JP4618562B2 - Manufacturing method of organic EL display - Google Patents

Description

  The present invention relates to a method for manufacturing an organic electroluminescence (hereinafter referred to as organic EL) display.

  As one of organic EL display panels using electroluminescence of organic compound materials, there is a passive matrix type (simple matrix type) display as shown in FIG. The passive matrix display includes a plurality of first electrodes on a transparent support substrate, a plurality of second electrodes orthogonal to the first electrodes, and an organic layer sandwiched between them. One pixel is formed with the light emitting portion in the intersecting region of the first electrode and the second electrode as one unit, and a display portion is formed by arranging a plurality of these pixels.

  In a passive matrix display, each row needs to emit light instantaneously within a selected time. As a result, a large current flows into the electrode as compared with the case where a voltage-driven display element such as a liquid crystal device is used. On the other hand, such an excessive current does not flow in a liquid crystal display device using a voltage driving element. Therefore, in the organic EL display, the second electrode, which is the cathode, is connected to the low resistance contact portion between the cathode into which the current flows and the drive circuit connection terminal to suppress a voltage increase due to this current, and the contact portion is It is structured to be connected to the drive circuit connection terminal.

  As the panel becomes larger, higher definition, and higher brightness, it is necessary to further reduce the resistance of the contact portion, and at the same time, the contact between the cathode and the contact portion and the contact between the drive circuit connection terminal and the contact portion. Low resistance is also required.

  The edges of the first electrode and the second electrode are portions where electric field concentration is likely to occur because the electrode shape changes rapidly, and the organic light emitting layer causes dielectric breakdown, resulting in the first electrode and the second electrode. Due to this short circuit, a display defect such as that all pixels arranged in parallel on the first electrode or the second electrode always emit light occurs. As a method for preventing a short circuit (crosstalk) between the first electrode and the second electrode, as disclosed in Patent Document 1, a method of forming an insulating film on the edge of the first electrode and the second electrode, or Patent Document As shown in FIG. 2, there is a method using polyimide, silicon oxide, silicon nitride or the like as the insulating film material. Among these, the advantage of using an organic material such as polyimide or novolak resin as an insulating film material is that a film having a sufficient withstand voltage can be easily formed using a method such as photolithography. The second electrode and one end of the contact portion can be connected using a part of the opening provided in the insulating film. On the other hand, the other end of the contact portion is connected to ITO as a lead line. A metal such as Mo, W, Ni, or Cr is used for the contact portion, and Al, Ag, or the like is applied as the second electrode. In particular, the contact characteristics between the second electrode and the contact part need not only be low resistance, but also stable against Joule heat generated in the contact part due to the flowing current, that is, it is necessary that the contact resistance is not easily raised by Joule heat. Therefore, stricter contact performance is required.

  On the other hand, when using an organic insulating film (one that uses an organic material as the material for the insulating film), the material applied to the organic insulating film is highly hygroscopic and may contain moisture that causes alteration of the organic layer. Therefore, a sufficient dehydration step is required before forming the organic layer. For example, in order to use an organic EL display in a field requiring high reliability such as a vehicle-mounted panel, a display with a small luminance reduction is required even under adverse conditions such as high temperature and high humidity. In particular, when driven at a high temperature, moisture release from the organic material is accelerated and diffuses into the organic layer. Due to this water release, the organic layer is altered and the light emitting area is reduced.

  In addition, before the organic layer is formed, cleaning and surface modification of the electrode surface are performed (for example, see Patent Document 3). The cleaning step immediately before forming the organic layer is indispensable in order not to reduce the carrier injection of the organic EL device. In general, UV ozone treatment, excimer UV treatment, oxygen plasma treatment and the like are applied. These are performed to adjust the dirt on the electrode surface and the work function of the electrode before the organic layer is formed.

  As described above, it is essential to perform these treatments while suppressing the adsorption of moisture into the organic insulating film. As one means for that, a method of performing UV ozone treatment at a high temperature is considered. In this method, the adsorption of moisture into the organic insulating film being processed is prevented, and cleaning of the electrodes is performed. However, an oxide film is formed on the electrode surface by this treatment, thereby reducing luminous efficiency (see Patent Document 3 above), and contact resistance is reduced by decomposing and reattaching the organic insulating film to the contact portion. Rising is a problem.

Japanese Patent No. 2911552 Japanese Patent Laid-Open No. 9-330792 JP 2000-12236 A Japanese Patent Laid-Open No. 5-134112 JP-A-7-218717 JP-A-7-306311 JP-A-5-119306 JP-A-7-104114 JP-A-6-300910 JP 7-128519 A JP-A-8-279394 JP-A-9-330793 JP-A-5-36475 JP-A-8-315981

  The present invention reduces the damage of the insulating film and the oxidation on the contact part, which cause the increase in resistance at the connection interface between the second electrode and the contact part in the pretreatment for film formation as described above, and reduces the increase in driving voltage. Therefore, the present invention provides a method for manufacturing an organic EL display.

  The present invention provides an organic EL comprising a first electrode, a second electrode disposed opposite to the first electrode, and an organic layer disposed between the first and second electrodes on a transparent support substrate. The present invention relates to a method for manufacturing a display panel. The method includes a step of forming a contact portion including a second electrode connection portion on a transparent support substrate, a step of forming a first electrode including a lead line of the first electrode on the transparent support substrate, A step of forming an insulating layer so as to partially overlap the edge of the first electrode between one electrode, a cleaning step of cleaning the first electrode, and forming an organic layer on the cleaned first electrode And the step of forming the second electrode, wherein the cleaning step is performed by UV ozone treatment, excimer UV treatment, or oxygen plasma treatment, and in this cleaning step, the second electrode connection portion, the contact portion, and The lead line of the first electrode is covered with a mask. Further, the mask is preferably a mask having an ultraviolet transmittance of 5% or less.

  Furthermore, the present invention provides a color conversion filter substrate by forming a color conversion filter layer including a color filter layer and / or a color conversion layer, and optionally a flattening layer and a passivation layer on the transparent support substrate. A process can be further included.

  According to the organic EL display and the manufacturing method thereof according to the present invention, it is possible to suppress a voltage rise during driving and to drive at a low voltage.

  The manufacturing method of the organic EL display of the present invention includes (1) a step of forming a contact portion including a second electrode connecting portion on a transparent support substrate, and (2) a lead wire for the first electrode on the transparent support substrate. Forming a first electrode including: (3) forming an insulating layer so as to partially overlap an edge of the first electrode between the first electrodes; and (4) cleaning the first electrode. A cleaning step, (5) a step of forming an organic layer on the cleaned first electrode, and (6) a step of forming the second electrode. In the present invention, the cleaning step is performed by UV ozone treatment, excimer UV treatment, or oxygen plasma treatment, and the second electrode connection portion, the contact portion, and the lead wire of the first electrode are covered with a mask in this cleaning step. It has the characteristics.

  The present invention will be described below with reference to the drawings.

  FIG. 2 is a partial plan view for explaining the first electrode and the insulating film provided in the organic EL display of the present invention. FIG. 3 is a partial sectional view thereof. FIG. 3 is a diagram of a monochromatic organic EL display which is a basic component of the present invention. Therefore, in the case of a color organic EL display, a color filter layer and / or a color conversion layer (hereinafter also referred to as a color conversion filter layer) provided between the transparent support substrate and the first electrode, and a flat surface for flattening. Constituent elements such as a passivation layer (for example, a polymer film layer) and a moisture-proof passivation layer (for example, an inorganic film layer) are not shown. However, it should be noted that the present invention includes a method for manufacturing a color organic EL display including these components as described later with reference to FIG.

  As shown in FIGS. 2 and 3, the passive organic EL display of the present invention has a first electrode 17, an insulating film 5, a second electrode 18, and a contact part 7 (second electrode) on the transparent substrate 1. It has the electrical connection part 3 (henceforth a 2nd electrode connection part) with the drive part for driving two electrodes, the organic layer 20, and the 2nd interelectrode insulating layer 6. In addition, as shown in FIG. 3, the contact part 7 including the second electrode connection part 3 may be composed of two parts of the second electrode connection part 3 and the contact part 7, and is formed integrally. Also good. The plurality of first electrodes 17 formed in a stripe shape include lead lines 2 to the external drive circuit. On the first electrode 17, an insulating film 5 having an area necessary for light emission as an opening is formed, and this opening forms a display section on the transparent support substrate 1. In the case where other components such as a color filter layer and a color conversion layer are formed on the support substrate, the opening is a portion that transmits light emitted from the organic layer.

  Below, the manufacturing method of the organic EL display of this invention is demonstrated along each process, referring FIG.

Steps (1) and (2) (FIG. 4 (a))
These steps are a step of forming a contact portion including a second electrode connection portion on a transparent support substrate and a step of forming a first electrode including a lead wire for the first electrode.

First, the contact portion 7 (including the second electrode connection portion) that contacts the second electrode 18 is formed on the transparent support substrate 1 by a photolithography method. Next, a transparent electrode film made of a conductive metal oxide such as SnO ₂ , In ₂ O ₃ , ITO, IZO, ZnO: Al is formed on the entire surface of the transparent support substrate 1 using a sputtering method, and by a photolithographic method, A stripe-shaped first electrode 17 including the lead line 2 is formed.

  The first electrode 17 preferably has a transmittance of 50% or more, more preferably 85% or more with respect to light having a wavelength of 400 to 800 nm. The first electrode 17 is desirably 50 nm or more, preferably 50 nm to 1 μm, more preferably 100 to 300 nm.

  The first electrode 17 is preferably formed as a plurality of striped electrodes extending in a direction intersecting (preferably orthogonal) with a second electrode 18 described later. In the present invention, it is preferable that passive matrix driving can be performed by adopting such a configuration.

Step (3) (FIG. 4B)
This step is a step of forming the insulating film 5. The insulating film is formed on the gap between the stripes of the first electrode 17 and the dummy pattern by using a photolithographic method. As the insulating film, a normal material used for an organic EL display such as polyimide can be used. Various conditions such as the thickness of the insulating film are the same as the conventional one, but the thickness can be set to 1 μm, for example.

  If necessary, a second electrode separation partition wall formed of a plurality of stripes extending in a direction perpendicular to the stripes of the first electrode 17 and having a reverse tapered cross section can be formed by a resist method. The second electrode separation partition wall can be formed using, for example, a method using a photoresist or a method described in Japanese Patent Application Laid-Open No. 8-3155981 (Patent Document 14). For example, when a chemically amplified negative photoresist is used, the resist is applied by spin coating to a film thickness of about 5 μm, pre-baked, and the exposure amount is set so as to reduce the cross-linking density on the substrate side of the resist. By performing post-exposure baking, a distribution of the dissolution rate in the developing solution is generated from the substrate side to the upper side of the resist, and an inversely tapered shape can be formed. Even when a positive photoresist is used, a reverse taper shape can be easily formed using a photoresist having a distribution of dissolution rate in a developer.

Step (4) (FIG. 4C)
This step is a step of cleaning the transparent support substrate on which the first electrode, the insulating film and the like are formed. The transparent support substrate 1 on which the first electrode, the insulating film and the like are formed as described above is placed in a dryer such as a vacuum dryer and dried (for example, 150 ° C. for 1 hour), and then washed. Cleaning can be performed using UV ozone treatment, excimer UV treatment, or oxygen plasma treatment.

  In the present invention, it is preferable to perform UV ozone treatment at a high temperature (for example, 150 ° C.). By this method, moisture is prevented from adsorbing into the organic insulating film being processed, and cleaning on the electrodes is performed. Furthermore, such a treatment can adjust the dirt on the electrode surface and the work function of the electrode before the organic layer is formed.

  In the cleaning process of the present invention, a mask that hides only the lead wire of the first electrode, the junction between the second electrode and the contact portion, and the second electrode connection portion without hiding the portion where the organic layer is formed. use. FIG. 5 shows an example (partial plan view) of a metal mask pattern used in the cleaning process of the present invention. As shown in FIG. 5, the mask has an opening in a portion where the organic layer is formed (portion described as “missing” in the drawing), the lead wire 2 of the first electrode, the second electrode 18. And the contact portion 7 and the second electrode connection portion 3 only. The present invention is characterized in that the mask is particularly provided with a region surrounded by a wavy line in FIG. 5, that is, a region covering the joint portion of the contact portion 7.

  By exposing only the surface on which the organic material is formed in this way, the electrode-organic material does not interfere with the injection barrier, and the formation of the second electrode does not increase the junction resistance at the contact portion before film formation. Processing can be performed.

  FIG. 5 is a partial cross-sectional view as described above, and the mask does not hide the surface on which the organic layer is formed, and the lead wire 2 of the first electrode, the second electrode 18 and the contact portion 7. Any shape may be used as long as only the joint portion and the second electrode connection portion 3 are hidden. For example, when the lead wire 2 of the first electrode, the second electrode connection portion 3, etc. are formed on the four sides around the transparent support substrate, the junction between the second electrode 18 and the contact portion 7 exists. It can be set as the mask which covers the four sides of a transparent support substrate.

Step (5) (FIG. 4 (d))
This step is a step of forming the organic layer 20. The organic layer 20 includes at least an organic light emitting layer, and includes a hole transport layer, a hole injection layer, an electron transport layer, and / or an electron injection layer as necessary. Each of these layers is formed to have a film thickness sufficient to realize desired characteristics in each layer. For example, the following layer structure is adopted. In these structures, an electrode functioning as an anode is connected to the left side, and an electrode functioning as a cathode is connected to the right side.

(1) Organic light emitting layer (2) Hole injection layer / organic light emitting layer (3) Organic light emitting layer / electron injection layer (4) Hole injection layer / organic light emitting layer / electron injection layer (5) Hole transport layer / Organic light emitting layer / electron injection layer (6) Hole injection layer / hole transport layer / organic light emitting layer / electron injection layer (7) Hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer

  Any known material can be used as the material of the organic light emitting layer. For example, in order to obtain light emission from blue to blue-green, for example, a condensed aromatic ring compound, a ring assembly compound, a metal complex (such as an aluminum complex such as Alq3), a styrylbenzene compound (4,4′-bis (diphenylvinyl) ) Biphenyl (DPVBi), etc.), porphyrin compounds, benzothiazole compounds, benzimidazole compounds, benzoxazole compounds such as fluorescent brighteners, and aromatic dimethylidin compounds are preferably used. Or you may form the organic light emitting layer which emits the light of a various wavelength range by adding a dopant to a host compound. Examples of the host compound include distyrylarylene compounds (eg, IDE-120 manufactured by Idemitsu Kosan Co., Ltd.), N, N′-ditolyl-N, N′-diphenylbiphenylamine (TPD), aluminum tris (8-quinolinolate) (Alq3) Etc. can be used. As dopants, perylene (blue purple), coumarin 6 (blue), quinacridone compounds (blue green to green), rubrene (yellow), 4-dicyanomethylene-2- (p-dimethylaminostyryl) -6-methyl- 4H-pyran (DCM, red), platinum octaethylporphyrin complex (PtOEP, red), or the like can be used.

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

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

  Optionally, a thin film (thickness of 10 nm or less) of an electron injecting material such as an alkali metal, an alkaline earth metal, an alloy containing them, or an alkali metal fluoride is formed at the interface between the organic layer 20 and the electrode used as the cathode. ) May be provided to increase the electron injection efficiency.

  Each layer and an optional layer constituting the organic layer 20 can be formed by using any means known in the art such as vapor deposition (resistance heating or electron beam heating). Values known in the art can be used for various conditions such as the thickness of each layer constituting the organic layer.

Step (6) (FIG. 4E)
This step is a step of forming the second electrode. The second electrode 18 is made of a striped electrode, and is preferably formed using a highly reflective metal, amorphous alloy, or microcrystalline alloy. High reflectivity metals include Al, Ag, Mo, W, Ni, Cr, and the like. High reflectivity amorphous alloys include NiP, NiB, CrP, CrB, and the like. The highly reflective microcrystalline alloy includes NiAl and the like. The second electrode 18 may be used as a cathode or an anode. When the second electrode 18 is used as a cathode, the aforementioned buffer layer may be provided at the interface between the second electrode 18 and the organic layer 20 to improve the efficiency of electron injection into the organic layer 20.

  The second electrode 18 may be formed using any means known in the art such as vapor deposition (resistance heating or electron beam heating), sputtering, ion plating, laser ablation, etc., depending on the material used. it can. A second electrode composed of a plurality of partial electrodes may be formed using a mask that gives a desired shape, or a second electrode composed of a plurality of partial electrodes using a separation partition having a reverse tapered cross-sectional shape. 18 may be formed.

  Each of the plurality of electrode groups constituting the second electrode 18 may have a stripe shape extending in the second direction, for example. Here, the first direction related to the first electrode 17 and the above-described second direction are preferably crossed, more preferably orthogonal. By adopting such a structure, by applying an electric field to one of the partial electrodes constituting the first electrode 17 and one of the partial electrodes constituting the second electrode 18, The layer can emit light, and passive matrix driving can be performed.

  Values known in the art can also be used for various conditions such as the film thickness of the second electrode.

  As described above, the passive organic EL display of the present invention can be manufactured.

  The method for producing an organic EL display of the present invention can also be applied to a method for producing a color organic EL display. In this case, a predetermined color conversion portion such as a predetermined color conversion layer and a color filter is formed on the transparent support substrate 1 before forming the contact portion, the first electrode, etc., and is flattened as necessary. After forming the chemical layer, the passivation layer, etc., the above steps (1) to (6) may be performed.

  Specifically, a color organic EL display having a structure as shown in FIG. 6 can be manufactured. Each component will be described below.

(I) Color Conversion Filter Layer In this specification, the color conversion filter layers 12, 13, and 14 are generic names 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 layer absorbs near-ultraviolet to visible light, particularly blue to blue-green light emitted from the organic layer 20, and emits visible light having different wavelengths as fluorescence. In order to enable full color display, an independent color conversion filter layer that emits light of at least the blue (B) region 14, the green (G) region 13, and the red (R) 12 region is provided. Each of the RGB color conversion layers includes at least an organic fluorescent dye and a matrix resin.

1) Organic fluorescent dye In the present invention, preferably, at least one fluorescent dye emitting fluorescence in the red region is used, and further combined with one or more fluorescent dyes emitting green region fluorescence. This is because when the organic layer 20 that emits light in the blue to blue-green region is used as the light source, if light from the organic layer 20 is passed through a simple red filter to obtain light in the red region, This is because the output light becomes extremely dark due to the small amount of light.

  Therefore, by converting the blue to blue-green region light from the organic layer 20 into the red region light by the fluorescent dye, it is possible to output the red region light having sufficient intensity. Examples of fluorescent dyes that absorb light in the blue to blue-green region emitted from the luminescent material and emit fluorescence in the red region include rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet 11 Pyridine dyes such as rhodamine dyes such as basic red 2, cyanine dyes, 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridinium perchlorate (pyridine 1) Or oxazine dyes. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.

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

  Further, regarding the light in the blue region, a blue conversion layer that performs wavelength distribution conversion of near-ultraviolet light or blue-green light emitted from the organic layer 20 and outputs blue light may be included. However, when the organic layer 20 emits blue to blue-green light, it is preferable to use only the blue color filter layer.

  When the organic layer 20 emits white light, a desired color can be obtained only by the color filter layer. However, by using each color conversion layer, light emission of the three primary colors can be performed with higher efficiency than in the case of only the color filter layer. Can be obtained.

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

  The color conversion layer of the present invention contains 0.01 to 5% by mass, more preferably 0.1 to 2% by mass of an organic fluorescent dye based on the weight of the color conversion layer. By using the organic fluorescent dye in the content range, it is possible to perform sufficient wavelength conversion without being accompanied by a decrease in color conversion efficiency due to effects such as concentration quenching.

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

  Specifically, the matrix resin is obtained by subjecting a composition film comprising (a) an acrylic polyfunctional monomer and oligomer having a plurality of acryloyl groups and methacryloyl groups, and light or heat polymerization initiator to light or heat treatment, Or a polymer obtained by generating a thermal radical, (b) a composition comprising a polyvinylcinnamic acid ester and a sensitizer dimerized by light or heat treatment, and (c) a chain or cyclic olefin A composition film composed of bisazide is irradiated with light or heat to generate nitrene, crosslinked with an olefin, and (d) 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 (a) and light or a thermal polymerization initiator is preferred. This is because the composition can be patterned with high definition and has high reliability such as solvent resistance and heat resistance after polymerization.

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

  A matrix resin (color conversion layer) is formed by applying a solution or dispersion containing a photocurable or photothermal combination curable resin, an organic fluorescent dye and an additive on a support substrate, and forming a resin layer, and It is formed by polymerizing a desired portion of a photocurable or photothermal combination type 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.

3) Configuration and shape Regarding red, it may be formed only from the red color conversion layer. However, when sufficient color purity cannot be obtained only by conversion with a fluorescent dye, a laminate of a red conversion layer and a color filter layer may be used. The film thickness as the laminate is preferably 1 to 1.5 μm when the 1 to 10 μm color filter layer is used in combination.

  Moreover, about green, you may form only from a green conversion layer. However, when sufficient color purity cannot be obtained only by conversion with a fluorescent dye, a laminate of a green conversion layer and a color filter layer may be used. When the color filter layer is used in combination, the thickness of the color filter layer is preferably 1 to 1.5 μm. Alternatively, when the light emission of the organic layer 20 sufficiently includes light in the green region, only the color filter layer may be used. When only the color filter layer is used, the thickness is preferably 0.5 to 10 μm.

  On the other hand, for blue, only the color filter layer can be used. When only the color filter layer is used, the thickness is preferably 0.5 to 10 μm.

  The shape of the color conversion filter layer may be a stripe pattern separated for each color as well known, or may have a structure separated for each sub-pixel of each pixel. In FIG. 6, patterns of the blue (B) region 14, the green (G) region 13, and the red (R) 12 region are shown as the color conversion filter layer, but the RGB arrangement is arbitrary.

(II) Black mask A black mask (not shown in FIG. 6) is preferably formed in a region between the color conversion filter layers corresponding to each color. By providing the black mask, it is possible to prevent leakage of light to the color conversion filter layer of the adjacent subpixel and obtain only a desired fluorescence conversion color without blur. In the organic EL display, it is preferable to perform sealing. However, on the condition that the sealing is not hindered, a black mask may be provided around the area where the color conversion filter layer is provided on the transparent support substrate 1. Good. The black mask preferably has a thickness of 0.5 to 2.0 μm.

(III) Planarization layer (polymer film layer) 15
The planarization layer 15 covering the color conversion filter layer can be formed without impairing the function of the color conversion filter layer, and can be formed from a material having appropriate elasticity. 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 color conversion filter layer, and does not deteriorate the function of the color conversion 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), electrical insulation, and barrier properties against moisture, oxygen, and low molecular components. It is. The planarizing layer 15 is an optional layer, but is preferably a layer provided for the above purpose.

Examples of such a polymer material include an imide-modified silicone resin (see Patent Documents 4 to 6) and an inorganic metal compound (TiO, Al ₂ O ₃ , SiO _2, etc.) dispersed in acrylic, polyimide, silicone resin, etc. Materials (see Patent Documents 7 and 8), resins having reactive vinyl groups of acrylate monomers / oligomers / polymers, resist resins (see Patent Documents 9 to 12), fluororesins (see Patent Documents 12 and 13), or Examples thereof include a photocurable resin and / or a thermosetting resin such as an epoxy resin having a mesogenic structure having a high thermal conductivity. There is no particular limitation on the method of forming the planarization layer 15 using these polymer materials. For example, it can be formed by a conventional method such as a dry method (sputtering method, vapor deposition method, CVD method, etc.) or a wet method (spin coating method, roll coating method, casting method, etc.).

  The planarization layer 15 may have a thickness of about 1 to 10 μm from the top of the color conversion filter layer. When forming by the cast method or the spin coat method, the planarization layer 15 preferably has a thickness of about 3 to 10 μm.

(IV) Passivation layer 16
A passivation layer 16 is provided to cover each layer such as the color conversion filter layer and the flattening layer formed as described above. The passivation layer 16 is effective in preventing permeation of low molecular components and moisture from the color conversion filter layer, and preventing functional deterioration of the organic layer 20 due to them. The passivation layer 16 is an optional layer, but is preferably a layer provided for the above purpose. The passivation layer 16 is preferably transparent in the light emission wavelength region in order to transmit the light emitted from the organic layer 20 to the color conversion filter layer.

In order to satisfy these requirements, the passivation layer 16 has high transparency in the visible region (transmittance of 50% or more in the range of 400 to 800 nm), electrical insulation, and a barrier against moisture, oxygen, and low molecular components. Preferably, it is formed of a material having a film hardness of pencil hardness 2H or more. For example, materials such as inorganic oxides and inorganic nitrides such as SiO _x , SiN _x , SiN _x O _y , AlO _x , TiO _x , TaO _x , and ZnO _x can be used. There is no restriction | limiting in particular as a formation method of this passivation layer, It can form by conventional methods, such as a sputtering method, CVD method, a vacuum evaporation method, a dip method, a sol-gel method.

In addition, various polymer materials can be used for the passivation layer. Imide-modified silicone resin (see Patent Documents 4 to 6), a material in which an inorganic metal compound (TiO, Al ₂ O ₃ , SiO ₂ or the like) is dispersed in acrylic, polyimide, silicone resin or the like (see Patent Documents 7 and 8) A resin having a reactive vinyl group of acrylate monomer / oligomer / polymer, a resist resin (see Patent Documents 9 to 12), a fluororesin (see Patent Documents 12 and 13), or a mesogenic structure having high thermal conductivity. Examples thereof include a photocurable resin such as an epoxy resin and / or a thermosetting resin. Even when these polymer materials are used, the formation method is not particularly limited. For example, it can be formed by a conventional method such as a dry method (sputtering method, vapor deposition method, CVD method, etc.) or a wet method (spin coating method, roll coating method, casting method, etc.).

  The above-described passivation layer 16 may be a single layer or a laminate of a plurality of layers. The thickness of the passivation layer 16 (the total thickness in the case of a laminate of a plurality of layers) is preferably 0.1 to 10 μm.

  Each of the above-described components can be formed on a transparent support substrate according to the above-described method, and then the steps (1) to (6) are applied to manufacture a color organic EL display.

Hereinafter, the present invention will be described in more detail with reference to examples. In the following examples, an example of manufacturing a CCM organic EL display to which the present invention is applied will be described with reference to FIG. The organic EL display was formed with a pixel number of 160 × 64 × RGB and a pixel pitch of 0.33 mm.
Example 1
A blue filter material (manufactured by Fuji Film Electronic Materials: Color Mosaic CB-7001) is applied on Corning glass (50 × 50 × 1.1 mm) as the transparent substrate 1 by using a spin coating method, and by a photolithographic method. Patterning was performed to obtain a line pattern of the blue filter 14 having a line 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). 100 parts by weight of a photopolymerizable resin “VPA100 / P5” (trade name, Nippon Steel Chemical Industry Co., Ltd.) was added and dissolved to obtain a coating solution. This coating solution is applied to the transparent substrate 1 on which the line pattern of the blue filter has been formed, using a spin coating method, and patterned by a photolithographic method, so that the line width of the green conversion filter 13 is 0. A line pattern of 1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm was obtained.

  Coumarin 6 (0.6 parts by weight), rhodamine 6G (0.3 parts by weight) and basic violet 11 (0.3 parts by weight) are dissolved in 120 parts by weight of propylene glycol monoethyl acetate (PGMEA) as a solvent. It was. 100 parts by weight of a photopolymerizable resin “V259PA / P5” (trade name, Nippon Steel Chemical Co., Ltd.) was added and dissolved to obtain a coating solution. This coating solution is applied to the transparent substrate 1 on which the line pattern of the blue filter and the green conversion filter has been formed by using a spin coating method, and patterned by a photolithographic method. A line pattern having a line width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm was obtained.

  A flattening layer (polymer film layer) 15 was formed on the fluorescence conversion filter. The flattening layer 15 is formed with a film thickness of 8 μm (film thickness from the top of the fluorescence conversion filter layer) by applying a UV curable resin (epoxy-modified acrylate) by spin coating and irradiating with a high-pressure mercury lamp. did. At this time, the pattern of the fluorescence conversion filter was not deformed, and the upper surface of the polymer film layer was flat.

  As the passivation layer (inorganic film layer) 16, a 300 nm SiOx film was formed at room temperature by DC sputtering. Si was used as the sputtering target, and a mixed gas of Ar and oxygen was used as the sputtering gas.

As the contact portion 7, a 300 nm Mo film was formed at room temperature by DC sputtering. Mo was used as the sputtering target, and Ar was used as the sputtering gas. After patterning the resist by photolithography, a pattern with a wiring width of 300 μm was formed by patterning using a mixed solution of H ₃ PO ₄ : HNO ₃ : CH ₃ COOH as an etchant.

  An In—Zn oxide pattern was formed as the first electrode. The first electrode is wired from the connection site with the external drive circuit to the center in the display panel. An In—Zn oxide film having a thickness of 200 nm was formed at room temperature by a DC sputtering method. An In—Zn oxide target was used as the sputtering target, and Ar and oxygen were used as the sputtering gas. After patterning the resist by photolithography, patterning was performed using oxalic acid as an etchant to form a pattern with a wiring width of 100 μm.

  Subsequently, an insulating film (polyimide film, Photo Nice manufactured by Toray Industries, Inc.) having a film thickness of 1 μm was formed on the gap between the stripes of the transparent conductive film (first electrode) 17 and the dummy pattern using a photolithographic method.

  Subsequently, a negative photoresist (ZPN 1168 manufactured by Nippon Zeon Co., Ltd.) is applied by spin coating, pre-baked, a predetermined pattern is baked using a photomask, and post-exposure baking is performed on a hot plate at 110 ° C. for 60 seconds. After that, development is performed, and finally, heating is performed on a hot plate at 160 ° C. for 15 minutes, the second electrode is formed of a plurality of stripes extending in a direction perpendicular to the stripes of the first electrode 17 and having a cross section of an inversely tapered shape. An electrode separation partition was formed.

  Next, the substrate 1 on which the transparent conductive film (first electrode) was formed was placed in a vacuum dryer, left at 150 ° C. for 1 hour, and then subjected to UV ozone treatment at 150 ° C. At that time, a metal mask as shown in FIG. 5 was used.

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

  Next, without breaking the vacuum, Mg / Ag with a thickness of 200 nm (mass ratio 10/1) was deposited to form the second electrode, and an organic EL device having the structure shown in FIG. 6 was obtained. .

The organic EL device thus obtained was sealed with a sealing glass (not shown) and a UV curable adhesive in a glove box in a dry nitrogen atmosphere (both oxygen and moisture concentrations were 10 ppm or less).
(Comparative Example 1)
For comparison with Example 1 described above, UV ozone treatment was performed without using a mask during UV ozone treatment at 150 ° C. All other processes were the same as in Example 1.

  For Example 1 and Comparative Example 1, the resistance between the cathodes was measured. The results are shown below.

  As is apparent from the results of the table, the organic EL display panel manufactured by the method of the present invention can significantly reduce the resistance between the cathodes as compared with the comparative example, and can realize a reduction in resistance.

  In the present invention, a monochrome organic EL display can also be manufactured by omitting the manufacturing process of the color conversion filter layer of the first embodiment.

It is a perspective view of a passive matrix type organic EL display panel. It is a figure which shows the formation area of the insulating film which concerns on this invention. FIG. 3 is a cross-sectional view of the passive matrix organic EL display panel shown in FIG. 2. It is a figure for demonstrating the manufacturing process of the passive matrix type organic electroluminescent display of this invention. It is a figure which shows the mask (a part is shown) concerning this invention. It is the schematic which shows the structure of the color organic electroluminescent display concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent support substrate 2 1st electrode lead wire 21 1st electrode 3 2nd electrode connection part 5 Insulating layer 6 2nd electrode insulating layer 7 Contact part 12 Red conversion filter 13 Green conversion filter 14 Blue filter 15 Flattening layer ( Polymer membrane layer)
16 Passivation layer 17 First electrode 18 Second electrode 20 Organic layer

Claims (3)

Manufacture of an organic EL display panel comprising a first electrode, a second electrode disposed opposite to the first electrode, and an organic layer disposed between the first and second electrodes on a transparent support substrate A method,
Forming a contact portion including a second electrode connection portion on a transparent support substrate;
Forming a first electrode including a lead line of the first electrode on a transparent support substrate;
Forming an insulating layer so as to partially overlap the edge of the first electrode between the first electrodes;
A cleaning step of cleaning the first electrode;
Forming an organic layer on the washed first electrode;
Forming the second electrode,
The cleaning step is performed by UV ozone treatment, excimer UV treatment, or oxygen plasma treatment, and in this cleaning step, the second electrode connection portion, the contact portion, and the lead wire of the first electrode are covered with a mask. A method for manufacturing an organic EL display. 2. The method of manufacturing an organic EL display according to claim 1, wherein the mask is a mask having an ultraviolet transmittance of 5% or less. Before the step of forming the contact portion, a color conversion filter layer including a color filter layer and / or a color conversion layer, and optionally a planarization layer and a passivation layer are formed on the transparent support substrate, The method for producing a color organic EL display according to claim 1, further comprising a step of obtaining a color conversion filter substrate.

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