably 25% by weight or more. Moreover, even if there is no solvent, it can also be set as a bank coating liquid with an acrylic resin, an epoxy resin, and a liquid repellent component (in this case, solid content concentration is 100 weight%).

The flattened hole transport layer 4 with less unevenness on the surface has uniform wettability with respect to the solvent for the bank and can suppress the occurrence of uneven drying in the finish of the organic layer to be formed next. The forming method is preferably formed by an inkjet method. In addition, as a drying and baking method after bank pattern film-forming, it can dry using a hot plate, clean oven, IR oven, or a convection oven.

Plate printing may be considered to pattern the bank coating liquid containing the liquid repellent material in a predetermined area, but it is difficult to print with a general organic material on the organic layer (hole transport layer 4). It is. Also, intaglio printing makes contact with the organic layer, so organic layer contamination cannot be avoided. Therefore, it is important to pattern the bank material by the ink jet method.

Furthermore, the bank pattern can be divided into a plurality of layers, and the bank can be formed by repeating the application of the bank coating liquid and vacuum drying for each layer to form a multilayer.

When performing multilayer film formation, the amount of bank coating liquid applied is the total amount that results in a film thickness such that the height of the bank pattern is 0.01 μm to 0.5 μm as a dry film thickness. At this time, the inkjet coating is applied uniformly so that the dry film thickness or the height of the finally formed bank is uniform over the entire area of the substrate. In order to reduce the meniscus of the light emitting layer, it is preferable that the bank height is low. However, since the amount of droplets can be controlled by the ink jet method, the bank can be thinned.

Furthermore, when performing multi-layer film formation, in such a drawing step, bank coating liquid droplets are displaced while overlapping from the same position in the bank pattern formation planned area on the charge transport layer, and are sequentially applied, and bank application is performed. It is possible to suppress the boundary line of the bank coating liquid from being bent at the joint between the liquid droplets. This also forms an accurate bank pattern. Further, in the drawing step, the concentration of the solid content in the bank coating liquid droplets can be decreased as the coating is performed later, and the drying speed of the bank coating liquid film formed in each successive coating can be matched. Thereby, an accurate bank pattern is formed.

In the case of multilayer film formation, for the lamination of the second half of the bank pattern, the liquid repellent component (liquid repellent) of the bank coating liquid can be adjusted to impart liquid repellency to the upper part of the formed bank. Another lyophobic agent having a property of repelling the organic coating liquid of the organic coating film formed in the subsequent step can be contained in the area partitioned by the bank.

In addition, prior to the drawing step by the ink jet method, the bank coating liquid is selectively formed from the charge transport layer other than the formation region with respect to the formation region of the bank pattern on the hole transport layer 4 of the charge transport layer. Affinity treatment step for carrying out treatment for increasing affinity, for example, the hole transport layer 4 of the charge transport layer other than the region to be formed is partially covered with a mask, and the region to be formed is subjected to plasma surface treatment or UV (ultraviolet) light irradiation treatment. It is preferable to include. Thereby, an accurate bank pattern is formed.

(Second organic layer forming step)
As shown in FIG. 7, the light emitting layer 5 is formed in the bank partition region, and is particularly preferably formed by an ink jet method. In this case, the light emitting layer material is dissolved in an appropriate solvent to prepare a composition for forming a light emitting layer, and a film is formed using the composition. That is, after being discharged and supplied as droplets by a droplet discharge nozzle NZ by an ink jet method onto the hole transport layer 4 of the charge transport layer exposed from the opening of the bank pattern, vacuum drying and solidification are performed, and at least One light emitting layer 5 is formed (light emitting layer forming step).

Next, as shown in FIG. 8, the electron transport layer 7 is similarly formed on the light emitting layer 5 formed in the bank partition region by the inkjet method.

In the second organic layer forming step, a predetermined solid containing a predetermined solid content to be each organic layer such as a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and an appropriate solvent for dispersing the solid content. After forming a predetermined coating liquid film from the organic coating liquid by the inkjet method in the same manner as described above, a drying step of drying the coating liquid film and a baking step of baking the dried predetermined coating liquid film, These steps are repeated for each organic layer to form a plurality of organic layers. That is, in the second organic layer forming step, the organic layer coating liquid containing the solid content of the organic layer material is ejected as droplets by the droplet ejection nozzle onto the charge transport layer partitioned by the banks of the bank pattern. After the supply, vacuum drying and solidification are performed to form at least one organic layer.

In the second organic layer forming step, in order to form an organic coating film on the charge transport layer partitioned by banks on the substrate, the solid content (remaining after drying) of each organic layer is removed with a solvent (after drying). A coating solution dissolved or dispersed in the component to be evacuated is supplied into the bank partition region.

In addition to the relief printing method, the dispenser method, and the slit coating method, this coating liquid can be supplied into the bank partition region by an ink discharge type such as an ink jet method (droplet discharge method) or a nozzle print method (liquid flow discharge method). A coating method is preferable, and an inkjet method is particularly preferable.

As a solvent of the coating solution used in the ink jet method, it is generally known to prevent nozzle drying and clogging by adding a relatively large amount of a high-boiling solvent component. It is preferable to select an optimal solvent in consideration. In particular, in the case of the ink jet method, the same applies to the bank formation step, but when the droplet is deposited on the surface to be coated with a droplet size of 20 pl, the droplet diameter after one minute has elapsed is 100 to 400 μm. A solvent is preferable, and the droplet diameter is more preferably 150 to 300 μm. Thereby, the occurrence of film thickness unevenness and pinholes can be prevented.

In the organic coating liquid, at least two kinds of solid contents (for example, a low-molecular host material and a guest material to be a light emitting layer) may be dispersed and mixed as solid contents. The solid concentration of the predetermined coating solution in the second organic layer forming step is preferably 3% by weight to 10% by weight. If the solid content is below this lower limit, the amount of solvent evaporation increases, which is inconvenient for vacuum drying. If the solid content exceeds the upper limit, nozzle drying and clogging are likely to occur. It is preferable that the solid content of the predetermined coating liquid in the second organic layer forming step is a low molecular compound having a molecular weight of 100 or more and 10,000 or less. When the molecular weight of the low molecular weight compound is below this lower limit, the amount of solvent evaporation increases, which is inconvenient for vacuum drying. When the molecular weight exceeds the upper limit, nozzle drying and clogging tend to occur. The standard boiling point of the solvent of the predetermined coating solution is preferably 200 ° C to 300 ° C. When the standard boiling point of the solvent is below this lower limit, nozzle drying and clogging are likely to occur, and when it exceeds the upper limit, it is inconvenient for vacuum drying. The vapor pressure at room temperature of the solvent of the predetermined coating solution is preferably 1 Pa to 70 Pa. When the vapor pressure of the solvent deviates from the lower limit and the upper limit, it becomes inconvenient for vacuum drying.

After supplying the coating liquid into the bank partition region, for example, a vacuum drying method is performed in which drying is performed in a vacuum chamber.

After the vacuum drying, the organic layer can be baked, for example, by heating the dried substrate at a temperature of 200 ° C. for about 30 minutes using a hot plate, clean oven, IR furnace, or the like.

Next, as shown in FIG. 9, an electron injection layer material is loaded into a vapor deposition source boat of a vacuum vapor deposition apparatus (not shown), vapor deposition is performed, and electrons are deposited on the electron transport layer 7 on the loaded substrate 1. An injection layer 8 is formed. According to the vacuum deposition method, each layer is formed as a thin film regardless of whether the electron injection layer material is an organic or inorganic material. When the electron injection layer material is an organic material, the film can be formed by a wet film formation method such as an ink jet method similar to the above.

(Second electrode formation step)
As shown in FIG. 10, a cathode metal material is loaded into a vapor deposition source boat of a vacuum vapor deposition apparatus (not shown) to perform vapor deposition, and a cathode 9 is formed on the electron injection layer 8 on the loaded substrate 1. . Generally, a substrate after baking is held on a substrate holder provided on the inner surface of a semicircular dome processing chamber of a vacuum vapor deposition apparatus, and a predetermined organic or inorganic material is placed on a vapor deposition source boat at the center position of the semicircular dome. Then, such a dome is slowly rotated around the center during film formation, for example, the film formation start pressure is increased to a high vacuum of about 10 ⁻⁴ Pa to improve the adhesion and film quality of the deposited film. In the vapor deposition of inorganic materials, the film forming temperature can be increased (300 ° C. to 400 ° C.), but plastic substrates and the like are deposited at a low temperature. The evaporation source can be evaporated by resistance evaporation (the organic or inorganic material is melted and evaporated by heating the electric resistance of the boat) or by electron beam evaporation (the electron gun is used to dissolve the focused electron beam into the boat's organic or inorganic material). Evaporate).

By adopting the present invention, first, since the bank pattern is formed only in a portion necessary for the ink jet method, the organic EL element is not affected by the photolithography process, and there is no performance deterioration. Second, because the bank is formed on the organic layer formed on the first lower electrode, the unevenness of the first electrode is smoothed by the organic layer, and the wettability of the charge transport layer is also uniform. A good bank pattern can be formed by the ink jet method.

Although the organic EL element has been described in the present embodiment, the organic EL panel manufacturing method of the present invention is not limited to an organic EL display that performs film formation by wet coating, organic EL illumination, an organic TFT using an organic layer, or an organic TFT. Needless to say, the present invention can also be applied to solar cells and color filters.

A substrate in which a transparent stripe anode of indium tin oxide (ITO) having a thickness of 400 μm and a thickness of 120 nm was formed on a glass substrate by photolithography was prepared to produce an organic electroluminescence panel. Specifically, in the experiment, the anode (ITO) / hole injection layer (30 nm thickness) / hole transport layer (15 to 60 nm thickness) / light emitting layer (40 to 60 nm) on the glass substrate by the inkjet process of the above-described embodiment. An organic EL element having a film configuration of (thickness) / electron transport layer (Alq3, 20 nm thickness) / cathode (Al, 100 nm thickness) / was produced. Here, a bank section (5 cm) in which the stacked bank BK (width 60 μm) was parallel (450 μm pitch) was formed on the hole transport layer, and the light emitting layer was formed into a film by an ink jet in the recess between the banks.

The inkjet head (droplet discharge nozzle) method for ejecting micro droplets from a thin nozzle tube onto an organic layer is an intermittent injection type (on-demand) so that droplets with uniform particle sizes can be generated continuously. Type). The head structure employs a piezo drive system in which the displacement of the drive unit is proportional to the voltage, and the size of the droplet is controlled by the nozzle tube diameter and the frequency when pressure (voltage) is applied. The conditions of the ink jet apparatus were a pulse width of 5 μs, a frequency of 1 KHz, and an applied voltage of 10V.

As a bank coating liquid for forming a bank film, an acrylic resin containing a fluorine monomer as a water repellent was mixed with a PGMEA bank solvent to prepare an organic coating liquid.

In addition, before the film formation of the bank coating solution, a plasma surface treatment or a UV ozone treatment was performed on the hole transport layer film as a treatment for increasing the affinity with the bank coating solution. In the plasma treatment, a bank coating liquid film substrate was loaded into a plasma surface treatment apparatus, and was treated with oxygen gas (500 sccm) plasma (power 500 W) for 30 seconds. Then, it formed into a film by 10 cm x 10 cm with the same application quantity of the bank coating liquid of each solid content concentration on the positive hole transport layer film | membrane, and vacuum-dried. Moreover, in order to improve the linearity of the bank edge, sequential application was performed. At that time, the second layer was formed by shifting the coating start position in the scanning direction by (coating pitch × 1/2) with respect to the first layer.

On the other hand, FIG. 11 shows a measurement result of the distribution of the film thickness of the bank coating liquid with respect to the distance from the center of the bank coating liquid film formed by spin coating.

As is clear from the above measurement results, the bank film thickness increases around the film (5 cm) when the solid concentration of the bank coating solution is 20% by weight. This is because when the solid content concentration is low, the number of rotations for forming a desired film thickness is slow, and the film thickness distribution becomes non-uniform. This is the same as in the case of ink jet, and there is a correlation between the film thickness distribution obtained by spin coating under a certain condition and the film stability when the film is formed by ink jet. It can be seen that a bank film having a substantially uniform film thickness can be obtained when it is at least%.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer 6 Hole blocking layer 7 Electron transport layer 8 Electron injection layer 9 Cathode

Claims

A plurality of organic electroluminescence elements arranged on a substrate and partitioned by a bank, each of the plurality of organic electroluminescence elements being stacked between a pair of first and second electrodes facing each other A method for producing an organic electroluminescence panel having an organic layer of
An organic layer forming step of covering the surface of the substrate having an electrode pattern on the main surface with at least one organic layer;
A bank forming step of forming a bank pattern by discharging a bank coating liquid containing a bank pattern material into a predetermined region on the organic layer as a droplet by a droplet discharge nozzle and drying it. Manufacturing method of organic electroluminescence panel.
2. The method of manufacturing an organic electroluminescence panel according to claim 1, wherein the bank pattern material has a solid content having liquid repellency.
3. The method of manufacturing an organic electroluminescence panel according to claim 2, wherein the solid content concentration of the bank coating liquid is 25 wt% or more and 100 wt% or less.
The method for producing an organic electroluminescence panel according to claim 1, wherein the drying is vacuum drying.
A light-emitting layer forming step of forming a light-emitting layer by discharging a light-emitting layer coating liquid containing a light-emitting layer material as droplets by a droplet discharge nozzle onto the organic layer partitioned by the bank of the bank pattern; Furthermore, the manufacturing method of the organic electroluminescent panel of Claim 4 characterized by the above-mentioned.
Before the bank forming step, an affinity processing step is provided for applying a process for increasing the affinity with the bank coating solution over the organic layer other than the predetermined area with respect to the predetermined area on the organic layer. The manufacturing method of the organic electroluminescent panel of any one of Claim 1 thru | or 5.
The method of manufacturing an organic electroluminescence panel according to claim 6, wherein the affinity treatment step includes plasma surface treatment.
The method of manufacturing an organic electroluminescence panel according to claim 6, wherein the affinity treatment step includes a UV light irradiation treatment.
In the bank formation step, the bank coating liquid droplets are sequentially applied while being displaced from the same position while overlapping in the bank pattern formation region on the organic layer. 9. The method of manufacturing an organic electroluminescence panel according to claim 1, wherein a boundary line of the bank coating solution is suppressed from being bent at a joint.
10. The organic electrophoretic device according to claim 9, wherein in the bank forming step, the bank coating liquid is applied such that the solid content in the droplets of the bank coating liquid is lowered as the concentration is later applied. Manufacturing method of luminescence panel.
11. The organic layer forming step according to claim 1, wherein the organic layer is formed as a two-layer structure of a hole injection layer and a hole transport layer that are sequentially formed. Manufacturing method of organic electroluminescence panel.