JP2006216466A - Organic el display panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of simply manufacturing an organic EL display panel which has a large numerical aperture of an " effective aperture part "and does not have deterioration of contrast ratio occurring at the time of incidence of the external light. <P>SOLUTION: The method of manufacturing the organic EL display panel comprises a process for preparing a transparent substrate, a process of forming a black matrix on the transparent substrate, a process of forming a plurality of kinds of color conversion filter layers in the gaps of the black matrix, a process of forming a transparent electrode consisting of a plurality of portions on the plurality of kinds of color conversion filter layers, a process in which the positive type photoresist is exposed from the transparent substrate side, an unexposed portion is formed at a position corresponding to the black matrix, and an exposed portion is formed at a position corresponding to the plurality of kinds of color conversion filter layers, a process of removing the exposed portions, a process of forming an organic EL layer on the transparent electrode, and a process of forming a reflecting electrode on the organic EL layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic EL (electroluminescent) display panel and a manufacturing method thereof. The organic EL display panel of the present invention can be used for display of personal computers, word processors, televisions, audios, videos, car navigation systems, telephones, portable terminals, commercial measuring instruments, and the like.

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

  Among these methods, the organic EL element having a plurality of light emitting portions used in the “color filter method” and the “color conversion method” includes a transparent electrode, an insulating film having a plurality of openings, the transparent electrode, and the transparent electrode. It includes at least an organic EL layer provided on the insulating film and a reflective electrode provided on the organic EL layer, and each of the plurality of openings of the insulating film is provided on the transparent electrode, and a plurality of light emission is performed by the openings. The position of the part is defined.

  On the other hand, for the purpose of improving the color purity of the light emitted from the filters used in the “color filter system” and “color conversion system”, a light shielding material is provided in the gap between the color filter layer and / or the color conversion layer of each adjacent color. It has been proposed to form a black matrix and to make the flatness of the upper surface of the color filter layer and / or the color conversion layer 2.0 μm or less (see Patent Document 1). When such a filter is used, the light emitted from the organic EL element having a plurality of light emitting portions passes through the color filter and / or the color conversion layer, and is finally emitted to the outside from the opening portion of the black matrix. .

  The brightness of the display panel is determined by the product of the brightness of the opening and the opening ratio (where the opening ratio is the area of the opening, (the area of the opening + the area of the light shielding portion (black matrix)) Ratio). Therefore, when the aperture ratio is increased, the brightness of the opening necessary for obtaining the same luminance can be kept low. In particular, in the case of an organic EL display panel, this can extend the life. It becomes possible.

  In the case of the organic EL display panel of the “color filter method” and “color conversion method” as described above, the “effective opening” and the opening ratio thereof are the opening of the black matrix and the opening of the insulating film of the organic EL element. In general, the insulating film is formed while being aligned with the opening of the black matrix by a photolithographic method using a predetermined photomask.

JP-A-10-241860

The following four cases are assumed as the shape of the insulating film formed in the conventional method.
(1) The opening of the insulating film is formed wider than the opening of the black matrix. (2) The opening of the insulating film is formed in the same shape as the opening of the black matrix. (3) The opening of the insulating film is black matrix. (4) The aperture ratio is determined by the insulating film without using the black matrix.

  In the case of (1) above, the aperture ratio of the “effective aperture” is determined by the aperture of the black matrix. When viewed from the light output side, since the end of the insulating film is covered with the black matrix, light scattering hardly occurs when external light is incident, and there is an advantage of achieving a high contrast ratio. However, when forming the insulating film, it is necessary to design the opening size of the insulating film in consideration of the misalignment of the photomask with respect to the black matrix. In addition, since the organic EL layer at the periphery of the opening of the insulating film is located above the black matrix, there is a problem in that light emission that cannot be extracted to the outside occurs and the substantial light emission efficiency is lowered.

  In the case of (2) above, since the misalignment of the photomask with respect to the black matrix during the formation of the insulating film cannot be made zero, the aperture ratio of the “effective opening” varies depending on the amount of the misalignment. . As a result, the display quality may be deteriorated such as luminance unevenness or hue unevenness.

  In the case of (3) above, the aperture ratio of the “effective opening” is determined by the opening of the insulating film. In this case, when viewed from the light output side, the edge of the insulating film can be seen at the periphery of the black matrix opening, and light scattering occurs at the edge of the insulating film when external light is incident, which may lead to a decrease in contrast ratio. There is.

  Finally, in the case of (4) above, the aperture ratio of the “effective opening” is determined by the opening of the insulating film.

  Accordingly, an object of the present invention is to provide a simple method for manufacturing an organic EL display panel in which the aperture ratio of the “effective opening” is large and the contrast ratio does not decrease when external light is incident.

  An organic EL display panel according to a first embodiment of the present invention includes a transparent substrate, a plurality of types of color conversion filter layers formed on the transparent substrate, and a black provided in a gap between the plurality of types of color conversion filter layers. A matrix, a transparent electrode composed of a plurality of portions formed on the plurality of kinds of color conversion filter layers, an insulating film provided in a gap between the plurality of portions of the transparent electrode, and an organic formed on the transparent electrode An organic EL display panel including an EL layer and a reflective electrode formed on the organic EL layer, wherein the insulating film has photosensitivity in the entire visible light region, and is disposed above the black matrix. And having the same dimensions as the black matrix. The organic EL display panel of the present embodiment includes a step of preparing a transparent substrate; a step of forming a black matrix on the transparent substrate; a step of forming a plurality of types of color conversion filter layers in the gaps of the black matrix; Forming a transparent electrode having a plurality of portions on the plurality of types of color conversion filter layers; attaching a positive photoresist so as to cover the transparent electrode; and forming the positive photo from the transparent substrate side. Exposing a resist to form an unexposed portion at a position corresponding to the black matrix, and forming an exposed portion at a position corresponding to the plurality of types of color conversion filter layers; removing the exposed portion; A method of forming an organic EL layer on the transparent electrode; and a step of forming a reflective electrode on the organic EL layer. It is possible to elephants.

  An organic EL display panel according to a second embodiment of the present invention includes a transparent substrate, a plurality of types of color conversion filter layers formed on the transparent substrate, and a height provided in a gap between the plurality of types of color conversion filter layers. A transmissivity layer; a transparent electrode comprising a plurality of portions formed on the plurality of types of color conversion filter layers; an insulating film provided in a gap between the plurality of portions of the transparent electrode; and formed on the transparent electrode. An organic EL display panel including an organic EL layer and a reflective electrode formed on the organic EL layer, wherein the insulating film is disposed above the high transmittance layer, and the high transmittance layer They have the same dimensions. The organic EL display panel according to this embodiment includes a step of preparing a transparent substrate; a step of forming a plurality of types of color conversion filter layers on the transparent substrate; and a high transmittance in a gap between the plurality of types of color conversion filter layers. A step of forming a layer; a step of forming a transparent electrode comprising a plurality of portions on the plurality of types of color conversion filter layers; a step of attaching a negative photoresist so as to cover the transparent electrode; and the transparent substrate Exposing the negative photoresist from the side, forming an exposed portion at a position corresponding to the high transmittance layer, and forming an unexposed portion at a position corresponding to the plurality of types of color conversion filter layers; Manufacturing by a method comprising: removing the unexposed portion; forming an organic EL layer on the transparent electrode; and forming a reflective electrode on the organic EL layer. Door can be.

  By adopting the above configuration and forming an insulating film using a self-alignment method for the black matrix or high transmittance layer, the need for aligning the photomask is eliminated, and the aperture ratio of the “effective aperture” Therefore, it is possible to manufacture an organic EL display panel capable of emitting light of high color purity without causing a decrease in contrast ratio when external light is incident. Due to the large aperture ratio of the “effective aperture”, the organic EL display panel of the present invention improves the luminous efficiency of the panel as a whole, lowers the current density necessary for obtaining a predetermined luminance, and thereby increases the length. Stable driving over a period becomes possible. Further, since there is no reduction in contrast ratio, the organic EL display panel of the present invention can display with high quality.

  FIG. 1 is a diagram showing a configuration example of the first embodiment of the organic EL display panel of the present invention, and FIG. 3 is a diagram for explaining a main part of the manufacturing process. In the configuration example of FIG. 1, three kinds of color conversion filter layers (a red conversion filter layer 2, a green conversion filter layer 3, and a blue conversion filter layer 4) and a gap between adjacent color conversion filter layers on the transparent substrate 1. The flattening layer 7 and the passivation layer 8 are provided so as to cover the color conversion filter layer and the black matrix 5. Then, the transparent electrode 9, the organic EL layer 10, and the reflective electrode 11 are sequentially laminated on the passivation layer 8, and the insulating film 12 is formed so as to overlap the gap and the end of the transparent electrode 9 composed of a plurality of portions. Is provided.

  The transparent substrate 1 is transparent to visible light (wavelength 400 to 700 nm) and light used for patterning the insulating film 12, and can withstand the conditions (solvent, temperature, etc.) used to form the laminated layers. Should be excellent in dimensional stability. Preferred transparent substrates include glass substrates and rigid resin substrates formed of resins such as polyolefins, acrylic resins (including polymethyl methacrylate), polyester resins (including polyethylene terephthalate), polycarbonate resins, or polyimide resins. . Alternatively, a flexible film formed from polyolefin, acrylic resin (including polymethyl methacrylate), polyester resin (including polyethylene terephthalate), polycarbonate resin, polyimide resin, or the like may be used as the substrate. Glass and resins such as polyethylene terephthalate and polymethyl methacrylate are included. Borosilicate glass or blue plate glass is particularly preferable.

  The color conversion filter layers 2 to 4 of the present invention are selected from the group consisting of a color conversion layer, a color filter layer, or a laminate of a color conversion layer and a color filter layer. Generally, the color conversion filter layers 2 to 4 of the present invention desirably have a film thickness of 5 to 15 μm. The color filter layer is a layer for transmitting a part of incident light and obtaining output light of a desired color. The color filter can be formed using, for example, a commercially available color filter material for liquid crystal (such as a color mosaic manufactured by Fuji Film Electronics Materials Co., Ltd.) used for a liquid crystal display device or the like. The color conversion layer is a layer containing a matrix resin and a color conversion dye that absorbs incident light and performs wavelength distribution conversion to emit visible light having different wavelengths. The color conversion layer may contain one or more color conversion dyes.

  In the organic EL display panel of the present invention, the red color conversion filter layer 2 and the green color conversion filter layer 3 desirably include a color conversion layer, and more preferably, in order to improve the color purity of output light, It is desirable to form a laminate with a color filter layer provided on the output side of the color conversion layer. About the green conversion filter layer 3, when the organic EL element used as a light source contains the green component of sufficient intensity | strength, you may be comprised only with a color filter layer. The blue color conversion filter layer 3 is generally composed of only a color filter layer.

  Examples of red conversion dyes that absorb blue to blue-green light emitted from a light source and emit red light include rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet. 11, Rhodamine dyes such as Basic Red 2, cyanine dyes, pyridines such as 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridinium perchlorate (pyridine 1) Examples thereof include dyes and oxazine dyes.

  Examples of a green conversion dye that absorbs light in a blue to blue-green region emitted from a light source and emits light in the green region 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, Coumarin dyes such as 4H-tetrahydro-8-trifluoromethylquinolidine (9,9a, 1-gh) coumarin (coumarin 153), or basic yellow 51 which is a coumarin dye dye, and solvent yellow 11 and solvent yellow. And naphthalimide dyes such as 116.

  Alternatively, the aforementioned color conversion dye may be kneaded into a resin to form a pigment. Resins that can be used include polymethacrylates, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resins, alkyd resins, aromatic sulfonamide resins, urea resins, melamine resins, benzoguanamine resins and mixtures of these resins. .

  When it is necessary to pattern the color conversion layer by a photolithography method or the like, the color conversion layer may be formed using a photocurable or photothermal combination type curable resin (resist). In this case, a cured product of a photocurable or photothermal combination type curable resin (resist) functions as a matrix resin. In order to perform patterning of the color conversion layer, the photocurable or photothermal combination type curable resin is desirably soluble or dispersible in an organic solvent or an alkaline solution in an unexposed state.

  The photocurable or photothermal combined type curable resin (resist) that can be used is specifically (1) an acrylic polyfunctional monomer and oligomer having a plurality of acroyl groups and methacryloyl groups, and a photo or thermal polymerization initiator. (2) a composition comprising a polyvinylcinnamic ester and a sensitizer, (3) a composition comprising a chain or cyclic olefin and bisazide (nitrene is generated to crosslink the olefin) And (4) a composition comprising a monomer having an epoxy group and an acid generator. In particular, it is preferable to use a composition comprising the acrylic polyfunctional monomer and oligomer (1) and a light or thermal polymerization initiator. This is because the composition can be patterned with high definition and has high reliability such as solvent resistance and heat resistance after being polymerized and cured. Here, in the case where 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 add a photopolymerization initiator and a thermal polymerization initiator. .

  Alternatively, a color conversion layer may be formed by preparing a solution containing a color conversion dye and a matrix resin, screen printing the solution, and drying. In this case, as the matrix resin, polymethacrylate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, alkyd resin, aromatic sulfonamide resin, urea resin, melamine resin, benzoguanamine resin, or a mixture of these resins Can be used.

  The black matrix 5 is a layer that is opaque to light emitted from the organic EL elements used as a light source, output light from the color conversion filter layers 2 to 4, and light (including ultraviolet rays) used for patterning the insulating film 12. The black matrix 5 is a resist material that is generally commercially available as a black matrix material for flat panel displays, or a material in which a black pigment such as carbon black is dispersed in a binder resin such as polymethyl methacrylate, polyacrylate, or polycarbonate. Can be formed. The black matrix 5 desirably has a film thickness with an absorbance of 97% or more (optical density (OD value) of 1.5 or more) in the entire visible light region.

  The flattening layer 7 is a layer that can be optionally provided on the color conversion filter to smooth the unevenness of the color conversion filter layer that causes a short circuit between the transparent electrode and the reflective electrode of the light emitting unit. . The planarization layer 7 covering the light output portion can be formed without impairing the function of the light output portion, and can be formed from a material having appropriate elasticity. The planarization layer 7 may be composed of a single layer or may be a laminate of a plurality of materials. A preferable material has a pencil hardness of 2H or more, a Young's modulus of 0.3 MPa or more, can form a smooth coating film on the light output portion, and does not deteriorate the function of the color conversion filter layer. It is a polymer material. More preferably, the material is a polymer material having high transparency in the visible region (transmittance of 50% or more in the range of 400 to 800 nm) and electrical insulation.

Examples of such polymer materials include imide-modified silicone resins, materials in which inorganic metal compounds (TiO, Al ₂ O ₃ , SiO _2, etc.) are dispersed in acrylic, polyimide, silicone resins, etc., acrylate monomers / oligomers / polymers And a photocurable resin and / or a thermosetting resin such as a resin having a reactive vinyl group, a resist resin, a fluorine resin, or an epoxy resin having a mesogenic structure having a high thermal conductivity.

It is a layer for further improving the reliability of the light source by further providing a passivation layer 8 which may be optionally provided, and adding barrier properties against oxygen, moisture and alkali. When such a passivation layer 8 is formed, for example, an inorganic oxide or an inorganic nitride such as SiO _x , SiN _x , SiN _x O _y , AlO _x , TiO _x , TaO _x or ZnO _x may be used. it can.

The transparent electrode 9 is required to inject electrons or holes efficiently into the organic EL layer 10 and to be transparent in the emission wavelength region of the organic EL layer 10. The transparent electrode 9 preferably has a transmittance of 50% or more with respect to light having a wavelength of 400 to 800 nm. The transparent electrode 9 can be formed by using a conductive inorganic compound such as ITO (indium / tin oxide), IZO (indium / zinc oxide), SnO ₂ , or ZnO _{2 which} is a transparent conductive material.

  When the transparent electrode 9 is used as a cathode, it is preferable to provide a buffer layer at a site in contact with the organic EL layer 10 to improve electron injection efficiency. The buffer layer is made of an alkali metal such as lithium or sodium, an alkaline earth metal such as potassium, calcium, magnesium, or strontium, or an electron injecting metal such as a fluoride thereof, or an alloy or compound with other metals. An extremely thin film (10 nm) can be used. By using these materials having a low work function, efficient electron injection can be performed, and by using an ultrathin film, it is possible to minimize the decrease in transparency due to these materials.

  In the first embodiment of the present invention, the insulating film 12 can be formed using a positive photoresist. As the positive photoresist that can be used, a photoresist based on a novolac resin or a polyimide resin can be used. In this embodiment, the transparent substrate 1, the planarization layer 7 and the passivation layer 8 are sufficiently transparent (50% or more, preferably 80% or more) to all visible light (400 to 700 nm region). A positive photoresist having photosensitivity to light in the entire visible light region can be used. In this case, light in a wavelength range that passes through the color conversion filter layers 2 to 4 (for example, e-ray (577 nm), f-ray (546 nm), g-ray (436 nm), h-ray (405 nm), or i of a mercury lamp) or i The positive photoresist can be patterned using a line (365 nm).

The organic EL layer 10 emits light in a blue to blue-green region. In the present invention, the organic EL layer 10 includes at least a light emitting layer, 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. Specifically, those having the following layer structure are employed.
(1) Light emitting layer (2) Hole injection layer / light emitting layer (3) Light emitting layer / electron injection layer (4) Hole injection layer / light emitting layer / electron injection layer (5) Hole injection layer / hole transport layer / Light emitting layer / electron injection layer (6) hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer (in the above, the anode is connected to the light emitting layer or the hole injection layer, and the cathode emits light) Layer or electron injection layer)

  Known materials are used as the material for each of the above layers. In order to obtain light emission from blue to blue-green, in the light emitting layer, for example, optical brighteners such as benzothiazole, benzimidazole, and benzoxazole, metal chelated oxonium compounds, styrylbenzene compounds, aromatics Group dimethylidin compounds are preferably used.

  The reflective electrode 11 preferably has a light reflectance of 80% or more with respect to visible light, and is a highly reflective metal (Al, Ag, Mo, W, Ni, Cr, etc.), amorphous alloy (NiP, NiB, CrP, CrB, etc.) or a microcrystalline alloy (NiAl, etc.) can be used.

  When the reflective electrode 11 is used as an anode, the hole injection efficiency can be improved as a laminated structure having a layer of a conductive metal oxide such as ITO or IZO having a large work function on the side in contact with the organic EL layer 10. Good.

  On the other hand, when the reflective electrode 11 is used as a cathode, an alkali metal such as lithium, sodium, or potassium, which is a material having a low work function, potassium, calcium, Electron injection efficiency can be improved by adding an alkaline earth metal such as magnesium or strontium to form an alloy. Alternatively, the buffer layer as described above may be formed at the interface with the organic EL layer 10.

  In the present invention, the transparent electrode 9 and the reflective electrode 11 are each composed of a plurality of partial electrodes having a stripe shape, and the direction in which the stripe of the transparent electrode 9 extends and the direction in which the stripe of the reflective electrode 11 extends (preferably , A passive matrix driving type organic EL element may be formed. Alternatively, one of the transparent electrode 9 and the reflective electrode 11 is constituted by a plurality of partial electrodes connected to a switching element such as a TFT in a one-to-one relationship, and the other is constituted by a common electrode formed integrally. A matrix type organic EL element may be formed.

  Next, with reference to FIG. 3, the manufacturing method of the organic electroluminescent display panel of this embodiment is demonstrated.

  Next, as shown in FIG. 3A, a black matrix 5 is formed on the transparent substrate 1. The black matrix 5 may be formed on the entire surface of the transparent substrate 1 using spin coating, dip coating, roll coating, casting, or the like, and then obtained in a desired shape and arrangement using photolithography. Alternatively, a screen printing method may be used to obtain a desired shape and arrangement without the need for patterning.

  First, as shown in FIG. 3B, color conversion filter layers 2 to 4 are formed in the gaps of the black matrix 5 on the transparent substrate 1. Each of the color conversion filter layers 2 to 4 has a desired shape and arrangement using a photolithographic method after being formed on the entire surface of the transparent substrate 1 using a spin coat, dip coat, roll coat, cast method or the like. Alternatively, a screen printing method may be used to obtain a desired shape and arrangement without the need for patterning.

  In the two steps described above, the color conversion filter layers 2 to 4 may be first formed on the transparent substrate 1 and then the black matrix 5 may be formed.

  Next, as shown in FIG. 3C, the planarization layer 7 and the passivation layer 8 that cover the color conversion layers 2 to 4 and the black matrix 5 are formed, and the transparent electrode 9 is formed thereon. The planarizing layer 7 can be formed by applying the above-described polymer material using a conventional method such as spin coating, dip coating, roll coating, or casting. The passivation layer 8 can also be formed by depositing the above-described inorganic oxide or inorganic nitride by a conventional method such as sputtering, CVD, or vacuum evaporation. The transparent electrode 9 is formed by depositing the above-described transparent conductive oxide using a sputtering method or the like. The transparent electrode 9 having a desired shape and arrangement can be obtained by patterning the transparent conductive oxide deposited on the entire surface using a photolithography method or the like, or by using a mask at the time of deposition.

  Next, as shown in FIG. 3D, the insulating film 12 is formed so as to cover the transparent electrode 9, and then the insulating film is patterned using a self-alignment method using the black matrix 5. First, a positive photoresist for forming the insulating film 12 is deposited on the entire surface using a conventional method such as spin coating or roll coating. After the adhesion, the coated material is carried into the exposure apparatus after performing a pre-baking process or the like as necessary. In the exposure apparatus, it is desirable that the coated material is supported by a support member (stage) around the transparent substrate 1 and at the minimum central portion of the transparent substrate 1 in order to prevent warping. When such support is performed, the support member may be opaque to light used for exposure.

  Then, the positive photoresist is exposed from the transparent substrate 1 side. The light used for exposure is determined depending on the type of positive photoresist used. For example, when the positive photoresist is sensitive to light in the ultraviolet to purple region (for example, g-line, h-line or i-line of a mercury lamp), light in the ultraviolet to purple region is used. Alternatively, when the positive photoresist is sensitive to light in the entire visible light region, light transmitted through the color conversion filter layers 2 to 4 can be used. The light used for exposure is incident on a positive photoresist other than the position corresponding to the black matrix 5 to make the exposed resist soluble or dispersible in the developer. The properties of the unexposed resist at the position corresponding to the black matrix 5 remain unchanged and remain insoluble and non-dispersible in the developer. Here, the distance between the black matrix 5 and the positive photoresist is defined by the film thicknesses of the planarization layer 7, the passivation layer 8, and partially the transparent electrode 9, and is about 2 to 20 μm. Therefore, although the light used for exposure is transmitted through the color conversion filter layers 2 to 4 and the like, the distance from the black matrix 5 functioning as a light shielding material is small and the straightness of the light is high. Unexposed portions having equivalent dimensions are formed in the photoresist.

  Next, the resist in the exposed portion is removed with a developing solution to obtain a structure in which the insulating film 12 remains only at a position corresponding to the black matrix 5 as shown in FIG. With respect to this structure, the organic EL display panel of the first embodiment of the present invention can be obtained by forming the organic EL layer 10 and the reflective electrode 11 by a conventional method.

  FIG. 2 is a diagram showing a configuration example of the first embodiment of the organic EL display panel of the present invention, and FIG. 4 is a diagram for explaining a main part of the manufacturing process. In the second embodiment shown in FIG. 2, 1) the high transmittance layer 6 is used in place of the black matrix 5, 2) the material for forming the insulating film 12 is a negative photoresist, and 3) the negative. The requirements of the color conversion filter layers 2 to 4 for the light used for the exposure of the mold photoresist are different from those of the first embodiment.

  The high transmittance layer 6 is a layer having a transmittance of 50% or more, preferably 80% or more, with respect to light in the ultraviolet to purple region, and can be manufactured using an acrylic material or the like. The high transmittance layer 6 desirably has a film thickness of 5 to 15 μm, which is equivalent to the color conversion filter layers 2 to 4. The high transmittance layer 6 functions as a layer that transmits light when the negative photoresist forming the insulating film 12 is subjected to pattern exposure.

  The insulating film 12 is formed from a negative photoresist. Since the patterning of the insulating film is performed using the high transmittance layer 6 as the light transmission part and the color conversion filter layers 2 to 4 as the light shielding part, the negative photoresist has a wavelength at least attenuated by the color conversion filter layer. It is required to have photosensitivity with respect to the light having Preferably, the negative photoresist used in the present invention is sensitive to light in the ultraviolet to purple region (for example, g-line, h-line, i-line, etc. of a mercury lamp). As the negative photoresist, those based on polymethyl methacrylate, polyacrylate or the like can be used.

  As described above, in the present embodiment, the color conversion filter layers 2 to 4 need to function as a light shielding portion when the insulating film 12 is patterned. Therefore, the color conversion filter layers 2 to 4 are made of a material having a transmittance of 30% or less, preferably 10% or less, with respect to the light used for patterning the insulating film 12 (light in the ultraviolet to violet region). It is formed. The color conversion filter layers 2 to 4 of this embodiment may be formed using a matrix resin having a transmittance in the above-described range, or a dye that absorbs light in the above-described region may be added. .

  With reference to FIG. 4, the manufacturing method of the organic electroluminescence display panel of this embodiment is demonstrated. First, as shown in FIG. 4A, color conversion filter layers 2 to 4 are formed on the transparent substrate 1. Each of the color conversion filter layers 2 to 4 has a desired shape and arrangement using a photolithographic method after being formed on the entire surface of the transparent substrate 1 using a spin coat, dip coat, roll coat, cast method or the like. Alternatively, a screen printing method may be used to obtain a desired shape and arrangement without the need for patterning.

  Following the step of FIG. 4A, as shown in FIG. 4B, the high transmittance layer 6 is formed in the gap between the color conversion filter layers 2-4. As in the case of the black matrix 5, the high-transmittance layer 6 is formed on the entire surface of the transparent substrate 1 using spin coating, dip coating, roll coating, casting, or the like, and then desired using photolithography or the like. A shape and arrangement may be obtained, or a screen printing method may be used to obtain a desired shape and arrangement without the need for patterning.

  In the above-described two steps, the high transmittance layer 6 may be first formed on the transparent substrate 1 and then the color conversion filter layers 2 to 4 may be formed.

  The step of forming the planarization layer 7 and the passivation layer 8 covering the color conversion layers 2 to 4 and the high transmittance layer 6 and forming the transparent electrode 9 thereon as shown in FIG. The embodiment can be carried out in the same manner as in FIG.

  Of the steps shown in FIG. 4D, the step of forming the insulating film 12 covering the transparent electrode 9 is the same as that of the first embodiment except that a negative photoresist is used instead of the positive photoresist. The same can be done. The exposure step can be performed using an apparatus similar to that of the first embodiment. In this embodiment, the light used for the exposure is the high transmittance layer 6, the planarization layer 7, and the passivation layer 8. And is blocked or at least attenuated by the color conversion filter layers 2 to 4. The exposure is performed using light in the ultraviolet to violet region. As a result of the exposure, light is incident on the negative photoresist at a position corresponding to the high transmittance layer 6, and the resist changes to insoluble and non-dispersible with respect to the developer. Also in this embodiment, the distance between the color conversion filter layers 2 to 4 and the negative photoresist is defined by the film thicknesses of the planarization layer 7, the passivation layer 8, and the transparent electrode 9, and is about 2 to 10 μm. is there. Therefore, although the light used for exposure is transmitted through the high transmittance layer 6 and the like, the distance from the color conversion filter layers 2 to 4 functioning as a light shielding material is small, and the straightness of light is high. An exposed portion having substantially the same dimensions as layer 6 is formed in the photoresist.

  Next, the resist in the exposed portion is removed with a developing solution to obtain a structure in which the insulating film 12 remains only at a position corresponding to the high transmittance layer 6 as shown in FIG. With respect to this structure, the organic EL display panel of the second embodiment of the present invention can be obtained by forming the organic EL layer 10 and the reflective electrode 11 by a conventional method.

[Example 1]
In this example, the organic EL display panel according to the first embodiment of the present invention is manufactured. An organic EL display panel having a pixel number of 160 × 120 (RGB) and a pixel pitch of 0.33 mm was produced.

  On a fusion glass (Corning 1737 glass, 100 × 100 × 1.1 mm) as a transparent substrate 1, a blue filter material (Fuji Film Electronics Materials Co., Ltd .: Color Mosaic CB-7001) is applied using a spin coating method. Coating and patterning by photolithography were performed to obtain a blue conversion filter layer 4 (consisting of only a color filter layer) composed of a plurality of stripes having a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm. .

  Coumarin 6 (0.7 parts by weight) as a fluorescent dye was dissolved in 120 parts by weight of a solvent, propylene glycol monoethyl acetate (PGMEA). To this solution, 100 parts by weight of V259PA / P5 manufactured by Nippon Steel Chemical Co., Ltd. was added and dissolved to obtain a coating solution. The coating solution is applied and patterned by a photolithographic method to form a green color conversion filter layer 3 (consisting of only a color conversion layer) having a plurality of stripes having a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm. Got).

  Coumarin 6 (0.6 parts by weight), rhodamine 6G (0.3 parts by weight) and basic violet 11 (0.3 parts by weight) were dissolved in 120 parts by weight of PGMEA as fluorescent dyes. To this solution, 100 parts by weight of V259PA / P5 manufactured by Nippon Steel Chemical Co., Ltd. was added and dissolved to obtain a coating solution. The coating liquid is applied, and patterning is performed by a photolithographic method, and the red conversion filter layer 2 (consisting of only the color conversion layer is formed by a plurality of stripes having a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm. Got).

  Next, a black matrix material (manufactured by FUJIFILM Electronics Materials Co., Ltd .: color mosaic CK-7800) is applied, patterning is performed by photolithography, and the width 0 provided in the gap between the color conversion filter layers 2 to 4 is applied. A black matrix 5 composed of a plurality of stripes having a thickness of 0.01 mm, a pitch of 0.11 mm, and a thickness of 10 μm was obtained.

  Next, a UV curable resin (epoxy-modified acrylate) is applied using a spin coating method, and irradiated with light from a high-pressure mercury lamp, and the planarizing layer 7 having a film thickness of 8 μm (on the color conversion filter layers 2 to 4). Formed. At this time, defects such as deformation did not occur in the color conversion filter layers 2 to 4 and the stripes of the black matrix 5, and the upper surface of the flattening layer 7 was flat.

Next, a 300 nm-thickness SiO ₂ film was deposited using a sputtering method using SiO ₂ as a target to obtain a passivation layer 8. A mixed gas of Ar and O ₂ was used as the sputtering gas.

  Next, 200 nm of IZO was deposited on the entire surface of the passivation layer 8 at room temperature using a DC sputtering method (target: Ir—Zn oxide, sputtering gas: oxygen and Ar). Next, patterning is performed by a photolithography method using an aqueous oxalic acid solution as an etching solution, and positioned above the color conversion filter layers 2 to 4 and extending in the same direction as the stripes of the color conversion filters 2 to 4, a width of 0.1 mm, A transparent electrode 9 composed of a plurality of stripes having a pitch of 0.33 mm was obtained.

  A positive photoresist (a mixture of JEM 700R2 made by JSR with the addition of e- and f-line photosensitizers and a photosensitive area of about 580 nm) is applied by a spin coat method so as to cover the transparent electrode 9, and is applied on a hot plate for 150 seconds. The prebaking process was performed by heating to 110 ° C. After performing the pre-baking treatment, the coated material was carried into the exposure apparatus, and exposure was performed by irradiating light from a high-pressure mercury lamp from the transparent substrate 1 side for about 120 seconds. Subsequently, development processing was performed using a tetramethylammonium hydroxide (TMAH) aqueous solution as a developer to form an insulating film 12 having a size equivalent to that of the black matrix 5 at a position corresponding to the black matrix 5.

A substrate on which the structure below the insulating film 12 is formed is 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 are sequentially formed without breaking the vacuum. The organic EL layer 10 was obtained. 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 aluminum chelate (Alq ₃ ) at 20 nm.

  Thereafter, using a mask that can obtain a stripe pattern having a width of 0.30 mm and a pitch of 0.33 mm orthogonal to the stripe of the transparent electrode 9 without breaking the vacuum, a 200 nm thick Mg / Ag (10: 1) is obtained. (Weight ratio) layer was deposited to form a reflective electrode 11 (cathode).

  Finally, the substrate on which the structure below the reflective electrode 11 is formed in a dry nitrogen atmosphere in the glove box (both oxygen and moisture concentrations are 10 ppm or less) is formed using a sealing glass (not shown) and a UV curable adhesive. Sealing was performed to obtain an organic EL display panel.

[Example 2]
In this example, an organic EL display panel according to the second embodiment of the present invention is produced. An organic EL display panel was produced according to the procedure of Example 1 except that the high transmittance layer 6 was formed in place of the black matrix 5 and that a negative photoresist was used as a material for forming the insulating film. .

  According to the procedure of Example 1, red, green and blue color conversion filter layers 2 to 4 were formed on the transparent substrate 1. Next, an acrylic material (manufactured by JSR, NN810) was applied by spin coating, and prebaked at 100 ° C. on a hot plate for 180 seconds. After that, patterning is performed by photolithography, and post-baking is performed, so that the color conversion filter layers 2 to 4 are provided in the gaps, and are formed from a plurality of stripes having a width of 0.01 mm, a pitch of 0.11 mm, and a film thickness of 10 μm. A high transmittance layer 6 was obtained. The upper surfaces of the high transmittance layer 6 and the color conversion filter layers 2 to 4 thus formed were flat.

  Subsequently, according to the procedure of Example 1, a planarizing layer 7, a passivation layer 8, and a transparent electrode 9 were formed. Next, a negative photoresist (manufactured by JSR, NN810, photosensitive area of 300 to 370 nm), which is an acrylic material, was applied by spin coating, and prebaked at 100 ° C. on a hot plate for 180 seconds. After performing the pre-baking process, patterning is performed by a photolithography method, and the post-baking process is performed, so that the insulating film 12 having the same dimensions as the high transmittance layer 6 is formed at a position corresponding to the high transmittance layer 6. Formed.

  And according to the procedure of Example 1, the organic electroluminescent layer 10 and the reflective electrode 11 were formed, and sealing was performed, and the organic electroluminescent display panel was obtained.

It is sectional drawing which shows the organic electroluminescent display panel of the 1st embodiment of this invention. It is sectional drawing which shows the organic electroluminescent display panel of the 2nd embodiment of this invention. It is a figure which shows the principal part of the manufacturing process of the organic electroluminescent display panel of the 1st embodiment of this invention. It is a figure which shows the principal part of the manufacturing process of the organic electroluminescent display panel of the 2nd embodiment of 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 5 Black matrix 6 High transmittance layer 7 Flattening layer 8 Passivation layer 9 Transparent electrode 10 Organic EL layer 11 Reflective electrode 10 Insulating film

Claims (4)

Formed on a transparent substrate, a plurality of types of color conversion filter layers formed on the transparent substrate, a black matrix provided in a gap between the plurality of types of color conversion filter layers, and the plurality of types of color conversion filter layers A transparent electrode comprising a plurality of portions, an insulating film provided in a gap between the plurality of portions of the transparent electrode, an organic EL layer formed on the transparent electrode, and a reflective electrode formed on the organic EL layer An organic EL display panel comprising:
The organic EL display panel, wherein the insulating film has photosensitivity in the entire visible light region, is disposed above the black matrix, and has the same dimensions as the black matrix. A transparent substrate, a plurality of types of color conversion filter layers formed on the transparent substrate, a high transmittance layer provided in a gap between the plurality of types of color conversion filter layers, and the plurality of types of color conversion filter layers A transparent electrode composed of a plurality of parts formed, an insulating film provided in a gap between the plurality of parts of the transparent electrode, an organic EL layer formed on the transparent electrode, and a reflection formed on the organic EL layer An organic EL display panel including an electrode,
The organic EL display panel, wherein the insulating film is disposed above the high transmittance layer and has the same dimensions as the high transmittance layer. Preparing a transparent substrate;
Forming a black matrix on the transparent substrate;
Forming a plurality of types of color conversion filter layers in the gaps of the black matrix;
Forming a transparent electrode comprising a plurality of portions on the plurality of types of color conversion filter layers;
Attaching a positive photoresist so as to cover the transparent electrode;
Exposing the positive photoresist from the transparent substrate side, forming an unexposed portion at a position corresponding to the black matrix, and forming an exposed portion at a position corresponding to the plurality of types of color conversion filter layers; When,
Removing the exposed portion;
Forming an organic EL layer on the transparent electrode;
And a step of forming a reflective electrode on the organic EL layer. Preparing a transparent substrate;
Forming a plurality of types of color conversion filter layers on the transparent substrate;
Forming a high transmittance layer in the gap between the plurality of types of color conversion filter layers;
Forming a transparent electrode comprising a plurality of portions on the plurality of types of color conversion filter layers;
Attaching a negative photoresist so as to cover the transparent electrode;
The negative photoresist is exposed from the transparent substrate side, an exposed portion is formed at a position corresponding to the high transmittance layer, and an unexposed portion is formed at a position corresponding to the plurality of types of color conversion filter layers. And a process of
Removing the unexposed portion;
Forming an organic EL layer on the transparent electrode;
And a step of forming a reflective electrode on the organic EL layer.

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