JP2014123540A - Organic electroluminescent element and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display panel which allows for manufacturing of an organic EL element free from uneven light emission, by depositing an organic luminescent medium layer in a light-emitting pixel on a substrate, with high planarity and a desired thickness, by using a letterpress printing method, and to provide a manufacturing method therefor.SOLUTION: Since an organic luminescent medium layer can be deposited in a light-emitting pixel on a substrate, with high planarity and a desired thickness, by a structure where the light-emitting pixel is formed on a pixel formation layer in convex shape, and the pixel formation layer is not provided between adjacent light-emitting pixels, an organic EL element free from uneven light emission can be manufactured.

Description

The present invention relates to an organic electroluminescence element (hereinafter, abbreviated as an organic EL element) expected to be used for a display such as an information display terminal, and a method for producing the same.

An organic electroluminescence display (hereinafter abbreviated as an organic EL display) includes at least an anode electrode, an organic light emitting layer, and a cathode electrode on a substrate. By applying an electric field between the electrodes, electrons and holes are generated in the organic light emitting layer. Since the organic EL element is injected and emits light, and the organic EL element is a self-luminous element, display is possible without using a backlight as in a liquid crystal display. In addition, since the element structure is simple, a thin and lightweight element can be manufactured, and active research is currently being conducted. A general organic EL device may include not only an organic light emitting layer but also a light emission auxiliary layer between an anode electrode and a cathode electrode. Examples of the light emission auxiliary layer include a hole transport layer, a hole injection layer, an electron transport layer, and an electron injection layer. Hereinafter, the organic light emitting layer and the light emission auxiliary layer are collectively referred to as an organic light emitting medium layer.

Organic light-emitting materials used for the organic light-emitting medium layer of organic EL devices include low-molecular materials and high-molecular materials. Generally, low-molecular materials are formed into thin films by vacuum film-forming methods (dry coating methods) such as vapor deposition. The However, when a full-color organic EL display is manufactured, for example, in the case of organic EL elements having three different colors of light emission such as R (red), G (green), and B (blue), the organic light emitting layer is a pixel. It is necessary to form a pattern every time. When patterning the organic light emitting layer by a vacuum film forming method, a vapor deposition mask having a fine pattern is used. In the method of performing patterning using a vapor deposition mask, there is a problem that it is difficult to obtain patterning accuracy as the substrate becomes larger. In addition, since it is a dry coating method, there is a problem that foreign matter and protrusions on the surface of the substrate cannot be sufficiently covered, and a short circuit is likely to occur. Moreover, the same problem arises also about organic light emitting medium layers other than an organic light emitting layer.

Thus, an organic light emitting medium material is dissolved or dispersed in a solvent to prepare an ink (coating liquid), and a method of forming a film by a wet coating method such as a coating method or a printing method has been attempted. By using the wet coating method, it is possible to form a thin film uniformly and at high speed. In particular, in a manufacturing process using a large substrate, it is possible to reduce the cost of mass-produced products.

The structure of the organic EL element using the coating type organic light emitting medium material is generally a structure in which an anode electrode / hole transport layer / organic light emitting layer / cathode electrode are laminated in this order, such as an anode electrode and a cathode electrode. Except for the electrodes, all can be produced by a wet coating method. Examples of wet coating methods for forming thin films include slit coating, spin coating, bar coating, dip coating, discharge coating, roll coating, and other coating methods, letterpress printing, ink jet printing, and intaglio printing. There are printing methods.

In particular, selective film formation by the printing method is effective for coating the organic light-emitting layer so as to have three different emission colors of R (red), G (green), and B (blue) for each pixel. It is a manufacturing method.

Among various printing methods, a method using a hard printing plate such as a gravure printing method is not suitable for an organic EL element having a glass substrate. Further, in offset printing using a rubber blanket having elasticity, the rubber blanket is easily swollen by an aromatic solvent that is a solvent of the organic light emitting medium material, and thus it is difficult to stably print with high accuracy. On the other hand, the relief printing method using a resin plate does not swell the plate as seen in offset printing, and because the resin has elasticity, printing on a glass substrate is also possible. Therefore, the relief printing method is most suitable as a method for producing an organic EL element.

In the organic EL element produced by the relief printing method, as shown in Patent Document 1, a pixel partition that divides adjacent pixels is provided. Usually, the pixel partition is patterned by a photolithography method using a photosensitive resin. Providing a pixel partition has effects such as accurate segmentation of the pixel area and prevention of color mixing between adjacent pixels, prevention of leakage current, and reduction of irregularities such as TFT circuits and electrode lines. A protective effect for a driving element such as a provided thin film transistor can also be expected.

However, the film thickness of the pixel partition contributes to the film thickness of the organic light emitting medium layer formed by the relief printing method and the shape within the pixel. More specifically, the ink of the organic light emitting medium layer formed by letterpress printing wets the pixel partition walls, and the amount of ink wetting varies depending on the height of the pixel partition walls, resulting in variations in pixel partition height. And the film thickness of the organic light emitting medium layer changes. When the film formation shape of the organic light emitting medium layer is deteriorated, a difference in film thickness occurs in the pixel, leading to a problem of uneven emission luminance.

The film thickness of the organic light emitting medium layer is important for efficiently emitting light from the organic EL element, and it is necessary to form a thin film of about 0.1 μm. Therefore, it is necessary to design a partition wall thickness for forming the organic light emitting medium layer in a desired film thickness by the relief printing method and flattening the film formation shape.

JP 2001-155858 A

The present invention is proposed to solve the above problems, and the problem to be solved by the present invention is that the organic light emitting medium layer is highly flat in the light emitting pixels on the substrate using a relief printing method, In addition, an organic EL element having no light emission unevenness is produced by forming a film with a desired film thickness.

In order to solve the above-mentioned problem, the invention according to claim 1 is a single layer having a substrate, a plurality of pixel electrodes provided on the substrate, and at least an organic light emitting layer provided on the pixel electrode. An organic EL element having a light emitting medium layer composed of a plurality of layers and a counter electrode facing the plurality of pixel electrodes across the light emitting medium layer, wherein the plurality of pixel electrodes are provided on the substrate. The plurality of pixel formation layers are formed independently of each other.

A second aspect of the present invention is the organic EL element according to the first aspect, wherein an inter-pixel layer is provided between the plurality of adjacent pixel formation layers.

A third aspect of the present invention is the organic EL element according to the first or second aspect, wherein an interlayer insulating film is provided on the pixel formation layer.

A fourth aspect of the present invention is the organic EL element according to the first or second aspect, wherein an interlayer insulating film is provided below the pixel formation layer.

Invention of Claim 5 is an organic EL element of Claim 3 or 4, Comprising: The said pixel formation layer contains either polyimide resin, epoxy resin, acrylic resin, or novolak resin The interlayer insulating film is either silicon nitride or silicon oxide.

A sixth aspect of the present invention is the organic EL element according to any one of the first to fifth aspects, wherein a thin film transistor is provided on the substrate as a driving element for driving the plurality of pixel electrodes. It is characterized by being.

The invention according to claim 7 is a light emitting medium comprising a substrate, a plurality of pixel electrodes provided on the substrate, and a single layer or a plurality of layers having at least an organic light emitting layer provided on the pixel electrode. A method of manufacturing an organic EL element having a layer and a counter electrode facing the plurality of pixel electrodes across the light emitting medium layer, the step of providing a plurality of pixel formation layers on the substrate independently of each other And a step of providing a pixel electrode on the plurality of pixel formation layers so as to cover the pixel formation layer, and a step of forming the light emitting medium layer on the plurality of pixel electrodes.

The invention according to claim 8 is the method of manufacturing an organic EL element according to claim 7, characterized by comprising a step of forming an inter-pixel layer between the plurality of pixel forming layers adjacent to each other. To do.

The invention according to claim 9 is the method of manufacturing an organic EL element according to claim 7 or 8, wherein an interlayer insulating layer is formed on the pixel formation layer before the pixel electrode is formed. It is characterized by including.

A tenth aspect of the present invention is the method of manufacturing the organic EL element according to the seventh or eighth aspect, wherein a step of forming an interlayer insulating layer on the substrate is formed before the pixel forming layer is formed. It is characterized by including.

Invention of Claim 11 is a manufacturing method of the organic EL element in any one of Claim 7 thru | or 10, Comprising: The process of forming the said organic light emitting medium layer is an organic light emitting medium layer on the said pixel electrode. It includes a step of applying a solution containing the material by a relief printing method.

According to the organic EL element and the manufacturing method thereof according to the present invention, the organic light emitting medium layer can be formed into a desired film thickness with high flatness in the light emitting pixels on the substrate, and the organic EL element having no light emission unevenness and the manufacturing thereof It becomes possible to provide a method.

In addition to the above effects, the present invention forms a light emitting pixel on an organic film having low elasticity, so that the organic light emitting medium layer is formed by a relief printing method compared to the case where the light emitting pixel is formed on glass or silicon nitride having high elasticity. Damage to the printing plate when applying is reduced. Therefore, the interval until the printing plate is replaced becomes longer, and as a result, the production efficiency can be increased.

In addition to the above effects, the present invention has a structure in which no barrier ribs are formed around the luminescent pixel. Therefore, when the organic luminescent medium layer is applied by the relief printing method, the luminescent pixel is the closest to the plate on the substrate. Therefore, it is not necessary to consider the interference with the printing due to the height of the partition wall, so that the thickness of the printing plate can be reduced. When forming a high-definition pattern using a flexographic plate, if the thickness of the plate is thick, the pattern will be twisted or tilted, so the plate can be made thinner. It can be formed with high yield.

It is a schematic diagram for demonstrating the schematic structure of the organic EL element of this invention. It is a cross-sectional schematic diagram for demonstrating the schematic structure and embodiment of the organic EL element of this invention. It is a conceptual diagram of the relief printing machine for producing the organic EL element of this invention. It is a cross-sectional schematic diagram for demonstrating the schematic structure and embodiment of the organic EL element in the 2nd Example of this invention. It is a cross-sectional schematic diagram for demonstrating the schematic structure and embodiment of the organic EL element in the comparative example of this invention. It is a schematic diagram for demonstrating the schematic structure of the organic EL element in the comparative example of this invention. It is a cross-sectional schematic diagram for demonstrating the schematic structure at the time of providing the layer between pixels in the organic EL element of this invention, and embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to this.

FIG. 1 is a schematic diagram for explaining an example of a schematic structure of an organic EL element 10 of the present invention.
On the insulating substrate 11, the light emitting pixels 12 are arranged in a matrix in the vertical and horizontal directions of the drawing. Although not shown in FIG. 1, a pixel electrode (for example, an anode electrode) and a pixel capacitor are formed in each light emitting pixel. Further, a selection transistor 13 for writing a voltage to the pixel capacitor and a driving transistor 14 for supplying a current to the light emitting pixel to emit light according to the voltage written to the pixel capacitor are provided around the light emitting pixel.

A signal line 15 for writing a voltage to the pixel capacitance of the light emitting pixel via the selection transistor 13 is arranged in the column direction (that is, the vertical direction in the drawing) along the arrangement of the light emitting pixels, and is orthogonal to the signal line 15. A scanning line 16 for selecting the selection transistor 13 in the row direction (that is, the horizontal direction in the drawing) and a power supply line 17 for supplying a current for light emission to the driving transistor 14 are provided. A counter electrode (for example, a cathode electrode) 19 composed of a single planar electrode (solid electrode) is formed in common with respect to the pixel electrodes of the plurality of light emitting pixels 12 two-dimensionally arranged on the insulating substrate 11.

In the embodiment of FIG. 1, the active matrix system in which thin film transistors are formed for each pixel is shown as the driving mode of the light emitting pixels. However, the present invention is not limited to the above system, and striped anode and cathode electrodes are used. It is also possible to carry out the present invention by a passive matrix system in which the two are opposed so as to be orthogonal to each other and light is emitted at the intersection.
In the embodiment of FIG. 1, the method of driving one light-emitting pixel by arranging two transistors, that is, a selection transistor and a driving transistor is shown, but driving by driving three or more transistors per light-emitting pixel. It is also possible to use this method.

FIG. 2 is a schematic cross-sectional view taken along the line AB of FIG. 1 for explaining an example of the structure of the organic EL element of the present invention. A light emitting pixel 12, a driving transistor 13, and a signal line 15 are provided on the substrate 11. Further, an interlayer insulating film 18 for protecting the transistors is provided on these transistors.

The light emitting pixel 12 includes a pixel forming layer 12a, a pixel electrode 12b, and an organic light emitting layer 12c. A counter electrode 19 is formed with respect to the pixel electrode 12b. The drive transistor 13 includes a gate electrode 13a, a gate insulating film 13b, a channel layer 13c, a channel protective layer 13d, an ohmic contact layer 13e, a source electrode 13f, and a drain electrode 13g.

Further, the organic EL element of the present invention may have a structure in which a light emission auxiliary layer is provided between the pixel electrode 12b and the counter electrode 19 in addition to the organic light emitting layer 12c. Examples of the light emission auxiliary layer include a hole injection layer, an electron transport layer, and an electron injection layer in addition to the hole transport layer. These light emission auxiliary layers are appropriately selected, and a plurality of them may be selected. The hole injection layer is provided between the anode electrode and the organic light emitting layer. The electron injection layer and the electron transport layer are provided between the organic light emitting layer and the cathode electrode. In the organic EL device of the present invention, the anode electrode, cathode electrode, organic light emitting layer, and hole transport layer may have a multilayer structure instead of a single layer structure.

In FIG. 2, a bottom-gate thin film transistor in which the gate electrode is located in the lower layer of the channel layer is shown as an embodiment of the thin film transistor. However, the present invention is not limited to the above method, and the gate electrode is formed in the upper layer of the channel layer. A top-gate thin film transistor may be used. The thin film transistor shown in the embodiment of FIG. 2 has a structure in which a channel protective layer is formed and the channel layer under the channel protective layer is protected during patterning of the channel layer. It is also possible to implement the present invention by employing a channel etch type thin film transistor that omits the step of forming the protective layer.

In addition, the organic EL device of the present invention is roughly classified into two types according to the method of extracting light for display. The bottom emission method for extracting emitted light from the substrate side and the emitted light from the side opposite to the substrate are extracted. Any of the top emission methods is possible. In the case of a bottom emission type organic EL element, the substrate 11, the pixel formation layer 12a, and the pixel electrode 12b shown in FIG. 2 need to have light transmittance, and in order to obtain a top emission type organic EL element. The counter electrode 19 needs to have optical transparency.

In the organic EL element of the present invention, contrary to FIG. 2, a pixel electrode 12b serving as a cathode electrode, an organic light emitting layer 12c, and a counter electrode 19 serving as an anode electrode may be provided on the substrate 11 in this order. If the organic light emitting layer 12c and the light emission auxiliary layer are collectively referred to as an organic light emitting medium layer, in any case, the pixel electrode 12b, the organic light emitting medium layer, and the counter electrode 19 are cross-sectionally configured in this order on the substrate 11.

Next, a method for manufacturing the organic EL element of the present invention shown in FIGS. 1 and 2 will be described. However, the present invention is not limited to these.

As the substrate 11 according to the present invention, any substrate can be used as long as the organic EL element forming surface has an insulating property. However, in the case of the bottom emission method in which light is emitted from the substrate side, it is necessary to use a transparent substrate.

For example, a glass substrate or a quartz substrate can be used as the transparent substrate. Further, it may be a plastic film or sheet such as polypropylene, polyethersulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate. By using a plastic film or sheet laminated with a metal oxide thin film, metal fluoride thin film, metal nitride thin film, metal oxynitride thin film, or polymer resin film as a substrate, moisture or gas Transmission can be reduced and the characteristics of the element can be stabilized.

Examples of the metal oxide thin film include silicon oxide and aluminum oxide. Examples of the metal fluoride thin film include aluminum fluoride and magnesium fluoride. Examples of the metal nitride thin film include silicon nitride and aluminum nitride. An example of the metal oxynitride thin film is silicon oxynitride. Examples of the polymer resin film include acrylic resin, epoxy resin, silicone resin, and polyester resin.

In the case of the top emission method, an opaque substrate can be used. For example, a silicon wafer, a metal foil such as aluminum or stainless steel, a metal sheet metal plate, or the like. It is also possible to use a plastic film or sheet obtained by laminating a metal thin film such as aluminum, copper, nickel or stainless steel.

In addition, it is more preferable to reduce the moisture adsorbed on the inside or the surface of the various substrates as much as possible by performing a heat treatment in advance. Further, in order to improve the adhesion depending on the material to be laminated on the substrate, it is preferable to use after performing surface treatment such as ultrasonic cleaning treatment, corona discharge treatment, plasma treatment, UV ozone treatment.

  After the surface treatment on the substrate 11, the gate electrode 13 a and the signal line 15 are formed on the substrate 11. The material of the gate electrode and the signal line is made of, for example, a single metal such as a Mo film, a Cr film, an Al film, or a Cu film, a Cr / Al laminated film, an AlTi alloy film, or an AlTiNd alloy film. It is not limited to materials. As a method for forming the material film, a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method can be used depending on the material. A metal film formed in a vacuum is coated with a photoresist, exposed and developed, and processed into a pattern by wet etching or dry etching.

  After the gate electrode 13a and the signal line 15 are formed, three layers of a gate insulating film 13b, a channel layer 13c, and a channel protective layer 13d are formed in vacuum. The three-layer film formation is performed using a vacuum film formation apparatus such as a CVD (Chemical Vapor Position) apparatus. It is desirable to form the three layers continuously without removing the substrate from the vacuum apparatus. The gate insulating film 13b and the channel protective layer 13d are made of, for example, silicon nitride or silicon oxide. The channel layer 13c is made of a silicon thin film or a metal oxide. The silicon thin film may be an amorphous silicon thin film, a polycrystalline silicon thin film, or a microcrystalline silicon thin film in which microcrystalline silicon is contained in the amorphous silicon thin film. Alternatively, a multilayer structure in which these layers are combined may be used. When an amorphous silicon thin film or a microcrystalline silicon thin film is used as the material of the channel layer 13c, it can be directly formed by CVD. However, when a polycrystalline silicon thin film is used, the amorphous silicon thin film is formed by CVD. After film formation, it is necessary to anneal the substrate with a laser or the like to crystallize amorphous silicon. A metal oxide may be used as the channel layer 13c, and a known metal oxide semiconductor such as ZnO or IGZO can be used.

  After the three-layer film formation, a photoresist is applied to the channel protective layer 13d, exposed and developed, and patterned by wet etching or dry etching. After the pattern processing, an ohmic contact layer 13e is formed. The ohmic contact layer 13e is formed by CVD like the channel layer 13c, but a silane gas containing donor-type impurities such as arsine and phosphine is used as a process gas. When a process gas containing a donor-type impurity is used, the ohmic contact layer 13e is formed of a silicon thin film containing a donor-type impurity, and the finally obtained thin film transistor 13 is an n-type thin film transistor. However, depending on the use of the thin film transistor 13, a p-type thin film transistor can be finally obtained by using a silane gas containing an acceptor type impurity such as diborane.

After the ohmic contact layer 13e is formed, a source electrode 13f and a drain electrode 13g are formed. Although not shown, the scanning line 16 and the power supply line 17 are formed at the same time as the source / drain electrodes.

When the ohmic contact layer 13e is formed of a silicon thin film containing impurities, the surface is easily covered with an oxide film in the atmosphere. Therefore, if the source electrode 13f and the drain electrode 13g are formed without performing surface treatment after the ohmic contact layer 13e is formed, the oxide film on the surface of the ohmic contact layer 13e becomes an insulating layer, and the ohmic contact layer 13e, the source electrode 13f, and the ohmic contact are formed. It becomes difficult to establish electrical conduction between the contact layer 13e and the drain electrode 13g. Therefore, it is necessary to remove the oxide film by performing a surface treatment after forming the ohmic contact layer 13e and immediately before forming the source / drain electrode film. The surface treatment is performed by a method such as showering the substrate surface with an ammonium fluoride solution, for example.

The source electrode 13f and the drain electrode 13g are made of, for example, a single metal such as a Mo film, a Cr film, an Al film, or a Cu film, a Cr / Al laminated film, an AlTi alloy film, or an AlTiNd alloy film. Is not limited to these materials. As a method for forming the material film, a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method can be used depending on the material. A metal film formed in a vacuum is coated with a photoresist, exposed and developed, and processed into a pattern by wet etching or dry etching.

Although omitted in FIGS. 1 and 2, contact holes are formed as necessary after patterning the channel protective layer 13d or after forming the ohmic contact layer 13e and before forming the source / drain electrode films. For example, the gate electrode of the selection transistor 14 and the scanning line 16 shown in FIG. 1 need to be electrically connected, but since they are not in the same layer, a contact hole is formed in advance for electrical connection. It is necessary to keep. Similarly, the electrical connection between the source electrode of the selection transistor 14 and the signal line 15 and the electrical connection between the source electrode 13f of the driving transistor 13 and the power supply line 17 are made through contact holes. The contact hole is formed by applying a photoresist to the channel protective layer 13d or the ohmic contact layer 13e, exposing and developing, and performing wet etching or dry etching.

After the patterning of the source electrode 13f and the drain electrode 13g, the ohmic contact layer 13e and the channel layer 13c are patterned. Pattern processing is performed by dry etching the substrate 11 without using photolithography. The ohmic contact layer covered with the source / drain electrodes and the channel layer 13c covered with the source / drain electrodes and the channel protective layer 13d are not etched even when placed in a dry etching environment. Only the ohmic contact layer 13e under the drain electrode and the channel layer 13c under the source / drain electrode and channel protective layer 13d remain on the substrate. The drive transistor 13 is formed by the above manufacturing method. Although omitted in the drawing, the selection transistor 14 may be formed simultaneously with the formation of the driving transistor 13.

In this embodiment, after forming the driving transistor 13, the pixel formation layer 12a is formed by a photolithography method. More specifically, it includes at least a step of applying a photosensitive resin composition to a substrate and a step of forming a pattern of a pixel formation layer by exposure, development, and baking.

As the photosensitive resin material for forming the pixel formation layer 12a, either a positive resist or a negative resist can be used, and a commercially available material can be used. Specific examples of the photosensitive resin material include, but are not limited to, polyimide, acrylic resin, novolac resin, and fluorene. Among these, the photosensitive polyimide is most suitable from the characteristics such as heat resistance, solvent resistance and low outgas. Further, in order to improve the display quality of the organic EL display panel and to prevent malfunction of the thin film transistor, a light shielding material may be included in the photosensitive material.

The photosensitive resin for forming the pixel formation layer 12a is applied using a known coating method such as a spin coater, bar coater, roll coater, die coater, or gravure coater. Next, a pixel formation pattern is formed by pattern exposure and development.

  In the above embodiment, a photosensitive resin material is used as a material for forming the pixel formation layer 12a. However, a non-photosensitive resin material may be used. In that case, in order to perform patterning, it is necessary to apply the resist continuously after applying the resin, pattern the resist by photolithography, and remove the resin material not protected by the resist by a method such as dry etching. It becomes. Examples of the non-photosensitive resin material include epoxy resins and acrylic resins.

  As the shape of the pixel forming layer 12a, the organic light emitting layer 12c is applied and formed around the top of the pixel forming layer 12a to form a light emitting region, so that the organic light emitting layer 12c can be formed with a uniform film thickness. The cross-sectional shape desirably has a flat portion at the top. Examples of such a cross-sectional shape include a rectangular shape and a trapezoidal shape having a flat top portion, but a shape in which the ink for forming the organic light emitting layer 12c does not flow out from the top portion of the pixel forming layer 12a and the film thickness is uniform. If it is, it will not specifically limit, The top part of the pixel formation layer 12a may draw the gentle arc. In addition, the top part of the pixel formation layer 12a here is an area | region in which pixel electrodes 12b other than the bottom face and side surface of the pixel formation layer 12a are formed.

Further, as the shape of the top of the pixel formation layer 12a viewed from the viewing side of the display, since the periphery of the top of the pixel formation layer 12a is a pixel region, pixel formation is performed when a plurality of pixel formation layers 12a are arranged in a matrix. A rectangular shape such as a rectangle, a square, or a combination thereof, in which the periphery of the top of the layer 12a can occupy the widest area, is desirable. With such a shape, the pixel region can be widened. In this case, the pixel formation layer 12a is formed in a matrix form independent from each other as shown in FIG. 1, and there is a region where the pixel formation layer 12a does not exist between the plurality of pixel formation layers 12a.
Note that the top area of the pixel formation layer 12a may be different for each emission color of the organic light emission layer 12c, or may be the same area.

  Furthermore, an inter-pixel layer 12d that connects the pixel formation layers 12a may be formed between the adjacent pixel formation layers 12a. The inter-pixel layer 12d can be formed in a separate process from the pixel formation layer 12a, but it is desirable to form the inter-pixel layer 12a simultaneously with the pixel formation layer 12a by using the same material and method as the pixel formation layer 12a. By forming the inter-pixel layer 12d that connects the adjacent pixel formation layers 12a, the distance between the drive transistor 13 and the selection transistor 14 and the counter electrode 19 is increased. The generation of parasitic capacitance can be reduced. In addition, by connecting the independent pixel formation layers 12a with the inter-pixel layer 12d, deformation of the pixel formation layer 12a due to pressure during printing can be prevented.

  As the shape of the inter-pixel layer 12d, when the film thickness of the inter-pixel layer 12d that connects the adjacent pixel formation layers 12a is larger than the film thickness of the pixel formation layer 12a, the film thickness of the ink film formed on the pixel formation layer 12a. It becomes difficult to make uniform. Therefore, the inter-pixel layer 12d is desirably less than or equal to the film thickness of the pixel formation layer 12a. When the pixel formation layer 12a is arranged as an independent matrix-shaped convex portion, for example, as shown in FIG. 12d is formed in a lattice shape.

In addition, it is desirable to form the inter-pixel layer 12d in at least one of the row direction or the column direction of the adjacent pixel formation layers 12a formed in a matrix, and in the direction parallel to the printing direction, the pixels Since it is more difficult for ink to be mixed when the layer that connects the forming layers 12a is not provided, it is particularly desirable to provide the ink in a direction orthogonal to the printing direction. In this case, the inter-pixel layer 12d is formed in a stripe shape between the pixel formation layers 12a.
Further, when a layer connecting adjacent pixel formation layers 12a covers the drive transistor 13, it is desirable to provide a through hole for electrical connection between the drive transistor 13 and the pixel electrode 12b.

Next, a pixel electrode 12b to be an anode electrode is formed on the pixel formation layer 12a. As the anode electrode forming material, transparent metal composite oxide such as ITO (indium tin composite oxide), IZO (indium zinc composite oxide), zinc aluminum composite oxide, etc., when the pixel electrode 12b needs translucency. When the pixel electrode 12b needs to be reflective, a metal material such as silver or aluminum can be used. A dry coating method can be used as a method of forming the pixel electrode layer. For example, resistance heating vapor deposition, electron beam vapor deposition, reactive vapor deposition, ion plating, and sputtering. Then, a photoresist can be applied to the film formed in vacuum, exposed and developed, and wet etched or dry etched to be processed into a pixel electrode pattern. In the case of a passive matrix organic EL element, the anode electrode is formed in a stripe shape. In the case of an active matrix organic EL element, the anode electrode is patterned in a dot shape, but the pixel electrode 12b of each light emitting pixel 12 needs to be electrically connected to the drain electrode 13g of the drive transistor 13.

After the pixel electrode 12b is formed, an interlayer insulating film 18 is formed. The interlayer insulating film 18 is made of, for example, silicon nitride or silicon oxide, and the insulating film serving as the interlayer insulating film is formed using a vacuum film forming apparatus such as a CVD apparatus. After the formation of the insulating film to be the interlayer insulating film 18, the insulating film is patterned. At least as a pattern processing, an organic light emitting layer 12c is formed on the pixel electrode 12b, that is, a rectangular shape is formed on the pixel electrode 12b on the pixel forming layer 12a in order to form a contact hole serving as a light emitting region of the organic EL element. In order to electrically connect the driving driver and FPC to the signal line 15, the scanning line 16, the power supply line 17, and the like in order to drive the organic EL element after the processing for forming the contact hole and the organic EL element are formed. The processing for forming the contact hole is performed. The contact hole is formed by applying a photoresist on an insulating film to be the interlayer insulating film 18, exposing and developing, and performing wet etching or dry etching.

After forming the interlayer insulating film 18, an organic light emitting medium layer including the organic light emitting layer 12c is formed. The organic light emitting layer 12c is a layer that emits light by passing a current. Examples of the organic light emitting material include coumarin, perylene, pyran, anthrone, porphyrene, quinacridone, N, N′-dialkyl substituted quinacridone. , Naphthalimide-based, N, N′-diaryl-substituted pyrrolopyrrole-based, iridium complex-based luminescent dyes dispersed in polymers such as polystyrene, polymethylmethacrylate, polyvinylcarbazole, polyarylene-based, Examples include arylene vinylene-based, polyphenylene vinylene-based, and polyfluorene-based polymer materials.

These organic light emitting materials are dissolved or stably dispersed in a solvent to form an organic light emitting ink. 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 from the viewpoint of solubility of the organic light emitting material. In addition, a surfactant, an antioxidant, a viscosity modifier, an ultraviolet absorber and the like may be added to the organic light emitting ink as necessary.

Further, as described above, one or more organic light emitting medium layers such as a hole transport layer, a hole injection layer, and an interlayer may be formed before forming the organic light emitting layer 12c. As a material used for the organic light emitting medium layer, a material generally used as a hole transport material can be preferably used. When an organic material is used, a polyaniline derivative, a polythiophene derivative, polyvinylcarbazole (PVK) Derivatives, poly (3,4-ethylenedioxythiophene) (PEDOT) and the like. When an inorganic material is used, Cu ₂ O, Cr ₂ O ₃ , Mn ₂ O ₃ , FeOx (x˜0.1), NiO, CoO, Bi ₂ O ₃ , SnO ₂ , ThO ₂ , Nb ₂ O ₅ Pr ₂ O ₃ , Ag ₂ O, MoO ₂ , ZnO, TiO ₂ , V ₂ O ₅ , Nb ₂ O ₅ , Ta ₂ O ₅ , MoO ₃ , WO ₃ , MnO _{2 and the} like can be used.

In the present invention, it is desirable that at least the organic light emitting layer 12c of the organic light emitting medium layer is formed using a relief printing method. Hereinafter, the relief printing method will be described in detail. As a relief printing plate that can be used to form part or all of the organic light emitting medium layer, it is preferable to use a water development type resin relief plate. Examples of the water-developable photosensitive resin constituting such a resin plate include a type having a hydrophilic polymer and a monomer containing an unsaturated bond, a so-called crosslinkable monomer and a photopolymerization initiator as constituent elements. In this type, polyamide, polyvinyl alcohol, cellulose derivatives and the like are used as hydrophilic polymers. Examples of the crosslinkable monomer include methacrylates having a vinyl bond, and examples of the photopolymerization initiator include aromatic carbonyl compounds. Among these, a polyamide-based water-developable photosensitive resin is preferable from the viewpoint of printability.

  In the organic light emitting medium layer, when an organic material is used as a material for the hole injection layer, the hole transport layer, or the interlayer, it is dissolved or dispersed in a solvent, and various coating methods using a spin coater, a slit coater, etc. It is formed using the same relief printing method as the organic light emitting layer 12c. In the case where an inorganic material is used as the material, the above-described inorganic material is formed using a vacuum evaporation method, a sputtering method, or a CVD method.

A printing press used for forming part or all of the organic light emitting medium layer can be used as long as it is a relief printing press using a flat plate as a substrate to be printed, but a printing press as shown below is desirable. FIG. 3 is a conceptual diagram of a relief printing press for producing the organic EL element of the present invention. This manufacturing apparatus has an ink chamber 108, an anilox roll 101, and a plate cylinder 105 to which a resin relief plate 104 is attached via a cushion tape 103. The ink chamber 108 contains an organic light emitting medium ink. The anilox roll 101 rotates in contact with the ink supply unit of the ink chamber 108 and the plate cylinder 105.

As the anilox roll 101 rotates, the organic light-emitting medium ink supplied from the ink chamber 108 is uniformly held on the surface of the anilox roll 101 by the doctor blade 102 and then uniformly on the convex portion of the resin relief plate 104 attached to the plate cylinder. Transition with film thickness. Further, the printing substrate 107 is fixed on a slidable substrate fixing stage (stage) 106, and the printing start position is adjusted while adjusting the position of the pattern of the plate and the pattern of the printing substrate (not shown). As the plate cylinder rotates, the convex portions of the resin relief plate further move while in contact with the substrate, transfer ink to a predetermined position on the substrate, and pattern the organic light emitting layer 12c.

Next, a counter electrode 19 to be a cathode electrode is formed. In the present invention, the counter electrode 19 is formed as a common electrode that covers a plurality of pixel electrodes and a pixel formation layer.
As a material for the cathode electrode, a substance having a high electron injection efficiency into the organic light emitting layer 12c is used. Specifically, a single metal such as Mg, Al, or Yb may be used, or a compound such as Li, oxidized Li, or LiF is sandwiched by about 1 nm at the interface contacting the light emitting medium, and Al having high stability and conductivity. Alternatively, Cu or Cu may be laminated. Alternatively, in order to achieve both electron injection efficiency and stability, one or more metals such as Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Y, and Yb having a low work function and stable Ag, An alloy system with a metal element such as Al or Cu may be used. Specifically, alloys such as MgAg, AlLi, and CuLi can be used. When the cathode electrode is used as a light-transmitting electrode, on the organic light-emitting layer 12c, after thinly forming Li and Ca having a low work function, ITO (indium tin composite oxide), indium zinc composite oxide, zinc aluminum A metal composite oxide such as a composite oxide may be stacked, or a metal oxide such as ITO doped with a small amount of a metal such as Li or Ca having a low work function may be stacked.

As a method of forming the counter electrode 19, a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method is used according to the above-described materials. Although there is no restriction | limiting in particular in the thickness of a cathode electrode, About 10 nm-1000 nm are desirable. If the thickness of the cathode electrode is less than 10 nm, the pinholes in the film are not sufficiently filled, causing a short circuit. On the other hand, when the thickness is larger than 1000 nm, the film formation time becomes long, and the productivity is deteriorated. Note that the cathode electrode can be patterned by using a mask formed in a desired pattern during film formation.

  In the above embodiment, the pixel formation layer 12a is formed after the drive transistor 13 is formed, and then the pixel electrode 12b and the interlayer insulating film 18 are formed. As another embodiment, as shown in FIG. 13 and the interlayer insulating film 18 may be formed on the driving transistor 13, and then the pixel formation layer 12a and the pixel electrode 12b may be formed.

When the surface of the pixel formation layer 12 a is covered with the interlayer insulating layer 18 as shown in FIG. 2, outgas from the pixel formation layer 12 a made of resin can be prevented by the interlayer insulating layer 18.
On the other hand, when the surface of the pixel formation layer 12a is not covered with the interlayer insulation layer 18 as shown in FIG. 4, there is a step of forming a contact hole of the interlayer insulation layer in accordance with the top of the pixel formation layer 12a serving as the light emitting region. Since it becomes unnecessary, manufacture becomes easy, and an opening part can be made wide compared with the case of FIG.

  Next, embodiments of the present invention will be specifically described with reference to the following examples, but the configuration of the present invention is not limited thereto.

Hereinafter, although the Example and comparative example of this invention are shown, this invention is not limited to this.
(Example 1)

(Process for producing printed substrate 107)
First, a 100 nm-thick Cr film was formed by sputtering on an alkali-free glass as a substrate. Thereafter, a photoresist was applied on the Cr film, exposed and developed, and patterned by wet etching to form the gate electrode 13a and the signal line 15.

Next, three layers of thin films were successively formed in the order of silicon nitride film / amorphous silicon film / silicon nitride film by a CVD apparatus. The three-layer thin film is processed into a gate insulating film 13b / channel layer 13c / channel protective layer 13d after pattern processing in a later step. The film thicknesses of the three layers were 350 nm / 50 nm / 120 nm, respectively. After three layers were continuously formed, a channel protective layer 13d was formed by applying a photoresist to the silicon nitride film, exposing and developing, performing dry etching, and patterning the outermost silicon nitride film.

After the channel protective layer 13d was formed, the ohmic contact layer 13e was formed by CVD using a mixed gas of silane gas and phosphine as a process gas. Thereafter, a photoresist was applied to the ohmic contact layer 13e, exposed and developed, and the ohmic contact layer 13e, the channel layer 13c, and the channel protective layer 13d were dry-etched to form contact holes.

Subsequently, after the substrate was treated with an ammonium fluoride solution, an AlTiNd alloy film having a film thickness of 400 nm was formed by sputtering, and patterned by wet etching by a photolithography method to form a source electrode 13f and a drain electrode 13g. . After the source / drain electrodes were formed, the ohmic contact layer 13e and the channel layer 13c were patterned by dry etching the substrate without removing the photoresist. The drive transistor 13 was formed by the above manufacturing method. The selection transistor 14 was also formed at the same time as the drive transistor 13 was formed.

  Next, the pixel formation layer 12a was formed. First, positive photosensitive polyimide was spin coated on the entire surface. The spin coating conditions were 300 rpm for 5 seconds, 800 rpm for 20 seconds, and the height of the photosensitive material after spin coating was 3.3 μm. After spin coating, the film was exposed by a photolithography method and developed. The film thickness of the pixel formation layer 12a thus formed was 2.5 μm.

  Subsequently, an ITO thin film having a thickness of 50 nm was formed by a sputtering method, and then wet etching was performed by a photolithography method to form a pixel electrode 12b serving as an anode electrode. Next, a silicon nitride film having a thickness of 200 nm was formed by a CVD apparatus, dry etching was performed by a photolithography method, and pattern processing was performed, thereby forming an interlayer insulating film 18.

Next, as a hole transport ink, PEDOT / PSS aqueous dispersion Vitron CH-8000 60%, ultrapure water 20%, and 1-propanol 20% were mixed to obtain an ink. A hole transport layer was formed on the substrate by the slit coat method using the above ink, and the film thickness was 50 nm. In addition, as a pretreatment, the substrate before applying the hole transport ink was irradiated with ultraviolet rays for 3 minutes using a UV / O3 cleaning device. In this way, a printed substrate 107 was produced.

(Process for producing organic light-emitting layer forming ink)
The following polymeric organic light-emitting inks consisting of three colors of red, green and blue (R, G, B) were dissolved in xylene and prepared. The red light emitting ink (R) is a xylene 1 wt% solution of a polyfluorene derivative (red light emitting material manufactured by Sumitomo Chemical Co., Ltd., trade name Red 1100). The green light emitting ink (G) is a 1 wt% xylene solution of a polyfluorene derivative (green light emitting material, trade name Green 1300, manufactured by Sumitomo Chemical Co., Ltd.). The blue light-emitting ink (B) is a 1 wt% xylene solution of a polyfluorene derivative (blue light-emitting material manufactured by Sumitomo Chemical Co., Ltd., trade name Blue 1100).

(Production process of resin relief plate 104)
42 nickel material having a thickness of 250 μm was used as the base material of the relief plate 104 made of a photosensitive resin, and an acrylic binder resin solution kneaded with a black pigment on the base material was applied to a dry film thickness of 10 μm and dried. An antireflection layer was formed.

Mainly water-soluble polyamide, dipentaerythritol hexakisacrylate as radical polymerizable monomer, 2,2-dimethoxy-1,2-diphenylethane-1-one as photopolymerization initiator (manufactured by Ciba Specialty Chemicals) The photosensitive resin composition obtained by kneading the resin is melt-coated on the surface of the substrate so that the total thickness of the plate material is 310 μm as a photosensitive resin layer, and the polyvinyl alcohol solution has a dry film thickness of 1 μm. A polyethylene terephthalate film (film thickness 125 μm: manufactured by Teijin DuPont Films Ltd.) was laminated. Thereby, the photosensitive resin relief plate 104 was produced.

Using a synthetic quartz base chromium mask as the original pattern of the resin relief plate 104, this mask is set in a proximity exposure apparatus and the photosensitive resin relief plate is exposed to produce a resin relief plate 104 with a desired pattern formed. did.

(Printing process of organic light emitting layer forming ink)
The resin relief plate 104 was fixed to the plate cylinder 105 of the sheet-fed printing apparatus via a cushion tape 103. Next, the organic organic light emitting ink was supplied to the ink chamber 108 and the anilox roll 101 was rotated to ink the entire surface. As the anilox roll 101, an anilox roll having 600 lines / inch and a volume of 11 cc was used. Thereafter, excess ink on the anilox roll 101 was scraped off with a doctor blade 102 and inked into the convex pattern portion of the resin relief plate 104.

The organic light emitting layer ink on the resin intaglio 104 inked as described above is line by line so that the inside of the pixel is filled in the long side direction of the pixel on the substrate by the relief printing apparatus (FIG. 3) on the substrate 107 to be printed. A total of 3 lines were formed.
After the film formation, the film was dried in an oven at 130 ° C. for 1 hour. As a result, the thickness of the organic light emitting medium layer in each line was 120 nm on average.

A cathode electrode material made of Ca and Al was deposited on the printed film by mask deposition so as to be deposited only on the pixel portion, thereby forming a cathode electrode layer having a thickness of 500 nm. Finally, in order to protect these organic EL constituents from external oxygen and moisture, they were hermetically sealed using a glass cap and an epoxy adhesive to produce an organic EL element.

In the periphery of the display portion of the obtained organic EL element, there are an extraction electrode on the anode electrode side connected to each pixel electrode and an extraction electrode on the cathode electrode side. By connecting these to a power source, organic EL A display panel was obtained.

(Example 2)
In the second embodiment, as shown in FIG. 4, the structure in which the light emitting pixel 12 is composed of the pixel forming layer 12a, the light emitting electrode 12b, and the organic light emitting layer 12c is the same as that in the first embodiment. The second embodiment is different from the first embodiment in that it is formed under the light emitting pixel 12. In the manufacturing method, the difference between the first embodiment and the second embodiment is described. In the first embodiment, after the driving transistor 13 is provided, the light emitting pixel 12 is formed, the pixel electrode 12b is formed, and the interlayer insulating film 18 is formed. On the other hand, the second embodiment is the same as the first embodiment up to the step of providing the driving transistor 13, but differs in that the interlayer insulating film 18 is formed before the light emitting pixel 12 is formed. After the interlayer insulating film 18 was formed, the light emitting pixels 12 were formed in the same manner as in Example 1, and the subsequent organic light emitting layer printing process and organic EL display panel creation process were also performed in the same process as in Example 1.

(Comparative example)
In the comparative example, an example of manufacturing an organic EL element having a structure in which partition walls are provided at both ends of a light emitting pixel is shown. As shown in FIG. 5, the process up to the step of providing the driving transistor 13 on the substrate 11 is the same as that of Example 1. However, in the comparative example, the pixel formation layer 12 a is not provided when the light emitting pixel 12 is formed. Formed. Thereafter, after the interlayer insulating film 18 was formed, the partition wall 20 was formed so as to surround the light emitting pixel 12. The material of the partition 20 was positive photosensitive polyimide, and the partition was formed under the condition that the film thickness after spin coating / exposure / development treatment was 2.5 μm. After the barrier ribs were formed, in the same manner as in Example 1, hole transport ink application, organic light emitting layer 12c printing, and subsequent organic EL display panel creation were performed.

  When the organic light emitting layer forming ink is printed according to the comparative example, the organic light emitting layer 12c is not formed in the light emitting pixel 12 with a uniform film thickness, and the light emission luminance in the pixel when the pixel is made to emit light after the organic EL display panel is manufactured. Bias occurred. In the structure of the comparative example, the reason why the organic light emitting layer 12c is not formed with a uniform film thickness in the light emitting pixel 12 is that the partition wall 20 is formed around the light emitting pixel 12 as shown in FIG. The partition wall 20 is provided to prevent the printed organic light emitting layer forming ink from flowing into the adjacent pixels, but the partition wall 20 has good wettability with respect to the organic light emitting layer forming ink. The ink for forming the organic light emitting layer printed in 12 adheres so as to be sucked up by the surrounding partition walls. As shown in FIG. 5, the barrier ribs 19 at both ends of the light emitting pixel 12 do not have a symmetrical shape due to the unevenness of the driving transistor 13 below the barrier ribs. Since the amount of the ink for forming the organic light emitting layer depends on the shape and height of the partition wall, the organic light emitting layer 12c is attached in an asymmetric shape, resulting in a bias in the film thickness, and the light emission luminance within the pixel. This is thought to be the cause of the bias.

On the other hand, in the structure of Example 1, there is no partition 20 around the light emitting pixel 12 as shown in FIG. 1, so there is no fear that the organic light emitting layer forming ink adheres to the peripheral partition. In addition, since the pixel forming layer 12a has a protruding shape and the pixel forming layer 12a is not formed in a non-light emitting region between adjacent light emitting pixels, the printing is performed at the time of printing. Even if the organic light emitting layer forming ink overflows from the light emitting pixel, the overflowed ink remains in the non-light emitting area formed in a concave shape, so that color mixing due to the ink moving to adjacent pixels is less likely to occur. Further, in the structure of Example 1, since the pixel electrode 12b is covered with the interlayer insulating film 18, color mixing is less likely to occur, and the margin of the viscosity and coating amount of the organic light emitting layer forming ink can be widened. It becomes possible. Therefore, when the organic light emitting layer forming ink was printed, the organic light emitting layer 12c was evenly applied on the pixel electrode 12b as shown in FIG. However, since the light emitting pixel 12 having the structure of Example 1 has a step between the pixel electrode 12b and the interlayer insulating film 18 at both ends of the pixel, ink may accumulate in the step and the film thickness may increase. Therefore, it is necessary to make adjustments such as increasing the taper angle during patterning of the interlayer insulating film 18.

Further, in the manufacturing example of Example 2, as in Example 1, there is no partition 20 around the light emitting pixel 12, and the pixel forming layer 12a is not formed in a non-light emitting region between adjacent light emitting pixels. Therefore, as a result of printing, as shown in FIG. 4, the organic light emitting layer 12 c was uniformly applied on the pixel electrode 12 b as in Example 1. Furthermore, since the light emitting electrode 12b on the pixel formation layer 12a is not covered with the interlayer insulating film 18 in the second embodiment, the organic light emitting layer is formed at the level difference between the pixel electrode 12b and the interlayer insulating film 18 as in the structure of the first embodiment. The forming ink was accumulated, the film thickness did not increase, and the light emitting area of the pixel could be made wider than in Example 1. However, since the light emitting electrode 12b is not covered with the layer insulating film 18 in the structure of Example 2, the printed organic light emitting layer forming ink may flow into adjacent pixels and cause color mixing. It is necessary to adjust the viscosity and the coating amount of the organic light emitting layer forming ink so that the ink does not flow.

DESCRIPTION OF SYMBOLS 10 Organic EL element 11 Insulating substrate 12 Light emitting pixel 12a Pixel formation layer 12b Pixel electrode 12c Organic light emitting layer 12d Inter-pixel layer 13 Drive transistor 13a Gate electrode 13b Gate insulating film 13c Channel layer 13d Channel protective layer 13e Ohmic contact layer 13f Source electrode 13 g Drain electrode 14 Select transistor 15 Signal line 16 Scan line 17 Power supply line 18 Interlayer insulating film 19 Counter electrode 20 Partition wall 101 Anilox roll 102 Doctor blade 103 Cushion tape 104 Resin relief plate 105 Plate cylinder 106 Substrate fixing base 107 Printed substrate 108 Ink Chamber

Claims (11)

A substrate, a plurality of pixel electrodes provided on the substrate, a single layer or a plurality of layers of a light emitting medium layer having at least an organic light emitting layer provided on the pixel electrode, and sandwiching the light emitting medium layer And an organic EL element having a counter electrode facing the plurality of pixel electrodes,
The plurality of pixel electrodes are formed on a plurality of pixel formation layers provided on the substrate,
The organic EL element, wherein the plurality of pixel formation layers are formed independently of each other. 2. The organic EL element according to claim 1, wherein an inter-pixel layer is provided between the plurality of pixel forming layers adjacent to each other. The organic EL element according to claim 1, wherein an interlayer insulating film is provided on the pixel formation layer. The organic EL element according to claim 1, wherein an interlayer insulating film is provided below the pixel formation layer. 4. The pixel forming layer includes any one of a polyimide resin, an epoxy resin, an acrylic resin, and a novolac resin, and the interlayer insulating film is either silicon nitride or silicon oxide. Or the organic EL element of 4. 6. The organic EL element according to claim 1, wherein a thin film transistor is provided on the substrate as a driving element for driving the plurality of pixel electrodes. A substrate, a plurality of pixel electrodes provided on the substrate, a single layer or a plurality of layers of a light emitting medium layer having at least an organic light emitting layer provided on the pixel electrode, and sandwiching the light emitting medium layer And a method of manufacturing an organic EL element having a counter electrode facing the plurality of pixel electrodes,
Providing a plurality of pixel formation layers on the substrate so as to be independent from each other;
Providing a pixel electrode on the plurality of pixel formation layers so as to cover the pixel formation layer;
Forming the light emitting medium layer on the plurality of pixel electrodes;
The manufacturing method of the organic EL element characterized by having. 8. The method of manufacturing an organic EL element according to claim 7, further comprising a step of forming an inter-pixel layer between the plurality of pixel forming layers adjacent to each other. 9. The method of manufacturing an organic EL element according to claim 7, further comprising a step of forming an interlayer insulating layer on the pixel formation layer before forming the pixel electrode. 9. The method of manufacturing an organic EL element according to claim 7, further comprising a step of forming an interlayer insulating layer on the substrate before forming the pixel formation layer. 11. The step of forming the organic light emitting medium layer includes a step of applying a solution containing an organic light emitting medium layer material on the pixel electrode by a relief printing method. Manufacturing method of organic EL element.

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