JP2008010417A - Insulating film for organic EL element and organic EL display device - Google Patents

Abstract

An insulating film for an organic EL element capable of aligning with high accuracy without causing light emitted from an organic EL layer to emit light from non-selected pixels around a selected pixel and without removing the insulating film around the marker. An organic EL display element using the same is provided.
An insulating film used in an organic EL display device in which a plurality of organic EL elements each having an organic EL layer sandwiched between a pair of electrodes is arranged, wherein the insulating film is in the visible light region. Insulating film for organic EL element, characterized in that it has a light absorption characteristic having a wavelength region in which the absorbance of EL light peak wavelength emitted from the organic EL layer is 1 or more and the absorbance is 0.3 or less, the organic EL In the periphery of each pixel light emitting part of the display device, one of the pair of electrodes is covered with the insulating film, and the organic EL display device and the organic EL element absorb light emitted, and the absorbed wavelength The organic EL display device further comprising a color conversion film that emits fluorescence having different wavelength distributions.
[Selection] Figure 1

Description

  The present invention relates to an insulating film for organic EL elements and an organic EL display device.

  One of the methods for realizing multicolor light emission using an organic EL element is a color conversion method. The color conversion method is a method for expressing multiple colors by arranging a color conversion film that absorbs light emitted from an organic EL element and emits light having a wavelength distribution different from the absorption wavelength in front of the organic EL element. Is disclosed in which a fluorescent dye is dispersed in a polymer resin (see, for example, Patent Documents 3 to 5). This method is easy to manufacture because the organic EL may be a single color, and development to a large screen display is being actively studied.

  This color conversion method has a feature that good color reproducibility can be obtained by combining a color conversion film and a color filter. However, in order to obtain sufficient efficiency with the disclosed color conversion film, it is necessary to increase the film thickness to about 10 μm, and in order to form an organic EL element on the upper surface, the unevenness of the color conversion layer is made smooth. Special techniques such as a technique for blocking moisture generated from the color conversion layer, and the like. This leads to an increase in panel costs.

  As a measure for solving the above problems, a layer having a color conversion ability may be disposed between the electrodes of the organic EL element by a dry process (see, for example, Patent Documents 6 to 11). If an optimum color conversion material can be selected, a highly efficient and thin film (1 μm or less) color conversion element free from moisture generation problems can be realized with the structures disclosed therein.

  As a method of realizing a display using an organic EL element, that is, a method of selectively emitting pixels, an organic EL layer is sandwiched between electrodes arranged in a matrix, and a current is selectively passed between the electrodes. A method of flowing current to a selected pixel using a TFT, such as a TFT liquid crystal display, can be mentioned.

  Here, when the above-described color conversion element is applied to a display, there is a problem that unselected pixels around the selected pixel are also lit. If pixels other than the selected pixel are turned on, color reproducibility deteriorates due to image blurring or color mixing, which is a serious problem.

  As is well known, the light that can be extracted to the outside by the organic EL element is a part of the generated light, and the light that cannot be extracted proceeds in the lateral direction of the element while being reflected between the electrode and the substrate. In an organic EL element that does not have a color conversion layer between electrodes, light traveling in the lateral direction cannot be extracted, resulting in a loss. However, in the case where the color conversion layer is disposed between the electrodes, a phenomenon occurs in which the color conversion layer is excited by light traveling in the lateral direction. Therefore, the color conversion layer also emits light in the peripheral pixels of the selected pixel. This is the cause of the above problems.

  In order to prevent light emission of non-selected adjacent pixels, it is necessary to prevent leakage of excitation light to adjacent pixels. Regarding how much light leakage can be a problem, for example, if the luminance of each color is controlled by gradation, leakage for one gradation or more may be a problem. Assuming that each color has 8 gradations (512 color display), when a certain subpixel emits light at the maximum brightness, if 1/8 of the light leaks to the adjacent subpixel, the light emission of the adjacent subpixel for one gradation will occur. The strength will be off. Since the allowable leakage amount varies greatly depending on the specifications of the panel to be manufactured and the lighting state of each pixel, it cannot be generally stated. However, as a color panel, 8 gradations are a low level, and a full color panel has 64 levels. Since high control such as gradation is required, the allowable value of leakage light is considered to be at least 1/10.

  Therefore, the author of the present invention studied to add a function for preventing excitation light leakage to the interlayer insulating layer disposed between the electrodes. As a similar measure, an idea of blackening the above-described interlayer insulating film for the purpose of inhibiting reflection of external light and improving the contrast of the organic EL display device is disclosed (see Patent Document 1).

  There is also a proposal for forming a color filter and a spacer containing a resin component between pixels on which organic EL elements are formed (see Patent Document 2).

JP-A-11-273870 JP 2005-294057 A JP-A-8-286033 JP 2000-119645 A JP 2003-64135 A JP-A-2-216790 JP-A-6-203963 JP-A-6-215874 JP-A-11-214160 JP 2001-279238 A JP 2005-056855 A

  The method described in Patent Document 1 is effective in improving contrast, but has several problems. The first is the alignment problem. Since the insulating film is disposed around the previously formed electrode pattern, a photolithographic method is widely used as a patterning method. In this case, if the insulating film is black, it becomes difficult to visually recognize the aligning marker through the insulating film after the entire surface of the insulating film is applied, and complicated processes such as wiping around the marker before the aligning work are performed. Is required. Normally, edge rinsing with a soluble solvent is used for wiping, but in this method, the solvent may be scattered around several millimeters from the rinsing portion, and as a result, the installation position of the marker is significantly limited.

  In addition, in the method described in Patent Document 2, an organic EL layer in which color filter pigments or fine particles such as carbon are dispersed in an insulating film easily generates submicron-order particles and requires high level particle management. It is very difficult to handle as a peripheral member.

  In order to perform alignment without removing the film around the marker as described above during patterning by photolithography, as an insulating film, EL light leakage to adjacent pixels is suppressed and marker observation is performed. What is necessary is just to set it as the film | membrane which can permeate | transmit a wavelength with a certain level. The transmission level of the marker observation wavelength also varies greatly depending on the aligning sensor sensitivity (wavelength dependence), light source, marker shape, required alignment accuracy, marker reflectivity, etc. As a result, the transmittance of the observation wavelength should be at least 50%. In the epi-illumination mode, the film passes through the film twice in order to observe the reflected light at the marker. Therefore, when a film having a transmittance of 50% is used and the marker reflectance is set to 60% (Cr or the like), the reflected light intensity is about 15% of the light source. When the marker is formed of a color filter having a low reflectance, a transparent electrode, or the like, a film having a higher transmittance or observation in a transmission mode is required. In the transmission mode, the amount of attenuation of the observation light is determined by the transmittance of the film. Therefore, the transmittance of the film is not a problem compared to the epi-illumination mode, but a combination of a light source and an observation system with precisely aligned optical axes is required. It can be implemented only by a device having the mechanism.

  As a result of diligent study in view of such a situation, the present inventor has obtained an insulating film having a high absorbance at the EL light peak wavelength emitted from the organic EL layer and a low visible light absorbance around each pixel between the electrodes. It has been found that alignment can be performed without removing the film from the periphery of the marker, and the present invention has been achieved.

  That is, the insulating film for organic EL elements of the present invention is an insulating film used for an organic EL display device in which a plurality of organic EL elements each having an organic EL layer sandwiched between a pair of electrodes are arranged, In the visible light region, the insulating film has a light absorption characteristic having a wavelength region in which an absorbance at an EL light peak wavelength emitted from the organic EL layer is 1 or more and an absorbance is 0.3 or less.

  In addition, the organic EL display device of the present invention is configured such that the pair of organic EL elements each having an organic EL layer sandwiched between a pair of electrodes are arranged in the vicinity of each pixel light emitting unit of the organic EL display device. One of the electrodes is covered with the insulating film of the present invention.

  The organic EL display device of the present invention further includes a color conversion film that absorbs light emitted from the organic EL element and emits fluorescence having a wavelength distribution different from the absorbed wavelength.

  According to the present invention, among the light emitted from the organic EL layer, the non-selected pixels around the selected pixel do not emit light that has traveled in the horizontal direction, and high without having to remove the insulating film around the marker. It is possible to provide an organic EL display device that can be aligned with high accuracy and can therefore produce a high-performance color panel.

First, the insulating film of the present invention will be described.
This insulating film is used in an organic EL display device in which a plurality of organic EL elements each having an organic EL layer sandwiched between a pair of electrodes are arranged. More specifically, each pixel light emitting unit of the organic EL display device In the periphery, it is used so as to cover one of the pair of electrodes. As a result, alignment can be performed without removing the film around the marker.
This insulating film has a wavelength region in which the absorbance of the peak wavelength of the EL light emitted from the organic EL layer is 1 or more (transmission amount 1/10 or less) and the absorbance is 0.3 or less in the visible light region. It has light absorption characteristics.

In order to make the insulating film exhibit such characteristics, the insulating film may be made of a matrix containing an organic dye.
Any organic dye may be used for the insulating film as long as it has an absorbance of 1 or more in the EL peak light wavelength region and can be uniformly dispersed in the matrix. Further, if the organic dye itself is excited by EL light and emits strong fluorescence, the color reproducibility is thereby lowered, which is not preferable. As a dye that does not emit strong fluorescence, a water-soluble anionic dye having an organic acid group as a skeleton and bonded to a cationic active agent can be applied. Examples of water-insoluble ones include acid dyes, azo dyes, and cyanine dyes. Moreover, the compound used for a dye-type color filter can also be used. A plurality of dyes having different absorption wavelengths can be added simultaneously, such as when the emission wavelength of EL light is broad. In this case, a part of the dye to be added may have a high fluorescence. For example, this is the case where excitation transfer occurs from a fluorescent dye to a low fluorescent dye and quenches.

  If the absorbance at the EL light peak wavelength is less than 1, the color conversion layer may be excited by the light emitted from the organic EL layer in the horizontal direction. If the absorbance of visible light exceeds 0.3, the alignment is performed. It tends to be difficult.

  As the matrix used for this insulating film, a photocurable or photothermal combination type curable resin (resist) is irradiated with light and / or heat to generate radical species or ionic species to be polymerized or crosslinked to be insoluble and infusible. Can be exemplified. In order to perform patterning of the fluorescence 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 for the polymerization and crosslinking of the matrix resin are preferably those that initiate polymerization by light having a wavelength that is not absorbed by the organic dye contained therein. As such a photopolymerization initiator, a sensitizer, and an acid generator, known materials used for ultraviolet curable resins can be used, although they may vary depending on the type of organic dye used. In the fluorescence conversion layer of the present invention, when the resin itself in the photocurable or photothermal combination type curable resin can be polymerized by light or heat, a photopolymerization initiator and a thermal polymerization initiator are not added. It is also possible.

  The insulating layer is formed by applying a solution or dispersion containing a photocurable or photothermal combination curable resin, an organic dye and an additive onto a support substrate to form a resin layer, and a desired portion of light. It is formed by polymerizing a curable or photothermal combination curable resin by exposure. 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.

Next, the organic EL display device of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing a bottom emission type organic EL display element, and FIG. 2 is a schematic view showing a top emission type organic EL display element.
The organic EL display device of the present invention is formed by arranging a plurality of organic EL elements each having an organic EL layer sandwiched between a pair of electrodes on a transparent support substrate 1.

  The organic EL element holds the organic EL layer 10 between a pair of electrodes (anode and cathode) 9, 11, or 12, 13, and the organic EL layer has holes generated by applying a voltage to the anode and the cathode. And an organic light emitting layer that emits light by recombination of electrons, and has a structure in which a hole injection layer, a hole transport layer, an electron transport layer and / or an electron injection layer are interposed as required. . Alternatively, a hole injection / transport layer having both hole injection and transport functions and an electron injection / transport layer having both electron injection and transport functions may be used. The hole injection transport layer has a function of transmitting holes injected from the anode to the light emitting layer, and the electron injection transport layer has a function of transmitting electrons injected from the cathode to the light emitting layer. Yes. Then, by interposing the hole injection transport layer between the light emitting layer and the anode, many holes are injected into the light emitting layer with a lower electric field, and electrons injected into the light emitting layer from the cathode or the electron injection layer It is known that since the hole injecting and transporting layer does not transport electrons, it is accumulated at the interface between the hole injecting and transporting layer and the light emitting layer and the luminous efficiency is increased.

Specifically, an organic EL element having the following layer structure is employed.
(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 transport layer / organic light emitting layer / electron injection layer / cathode (6) Anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / Cathode (7) Anode / hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer / cathode

  In the above structures (1) to (7), it is desirable that at least one of the anode and the cathode is transparent in the wavelength range of light emitted by the organic light emitter, and emits light through the transparent electrode. Light is incident on the color conversion filter layers 3, 4, and 5. The other electrode is preferably a reflective electrode. The transparent electrodes 9 and 14 may be anodes or cathodes.

The transparent electrodes 9 and 14 are formed by stacking conductive metal oxides such as SnO ₂ , In ₂ O ₃ , ITO, IZO, and ZnO: Al by sputtering. The transmittance of the transparent electrode is preferably 50% or more, and more preferably 85% or more with respect to light having a wavelength of 400 to 800 nm. The anode 11 can have a thickness of usually 50 nm or more, preferably 50 nm to 1 μm, more preferably 100 to 300 nm.

  The reflective electrodes 11 and 13 are preferably formed using a highly reflective metal, amorphous alloy, microcrystalline alloy, or the like. Examples of the highly reflective metal include Al, Ag, Mo, W, Ni, and Cr. Examples of the high reflectivity amorphous alloy include NiP, NiB, CrP, and CrB. Examples of the highly reflective microcrystalline alloy include NiAl. Alternatively, other alloys (for example, Mg / Ag alloy) containing the above-described highly reflective metal can be used.

  Next, the organic EL display device of the present invention will be described. The organic EL display device of the present invention includes a plurality of organic EL elements each having an organic EL layer 10 sandwiched between a pair of electrodes 9, 11; 13, 14, and each of the organic EL elements is a pixel. A light emitting portion is formed, and one of the pair of electrodes is covered with the insulating film 8 around the pixel light emitting portion.

  In the case of the bottom emission organic EL display device shown in FIG. 1, the periphery of the transparent electrode 9 that is an anode is covered with the insulating film 8 around the pixel light emitting portion.

  In the case of the top emission type shown in FIG. 2, the transparent electrode 14 is a cathode, and the insulating film 8 covers the periphery of the reflective electrode 13 that is an anode.

  Color conversion filter layers 3, 4, and 5 are provided on the transparent electrode side of the organic EL element through a gas barrier layer 7, a protective layer 6, and the like as necessary. The color conversion filter layer is a general term for a color filter layer, a color conversion layer, and a laminate of a color filter layer and a color conversion layer. The color conversion filter layer is composed of at least three types of color conversion filter layers having transmission regions in different wavelength ranges, and examples of the three types of color conversion filter layers include red, green, and blue color conversion filter layers. .

  As the name suggests, the protective layer 6 is disposed for the purpose of protecting the color conversion filter layer and for the purpose of smoothing the film surface. The protective layer 6 must be formed by selecting a process that is formed of a material having high light transmittance and that does not deteriorate the color conversion filter layer. Since the protective layer also has the purpose of smoothing, it is generally formed by a coating method. In this case, as a material that can be applied, a photocurable or photothermal combination type curable resin is subjected to light and / or heat treatment to generate radical species or ionic species to be polymerized or crosslinked to be insoluble and infusible. Is common. Further, it is desirable that the photocurable or photothermal combined type curable resin is soluble in an organic solvent or an alkali solution before curing.

  Specifically, the photocurable or photothermal combination type curable resin means (1) a composition film comprising an acrylic polyfunctional monomer and oligomer having a plurality of acryloyl groups and methacryloyl groups, and light or a thermal polymerization initiator. Heat treated to generate photo radicals and heat radicals for polymerization, (2) A composition comprising polyvinyl cinnamate ester and sensitizer dimerized by light or heat treatment, and (3) chain A composition film composed of a cyclic or cyclic olefin and bisazide is generated by light or heat treatment to generate nitrene and crosslinked with the olefin, and (4) a composition film composed of a monomer having an epoxy group and a photoacid generator is subjected to light or heat treatment. In other words, the acid (cation) is generated and polymerized. In particular, the photocurable or photothermal combination type curable resin (1) can be patterned with high definition, and is preferable in terms of reliability such as solvent resistance and heat resistance.

The gas barrier layer 7 is required to be a transparent and dense pinhole film, such as inorganic oxides or inorganic nitrides such as SiO _x , SiN _x , SiN _x O _y , AlO _x , TiO _x , TaO _x , ZnO _x , etc. Can be used. There is no restriction | limiting in particular as a formation method of this gas barrier layer, It can form by common methods, such as a sputtering method, CVD method, and a vacuum evaporation method.

  3 and 4 show an example in which a color conversion film is applied to some pixels as a colorization method. Examples of the color conversion film include those having a film thickness of 2 μm or less including the first dye and the second dye. The first dye absorbs light incident on the color conversion film and transfers the energy to the second dye. The second dye receives the energy from the first dye and emits light. The first dye is present in the color conversion film in an amount capable of sufficiently absorbing the incident light, and the two dyes are 10 mol% or less based on the total number of molecules constituting the color conversion film, preferably It is present in an amount of 0.1 to 5 mol%. Here, the first dye is preferably present in an amount of 50 to 99.99 mol% based on the total number of constituent molecules of the color conversion film.

  Examples of the dye that can be suitably used as the first dye include 3- (2-benzothiazolyl) -7-diethylaminocoumarin (coumarin 6), 3- (2-benzimidazolyl) -7-diethylaminocoumarin (coumarin 7), coumarin 135, and the like. Of coumarin pigments. Alternatively, naphthalimide dyes such as Solvent Yellow 43 and Solvent Yellow 44 may be used as the first dye.

  The second dye is a dye that receives energy transferred from the first dye and emits light. Dyes that can be suitably used as the second dye are 4-dicyanomethylene-2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM-1, (I)), DCM-2 (II ), And cyanine dyes such as DCJ TB (III); 4,4-difluoro-1,3,5,7-tetrafer-4-bora-3a, 4a-diaza-s-indacene (IV), lumogen F red, Including Nile Red (V). Alternatively, xanthene dyes such as rhodamine B and rhodamine 6G, or pyridine dyes such as pyridine 1 may be used.

  The color conversion layer of the present invention is preferably formed by a vapor deposition method (including resistance heating type and electron beam heating type), more preferably by co-evaporation of the first dye and the second dye. This is because it is necessary to disperse the second dye in the first dye in order to prevent concentration quenching.

  A preliminary mixture in which the first pigment and the second pigment are mixed at a predetermined ratio may be formed in advance, and co-evaporation may be performed using the preliminary mixture. Or a 1st pigment | dye and a 2nd pigment | dye may be arrange | positioned in a separate heating site | part, and each may be heated separately and co-evaporation may be performed. In particular, the latter method is effective when there is a large difference in characteristics (evaporation rate, vapor pressure, etc.) between the first dye and the second dye.

  Hereinafter, although this invention is demonstrated using a specific example, an Example does not limit the application range of this invention.

<Example 1>
This example is a more specific embodiment of the embodiment of FIG.
(Formation of color filter)
A CK7800 made by Fuji Film Electronics Materials was used on Corning 1737 glass to form a grid-like black matrix 2 having a subpixel opening of 100 μm × 300 μm and a gap between subpixels of 30 μm. After that, using CR7001, CG7001, and CB7001 made by the same company, a red, green, and blue stripe pattern with a width of 0.12 mm and a pitch of 0.33 mm was formed by a photolithographic method so that they would not overlap each other. Color filters 3, 4, and 5 having pixels were formed.

(Formation of protective layer)
A color filter protective / smooth layer 6 having a thickness of 1 μm was formed on the upper surfaces of the color filters 3, 4, and 5 using Nippon Steel Chemical's VPA100.

(Formation of gas barrier layer)
A gas barrier layer 7 made of a 0.5 μm SiOx film was obtained by sputtering. The sputtering apparatus used was an RF-planar magnetron, and the target used was SiO ₂ . Ar was used as the sputtering gas during film formation. The substrate temperature at the time of formation was 80 ° C.

(Formation of transparent electrode)
A transparent electrode (ITO) was entirely formed on the upper surface of the gas barrier layer 7 which is the outermost layer of the color filter substrate composed of the substrate 1, the color filters 3, 4 and 5, the protective layer 6, and the gas barrier layer 7 by sputtering. After applying a resist agent “OFRP-800” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) on ITO, patterning is performed by a photolithography method, and the light emitting portions (red, green, and blue) of each color are positioned. A transparent electrode 9 having a stripe pattern with a width of 0.12 mm, a pitch of 0.14 mm, and a film thickness of 100 nm was obtained.

(Formation of insulating layer)
A gas barrier in which a transparent electrode is formed by adding 0.5 parts by weight of Coumarin 6 and the following cyanine dyes to 100 parts by weight of VPA100 manufactured by Nippon Steel Chemical Co., Ltd. The film was coated on the layer 7, and an interlayer insulating film 8 having a thickness of 1.5 μm having the same shape as the black mask was formed by photolithography.

(Formation of organic EL layer)
On the filter part produced as described above, / organic EL layer 10 (four layers of hole injection layer / hole transport layer / organic light emitting layer / electron injection layer) / metal electrode 11 was formed in this order.
That is, the substrate on which the anode 9 was formed was mounted in a resistance heating vapor deposition apparatus, and a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron injection layer were sequentially formed without breaking the vacuum. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. As the hole injection layer, copper phthalocyanine (CuPc) was laminated to a thickness of 100 nm. As the hole transport layer, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) was laminated to 20 nm. The light emitting layer was formed by laminating 30 nm of 4,4′-bis (2,2′-diphenylvinyl) biphenyl (DPVBi). The electron injection layer was formed by laminating 20 nm of aluminum chelate (Alq). Thereafter, using a mask capable of obtaining a stripe pattern having a width of 0.32 mm, a pitch of 0.33 mm, and a gap of 0.01 mm perpendicular to the anode (ITO) 9 line, a 200 nm thick Mg / Ag (10: 1) The electrode 11 composed of (weight ratio) layer was formed without breaking the vacuum. The organic light emitting device thus obtained was sealed with a sealing glass and a UV curable adhesive in a dry nitrogen atmosphere in the glove box (both oxygen and moisture concentrations were 10 ppm or less).

  The display element thus obtained was measured for chromaticity at the time of RGB single color lighting using a spectral radiance meter (CS1000, manufactured by Konica Minolta). The results are shown in Table 1.

<Example 2>
This example is a more specific embodiment of the embodiment of FIG.
(Formation of color filter substrate)
A color filter substrate was formed in the same manner as in Example 1 until the formation of the gas barrier layer 7.

(Formation of reflective electrode)
A 500 nm thick Al layer and a 100 nm thick IZO layer are laminated on a TFT substrate and a glass substrate 12 previously provided with an insulating flattening film having an opening at the source electrode of the TFT by a sputtering method using a mask. The reflective electrode 13 divided into a plurality of portions corresponding to each of the TFTs on a one-to-one basis was formed. Each portion of the electrode 13 has a size of 0.32 mm in the vertical direction × 0.12 mm in the horizontal direction, and the divided reflective electrodes 13 are arranged in a matrix with a gap of 0.01 mm in both the vertical and horizontal directions.

(Formation of insulating film)
Using the insulating film coating liquid used in Example 1, a grid-like insulating layer 8 was formed so as to cover 0.01 mm from the end of the reflective electrode 13 by photolithography.

(Formation of organic EL layer)
On the reflective electrode 13 manufactured as described above, / organic EL layer 10 (four layers of hole injection layer / hole transport layer / organic light emitting layer / electron injection layer) / metal electrode 14 was sequentially formed. .
That is, the substrate on which the anode 13 was formed was mounted in a resistance heating vapor deposition apparatus, and a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron injection layer were sequentially formed without breaking the vacuum. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. As the hole injection layer, copper phthalocyanine (CuPc) was laminated to a thickness of 100 nm. As the hole transport layer, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) was laminated to 20 nm. The light emitting layer was formed by laminating 30 nm of 4,4′-bis (2,2′-diphenylvinyl) biphenyl (DPVBi). The electron injection layer was formed by laminating 20 nm of aluminum chelate (Alq). Thereafter, the laminate on which the organic EL layer was formed was moved to the counter sputtering apparatus without breaking the vacuum. A transparent electrode was formed by depositing IZO having a thickness of 100 nm to obtain an organic EL element having a laminated structure of reflective electrode / organic EL layer / transparent electrode. Further, the film is moved to a plasma CVD apparatus without breaking the vacuum, and is nitrided with a thickness of 1 μm by using a plasma CVD method using monosilane (SiH ₄ ), ammonia (NH ₃ ) and nitrogen (N ₂ ) as source gases. Silicon was deposited to form the gas barrier layer 15.

(Lamination)
Next, the color filter substrate was carried into a glove box controlled to have a moisture concentration of 1 ppm and an oxygen concentration of 1 ppm. Then, an ultraviolet curable adhesive (trade name 30Y-437, manufactured by ThreeBond Co., Ltd.) in which beads having a diameter of 20 μm were dispersed was applied to the outer periphery of the color filter substrate as a peripheral sealing layer using a dispenser robot. While aligning, the color filter and the organic EL light emitting element were adhered to form an assembly. Subsequently, using a UV lamp, 100 mW / cm ² of ultraviolet rays was irradiated for 30 seconds to cure the outer peripheral sealing layer to obtain an organic EL display.
The display device thus obtained was measured in the same manner as in Example 1 for chromaticity when RGB single color lighting was performed. The results are shown in Table 1.

<Example 3>
After forming the protective layer, except that a color conversion layer made of coumarin 6 and DCM-2 having a width of 0.12 mm and a pitch of 0.33 mm was formed in a position corresponding to a red pixel by a vacuum deposition method using a metal mask. An element was formed by the same method as in Example 1. A color conversion layer having a thickness of 200 nm was produced by co-evaporation in which coumarin 6 and DCM-2 were heated in separate crucibles in the vapor deposition apparatus. At this time, the heating temperature of each crucible was controlled so that the deposition rate of coumarin 6 was 0.3 nm / s and the deposition rate of DCM-2 was 0.005 nm / s. The color conversion film of this example contained 2 mol% of DCM-2 based on the total number of constituent molecules of the color conversion film (in this case, the number of moles of all dyes) (coumarin 6: mole of DCM-2). The ratio is 4'9: 1).

<Example 4>
After forming the transparent electrode 14, an element was formed in the same manner as in Example 2 except that a color conversion layer was formed at a position corresponding to a red pixel by the method described in Example 3.

<Comparative Example 1>
A display device was produced in the same manner as in Example 1 except that no dye was added to the coating liquid for forming the insulating layer. The chromaticity at the time of RGB single color lighting of the obtained display device was measured in the same manner as in Example 1. The results are shown in Table 1.

<Comparative example 2>
A display device was produced in the same manner as in Example 2 except that no dye was added to the coating liquid for forming the insulating layer. The chromaticity at the time of RGB single color lighting of the obtained display device was measured in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Example 3>
A display device was produced in the same manner as in Example 3 except that no dye was added to the coating liquid for forming the insulating layer. The chromaticity at the time of RGB single color lighting of the obtained display device was measured in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Example 4>
A display device was produced in the same manner as in Example 4 except that no dye was added to the coating liquid for forming the insulating layer. The chromaticity at the time of RGB single color lighting of the obtained display device was measured in the same manner as in Example 1. The results are shown in Table 1.

  From Table 1, it can be seen that in each comparative example, the chromaticity of blue and green is lower than that of the example. Since the difference between the example and the comparative example is only the presence or absence of the dye, it can be seen that the display device of the comparative example has the blue and green chromaticities due to light emission from the adjacent non-selected pixels.

  It can be seen that Examples 3 and 4 and Comparative Examples 3 and 4 using the color conversion layer have a greater influence. When there is a color conversion film, it is considered that the color conversion film is excited and emits light by leaking light, so that there is a greater influence.

  According to the present invention, the non-selected pixels around the selected pixel do not emit light, and the insulating film pattern can be aligned with high accuracy without removing the insulating film around the marker. An organic EL display device capable of producing a high-performance color panel can be provided.

It is the schematic which shows one embodiment of the organic electroluminescence display of this invention. It is the schematic which shows the other embodiment of the organic electroluminescence display of this invention. It is the schematic which shows other embodiment of the organic electroluminescence display of this invention. It is the schematic which shows other embodiment of the organic electroluminescence display of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent support substrate 2 Black matrix 3 Color conversion filter layer Blue 4 Color conversion filter layer Green 5 Color conversion filter layer Red 6 Protective layer 7 Gas barrier layer 8 Insulating film 9 Transparent electrode 10 Organic EL layer 11 Reflective electrode 12 Support substrate 13 Reflective electrode 14 Transparent electrode 15 Gas barrier layer 16 Color conversion film

Claims (8)

  An insulating film used in an organic EL display device in which a plurality of organic EL elements each having an organic EL layer sandwiched between a pair of electrodes are arranged, wherein the insulating film is separated from the organic EL layer in a visible light region. An insulating film for an organic EL element, which has a light absorption characteristic having a wavelength region in which the absorbance at an emitted EL light peak wavelength is 1 or more and the absorbance is 0.3 or less.   2. The insulating film for an organic EL element according to claim 1, wherein the insulating film is obtained by dispersing an organic dye having absorption at an EL light peak wavelength in a resin.   The one of the pair of electrodes is one of the pair of electrodes in the vicinity of each pixel light emitting portion of the organic EL display device in which a plurality of organic EL elements each having an organic EL layer sandwiched between the pair of electrodes is arranged. An organic EL display device characterized by being covered with an insulating film.   4. The organic EL display device according to claim 3, wherein the electrode covered with the insulating film is a transparent electrode on the light extraction side in the bottom emission type organic EL display element.   4. The organic EL display device according to claim 3, wherein the electrode covered with the insulating film is a reflective electrode in a top emission type organic EL display element.   The organic EL display device according to claim 3, further comprising a color conversion film that absorbs light emitted from the organic EL element and emits fluorescence having a wavelength distribution different from the absorbed wavelength.   The organic EL display device according to claim 6, wherein the organic EL element is a bottom emission type organic EL display element.   The organic EL display device according to claim 6, wherein the organic EL element is a top emission type organic EL display element.

Images