JP2014157764A - Precision printing method and precision printed product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a uniform printing pattern having no cissing of a printed film and no nonuniformity due to deviation when forming a light emitting layer of an organic EL element on an inorganic film surface in a pixel as a precision printing pattern.SOLUTION: The precision printing method for forming a precision printing pattern on an inorganic film surface on a substrate includes: coating the inorganic film surface with a printing auxiliary organic layer 20; forming a precision organic light emitting layer 5 on the printing auxiliary organic layer by a flexographic printing method; and letting the ink film absorb the printing auxiliary organic layer.

Description

  The present invention relates to a manufacturing method for forming a fine pattern with high accuracy using a flexographic printing method, a pattern in a color filter for a liquid crystal display (LCD), a light emitting layer or a charge transport layer of an organic electroluminescence (EL) element. The present invention relates to a precision printing method and a precision printing product for forming an electrode pattern on an organic thin film transistor (TFT) substrate, a shield pattern on an electromagnetic wave shield, and the like with high definition.

  Conventionally, a photolithography method has been mainly used as a method for forming a fine pattern on a substrate to be printed with uniform in-plane and high positional accuracy, and continuously and stably. However, this photolithography method has a problem that the process is complicated and the manufacturing equipment necessary for pattern formation is expensive, resulting in an increase in manufacturing cost.

  Also, instead of the photolithography method, there is known a letterpress reverse offset printing method in which a printing blanket using silicone rubber is used, and printing ink is transferred from a printing blanket to a substrate such as glass as a substrate to be printed. ing. However, this method has a drawback that the ink in the non-image area where the pattern is not formed is removed by the printing plate and discarded.

  Therefore, in recent years, a relief printing method with high material utilization efficiency has been attracting attention in place of such a method. Note that the relief printing method is a printing method in which a plate having an image line portion having a convex shape, that is, a relief plate, is used as a printing plate, ink is held on the projection and transferred to a substrate to be printed.

  There has been proposed an attempt to form a light emitting layer by a known printing method by dissolving a polymer organic light emitter in a solvent and dispersing it into an ink. This printing method is excellent in mass productivity and can reduce the manufacturing cost. Specific printing methods include offset printing and gravure printing (Patent Documents 1 and 2).

  Flexographic printing is a printing method using a flexible relief printing plate made of rubber or resin, an inking roll called a anilox roll with engraved fine recesses on the surface, and solvent-drying ink. Widely used for printing simple prints. This flexographic printing is particularly suitable for forming a thin and stable printing layer having a film thickness of about 0.01 to 0.2 μm.

  In addition, flexographic printing is flexible on the relief printing plate part, and it is printing at a very low printing pressure called kiss touch, so a glass substrate or a transparent electrode whose characteristics are destroyed by applying high pressure, etc. It is also suitable for printing on a substrate on which is formed. For this reason, it is a printing method especially suitable for formation of the light emitting layer of an organic EL element. However, the flexographic printing method formed on the inorganic film is caused by low ink wettability with respect to the inorganic film.

  In the ink supply device of a printing press that prints the light emitting layer of the organic EL element, the ink is supplied in a closed system to suppress volatilization of the ink solvent, and the lower part of the anilox roll is used to prevent the ink from drying on the anilox roll surface. It is necessary to always wet the anilox roll surface by rotating the peripheral surface while dipping it in the ink reservoir of the ink fountain. For this purpose, the ink is supplied to an ink fountain with a closed structure called a closed chamber, rotated while immersing the lower peripheral surface of the anilox roll therein, and on the upper peripheral surface of the anilox roll exposed from the closed chamber, A method of scraping excess ink with a doctor and applying the ink onto the flexographic plate has been used. However, the ink film formed on the inorganic film by flexographic printing has a problem that the printed film is repelled or uneven in the pixel shape.

JP 2001-185352 A JP 2005-59348 A

  In order to solve the above problems, when forming a light-emitting layer of an organic EL element as a high-definition printing ink pattern on the surface of an inorganic film in a pixel, printing film repelling or biasing It is to form a uniform print pattern without unevenness.

As means for solving the above problems, the invention according to claim 1 is a precision printing method for forming a high-definition printing ink pattern on the surface of an inorganic film on a substrate,
The inorganic film surface is coated with a printing auxiliary organic layer, and a high-definition ink film pattern is formed on the printing auxiliary organic layer by a flexographic printing method.
The printing auxiliary organic layer is absorbed by the ink film, and the printing auxiliary organic layer is removed from a portion without the ink film.

  The invention according to claim 2 is the precision printing method according to claim 1, wherein the printing auxiliary organic layer is a fluorine-based or silicone-based surfactant.

  According to a third aspect of the present invention, in the precision printing method according to the first or second aspect, the method for removing the printing auxiliary organic layer is a heat treatment at 50 ° C. to 250 ° C. is there.

  The invention according to claim 4 is characterized in that the printing auxiliary organic layer in which the printing ink pattern is not formed is removed by pouring a solvent. This is a precision printing method.

  The invention according to claim 5 is a precision printing product manufactured using the precision printing method according to any one of claims 1 to 4.

  According to the precision printing method of the present invention, there is no problem of ink wettability even with respect to an inorganic film, and a precision printing product free from repelling or biasing of the printed film within the pixel can be provided.

It is the conceptual diagram which showed the flow of the precision printing method of this invention. It is the schematic which showed the organic EL element structure concerning this invention. It is the schematic which shows the whole structure of a flexographic printing machine at the time of applying the printing machine for organic EL concerning this invention to the flexographic printing machine suitable for the light emitting layer printing of an organic electroluminescent display element. It is the schematic which shows the operation | movement at the time of the ink transfer of the printing machine in this Embodiment.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The organic EL printer according to the present invention is not limited to the embodiments described below.

  FIG. 1 shows the flow of the precision printing method of the present invention. A pixel electrode 2 is patterned on a substrate 1 and pixels partitioned by an insulating layer 3 are provided. In general, the hole transport layer 4 and the organic light emitting layer 5 are laminated on the pixel. However, in the present invention, after providing the hole transport layer 4, the printing auxiliary organic layer 20 is laminated, and further organic The light emitting layer 5 is laminated.

  The printing auxiliary organic layer 20 where the organic light emitting layer 5 is not provided is removed by solvent treatment, and the printing auxiliary organic layer 20 where the organic light emitting layer 5 is provided is dissolved in the organic light emitting layer 5 by heat treatment. Absorbed.

  FIG. 2 is a cross-sectional view showing the structure of the organic EL element according to the embodiment of the present invention. FIG. 3 is a schematic diagram showing an overall configuration of a flexographic printing machine when the organic EL printing machine according to the present invention is applied to a flexographic printing machine suitable for light emitting layer printing of an organic EL element, and FIG. It is the schematic which shows the operation | movement at the time of the ink transfer of a printing machine.

  Hereinafter, an example in which the embodiment of the present invention is applied to a passive matrix type organic EL element will be described. The passive matrix method is a method in which stripe-shaped electrodes are opposed to each other so as to be orthogonal to each other, and light is emitted at the intersection, whereas the active matrix method uses a so-called thin film transistor (TFT) substrate in which a transistor is formed for each pixel. Thus, the light is emitted independently for each pixel.

  As the substrate 1, a glass substrate or a plastic film or sheet can be used. If a plastic film is used, a polymer EL element can be produced by winding, and a display panel can be provided at a low cost. In addition, as the plastic in that case, for example, polyethylene terephthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate, or the like can be used. Further, these films are barrier layers made of metal oxide such as silicon oxide showing water vapor barrier property and oxygen barrier property, oxynitride such as silicon nitride, polyvinylidene chloride, polyvinyl chloride, saponified ethylene-vinyl acetate copolymer. Is provided as necessary.

  A pixel electrode 2 patterned as an anode is provided on the substrate 1. As the material of the pixel electrode 2, transparent electrode materials such as ITO (indium tin composite oxide), IZO (indium zinc composite oxide), tin oxide, zinc oxide, indium oxide, and aluminum oxide composite oxide can be used.

  ITO is preferred because of its low resistance, solvent resistance, transparency, and the like. ITO is formed on the substrate by a sputtering method and patterned by a photolithography method to form a line-shaped pixel electrode 2.

  And after forming this line-shaped pixel electrode 2, the insulating layer 3 is formed by the photolithographic method using a photosensitive material between adjacent pixel electrodes.

  The insulating layer 3 desirably has a thickness in the range of 0.5 μm to 5.0 μm. In addition, by providing an insulating layer between adjacent pixel electrodes, it is possible to suppress the spread of ink printed on each pixel electrode, and to prevent color mixing in which ink flows into adjacent pixels when a display is formed. If the insulating layer is too low, ink spreading cannot be prevented and ink flows into adjacent pixels, resulting in color mixing.

  For example, in an organic EL element of a passive matrix type, when an insulating layer is provided between pixel electrodes, the cathode layer is formed by directing the insulating layer. When the cathode layer is formed so as to straddle the insulating layer in this way, if the insulating layer is too high, the cathode layer is disconnected, resulting in a display defect. When the height of the insulating layer exceeds 5.0 μm, disconnection of the cathode tends to occur.

  The photosensitive material for forming the insulating layer 3 may be either a positive type resist or a negative type resist, and may be a commercially available one, but it must have insulating properties. In addition, when the partition does not have sufficient insulation, a current flows to the adjacent pixel electrode 2 through the partition and a display defect occurs. Specific examples thereof include polyimide, acrylic resin, novolac resin, and fluorene, but are not limited thereto. Further, for the purpose of improving the display quality of the organic EL element, a light shielding material may be included in the photosensitive material.

  The photosensitive resin forming the insulating layer 3 is applied using a coating method such as a spin coater, a bar coater, a roll coater, a die coater, or a gravure coater, and is patterned by a photolithography method. Alternatively, the insulating layer may be formed using a gravure offset printing method, a reverse printing method, a flexographic printing method, or the like without using a photosensitive resin.

  The hole transport layer 4 is formed on the pixel electrode 2 and is a layer that transports holes. Examples of the material for the hole transport layer 4 include polyaniline derivatives, polythiophene derivatives, polyvinylcarbazole (PVK) derivatives, poly (3,4-ethylenedioxythiophene) (PEDOT), and the like.

  These materials are dissolved or dispersed in a solvent, and the hole transport layer 4 is formed by using various coating methods using a spin coater or the like and a relief printing method.

In the case of using an inorganic material as the material of the hole transport layer 4, as the inorganic material, _{e.g., Cu 2 O, Cr 2 O} 3, Mn 2 O 3, FeO x (x~0.1), NiO, CoO , Pr ₂ O ₃ , Ag ₂ O, MoO ₂ , Bi ₂ O ₃ , ZnO, TiO ₂ , SnO ₂ , ThO ₂ , V ₂ O ₅ , Nb ₂ O ₅ , Ta ₂ O ₅ , MoO ₃ , WO ₃ , An inorganic material such as MnO ₂ is used.

The material of the hole transport layer 4 is not limited to the above-described material. Here, after forming the insulating layer 3, the hole transport layer 4 is deposited by resistance heating or electron beam (EB) in vacuum, or by reactive sputtering using Ar gas and O ₂ gas. Alternatively, it is formed by a method such as a CVD method.

  Next, when an inorganic material is used as the material of the hole transport layer 4, the printing auxiliary organic layer in the embodiment of the present invention is formed. The printing auxiliary organic layer is a layer that supports the wetting and spreading of the printing ink when printing the organic light emitting layer 5. The material for forming the printing auxiliary organic layer is a printing ink for printing the organic light emitting layer 5. It is desirable that the surfactant be dissolved in the ink and reduce the surface tension of the printing ink. For example, a fluorine-type or silicone-type material is mentioned.

  Next, as the printing auxiliary organic layer 20 material, a surfactant is effective, and ionic, nonionic, and amphoteric surfactants can be used. In particular, a fluorosurfactant is suitable, such as Novec HFE7300 manufactured by Sumitomo 3M Limited. BYK-370 manufactured by Big Chemie Japan Co., which is a polyester-modified polydimethylsiloxane solution having a hydroxyl group as a reactive silicone-based surface conditioner.

As the method for coating the printing auxiliary organic layer 20, a gravure offset printing method, a reversal printing method may be used, even if a film is formed on the entire surface using a coating method such as a spin coater, bar coater, roll coater, die coater, gravure coater, etc. Alternatively, it may be formed only in the pixel region using a flexographic printing method or the like.

  Examples of the method for removing only the printing auxiliary organic layer 20 after forming the organic light emitting layer 5 include a method of applying heat at 50 to 250 ° C. to the substrate and a method of applying a solvent to the substrate. Examples of the solvent to be poured include toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, polyethylene glycol, glycerin, ethyl acetate, butyl acetate, isopropyl acetate, and methyl acetate. Examples thereof include cellosolve, ethyl acetate cellosolve, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethyl lactate, ethylene glycol diethyl ether, 1-propanol, methoxypropanol, ethoxypropanol, and water alone or a mixed solvent thereof.

  The organic light emitting layer 5 is a layer that emits light by passing an electric current, and the organic light emitting material forming the organic light emitting layer 5 is, for example, a coumarin type, a perylene type, a pyran type, an anthrone type, a porphyrene type, a quinacridone type, N, N'-dialkyl-substituted quinacridone-based, naphthalimide-based, N, N'-diaryl-substituted pyrrolopyrrole-based, iridium complex-based luminescent dyes dispersed in polymers such as polystyrene, polymethyl methacrylate, polyvinyl carbazole, etc. And polyarylene-based, polyarylene vinylene-based, and polyfluorene-based polymer materials.

  These organic light emitting materials are dissolved or stably dispersed in a solvent to form an organic light emitting ink. Examples of the solvent for dissolving or dispersing the organic light-emitting material include toluene, xylene, acetone, anisole, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, or a mixed solvent thereof. Among these, aromatic organic solvents such as toluene, xylene, and anisole are preferable from the viewpoint of solubility of the organic light emitting material. Moreover, surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber, etc. may be added to organic luminescent ink as needed.

  As a method for forming the organic light emitting layer 5, when using a letterpress printing method, a resin letterpress suitable for an organic light emitting ink can be used, and a water developing type photosensitive resin letterpress is particularly preferable.

  The viscosity of the organic light emitting ink is preferably 10 to 200 mPa / s. In the relief printing method used in this embodiment, the ink is first transferred from the anilox roll 151 onto the relief plate, but after the ink is transferred from the anilox roll 151 onto the relief plate at a viscosity of 200 mPa / s or more. Insufficient ink leveling on the letterpress will cause unevenness. Further, if it is 10 mPa / s or less, the non-uniformity is likely to occur in the pixel, resulting in nonuniformity.

  Next, after forming the organic light emitting layer 5 as described above, the cathode layer 6 is formed in a line pattern orthogonal to the line pattern of the pixel electrode 2. As the material of the cathode layer 6, materials according to the light emission characteristics of the organic light emitting layer can be used. For example, simple metals such as lithium, magnesium, calcium, ytterbium and aluminum, and stable metals such as gold and silver can be used. And alloys thereof. Alternatively, a conductive oxide such as indium, zinc, or tin can be used. Examples of the method for forming the cathode layer 6 include a formation method by a vacuum vapor deposition method using a mask.

The organic EL element of the present embodiment has a configuration in which the hole transport layer 4 and the organic light emitting layer 5 are laminated from the anode layer side between the pixel electrode 2 that is an anode and the cathode layer 6. In addition to the hole transport layer 4 and the organic light emitting layer 5, a layered structure in which a layer such as a hole block layer, an electron transport layer, and an electron injection layer is selected as necessary can be adopted between the cathode layers 6. The formation method of the present invention can also be used when forming these layers.

  Finally, in order to protect these organic EL constituents from external oxygen and moisture, the organic EL element can be obtained by hermetically sealing with a glass cap 7 and an adhesive 8. Moreover, when the board | substrate 1 has flexibility, you may seal using a sealing agent and a flexible film.

  The overall configuration of the flexographic printing machine in the embodiment of the present invention will be described below. As shown in FIGS. 3 and 4, the flexographic printing machine shown in this embodiment includes a rotary plate cylinder 10 that is rotatably supported at a fixed position, and a light emission pattern that is mounted on the peripheral surface of the plate cylinder 10. A forming relief plate (flexo printing plate) 11, a support base 12 positioned horizontally below the plate cylinder 10, and a rotation axis of the plate cylinder 10 perpendicular to the support base 12 via a guide. A surface plate 13 movably installed in the horizontal direction, a printing substrate 14 placed on the surface plate 13, an ink supply means 15 for supplying ink for the light emitting layer to the surface of the relief plate 11, An ink replenishing unit 16 that periodically supplies ink to the ink supplying unit 15 is provided.

  The ink supply means 15 has an angle range of 90 ° from the contact point between the relief plate 11 and the printing substrate 14 (directly below the plate cylinder 10) to the direction opposite to the rotation direction of the plate cylinder 10 (direction of arrow F). The plate cylinder 10 is disposed so as to face the peripheral surface of the plate cylinder 10.

  The ink supply means 15 is located within an angle range of 90 ° from the printing start end of the relief plate 11 in the direction opposite to the rotation direction of the plate cylinder 10 and is in contact with the plate surface of the relief plate 11 in parallel with the rotation axis of the plate cylinder 10. An anilox roll 151 that is arranged so as to supply ink 9 for the light-emitting layer to the plate surface of the relief plate 11 and an ink reservoir that maintains the peripheral portion located below of the entire peripheral surface of the anilox roll 151 in a dipped state And a doctor 153 that scrapes off excess ink adhering to the surface of the anilox roll 151.

  As long as the ink supply means 15 does not interfere with the surface plate 13 and the substrate 14, the position where the anilox roll 151 and the relief plate 11 abut is directly below the plate cylinder 10, that is, with the rotation of the plate cylinder 10, the relief plate 11 and the printing target. The one closer to the contact point with the substrate 14 is advantageous because the distance from the ink supply position to the relief plate 14 to the contact point can be shortened and at the same time the time during which the ink is applied to the plate surface of the relief plate 12 is shortened. .

  The anilox roll 151 is rotated at the same peripheral speed as that of the plate cylinder 10, and a fine relief (for holding ink) is provided on the outer peripheral surface of the anilox roll 151 as shown in FIG. The recesses are engraved.

  The reason why the peripheral speeds of the anilox roll 151 and the plate cylinder 10 are the same is that the relief is engraved on the outer peripheral surface of the anilox roll 151, so if the peripheral speed with the plate cylinder 11 is different, the plate surface of the relief plate 11 is damaged. This is to prevent giving.

  The doctor 153 scrapes off the ink 9 excessively attached to the surface of the anilox roll 151 that has come out of the ink reservoir due to rotation, and leaves the ink only in the relief 151 a of the anilox roll 151. The doctor 153 has a blade-like shape or a roll-like shape, and any of them may be used. The doctor 153 is positioned between the ink reservoir and the point of contact with the relief plate 12 in the rotational direction of the anilox roll 151, and is disposed closer to the ink reservoir than the top of the anilox roll 151, and scraped ink. A method in which the ink drops into the ink reservoir is most preferable.

The ink replenishing means 16 includes an ink tank 161 and an ink replenishing pump 162, and the ink tank 161 and the ink fountain 152 are connected by an ink replenishing tube 163 via the ink replenishing pump 162. The ink replenishment pump 162 is driven periodically according to the number of printings, whereby ink is supplied from the ink tank 163 to the ink fountain 152, so that the ink amount and viscosity of the ink reservoir can be maintained constant. Conversely, a mechanism for sucking out the ink in the ink reservoir from the ink fountain may be provided so that the ink in the ink reservoir can be replaced.

  Next, the ink transfer operation of the organic EL flexo printing machine according to the present embodiment will be described with reference to FIGS.

  When the ink is transferred to the printing substrate 14, as shown in FIG. 3, the printing substrate 14 to which the ink is transferred is fixed on the surface plate 13, and the surface plate 13 is moved directly below the plate cylinder 10. At the same time, the plate cylinder 10 is rotated at the same peripheral speed as the moving speed of the surface plate 13. At this time, the relief plate 11 installed on the plate cylinder 10 comes into contact with the anilox roll 151 as the plate cylinder 10 rotates, and the ink in the relief on the surface of the anilox roll 151 is applied to the plate surface of the relief plate 12. Thereafter, the ink applied to the plate surface of the relief plate 12 is transferred onto the substrate 14 to be printed when it is rotated to just below the plate cylinder 10. Thereby, the transfer of the ink 9 from the ink supply means 15 to the relief plate 11 and the transfer of the ink 9 from the relief plate 11 to the printing substrate 14 can be performed simultaneously.

  In the printing by the flexographic printing machine, the surface of the anilox roll 151 exposed from the ink reservoir is easy to dry, and when the ink in the relief is hardened, the ink supply amount becomes uneven. For this reason, it is desirable to continue the rotation of the anilox roll 151 during the standby time other than the time of ink transfer so that the surface of the anilox roll 151 is periodically immersed in the ink reservoir and wetted.

  Therefore, it is preferable to provide a mechanism in which the anilox roll 151 or the entire ink supply means 15 is retracted from the plate cylinder 10 so that ink is not applied to the plate surface of the relief plate 11 except during ink transfer. Alternatively, the surface of the plate cylinder 10 on which the relief plate 11 is not installed is configured in a shape that does not come into contact with the anilox roll 151, and during the waiting time, the shape portion that does not come into contact with the anilox roll 151 is used. Alternatively, the plate cylinder 10 can be moved up and down, and during the standby time other than the time of ink transfer, the plate cylinder 10 is raised to separate the relief plate 11 from the anilox roll 151, and at the time of ink transfer, the plate cylinder 10 is lowered to remove the relief plate 11. A method of contacting the anilox roll 151 may be used.

  In the present embodiment, the method in which the surface plate 13 moves in the horizontal direction under the plate cylinder 10 has been described. However, the present invention is not limited to this, and the surface plate 13 is fixed and the plate cylinder 10 and the ink supply are supplied. Ink transfer can be performed in the same manner even when the means 16 moves in the horizontal direction.

  Next, examples of the present invention will be described. Here, trial manufacture and measurement were performed for the following Example 1 and Comparative Example 1. First, an ITO (indium-tin oxide) thin film is formed on a 300 mm square glass substrate 1 by sputtering, and the ITO film is patterned by photolithography and etching with an acid solution to obtain a 5 inch diagonal size. The pixel electrode 2 was formed so that two displays could be taken. The line pattern of the pixel electrode 2 per surface of the display was a pattern in which 1950 lines were formed with a line width of 40 μm and a space of 20 μm.

Next, the insulating layer 3 was formed as follows. First, a polyimide resist material was spin coated on the entire surface of the glass substrate 1 on which the pixel electrode 2 was formed. The spin coating condition was rotated at 150 rpm for 5 seconds, and then rotated at 500 rpm for 20 seconds to form a single coating, and the height of the insulating layer 3 was 1.5 μm. An insulating layer 3 having a line pattern was formed between the pixel electrodes 2 by photolithography using a photoresist material applied to the entire surface.

Next, the hole transport layer 4 was formed by sputtering the inorganic material MoO ₂ as the hole transport layer 4. As a result, the film thickness was 50 nm.

  Next, the printing auxiliary organic layer 20 was formed as follows. First, HFE7300 manufactured by 3M, which is a fluorosurfactant, was spin coated on the entire surface of the substrate. The spin coating conditions were rotated at 150 rpm for 5 seconds, and then rotated at 500 rpm for 20 seconds to form a single coating.

  Next, a polyphenylene vinylene derivative which is an organic light emitting material is dissolved in toluene, and an organic light emitting ink having a concentration of 2% and a viscosity of 50 mPa / s is aligned with the line pattern directly above the pixel electrode 2 sandwiched between the insulating layers 3. The organic light emitting layer 5 was printed by a relief printing method. At this time, an anilox roll of 750 lines / inch and a photosensitive resin plate of water development type were used. After printing, it is baked in an oven at 200 ° C. for 30 minutes, and the fluorosurfactant of the printing auxiliary organic layer 20 is partially absorbed and partially vaporized in the organic light emitting layer 5, and the film thickness of the organic light emitting layer 5 after baking. Was 80 nm.

  On the other hand, the portion of the fluorosurfactant where the organic light emitting layer 5 is not provided is vaporized and removed by baking in an oven at 200 ° C.

  A cathode layer made of Ca and Al was formed thereon by mask vapor deposition using a resistance heating vapor deposition method in a line pattern orthogonal to the pixel electrode line pattern. Finally, in order to protect these organic EL constituents from external oxygen and moisture, they were hermetically sealed using a glass cap and an adhesive to produce an organic EL display panel. In the periphery of the display portion of the organic EL display panel obtained in this way, there are an extraction electrode on the anode side connected to each pixel electrode and an extraction electrode on the cathode side, which are obtained by connecting them to a power source. The lighting display of the obtained organic EL display panel was confirmed.

<Comparative Example 1>
The procedure was the same as in Example 1 except that no printing auxiliary organic layer was formed.

  Table 1 shows the evaluation results comparing the panel emission states in Example 1 and Comparative Example 1 as described above.

It can be seen that better results are obtained with the examples of the present invention than with the comparative examples.

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Pixel electrode 3 ... Insulating layer 4 ... Hole transport layer 5 ... Organic light emitting layer 6 ... Cathode layer 7 ... Glass cap 8 ... Adhesive DESCRIPTION OF SYMBOLS 9 ... Ink 10 ... Plate cylinder 11 ... Letterpress plate 12 ... Support base 13 ... Surface plate 14 ... Substrate 15 ... Ink supply means 151 ... Anilox roll 152 ... Reliefs (recesses)
153: closed chamber 16: ink replenishing means 161 ... ink tank 162 ... ink replenishing pump 163 ... ink supply tube 20 ... printing auxiliary organic layer

Claims (5)

A precision printing method for forming a high-definition printing ink pattern on the surface of an inorganic film on a substrate,
The inorganic film surface is coated with a printing auxiliary organic layer, and a high-definition ink film pattern is formed on the printing auxiliary organic layer by a flexographic printing method.
A precision printing method characterized in that the printing auxiliary organic layer is absorbed by the ink film, and the printing auxiliary organic layer is removed from a portion without the ink film.   The precision printing method according to claim 1, wherein the printing auxiliary organic layer is a fluorine-based or silicone-based surfactant.   3. The precision printing method according to claim 1, wherein the method for removing the printing auxiliary organic layer is a heat treatment at 50 ° C. to 250 ° C. 4.   The precision printing method according to any one of claims 1 to 3, wherein the printing auxiliary organic layer on which the printing ink pattern is not formed is removed by pouring a solvent.   A precision printing product manufactured using the precision printing method according to claim 1.