KR20140084002A - Thin film forming method - Google Patents

Abstract

According to the present invention, the ejection orifices of the plurality of nozzles 23 are brought close to the film 28 of the image receiving layer to be inspected for ejection, and the image receiving layer film 28 and the plurality of nozzles 23 are moved relative to each other The ink is ejected from the plurality of nozzles 23 to perform the test application. Then, at the time of test application, the line width of the locus drawn by each of the nozzles 23 is measured. Then, the test application and the line width measurement are repeated while changing the flow rate of the ink to be supplied to the nozzle 23 to supply the nozzle 23 with the same line width of the trajectory drawn by each of the nozzles 23 To obtain a combination of flow rates. By ejecting the ink using a combination of the obtained flow rates, the discharge amount of the ink can be made constant.

Description

Thin Film Forming Method {THIN FILM FORMING METHOD}

The present invention relates to a thin film forming method, and more particularly to a thin film forming method usable for forming a functional layer of an organic electroluminescence (EL) device.

In recent years, a film-forming technique using an ink-jet method has received attention. The ink-jet method is characterized in that it is possible to form a fine pattern or to form a thin film having a desired film thickness because a minute ink can be discharged at a desired position according to the resolution of the head to be used. Using this feature, the ink-jet method is used for the production of organic EL devices and color filters which require finely divided application. Further, there is proposed a technique in which a functional material in a paste state is continuously discharged from a nozzle having a small number or a plurality of discharge ports to form a predetermined pattern on a substrate.

When the inkjet method or the nozzle method is applied to the production of an organic EL device, the use efficiency of the EL material is improved compared to the vapor deposition method or the sputtering method by dispersing or dissolving a necessary amount of an EL material in a predetermined solvent There is an advantage to be able to.

However, in the nozzle method, in the case of coating with one nozzle, the larger the size of the substrate, the longer the tact time, and the productivity is lowered. The use of a plurality of nozzles can shorten the tact time to increase the productivity. However, if the discharge amount of each nozzle is not constant, the film thickness of the functional film to be formed is different, and in the case of the organic EL element,

As a method for adjusting the discharge amount of each of a plurality of nozzles, there is a method of distributing a functional liquid stored in a single supply source to a plurality of nozzles in a branched manner and simultaneously applying the functional liquid on the substrate from each nozzle, Is proposed. In order to discharge an accurate discharge amount from the nozzle, it is necessary to measure and manage the actual discharge flow rate discharged from the nozzle. For example, the actual discharge flow rate discharged from the nozzle is measured by the weight in the vessel with respect to the unit discharge time, which is discharged from the nozzle into the predetermined vessel (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2006-205024

However, in the case of a coating apparatus which simultaneously discharges from a plurality of nozzles, it is necessary to measure the actual discharge flow rate for each nozzle system to derive the respective relational expressions. Further, in order to derive a high-precision relational expression, it is necessary to measure the actual discharge flow rate at a plurality of points at different flow rates with respect to one nozzle system. In addition, in the coating apparatus having a plurality of nozzles, when the functional liquid to be applied is changed, it is necessary to measure the actual discharge flow rate even after the functional liquid is changed, so that the number of flow control processes of the coating apparatus is increased. Further, when the actual discharge flow rate measurement time of the application device becomes longer, the actual discharge flow rate may fluctuate due to evaporation of the solvent in the functional fluid discharged into the container, which may make it difficult to accurately measure the actual discharge flow rate.

Therefore, an object of the present invention is to provide a thin film forming method which facilitates adjustment of the discharge amount of liquid discharged from each of a plurality of nozzles.

The present invention relates to a thin film forming method for forming a thin film by applying ink to a plurality of regions partitioned on a substrate by using a plurality of nozzles. The thin film forming method according to the present invention includes the steps of bringing a discharge port of a plurality of nozzles close to the surface of a test substrate and ejecting ink from a plurality of nozzles while moving the test substrate and the plurality of nozzles relative to each other, A step of measuring the line width of the locus drawn by each of the plurality of nozzles at the time of applying the test, a step of applying the test while changing the flow rate of ink supplied to each of the plurality of nozzles, Repeatedly obtaining a combination of the flow rates of the inks to be supplied to the plurality of nozzles so that the line width of the locus drawn by each of the plurality of nozzles becomes equal to each other; The ink is ejected from the plurality of nozzles onto the substrate by using the combination of the flow rates obtained in the step of obtaining the combination of the flow rates while relatively moving the plurality of nozzles Key is provided with a step.

Alternatively, the method for forming a thin film according to the present invention is a method for forming a thin film, comprising: a step of bringing a discharge port of a plurality of nozzles close to a surface of a test substrate, discharging ink from a plurality of nozzles while relatively moving the test substrate and a plurality of nozzles A step of measuring a line width of a locus drawn by each of a plurality of nozzles at the time of applying a test, a step of performing test application while changing a relative movement speed of a plurality of nozzles and a test substrate, A step of repeating the steps so as to obtain a combination of relative moving speeds of a plurality of nozzles in which a line width of a locus drawn by each of the plurality of nozzles is equal to each other; The ink is ejected onto the substrate from the plurality of nozzles while relatively moving the plurality of nozzles and the substrate at the relative moving speed obtained in the step of obtaining the combination of the nozzles It comprises the step of.

According to the present invention, when a thin film is formed by applying ink using a plurality of nozzles, the discharge amount of each nozzle is adjusted based on the line width of the coating trace applied to the test application portion, Can be reduced.

1 is a cross-sectional view of an organic EL element substrate according to an embodiment.
2 is a schematic view of a thin film forming apparatus using a nozzle coating method.
Fig. 3 is a detailed view of a cross section of the nozzle head.
4 is a schematic view of the test ejection apparatus.
5 is a graph showing the relationship (before adjustment) between the line width and the flow rate.
6 is a graph showing the relationship (after adjustment) between the line width and the flow rate.
7 is a graph showing the relationship between the speed and the discharge amount.
8 is a graph showing the relationship (before adjustment) between the line width and the flow rate.
9 is a graph showing the relationship (after adjustment) between the line width and the flow rate.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the present invention is described on the basis of an example in which an organic EL element substrate is manufactured by using a nozzle applying apparatus. However, the present invention is not limited to the organic EL, As shown in Fig. As an optical component other than the organic EL, a color filter, a circuit substrate, a thin film transistor, a microlens, a biochip, and the like can be exemplified.

Hereinafter, the patterned bodies of the hole injection layer, the hole transporting layer and the organic luminescent layer included in the organic EL element are collectively referred to as a functional layer, and the functional layer is formed by using the coating apparatus according to the above embodiment, .

(Preparation of Substrate)

An organic EL element is formed on a substrate. As the substrate, the translucent substrate 1 is suitably used. As the transparent substrate 1, a glass substrate or a plastic film or sheet can be used. In the case of using a plastic film, the polymer EL device can be wound at the time of production, and the display panel can be provided at low cost. As the plastic film, for example, polyethylene terephthalate, polypropylene, cycloolefin polymer, polyamide, polyether sulfone, polymethyl methacrylate, polycarbonate and the like can be used. These films are also provided with a barrier layer comprising a metal oxide such as silicon oxide exhibiting water vapor barrier property and oxygen barrier property, an oxynitride such as silicon nitride, a polyvinylidene chloride, a polyvinyl chloride, and an ethylene- Is preferably formed as needed.

(Fabrication of pixel electrode)

On the transparent substrate 1, a patterned pixel electrode 2 is formed as an anode. As the material of the pixel electrode 2, a transparent electrode material such as ITO (indium tin composite oxide), IZO (indium zinc composite oxide), tin oxide, zinc oxide, indium oxide, aluminum oxide composite oxide and the like can be used. Among these electrode materials, it is preferable to use ITO in terms of low resistance, solvent resistance, transparency, and the like. The ITO is formed on the transparent substrate by the sputtering method, and is patterned by the photolithography method to form the line-shaped pixel electrode 2.

(Fabrication of barrier ribs)

After the formation of the line-shaped pixel electrodes 2, the barrier ribs 3 are formed between the adjacent pixel electrodes 2. The barrier ribs 3 are formed in a lattice shape or a stripe shape on the substrate and the inspection substrate. Each of the regions surrounded by the barrier ribs 3 serves as a discharge region which is a target for forming a thin film of ink by applying a nozzle. The barrier ribs 3 are formed by photolithography using a photosensitive material. As the photosensitive material for forming the barrier ribs 3, any of a positive type resist and a negative type resist may be used, but it is required to have insulating properties. If the barrier ribs 3 do not have sufficient insulating properties, current flows to the adjacent pixel electrodes through the barrier ribs, resulting in display defects. Specific examples thereof include polyimide, acrylic resin, novolac resin, fluorene, and the like, but are not limited thereto. Further, for the purpose of increasing the display quality of the organic EL device, a light-shielding material may be contained in the photosensitive material. Further, by adding an appropriate amount of a repellent ink such as a fluorine-containing compound or a silicon-containing compound to the barrier rib material, appropriate ink repellency can be obtained.

The thickness (height) of the partition 3 according to the present embodiment is preferably 0.5 to 5.0 mu m. By forming the barrier ribs 3 between adjacent pixel electrodes 2, the diffusion of the hole transport ink printed on each pixel electrode can be suppressed, and the occurrence of a short circuit from the ends of the transparent conductive film can be prevented. If the barrier ribs are too low, the effect of preventing short-circuiting may not be obtained, so care must be taken.

(Adjustment of Hole Injection Layer Ink)

The ink adjustment for forming the hole injection layer 4 will be described. The volume resistivity of the hole injection layer 4 to be formed is preferably 1 x 10 < ⁶ > OMEGA .cm or less from the viewpoint of luminous efficiency. Examples of the hole injecting material include metal phthalocyanines such as copper phthalocyanine and tetra (t-butyl) copper phthalocyanine, metal phthalocyanines such as nonmetal phthalocyanines, quinacridone compounds, 1,1-bis (4-di- Bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine, N, N'-di (1-naphthyl) Aromatic amine-based low-molecular hole injection transporting materials such as N, N'-diphenyl-1,1'-biphenyl-4,4'-diamine, and polymeric holes such as poly (p-phenylenevinylene) An injection material, a polythiophene oligomer material, and other known hole injection materials.

Examples of the solvent for dissolving or dispersing the hole injecting material include halogenated solvents such as chloroform, dichloromethane, dichloroethane, trichlorethylene, ethylene dichloride, tetrachloroethane and chlorobenzene, N-methyl- Aprotic polar solvents such as NMP, dimethylformamide (DMF), dimethylacetamide (DMAc) and dimethylsulfoxide (DMSO), propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono And polar solvents such as alkoxy alcohols such as ethyl ether.

(Preparation of Ink for Hole Transport Layer)

The ink adjustment for forming the hole transport layer 5 will be described. Examples of the hole transporting material include poly (N-vinylcarbazole) (hereinafter also referred to as PVK), poly (para-phenylenevinylene), carbazolebiphenyl N'-bis (1-naphthyl) -1,1'-biphenyl-4,4'-diamine (hereinafter also referred to as NPD), N, (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine (hereinafter also referred to as TPD) and 4,4'-bis (10-phenothiazinyl) 4,6-triphenyl-1,3,5-triazole, polyfluorene derivatives, copolymers of triphenylamine and fluorene, and the like.

Examples of the solvent of the functional ink forming the hole transporting layer include cymene, tetralin, cumene, decalin, durene, cyclohexylbenzene, dihexylbenzene, tetramethylbenzene and dibutylbenzene.

(Preparation of Ink for Organic Light Emitting Layer)

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 flowing an electric current. Examples of the organic light-emitting material for forming the organic light-emitting layer 6 include coumarin-based, perylene-based, pyran-based, anthrone-based, porphyrin-based, quinacridone-based, N, A dispersion of a light-emitting pigment such as an imide, N, N'-diaryl-substituted pyrrolopyrrole or iridium complex system in a polymer such as polystyrene, polymethylmethacrylate, or polyvinylcarbazole, Based polymer material such as an allylene vinylene-based or polyfluorene-based polymer material. Examples of the solvent for the functional ink forming the organic light-emitting layer 6 include cymene, tetralin, cumene, decalin, durene, cyclohexylbenzene, dihexylbenzene, tetramethylbenzene and dibutylbenzene.

(Formation of hole injection layer)

The functional ink including the hole injecting material is discharged onto the substrate 1 having the partition 3 formed thereon by a nozzle coating method to be described later to form the hole injecting layer 4.

(Formation of hole transport layer)

After the hole injecting layer 4 is formed, the functional ink containing the hole transporting material is discharged by the nozzle coating method described later to form the hole transporting layer 5.

(Formation of organic luminescent layer)

After the formation of the hole transport layer 5, the functional ink containing the organic light emitting material is ejected by the 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 into a line pattern orthogonal to the line pattern of the pixel electrode 2. [ The material of the cathode layer 7 may be selected from the group consisting of metals such as lithium, magnesium, calcium, ytterbium and aluminum, and metals such as gold and silver And the like. In addition, conductive oxides such as indium, zinc, and tin may be used. The negative electrode layer may be formed by a vacuum deposition method using a mask.

(Explanation of Sealing Process)

Finally, in order to protect these organic EL constructs from external oxygen or moisture, the glass caps 8 and the adhesive 9 are used to hermetically seal the organic EL display panel to obtain an organic EL display panel. As the sealing method, any method may be employed as long as it can protect the organic EL construct from external oxygen or moisture. When the transparent substrate 1 has flexibility, sealing may be performed using a sealing agent and a flexible film.

In the organic EL device according to the present embodiment, a hole injection layer 4, a hole transport layer 5, and an organic light emitting layer (hereinafter, also referred to as " Layer structure in which layers such as a hole blocking layer, an electron transport layer, and an electron injection layer are formed as needed in addition to the hole transport layer 5 and the organic light emission layer 6 are formed between the anode layer and the cathode layer . Further, when these layers are formed, the same forming method as that of the organic light-emitting layer 6 can be applied.

(Configuration of nozzle coating device)

Hereinafter, a configuration example of a nozzle coating device used for forming the hole injection layer, the hole transport layer, and the organic light emitting layer will be described with reference to FIG. 2, but the present invention is not limited thereto.

2 includes an ink supply tank 10, an ink supply tube 12, a flow meter 16, a flow control valve 15, and a nozzle head 13. The ink supply tank 10, the ink supply tube 12, The ink 11 charged in the ink supply tank 10 is supplied to the nozzle head 13 through the inside of the ink supply tube 12. [ The supply of the ink 11 to the nozzle head 13 is performed by pressing the inside of the ink supply tank 10 with the pressurizer 14 and extruding the ink 11 from the ink supply tank 10. A flow control valve 15 for controlling the discharge amount of the ink 11 and a flow rate of the ink 11 supplied to the nozzle head 13 are measured between the ink supply tank 10 and the nozzle head 13 A flow meter 16 is disposed. The flow control valve 15 is controlled based on the information (i.e., the ink flow rate) from the flow meter 16, and the ink flow rate can be adjusted, so that a stable desired ink flow rate can be obtained. When a plurality of nozzle heads 13 are formed in the nozzle coating apparatus, a plurality of configurations from the nozzle head 13 to the ink supply tank 10 are formed.

The nozzle applying apparatus further includes a table 17 and a movable stage 19 disposed on the table 17 and movable on the table 17 in the X direction and the Y direction orthogonal thereto. The movable stage 19 is continuously moved in the Y direction or the Y 'direction (or the X direction or the X' direction) while the ink 11 is ejected from the ejection port of the nozzle head 13, It is possible to form a coating film on the transparent substrate 18 disposed on the transparent substrate 18. For example, a translucent substrate 18 in which a plurality of pixel forming regions extending in parallel to each other in the X direction are formed in a stripe shape is disposed on the movable stage 19, and the movable stage 19 and the nozzle head 13 are arranged, In the Y direction. At this time, the movement of the movable stage 19 and the nozzle head 13 is synchronized with the movement of the movable stage 19 and the nozzle head 13 based on the position information of the movable stage 19 and the nozzle head 13, The ink 11 is continuously applied to one of the pixel formation regions to form a coating film. After the coating film is formed on one pixel formation region of R, G, or B, the movable stage 19 and the nozzle head 13 are relatively moved in the X direction to form a coating film on the next pixel formation region.

Next, the nozzle head will be described using the nozzle head sectional view of FIG. The ink 11 enters the case 22 having a cylindrical or rectangular parallelepiped shape made of SUS (stainless steel) or the like from the ink supply tube 12. The case 22 is generally made of metal, but any type of ink may be used as long as it has ink resistance. The inside of the case 22 is a manifold, and the liquid column 25 is discharged from the nozzle 23 having a small hole having a diameter of about 5 to 20 탆. The nozzle is a film of polyimide or the like in general, but it may be any type of hole that can be drilled with high precision.

In consideration of clogging of the nozzles and deflection of the ink due to drying of the ink, it is preferable that the ink ejected from the nozzles is continuously ejected. Thereby, there is a case of masking parts which are not intended to be ejected, or forming a dummy pattern. However, any method may be adopted if there is no problem as a panel.

(Configuration of test application device)

Fig. 4 shows a schematic configuration of a test application device for performing test application of the present invention.

The test applying apparatus shown in Fig. 4 includes an image receiving layer film 28 and a linewidth inspection unit (not shown) for optically capturing information of the line width inspection image recorded on the image receiving layer film 28 An image information processing section 32 for inspecting the line width from the image information captured by the line width inspecting section 34, a film section 36 for feeding and winding the image receiving layer film 28, (Not shown) for controlling the operation of the vehicle.

The image-receiving layer film 28 is a recording medium for line width inspection for producing an image 35 for line width inspection of a trajectory shape to be drawn by ejecting ink from a plurality of nozzles. As the image-receiving layer film 28, ordinary commercially available ones can be used. For example, a PET (polyethylene terephthalate) film may be used as the transparent film, and a coating layer formed by uniformly dispersing a fine pigment may be used as the image receiving layer. The type of the functional liquid to be used, It may be suitably selected in accordance with conditions such as specifications.

The line width inspection image 35 recorded on the image receiving layer film 28 is moved to the place where the linewidth inspection section 34 is located by the drive roller 37. [ The linewidth inspection unit 34 captures the linewidth inspection image as the image information and transfers the image information to the image information processing unit 32. [ When the camera 27 captures the information of the inspection image, the illumination 29 is turned on to illuminate the inspection image recorded on the receiving layer film, thereby giving contrast and clearly recognizing the shape of the inspection image So that it can be captured. The camera 27 may capture an image by installing the illumination 29 on the camera side rather than the image-receiving layer film or using only external light. In capturing the image information, even if the inspection image recorded on the image-receiving layer film 28 is fine, the resolution, viewing angle, and the like of the optical camera of the image information detection section can be appropriately selected.

The gap between the image-receiving layer film 28 and the nozzle is provided so as to be equal to the gap between the base material and the nozzle when the base material is placed on the stage of the nozzle applying device. In addition, the test application device is installed so that the drive direction of the water layer film is perpendicular to the drive direction of the nozzle of the nozzle application device. The application device and the test application device are installed adjacent to each other. Further, when the test was applied, when the test was not conducted, the test was performed again by discharging. That is, the non-discharge test can be performed at the same time.

(Adjustment method of discharge amount)

Next, a method of adjusting the discharge amount from the line width measurement result in the test application apparatus will be described. When the nozzles are discharged from the plurality of nozzles in accordance with the value of the flowmeter, the actual discharging amounts actually discharged from the respective nozzles are slightly different from each other. This is because the nozzle diameters of the nozzles are different or the accuracy of the flow meter is different for each device.

Therefore, in order to adjust the discharge amount of each nozzle, the relationship between the line width and the flow rate is first grasped. The flow rate of each nozzle is made uniform, a line width inspection image is created, and line width data of each nozzle is acquired. By repeating this at a plurality of flow rates, the relationship between the flow rate of each nozzle and the line width is obtained.

Fig. 5 shows the line width of each nozzle when three nozzles are used and the flow rate is applied at five levels of a1 to a5. As shown in Fig. 5, the line width is different even when the flow rate is regularized for each nozzle. Then, the flow rate is adjusted so that the target line width is obtained from the relationship between the flow rate of each nozzle and the line width. In order to match the line widths of the nozzles 2 and 3 to the line width of the nozzle 1, an approximate straight line of the flow rate and line width of each nozzle is obtained. The line width of the nozzles 2 and 3 is calculated to be equal to the line width of the nozzle 1 from the approximate straight line. By adjusting the flow rates of the respective nozzles, it becomes possible to match the line widths of the nozzles 2 and 3 with the line width of the nozzles 1 as shown in Fig. Since the line width and the discharge amount are in a proportional relation, the discharge amount becomes even if the line width is matched.

As a method of adjusting the line width, there are a method of producing the above-mentioned flow rate and a method of adjusting the speed of the nozzle relative to the substrate. When the flow rate is fixed and the speed is changed, the discharge rate and speed represent the relationship of the exponent function. Therefore, as in the case where the line width is adjusted by the flow rate, the line width can be adjusted by changing the speed. The relationship between the velocity and the flow rate is shown in Fig. Further, in the case of adjusting the line width by the relative speed of the nozzle and the substrate, each of the plurality of nozzles is configured to be movable independently at different speeds. In the test application apparatus, a plurality of line width inspection images may be created while changing the relative moving speed of each nozzle, and the relationship between the relative speed and the line width of each nozzle as shown in Fig. 7 may be obtained.

Although the hole injecting layer, the hole transporting layer and the organic light emitting layer are formed by the nozzle coating method in the present embodiment, it is not necessary to form all these layers by the nozzle coating method.

Example

EXAMPLES Next, concrete examples of the present invention will be described.

An ITO (indium-tin oxide) thin film was formed on a glass substrate having a size of 3 inches diagonal by sputtering, and the ITO film was patterned by photolithography and etching with an acid solution to form a pixel electrode. The line pattern of the pixel electrode was a pattern having a line width of 70 mu m and a space of 60 mu m, and formed with about 590 lines with a side of about 7.6 mm.

Then, an insulating layer was formed as follows. First, a polyimide-based resist material was spin-coated on the entire surface of a glass substrate on which pixel electrodes were formed. The spin coating conditions were rotated at 150 rpm for 5 seconds and then rotated at 500 rpm for 20 seconds to coat once, and the height of the insulating layer was 2.5 탆. A partition wall serving as an insulating layer having a stripe pattern was formed between the pixel electrodes by photolithography on the entire surface of the photoresist material.

This partition wall has ink repellency.

Subsequently, a mixture of a polymer hole injection material such as poly (p-phenylenevinylene), polyaniline and the like and propylene glycol monobutyl ether were used as the hole injecting ink to prepare an ink having a solid concentration of 1.5% and a viscosity of 7 mPa.s Ink.

The prepared hole injection ink was put into the ink supply tank. The hole injection ink in the ink supply tank is supplied to the nozzle head through the ink supply tube by pressing the ink supply tank. A flow control valve for controlling the amount of ink to be ejected is provided between the ink supply tank and the nozzle and a flow meter for measuring the flow rate of ink flowing through the nozzle head. Based on the information of the ink flow meter, A stable desired ink flow rate can be obtained.

The nozzle head and the table are relatively fixed in position, and the translucent substrate having the above-mentioned ink-repellent stripe pattern partitions is fixed to the movable stage. The above-described movable stage can move the above table in the Y or Y 'direction, which is the longitudinal direction. Further, the nozzle head can move in the X or X 'direction, which is the transverse direction orthogonal to the Y or Y' direction. The stage and the nozzle or the nozzle unit move relative to each other to form a coating film continuously acting as a pixel in the pixel formation region of the substrate on the stage.

The ink enters the nozzle head of a rectangular parallelepiped shape made of stainless steel from the ink supply tube. The inside of the nozzle head is a manifold, and it can be discharged in a vertical direction from a nozzle of a polyimide film having a minute hole having a diameter of 8 mu m to the transparent substrate. In this embodiment, three nozzles are used.

In the state in which the ink was ejected from the three nozzles, the ejection port was adjusted so as to have a desired line width in the test ejection apparatus. FIG. 8 shows the relationship between the flow rate before adjustment and the line width, FIG. 9 shows the relationship between the flow rate after adjustment and line width, and Table 1 shows the flow rate and line width of each nozzle before and after adjustment.

Subsequently, the hole injection layer was coated and formed at the adjusted flow rate. By feedback control of the flow control valve using the information of the flowmeter, the amount of ink ejected from the nozzle is kept uniform. Thereafter, the substrate after ink application was placed on a hot plate at 200 캜 for 30 minutes to form a hole injection layer. Thereafter, it was confirmed that the hole injection layer having a desired film thickness was obtained by measuring the film thickness.

Subsequently, an ink having a solid content concentration of 4.0% and a viscosity of 10 mPa · s was prepared using a hole transporting material containing a polyfluorene derivative and cyclohexylbenzene.

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

Next, using an RGB organic electroluminescent material and cyclohexylbenzene containing a poly (paraphenylene vinylene) derivative, an R ink having a solid content concentration of 7.0% and a viscosity of 30 mPa · s, an ink concentration of 5.0%, a viscosity of 5 m A G ink of Pa 占 퐏, a B ink having a solid content concentration of 6.0% and a viscosity of 20 mPa 占 s.

When the organic light emitting layer was formed, ejection was performed on the substrate on which the hole transporting layer was formed by the same apparatus and procedure as the above-described case of forming the hole injection layer. After ejection, the organic light emitting layer was formed by firing at 130 DEG C for 30 minutes in a nitrogen atmosphere. Thereafter, it was confirmed that an organic light emitting layer having a desired film thickness was obtained by measuring the film thickness.

And a negative electrode layer containing Ca and Al was formed thereon by resistive heating vapor deposition in a line pattern orthogonal to the line pattern of the pixel electrode. Finally, in order to protect these organic EL constructs from external oxygen or moisture, they were hermetically sealed with a glass cap and an adhesive to prepare an organic EL display panel.

On the periphery of the display portion of the organic EL element substrate thus obtained, there are an extraction electrode on the anode side and a extraction electrode on the cathode side connected to the respective pixel electrodes. By connecting these electrodes to the power source, And the emission state was checked. As in the present embodiment, by matching the line widths of the inks ejected from the respective nozzles, an organic EL element substrate having a material utilization efficiency of 90% and having no light emission luminance unevenness was obtained.

(Comparative Example 1)

As a comparative example, when ink is applied with the amount of ejection from each nozzle before adjustment in Table 1, a difference in film thickness occurs due to the difference in ejection amount of each nozzle in the light emission region of the panel, So that a high-quality organic EL element substrate could not be obtained.

≪ Industrial applicability >

The present invention can be used for the production of organic EL devices and the like.

1: Transparent substrate
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: Presser
15: Flow control valve
16: Flowmeter
17: Table
18: Transparent substrate
19: Operation stage
22: Case
23: Nozzle
25: liquid column
26: Head unit
27: Camera
28: Receiving Layer (Receiving Layer) Film (Recording Medium for Discharge Inspection)
29: Lighting
30: Feed roller
31: take-up roller
32: Image information processing section
33: line width indication mechanism
34: linewidth inspection section
35: Image for line width inspection
36: Film section
37: drive roller

Claims (2)

A thin film forming method for forming a thin film by applying ink to a plurality of regions partitioned on a substrate by using a plurality of nozzles,
A step of bringing a discharge port of the plurality of nozzles close to a surface of a test substrate and discharging ink from the plurality of nozzles while moving the test substrate and the plurality of nozzles relative to each other,
Measuring a line width of a locus drawn by each of the plurality of nozzles at the time of applying the test;
Wherein the step of applying the test and the step of measuring the line width are repeated while varying the flow rate of ink supplied to each of the plurality of nozzles so that the line widths of the traces drawn by the plurality of nozzles are the same Obtaining a combination of a flow rate of ink supplied to each of the plurality of nozzles,
Wherein a plurality of nozzles are brought close to the surface of the base material and a combination of the flow rates obtained in the step of obtaining the combination of the flow rates while relatively moving the base material and the plurality of nozzles is used, And a step of discharging the ink. A thin film forming method for forming a thin film by applying ink to a plurality of regions partitioned on a substrate by using a plurality of nozzles,
A step of bringing a discharge port of the plurality of nozzles close to a surface of a test substrate and discharging ink from the plurality of nozzles while moving the test substrate and the plurality of nozzles relative to each other,
Measuring a line width of a locus drawn by each of the plurality of nozzles at the time of applying the test;
A step of performing the test application while changing a relative moving speed of the plurality of nozzles and the test substrate and a step of measuring the line width are repeated so that the line widths of the traces drawn by the plurality of nozzles are the same Obtaining a combination of relative moving speeds of the plurality of nozzles,
And moving the plurality of nozzles and the substrate relative to each other at a relative moving speed obtained by bringing the plurality of nozzles close to the surface of the base material and obtaining a combination of the relative moving speeds, And a step of discharging the ink.

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