阅读说明：本技术 有机电子器件的制造方法 (Method for manufacturing organic electronic device ) 是由 吉冈秀益 于 2019-07-22 设计创作，主要内容包括：本发明的一个实施方式的有机电子器件的制造方法具备：有机功能层形成工序,在长条的挠曲性膜(10)上形成的第1电极层上,形成具有单层结构或多层结构的有机功能层；和第2电极层形成工序,在有机功能层上形成第2电极层,有机功能层形成工序具有涂布层形成工序,利用涂布法形成涂布层(181a)；和加热工序,一边利用表面(28a)的材料为红外线吸收材料的辊(28)输送挠曲性膜,一边利用红外线加热涂布层而得到功能层,红外线吸收材料的波长3μm～10μm的范围的红外线的平均吸收率为0.8以上。(A method for manufacturing an organic electronic device according to an embodiment of the present invention includes: an organic functional layer forming step of forming an organic functional layer having a single-layer structure or a multi-layer structure on the 1 st electrode layer formed on the long flexible film (10); and a 2 nd electrode layer forming step of forming a 2 nd electrode layer on the organic functional layer, the organic functional layer forming step having a coating layer forming step of forming a coating layer (181a) by a coating method; and a heating step of heating the coating layer by infrared rays while conveying the flexible film by a roller (28) whose surface (28a) is made of an infrared absorbing material, thereby obtaining a functional layer, wherein the infrared absorbing material has an average infrared absorption rate of 0.8 or more in a wavelength range of 3 to 10 [ mu ] m.)

1. A method for manufacturing an organic electronic device, comprising:

an organic functional layer forming step of forming an organic functional layer having a single-layer structure or a multi-layer structure on the 1 st electrode layer formed on the long flexible film; and

a 2 nd electrode layer forming step of forming a 2 nd electrode layer on the organic functional layer,

the organic functional layer forming step includes:

a coating layer forming step of forming a coating layer by a coating method; and

a heating step of heating the coating layer by infrared rays while conveying the flexible film by a roller whose surface is made of an infrared absorbing material to obtain a functional layer,

the infrared absorbing material has an average absorptivity of infrared rays in a wavelength range of 3 to 10 [ mu ] m of 0.8 or more.

2. The method of manufacturing an organic electronic device according to claim 1,

the roller has:

metal roller body and

a coating layer coated on the surface of the roller body,

the material of the coating layer is the infrared absorption material.

3. The method of manufacturing an organic electronic device according to claim 1 or 2,

in the heating step, the flexible film is heated to 100 ℃ or higher.

4. The method for manufacturing an organic electronic device according to any one of claims 1 to 3,

in the heating step, the wind speed within 10mm from the surface of the flexible film on which the 1 st electrode layer is formed is 0.1m/s or less.

5. The method for manufacturing an organic electronic device according to any one of claims 1 to 4,

the infrared absorbing material is an inorganic oxide.

6. The method of manufacturing an organic electronic device according to claim 5,

the inorganic oxide is alumina.

7. The method for manufacturing an organic electronic device according to any one of claims 1 to 6,

the coating method is an inkjet printing method.

Technical Field

The present invention relates to a method of manufacturing an organic electronic device.

Background

As a conventional technique in this field, there is a method for manufacturing an organic electronic device having a transparent electrode (1 st electrode layer) and at least one organic layer (functional layer) formed by roll-to-roll wet coating on a flexible transparent substrate (flexible film) (see patent document 1).

Documents of the prior art

Patent document

Patent document 1: international publication No. 2010/090087

Disclosure of Invention

Problems to be solved by the invention

As described in patent document 1, when a functional layer included in an organic electronic device is formed by roll-to-roll wet coating, a heating step is first performed in which a coating layer is formed on a flexible film, and then the coating layer is subjected to a heating treatment while the flexible film is conveyed by a conveying roller. The transport rollers are typically metal rollers. Therefore, when the flexible film heated in the heating step comes into contact with the transport roller, the temperature of the flexible film is abruptly lowered at the contact portion. As a result, distortion, wrinkles, and the like are generated in the flexible film. If distortion, wrinkles, or the like occurs in the flexible film, film thickness unevenness occurs in the coating layer before heating and drying, and the functional layer cannot be formed with a desired thickness.

Accordingly, an object of the present invention is to provide a method for manufacturing an organic electronic device in which at least one functional layer included in an organic functional layer can be easily formed with a desired thickness.

Means for solving the problems

A method for manufacturing an organic electronic device according to an aspect of the present invention includes: an organic functional layer forming step of forming an organic functional layer having a single-layer structure or a multi-layer structure on the 1 st electrode layer formed on the long flexible film; and a 2 nd electrode layer forming step of forming a 2 nd electrode layer on the organic functional layer. The organic functional layer forming step includes: a coating layer forming step of forming a coating layer by a coating method; and a heating step of heating the coating layer by infrared rays while conveying the flexible film by a roller whose surface is made of an infrared absorbing material to obtain a functional layer. The infrared absorbing material has an average absorptivity of 0.8 or more for infrared rays having a wavelength in a range of 3 to 10 μm.

In the above production method, the organic functional layer forming step includes a coating layer forming step and a heating step in which the coating layer is heated by infrared rays. Therefore, the coating layer is less likely to have uneven film thickness than when hot air is used. In the heating step, since the flexible film is conveyed by the roller, the surface of the roller is heated by infrared rays. Thus, even if the flexible film comes into contact with the roller, the temperature of the contact portion is not easily lowered, and the occurrence of distortion, wrinkles, or the like in the flexible film can be suppressed. As a result, the functional layer can be formed with a desired thickness.

The roller may include a metallic roller body and a coating layer applied to a surface of the roller body. The material of the coating layer may be the infrared absorbing material.

In the heating step, the flexible film may be heated to 100 ℃. When the temperature of the flexible film is heated to 100 ℃ or higher, if a temperature drop occurs in a part of the film, wrinkles and the like are likely to occur. Thus, the method for manufacturing the organic electronic device is more effective when the flexible film is heated to 100 ℃ or higher in the heating step.

In the heating step, the wind speed within 10mm from the surface of the flexible film on which the 1 st electrode layer is formed may be 0.1m/s or less. This makes it less likely to cause film thickness unevenness in the coating layer, and makes it easier to form a functional layer having a desired thickness.

The infrared absorbing material may be an inorganic oxide. In this case, durability can be ensured. An example of the above inorganic oxide is alumina.

The coating method may be an inkjet printing method. The ink used in the inkjet printing method has a low viscosity. Therefore, for example, the thickness of the coating layer formed by the inkjet printing method is easily affected by irregularities due to the occurrence of distortion, wrinkles, and the like of the flexible film. Thus, when the coating method is an inkjet printing method, the method for manufacturing an organic electronic device in which the occurrence of warpage, wrinkles, and the like of the flexible film is suppressed in the heating step as described above is more effective.

Effects of the invention

According to the present invention, it is possible to provide a method for manufacturing an organic electronic device in which at least one functional layer included in an organic functional layer can be easily formed in a desired thickness.

Drawings

Fig. 1 is a plan view of a long flexible film used in a method for manufacturing an organic EL device (organic electronic device) according to an embodiment.

Fig. 2 is a view schematically showing a method for manufacturing an organic EL device by a roll-to-roll method.

Fig. 3 is a schematic diagram schematically showing the structure of the manufactured organic EL device (organic electronic device).

Fig. 4 is a diagram for explaining the organic functional layer forming step.

Fig. 5 is a diagram for explaining a heating step included in the organic functional layer forming step.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same elements are denoted by the same reference numerals, and redundant description thereof is omitted. The dimensional ratios in the drawings do not necessarily correspond to the dimensional ratios illustrated. Examples of the organic electronic device include an organic EL device, an organic solar cell, and an organic photodetector. In the embodiments described below, unless otherwise specified, the organic electronic device is an organic EL device, and a method for manufacturing a bottom emission type organic EL device will be described.

Fig. 1 is a plan view of a long flexible film 10 used in a method for manufacturing an organic EL device according to an embodiment. In the present specification, the long flexible film 10 refers to a flexible film that extends in one direction and has a length in the extending direction (i.e., the longitudinal direction) that is longer than a length in a direction (width direction) perpendicular to the longitudinal direction. Here, the flexible film is a film having flexibility. The flexibility is a property that an object (in the present specification, a film) can be bent without shearing or breaking even when a predetermined force is applied to the object.

The flexible film 10 has a light-transmitting property at least with respect to visible light (light having a wavelength of 400nm to 800 nm). The thickness of the flexible film 10 is, for example, 30 μm or more and 500 μm or less.

The flexible film 10 is a resin film such as a plastic film. Examples of the material of the flexible membrane 10 include polyether sulfone (PES); polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefin resins such as Polyethylene (PE), polypropylene (PP), and cyclic polyolefin; a polyamide resin; a polycarbonate resin; a polystyrene resin; a polyvinyl alcohol resin; saponified ethylene-vinyl acetate copolymers; polyacrylonitrile resin; an acetal resin; a polyimide resin; epoxy resins, and the like.

Among the above resins, the material of the flexible film 10 is preferably a polyester resin or a polyolefin resin, and more preferably polyethylene terephthalate or polyethylene naphthalate, because of high heat resistance, low linear expansion coefficient, and low production cost. These resins may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

A barrier layer (particularly, a barrier layer for shielding moisture) for shielding gas, moisture, or the like may be disposed on the surface 10a of the flexible film 10.

In the manufacture of the organic EL device, a plurality of device formation regions DA are virtually set in the longitudinal direction of the long flexible film 10, and an anode layer (1 st electrode layer), an organic functional layer, a cathode layer (2 nd electrode layer), and the like are formed on the device formation regions DA. In the embodiment in which the shielding layer is formed on the surface 10a of the flexible film 10, an anode layer, an organic functional layer, a cathode layer, and the like are formed on the shielding layer.

Fig. 2 is a schematic diagram of a method for manufacturing an organic EL device according to an embodiment, and is a schematic diagram of a method for manufacturing an organic EL device using a roll-to-roll method. In the case of manufacturing an organic EL device by a roll-to-roll method, the roll-shaped flexible film 10 is attached to the lead-out portion 12A, and the flexible film 10 is led out. While the led flexible film 10 is being conveyed by the conveying roller 14 toward the winding section 12B, the anode layer forming step (1 st electrode layer forming step) S11, the organic function layer forming step S12, and the cathode layer forming step (2 nd electrode layer forming step) S13 are sequentially performed. Thereafter, the flexible film 10 is wound into a roll by the winding section 12B. The lead-out portion 12A, the winding portion 12B, and the conveying roller 14 may be part of a conveying mechanism of the flexible film 10. The conveying mechanism may further include known components such as a tension adjusting mechanism. The winding step and the drawing step may be provided in each step. In addition, after the flexible film 10 is wound and stored in each step, the flexible film 10 may be removed again and the following steps may be performed.

[ Anode layer Forming Process ]

In the anode layer forming step S11, the anode layer (1 st electrode layer) 16 is formed in each of the plurality of device formation regions DA virtually set along the longitudinal direction of the flexible film 10. Thus, in the flexible film 10, the anode layer 16 is separately formed along the length direction thereof. The anode layer 16 may have a network structure in which a conductor (e.g., metal) is formed in a network shape. Examples of the thickness of the anode layer 16 are generally 10nm to 10 μm, preferably 20nm to 1 μm, and more preferably 50nm to 500 nm.

The anode layer 16 can be formed by, for example, a dry film formation method, a plating method, a coating method, or the like. Examples of the dry film formation method include a vacuum deposition method, a sputtering method, an ion plating method, and a CVD method. The coating method is a method of forming a layer using a solution in which a material of a layer to be formed is dissolved in a solvent. Examples of the coating method include a micro gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, a nozzle printing method, an inkjet printing method, and the like.

[ organic functional layer Forming Process ]

In the organic functional layer forming step S12, the organic functional layer 18 is formed on the anode layer 16 formed on the flexible film 10. The organic functional layer 18 is a device functional portion that participates in the movement of charges, the recombination of charges, and the like of the organic EL device according to the power applied to the organic EL device. The organic functional layer 18 has a light-emitting layer as an organic layer.

The light-emitting layer is a functional layer having a function of emitting light of a predetermined wavelength. The optimum value of the thickness of the light-emitting layer varies depending on the material used, and is set appropriately so that the driving voltage and the light-emitting efficiency are appropriate values. The thickness of the light-emitting layer is, for example, 1nm to 1 μm, preferably 2nm to 500nm, and more preferably 10nm to 200 nm.

The light-emitting layer usually contains a light-emitting material that mainly emits at least one of fluorescence and phosphorescence, or contains the light-emitting material and a dopant material for light-emitting layer that assists the light-emitting material. The organic material of the light-emitting material that emits at least one of fluorescence and phosphorescence may be a low-molecular compound or a high-molecular compound. Examples of the light-emitting material include the following dye materials, metal complex materials, and polymer materials.

(pigment Material)

Examples of the coloring material include cyclopentamine and its derivatives, tetraphenylbutadiene and its derivatives, triphenylamine and its derivatives, oxadiazole and its derivatives, pyrazoloquinoline and its derivatives, distyrylbenzene and its derivatives, distyrylarylene and its derivatives, pyrrole and its derivatives, thiophene compounds, pyridine compounds, perinone and its derivatives, perylene and its derivatives, oligothiophene and its derivatives, oxadiazole dimers, pyrazoline dimers, quinacridone and its derivatives, and coumarin and its derivatives.

(Metal Complex Material)

Examples of the metal complex material include metal complexes having a rare earth metal such as Tb, Eu, and Dy as a central metal, or a metal complex having a structure such as Al, Zn, Be, Pt, and Ir as a ligand, including oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, and quinoline. Examples of the metal complex include metal complexes having luminescence from a triplet excited state, such as iridium complexes and platinum complexes, aluminum hydroxyquinoline complexes, beryllium benzohydroxyquinoline complexes, zinc benzoxazolyl complexes, zinc benzothiazolyl complexes, zinc azomethylzinc complexes, zinc porphyrin complexes, and europium phenanthroline complexes.

(Polymer Material)

Examples of the polymer material include polyparaphenylene vinylene and its derivatives, polythiophene and its derivatives, polyparaphenylene and its derivatives, polysilane and its derivatives, polyacetylene and its derivatives, polyfluorene and its derivatives, polyvinylcarbazole and its derivatives, and a material obtained by polymerizing the above-mentioned pigment material or metal complex material.

The dopant material for the light-emitting layer is added, for example, to improve the light-emitting efficiency and to change the light-emitting wavelength. Examples of the dopant material for the light-emitting layer include perylene and a derivative thereof, coumarin and a derivative thereof, rubrene and a derivative thereof, quinacridone and a derivative thereof, squarylium and a derivative thereof, porphyrin and a derivative thereof, styryl pigment, tetracene and a derivative thereof, pyrazolone and a derivative thereof, decacycloalkene and a derivative thereof, and phenoxazone and a derivative thereof.

The organic functional layer 18 may have a multilayer structure including functional layers other than the light-emitting layer. Examples of the functional layer that can be provided between the anode layer and the light-emitting layer include a hole injection layer and a hole transport layer. Examples of the functional layer that can be provided between the cathode layer and the light-emitting layer include an electron injection layer and an electron transport layer. Examples of layer structures that the organic functional layer can take are given below. In the following examples of the layer structure, the anode layer and the cathode layer are also described in parentheses for the purpose of explanation.

(a) (anode layer)/luminescent layer/(cathode layer)

(b) (anode layer)/hole injection layer/light emitting layer/(cathode layer)

(c) (anode layer)/hole injection layer/luminescent layer/electron injection layer/(cathode layer)

(d) (anode layer)/hole injection layer/luminescent layer/electron transport layer/electron injection layer/(cathode layer)

(e) (anode layer)/hole injection layer/hole transport layer/light emitting layer/(cathode layer)

(f) (anode layer)/hole injection layer/hole transport layer/light emitting layer/electron injection layer/(cathode layer)

(g) (anode layer)/hole injection layer/hole transport layer/light emitting layer/electron transport layer/electron injection layer/(cathode layer)

(h) (anode layer)/light-emitting layer/electron injection layer/(cathode layer)

(i) (anode layer)/luminescent layer/electron transport layer/electron injection layer/(cathode layer)

The symbol "/" indicates that the layers are stacked adjacently with the symbol "/" interposed therebetween. The configuration of the above configuration example (a) is an example when the organic functional layer 18 has a single-layer structure formed of a light-emitting layer.

As the material of the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer, a known material can be used. Typically, the hole transport layer and the electron transport layer are organic layers. The hole injection layer and the electron injection layer may be organic layers or inorganic layers. The electron injection layer may for example be part of the cathode layer. The thicknesses of the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer can be appropriately set in consideration of electrical characteristics, ease of film formation, and the like. The thicknesses of the hole injection layer, the hole transport layer, the electron injection layer and the electron transport layer are in submicron order.

The functional layer constituting the organic functional layer 18 may be formed by a coating method. The coating method may be the same as the coating method exemplified in the description of the anode layer forming step S11. When the organic functional layer 18 has a multilayer structure, the functional layers may be formed in this order from the anode layer 16 side.

[ cathode layer Forming Process ]

In the cathode layer forming step S13, the cathode layer (2 nd electrode layer) 20 is formed on the organic functional layer 18. A part of the cathode layer 20 may be formed on the flexible film 10. In order to reflect the light from the organic functional layer 18 at the cathode layer 20 and reach the anode layer 16 side, the material of the cathode layer 20 is preferably a material having a high reflectance with respect to the light from the organic functional layer 18. As the material of the cathode layer 20, for example, alkali metal, alkaline earth metal, transition metal, periodic table group 13 element, and the like are used. As the cathode layer 20, for example, a transparent conductive electrode containing a conductive metal oxide, a conductive organic substance, or the like can be used. Specific examples of the conductive metal oxide include indium oxide, zinc oxide, tin oxide, ITO, IZO, and the like, and examples of the conductive organic material include polyaniline and a derivative thereof, polythiophene and a derivative thereof, and the like.

The thickness of the cathode layer 20 is set in consideration of electrical conductivity, durability, and the like. The thickness of the cathode layer 20 is usually 10nm to 10 μm, preferably 20nm to 1 μm, and more preferably 50nm to 500 nm. The cathode layer 20 may be formed in the same manner as the anode layer 16.

Examples of the method for forming the cathode layer 20 include a dry film formation method, a plating method, and a coating method. Examples of the dry film forming method and the coating method may be the same as those exemplified in the description of the anode layer forming step S11. From the viewpoint of easily exhibiting conductivity immediately after film formation, a dry film formation method is preferable. From the viewpoint of suppressing damage to the light-emitting layer, the vacuum deposition method is preferable.

Through the cathode layer forming step S13, the organic EL device 2 (see fig. 3) including the flexible film 10, the anode layer 16 formed on the flexible film 10, the organic functional layer 18 formed on the anode layer 16, and the cathode layer 20 formed on the organic functional layer 18 is formed for each device formation region DA. In this way, by performing the singulation step of singulating the flexible film 10 for each device formation region DA, the organic EL device 2 having a product size can be obtained.

The organic EL device 2 may include a sealing member that seals at least the organic functional layer 18. The sealing member is bonded to the flexible film 10 and the structure (anode layer, organic functional layer, and cathode layer) on the flexible film 10. The sealing member has a moisture barrier function of preventing the intrusion of moisture into the organic functional layer 18. The sealing member may also have a gas shielding function.

In the embodiment in which the organic EL device 2 includes the sealing member, the bonding step of bonding the sealing member to the flexible film 10 (i.e., the flexible film with the cathode layer) having passed through the cathode layer forming step S13 may be performed between the cathode layer forming step S13 and the singulation step. In this bonding step, for example, a long sealing member is bonded to the flexible film with a cathode layer. The size, bonding position, and the like of the sealing member may be set so that power can be supplied to the organic EL device 2.

The organic functional layer forming step S12 will be described in detail below. Fig. 4 is a view schematically showing the coating layer forming step and the heating step included in the organic functional layer forming step S12. At least one functional layer included in the organic functional layer 18 is referred to as a functional layer 181, and a method for forming the functional layer 181 will be described. Here, for the sake of simplicity of explanation, a case where a functional layer 181 is formed in contact with the anode layer 16 will be described as an example as shown in fig. 4 unless otherwise specified.

First, a coating layer 181a is formed on the anode layer 16 by a coating method (coating layer forming step). Fig. 4 shows a method of forming the coating layer 181a by an inkjet printing method as an example of a coating method. Specifically, a coating liquid (e.g., ink) 24 in which a material of the functional layer 181 to be formed is dissolved in a solvent is dropped from the ink jet device 22 onto the anode layer 16 to form a coating layer 181 a. In the present specification, the coating layer is a film of the coating liquid before drying and curing. Then, the coating layer 181a is heated and dried in a heating furnace 26 provided on the conveyance path of the flexible film 10, thereby obtaining the functional layer 181 (heating step). Therefore, the organic functional layer forming step S12 includes the coating layer forming step and the heating step.

When another functional layer is already formed between the anode layer 16 and the functional layer 181 to be formed, the coating layer 181a may be formed on the underlying layer using the other functional layer as an underlying layer in the coating layer forming step.

Fig. 5 is a diagram for explaining the heating step. In the heating step, the flexible film 10 having passed through the coating layer forming step is fed into the heating furnace 26 from the feed port 26a of the heating furnace 26. In fig. 5, one set of the anode layer 16 and the coating layer 181a is shown. However, as described above, the anode layers 16 are provided separately in the longitudinal direction of the flexible film 10, and the coating layer 181a is formed on each anode layer 16.

In the heating furnace 26, the fed flexible film 10 is conveyed by a conveying roller 28 provided in the heating furnace 26. While the flexible film 10 is conveyed in the longitudinal direction thereof, the coating layer 181a is heated and dried by irradiating infrared rays 32 from an infrared ray irradiation unit 30 disposed in the heating furnace 26. Thereafter, the flexible film 10 is continuously fed out from the feed-out port 26 b.

The infrared irradiation unit 30 outputs infrared rays 32 including infrared rays having a wavelength in a range of 3 to 10 μm in order to heat the coating layer 181 a. An example of the infrared irradiation unit 30 is an infrared heater. In the heating furnace 26, a plurality of infrared irradiation units 30 are arranged along the conveyance direction. As shown in fig. 5, the infrared irradiation part 30 may be disposed on both sides in the thickness direction of the flexible film 10, or may be disposed only on the side facing the coating layer 181a, for example.

As shown in fig. 5, the conveying roller 28 includes a metal roller main body 281 and a coating layer 282 provided on a surface of the roller main body 281. An example of the material of the roller body 281 is stainless steel (SUS). The material of the coating layer 282 is an infrared absorbing material. Thus, the material of the surface 28a of the conveying roller 28 is an infrared absorbing material.

The infrared absorbing material absorbs the infrared rays 32 output from the infrared irradiation unit 30. The infrared absorbing material has an average absorption rate of 0.8 or more for infrared rays having a wavelength in the range of 3 to 10 μm. An example of the infrared absorbing material is an inorganic oxide, and an example of the above inorganic oxide is alumina.

When the average absorptance is α, the average absorptance α in a predetermined wavelength range is calculated by the following equation.

[ mathematical formula 1]

In the above formula, λ is a wavelength in the above-mentioned predetermined wavelength range, k (λ) is an absorption rate at the wavelength λ, λ₁Is the lower limit value of the above-mentioned predetermined wavelength range, λ₂Is the above-specified waveUpper limit of the long range. Thus, when the predetermined wavelength range is a range of wavelengths from 3 μm to 10 μm, λ is₁Is 3 μm, λ₂Is 10 μm. As a method for measuring the absorbance at the wavelength λ, a method according to JIS K0117: 2000 general rules for infrared spectroscopy, a fourier transform infrared spectrophotometer using a fourier transform method is particularly preferably used for the measurement by the apparatus described in the above section.

In the heating furnace 26, an air nozzle 34 for discharging air may be disposed as indicated by a broken line in order to ventilate the heating furnace 26 and effectively discharge the solvent.

In the heating step, the intensity, the conveyance speed, and the like of the infrared ray 32 from the infrared ray irradiation unit 30 may be adjusted so that the coating layer 181a is heated and dried in the heating furnace 26. In the heating step, the flexible film 10 may also be heated to 100 ℃. In the heating step, the wind speed in the environment within 10mm from the surface (the surface on which the 1 st electrode layer is formed) 10a (see fig. 1) of the flexible film 10 is preferably 0.1m/s or less.

An example of the coating method used in the coating layer forming step is an inkjet printing method. However, the coating layer 181a may be formed by a coating method other than the inkjet printing method described in the anode layer forming step S11.

In the embodiment in which the organic functional layer 18 has a plurality of functional layers, at least one functional layer may be formed by the coating layer forming step and the heating step. In other words, the organic functional layer 18 may have a functional layer formed by a known forming method in an embodiment having a plurality of functional layers. For example, the electron injection layer can be formed by a vacuum evaporation method.

The method for manufacturing the organic EL device 2 includes a heating step for forming at least one functional layer 181 included in the organic functional layer 18, and infrared rays 32 are used as a method for heating the coating layer 181a in the heating step. As a result, wind streaks (uneven film thickness) are less likely to occur in the coating layer 181a than in the case of using hot air. The material of the surface 28a of the conveying roller 28 is an infrared absorbing material having an average infrared absorption rate of 0.8 or more in a wavelength range of 3 to 10 μm. Thus, in the heating step, since the infrared ray 32 irradiated from the infrared irradiation unit 30 is absorbed by the infrared absorbing material, the surface 28a of the transport roller 28 becomes hot as compared with the case where the infrared ray 32 is not absorbed. When the surface 28a of the conveying roller 28 becomes hot, even if the flexible film 10 comes into contact with the conveying roller 28, the temperature decrease in the contact portion is suppressed, and therefore, the occurrence of distortion, wrinkles, and the like of the flexible film 10 accompanying the temperature decrease can be prevented. This makes it difficult for uneven film thickness to occur in the coating layer 181a on the flexible film 10, and the functional layer 181 can be formed with a desired thickness with high accuracy, so that a reduction in the characteristics of the organic EL device 2 can be prevented. For example, light emission unevenness can be prevented.

In the heating step, the flexible film 10 is conveyed by the conveying rollers 28 in the heating furnace 26, and therefore, the flexible film 10 can be prevented from being loosened. This can increase the size of the heating furnace 26. For example, the length of the heating furnace 26 along the conveying direction can be made longer. Even if the heating furnace 26 is lengthened, the coating layer 181a can be heated by disposing the infrared ray irradiation part 30, and the heating temperature of the coating layer 181a can be increased by the intensity of the infrared ray 32 and the like. As a result, the productivity of the organic EL device 2 can be improved.

In the heating step, the flexible film 10 is transported by using the transport rollers 28, instead of transporting the flexible film 10 in a floating manner by using, for example, a gas. This also prevents the occurrence of wind marks due to the gas used to float the flexible film 10.

Since the surface 28a of the conveying roller 28 is heated by the infrared rays 32 used in the heating of the coat layer 181a, the operation cost can also be suppressed as compared with, for example, the case of using a heat roller.

In general, when the flexible film 10 is conveyed by the conveying rollers 14 and 28 as in the roll-to-roll system, the machining accuracy of the rollers (known as the accuracy of the cylinder degree, the straightness, the roundness, and the like) tends to be required to a high level. In the form in which the conveying roller 28 includes the roller main body 281 and the coating layer 282, the roller main body 281 is formed with the same processing accuracy as that of the conventional art, and thus the processing accuracy of the conveying roller 28 can be easily maintained. In addition, since the conveyor roller 28 can be generally produced by applying an infrared absorbing material to a metallic conveyor roller used in the roll-to-roll system, the conveyor roller 28 can be easily prepared.

Further, in the mode in which the infrared absorbing material is an inorganic oxide, durability can be improved as compared with the case of using plastic, and also processing accuracy is easily obtained.

When the temperature of the flexible film 10 reaches 100 ℃ or higher in the heating step, the above-described distortion, wrinkle, or the like is likely to occur as the temperature decreases. Therefore, the method for manufacturing an organic EL device having the heating step capable of preventing a temperature decrease is effective in the case where the temperature of the flexible film 10 in the heating step is 100 ℃. In general, when the coating layer 181a is heated and dried, the temperature of the flexible film 10 tends to be 100 ℃.

In the inkjet printing method, the viscosity of the ink can be generally set to a low viscosity. Therefore, for example, the thickness of the coating layer is easily affected by distortion, wrinkles, and the like of the flexible film. In the heating step of the method for producing an organic EL device, since the distortion, the wrinkle, or the like can be suppressed, the method is effective for forming a coating layer by an inkjet printing method.

Next, the operation and effect when the conveying roller 28 is used in the heating step will be further described with reference to the experimental results.

(Experimental example 1)

In the experimental example 1, the conveying roller 28 was coated by thermally spraying alumina (average absorption rate of infrared ray in a wavelength range of 3 to 10 μm: 0.82) on the surface of a metal roller (roller body). The infrared irradiation unit 30 uses an infrared heater, and the temperature of the infrared heater is set to 160 ℃. In experimental example 1, a PEN film having a thickness of 100 μm was used as the flexible film 10, and a light-emitting layer was formed as the functional layer 181 on the flexible film 10. Specifically, after the coating layer 181a is formed by the inkjet printing method, the coating layer 181a is heated and dried by infrared rays while the flexible film 10 is conveyed in the heating furnace 26 at a conveyance speed of 1m/min, thereby obtaining the functional layer 181. At this time, a thermometer is attached to the surface of the flexible film 10, and the temperature of the flexible film 10 during conveyance is measured.

As a result, the flexible film 10 was maintained at substantially 150 ℃ in the heating furnace 26, and no rapid temperature change was observed even in the contact portion with the conveying roller 28. More specifically, no temperature change of 1 ℃ or more was observed. In addition, no wrinkles were observed in the flexible film 10 sent out from the heating furnace 26, and no film thickness unevenness was observed in the obtained functional layer 181.

(Experimental example 2)

Experimental example 2 is a comparative experiment of experimental example 1. Experimental example 2 an experiment was performed in the same manner as in experimental example 1, except that a metal roller whose surface is also made of metal was used instead of the conveying roller 28 used in experimental example 1. As a result, a temperature drop of 10 ℃. Significant wrinkles were observed in the flexible film 10 sent out from the heating furnace, and film thickness unevenness was observed in the resulting functional layer.

As can be understood from comparison between experimental example 1 and experimental example 2, when the coating layer 181a is heated and dried by irradiation with infrared rays, the temperature of the roller contact portion can be prevented from being lowered by using the conveying roller 28 having the surface 28a made of the infrared absorbing material. As a result, wrinkles in the flexible film 10 and film thickness unevenness of the functional layer to be formed can be prevented, and the functional layer having a desired thickness can be easily realized.

Various embodiments and modifications of the present invention have been described above. However, the present invention is not limited to the various embodiments and modifications described as examples, and is intended to include the scope defined by the claims and all modifications within the meaning and scope equivalent to the claims.

In the method for manufacturing the organic EL device illustrated in fig. 2, an anode layer forming step is performed. However, a flexible film in which an anode layer is formed in advance may be used. That is, the anode layer forming step may not be performed.

In the method for manufacturing an organic EL device illustrated in fig. 2, all steps up to the anode layer formation step, the organic functional layer formation step, and the cathode layer formation step are performed in a roll-to-roll manner. However, the heating step shown in fig. 5 may be performed at least by a roll-to-roll method. In general, the coating layer forming step and the heating step may be continuously performed by a roll-to-roll method.

The anode layer is illustrated as an example of the 1 st electrode layer, and the cathode layer is illustrated as an example of the 2 nd electrode layer. However, the 1 st electrode layer may be a cathode layer and the 2 nd electrode layer may be an anode layer. That is, the cathode layer may be disposed on the flexible film side. The organic EL device that should be manufactured may also be a top emission type device.

In the above embodiment, a method for manufacturing an organic EL device as an example of an organic electronic device is described. However, the present invention can be applied to the manufacture of organic electronic devices such as organic photodetectors, organic thin-film solar cells, and organic transistors, in addition to the manufacture of organic EL devices.

Description of the reference numerals

2 organic EL device (organic electronic device), 10 flexible film, 10a surface (surface of flexible film on which 1 st electrode layer is formed), 16 anode layer (1 st electrode layer), 18 organic functional layer, 20 cathode layer (2 nd electrode layer), 26 heating furnace, 28 transport roller (roller), 28a surface (roller surface), 30 infrared ray irradiation section, 32 infrared ray, 181 functional layer, 181a coating layer, 281 roller body, 282 coating layer.