JP2006351472A - Color conversion filter substrate, organic el display and their manufacturing methods - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nice-looking color organic EL display maintaining stable light emission characteristic by uniformly forming film thickness of a color conversion filter layer. <P>SOLUTION: In this color conversion filter substrate provided a transparent supporting substrate and at least three or more kinds of color conversion filter layers on the transparent supporting substrate, 2(n-1) subpixels constitutes one pixel where n is the number of colors in the color conversion filter layer, the subpixel of the color of each color other than one color is one subpixel per pixel, and subpixels of the one color are not adjacent to each other and arranged in positions sandwiching one end and one subpixel of other color. The organic EL display and their manufacturing methods are provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a color conversion filter substrate, an organic EL display, and a method for manufacturing the same, and more particularly, a color conversion filter substrate that enables multicolor display with high definition, excellent environmental resistance, and high productivity. The present invention relates to a multicolor organic EL display including a conversion filter substrate and a method for manufacturing the same. This organic EL display is suitable for display of image sensors, personal computers, word processors, televisions, facsimiles, audio, video, car navigation, electric desk calculators, telephones, portable terminals and industrial measuring instruments.

  In recent years, information has been diversified. Among them, display devices in the information field including solid-state image sensors are required to be “beautiful, light, thin, and excellent”, and are actively being developed for low power consumption and high-speed response. As a display device, a high-definition full-color display device is required.

It has a thin film laminated structure of organic molecules having the following characteristics, which is excellent in viewing angle dependency and high-speed response with respect to a liquid crystal display element, etc., and has a high luminance of 1000 cd / m ² or more at an applied voltage of 10 V. Since an organic EL device that emits light is reported by Tang et al., Organic EL devices have been actively researched for practical use (Non-patent Document 1). reference). Similar devices using organic polymer materials are also being actively developed.

  Since an organic EL element can realize a high current density at a low voltage, it can be expected to have higher light emission luminance and light emission efficiency than an inorganic EL element or LED. As the display element, (1) high brightness and high contrast, (2) low voltage driving and high luminous efficiency, (3) high resolution, (4) wide viewing angle, (5) high response speed, (6) It has excellent features such as miniaturization and colorization, and (7) lightness and thinness. In view of the above, it is expected to be applied to “beautiful, light, thin, excellent” flat panel displays.

  Pioneer has already commercialized a green monochrome organic EL display for use in vehicles since November 1997, and has long-term stability and high-speed response to meet the diverse needs of society. Or, there is an urgent need for practical use of an organic EL display capable of high-definition full color display.

  An example of a method for making the organic EL display multi-colored or full-colored is a method in which light emitters of three primary colors of red (R), green (G), and blue (B) are separately arranged in a matrix and light is emitted. (See Patent Documents 1 to 3). In the case of colorization using an organic EL element, it is technically difficult and cannot be manufactured at low cost because three types of RGB light emitting materials must be arranged on the matrix with high definition. In addition, since the lifetimes (luminance change characteristics) of the three kinds of light emitting materials are different from each other, there is a disadvantage that chromaticity is shifted due to long-term use.

  In addition, a method for transmitting three primary colors using a color filter for a backlight that emits white light (for example, see Patent Documents 4 to 6) is known. However, a long lifetime necessary for obtaining high-luminance RGB light is known. In addition, a high-luminance white light-emitting organic EL element has not yet been obtained.

  Alternatively, there is also known a method in which light emitted from a light emitter is absorbed by phosphors separated and arranged in a plane, and multicolor fluorescence is emitted from each phosphor (see Patent Document 7). Here, the method of emitting multicolor fluorescence from a certain light emitter using a phosphor has a track record in applications such as CRT and plasma display.

  In recent years, color conversion methods have been studied in which a fluorescent material that absorbs light in the light emitting region of an organic EL element and emits fluorescence in the visible light region is used as a filter (see, for example, Patent Documents 7 and 8). Since the light emission color of the organic EL element is not limited to white, an organic EL element with higher luminance can be applied as a light source. In a color conversion method using a blue light emitting organic EL element, blue light is converted into green light and The wavelength is converted into red light (see, for example, Patent Document 7 and Patent Documents 9 and 10). If such a color conversion layer containing a fluorescent dye is patterned with high definition, a full-color light-emitting display can be constructed even using weak energy rays such as near-ultraviolet light or visible light of a light emitter. Hereinafter, the filter layer and / or the color conversion layer are collectively referred to as a color conversion filter layer. The color conversion filter layer may consist of only the color filter layer or the color conversion layer, or may be a laminate of the filter layer and the color conversion layer.

  As a patterning method for the color conversion filter layer, (1) as in the case of the inorganic phosphor, a fluorescent dye or the like is dispersed in a liquid resist (photoreactive polymer), and the dispersion is subjected to spin coating or the like. After forming a film using the method, patterning is performed by a photolithography method (see Patent Documents 8 and 11), or (2) a fluorescent dye is dispersed in a basic matrix, and the dispersion is etched using an acidic aqueous solution. (Refer to Patent Document 10).

JP-A-57-157487 Japanese Patent Laid-Open No. 58-147899 JP-A-3-214593 JP-A-1-315988 JP-A-2-27396 Japanese Patent Laid-Open No. 3-194485 Japanese Patent Laid-Open No. 3-152897 JP-A-5-258860 JP-A-8-286033 Japanese Patent Laid-Open No. 9-208944 C. W. Tang, S. A. VanSlike, Appl. Phys. Lett. 51, 913 (1987)

  That is, in the prior art, as shown in FIG. 1, after forming and patterning a color conversion filter layer for one color of RGB, a color conversion filter layer for another color of RGB is formed and patterned, and then the rest A color conversion filter layer of one color is formed and patterned.

  However, the color conversion filter layer is as thick as 5 to 15 μm. As shown in FIGS. 1-2 and 1-3, the second and subsequent color conversion filter layers are formed in the vicinity thereof. Due to the influence of the color conversion filter layer, the film thickness cannot be formed uniformly. Also, the cross-sectional shape of the one end becomes thick, and the left and right non-uniform film thickness tends to be obtained.

  For this reason, the color conversion filter layer is formed thick so that the conversion efficiency is almost constant even if the film thickness varies, but this further increases the level difference, resulting in a film with a non-uniform film thickness. The thickness variation is promoted, and the color conversion layer is covered to make it difficult to form a polymer flattening film that is transparent and flat.

  When the above-described film thickness variation that causes non-uniform film thickness occurs, the reflection of external light varies depending on the angle and color due to the inclination caused by the non-uniform film thickness. As a result, when the light hits the display, different colors are reflected depending on the angle, and the panel appears to be colored at first glance, which causes a great problem with the appearance of the panel.

  The present invention has been made in view of the above-described problems. The film thickness of the color conversion filter layer is formed uniformly, and the formation of a polymer flattening film covering the color conversion filter layer is facilitated, and stable light emission is achieved. An object of the present invention is to provide a color organic EL display having good appearance and maintaining characteristics.

  The color conversion filter substrate of the present invention is a color conversion filter substrate having at least a transparent support substrate and three or more color conversion filter layers provided on the transparent support substrate, wherein the color conversion filter layer includes the number of colors. Where n is 2 (n-1) sub-pixels, and each color other than one color is one sub-pixel per pixel. Is characterized in that the sub-pixels of the color are not adjacent to each other and are arranged at positions sandwiching one end and one sub-pixel of the other color.

  The organic EL display of the present invention is characterized by having a color conversion filter substrate, at least a transparent electrode, and an organic EL element comprising an organic EL layer sandwiched between reflective electrodes.

  Moreover, the method for producing a color conversion filter substrate of the present invention is the method for producing a color conversion filter substrate having at least a transparent support substrate and three or more color conversion filter layers provided on the transparent support substrate. When the number of colors is n in the color conversion filter layer, one pixel is composed of 2 (n−1) subpixels, and each color other than one color has one subpixel of that color per pixel. The one color is a color conversion filter layer arranged at a position sandwiching one end and one subpixel of the other color without the subpixels of that color being adjacent to each other. In the formation, the sub-pixels of colors other than the one color are sequentially formed with a region where one sub-pixel is formed therebetween, and then the sub-pixel of the one color is finally formed. .

  In addition, the organic EL display manufacturing method of the present invention is characterized in that at least a transparent electrode, an organic EL layer, and a reflective electrode are sequentially laminated on the color conversion filter substrate manufactured by the above manufacturing method.

  In addition, another organic EL display manufacturing method of the present invention includes a color conversion filter substrate manufactured by the above manufacturing method, and an organic EL in which at least a reflective electrode, an organic EL layer, and a transparent electrode are sequentially stacked on a holding substrate. The element is bonded to the element.

  According to the present invention, the present invention has been made in view of the above-mentioned problems, and it is possible to form a uniform film thickness of the color conversion filter layer and to form a polymer flattening film that covers the color conversion filter layer. It is possible to provide a color organic EL display that has a good appearance and facilitates and maintains stable light emission characteristics.

  An example of the organic EL display panel of the present invention is shown in FIG. In this organic EL display panel, an organic EL light emitting element 30 is laminated on the gas barrier layer 6 of the color conversion filter substrate 20. FIG. 2 shows a portion corresponding to one pixel and a portion of adjacent pixels in an organic multicolor display having a plurality of pixels for use as a color conversion type multi-color or full-color display.

  In FIG. 2, a color conversion filter substrate 20 includes a red conversion filter layer 2, a green conversion filter layer 3, and a blue conversion filter layer 4 having a predetermined pattern formed on a transparent support substrate 1. A set of filter layers are arranged in a matrix. A polymer flattening film 5 that covers the color conversion filter layer and flattens the upper surface thereof is formed, and a gas barrier layer 6 is formed on the polymer flattening film 5. The upper surface of the gas barrier layer 6 is flat.

  The organic EL light emitting device of FIG. 2 is provided with a transparent electrode (first electrode) 7 at a position corresponding to each of the color conversion filter layers 2, 3 and 4 on the gas barrier layer 6 of the color conversion filter substrate 20. A hole injection layer 8, a hole transport layer 9, an organic light emitting layer 10, an electron injection layer 11, and a reflective electrode (second electrode) 12 are sequentially stacked. Hereinafter, each layer will be described in detail.

A. 1. Color conversion filter substrate Color Conversion Filter Layer The color conversion filter layer is 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 does not have a color conversion function and transmits light of a wavelength in a selected range to improve the color purity of output light. When using the laminated body of a color filter layer and a color conversion layer, a color filter layer is normally arrange | positioned between a transparent substrate and a color conversion layer. The color filter layer can be formed using any material known in the art such as a material used in a liquid crystal display or the like.

  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 light emitting layer. Thus, it is a pigment that emits light in a desired wavelength band (for example, blue, green, or red).

1) Color Conversion Dye In the present invention, the color conversion dye absorbs light in the near-ultraviolet region or visible region, particularly light in the blue or blue-green region, emitted from the light emitter, and emits visible light of different wavelengths as fluorescence. Is. Preferably, at least one fluorescent dye that emits fluorescence in the red region may be used, and may be combined with one or more fluorescent pigments that emit fluorescence in the green region.

  That is, when an organic EL element that emits light in the blue or blue-green region is used as the light source, if light from the element is passed through a simple red filter to obtain light in the red region, light having a wavelength in the red region is originally used. Because there is little, it becomes very dark output light. On the other hand, light in the red region having sufficient intensity can be output by converting the light in the blue or blue-green region from the element into light in the red region by the color conversion dye in the red conversion layer. It becomes. Therefore, in the present invention, the red color conversion filter layer 2 is preferably composed of a color conversion layer, and more preferably is composed of a laminate of a color filter layer and a color conversion layer.

  On the other hand, the light in the green region may be output after the light from the element is converted into the light in the green region by another color conversion dye, similarly to the light in the red region. Alternatively, if the light emission of the element sufficiently includes light in the green region, the light from the element may simply be output through the green filter. Furthermore, regarding the light in the blue region, the light from the organic EL element can be output through a simple blue filter.

  Examples of fluorescent dyes that absorb light in the blue to blue-green region emitted from the luminescent material and emit fluorescence in the red region include rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet 11 Pyridine dyes such as rhodamine dyes such as basic red 2, cyanine dyes, 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridinium perchlorate (pyridine 1) Or oxazine dyes. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.

  Examples of fluorescent dyes that absorb blue to blue-green light emitted from a light emitter and emit green light include 3- (2′-benzothiazolyl) -7-diethylamino-coumarin (coumarin 6), 3- (2′-Benzimidazolyl) -7-diethylamino-coumarin (coumarin 7), 3- (2′-N-methylbenzimidazolyl) -7-diethylamino-coumarin (coumarin 30), 2,3,5,6-1H, 4H -Coumarin-based dyes such as tetrahydro-8-trifluoromethylquinolidine (9,9a, 1-gh) coumarin (coumarin 153), or basic yellow 51 which is a coumarin dye-based dye, solvent yellow 11, solvent yellow 116 And naphthalimide dyes. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.

  The color conversion dye used in the present invention includes polymethacrylate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, alkyd resin, aromatic sulfonamide resin, urea resin, melamine resin, benzoguanamine resin, and these resins. An organic color conversion pigment may be obtained by kneading into a mixture or the like in advance to obtain a pigment. In addition, these color conversion dyes and organic color conversion pigments (in the present specification, the above two are collectively referred to as color conversion dyes) may be used singly, and two kinds may be used to adjust the hue of fluorescence. A combination of the above may also be used.

  The color conversion pigment used in the present invention is contained in the color conversion layer in an amount of 0.01 to 5% by mass, more preferably 0.1 to 2% by mass, based on the weight of the color conversion layer. If the content of the color conversion dye is less than 0.01% by mass, sufficient wavelength conversion cannot be performed, or if the content exceeds 5%, the color conversion efficiency decreases due to effects such as density quenching. Bring.

2) Matrix resin The matrix resin used in the color conversion layer of the present invention is polymerized or polymerized by generating radical species or ionic species by light and / or heat treatment of a photocurable or photothermal combination type curable resin (resist). Cross-linked and insoluble and infusible. In order to perform patterning of the color conversion layer, it is desirable that the photocurable or photothermal combination type curable resin is soluble in an organic solvent or an alkaline solution in an unexposed state.

  Specifically, the matrix resin is obtained by subjecting a composition film comprising (1) an acrylic polyfunctional monomer and oligomer having a plurality of acryloyl groups and methacryloyl groups, and light or thermal polymerization initiator to light or heat treatment, Or a polymer obtained by generating thermal radicals, (2) a composition comprising a polyvinylcinnamic acid ester and a sensitizer dimerized by light or heat treatment, and (3) a chain or cyclic olefin A composition film composed of bisazide is irradiated with light or heat to generate nitrene and crosslinked with olefin, and (4) a composition film composed of a monomer having an epoxy group and an acid generator is subjected to light or heat treatment, Including those polymerized by generating an acid (cation). In particular, a polymer obtained by polymerizing a composition comprising the acrylic polyfunctional monomer and oligomer (1) and light or a thermal polymerization initiator is preferred. This is because the composition can be patterned with high definition and has high reliability such as solvent resistance and heat resistance after polymerization.

  The photopolymerization initiator, sensitizer, and acid generator that can be used in the present invention are preferably those that initiate polymerization by light having a wavelength that is not absorbed by the fluorescent conversion dye contained therein. In the fluorescence conversion filter layer of the present invention, a photopolymerization initiator and a thermal polymerization initiator are added when the resin itself in the photocurable or photothermal combination type curable resin can be polymerized by light or heat. It is also possible not to.

2. Polymer Flattening Film The polymer flattening film 5 can be formed without impairing the function of the color conversion filter layer, and can be formed from a material having appropriate elasticity. As a material constituting the polymer flattening film, transparency in the visible region is high (transmittance of 50% or more in the range of 400 to 800 nm), surface hardness is pencil hardness of 2H or more, and Tg is 100 ° C. or more. Any polymer that can form a smooth coating film on the color conversion filter layer and does not deteriorate the function of the color conversion layer may be used.

Examples of such polymer materials include imide-modified silicone resins, materials in which inorganic metal compounds (TiO ₂ , Al ₂ O ₃ , SiO _2, etc.) are dispersed in acrylic, polyimide, silicone resins, etc., acrylate monomers / oligomers / Examples of the resin include a resin having a reactive vinyl group, a resist resin, a thermosetting resin such as a fluorine resin, and / or a thermosetting resin. Alternatively, the planarization layer 13 may be formed using an inorganic compound formed by a sol-gel method. In addition, it is possible to dissipate heat from the organic EL element toward the transparent substrate 1 by using a photocurable resin such as an epoxy resin having a mesogenic structure having a high thermal conductivity.

3. Gas Barrier Layer The gas barrier layer 6 formed on the polymer flattening film 5 has excellent moisture / oxygen barrier properties, and is therefore a layer for preventing the transmission of moisture and oxygen from the color conversion filter layer. . In order to transmit light from the organic EL element to the color conversion filter layer, the gas barrier layer 6 preferably has high transparency in the visible region (transmittance of 50% or more in the range of 400 to 800 nm). Further, since it is necessary to form a transparent electrode 7 composed of a plurality of electrically independent portions on the gas barrier layer 6, the gas barrier layer 6 is required to have electrical insulation at least on its upper surface. Moreover, it is preferable that the gas barrier layer 6 has a film hardness of pencil hardness 2H or more.

  The gas barrier layer 6 is composed of an inorganic film such as an oxide, nitride, carbide, or oxynitride. The gas barrier layer 6 may be a laminate or mixture of the above compounds. The gas barrier layer 6 is preferably configured to completely cover the polymer flattening film 5 as shown in FIG. By doing so, it is possible to prevent the polymer flattening film 5 from coming into contact with the atmosphere after the gas barrier layer 6 is formed and adsorbing a gas such as water vapor, thereby preventing degassing from the gas barrier layer 6 itself after the organic EL element is formed. be able to.

  In addition, since the gas barrier layer 6 is made of an inorganic film, it is possible to improve moisture and oxygen trapping properties and to prevent moisture and oxygen from being transferred from the color conversion filter layer to the organic EL element.

  The film thickness of this inorganic film can be increased as long as it has transparency in the visible range described above, but is usually in the range of 50 to 300 nm. By forming a film having a film thickness in such a range, the above-mentioned required characteristics including transparency in the visible range are satisfied, and at the same time, the occurrence of defects such as pinholes is suppressed, and a good gas (water content) And oxygen) barrier properties can be provided.

4). Transparent support substrate In this invention, the transparent support substrate 1 used for a color conversion filter board | substrate needs to be transparent with respect to the light from the above-mentioned color conversion filter layer. Moreover, it should be able to withstand the conditions (solvent, temperature, etc.) used for forming the layer to be laminated, and preferably has excellent dimensional stability. A preferable support substrate 1 includes a glass substrate and a resin substrate such as polyolefin, polymethyl methacrylate, polyethylene terephthalate, polycarbonate resin, or polyimide resin. A flexible film made of the same resin may be used as the support substrate 1. Among these, borosilicate glass and blue plate glass are preferable.

5. Color Conversion Filter Substrate The color conversion filter substrate has three or more color conversion layers formed in a desired pattern on the transparent support substrate 1 described above. That is, when the number of colors is n (n ≧ 3), 2 (n−1) sub-pixels constitute one pixel, and each color other than one color has one sub-pixel per pixel. There is only one subpixel, and only that one color occupies a plurality of subpixels.

  The pixels of the one color are arranged every other pixel from one end, and the other colors are arranged between the pixels of the one color or the ends opposite to the ends where the pixels of the one color are arranged (others). At the end).

  When the color conversion layer has three colors, red (R), green (G), and blue (B) are preferable, and when there are four or more colors, other intermediate colors can be used as appropriate. Hereinafter, the case of three colors will be further described as an example.

  In the present invention, the desired pattern (color combination) of the color conversion filter layer depends on the application used. A rectangular or circular area (red / green / red / blue, red / green / blue, plus one red, green and blue subpixels for each red, green and blue subpixel) -Green or red / blue / green / blue) may be formed as one pixel on the entire surface of the transparent support substrate 1. Alternatively, parallel stripes of red, green and blue (any stripe of any one color of red, green and blue having a desired width and having a length corresponding to the length of the transparent support substrate 1) Additions (red / green / red / blue, red / green / blue / green, or red / blue / green / blue) may be formed on the entire surface of the transparent support substrate.

  In the present invention, the color conversion filter layers of a specific color can be arranged in a larger area than the color conversion filter layers of other colors. It is preferable that the color conversion filter layer of a color arranged in a large area is a color conversion filter layer of a color occupying a plurality of subpixels per pixel.

  In the present invention, since the sub-pixels of each color are arranged as described above, when the color conversion filter layers occupying a single sub-pixel per pixel are sequentially formed in advance, the color conversion filter layers are Since the color conversion filter layer does not exist in the adjacent position, the color conversion filter layer is not greatly affected by the other color conversion layers formed earlier, and therefore the color conversion filter layer has the same height on the left and right. Since the color conversion filter layer occupying a plurality of subpixels per pixel formed at the end is already formed with color conversion filter layers on both sides, the color conversion filter layers are affected in substantially the same manner. Again, the color conversion filter layer has a height close to that of the left and right. Since the end color conversion filter layer at the end of the adjacent pixel is formed adjacent to the end subpixel in one pixel, the color conversion filter layer at the end of the pixel is similarly a color conversion filter having a height close to the left and right. Become a layer.

  Since the current color conversion material has low red light emission efficiency, it is necessary to increase the light emission of the organic EL light emitting element in the red position or increase the red aperture ratio. However, if the emission of the organic EL light-emitting element is increased, the deterioration of the organic EL light-emitting element is accelerated, so adjustment by the aperture ratio is desirable. In the present invention, the color occupying a plurality of subpixels per pixel is red. This is preferable because the color conversion filter layer can be flattened and the red aperture ratio can be adjusted simultaneously.

B. Organic EL Display The organic EL display of the present invention includes the aforementioned color conversion filter substrate and an organic EL light emitting element provided on the gas barrier layer of the color conversion filter substrate. In this organic EL display, the organic EL light emitting element may be formed on the color conversion filter substrate, or after the organic EL light emitting element is separately formed, the organic EL light emitting element and the color conversion filter substrate may be overlapped. Good. The near-ultraviolet to visible light, preferably blue to blue-green light emitted from the organic EL light emitting element is incident on the color conversion filter layer, and visible light having different wavelengths is emitted from the color conversion filter layer. It is a thing.

  An organic EL light-emitting element is one in which an organic light-emitting layer is held between at least a pair of electrodes (a transparent electrode and a reflective electrode), and a hole transport layer, a hole injection layer and / or an electron injection layer are provided as necessary. It has an intervening structure. Each of these layers has a film thickness sufficient to achieve the desired characteristics. For example, what consists of the following layer structures is employ | adopted.

(1) Anode / organic light emitting layer / cathode (2) Anode / hole injection layer / organic light emitting layer / cathode (3) Anode / organic light emitting layer / electron injection layer / cathode (4) Anode / hole injection layer / organic Light emitting layer / electron injection layer / cathode (5) Anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode

  In the above layer configuration, at least one of the anode and the cathode is preferably transparent in the wavelength range of light emitted from the organic EL light emitting element, and light is incident on the color conversion filter layer through the transparent electrode. In this technique, it is known that it is easy to make the anode transparent, and it is preferable to make the anode transparent also in the present invention.

  The anode is ITO (In-Sn oxide), NESA film, Sn oxide, In oxide, IZO (In-Zn oxide), Zn oxide, Zn-Al oxide, Zn-Ga oxide, or these It can be formed using a conductive transparent metal oxide in which a dopant such as F or Sb is added to the oxide. The cathode 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. High reflectivity microcrystalline alloys include NiAl and the like.

  Each of the transparent electrode and the reflective electrode may be formed from a plurality of stripe-shaped partial electrodes, and may be configured to extend in a direction in which the transparent electrode stripe and the reflective electrode stripe intersect (preferably in a direction orthogonal). . If such a structure is taken, if one of the partial electrodes of the transparent electrode and one of the partial electrodes of the reflective electrode are selected and a voltage is applied, the organic light-emitting layer located at the intersection of them will emit light. Matrix driving is possible.

  In addition, either the transparent electrode or the reflective electrode is formed as a common electrode, and the other electrode is manufactured from a plurality of partial electrodes, and a switching element (TFT or the like) is provided for each of the plurality of partial electrodes. It is possible to adopt a configuration in which a pair is connected. In such a configuration, the active matrix driving in which the organic light emitting layer at the corresponding position emits light by turning on the switching element corresponding to the desired position becomes possible.

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 Alq ₃ ), a styrylbenzene compound (4,4′-bis (diphenyl) (Vinyl) 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) (Alq ₃ ). ) 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.

As the material for the electron injection layer, an aluminum complex such as Alq ₃ or an aluminum quinolinol complex doped with an alkali metal or an alkaline earth metal can be used.

  Next, the manufacturing method of the color conversion filter substrate and organic EL display of the present invention will be described. Regarding the manufacturing method, the case where the color of the color conversion filter layer is three types of red (R), green (G), and blue (B) will be described. For convenience of explanation, a case where the color of the color conversion layer occupying a plurality of subpixels in one pixel is red will be described as an example.

  In the present invention, a green or blue color conversion filter layer is formed on a support substrate.

  The color conversion filter layer is formed by using a spin coating method, a roll coating method, a casting method, a dip coating method, or the like using a solution or dispersion containing a photocurable or photothermal combination type curable resin, a color conversion dye and an additive. A resin layer is formed by coating on the transparent substrate 11, and a desired portion of the photocurable or photothermal combination type curable resin is exposed to light to be polymerized. Patterning is performed after exposing the desired portion to insolubilize the photocurable or photothermal combination type curable resin. The patterning can be performed by a conventional method such as removing the resin in the unexposed portion using an organic solvent or an alkali solution in which the resin in the unexposed portion is dissolved or dispersed.

  In FIG. 3, the blue color conversion filter layer 4 is formed first. Since there is nothing on the substrate, the left and right heights of this color conversion filter layer are the same as shown in FIG.

  Next, a coating liquid for the green color conversion filter layer 3 is applied on the substrate 1 on which the blue color conversion filter layer 4 is formed (FIG. 3-1), and the green color conversion filter layer 3 is formed by patterning (FIG. 3-2). Since the blue conversion filter layer 4 in the same pixel and the blue return filter layer 4 ′ of the adjacent pixel are each separated by one subpixel, the green conversion filter layer 3 is greatly affected by the blue conversion filter layers 4 and 4 ′. In addition, the left and right heights are equal as shown in FIG.

  Next, the red color conversion filter layer 2 is formed on the substrate 1 on which the blue color conversion filter layer 4 and the green color conversion filter layer 3 are formed. The red color conversion filter layer 2 is formed between the blue color conversion filter layer 4 and the green color conversion filter layer 3 in the same pixel and between the green color conversion filter layer 3 in the same pixel and the blue color conversion filter layer 4 ′ of the adjacent pixel. (FIG. 3-3). The red color conversion filter layer 2 is affected by the adjacent blue color conversion filter layers 4, 4 ′ and the green color conversion filter layer 3.

  Although there may be a slight difference in the height of the blue conversion filter layers 4 and 4 'and the green conversion layer 3, there is a color conversion filter layer of another color on one side as in the prior art, and the opposite. Compared to the case where there is nothing at the position of the horizontal subpixel on the side, the difference in influence from the color conversion filter layers on both sides is small, and the left and right heights of the red conversion layer 2 are substantially equal.

  A polymer flattening film 5 and a gas barrier layer 6 may be formed on the substrate 1 on which the color conversion filter layer is formed, if necessary.

  There is no particular limitation on the method for forming the polymer flattening film 5. For example, it can be formed by a conventional method such as a dry method (sputtering method, vapor deposition method, CVD method, etc.) or a wet method (spin coating method, roll coating method, casting method, etc.).

  When the gas barrier layer 6 is formed, it is formed on the polymer flattening film 5. When an inorganic film is formed as the gas barrier layer 6, this inorganic film can be formed by vapor deposition, sputtering (including reactive sputtering), or chemical vapor deposition (CVD). In particular, when an oxide film is formed, it is preferable to use a sputtering method (including a reactive sputtering method) from the viewpoints of adhesion, film thickness uniformity, and productivity.

  The organic EL display of the present invention can be obtained by sequentially laminating at least a transparent electrode, an organic EL layer and a reflective electrode on the color conversion filter substrate thus obtained.

  The transparent electrode is formed using a vapor deposition method, a sputtering method (including a reactive sputtering method), or a chemical vapor deposition (CVD) method, and preferably formed using a sputtering method (including a reactive sputtering method).

  For each layer of the organic EL layer including an organic light emitting layer sandwiched between a transparent electrode and a reflective electrode to form an organic light emitting element, any means known in the art such as vapor deposition (resistance heating or electron beam heating) is used. Can be formed.

  The reflective electrode can be 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. When a reflective electrode composed of a plurality of partial electrodes is required, a reflective electrode composed of a plurality of partial electrodes may be formed using a mask that gives a desired shape, or an inversely tapered cross-sectional shape may be formed. You may form the reflective electrode which consists of a some partial electrode using the separation partition which has.

  In the present invention, an organic EL device in which a reflective electrode, each layer including an organic light emitting layer, and a transparent electrode are formed on a separate support substrate, and the color conversion filter substrate and the transparent electrode and the gas barrier layer are opposed to each other. An organic EL display may be formed by bonding.

  The color conversion filter substrate and the organic EL element can be bonded together using any means known in the art such as an ultraviolet curable adhesive.

  Hereinafter, the organic EL display of the present invention will be described using examples with reference to the drawings.

  In each example and comparative example, a color organic EL display having a pixel number of 60 × 80 and a pixel pitch of 0.33 mm was produced.

Example 1
[Preparation of Blue Filter Layer 4]
After applying a blue filter material (Fuji Hunt Electronics Technology Co., Ltd., Color Mosaic CB-7001) to a 50 × 50 × 1.0 mm Corning glass by spin coating, patterning is carried out by photolithography. A blue filter layer 4 having a line pattern with a line width of 95 μm, a pitch of 330 μm, and a film thickness of 10 μm was obtained.

[Preparation of green conversion layer 3]
Next, coumarin 6 (0.7 parts by mass) was dissolved in propylene glycol monomethyl ether acetate (PEGMA, 120 parts by mass) as a fluorescent dye. Next, 100 parts by mass of photopolymerizable resin VPA100 / P5 (trade name, manufactured by Nippon Steel Chemical Co., Ltd., refractive index: 1.59) was added and dissolved to obtain a coating solution. As shown in FIG. 3A, this coating solution is applied by spin coating on the coning glass on which the line pattern of the blue filter layer 4 is formed, and patterned by photolithography, and the line width is 95 μm. A green conversion layer 3 composed of a plurality of stripes having a pitch of 330 μm and a thickness of 10 μm was formed (FIG. 3-2).

  Since the height of the color conversion filter layer is 10 μm and the step between the color conversion filter layer portion and the surface of the coning glass is large, one pixel in the prior art is composed of one subpixel of three colors of red, green, and blue. As shown in FIGS. 1-1 to 1-3, the upper surface of the color conversion layer is likely to be inclined due to the effect of the step formed by the previously formed color conversion filter layer. On the other hand, in the present invention, the green color conversion layer is located in the middle of the adjacent blue filter layer formed as shown in FIG. 3-2 and is further separated by one subpixel from the blue color conversion layer. Therefore, the effect of the step due to the blue filter layer works equally on the left and right, so that the film thickness variation of the green conversion layer is suppressed and the upper surface is not inclined.

[Production of red conversion layer]
As fluorescent dyes, coumarin 6 (0.6 parts by mass), rhodamine 6G (0.3 parts by mass) and basic violet 11 (0.3 parts by mass) were dissolved in 120 parts by mass of PEGMA. Next, 100 parts by mass of a photopolymerizable resin VPA100 / P5 was added and dissolved to obtain a coating solution. This coating solution is applied by spin coating on the above-mentioned Corning glass on which the line pattern of the blue filter layer and the green conversion layer is formed, and patterning by photolithography is performed, and the blue filter layer and the green conversion layer are formed. A red conversion layer having a line pattern with a line width of 55 μm, a pitch of 165 μm, and a film thickness of 10 μm was formed between the blue filter layers (both sides of the green conversion layer).

  In the case where one pixel of the prior art is composed of one sub-pixel of three colors of red, green, and blue, as shown in FIG. 1-3, the green color in which the film thickness fluctuates due to the influence of the blue filter layer and the blue filter layer. The film thickness of the red color conversion layer fluctuates unevenly due to the effect of the level difference of the conversion layer. On the other hand, in the present invention, since the film thickness variation of the green color conversion layer is suppressed, the film thickness difference between the blue filter layer and the green color conversion layer is reduced, and therefore the film thickness variation of the red color conversion layer is also reduced.

[Formation of polymer flattening layer]
A UV curable resin (epoxy-modified acrylate) is applied onto the substrate on which the blue filter layer, green conversion layer, and red conversion layer are formed by spin coating, and exposed to a high-pressure mercury lamp to expose the color conversion filter layer. The flattening layer 13 was formed so that the thinnest thickness of the flattening layer was 5 μm. At this time, the pattern of the color conversion filter layer 12 of each color was not deformed, and the upper surface of the planarizing layer 13 was flat.

[Formation of gas barrier layer]
Next, as a gas barrier layer, a 300-nm-thick SiO _x film formed by RF magnetron sputtering at room temperature was formed. At this time, Si was used as a sputtering target, and a mixed gas of Ar and oxygen was used as a sputtering gas.

[Production of organic EL element]
On the color conversion filter substrate thus obtained, as shown in FIG. 2, an organic EL device having a six-layer structure of anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode is formed. Formed.

  First, a transparent electrode IDIXO (produced by Idemitsu Kosan Co., Ltd., a mixture of indium and zinc oxide and indium oxide) was formed on the entire surface of the upper surface of the gas barrier layer, which is the uppermost layer of the color conversion filter substrate, by sputtering. Next, patterning is performed by a photolithographic method using OFRP-800 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a resist, and the light emission of the 90 μm width and red conversion layer located in the light emitting part of each blue filter layer and green conversion layer. A transparent electrode composed of a plurality of stripe-shaped partial electrodes having a width of 50 μm, a gap of 12.5 μm, and a film thickness of 100 nm was formed.

Next, the substrate on which the transparent electrode is formed is mounted in a resistance heating vapor deposition apparatus, and the organic EL layer composed of four layers of hole injection layer / hole transport layer / organic light emitting layer / electron injection layer is formed without breaking the vacuum. Films were sequentially formed. 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) as the organic light-emitting layer, 30 nm-thick 4,4′-bis (2,2′-diphenylvinyl) biphenyl (DPVBi), and as the electron injection layer, 20 nm-thick tris (8-hydroxy) A quinoline) aluminum complex (Alq ₃ ) was laminated.

  Subsequently, a 200 nm thick Mg / Ag (with a thickness of 300 μm and a pitch of 330 μm (gap width of 30 μm) is used to obtain a Mg / Ag (200 nm thick) film without breaking the vacuum. A reflective electrode composed of a plurality of striped partial electrodes was formed by depositing a mass ratio of 10/1).

  The thus obtained laminate is 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 are 10 ppm or less), and a color organic EL display Got.

The obtained color organic EL display was connected to a drive circuit, and an image was displayed at 100 cd / cm ² . The visibility (color reproducibility, coloring of reflection) of the panel display when the panel surface was irradiated with a xenon lamp having an illuminance of 2000 lx was examined. The results are shown in Table 1.

(Example 2)
The blue filter layer, the green color conversion layer, and the red color conversion layer have a line width and a pitch of 75 μm and a pitch of 330 μm, respectively, and in the formation of transparent electrodes, a stripe pattern having a line width of 70 μm and a gap of 15 μm located in each light emitting portion A color organic EL display was produced in the same manner as in Example 1 except that. In the same manner as in Example 1, the obtained color organic EL display was connected to a drive circuit to display an image, and the visibility of the panel display upon irradiation with a xenon lamp was examined. The results are shown in Table 1 together with the results of Example 1.

  As in the case of Example 1, the effect of the step between the blue filter layer portion and the surface of the coning glass was equal left and right, and the film thickness variation of the green conversion layer was suppressed. Furthermore, the width of the red color conversion layer is wider than that in Example 1, and the influence of the steps based on the left and right blue filter layers and the green color conversion layer is further suppressed, and the film thickness variation of the red color conversion layer is further reduced.

(Comparative Example 1)
Each pixel consists of one sub-pixel of three colors of red, green, and blue, that is, a line having a line width of 100 μm, a pitch of 330 μm, and a film thickness of 13 μm. A color conversion filter layer was obtained in the same manner as in Example 1 except that the pattern was formed.

  As shown in FIGS. 1-1 to 1-3, the obtained color conversion filter layer has an upper surface of the green conversion layer that is slanted under the influence of the step formed by the blue filter layer formed earlier. Under this influence, the film thickness of the red color conversion layer fluctuated unevenly as shown in FIG.

  Using this color conversion layer, in the formation of the transparent electrode, a color organic EL device was formed in the same manner as in Example 1 except that a stripe pattern having a line width of 90 μm, a gap of 20 μm, and a film thickness of 100 nm was formed. A display was made. In the same manner as in Example 1, the obtained color organic EL display was connected to a drive circuit to display an image, and the visibility of the panel display upon irradiation with a xenon lamp was examined. The results are shown in Table 1 together with the results of Examples 1 and 2.

  From Table 1, in Comparative Example 1, which is the prior art, the film thickness variation of the color conversion filter layer is large and the visibility of the panel display at the time of xenon lamp irradiation is inferior, whereas in Examples 1 and 2 according to the present invention, It can be seen that the film thickness variation of the color conversion layer is small and the visibility of the panel display is excellent.

  ADVANTAGE OF THE INVENTION According to this invention, the film thickness of a color conversion filter layer can be formed uniformly, and the good-looking color organic EL display which maintains the stable light emission characteristic can be provided.

It is a schematic sectional drawing which shows the formation process of the color conversion filter layer by a prior art. It is a schematic sectional drawing which shows one embodiment of the organic electroluminescent display of this invention. It is a schematic sectional drawing which shows the formation process of the color conversion filter layer by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Red conversion filter layer 3 Green conversion filter layer 4 Blue conversion filter layer 4 Blue conversion filter layer of adjacent pixel 5 Polymer flattening film 6 Gas barrier layer 7 Transparent electrode 8 Hole injection layer 9 Hole transport layer DESCRIPTION OF SYMBOLS 10 Organic light emitting layer 11 Electron injection layer 12 Reflective electrode 20 Color conversion filter substrate 30 Organic EL element

Claims (9)

  In a color conversion filter substrate having at least three types of color conversion filter layers provided on the transparent support substrate and the transparent support substrate, when the number of colors is n, the color conversion filter layer is 2 ( n-1) One sub-pixel constitutes one pixel, and for each color other than one color, the sub-pixel of that color is one sub-pixel per pixel. A color conversion filter substrate, wherein the color conversion filter substrate is arranged without being adjacent to each other and sandwiching one end and one sub-pixel of another color.   2. The color conversion filter according to claim 1, wherein the color conversion filter layer comprises three colors of red (R), green (G), and blue (B), and the number of sub-pixels constituting one pixel is four. substrate.   3. The color conversion filter substrate according to claim 1, wherein the one color is red.   4. An organic EL display comprising: the color conversion filter substrate according to claim 1; and an organic EL element including an organic EL layer sandwiched between at least a transparent electrode and a reflective electrode.   In the method for manufacturing a color conversion filter substrate having at least three or more kinds of color conversion filter layers provided on the transparent support substrate and the transparent support substrate, when the color conversion filter layer has n as the number of colors 2 (n-1) sub-pixels form one pixel, and each color other than one color has one sub-pixel per pixel, and that one color is a sub-pixel of that color. In forming a color conversion filter layer in which pixels are not adjacent to each other and positioned at one end and one subpixel of another color, the subpixels of colors other than the one color are A method of manufacturing a color conversion filter substrate, comprising sequentially forming a region where one subpixel is formed in between, and then forming a subpixel of the one color at the end.   6. The color conversion filter according to claim 5, wherein the color conversion filter layer comprises three colors of red (R), green (G), and blue (B), and the number of sub-pixels constituting one pixel is four. A method for manufacturing a substrate.   7. The method of manufacturing a color conversion filter substrate according to claim 5, wherein the one color is red.   8. A method for manufacturing an organic EL display, comprising: sequentially laminating at least a transparent electrode, an organic EL layer, and a reflective electrode on a color conversion filter substrate manufactured by the manufacturing method according to claim 5.   A color conversion filter substrate manufactured by the manufacturing method according to claim 5 and an organic EL element in which at least a reflective electrode, an organic EL layer, and a transparent electrode are sequentially laminated on the holding substrate are bonded together. An organic EL display manufacturing method characterized by the above.

Images