JP4747776B2 - Organic EL panel, organic EL display, and manufacturing method thereof - Google Patents

Description

  The present invention relates to an organic EL panel, an organic EL display, and a manufacturing method thereof.

  Organic EL display panel production methods include “three-color light emission method” in which organic EL elements that emit red, blue, and green light when applied to an electric field, and white light emitted by organic EL elements using color filters. "Color filter system" that expresses red, blue, and green, and absorbs near-ultraviolet light, blue light, blue-green light, or white light emitted by organic EL elements, and converts the wavelength distribution to visible light A “color conversion method” using a color conversion layer including a color conversion pigment that emits light in the region has been proposed.

  Among these methods, a color mask layer and / or a color conversion layer having a desired shape and arrangement can be formed by using a photo process without using a metal mask during film formation. The “filter method” and “color conversion method” are considered to be advantageous for increasing the screen size and resolution.

  An important practical issue as a color display is that it has a fine color display function and has long-term stability including color reproducibility. However, the color organic EL display has a drawback that the light emission characteristics (current-luminance characteristics) are lowered by driving for a certain period.

  A typical cause of the deterioration of the light emission characteristics is the growth of dark spots. A dark spot is a light emitting defect point. When oxidation proceeds during driving and during storage, the growth of dark spots proceeds and spreads over the entire light emitting surface. This dark spot is considered to be caused by oxidation or aggregation of the laminated material constituting the element due to oxygen or moisture in the element. The growth proceeds not only during energization but also during storage. In particular, the growth is accelerated by (1) oxygen or moisture present around the element, and (2) oxygen or moisture present as an adsorbate in the organic laminated film. And (3) it is considered that it is also affected by moisture adsorbed on components at the time of device fabrication or moisture intrusion at the time of production.

  As a technique for preventing the moisture from entering the organic EL element, it has been proposed to provide an insulating moisture / oxygen barrier layer on the substrate. As a moisture / oxygen barrier layer, a technique for disposing an organic resin such as a polyimide-modified silicone resin (see, for example, Patent Documents 1 to 3), and an inorganic oxide layer having a thickness of 0.01 to 200 μm (see Patent Document 4) A technique for disposing the above is known. The inorganic oxide film layer is required to have high moisture resistance in order to maintain the life of the organic light emitting layer.

  In the case of the “color filter method” and “color conversion method”, there is a method of forming SiOx and SiNx by DC sputtering on the polymer film layer formed on the color filter layer, thereby improving the adhesion of the transparent conductive film. The effect which makes it known is known (refer patent document 5 and 6). There is also a method of sintering low-melting glass (see Patent Document 7).

  With regard to the performance degradation of organic EL elements, active research has been conducted in various places, and various causes have been announced so far. In particular, since the organic EL layer including the light emitting layer is made of a material having low resistance to oxygen and moisture, performance degradation due to moisture and oxygen released when the device is driven is a serious problem.

Japanese Patent Laid-Open No. 5-134112 JP-A-7-218717 JP-A-7-306311 JP-A-8-279394 Japanese Patent Laid-Open No. 7-146480 Japanese Patent Laid-Open No. 10-10518 JP 2000-214318 A JP 2003-233330 A

  However, it is known that an inorganic oxide film such as SiOx or SiNx used as a moisture / oxygen barrier layer in the “color filter system” and “color conversion system” may have pinholes formed therein. It has been. When such pinholes are formed, moisture or oxygen may reach the organic EL layer through the pinholes and dark spots may grow. In particular, it has been clarified that the dark spot grows rapidly at the outer peripheral portion near the display portion.

  Since the display structure is different on the outer periphery of the display unit, it is considered that moisture or oxygen inside the display is released from the substrate due to heat generated by driving the organic EL element, reaches the organic EL layer, and grows a dark spot.

  As a technique paying attention to the difference in display structure on the outer periphery of the display unit, there is one described in Patent Document 8. This technology aims to stabilize the amount of ink ejected by the ink jet method or to homogenize the density of vaporized material by the vapor deposition method. Adjacent to the effective display area, a pseudo pixel group such as an organic EL film is formed. (Claim 1, [0007] [0014], etc.). The pseudo pixel group requires a bank film as a minimum as in the effective display area. However, since the purpose of the technique described in Patent Document 8 is to homogenize the EL functional layer, the pseudo pixel group has a function of blocking moisture and oxygen released from the “color filter layer” and the “color conversion layer”. I don't have it. For example, Patent Document 8 describes an example without an ITO film (Example 1) and an example in which an ITO film is formed in an island shape (Examples 2 and 3). As described above, in the technique described in Patent Document 8, the moisture and oxygen blocking performance of the transparent conductive film is not considered.

  Therefore, particularly in the case of a substrate structure using a color filter, there is a strong demand to prevent the occurrence of dark spots by reliably preventing the entry of moisture and oxygen into the organic EL layer.

According to one aspect of the present invention, there is provided an organic EL panel for an organic EL display that displays information by individually driving a plurality of pixels provided in a matrix in a display region,
A transparent substrate;
On the transparent substrate, a color modulation unit provided at a position corresponding to each of the pixels;
A first electrode provided at a position corresponding to each of the columns of pixels on the color modulation unit;
On the first electrode, at least an organic light emitting layer provided at a position corresponding to each of the pixels,
A second electrode provided on the organic light emitting layer at a position corresponding to each row of the pixels;
There is provided an organic EL panel having an organic light emitting layer protecting part provided on at least a part of the periphery of the display area on the same surface as the first electrode.

According to another aspect of the present invention, there is provided a method of manufacturing an organic EL panel for an organic EL display for individually displaying a plurality of pixels provided in a matrix in a display area and displaying information.
Providing a transparent substrate;
Providing a color modulation section on the transparent substrate at a position corresponding to each of the pixels;
Providing a first electrode at a position corresponding to each of the columns of pixels on the color modulator;
Providing an organic light emitting layer protective part on at least a part of the periphery of the display area on the same surface as the first electrode;
Providing an organic light emitting layer on the first electrode at a position corresponding to at least each of the pixels;
Providing a second electrode on the organic light emitting layer at a location corresponding to each of the rows of pixels.

  As described in detail below, according to the present invention, an organic light emitting layer protective layer (preferably a transparent conductive oxide film or metal film excellent in moisture and oxygen barrier properties) is provided, and organic light emission from the substrate side is performed. It becomes possible to effectively prevent moisture and oxygen from entering the layer. Therefore, according to the present invention, it is possible to provide an organic EL panel capable of maintaining excellent light emission characteristics over a long period of time without generating dark spots.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

  As described above, according to one aspect of the present invention, an organic EL panel for an organic EL display that displays information by individually driving a plurality of pixels provided in a matrix in a display area. An organic EL panel having a transparent substrate, a color modulation part, a first electrode, an organic light emitting layer protection part, an organic light emitting layer, and a second electrode is provided.

  The organic EL panel according to the present invention is for an organic EL display. The organic EL display can display information by individually driving a plurality of pixels provided in a matrix in the display area. Note that a plurality of types of sub-pixels (for example, blue, green, and red sub-pixels) may be provided as the pixels.

  The organic EL panel according to the present invention has a transparent substrate. The transparent substrate is preferably transparent to visible light (wavelength 400 to 700 nm). The transparent substrate is preferably one that can withstand the conditions (solvent, temperature, etc.) used to form the layer to be laminated. The transparent substrate is preferably excellent in dimensional stability. Examples of transparent substrates include glass substrates, rigid resin substrates formed of resins such as polyolefins, acrylic resins (including polymethylmethacrylate), polyester resins (including polyethylene terephthalate), polycarbonate resins, and polyimide resins. A flexible film substrate may be mentioned. The thickness of the transparent substrate can be, for example, 1.1 mm.

  In addition, the organic EL panel according to the present invention further includes a color modulation unit provided at a position corresponding to each of the pixels on the transparent substrate. In this specification, “provided on” intends to be provided in the direction in which the organic light emitting layer exists with respect to the substrate. The provision of the color modulation unit on the transparent substrate includes not only the case where the color modulation unit is provided directly on the transparent substrate but also the case where the color modulation unit is provided on the transparent substrate via some member. The same applies to other members.

  The color modulation part can be composed of a color filter layer, a color conversion layer, or a laminate of a color filter layer and a color conversion layer. The color filter layer is a layer that transmits only light in a desired wavelength range. Further, when adopting a laminated structure of the color filter layer and the color conversion layer, the color filter layer is effective in improving the color purity of the light subjected to wavelength distribution conversion in the color conversion layer. Examples of the material for the color filter layer include commercially available color filter materials for liquid crystals (such as color mosaic manufactured by Fuji Film Electromaterials).

  The color conversion layer is preferably a layer having a color conversion dye and a matrix resin. The color conversion dye is a dye that converts the wavelength distribution of incident light and emits light in different wavelength ranges, and preferably has a wavelength of light from an organic light emitting layer (for example, near ultraviolet light or blue to blue-green light). A pigment that performs distribution conversion and emits light in a desired wavelength band (for example, blue, green, or red). Examples of color conversion dye materials include rhodamine dyes and cyanine dyes that emit red light; coumarin dyes and naphthalimide dyes that emit green light; and coumarin dyes that emit blue light. .

  The color modulation unit is provided at a position corresponding to each pixel. When a plurality of types of sub-pixels (for example, red, green, and blue sub-pixels) are provided as pixels, it is preferable that a plurality of types of color modulation units are provided according to the corresponding sub-pixels. Specifically, as color modulation units for red, green, and blue sub-pixels, for example, a red modulation unit that absorbs light from an organic light emitting layer and emits red light, and a green modulation unit that emits green light, respectively. In addition, a blue modulation unit that emits blue light can be provided. As will be apparent to those skilled in the art, full color display is possible by arranging a plurality of types of color modulation sections in a matrix.

  The thickness of the color modulation part can be set to 10 μm, for example. In addition, the size of the color modulation unit can be set, for example, to a width of 0.08 mm and a pitch of 0.11 mm.

  The color modulation part can be formed by applying the material of each color modulation part using a spin coating method, a roll coating method, a casting method, a dip coating method, or the like, and patterning using a photolithographic method or the like.

  The organic EL panel according to the present invention preferably further includes a planarization layer provided so as to cover the color modulation part between the color modulation part and the first electrode. By providing the planarization layer, the surface for forming the electrode can be further planarized. As a material for the planarization layer, a known material such as a transparent organic resin can be used. The thickness of the planarization layer can be set to 0.1 to 10 μm, for example, on the color modulation portion. The planarization layer can be formed by any known method. For example, the planarization layer can be formed by applying an organic resin by a spin coating method and patterning by a photolithography method.

  The organic EL panel according to the present invention preferably further includes a passivation layer provided so as to cover the color modulation part between the color modulation part (preferably a planarization layer) and the first electrode. By providing the passivation layer, oxygen and / or moisture can be blocked. Examples of the material for the passivation layer include insulating inorganic oxides such as SiOx, SiNx, SiNxOy, AlOx, TiOx, TaOx, and ZnOx, inorganic nitrides, and inorganic oxynitrides. The thickness of the passivation layer can be set to 0.1 to 1 μm, for example. The passivation layer can be formed by a known method such as sputtering.

The organic EL panel according to the present invention further includes a first electrode provided at a position corresponding to each of the pixel columns on the color modulation section (preferably a passivation layer). In other words, the organic EL panel has a plurality of striped first electrodes extending in the first direction. The first electrode is preferably a transparent electrode, and specifically has a transmittance of preferably 50% or more, more preferably 85% or more with respect to light having a wavelength of 400 to 800 nm. As an example of the material of the first electrode, a conductive metal oxide such as SnO ₂ , In ₂ O ₃ , ITO, IZO, an alloy of ZnO and Al can be used. The thickness of the first electrode is usually 50 nm or more, preferably 50 nm to 1 μm, more preferably 100 to 500 nm. The first electrode can be formed by a known method such as sputtering.

  The organic EL panel according to the present invention preferably further includes an auxiliary electrode. The resistance of the first electrode (transparent electrode) can be suppressed by the auxiliary electrode. Examples of the material of the auxiliary electrode include metals such as Al, Mo, Ni, Cr, and W. The auxiliary electrode can be provided in either the display region or a region where a lead line with the external drive circuit of the first electrode is formed. For example, in the display area, it is arranged along the edge of the first electrode so as to be in contact with the first electrode in parallel with the first electrode so as not to prevent light emission from the organic light emitting layer. Can do. In the lead line formation region, it can be formed with the same width as the first electrode for the purpose of reducing the electric resistance of the first electrode (transparent electrode). The thickness of the auxiliary electrode is usually 50 nm or more, preferably 50 nm to 1 μm. FIG. 4 shows a schematic plan view of the first electrode 6 and the auxiliary electrodes 12 (for three rows) in the organic EL panel according to the present invention.

  The organic EL panel according to the present invention further includes an organic light emitting layer protection part provided on at least a part of the periphery of the display area on the same surface as the first electrode. The organic light emitting layer protective part is provided on the same surface as the first electrode. In particular, the organic light emitting layer protective part is preferably provided on the planarization layer or the passivation layer. The thickness of the organic light emitting layer protective part is preferably 50 nm to 1 μm, and more preferably 100 to 500 nm.

  Further, the organic light emitting layer protection part is provided at least at a part around the display area. In particular, the organic light emitting layer protection part is preferably provided in a region outside the display region other than a region where a lead line connecting the first electrode and the external drive circuit is formed. By forming the organic light emitting layer protection part in as wide a region as possible, the generation of dark spots can be suppressed.

  Moreover, it is preferable that the organic light emitting layer protection part has a blocking ability against moisture and / or oxygen. Here, the same material (transparent conductive oxide) as that of the first electrode and the same material (metal) as that of the auxiliary electrode have a blocking ability against moisture and / or oxygen. For this reason, the organic light emitting layer protection part can be formed as a dummy pattern using the same material as the first electrode or the auxiliary electrode. In this case, the dummy pattern is preferably not connected to the external drive circuit and separated from the first electrode and the auxiliary electrode. In other words, the organic light emitting layer protection portion can be provided by forming a metal film or an oxide conductive film that is not connected to the external drive circuit around the display region on the same surface as the first electrode.

In other words, the organic light emitting layer protective part is preferably a metal film or an oxide conductive film. Specifically, it is preferable that the metal film is made of a material selected from the group consisting of Al, Mo, Ni, Cr, and W and alloys containing these as main components. The oxide conductive film is preferably made of a material selected from the group consisting of SnO ₂ , In ₂ O ₃ , ITO, IZO, and an alloy of ZnO and Al. In consideration of the function as a moisture and / or oxygen barrier layer, a material different from the first electrode and the auxiliary electrode can also be used for the organic light emitting layer protection part. For example, the results show that the IZO film has a higher function as a moisture and / or oxygen barrier layer than the ITO film. Without being bound by theory, it is predicted that this is because the passage of moisture and oxygen such as crystal grain boundaries is small because the IZO film is amorphous.

  The organic light emitting layer protective part can be formed by a known method such as a sputtering method, similarly to the first electrode and the auxiliary electrode. In addition, it is preferable that the step which provides a 1st electrode and the step which provides an organic light emitting layer protection part are performed by the same process. That is, the organic light emitting layer protection part is formed as a dummy pattern using the same material as the first electrode or auxiliary electrode. In this case, patterning is performed to form the first electrode or auxiliary electrode. At the same time, the organic light emitting layer protective part can be formed.

  As described above, as a result of various studies, the present inventor has found that dark spots often occur in the periphery of the display area. This part is a part adjacent to the boundary where the display structure changes. That is, in the display area, generally, a planarization layer (polymer film layer) is formed on a color filter layer or the like, and a passivation layer (inorganic moisture barrier film) such as SiOx or SiNx is formed thereon, and then light emission is performed. A first electrode for forming the part is formed. On the other hand, the first electrode is not formed outside the display area because it does not function as a light emitting portion. This fact indicates that the first electrode such as a transparent conductive oxide film or a metal film has an extremely excellent barrier property against moisture and oxygen. Based on this finding, the present invention provides an organic EL element that can more effectively prevent the occurrence of dark spots.

  The organic EL panel according to the present invention preferably has an insulating film between adjacent first electrodes and / or between the organic light emitting layer protecting part and the second electrode. Examples of the material for the insulating film include polyimide. The thickness of the insulating film can be set to, for example, 100 nm to 3 μm on the organic light emitting layer protection part. The insulating film can be formed by a known method such as a photolithography method.

The organic EL panel according to the present invention is an organic light-emitting device provided on the first electrode at a position corresponding to at least each of the pixels (preferably integrally covering the positions corresponding to all the pixels). It further has a layer. The organic EL panel can further have a hole injection layer, a hole transport layer, an electron transport layer, and / or an electron injection layer as necessary. Specifically, the organic light emitting device can have the above layers in the order shown below, for example. In the organic EL panel having the following laminated structure (1) to (6), the anode is in electrical contact with the organic light emitting layer or the hole injection layer, and the organic light emitting layer, electron transport layer or electron The cathode is in electrical contact with the injection layer.
(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 Alq ₃ ), a styrylbenzene compound (4,4′-bis (diphenyl) (Vinyl) biphenyl (DPVBi), etc.), porphyrin-based compounds, benzothiazole-based, benzimidazole-based, benzoxazole-based fluorescent brighteners, and aromatic dimethylidin-based 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) (Alq ₃ ). ) Etc. can be used. As dopants, perylene (blue purple), coumarin 6 (blue), quinacridone compounds (blue green to green), rubrene (yellow), 4-dicyanomethylene-2- (p-dimethylaminostyryl) -6-methyl- 4H-pyran (DCM, red), platinum octaethylporphyrin complex (PtOEP, red), or the like can be used.

  As the forest 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.

The material of the electron transport layer, aluminum complexes such as A1q _3; PBD, oxadiazole derivatives such as TPOB; thiophene derivatives such as BMB-2T; triazine derivatives; phenylquinoxalines such triazole derivatives such as TAZ Can be used. As the material for the electron injection layer, an aluminum complex such as Alq ₃ or an aluminum quinolinol complex doped with an alkali metal or an alkaline earth metal can be used.

  Optionally, an electron injecting material such as an alkali metal, an alkaline earth metal, an alloy containing them, or an alkali metal fluoride is provided at the interface between the organic light emitting layer (or electron transport layer or electron injection layer) and the cathode. By providing a buffer layer of a thin film (for example, a film thickness of 10 nm or less), the electron injection efficiency can be increased.

  The thicknesses of the hole injection layer, the hole transport layer, the organic light emitting layer, the electron transport layer, and the electron injection layer should be appropriately set so as to be sufficient for realizing the desired characteristics in each. For example, it can be set to 100 nm, 20 nm, 30 nm, 20 nm, and 10 nm, respectively. In addition, the hole injection layer, the hole transport layer, the organic light emitting layer, the electron transport layer, and the electron injection layer are formed by using any means known in the art such as vapor deposition (resistance heating or electron beam heating). can do.

  The organic EL panel according to the present invention further includes a second electrode provided on the organic light emitting layer at a position corresponding to each row of the pixels. In other words, the organic EL panel has a plurality of striped second electrodes extending in a second direction that intersects (preferably orthogonally) the first direction applied to the first electrode. In this manner, passive matrix driving can be performed by providing the first electrode and the second electrode that intersect in a matrix.

  The second electrode is preferably a reflective 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 may be used as a cathode or an anode. When the second electrode is used as a cathode, the aforementioned buffer layer may be provided at the interface between the second electrode and the organic light emitting layer to improve the efficiency of electron injection into the organic light emitting layer.

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

  Each of the second electrodes may have a stripe shape extending in the second direction, for example. Here, the first direction relating to the first electrode and the second direction are preferably crossed, more preferably orthogonal. By adopting such a configuration, a passive matrix drive in which an electric field is applied to one of the first electrodes and one of the second electrodes to emit light from the organic light emitting layer at the intersection of the electrodes. It can be performed.

  An organic EL panel according to the present invention is a first electrode for electrically connecting the first electrode and an external drive circuit, which is provided in electrical connection with one end of the first electrode. It is preferable to further have a connection electrode. In addition, an organic EL panel according to the present invention is provided to electrically connect the second electrode and an external drive circuit provided electrically connected to one end of the second electrode. It is preferable to further have two connection electrodes. Through these first and second connection electrodes, the first and second electrodes of the organic EL panel can be electrically connected to an external drive circuit.

  FIG. 1 shows a schematic plan view of an organic EL panel according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view in a plane perpendicular to the first electrode of the organic EL panel according to the first embodiment of the present invention (a-a cross section in FIG. 1). As shown in FIGS. 1 and 2, the organic EL device according to the first embodiment of the present invention includes a transparent substrate 1, color modulation units 2R, 2G, and 2B, a black matrix 3, and a planarization layer 4. The passivation layer 5, the first electrode (transparent electrode) 6, the organic light emitting layer protection part 7, the organic light emitting layer 8, the second electrode (reflective electrode) 9, the first electrode and an external drive circuit A first connection electrode 10 for electrically connecting the second electrode and a second connection electrode 11 for electrically connecting the second electrode and the external drive circuit.

  In the organic EL panel according to the first embodiment, the first electrode and the second electrode are provided in a matrix so as to be orthogonal to each other, and a pixel is formed at each of the intersecting portions. As a whole, a rectangular display area is formed. Of the four sides of the display area, a first connection electrode is provided in the vicinity of the two sides perpendicular to the first electrode, and in the vicinity of the two sides parallel to the first electrode. A second connection electrode is provided. With respect to the first electrode, the display region is divided into two regions perpendicular to the first electrode at the center, and the first electrode in each region is electrically connected to the first connection electrode located closer to it. It is connected to the. The second electrode is electrically connected to the second connection electrode at both ends thereof. An organic light emitting layer protective portion made of a transparent conductive oxide is provided in the same plane as the first electrode as a dummy pattern in a region between the display region and the second connection electrode in the periphery of the display region. It has been. The dummy pattern is not connected to the external drive circuit and is also separated from the first electrode.

  FIG. 3 shows a schematic plan view of an organic EL panel according to the second embodiment of the present invention. In the organic EL panel according to the second embodiment, the first connection electrode is provided in the vicinity of one side perpendicular to the first electrode among the four sides of the display region, A second connection electrode is provided in the vicinity of one side parallel to the first electrode. The first electrode is electrically connected to the first connection electrode located at one end thereof. Similarly, the second electrode is electrically connected to a second connection electrode located at one end thereof. Protection of the organic light emitting layer made of a transparent conductive oxide in the same plane as the first electrode as a dummy pattern in all areas around the display area except between the display area and the first connection electrode Is provided.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to the examples described below.

[Example 1]
As Example 1, an organic EL panel according to the above-described first embodiment of the present invention was produced. The number of pixels was 160 × 120 (RGB), and the pixel pitch was 0.33 mm.

  As the transparent substrate 1, fusion glass (Corning 1737 glass, 100 × 100 × 1.1 mm) was used.

  On the transparent substrate, the black matrix 3 was formed as follows. That is, a black matrix material (Fuji Film Electronics Materials Co., Ltd .: Color Mosaic CK-7800) was applied using a spin coating method, and patterning was performed by a photolithography method. As a result, a black matrix having openings with a width of 0.03 mm, a pitch of 0.11 mm, and a film thickness of 1 μm was obtained.

  Then, the blue conversion filter layer 2B was formed on the transparent substrate as follows. That is, a blue filter material (manufactured by Fuji Film Electronics Materials Co., Ltd .: Color Mosaic CB-7001) was applied using a spin coating method, and patterning was performed by a photolithography method. As a result, a blue color conversion filter layer composed of a plurality of stripes having a width of 0.08 mm, a pitch of 0.33 mm, and a thickness of 10 μm was obtained.

  Thereafter, a green color conversion filter layer 2G was formed on the transparent substrate as follows. That is, 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 the obtained solution, 100 parts by weight of Nippon Steel Chemical VPA100 was added and dissolved to obtain a coating solution. This coating solution was applied, and patterning was performed by a photolithography method. As a result, a green color conversion filter layer composed of a plurality of stripes having a width of 0.08 mm, a pitch of 0.33 mm, and a thickness of 10 μm was obtained. The green color conversion filter layer is composed of only a color conversion layer.

  Thereafter, a red color conversion filter layer 2R was formed on the transparent substrate as follows. That is, coumarin 6 (0.6 parts by weight), rhodamine 6G (0.3 parts by weight) and basic violet (0.3 parts by weight) were dissolved in 120 parts by weight of PGMEA as fluorescent dyes. To the obtained solution, 100 parts by weight of Nippon Steel Chemical VPA100 was added and dissolved to obtain a coating solution. This coating solution was applied, and patterning was performed for photolithography. As a result, a red color conversion filter layer composed of a plurality of stripes having a width of 0.08 mm, a pitch of 0.33 mm, and a thickness of 10 μm was obtained. The red color conversion filter layer is composed only of a color conversion layer.

  Thereafter, the planarizing film 4 was formed on the black matrix and the color conversion filter layer of each color as follows. That is, a planarizing material (manufactured by JSR: NN810) was applied using a spin coating method so as to cover the color conversion layer and the black matrix, and patterning was performed by a photolithography method. The thickness of the planarizing layer was 5 μm on the black matrix. By providing the planarizing film having this thickness, a thin planarizing film is formed on the color filter layers (2R, 2G, 2B).

Thereafter, a passivation layer 5 was formed on the planarizing film as follows. That is, a SiO ₂ film was deposited by sputtering using SiO ₂ as a target and a mixed gas of Ar and O ₂ as a sputtering gas. Thereby, a passivation layer having a thickness of 300 nm was obtained.

Thereafter, on the passivation layer, a first electrode (transparent electrode) 6, an organic light emitting layer protection part (dummy pattern) 7, and a lead wire for the second electrode were formed as follows. That is, using a DC sputtering method (target In—Zn oxide, sputtering gas: O ₂ and Ar), 200 nm of IZO was deposited on the entire surface of the passivation layer at room temperature. Thereafter, patterning was performed by a photolithography method using an oxalic acid aqueous solution as an etching solution. Thereby, a transparent electrode, a dummy pattern, and a lead line for the second electrode were formed. The transparent electrode was positioned above the color conversion filter layers 2R, 2G, and 2B and formed in a stripe shape having a width of 0.1 mm, a pitch of 0.11 mm, and a thickness of 200 nm extending in the same direction as the stripe of the color conversion filter. Further, as described above in connection with the first embodiment, the dummy pattern is located outside the display region and inside the position where the second connection electrode is formed, and has a width of 0.5 mm and a length. The thickness was 40.25 mm and the thickness was 200 nm. The lead wire of the second electrode had a width of 0.3 mm, a pitch of 0.33 mm, and a thickness of 200 nm in a direction perpendicular to the first electrode.

  Thereafter, an insulating film (polyimide film, Photo Nice manufactured by Toray Industries, Inc.) (not shown) was formed on the gap between the transparent electrodes and the dummy pattern by using a photolithographic method.

  Thereafter, a reflecting electrode partition wall (not shown) was formed on the first electrode as follows. That is, on the first electrode, a negative type photoresist (ZPN 1168 manufactured by Zeon) is applied by spin coating, pre-baked, a predetermined pattern is baked using a photomask, and hot hot at 110 ° C. for 60 seconds. Development was performed after post-exposure baking on the plate, and heating was further performed on a hot plate at 160 ° C. for 15 minutes. As a result, a stripe-shaped reflective electrode that extends in a direction perpendicular to the stripe of the transparent electrode 20 and has a cross section of an inversely tapered shape (a shape that narrows upward) in a region where the second electrode (reflective electrode) is not provided. A dividing wall was formed.

Thereafter, a hole injection layer (not shown), a hole transport layer (not shown), an organic light emitting layer 8 and an electron injection layer (not shown) were formed on the first electrode as follows. . That is, a substrate having a structure below the reflective 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 formed without breaking the vacuum. did. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. Copper phthalocyanine (CuPc) with a film thickness of 100 nm is used as the hole injection layer, and 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α with a film thickness of 20 nm is used as the hole transport layer. -NPD) as an organic light-emitting layer, 30 nm-thick 4,4'-bis (2,2'-diphenylvinyl) biphenyl (DPVBi), and 20 nm-thick Alq ₃ as an electron injection layer. .

  Thereafter, the second electrode (reflective electrode) 9 was formed on the electron injection layer as follows without breaking the vacuum. That is, Mg / Ag (mass ratio 10/1) was deposited using a mask having an opening at the junction between the display region and the second electrode lead line. Thereby, a reflective electrode having a thickness of 200 nm was formed.

  Thereafter, the obtained organic EL panel was sealed with a sealing glass (not shown) and a UV curable adhesive in a dry nitrogen atmosphere in the glove box (both oxygen and moisture concentrations were 10 ppm or less).

[Example 2]
An organic EL panel according to Example 2 was formed in the same manner as in Example 1 except that an Al film having a film thickness of 300 nm was formed as a dummy pattern.

[Comparative Example 1]
An organic EL panel according to Comparative Example 1 was formed in the same manner as in Example 1 except that no dummy pattern was formed.

[Evaluation]
Table 1 shows an outline of the organic EL panels obtained in Examples 1 and 2 and Comparative Example 1. For each of these 10 organic EL panels, the occurrence of dark spots in the display area at 1000 hours when the driving duty was 1/60, the initial luminance was 150 cd / m ² , and the driving atmosphere was 85 ° C. was observed. The results are shown in Table 2. The dark spot density was calculated as follows. That is, in the lighting state of the organic EL panel, the locations where the area of the non-lighting region (the portion whose luminance is 50% or more lower than the surroundings) out of all the display regions was counted 10 μm ² or more. Divided by 20.9Cm ² is the area of the display region which was calculated dark number of spots per cm ^2.

  As can be seen from Table 2, the devices of Examples 1 and 2 have less dark spots generated in the device of the comparative example. From this, it can be seen that the dummy pattern effectively functions as a layer for protecting the organic light emitting layer from moisture and oxygen. From the above, it can be seen that forming an organic light emitting layer protective layer around the display region is effective in preventing the occurrence of dark spots and thus extending the life of the organic EL panel.

FIG. 1 shows a schematic plan view of an organic EL panel according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view in a plane perpendicular to the first electrode of the organic EL panel according to the first embodiment of the present invention. FIG. 3 shows a schematic plan view of an organic EL panel according to the second embodiment of the present invention. FIG. 4 shows a schematic plan view of the first electrode and the auxiliary electrode in the organic EL panel according to the present invention.

Explanation of symbols

1: Transparent substrates 2R, 2G, 2B: Color modulation unit 3: Black matrix 4: Flattening layer 5: Passivation layer 6: First electrode (transparent electrode)
7: Organic light emitting layer protective part 8: Organic light emitting layer 9: Second electrode (reflective electrode)
10: First connection electrode 11: Second connection electrode 12: Auxiliary electrode

Claims (7)

An organic EL panel for an organic EL display that displays information by individually driving a plurality of pixels provided in a matrix in a display area,
A transparent substrate;
On the transparent substrate, a color modulation unit provided at a position corresponding to each of the pixels;
A first electrode provided at a position corresponding to each of the columns of pixels on the color modulation unit;
On the first electrode, at least an organic light emitting layer provided at a position corresponding to each of the pixels,
A second electrode provided on the organic light emitting layer at a position corresponding to each row of the pixels;
Provided on at least a part of the periphery of the display region on the same surface as the first electrode, and selected from the group consisting of a metal film or SnO ₂ , In ₂ O ₃ , IZO and an alloy of ZnO and Al. The organic electroluminescent panel which has an organic light emitting layer protective part which is an oxide electrically conductive film . The organic light emitting layer protection unit is separated from the first electrode, is not connected to the external drive circuit, and is provided in a region other than a region where a lead line connecting the first electrode and the external drive circuit is formed. The organic EL panel according to claim 1. The organic EL panel according to claim 1 , wherein the organic light emitting layer protective part has a blocking ability against moisture and / or oxygen. The organic EL panel according to any one of claims 1 to 3, wherein the metal film is made of a material selected from the group consisting of Al, Mo, Ni, Cr, and W and an alloy containing these as a main component. A method of manufacturing an organic EL panel for an organic EL display that displays information by individually driving a plurality of pixels provided in a matrix in a display area,
Providing a transparent substrate;
Providing a color modulation section on the transparent substrate at a position corresponding to each of the pixels;
Providing a first electrode at a position corresponding to each of the columns of pixels on the color modulator;
An oxide selected from the group consisting of a metal film or SnO ₂ , In ₂ O ₃ , IZO and an alloy of ZnO and Al on at least a part of the periphery of the display region on the same surface as the first electrode Providing an organic light emitting layer protective part which is a conductive film ;
Providing an organic light emitting layer on the first electrode at a position corresponding to at least each of the pixels;
Providing a second electrode on the organic light emitting layer at a position corresponding to each of the rows of pixels. The step of providing the organic light emitting layer protection portion is further separated from the first electrode, is not connected to the external drive circuit, and other than a region for forming a lead line connecting the first electrode and the external drive circuit The method according to claim 5, wherein the step of providing the organic light emitting layer protective part in the region is provided. In the case where the material of the first electrode and the material of the organic light emitting layer protective part are the same material, the step of providing the first electrode and the step of providing the organic light emitting layer protective part are the same. The method according to claim 5 or 6, wherein the method is carried out by processing.

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