JP2010160946A - Method for manufacturing organic electroluminescence device - Google Patents

Abstract

An organic EL device that facilitates relative alignment between a substrate and a relief printing plate and can form an organic light-emitting layer with a uniform film thickness in a desired region by a simple method without reducing manufacturing efficiency. An apparatus manufacturing method is provided.
A method of manufacturing an organic EL device is a method of manufacturing an organic EL device including an organic EL element including an anode, a cathode, and an organic light emitting layer, and a substrate on which the organic EL element is mounted. A step of disposing a plurality of partition walls 15 substantially in parallel on the substrate 11, a step of performing a liquid repellent treatment on the surface of the substrate 11 provided with the partition walls 15, and a lyophilic base layer 19 on the surface of the anode 12. A step of forming the organic light emitting layer 23 in a region partitioned by the partition wall 15, and the step of forming the organic light emitting layer 23 is substantially parallel to the arrangement of the plurality of partition walls 15. An organic luminescent ink is supplied between the plurality of partition walls 15 along the longitudinal direction of the partition walls 15 using a relief printing plate having a plurality of convex portions arranged.
[Selection] Figure 1-7

Description

  The present invention relates to a method for manufacturing an organic electroluminescence device having a plurality of organic electroluminescence elements (hereinafter sometimes referred to as organic EL elements) on a substrate.

  The organic EL element includes a pair of electrodes and an organic light emitting layer. When a voltage is applied to the organic EL element, holes and electrons are injected from each electrode, and light is emitted by combining the injected holes and electrons in the light emitting layer. Compared to inorganic EL elements, organic EL elements can be driven at a low voltage and have high luminance. Therefore, practical application of organic EL devices such as display devices and lighting devices having a plurality of organic EL elements has been studied. ing.

  In a display device using a plurality of organic EL elements, for example, a grid-like partition is provided on a substrate, and each organic EL element is provided in a region partitioned by the partition (hereinafter sometimes referred to as a pixel region). Therefore, it is necessary to form an organic light emitting layer constituting each organic EL element for each pixel region.

  As a method for forming an organic light emitting layer in each pixel region, a coating method has been studied from the simplicity of the process. For example, an ink containing an organic light-emitting material (hereinafter sometimes referred to as an organic light-emitting ink) is selectively supplied to each pixel area using a coating method such as a relief printing method or an ink-jet printing method, and further dried to emit organic light. A method of forming a layer has been proposed (see, for example, Patent Document 1).

  When an organic light emitting layer is formed by a coating method, in order to prevent the ink supplied to a predetermined pixel area from flowing out to other adjacent pixel areas, usually, ink repellency is given to the partition wall surface in advance. Yes. With reference to FIGS. 4-1 and 4-2, the outline of the formation method of the organic light emitting layer by the said prior art is demonstrated. As shown in FIG. 4A, a plurality of first electrodes 102 made of an ITO film, an inorganic insulating layer 103 that insulates between adjacent first electrodes 102, and an organic partition layer 104 are first formed on a substrate 101. To do. At the stage where the inorganic insulating layer 103 and the organic partition layer 104 are formed, these are members that are lyophilic with respect to the organic light emitting ink.

Next, CF ₄ plasma treatment (liquid repellency treatment) is performed on the surface of the substrate 101 on which the above-described members are formed. Since members made of organic material (organic partition wall layer 104) is likely to be fluorinated by the CF ₄ plasma treatment, the organic partition wall layer 104 by the CF ₄ plasma treatment surface readily fluorinated, liquid repellency is imparted. Member (inorganic insulating layer 103, first electrode 102) made of other inorganic Because hardly fluorinated by CF ₄ plasma treatment, this CF ₄ inorganic insulating layer 103 by plasma treatment, the first electrode 102 is maintained lyophilic To do. Therefore, only the organic partition layer 104 is selectively given liquid repellency to the organic light emitting ink by the CF ₄ plasma treatment, and the surface state is selectively changed.

  In the prior art shown in FIG. 4B, the organic light emitting ink 106 is discharged from the inkjet head 105 to the pixel region (between the organic partition wall layers 104). The organic light-emitting ink 106 that has landed on a predetermined pixel region is repelled by the organic partition layer 104 having liquid repellency, so that it does not flow out to the adjacent pixel region beyond the organic partition layer 104, and does not flow into the landed pixel region. It is kept as it is. By drying the organic light-emitting ink 106, the organic light-emitting layer can be patterned on the first electrode 102.

JP 2006-286243 A

  When supplying organic luminescent ink to each pixel area using a relief printing plate instead of the inkjet printing method described above, the plurality of projections provided on the relief printing plate and the plurality of pixel areas are accurately aligned with each other. There is a need to. In the ink jet printing method, it is only necessary to move either the ink jet head 105 or the substrate, so that the alignment is relatively easy. However, in the relief printing method, a plurality of convexes can be formed while moving both the relief printing plate and the substrate. Part and a plurality of pixel areas must be accurately aligned with each other, so the displacement tolerance is small, the positional accuracy in the axial direction and circumferential direction of the relief printing plate, and the angular accuracy in the feed direction of the substrate There was a problem that it became difficult and efficient production became difficult.

  Although the surface of the layer on which the organic light emitting layer is formed (the first electrode 102 in FIG. 4) is lyophilic as described above, the organic light emitting ink is still selectively supplied into each pixel region. Sometimes, the organic light emitting ink is repelled in the periphery of the pixel region and in the pixel region, and there is a possibility that uniform application of the organic light emitting ink to the entire pixel region may not be realized. In the relief printing method, since ink is supplied to the pixel area through the relief printing plate, the ink is dried on the relief printing plate, and ink having a high viscosity is supplied to the pixel area. Therefore, in particular, the relief printing method makes it difficult for the ink to wet and spread in the pixel area, and it is difficult to uniformly apply the organic light-emitting ink to the entire pixel area. The organic light emitting layer thus formed has a non-uniform film thickness, and in some cases, a hole is generated in a portion where the organic light emitting ink is repelled. For this reason, the area of the pixel region that actually emits light may be less than the design value, or unevenness in light emission may occur, and as a result, the light emission characteristics will be significantly degraded.

  The present invention has been made in view of the above-described problems of the prior art, and the problem is that the alignment between the substrate and the relief printing plate can be facilitated, and a uniform technique can be obtained without reducing the production efficiency. An object of the present invention is to provide a method of manufacturing an organic EL device capable of forming an organic light emitting layer having a thickness in a desired region.

In order to solve the above problems, the present invention employs the following configuration.
[1] A plurality of organic electro circuits each including a first electrode, a second electrode paired with the first electrode, and an organic light emitting layer disposed between the first electrode and the second electrode. A method for producing an organic electroluminescence device comprising a luminescence element and a substrate on which the plurality of organic electroluminescence elements are mounted,
A preparation step of preparing a substrate on which the first electrode is formed;
A partition arrangement step of arranging a plurality of partition walls substantially in parallel on the substrate on which the first electrode is formed;
A liquid repellent treatment step of performing a liquid repellent treatment on the substrate surface provided with the partition wall from the side on which the organic electroluminescence element is mounted in the thickness direction of the substrate;
A lyophilic underlayer that forms a lyophilic underlayer having higher lyophilicity on the ink containing the organic light emitting material for forming the organic light emitting layer than the partition subjected to the liquid repellent treatment. Formation formation process;
After the lyophilic underlayer forming step, an organic light emitting layer forming step of forming an organic light emitting layer by supplying ink containing the organic light emitting material in a region partitioned by the partition;
Forming the second electrode;
Including
In the organic light emitting layer forming step, the organic light emission is performed along a longitudinal direction of the partition using a relief printing plate having a plurality of convex portions arranged substantially parallel to the arrangement of the plurality of partitions. Supplying ink including a material between the plurality of partition walls;
A method for manufacturing an organic electroluminescence device.
[2] The method for producing an organic electroluminescent device according to [1], wherein in the lyophilic underlayer forming step, the lyophilic underlayer is formed by a dry method.
[3] The method for producing an organic electroluminescence device according to [1] or [2], wherein the lyophilic underlayer is a layer made of a metal oxide or a metal complex oxide.
[4] The method for producing an organic electroluminescence device according to [3], wherein the metal oxide forming the lyophilic underlayer is molybdenum oxide or tungsten oxide.
[5] The method for manufacturing an organic electroluminescence device according to any one of [1] to [4], wherein the liquid repellent treatment is a plasma treatment using a fluorine-based gas.
[6] The organic electroluminescence according to any one of [1] to [5], wherein an insulating layer defining a plurality of pixel regions in which pixels are formed is provided on the substrate on which the first electrode is formed. Device manufacturing method.
[7] From the above [1], the relief printing plate has a cylindrical shape or a columnar shape, and the plurality of projections are arranged so that longitudinal directions of the plurality of projections overlap in a circumferential direction. The manufacturing method of the organic electroluminescent apparatus as described in any one of [6].

According to the method for manufacturing an organic EL device of the present invention, it is easy to align the substrate and the relief printing plate, and the organic light-emitting layer having a uniform thickness can be formed by a simple method without reducing the manufacturing efficiency. An organic EL device including an organic EL element that can be formed in a region and has little emission unevenness can be manufactured.
Therefore, the organic EL device produced by the method for producing an organic EL device of the present invention can be suitably applied as a display device such as an illumination device, a planar light source, and a flat panel display.

  Embodiments of the present invention will be described below with reference to the drawings. For ease of understanding, the scale of each member in the drawing may differ from the actual scale. The present invention is not limited to the following description, and can be appropriately changed without departing from the gist of the present invention. In an organic EL device equipped with an organic EL element, there are members such as electrode lead wires. However, in the explanation of the present invention, description thereof is omitted because it is not required directly. For convenience of explanation of the layer structure and the like, in the example shown below, the explanation will be made together with a diagram in which the substrate is arranged below. However, the organic EL element and the organic EL device equipped with the organic EL element are not necessarily arranged in this arrangement. Is not done. In the following description, one of the thickness directions of the substrate may be referred to as “upper” or “upper”, and the other of the substrate thickness directions may be referred to as “lower” or “lower”.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
An embodiment of a method for manufacturing an organic EL device according to the present invention will be described, and then an embodiment of the structure of the organic EL device targeted by the manufacturing method according to the present invention will be described.
A plurality of pixels are provided in the organic EL device 10 (see FIG. 1-7) manufactured according to the first embodiment. A region in which pixels are formed, that is, a pixel region, is partitioned by a partition wall surrounding the region, and a planar shape thereof is appropriately set according to specifications, for example, a substantially rectangular shape, a substantially elliptical shape, or an oval shape. Each pixel is composed of an organic EL element. An organic EL element includes a light emitting layer containing an organic compound (hereinafter referred to as “organic light emitting layer”) sandwiched between a pair of electrodes and the electrodes, and various layers are sequentially stacked on a substrate. Made.

  The method for manufacturing an organic EL device of the present invention includes a first electrode, a second electrode paired with the first electrode, and an organic light emitting layer disposed between the first electrode and the second electrode. A method for manufacturing an organic electroluminescence device, comprising: a plurality of organic electroluminescence elements comprising: a substrate on which the plurality of organic electroluminescence elements are mounted; and a preparation for preparing a substrate on which a first electrode is formed A step of arranging a plurality of barrier ribs substantially in parallel on the substrate on which the first electrode is formed; and the organic electroluminescence element in the thickness direction of the substrate is mounted. From the side, a liquid repellent treatment process for repelling the surface of the substrate provided with the partition walls, and an ink containing an organic light emitting material for forming an organic light emitting layer rather than the liquid repellent partition walls. A lyophilic underlayer forming step for forming a lyophilic underlayer having high lyophilicity on the first electrode; and after the lyophilic underlayer forming step, in a region partitioned by the partition wall An organic light emitting layer forming step of forming an organic light emitting layer by supplying ink containing the organic light emitting material; and a step of forming the second electrode. In the organic light emitting layer forming step, the plurality of partition walls An ink containing the organic light emitting material is supplied between the plurality of partition walls along the longitudinal direction of the partition walls using a relief printing plate having a plurality of protrusions disposed substantially in parallel with each other. To do.

<A> Substrate Preparation Step The substrate preparation step is a preparation step of preparing a substrate on which the first electrode is formed. A substrate on which the first electrode is formed is prepared by forming the first electrode on the substrate. Alternatively, a substrate on which the first electrode is formed may be prepared by obtaining a substrate on which the first electrode is formed from the market. In this embodiment, the first electrode is used as an anode and the second electrode is used as a cathode. However, as another embodiment, the first electrode may be used as a cathode and the second electrode may be used as an anode.
FIG. 1-1 is a cross-sectional configuration diagram illustrating a substrate preparation process of the method for manufacturing an organic EL device according to the first embodiment of the present invention, and is a cross-sectional line (II)-(I It is sectional drawing seen from -I). FIG. 2A is a plan view of the substrate of FIG. 1-1. In this embodiment, an anode is formed as a first electrode on a substrate to prepare a substrate on which the first electrode is formed. In the substrate preparation step, first, a substrate made of a substrate material is prepared. When using a substrate having a low gas barrier property such as a plastic substrate, a lower sealing film is formed on the substrate 11 as necessary.

  An anode 12 corresponding to the first electrode is pattern-formed on the substrate 11 using any of the anode materials described later. When the anode 12 is a transparent electrode, as described later, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), tin oxide, zinc oxide, indium oxide, A transparent electrode material such as zinc aluminum composite oxide is used. For example, in the case of using ITO, the electrode pattern is formed as a uniform deposited film on the substrate 11 by a sputtering method, and then patterned into an island shape or a line shape by photolithography. In addition to the sputtering method, the anode may be formed by a vacuum deposition method, an ion plating method, a plating method, or the like.

<B> Insulating Layer Forming Step The insulating layer forming step is a step of forming a pixel region by providing an insulating layer so as to cover the exposed surface of the first electrode formed on the substrate in the substrate preparing step.
FIG. 1-1 is a cross-sectional configuration diagram illustrating an insulating layer forming step of the method for manufacturing an organic EL device according to the first embodiment of the present invention, and is a cross-sectional line (II)-( It is sectional drawing seen from II). FIG. 2A is a plan view of the substrate of FIG. 1-1.

After the anode 12 is formed, for example, a lattice-like insulating layer 13 is formed. The insulating layer 13 is formed by forming an insulating film made of an inorganic insulating material such as SiO ₂ or SiN by a known method such as a plasma CVD method or a sputtering method, and then performing photolithography and etching, followed by patterning. obtain. A region where the insulating film is removed corresponds to the pixel region 14. It is important that the insulating layer 13 exhibits insulating properties. If the insulating layer 13 does not have insulating properties, current may flow between different pixels, which may cause display defects.

As shown in FIG. 2A, the rectangular region covered with the lattice-like insulating layer 13 becomes the pixel region 14, and the patterned anode 12 is exposed in the pixel region 14.
In addition, the opening shape of the pixel partitioned by the insulating layer 13 may be any of a circular shape, an elliptical shape, and a square shape. However, since the ink composition has surface tension, in the case of a square shape, the corner portion is rounded. It is preferable to be tinged.
In the case where the insulating layer 13 is not provided, the anode 12 is exposed in a strip shape, but this strip-shaped region becomes a pixel region.

<C> Partition Disposition Step The partition disposition step is a step of disposing a plurality of partition walls substantially in parallel on the substrate on which the first electrode is formed.
1-2 is a cross-sectional configuration diagram illustrating a partition arrangement step of the method for manufacturing an organic EL device according to the first embodiment of the present invention, and is a cross-sectional line (I-II)-( It is sectional drawing seen from I-II). FIG. 2-2 is a plan view of the substrate on which the partition walls are formed, and is a plan view of the substrate on which the partition walls shown in FIG. 1-2 are formed.
After forming the insulating layer 13, in the partitioning step, first, a photosensitive material is applied on the substrate 11 on which the insulating layer 13 is formed, and a photoresist film is laminated. Next, this photoresist film is patterned in a stripe shape by photolithography. As shown in FIGS. 1-2 and 2-2, by patterning the photoresist film of the substrate 11 in a stripe shape, a plurality of insulating partition walls 15 arranged in a stripe shape are formed on the anode 12. To do. Further, the region partitioned by the partition wall 15 forms a concave groove 16, and the light emitting layer forming region 17 in which the organic light emitting layer is formed is partitioned into stripes when viewed from one side in the thickness direction of the substrate.
Here, “arranged in stripes” means that the plurality of partition walls 15 are arranged in parallel in vertical stripes or horizontal stripes.
In the present embodiment, the anodes 12 are arranged in stripes, and the partition walls 15 are disposed so as to overlap the gaps between the anodes 12 in the extending direction of the anode 12 when viewed from one side in the thickness direction of the substrate 11. 2, a plurality of pixel regions 14 in which pixels are formed are set along the partition wall 15. The partition walls 15 may be arranged in a stripe shape in a direction orthogonal to the direction in which the anode 12 extends.
The light emitting layer forming region 17 is a region sandwiched between the facing surfaces 15 a of the adjacent partition walls 15. 1-2 to 1-8, the cross-sectional shape of the partition wall 15 cut along a plane perpendicular to the extending direction of the partition wall 15 is a trapezoidal shape having a wide substrate 11 side. As the distance from the insulating layer 13 increases, the width increases.

  As described above, the insulating layer 13 that defines the plurality of pixel regions 14 in which pixels are formed is provided on the substrate 11 on which the anode 12 is formed, and the partition 15 is provided on the insulating layer 13, so that the adjacent partition A plurality of pixel regions 14 are provided between 15 and along the partition.

  The main role of the partition 15 is to prevent insulation between adjacent pixels partitioned by the partition 15 and to prevent color mixing between adjacent pixels. Therefore, the height dimension is set high. Therefore, the partition wall 15 may be formed somewhat thicker than the total thickness of laminated films such as a lyophilic underlayer and an organic light emitting layer formed on the pixel region 14. On the other hand, the role of the insulating layer 13 is to insulate a plurality of pixels of the same color arranged along the partition wall 15 and has no role in preventing color mixing. When the insulating layer 13 becomes thicker, the device becomes thicker by that amount, and a step formed near the boundary between the exposed surface 13a of the insulating layer 13 and the pixel region 14 may affect the properties of the organic light emitting layer. Therefore, the thickness of the insulating layer 13 is preferably thin as long as electrical insulation can be achieved. In this embodiment, the height of the insulating layer 13 from the substrate 11 is the insulating layer 13 of the partition wall 15. It is designed to be lower than the height from. From this standard, it is preferable to set the height of the partition wall 15 to 2 to 3 μm and the height of the insulating layer 13 to 0.1 to 0.2 μm. Note that the insulating layer 13 can be omitted depending on the electrical conductivity of the organic material.

  The insulating photosensitive material (photoresist composition) forming the partition wall 15 may be either a positive resist or a negative resist. As the insulating photosensitive material for constituting the partition wall 15, specifically, polyimide, acrylic resin, and novolak resin photosensitive compounds can be used. This photosensitive material may contain a light-shielding material for the purpose of improving the display quality of the organic EL element.

The method for producing the partition wall 15 having the above structure is not particularly limited, but for example, it can be produced as follows.
A photoresist layer having a thickness of 2 to 3 μm is formed on the grid-like insulating layer 13, and the photoresist layer is exposed through a stripe-shaped mask, so that the resist is only between a plurality of anodes 12 arranged in the stripe shape. Develop and heat cure to leave a layer.
The resist layer patterned in the stripe form constitutes the partition wall 15.

  The photosensitive material (photoresist composition) for forming the photoresist layer can be applied by a coating method using a spin coater, bar coater, roll coater, die coater, gravure coater, slit coater or the like. . After curing, the coating film is patterned into stripes having a desired dimension using conventional photolithography.

  As shown in FIGS. 1-2 to 1-7, the sectional shape of the partition wall 15 cut along a plane perpendicular to the extending direction of the partition wall 15 is a trapezoidal shape having a wide substrate 11 side. The shape is not limited to this, and may be a rectangular shape or a bowl shape.

  Further, the anodes 12 are insulated from each other by the insulating layer 13 on the substrate 11, and the light emitting layer forming region 17 is partitioned by the partition wall 15, but between the striped anodes 12 formed on the substrate 11. In the case where the partition wall 15 is formed on the substrate and the striped pixel region is formed, the insulating layer 13 is omitted, and the partition 15 has a function of insulating the anodes 12 from each other and a function of partitioning the ink applied between the partition walls. You may make it have simultaneously. In this case, the partition wall to be formed is formed using the same material as the partition wall 15 described above.

<D> Liquid-repellent treatment step The liquid-repellent treatment step is a step of performing a liquid-repellent treatment on the substrate surface provided with the partition walls from the side on which the organic EL element is mounted in the thickness direction of the substrate.
In the present specification, “liquid repellency” means that the ink supply target surface has a low affinity for an ink (organic light-emitting ink) (or a solvent thereof) containing an organic light-emitting material for forming an organic light-emitting layer. . The presence or absence of liquid repellency can be determined by the contact angle between the organic light emitting ink and the substrate. The contact angle is defined as the angle formed by the contact portion of the liquid droplet dropped on the solid surface and the solid surface.

  In this specification, it is defined that the solid surface has liquid repellency when the contact angle between the droplet and the solid surface is 30 ° or more. In addition, when the contact angle is less than 30 °, the solid surface is defined as being lyophilic with respect to the liquid and easily wet. In this case, when a liquid is applied, a good quality film is formed which spreads uniformly on the solid surface.

The liquid repellent treatment is a treatment for increasing the contact angle between the droplet and the solid surface, and includes a method of performing plasma treatment using a fluorine-based gas and a method of applying a material having liquid repellency, These can be appropriately selected depending on the material of the surface to which liquid repellency is desired.
When the surface to which liquid repellency is to be imparted is formed of an organic material, both a method of applying a material having liquid repellency as a liquid repellency treatment and a method of performing a plasma treatment using a fluorine-based gas You can choose. In plasma treatment using a fluorine-based gas, vacuum plasma treatment using a fluorine-based gas such as CF ₄ or SF ₆ or atmospheric pressure plasma treatment can be applied.

  On the other hand, when the surface to which liquid repellency is to be imparted is formed of an inorganic material, it is difficult to impart good liquid repellency even when plasma treatment using a fluorine-based gas is performed. Therefore, it is preferable to perform the liquid repellent treatment by a method of applying a liquid repellent material. As the liquid repellent material, a fluorine-based resin having a fluorine in the molecule, a surfactant, a silane coupling material, or the like can be used.

As shown in FIG. 1C, in this embodiment, the surface of the partition wall 15 is subjected to a liquid repellent treatment, and the liquid repellent layer 18 is formed on the surface of the partition wall 15. Thereby, high liquid repellency can be imparted to the surface of the partition wall 15.
1-3 to 1-7, the liquid repellent layer 18 represents the state of the surface of the partition wall 15 that has been subjected to the liquid repellent treatment. In the case of using the plasma treatment, actually, until the layer is formed. However, for the sake of convenience of illustration, it is represented as a layer. In addition, when using a method of applying a material having liquid repellency without using plasma treatment, a layer is formed.

As a method of forming a liquid repellent film on the surface of the partition wall 15 after the partition wall 15 is formed, a method of modifying the surface by replacing the functional group of the organic material on the surface of the partition wall 15 with fluorine, The method of vaporizing and depositing on the partition 15 surface can be mentioned. Specifically, plasma treatment using CF ₄ gas as an introduction gas can be given. Compared to the electrode such as the anode 12 and the insulating layer 13, the organic partition 15 is easily fluorinated by CF ₄ gas, and the surface of the partition 15 can be selectively made liquid-repellent by performing plasma treatment.

In the present embodiment, the partition wall 15 is formed of an organic material, the anode 12, and the insulating layer 13 are formed of an inorganic material. Since the partition 15 which is a surface to which liquid repellency is desired is formed of an organic material, the surface of the substrate 11 is subjected to plasma treatment using a fluorine-based gas. By this treatment, the liquid repellent layer 18 is formed on the surface of the partition wall 15, and high liquid repellency can be imparted only to the surface of the partition wall 15.
Note that since the anode 12 and the insulating layer 13 are formed of an inorganic material, the anode 12 and the insulating layer 13 remain in a lyophilic surface even when the plasma treatment is performed.

  When the anode 12, the insulating layer 13, and the partition wall 15 are all formed of an inorganic material, the partition wall 15 that is a surface to which liquid repellency is desired is formed of an inorganic material. The process which apply | coats the material which has property is performed. Thereby, liquid repellency is imparted to the surfaces of the anode 12, the insulating layer 13, and the partition wall 15.

  In addition, in order to impart liquid repellency to the surface of the partition wall 15, the partition wall 15 is formed and then coated with a liquid repellent material to impart liquid repellency to the surface of the partition wall 15. A liquid repellent substance may be added to the photosensitive material for formation. The liquid repellency is preferably liquid repellant even with respect to an ink for forming a hole injection layer, which will be described later, and an organic light emitting ink containing an organic light emitting material for forming an organic light emitting layer.

  As the liquid repellent compound used when a liquid repellent substance is added to the photosensitive material, a silicone compound or a fluorine-containing compound is used. Since these liquid repellent compounds exhibit liquid repellency in both the organic light emitting ink (coating liquid) used for forming the organic light emitting layer described later and the organic material ink (coating liquid) such as a hole injection layer, the liquid repellent compound is suitably used. Can be used.

<E> Lipophilic underlayer forming step In the lyophilic underlayer forming step, an ink (organic light emitting ink) containing an organic light emitting material for forming an organic light emitting layer rather than a liquid-repellent partition wall is used. This is a step of forming a lyophilic underlayer having high lyophilicity on the first electrode.

As shown in FIG. 1-4, a lyophilic ground layer 19 is formed on the anode 12 and the insulating layer 13 in the light emitting layer forming region 17. The region where the lyophilic underlayer 19 is formed is in the light emitting layer forming region 17.
In this step, the mask 20 having the opening 20a is disposed on the substrate 11, and the lyophilic underlayer 19 is formed in the light emitting layer forming region 17 by vacuum vapor deposition. The lyophilic underlayer 19 is for making the organic luminescent ink uniformly wet and spread on it in a later step, and provides a lyophilic surface.

  Further, as a method of forming the lyophilic underlayer 19 having a predetermined pattern, a lyophilic underlayer is formed on the entire surface of the anode 12 and the insulating layer 13 in the light emitting layer forming region 17 of the substrate 11 in addition to the above-described vacuum deposition method. A method of patterning the lyophilic underlayer 19 by a photolithography process after forming 19 may be employed.

  In the present embodiment, the lyophilic underlayer 19 provided between the anode and the organic light emitting layer functions as at least one of layers such as a hole injection layer, a hole transport layer, and an electron blocking layer as described later. .

In this embodiment, the surface of the partition wall 15 is subjected to a liquid repellent treatment to form the liquid repellent layer 18, and then the lyophilic ground layer 19 is formed in the light emitting layer forming region 17 of the substrate 11. Thus, when an inorganic material is used as the lyophilic underlayer 19, the lyophilic underlayer 19 remains in a lyophilic surface even when plasma treatment using CF ₄ gas as the introduction gas is performed. The liquid repellent layer 18 can be formed only on the surface of the partition wall 15. Therefore, when an inorganic material is used as the lyophilic underlayer 19, after the lyophilic underlayer 19 is formed by reversing the order of the lyophobic treatment step and the lyophilic underlayer step, The liquid repellent layer 18 may be formed on the surface of the partition wall 15 by processing.

<F> Organic Light-Emitting Layer Forming Process The organic light-emitting layer forming process is an organic light emitting process in which an ink containing an organic light-emitting material (organic light-emitting ink) is supplied into a region partitioned by a partition after the lyophilic underlayer forming process It is a process of forming a layer.
As shown in FIG. 1-5, after the lyophilic underlayer 19 which is a lyophilic region is formed, the organic light emitting ink 21 is supplied into the region (light emitting layer forming region) partitioned by the partition 15.
The organic light emitting layer forming step is characterized in that the organic light emitting ink 21 is applied using a relief printing method, and a relief printing plate used in that case is formed between the plurality of partition walls 15 as shown in FIG. A plurality of strips each having a width corresponding to the width and arranged in stripes in the circumferential direction perpendicular to the axial direction Y of the plate cylinder at intervals corresponding to the intervals at which the plurality of partition walls 15 are arranged. It is to use a relief printing plate 23 provided with the projections 22. Further, the relief printing plate 23 is preferably cylindrical or columnar, and the plurality of projections 22 are preferably arranged so that the longitudinal direction of the projections 22 overlaps the circumferential direction.

  The surface of the lyophilic base layer 19 is lyophilic, and the surface of the surrounding partition 15 (the liquid repellent layer 18) is lyophobic. The organic light emitting ink 21 applied to the lyophilic undercoat layer 19 is repelled by the liquid repellent layer 18, so that it does not flow into the other light emitting layer forming region 17 adjacent to the partition wall 15, but is partitioned by the partition wall 15. The light emitting layer forming region 17 is accommodated. Thereby, the organic light emitting ink 21 is disposed on the lyophilic underlayer 19 in the light emitting layer forming region 17.

  In addition, when the organic light emitting ink 21 which is a coating method is applied to the entire surface of the substrate 11 by the relief printing method, the organic light emitting ink 21 may be applied on the partition wall 15. In this case, the organic light emitting ink 21 on the partition wall 15 is applied. Is repelled by the surface of the liquid repellent layer 18 exhibiting liquid repellency, and flows into the light emitting layer forming region 17 divided by the partition wall 15, and is disposed on the lyophilic underlayer 19 in each light emitting layer forming region 17. Is done.

  In addition, after the partition wall 15 is formed as described above, the partition surface 15 is subjected to a liquid repellent treatment so that the opposing surface 15a where the partition walls 15 face each other is also subjected to the liquid repellent treatment, thereby forming the liquid repellent layer 18. Therefore, the organic light emitting ink 21 disposed on the exposed surface 13a of the insulating layer 13 in the light emitting layer forming region 17 after the partition wall 15 is formed is caused by the liquid repellent layer 18 on the surface of the facing surface 15a where the partition walls 15 face each other. In the vicinity where the exposed surface 13a and the opposing surface 15a come into contact with each other, the organic light emitting ink 21 is not disposed and coating unevenness may occur in a part of the light emitting layer forming region 17. However, since there is a gap between the facing surface 15a of the partition wall 15 and the pixel region 14 by the exposed surface 13a of the insulating layer 13, the pixel region 14 is not affected by the liquid repellent layer 18 on the facing surface 15a. The organic light-emitting ink 21 can be disposed on the entire surface of the pixel region 14 on the lyophilic underlayer 19.

As the organic light emitting material used for the organic light emitting layer, a polymer organic light emitting material and / or a low molecular organic light emitting material is used as described later.
In the case of using a polymer organic light emitting material, an ink (organic light emitting ink) containing the organic light emitting material is prepared by dissolving or stably dispersing the polymer material in a solvent. Examples of the solvent for dissolving or dispersing the organic light-emitting material include toluene, xylene, acetone, anisole, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, or a mixed solvent thereof. Among these, aromatic organic solvents such as toluene, xylene, and anisole are preferable because they have good solubility of the organic light emitting material. Moreover, you may add surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber, etc. to the ink of organic luminescent material as needed.

Next, as shown in FIGS. 1-6, the organic light emitting ink 21 is dried to form the organic light emitting layer 24 on the lyophilic underlayer 19.
By drying the organic light emitting ink 21, an organic light emitting layer 24 made of an organic light emitting material is formed on the lyophilic underlayer 19.
The organic light-emitting ink 21 can be dried by a drying mechanism such as a hot plate, an oven, or a dryer while adjusting the temperature by a temperature adjusting mechanism attached to a stage (not shown) that holds the substrate 11.

In addition, you may repeat the application | coating process and drying process of the organic luminescent ink 21 in multiple times. By repeating a plurality of times in this manner, the organic light emitting layer 24 having a desired thickness can be obtained, and the organic light emitting layer 24 having a more uniform thickness can be formed by dispersing coating unevenness.
Moreover, you may repeat an application | coating process and a drying process in multiple times using the different organic luminescent ink 21. FIG. Thus, the organic light emitting layer 24 having a more complicated layer structure can be formed by using a plurality of types of organic light emitting inks 21.

  As described above, in the present invention, before supplying the organic light emitting ink 21, the lyophilic underlayer 19 is provided in advance between the anode 12 and the organic light emitting layer 24, and is substantially corresponding to the arrangement of the plurality of partition walls 15. An ink (organic light-emitting ink) 21 containing an organic light emitting material is supplied between the plurality of partition walls 15 along the longitudinal direction of the partition walls 15 using a relief printing plate 23 having a plurality of convex portions 22 arranged in parallel. Thus, the organic light emitting layer 24 is formed.

  When an organic EL element is manufactured using a substrate provided with a grid-like partition wall as in the prior art, a plurality of regularly arranged rows and columns are arranged so as to correspond to the grid-like partition wall. Since a relief printing plate having projections was used, it was necessary to align both the row direction and the column direction during printing, and the tolerance in printing accuracy was small. Therefore, in the conventional manufacturing method using a substrate provided with a grid-like partition wall, the axial center direction of the relief printing plate, the positional accuracy in the circumferential direction, and the angular accuracy in the feeding direction of the substrate become strict, and efficient manufacturing is difficult. there were. On the other hand, in the present invention, a plurality of convex portions are formed by forming striped (vertical striped or horizontal striped) partition walls 15 on the substrate 11 and arranged substantially parallel to the layout of the plurality of partition walls 15. Since the organic luminescent ink 21 is supplied and printed between the plurality of partition walls 15 along the longitudinal direction of the partition wall 15 using the relief printing plate 23 having 22, it is necessary to align the partition wall 15 in the longitudinal direction. Rather than just aligning in the short direction. As a result, the alignment accuracy in the longitudinal direction of the partition wall 15 can be relaxed, and the manufacturing efficiency of the organic EL device can be improved.

  Further, when the organic light emitting ink 21 is applied in the partition wall 15, in the conventional method, the organic light emitting ink 21 is repelled on the surface of the layer on which the organic light emitting layer 24 is provided, and the coating film is deficient (uneven coating). Sometimes occurred. On the other hand, in this embodiment, before forming the organic light emitting layer 24, the organic light emitting ink 21 is formed by forming the lyophilic underlayer 19 on the anode 12 and the insulating layer 13 in the light emitting layer forming region 17 in advance. On the other hand, it can have higher lyophilicity than the surface of the liquid repellent layer 18. Therefore, the organic light emitting ink 21 supplied into the light emitting layer forming region 17 partitioned by the partition wall 15 is applied so as to spread over the entire surface of the pixel region 14 defined by the insulating layer 13 without causing uneven coating. An organic light emitting coating film can be formed on the entire surface of each pixel region 14, and the organic light emitting layer 24 can be formed on the entire surface of the pixel region 14.

  Further, the surface after the lyophilic underlayer 19 is formed has the light emitting layer forming region 17 lyophilic and the portion of the facing surface 15a of the partition 15 is lyophobic. Even when the organic light emitting ink 21 is supplied so as to protrude from the light emitting layer forming region 17, the organic light emitting ink 21 is repelled outside the light emitting layer forming region 17, and the organic light emitting ink 21 is supplied only to the light emitting layer forming region 17. It becomes a state. Therefore, the organic light emitting layer 24 can be formed in the light emitting layer forming region 17 with almost no defects.

  According to this embodiment, before supplying the organic light emitting ink 21, the lyophilic underlayer 19 is provided on the anode 12 in advance, and the organic light emitting layer 24 is formed by the method of supplying the organic light emitting ink 21 using the relief printing plate 23. By forming the barrier ribs on the substrate 11, the printing deviation when supplying the organic light-emitting ink 21 to the plurality of pixel regions 14 on the substrate 11 by the relief printing method can be prevented, and the manufacturing cost is low and the method is simple. The alignment accuracy in the longitudinal direction of 15 can be relaxed, and the manufacturing efficiency can be improved while forming the organic light emitting layer 24 with high accuracy and no color mixing in the pixel region 14.

<G> Cathode Formation Step As shown in FIG. 1-7, the cathode 25 is formed on the surface of the organic light emitting layer 24. The cathode 25 is formed using any of the materials described later by a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, a laser ablation method, a laminating method for press-bonding a metal thin film, or the like.

  After the cathode 25 is formed, an upper sealing film is formed in order to protect the light emitting function part 26 having the anode 12 -the organic light emitting layer 24 -the cathode 25 as a basic structure. The upper sealing film is composed of at least one inorganic layer and at least one organic layer as necessary. The number of these layers is determined as necessary. Basically, the inorganic layers and the organic layers are alternately stacked.

  As described above, the method of manufacturing the organic EL device according to the present embodiment is characterized in that a partition wall disposing step of disposing a plurality of partition walls substantially in parallel on the substrate on which the first electrode is formed, and the substrate Of the thickness direction of the substrate, from the side where the organic EL element is mounted, a liquid-repellent treatment step for liquid-repellent treatment of the substrate surface provided with the partition wall, and forming an organic light emitting layer than the liquid-repellent-treated partition wall A lyophilic underlayer forming step of forming on the first electrode a lyophilic underlayer having high lyophilicity with respect to the ink containing an organic light-emitting material, and the lyophilic underlayer forming step And an organic light emitting layer forming step of forming an organic light emitting layer by supplying ink containing the organic light emitting material into a region partitioned by the partition, wherein the plurality of partition walls are formed in the organic light emitting layer forming step. Convex with a plurality of convex portions arranged substantially parallel to the arrangement of Using the printing plate, it is an ink containing an organic luminescent material along the longitudinal direction of the partition wall to be supplied to between the plurality of partition walls. The details of each of these steps are as described above.

Therefore, according to the manufacturing method of the organic EL device according to the present embodiment described above, the organic luminescent ink is provided in advance by providing the lyophilic underlayer on the first electrode before supplying the organic luminescent ink. Since the wettability of the surface to which is applied can be increased, the organic light-emitting ink can be spread uniformly over the pixel region.
Further, by using a relief printing plate having convex portions arranged substantially parallel to the arrangement of the partition walls, by supplying the organic light emitting ink between the partition walls along the longitudinal direction of the partition walls, The organic light emitting ink can be supplied to the plurality of pixel regions on the substrate while relaxing the alignment accuracy in the longitudinal direction of the partition on the substrate and preventing printing displacement. For this reason, it is possible to easily form an organic light-emitting layer that does not cause color mixing with high accuracy in each of the pixel regions, thereby improving the manufacturing efficiency of the organic EL device.
Therefore, if the manufacturing method of the organic EL device according to the present embodiment is used, the relative alignment between the substrate and the relief printing plate is facilitated, and the organic light emission having a uniform film thickness is achieved by a simple method without reducing the manufacturing efficiency. The layer can be formed in a desired region, and the light emission unevenness can be reduced while improving the manufacturing efficiency.
Therefore, the organic EL device of the present invention can be preferably used as a display device such as a lighting device, a planar light source, and a flat panel display.

  Next, each configuration of the organic EL device manufactured by the above-described method for manufacturing an organic EL device will be described.

<a> Substrate Any substrate may be used as long as it does not change in the process of forming the organic EL device, and may be a rigid substrate or a flexible substrate. For example, a glass plate, a plastic plate, a polymer film, a silicon plate, and these For example, a laminated board in which is laminated is preferably used. Further, a plastic, a polymer film or the like that has been subjected to a low water permeability treatment can also be used. A commercially available substrate can be used as the substrate. Moreover, the said board | substrate can also be manufactured by a well-known method.

In the bottom emission type organic EL device that extracts light from the organic light emitting layer from the substrate side, a substrate having a high light transmittance in the visible light region is preferably used.
In the top emission type organic EL device that takes out light from the organic light emitting layer from the cathode side, the substrate may be transparent or opaque.

<B> First electrode The first electrode is one of an anode and a cathode, and is provided closer to the substrate than the second electrode which is the other electrode. The first electrode in the present embodiment is an anode, and the anode is a transparent electrode that transmits light from the organic light emitting layer. However, as another form, an organic EL device in which the cathode is formed of a transparent electrode is also possible. is there. As the anode, a metal oxide, metal sulfide or metal thin film having high electrical conductivity can be used, and a high transmittance can be suitably used. The anode can be appropriately selected according to the constituent material of the organic light emitting layer. Can be used. As a material for the transparent anode, for example, a thin film of indium oxide, zinc oxide, tin oxide, ITO, IZO, gold, platinum, silver, copper, or the like is used. Among these, ITO, IZO, and tin oxide are preferable.

  Further, as the constituent material of the anode, a transparent organic conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used.

  In addition, from the viewpoint of facilitating charge injection into the organic light emitting layer, a conductive polymer such as a phthalocyanine derivative and a polythiophene derivative, Mo oxide, amorphous carbon, fluoride is formed on the surface of the anode on the organic light emitting layer side. A layer of 1 nm or more and 200 nm or less, such as carbon or a polyamine compound, or a layer having an average film thickness of 10 nm or less made of a metal oxide, a metal fluoride, an organic insulating material, or the like may be provided.

  The film thickness of the anode can be appropriately selected in consideration of light transmittance and electrical conductivity, and is, for example, 5 nm or more and 10 μm or less, preferably 10 nm or more and 1 μm or less, more preferably 20 nm or more. , 500 nm or less.

<C> Insulating layer The insulating layer ensures electrical insulation between the organic EL elements and defines a pixel region in which the organic light emitting layer is formed. After forming the anode, usually, an insulating layer is formed on the anode and further patterned, so that the pixel region where the organic light emitting layer is formed is divided as viewed from one side in the thickness direction of the substrate. The pixel area corresponds to a light emitting area.

The insulating layer 13 is formed using an inorganic insulating material such as SiO ₂ or SiN. Further, the insulating layer 13 may be formed using the same material as the partition wall 15 described later.

  When a plurality of organic EL elements are formed on a substrate, the insulating layer is patterned to ensure electrical insulation between the organic EL elements and to define a light emitting region. The thickness of the insulating layer is usually set to 0.1 μm or more and 0.2 μm or less.

<D> Partition The partition defines an application region of a constituent material of each organic light emitting layer. After the insulating layer 13 is formed and the pixel region 14 is formed, a photosensitive material is applied to the substrate on which the anode is formed, and a photoresist film is laminated. Next, this photoresist film is patterned into a stripe shape by photolithography to form an insulating partition.

  As described above, the insulating photosensitive material (photoresist composition) for forming the partition wall 15 may be either a positive resist or a negative resist. As for the photosensitive material (photoresist composition) constituting the partition wall 15, as described above, polyimide, acrylic resin, and novolak resin photosensitive compounds are used. This photosensitive material may contain a light-shielding material for the purpose of improving the display quality of the organic EL element.

  As described above, the photosensitive material (photoresist composition) for forming the partition walls 15 can be applied by a coating method using a spin coater, bar coater, roll coater, die coater, gravure coater, slit coater, or the like. it can. After curing, the coating film is patterned into a lattice shape having a desired dimension using conventional photolithography.

<E> Liquid-repellent layer The liquid-repellent layer is a layer formed on the surface of the partition wall by subjecting the substrate on which the light emitting layer forming region is divided by forming the partition wall to liquid-repellent treatment. The liquid repellent layer is formed by a plasma process using a fluorine-based gas or a process of applying a liquid repellent material on the substrate. According to such a configuration, when the surface to be subjected to the liquid repellent treatment is made of an organic substance, it is possible to select from both the plasma treatment using the fluorine-based gas and the treatment for applying the liquid repellent material. Also, when the surface to be subjected to the liquid repellent treatment is made of an inorganic material such as metal or metal oxide, the plasma treatment using a fluorine-based gas is difficult to impart liquid repellency because the surface is hardly fluorinated. The liquid repellent treatment can be carried out by applying the material.

  In this embodiment, the partition wall 15 to be subjected to the liquid repellent treatment is made of an organic material, and the anode 12 and the insulating layer 13 are made of an inorganic material such as a metal or a metal oxide. In order to form the liquid repellent layer 18 and prevent the liquid repellent layer 18 from being formed on the anode 12 and the insulating layer 13, the liquid repellent layer 18 is formed using plasma treatment using a fluorine-based gas as the liquid repellent treatment. In FIGS. 1-3 to 1-7, the liquid repellent layer 18 represents the state of the surface of the partition wall 15 that has been subjected to the liquid repellent treatment as described above. However, for convenience of illustration, it is shown as a layer. In addition, when using a method of applying a material having liquid repellency without using plasma treatment, a layer is formed.

<F> Lipophilic underlayer The lyophilic underlayer is a layer that is provided in contact with the surface of the organic light emitting layer on the anode side, and serves to form the organic light emitting layer uniformly by a coating method. Has lyophilicity to ink.

  In the light emitting layer forming region 17, layers such as a hole injection layer, a hole transport layer, and an electron blocking layer are provided between the anode 12 and the organic light emitting layer 24 as necessary. In the present embodiment, the lyophilic ground layer 19 provided between the anode 12 and the organic light emitting layer 24 functions as at least one of the hole injection layer, the hole transport layer, the electron blocking layer, and the like.

<F-1> Material of the lyophilic underlayer Further, in the present embodiment, the lyophilic underlayer can use an inorganic material or an organic material, and is not particularly limited.
As the inorganic material, a metal oxide or a metal composite is preferable. Specific examples include tungsten oxide, vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide, nickel oxide, barium titanate, and strontium titanate. be able to.
Examples of the organic material include organic materials that are insoluble in organic light-emitting inks, such as organic materials used for a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer.

<F-2> Method for Forming Lipophilic Underlayer In this embodiment, the lyophilic underlayer 19 is directly formed on the surface of the anode 12 and the insulating layer 13 on the light emitting layer forming region 17.

  In the step of forming the lyophilic foundation layer 19, the lyophilic foundation layer 19 is formed by a dry method. By forming the lyophilic underlayer 19 by a dry method rather than a coating method, the lyophilic underlayer 19 can be formed without being affected by the wettability of the surface on which the lyophilic underlayer 19 is formed. it can. As the dry method, general methods such as vapor deposition, sputtering, and CVD can be used. In addition, as a method for patterning the lyophilic underlayer by a dry method, for example, a method using a mask having a film formation region as an opening can be employed.

<G> Organic light emitting layer The light emitting layer is a layer containing a light emitting material, and the organic light emitting layer is a layer containing an organic compound as the light emitting material. The organic light emitting layer contains an organic substance (low molecular compound and / or high molecular compound) that mainly emits fluorescence and / or phosphorescence. Low-molecular compounds and high-molecular compounds used as organic compounds that emit fluorescence and / or phosphorescence are used as light-emitting materials. In the present specification, the polymer is a compound having a polystyrene-equivalent number average molecular weight of 10 ³ or more. Although there is no particular reason for defining the upper limit in the present invention, it is usually a compound having a polystyrene-equivalent number average molecular weight of 10 ⁸ or less. The organic light emitting layer may further contain a dopant material. Examples of the material for forming the organic light emitting layer that can be used in the present invention include the following dye-based materials, metal complex-based materials, polymer-based materials, and dopant materials. In addition, although the organic EL element of the above-mentioned embodiment includes only one organic light emitting layer between the anode and the cathode, it may have a plurality of organic light emitting layers.

<G-1> Dye-type material Examples of the dye-type material include cyclopentamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, and distyrylarylene. Derivatives, pyrrole derivatives, thiophene ring compounds, pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, oxadiazole dimers, pyrazoline dimers, and the like.

<G-2> Metal complex materials Examples of metal complex materials include metal complexes having light emission from triplet excited states such as iridium complexes and platinum complexes, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, and benzoxazolyls. A zinc complex, a benzothiazole zinc complex, an azomethylzinc complex, a porphyrin zinc complex, a europium complex, etc. can be mentioned. Further, as another example of the metal complex material, the center metal has Al, Zn, Be, Ir or the like, or the rare earth metal such as Tb, Eu, Dy or the like, and the ligand is oxadiazole, thiadiazole, phenylpyridine. , Phenylbenzimidazole, metal complexes having a quinoline structure, and the like.

<G-3> Polymeric material Examples of the polymeric material include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, quinacridone derivatives, and coumarins. Derivatives, thiophene ring compounds, those obtained by polymerizing the above dye bodies and metal complex light emitting materials, and the like.
Among the above light-emitting materials, examples of materials that emit blue light include distyrylarylene derivatives, oxadiazole derivatives, and polymers thereof, polyvinylcarbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives. it can. Of these, polymer materials such as polyvinyl carbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives are preferred.
Examples of materials that emit green light include quinacridone derivatives, coumarin derivatives, and polymers thereof, polyparaphenylene vinylene derivatives, polyfluorene derivatives, and the like. Of these, polymer materials such as polyparaphenylene vinylene derivatives and polyfluorene derivatives are preferred.
Examples of materials that emit red light include coumarin derivatives, thiophene ring compounds, and polymers thereof, polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives. Among these, polymer materials such as polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives are preferable.

<G-4> Dopant material A dopant may be added to the light emitting layer for the purpose of improving the light emission efficiency or changing the light emission wavelength. Examples of such dopants include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazolone derivatives, decacyclene, phenoxazone, and the like. In addition, the thickness of such a light emitting layer is usually about 2 nm or more and 2000 nm or less.

<G-5> Method for Forming Organic Light-Emitting Layer The organic light-emitting layer can be formed using the above-described relief printing method.

<H> Second electrode The second electrode is an electrode having a polarity different from that of the first electrode. In this embodiment in which the first electrode corresponds to the anode, the second electrode is the cathode 25. As a material for the cathode, a material having a small work function and easy electron injection into the organic light emitting layer is preferable. The cathode material is preferably a material having high electrical conductivity and high visible light reflectance. Specific examples of such cathode materials include metals, metal oxides, alloys, graphite or graphite intercalation compounds, and inorganic semiconductors such as zinc oxide (ZnO).

  As the metal, an alkali metal, an alkaline earth metal, a transition metal, a group 13 metal of the periodic table, or the like can be used. Specific examples of these metals include lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin, and aluminum. , Scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and the like.

  Examples of the alloy include an alloy containing at least one of the above metals. Specifically, a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, Examples thereof include a lithium-magnesium alloy, a lithium-indium alloy, and a calcium-aluminum alloy.

  The cathode is an electrode having optical transparency as required, for example, when light is taken out from the cathode side. Examples of such light-transmitting cathode materials include conductive oxides such as indium oxide, zinc oxide, tin oxide, ITO and IZO, and conductive organic materials such as polyaniline or derivatives thereof, polythiophene or derivatives thereof. Can do.

  Note that the cathode may have a laminated structure of two or more layers. Moreover, an electron injection layer may be used as a cathode.

  The thickness of the cathode can be appropriately selected in consideration of electric conductivity and durability, but is, for example, 10 nm or more and 10 μm or less, preferably 20 nm or more and 1 μm or less, more preferably 50 nm or more, 500 nm or less.

  Examples of the method for forming the cathode include a vacuum deposition method, a sputtering method, and a laminating method in which a metal thin film is thermocompression bonded as described above. Note that the cathode may have a laminated structure of two or more layers.

<I> Protective film After the cathode 25 is formed as described above, the basic structure includes (anode)-(layer between the anode and the organic light emitting layer)-(organic light emitting layer)-(cathode). In order to protect the light emitting function part 26, a protective film (upper sealing film) for sealing the light emitting function part 26 is formed. This protective film usually has at least one inorganic layer and at least one organic layer. The number of stacked layers is determined as necessary. Basically, inorganic layers and organic layers are alternately stacked.

  Note that a plastic substrate is higher in gas and liquid permeability than a glass substrate, and a light emitting substance such as an organic light emitting layer is easily oxidized and deteriorated by contact with water. When used, even if the light emitting function part is encapsulated by the substrate and the protective film, it is easy to change over time. Therefore, a lower sealing film having a high barrier property against gas and liquid is laminated on the plastic substrate, and then this The light emitting function part is laminated on the lower sealing film. This lower sealing film is usually formed with the same configuration and the same material as the protective film (upper sealing film).

<J> Layer Provided Between Anode and Organic Light-Emitting Layer At least a lyophilic ground layer 19 is provided between the anode 12 and the organic light-emitting layer 24. In addition to the lyophilic base layer 19, a hole injection layer, a hole transport layer, an electron block layer, and the like may be provided. The lyophilic underlayer 19 functions as at least one of these hole injection layer, hole transport layer, and electron block layer.

  The hole injection layer is a layer having a function of improving hole injection efficiency from the anode. The hole transport layer is a layer having a function of improving hole injection from an anode, a hole injection layer, or a hole transport layer closer to the anode. The electron blocking layer is a layer having a function of blocking electron transport. When the hole injection layer and / or the hole transport layer has a function of blocking electron transport, these layers may also serve as an electron blocking layer. The fact that the electron blocking layer has a function of blocking electron transport makes it possible, for example, to produce an element that allows only electron current to flow and confirm the blocking effect by reducing the current value.

<J-1> Hole Injection Layer As described above, the hole injection layer can be provided between the anode and the hole transport layer or between the anode and the organic light emitting layer. As a material constituting the hole injection layer (hole injection material), an ionization potential between one surface of the hole injection layer and two ionization potentials provided adjacent to the other surface is used. The material which has is preferable. Specifically, the material has an ionization potential that is between the ionization potential of the anode 12 and the ionization potential of the surface portion of the organic light emitting layer 23 on the anode 12 side. For example, phenylamine, starburst amine, phthalocyanine, hydrazone derivative, carbazole derivative, triazole derivative, imidazole derivative, oxadiazole derivative having amino group, vanadium oxide, tantalum oxide, tungsten oxide, molybdenum oxide, ruthenium oxide And oxides such as aluminum oxide, amorphous carbon, polyaniline, polythiophene derivatives, and the like.

  As a method for forming the hole injection layer, a method of applying a solution containing a hole injection material on a base layer on which the hole injection layer is laminated, a vacuum deposition method, a transfer method, or the like can be used. As a solvent used for film formation from a solution, any solvent that dissolves a hole injection material may be used. For example, water, a chlorine-based solvent such as chloroform, methylene chloride, dichloroethane, an ether-based solvent such as tetrahydrofuran, toluene, Examples thereof include aromatic hydrocarbon solvents such as xylene, ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate. Specifically, the film can be formed by applying a coating solution in which a material to be a hole injection layer (hole injection material) is dissolved by a coating method in a solvent that dissolves the hole injection material.

  Examples of a method for applying a solution containing a hole injection material on the base layer on which the hole injection layer is laminated include, for example, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, and a roll coating. Method, wire bar coating method, dip coating method, slit coating method, capillary coating method, spray coating method, nozzle coating method and other coating methods, gravure printing method, screen printing method, flexographic printing method, offset printing method, reverse printing method A coating method such as a printing method such as an inkjet printing method can be used, and it is preferably formed by a relief printing method similar to the method for forming the light emitting layer described above.

  The thickness of the hole injection layer is preferably about 5 nm to 300 nm. If the thickness is less than 5 nm, the production tends to be difficult. On the other hand, if the thickness exceeds 300 nm, the driving voltage and the voltage applied to the hole injection layer tend to increase.

<J-2> Hole transport layer Although there is no restriction | limiting in particular as a material which comprises a hole transport layer, For example, N, N'-diphenyl-N, N'-di (3-methylphenyl) 4,4 Aromatic amine derivatives such as' -diaminobiphenyl (TPD), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB), polyvinylcarbazole or derivatives thereof, polysilane or derivatives thereof, Polysiloxane derivative having aromatic amine compound group in side chain or main chain, pyrazoline derivative, arylamine derivative, stilbene derivative, triphenyldiamine derivative, polyaniline or derivative thereof, polythiophene or derivative thereof, polyarylamine or derivative thereof, polypyrrole Or its derivatives, poly (p-phenylene vinylene) Properly derivative thereof or a poly (2,5-thienylene vinylene) or derivatives thereof is illustrated.

  Among these, as the hole transport material used for the hole transport layer, polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain, polyaniline or a derivative thereof, Polymeric hole transport materials such as polythiophene or derivatives thereof, polyarylamine or derivatives thereof, poly (p-phenylene vinylene) or derivatives thereof, or poly (2,5-thienylene vinylene) or derivatives thereof are preferred, and more preferred Is polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, and a polysiloxane derivative having an aromatic amine in the side chain or main chain. In the case of a low-molecular hole transport material, it is preferably used by being dispersed in a polymer binder.

  The method for forming the hole transport layer is not particularly limited, but in the case of a low molecular hole transport material, film formation from a mixed solution containing a polymer binder and a hole transport material can be exemplified. Examples of molecular hole transport materials include film formation from a solution containing a hole transport material.

The solvent used for film formation from a solution is not particularly limited as long as it can dissolve a hole transport material. Chlorine solvents such as chloroform, methylene chloride, dichloroethane, ether solvents such as tetrahydrofuran, toluene, xylene And aromatic hydrocarbon solvents such as acetone, ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate.
Examples of the film forming method from a solution include the same coating method as the above-described film forming method of the hole injection layer.

  As the polymer binder to be mixed, those that do not extremely inhibit charge transport are preferable, and those that weakly absorb visible light are preferably used. For example, polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, poly Examples thereof include vinyl chloride and polysiloxane.

  The thickness of the hole transport layer is not particularly limited, but can be appropriately changed according to the intended design, and is preferably about 1 nm or more and 1000 nm or less. When this thickness is less than the lower limit, production becomes difficult. Or, there is a tendency that the effect of hole transport is not sufficiently obtained. On the other hand, when the upper limit is exceeded, the driving voltage and the voltage applied to the hole transport layer tend to increase. Therefore, as described above, the thickness of the hole transport layer is preferably 1 nm or more and 1000 nm or less, more preferably 2 nm or more and 500 nm or less, and further preferably 5 nm or more and 200 nm or less. .

<J-3> Electron block layer The electron block layer is a layer having a function of blocking electron transport. When the hole injection layer and / or the hole transport layer has a function of blocking electron transport, these layers may also serve as an electron blocking layer.
The fact that the electron blocking layer has a function of blocking electron transport makes it possible, for example, to produce an element that allows only electron current to flow and confirm the blocking effect by reducing the current value.
As an electron block layer, the various materials illustrated as a material of the said positive hole injection layer or a positive hole transport layer, for example can be used.

<Layer provided between cathode and organic light emitting layer>
An electron injection layer, an electron transport layer, a hole blocking layer, and the like are provided between the organic light emitting layer and the cathode as necessary.

When only one layer is provided between the organic light emitting layer and the cathode, the layer is referred to as an electron injection layer. When both the electron injection layer and the electron transport layer are provided between the organic light emitting layer and the cathode, the layer in contact with the cathode is referred to as the electron injection layer, and the layers other than the electron injection layer are referred to as the electron transport layer. .
The electron injection layer is a layer having a function of improving electron injection efficiency from the cathode.
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.
The hole blocking layer is a layer having a function of blocking hole transport.
In the case where the electron injection layer and / or the electron transport layer have a function of blocking hole transport, these layers may also serve as the hole blocking layer.
The fact that the hole blocking layer has a function of blocking hole transport makes it possible, for example, to produce an element that allows only a hole current to flow, and confirm the blocking effect by reducing the current value.

<K-1> Electron Injection Layer As described above, the electron injection layer is provided between the electron transport layer and the cathode, or between the organic light emitting layer and the cathode. The material of the electron injecting layer is appropriately selected according to the type of the organic light emitting layer, and as the material, an alkali metal, an alkaline earth metal, an alloy containing one or more of the metals, an oxide of the metal, a halogen, or the like And a mixture of the above substances.

  Examples of alkali metals or oxides, halides and carbonates thereof include lithium, sodium, potassium, rubidium, cesium, lithium oxide, lithium fluoride, sodium oxide, sodium fluoride, potassium oxide, potassium fluoride, rubidium oxide. , Rubidium fluoride, cesium oxide, cesium fluoride, lithium carbonate and the like.

  Examples of the alkaline earth metals or oxides, halides and carbonates thereof include magnesium, calcium, barium, strontium, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, barium oxide, barium fluoride, and oxide. Examples include strontium, strontium fluoride, and magnesium carbonate.

  Furthermore, a metal, a metal oxide, an organometallic compound doped with a metal salt, an organometallic complex compound, or a mixture thereof can also be used as a material for the electron injection layer.

This electron injection layer may have a stacked structure in which two or more layers are stacked. Specifically, Li / Ca etc. are mentioned. This electron injection layer is formed by vapor deposition, sputtering, printing, or the like.
The thickness of the electron injection layer is preferably about 1 nm or more and 1 μm or less.

<K-2> Electron transport layer As materials for forming the electron transport layer, known materials can be used, such as oxadiazole derivatives, anthraquinodimethane or derivatives thereof, benzoquinone or derivatives thereof, naphthoquinone or derivatives thereof, anthraquinone or Derivatives thereof, tetracyanoanthraquinodimethane or derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene or derivatives thereof, diphenoquinone derivatives, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinoline or derivatives thereof, polyquinoxaline or derivatives thereof, poly Examples include fluorene or a derivative thereof.

  Of these, oxadiazole derivatives, benzoquinone or derivatives thereof, anthraquinones or derivatives thereof, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinoline or derivatives thereof, polyquinoxaline or derivatives thereof, polyfluorene or derivatives thereof are preferred, 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum, and polyquinoline are more preferable.

Although there is no restriction | limiting in particular as the film-forming method of an electron carrying layer, In the low molecular electron transport material, the vacuum evaporation method from powder or the method by the film-forming from a solution or a molten state is illustrated. Examples of the polymer electron transport material include a method of film formation from a solution or a molten state.
Further, when forming a film from a solution or a molten state, a polymer binder may be used in combination.
Examples of the method for forming the electron transport layer from the solution include the same film formation method as the method for forming the hole injection layer from the above-described solution.

  The film thickness of the electron transport layer varies depending on the material used, and is selected so that the driving voltage and the light emission efficiency are appropriate values. At least a thickness that does not cause pinholes is required. Too much is not preferable because the driving voltage of the element increases. Therefore, the thickness of the electron transport layer is, for example, 1 nm or more and 1 μm or less, preferably 2 nm or more and 500 nm or less, and more preferably 5 nm or more and 200 nm or less.

<K-3> Hole blocking layer The hole blocking layer is a layer having a function of blocking hole transport. In the case where the electron injection layer and / or the electron transport layer have a function of blocking hole transport, these layers may also serve as the hole blocking layer.
The fact that the hole blocking layer has a function of blocking hole transport makes it possible, for example, to produce an element that allows only a hole current to flow, and confirm the blocking effect by reducing the current value.

<L> Combinations of Layer Configurations of Light-Emitting Functional Units Containing Anode, Cathode, and Organic Light-Emitting Layer In the organic EL device of the present invention, examples of combinations of layer configurations from the anode 12 to the cathode 25 are shown below.
a) Anode / hole injection layer / organic light emitting layer / cathode b) Anode / hole injection layer / organic light emitting layer / electron injection layer / cathode c) Anode / hole injection layer / hole transport layer / organic light emitting layer / Cathode d) anode / hole injection layer / organic light emitting layer / electron transport layer / electron injection layer / cathode e) anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode f) anode / Hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer / cathode (where the symbol “/” indicates that the layers sandwiching the symbol “/” are stacked adjacent to each other) The same shall apply hereinafter.)
In a) to f), one of the layers provided between the anode and the organic light emitting layer is a lyophilic underlayer.

In the embodiment shown in FIGS. 1-7 and the like, a set of organic light emitting layers is provided. However, as a modification thereof, a mode in which two or more sets of organic light emitting layers are provided in an overlapping manner can be employed. Here, in any one of the layer configurations of (a) to (f) above, when the layered body sandwiched between the anode and the cathode is “repeating unit A”, for example, the following (g) The layer structure shown can also be employed.
g) Anode / (repeat unit A) / charge generation layer / (repeat unit A) / cathode

As an organic EL device having three or more organic light emitting layers, when “(repeating unit A) / charge generation layer” is “repeating unit B”, for example, the layer structure shown in (h) below can be cited. it can.
h) Anode / (Repeating unit B) _n / (Repeating unit A) / Cathode

The symbol “n” represents an integer of 2 or more. (Repeating unit B) _n represents a laminate in which n layers of repeating units B are laminated.
In the layer configurations g) and h), layers other than the anode, electrode, cathode, and organic light emitting layer may be omitted as necessary.

  The charge generation layer is a layer that generates holes and electrons by applying an electric field. Examples of the charge generation layer include a thin film made of vanadium oxide, ITO, molybdenum oxide, or the like.

  In an organic EL element, an anode is usually disposed on the substrate side, but a cathode may be disposed on the substrate side.

  In the organic EL device of this embodiment, an insulating layer having a thickness of 2 nm or less may be provided adjacent to the electrode in order to further improve the adhesion with the electrode or improve the charge injection property from the electrode. In addition, a thin buffer layer may be inserted between each of the aforementioned layers in order to improve adhesion at the interface or prevent mixing.

  The organic EL device according to this embodiment is a bottom emission type element that transmits light from the organic light emitting layer through the transparent anode and emits the light from the transparent substrate to the outside. However, the light from the organic light emitting layer is transparent. The present invention can be similarly applied to other forms of the top emission type in which the cathode is transmitted and emitted from the transparent protective layer to the outside.

  In said other embodiment, the metal thin film illustrated as an anode can be used as a transparent cathode for the transparent cathode which permeate | transmits the light from an organic light emitting layer, for example. In addition, since the metal thin film used for the transparent cathode is formed into a thin film to such an extent that light can be transmitted, the sheet resistance is increased. Therefore, the transparent cathode is preferably constituted by a laminate in which transparent electrodes such as ITO thin films are laminated in a metal foil film shape. Moreover, it is preferable to provide a reflective film having a high reflectance such as silver between the anode and the substrate, and by providing such a reflective film, light directed toward the substrate side can be reflected to the transparent cathode side. And the light extraction efficiency can be improved.

In the method for manufacturing the organic EL device 10 according to the present embodiment, the organic EL device having the configuration in which the anode 12 is disposed as the first electrode on the substrate 11 side has been described. However, the cathode is disposed as the first electrode on the substrate 11 side. An organic EL device configured as described above is also possible. In this configuration, the organic EL device has a cathode (first electrode), a lyophilic underlayer (electron injection layer) 19, an organic light emitting layer 24, an anode (second electrode) on the substrate 11 from the cathode side toward the anode. Electrode) are stacked in this order.
When the first electrode is a cathode and the second electrode is an anode, the lyophilic underlayer 19 functions as at least one of an electron injection layer, an electron transport layer, and an electron block layer.

<Manufactured organic EL device>
As described above, the organic EL device 10 (see FIGS. 1-7) that can be manufactured by the method of manufacturing the organic EL device of the present invention has a plurality of pixels composed of organic EL elements mounted as described above. Device. Regarding the installation of electrical wiring, driving means, etc., various modes in the manufacture of a normal organic EL device can be adopted.

  The organic EL device that can be manufactured by the manufacturing method of the present invention can be used for a display device.

  The organic EL device manufactured by the manufacturing method of the above embodiment is a passive matrix display device manufactured by forming a stripe-shaped first electrode. The manufacturing method of the organic EL device of the present invention is not limited to a passive matrix display device, but an active matrix type using a TFT (Thin Film Transistor) substrate and forming first electrodes arranged in a matrix in an island shape. The present invention can also be applied to the manufacturing of such display devices.

  Further, instead of reducing the shape of each organic EL element as in a display device, the size of each organic EL element is made suitable for illumination or a planar light source, and thus manufactured by the manufacturing method of the present invention. The organic EL device can be suitably applied to a planar light source such as an illumination or a light source of a backlight and a scanner.

  Hereinafter, the present invention will be described more specifically based on production examples and comparative examples, but the present invention is not limited to the following production examples.

  In the following Production Examples 1-1 to 1-4 and Comparative Example 1, in order to confirm the effect of providing the lyophilic underlayer for forming the organic light emitting layer, between the anode and the organic light emitting layer, An organic EL element having a laminated structure provided with a lyophilic underlayer was produced.

(Production Example 1-1)
A substrate obtained by patterning indium tin oxide (ITO) as a first electrode on a transparent glass substrate was prepared.
Next, a positive photoresist (manufactured by Tokyo Ohka Co., Ltd .: OFPR-800) was applied to the entire surface by a spin coating method and dried to form a photoresist layer having a thickness of 1 μm.
Next, after irradiating ultraviolet rays with an alignment exposure machine using a photomask designed to cover the ITO edge, the photoresist in the exposed area is removed with a resist developer (manufactured by Tokyo Ohka Kogyo Co., Ltd .: NMD-3). did. Next, a heat treatment was performed at 230 ° C. for 1 hour on a hot plate to completely heat and cure the resist to obtain an organic insulating layer.

Next, a liquid repellent treatment was performed on the surface of the insulating layer by a vacuum plasma apparatus using CF ₄ gas.
Next, through a metal mask designed so that at least the ITO exposed portion (opening portion) becomes the opening portion, molybdenum oxide was patterned as a lyophilic underlayer by a resistance heating method using a vacuum vapor deposition machine.

(Evaluation 1)
As a result of contact angle measurement with an anisole (surface tension 35 dyn / cm) on an insulating layer and a lyophilic underlayer with an automatic contact angle measuring device (manufactured by EKO Co., Ltd .: OCA20), 48.7 was measured on the organic insulating layer. °, 10 ° or less on the lyophilic underlayer. As a result, it was confirmed that the insulating layer was a liquid repellent layer and the lyophilic underlayer was a lyophilic surface.

  Next, a liquid material using MEH-PPV (poly (2-methoxy-5- (2′-ethyl-hexyloxy) -para-phenylenevinylene) having a weight average molecular weight of about 200,000 as a thin film forming material manufactured by Aldrich Using a mixed solvent of toluene and anisole as a solvent, the concentration of PPV in the prepared liquid material was 1% by weight, and ink was applied onto the molybdenum oxide layer, which is a lyophilic underlayer, by a nozzle coating method. The prepared liquid material was applied and dried to prepare an organic light emitting layer having a thickness of 1000 mm.

(Evaluation 2)
As a result of observing the vicinity of the ITO opening with an optical microscope and observing the pattern formation state of the organic light emitting layer, it was confirmed that the organic light emitting layer was satisfactorily formed on the lyophilic underlayer.

  Next, calcium was vapor-deposited with a thickness of 100 mm as a second electrode, and silver was vapor-deposited with a thickness of 2000 mm as a protective layer. Thus, an organic EL element having a bottom emission structure was produced.

(Evaluation 3)
As a result of connecting the ITO electrode (first electrode) side to the positive electrode and the metal electrode (second electrode) side to the negative electrode, applying a direct current with a source meter and observing the state of the light emitting part, a good light emitting state is obtained. I confirmed that.

(Production Example 1-2)
In Production Example 1-1, elements were produced by the same process except that CF ₄ gas was used as a reactive gas and liquid repellent treatment was performed using an atmospheric pressure plasma apparatus.

(Evaluation 1)
After plasma treatment, contact angle measurement was performed with an anisole (surface tension 35 dyn / cm) using an automatic contact angle measurement device (Eihiro Seiki Co., Ltd .: OCA20). As a result, 52.4 ° on the organic insulating layer, lyophilic underlayer The angle was 10 ° or less. As a result, it was confirmed that the insulating layer was a liquid repellent layer and the lyophilic underlayer was a lyophilic surface.
(Evaluation 2)
After forming the organic light emitting layer, the periphery of the ITO opening was observed with an optical microscope, and the pattern formation state of the organic light emitting layer was observed. As a result, it was confirmed that the organic light emitting layer was well formed on the lyophilic underlayer did.
(Evaluation 3)
The ITO electrode side was connected to the positive electrode, the metal electrode side was connected to the negative electrode, a direct current was applied by a source meter, and the state of the light emitting part was observed. As a result, it was confirmed that a good light emitting state was obtained.

(Production Example 1-3)
Indium tin oxide (ITO) was patterned as a first electrode on the transparent glass substrate.
Next, a silicon oxide layer having a thickness of 2000 mm was formed by a sputtering method.
Next, a positive photoresist (manufactured by Tokyo Ohka Co., Ltd .: OFPR-800) was applied to the entire surface by a spin coating method and dried to form a photoresist layer having a thickness of 1 μm.
Next, after irradiating ultraviolet rays with an alignment exposure machine using a photomask designed to cover the ITO edge, the photoresist in the exposed area is removed with a resist developer (manufactured by Tokyo Ohka Kogyo Co., Ltd .: NMD-3). did.

Next, the silicon oxide was etched using a gas in which CF ₄ and oxygen were mixed by a vacuum dry etching apparatus. Thereafter, the photoresist layer was peeled off to form an inorganic insulating layer.
Next, as a liquid repellent treatment, fluoroalkylsilane (manufactured by Tochem Products Co., Ltd .: MF-160E) was applied by a spin coat method and dried to form a liquid repellent layer.
Next, through a metal mask designed so that at least the ITO exposed portion (opening portion) becomes the opening portion, molybdenum oxide was patterned as a lyophilic underlayer by a resistance heating method using a vacuum vapor deposition machine.

(Evaluation 1)
As a result of contact angle measurement with an anisole (surface tension 35 dyn / cm) on an insulating layer and a lyophilic underlayer using an automatic contact angle measuring device (Eihiro Seiki Co., Ltd .: OCA20), 60.5 ° on the insulating layer. It was 10 ° or less on the lyophilic underlayer. As a result, it was confirmed that the insulating layer was a liquid repellent layer and the lyophilic underlayer was a lyophilic surface.

  A liquid material was prepared using MEH-PPV (poly (2-methoxy-5- (2′-ethyl-hexyloxy) -para-phenylenevinylene) having a weight average molecular weight of about 200,000 as a thin film forming material manufactured by Aldrich. Using a mixed solvent of toluene and anisole as a solvent, the concentration of PPV in the produced liquid material was 1% by weight, and ink was applied on the molybdenum oxide layer, which is a lyophilic underlayer, by a nozzle coating method, An organic light emitting layer having a thickness of 1000 mm was prepared by drying.

(Evaluation 2)
As a result of observing the vicinity of the ITO opening with an optical microscope and observing the pattern formation state of the organic light emitting layer, it was confirmed that the organic light emitting layer was satisfactorily formed on the lyophilic underlayer.

  Next, calcium was vapor-deposited with a thickness of 100 mm as a second electrode, and silver was vapor-deposited with a thickness of 2000 mm as a protective layer.

(Evaluation 3)
The ITO electrode side was connected to the positive electrode, the metal electrode side was connected to the negative electrode, a direct current was applied by a source meter, and the state of the light emitting part was observed. As a result, it was confirmed that a good light emitting state was obtained.

(Production Example 1-4)
In Production Example 1-4, an organic EL element having a top emission structure was produced.
First, the board | substrate which patterned the laminated body formed in order of Cr and indium tin oxide (ITO) as a 1st electrode on the transparent glass substrate was prepared.
Next, a positive photoresist (manufactured by Tokyo Ohka Co., Ltd .: OFPR-800) was applied to the entire surface by a spin coating method and dried to form a photoresist layer having a thickness of 1 μm.
Next, after irradiating ultraviolet rays with an alignment exposure machine using a photomask designed to cover the ITO edge, the photoresist in the exposed area is removed with a resist developer (manufactured by Tokyo Ohka Kogyo Co., Ltd .: NMD-3). did. Next, a heat treatment was performed at 230 ° C. for 1 hour on a hot plate to completely heat and cure the resist to obtain an organic insulating layer.

Next, a liquid repellent treatment was performed on the surface of the insulating layer by a vacuum plasma apparatus using CF ₄ gas.
Next, through a metal mask designed so that at least the ITO exposed portion (opening portion) becomes the opening portion, molybdenum oxide was patterned as a lyophilic underlayer by a resistance heating method using a vacuum vapor deposition machine.

(Evaluation 1)
As a result of contact angle measurement with an anisole (surface tension 35 dyn / cm) on an insulating layer and a lyophilic underlayer with an automatic contact angle measuring device (manufactured by EKO Co., Ltd .: OCA20), 48.7 was measured on the organic insulating layer. °, 10 ° or less on the lyophilic underlayer. As a result, it was confirmed that the insulating layer was a liquid repellent layer and the lyophilic underlayer was a lyophilic surface.

  Next, a liquid material using MEH-PPV (poly (2-methoxy-5- (2′-ethyl-hexyloxy) -para-phenylenevinylene) having a weight average molecular weight of about 200,000 as a thin film forming material manufactured by Aldrich Using a mixed solvent of toluene and anisole as a solvent, the concentration of PPV in the prepared liquid material was 1% by weight, and ink was applied onto the molybdenum oxide layer, which is a lyophilic underlayer, by a nozzle coating method. (Solution) was applied and dried to prepare an organic electroluminescence layer (organic light emitting layer) having a thickness of 1000 mm.

(Evaluation 2)
The periphery of the ITO opening was observed with an optical microscope to observe the state of pattern formation of the organic light emitting layer, and it was confirmed that the organic light emitting layer was satisfactorily formed on the lyophilic underlayer.

  Next, as a second electrode, calcium is deposited to a thickness of 100 mm, and subsequently aluminum is deposited to a thickness of 50 mm. Further, a transparent electrode layer is formed to a thickness of 2000 mm by a counter target type film forming apparatus using indium tin oxide (ITO) as a target. Vapor deposited. Thereby, an organic EL element having a top emission structure was produced.

(Evaluation 3)
The electrode on the laminate side of Cr and ITO is connected to the positive electrode, the electrode side of only ITO is connected to the negative electrode, a direct current is applied by a source meter, and the state of the light emitting part is observed. It was confirmed that a proper light emission state was obtained.

(Comparative Example 1)
In Production Example 1-1, elements were produced by the same process except that the liquid repellent treatment was not performed.

(Evaluation 1)
As a result of contact angle measurement with an anisole (surface tension 35 dyn / cm) using an automatic contact angle measurement device (Eihiro Seiki Co., Ltd .: OCA20) on the insulating layer and the lyophilic underlayer, 12 ° on the organic insulating layer, It was 10 ° or less on the lyophilic underlayer. Thereby, it was confirmed that both the insulating layer and the lyophilic underlayer are lyophilic surfaces.
(Evaluation 2)
After forming the light emitting layer, the periphery of the ITO opening was observed with an optical microscope and the pattern formation state of the organic light emitting layer was observed. As a result, it was confirmed that the organic light emitting layer was significantly wider than the width of the lyophilic underlayer. confirmed.
(Evaluation 3)
When the ITO electrode side was connected to the positive electrode, the metal electrode side was connected to the negative electrode, and a direct current was applied by a source meter, the electrodes were short-circuited, and light emission could not be confirmed.

(Production Example 2)
In Production Example 2 below, organic light emitting ink is provided using a relief printing plate provided with partition walls arranged substantially in parallel, and having concave portions between the partition walls (corresponding to pixel regions) having convex portions corresponding to the concave grooves. The production effect of forming the organic light emitting layer was confirmed.

(Preparation of substrate and formation of anode)
First, an ITO thin film was formed on a transparent glass plate of 200 mm (vertical) × 200 mm (horizontal) × 0.7 mm (thickness), and further patterned to form a striped anode. The repetition interval (pitch) of the anode was 80 μm, and the interval (space width) between the anodes was 10 μm with respect to the anode width (line width) of 70 μm (line / space = 70 μm / 10 μm). The thickness of the anode was 150 nm. A pixel region in which pixels are formed when viewed from one side in the thickness direction of the substrate is set in an island shape on the ITO thin film extending in one direction at a predetermined interval in the one direction.

(Formation of electrical insulation layer)
Next, an insulating film made of SiO ₂ was formed by plasma CVD, and then a plurality of rectangular pixel regions having a width of 50 μm and a length of 150 μm were removed by photolithography and etching to form an electrical insulating layer.

(Formation of partition walls)
Next, a positive photoresist (trade name “OFPR-800”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is used on the entire surface of the substrate, and the conventional photolithography is performed. The partition wall 15 having the shape shown in FIG. 2-2 was formed. The formed partition wall 15 had a width dimension of 30 μm and a height dimension of 2 μm. Further, the adjacent dimension between the partition walls 15 was set to 75 μm.

Next, the partition wall 15 was subjected to a liquid repellency treatment using a vacuum plasma apparatus (trade name “RIE-200L” manufactured by Samco International Co., Ltd.) using CF ₄ gas.

(Letterpress printing plate)
A flexographic printing plate (material: polyester resin) having a structure shown in FIG. 3 was prepared as a relief printing plate having convex portions corresponding to the partition walls. The convex portion 22 of the relief printing plate 23 had a height dimension of 100 μm, a width dimension of 30 μm, and a pitch width of 75 μm, and was formed in stripes in the circumferential direction perpendicular to the axial direction Y of the plate cylinder.

(Formation of hole injection layer)
Next, a suspension of poly (3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (manufactured by Bayer, trade name “BaytronP AI4083”) is prepared, and this suspension is filtered through a 0.2 μm membrane filter. did. This filtrate was applied to the pixel region using the relief printing plate. Subsequently, the coating layer was heat-treated at 200 ° C. for 20 minutes to form an 80 nm-thick hole injection layer.

(Formation of light emitting layer)
As organic light emitting materials, polymer light emitting materials of three colors of red, green, and blue (trade names “RP158 (red)”, “GP1300 (green)”, “BP361 (blue)” manufactured by Summation Co., Ltd.)) are respectively used as solvents ( An organic light emitting ink of 3 colors (concentration: 1% by weight) dissolved in anisole / cyclohexylbenzene = a mixed solvent having a weight ratio of 1/1) was prepared.

  Using the flexographic printing plate having the stripe-shaped convex portion having the above structure, red organic light emitting ink was printed on the corresponding pixel region on the substrate and dried to form a red organic light emitting layer. Similarly, a green organic light emitting ink and a blue organic light emitting ink were sequentially printed and dried to form a green organic light emitting layer and a blue organic light emitting layer. The thickness of the organic light emitting layer of each color was almost the same dimension of 100 nm.

  For printing at this time, “Angstromer SDR-0023 (trade name), plate drum diameter: 80 mm” manufactured by Nissha Printing Co., Ltd. was used as a printing machine. The printing speed was 50 mm / second. Printing was performed in a state in which the plate and the substrate were in contact with each other with a printing push amount of 0 μm, and the plate was pressed from that position by 50 μm (print push amount = 50 μm).

  When the shape of the organic light emitting layer formed in each pixel region was observed with an optical microscope (manufactured by Nikon Corporation, trade name “Optiphoto 88”, objective lens magnification: 50 ×), each organic light emitting layer was separated from the pixel region. It was confirmed that the film was formed in the pixel region without deviation.

(Formation of cathode)
Next, on the organic light emitting layer, calcium was vapor-deposited with a thickness of 100 mm as a cathode, and aluminum was vapor-deposited with a thickness of 2000 mm as an oxidation protective layer. Thus, an organic EL element having a bottom emission structure was produced.

  When the organic light-emitting device obtained as described above was caused to emit light, no blur was observed in multicolor light emission, and a clear multicolor display was obtained.

(Comparative Example 2)
Using a printing plate and printing conditions similar to those of Production Example 2 above, using a substrate provided with partition walls formed in a lattice shape and a relief printing plate having projections corresponding to pixel regions defined by the partition walls, The organic light emitting ink was printed and dried to form an organic light emitting layer. Other than that was carried out similarly to the said manufacture example 2, and manufactured the organic EL element. The formed partition wall had a height of 2 μm, a width of 50 μm, and a length of 150 μm.

  When the manufactured organic EL element was made to emit light, there was bleeding (mixed color) in color development and display unevenness occurred.

It is a section lineblock diagram showing a substrate preparation process of a manufacturing method of an organic EL device concerning a 1st embodiment of the present invention. It is a section lineblock diagram showing a partition arrangement process of a manufacturing method of an organic EL device concerning a 1st embodiment of the present invention. It is a section lineblock diagram showing a liquid repellent layer formation process of a manufacturing method of an organic EL device concerning a 1st embodiment of the present invention. It is a cross-sectional block diagram which shows the lyophilic base layer formation process which forms the lyophilic base layer of the manufacturing method of the organic EL apparatus which concerns on the 1st Embodiment of this invention. It is a section lineblock diagram showing the process of applying organic luminescent ink of the manufacturing method of the organic EL device concerning a 1st embodiment of the present invention. It is a cross-sectional block diagram which shows the light emitting layer formation process of the manufacturing method of the organic electroluminescent apparatus concerning the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the organic electroluminescent apparatus manufactured with the manufacturing method of the organic electroluminescent apparatus concerning the 1st Embodiment of this invention. It is a top view of the board | substrate of FIGS. 1-1. It is a top view of the board | substrate with which the partition concerning FIG. 1-2 was formed. It is the perspective view which showed the structure of the relief printing plate used for this invention, and the positional relationship with the board | substrate at the time of the printing of the organic light emitting layer using this relief printing plate. It is sectional drawing which shows the board | substrate before forming the organic light emitting layer which concerns on a prior art. It is sectional drawing which shows the process of forming the organic light emitting layer which concerns on a prior art.

DESCRIPTION OF SYMBOLS 10 Organic EL device 11 Substrate 12 Anode 13 Insulating layer 13a Exposed surface 14 Pixel region 15 Partition 15a Opposing surface 16 Concave groove 17 Light emitting layer forming region 18 Liquid repellent layer 19 Lipophilic underlayer 20 Mask 20a Opening 21 Organic light emitting ink 22 convex part 23 letterpress printing plate 24 organic light emitting layer 25 cathode 26 light emitting functional part

Claims (7)

A plurality of organic electroluminescence elements each including a first electrode, a second electrode paired with the first electrode, and an organic light emitting layer disposed between the first electrode and the second electrode; A method for producing an organic electroluminescence device comprising a substrate on which the plurality of organic electroluminescence elements are mounted,
A preparation step of preparing a substrate on which the first electrode is formed;
A partition arrangement step of arranging a plurality of partition walls substantially in parallel on the substrate on which the first electrode is formed;
A liquid repellent treatment step of performing a liquid repellent treatment on the surface of the substrate provided with the partition wall from the side on which the organic electroluminescence element is mounted in the thickness direction of the substrate;
A lyophilic underlayer that forms a lyophilic underlayer having higher lyophilicity on the ink containing the organic light emitting material for forming the organic light emitting layer than the partition subjected to the liquid repellent treatment. Formation formation process;
After the lyophilic underlayer forming step, an organic light emitting layer forming step of forming an organic light emitting layer by supplying ink containing the organic light emitting material in a region partitioned by the partition;
Forming the second electrode;
Including
In the organic light emitting layer forming step, the organic light emission is performed along a longitudinal direction of the partition using a relief printing plate having a plurality of convex portions arranged substantially parallel to the arrangement of the plurality of partitions. Supplying ink including a material between the plurality of partition walls;
A method for manufacturing an organic electroluminescence device.   The method for producing an organic electroluminescent device according to claim 1, wherein in the lyophilic underlayer forming step, the lyophilic underlayer is formed by a dry method.   The manufacturing method of the organic electroluminescent apparatus of Claim 1 or 2 whose said lyophilic base layer is a layer which consists of a metal oxide or a metal complex oxide.   The manufacturing method of the organic electroluminescent apparatus of Claim 3 whose metal oxide which forms the said lyophilic base layer is molybdenum oxide or tungsten oxide.   The method for manufacturing an organic electroluminescence device according to claim 1, wherein the liquid repellent treatment is a plasma treatment using a fluorine-based gas.   6. The method of manufacturing an organic electroluminescence device according to claim 1, wherein an insulating layer defining a plurality of pixel regions in which pixels are formed is provided on a substrate on which the first electrode is formed.   The said relief printing plate is cylindrical or column shape, The said some convex part is arranged so that the longitudinal direction of the said several convex part may overlap in the circumferential direction. The manufacturing method of the organic electroluminescent apparatus as described in 1 item | term.

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