JP4581644B2 - Manufacturing method of organic EL display panel - Google Patents

Description

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

  A color filter or the like is formed on a substrate as one of the coloring methods of an organic EL display panel, and the light from the organic EL element is separated into three primary colors of red, green and blue by using this, or three primary colors are generated. There is a method.

  In this method, a step is formed to form a color filter or the like on the substrate, and when the first electrode such as the transparent electrode and the auxiliary wiring is formed on the substrate as it is, the transparent electrode and the auxiliary wiring are disconnected, and the organic EL element May not function as Therefore, even if a transparent electrode and an auxiliary wiring are formed on the color filter by covering it with a flattening layer made of a polymer made of a thermosetting resin or an ultraviolet curable resin, there is no disconnection. .

  However, when an organic EL element composed of the first electrode, the organic EL layer, and the second electrode is formed directly on the flattening layer, moisture and organic solvent components in the flattening layer are volatilized due to heat generated when the display is driven. There is a problem in that it is released as a gas, which adversely affects the organic EL element, the light emitting element function is deteriorated, and the reliability is lowered.

In order to solve such a problem, there is a proposal to form a passivation layer made of an inorganic compound between a planarizing layer made of a polymer and an organic EL element (for example, see Patent Document 1). The performance required for the passivation layer includes high moisture resistance, high flatness, a small difference in refractive index from the substrate and the organic EL structure, and high productivity. From the viewpoint of the difference in refractive index, when an acrylic resin is used as the flattening layer and ITO is used as the transparent electrode, silicon oxide is preferable as the inorganic compound forming the passivation layer. Further, since the passivation film is formed on the planarization layer, the formation of the passivation layer requires low-temperature film formation in a range where the polymer constituting the planarization layer does not change. A method using plasma such as a CVD method is used.
Patent Document 1 exemplifies a method of forming a passivation layer made of silicon oxide by an RF sputtering method.

JP-A-11-260562 JP 2002-134268 A

  However, when forming a passivation layer made of, for example, silicon oxide by using the sputtering method, for example, when Si is used as the target, it is necessary to use an oxygen-containing gas as the sputtering gas. In order to bring the ratio of oxygen to silicon in the passivation layer close to 2, it is necessary to introduce 20 to 40% of oxygen into the sputtering gas.

  The planarized layer surface is often damaged by the plasma containing oxygen. In fact, when silicon oxide is formed on the surface of the planarization layer by sputtering using a sputtering gas containing oxygen, the surface roughness of the passivation layer tends to increase. If the surface roughness is large, the first electrode − Due to the short circuit between the second electrodes, it becomes easy to form a fracture hole. This tendency for the surface roughness to increase is considered to be due to the ashing of the planarized layer surface by oxygen plasma.

  In view of such circumstances, an object of the present invention is to provide an organic EL display panel having a silicon oxide film as a passivation layer and having little damage to a planarization layer, and a method for manufacturing the same.

  That is, the organic EL display panel of the present invention includes a color conversion layer formed by patterning on a transparent support substrate, a planarization layer formed on the color conversion layer, and the planarization layer. A passivation layer mainly composed of silicon oxide formed thereon, and an organic EL display panel provided with an organic EL element on the passivation layer, the organic EL element comprising: a first electrode; and the first electrode A second electrode disposed opposite to the electrode, and an organic EL layer disposed between the first and second electrodes, wherein the leveling layer side of the passivation layer is lower than the organic EL element side. It consists of a silicon oxide layer having an oxygen concentration.

  The organic EL display panel manufacturing method of the present invention includes a color conversion layer forming step of forming at least a patterned color conversion layer on a transparent support substrate, and a transparent support substrate obtained in the color conversion layer forming step. A planarization layer forming step for forming a planarization layer on the upper color conversion layer, and a passivation layer formation for forming a passivation layer mainly composed of silicon oxide on the planarization layer obtained in the planarization layer formation step. A first electrode on the passivation layer obtained in the passivation layer forming step, a second electrode disposed opposite to the first electrode, an organic EL layer disposed between the two electrodes, An organic EL display panel manufacturing method including an organic EL element forming step of forming an organic EL element comprising: a passivation layer forming step in an oxygen-containing atmosphere A sputtering method using silicon as a sputtering target, by performing sputtering at a lower oxygen concentration atmosphere, after forming the layer in contact with the planarization layer, and performing a sputtering with a higher oxygen concentration atmosphere.

  In addition, another method for producing an organic EL display panel according to the present invention includes a color conversion layer forming step of forming at least a patterned color conversion layer on a transparent support substrate, and a transparent obtained by the color conversion layer forming step. A planarization layer forming step for forming a planarization layer on the color conversion layer on the support substrate, and a passivation for forming a passivation layer mainly made of silicon oxide on the planarization layer obtained in the planarization layer formation step. A layer forming step, a first electrode on the passivation layer obtained in the passivation layer forming step, a second electrode disposed opposite to the first electrode, and an organic EL disposed between the two electrodes And an organic EL element forming step of forming an organic EL element comprising a layer, wherein the passivation layer forming step is flat Layer in contact with the layer is oxidized after it is deposited silicon by sputtering to form a silicon oxide layer, characterized by directly casting the silicon oxide film by sputtering thereon.

  The organic EL display of the present invention has a small surface roughness of the passivation film and can be driven stably for a long time. Further, according to the method for manufacturing an organic EL display panel of the present invention, since the ashing of the planarization layer does not occur in forming the passivation film, the surface roughness of the passivation film is small, and an organic EL display that can be driven stably for a long time is manufactured. be able to.

FIG. 1 is a diagram for explaining a configuration example of an organic EL display panel according to the present invention.
In the example of FIG. 1, a blue color conversion layer 2, a green color conversion layer 3, and a red color conversion layer 4 are each formed with a predetermined pattern on the transparent support substrate 1, and the planarization layer 5 covers these layers. Is formed. As will be described later, the green conversion layer 3 may be a green filter layer. The blue conversion layer 2 is preferably a blue filter layer. In this specification, the color conversion layer and the filter layer are collectively referred to as “color conversion filter layer”. A passivation film 6 is formed on the organic layer 5. The passivation film 6 is mainly made of silicon oxide, and is preferably silicon oxide represented by SiO _x (x = 1.5 to 2.0) except for at least the vicinity of the planarization layer of the passivation film. On the other hand, the vicinity of the planarization layer of the passivation film is preferably silicon or silicon oxide represented by SiO _y (y = 0 to 1.4).

A first electrode group 7, an organic EL layer, and a second electrode group 15 are formed on the passivation film 6, and are sealed with a sealing material to form an organic EL display.
In the example of FIG. 1, the organic EL layer includes a hole injection layer 11, a hole transport layer 12, a light emitting layer 13, and an electron transport layer 14. Hereinafter, each layer will be described in detail.

1. Color Conversion Layer 1) Organic Fluorescent Dye In the present invention, the organic fluorescent dye absorbs light in the near ultraviolet region or visible region, particularly blue or blue-green region emitted from the light emitter, and fluoresces visible light of different wavelengths. As the light is emitted. Preferably, at least one fluorescent dye that emits fluorescence in the red region may be used, and may be combined with one or more fluorescent pigments that emit fluorescence in the green region. That is, when an organic light-emitting element that emits light in the blue or blue-green region is used as a light source, if light from the element is simply passed through a red filter to obtain light in the red region, the light of the wavelength in the red region is originally used. Because there is little, it becomes very dark output light.

  Therefore, by converting the light in the blue or blue-green region from the element into the light in the red region by the fluorescent dye, the light in the red region having sufficient intensity can be output. On the other hand, the light in the green region may be output after the light from the element is converted into the light in the green region by another organic fluorescent dye, similarly to the light in the red region. Alternatively, if the light emission of the element sufficiently includes light in the green region, the light from the element may simply be output through the green filter. Furthermore, regarding the light in the blue region, the light from the organic light emitting element can be output through a simple blue filter.

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

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

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

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

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

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

2. Flattening layer The flattening layer is highly transparent in the visible region (transmittance of 50% or more in the range of 400 to 700 nm), has a Tg of 100 ° C. or more, a surface hardness of 2H or more, and a color conversion filter layer. Any material can be used as long as the coating film can be smoothly formed thereon and the functions of the color conversion filter layers 2 to 4 are not deteriorated. For example, an imide-modified silicone resin, 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, and has a reactive vinyl group of acrylate monomer / oligomer / polymer. A photo-curing resin and / or a thermosetting resin such as an acrylic resin, a resist resin, or a fluorine-based resin. In these, an acrylic resin can be used preferably.

3. Passivation layer In the present invention, the passivation layer is mainly composed of silicon oxide. That is, all of the passivation layer may be made of silicon oxide, and may contain a portion made of metal silicon in addition to silicon oxide. In the present invention, the planarization layer side of the passivation layer is composed of a silicon oxide layer having a lower oxygen concentration than the organic EL element side. When the passivation layer includes a layer made of metallic silicon, the layer made of metallic silicon is a portion facing the planarization layer.

  The ratio of oxygen to silicon in the passivation layer on the organic EL element side is preferably close to 2. In this way, when ITO or IZO is used as the first electrode, it is preferable because the difference in refractive index between the first electrode and the passivation layer becomes small.

  On the other hand, if the flattening layer side of the passivation layer is also silicon dioxide, it is necessary to increase the oxygen concentration in the atmosphere when forming a silicon dioxide film by sputtering, and the surface of the flattening layer surface is required by gas plasma during sputtering. Ashing occurs, the surface roughness of the upper surface of the passivation layer is increased, and a breakdown hole is easily formed due to a short circuit between the first electrode and the second electrode. In order to avoid this, the passivation layer facing the planarization layer is other Compared to this aspect, the silicon oxide has a low oxygen concentration. The surface facing the planarization layer may be made of metallic silicon. The thickness of the low oxygen concentration silicon oxide layer (which may partially include a metal silicon layer) facing the planarizing layer is preferably about 5 to 20 nm, and if a metal silicon layer is present, the thickness thereof Is preferably 5 nm or less. The thickness of the higher oxygen concentration silicon oxide layer in the passivation layer is preferably 100 to 1000 nm.

4). Organic EL element An organic EL element is formed on the passivation layer. The organic EL element includes an organic EL layer disposed between a first electrode and a second electrode disposed to face the first electrode. The organic EL layer includes an organic light emitting layer, and further, if necessary. Thus, a hole injection layer, an electron injection layer, and the like are interposed. Specifically, an organic EL element having the following layer structure is employed.
(1) Anode / organic light emitting layer / cathode (2) Anode / hole injection layer / organic light emitting layer / cathode (3) Anode / organic light emitting layer / electron injection layer / cathode (4) Anode / hole injection layer / organic Light emitting layer / electron injection layer / cathode (5) Anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode

  In the organic EL display of the present invention, the first electrode is an anode made of a transparent electrode, and includes a display portion, a connection portion with an external drive circuit, and a lead portion. As the transparent electrode, ITO, In—Zn oxide, ATO, etc. can be used. As the In—Zn oxide, a relatively low resistance film can be obtained by film formation at room temperature, and patterning with a weak acid becomes possible. preferable. The first electrode is formed, for example, on a line pattern composed of a plurality of conductive films parallel to each other. The end portion of the first electrode is preferably tapered.

  An insulating film having an area necessary for light emission (subpixel) as an opening is formed on the first electrode. As the insulating film material, a photosensitive material such as a novolac resin or an organic material such as polyimide can be used, and an inorganic insulating material can be used by a method such as lift-off. An organic light emitting layer, a hole injection layer, an electron injection layer, and the like are formed in the opening. Known materials are used as the material for each of the above layers. In order to obtain light emission from blue to blue-green, the organic light-emitting layer is composed of, for example, fluorescent brighteners such as benzothiazole, benzimidazole, and benzoxazole, metal chelated oxonium compounds, styrylbenzene compounds, aromatic Group dimethylidin compounds are preferably used. Examples of the electron injection layer include alkali metals such as lithium and sodium, alkaline earth metals such as potassium, calcium, magnesium, and strontium, or electron injecting metals such as fluorides thereof, and alloys with other metals. Or a material such as a compound can be used. As the electron transport layer, a metal complex such as an aluminum quinoline complex, oxadiazole, a triazole compound, or the like can be used. For the hole injection layer, aromatic amine compounds, starburst amines, benzidine amine multimers, copper phthalocyanine (CuPc), and the like can be used. As the hole transport layer, a starburst amine, an aromatic diamine, or the like can be used.

Below, the manufacturing method of the organic electroluminescent display of this invention is demonstrated.
Manufacturing method 1
In the color conversion layer forming step, a solution or dispersion containing a photocurable or photothermal combination type curable resin, an organic fluorescent dye and an additive is applied onto a transparent support substrate to form a resin layer, and It is formed by polymerizing the exposed portion of the 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.

  The flattening layer forming step is not particularly limited. For example, 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.). Can be formed.

  The passivation layer forming step is performed by sputtering using silicon as a sputtering target in an oxygen-containing atmosphere. First, sputtering is performed in a lower oxygen concentration atmosphere to form a layer in contact with the planarization layer, and then a higher oxygen concentration is formed. Sputtering is performed in a concentration atmosphere. As the sputtering method, any of DC, RF, and dual cathode methods may be used.

  The electric conductivity of the silicon target is preferably 0.01 to 10 Ωcm, and silicon added with boron is preferably used as the target. Argon and oxygen are used as the sputtering gas.

  When forming the layer in contact with the planarizing layer, the amount of oxygen introduced into the sputtering gas is preferably 2 to 10%. By setting the oxygen concentration in the sputtering gas to such a low concentration, ashing of the planarization layer can be suppressed. The thickness of the low oxygen concentration silicon oxide layer in contact with the planarizing layer is preferably 5 to 20 nm as described above.

  After the formation of this low oxygen concentration silicon oxide layer, the amount of oxygen introduced is increased to form a higher oxygen concentration silicon oxide layer. At this time, the oxygen concentration in the sputtering gas is preferably 20 to 40%.

  Next, ITO, In-Zn oxide, ATO or the like is formed on the passivation layer by a method such as sputtering, and after resist is patterned by a photolithographic method, etching is performed from the line-patterned conductive layer. The first electrode can be formed. One method for processing the end portion of the first electrode into a tapered shape is to reduce the adhesion between the photoresist and the material forming the first electrode when patterning by the photolithographic method is performed. A method for facilitating the entry of an etchant into the interface between the photoresist and the electrode material can be mentioned. Examples of the method for reducing the adhesion between the photoresist and the electrode material include a method for lowering the baking temperature at the time of forming the photoresist and a method for shortening the baking time.

  Next, an insulating film having an opening necessary for light emission is formed on the first electrode. Any method can be used for forming the insulating film as long as it can form a predetermined pattern. However, since the patterning is easy and the cross-sectional shape in the width direction is easy to reverse taper type, a negative photoresist is used. It is preferable to use the photolithographic method.

  The organic light emitting layer or the like may be formed in order by using a resistance heating vapor deposition apparatus or the like according to the configuration adopted in the above-described various forms without breaking the vacuum.

  The second electrode is, for example, an alkali metal such as lithium or sodium, an alkaline earth metal such as potassium, calcium, magnesium or strontium, or an electron injecting metal made of a fluoride thereof, or an alloy with another metal. It is obtained by vapor deposition using a heating vapor deposition apparatus without breaking the vacuum as it is, following the formation of the organic EL layer, using a material such as or a compound.

  Since the manufacturing method 2 and 3 are the same as those described in the manufacturing method 1 except for the passivation layer forming step, these manufacturing methods will be described only for the passivation layer forming step.

Manufacturing method 2
In the manufacturing method 2, in the passivation layer forming step, first, a Si layer is formed as a layer in contact with the planarization layer by performing a sputtering method using silicon as a sputtering target in an oxygen-free atmosphere. The thickness of this Si layer is 3 to 7 nm. Next, the surface of the Si layer is oxidized by introducing oxygen gas into the chamber. Next, sputtering is performed in a high oxygen concentration atmosphere. As the sputtering method, any of DC, RF, and dual cathode methods may be used. By forming a Si layer on the planarizing layer, it functions as an anti-ashing layer at the time of sputtering in a subsequent high oxygen concentration atmosphere, and the light transmittance can be improved by being oxidized.

  An example of producing the organic EL display of the present invention will be described below with reference to the drawings. The organic EL display was formed with a pixel number of 160 × 120 × RGB and a pixel pitch of 0.33 mm.

Example 1
[Production of blue filter]
Blue filter material (manufactured by Fuji Hunt Electronics Technology: Color Mosaic CB-7001) is applied onto Corning glass (50 × 50 × 1.1 mm) as the transparent support 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 2 having a line width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 10 μm.

[Production of green conversion layer]
Coumarin 6 (0.7 part by mass) as a fluorescent dye was dissolved in 120 parts by mass of propylene glycol monoethyl acetate (PGMEA) as a solvent. To the obtained solution, 100 parts by mass of “V259PA / P5” (trade name, manufactured by Nippon Steel Chemical Co., Ltd.), which is a photopolymerizable resin, was added and dissolved to obtain a coating solution. This coating solution is applied on the transparent substrate 1 on which the blue filter pattern has been previously formed by using a spin coating method, and patterned by a photolithographic method, so that the green conversion layer 3 has a line width of 0.1 mm and a pitch. A line pattern of 0.33 mm and a film thickness of 10 μm was obtained.

[Create red conversion layer]
Coumarin 6 (0.6 parts by mass), rhodamine 6G (0.3 parts by mass) and basic violet 11 (0.3 parts by mass) were dissolved in 120 parts by mass of propylene glycol monoethyl acetate (PGMEA) as a solvent. . To the obtained solution, 100 parts by mass of “V259PA / P5” (trade name, manufactured by Nippon Steel Chemical Co., Ltd.), which is a photopolymerizable resin, was added and dissolved to obtain a coating solution. This coating solution is applied onto the transparent substrate 1 on which the blue filter and green conversion layer patterns have been previously formed using a spin coating method, and patterned by a photolithographic method, so that the line width of the red conversion layer 4 is 0. A line pattern having a thickness of 1 mm, a pitch of 0.33 mm, and a thickness of 10 μm was obtained.

[Fabrication of planarization layer]
On this color conversion layer, a UV curable resin (epoxy modified acrylate; NN810, manufactured by JSR Corporation) is applied as a flattening layer by spin coating, and irradiated with a high-pressure mercury lamp. Cured. The film thickness of the obtained flattening layer was 8 μm, the conversion layer pattern was not deformed, and the upper surface of the flattening layer was flat.

[Preparation of passivation layer]
As the passivation layer 6, a silicon oxide film having a thickness of 300 nm was formed on the planarization layer at room temperature by an AC sputtering method using RF sputtering. As a sputtering target, Si having a resistance of 0.1 Ωcm added with boron is used. In the initial stage of sputtering, a mixed gas of Ar24 sccm and oxygen 2 sccm is used to form a silicon oxide layer of about 10 nm, and then the sputtering gas is Ar24 sccm, Oxygen was changed to 6 sccm, and film formation was performed.
The distance between the target and the substrate is 60 mm, the film forming pressure is 0.5 Pa, the power density is 2 W / cm ² , the transfer speed is 500 mm / min in the initial stage of film formation, and then the folded transfer speed is about 20 mm / min in the chamber. did. The ratio of silicon oxide to silicon in the initial stage of sputtering was about 0.5, and the ratio of silicon oxide to silicon in the silicon oxide formed thereafter was about 2.

[Formation of first electrode]
As the first electrode 7, a conductive layer having a line pattern made of In—Zn oxide was formed on the passivation layer with a film thickness of 200 nm at room temperature by DC sputtering. The first electrode is wired from the connection site with the external drive circuit to the center of the display panel. 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, a pattern having a wiring width of 100 μm was formed by patterning using oxalic acid as an etching solution.

[Formation of insulating film]
As the insulating film 8, a silicon nitride film was formed by a lift-off method. After the lift-off resist was formed at the junction between the first bus electrode and the transparent conductive film and the junction between the external drive circuit, a 300 nm silicon nitride film was formed at room temperature by RF sputtering. Thereafter, the lift-off resist was removed with a resist stripping solution, and an insulating film was formed except for the junction between the first bus electrode and the transparent electrode and the junction between the external drive circuit.

[Formation of organic EL layer]
Next, the substrate 1 on which the insulating film is formed is mounted in a resistance heating vapor deposition apparatus, and the hole injection layer 11, the hole transport layer 12, the organic light emitting layer 13, and the electron injection layer 14 are sequentially formed without breaking the vacuum. A film was formed. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. As the hole injection layer, copper phthalocyanine (CuPc) was laminated to a thickness of 100 nm. As the hole transport layer, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) was laminated to 20 nm. The light emitting layer was formed by laminating 30 nm of 4,4′-bis [2,2′-diphenylvinyl) biphenyl (DPVBi). The electron injection layer was formed by laminating 20 nm of aluminum chelate (Alq).

[Formation of second electrode]
Subsequent to the production of the organic EL layer, the second electrode was produced without breaking the vacuum. A second layer composed of a Mg / Ag (10: 1 weight ratio) layer having a thickness of 200 nm is used by using a mask capable of obtaining a stripe pattern having a width of 0.165 mm and a gap of 0.03 mm perpendicular to the line of the first electrode. The electrode (cathode) was formed without breaking the vacuum. The organic EL display panel thus obtained was sealed with a sealing glass and a UV curable adhesive under a dry nitrogen atmosphere in the glove box (both oxygen and moisture concentrations were 10 ppm or less).

Table 1 shows the passivation layer surface roughness (Ra) and the maximum height difference (PV) after the passivation layer was prepared. Further, the obtained organic EL display was subjected to a continuous lighting test for 100 hours at an initial surface luminance of 100 cd / m ² , and the density measurement results of the fracture holes due to the short circuit between the first electrode and the second electrode after the test are shown in Table 1. Shown in

(Example 2)
An organic EL display panel was produced in the same manner as in Example 1 except that [Preparation of Passivation Layer] was as follows.

The sputtering target was prepared by an AC sputtering method using RF sputtering at room temperature using Si with resistance of 0.1 Ωcm added with boron. In the initial stage of film formation, a gas of Ar 24 sccm was used as a sputtering gas, the transfer speed was set to 1000 mm, an Si layer of about 5 nm was formed, and the Si layer formed by introducing oxygen gas was used as a silicon oxide layer. Thereafter, the sputtering gas was changed to Ar 24 sccm and oxygen 6 sccm to form a film. A passivation layer of approximately 300 nm was formed at a distance of 60 mm between the target and the substrate, a film forming pressure of 0.5 Pa, and a power density of 2 W / cm ² . The ratio of oxygen to silicon in the layer formed at the initial stage of sputtering was about 0.2, and the ratio of oxygen of silicon oxide formed thereafter to silicon was about 2. Passivation layer surface roughness (Ra), maximum height difference (P-V) after creation of the passivation layer, and the first electrode after the lighting test similar to that performed in Example 1 and a fracture hole due to a short circuit between the second electrodes The density measurement results are shown in Table 1.

(Comparative Example 1)
As the passivation layer 6, a silicon oxide film having a thickness of 300 nm was formed on the planarization layer at room temperature by an AC sputtering method using RF sputtering. As a sputtering target, Si having resistance of 0.1 Ωcm with boron added is used, a mixed gas of Ar 24 sccm and oxygen 6 sccm is used as a sputtering gas, the distance between the target and the substrate is 60 mm, the film forming pressure is 0.5 Pa, and the power density is 2 W / cm. ² and the conveyance speed was 20 mm / min. Passivation layer surface roughness (Ra), maximum height difference (P-V) after creation of the passivation layer, and the first electrode after the lighting test similar to that performed in Example 1 and a fracture hole due to a short circuit between the second electrodes The density measurement results are shown in Table 1.

  From the results shown in Table 1, it can be seen that the samples produced in Examples 1, 2, and 3 have a small surface roughness on the surface of the passivation layer and can suppress the generation of fracture holes in the continuous lighting test, so that they can be driven stably for a long time.

  The organic EL display of the present invention is a highly reliable display panel and can be produced by a simple method, and thus is useful for various displays.

It is a schematic diagram which shows an example of the structure of a passive matrix type organic electroluminescent display panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent support substrate 2 Blue filter 3 Green conversion layer 4 Red conversion layer 5 Flattening layer 6 Passivation layer 7 1st electrode 11 Hole injection layer 12 Hole transport layer 13 Light emitting layer 14 Electron transport layer 15 2nd electrode

Claims (1)

  A color conversion layer forming step for forming at least a patterned color conversion layer on the transparent support substrate, and a planarizing layer is formed on the color conversion layer on the transparent support substrate obtained in the color conversion layer formation step. A planarization layer forming step, a passivation layer forming step of forming a passivation layer mainly composed of silicon oxide on the planarization layer obtained in the planarization layer formation step, and a passivation layer obtained in the passivation layer formation step Forming an organic EL element comprising: a first electrode; a second electrode disposed opposite to the first electrode; and an organic EL layer disposed between the two electrodes. A layer in which the passivation layer forming step is in contact with the planarizing layer is formed by forming a silicon film by sputtering and then oxidizing the silicon oxide layer. Formed, an organic EL display manufacturing method, which comprises directly casting a silicon oxide film by sputtering thereon.

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