JP2013077502A - Application device, application method, and method of manufacturing organic functional element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a high material use efficiency and a uniform applied film in a pixel formation region even when a high-speed operation is performed in an application device that continuously forms an applied film on a substrate by relatively reciprocatingly moving a stage for disposing a base material thereon and a nozzle for discharging a liquid column-shaped ink.SOLUTION: An application device includes: a stage for disposing a base material thereon; a nozzle for continuously discharging a liquid column-shaped ink on the base material; and a movement mechanism that permits a relative movement of the stage and the nozzle by moving at least one of the stage and the nozzle in a plane direction of the base material. A discharge flow of the ink discharged from the nozzle is controlled on the basis of information of a relative movement speed of the base material with respect to the nozzle.

Description

  The present invention relates to an application apparatus and method for forming a coating film on a substrate by applying liquid columnar ink using a nozzle. More specifically, the present invention relates to an application apparatus and method for forming a coating film on a substrate by applying ink using a liquid columnar organic EL material using a nozzle.

  Organic EL (Electro-Luminescence) panels display by self-emission, which eliminates the need for a backlight like a liquid crystal display, and has features such as high contrast, wide viewing angle, high-speed response, and low power consumption. It is expected to be a generation panel and is being put to practical use. Conventionally, a vacuum deposition method using a metal mask has been used to fabricate an organic EL element substrate. However, regarding the enlargement of an organic EL panel, for example, color unevenness due to metal mask deformation due to pressure or heat occurs. There is a problem that a large-scale vacuum vapor deposition facility is required, or a problem that material utilization efficiency is poor.

  In order to solve the above problems, for example, the production of an organic EL element substrate by an ink jet method has been studied. The ink jet method can discharge a minute amount of ink to a desired position according to the resolution of the head to be used, so that it is easy to form a fine pattern or a thin film having a desired film thickness. It has the feature. Taking advantage of this feature, the inkjet method is used for manufacturing organic EL elements and color filters that require fine coating.

  When these ink jet methods are applied to the manufacture of organic EL elements, the required amount of EL material can be dispersed or dissolved in a predetermined solvent to form an ink, so that different colors can be applied. There is an advantage that the utilization efficiency of the EL material can be improved as compared with the vapor deposition method. However, in the ink jet method, since the ink jet nozzle port is in contact with the atmosphere, the nozzle surface is likely to dry, and nozzle clogging may occur. In order to avoid this nozzle clogging, the ink solvent is limited to those having a relatively high boiling point, but the high boiling point solvent tends to remain on the panel and often affects the light emission characteristics of the organic EL.

  Therefore, in recent years, in order to solve these problems, a coating apparatus that discharges liquid columnar ink continuously from a nozzle having a fine discharge port and a coating method using the coating apparatus have been proposed. 1 is described. Since this coating apparatus can also use a low boiling point solvent as an ink solvent, there is an advantage that the light emitting characteristics of the organic EL are less affected. When applying using such an apparatus, the substrate is formed by continuously applying the stage on which the substrate is placed and the nozzle that ejects ink onto the substrate while reciprocally moving relative to each other. A coating film serving as pixels can be uniformly formed in the region.

  Since the relative speed between the stage and the nozzle performs a reciprocating operation, deceleration, stop, acceleration, and steady state are repeated in order from a steady constant speed state. In order to form a uniform coating film in the pixel formation region, the ink ejected from the nozzle needs to move at a constant speed in the pixel formation region, and perform deceleration, stop, and acceleration operations outside the pixel formation region. When the discharge amount per unit time increases, the pixel film thickness increases, and when the discharge amount per unit time decreases, the pixel film thickness decreases. In this coating apparatus, in order to obtain a uniform film thickness in the pixel formation region, it is necessary to perform ejection to the pixel formation region during constant speed movement, and during high speed operation, a large amount of ink is ejected outside the pixel formation region. Therefore, there is a problem that the material utilization efficiency is low.

JP 2002-75640 A

  An object of the present invention has been made in view of the above-described circumstances, and continuously coats a film on a substrate while relatively reciprocally moving a stage on which a base material is installed and a nozzle for discharging liquid columnar ink. In a coating apparatus (so-called nozzle coating apparatus) for forming a film, a coating apparatus having a high material utilization efficiency and a uniform coating film in a pixel forming region even when a high-speed operation is performed, a coating method using the coating apparatus, and a coating apparatus therefor It aims at providing the manufacturing method of the used organic functional element.

  The present invention has been made to solve the above problems, and the first invention includes a stage on which a substrate is installed, a nozzle that continuously discharges liquid columnar ink on the substrate, the stage, and the stage. And a moving mechanism that is movable relative to each other by moving at least one of the nozzles in the surface direction of the base material, and a relative movement speed of the base material with respect to the nozzle. An application apparatus that controls the discharge flow rate of ink discharged from the nozzles based on information.

  According to a second invention, in the first invention, the relative movement between the stage and the nozzle is a reciprocating operation, and the discharge flow rate decreases when the relative movement speed is decelerated from a steady state, In the coating apparatus, the discharge flow rate increases when the relative movement speed is accelerated to a steady state.

  A third invention is the coating apparatus according to the first or second invention, wherein the information on the relative movement speed is an acceleration characteristic and a deceleration characteristic of the relative movement speed measured in advance.

  A fourth invention is the coating apparatus according to any one of the first to third inventions, wherein the discharge flow rate is controlled using an ink flow rate control valve.

  According to a fifth invention, in any one of the first to fourth inventions, when the relative movement speed is zero in the reciprocating operation, the discharge flow rate is a steady state of the relative soot movement speed. It is a coating apparatus characterized by being less than zero and not zero.

  6th invention is the coating method which apply | coats an ink to the said base material using the coating device of any one invention from 1st to 5th, Comprising: The said base material is made into many area | regions on the said base material A partition wall is formed, and a region of relative acceleration and relative deceleration of the substrate with respect to the nozzle is provided while ink is ejected to each of the regions partitioned by the partition wall, and the substrate with respect to the nozzle is provided. The coating method is characterized in that the discharge flow rate of the ink discharged from the nozzle is controlled based on the information on the relative movement speed.

  7th invention is a manufacturing method of the organic functional element which forms a some organic functional layer on a board | substrate, Comprising: Said 1st to 5th as said base material with the coating device of any one invention from 5th A method for producing an organic functional element, comprising forming the organic functional layer using an ink applied on a substrate. A method for producing an organic functional element, comprising forming an organic functional layer.

  According to the present invention, in a so-called nozzle coating apparatus that continuously forms a coating film on a substrate while relatively reciprocating a stage on which a substrate is installed and a nozzle that ejects liquid columnar ink, a high-speed operation is performed. Even if it goes, it can be set as the coating device with high material utilization efficiency and the uniform coating film of a pixel formation area.

The embodiment of the present invention is a schematic diagram of a cross section of an organic EL element substrate The schematic diagram of the device which shows the embodiment of the present invention and uses the nozzle coating method The embodiment of the present invention is shown, and a detailed view of a nozzle cross section 4 shows an embodiment of the present invention, and shows the pixel formation area and acceleration / deceleration when the discharge flow rate of the nozzle is constant with respect to the relationship between the relative speed between the stage and the nozzle and the amount of ink discharged from the nozzle. Figure The figure which shows embodiment of this invention and showed adjusting the discharge amount of the ink discharged from a nozzle based on the information of the relative moving speed of the base material with respect to a nozzle FIG. 4, showing an embodiment of the present invention, shows that the relative velocity between the nozzle and the base material changes in the pixel formation region. FIG. 4 shows an embodiment of the present invention, and the amount of ink discharged from the nozzle was adjusted based on information on the relative movement speed of the base material with respect to the nozzle, but the ink lower limit discharge region was not provided. Figure

  Preferred embodiments of the present invention will be described below with reference to the drawings. In the present invention, an organic EL element substrate is manufactured using a nozzle coating apparatus, but the present invention is not limited to the organic EL, and as an optical component constituting the display screen of other display displays. It can be suitably used. In this case, a large number of the regions correspond to pixels constituting the display screen. As optical components other than organic EL, color filters, circuit boards, thin film transistors, microlenses, biochips, and the like can be manufactured.

  Hereinafter, the pattern forming body of the hole injection layer, the hole transport layer, and the organic light emitting layer included in the organic EL element is collectively referred to as a functional layer, and this functional layer is formed using the coating apparatus according to the above embodiment. This will be described with reference to FIG.

(Preparation of substrate)
The organic EL element is formed on a substrate (base material). A translucent substrate 1 is preferably used as the substrate. As the translucent substrate 1, a glass substrate or a plastic film or sheet can be used. When a plastic film is used, a polymer EL element can be produced by winding, and a display panel can be provided at a low cost. Examples of the plastic film that can be used include polyethylene terephthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, and polycarbonate. These films are made of a metal oxide such as silicon oxide having water vapor barrier property and oxygen barrier property, oxynitride such as silicon nitride, polyvinylidene chloride, polyvinyl chloride, saponified ethylene-vinyl acetate copolymer. It is preferable to provide a barrier layer as necessary.

(Production of pixel electrode)
A pixel electrode 2 patterned as an anode is provided on the translucent substrate 1. As the material of the pixel electrode 2, transparent electrode materials such as ITO (indium tin composite oxide), IZO (indium zinc composite oxide), tin oxide, zinc oxide, indium oxide, and aluminum oxide composite oxide can be used. It is preferable to use ITO because of its low resistance, solvent resistance and transparency. ITO is formed on the translucent substrate 1 by a sputtering method, and is patterned by a photolithography method to form a line-shaped pixel electrode 2.

(Production of partition walls)
After the line-shaped pixel electrode 2 is formed, the partition wall 3 is formed by a photolithography method using a photosensitive material between the adjacent pixel electrodes 2. On the substrate and the inspection substrate, there are provided matrix-like or stripe-like partition walls 3 for dividing the substrate and the inspection substrate into a large number of regions. A region surrounded by the partition walls 3, that is, each region divided by the partition walls 3, becomes a discharge region in which a film made of ink for nozzle application is formed. The photosensitive material for forming the partition wall 3 may be either a positive type resist or a negative type resist, but it must have insulating properties. If the partition 3 does not have sufficient insulation, a current flows to the adjacent pixel electrode 2 through the partition 3 and a display defect occurs. Specific examples include polyimide, acrylic resin, novolac resin, and fluorene, but the present invention is not limited thereto. Further, for the purpose of improving the display quality of the organic EL element, a light shielding material may be included in the photosensitive material. Further, by adding an appropriate amount of an ink repellent agent such as a fluorine-containing compound or a silicon-containing compound to the partition wall material, an appropriate ink repellency can be provided.

  As for the partition 3 in this invention, it is desirable that the thickness exists in the range of 0.5 micrometer-5.0 micrometers. By providing the partition wall 3 between the adjacent pixel electrodes 2, it is possible to suppress the spread of the hole transport ink printed on each pixel electrode 2 and to prevent the occurrence of a short circuit from the edge of the transparent conductive film. Note that if the partition wall 3 is too low, the effect of preventing a short circuit may not be obtained.

(Adjustment of hole injection layer ink)
The ink adjustment for forming the hole injection layer 4 will be described. The hole injection layer 4 to be formed preferably has a volume resistance efficiency of 1 × 10 ⁶ Ω · cm or less from the viewpoint of light emission efficiency. Hole injection materials include metal phthalocyanines such as copper phthalocyanine and tetra (t-butyl) copper phthalocyanine, metal-free phthalocyanines, quinacridone compounds, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N , N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine, N, N′-di (1-naphthyl) -N, N′- Aromatic amine low molecular hole injection / transport materials such as diphenyl-1,1′-biphenyl-4,4′-diamine, polymer hole injection materials such as poly (p-phenylene vinylene) and polyaniline, polythiophene oligomers The material can be selected from other known hole injection materials.
Examples of the solvent for dissolving or dispersing the hole injection material include halogen solvents such as chloroform, dichloromethane, dichloroethane, trichloroethylene, ethylene chloride, tetrachloroethane, and chlorobenzene, N-methyl-2-pyrrolidone (NMP), and dimethyl. Polar solvents such as aprotic polar solvents such as formamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), and alkoxy alcohols such as propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether Etc.

(Preparation of hole transport layer ink)
The ink adjustment for forming the hole transport layer 5 will be described. Examples of the hole transporting substance include poly (N-vinylcarbazole) (hereinafter also referred to as PVK), poly (para-phenylene vinylene), carbazole biphenyl (hereinafter also referred to as CBP), and N, N′-diphenyl. -N, N'-bis (1-naphthyl) -1,1'-biphenyl-4,4'-diamine (hereinafter also referred to as NPD), N, N'-diphenyl-N, N'-bis (3- Methylphenyl) -1,1′-biphenyl-4,4′-diamine (hereinafter also referred to as TPD), 4,4′-bis (10-phenothiazinyl) biphenyl, 2,4,6-triphenyl-1 , 3,5-triazole, a polyfluorene derivative, a copolymer of triphenylamine and fluorene, and the like. Examples of the solvent for the functional ink that forms the hole transport layer 5 include cyclone, tetralin, cumene, decalin, durene, cyclohexylbenzene, dihexylbenzene, tetramethylbenzene, and dibutylbenzene.

(Preparation of organic light emitting layer ink)
The ink adjustment for forming the organic light emitting layer 6 will be described. The organic light emitting layer 6 is a layer that emits light by passing an electric current, and the organic light emitting material forming the organic light emitting layer 6 is, for example, a coumarin type, a perylene type, a pyran type, an anthrone type, a porphyrene type, a quinacridone type, N, N'-dialkyl-substituted quinacridone-based, naphthalimide-based, N, N'-diaryl-substituted pyrrolopyrrole-based, iridium complex-based luminescent dyes dispersed in polymers such as polystyrene, polymethylmethacrylate, polyvinylcarbazole, etc. And polyarylene-based, polyarylene vinylene-based, and polyfluorene-based polymer materials. Examples of the solvent for the functional ink that forms the organic light emitting layer 6 include siemen, tetralin, cumene, decalin, durene, cyclohexylbenzene, dihexylbenzene, tetramethylbenzene, and dibutylbenzene.

(Formation of hole injection layer)
A functional ink containing a hole injecting material is ejected onto the substrate 1 on which the partition walls 3 baked as described above are formed by a nozzle coating method, which will be described later, to form the hole injecting layer 4.

(Formation of hole transport layer)
After the hole injection layer 4 is formed, the hole transport layer 5 is formed by discharging functional ink containing a hole transport material by a nozzle coating method described later.

(Formation of organic light emitting layer)
After the hole transport layer 5 is formed, a functional ink containing an organic light emitting material is ejected by a nozzle coating method described later to form the organic light emitting layer 6.

(Formation of cathode layer)
After the organic light emitting layer 6 is formed, the cathode layer 7 is formed in a line pattern orthogonal to the line pattern of the pixel electrode 2. As the material of the cathode layer 7, materials corresponding to the light emission characteristics of the organic light emitting layer 6 can be used. For example, simple metals such as lithium, magnesium, calcium, ytterbium, and aluminum, and stable metals such as gold and silver can be used. And alloys thereof. Alternatively, a conductive oxide such as indium, zinc, or tin can be used. Examples of the method for forming the cathode layer 7 include a formation method by a vacuum vapor deposition method using a mask.

(Description of sealing process)
Finally, in order to protect these organic EL constituents from external oxygen and moisture, an organic EL display panel can be obtained by hermetically sealing with a glass cap 8 and an adhesive 9. As a sealing method, any method may be used as long as the organic EL component can be protected from external oxygen and moisture. Moreover, when the translucent board | substrate 1 has flexibility, you may seal using a sealing agent and a flexible film.

  The organic EL device of the present invention has a structure in which a hole injection layer, a hole transport layer, and an organic light emitting layer are laminated from the anode layer side between a pixel electrode that is an anode and a cathode layer. In addition to the hole transport layer and the organic light emitting layer, a layered structure in which a layer such as a hole block layer, an electron transport layer, and an electron injection layer is selected as needed can be formed between the cathode layer and the cathode layer. Moreover, when forming these layers, the formation method similar to a light emitting layer can be used.

(Configuration of nozzle coating device)
Hereinafter, an example of the configuration of the nozzle coating apparatus used to form the hole injection layer 4, the hole transport layer 5, and the organic light emitting layer 6 will be described with reference to FIG. 2, but the present invention is not limited to this. Absent.
In FIG. 2, the ink 11 filled in the ink supply tank 10 is supplied to the nozzle head 13 through the inside of the ink supply tube 12. When the ink 11 is supplied to the nozzle head 13, the ink 11 can be supplied from the ink supply tank 10 to the nozzle head 13 by pressurizing the inside of the ink supply tank 10 with the pressurizer 14. Between the ink supply tank 10 and the nozzle head 13, there are a flow rate control valve 15 for controlling the discharge amount of the ink 11 and a flow meter 16 for measuring the flow rate of the ink 11 supplied to the nozzle head 13. Therefore, the flow control valve 15 can be adjusted based on information from the flow meter 16 (that is, ink flow rate). Thus, since the ink flow rate can be adjusted, a stable desired ink flow rate can be obtained.

  Next, the ink 11 supplied from the ejection port of the nozzle head 13 is ejected, and the movable stage 19 placed on the table 17 is defined in the surface direction of the translucent substrate 18 (direction parallel to the surface). By moving in the Y direction or the Y ′ direction that is the reverse direction of the Y direction (or the X direction orthogonal to the Y direction defined in the plane direction or the X ′ direction that is the reverse direction of the X direction) Then, a coating film is continuously formed on the translucent substrate 18 disposed on the movable stage 19. For example, the translucent substrate 18 having a stripe-shaped pixel formation region parallel to the X direction is disposed on the movable stage 19, and the movable stage 19 and the nozzle head 13 are relatively moved in the X direction. At this time, the movement of the movable stage 19 and the nozzle head 13 is synchronized by the positional information of the movable stage 19 and the nozzle head 13, and the stripe-shaped R (Red), G (Green), or B (Blue) pixel. The ink 11 is continuously applied to the formation region to form a coating film to be a pixel. Then, after a coating film is formed on one stripe-shaped R, G, or B pixel formation region, the movable stage 19 and the nozzle head 13 are relatively moved in the Y direction, and the coating film is formed on the next pixel formation region. Form. In moving the movable stage 19 and the nozzle head 13 relative to each other in the X direction or the X ′ direction and the Y direction or the Y ′ direction, at least one of the movable stage 19 and the nozzle head 13 is subjected to nozzle application. What is necessary is just to actually move with respect to the table 17 as a position reference | standard of an apparatus.

Next, the nozzle head 13 will be described using the nozzle head cross-sectional view of FIG.
The ink 20 enters a cylindrical or rectangular parallelepiped case 22 made of SUS or the like from the ink supply tube 21. The case is generally a metal, but any case may be used as long as it has ink resistance. The inside of the case is a manifold, and the liquid column 25 is discharged from the nozzle 23 having a minute hole having a diameter of about 5 to 20 microns to the translucent substrate 24. The nozzle 23 is generally a film made of polyimide or the like, but any nozzle can be used as long as the hole can be accurately formed.

  The ink 20 ejected from the nozzles 23 is preferably continuously ejected in consideration of nozzle clogging and flight bending due to ink drying. For this reason, a portion that is not desired to be ejected may be masked or a dummy pattern may be provided, but any method may be used as long as there is no problem as a panel.

The relative speed between the substrate and the nozzle 23 and the amount of ink discharged from the nozzle 23 (= discharge flow rate) will be described with reference to FIG. Since the relative speed between the base material and the nozzle 23 is reciprocated, the deceleration B, the stop C, the acceleration D, and the steady state A are repeated in order from the steady constant speed state A.
The ink 20 ejected from the nozzles 23 feeds back the flow meter information to the flow control valve and continues to eject a uniform amount. As the discharge amount per unit time, that is, the discharge flow rate increases, the pixel film thickness increases. In order to form a uniform coating film in the pixel formation region P, it is necessary to perform the pixel formation region in the constant speed state A and perform deceleration B, stop C, and acceleration operation D outside the pixel formation region Q. Therefore, when the relative speed operates at a high speed, the ink 20 is often ejected outside the pixel formation region, resulting in a low material utilization efficiency.

  Therefore, the ejection amount (= ejection flow rate) of the ink 20 ejected from the nozzle 23 is adjusted based on the information on the relative movement speed of the base material with respect to the nozzle 23 as shown in FIG. Specifically, when the relative movement speed is decelerated from the steady state, the discharge amount is decreased in accordance with the deceleration, and when the relative movement speed is accelerated to the steady state, the discharge amount is increased in accordance with the acceleration. . However, the nozzle 23 in this nozzle coating apparatus can perform stable discharge even when a low boiling point solvent is used by performing continuous discharge. Accordingly, when the relative movement speed is zero, if the discharge amount is also zero, it becomes impossible to discharge again. Therefore, it is possible to stably discharge by providing the lower limit flow rate region R so as not to be below a certain flow rate. it can. By controlling the ink discharge flow rate from the nozzle 23 based on the acceleration characteristic and the deceleration characteristic of the relative movement speed until the lower limit flow rate, the pixel formation region P ′ becomes significantly wider than the conventional pixel formation region P. Since the outside Q ′ of the pixel formation region is also significantly narrowed, a panel with a larger size can be manufactured with the same apparatus. As the acceleration characteristic and the deceleration characteristic, those measured in advance can be used.

  In this specification, the hole injection layer, the hole transport layer, and the organic light emitting layer are formed by the nozzle coating method, but it is not necessary to use the nozzle coating method for all the layers.

Next, examples of the present invention will be described.
An ITO (indium-tin oxide) thin film is formed on a 3 inch diagonal glass substrate by sputtering, and the ITO film is patterned by photolithography and etching with an acid solution. Formed. The line pattern of the pixel electrode 2 is a pattern in which a line width is 70 μm, a space is 60 μm, and a line is formed in about 590 mm within about 7.6 mm square.

  Next, an insulating layer was formed as follows. First, a polyimide resist material was spin coated on the entire surface of the glass substrate on which the pixel electrode 2 was formed. The spin coating condition was rotated at 150 rpm for 5 seconds, and then rotated at 500 rpm for 20 seconds to form a single coating. The height of the insulating layer was 2.5 μm. A partition wall 3, which is an insulating layer having a stripe pattern, is formed between the pixel electrodes 2 by photolithography on the photoresist material applied to the entire surface. This partition 3 has ink repellency.

  Next, as a hole injection ink, a mixture of polymer hole injection materials such as poly (p-phenylene vinylene) and polyaniline is prepared using propylene glycol monobutyl ether, and the ink has a solid content concentration of 3.0% and a viscosity. An ink of 10 mPa · s was prepared.

The prepared hole injection ink was placed in the ink supply tank 10. The hole injection ink in the ink supply tank 10 is supplied to the nozzle head 13 through the ink supply tube 12 by pressurizing the ink supply tank 10. Between the ink supply tank 10 and the nozzle 23, a flow rate control valve 15 for controlling the amount of ink 20 to be discharged and a flow meter 16 for measuring the flow rate of ink flowing through the nozzle head 13 are provided. Based on the above information, it is possible to obtain a stable desired ink flow rate by feeding back to the flow rate control valve 15 and adjusting the flow rate.
The positions of the nozzle head 13 and the table 17 are relatively fixed, and the translucent substrate 24 having the stripe pattern partition wall 3 imparted with the ink repellency is fixed to the movable stage 19. The movable stage 19 can move on the table 17 in the vertical Y direction or Y ′ direction. In addition, the nozzle head 13 can move in the X direction or the X ′ direction in the lateral direction orthogonal to the Y direction or the Y ′ direction. By moving the movable stage 19 and the nozzle 23 or the nozzle unit relative to each other, it is possible to continuously form a coating film serving as a pixel in the pixel formation region of the base material on the stage.
The ink 11 enters a rectangular parallelepiped nozzle head 13 made of stainless steel from an ink supply tube 12. The inside of the nozzle head 13 is a manifold, and can be discharged in the vertical direction from the polyimide film nozzle 23 having a small hole having a diameter of 10 microns to the translucent substrate 18.

  The ink 20 ejected from the nozzles 23 feeds back information from the flow meter 16 to the flow control valve 15 and continues to eject a uniform amount. Based on the information on the relative movement speed of the base material with respect to the nozzle 23, when the relative speed of the discharge amount of the ink 20 discharged from the nozzle 23 is decreased, the discharge amount is also decreased in accordance with the deceleration. The ink discharge flow rate from the nozzle 23 was controlled based on the acceleration and deceleration characteristics until reaching the lower limit flow rate so that the lower limit flow rate at which the nozzle 23 can discharge the hole injection ink was not more than 10 μl / min. Thereafter, the hole injection layer 4 was formed by placing it on a hot plate at 200 ° C. for 30 minutes. Thereafter, it was confirmed that the hole injection layer 4 having a desired film thickness was obtained by measuring the film thickness.

  Next, a hole transport material composed of a polyfluorene derivative was prepared using cyclohexylbenzene to prepare an ink having an ink solid content concentration of 4.0% and a viscosity of 10 mPa · s.

  When the hole transport layer 5 was formed, ejection was performed on the substrate on which the above-described hole injection layer 4 was formed by the same apparatus and procedure as the above-described hole injection layer 4 was formed. After discharging, it was confirmed that the hole transport layer 5 was formed by firing at 200 ° C. for 1 hour in a nitrogen atmosphere to obtain the hole transport layer 5 having a desired film thickness.

  Next, an RGB organic light emitting material composed of a poly (paraphenylene vinylene) derivative was prepared using cyclohexylbenzene, and the solid content concentration of the ink was 7.0%, the R ink had a viscosity of 30 mPa · s, and the solid content concentration was 5. A G ink having a viscosity of 0% and a viscosity of 5 mPa · s, and a B ink having a solid content concentration of 6.0% and a viscosity of 20 mPa · s were prepared.

  When the organic light emitting layer 6 was formed, ejection was performed on the substrate on which the hole transport layer 5 was formed by the same apparatus and procedure as those for forming the hole injection layer 4 described above. After discharge, RGB organic light emitting layer 6 was formed by baking at 130 ° C. for 30 minutes in a nitrogen atmosphere. Then, it confirmed that the organic light emitting layer 6 of the desired film thickness was obtained by the film thickness measurement.

  A cathode layer 7 made of Ca and Al was formed thereon by mask vapor deposition using a resistance heating vapor deposition method in a line pattern orthogonal to the line pattern of the pixel electrode 2. Finally, in order to protect these organic EL constituents from external oxygen and moisture, they were hermetically sealed using a glass cap 8 and an adhesive 9 to produce an organic EL display panel. The peripheral part of the display part of the organic EL element substrate obtained in this way has an extraction electrode on the anode side connected to each pixel electrode 2 and an extraction electrode on the cathode side. By connecting these to the power source, The lighting display of the obtained organic EL element substrate was confirmed, and the light emission state was checked. By linking the nozzle discharge flow rate during the acceleration and deceleration of the nozzle as in the present invention, an organic EL element substrate with a material utilization efficiency of 90% and no unevenness in light emission luminance can be obtained.

(Comparative Example 1)
If the amount of ink discharged from the nozzle 23 is not adjusted as shown in FIG. 4 and the discharge is performed at a constant relative movement speed of the substrate with respect to the nozzle 23 in the pixel formation region, the acceleration / deceleration region is large and the material utilization efficiency is 50%. there were.

(Comparative Example 2)
As shown in FIG. 6, when a constant flow rate is discharged without adjusting the discharge amount (= discharge flow rate) of the ink discharged from the nozzle 23 based on information on the relative movement speed of the base material with respect to the nozzle 23 in the pixel formation region, A difference in film thickness due to relative speed fluctuations occurred in the light emitting region of the panel, resulting in uneven luminance of light emission, and a high-quality organic EL element substrate could not be obtained.

(Comparative Example 3)
As shown in FIG. 7, when the discharge amount (= discharge flow rate) of the ink 20 is changed based on the information on the relative movement speed of the base material with respect to the nozzle 23 without providing the lower limit flow rate of the ink, the ink 20 is discharged from the nozzle 23. In other words, non-ejection that does not eject occurs, and light emission streaks occur, and a high-quality organic EL element substrate cannot be obtained.

  The present invention is suitable for manufacturing an organic EL panel, for example.

1 ... Translucent substrate (base material)
2 ... Pixel electrode 3 ... Partition wall 4 ... Hole injection layer 5 ... Hole transport layer 6 ... Organic light emitting layer 7 ... Cathode layer 8 ... Glass cap 9 ... Adhesive 10 ... Ink supply tank 11 ... Ink 12 ... Ink supply tube 13 ... Nozzle head 14 ... Pressurizer 15 ... Flow control valve 16 ... Flow meter 17 ... Table 18 ... Translucent substrate 19 provided with electrodes and partition walls ... Movable stage 20 ... Ink 21 ... Ink supply tube 22 ... Case 23 ... Nozzle 24 ... Translucent Substrate (base material)
25 ... Liquid column A ... Constant velocity state B ... Deceleration state C ... Stop state D ... Acceleration state P ... Pixel formation region Q ... Outside pixel formation region P '... -Pixel formation region Q 'with adjusted ink flow rate ... Outside pixel formation region with adjusted ink flow rate R ... Lower limit flow rate region

Claims (7)

A stage on which the substrate is placed;
A nozzle that continuously ejects liquid columnar ink on the substrate;
A moving mechanism that is relatively movable by moving at least one of the stage and the nozzle in the surface direction of the base material,
An application apparatus that controls the discharge flow rate of ink discharged from the nozzle based on information on a relative movement speed of the substrate with respect to the nozzle.   The relative movement between the stage and the nozzle is a reciprocating operation, and when the relative movement speed is decelerated from the steady state, the discharge flow rate is decreased, and when the relative movement speed is accelerated to the steady state. The coating apparatus according to claim 1, wherein the discharge flow rate is increased.   The coating apparatus according to claim 1, wherein the information on the relative movement speed includes acceleration characteristics and deceleration characteristics of the relative movement speed actually measured in advance.   The coating apparatus according to any one of claims 1 to 3, wherein the discharge flow rate is controlled using an ink flow rate control valve.   5. The discharge flow rate when the relative movement speed is zero in the reciprocating operation is less than that when the relative saddle movement speed is in a steady state and is not zero. The coating apparatus of Claim 1. An application method for applying ink to the substrate using the application apparatus according to any one of claims 1 to 5,
Forming a partition that divides the substrate into a number of regions on the substrate;
While ejecting ink to each of the regions divided by the partition, a region for relative acceleration and relative deceleration of the base material with respect to the nozzle is provided, and information on the relative movement speed of the base material with respect to the nozzle is provided. And a control method for controlling a discharge flow rate of the ink discharged from the nozzle. A method for producing an organic functional element that forms a plurality of organic functional layers on a substrate,
The organic functional layer is formed by forming the organic functional layer by using the ink applied on the substrate as the base material by the coating apparatus according to any one of claims 1 to 5. Method.

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