JP2017091741A - Method for forming membrane fine-line pattern with screen printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a membrane fine-line pattern on a substrate by using only screen printing.SOLUTION: The present invention relates to a method for forming a predetermined membrane fine-line pattern (14) on a substrate (11) and the method includes first to third steps. In the first step, a resist layer (12) that becomes a reverse pattern with respect to the membrane fine-line pattern, is formed on the substrate by screen printing using a first screen printing plate. In the second step, a second screen printing plate is positioned at an installation position of the first screen printing plate in the first step and in the substrate, at least in a region where the resist layer is not formed, a membrane (13) is formed by screen printing using the second screen printing plate. In the third step, the predetermined membrane fine-line pattern is formed by removing the resist layer on the substrate after the second step.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of forming a pattern, for example, a thin thin film pattern by screen printing.

  Screen printing does not require expensive equipment and is relatively easy to enlarge, so it is widely used in the industry. Its applications include character printing for signboards and industrial parts, printed circuits, IC circuits, printing of electronic component substrates for various display devices, electrode formation for solar cells, etc., such as thick film printing, thick film patterns, and hole filling printing. Spread to the field.

  Screen printing is widely used as a printing technology that can form a thick film pattern of about 2 μm to several tens of μm in a single printing. However, vacuum printing, sputtering, chemical vapor deposition, etc. Compared to the dry method, it does not require large and expensive equipment, and it does not require precise control of the component gas pressure in the vacuum device during operation. In addition, it is expected to be used in the field of thin film formation as a process capable of increasing the area. For example, for the formation of transparent conductive films (ITO films) and electronic devices having organic thin films, specifically, organic electroluminescence elements, organic photoelectric conversion elements, organic thin film transistors, organic sensors, organic memories, etc. (Patent Document 1, Patent Document 2).

  Here, a film formed by a dry method such as vapor deposition is a thin film having a thickness of 1 μm or less, and in order to form such a thin film by a wet method such as screen printing, the concentration of solids contained in the ink is set. Diluted low-viscosity ink is used (Patent Document 3, Non-Patent Document 1), or a screen printing plate using a thin metal plate (Patent Document 1, Patent Document 3) is used. .

  However, in the method of obtaining a thin film by diluting the concentration of solids contained in the ink, since the solution viscosity is low, the edge of the pattern is blurred and it is difficult to form a fine print pattern. Therefore, a device for reducing bleeding is required (Patent Document 3). In particular, when the surface of the substrate to be printed is inferior in smoothness, the ink bleeding becomes more prominent, making it difficult to form a fine pattern, and various devices have been proposed for screen printing masks (Patent Documents). 4 and Patent Document 5) are not low-cost and high-productivity pattern formation techniques, such as requiring special materials.

  In addition to the method of directly forming a thin film pattern as described above, a reverse pattern resist is formed before thin film formation, and then a thin film is formed on the entire surface by a vapor phase method, together with the reverse pattern resist. A lift-off method, in which an unnecessary thin film is removed to obtain a target thin film pattern, has been conventionally studied (Patent Document 6 and Patent Document 7), but none of them applies screen printing to the formation of the thin film.

JP 2002-170674 A International Publication No. WO2011 / 155635 JP 2008-73911 A JP 2009-107208 A JP 2006-347077 A Japanese Patent Laid-Open No. 62-171169 JP2013-257669A

IEEE Journal on selected topics in quantum electronics, 2001, Vol. 7, No. 5, P769

  Here, when printing a predetermined pattern by screen printing, it is desired to suppress bleeding of the printing material and form a high-definition pattern as described in Patent Documents 3 to 5. An object of the present invention is to form a high-definition pattern by means different from Patent Documents 3 to 5.

  In Patent Document 6 and Patent Document 7 using the lift-off method, although screen printing is applied to the formation of a thick-film lift-off layer (resist layer) that is a reverse pattern of a predetermined thin-film pattern, the thin film has a lift-off layer. The entire surface is formed by a dry method such as vapor deposition or sputtering, and the screen printing method is not used.

  The present invention provides a method of forming a thin film fine line pattern on a substrate by using only screen printing.

  That is, the first invention is a method for forming a predetermined thin film fine line pattern on a substrate, and includes the first to third steps. In the first step, a resist layer having a pattern opposite to the thin film thin line pattern is formed on the substrate by screen printing using the first screen printing plate. In the second step, the second screen printing plate is positioned at the installation position of the first screen printing plate in the first step, and the second screen printing is performed on at least a region of the base material where the resist layer is not formed. A thin film is formed by screen printing using a plate. In the third step, after the second step, the resist layer on the base material is removed to form a thin film fine line pattern.

  Further, the second invention is the thin film thin line pattern according to the first invention, wherein the thin film thin line pattern is a thin line pattern having an average thickness of 1 μm or less and a minimum width of 100 μm or less. It is a forming method.

  Furthermore, a third invention is a method of forming a thin film fine line pattern according to the first or second invention, wherein the resist layer is a water-soluble resist layer.

  According to a fourth aspect of the present invention, in the first to third aspects of the present invention, the second screen printing plate is formed with a pattern so that a thin film is formed also in a region covering the peripheral portion of the resist layer. The thin film fine line pattern forming method characterized in that the area of the thin film calculated from the pattern of the screen printing plate and covering the periphery is 60% or less with respect to the total area of the surface of the resist layer parallel to the substrate It is.

  Furthermore, a fifth invention is characterized in that, in the first to fourth inventions, the average thickness of the resist layer is not less than 2 times and not more than 20 times the average thickness of the thin film thin wire pattern. It is a forming method.

  Further, a sixth aspect of the present invention is the thin film thin line pattern according to any one of the first to fifth aspects, wherein the viscosity of the ink used for forming the thin film is 0.01 Pa · S or more and 40 Pa · S or less. It is a forming method.

  Furthermore, a seventh invention is a method for forming a thin film fine line pattern according to any one of the first to sixth inventions, wherein the arithmetic average roughness Ra of the surface of the substrate is 5 μm or less.

  Further, in an eighth aspect based on the first to seventh aspects, at least a portion of the first screen printing plate that forms a reverse pattern and a portion of the second screen printing plate that forms at least a thin film. The screen is a mesh fabric woven so that warps and wefts made of metal or synthetic wire cross each other, the warp and weft wire diameters are 25 μm or less, and the number of meshes in the direction in which the warps and wefts extend Is a thin film fine line pattern forming method characterized in that each has 325 or more.

Furthermore, a ninth invention is the method for forming a thin film thin line pattern according to the eighth invention, wherein the mesh fabric has a Young's modulus of 10,000 N / mm ² or more.

  According to the present invention, a thin thin line pattern can be formed only by screen printing without the need for large and expensive equipment such as a dry method, so that the productivity is low and the area is large. A method capable of being applied to pattern formation on a substrate can be provided.

It is a schematic diagram of the process of forming a thin film thin line pattern. It is a model figure which shows the process of forming the screen printing plate which has a desired pattern. It is a schematic diagram of a structure of a combination screen printing plate. It is a pattern diagram of a mask used when creating a screen printing plate for forming a resist layer. It is a pattern figure of the mask used when producing the screen printing plate for thin film pattern formation. It is a figure explaining the calculation method of a coverage. It is a figure which shows the thin film thin wire | line pattern in Example 1b. It is a figure which shows the fine line pattern in the comparative example 1b. It is a figure which shows the thin film pattern in the comparative example 2.

  Hereinafter, in the present embodiment, a method of forming a pattern, for example, a thin film thin line pattern (referred to as a thin film thin line pattern) on a substrate only by screen printing will be described in detail.

  FIG. 1 is a schematic diagram of a process of forming a thin film fine line pattern of the present embodiment. In FIG. 1A, a resist printing ink is printed on a substrate 11 using a screen printing plate having a reverse pattern with respect to a predetermined thin film thin line pattern, dried and solidified to form a predetermined thin film thin line pattern. On the other hand, it is a figure which shows the process of forming the resist layer 12 of a reverse pattern. The reverse pattern is a pattern formed in an area on the substrate 11 excluding a predetermined thin film thin line pattern. FIG. 1B shows a predetermined screen ink (hereinafter referred to as “screen ink”) using a screen printing plate that forms a pattern corresponding to a predetermined thin film thin line pattern and having a pattern width equal to or larger than the width (design value) of the predetermined thin film thin line pattern. (Also referred to as thin film ink) is printed on the substrate 11, dried and solidified, so that the thin film 13 having a predetermined thickness is formed in the region where the resist layer 12 is not formed and the peripheral portion of the upper surface of the resist layer 12. It is a figure which shows the process of forming a pattern. In the screen printing of the thin film ink, the width of the pattern formed on the screen printing plate is equal to or larger than the width (design value) of the thin film thin line pattern, so the thin film 13 formed of the thin film ink is formed by the resist layer 12. In some cases, it may be formed not only in the region that is not formed but also in the peripheral portion of the upper surface of the resist layer 12. Thereafter, in the cleaning process, the resist layer 12 is removed to form a predetermined thin-film pattern 14 as shown in FIG. The pattern of the thin film 13 left after the resist layer 12 is removed becomes a thin film thin line pattern 14.

  As described above, this embodiment is an extremely simple process in which the screen printing process and the cleaning process are performed twice as the main processes, and drying is performed after the main processes (screen printing process and cleaning process). Thus, this is an epoch-making technique that has made it possible to create the thin film thin line pattern 14. The feature is that screen printing is performed by forming a pattern having a pattern width equal to or larger than a predetermined width (design value) of the thin film thin line pattern 14 in a screen printing plate for thin film thin line pattern printing.

  When a pattern having a predetermined film thickness is formed on the entire surface (the entire upper surface) of the resist layer 12 which is a reverse pattern, it takes a long time to remove the resist layer 12 in the cleaning process, and the resist layer becomes difficult to remove. 12 may remain, and special cleaning such as jet cleaning, ultrasonic cleaning, and brushing cleaning may be required to completely remove the resist layer 12. There is a problem that a pattern formed after removing the layer 12 is peeled off. For this reason, it is desirable to use a screen printing plate designed so that no film is formed on the entire surface of the resist layer 12. On the other hand, even when a film is formed on the entire surface of the resist layer 12, the above-described difficulty is hardly generated by forming the thin film 13 having a reduced thickness. Therefore, a screen printing plate designed to cover the entire surface of the resist layer 12 with the thin film 13 can also be used.

  In this embodiment, since the screen printing plate is used for forming the resist layer 12 and the thin film 13, the resist layer 12 is formed by arranging these screen printing plates on the basis of a predetermined position. Positioning when forming the thin film 13 with respect to the substrate 11 is facilitated, and the thin film 13 is easily formed in a region where the resist layer 12 is not formed. Moreover, the thin film 13 can be formed without covering the entire surface of the resist layer 12 by setting the pattern width of the screen printing plate for thin film thin line pattern printing to be equal to or larger than the width (design value) of the predetermined thin film thin line pattern 14. .

  On the other hand, in the above-described screen printing plate for thin film fine line pattern printing, the thin film ink is printed so as not to cover the entire surface of the resist layer 12, so that the thin film ink spreads over the entire surface of the resist layer 12. Even if the entire surface of the layer 12 is covered, the thickness of the thin film 13 formed on the entire surface of the resist layer 12 can be reduced. That is, when the thin film 13 is formed, the amount of the thin film ink is adjusted so that the thin film 13 having a predetermined thickness is formed. Therefore, even if the thin film ink spreads over the entire surface of the resist layer 12, the resist layer 12. On the upper surface, the thickness of the thin film 13 can be reduced. In the region where the resist layer 12 is not formed, the thin film 13 having a predetermined thickness can be formed because the resist layer 12 prevents the thin film ink from spreading.

  As described above, the thin film 13 does not cover the entire surface of the resist layer 12, or even if the thin film 13 covers the entire surface of the resist layer 12, the thickness of the thin film 13 covering the entire surface of the resist layer 12 is reduced. This facilitates removal of the resist layer 12. As described above, the thin film thin line pattern 14 can be formed only by a simple process of screen printing in the present embodiment, so that the productivity can be reduced at a low cost without requiring a large and expensive facility such as a dry method. It can be said that this is a method that can be applied to the formation of the thin-film thin-line pattern 14 on the substrate 11 having a large area.

  As the resist ink for forming the resist layer 12, a reverse pattern of a predetermined thin film thin line pattern (hereinafter also referred to as a thin film pattern) 14 can be formed on the base material 11 and washed with an appropriate solvent. As long as the resist layer 12 can be removed from the base material 11 by this, its constituent components and component ratios may be any. Here, as the cleaning solvent, it is sufficient that the resist layer 12 can be removed by cleaning with water, an aqueous solution of alkali or acid, various organic solvents, or a combination thereof, and the material of the resist layer 12 is taken into consideration. A specific cleaning solvent may be determined.

  In particular, if a water-soluble resist layer 12 is used, the cleaning solvent may be water alone, or a cleaning solvent containing water as a main component can be used. In view of the complexity and cost, it is more preferable if it can be washed only with water.

  As a constituent component of the water-soluble resist layer 12, for example, a water-soluble polymer such as a natural polymer, a semi-synthetic polymer, or a synthetic polymer may be used. Natural polymers include starches such as corn starch, sugars such as mannan and pectin, seaweeds such as agar and alginic acid, plant mucous substances such as various gums, microbial mucous substances such as dextran and bullulan, proteins such as glue and gelatin. Etc. can be used. As the semi-synthetic polymer, celluloses such as methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose such as hydroxypropyl cellulose, and starches such as modified starch such as sodium starch phosphate ester and oxidized starch can be used. . Furthermore, synthetic polymers include polyvinyl alcohol, polyacrylamide, sodium polyacrylate, polyvinyl pyrrolidone, polyethylene oxide, polyethyleneimine, copolymers of methyl vinyl ether and maleic anhydride, and copolymers of isobutylene and maleic anhydride. Can be used.

  Among the water-soluble polymers, polyvinyl alcohol, hydroxypropyl cellulose and polyvinyl pyrrolidone are commercially available in various degrees of polymerization, all of which have strong hydrophilicity, water solubility, film-forming properties, adhesiveness, emulsifying properties, chemical properties. It is widely used as various industrial raw materials and processing agents utilizing its unique characteristics such as mechanical stability, and is particularly suitable as a constituent component for forming a resist layer in this embodiment.

  Further, since polyvinyl alcohol is an essential component of the emulsion for screen printing, the emulsion for screen printing itself can be used as the resist ink in this embodiment. The typical composition of the emulsion for screen printing is 30 to 70% by mass of water and various additives such as polyvinyl alcohol, vinyl acetate emulsion, photopolymerizable resin, photosensitizer and surfactant. According to the characteristics, it is appropriately formulated. Therefore, the resist ink is not particularly limited as long as it can remove the resist layer 12 with water or an appropriate solvent. The emulsion for screen printing can be used as it is, or a component such as a photopolymerizable resin can be diluted. It may be used by removing a component or adjusting the amount thereof, changing a component, or adding a new component.

  That is, the solvent contained in the resist ink of the present embodiment can be appropriately selected according to the composition of the resist ink and the method of use thereof, and is not particularly limited. As the solvent, for example, water is most preferable, but other alcohols such as methanol, ethanol, 1-propanol, 2-propanol, t-butyl alcohol and allyl alcohol, and polyvalents such as ethylene glycol and 1,2 propanediol are used. Alcohols, ethers such as ethyl ether, propylene oxide and 1,4 dioxane, aldehydes such as acetaldehyde, propionaldehyde and acrolein, ketones such as acetone, methyl ethyl ketone and acetylacetone, aromatic hydrocarbons such as benzene and toluene, Phenols and halogenated hydrocarbons may be used alone, or two or more kinds may be added or mixed. In short, the water-soluble resist layer 12 may be any resist layer 12 that can be washed and removed only with water, and a solvent other than water may be contained in the composition of the resist ink.

  Here, a dispersant may be used in order to increase the stability of the resist ink, and as the dispersant, for example, a surfactant or a polymer dispersant can be used.

  Specifically, anionic surfactants, cationic surfactants, nonionic surfactants and amphoteric surfactants can be used as the surfactant. The anionic surfactant may have a carboxylic acid, sulfonic acid, or phosphoric acid as a hydrophilic group. Moreover, as a carboxylic acid type | system | group, it can be set as the fatty acid salt and cholate which are the main components of soap, for example. Examples of the sulfonic acid series include sodium linear alkylbenzene sulfonate and sodium lauryl sulfate which are frequently used in synthetic detergents. More specifically, fatty acid soda soap, potassium oleate soap, carboxylate such as alkyl ether carboxylate, sodium lauryl sulfate, higher alcohol sodium sulfate, lauryl sulfate triethanolamine, polyoxyethylene lauryl ether sodium sulfate, polyoxyethylene Sulfates such as sodium oxyethylene alkyl ether sodium sulfate, sodium dodecylbenzene sulfonate, sodium alkyl naphthalene sulfonate, sodium alkyl diphenyl ether disulfonate, sodium alkane sulfonate, sodium salt of aromatic sulfonic acid formalin condensate, Alkyl phosphate potassium salt, sodium hexametaphosphate, dialkylsulfosuccinic acid and the like can be mentioned. These may be used alone or in combination.

  Cationic surfactants include tetramethylammonium chloride, tetramethylammonium hydroxide, tetrabutylammonium chloride, dodecyldimethylbenzylammonium chloride, alkyltrimethylammonium chloride, octyltrimethylammonium chloride, stearyltrimethylammonium chloride, alkyltrimethylammonium bromide. Quaternary ammonium salt types such as hexadecyltrimethylammonium bromide, benzyltrimethylammonium chloride, benzalkonium chloride, and alkylamine salt types such as monomethylamine hydrochloride, dimethylamine hydrochloride, trimethylamine hydrochloride, and butyl chloride Types having a pyridine ring such as pyridinium and dodecylpyridinium chloride may be used alone or in combination.

  Nonionic surfactants include alkylphenol ethylene oxide adduct and higher alcohol ethylene oxide adduct, polyoxyethylene fatty acid ester, fatty acid ethylene oxide adduct and polyethylene glycol fatty acid ester, higher alkylamine ethylene oxide adduct and fatty acid amide ethylene oxide adduct, Polyoxyethylene alkylamine and polyoxyethylene fatty acid amide, polypropylene glycol ethylene oxide adduct, nonionic surfactant glycerin and pentaerythritol fatty acid ester, sorbitol and sorbitan fatty acid ester, sucrose fatty acid ester, alkylpolyglycoside fatty acid, alkanol Examples include amides. These may be used alone or in combination.

  Amphoteric surfactants include alkylbetaine types such as lauryldimethylaminoacetic acid betaine and dodecylaminomethyldimethylsulfopropylbetaine, fatty acid amidepropylbetaine types such as cocamidopropylbetaine, and amino acid types such as sodium lauroylglutamate. An amine oxide type such as lauryldimethylamine N-oxide may be used.

  Furthermore, as the polymeric dispersant, polyurethane prepolymer, styrene / polycarboxylic acid copolymer, lignin sulfonate, carboxymethyl cellulose, acrylate, polystyrene sulfonate, acrylamide, polyvinyl pyrrolidone, casein, gelatin, As the oligomer and prepolymer, unsaturated polyester, unsaturated acrylic, epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, polybutadiene acrylate, silicone acrylate, maleimide, polyene / polythiol, alkoxy oligomer, etc. may be used. .

  In addition to the configuration described above, the resist ink of this embodiment may further contain additives, functional agents, and the like as necessary. Additives or functional agents include thickeners, viscosity modifiers, stabilizers, drying modifiers, plasticizers, desiccants, curing agents, anti-skinning agents, leveling agents, anti-sagging agents, antifungal agents, antibacterial agents Agents, heat ray absorbents, lubricants, catalysts, antireflection materials, and the like, and these may be used in appropriate mixture.

  Since the screen used in the screen printing plate for forming the resist layer 12 has a reverse pattern of the thin film thin line pattern 14, it is desirable that the screen has the same level as the screen of the screen printing plate used for forming the thin film 13. . As screens, mesh fabrics that are woven so that warp yarns and weft yarns made of metal or synthetic fiber cross each other, or metal with many holes through which resist ink passes by etching on a metal flat plate There are metal plate-like porous bodies manufactured by masking and electroforming, and any of them can be used, but a mesh fabric is preferable from the viewpoint of manufacturing cost, handleability, and durability.

  The thin film thin line pattern 14 in the present invention is a thin line pattern 13 having an average thickness of 2 μm or less and a minimum width of 100 μm or less. Here, the present invention can be suitably used in forming the thin film thin line pattern 14 having an average thickness of the thin film 13 of 1 μm or less. The pattern printing of the thin film 13 of 1 μm or less by screen printing is hardly performed, and generally, the thinner the printed film thickness, the lower the viscosity of the thin film ink used, and the easier it is for the thin film ink to bleed. Formation becomes difficult. Since the thin film thin line pattern 14 is formed, the minimum thickness of the thin film 13 becomes larger than 0 μm and the minimum width of the thin line pattern becomes larger than 0 μm.

  A thin line pattern in which the minimum line width or dot diameter is 100 μm or less when a pattern is formed by screen printing using a relatively high viscosity ink, such as electrode printing or resist layer printing in this embodiment. In the case of the above, the wire diameter of the mesh fabric to be used is not more than the pattern width, preferably not more than 2/3 times the pattern width, more preferably not more than 1/2 times. However, since the strength of the wire decreases as the wire diameter of the mesh fabric decreases, it is preferable to increase the number of meshes in order to give the mesh fabric a strength that enables screen printing. When a mesh fabric is woven with warp and weft having a wire diameter of 25 μm or less, the number of meshes in the direction in which the warp and weft extend is preferably 325 or more. Here, the number of meshes means the number of wefts or warps per 25.4 mm (1 inch) length parallel to the warps or wefts of the mesh fabric.

  The mesh fabric used for forming the thin thin wire pattern 14 needs to have a high strength of the wire, and a liquid crystal polymer or metal is used as the wire. As the metal wire, soft stainless steel is widely used, but if a mesh fabric woven from high-strength stainless steel or tungsten with higher Young's modulus is used as the wire, the rate of increase in the number of meshes even if the wire diameter is reduced Is more suitable for forming the thin-film thin line pattern 14. The screen used to form the thin line pattern 14 having a minimum line width or dot diameter of 50 μm or less is formed of a thin wire having a wire diameter of 20 μm or less, and has a high number of warp and weft meshes of 380 or more. It is preferable to use a woven fabric.

Furthermore, a mesh fabric woven using high-strength stainless steel or tungsten, such as a high Young's modulus, and having a warp and weft wire diameter of 25 μm or less and a warp and weft mesh count of 325 or more, respectively. If the Young's modulus is 10,000 N / mm ² or more, the durability during use is remarkably improved, so that the positional deviation at the time of printing can be suppressed to a very small value even if it is continuously used. Here, the Young's modulus of the mesh fabric is a Young's modulus calculated according to the strip method relating to the measurement of tensile strength and elongation of JIS L 1096. Specifically, a curve of elongation and tensile load when applying a tensile load at a rate of 100 mm / min to a strip sample cut to a width of 50 mm and a gripping interval of 200 mm parallel to the warp or weft of the mesh fabric. From the S-S curve, the Young's modulus calculated as the average between the two points using the elongation at two points of the tensile load of 100 N / 5 cm and 200 N / 5 cm, the number of yarns in the tensile direction and the yarn diameter is the mesh. The Young's modulus of the fabric.

  In the present embodiment, the resist ink printed on the substrate 11 is dried and solidified by a method suitable for the configuration of the resist ink, such as heating, ultraviolet irradiation, and electron beam irradiation. A pattern (a reverse pattern of the thin thin line pattern 14) is formed. Here, the average thickness of the resist layer 12 is preferably not less than 2 times and not more than 20 times the average thickness of the predetermined thin film fine line pattern 14. The average thickness means the average value of the thickness of the resist layer 12 or the thin film thin line pattern 14 on the basis of the surface of the substrate 11, for example, a contact type (stylus type) that is a means for measuring the surface roughness. Or an arithmetic average value of a plurality of points selected at random using a non-contact type (optical type or the like) measuring instrument or an integrated average value of measurement patterns. When the average thickness of the resist layer 12 is less than twice the average thickness of the thin film thin line pattern 14, the resist layer 12 is not formed when the thin film ink is printed in a region where the resist layer 12 is not formed. The thin film ink does not stay in the region, and it becomes easy to diffuse on the upper surface of the resist layer 12 beyond the periphery of the resist layer. Here, the peripheral edge portion of the resist layer is a region adjacent to the edge of the resist layer 12 on the upper surface of the resist layer 12. In this case, the permeation of the cleaning liquid from the thickness direction of the resist layer 12 is suppressed at the time of cleaning, and it becomes difficult to remove the resist layer 12, or it takes too much time to remove the resist layer 12. Further, when the average thickness of the resist layer 12 is larger than 20 times the average thickness of the thin-film thin line pattern 14, unevenness is formed between the region where the resist layer 12 is formed and the region where the resist layer 12 is not formed. Since it becomes remarkable, the screen wrinkle of the screen printing plate at the time of thin-film ink printing cannot follow the movement of the squeegee, making stable printing difficult, or the groove formed between the two resist layers 12 (that is, There is a problem that the thin film thin line pattern 14 after printing is disconnected by air remaining without spreading the thin film ink over the entire region where the thin film thin line pattern 14 is to be formed.

  Next, the substrate 11 on which the resist layer 12 having the reverse pattern is formed is screen-printed using a screen printing plate for forming a thin film thin line pattern having a pattern equal to or larger than the width (design value) of the predetermined thin film thin line pattern 14. Print the ink for thin film. Here, the screen printing plate for forming the thin film fine line pattern is positioned with respect to the position where the screen printing plate for forming the resist layer is disposed. The means for positioning these screen printing plates can be appropriately selected. For example, positioning markers (so-called “register mark” marks) are formed at the four corners of the screen printing plate, and the screen printing plate is positioned in micron units with a CCD camera attached to the printing machine using this marker as a reference. To do is widely done.

  In order to spread the thin film ink over the entire region where the thin film thin line pattern 14 is to be formed (that is, the groove formed between the two resist layers 12), in the thin film ink, the solid content after drying and solidification It is necessary to reduce the amount of components. Therefore, the viscosity of the thin film ink is preferably 0.01 Pa · S or more and 40 Ps · S or less. If the viscosity of the ink for the thin film is less than 0.01 Pa · S, the ink for the thin film cannot be sufficiently held on the upper part of the screen printing plate, and even a slight vibration of the squeegee operation is easy from the opening of the screen ridge. Since the thin film ink is discharged, it is difficult to control the discharge amount, or the discharged thin film ink spreads widely on the upper surface of the resist layer 12, making it difficult to remove the resist layer 12 during cleaning. There is. Further, if the viscosity of the thin film ink is higher than 40 Pa · S, the thin film ink is not sufficiently filled in the region where the thin film thin line pattern 14 is to be formed (that is, the groove formed between the two resist layers 12). There are disadvantages such as chipping in the thin film thin line pattern 14 after printing. That is, when the thin film ink is printed, in order to sufficiently replace the air existing in the groove between the two resist layers 12 with the thin film ink, the viscosity needs to be 40 Pa · S or less. It is.

  Here, the viscosity of the ink for a thin film in the present embodiment is a value measured with an RST rheometer (Hideki Seiki Co., Ltd., model RST-CPS) which is a widely used Brookfield viscometer. The shear rate in the viscosity measurement was the geometric mean value when measured at two points of 10 [1 / sec] and 100 [1 / sec]. However, in the thin film ink, the viscosity dependency on the shear rate is extremely low, and the measured values at the two points almost coincide with each other, so that the thin film ink can be handled as a Newtonian fluid.

  When such a low-viscosity thin film ink is intended to be printed directly on the substrate 11, the thin film ink transferred during printing easily spreads on the upper surface of the substrate 11, so that bleeding at the boundary surface of the print pattern is likely to occur. . The screen printing plate used in the screen printing is composed of an opening and a non-opening which is a mesh fabric, and the thin film ink passes through the opening of the screen printing plate, so that the surface of the substrate 11 is formed. The thin film ink is transferred. The thin film ink transferred to the base material 11 forms a predetermined pattern by spreading to the non-transfer portion of the thin film ink corresponding to the mesh fabric which is a non-opening portion. Bleeding easily occurs at the boundary of the pattern. Moreover, when the surface smoothness of the base material 11 is inferior, the adhesion between the screen of the screen printing plate and the base material 11 is deteriorated, and it becomes difficult to transfer the thin film ink to a desired position of the base material 11. Bleeding at the boundary surface becomes more prominent, and pattern formation with thin lines becomes difficult.

  In this embodiment, since the resist layer 12 having a reverse pattern with the resist ink is provided on the base material 11 in advance, even if the surface smoothness of the base material 11 is inferior, the thin film ink is used as the resist layer. 12 fits in a groove forming a predetermined pattern. Further, even if there is a thin film ink that does not fit in the groove forming the predetermined pattern, the thin film ink can be retained at the periphery of the resist layer. Thereafter, the thin film 13 remaining on the periphery of the resist layer is removed together with the resist layer 12 having a reverse pattern, so that bleeding at the boundary portion of the thin film thin line pattern 14 occurs even when the surface smoothness of the substrate 11 is inferior. It is possible to form a fine line pattern accurately.

  Here, as the surface smoothness of the base material 11, the arithmetic average roughness Ra on the surface of the base material 11 is preferably 5 μm or less. In particular, when the thin film fine line pattern 14 having a thickness of 1 μm or less is formed, the arithmetic average roughness Ra is preferably 5 μm or less. When the arithmetic average roughness Ra is larger than 5 μm, the adhesion of the screen printing plate to the base material 11 is deteriorated, and the resist ink easily flows out to an area outside the original printing area. It is difficult to form the thin film thin line pattern 14 using the film, the uniformity and continuity of the thin film thin line pattern 14 is inferior, and the generated thin film thin line pattern 14 cannot sufficiently perform its original function. This is because the adhesion of the thin film pattern 14 to the base material 11 becomes weak and inconveniences such as poor durability occur.

  In the present embodiment, the pattern of the screen printing plate for printing the thin film thin line pattern is set to a pattern equal to or larger than the width (design value) of the predetermined thin film thin line pattern 14, and alignment is performed at the time of printing the thin film thin line pattern. A pattern of the thin film 13 can be formed in a region where 12 is not formed. Further, even when the thin film ink covers not only the region where the resist layer 12 is not formed but also the upper surface (a part or the whole) of the resist layer 12, it is unnecessary to be formed on the upper surface of the resist layer 12 during cleaning. The resist layer 12 can be easily removed together with the thin film 13.

  Here, the pattern of the thin film 13 is printed by the screen printing plate having a pattern designed so that the surface area of the resist layer 12 covered with the thin film 13 is 60% or less with respect to the total surface area of the upper surface of the resist layer 12. It is preferred that Further, the pattern of the thin film 13 is printed by a screen printing plate having a pattern designed such that the surface area of the resist layer 12 covered with the thin film 13 is 40% or less with respect to the total surface area of the upper surface of the resist layer 12. More preferably. Here, the upper surface of the resist layer 12 is the outer surface of the resist layer 12 parallel to the surface of the substrate 11. A screen printing plate for thin-film thin-line pattern printing having a designed pattern width may be used so that the thin film 13 does not cover an area that is calculated to be larger than 60% of the total surface area of the upper surface of the resist layer 12. When a screen printing plate that covers an area larger than 60% of the upper surface of the resist layer 12 by calculation with the thin film 13 is used, the resist layer 12 is removed when the resist layer 12 is removed from the substrate 11 by washing. The thin film 13 formed on the upper surface of the substrate obstructs the removal of the resist layer 12 by a standard cleaning method, so that the resist layer 12 remains on the substrate 11, or an enhanced jet cleaning or brushing cleaning is required. It takes a long time for cleaning and removal.

  In the present embodiment, as a screen printing plate for forming a resist layer, a screen printing plate that prints a resist layer 12 that is a reverse pattern of a predetermined thin film thin line pattern 14 on a substrate 11 is used to form the thin film thin line pattern 14. The screen printing plate is characterized in that a screen printing plate having a pattern width equal to or larger than the width (design value) of a predetermined thin film thin line pattern is used. In any screen printing plate, the conditions required for the above-described resist layer forming screen printing plate, that is, the condition that the wire diameter is thin, the number of meshes is high, and the strength is high are the same. In addition, there is no difference in the method of creating the screen printing plate for forming the thin film thin line pattern and for forming the resist layer, and a process for forming a desired pattern on the screen printing plate of the present embodiment using a mesh fabric below. explain. As described above, the entire surface of the resist layer 12 can be covered with the thin film 13, and in this case, it is not necessary to form a desired pattern on the screen printing plate.

  FIG. 2 is a model diagram showing a process of forming a screen printing plate on which a desired pattern of this embodiment is formed. FIG. 2A is a cross section of a mesh fabric 21 constituting a screen printing plate, in which a photosensitive resin film 22 is formed on a pattern forming portion of the mesh, and a positive mask (image) having a desired pattern is formed on the surface. The outline shows that the photosensitive resin film 22 not covered with the mask 23 is exposed and cured by irradiating the ultraviolet ray UV with the film 23 or the glass mask) 23 overlapped. FIG. 2B shows a cured photosensitive resin film having a predetermined pattern by removing (developing) the photosensitive resin film 22 having a desired pattern that has not been cured by washing or the like after the exposure processing of FIG. It is sectional drawing of the mesh fabric 21 in which 31 was formed.

  A direct printing method for forming a photosensitive resin film 22 having a predetermined thickness is widely used as a screen printing plate for screen printing by repeatedly applying and drying a photosensitive emulsion on a pattern forming portion of a mesh fabric 21 to which a certain tension is applied. It has been. Further, the direct method of transferring a film made of the photosensitive resin film 22 to the mesh fabric 21 is also used taking advantage of its simplicity and characteristics. In any method, after a photosensitive resin film 22 having a predetermined thickness is formed, a positive mask 23 having a desired pattern is overlaid on the surface, and the exposed portion of the photosensitive resin film 22 is irradiated with ultraviolet rays UV. After the exposed portion of the photosensitive resin film 22 is cured, the uncured resin film portion can be washed away to form a desired pattern.

  In the state shown in FIG. 2A, in the portion where the photosensitive resin film 22 is cured, the ultraviolet UV passing through the opening 22 of the mask 23 is transmitted to the inside of the photosensitive resin film 22, and the photosensitive resin film. 22 is cured. On the other hand, in the part from which the photosensitive resin film 22 is removed (the part corresponding to the opening 32 formed by removing the resin film 22 in FIG. 2B), the ultraviolet ray UV is shielded by the mask 23 and is photosensitive. Resin 22 remains uncured.

  As a screen printing plate used for screen printing, a so-called full screen printing plate or a so-called combination screen printing plate is used. In full-screen screen printing plates, synthetic fiber mesh and metal fiber mesh are bonded and fixed to a resin or metal frame with tension applied, and the screen part inside the frame is made from a single material. Become. In the combination screen printing plate, a mesh such as a synthetic fiber that is bonded to a frame and constitutes a peripheral portion of the screen, and a mesh such as a metal that is formed in the central portion of the screen and is actually used for pattern formation. Consists of. In a combination screen printing plate, a screen composed of a mesh such as synthetic fiber is generally called a support screen. A schematic diagram of a typical combination screen printing plate 100 is shown in FIG.

  The combination screen printing plate 100 shown in FIG. 3 includes a frame 101, a pattern forming screen 102, and a support screen 103. The frame 101 is a holding frame that holds the screens 102 and 103. The pattern forming screen 102 is a screen that actually forms a pattern in the combination screen printing plate 100. As the pattern forming screen 102, for example, a metal mesh fabric can be used. The support screen 103 is fixed to the frame 101 and supports the pattern forming screen 102. The support screen 103 is a screen disposed around the pattern forming screen 102 and is a screen formed of a material such as synthetic fiber as described above.

  A metal fiber mesh can be used as the screen of the whole surface screen printing plate. However, soft stainless steel, which is widely used as a metal fiber, may exceed the elastic limit of metal, that is, the yield point, due to repeated expansion and contraction of the screen as the number of screen printing increases. For this reason, when a metal fiber mesh is used as a screen for a full-screen screen printing plate, the printing accuracy tends to decrease particularly with time, and there may be a problem in durability.

  Further, in high-definition printing, that is, screen printing for forming a fine or fine pattern, a metal fiber mesh capable of weaving a thin wire having a thickness of 20 μm or less which is difficult to produce with synthetic fibers at high density is suitable. However, metal fiber mesh is expensive to manufacture, and its use as a full-screen screen printing plate is disadvantageous in terms of cost. Therefore, a combination screen printing plate using a metal fiber mesh is used only for the part used for pattern formation. Often done. In this embodiment, a straight screen printing plate can be used. However, in forming the thin film thin line pattern 14, the combination screen printing plate 100 is used for both resist layer printing and thin film thin line pattern printing. Is preferred.

  A combination screen printing plate 100 using a soft stainless mesh fabric as the pattern forming screen 102 and a synthetic fabric mesh fabric as the support screen 103 is widely used. In order to increase the durability against the increase in the thickness, it is preferable to use a mesh fabric with higher strength as the pattern forming screen 102 and the support screen 103.

  Examples of the high strength mesh fabric include a hard high strength stainless mesh fabric and a tungsten mesh fabric. In these high-strength mesh fabrics, the stress / strain curve shows a linear relationship in almost the entire region, so that the change in printing accuracy with time is extremely small, and printing with good reproducibility of the printing pattern is possible. Further, high strength stainless steel and tungsten have higher tensile strength than ordinary soft stainless steel, so that they are excellent in durability, reproducibility, and can be printed repeatedly. Furthermore, because of the mechanical characteristic that the yield point is in the vicinity of the breaking strength, local deformation of the pattern forming screen 102 is suppressed, and the pattern forming screen 102 has a wide area where a pattern can actually be formed. And the utilization rate as a screen printing plate is increased.

  When a high-strength stainless steel or tungsten mesh fabric is used as the pattern forming screen 102, a conventional polyester or nylon mesh fabric can be used as the support screen 103. However, it is preferable to use a synthetic elastic mesh fabric having a high elastic modulus and high strength as the support screen 103 because printing with higher definition and higher positional accuracy is possible.

  Examples of high elastic modulus and high strength synthetic fibers include aramid, polyarylate, ultrahigh molecular weight polyethylene, polyparaphenylene benzobisoxazole (PBO), polyparaphenylene benzobisthiazole (PBT), and polyparaphenylene benzobisimidazole. (PBI), carbon fibers, other liquid crystal polymers, and two or more kinds of materials mainly composed of the above materials, for example, core-sheath type composite fibers. In the core-sheath type composite fiber, the materials different from each other can be used as the material of the core part and the sheath part.

  In this embodiment, after the resist layer 12 having the reverse pattern is formed on the substrate 11, the pattern of the thin film 13 is printed by screen printing using a screen printing plate for forming a thin film thin line pattern. When printing the pattern of the thin film 13, it is necessary to transfer the thin film ink to the region of the surface of the base material 11 where the resist layer 12 is not formed without deviation, and the width of the thin film thin line pattern 14 becomes smaller. The influence of the positional accuracy when the pattern of the thin film 13 is printed becomes large. Therefore, when the combination screen printing plate 100 is used, it is more preferable to use the high-strength mesh fabric as described above as the pattern forming screen 102 and the support screen 103.

  Moreover, since the screen printing plate for forming a thin film thin line pattern is used for printing the pattern of the thin film 13 on the substrate 11 on which the resist layer 12 is formed, the thickness of the screen printing plate (particularly the screen) is used. It is desirable to reduce the amount of ink for thin film to be transferred. If the thickness of the screen is reduced, the amount of thin film ink held on the screen can be suppressed, and as a result, the amount of thin film ink transferred to the substrate 11 can be suppressed. In particular, by using a mesh fabric by so-called calendering, which is smoothed by pressure processing, as the screen of the screen printing plate, the thickness of the screen printing plate can be reduced and is suitable for printing the pattern of the thin film 13. .

  The thin film ink transferred to a region on the substrate 11 where the resist layer 12 is not formed (which may include the upper surface of the resist layer 12) is composed of the thin film ink such as heating, ultraviolet irradiation, and electron beam irradiation. The thin film 13 is formed by being dried and solidified by a method adapted to the above. Thereafter, by removing the resist layer 12 by washing, a predetermined thin film thin line pattern 14 can be formed on the substrate 11. Here, even if the dried and solidified thin film 13 covers the periphery of the resist layer, the unnecessary thin film 13 covering the periphery of the resist layer can be removed at the same time by washing and removing the resist layer 12. A predetermined thin film thin line pattern 14 can be formed on 11. Even if the entire surface of the resist layer 12 is covered with the thin film 13, as described above, the thickness of the thin film 13 covering the entire surface of the resist layer 12 can be reduced. A predetermined thin film thin line pattern 14 can be formed thereon.

  Here, a cleaning solvent corresponding to the constituent components of the resist layer 12 may be used for cleaning and removing the resist layer 12, and the cleaning solvent is not particularly limited. If a water-soluble resist layer 12 is used, the cleaning solvent may be only water, which is preferable from the viewpoints of handling in the cleaning process, safety, complexity of waste liquid treatment and cost. In addition, if no adverse effects such as peeling or disconnection of the thin thin film pattern 14 occur, the resist layer can be obtained by heating the cleaning solvent, using an ultrasonic cleaner, or appropriately combining jet cleaning or brushing cleaning. 12 may be removed in a short time, or a process such as removing the residue of the resist layer 12 may be performed.

  According to the present embodiment, the resist layer 12 having a reverse pattern with respect to the predetermined thin film thin line pattern 14 is provided in advance on the substrate 11 by screen printing, and then the region where the resist layer 12 is not formed (the resist layer 12 A predetermined thin film thin line pattern 14 can be formed by removing the resist layer 12 after the pattern of the thin film 13 is formed by screen printing on the upper surface (which may include the upper surface). As described above, since the predetermined thin film fine line pattern 14 can be formed only by screen printing, it does not require a large and expensive facility unlike the dry method, so the productivity is low and the productivity is low. Application to pattern printing on a large-area substrate 11 with a limit is possible.

  Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples.

Example 1
As described below, a combination screen printing plate 100 including a pattern forming screen 102 and a support screen 103 was produced as a screen plate for forming a resist layer and forming a thin film pattern. Here, a combination screen printing plate for forming a resist layer (hereinafter referred to as a resist layer plate) and a combination screen plate for forming a thin film pattern (hereinafter referred to as a thin film pattern plate) are the basis for pattern formation. Only the pattern of the mask 23 is different, and the method for producing the screen plate is the same.

  First, as a mesh for the pattern forming screen 102 (referred to as a pattern forming mesh), a screen mesh woven into 400 mesh using a general soft stainless steel wire having a wire diameter of 19 μm (manufactured by NBC Metal Mesh Co., Ltd., M10-). 400-019) was cut into a square of 240 mm × 240 mm with an angle of 23 ° with respect to the warp direction. As a mesh for the support screen 103 (referred to as a support mesh), a mesh (EX-225HD, manufactured by NBC Meshtec Co., Ltd.) in which a yarn made of polyester having a fiber diameter of 55 μm is woven into 225 mesh is used. Were prepared by cutting them into parallel squares of 500 mm × 500 mm. Then, the sides of the pattern formation mesh and the support mesh were parallel, and the two meshes were overlapped so that the center portions of these meshes coincided. Next, the peripheral portion of the pattern forming mesh was bonded to the support mesh with an adhesive with the width of the bonded portion being 10 mm each. Thereafter, a part of the support mesh that overlaps the pattern forming mesh inside the bonded portion was cut off to obtain a combination screen in which the pattern forming screen 102 and the support screen 103 were integrated.

  As the frame body 101 of the combination screen printing plate 100, an aluminum frame body (outer dimension: 320 mm × 320 mm, inner shape dimension: 290 mm × 290 mm, thickness 20 mm, thickness 1.5 mm hollow structure) 101 was used. A combination screen in which the frame 101 and the pattern forming screen 102 and the support screen 103 are integrated is arranged so that one side of the frame 101 and the warp direction of the support screen 103 are parallel to each other. It was stretched by a regular method. Here, the tension at the center of the pattern forming screen 102 was 1.0 mm as measured using a tension gauge STG-75B (manufactured by Sun Giken).

  A tension plate with a combination screen is vertically mounted on a bucket type coating machine. Then, by applying and drying a diazo photosensitive emulsion (trade name: V1 emulsion, manufactured by NBC Meshtec Co., Ltd.) 5 times by the bucket method on the pattern forming screen 102 of the tension plate, the thickness of 10 μm is increased. A photosensitive resin film 22 was formed (hereinafter referred to as a coating plate).

In the resist layer plate, a coating plate on which a photosensitive resin film 22 is formed and a mask 23 having a predetermined thin film thin line pattern (hereinafter also referred to as a positive pattern) shown in FIG. -1000FL), and the mask 23 was brought into close contact with the photosensitive resin film 22 of the coating plate by a pressure bonding method. The area for forming the positive pattern on the pattern forming screen 102 was 150 mm × 150 mm, and four positive patterns were arranged at equal intervals in each of the X and Y directions orthogonal to each other. In the X direction, the width of the pattern line extending in the Y direction (dimension in the X direction) is 30 μm, 50 μm, 75 μm, and 100 μm, and the interval between two adjacent pattern lines in the X direction is 30 μm, 50 μm, 75 μm, and 100 μm. Four striped positive patterns are arranged. In the Y direction, four striped positive patterns having the same pattern line width and interval are arranged. The coating plate to which the mask 23 was adhered was exposed for 100 seconds at a power of 7.2 mW / cm ² using a metal halide lamp as a light source to obtain an appropriate exposure amount. Thereafter, the uncured photosensitive resin film 22 is dissolved and removed by washing in warm water of 40 ° C., and a resist layer forming combination plate (hereinafter also referred to as a resist layer plate) on which a pattern is formed is obtained. Obtained.

  The thin film pattern plate is the same as that for forming the resist layer plate except that the mask 23 having a reverse pattern (hereinafter also referred to as a negative pattern) used in the production of the resist layer plate is used. Created by the method. Here, in the area (150 mm × 150 mm) where the negative pattern is formed, four positive patterns are arranged at equal intervals in each of the X direction and the Y direction. In the 16 positive patterns shown in FIG. 5, the widths and intervals of the pattern lines are different from each other. For positive patterns arranged in the Y direction, the coverage of the thin film 13 on the upper surface of the resist layer 12 formed by the resist layer plate described above is four types of 0%, 20%, 40%, and 60%. Thus, the width and interval of the pattern lines are set. Here, the coverage of the thin film 13 is not a value when the upper surface of the resist layer 12 is actually covered with the thin film 13, but of a pattern (pattern for forming the resist layer 12) formed on the resist layer plate. It means the coverage calculated from the width W1 and the width W2 of the pattern (pattern for forming the thin film 13) formed on the thin film pattern plate.

A method for calculating the coverage will be described with reference to FIG. In FIG. 6, W11 is the width of the resist layer 12, and W12 is the interval between two adjacent resist layers 12. W21 is the width of the thin film 13, and W22 is the distance between two adjacent thin films 13. It is assumed that the midpoint of the region of width W11 coincides with the midpoint of the interval W22. In addition, it is assumed that the midpoint of the area of the interval W12 coincides with the midpoint of the area of the width W21. At this time, the coverage R is represented by the following formula (1).

  When the coverage of the thin film 13 is 0%, the thin film 13 is formed only in the region where the resist layer 12 is not formed, and the thin film 13 is not formed on the upper surface of the resist layer 12. Here, the thin film pattern plate formed by the mask 23 having the negative pattern shown in FIG.

  A polyester film was used as the substrate 11, and TSM-397 manufactured by Kyoyo Chemical Industry Co., Ltd. was used as the resist ink. Then, using the resist layer plate prepared above, the resist ink was printed under the following printing conditions, the resist ink was dried, and a sample in which the resist layer 12 was formed was prepared. As the thin film ink, an organic material comprising polyvinyl carbazole, 2-4 biphenylyl 6-phenylbenzoxazole, and coumarin 6 dissolved in a solvent isophorone so that a mass ratio of 160: 40: 1 is 20% by mass. A light emitting layer composition liquid for EL was used. The viscosity of this solution was 1 Pa · S, and the ink for thin film was printed on the sample on which the resist layer 12 was formed under the same printing conditions as when the resist layer 12 was formed. In order to print the thin film ink on the sample on which the resist layer 12 is formed, accurate alignment is necessary. Therefore, by using a CCD camera, the thin film pattern plate A was installed within an error range of ± 1 μm or less with respect to the installation position of the resist layer plate. As described above, for example, by using a marker (a so-called “register mark” mark), the resist layer plate and the thin film pattern plate A can be positioned within an error range of ± 1 μm or less.

The resist layer forming printing and the thin film fine line pattern forming printing were performed by the following printing machine and printing conditions.
Printing machine: MT-320Z manufactured by Microtec
Squeegee: Urethane rubber flat squeegee Squeegee hardness: 70 °
Squeegee angle: 70 °
Squeegee width: 170mm
Printing speed: 100mm / sec
Total pressure: 130KPa
Actual printing pressure: + 30KPa
Resist ink: TSM-397 manufactured by Kyoyo Chemical Industry Co., Ltd., viscosity 25 Pa · S (25 ° C.)
Thin film ink: Composition for organic EL light emitting layer, viscosity 1 Pa · S (25 ° C.)
Printing object: Polyester film Temperature / Humidity: 22 ° C-23 ° C / 50-60%
Note that the clearance is the minimum distance at which the screen printing plate can be separated in each screen printing plate.

  After drying each sample on which the pattern of the thin film 13 was printed, the resist layer 12 was washed and removed by washing with warm water of about 40 ° C. to form the thin film fine line pattern 13. Samples in which the coverage of the thin film 13 was 0%, 20%, 40%, and 60% were designated as Example 1a, Example 1b, Example 1c, and Example 1d, respectively.

(Example 2)
In Example 1, a thin film pattern plate B was prepared such that the coverage of the thin film 13 was 80% and 100%, and the thin film 13 was printed. The portion where the coverage of the thin film 13 of the thin film pattern plate B is 100% means a portion where the photosensitive resin film 22 is not formed. Here, a sample in which the coverage of the thin film 13 was 80% was taken as Example 2a. Moreover, the sample whose coverage of the thin film 13 is 100% was made into Example 2b. The printing conditions were the same as in Example 1 except that the thin film pattern plate B was used.

(Example 3)
As the thin film ink, an organic EL light emitting layer ink adjusted to have a viscosity of 0.1 Pa · S was used. This organic EL light emitting layer ink was obtained by dissolving polyvinyl carbazole, 2-4 biphenylyl 6 phenylbenzoxazole, and coumarin 6 in a solvent of isophorone so that a mixture of 160: 40: 1 by mass ratio was 10% by mass. Is. A sample in which the thin film thin line pattern 14 was formed was obtained in the same manner as in Example 1 except for the viscosity of the thin film ink.

Example 4
In contrast to Example 1, the material of the substrate 11 was replaced with glass, and an ITO ink having a viscosity of 18 Pa · S (trade name: Nano Disper, manufactured by Okuno Pharmaceutical Co., Ltd.) was used as the thin film ink. Except for this, a sample on which the thin film fine line pattern 14 was formed was obtained in the same manner as in Example 1.

(Example 5)
The thin film ink having a viscosity adjusted to 0.01 Pa · S was prepared by diluting the thin film ink used in Example 3 with an isophorone solvent. Further, a thin film ink having a viscosity adjusted to 40 Pa · S by diluting a silver paste (TEC-PA051 manufactured by InkTec Co.) having a viscosity of 190 Pa · S with ethyl carbide acetate was used. A sample was prepared in the same manner as in Example 1 except for this. Here, in Examples 5-8, it was set as evaluation in the pattern whose coverage of the thin film 13 is 20%. The case where a thin film ink having a viscosity of 0.01 Pa · S was used was designated as Example 5a, and the case where a thin film ink having a viscosity of 40 Pa · S was used was designated as Example 5b.

(Example 6)
As a resist ink, in place of TSM-397 manufactured by Kyodo Chemical Industry Co., Ltd. used in Example 1, a water-soluble polymer PVP3500 (polyvinylpyrrolidone) manufactured by Acros Organics was used in JELCON MS-03C manufactured by Jujo Chemical Co. What mixed 3 mass% was used. Except for this, a sample on which the thin film fine line pattern 14 was formed was obtained in the same manner as in Example 1.

(Example 7)
In order to see the influence of the surface roughness of the base material 11 instead of the polyester film that is the base material 11 used in Example 1, Sumitomo 3M Co., Ltd., abrasive paper # 8000 was used. The arithmetic average roughness Ra of the surface was set to 0.4 μm (Example 7a). Moreover, the arithmetic average roughness Ra of the base material 11 was 2.1 μm using abrasive paper # 4000 (Example 7b). Furthermore, using the abrasive paper # 1000, the arithmetic average roughness Ra of the substrate 11 was set to 3.8 μm (Example 7c). Except for this, a sample on which the thin film fine line pattern 14 was formed was obtained in the same manner as in Example 1.

(Example 8)
As the pattern forming screen 102, a screen (M-10, manufactured by NBC Metal Mesh Co., Ltd.) smoothed so that the mesh thickness is reduced by 40% as compared with the pattern forming screen 102 used in Example 1 by pressure processing. 400-019 Cal). Other than this, a sample in which the thin-film thin line pattern 14 was formed by the same method as in Example 1 was obtained (Example 8a). Further, as the pattern forming screen 102, a screen mesh (manufactured by NBC Metal Mesh Co., Ltd., M-30, 360-016) in which a high-strength stainless steel wire having a wire diameter of 16 μm was woven into 360 mesh was used. Here, as the support screen 103, V330 (manufactured by NBC Meshtec Co., Ltd., trade name V screen) in which yarns having a fiber diameter of 23 μm made of polyarylate are woven into 330 mesh was used. Except for this, a sample in which the thin-film thin line pattern 14 was formed was obtained in the same manner as in Example 1 (Example 8b). As the pattern forming screen 102, a screen mesh (M-10, 325-024, manufactured by NBC Metal Mesh Co., Ltd.) woven into a 325 mesh using a general soft stainless steel wire having a wire diameter of 24 μm was used. (Example 8c). As the pattern forming screen 102, a screen mesh (M-10, 250-030, manufactured by NBC Metal Mesh Co., Ltd.) woven into 250 mesh using a general soft stainless steel wire having a wire diameter of 30 μm was used. (Example 8d). Except for this, a sample on which the thin film fine line pattern 14 was formed was obtained in the same manner as in Example 1.

(Comparative Example 1)
Without forming the resist layer 12, the pattern printing of the thin film 13 was directly performed on the base material 11 of the polyester film. As the thin film ink, an ITO ink having a viscosity of 18 Pa · S (trade name Nano Disper, manufactured by Okuno Pharmaceutical Co., Ltd.) was used (Comparative Example 1a). Moreover, the silver paste (InkTec Co. make TEC-PA051 diluted with ethyl carbide acetate) which adjusted the viscosity to 100 Pa * S was used (comparative example 1b). The printing conditions were the same as in Example 1, and the evaluation was performed with a pattern in which the coverage of the thin film 13 was 0%.

(Comparative Example 2)
Without forming the resist layer 12, the pattern printing of the thin film 13 was directly performed on the base material 11 of the polyester film. Here, the thin film pattern plate is prepared using a combination screen printing plate 100 on which a photosensitive resin film 22 is formed and a mask 23 designed to form line-shaped patterns with a line width of 100 μm at intervals of 500 μm. did. The thin film ink and printing conditions used in screen printing were the same as in Example 1.

(Evaluation method)
As the evaluation of the formation of the thin film thin line pattern 14, the ease of cleaning of the resist layer 12, the removed state of the resist layer 12 by the cleaning, and the striped thin lines of the thin film thin line pattern 14 are connected by bleeding of the thin film ink. On the contrary, whether or not the thin wire is broken was evaluated by visual observation by enlarging the surface of the substrate 11 in Examples and Comparative Examples using a coordinate measuring machine PCM-1300 (manufactured by Sokkia Co., Ltd.).

(Evaluation method of cleaning removal property of resist layer 12)
Whether the resist layer 12 having a pattern opposite to the pattern of the mask 23 shown in FIG. 4 can be removed by standard cleaning, whether strong jet cleaning or brushing cleaning is required, and whether or not the resist layer 12 remains after cleaning. The degree was evaluated by visual observation using the coordinate measuring machine PCM-1300 (manufactured by Sokkia Co., Ltd.). The case where there is no residue of the resist layer 12 by standard cleaning, the case where there is no residue of the resist layer 12 if strong cleaning is performed, and the case where the residue of the resist layer 12 remains slightly even by strong cleaning. The case where the resist layer 12 could not be removed sufficiently by washing was evaluated as x and evaluated in four stages.

(Evaluation method of formability of thin film thin line pattern 14)
The presence or absence of defects such as connection and disconnection of the thin film pattern 14 was evaluated by visual observation using the coordinate measuring machine PCM-1300 (manufactured by Sokkia Co., Ltd.). As the evaluation rank, when the line width is 50 μm or more, there is no defect, and when the line width is 30 μm, the defect is 20% or less. Evaluation AAA, when the line width is 50 μm or more, there is no defect, evaluation AA, line width Is evaluated as A when the line width is 100 μm and there is no defect B. When the line width is 100 μm and the defect is 50% or less, the evaluation is C. When the line width is 100 μm The case where the above defects were higher than 50% was designated as evaluation D.

  Here, as an example of formation of a typical thin film thin line pattern 14, FIG. 7 shows a case where the width of the pattern line is 50 μm and the interval between the two pattern lines is 50 μm in Example 1b. FIG. 7 shows the total value of the width (50 μm) and the interval (50 μm).

  In Examples 1 to 8 and Comparative Examples 1 and 2, the type (line diameter and mesh number) and elastic modulus of the pattern forming screen 102 and the support screen, the type of resist ink, the viscosity of the thin film ink, the resist layer Table 1 shows the evaluation results of the coverage of the thin film 13 on the surface of 12, the surface roughness of the substrate 11 (arithmetic average roughness Ra), the washability of the resist layer 12, and the formability of the thin film thin line pattern 14. Here, in the evaluation of the formability of the final thin film fine line pattern 14, C rank or higher is required.

  As shown in Table 1, the lower the coverage, the better the cleaning and removing performance of the resist layer 12. That is, since the resist layer 12 is more easily peeled as the coverage is lower, a finer thin film pattern 14 can be formed. When the coverage is high, the discharge amount of the thin film ink increases, and the area ratio of the thin film 13 formed on the resist layer 12 (the ratio of the area where the thin film 13 is formed to the total area of the upper surface of the resist layer 12) ) Or the thickness of the thin film 13 formed on the resist layer 12 is increased, it becomes difficult to remove the resist layer 12 by cleaning. Further, if the resist layer 12 is peeled off by strengthening the cleaning, a part of the thin film thin line pattern 14 is also peeled off. In particular, the finer thin film thin line pattern is likely to be peeled off.

  In Example 1, the average thickness of the thin film 13 was approximately 0.5 μm regardless of the coverage, and the average thickness of the resist layer 12 was 3.3 μm.

  In the case of Example 3 where the viscosity of the thin film ink is lower than that of the other examples, the average thickness of the thin film 13 is as thin as 0.2 μm, so that the resist layer 12 can be easily removed by cleaning. For this reason, even if the coverage is high, the thin film thin line pattern 14 is easily formed. On the contrary, when the viscosity of the thin film ink is increased as in Example 4, the average thickness of the thin film 13 is increased to 0.77 μm, and the resist layer 12 tends to be difficult to peel off.

  As the coverage is lower, the thin film 13 covering the resist layer 12 is reduced, and therefore the resist layer 12 can be easily peeled off by cleaning. Therefore, it can be said that a lower coverage is desirable in terms of cleaning and removing the resist layer 12. Here, if the coverage is too low, there is a difficulty in that a more precise workability is required for the alignment of the screen printing plate for forming the pattern of the thin film 13 after the formation of the resist layer 12. In screen printing, as the number of times of printing increases, the pattern forming screen 102 constituting the screen printing plate 100 is subjected to plastic deformation due to expansion and contraction. Therefore, even if the initial alignment is strictly performed, the number of times of screen printing is reduced. As the number increases, the positional deviation of the pattern of the thin film 13 tends to occur gradually. Therefore, it is preferable to increase the coverage to some extent in consideration of workability of screen printing and plastic deformation of the pattern forming screen 102. Further, when the thin film 13 is formed on the resist layer 12, the lower the viscosity of the thin film ink, the easier the thin film ink spreads on the resist layer 12. Therefore, the coating rate is set in consideration of the viscosity of the thin film ink. I can decide.

  In the conventional method in which pattern printing is directly performed on the substrate 11 without forming the resist layer 12, no pattern having a line width of 100 μm was formed even in Comparative Example 1a having a relatively high viscosity. The viscosity of the thin film ink capable of forming a pattern having a line width of 100 μm was about 100 Pa · S in Comparative Example 1b, but the average thickness of the pattern of the thin film 13 in Comparative Example 1b was 2.1 μm, which was 1 μm. It was not the following thin film. Here, the pattern in the comparative example 1b is shown in FIG. 200 μm shown in FIG. 8 is the total value of the line width of the pattern and the interval between the two patterns. In Comparative Example 2, as shown in FIG. 9, the linearity is inferior at both ends in the width direction of the pattern, and the average width of the pattern is widened to about 230 μm, making it difficult to form the thin film thin line pattern 14. Met.

DESCRIPTION OF SYMBOLS 11: Base material 12: Resist layer 13: Thin film 14: Thin wire pattern 21: Mesh fabric 22: Photosensitive resin film 23: Mask UV: Ultraviolet ray 31: Cured photosensitive resin film 32: Opening part 100: Combination screen printing plate 101: Frame 102: Screen for pattern formation 103: Screen for support

Claims (9)

A method of forming a predetermined thin film thin line pattern on a substrate,
A first step of forming a resist layer on the substrate, which is a reverse pattern with respect to the thin film thin line pattern, by screen printing using a first screen printing plate;
The second screen printing plate is positioned at an installation position of the first screen printing plate in the first step, and the second screen printing is performed on a region of the substrate where at least the resist layer is not formed. A second step of forming a thin film by screen printing using a plate;
After the second step, a third step of removing the resist layer on the substrate to form the thin film fine line pattern;
A method for forming a thin-film thin line pattern, comprising:   2. The method of forming a thin film thin line pattern according to claim 1, wherein the thin film thin line pattern is a thin film having an average thickness of 1 [mu] m or less and a minimum width of 100 [mu] m or less.   3. The thin film fine line pattern forming method according to claim 1, wherein the resist layer is a water-soluble resist layer. In the second screen printing plate, a pattern is formed so that the thin film is also formed in a region covering a peripheral portion of the resist layer,
Calculated from the pattern of the second screen printing plate, and the area of the thin film covering the peripheral edge is 60% or less with respect to the total area of the surface of the resist layer parallel to the substrate. The method for forming a thin film thin line pattern according to any one of claims 1 to 3.   The average thickness of the resist layer is not less than 2 times and not more than 20 times the average thickness of the thin film fine line pattern, The thin film fine line pattern formation according to any one of claims 1 to 4, Method.   6. The method of forming a thin film thin line pattern according to claim 1, wherein the viscosity of the ink used for forming the thin film is 0.01 Pa · S or more and 40 Pa · S or less. .   The thin film fine line pattern forming method according to any one of claims 1 to 6, wherein an arithmetic average roughness Ra of the surface of the substrate is 5 µm or less.   The screen of at least the portion forming the reverse pattern of the first screen printing plate and the screen of the second screen printing plate forming at least the thin film are warp yarns made of metal or synthetic fiber wire. And the mesh fabric woven so that the wefts cross each other, the wire diameters of the warp and the wefts are 25 μm or less, and the number of meshes in the direction in which the warp and the wefts extend is 325 or more, respectively. The thin-film thin line pattern forming method according to claim 1, wherein the thin-film thin line pattern is formed. The thin film fine line pattern forming method according to claim 8, wherein the mesh fabric has a Young's modulus of 10,000 N / mm ² or more.