JP7250633B2 - Method for manufacturing organic EL device - Google Patents

Description

The present invention relates to a method for manufacturing an organic EL device.

An organic EL (electroluminescence) device is a device including a light-emitting element utilizing electroluminescence of an organic compound.
Japanese Patent Application Laid-Open No. 2009-164113 (Patent Document 1) discloses that a coating film containing a solvent is subjected to a first heating step, a first cooling step and a second heating step to form a hole injection layer and / Or forming a hole transport layer is described.

JP 2009-164113 A

When the organic layer of an organic EL device is formed by a coating method (a method including forming a coating film by applying a coating liquid and drying the coating film) as described in Patent Document 1, the organic layer formed has a There was a problem that annual ring-shaped unevenness as shown in 5 occurred. This annual-ring-like unevenness is accompanied by thickness unevenness of the organic layer.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing an organic EL device that can form an organic layer by a coating method while suppressing annual-ring-like unevenness.

The present invention provides a method for manufacturing an organic EL device as described below.
[1] A method for manufacturing an organic EL device having a light emitting region, comprising:
The organic EL device comprises a substrate and a bank provided on the substrate and having a thickness and a width for defining the light emitting region,
At least the upper surface of the bank has liquid repellency,
The light emitting region has an area of 1 mm ² or more,
The manufacturing method is
a coating step of coating a coating liquid containing an organic solvent on the light emitting region to form a first coating film;
a drying step of heating the first coating film to form a first organic layer;
including
In the coating step of forming the first coating film, the first organic layer has a portion (A1) arranged in the light emitting region and a length L _B1 in the width direction of the bank, and is above the bank. and a portion (B1) located in
The drying step includes a temperature raising step for heating the first coating film to reach the drying atmosphere temperature in its initial stage,
The method for manufacturing an organic EL device, wherein in the temperature raising step, the heating temperature reaches 80% of the drying atmosphere temperature at an average temperature raising rate of 1° C./second or more.
[2] The method for manufacturing an organic EL device according to [1], wherein the applying step is performed so that all the edges of the first organic layer are located on the bank.
[3] The method for manufacturing an organic EL device according to [1] or [2], further including the step of forming a second organic layer before the coating step.
[4] In the step of forming a second organic layer, the second organic layer has a portion (A2) arranged in the light emitting region and a length L _B2 in the width direction of the bank, and the bank The method for manufacturing an organic EL device according to [3], which is carried out so as to have a portion (B2) arranged thereon.
[5] The method for manufacturing an organic EL device according to [4], wherein the L _B1 is the same as or larger than the L _B2 .
[6] The method for manufacturing an organic EL device according to any one of [1] to [5], wherein the first organic layer is a light-emitting layer.

It is possible to provide a method for manufacturing an organic EL device that can form an organic layer by a coating method while suppressing annual-ring-like unevenness.

1 is a schematic plan view showing an example of a banked substrate that can be used in the method of manufacturing an organic EL device according to the present invention; FIG. FIG. 2 is a schematic cross-sectional view partially enlarging a periphery of a bank in an example of an organic EL device obtained by the manufacturing method according to the present invention; FIG. 4 is a schematic cross-sectional view showing a partially enlarged bank periphery in another example of the organic EL device obtained by the manufacturing method according to the present invention; FIG. 10 is a diagram showing temperature profiles of a substrate in a temperature rising process in Example 1 and Comparative Example 1; 4 is a diagram showing the state of annual-ring-shaped unevenness in the light-emitting region, which was confirmed when the first organic layer 1 obtained in Comparative Example 1 was irradiated with ultraviolet rays to cause the first organic layer 1 to emit light. FIG. .

Hereinafter, the present invention will be described while showing embodiments. The same reference numerals are given to the same elements. Redundant explanations are omitted. The dimensional proportions in the drawings may not necessarily match those in the description.

An organic EL device according to the present invention (hereinafter also simply referred to as an "organic EL device") includes a substrate, a bank arranged on the substrate, and a first organic layer. The bank defines the light emitting region of the organic EL device and is arranged on the substrate so as to surround the light emitting region. The light-emitting region of the organic EL device means the area surrounded by the banks, among the two-dimensional areas that emit light when voltage is applied.
The organic EL device may have only one light-emitting region, or may have two or more light-emitting regions.
For example, two or more light emitting regions may be arranged in a two-dimensional array (or matrix) on the substrate. The spacing between the light-emitting regions in each column, the spacing between the light-emitting regions in each row, the arrangement example of the light-emitting regions, the number of light-emitting regions, and the like are appropriately set according to the specifications of the organic EL device.
The organic EL device may be a top emission type device or a bottom emission type device.

A light-emitting region of the organic EL device is provided with a light-emitting portion, which is a structural portion for causing light emission. The light emitting section includes at least a first electrode (eg, anode), a first organic layer, and a second electrode (eg, cathode) in order from the substrate side. One or more organic layers other than the first organic layer may be provided between the first electrode and the second electrode. The first organic layer and other organic layers are layers that contribute to light emission of the organic EL device.

A method for manufacturing an organic EL device according to the present invention (hereinafter also simply referred to as "method for manufacturing an organic EL device") includes a step of forming a first organic layer (first organic layer forming step), The layer forming step includes the following steps.
a coating step (first coating step) of coating a first organic layer-forming coating liquid containing an organic solvent on the light-emitting region to form a first coating film;
A drying step of heating the first coating film to form a first organic layer (first drying step).

The method for manufacturing an organic EL device comprises a step of forming a second organic layer, which is one of the other organic layers (second organic layer formation step) may be further included. Preferably, the method for manufacturing an organic EL device further includes a second organic layer forming step.
When the method for manufacturing an organic EL device further includes a second organic layer forming step, the light-emitting portion of the obtained organic EL device includes, in order from the substrate side, a first electrode, a second organic layer, a first organic layer, and a second electrode.

The light emitting portion can include three or more organic layers. In this case, the method for manufacturing the organic EL device includes a step of forming the third organic layer (third organic layer forming step), or in addition to this, a further organic layer forming step.

The structure of the organic EL device and the method of manufacturing the organic EL device will be described in more detail.

<Structure of organic EL device>
(1) Substrate FIG. 1 is a schematic plan view showing an example of a banked substrate that can be used in a method for manufacturing an organic EL device. The banked substrate 10 shown in FIG. 1 has a substrate 11 , a first electrode 12 (eg, an anode), and a bank 13 .
The substrate 11 is a support that supports the first electrodes 12 and the banks 13, and is, for example, a plate-like transparent member that transmits visible light (light with a wavelength of 400 nm to 800 nm).
The thickness of the substrate 11 is, for example, 30 μm or more and 1100 μm or less. The substrate 11 may be, for example, a rigid substrate such as a glass substrate or a silicon substrate, or a flexible substrate such as a plastic substrate or a polymer film. By using a flexible substrate, the organic EL device can have flexibility.

A circuit for driving the light emitting unit may be formed in advance on the substrate 11 . For example, a TFT (Thin Film Transistor), a capacitor, or the like may be formed in advance on the substrate 11 .

(2) First Electrode The first electrode 12 is, for example, an anode. However, the first electrode 12 may be the cathode and the second electrode may be the anode.
The shape of the first electrode 12 in a plan view (the shape viewed from the thickness direction of the substrate 11) may be, for example, a rectangle, a square such as a square, other polygons, and a rectangle or other polygon with rounded corners. and the like. The planar shape of the first electrode 12 may be circular or elliptical. The planar shape of the first electrode 12 may be a quadrangle or other polygon with at least one side arcuate (for example, arcuate).
In this specification, "planar view" means viewing from the thickness direction of a layer or the like.

The first electrode 12 can use a thin film made of metal oxide, metal sulfide, metal, or the like. Specifically, indium oxide, zinc oxide, tin oxide, indium tin oxide (abbreviated as ITO ), Indium Zinc Oxide (abbreviated as IZO), gold, platinum, silver, copper, or the like.
When the organic EL device emits light from the substrate 11 side, the first electrode 12 exhibiting optical transparency is used.

The thickness of the first electrode 12 can be appropriately determined in consideration of light transmittance, electrical conductivity, and the like. The thickness of the first electrode 12 is, for example, 10 nm or more and 10 μm or less, preferably 20 nm or more and 1 μm or less, and more preferably 50 nm or more and 500 nm or less.

In one embodiment, a layer composed of an insulating layer or the like may be provided between the first electrode 12 and the substrate 11 . A layer composed of an insulating layer or the like can also be regarded as part of the substrate 11 .

(3) Bank The bank 13 is a partition wall having a thickness and width for defining the light emitting region 14 of the organic EL device. be. The bank 13 is arranged on the substrate 11 , more specifically on the first electrode 12 formed on the substrate 11 . At this time, from the viewpoint of preventing a short circuit between the first electrode 12 and the second electrode, as shown in FIG. preferably.

Defining the light-emitting region 14 by providing the bank 13 on the substrate 11 and forming the organic layer constituting the light-emitting portion thereon is advantageous for suppressing annual-ring-like unevenness that may occur in the organic layer. was clarified by the study of the present inventor.
When an organic layer is formed by a coating method in a light-emitting region not defined by the bank 13, it is difficult to suppress annual-ring-like unevenness even if the conditions of the drying process are appropriately controlled according to the present invention. be.

The banks 13 are provided on the substrate 11 in a pattern having openings in order to define light emitting regions 14 preset on the surface of the substrate 11 .
In the example shown in FIG. 1, the planar shape of the bank 13 has a rectangular frame shape, but it is not limited to this, and the opening shape and the outer shape of the bank 13 (both are planar view shapes). is appropriately selected according to the desired shape of the light emitting region 14 and the shape of the substrate 11 (both are planar view shapes).
The shape of the opening of the bank 13 (that is, the shape of the light emitting region 14) is usually 1 mm ² or more, preferably 5 mm ² or more, and usually 1 m ² or less.

In one embodiment, the shape of the opening of the bank 13 (that is, the shape of the light emitting region 14) is rectangular such as a square or rectangle, as shown in FIG.
When the opening of the bank 13 has a square shape, the length of at least one side is usually 1 mm or longer, and two or more sides or all sides may have a length of 1 mm or longer. The length of the side may be 5 mm or longer, 10 mm or longer, or 20 mm or longer. When the bank 13 has a rectangular opening, the length of one side is usually 1000 mm or less.
In a surface-emitting organic EL device, the larger the area of the light-emitting region 14, the ^more likely it is that annual ring-shaped unevenness is visually recognized. It is particularly advantageous if the area of region 14 is large.

The bank 13 can be composed of, for example, one or more resin compositions.
When the organic layer such as the first organic layer that constitutes the light-emitting portion is formed by a coating method, the bank 13 is formed so that the light-emitting region 14 can be suitably defined (divided) by the bank from the viewpoint of suppressing annual ring-shaped unevenness. and from the viewpoint of preventing the organic layer from wetting and spreading outside the bank 13, at least its upper surface (the surface opposite to the substrate 11) has liquid repellency. and its side surface has liquid repellency.
The fact that at least the top surface of the bank 13 has liquid repellency suppresses uneven contraction of the coating film in the drying process of heating the coating film formed in contact with at least the top surface of the bank 13 to form an organic layer. It is also advantageous for

The term "liquid repellency" as used herein means repellency to a coating liquid for forming an organic layer used in a coating method. The organic layer in the “liquid repellency with respect to the coating liquid for forming the organic layer” is usually the first organic layer formed on the first electrode 12 (the organic layer closest to the first electrode 12). The organic layer initially formed on the first electrode 12 may be the first organic layer, the second organic layer, or the like.

As the bank 13 having at least the liquid repellent upper surface, a layer made of a thermoplastic resin composition containing a liquid repellent agent, a layer made of a cured photosensitive resin composition containing a liquid repellent agent, or a thermosetting resin composition containing a liquid repellent agent. At least the upper surface of a bank that is a layer made of a cured product of a curable resin composition, a layer made of a thermoplastic resin, a layer made of a cured product of a photosensitive resin composition, a layer made of a cured product of a thermosetting resin composition, etc. A bank or the like obtained by applying a liquid-repellent treatment to the substrate is exemplified.
Examples of the liquid-repellent treatment include a treatment of applying a liquid-repellent agent containing a fluorine resin or the like, and a treatment of irradiating the coated surface with an active energy ray such as ultraviolet rays after applying the liquid-repellent agent.
The liquid repellency of at least the upper surface of the bank 13 may be controlled by UV ozone treatment.
On at least the upper surface of a layer made of a thermoplastic resin composition containing a liquid repellent agent, a layer made of a cured photosensitive resin composition containing a liquid repellent agent, or a layer made of a cured thermosetting resin composition containing a liquid repellent agent The liquid-repellent treatment may be further applied.

In order to suppress annual-ring-shaped unevenness occurring in the first organic layer, the first organic layer 1 has a portion (A1) disposed within the light emitting region 14 and a portion disposed on the bank 13, as will be described later. (B1). In this case, the first coating film forming the first organic layer is formed in contact with at least the upper surface of the bank 13 in order to suppress annual-ring-like unevenness that occurs in the first organic layer, forming the first coating film. The contact angle of at least the upper surface of the bank 13 with respect to the coating liquid for coating is preferably 30 degrees or more and 35 degrees or less. For the same reason, when the first coating film is formed in contact with the side surface of the bank 13, the contact angle of the side surface of the bank 13 with respect to the coating liquid for forming the first coating film is preferably 30 degrees or more and 35 degrees. degree or less. As will be described later, the first organic layer is preferably a light-emitting layer or the like.
The contact angle is measured according to the method described in [Examples] below.

The bank 13 may have a single-layer structure, or may have a multi-layer structure in which two or more layers are laminated in the thickness direction. The bank 13 is preferably a single layer structure because it is easier to fabricate the bank 13 .

The cross-sectional shape of the bank 13 is not particularly limited. For example, the side surface of the bank 13 facing the light emitting region 14 may be perpendicular to the surface of the substrate 11 or may be inclined at an acute angle. (forward taper type).

The thickness (height) of the bank 13 is, for example, about 0.3 μm or more and 10 μm or less, preferably 0.5 μm or more and 5 μm or less.
The width of the bank 13 (W shown in FIG. 1) is, for example, about 0.5 mm or more and 20 mm or less, preferably 1 mm or more and 10 mm or less.
When the outer shape (planar view) of the bank 13 is rectangular, the length of one side thereof is, for example, about 0.5 mm or more and 1000 mm or less, preferably about 1 mm or more and 1000 mm or less.

The banked substrate 10 can be manufactured, for example, by forming the bank 13 after forming the first electrode 12 on the light-emitting region 14 preset on the substrate 11 .

The bank 13 can be formed using, for example, a coating method. Specifically, the coating film obtained by applying the coating liquid containing the material of the bank 13 to the substrate 11 on which the first electrodes 12 are formed is dried, and after performing a curing treatment as necessary, the coating film is dried. can be formed by patterning into a predetermined shape. Examples of coating methods include a spin coating method and a slit coating method. The solvent of the coating liquid containing the material of the bank 13 may be any solvent that can dissolve the material of the bank 13 .

Further, the bank 13 is formed by forming a patterned coating film by, for example, an inkjet coating method, a screen printing method, a gravure printing method, a flexographic printing method, a dispenser coating method, a nozzle coating method, or the like, and a hardening treatment is performed as necessary. It can also be formed by a drawing method.

(4) Organic layer As described above, a light-emitting portion is provided in the light-emitting region of the organic EL device. A layer or two or more organic layers and a second electrode (eg, cathode). An organic layer other than the first organic layer is usually provided in the light emitting section.

The first organic layer may be the first organic layer formed on the first electrode 12 (the organic layer closest to the first electrode 12), or may be formed on the first electrode 12 via another organic layer. It may be a laminated organic layer. The first organic layer can be, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, or the like, but is preferably a light emitting layer.
When the first organic layer is a hole injection layer, a hole transport layer, an electron transport layer, or an electron injection layer, the light emitting section further has at least a light emitting layer as an organic layer other than the first organic layer.
When the first organic layer is a light-emitting layer, the light-emitting part may have only the first organic layer as the organic layer, but preferably further includes one or more other organic layers.

The hole injection layer is an organic layer that has the function of improving the efficiency of hole injection from the anode (eg, first electrode 12) to the light emitting layer.
A known hole injection material can be used for the material of the hole injection layer. Examples of hole injection materials include oxides such as vanadium oxide, molybdenum oxide, ruthenium oxide and aluminum oxide; phenylamine compounds; starburst type amine compounds; phthalocyanine compounds; and polythiophene derivatives such as

The optimum thickness of the hole injection layer varies depending on the material used, and is appropriately determined in consideration of the required properties, ease of layer formation, and the like. The thickness of the hole injection layer is, for example, 1 nm or more and 1 μm or less, preferably 2 nm or more and 500 nm or less, and more preferably 5 nm or more and 200 nm or less.

A hole-transporting layer is a layer having a function of improving hole injection from an anode, a hole-injecting layer, or the like to a light-emitting layer.
A known hole-transporting material can be used as the material for the hole-transporting layer. Materials for the hole transport layer include, for example, polyvinylcarbazole or derivatives thereof, polysilane or derivatives thereof, polysiloxane having aromatic amines in side chains or main chains or derivatives thereof, pyrazolines or derivatives thereof, arylamines or derivatives thereof, stilbene or derivatives thereof, triphenyldiamine or derivatives thereof, polyaniline or derivatives thereof, polythiophene or derivatives thereof, polyarylamines or derivatives thereof, polypyrrole or derivatives thereof, poly(p-phenylene vinylene) or derivatives thereof, and poly(2, 5-thienylene vinylene) or derivatives thereof. Further, a hole transport material disclosed in JP-A-2012-144722 can also be mentioned.

The optimum thickness of the hole transport layer varies depending on the material used, and is appropriately set so that the drive voltage and luminous efficiency are moderate. The thickness of the hole transport layer is, for example, 1 nm or more and 1 μm or less, preferably 2 nm or more and 500 nm or less, and more preferably 5 nm or more and 200 nm or less.

A light-emitting layer is an organic layer having a function of emitting light of a predetermined wavelength.
The light-emitting layer is usually formed of an organic material that mainly emits fluorescence and/or phosphorescence, or the organic material and a dopant that assists this. A dopant is added, for example, to improve the luminous efficiency or change the luminous wavelength.
The organic substance contained in the light-emitting layer may be a low-molecular-weight compound or a high-molecular-weight compound. Examples of the light-emitting material constituting the light-emitting layer include the following dye-based materials, metal complex-based materials, polymer-based materials, and dopant materials.

Examples of dye-based luminescent materials include cyclopentamine or its derivatives, tetraphenylbutadiene or its derivatives, triphenylamine or its derivatives, oxadiazole or its derivatives, pyrazoloquinoline or its derivatives, distyrylbenzene or its derivatives. derivatives, distyrylarylene or its derivatives, pyrrole or its derivatives, thiophene ring compounds, pyridine ring compounds, perinone or its derivatives, perylene or its derivatives, oligothiophene or its derivatives, oxadiazole dimer or its derivatives, pyrazoline dimer or derivatives thereof, quinacridone or derivatives thereof, coumarin or derivatives thereof, and the like;

Examples of metal complex-based light-emitting materials include rare earth metals such as Tb, Eu, and Dy, or Al, Zn, Be, Pt, and Ir. Examples thereof include metal complexes having imidazole, quinoline structures, etc. as ligands. Examples of metal complexes include metal complexes that emit light from a triplet excited state such as iridium complexes and platinum complexes, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, benzoxazolylzinc complexes, benzothiazolezinc complexes, and azomethylzinc complexes. , porphyrin-zinc complex, phenanthroline-europium complex, and the like.

Polymer-based luminescent materials include, for example, polyparaphenylenevinylene or its derivatives, polythiophene or its derivatives, polyparaphenylene or its derivatives, polysilane or its derivatives, polyacetylene or its derivatives, polyfluorene or its derivatives, polyvinylcarbazole or In addition to derivatives thereof, materials obtained by polymerizing the dye materials and metal complex materials described above may be used.

Among the above light-emitting materials, materials that emit red light (hereinafter also referred to as "red light-emitting materials") include, for example, coumarin or derivatives thereof, thiophene ring compounds, polymers thereof, polyparaphenylene vinylene or derivatives thereof. , polythiophene or its derivatives, polyfluorene or its derivatives, and the like. Materials disclosed in Japanese Patent Application Laid-Open No. 2011-105701 can also be used as red light-emitting materials.

Materials that emit green light (hereinafter also referred to as "green light-emitting materials") include, for example, quinacridone or derivatives thereof, coumarin or derivatives thereof, polymers thereof, polyparaphenylene vinylene or derivatives thereof, polyfluorene or derivatives thereof, derivatives and the like. Materials disclosed in Japanese Patent Laid-Open No. 2012-036388 can also be used as green light-emitting materials.

Materials that emit blue light (hereinafter also referred to as “blue light emitting materials”) include, for example, distyrylarylene or derivatives thereof, oxadiazole or derivatives thereof, polymers thereof, polyvinylcarbazole or derivatives thereof, polyparallel Phenylene or derivatives thereof, polyfluorene or derivatives thereof, and the like are included. Materials disclosed in Japanese Unexamined Patent Application Publication No. 2012-144722 are also examples of blue light-emitting materials.

Dopant materials include, for example, perylene or its derivatives, coumarin or its derivatives, rubrene or its derivatives, quinacridone or its derivatives, squalium or its derivatives, porphyrin or its derivatives, styryl dyes, tetracene or its derivatives, pyrazolone or its derivatives, decacyclene or derivatives thereof, phenoxazone or derivatives thereof, and the like.

The optimum thickness of the light-emitting layer varies depending on the material used, and is appropriately determined in consideration of the required properties, ease of layer formation, and the like. The thickness of the light-emitting layer is, for example, 1 nm or more and 1 μm or less, preferably 2 nm or more and 500 nm or less, and more preferably 5 nm or more and 200 nm or less.

The electron transport layer is a layer having a function of improving electron injection from the cathode, electron injection layer, or the like. A known electron transport material can be used for the electron transport layer.
Although the thickness of the electron transport layer varies depending on the material used, it is, for example, 1 nm or more and 1 μm or less, preferably 2 nm or more and 500 nm or less, and more preferably 5 nm or more and 200 nm or less.

The electron injection layer is a layer having a function of improving electron injection efficiency from the cathode to the light emitting layer.
A known electron injection material can be used for the electron injection layer.
The thickness of the electron injection layer is, for example, 1 nm or more and 50 nm or less, although it varies depending on the material used.

(5) Second electrode The second electrode is, for example, a cathode.
A cathode is provided on one or more organic layers included in the light-emitting portion.
As a material for the cathode, a material having a small work function, easy injection of electrons into the light-emitting layer, and high electrical conductivity is preferable. When the organic EL device emits light from the anode side, a material having a high visible light reflectance is preferable as the cathode material so that the cathode reflects the light emitted from the light-emitting layer toward the anode side.
Specifically, alkali metals, alkaline earth metals, transition metals, group 13 metals of the periodic table, or the like can be used for the cathode, for example. Also, as the cathode, a transparent conductive cathode made of a conductive metal oxide, a conductive organic substance, or the like can be used.

The thickness of the cathode is appropriately set in consideration of electrical conductivity and durability. The thickness of the cathode is, for example, 10 nm or more and 10 μm or less, preferably 20 nm or more and 1 μm or less, and more preferably 50 nm or more and 500 nm or less.

When the organic EL device has two or more light-emitting regions 14 (thus, two or more light-emitting portions), a cathode may be provided for each light-emitting region, or a common cathode for all light-emitting regions 14 across the banks 13 may be provided. may be provided.

A sealing substrate is usually provided on the second electrode of the organic EL device. In addition, the organic EL device may include other known elements included in, for example, an organic EL lighting device or an organic EL display.

<Method for manufacturing organic EL device>
A method for manufacturing an organic EL device according to an embodiment of the present invention includes the following steps in the order below.
a step of forming a bank 13 having a thickness and a width on the substrate 11 for defining the light emitting region 14 (bank forming step);
a step of forming a first organic layer (first organic layer forming step);

In the method for manufacturing an organic EL device according to one embodiment of the present invention, the first organic layer forming step includes the following steps.
a coating step (first coating step) of coating a first organic layer forming coating liquid containing an organic solvent on the light emitting region 14 to form a first coating film;
A drying step of heating the first coating film to form a first organic layer (first drying step).

In one embodiment, the method for manufacturing an organic EL device includes a step of forming a second organic layer, which is one of the other organic layers, before the first coating step, i.e., before the first organic layer forming step. (Second organic layer forming step) may be further included.
In one embodiment, the method for manufacturing an organic EL device may include a step of forming a third organic layer (third organic layer forming step), or in addition to this, a further organic layer forming step.

(1) Bank Forming Step The bank forming step is usually a step of fabricating a banked substrate 10 as shown in FIG. 1, for example. The substrate 11, the first electrodes 12 and the banks 13 that constitute the substrate 10 with banks, and the method of manufacturing the substrate 10 with banks are described above.

As described above, from the viewpoint of suppressing annual-ring-like unevenness, from the viewpoint of suitably defining (dividing) the light-emitting region 14 by the bank 13, and from the viewpoint of preventing the organic layer from wetting and spreading outside the bank 13. Therefore, at least the upper surface of the bank 13 (the surface opposite to the substrate 11) has liquid repellency, and preferably the upper surface and side surfaces have liquid repellency. For this reason, the bank formation process may include a liquid repellency control process for controlling the liquid repellency of the upper surface of the bank 13 . The liquid repellency control process is a process for adjusting the liquid repellency of at least the upper surface of the bank 13 .
The fact that at least the top surface of the bank 13 has liquid repellency suppresses uneven contraction of the coating film in the drying process of heating the coating film formed in contact with at least the top surface of the bank 13 to form an organic layer. It is also advantageous for

Methods for adjusting (controlling) the liquid repellency of at least the upper surface of the bank 13 include a layer made of a thermoplastic resin composition containing a liquid repellent agent, a layer made of a cured photosensitive resin composition containing a liquid repellent agent, or a layer made of a cured photosensitive resin composition containing a liquid repellent agent. A method of forming the bank 13 as a layer made of a cured product of a thermosetting resin composition containing a liquid agent, a layer made of a thermoplastic resin, a layer made of a cured product of a photosensitive resin composition, or a layer made of a cured product of a thermosetting resin composition. For example, after forming the bank 13 as a layer made of a cured product, at least the upper surface of the bank 13 is subjected to a liquid-repellent treatment.
Examples of the liquid-repellent treatment include a treatment of applying a liquid-repellent agent containing fluorine resin or the like, and a treatment of irradiating the coated surface with active energy rays such as ultraviolet rays after applying the liquid-repellent agent.
The liquid repellency of at least the upper surface of the bank 13 may be controlled by UV ozone treatment.
On at least the upper surface of a layer made of a thermoplastic resin composition containing a liquid repellent agent, a layer made of a cured photosensitive resin composition containing a liquid repellent agent, or a layer made of a cured thermosetting resin composition containing a liquid repellent agent The liquid-repellent treatment may be further applied.

The contact angles of the top surface and the side surface of the bank 13 with respect to the coating liquid for forming the first coating film are as described above.

(2) Step of Forming First Organic Layer A first organic layer forming coating liquid containing an organic solvent is applied onto the light emitting regions 14 (openings of the banks 13) of the substrate 10 with banks to form a first coating film. (first coating step), and then heating and drying the first coating film (first drying step), the first organic layer can be formed.
The coating liquid for forming the first organic layer includes, for example, a coating liquid containing a hole injection material, a coating liquid containing a hole transporting material, a coating liquid containing a light emitting material, a coating liquid containing an electron transporting material, and an electron injection material. It is a coating liquid containing a functional material such as a coating liquid containing a luminescent material, preferably a coating liquid containing a luminescent material.

The organic solvent contained in the coating liquid can dissolve the functional material contained in the coating liquid. Examples include chloride solvents such as chloroform, methylene chloride and dichloroethane; ether solvents such as tetrahydrofuran and butyl cellosolve; Aromatic hydrocarbon solvents such as benzene; Ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone; Ester solvents such as ethyl acetate, butyl acetate, ethyl cellosolve acetate and butyl lactate; Alcohols such as methanol, ethanol, propanol and 2-ethylhexanol. A solvent etc. are mentioned.
Only 1 type may be used for an organic solvent and it may use 2 or more types together.

Among them, the organic solvent preferably has a boiling point of 160° C. or higher and 240° C. or lower at atmospheric pressure from the viewpoint of the coating properties of the coating liquid, particularly in the inkjet coating method.
When two or more organic solvents are used in combination, at least one organic solvent preferably has a boiling point within the above range, and more preferably all organic solvents have a boiling point within the above range.

Examples of the method of applying the coating liquid for forming the first organic layer in the first coating step include an inkjet printing method. However, other known coating methods, such as micro gravure coating, gravure coating, bar coating, roll coating, wire bar coating, and spraying, may be used as long as the coating method is capable of forming a layer in the openings of the banks 13. A coating method, screen printing method, flexographic printing method, offset printing method, or nozzle printing method may be used.

In the first coating step, from the viewpoint of suppressing annual ring-shaped unevenness, the first organic layer obtained through the first drying step is arranged on the portion (A1) arranged in the light emitting region 14 and on the bank 13. (B1).

FIG. 2 is a schematic cross-sectional view showing a partially enlarged bank periphery in an example of the organic EL device obtained by the manufacturing method according to the present invention.
In the example shown in FIG. 2, the first organic layer 1 has a portion (A1) located within the light emitting region 14 and a portion (B1) located above the bank 13. In the example shown in FIG. The length of the portion where the first organic layer 1 extends over the light emitting region 14 and onto the bank 13, that is, the portion (B1) is the length in the direction of the width W of the bank 13, which is the length L _B1 . Yes, and L _B1 is greater than zero and preferably less than the width W of bank 13 .

Forming the first organic layer 1 so as to have the portion (B1), that is, so that the end portion is located on the bank 13, is advantageous in suppressing annual-ring-like unevenness that occurs in the first organic layer. It is also advantageous for reducing unevenness in light emission luminance within the light emitting region 14 .

From the viewpoint of suppressing annual-ring-like unevenness and/or reducing unevenness in emission luminance, the length L _B1 is preferably 2.5 mm or more, more preferably 3 mm or more.
The length L _B1 is measured using a precision length measuring machine for the formed first organic layer.

From the viewpoint of more effectively suppressing annual ring-shaped unevenness and/or from the viewpoint of reducing unevenness in light emission luminance over as wide a region as possible in the light emitting region 14, the first coating step is the first coating obtained through the first drying step. It is preferable that as many edges of the organic layer 1 as possible are located on the banks 13 , more preferably all edges of the first organic layer 1 are located on the banks 13 . preferable.

From the viewpoint of suppressing annual-ring-shaped unevenness and/or reducing unevenness in emission luminance, the first coating film is formed so that the portion corresponding to the portion (B) of the first organic layer 1 is in contact with at least the upper surface of the bank 13. preferably. For the same reason, even when another organic layer such as a second organic layer is formed between the first organic layer 1 and the first electrode 12, the first coating film is the first organic layer 1 portion. It is preferable that the portion corresponding to (B) is formed so as to be in contact with at least the top surface of the bank 13 .

The first drying step is a step of forming the first organic layer 1 by heating the first coating film formed in the first coating step and performing a drying treatment to remove the organic solvent in the first coating film. be.
The first drying step includes a temperature raising step for causing the heating temperature of the first coating film to reach the drying atmosphere temperature in its initial stage.

The "heating temperature of the first coating film" refers to the temperature of the first coating film being subjected to the first drying step. The temperature of the substrate 11) of the banked substrate 10 having one coating film is regarded as the temperature of the first coating film subjected to the first drying step. The temperature of the substrate 11 having the first coating film subjected to the first drying step and the temperature of the first coating film subjected to the first drying step are substantially the same.
The “drying atmosphere temperature” refers to the temperature of the atmosphere in which the substrate 11 having the first coating film (the substrate 11 of the banked substrate 10 having the first coating film) is placed during the first drying process.
The drying atmosphere temperature is typically constant or substantially constant (eg, fluctuations of the order of ±2° C. are possible) throughout the first drying step.

In the heating step, the average heating rate until the heating temperature of the first coating film reaches 80% of the drying atmosphere temperature is 1° C./second or more. A light-emitting region 14 is defined by placing a bank 13 having liquid repellency at least on its upper surface on a substrate 11, and a portion (A1) arranged in the light-emitting region 14 and arranged on the bank 13 are provided. After adopting a method of forming the first organic layer 1 so as to have a portion (B1) where the Ring-shaped unevenness can be effectively suppressed or eliminated.
From the viewpoint of effectively suppressing annual ring-shaped unevenness, the average temperature increase rate may be 2° C./second or more, 5° C./second or more, or 10° C./second or more. good too.

The average heating rate is usually 150° C./second or less, preferably 100° C./second or less, more preferably 50° C./second or less, still more preferably 30° C./second or less.
If the average rate of temperature increase exceeds 150° C./sec, the surface of the first organic layer 1 may become rough, resulting in unevenness in the thickness of the first organic layer 1 .

The temperature of the first coating film (the temperature of the substrate 11) at the start of the heating step (first drying step) is usually 15°C or higher and 50°C or lower, preferably 15°C or higher and 40°C or lower.
The temperature of the drying atmosphere in the first drying step depends on the type and boiling point of the organic solvent contained in the coating liquid for forming the first organic layer, but is usually 40° C. or higher and 200° C. or lower, preferably 50° C. or higher and 180° C. or higher. ° C. or less, more preferably 60° C. or higher and 150° C. or lower.

The first drying step and the temperature raising step included therein may be a step of heating the substrate 11 having the first coating film (the substrate 11 of the banked substrate 10 having the first coating film) under atmospheric pressure. , heating under reduced pressure.
Examples of the heating method include a method of putting into a hot air drying oven, a method of heating with a hot plate, heating with an infrared heater, heating with microwave irradiation, and a combination of two or more of these.
The time for the first drying step (the time from the start to the end of heating) is usually 0.5 minutes or more and 60 minutes or less, preferably 1 minute or more and 30 minutes or less.

(3) Second organic layer forming step In one embodiment, the method for manufacturing an organic EL device includes a step of forming a second organic layer ( Second organic layer forming step) may be further included. In this case, a second coating film is formed by coating a coating liquid containing an organic solvent for forming a second organic layer on the light-emitting regions 14 (openings of the banks 13) of the substrate 10 with banks (second coating step ), and then the second coating film is heated and dried (second drying step) to form the second organic layer. After forming the second organic layer, the first organic layer 1 is formed as described above.

The coating liquid for forming the second organic layer includes, for example, a coating liquid containing a hole injection material, a coating liquid containing a hole transporting material, a coating liquid containing a light emitting material, a coating liquid containing an electron transporting material, and an electron injection material. Although it may be a coating liquid containing a functional material such as a coating liquid containing a functional material, it is preferably a coating liquid containing a hole-injecting material or a coating liquid containing a hole-transporting material.
In one embodiment, the second organic layer is a hole-injecting or hole-transporting layer and the first organic layer 1 is a light-emitting layer. The first organic layer 1 and the second organic layer may or may not be in contact.

For details of the conditions of the second coating step, the second drying step, the coating liquid for forming the second organic layer, etc., refer to the first coating step, the first drying step, the coating liquid for forming the first organic layer, etc. is quoted above. In the starting stage of the second drying step, the heating temperature of the second coating film is increased to reach the drying atmosphere temperature. The rate of temperature rise does not necessarily have to be 1°C/sec or more, but from the viewpoint of suppressing annual-ring-like unevenness that may occur in the first organic layer 1 and the second organic layer, the average rate of temperature rise is 1°C. / second or more.

With reference to FIG. 3, which is a schematic cross-sectional view showing a partially enlarged bank periphery in another example of an organic EL device obtained by the manufacturing method according to the present invention, the first organic layer 1 and the second organic layer have From the viewpoint of more effectively suppressing the resulting ring-shaped unevenness and/or from the viewpoint of reducing the unevenness of the light emission luminance in the light emitting region 14, the second coating step is the second organic layer obtained through the second drying step. 2 has a portion (A2) located within the light emitting region 14 and a portion (B2) located above the bank 13 with a length _LB2 in the direction of the width W of the bank 13. preferably. Length _LB2 is greater than zero and preferably less than width W of bank 13 .
The method of measuring the length _LB2 is the same as the method of measuring the length _LB1 .

From the viewpoint of more effectively suppressing annual ring-shaped unevenness that may occur in the first organic layer 1 and the second organic layer 2 and/or from the viewpoint of reducing unevenness in light emission luminance within the light emitting region 14, the first organic layer 1 The length L _B1 of the portion (B1) of the second organic layer 2 is preferably equal to or greater than the length L _B2 of the portion (B2) of the second organic layer 2 .
The difference between the length L _B1 and the length L _B2 is from the viewpoint of more effectively suppressing annual ring-shaped unevenness that may occur in the first organic layer 1 and the second organic layer 2 and/or light emission within the light emitting region 14. From the viewpoint of reducing luminance unevenness, the thickness is preferably 0 mm or more and 1 mm or less.

From the viewpoint of more effectively suppressing annual-ring-shaped unevenness that can occur in the first organic layer 1 and the second organic layer 2 and/or from the viewpoint of reducing unevenness in light emission luminance over as wide a region as possible in the light-emitting region 14, the second The coating step is preferably carried out so that as many edges as possible of the second organic layer 2 obtained through the second drying step are positioned on the banks 13, and all edges of the second organic layer 2 are It is more preferably implemented so as to be located on bank 13 .

(4) Third organic layer forming step In one embodiment, the method for manufacturing an organic EL device includes a step of forming a third organic layer (third organic layer forming step), or a further organic layer forming step in addition to this. may contain.
A coating solution for forming a third organic layer containing an organic solvent is applied onto the light-emitting regions 14 (openings of the banks 13) of the substrate 10 with banks to form a third coating film (third coating step). The third organic layer can be formed by heating and drying the third coating film (third drying step).

The position of the third organic layer is arbitrary. However, in this specification, the second organic layer 2 is arranged below the third organic layer (on the substrate 11 side).
For example, the position of the third organic layer may be between the second organic layer 2 and the first organic layer 1, or on the first organic layer 1 (opposite to the substrate 11).
The coating liquid for forming the third organic layer includes, for example, a coating liquid containing a hole injection material, a coating liquid containing a hole transporting material, a coating liquid containing a light emitting material, a coating liquid containing an electron transporting material, and an electron injection material. Although it may be a coating liquid containing a functional material such as a coating liquid containing a functional material, it is preferably a coating liquid containing a hole-transporting material or a coating liquid containing an electron-transporting material.
In one embodiment, the second organic layer is a hole injection layer, the third organic layer is a hole transport layer and the first organic layer 1 is a light emitting layer.

For details of the conditions of the third coating step, the third drying step, the coating solution for forming the third organic layer, etc., refer to the first coating step, the first drying step, the coating solution for forming the first organic layer, etc. is quoted above. In the starting stage of the third drying step, the heating temperature of the third coating film is increased to reach the drying atmosphere temperature. Although the temperature increase rate does not necessarily have to be 1° C./second or more, the temperature that can occur in the first organic layer 1 (when the third organic layer is arranged below the first organic layer 1) and the third organic layer From the viewpoint of suppressing ring-shaped unevenness, the average temperature increase rate is preferably 1° C./second or more.

From the viewpoint of suppressing annual ring-shaped unevenness that may occur in the first organic layer 1 (when the third organic layer is arranged under the first organic layer 1) and the third organic layer and/or light emission within the light emitting region 14 From the viewpoint of reducing luminance unevenness, in the third coating step, the third organic layer obtained through the third drying step is arranged in a portion (A3) in the light emitting region 14 and in the width W direction of the bank 13. and a portion (B3) located above bank 13 with length _LB3 . Length _LB3 is greater than zero and preferably less than width W of bank 13 .
The method of measuring the length _LB3 is the same as the method of measuring the length _LB1 .

From the viewpoint of reducing unevenness in light emission luminance within the light emitting region 14, the length L _B3 of the portion (B3) of the third organic layer is the same as the length L _B2 of the portion (B2) of the second organic layer 2. or preferably larger. The difference between the length L _B3 and the length L _B2 is preferably 0 mm or more and 1 mm or less from the viewpoint of reducing unevenness in light emission luminance within the light emission region 14 .
From a similar point of view, when the third organic layer is arranged below the first organic layer 1, the length L _B1 of the portion (B1) of the first organic layer 1 is equal to the length of the portion (B3) of the third organic layer 1 It is preferably equal to or greater than the length _LB3 . The difference between the length L _B1 and the length L _B3 is preferably 0 mm or more and 1 mm or less from the viewpoint of reducing unevenness in light emission luminance within the light emission region 14 .
From a similar point of view, when the third organic layer is disposed on the first organic layer 1, the length L _B3 of the portion (B3) of the third organic layer is the length of the portion (B1) of the first organic layer 1. It is preferably about the same as the length L _B1 . The difference between the length L _B3 and the length L _B1 is preferably 0 mm or more and 0.5 mm or less from the viewpoint of reducing unevenness in light emission luminance within the light emission region 14 .

From the viewpoint of suppressing annual ring-shaped unevenness that may occur in the first organic layer 1 (when the third organic layer is arranged under the first organic layer 1) and the third organic layer and/or light emission within the light emitting region 14 From the viewpoint of reducing luminance unevenness, the third coating step is preferably performed so that as many ends of the third organic layer obtained through the third drying step as possible are located on the banks 13. More preferably, all the edges of the three organic layers are located on the bank 13 .

An organic EL device can be obtained by performing a step of forming a second electrode (for example, a cathode) after forming a desired one or more organic layers. As a method for forming the second electrode, for example, the same vapor deposition method and coating method as in the case of the first electrode 12 can be used.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The measurement methods for the following items are as follows.
[a] Contact angle of bank top surface and side surface The contact angle of the top surface and side surface of the bank 13 with respect to the coating liquid for forming the first organic layer was measured using "Auto Dispenser System AD-31S" (manufactured by Kyowa Interface Science Co., Ltd.). , and the temperature was 23°C.

[b] Thickness and length of layer portion An image was acquired and measurements were taken at one point arbitrarily selected from this image. The central film thickness refers to the film thickness at the central point of the portion (A1).
The length L _B1 in the width W direction of the bank 13 of the first organic layer 1 was measured using a precision length measuring machine after drying the first coating film. L _B2 and L _B3 were also measured in the same manner. The values of L _B1 , L _B2 and L _B3 shown in the examples below are averages (average of four points) of measurements at the center position of each side of the organic layer formed in a square shape.

<Example 1>
A substrate 10 with banks having the configuration shown in FIG. 1 was prepared.
The outer shape of the substrate 11 was a square with a side length of about 50 mm. The material of the substrate 11 is glass.
The external shape of the bank 13 was a square with a side length of about 34 mm, the opening shape of the bank 13 was a square with a side length of about 22 mm, and the width W of the bank 13 was about 6 mm. The bank 13 is a layer (single-layer structure) formed by curing a photosensitive resin composition containing a liquid-repellent agent. The contact angle of the top surface and side surface of the bank 13 with respect to the coating liquid for forming the organic layer was reduced to about 30 degrees.
The bank 13 is aligned to be located directly over a portion of the periphery of the first electrode 12 (anode).

A first organic layer 1 (light-emitting layer) was formed in the light-emitting region 14 (opening of the bank 13) of the banked substrate 10 by the following procedure.
A coating liquid for forming a first organic layer containing a light-emitting material was prepared. A white light-emitting material was used as the light-emitting material. A mixed solvent of cyclohexylbenzene and 4-methylanisole was used as the organic solvent contained in the coating liquid. The viscosity of the coating liquid at 25° C. measured using a rotational viscometer was 2 mPa·s.

Using this coating liquid, a first coating film was formed on the light emitting region 14 by an inkjet printing method. Subsequently, a drying process is performed in which the banked substrate 10 having the first coating film is transported and introduced into a drying furnace heated by an infrared heater, and the first coating film is dried to form the first organic layer 1 (light emitting layer). bottom. The transfer speed of the banked substrate 10 having the first coating film was set to 2 m/min, and the drying atmosphere temperature in the drying furnace was set to 100°C. The drying time was 4 minutes.

FIG. 4 shows the temperature profile of the substrate in the heating process at the start stage of the drying process. The average heating rate until the heating temperature of the first coating film reached 80% of the drying atmosphere temperature obtained from this temperature profile was 1.0° C./sec. The temperature of the first coating film was 23° C. at the start of the heating step (first drying step). The temperature on the vertical axis in FIG. 4 is the temperature of the first coating film being subjected to the drying process (the temperature of the substrate 11 of the banked substrate 10 having the first coating film being subjected to the drying process).

All edges of the first organic layer 1 thus obtained were located on the banks 13 . That is, the first organic layer 1 had portions (B1) arranged on the banks 13 for all its ends. The central film thickness of the portion (A1) disposed within the light emitting region 14 of the obtained first organic layer 1 was 75 nm, and the length L _B1 of the portion (B1) was 3 mm. As described above, the value of L _B1 is the average (average of 4 points) of the measured values at the center position of each side of the first organic layer formed in a square shape. The first organic layer had a length substantially equal to the above average at any position of the portion (B1) formed over the entire circumference of the bank 13 .

When the first organic layer 1 was made to emit light by irradiating the first organic layer 1 with ultraviolet rays and the presence or absence of annual-ring-shaped unevenness was visually confirmed, no annual-ring-shaped unevenness was confirmed.

<Comparative Example 1>
In the heating step, the first organic film was heated in the same manner as in Example 1 except that the average heating rate until the heating temperature of the first coating film reached 80% of the drying atmosphere temperature was 0.6 ° C./sec. Layer 1 was formed, and the presence or absence of annual-ring-like unevenness was confirmed. FIG. 5 shows the state of annual-ring-shaped unevenness confirmed in the light-emitting region. As shown in FIG. 5, annual ring-shaped unevenness was clearly recognized.
FIG. 4 shows the temperature profile of the substrate in the heating process at the start stage of the drying process. The temperature of the first coating film was 23° C. at the start of the heating step (first drying step).

<Example 2>
A first organic layer 1 was formed in the same manner as in Example 1 except that a hot plate was used instead of a drying furnace for the drying process, the drying atmosphere temperature was 40 ° C., and the drying time was 20 minutes. , the presence or absence of annual-ring-like unevenness was confirmed (the average heating rate until the heating temperature of the first coating film reached 80% of the drying atmosphere temperature was 1.0° C./sec). Annual ring-shaped unevenness was not confirmed.

<Example 3>
Same as Example 2, except that the drying atmosphere temperature was 80° C. and the average heating rate until the heating temperature of the first coating film reached 80% of the drying atmosphere temperature was 8.7° C./sec. Then, the first organic layer 1 was formed, and the presence or absence of annual-ring-like unevenness was confirmed. Annual ring-shaped unevenness was not confirmed.

<Comparative Example 2>
An organic EL device was produced in the same manner as in Example 2, except that the bank 13 surrounding the light emitting region 14 was not provided, and the presence or absence of annual ring-like unevenness was confirmed. An annual ring-shaped unevenness was clearly recognized.

<Comparative Example 3>
An organic EL device was produced in the same manner as in Example 3 except that the bank 13 surrounding the light emitting region 14 was not provided, and the presence or absence of annual ring-like unevenness was confirmed. An annual ring-shaped unevenness was clearly recognized.

<Example 4>
A substrate 10 with banks identical to that used in Example 1 was prepared.
The second organic layer (hole injection layer), the third organic layer (hole transport layer) and the first organic layer (light emitting layer) were formed in the light emitting region 14 (opening of the bank 13) of the substrate 10 with banks according to the following procedure. layers) were formed in this order.
A coating liquid for forming a second organic layer containing a hole injection material was prepared. Using this coating solution, a second coating film was formed on the light emitting region 14 by an inkjet printing method, and then the second coating film was dried with a hot plate to form a second organic layer. The second organic layer was located on bank 13 with all its edges.
Next, a coating solution for forming a third organic layer containing a hole-transporting material is prepared, and this coating solution is used to form a third coating film on the second organic layer by an inkjet printing method. A third organic layer was formed by drying the coating film with a hot plate. The third organic layer was located on bank 13 with all its edges.
Next, the same coating liquid for forming the first organic layer as that used in Example 1 was prepared, and under the same conditions as in Example 1, a first coating film was formed on the third organic layer, and then a drying step was performed. was carried out to form a first organic layer.

The length L B2 of the second organic layer portion ( _B2 ) and the length L _B3 of the third organic layer portion (B3) were set to 3 mm, which is the same as the length L _B1 of the first organic layer portion (A1). . As described above, the values of L _B1 , L _B2 and L _B3 are measured at the center position of each side of the first organic layer, the second organic layer and the third organic layer formed in a square shape, respectively. (average of 4 points). The first organic layer had a length substantially equal to the above average at any position of the portion (B1) formed over the entire circumference of the bank 13 . Similarly, the second organic layer has a length substantially equal to the above average at any position of the portion (B2) formed over the entire circumference of the bank 13, and the third organic layer has a length At any position of the portion (B3) formed over the entire circumference of 13, it had a length approximately equal to the above average.
The average heating rate until the heating temperature of the first coating film, the second coating film, and the third coating film reaches 80% of the drying atmosphere temperature was set to 1.0° C./sec.

An electron transport layer and a second electrode (cathode) were formed on the first organic layer to obtain an organic EL device.
A current was applied to the organic EL device to cause the light-emitting region to emit light, and the presence or absence of annual-ring-shaped unevenness was visually confirmed. As a result, no annual-ring-shaped unevenness was observed.

1 first organic layer, 2 second organic layer, 10 substrate with bank, 11 substrate, 12 first electrode, 13 bank, 14 light emitting region.

Claims (6)

A method for manufacturing an organic EL device having a light-emitting region, comprising:
The organic EL device comprises a substrate and a bank provided on the substrate and having a thickness and a width for defining the light emitting region,
At least the upper surface of the bank has liquid repellency,
The light emitting region has an area of 1 mm ² or more,
The manufacturing method is
a coating step of coating a coating liquid containing an organic solvent on the light emitting region to form a first coating film;
a drying step of heating the first coating film to form a first organic layer;
including
In the coating step of forming the first coating film, the first organic layer has a portion (A1) arranged in the light emitting region and a length L _B1 in the width direction of the bank, and is above the bank. and a portion (B1) located in
The drying step includes a temperature raising step for heating the first coating film to reach the drying atmosphere temperature in its initial stage,
The method for manufacturing an organic EL device, wherein in the temperature raising step, the heating temperature reaches 80% of the drying atmosphere temperature at an average temperature raising rate of 1° C./second or more. 2. The method of manufacturing an organic EL device according to claim 1, wherein said applying step is performed such that all edges of said first organic layer are located on said bank. 3. The method of manufacturing an organic EL device according to claim 1, further comprising the step of forming a second organic layer before said applying step. In the step of forming a second organic layer, the second organic layer has a portion (A2) arranged in the light emitting region and a length _LB2 in the width direction of the bank and is arranged on the bank. 4. The method of manufacturing an organic EL device according to claim 3, which is carried out so as to have a portion (B2) where the 5. The method of manufacturing an organic EL device according to claim 4, wherein said _LB1 is the same as or larger than said _LB2 . 6. The method for manufacturing an organic EL device according to claim 1, wherein said first organic layer is a light-emitting layer.

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