JPWO2017082173A1 - Manufacturing method of organic EL device and organic EL device - Google Patents

Abstract

In an organic EL device 1 according to an embodiment, an organic light emitting layer 23 is formed by a coating method on a first electrode 12 provided in a pixel region 2a defined by a bank 13 having a substrate 10 with a bank. A step of calculating the flatness of the organic light emitting layer, a step of determining whether the flatness is equal to or higher than a desired flatness, and a step of forming the second electrode 30. When the minimum thickness of the light emitting layer is d (nm), the area of the organic light emitting layer having (d + predetermined value) nm or less is A1, and the area of the pixel region is A2, the flatness is (A1 / A2) When the flatness is greater than or equal to a desired value in the determination step, the step of forming the second electrode is performed, and in the determination step, the organic light emission is performed when the flatness is less than the desired value. The organic light emitting layer is formed by changing the layer formation conditions.

Description

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

  As an organic EL device, a device in which a plurality of pixels are defined by banks (partition walls) as in Patent Document 1 is known. In such an organic EL device, an organic light emitting layer is provided in each pixel, and light is emitted for each pixel.

International Publication No. 2008/149499

  When the thickness of the organic light emitting layer in the pixel of the organic EL device is not uniform, luminance characteristics (for example, luminance uniformity) in the pixel deteriorate. In order to make the thickness of the organic light emitting layer uniform, that is, to flatten the organic light emitting layer, it has been conventionally required to flatten the layer serving as the base of the organic light emitting layer. However, in this case, it is necessary to evaluate the flatness of each layer, and the manufacturing process becomes complicated. In addition, since the relationship between the flatness of the organic light-emitting layer and the luminance is unknown, the desired luminance characteristics are required until the organic EL device is made to emit light after being manufactured once by forming an electrode on the organic light-emitting layer. I don't know if Therefore, when desired luminance characteristics are not obtained, it is necessary to form not only the organic light emitting layer but also an electrode to be provided on the organic light emitting layer, which reduces the productivity of the organic EL device.

  Then, an object of this invention is to provide the manufacturing method and organic EL device of an organic EL device which can aim at the improvement of productivity.

That is, a banked substrate according to one aspect of the present invention includes a substrate, a bank provided on the substrate for defining a pixel, and a first region provided on a pixel region corresponding to the pixel on the substrate. A step of forming an organic light emitting layer by a coating method on the first electrode of the banked substrate including electrodes, a step of calculating the flatness of the organic light emitting layer, and a flatness of the organic light emitting layer is desired. A step of determining whether or not the flatness of the organic light-emitting layer is equal to or greater than the thickness of the organic light-emitting layer, and a step of forming a second electrode on the organic light-emitting layer. The thickness of the organic light emitting layer is (d + predetermined value) nm or less when viewed from the thickness direction of the substrate, and the area of the organic light emitting layer is A1, the area of the pixel region is A2, and the flatness is where α is the flatness, In the step of calculating and determining in step 1), if the flatness is greater than or equal to a desired value, the step of forming the second electrode is performed, and in the step of determining, the flatness is a desired value. If it is less, the organic light emitting layer is formed by changing the formation conditions of the organic light emitting layer in the step of forming the organic light emitting layer.
α = (A1 / A2) × 100 (1)

  When the flatness of the organic light emitting layer formed in the pixel defined by the bank is defined as described above, the inventors of the present application have a certain relationship between the flatness and the organic light emitting layer to the luminance state. I found.

  In the above manufacturing method, an organic EL device having an organic light emitting layer having a flatness equal to or higher than a desired value in a pixel can be manufactured. In such an organic EL device, according to the knowledge found by the inventors of the present application, light can be emitted from the pixel in a luminance state substantially corresponding to the desired value. In this case, in the manufacture of the organic EL device, by adjusting the flatness of the organic light emitting layer, an organic EL device capable of emitting light in a desired luminance state from the pixel can be manufactured. Therefore, the productivity of the organic EL device is improved.

  The desired flatness is set based on the relationship between the flatness defined by the above formula (1) for the luminance distribution rate calculation pixel and the luminance distribution rate in the luminance distribution rate calculation pixel. The luminance distribution rate may be a ratio of the area of a region having 70% or more of the maximum luminance of the area of the luminance distribution rate calculation pixel in the luminance distribution rate calculation pixel.

  Due to the relationship between the flatness and the luminance distribution rate, the desired luminance distribution rate can be realized by setting the flatness of the organic light emitting layer to a desired value or more.

  The desired flatness can be 70%, preferably 80%.

  You may further provide the process of forming the organic structure containing an at least 1 organic layer on the said 1st electrode of the said board | substrate with a bank. In this case, in the step of forming the organic light emitting layer, the organic light emitting layer may be formed on the organic structure.

  In the embodiment including the step of forming the organic light emitting layer, in the step of calculating the flatness, the thickness distribution of the organic light emitting layer is changed to the thickness distribution of the organic structure and the organic on the organic structure. The flatness can be calculated on the basis of the thickness distribution of the organic light emitting layer by calculating the difference from the thickness distribution of the laminate formed with the light emitting layer.

  An organic EL device according to another aspect of the present invention includes (A) a substrate, a bank provided on the substrate for defining a pixel, and (B) a pixel region corresponding to the pixel on the substrate. A banked substrate having a first electrode provided; (C) an organic light emitting layer provided on the first electrode; and (D) a second electrode provided on the organic light emitting layer. The minimum thickness of the organic light emitting layer is d (nm), the area of the organic light emitting layer that is (d + predetermined value) nm or less when viewed from the thickness direction of the substrate is A1, and the area of the pixel region Is A2, and the flatness of the organic light emitting layer is (A1 / A2) × 100 [%], the flatness is 70% or more.

  From the relationship between the flatness found by the present inventors and the luminance distribution rate, the organic EL device can achieve a luminance distribution rate corresponding to a flatness of 70% or more. Since this organic EL device can be manufactured by the manufacturing method of the organic EL device, productivity can be improved.

  The predetermined value may be 2 or more and 15 or less, for example. The predetermined value may be 10.

  According to the present invention, it is possible to provide an organic EL device manufacturing method and an organic EL device capable of improving productivity.

FIG. 1 is a plan view of an organic EL device according to an embodiment as viewed from the banked substrate side. FIG. 2 is a partially enlarged view of a cross section taken along line II-II in FIG. FIG. 3 is a diagram illustrating a banked substrate included in the organic EL device of FIG. FIG. 4 is a flowchart of an example of a method for manufacturing an organic EL device according to an embodiment. FIG. 5 is a drawing for explaining the organic structure forming step. FIG. 6 is a view for explaining an organic light emitting layer forming step. FIG. 7 is a schematic diagram for explaining the relationship between the drying rate and the thickness distribution of the organic light emitting layer. FIG. 8 is a drawing schematically showing the configuration of the organic EL device of the example. FIG. 8A schematically shows the configuration of the organic EL device of Experimental Examples 1 to 4, and FIG. (B) of FIG. 8 schematically illustrates the configuration of the organic EL devices of Experimental Examples 5 to 9, and FIG. 8 (c) schematically illustrates the configuration of the organic EL devices of Experimental Examples 10 to 14. Yes. FIG. 9 is a drawing showing experimental results of Experimental Examples 1 to 14. FIG. 10 is a drawing showing the thickness distribution of the organic light emitting layer in Experimental Examples 1 to 4. FIG. 11 is a drawing showing the thickness distribution of the organic light emitting layer in Experimental Examples 5 to 9. FIG. 12 is a drawing showing the thickness distribution of the organic light emitting layer in Experimental Examples 10 to 14.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same symbols are assigned to the same elements. A duplicate description is omitted. The dimensional ratios in the drawings do not necessarily match those described.

  An organic electroluminescence (organic EL) device 1 shown in FIG. 1 is an organic EL display panel, and has a plurality of pixels 2. Each pixel 2 is an organic EL element part. That is, the organic EL device 1 has a configuration in which a plurality of organic EL element units are integrally connected. In the present embodiment, “pixel” means a minimum unit (or minimum region) that emits light, and the pixel 2 has color information by light emission of the pixel 2. In FIG. 1, the pixel 2 is schematically indicated by a broken line.

  Each of the plurality of pixels 2 emits red, green, or blue light. From this viewpoint, the organic EL device 1 includes three types of pixels 2, that is, a red pixel 2R that emits red light, a green pixel 2G that emits green light, and a blue pixel 2B that emits blue light. In the following description, when distinguishing the colors emitted by the pixel 2, the pixel 2 may be referred to as a red pixel 2R, a green pixel 2G, and a blue pixel 2B as described above.

The plurality of pixels 2 are arranged in a two-dimensional array (or matrix). Two directions orthogonal to each other in the two-dimensional array are also referred to as an X direction (or row direction) and a Y direction (or column direction). In this case, for example, the three types of red pixel 2R, green pixel 2G, and blue pixel 2B constituting the plurality of pixels 2 are arranged in the order of the following columns (i), (ii), and (iii) in this order. By repeating the arrangement, the arrangement is performed in an aligned manner.
(I) A column in which the red pixels 2R are arranged at a predetermined interval in the X direction.
(Ii) A column in which the green pixels 2G are arranged at predetermined intervals in the X direction.
(Iii) A column in which the blue pixels 2B are arranged at predetermined intervals in the X direction.

  For example, the organic EL device 1 controls the red pixel 2R, the green pixel 2G, and the blue pixel 2B included in the display pixel unit by using the red pixel 2R, the green pixel 2G, and the blue pixel 2B arranged in parallel as one display pixel unit. Therefore, full color display can be performed.

  An interval between the pixels 2 in each column, an interval between the pixels 2 in each row, an arrangement example of the pixels 2, the number of the pixels 2, and the like are appropriately set according to the specifications of the organic EL device 1.

  The configuration of the organic EL device 1 will be described in detail. The organic EL device 1 includes a banked substrate 10, a plurality of organic EL structure units 20, and a cathode (second electrode) 30. The organic EL device 1 may be a top emission type device or a bottom emission type device. Hereinafter, unless otherwise specified, a bottom emission type, that is, a case where light is extracted from the banked substrate 10 side will be described.

  As shown in FIGS. 2 and 3, the banked substrate 10 includes a substrate 11, a plurality of anodes (first electrodes) 12, and a bank 13. 3 corresponds to a partially enlarged view of the cross section of the banked substrate 10 along the line II-II in FIG. 1, and corresponds to the drawing in which components other than the banked substrate 10 are omitted in FIG. To do.

  The substrate 11 is a plate-like transparent member that is transparent to visible light (light having a wavelength of 400 nm to 800 nm). The substrate 11 is a support that supports the anode 12 and the bank 13. An example of the thickness of the substrate 11 is 30 μm or more and 1100 μm or less. The substrate 11 may be a rigid substrate such as a glass substrate and a silicon substrate, or may be a flexible substrate such as a plastic substrate and a polymer film. By using a flexible substrate, the organic EL device 1 can have flexibility.

  A circuit for driving each pixel 2 may be formed in advance on the substrate 11. For example, a TFT (Thin Film Transistor) or a capacitor may be formed on the substrate 11 in advance.

  The plurality of anodes 12 are provided on the pixel region 2 a corresponding to each pixel 2 on the surface 11 a of the substrate 11. Examples of the shape of the anode 12 in plan view (the shape seen from the thickness direction of the substrate 11) include a quadrangle such as a rectangle and a square, and other polygons. The shape of the anode 12 in plan view may be circular or elliptical.

  For the anode 12, a thin film made of metal oxide, metal sulfide, metal, or the like can be used. Specifically, indium oxide, zinc oxide, tin oxide, indium tin oxide (Indium Tin Oxide: abbreviated as ITO), A thin film made of indium zinc oxide (abbreviated as IZO), gold, platinum, silver, copper, or the like is used. As mainly described in the present embodiment, when the organic EL device 1 emits light from the banked substrate 10 side, an anode 12 exhibiting light transmittance is used.

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

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

  As shown in FIGS. 2 and 3, the bank 13 is provided around each anode 12. The bank 13 is also provided between the adjacent anodes 12. A part of the bank 13 may cover the peripheral edge of the anode 12. The bank 13 is a partition that partitions the pixel 2 or the pixel region 2a. That is, the bank 13 is provided on the substrate 11 in such a pattern as having an opening that partitions the pixel area 2 a set in advance on the surface 11 a of the substrate 11. In the present embodiment, as shown in FIG. 1, since the plurality of pixels 2 are arranged in a two-dimensional array, a lattice bank 13 is provided on the substrate 11.

  An example of the material of the bank 13 is resin. The bank 13 is a cured product of a photosensitive resin composition containing a liquid repellent, for example. An example of the liquid repellent is a liquid repellent containing a fluororesin. As will be described later, an organic layer such as an organic light emitting layer 23 is formed on the pixel region 2a defined by the bank 13 by a coating method. Therefore, the bank 13 usually has characteristics (for example, wettability) that can suitably form the organic layer when the organic layer is formed on the pixel region 2a defined by the bank 13 using a coating method. It is formed as follows.

  The shape of the bank 13 and the arrangement thereof are appropriately set according to the specifications of the organic EL device 1 such as the number of pixels 2 and the resolution, ease of manufacture, and the like. For example, in FIGS. 2 and 3, the side surface 13 a facing the pixel region 2 a of the bank 13 is substantially orthogonal to the surface 11 a of the substrate 11. However, the side surface 13a may be inclined to form an acute angle with respect to the surface 11a, or may be inclined to form an obtuse angle. When the side surface 13a and the surface 11a have an acute angle, the shape of the bank 13 is known as a forward taper type, and when the side surface 13a and the surface of the substrate 11 have an obtuse angle, the shape of the bank 13 has a reverse taper type. Known as. An example of the thickness (height) of the bank 13 is about 0.3 μm to 5 μm.

  The banked substrate 10 can be manufactured, for example, by forming the banks 13 after forming the anodes 12 on the plurality of pixel regions 2 a set in advance on the substrate 11.

  The anode 12 can be formed by a vapor deposition method or a coating method. In the case of forming by vapor deposition, after forming a layer made of the material of the anode 12 on the substrate 11, the layer may be patterned into a pattern of a plurality of anodes 12. When the anode 12 is formed by a coating method, the coating liquid containing the material of the anode 12 can be formed on the substrate 11 in a pattern corresponding to the plurality of anodes 12 and then dried. Alternatively, a coating film made of a material to be the anode 12 may be formed on the substrate 11 and dried, and then patterned into the pattern of the anode 12.

  In the case where a coating method is used in forming the anode 12, examples of the coating method include an inkjet printing method, but other known coating methods such as a slit coating method, a micro gravure coating method, a gravure coating method, a bar coating method, and the like. A 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, and the like may be used. The solvent of the coating solution containing the material of the anode 12 may be any solvent that can dissolve the material of the anode 12.

  The bank 13 is formed using, for example, a coating method. Specifically, it is formed by drying a coating film formed by coating a coating solution containing the material of the bank 13 on the substrate 11 on which the anode 12 is formed, and then patterning the coating film into a predetermined pattern. obtain. Examples of the coating method may include a spin coating method and a slit coating method. The solvent of the coating solution containing the bank 13 may be any solvent that can dissolve the material of the bank 13.

  As shown in FIG. 2, the plurality of organic EL structure portions 20 are provided in the recess 14 (see FIGS. 2 and 3) formed by the bank 13 and the anode 12 in the banked substrate 10. The organic EL structure unit 20 includes a hole injection layer 21, a hole transport layer 22, and an organic light emitting layer 23.

  The hole injection layer 21 is an organic layer having a function of improving hole injection efficiency from the anode 12 to the organic light emitting layer 23. A known hole injection material can be used as the material of the hole injection layer 21. Examples of hole injection materials include oxides such as vanadium oxide, molybdenum oxide, ruthenium oxide, and aluminum oxide, phenylamine compounds, starburst amine compounds, phthalocyanine compounds, amorphous carbon, polyaniline, and polyethylenedioxy Mention may be made of polythiophene derivatives such as thiophene (PEDOT).

  The thickness of the hole injection layer 21 has an optimum value depending on the material to be used, and is appropriately determined in consideration of required characteristics and ease of layer formation. The thickness of the hole injection layer 21 is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

  The hole injection layer 21 is provided with a different material or thickness for each type of pixel 2, that is, for each of the red pixel 2R, the green pixel 2G, and the blue pixel 2B, as necessary. From the viewpoint of simplicity of the formation process of the hole injection layer 21, all the hole injection layers 21 may be formed with the same material and the same thickness.

  The hole transport layer 22 is a layer having a function of improving hole injection from the anode 12, the hole injection layer 21, or the hole transport layer 22 closer to the anode 12 to the organic light emitting layer 23. As the material of the hole transport layer 22, a known hole transport material can be used. Examples of the material of the hole transport layer 22 include: polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, polysiloxane having an aromatic amine in a side chain or a main chain, or a derivative thereof, pyrazoline or a derivative thereof. , Arylamine or a derivative thereof, stilbene or a derivative thereof, triphenyldiamine or a derivative thereof, polyaniline or a derivative thereof, polythiophene or a derivative thereof, polyarylamine or a derivative thereof, polypyrrole or a derivative thereof, poly (p-phenylene vinylene) or a derivative thereof Derivatives, poly (2,5-thienylene vinylene) or derivatives thereof may be mentioned. Moreover, the hole transport layer material currently disclosed by Unexamined-Japanese-Patent No. 2012-144722 can also be mentioned.

  The thickness of the hole transport layer 22 varies depending on the material used, and is appropriately set so that the drive voltage and the light emission efficiency are appropriate. The thickness of the hole transport layer 22 is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

  The hole transport layer 22 is provided with a different material or thickness for each type of the pixel 2, that is, for each of the red pixel 2R, the green pixel 2G, and the blue pixel 2B, as necessary. From the viewpoint of simplicity of the formation process of the hole transport layer 22, all the hole injection layers 21 may be formed with the same material and the same thickness.

  The organic light emitting layer 23 is provided on the hole transport layer 22. The organic light emitting layer 23 is an organic layer having a function of emitting light of a predetermined wavelength. The organic light emitting layer 23 is usually formed of an organic substance that mainly emits fluorescence and / or phosphorescence, or an organic substance and a dopant that assists the organic substance. The dopant is added, for example, in order to improve the luminous efficiency and change the emission wavelength. The organic substance contained in the organic light emitting layer 23 may be a low molecular compound or a high molecular compound. Examples of the light emitting material constituting the organic light emitting layer 23 may include the following dye materials, metal complex materials, polymer materials, and dopant materials.

  Examples of dye-based luminescent materials include cyclopentamine or derivatives thereof, tetraphenylbutadiene or derivatives thereof, triphenylamine or derivatives thereof, oxadiazole or derivatives thereof, pyrazoloquinoline or derivatives thereof, distyrylbenzene or derivatives thereof. Distyrylarylene or a derivative thereof, pyrrole or a derivative thereof, thiophene ring compound, pyridine ring compound, perinone or a derivative thereof, perylene or a derivative thereof, oligothiophene or a derivative thereof, oxadiazole dimer or a derivative thereof, pyrazoline dimer or a derivative thereof Derivatives, quinacridone or derivatives thereof, coumarin or derivatives thereof, and the like may be mentioned.

  Examples of the metal complex-based light emitting material include rare earth metals such as Tb, Eu, and Dy, or Al, Zn, Be, Pt, Ir, and the like as a central metal, and oxadiazole, thiadiazole, phenylpyridine, and phenylbenzimidazole. And a metal complex having a quinoline structure or the like as a ligand. Examples of metal complexes include metal complexes having light emission from triplet excited states such as iridium complexes and platinum complexes, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, benzoxazolyl zinc complexes, benzothiazole zinc complexes, azomethyl zinc complexes, A porphyrin zinc complex, a phenanthroline europium complex, etc. may be mentioned.

  Examples of the polymer light-emitting material include polyparaphenylene vinylene or derivatives thereof, polythiophene or derivatives thereof, polyparaphenylene or derivatives thereof, polysilane or derivatives thereof, polyacetylene or derivatives thereof, polyfluorene or derivatives thereof, polyvinylcarbazole or derivatives thereof. Derivatives, dye materials, materials obtained by polymerizing metal complex materials, and the like can be given.

  Among the above light emitting materials, materials emitting red light (hereinafter referred to as “red light emitting materials”) include coumarin or derivatives thereof, thiophene ring compounds, and polymers thereof, polyparaphenylene vinylene or derivatives thereof, polythiophene or A derivative thereof, polyfluorene or a derivative thereof, and the like can be given. Of these, polymer materials such as polyparaphenylene vinylene or derivatives thereof, polythiophene or derivatives thereof, and polyfluorene or derivatives thereof are preferable. Examples of the red light emitting material include materials disclosed in JP2011-105701A.

  Examples of materials that emit green light (hereinafter referred to as “green light-emitting materials”) include quinacridone or derivatives thereof, coumarin or derivatives thereof, and polymers thereof, polyparaphenylene vinylene or derivatives thereof, polyfluorene or derivatives thereof, and the like. May be mentioned. Among them, polymer materials such as polyparaphenylene vinylene or a derivative thereof, polyfluorene or a derivative thereof are preferable. Examples of the green light emitting material include materials disclosed in JP2012-036388.

  Materials that emit blue light (hereinafter referred to as “blue light-emitting materials”) include distyrylarylene or derivatives thereof, oxadiazole or derivatives thereof, polymers thereof, polyvinylcarbazole or derivatives thereof, polyparaphenylene or derivatives thereof. Derivatives, polyfluorene or derivatives thereof, and the like can be given. Among these, polyvinylcarbazole or a derivative thereof, polyparaphenylene or a derivative thereof, and polyfluorene or a derivative thereof are preferable. Examples of the blue light emitting material include materials disclosed in JP2012-144722A.

  Examples of dopant materials include perylene or derivatives thereof, coumarin or derivatives thereof, rubrene or derivatives thereof, quinacridone or derivatives thereof, squalium or derivatives thereof, porphyrin or derivatives thereof, styryl dyes, tetracene or derivatives thereof, pyrazolone or derivatives thereof, decacyclene Alternatively, derivatives thereof, phenoxazone or derivatives thereof, and the like can be mentioned.

  The organic light emitting layer 23 is provided according to the type of the pixel 2, that is, the red pixel 2R, the green pixel 2G, and the blue pixel 2B. An organic light-emitting layer 23 that emits red light is provided on the hole transport layer 22 of the recess 14 corresponding to the red pixel 2R, and green is displayed on the hole injection layer 21 of the recess 14 corresponding to the green pixel 2G. An organic light emitting layer 23 that emits light is provided, and an organic light emitting layer 23 that emits blue light is provided on the hole transport layer 22 of the recess 14 corresponding to the blue pixel 2B. Hereinafter, the organic light emitting layer 23 included in the red pixel 2R, the green pixel 2G, and the blue pixel 2B may be referred to as a red light emitting layer 23R, a green light emitting layer 23G, and a blue light emitting layer 23B.

  The cathode 30 is provided on the organic light emitting layer 23. The material of the cathode 30 is preferably a material having a low work function, easy electron injection into the organic light emitting layer 23, and high electrical conductivity. Further, as described in the present embodiment, when the organic EL device 1 takes out light from the anode 12 side, the light emitted from the organic light emitting layer 23 is reflected by the cathode 30 toward the anode 12 side. The material of the cathode 30 is preferably a material having a high visible light reflectance. For the cathode 30, for example, an alkali metal, an alkaline earth metal, a transition metal, a Group 13 metal of the periodic table, or the like can be used. As the cathode 30, a transparent conductive cathode made of a conductive metal oxide, a conductive organic material, or the like can be used.

  The thickness of the cathode 30 is appropriately set in consideration of electric conductivity and durability. The thickness of the cathode 30 is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.

  In the present embodiment, the cathode 30 is formed over the entire display area where the plurality of pixels 2 are provided. That is, the cathode 30 is formed not only on the organic light emitting layer 23 but also on the bank 13 and is provided as the anode 12 common to the plurality of pixels 2.

  The cathode 30 is provided on the organic light emitting layer 23. For example, a predetermined inorganic layer may be provided between the organic light emitting layer 23 and the cathode 30 provided thereon.

  Although not shown in FIGS. 1 and 2, a sealing substrate is usually provided on the cathode 30 of the organic EL device 1. In addition, the organic EL device 1 may have a known configuration provided in, for example, an organic EL panel display panel.

  In the organic EL device 1 having the above configuration, the structure in each pixel 2, that is, the pixel region 2a portion of the substrate 11, the anode 12, the organic EL structure portion 20, and the pixel region 2a portion of the cathode 30 constitute an organic EL element portion. doing. Therefore, the organic EL device 1 has a configuration in which a plurality of organic EL element portions partitioned by the bank 13 are integrally connected with the substrate 11 and the anode 12 in common.

In the organic EL device 1, as shown in FIG. 2, the minimum thickness of the organic light emitting layer 23 in the pixel 2, that is, the organic light emitting layer 23 in the recess 14 is d (nm), and the thickness direction of the substrate 11 is The area of the organic light emitting layer 23 that is equal to or less than (d + predetermined value) [nm] is A1, the pixel area is A2, and the flatness α (%) of the organic light emitting layer 23 is expressed by the following formula (I). The flatness α is 70% or more.
α = (A1 / A2) × 100 (I)
The pixel area is the area of the pixel region 2a, and is also the area of the region defined by the end 13b (see FIGS. 2 and 3) facing the pixel region 2a in the bank 13. The predetermined value (nm) is preferably 2 or more and 15 or less. If it is this range, it will be easy to evaluate flatness more appropriately. The predetermined value is more preferably 5 or more and 12 or less, and may be 10, for example.

  The minimum thickness d (nm) may be different in each of the red light emitting layer 23R, the green light emitting layer 23G, and the blue light emitting layer 23B. In this case, in the organic EL device 1, the flatness α of each of the red light emitting layer 23R, the green light emitting layer 23G, and the blue light emitting layer 23B is 70% or more.

  Next, the manufacturing method of the organic EL device 1 will be described. Here, the manufacturing method of the organic EL device 1 after preparing the board | substrate 10 with a bank is demonstrated. As shown in FIG. 4, the manufacturing method of the organic EL device 1 includes a step of forming the organic structure 40 (organic structure forming step) S10 and a step of forming the organic light emitting layer 23 (organic light emitting layer forming step). S12, a step of calculating the flatness α of the organic light emitting layer 23 (flatness calculation step) S14, a step of determining whether the flatness α is equal to or higher than a desired value (determination step) S16, and the cathode 30 are formed. Step (cathode formation step) S18.

  When manufacturing the organic EL device 1, first, an organic structure forming step S10 is performed. In the organic structure forming step S10, as shown in FIG. 5, the hole injection layer 21 and the hole transport layer 22 are provided on the anode 12 provided in the pixel region 2a, in other words, provided in the recess 14. An organic structure 40 that is a laminate of the hole injection layer 21 and the hole transport layer 22 is formed in this order by a coating method.

  Specifically, a coating liquid containing a hole injection material is dropped on the anode 12 of the recess 14 to form a coating film, and then the hole injection layer 21 is formed by drying the coating film.

  Examples of the coating method include an ink jet printing method. However, as long as it is a coating method capable of forming a layer in the recess 14, other known coating methods such as a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, and a spray coating method are used. The screen printing method, the flexographic printing method, the offset printing method, and the nozzle printing method may be used. Preferably, the screen printing method, the flexographic printing method, the offset printing method, and the nozzle printing method may be used.

  The solvent used in the coating solution is not limited as long as the hole injection material can be dissolved. For example, a chloride solvent such as chloroform, methylene chloride, and dichloroethane, an ether solvent such as tetrahydrofuran, and an aromatic hydrocarbon solvent such as toluene and xylene. Ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate.

  The method for drying the coating film is not limited as long as the coating film can be dried, and examples thereof include vacuum drying and heat drying.

  Next, a coating liquid containing a hole transport material is dropped on the hole injection layer 21 in the recess 14 to form a coating film, and then the coating film is dried to form the hole transport layer 22. Examples of the solvent and the drying method may be the same as those for the hole injection layer 21.

  The structure obtained through the organic structure forming step S10, that is, the structure including the banked substrate 10 and the organic structure 40 formed in the recess 14 is referred to as an intermediate structure 3. In the organic structure forming step S <b> 10, two intermediate structures 3 are prepared, and the thickness distribution of the organic structure 40 included in one of the intermediate structures 3 is measured in order to obtain the thickness of the organic light emitting layer 23. Keep it.

  As shown in FIG. 4, after performing organic structure formation process S10, organic light emitting layer formation process S12 is implemented. In the organic light emitting layer forming step S12, as shown in FIG. 6, the organic light emitting layer 23 is formed on the organic structure 40 by a coating method. Specifically, a coating liquid containing a light emitting material to be the organic light emitting layer 23 is dropped into the recess 14 to form a coating film (coating film forming process), and then the coating film is dried (drying process). Then, the organic light emitting layer 23 is formed. In the concave portions 14 corresponding to the red pixel 2R, the green pixel 2G, and the blue pixel 2B, a red light emitting layer 23R and a green light emitting layer are respectively formed using a coating liquid containing a red light emitting material, a green light emitting material, and a blue light emitting material. 23G and the blue light emitting layer 23B are formed.

  As the coating method, an inkjet printing method is exemplified, but other known coating methods exemplified in the case of the hole injection layer 21 can also be used. The solvent used in the coating solution is not limited as long as it can dissolve the light emitting material, and may be the same as the solvent exemplified in the formation of the hole injection layer 21.

  The method for drying the coating film is not limited as long as the coating film can be dried as in the case of the hole injection layer 21, and examples thereof include vacuum drying and heat drying.

  By the organic light emitting layer forming step S <b> 12, a laminated body 41 including the organic structure 40 and the organic light emitting layer 23 is formed on the anode 12 in the recess 14.

  In the organic light emitting layer forming step S12, the organic light emitting layer 23 is formed on the organic structure 40 included in each of the two intermediate structures 3 prepared in the organic structure forming step S10. The thickness of the laminate 41 formed in the intermediate structure 3 used for the measurement of the thickness of the organic structure 40 is measured, and the thickness distribution of the laminate 41 is acquired.

  As shown in FIG. 4, after performing the organic light emitting layer forming step S12, the flatness calculating step S14 is performed. In the flatness calculation step S14, first, the thickness distribution of the organic light emitting layer 23 is calculated. Specifically, the thickness of the organic light emitting layer 23 is based on the thickness distribution of the organic structure 40 acquired in the organic structure forming step S10 and the thickness distribution of the stacked body 41 acquired in the organic light emitting layer forming step S12. Calculate the height distribution. That is, when viewed from the thickness direction of the substrate 11, the thickness of the organic light emitting layer 23 is calculated by calculating the difference in the thickness of the organic structure 40 from the thickness of the stacked body 41 at each position in the recess 14. Get the distribution. Next, the flatness α is calculated using the calculated thickness distribution of the organic light emitting layer 23 and the formula (I).

  As shown in FIG. 4, after the flatness calculation step S14 is performed, the determination step S16 is performed. In the determination step S16, it is determined whether or not the flatness α is greater than or equal to a desired value. In the present embodiment, the “desired value” is 70%. At this time, when the flatness α is different in the red light emitting layer 23R, the green light emitting layer 23G, and the blue light emitting layer 23B, the flatness that is the smallest of the flatness α in the red light emitting layer 23R, the green light emitting layer 23G, and the blue light emitting layer 23B. Judge by the value of degree α. The flatness α of the plurality of organic light emitting layers 23 corresponding to the same color (red, green, or blue) can be regarded as the same flatness α because the formation conditions of the material of the coating liquid are the same. Therefore, for example, for one color, the flatness α of one organic light emitting layer 23 may be calculated. However, as in the case of different colors, a plurality of organic light emitting layers 23 may be sampled and the smallest flatness α among them may be used for the determination.

  In the determination step S16, when the flatness α is 70% (desired value) or more (“Yes” in S16 of FIG. 4), the step of forming the cathode 30 on the organic light emitting layer 23 (cathode formation step) S18 To implement. Examples of the method for forming the cathode 30 include vapor deposition methods and coating methods similar to those for the anode 12. In this step, the cathode 30 is formed over the organic light emitting layer 23 formed in the plurality of recesses 14. Thereby, the organic EL device 1 shown in FIGS. 1 and 2 is obtained.

  In the determination step S16, when the flatness α is less than 70% (desired value) (in the case of “No” in S16 of FIG. 4), the step of changing the formation condition of the organic light emitting layer 23 (formation condition changing step) S20 To implement. For example, the example of the forming conditions to be changed is the drying speed in the step of drying the coating film formed by dropping the light emitting material onto the recesses 14 by the coating method in the organic light emitting layer forming step S12.

  Here, the relationship between the drying speed and the thickness distribution of the organic light emitting layer will be described with reference to FIG. FIG. 7 schematically shows the relationship between the drying rate and the thickness distribution of the organic light emitting layer. Specifically, an example of the thickness distribution when the drying speed is increased, an example of the thickness distribution when the drying speed is decreased, and an example of the thickness distribution between them are schematically shown. In the three thickness distributions, the horizontal axis indicates the position of the recess 14 in the cross section, and x1 and x2 indicate the positions of the side surfaces 13a and 13a of the bank 13 that define the recess 14, respectively. In the above three thickness distributions, the vertical axis indicates the thickness.

  According to the knowledge of the inventors of the present application, when the drying speed is high, the thickness of the central portion of the organic light emitting layer 23 becomes thin and concave as shown schematically in the thickness distribution on the left side in FIG. When the drying speed is low, the organic light emitting layer 23 schematically shown in the thickness distribution on the right side in FIG. 7 tends to be convex due to the thick central portion. Therefore, the thickness distribution of the organic light emitting layer 23 can be adjusted by adjusting the drying speed based on the thickness distribution of the organic light emitting layer 23 used in the determination step S16. The thickness shown in the center in FIG. The organic light emitting layer 23 having a flat thickness distribution like the thickness distribution can be realized.

  Other parameters that can be changed in the formation conditions of the organic light emitting layer 23 include, for example, the composition ratio of the coating liquid.

  After performing the formation condition changing step S20, the organic light emitting layer 23 is formed again under the changed formation conditions. In FIG. 4, the case where it returns to organic light emitting layer formation process S12 after formation condition change process S20 is illustrated as an example. If it is such a flowchart, in the organic structure formation process S10, the some intermediate structure 3 is produced, and it returns to the organic light emitting layer formation process S12, and the intermediate structure which has not formed the organic light emitting layer 23 What is necessary is just to form the organic light emitting layer 23 on the organic structure 40 which 3 has. Or you may return to organic structure formation process S10 after formation condition change process S20.

The inventors of the present application have conducted intensive studies and found that there is a certain relationship between the flatness α of the organic light emitting layer and the luminance distribution rate β. The luminance distribution ratio beta, luminance distribution rate for calculating (or test) organic EL devices of the pixels (luminance distribution ratio calculation pixels) of when light is emitted, the maximum brightness of the pixel is I _MAX, (I _MAX × When an area having a luminance of 0.7) or higher is A3 and a pixel area is A4, the area is defined by the following formula (II).
β = (A3 / A4) × 100 (II)
The definition of the pixel area A4 is the same as the pixel area A3 in the organic EL device 1 used for calculating the luminance distribution rate β.

  The relationship between the flatness α of the organic light emitting layer and the luminance distribution rate β will be described based on Experimental Examples 1 to 15. In the description of Experimental Examples 1 to 15, the components corresponding to the components of the organic EL device 1 are denoted by the same reference numerals for the sake of convenience. In Experimental Examples 1 to 15, the predetermined value for defining the area A1 for calculating the flatness α was 10. That is, in Experimental Examples 1 to 15, the area A1 of the organic light emitting layer 23 that was (d + 10) nm or less was used.

  In Experimental Examples 1 to 4, organic EL devices E1 to E4 shown in FIG. That is, the hole injection layer 21, the hole transport layer 22, and the organic light emitting layer 23 were formed from the anode 12 side in the recess 14 of the banked substrate 10, and the cathode 30 was formed on the organic light emitting layer 23. The hole injection layer 21, the hole transport layer 22, and the organic light emitting layer 23 were formed by forming a coating film using a coating solution corresponding to each layer by an ink jet printing method and vacuum drying. A blue light emitting layer 23 </ b> B was used as the organic light emitting layer 23 in each recess 14. Therefore, the organic EL devices E1 to E4 are the organic EL devices 1 that emit blue light.

  The same hole injection material, hole transport material, and blue light emitting material were used for the hole injection layer 21, the hole transport layer 22, and the organic light emitting layer 23 in the organic EL devices E1 to E4. However, in the organic EL devices E <b> 1 to E <b> 4, the composition ratio of the coating liquid when forming the corresponding hole injection layer 21, hole transport layer 22 and organic light emitting layer 23 is different. In the vacuum drying performed when forming the organic light emitting layer 23 of the organic EL devices E1 to E4, the temperature in the vacuum chamber was 13 ° C to 30 ° C. In vacuum drying, the drying speed of the coating film was slow in the order of the organic EL device E1, the organic EL device E2, the organic EL device E3, and the organic EL device E4.

The flatness α of the organic light emitting layer 23 included in the organic EL devices E1 to E4 is as shown in Table 1. The luminance distribution rate β when the organic EL devices E1 to E4 were caused to emit light under the same conditions was as shown in Table 1. The pixel areas A2 and A4 used in the calculation of the flatness α and the luminance distribution rate β were the same.

  In Experimental Examples 5 to 9, organic EL devices E5 to E9 shown in FIG. The configuration of the organic EL devices E5 to E9 has the same configuration as that of the organic EL devices E1 to E4 except that the green light emitting layer 23G is used as the organic light emitting layer 23 instead of the blue light emitting layer 23B. The organic EL devices E5 to E9 are organic EL devices 1 that emit green light. Also in the manufacture of organic EL devices E5 to E9. The hole injection layer 21, the hole transport layer 22, and the organic light emitting layer 23 were formed by forming a coating film using a coating liquid corresponding to each layer by an ink jet printing method and vacuum drying. In the vacuum drying performed when the organic light emitting layer 23 was formed, the temperature in the vacuum chamber was 13 ° C to 30 ° C.

  For the hole injection layer 21 and the hole transport layer 22 in the organic EL devices E5 to E9, the same hole injection material and hole transport material as in the organic EL devices E1 to E4 were used. However, in the organic EL devices E5 to E9, the composition ratio of the coating liquid when forming the hole injection layer 21, the hole transport layer 22, and the organic light emitting layer 23 is different. In vacuum drying at the time of forming the organic light emitting layer 23 of the organic EL devices E5 to E9, the organic EL device E5, the organic EL device E6, the organic EL device E7, the organic EL device E8, and the organic EL device E9 are sequentially coated. The drying speed was fast.

Table 2 shows the flatness α of the organic light emitting layer 23 included in the organic EL devices E5 to E9. Table 2 shows the luminance distribution ratio β when the organic EL devices E5 to E9 were made to emit light under the same conditions as the organic EL devices E1 to E4. The pixel areas A2 and A4 used in the calculation of the flatness α and the luminance distribution rate β were the same.

  In Experimental Examples 10 to 14, organic EL devices E10 to E14 shown in FIG. The configuration of the organic EL devices E10 to E14 has the same configuration as that of the organic EL devices E1 to E5 except that the red light emitting layer 23R is used as the organic light emitting layer 23 instead of the blue light emitting layer 23B. The organic EL devices E10 to E14 are organic EL devices that emit red light. The hole injection layer 21, the hole transport layer 22, and the organic light emitting layer 23 (red light emitting layer 23R) are coated using a coating liquid corresponding to each layer by an ink jet printing method as in the case of the organic EL devices E1 to E4. After the film was formed, it was formed by vacuum drying. In the vacuum drying performed when the organic light emitting layer 23 was formed, the temperature in the vacuum chamber was 13 ° C to 30 ° C.

  For the hole injection layer 21 and the hole transport layer 22 in the organic EL devices E10 to E14, the same hole injection material and hole transport material as in the organic EL devices E1 to E4 were used. In the organic EL devices E10 to E14, the composition ratios of the coating liquids when forming the hole injection layer 21, the hole transport layer 22, and the organic light emitting layer 23 are different. In vacuum drying at the time of forming the organic light emitting layer 23 of the organic EL devices E10 to E14, the coating film is formed in the order of the organic EL device E10, the organic EL device E11, the organic EL device E12, the organic EL device E13, and the organic EL device E14. The drying rate was slow.

The flatness α of the organic light emitting layer 23 included in the organic EL devices E10 to E14 was as shown in Table 3. Table 3 shows the luminance distribution ratio β when the organic EL devices E10 to E14 are caused to emit light under the same conditions as the organic EL devices E1 to E4. The pixel areas A2 and A4 used in the calculation of the flatness α and the luminance distribution rate β were the same.

  FIG. 9 is a graph showing the relationship between the flatness α (%) and the luminance distribution rate β (%) shown in Tables 1 to 3. In FIG. 9, the horizontal axis indicates the flatness (%), and the vertical axis indicates the luminance distribution rate (%). In FIG. 9, the same symbols (rectangles, triangles, etc.) are adopted for each color as the symbols plotted with the luminance distribution rate β (%) corresponding to each flatness α (%) shown in Tables 1 to 3. doing. And the number attached | subjected to each symbol has shown the number of the experiment example.

  FIG. 10 is a drawing showing the thickness distribution of the organic light emitting layer 23 (blue light emitting layer 23B) in the organic EL devices E1 to E4. FIG. 11 is a drawing showing the thickness distribution in the recess 14 of the organic light emitting layer 23 (green light emitting layer 23G) in the organic EL devices E5 to E9. FIG. 12 is a drawing showing the thickness distribution in the recess 14 of the organic light emitting layer 23 (red light emitting layer 23R) in the organic EL devices E10 to E14. 10 to 12, the horizontal axis indicates the position of the recess 14 in the cross section, and the positions of x1 and x2 indicate the positions of the side surfaces 13a and 13a of the bank 13 that define the recess 14, respectively. However, the positions of x1 and x2 vary due to experimental errors and plots, but in FIGS. 10 to 12, x1 and x2 are roughly arranged near the positions corresponding to the side surfaces 13a and 13a. Yes. The vertical axis | shaft of FIGS. 10-12 has shown the thickness of the organic light emitting layer 23. FIG.

  From the results shown in FIG. 9, it can be understood that the flatness α and the luminance distribution rate β are substantially linear, that is, one-to-one for each of blue, green, and red. Therefore, the luminance distribution rate β can be adjusted by determining the flatness α. The materials of the blue light emitting layer 23B, the green light emitting layer 23G, and the red light emitting layer 23R are different. Therefore, the relationship between the flatness α and the luminance distribution rate β is satisfied without depending on the material of the organic light emitting layer 23.

  As described above, since the flatness α and the luminance distribution rate β have a certain relationship, the luminance distribution can be obtained by adjusting the flatness α of the organic light emitting layer 23 as described in the method of manufacturing the organic EL device 1. A certain value or more can be realized as the rate β. For example, if the flatness α is 70% or more, a luminance distribution rate β of 70% or more can be realized. Accordingly, the thickness of the layers below the organic light emitting layer 23 (in the example shown in FIG. 2, the hole injection layer 21 and the hole transport layer 22) is measured, and the layers made of different materials are made flat. The productivity of the organic EL device 1 is significantly improved as compared with the case where the manufacturing conditions are adjusted every time.

  Based on the relationship between the flatness α and the luminance distribution ratio β, the luminance distribution ratio β of the manufactured organic EL device 1 can be estimated by evaluating the flatness α. Therefore, the manufacturing cost of the organic EL device 1 can also be reduced. This point will be described in comparison with a case where an organic EL device is manufactured once by forming a cathode on the organic light emitting layer, and then a luminance distribution rate is measured and fed back to the formation conditions of the organic light emitting layer.

  In order to manufacture an organic EL device once by forming a cathode on the organic light emitting layer, the cathode must be formed at least on the organic light emitting layer. Therefore, after manufacturing, the luminance distribution ratio β of the organic EL device is calculated. As a result, if it is necessary to change the formation conditions of the organic light emitting layer, it is necessary to form a cathode again. On the other hand, in the method for manufacturing the organic EL device 1, the luminance distribution rate β of the organic EL device 1 is estimated based on the relationship between the flatness α and the luminance distribution rate β at the stage where the organic light emitting layer 23 is formed. it can. As a result, unnecessary cathode formation can be omitted, and as a result, the manufacturing cost can be reduced.

  The organic EL device 1 shown in FIG. 1 can be manufactured by the manufacturing method shown in FIG. Therefore, the configuration of the organic EL device 1 can be a configuration that contributes to an improvement in productivity. Further, since the flatness α of the organic light emitting layer 23 included in the organic EL device 1 is 70% or more, the organic EL device 1 can realize 70% or more as the luminance distribution ratio β.

  As described above, when forming the blue light emitting layer 23B of the organic EL devices E1 to E4, the drying speed of the coating film was slow in the order of the organic EL devices E1 to E4. When forming the green light emitting layer 23G of the organic EL devices E5 to E9, the drying speed of the coating film was higher in the order of the organic EL devices E5 to E9. When forming the red light emitting layer 23R of the organic EL devices E10 to E14, the drying rate of the coating film was slow in the order of the organic EL devices E110 to E14. 10 to 12, as shown in FIG. 7, when the drying speed of the coating film to be the organic light emitting layer 23 is high, the organic light emitting layer 23 tends to be formed so that the central portion is concave. It can be seen that the organic light-emitting layer 23 tends to be formed so that the central portion becomes convex as the drying speed of the coating film decreases. Therefore, for example, the flatness α of the organic light emitting layer 23 can be adjusted by adjusting the drying speed.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. For example, although the hole injection layer and the hole transport layer are formed between the organic light emitting layer and the electrode of the banked substrate, they may not be formed. For example, the organic light emitting layer may be formed adjacent to the electrode of the substrate with bank. Alternatively, the hole transport layer may not be formed, and the organic light emitting layer may be formed adjacent to the hole injection layer.

  An electron injection layer may be provided between the organic light emitting layer and the cathode. The electron injection layer is a layer having a function of improving electron injection efficiency from the cathode to the organic light emitting layer. A known electron injection material can be used for the electron injection layer. Thus, when providing an electron injection layer, an electron carrying layer may be provided between an electron injection layer and an organic light emitting layer. The electron transport layer is a layer having a function of improving electron injection from the cathode, the electron injection layer, or the electron transport layer closer to the cathode. A known electron transport material can be used for the electron transport layer.

  In the description so far, the first electrode included in the banked substrate is the anode, and the second electrode is the cathode. However, the first electrode may be a cathode and the second electrode may be an anode. In the above description, the organic EL device has three types of pixels, that is, the red pixel 2R, the green pixel 2G, and the blue pixel 2B. However, the color type is not particularly limited, and all the pixels The same color may be emitted.

  Although the desired value in the determination step S16 has been described as 70%, the desired value is not limited to 70%. What is necessary is just to set according to the performance requested | required in an organic EL device. The desired value is preferably 70% or more, and the desired value exceeding 70% is preferably 80%. Examples of organic EL devices are not limited to organic display panels, and may be organic light emitting devices.

  DESCRIPTION OF SYMBOLS 1 ... Organic EL device, 2 ... Pixel, 2a ... Pixel region, 10 ... Substrate with bank, 11 ... Substrate, 11a ... Surface, 12 ... Anode (first electrode), 13 ... Bank, 20 ... Organic EL structure DESCRIPTION OF SYMBOLS 21 ... Hole injection layer, 22 ... Hole transport layer, 23 ... Organic light emitting layer, 30 ... Cathode, 40 ... Organic structure, 41 ... Laminated body.

Claims (10)

On the first electrode of the bank-equipped substrate, comprising: a substrate; a bank provided on the substrate for defining a pixel; and a first electrode provided on a pixel region corresponding to the pixel on the substrate. And a step of forming an organic light emitting layer by a coating method;
Calculating the flatness of the organic light emitting layer;
Determining whether the flatness of the organic light emitting layer is equal to or higher than a desired flatness;
Forming a second electrode on the organic light emitting layer;
With
In the step of calculating the flatness, the minimum thickness of the organic light emitting layer is d (nm), and the area of the organic light emitting layer that is (d + predetermined value) nm or less when viewed from the thickness direction of the substrate is When A1 is set, the area of the pixel region is A2, and the flatness is α, the flatness is calculated by the following formula (1).
In the determining step, when the flatness is equal to or higher than a desired value, the step of forming the second electrode is performed,
In the determining step, when the flatness is less than a desired value, in the step of forming the organic light emitting layer, the organic light emitting layer is formed by changing the formation conditions of the organic light emitting layer.
Manufacturing method of organic EL device.
α = (A1 / A2) × 100 (1) The predetermined value is 2 or more and 15 or less,
The manufacturing method of the organic EL device of Claim 1. The predetermined value is 10.
The manufacturing method of the organic EL device of Claim 1. The desired flatness is set based on the relationship between the flatness defined by the equation (1) for the luminance distribution ratio calculation pixel and the luminance distribution ratio in the luminance distribution ratio calculation pixel. ,
The luminance distribution rate is a ratio of the area of a region having 70% or more of the maximum luminance of the area of the luminance distribution rate calculation pixel in the luminance distribution rate calculation pixel.
The manufacturing method of the organic EL device as described in any one of Claims 1-3. The desired flatness is 70%.
The manufacturing method of the organic EL device as described in any one of Claims 1-4. Forming an organic structure including at least one organic layer on the first electrode of the banked substrate;
In the step of forming the organic light emitting layer, the organic light emitting layer is formed on the organic structure.
The manufacturing method of the organic EL device as described in any one of Claims 1-5. In the step of calculating the flatness,
The thickness distribution of the organic light emitting layer is calculated from the difference between the thickness distribution of the organic structure and the thickness distribution of the laminate in which the organic light emitting layer is formed on the organic structure,
The flatness is calculated based on the thickness distribution of the organic light emitting layer.
The manufacturing method of the organic EL device of Claim 6. A banked substrate having a substrate, a bank provided on the substrate for defining pixels, and a first electrode provided on a pixel region corresponding to the pixel on the substrate;
An organic light emitting layer provided on the first electrode;
A second electrode provided on the organic light emitting layer;
With
The minimum thickness of the organic light-emitting layer is d (nm), the area of the organic light-emitting layer that is (d + predetermined value) nm or less when viewed from the thickness direction of the substrate is A1, and the area of the pixel region is When A2 and the flatness of the organic light emitting layer is (A1 / A2) × 100 [%],
The flatness is 70% or more,
Organic EL device. The predetermined value is 2 or more and 15 or less,
The organic EL device according to claim 8. The predetermined value is 10.
The organic EL device according to claim 8.

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