JP2007287457A - Organic el display element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display element capable of preventing occurrence of a dark spot by blocking certainly invasion of moisture and oxygen into the organic EL layer from a color conversion filter layer, and its manufacturing method. <P>SOLUTION: The organic EL display element comprises a first aperture part 30a in which a second passivation layer 30 forms a pixel region by connecting a first electrode 20a to an organic EL layer 60, a second aperture part 30b to connect a second drawing electrode 20c to a second electrode 70, and a third and a fourth apertures 30c, 30d to connect the first and the second drawing electrodes 20b, 20c respectively to an external drive circuit. The shoulder part of each electrode of the first electrode 20a, the first drawing electrode 20b, and the second drawing electrode 20c is covered. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organic EL display element suitable for use in an organic EL display panel and a method for producing the same.

  The organic EL display panel can be manufactured using the “three-color light emission method” in which organic EL elements that emit light in red, blue, and green are arranged by applying an electric field, and the white light emitted by the organic EL elements in color. “Color filter method” that expresses red, blue, and green by cutting with a filter, absorbs near-ultraviolet light, blue light, blue-green light, or white light emitted by organic EL elements, and converts the wavelength distribution to visible A “color conversion method” using a color conversion layer including a color conversion dye that emits light in the light region has been proposed.

  Of these methods, it is not necessary to use a fine metal mask during film formation, and a color filter layer and / or a color conversion layer (hereinafter collectively referred to as a “color conversion filter layer”) having a desired shape and arrangement using a photo process. It is considered that the “color filter method” and the “color conversion method” are advantageous for increasing the screen size and the definition of the display panel.

An important practical issue as a color display panel is to have a fine color display function and long-term stability including color reproducibility. However, the color organic EL display panel has a drawback that the light emission characteristics (current-luminance characteristics) are remarkably lowered by driving for a certain period.
A typical cause of the deterioration of the light emission characteristics is the growth of dark spots. This dark spot is a light emitting defect point. When oxidation proceeds during driving and during storage, the growth of dark spots proceeds and spreads over the entire light emitting surface. This dark spot is considered to be caused by oxidation or aggregation of the laminated material constituting the element due to oxygen or moisture in the element. The growth proceeds not only during energization but also during storage. In particular, the growth is accelerated by (1) oxygen or moisture present around the element, and (2) oxygen or moisture present as an adsorbate in the organic laminated film. And (3) it is considered that it is also affected by moisture adsorbed on components at the time of device fabrication or moisture intrusion at the time of production.

  As a moisture supply source, it is considered that moisture inherent in the color filter layer and / or the color conversion layer is released. As a technique for preventing moisture from entering the organic EL element, an inorganic oxide layer having a thickness of 0.01 to 200 μm is disposed between the phosphor layer (color conversion layer) and the organic EL element (Patent Document 1). It has been proposed to use an inorganic oxide for the flattening layer covering the color conversion layer (Patent Document 2) and to function as a moisture / oxygen barrier layer (passivation layer).

  However, even in the panel using the moisture / oxygen barrier layer, it has been found through experiments by the inventors that a dark spot grows between the electrodes formed on the moisture / oxygen barrier layer when driven for a long time. Yes. This is because pinholes generated when the moisture / oxygen barrier layer is formed and film formation defects due to adhesion of dust occur, so that moisture / oxygen enters the organic EL element from the portions not covered by the electrodes. Met.

In order to compensate for this defect, there is a method in which a moisture / oxygen barrier layer is formed between the electrodes in addition to the above structure (Patent Document 3). Patent Document 3 is a method of forming a second passivation layer made of an insulating inorganic compound film between electrodes using a lift-off method, and moisture / oxygen enters the organic EL element from the gap between the passivation layer and the electrode. There are drawbacks. In addition, since it is difficult to maintain the uniformity of the lift-off resist shape and the uniformity of the coating state of the film-forming particles with respect to the lift-off resist, the lift-off method tends to leave a residue on the substrate during the lift-off process. It is done. This residue causes problems such as a starting point of a short circuit between the cathode and the anode. Furthermore, there is a drawback that the difficulty of controlling the lift-off plane increases as the substrate becomes larger.
JP-A-8-27939 Japanese Patent No. 3304287 JP 2004-39311 A JP 2005-26103 A

  As a method for solving the difficulty of in-plane control of the lift-off method, there is a method of patterning an inorganic insulating film by dry etching (Patent Document 4), and the dry etching method can perform etching with high in-plane uniformity. If the first and second passivation films are made of the same material as in Patent Document 3, simply adopting the dry etching method, the first passivation film is etched when the second passivation film is etched. As a result of etching the first passivation film, there is a problem that the moisture / oxygen blocking performance is lowered.

  In view of the above points, the present invention reliably prevents moisture and oxygen from entering the organic EL layer from the color conversion filter layer even when the opening of the second passivation layer is formed by dry etching. An object of the present invention is to provide an organic EL display element capable of preventing the occurrence of dark spots and a method for manufacturing the same.

  In order to achieve the above object, the organic EL display element of the present invention is a color in which at least a patterned color conversion filter layer is formed on a transparent substrate, and a first passivation layer is formed thereon. A first electrode having a conversion filter substrate and patterned corresponding to the color conversion filter layer, a first extraction electrode following the first electrode, an organic EL layer formed on the first electrode, and an organic EL An organic EL display element comprising a second electrode disposed opposite to a first electrode across a layer and a second lead electrode connected to the second electrode on a color conversion filter substrate, One electrode, a first extraction electrode, and a second extraction electrode are formed by patterning on the surface of the color conversion filter substrate, and the surface of each electrode and the surface of the color conversion filter substrate between the electrodes are formed. Cover to cover A second passivation layer made of a passivation film, the second passivation layer is opened by dry etching the passivation film using the first electrode as a stopper, and the first electrode is connected to the organic EL layer to form a pixel A first opening for forming a region, and a second opening for connecting the second extraction electrode to the second electrode, which is opened by dry etching the passivation film using the second extraction electrode as a stopper. Openings are formed by dry etching the passivation film using the first and second lead electrodes as stoppers, respectively, and third and fourth holes for connecting the first and second lead electrodes to an external drive circuit, respectively. A first electrode, a first extraction electrode, and a second extraction current Characterized in that it covers the shoulder portion of each electrode of.

Here, the first electrode and the second electrode are composed of a plurality of electrodes arranged in a matrix crossing each other, and the first of the second passivation layer for forming a pixel region at each crossing portion. Are preferably formed, and the second passivation layer is preferably made of a material selected from silicon oxide, silicon nitride, and silicon oxynitride.
In such a method for producing an organic EL display device of the present invention, at least a patterned color conversion filter layer and a planarization layer are formed on a transparent substrate, and a first passivation layer is formed thereon. Forming a first electrode, a first extraction electrode, and a second extraction electrode on the color conversion filter substrate, and a passivation film for covering the color conversion filter substrate on which the electrode is formed with a passivation film A covering step, a resist film forming step of forming a resist film having openings corresponding to the first to fourth openings on the passivation film, and dry etching the passivation film on which the resist film has been formed. First to fourth openings are formed by using each of the first electrode, the first extraction electrode, and the second extraction electrode as a stopper. Characterized in that it comprises a dry etching process for the second passivation layer.

Here, the dry etching process is preferably performed in an atmosphere containing a fluorine-based gas and an oxygen gas.
In the present invention, the first to fourth openings are arranged in the portions where the first electrode, the first extraction electrode, and the second extraction electrode are located in the lower layer, and dry etching is performed using each electrode as a stopper. Therefore, the first passivation layer is not over-etched when the first to fourth openings of the second passivation layer are formed by dry etching.

  In addition, since the second passivation layer covers the shoulders of the first electrode, the first extraction electrode, and the second extraction electrode, intrusion of moisture and oxygen therefrom is prevented. The

  According to the present invention, the first to fourth openings of the second passivation layer are formed by dry etching using the first electrode, the first extraction electrode, and the second extraction electrode as a stopper. Over-etching of the first passivation layer during formation is prevented, and the second passivation layer covers the shoulders of the electrodes of the first electrode, the first extraction electrode, and the second extraction electrode By doing so, the moisture / oxygen blocking performance of the first passivation layer and the second passivation layer is ensured, and the penetration of moisture and oxygen from the color conversion filter layer to the organic EL layer is surely prevented. It is possible to provide an organic EL display element that prevents generation of spots and maintains excellent light emission characteristics over a long period of time.

As a result of various studies, the present inventors have found that for the suppression of dark spots,
It has been found that it is effective to form a first passivation layer on top of the color conversion filter layer, and to cover between adjacent first electrodes with a second passivation layer.
In order to reduce damage to the first passivation layer that occurs when the second passivation layer formed on the first electrode is etched, the second passivation layer formed on the first electrode is
A pixel region (a portion where the organic EL layer is sandwiched between the first electrode and the second electrode and functions as a light emitting region);
A connection site between the second electrode and the second extraction electrode;
A connection portion between the extraction electrode and the external drive circuit;
It was found that there is an effect by forming except for.

Based on this finding, the present invention provides an organic EL display element that can more effectively prevent the occurrence of dark spots.
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 2 is a schematic plan view showing a main part of an embodiment of the organic EL display element according to the present invention, and FIG. 1 is a schematic cross-sectional view taken along the line AA ′.

  As shown in FIGS. 1 and 2, the organic EL display element according to the embodiment of the present invention includes patterned color conversion filter layers 2, 4, 5 formed on a transparent substrate 1, and a first A color conversion filter substrate 10 on which a passivation layer 7 is formed is provided. A first electrode 20a patterned corresponding to the color conversion filter layer 10, a first extraction electrode 20b following the first electrode 20a, and a first electrode An organic EL layer 60 formed as a continuous film on a display region indicated by a one-dot chain line in FIG. 2 on the plane 20a, and a second electrode disposed opposite to the first electrode 20a with the organic EL layer 60 interposed therebetween. The organic EL display element includes the first electrode 20a and the first extraction electrode 20b. The organic EL display element includes the second electrode 70 and the second extraction electrode 20c connected to the second electrode 70 on the color conversion filter substrate 10. And a second drawer A pole 20c is formed by patterning on the surface of the color conversion filter substrate 10 and covers the surface of the electrodes 20a, 20b, 20c and the surface of the color conversion filter substrate between the electrodes 20a, 20b, 20c. The second passivation layer 30 is made of a film, and the second passivation layer 30 is opened by dry etching the passivation film using the first electrode 20a as a stopper, and the first electrode 20c is formed in the organic EL layer 60. A first opening 30a for connecting and forming a pixel region is opened by dry etching the passivation film using the second extraction electrode 20c as a stopper, and the second extraction electrode 20c is formed as the second electrode 70. A second opening 30b for connection to the first and second lead electrodes 20b Openings are formed by dry etching the passivation film using 20c as a stopper, respectively, and third and fourth openings 30c for connecting the first and second lead electrodes 20b and 20c to an external drive circuit (not shown), respectively. , 30d, and covers the shoulders of the first electrode 20a, the first extraction electrode 20b, and the second extraction electrode 20c.

Here, as shown in FIG. 2, the first electrode 20a (vertical broken line) and the second electrode 70 (horizontal two-dot chain line) are composed of a plurality of electrodes arranged in a matrix intersecting each other. A first opening 30a of a second passivation layer for forming a pixel region is formed at each intersection.
The transparent substrate 1 is transparent to visible light (wavelength 400 to 700 nm), withstands the conditions (solvent, temperature, etc.) used for forming the layer to be laminated, and has excellent dimensional stability. It is preferable. A preferable transparent substrate 1 is a glass substrate and a rigid resin substrate formed of a resin such as polyolefin, acrylic resin (including polymethyl methacrylate), polyester resin (including polyethylene terephthalate), polycarbonate resin, or polyimide resin. Including. Alternatively, a flexible film formed from polyolefin, acrylic resin (including polymethyl methacrylate), polyester resin (including polyethylene terephthalate), polycarbonate resin, polyimide resin, or the like may be used as the substrate.

  The color conversion filter layers 3, 4, and 5 provided on the transparent substrate 1 can be composed of a color filter layer, a color conversion layer, or a laminate of a color filter layer and a color conversion layer. The color filter layer is a layer that transmits only light in a desired wavelength range. In the case of adopting a laminated structure with the color conversion layer, the color filter layer is effective in improving the color purity of the light subjected to wavelength distribution conversion in the color conversion layer. The color filter layer can be formed using, for example, a commercially available color filter material for liquid crystal (such as a color mosaic manufactured by Fuji Film Electromaterials).

  The color conversion layer is a layer made of a color conversion dye and a matrix resin. The color conversion dye is a dye that converts the wavelength distribution of incident light and emits light in different wavelength ranges, and preferably converts the wavelength distribution of near-ultraviolet light or blue to blue-green light from the organic EL layer 60. And a dye that emits light in the desired wavelength range (eg, blue, green or red). Color conversion dyes are known in the art, such as rhodamine dyes and cyanine dyes that emit red light; coumarin dyes and naphthalimide dyes that emit green light; and coumarin dyes that emit blue light. Any thing that can be used.

  On one transparent substrate 1, a plurality of types of color conversion filter layers, for example, a color conversion filter layer 3 that absorbs light from the organic EL layer 60 and emits red light, a color conversion filter layer 4 that emits green light, You may provide the color conversion filter layer 5 etc. which radiate | emit blue light. By arranging the color conversion filter layers 3, 4, 5 of the three primary colors in a matrix, full color display can be realized.

The color conversion filter layers 3, 4, and 5 are formed by applying the material of each layer using a spin coating method, a roll coating method, a casting method, a dip coating method, etc., and then patterning using a photolithographic method or the like. can do.
A black matrix 2 is formed between the color conversion filter layers 3, 4, and 5 as necessary, and between the color conversion filter layers 3, 4, 5 and the color conversion filter layers 3, 4, 4. 5 is made of an organic resin for relaxing the steps of the color conversion filter layers 3, 4, 5 and ensuring the adhesion of the first passivation layer 7, if necessary, usually 1 μm or more, preferably Can cover the color conversion filter layers 3, 4, and 5 by providing a planarizing layer 6 having a thickness in the range of 2 μm to 10 μm. As the organic resin, a material having a high visible light transmittance such as an acrylic material is used.

  A first passivation layer 7 is formed on the color conversion filter layers 3, 4, and 5. The first passivation layer 7 functions as a passivation film that prevents moisture released from the color conversion filter layers 3, 4, 5 and the planarization layer 6 to be propagated to the organic EL layer 60 side. As the material, insulating inorganic oxides such as SiOx, SiNx, SiNxOy, AlOx, TiOx, TaOx, ZnOx, inorganic nitride, inorganic oxynitride, and the like can be used. Desirably, the material of the color conversion filter layers 3, 4, 5 and SiOx, SiNxOy having a small difference in refractive index are selected. In a normal case, the first passivation layer 7 is formed to a thickness of 100 nm to 1 μm.

The first passivation layer 7 is formed using a plasma CVD method or a sputtering method.
The electrodes 20a, 20b, and 20c are composed of a plurality of transparent electrodes, and are formed by depositing a conductive metal oxide such as SnO ₂ , In ₂ O ₃ , ITO, IZO, ZnO: Al using a sputtering method. The The first electrode 20a preferably has a transmittance of 50% or more, more preferably 85% or more with respect to light having a wavelength of 400 to 800 nm. It is desirable that the first electrode 20a has a thickness in the range of usually 50 nm or more, preferably 50 nm to 1 μm, more preferably 100 to 300 nm.

The lead electrodes 20b and 20c preferably surround the display area in order to connect the first electrode 20a and the second electrode 70 provided with the organic EL layer 60 sandwiched in the display area to an external drive circuit (not shown). It is formed in the terminal region at the periphery of the substrate 10.
In order to suppress the resistance of the electrodes 20a, 20b, and 20c, a metal such as Al, Mo, Ni, Cr, and W can be used as an auxiliary electrode. Even if the auxiliary electrode is formed on any of the electrodes 20a, 20b, and 20c, it has an effect of suppressing resistance.

In particular, at the portion where the second electrode 70 and the second lead electrode 20c are joined, a structure is adopted in which the auxiliary electrode and the second electrode 70 are joined directly in order to prevent them from contacting and oxidizing. You can also.
The first electrode 20a is formed as a plurality of striped electrodes extending in a direction intersecting (preferably orthogonal) to the first direction of the second electrode 70 so that passive matrix driving can be performed. It is preferable to configure.

As shown in FIG. 3, the second passivation layer 30 formed on the top of the first electrode 20a is
A first opening 30a that forms a pixel region (a portion in which the organic EL layer 60 is sandwiched between the first electrode 20a and the second electrode 70 and functions as a light emitting region);
A second opening 30b that forms a connection site between the second electrode 70 and the second lead electrode 20c;
Third and fourth openings 30c and 30d that form connection portions between the extraction electrodes 20b and 20c and an external drive circuit (not shown), respectively.
Is formed on the entire surface of the color conversion substrate 10.

  As shown in FIG. 4, the first opening 30a in the display area is formed by the second passivation layer 30 covering the shoulder of the first electrode 20a and the first opening 20a between the adjacent first electrodes 20a. By covering the surface of one passivation layer 7 (that is, the surface of the color conversion filter substrate 10), a light emitting region (pixel region) of each pixel as a connection portion between the first electrode 20a and the organic EL layer 60 is defined. In addition, it has a function of preventing the permeation of moisture penetrating the first passivation layer 7.

  As a material of the second passivation layer 30, an insulating inorganic oxide such as SiOx, SiNx, SiNxOy, AlOx, TiOx, TaOx, ZnOx, inorganic nitride, inorganic oxynitride, or the like can be used. Desirably, SiNx, SiNxOy, and SiOx having high passivation properties are selected. In a normal case, the second passivation layer 30 is formed to a thickness of 100 nm to 1 μm.

The second passivation layer 30 is formed using a plasma CVD method or a sputtering method. For dry etching for forming the first to fourth openings 30a to 30d of the second passivation layer 30, RIE plasma or ICP plasma can be used.
As shown in FIGS. 4 and 5, the angle of contact with the first electrode 20a and the extraction electrode 20c of the second passivation layer 30 is an acute angle, and the selection ratio with the metal electrode used as the first electrode 20a and the auxiliary electrode is In order to make it large, dry etching uses a mixed gas of fluorine-based gas and oxygen. For example, when using a SiNx the second passivation layer 30, the dry etching or the like can be used a mixed gas of SF ₆ gas and a mixed gas of oxygen, SF ₆ and HCl and oxygen. When SiOx is used, a mixed gas of CF ₄ and oxygen, a mixed gas of SF ₆ , CHF ₃ and oxygen, or the like can be used.

The organic EL layer 60 includes at least an organic light emitting layer, and includes a hole transport layer, a hole injection layer, an electron transport layer, and / or an electron injection layer as necessary. Each of these layers is formed to have a film thickness sufficient to realize desired characteristics in each layer. For example, what consists of the following layer structures is employ | adopted.
(1) Organic light emitting layer (2) Hole injection layer / organic light emitting layer (3) Organic light emitting layer / electron injection layer (4) Hole injection layer / organic light emitting layer / electron injection layer (5) Hole transport layer / Organic light emitting layer / electron injection layer (6) Hole injection layer / hole transport layer / organic light emitting layer / electron injection layer (7) Hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection Layer (In the above configuration, the electrode functioning as the anode is connected to the left side, and the electrode functioning as the cathode is connected to the right side)
Any known material can be used as the material of the organic light emitting layer. For example, in order to obtain light emission from blue to blue-green, for example, a condensed aromatic ring compound, a ring assembly compound, a metal complex (such as an aluminum complex such as Alq3), a styrylbenzene compound (4,4′-bis (diphenylvinyl) ) Biphenyl (DPVBi), etc.), porphyrin compounds, benzothiazole compounds, benzimidazole compounds, benzoxazole compounds such as fluorescent brighteners, and aromatic dimethylidin compounds are preferably used. Or you may form the organic light emitting layer which emits the light of a various wavelength range by adding a dopant to a host compound. Examples of host compounds include distyrylarylene compounds (for example, IDE-120 manufactured by Idemitsu Kosan Co., Ltd.), N, N′-ditolyl-N, N′-diphenylbiphenylamine (TPD), aluminum tris (8-quinolinolate) (Alq3) Etc. can be used. As dopants, perylene (blue purple), coumarin 6 (blue), quinacridone compounds (blue green to green), rubrene (yellow), 4-dicyanomethylene-2- (p-dimethylaminostyryl) -6-methyl- 4H-pyran (DCM, red), platinum octaethylporphyrin complex (PtOEP, red), or the like can be used.

  As a material for the hole injection layer, Pc (including CuPc) or indanthrene compounds can be used. The hole transport layer can be formed using a material having a triarylamine partial structure, a carbazole partial structure, or an oxadiazole partial structure. Materials that can be used preferably include TPD, [alpha] -NPD, MTDAPB (o-, m-, p-), m-MTDATA, and the like.

  Materials for the electron transport layer include aluminum complexes such as Alq3; oxadiazole derivatives such as PBD and TPOB; triazole derivatives such as TAZ; triazine derivatives such as those having the following structures; phenylquinoxalines; BMB A thiophene derivative such as -2T can be used. As the material for the electron injection layer, an aluminum complex such as Alq3 or an aluminum quinolinol complex doped with an alkali metal or an alkaline earth metal can be used.

Optionally, a thin film (thickness: 10 nm) of an electron injecting material such as an alkali metal, an alkaline earth metal, an alloy containing them, or an alkali metal fluoride is formed at the interface between the organic EL layer 60 and the electrode used as the cathode. The buffer layer formed in the following may be provided to increase the electron injection efficiency.
Each layer constituting the organic EL layer 60 and, optionally, any means known in the art such as vapor deposition (resistance heating or electron beam heating) can be used.

  The second electrode 70 includes a plurality of electrode groups, and is preferably formed using a highly reflective metal, amorphous alloy, or microcrystalline alloy. High reflectivity metals include Al, Ag, Mo, W, Ni, Cr, and the like. High reflectivity amorphous alloys include NiP, NiB, CrP, CrB, and the like. The highly reflective microcrystalline alloy includes NiAl and the like. The second electrode 70 may be used as a cathode or an anode. When the second electrode 70 is used as a cathode, the aforementioned buffer layer may be provided at the interface between the second electrode 70 and the organic EL layer 60 to improve the efficiency of electron injection into the organic EL layer 30. .

  The second electrode 70 is formed using any means known in the art such as vapor deposition (resistance heating or electron beam heating), sputtering, ion plating, laser ablation, etc., depending on the material used. Can do. The second electrode 70 composed of a plurality of partial electrodes may be formed using a mask that gives a desired shape, or the second electrode 70 composed of a plurality of partial electrodes may be formed using a separation partition wall having an inversely tapered cross section. Two electrodes 70 may be formed.

  Each of the plurality of electrode groups constituting the second electrode 70 may have a stripe shape extending in the second direction, for example. Here, the first direction of the first electrode 20a and the second direction of the second electrode 70 are preferably crossed, more preferably orthogonal. By adopting such a configuration, by applying an electric field to one of the partial electrodes constituting the first electrode 20a and one of the partial electrodes constituting the second electrode 70, the partial electrodes intersect each other. Passive matrix driving in which the organic EL layer 60 at the site emits light can be performed.

  As shown in FIGS. 6A to 6D, the method for manufacturing the organic EL display element according to the embodiment of the present invention has the color conversion filter layers 3, 4 and 4 patterned on the transparent substrate 1. 5 and the planarization layer 6 are formed, and the first electrode 20a, the first extraction electrode 20b, and the second extraction are formed on the color conversion filter substrate 10 on which the first passivation layer 7 is formed. An electrode forming step for forming the electrode 20c, a passivation film covering step (FIG. 6A) for covering the color conversion filter substrate 10 on which the electrodes 20a, 20b, and 20c are formed with the passivation film 30 ′, and the passivation film 30 ′. A resist film forming step (FIG. 6B) for forming a resist film 50 having openings corresponding to the first to fourth openings 30a to 30d on the top, and a pattern on which the resist film 50 has been formed. By dry etching the passivation film 30 ′ in an atmosphere containing a fluorine-based gas and an oxygen gas, the first electrode 20a, the first extraction electrode 20b, and the second extraction electrode 20c are used as stoppers. A dry etching step (FIGS. 6C and 6D) that forms the first to fourth openings 30 a to 30 d to form the second passivation layer 30.

  Here, the entire surface of the color conversion filter substrate 10 on which the first electrode 20a, the first extraction electrode 20b, and the second extraction electrode 20c are formed is covered with a passivation film 30 ′, and the electrodes 20a to 20c are covered. The openings of the resist film 50 are provided only on the electrodes, and dry etching is performed using the electrodes 20a to 20c as stoppers, thereby preventing over-etching when the openings 30a to 30d are formed in the passivation film 30 ′.

  That is, as shown in the reference examples of FIGS. 6E to 6G, when only dry etching is performed to form a pixel region, a resist film is formed on the extraction electrodes (20b, 20c) that need to be connected. Since there is no need to provide 50, there is a concern that the overetched portion 7a is formed in the first passivation layer 7 and the moisture-proof performance is lowered.

An example in which the above-described embodiment is made more specific will be described below.
In this example, an organic EL display panel having a pixel number of 160 × 120 (RGB) and a pixel pitch of 0.33 mm was produced as an example of the organic EL display element of the present invention.
On a fusion glass (Corning 1737 glass, 100 × 100 × 1.1 mm) as the transparent substrate 1, a black matrix material (Fuji Film Electronics Materials Co., Ltd .: Color Mosaic CK-7800) is applied using a spin coating method. Application and patterning were performed by a photolithography method to form a black matrix 2 having openings with a width of 0.03 mm, a pitch of 0.11 mm, and a thickness of 1 μm.

Next, a blue filter material (Fuji Film Electronics Materials Co., Ltd .: Color Mosaic CB-7001) is applied using a spin coating method, and patterning is performed by a photolithography method. The width is 0.08 mm, the pitch is 0.33 mm, A blue color conversion filter layer 3 composed of a plurality of stripes having a thickness of 10 μm was formed.
Coumarin 6 (0.7 parts by weight) as a fluorescent dye was dissolved in 120 parts by weight of a solvent, propylene glycol monoethyl acetate (PGMEA). To this solution, 100 parts by weight of V259PA / P5 manufactured by Nippon Steel Chemical Co., Ltd. was added and dissolved to obtain a coating solution. The coating liquid is applied, and patterning is performed by a photolithography method, so that the green conversion filter layer 4 (consisting of only the color conversion layer is composed of a plurality of stripes having a width of 0.08 mm, a pitch of 0.33 mm, and a thickness of 10 μm. Formed).

  Coumarin 6 (0.6 parts by weight), rhodamine 6G (0.3 parts by weight) and basic violet (0.3 parts by weight) were dissolved in 120 parts by weight of PGMEA as fluorescent dyes. 100 parts by weight of B259PA / P5 manufactured by Nippon Steel Chemical Co., Ltd. was added to and dissolved in the solution to obtain a coating solution. After applying this coating solution and patterning for photolithography, a red conversion filter layer 5 (consisting of only a color conversion layer consisting of a plurality of stripes having a width of 0.08 mm, a pitch of 0.33 mm, and a thickness of 10 μm). Formed).

Subsequently, the planarization layer 6 was formed for the purpose of relaxing the steps of the color conversion filter layers 3, 4, and 5 for blue, green, and red. A flattened acrylic material (manufactured by JSR Corporation: NN810) was applied and exposed with a photomask having an opening wider than the black matrix formation region to form a pattern with a thickness of 5 μm.
Next, using a parallel plate type plasma CVD apparatus, the first passivation layer 7 made of a SiNx film was formed to a thickness of about 300 nm, and the color conversion filter substrate 10 was obtained. At that time, the atmosphere was SiH ₄ gas 50 sccm and N ₂ gas 200 sccm, the RF applied power was 150 W, and the substrate stage temperature was 100 ° C.

Thereafter, 200 nm of IZO was deposited on the entire surface of the passivation layer 7 of the color conversion filter substrate 10 at room temperature using DC sputtering (target: In—Zn oxide, sputtering gas: O ₂ and Ar). Then, the IZO film is patterned by a photolithography method using an aqueous oxalic acid solution as an etching solution, positioned above the color conversion filter layers 3, 4, 5, and in the same direction as the stripes of the color conversion filter layers 3, 4, 5 A first electrode 20a composed of a plurality of stripes having a width of 0.1 mm and a pitch of 0.11 mm, a first extraction electrode 20b connected to them, and a second extraction electrode 20c are formed.

Next, a passivation film 30 'made of a SiNx film was formed on the entire surface by using a parallel plate type plasma CVD apparatus (FIG. 6A). At that time, the atmosphere was SiH ₄ gas 50 sccm and N ₂ gas 200 sccm, the RF applied power was 150 W, and the substrate stage temperature was 100 ° C.
Thereafter, a positive resist (Tokyo Ohka Kogyo Co., Ltd .: TFR-1250) is applied to the entire surface, and an 80 × 300 μm opening (corresponding to the first opening 30a) is aligned with the opening of the black matrix in the pixel portion. And a mask having openings (corresponding to the second to fourth openings 30b to 30d) at the joint between the second electrode 20a and the lead electrode 20c and at the joint between the lead electrodes 20b and 20c and the external drive circuit, respectively. Then, exposure was performed to form a resist film 50 having a resist pattern (FIG. 6B).

Next, the passivation film 30 ′ was etched using an ICP plasma type dry etching apparatus with an atmosphere of SF ₆ gas 100 cc, oxygen gas 50 cc, and applied power 1500 W. Thereafter, the resist was peeled off to obtain a second passivation layer 30 composed of a passivation film 30 ′ having a pattern of the first to fourth openings 30a to 30d. (Fig. 6 (C), (D))
Subsequently, a negative photoresist (ZPN 1168 manufactured by Nippon Zeon Co., Ltd.) is applied by spin coating, pre-baked, a predetermined pattern is baked using a photomask, and post-exposure baking is performed on a hot plate at 110 ° C. for 60 seconds. Then, development is performed, and finally, heating is performed on a hot plate at 160 ° C. for 15 minutes to extend in a direction perpendicular to the stripe of the first electrode 20a, and a plurality of stripes each having a plurality of stripes having a reverse taper-shaped cross section are formed. A separation partition wall for the second electrode 70 was formed.

Next, the substrate 10 having a structure below the separation partition wall of the second electrode 70 is mounted in a resistance heating vapor deposition apparatus, and the hole injection layer, the hole transport layer, the organic light emitting layer, and the electron injection layer are broken. The film was formed in sequence without. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. Copper phthalocyanine (CuPc) with a film thickness of 100 nm is used as the hole injection layer, and 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α with a film thickness of 20 nm is used as the hole transport layer. -NPD) was used as an organic light-emitting layer, and 4,4'-bis (2,2'-diphenylvinyl) biphenyl (DPVBi) with a thickness of 30 nm was stacked, and Alq3 with a thickness of 20 nm was stacked as an electron injection layer.

Next, without breaking the vacuum, Mg / Ag (mass ratio 10/1) having a thickness of 200 nm is deposited to form the second electrode 70, and the organic EL having the structure shown in FIGS. A display panel was obtained.
The organic EL display panel thus obtained was sealed with a sealing glass (not shown) and a UV curable adhesive in a glove box in a dry nitrogen atmosphere (both oxygen and moisture concentrations were 10 ppm or less).
(Comparative example)
Instead of the second passivation layer made of the SiNx film of the above-described example, a positive resist (manufactured by JSR Corporation: JEM700) was used to form the same pattern as the example.

Other than this, an organic EL display panel of a comparative example was produced in the same manner as in the example.
(Evaluation)
The number of dark spots after driving for 1000 hours at a room brightness of 100 cd / m ² at room temperature with a Duty 1/60 was compared. The number of panels was 10 each, and the entire panel was observed.

表１から分かるように、実施例のパネルは、比較例のパネルにおいて発生するダークスポットの発生が少なく、ＳｉＮｘ膜からなる第２のパッシベーション層が、水分および酸素から有機ＥＬ層６０を保護するパッシベーション膜として有効に機能していることが分かる。

As can be seen from Table 1, in the panel of the example, the dark spots generated in the panel of the comparative example are small, and the second passivation layer made of the SiNx film protects the organic EL layer 60 from moisture and oxygen. It turns out that it functions effectively as a film.

FIG. 3 is a schematic cross-sectional view taken along the line A-A ′ of FIG. 2 illustrating a main part of an embodiment of the organic EL display element according to the present invention. It is a plane schematic diagram which shows the principal part of embodiment of the organic EL display element which concerns on this invention. It is a plane schematic diagram which shows arrangement | positioning of the 1st-4th opening part provided in the 2nd passivation layer of embodiment of the organic electroluminescent display element which concerns on this invention. It is a cross-sectional schematic diagram which shows the state in which the 2nd passivation layer of embodiment of the organic electroluminescent display element which concerns on this invention covers the shoulder part of a 1st electrode around the 1st opening part. It is a cross-sectional schematic diagram which shows the state in which the 2nd passivation layer of embodiment of the organic electroluminescent display element which concerns on this invention covers the shoulder part of the 2nd extraction electrode around the 3rd, 4th opening part. It is process drawing which shows the manufacturing process ((A)-(D)) of embodiment of the organic EL display element which concerns on this invention with a reference example ((E)-(G)).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Black matrix 3-5 Color conversion filter layer 6 Flattening layer 7 First passivation layer 10 Color conversion filter substrate 20a 1st electrode 20b 1st extraction electrode 20c 2nd extraction electrode 30 2nd passivation Layer 30a First opening 30b Second opening 30c Third opening 30d Fourth opening 50 Resist film 60 Organic EL layer 70 Second electrode

Claims (5)

On the transparent substrate, at least a patterned color conversion filter layer is formed, and a color conversion filter substrate is formed on which a first passivation layer is formed, and patterned corresponding to the color conversion filter layer The first electrode, the first extraction electrode following the first electrode, the organic EL layer formed on the first electrode, and the organic EL layer sandwiched between the first electrode and the first electrode. An organic EL display element comprising a second electrode and a second lead electrode connected to the second electrode on the color conversion filter substrate,
The first electrode, the first lead electrode, and the second lead electrode are formed by patterning on the surface of the color conversion filter substrate, and the color conversion filter between the surface of each electrode and each electrode A second passivation layer comprising a passivation film covering the surface of the substrate;
The second passivation layer comprises:
An opening formed by dry etching the passivation film using the first electrode as a stopper, and a first opening for connecting the first electrode to the organic EL layer to form a pixel region;
A second opening for opening the passivation film by dry etching using the second extraction electrode as a stopper, and connecting the second extraction electrode to the second electrode;
The passivation film is opened by dry etching using the first and second lead electrodes as stoppers, respectively, and third and fourth holes for connecting the first and second lead electrodes to an external drive circuit, respectively. And having an opening,
An organic EL display element, wherein shoulders of the respective electrodes of the first electrode, the first extraction electrode, and the second extraction electrode are covered.   The first electrode and the second electrode are composed of a plurality of electrodes arranged in a matrix intersecting each other, and the first passivation layer first layer for forming a pixel region at each intersection is formed. The organic EL display element according to claim 1, wherein an opening is formed.   The organic EL display element according to claim 1, wherein the second passivation layer is made of a material selected from silicon oxide, silicon nitride, and silicon oxynitride. In the manufacturing method of the organic electroluminescent display element in any one of Claims 1-3,
On the transparent substrate, at least a patterned color conversion filter layer is formed, and a first passivation layer is formed thereon. On the color conversion filter substrate, the first electrode and the first extraction electrode are formed. And an electrode forming step of forming a second lead electrode;
A passivation film coating step of coating the color conversion filter substrate on which the electrode is formed with a passivation film;
Forming a resist film having openings corresponding to the first to fourth openings on the passivation film; and
By dry-etching the passivation film on which the resist film is formed, the first to fourth openings are formed using the first electrode, the first lead electrode, and the second lead electrode as a stopper. A dry etching step of forming the second passivation layer to form the organic EL display element.   The method for manufacturing an organic EL display element according to claim 4, wherein the dry etching step is performed in an atmosphere containing a fluorine-based gas and an oxygen gas.

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