JP2004355995A - Organic electroluminescent display device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high luminance image display by achieving arrangement of a transparent conductive anode electrode with a high forming temperature in an upper area of a luminance layer, where the heat resistance is low. <P>SOLUTION: Organic electroluminescent layers 4a, 4b, 4c as a first organic layer with a low heat resistance are formed on a main substrate as an insulation substrate, and the anode electrode 8 with a high forming temperature is formed on a heat resistant and transparent cover film 7, both of which are then laminated to achieve arrangement of the transparent conductive anode electrode with a high forming temperature on the organic electroluminescent layers 4a, 4b, 4c, where the heat resistance is low. The second organic layer having a function for increasing the luminescence efficiency is formed on the transparent conductive anode electrode 8 before laminating on the organic electroluminescent layer 4a, 4b, 4c, enabling a tight connection between the organic materials. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an organic light emitting display using an organic electroluminescent light emitting device and a method for manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art In recent years, a display device (organic electroluminescence display device) using an organic electroluminescence (so-called organic EL) light emitting element (organic light emitting element) utilizing a phenomenon that a specific organic substance is sandwiched between electrodes and emits light by giving a charge is used. , Also referred to as an organic light emitting display device or an organic EL display). Organic EL displays use self-luminous elements, so they do not require a backlight unlike liquid crystal displays, and they also eliminate the disadvantages pointed out in liquid crystal displays, such as high contrast and fast response speed. It has.
Regarding the organic electroluminescence device, a three-layer structure of a hole transport layer, a light-emitting layer, and a cathode (cathode), which is a typical structure, is described in “Patent Document 1,” and a two-layer electron transport layer is described in “Patent Document 2.” A method that also serves as a light emitting layer and a method that also serves as a hole transport layer and a light emitting layer are described. Patent Document 3 discloses a three-layer structure in which a carrier blocking layer is interposed between an electron transporting layer and a hole transporting layer, and the electron transporting light emitting layer and the hole transporting light emitting layer function separately. It is described in.
[0003]
Further, as a structure for extracting light generated in the light emitting layer to the outside, a bottom emission structure for extracting light from the side opposite to the surface on which the light emitting layer and the electrodes are stacked, and a top emission structure for extracting light from the stacked side are disclosed in Japanese Patent Application Laid-Open No. H10-163873. "It is described in. In the bottom emission structure, light emission is extracted to the back side of an insulating substrate (hereinafter, also simply referred to as a substrate) such as glass on which a driving circuit using a thin film transistor TFT or the like is formed, so that light is blocked by wiring of the driving circuit or the like. Low aperture ratio. On the other hand, the top emission structure can emit light without interference of the driving circuit and has a high aperture ratio. If the light extraction efficiency is high, the charge (current) given to obtain the same amount of light can be reduced, which is effective in suppressing power consumption.
[0004]
In addition, in the organic EL device having a top emission structure, a substrate (a main substrate, an organic EL device) on which an organic EL element (organic light emitting element) is formed in order to suppress deterioration of characteristics of the organic EL light emitting element due to moisture or oxygen. An organic EL panel is provided with a sealing member covering the organic light emitting element. As this sealing member, a glass plate or a transparent film is used. Patent Literature 5 discloses an organic resin that is coated on an organic light-emitting element of a main substrate, and is further coated with a diamond-like carbon film.
[0005]
[Patent Document 1]
Japanese Patent Publication No. 6-32307
[Patent Document 2]
Japanese Patent No. 2879080
[Patent Document 3]
Japanese Patent No. 2937015
[Patent Document 4]
JP 2002-328614 A
[Patent Document 5]
JP-A-2002-93586
[Patent Document 6]
JP-A-2002-243928
[0006]
[Problems to be solved by the invention]
To form a top emission structure in an organic electroluminescence device, a metal anode electrode, an electron transport layer, a red (R), green (G), blue (B) light emitting layer, a hole transport layer, and a transparent conductive film are formed on a substrate. The structure is such that the cathode electrodes are sequentially laminated. However, as a method of forming a cathode electrode of a transparent conductive film, a sputtering method, an ion plating method, a CVD method, and the like are generally used, but all of these methods form a film in a high-temperature state and are already formed on a substrate. A problem arises in the heat resistance of the organic light-emitting layer (RGB light-emitting layer) made of an organic substance. For this reason, a bottom emission structure in which a cathode electrode of a transparent electrode film, a hole transport layer, an RGB light emitting layer, an electron transport layer, and a metal anode electrode are stacked in this order on a substrate is common, and a top emission having a high aperture ratio is formed. In order to manufacture an organic EL panel having a structure, a technique of laminating a transparent electrode above the RGB light emitting layer is an issue.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a transparent conductive film and a transparent film having a high light transmittance capable of extracting light with a high aperture ratio above a substrate on which a drive circuit is formed without being affected by shielding by a drive circuit element, wiring, and the like. And a method of manufacturing the same.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a light emitting device in which an organic layer having at least a light emitting layer is formed inside a pixel separation bank on a cathode electrode and sandwiched between the anode electrode and a substrate (also referred to as a main substrate). Wherein an organic layer having a light emitting layer (first organic layer) is formed inside a pixel separation bank on the substrate, and an anode electrode of a transparent conductive film is separately formed from above the organic layer. The above organic layer is in close contact with a cover film which is preferably formed of a heat-resistant transparent film material on which an organic layer (second organic layer) having a function of improving luminous efficiency is formed. The structure was superimposed so that
[0009]
Further, the cover film and the anode electrode on the cover film have a high light transmittance with respect to light in a visible light region, and emit light generated in a light emitting layer (first organic layer) to the cover film and the anode electrode. With a small attenuation through the main substrate.
[0010]
Further, a terminal made of a conductive adhesive or the like is provided on the anode electrode, and the cover film and the main substrate are overlapped and bonded to each other, and when the two are integrated, the upper electrode provided on the main substrate is provided. Connected to the external take-out terminal.
[0011]
In addition, an insulator is provided between the anode electrode and the external lead-out terminal for the drive circuit on the main substrate to maintain the insulation.
[0012]
Further, when the cover film and the main substrate were overlapped, the cover film and the substrate were fixed by a sealing material applied in advance on the main substrate.
[0013]
Thus, in the present invention, the first organic layer having the light emitting layer is formed on the cathode electrode on the main substrate. On the other hand, the anode electrode is formed on a transparent cover film having heat resistance, and a second organic layer contributing to the improvement of the light emission characteristics is further formed on the anode electrode so that the main substrate and the cover film emit light. By overlapping the first organic layer having the layer and the second organic layer contributing to the improvement of the light emitting characteristics so as to be in contact with each other, the anode electrode can be provided above the first light emitting layer having low heat resistance. . Further, the contact portion between the first organic layer and the second organic layer is in contact with the organic layers, so that a closer contact is possible. In addition, through the anode electrode and the heat-resistant cover film having high transmittance of visible light, light emission generated in the light-emitting layer can be extracted with a small attenuation and at a high aperture ratio without being affected by elements and wiring of the drive circuit arrangement, A high-luminance image display can be obtained.
[0014]
It should be noted that the present invention is not limited to the above configuration and the configuration of the embodiment described later, and it is needless to say that various modifications can be made without departing from the technical idea of the present invention.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an organic light emitting embodiment according to the present invention will be described. In the organic light emitting display device, there are a low molecular material system and a high molecular material system as an organic material constituting a first organic layer used for a portion contributing to light emission, but the present invention is not limited thereto. An organic light emitting display device in which both are mixed may be used. In addition, the present invention is not limited to materials, compositions, and the like used in Examples described below.
[0016]
[First embodiment]
FIG. 1 is a cross-sectional view of a principal part schematically illustrating a configuration of a first example illustrating an embodiment of an organic light emitting display device according to the present invention. The reference numerals in the figure are as follows.
1 is a main substrate, 2 is a cathode electrode, 3 is a pixel separation bank, 3a is a pixel separation bank outermost wide pattern, 4a is a red (R) light emitting layer, 4b is a green (G) light emitting layer, 4c is Each of the blue (B) organic light emitting layers (that is, the first organic layer), 5 is an external extraction terminal for a drive circuit, 6 is an external extraction terminal for an upper electrode, 7 is a heat-resistant transparent cover film, and 8 is transparent. An anode electrode made of a conductive film, 9 is a hole transport layer, 10 is a conductive adhesive, and 11 is a sealing material.
[0017]
The main substrate 1 is formed of an insulating plate such as a glass substrate, and has a drive circuit such as a thin film transistor (hereinafter abbreviated as TFT) and wiring on the surface thereof. TFTs include an amorphous silicon TFT and a low-temperature polysilicon TFT. The pixel separation bank 3 is provided between the patterns of the cathode electrode 2 and separates between adjacent pixels. The red light emitting layer 4a, the green light emitting layer 4b, and the blue light emitting layer 4c have a single layer structure or a multilayer structure depending on the material system. The drive circuit external lead-out terminal 5 is used for externally controlling the drive circuit on the main substrate 1. The cover film 7 is a transparent film material and has heat resistance enough to withstand the formation of the anode electrode 8 made of a transparent conductive film by a sputtering method or the like. Further, the cover film 7 and the anode electrode 8 have high light transmittance in the visible light region.
[0018]
The hole transport layer 9 is formed on the anode electrode 8 on the cover film 7, and then the main substrate 1 and the hole transport layer 9 are brought into contact with the light emitting layers 4 of each color and the pixel separation bank 3 on the main substrate 1. Are closely overlapped and fixed by the sealing material 11.
At this time, the upper electrode external extraction terminal 6 and the anode electrode 8 are connected via the conductive adhesive 10, and the anode electrode 8 can be controlled from the outside. In addition, the drive circuit external extraction terminal 5, the anode electrode 8, and the hole transport layer 9 are kept insulated by the outermost wide pattern 3a of the pixel separating bank 3 made of an insulator. Thus, the light emission of each color generated in the light emitting layer 4 is not affected by the drive circuit and the like provided on the main substrate 1 and remains at a high aperture ratio through the anode electrode 8 and the cover film 7 having a high transmittance of visible light. Can be effectively taken out. The cathode electrode 2, the light emitting layer 4, the hole transport layer 9, and the anode electrode 8 contribute to light emission. In the present invention, these are collectively referred to as a light emitting element.
[0019]
2 (a), 2 (b), 2 (c) and 2 (d) are main parts schematically illustrating a series of manufacturing steps of a method of manufacturing a main substrate in the first embodiment of the organic light emitting display device according to the present invention. It is sectional drawing. 3 (a) and 3 (b) are cross-sectional views of main parts schematically illustrating a series of manufacturing steps of a manufacturing method of a cover film, and FIG. 3 (c) shows a main substrate manufactured in FIG. 2 and FIG. 3 (a). It is principal part sectional drawing which shows the state which bonded the cover film manufactured in (b).
[0020]
In this embodiment, first, as shown in FIG. 2A, a cathode electrode 2 is provided on a substrate 1 having a driving circuit such as a TFT, and a driving circuit such as a TFT is provided on a part of the outer periphery of the main substrate 1 from outside. A drive circuit external lead-out terminal 5 and an upper electrode external terminal 6 for control are formed. In this embodiment, a glass substrate (# 1737, manufactured by Corning) having a thickness of 0.7 mm was used as the main substrate 1. Further, in this embodiment, since the display area of the image composed of the light emitting layer is formed in a nominal 15.2 inch size with an aspect ratio of 3: 4, the size of the main substrate is about each side of the light emitting layer forming area which is the display area. The size was increased by 25 mm to 358 mm × 280 mm. The cathode electrode 2 is preferably made of a metal material having high conductivity, such as Cr, Mo-Ta, Ta, or Al.
[0021]
Similarly, a material having high conductivity is preferable for the external lead-out terminal 5 for the drive circuit and the external lead-out terminal 6 for the upper electrode. In this embodiment, the cathode electrode 2, the drive circuit external extraction terminal 5, and the upper electrode external extraction terminal 6 were formed to a film thickness of 100 nm, respectively, after being coated with Al by sputtering and then exposed and developed. The surface of the cathode electrode 2 is preferably smoother.
[0022]
Next, as shown in FIG. 2 (b), a pattern 3a for the outermost periphery of the pixel separating bank is formed between the pattern of the cathode electrode 2 and the vicinity of the pixel extracting bank 3 and the driving circuit external lead-out terminal 5. As a forming method, there are a method of performing patterning by exposing and developing after coating the entire surface with an insulating material, and a method of performing direct patterning such as a printing method. As the material, a photosensitive material is used for the former, and a thermosetting polyimide paste, maleimide varnish, polyamide paste, or the like is used for the latter. Both may have low hygroscopicity and generate little gas.
[0023]
In the present embodiment, the display area size of one pixel (one sub-pixel in color display) is 280 μm vertically and 80 μm horizontally, and the pitch is 300 μm vertically and 100 μm horizontally. Since the pixel separating bank 3 needs to cover the area other than the display area, the dimensions thereof are 20 μm in the line width in both the vertical and horizontal directions, the horizontal line pitch is 300 μm, and the vertical line pitch is 100 μm. Further, the width of the outermost peripheral wide pattern 3a for the pixel separation bank was set to 4 mm, and the width of the outer peripheral portion of the other pixel separation bank 3 was set to 1 mm. The size of the formation region of the pixel separation bank 3 and the pixel separation bank outermost peripheral wide pattern 3a is about 312.2 mm × 232.4 mm. The display area has a nominal diagonal of about 15.2 inches, and includes 1024 × 3 pixels (for three colors of red, green, and blue) in the horizontal direction, totaling 3072 pixels, and 768 pixels in the vertical direction. Will be arranged.
[0024]
In the present embodiment, a photosensitive thermosetting polyimide manufactured by Hitachi Chemical Co., Ltd. is applied to the front surface of the main substrate 1 by a spinner, exposed and developed, and then from room temperature to 220 ° C. in a nitrogen atmosphere. The temperature was raised at a rate of 5 ° C./min, and after reaching 220 ° C., it was cured by holding for 60 minutes. By adjusting the exposure, development, and curing steps, a taper of about 45 degrees was formed on the side surface of the pixel separation bank. In order to improve the followability of the anode and the cover film of the transparent conductive film provided in a later step, it is preferable to reduce the taper as much as possible.
[0025]
In this example, a polymer-based material was used as the material of the light emitting layer as the first organic layer. As a method for forming the polymer-based light emitting layer, there are an ink jet method, a printing method, and the like. In this embodiment, the polymer light emitting layer is formed by an ink jet method. The polymer-based light emitting layer uses diluted ink for application by a wet process. Therefore, the film thickness of the light emitting layer changes immediately after application and after drying in which the solvent has evaporated. In this embodiment, the red, green, and blue light-emitting layers used were each diluted to a solid concentration of 10%, and the film thickness after drying was designed to be 0.1 μm. The film thickness in this state is 1.0 μm. For this reason, the pixel separation bank 3 has a film thickness of 1.0 μm, which is the same as that. Note that the pixel separation bank 3 was subjected to a liquid repellent treatment by performing a plasma treatment or the like, thereby preventing the pixel separation bank 3 from protruding to the surface side of the pixel separation bank. It is preferable that the difference in film thickness between the pixel separation bank 3 and the light-emitting layer be as small as possible in order to improve the followability of the anode electrode and the cover film which are disposed in a later step and are overlapped from above.
[0026]
Further, when the anode electrode 8 and the hole transport layer 9 are overlapped from above the first organic layer 4 of the main substrate 1 in a later step, the pixel separation bank is so arranged that they do not come into contact with the driving circuit external extraction terminal 5. The pattern 3 in the vicinity of the drive circuit external lead-out terminal 5 is an outermost wide pattern 3a. In this embodiment, the pixel separating bank 3 made of an insulator is used. However, an insulating material is separately provided between the anode electrode 8 and the hole transport layer 9 and the external lead-out terminal 5 for the driving circuit. Is also good.
[0027]
Next, as shown in FIG. 2C, a red light emitting layer 4a, a green light emitting layer 4b, and a blue light emitting layer 4c, which are first organic layers, are formed in the pixel separation bank. In the present embodiment, the polymer organic material was used as the light emitting layer as the first organic layer as described above, and was applied to the inside of the pixel separating bank 3 by an ink jet method. As an ink of a light emitting material that emits each color, the red light emitting layer 4a was prepared by mixing Red-F manufactured by Dow with 1, 2, 3, 4-tetramethylbenzene, and the green light emitting layer 4b was formed by Green- manufactured by Dow. K was prepared using 1,2,3,4-tetramethylbenzene, and the blue light emitting layer 4c was prepared using Blue-C manufactured by Dow with 1,3,5-trimethylbenzene.
[0028]
Next, as shown in FIG. 2D, a sealing material 11 is applied to the outer periphery of the main substrate 1. As a method of applying the sealing material 11, there are a dispenser, a screen printing method and the like. In this example, the sealing material 11 was applied using a dispenser. The sealing material 11 collapses and spreads when the main substrate 1 and the cover film 7 are overlapped. Since the transmittance of visible light is not high, it is formed so as not to cover the pixel formation region after overlapping.
[0029]
Next, as shown in FIG. 3A, an anode electrode 8 of a transparent conductive film is formed on the cover film 7. Examples of the method include a sputtering method, a vapor deposition method, and a CVD method.
The material of the anode electrode 8 is preferably a metal oxide film from the viewpoint of transparency, conductivity, and mechanical properties, and is preferably ITO (Indium Tin Oxide) or IZTO (Indium Zin Tin Oxide). In this embodiment, an anode electrode 8 made of ITO having a film thickness of 150 nm, a specific resistance of 1 Ωcm, and a transmittance in the visible light region of 99% was formed by sputtering.
[0030]
Further, the anode electrode 8 is provided at one end with an area for forming a conductive adhesive material 10 to be brought into contact with the upper electrode lead-out terminal 6 on the main substrate 1. In the present embodiment, an area for forming the conductive adhesive 10 having a width of 5 mm is provided outside the short side opposite to the outermost peripheral wide pattern 3a for pixel separation banks. When the main substrate 1 and the cover film 7 are overlapped with each other, the transparent conductive film anode electrode 8 comes into contact with the outermost peripheral portion of the pixel outermost bank wide pattern 3a and the outermost portion of the long side of the pixel isolating bank 3 with a width of 1 mm, The solid pattern was formed in a size of about 316.2 mm × 232.4 mm so as to protrude 5 mm outward from the opposite short side of the outermost peripheral pattern 3 a for pixel separation bank. It is preferable to use a material having high heat resistance and high visible light transmittance for the cover film 7. To reduce the conductivity of the anode electrode 8, a heat treatment at 300 to 350 ° C. is indispensable. In this embodiment, a transparent polyimide film having a thickness of 100 μm, heat resistance of 350 ° C., and transmittance of 99% in a visible light region was used. The size of each side was about 15 mm larger than the light emitting layer forming area (display area), and was 338 mm × 260 mm.
[0031]
Next, as shown in FIG. 3B, a hole transport layer 9 as a second organic layer and a conductive adhesive 10 are formed on the anode electrode 8. The hole transport layer was common to all colors. As a forming method, there is a method in which a front surface is coated by a spinner and then patterned by exposure and development, and a method in which a pattern is directly drawn by a roll coating method, a printing method, an ink jet method or the like. In this embodiment, when the substrate 1 and the heat-resistant film 7 are overlapped with each other by the ink jet method, the substrate 1 is brought into contact with the outermost peripheral portion of the pixel separating bank 3 including the outermost peripheral wide pattern 3a with a width of 1 mm. Then, a solid pattern of about 309.2 mm × 232.4 mm was formed in accordance with one of the short sides on the anode electrode 8.
[0032]
Further, as an ink of a hole transport material, a water colloid solution containing poly (3,4-ethylenedioxythiophene) as a conductive polymer and polystyrenesulfonic acid as a dopant (BYTORON P-CH-8000 manufactured by Bayer) is used. ) Was used. When the hole transport layer 9 as the first organic layer and the light emitting layer 4 as the second organic layer are laminated on the same substrate, the same system of solvents cannot be used in order to prevent mixing between the layers. In the example, since the light emitting layer and the hole transport layer are formed on separate substrates (main substrate 1) and cover film 7, respectively, it is possible to use the same type of solvent. In this embodiment, the hole transport layer 9 is formed. However, the present invention is not limited to the hole transport layer, but may be any organic layer made of an organic material and contributing to the improvement of the light emission characteristics.
[0033]
The conductive adhesive 10 was formed on the end of the anode electrode 8 where the hole transport layer 9 was not formed by a dispenser. Since the conductive adhesive 10 has a low light transmittance in the visible light region, when the main substrate 1 and the cover film 7 are overlapped, they are formed in an area that does not cover the light emitting layer forming area, which is a display area. Further, the conductive adhesive 10 is used to bring the upper electrode external lead-out terminal 6 on the main substrate 1 into contact with the main substrate 1 and control the same from outside when the main substrate 1 and the cover film 7 are overlapped. It is preferable that the conductive material has as high a conductivity as possible and a high adhesive force to the upper electrode external extraction terminal 6 and the cathode electrode 8. In this example, a low-temperature-fired Ag paste adhesive (manufactured by Harima Chemicals, Inc.) using nano-silver particles having an average particle diameter of 7 nm was used.
[0034]
Next, as shown in FIG. 3 (c), the light emitting layers 4a, 4b, 4c of the respective colors constituting the first organic layer formed on the main substrate 1, the pixel separating bank 3, and the outermost peripheral width of the pixel separating bank are widened. After the cover film 7 is overlaid so that the hole transport layer 9 as the second organic layer contacts the pattern 3a, the sealing material 11 is cured to fix the main substrate 1 and the cover film 7. Since the light emitting layers 4a, 4b, 4c and the hole transport layer 9 of each color are both made of an organic material, the contact is more intimate than the contact between an organic material and an inorganic material such as a metal electrode. Further, when the main substrate 1 and the cover film 7 are overlapped, the conductive adhesive 10 and the external extraction terminal 6 for the upper electrode come into contact with each other. Further, the insulation between the anode electrode 8 and the hole transport layer 9 and the external lead-out terminal 5 for the driving circuit is maintained by the outermost peripheral wide pattern 3a for the pixel separating bank.
[0035]
In this embodiment, the hole transport layer 9 is positioned and overlapped so as to contact the outer peripheral portion of the pixel separating bank 3 with a width of about 1 mm. The width of the pixel separation bank outermost peripheral wide pattern 3a is 4 mm, and the hole transport layer 9 does not protrude from above the pixel separation bank outermost peripheral wide pattern 3a to prevent contact with the drive circuit external extraction terminal 5. Was completed. Further, after the main substrate 1 and the cover film 7 are overlapped with each other in a state where the surrounding atmosphere is in a vacuum (about 1 Pa) and opened to the atmosphere, the sealing material is selectively irradiated with ultraviolet light from the cover film 7 side. And further heated at 80 ° C. for 1 hour to cure. After overlapping under low pressure, the main substrate 1 and the cover film 7 are always pressed in a direction in which the main substrate 1 and the cover film 7 are brought into close contact with each other because the sealing material is released to the atmosphere and the light emitting layers 4a, 4b, 4c of the respective colors are applied. And the hole transport layer 9 are in closer contact with each other.
[0036]
In this embodiment, the superimposition is performed by the above method, but the superposition may be performed by a laminator method or the like. The step between the pixel separating bank 3 and the light-emitting layers 4a, 4b, 4c of each color is 0.9 μm, but the cover film 7 is 100 μm. There is no visual effect.
[0037]
Next, an organic light emitting display device was manufactured by externally connecting a control system to the drive circuit external extraction terminal 5 and the upper electrode external extraction terminal 6. With the organic light emitting display device thus manufactured, an image displayed through the cover film 7 could be seen.
[0038]
[Second embodiment]
The second embodiment of the present invention is the same as the first embodiment except that an inorganic film layer is formed on a cover film. In this embodiment, an organic light emitting display is manufactured in the same manner as in the first embodiment except that an inorganic film layer is formed on a cover film.
[0039]
FIG. 4 is a schematic view showing the manufacturing process of the second embodiment of the present invention, and shows the manufacturing process after the formation of the inorganic film layer on the cover film. In FIG. 4, reference numeral 12 denotes an inorganic film layer. In this embodiment, first, the same steps as those shown in FIGS. 2A to 2D for describing the first embodiment are performed, and red and red are formed on the cathode electrode 2 in the pixel separation bank 3 on the main substrate 1. The green and blue light emitting layers 4a, 4b, 4c are formed. In this embodiment, the materials except for the inorganic film layer 12 have the same structure as that of the first embodiment.
[0040]
As shown in FIG. 4A, the inorganic film layer 12 is formed on the cover film 7. As the inorganic film layer, diamond-like carbon (hereinafter, referred to as DLC), SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ Among them, those having low permeability of moisture and oxygen and high transmittance of visible light are preferable. Examples of a method for forming the inorganic film layer 12 include a plasma CVD method, a bias sputtering method, a vapor deposition method, and an ion plating method. In this embodiment, DLC was used as the inorganic film layer.
[0041]
In the plasma CVD method, the inorganic film layer composed of DLC is applied with a high-frequency or the like in a vacuum vessel, and a heat-resistant film is fixed on a temperature-adjustable electrode substrate. In some cases, a gas to which hydrogen gas is added is used as a source gas, and carbon ions decomposed by plasma are grown on a heat-resistant film. In the bias sputtering method, a target such as graphite made of carbon is used as a target, and carbon atoms are deposited on the heat-resistant film by sputtering with a gas such as argon using an electric field or the like in a vacuum vessel to form a heat-resistant film serving as a substrate. , The ions of argon collide with carbon atoms, and are formed by the ion assist effect.
[0042]
In this embodiment, a hydrocarbon gas and a hydrogen gas are used as source gases, and a 50 nm-thick inorganic film layer 12 made of DLC is formed on the entire surface of one side of the heat-resistant film 7 by a plasma CVD method. The inorganic film layer 12 made of DLC has a low oxygen permeability, and by forming the inorganic film layer 12, the permeability of moisture and oxygen can be reduced by about 2 to 4 times as compared with the case where the inorganic film layer 12 is not formed. Thus, the effect of extending the life of the panel can be obtained by suppressing deterioration of the light emitting layer due to permeated moisture and permeated oxygen. In addition, the visible light transmittance of the inorganic film layer 12 made of DLC formed in this embodiment is 99%.
[0043]
Next, the steps shown in FIGS. 4B to 4D are performed to form an anode electrode 8 made of a transparent conductive film on the inorganic film layer 12 on the cover film 7, a hole transport layer 9 as a second organic layer, and a conductive material. After forming the adhesive 10, the light emitting layers 4 a, 4 b, and 4 c of each color of the main substrate 1 are overlapped and sealed so that the hole transport layer 9 is in close contact. 3A to 3C except that the inorganic film layer 12 is formed on the cover film 7, and a description thereof will not be repeated.
[0044]
Next, an organic light emitting display device was manufactured by externally connecting a control system to the drive circuit external extraction terminal 5 and the upper electrode external extraction terminal 6. In this organic light-emitting display device, a high-luminance image could be seen through the cover film 7. In addition, the time required to reach the half-life of light emission can be more than doubled as compared with the panel manufactured in the first embodiment.
[0045]
[Third embodiment]
In this example, an organic light-emitting display device was manufactured in the same manner as in the above-described first and second examples, except that a color filter layer was formed on a cover film.
[0046]
FIG. 5 is a schematic diagram showing the manufacturing process of the third embodiment of the present invention, and is a schematic diagram showing the manufacturing process after the formation of the color filter layer. In FIG. 5, reference numeral 13 denotes a black matrix having a light-shielding property, 14a denotes a red coloring layer, 14b denotes a green coloring layer, 14c denotes a blue coloring layer, 15 denotes relaxation of surface steps and diffusion of impurities from the coloring layer and the black matrix. This is an overcoat layer for preventing the occurrence of Reference numeral 16 denotes a color filter layer including a black matrix 13, a red coloring layer 14a, a green coloring layer 14b, and a blue coloring layer 14c.
[0047]
As described above, the color filter layer 16 is composed of the black matrix 13, the red coloring layer 14a, the green coloring layer 14b, the coloring layer of each color of the blue coloring layer 14c, and the overcoat layer 15, and the surface of the anode is formed of a transparent conductive film. In order to form 8, it is preferable that the surface has high flatness and the constituent members have high heat resistance. Examples of the method for forming the color filter layer 16 include a pigment dispersion method, a dyeing method, an electrodeposition method, a printing method, and an ink-jet method.
[0048]
The black matrix 13 may be formed by, for example, forming a chromium film on the inorganic film layer 12 on the cover film 7 by a sputtering method and then patterning the film by a photolithography method. A method in which a mixture in which a pigment is dispersed is formed on the entire surface of the inorganic film layer 12 by a spinner or a coating method, and then patterned by photolithography, or a method in which a black pigment is dispersed in a thermosetting polyimide resin or the like There is a method of forming a body by simultaneously performing film formation and patterning by screen printing or the like.
[0049]
In addition, when the coloring layers of each color of the red coloring layer 14a, the green coloring layer 14b, and the blue coloring layer 14c are formed by a printing method or an ink-jet method, the material is a coloring agent such as a dye or a pigment, and heat treatment or light irradiation. A curable colored resin composition containing a resin that is cured by applying energy is used. As the resin composition, for example, a combination of a known resin and a crosslinker described in “Patent Document 6” can be used. Specifically, the thermosetting resin includes a melamine resin, an epoxy resin, a polyimide resin, and the like. As the photocurable resin composition, a commercially available negative resist is preferably used. The overcoat layer 15 is formed by a spinner or a coater method so as to cover the black matrix and the colored layers of each color, and is made of a highly transparent material such as an epoxy resin or a polyimide resin.
[0050]
In the present embodiment, first, as in the first and second embodiments, the same steps as those shown in FIGS. 2A to 2D are performed so that the pixel separation bank 3 on the main substrate 1 is removed. Red, green, and blue light emitting layers 4a, 4b, and 4c are formed on the cathode electrode 2 of FIG. In this embodiment, the materials except for the color filter layer 16 were the same as those in the first and second embodiments.
[0051]
Next, as shown in FIG. 5A, a heat-resistant color filter layer 16 is formed on the cover film 7. In this embodiment, the inorganic film layer 12 is formed on the cover film 7, and the color filter layer 16 is formed thereon. However, although the oxygen barrier property is reduced, the inorganic film layer 12 may not be provided.
[0052]
In this embodiment, the black matrix 13 is formed by a screen printing method, and as a material thereof, black ultra-fine particles NanoTek Co3O4 manufactured by C.I. And (60% by volume). The opening, width, and pitch of the black matrix 13 were the same as those of the opposing pixel separation bank 3. However, the width of the outer peripheral pattern is 1 mm for those located on the long side and the outermost peripheral pattern 3a for pixel separation bank, and 6 mm for the opposite side of the outermost peripheral pattern 3a for pixel separation bank. It was about 309.2 mm × 232.4 mm, the same as the anode electrode 8 formed above, and was formed to a film thickness of 1 μm.
[0053]
Next, the red coloring layer 14a, the green coloring layer 14b, and the blue coloring layer 14c were formed in a thickness of 0.8 μm by sequentially arranging the respective colors in the openings of the black matrix 13 by a screen printing method. As a material of the coloring layer, a red coloring pigment (NanoTek α Fe) manufactured by C.I. ₂ O ₃ ) Is mixed at a concentration of 5% by volume, and the green coloring layer 14b is made of a polyimide resin and a green coloring pigment (NanoTek Cobalt Green CoO-TiO) manufactured by C.I. ₂ -NiO-ZnO) mixed at a concentration of 5% by volume, and the material of the blue colored layer 14c is a polyimide resin and a blue colored pigment (NanoTek Cobalt Blue Al) manufactured by C.I. ₂ O ₃ —CoO) mixed at a concentration of 5% by volume. The arrangement of each color is the same as that of the opposing light emitting layer.
By adjusting the color of these colored layers, the color purity of the light emitted from the light emitting layer can be further increased, and the color coordinates can be made closer to the three primary color assumed color coordinates of the NTSC (National Television System Committee) color TV system.
[0054]
Next, a photosensitive polyimide resin is applied over the entire surface of the inorganic film layer 12 and the cover film 7 including the red, green, and blue colored layers 14a, 14b, and 14c and the black matrix 13 by a spinner, and then exposed and developed. The overcoat layer 15 having the same dimensions as the black matrix and a film thickness of 1.0 μm was formed. Due to the overcoat layer 15, the level difference between the black matrix 13 and the red, green, and blue colored layers 14a, 14b, and 14c was reduced from 0.2 μm to 0.05 μm or less. Although the overcoat layer is formed in this embodiment, the step between the black matrix and the colored layer is small, and if there is no divergence of impurities from the colored layer and the black matrix, the overcoat layer can be omitted. Good.
[0055]
Next, the steps of FIGS. 5B to 5D are performed, and the anode electrode 8, the hole transport layer 9 as the second organic layer, and the conductive adhesive 10 are placed on the color filter layer 16 above the cover film 7. After the formation, the red, green, and blue light emitting layers 4a, 4b, and 4c, which are the first organic layers of the main substrate 1, are brought into close contact with the hole transport layer 9 to form the red, green, and blue light emitting layers 4a, 4b, and 4c. The red, green, and blue colored layers 14a, 14b, and 14c of the color filter layer 16 are overlapped and sealed so as to overlap each other. 3A to 3C except that the color filter layer 16 is formed above the cover film 7, and a description thereof will be omitted.
[0056]
Next, an organic light emitting display device was manufactured by externally connecting a control system to the drive circuit external extraction terminal 5 and the upper electrode external extraction terminal 6. In this organic light-emitting display device, a high-luminance image could be seen through the cover film 7. Further, the three primary color assumed color coordinates of the NTSC color TV system could be approached from the panels manufactured in the first and second embodiments.
[0057]
[Fourth embodiment]
In the fourth embodiment of the present invention, an organic light emitting display device was manufactured in the same manner as in the third embodiment except that a white light emitting layer was formed on the light emitting layer. The description of the same structure and steps as in the third embodiment is omitted.
[0058]
FIG. 6 is a cross-sectional view of a principal part schematically illustrating a structure of a fourth embodiment of the present invention, and shows a basic configuration of an organic light emitting display having a white light emitting layer as a first organic layer. In FIG. 6, reference numeral 17 denotes a white light emitting layer that is a first organic layer. The white light-emitting layer 17 includes a structure in which red, green, and blue light-emitting layers are laminated to obtain white light by mixing colors, and a material in which the material itself is a single layer that emits white light. In this embodiment, a red light emitting material, a green light emitting material, and a blue light emitting material used in the third embodiment are stacked to form a white light emitting layer. The device was manufactured. In this organic light-emitting display device, the light emission of the white light-emitting layer 17 is caused by the red, green, and blue colored layers 14a, 14b, and 14c of the color filter layer 16 formed on the cover film 7 side in the same manner as described with reference to FIG. , And the image was able to be seen through the cover film 7. In addition, a high-luminance image display was obtained in each color with the same color purity as that manufactured in the third embodiment.
[0059]
[Fifth embodiment]
In the fifth embodiment of the present invention, the organic light-emitting device is manufactured in the same manner as in the third to fourth embodiments except that a heat-resistant conductive color filter layer is formed instead of the color filter layer 16 described above. A display device was manufactured.
[0060]
FIG. 7 is a cross-sectional view of a principal part schematically illustrating a structure of a fifth embodiment of the present invention, and schematically illustrates a basic configuration of an organic organic light-emitting display device having a heat-resistant conductive color filter layer. 7, reference numeral 18 denotes a conductive black matrix having conductivity and light-shielding properties, 19a denotes a red conductive coloring layer, 19b denotes a green conductive coloring layer, 19c denotes a blue conductive coloring layer, and 20 denotes a conductive coloring layer. A conductive overcoat layer 21 for alleviating surface steps and preventing diffusion of impurities from the coloring layer and the black matrix, and 21 is a conductive heat-resistant color filter layer.
[0061]
The conductive heat-resistant color filter layer 21 includes the conductive black matrix 18, the conductive colored layers 19a, 19b, 19c of each color, and the conductive overcoat layer 20, and forms the transparent conductive anode 8 on the surface thereof. . Therefore, it is preferable that the conductive heat-resistant color filter layer 21 has high flatness on the surface, high heat resistance of the constituent members, and high conductivity. The conductive color filter layer 21 is formed in the order of the conductive black matrix 18 → the conductive coloring layers 19a, 19b, 19c of each color → the conductive overcoat layer 20.
[0062]
As a method for forming the conductive black matrix 18, there is a method of forming a film of chromium on the cover film 7 by a sputtering method and then patterning the film by a photolithography method. Note that a black matrix made of chromium formed by sputtering has a large reflection, and a two-layer structure of chromium and chromium oxide is used for low reflection. The material of the colored layers 19a, 19b, and 19c of each color includes a polyimide that has heat resistance and is cured by heat treatment or energy application such as light irradiation, and a coloring agent such as a dye or a pigment. A curable conductive colored resin composition containing such a resin is used. As a forming method, a film is formed on the entire surface of the black matrix for each color by a spinner or a coating method, and then unnecessary portions are patterned by a photolithography method. A method in which the same material is simultaneously formed in a predetermined black matrix opening by three colors by an ink jet method, and selectively formed in a predetermined black matrix opening by one color by a screen printing method or the like, and in the case of three colors, this is repeated. And the like.
[0063]
The conductive overcoat layer 20 is formed by a spinner or a coater method so as to cover the conductive black matrix 18 and the colored layers 19a, 19b, and 19c of all colors. As the material, a material in which conductive particles such as ITO particles are mixed into a highly transparent material such as a polyimide resin having heat resistance is used.
[0064]
The conductive black matrix 18 made of chromium has higher conductivity than the anode electrode 8 made of a transparent conductive film made of ITO or the like formed thereabove, and can be used as an auxiliary electrode when driving a pixel. Further, by making the coloring layer formed in the conductive black matrix a conductive coloring layer having conductivity, the effect of the auxiliary electrode of the conductive black matrix can be further enhanced.
[0065]
In this embodiment, the conductive black matrix 18 is formed of chromium oxide and then chromium to form a two-layer structure. The color layers of the respective colors were formed by a screen printing method using a mixture of the coloring materials of the respective colors used in the above third and fourth embodiments and ITO particles manufactured by Nanotech Co., Ltd. at a concentration of 10% by volume. Was formed. In addition, ITO particles (NanoTek In) manufactured by C-I Kasei Co., Ltd. were used for the overcoat layer material used in the third and fourth embodiments. ₂ O ₃ -SnO ₂ ) Was applied at a concentration of 10% by volume, applied over the entire surface by a spinner, and then exposed and developed to form a conductive overcoat layer 20 having the same dimensions as the black matrix and a film thickness of 1.0 μm. Except for this, the organic light emitting display was manufactured in the same manner as in the third to fourth embodiments.
[0066]
Also in the organic light emitting display according to the present embodiment, a high-luminance image could be seen through the cover film 7. Further, the same amount of light could be obtained with lower driving power than those manufactured in the third to fourth embodiments. In this embodiment, the overcoat layer 20 is formed, but the step between the conductive black matrix and the conductive coloring layer of each color is small, and the diffusion of impurities from the conductive coloring layer of each color and the black matrix is reduced. If not, the conductive overcoat layer 20 need not be formed.
[0067]
FIG. 8 is a schematic diagram showing a process of manufacturing a low-temperature polysilin thin film transistor constituting a drive circuit provided on a main substrate used in the first to fifth embodiments of the present invention. 8, reference numeral 101 denotes a glass substrate as a main substrate, 102 denotes a SiN film, 103 denotes an SiO film, 104 denotes an amorphous silicon film, 105 denotes a modified silicon film, 106 denotes a gate wiring, and 107 denotes a source / drain wiring. , 108 is an insulating film, 109 is a passivation film, and 110 is a cathode electrode.
[0068]
First, as shown in FIG. 8A, an SiN film 102 and a SiO film 103 functioning as a barrier film are thinly deposited on a glass substrate 101 by means such as CVD, and an amorphous silicon film 104 of about 50 nm is formed thereon. It is deposited to a thickness by a CVD method. It should be emphasized that the layer configuration and thickness of the barrier film, the thickness of the silicon film, and the like described herein are merely examples, and that the description does not limit the present invention.
[0069]
Next, as shown in FIG. 8B, the silicon film in a portion where a pixel circuit, that is, a pixel drive circuit is to be formed, is modified by modifying means such as an excimer laser irradiation method.
[0070]
Next, the modified silicon film 105 formed as described above is etched to form a predetermined circuit as shown in FIG. 8C, and a gate insulating film (not shown), a gate wiring 106, a source By sequentially forming the drain wiring 107, the interlayer insulating film 108, the passivation film 109, and the cathode electrode 110, a main substrate (also referred to as an active matrix substrate) having a thin film transistor circuit arranged in a pixel portion is formed. The number of thin film transistors TFT per pixel is selected from 2 to 5, and a circuit configuration optimal for driving the pixels of the organic light emitting element may be used. The details of the processing technology related to the formation of such circuits and electrodes are well known to those skilled in the art. It is also known that additional steps such as ion implantation and activation annealing are required in the middle of the process. However, the method of manufacturing the thin film transistor TFT in the organic light emitting display device of the present invention is not limited to the above embodiment, but may be a method used for a conventional liquid crystal panel or the like.
[0071]
FIG. 9 is an external view of a television receiver as an example of an electronic device equipped with the image display device of the present invention. Reference numeral DSP denotes a display unit, and STD denotes a stand unit. An image display device having any of the configurations of the above embodiments is mounted on the display unit DSP. In addition, it goes without saying that the organic light-emitting display device of the present invention can be mounted on a monitor of a personal computer or various information processing devices, and a high-brightness image display with a high aperture ratio can be obtained.
[0072]
【The invention's effect】
As described above, according to the present invention, the first organic layer constituting the light emitting layer of a plurality of colors (red, green, blue) having low heat resistance and the transparent conductive anode electrode having a high forming temperature are separately provided. Is formed on a substrate (a main substrate such as a glass plate and a transparent cover film having heat resistance) and then superposed on each other, so that a high temperature is formed on the light emitting layer which is the first organic layer having low heat resistance. It is possible to provide a transparent conductive anode electrode. Further, by forming an organic layer (second organic layer) having a function of improving luminous efficiency on the transparent conductive anode electrode and then superimposing the organic layer on the RGB light emitting layer constituting the first organic layer, the organic substances can be separated from each other. The connection enables more precise connection. As a result, the light generated in the light emitting layer through the anode electrode of the transparent conductive film having a high transmittance in the visible light region and the heat-resistant transparent cover film is reduced with little attenuation, and is not affected by the shielding of the drive circuit on the main substrate. An organic light-emitting display device capable of taking out light at a high aperture ratio can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a principal part schematically illustrating a configuration of a first embodiment of an organic light emitting display device according to the present invention.
FIG. 2 is a cross-sectional view of a main part schematically illustrating a series of manufacturing steps of a method of manufacturing a main substrate in the first embodiment of the organic light emitting display device according to the present invention.
FIG. 3 is a cross-sectional view of a main part showing a series of manufacturing steps of a method of manufacturing a cover film in a first embodiment of the organic light-emitting display device according to the present invention and a state where a main substrate is bonded.
FIG. 4 is a schematic view showing a manufacturing process of a second embodiment of the organic light emitting display device according to the present invention.
FIG. 5 is a schematic view showing a manufacturing process of a third embodiment of the organic light emitting display according to the present invention.
FIG. 6 is a sectional view of a main part schematically illustrating the structure of a fourth embodiment of the present invention.
FIG. 7 is a sectional view of a main part schematically illustrating the structure of a fifth embodiment of the present invention.
FIG. 8 is a schematic diagram showing a manufacturing process of a low-temperature polysilin thin film transistor constituting a drive circuit provided on a main substrate used in the first to fifth embodiments of the present invention.
FIG. 9 is an external view of a television receiver as an example of an electronic apparatus equipped with the image display device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Insulating substrate (main substrate), 2 ... Cathode electrode, 3 ... Bank for pixel separation, 3a ... Widest pattern of outermost peripheral pattern for bank for pixel separation, 4 ... Light emitting layer (first organic) Layer), 5 ... External extraction terminal for drive circuit, 6 ... External extraction terminal for upper electrode, 7 ... Heat-resistant and transparent cover film, 8 ... Anode electrode made of transparent conductive film, 9 ... Hole transport layer (second organic layer), 10 ... conductive adhesive, 11 ... sealing material, 12 ... inorganic film layer, 13 ... black matrix, 14a ... red Coloring layer, 14b Green coloring layer, 14c Blue coloring layer, 15 Overcoat layer, 16 Color filter layer, 17 White light emitting layer, 18 Conductive black Matrix, 19a ... red conductive coloring layer, 19b: green conductive colored layer, 19c: blue conductive colored layer, 20: conductive overcoat layer, 21: conductive color filter layer, 101: glass substrate, 102 ... -SiN film, 103 ... SiO film, 104 ... amorphous silicon film, 105 ... modified silicon film, 106 ... gate wiring, 107 ... source / drain wiring, 108 ... Insulating film, 109 ... passivation film, 110 ... cathode electrode.

Claims (14)

An organic light-emitting display device having a plurality of pixels formed of a light-emitting element including a cathode electrode, an organic light-emitting layer, and an anode electrode in a display region on an insulating substrate,
The cathode electrode is formed for each of the plurality of pixels,
Having a plurality of pixel separation banks between adjacent pixels;
A first organic layer forming a light emitting layer of the light emitting element is formed between the pixel separating banks;
A cover film formed on the inner surface of the anode electrode and disposed over an upper layer of the first organic layer;
An organic light emitting display device comprising a second organic layer on the anode electrode formed on the cover film, the second organic layer being in close contact with the first organic layer and improving the luminous efficiency of the first organic layer. . The OLED display of claim 1, wherein the cover film and the anode have a high light transmittance in a visible light region. The organic light emitting display device according to claim 1, wherein the cover film has heat resistance enough to withstand the formation of the anode electrode. The organic light emitting display device according to claim 1, further comprising an inorganic film layer having low moisture and oxygen permeability between the cover film and the anode electrode. The organic light emitting display device according to claim 4, wherein the inorganic film layer is a diamond-like carbon layer. The organic light emitting display device according to claim 1, wherein light emission wavelengths of the light emitting elements constituting a plurality of pixels adjacent to the plurality of pixels are different. The organic light emitting display device according to claim 6, wherein the cover film includes a color filter layer for transmitting the emission wavelength of each of the plurality of adjacent pixels for each of the plurality of pixels. The organic light emitting display device according to claim 7, wherein the color filter layer is provided between the anode electrode and the cover film. The OLED display of claim 6, wherein the plurality of adjacent pixels are red, green, and blue. A method for manufacturing an organic light-emitting display device, in which a plurality of pixels including a light-emitting element including a cathode electrode, an organic light-emitting layer, and an anode electrode are formed in a display region on an insulating substrate,
The manufacturing method comprises a main substrate forming step, a cover film forming step, and a main substrate / cover film integrating step of bonding a cover film to the main substrate,
The main substrate forming step,
A main substrate forming first step of forming a cathode electrode on the insulating substrate;
A main substrate forming second step of forming a pixel separation bank for exposing the cathode electrode for each of the plurality of pixels between adjacent pixels of the insulating substrate on which the cathode electrode is formed;
A third main substrate forming step of forming a first organic layer having at least a light emitting layer on the cathode exposed between the pixel separation banks,
The cover film forming step,
A cover film forming first step of forming an anode electrode made of a transparent conductive film on the heat-resistant transparent film;
A cover film forming second step of forming a second organic layer on the anode electrode to improve the luminous efficiency of the first organic layer,
The main substrate / cover film integration step,
An organic light-emitting display device comprising a bonding step of adhering the second organic layer of the cover film after the cover film forming step to the first organic layer of the main substrate after the main substrate forming step. Manufacturing method. The method according to claim 10, further comprising a step of forming a diamond-like carbon layer before the first step of forming the cover film in the cover film forming step. 12. The organic light emitting display device according to claim 10, wherein an emission wavelength of the first organic layer formed in the plurality of adjacent pixels uses an organic material different for the plurality of adjacent pixels. Method. Forming a color filter corresponding to an emission wavelength of the first organic layer formed on the plurality of pixels before the first cover film forming step of the cover film forming step. Item 13. A method for manufacturing an organic light emitting display device according to item 12. 14. The method according to claim 12, wherein light emission wavelengths of different organic materials correspond to red, green, and blue in a plurality of pixels adjacent to the first organic layer.

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