JP2010277755A - Manufacturing method of organic electroluminescent element, and organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an organic EL element of reduced manufacturing cost with excellent performance stability, especially, a stable one of reduced manufacturing cost and without leak current. <P>SOLUTION: The manufacturing method of the organic EL element consisting of a first electrode patterned on a substrate, an organic layer containing an organic light-emitting layer arranged on the first electrode, and a second electrode arranged on the organic layer, includes a process in which the first electrode is formed by patterning with the use of printing of resist liquid or etchant liquid. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is produced by a method for producing an organic electroluminescent element having a step of continuously forming an organic electroluminescent structure at a predetermined interval on a flexible strip-shaped substrate, and the method for producing the organic electroluminescent element. The present invention relates to an organic electroluminescence device.

  In recent years, organic electroluminescence elements (hereinafter also referred to as organic EL elements) have attracted attention as self-luminous elements.

  An organic EL element has an organic EL structure having a structure in which an organic layer including a light emitting layer (organic light emitting layer) of an organic compound is sandwiched between two electrodes, a first electrode and a second electrode, on a substrate such as glass. The element emits light from the organic light emitting layer by supplying a current between the first electrode and the second electrode.

  Recently, organic EL elements using a flexible base material such as a resin film have also appeared due to expansion of applications of the organic EL element, and roll-to-roll by using such a flexible base material. An organic EL element has been manufactured by a roll method (see, for example, Patent Document 1).

  The roll-to-roll manufacturing method refers to forming a flexible strip-like substrate wound in a roll shape to form an organic EL structure on the substrate, and then rolling the substrate on which the organic EL structure is formed again The manufacturing method of the form wound up is called.

  The roll-to-roll manufacturing has the advantage that production efficiency can be improved because continuous production is possible.

  By the way, in most cases, a transparent electrode called Indium-Tin-Oxide (ITO) is used as the first electrode of the organic EL element.

  The ITO manufacturing method is formed on a transparent substrate to have a predetermined thickness using various methods such as sputtering vapor deposition and electron beam vapor deposition (EB). The surface of ITO formed by any method is as follows. The value is rough, and the maximum surface roughness height (Rmax) defined in the definition and display (BO6O1) of the surface roughness defined in Japanese Industrial Standard (JIS) is on the order of several to several tens of nm. .

  However, in the case of an organic EL element, the thickness of the organic compound layer laminated on the anode is at most 100 nm to 200 nm, and the surface roughness of ITO cannot be ignored.

  When protrusions are present on the surface of ITO, the distance between the anode and the cathode is reduced accordingly, and when a voltage is applied to the element, a phenomenon occurs in which current flows intensively in that portion. This is a leakage current.

  When a voltage is applied to the element in the positive direction (the direction in which the element emits light) and a leak current is generated during light emission of the element, not only the luminance (current-luminance characteristics) with respect to the flowing current decreases, but also the anode in that portion In some cases, the cathode is short-circuited, and current flows only there, and the device does not emit light.

In the case of an organic EL element, when a reverse voltage is applied (reverse bias), the current value is stable at a low level of 1 × 10 ⁻⁷ A / cm ² or less although it ^{depends on} the film thickness of the organic EL element. On the other hand, when a leak current occurs, the current tends to flow in the reverse direction at that portion, so that the reverse bias current of the element increases and the current value is not stabilized.

  The deterioration of the reverse bias characteristic that occurs when the leak current is generated becomes a problem even when a reverse bias is applied to the element for convenience of driving or a circuit for actually driving the element.

  For this reason, what has been studied up to now is a stable organic EL element having no leakage current during light emission driving.

  For example, the surface of ITO is polished and polished by polishing, lapping, tape wrapping, etc., and the surface of ITO is defined and displayed as defined by Japanese Industrial Standards (JIS). An organic EL element using ITO polished so that the maximum height (Rmax) of the surface roughness defined in BO6O1) is 5 nm or less is known (for example, see Patent Document 2).

  An organic EL element using ITO in which the surface of ITO is polished to 1 nm or less by a chemical mechanical polishing method is known (for example, see Patent Document 3).

  However, the techniques described in Patent Document 2 and Patent Document 3 have a considerable effect in preventing leakage current generation, but have high luminous efficiency, high luminance, and low consumption, which are required for recent organic EL elements. It is still inadequate for power and longer life.

  In addition, recently, a method is known in which ITO is patterned by a photolithography method and further polished (see, for example, Patent Document 4).

  This is because organic EL elements usually use patterned ITO, and photolithography is the mainstream for patterning, but the edge of ITO becomes unstable and causes burrs, irregularities, etc. This is because it is easy to concentrate the electric field, which causes leakage current.

  However, unlike the case where a glass substrate is used, a flexible belt-like substrate such as a resin film used in a roll-to-roll manufacturing method is subjected to a polishing process because the substrate is scratched by polishing. It is difficult to remove burrs at the edge of ITO.

  From such a situation, even in the roll-to-roll method, development of a stable organic EL element having no leakage current and a method for manufacturing the organic EL element is desired at the time of light emission driving.

International Publication No. 01/005194 Pamphlet Japanese Patent Laid-Open No. 9-245965 JP 2004-152616 A JP 2007-12358 A

  An object of the present invention is to provide a method for producing an organic EL element having low production cost and excellent performance stability, and particularly to provide a method for producing a stable organic EL element having low production cost and no leakage current. That is.

  The object of the present invention has been achieved by the following constitution.

1. Fabrication of an organic electroluminescence device comprising a first electrode patterned on a substrate, an organic layer including an organic light emitting layer disposed on the first electrode, and a second electrode disposed on the organic layer In the method
An organic electroluminescence element comprising: a step of providing a material for forming the first electrode on the substrate; and a step of forming the first electrode by patterning using printing of a resist solution or an etchant solution. Manufacturing method.

  2. 2. The method for producing an organic electroluminescent element according to 1 above, wherein the substrate is a flexible strip-shaped substrate.

  3. 3. The method for producing an organic electroluminescent element according to 1 or 2, wherein the printing is screen printing.

  4). 4. The method for producing an organic electroluminescent element according to any one of 1 to 3, wherein the linearity of the edge portion of the first electrode is 100 μm or less.

  5. 5. The method for producing an organic electroluminescent element according to any one of 1 to 4, wherein an angle θ of the edge portion of the first electrode is 30 degrees to 75 degrees.

  6). 6. An organic electroluminescence device produced by the method for producing an organic electroluminescence device according to any one of 1 to 5 above.

  According to the present invention, a manufacturing method of an organic electroluminescence device having a small number of steps and low equipment cost and low manufacturing cost and excellent performance stability can be provided. In particular, a plurality of organic EL structures can be formed on a strip-shaped substrate. It was possible to provide a stable organic EL element having a low manufacturing cost and no leakage current, using the belt-shaped substrate having the above structure.

It is a schematic sectional drawing explaining the structure of an organic EL element. It is a schematic plan view of the strip | belt-shaped base material which arrange | positioned the strip | belt-shaped sealing member on the some organic EL structure. It is a block diagram which shows an example of the manufacturing method of the organic EL element of this invention. It is a schematic process figure and block diagram about the pattern formation method of the transparent conductive film of this invention using the rotary screen printing of a resist liquid. It is the schematic process figure and block diagram about the pattern formation method of the transparent conductive film of this invention using the screen printing of a resist liquid. It is a general | schematic process figure and block diagram about the pattern formation method of the transparent conductive film of this invention using the screen printing of an etchant liquid. It is a schematic diagram of the preparation process which produces an organic EL structure. It is a schematic diagram of the manufacturing process of bonding of a sealing member, and cutting. The expansion schematic in the case of the surface shape which the edge part of the 1st electrode inclined is shown.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

  The present invention provides a first electrode disposed on a flexible belt-shaped substrate, an organic layer including an organic light emitting layer disposed on the first electrode, and a first electrode disposed on the organic layer. A method for producing an organic EL element from an organic EL structure including two electrodes by a roll-to-roll method, wherein the first electrode is formed by patterning using printing of a resist solution or an etchant solution. It is characterized by being.

  By patterning using printing, chamfering is formed at corners without additional processing such as polishing. As a result, the occurrence of burrs that cause leakage current is eliminated at the corners of the first electrode where burrs are likely to occur during patterning.

  However, patterning of the first electrode using printing of a resist solution or an etchant solution has a tendency that the linearity of the edge portion is worse than the photolithography method, and when the value exceeds a certain value, abnormal light emission occurs at the edge portion. It is known that leakage current increases.

  As an index of the linearity of the edge part, the evaluation is made by measuring the difference between the maximum dimension and the minimum dimension of the substantially rectangular first electrode at several points, and when the difference becomes 100 μm or more, the leakage current deteriorates. I know.

  In the present invention, the first electrode is formed by patterning using printing of a resist solution or an etchant solution, and by making the linearity of the edge portion of the first electrode within a certain range, the manufacturing cost is low and the leakage current is reduced. A stable organic EL device is obtained.

<< Organic EL element >>
The organic EL element has a configuration having a sealing layer on the organic EL structure.

  FIG. 1 is a schematic diagram illustrating an example of the configuration of the organic EL element 10.

  The organic EL structure includes a first electrode disposed on a substrate, an organic layer including an organic light emitting layer disposed on the first electrode, and a second electrode disposed on the organic layer. It is a structure.

  In the example shown in FIG. 1, the organic EL element 10 includes a first electrode 12, an organic layer 13 including an organic light emitting layer, and a second electrode 14 formed on a substrate 11 to form an organic EL structure, and further an organic EL element. A sealing layer 16 is laminated on the upper surface of the structure via an adhesive layer 15.

  The sealing layer 16 may be laminated via the adhesive layer 15 as in the above example, or may be laminated directly without using the adhesive layer. In the present invention, a mode in which layers are laminated via an adhesive layer is a preferable mode.

  As shown in FIG. 1, in the organic EL element, the upper surface portion of the organic EL structure is covered with a sealing layer 16, and a part of the first electrode 12 is exposed on the left side of the sealing layer 16 in the drawing, A part of the second electrode 14 is exposed on the right side of the stop layer 16 in the figure.

  An organic light emitting layer in the organic layer 13 by supplying current from the exposed portion (first electrode lead portion) 12a of the first electrode and the exposed portion (second electrode lead portion) 14a of the second electrode. Emits light.

  The first electrode 12 is an anode, and when it is transparent, the work function of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), etc. is 4 eV or more and the transmittance is 50% or more. An electrode made of a conductive material is preferable.

  The organic light emitting layer is a layer containing a phosphor of an organic compound. The organic light emitting layer is preferably several nm to several μm. Between the two electrodes and the organic light emitting layer, a hole transport layer may be provided as described later.

  The second electrode 14 is a cathode and is an electrode made of a metal material having a work function of less than 4 eV and a reflectivity of 60% or more such as aluminum, sodium, lithium, magnesium, silver, calcium, etc. is there.

  The organic EL element utilizes the excitation energy generated by the combination of electrons and holes in the organic light emitting layer due to the current supplied to the first electrode (anode) 12 and the second electrode (cathode) 14 from the outside. It is an element that emits light.

  The light emitted from the organic light emitting layer of the organic EL element 10 is extracted through the first electrode 12 and the base material 11, but the second electrode (cathode) is laminated with a thin film cathode material and a highly transmissive anode material. It is also possible to adopt a so-called top emission configuration in which the light is extracted from the cathode by being substantially transparent.

  Moreover, it is preferable to have a hole transport layer, a hole injection layer, etc. between the 1st electrode 12 and an organic light emitting layer, and an electron transport layer, an electron injection layer, etc. between the 2nd electrode 14 and an organic light emitting layer. It is preferable to have.

  FIG. 2 is a plan view of a band-shaped substrate having a plurality of organic EL structures and further having a band-shaped sealing layer.

  The strip-shaped base material 11 has a plurality of organic EL structures in the longitudinal direction of the base material 11, and has a strip-shaped sealing layer 16 on the organic EL structure.

  In the present invention, the sealing layer 16 is preferably made of a band-shaped sealing member disposed so as to face the base material 11 from the viewpoint of manufacturing cost and dark spot generation prevention.

  The first electrode lead portion and the second electrode lead portion of the organic EL structure are disposed to face both ends of the base material 11 in the lateral direction, and the first electrode lead portion and the second electrode lead portion The portions 12b and 14b that are exposed without being covered with the sealing layer 16 are disposed on both ends in the lateral direction.

(Strip-shaped substrate)
The belt-like base material used in the method for producing the organic EL element is a belt-like plate-like body (sheet) that can carry the organic EL structure. As the base material, a flexible base material is preferable. For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), polyether imide, polyether ether ketone, polyphenylene sulfide, poly Examples include arylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), and cellulose acetate propionate (CAP).

  The thickness of the band-shaped substrate is preferably 10 μm to 1 mm, and more preferably 50 μm to 300 μm.

  When a transparent resin film is used as the belt-like substrate, a gas barrier film is preferably formed on the surface of the resin film as necessary. Examples of the gas barrier film include an inorganic film, an organic film, or a hybrid film of both.

As a characteristic of the gas barrier film, water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by a method according to JIS K 7129-1992 is 0.01 g / (m ² 24h) The following barrier film is preferable, and the oxygen permeability measured by a method according to JIS K 7126-1987 is 10 ⁻³ ml / (m ² · 24 hr · MPa) or less, A high barrier film having a water vapor permeability of 10 ⁻⁵ g / (m ² · 24 h) or less is preferable.

  As a material for forming the gas barrier film, any material may be used as long as it has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and layers made of organic materials. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times. The method for forming the gas barrier film is not particularly limited. For example, the vacuum deposition method, the sputtering method, the reactive sputtering method, the molecular beam epitaxy method, the cluster ion beam method, the ion plating method, the plasma polymerization method, the atmospheric pressure plasma polymerization method. A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

  The present invention is a transparent conductive film pattern forming method for forming a transparent conductive film pattern on a substrate by patterning using printing of a resist solution or an etchant solution on the substrate.

  In addition, as a board | substrate, the flexible strip | belt-shaped board | substrate in which the transparent conductive film conveyed continuously is formed is preferable.

  Therefore, by continuously forming the transparent conductive film pattern on the substrate, productivity can be improved and costs can be reduced by reducing the number of processes, and a high-quality transparent conductive film pattern can be formed. As a result, it is possible to produce an organic electronic device having no leakage current and excellent performance stability.

  From the viewpoint of cost reduction, it is preferable to use a flexible belt-like substrate on which a transparent conductive film that is continuously conveyed is formed.

  The transparent conductive film used in the present invention is a transparent metal film having a total light transmittance of 50% or more, such as indium tin oxide (ITO), indium zinc oxide (IZO), and aluminum zinc oxide (AZO). It is a thin film used for this electrode.

  The film forming method of the transparent conductive film is a vacuum process performed by a method called physical vapor deposition (PVD). In a vacuum environment, a sputtering method in which high-energy atoms excited in the plasma space are struck against a metal or oxide target and the target atoms are repelled to form a film on a resin film, or an oxide target is disposed as an anode. It is possible to use an ion plating method in which a plasma beam is supplied to evaporate the material evaporation source so that some of the evaporated particles become ions or excited particles, and the activated evaporated particles are deposited on a resin film.

  The ion plating method uses a pressure gradient type plasma gun to directly irradiate a raw material such as ITO with a plasma beam to evaporate, ionize the evaporated raw material in a plasma atmosphere, and these ionized substances are converted into plasma in the plasma atmosphere. This is a desirable film formation method because it is accelerated by the potential, reaches and is deposited on the resin substrate with large energy, and forms a dense transparent conductive film with low resistance.

  Here, the vacuum environment when forming the transparent conductive film is a pressure environment of 100 Pa or less necessary for maintaining a plasma space and maintaining an environment in which impurities are not easily mixed into the film formation species.

(Sealing layer)
The sealing layer according to the present invention is a layer that can reduce the influence of outside air, and includes a sealing member that is a film of an organic substance such as a resin or an inorganic substance such as a nitride.

  Examples of the resin that can be used for the sealing layer according to the present invention include ethylene tetrafluoroethyl copolymer (ETFE), high-density polyethylene (HDPE), expanded polypropylene (OPP), polystyrene (PS), polymethyl methacrylate ( PMMA), stretched nylon (ONy), polyethylene terephthalate (PET), polycarbonate (PC), polyimide, polyether styrene (PES), polyethylene naphthalate (PEN), and the like.

  The sealing layer may be composed of a plurality of layers, and particularly preferably has a gas barrier layer.

Examples of the gas barrier layer include an inorganic vapor deposition film and a metal foil. As inorganic vapor deposition films, thin film handbooks p879-p901 (Japan Society for the Promotion of Science), vacuum technology handbooks p502-p509, p612, p810 (Nikkan Kogyo Shimbun), vacuum handbook revised editions p132-p134 (ULVAC Japan Vacuum Technology KK) Inorganic films as described in (1). For example, metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, Fe ₂ O ₃ , Y ₂ O ₃ , TiO ₂ , Cr ₂ O ₃ , Si _x O _y (x = 1, y = 1.5 to 2.0), Ta ₂ O ₃ , ZrN, SiC, TiC, PSG, Si ₃ N ₄ , single Crystalline Si, amorphous Si, W, etc. are used.

  Moreover, as a material of the metal foil, for example, a metal material such as aluminum, copper, or nickel, or an alloy material such as stainless steel or an aluminum alloy can be used, but aluminum is preferable in terms of workability and cost. The film thickness is about 1 μm to 100 μm, preferably about 10 μm to 50 μm.

  Furthermore, a protective layer may be provided on the gas barrier layer. The thickness of the protective layer is preferably 100 nm to 200 μm in consideration of stress cracking resistance, electrical insulation resistance of the gas barrier layer, adhesiveness (adhesive force, step following ability) and the like when used as a sealant layer. The protective layer is preferably a thermoplastic resin film having a melt flow rate of 5 g / 10 min to 20 g / 10 min as defined in JIS K 7210, more preferably a thermoplastic resin film of 6 g / 10 min to 15 g / 10 min or less. Is preferably used.

  The thermoplastic resin film is not particularly limited as long as it satisfies the above numerical values. For example, low-density polyethylene (LDPE), which is a polymer film described in Toray Research Center, Inc., a new development of functional packaging materials, HDPE, linear low density polyethylene (LLDPE), medium density polyethylene, unstretched polypropylene (CPP), OPP, ONy, PET, cellophane, polyvinyl alcohol (PVA), stretched vinylon (OV), ethylene-vinyl acetate copolymer ( EVOH), ethylene-propylene copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, vinylidene chloride (PVDC), and the like can be used. Among these thermoplastic resin films, various PE, PET, and PEN are particularly preferable.

  For the formation of the sealing layer, it is preferable to use a laminated film shape in which a gas barrier layer (a protective layer as required) is formed on a resin substrate. As a method for producing a laminated film, various methods generally known on the inorganic layer of a thermoplastic resin film deposited with an inorganic material and a thermoplastic resin film laminated with an aluminum foil, such as a wet laminating method and a dry laminating method, are used. It can be made by using a method, a hot melt laminating method, an extrusion laminating method, or a thermal laminating method.

  As a sealing layer on the organic EL structure, a mode in which the sealing member is directly bonded by heat by lamination or the like, a mode in which the sealing member is bonded via an adhesive layer, direct by vapor deposition or application Although there is an aspect of being formed, an aspect of being bonded through an adhesive layer is a preferable aspect.

  The sealing layer bonded through the adhesive layer is obtained by laminating the sealing member and the organic EL structure through the adhesive layer therebetween.

  As the adhesive used in the adhesive layer used in the method of adhering the sealing member via the adhesive layer, a heat or photo-curing adhesive is preferably used, and the sealing member is interposed via the adhesive. A method of curing the adhesive and providing the sealing member on the organic EL structure is a preferable embodiment.

  Sealing in which an adhesive layer capable of forming an adhesive layer is applied to the entire surface, particularly in a method in which an adhesive layer is cured and then a sealing member is provided on the organic EL structure after being bonded through the adhesive layer A method in which a member is bonded onto an organic EL structure and bonded is a preferred embodiment from the viewpoints of manufacturing cost and dark spot generation prevention.

<< Method for producing organic EL element >>
In the method for producing an organic EL element, the first electrode lead portion and the second electrode lead portion possessed by the organic EL structure are particularly opposed to the both ends of the belt-like substrate in the lateral direction. Use the one arranged.

  Since the first electrode lead portion and the second electrode lead portion are located opposite to both ends in the width direction, a sealing member described later is provided only in the center portion in the width direction of the base material, By cutting every two organic EL elements, it is possible to provide an organic EL element that is excellent in manufacturing cost and dark spot generation prevention properties.

  In the production method of the present invention, a roll-to-roll method is preferably used as a method used for producing the organic EL structure.

  The roll-to-roll method uses a strip-shaped base material wound around a roll, feeds out the strip-shaped base material, and provides an organic EL structure on the base material while being transported. This is a method in which the belt-shaped substrate is wound around a roll again, but generally includes a method in which a flexible belt-shaped substrate wound around a roll is used to continuously process the product. This may be superior in terms of manufacturing cost (yield, production space).

  FIG. 3 is a block diagram showing an example of a method for producing the organic EL element of the present invention.

  The organic EL device manufacturing method of the present invention includes a first electrode forming step 51 for forming a first electrode on a flexible strip-shaped substrate, an organic EL structure forming step 52, a sealing layer forming step 55, and a cutting step 56. It is possible to obtain an organic EL device having low cost and excellent performance stability.

  The first electrode forming step 51 is a step of forming a first electrode by patterning a band-shaped base material on which a transparent conductive film such as ITO is formed.

  A feature of the first electrode forming process according to the present invention is that the first electrode forming process is formed by patterning using printing of a resist solution or an etchant solution.

  Examples of the printing means include, but are not limited to, a screen printing method, a flexographic printing method, an offset printing method, a gravure printing method, an ink jet method, and a spray coating method using a mask.

  The etchant solution (also referred to as an etching solution) according to the present invention is a solution that dissolves the first electrode, and the resist solution according to the present invention is a solution that prevents the first electrode from being dissolved by the etchant solution. .

  In the case of using a resist solution, the resist solution is placed on the electrode forming portion by printing, and thereafter, the first electrode is patterned by performing an etching process and removing the resist.

  In the case of using the etchant liquid, the etchant liquid is installed on the electrode removal portion by printing, and is etched by heating or the like, whereby the first electrode is patterned.

  The organic EL structure forming step 52 is a step of forming a plurality of organic EL structures on a strip-shaped substrate on which the first electrode is formed. The sealing layer forming step 55 is a step of sealing the organic EL structure while leaving a part of the first electrode lead portion and the second electrode lead portion.

  The cutting step 56 is a step of cutting each base material on which the organic EL structure is disposed to produce each organic EL element.

  In the roll-to-row method, roll feeding, organic EL structure forming process, and roll winding are performed in this order, and roll feeding, sealing layer forming process 55, and cutting process 56 are performed in this order.

  Next, with reference to FIGS. 4, 5, and 6, a process of patterning the first electrode according to the present invention will be described.

  FIG. 4 is a schematic view showing an example in which rotary screen printing is used as a printing unit and the first electrode is patterned by using a resist solution.

  In FIG. 4, the transparent conductive film of the present invention that forms a pattern on a long substrate on which a transparent conductive film that is continuously conveyed when a resist solution (for example, etching resist SPR081 manufactured by Kansai Paint) is used is formed. The schematic process drawing and block diagram about an example of the pattern formation method are shown.

  In FIG. 4, reference numeral 1 denotes a roll of a flexible belt-like substrate S on which a transparent conductive film is formed.

  The transparent conductive film may be formed by a vacuum process such as vapor deposition or sputtering, or by any method such as a plasma CVD method or a method using coating such as a sol-gel method, but is preferably formed by a dry process. A transparent conductive film made of, for example, ITO or the like formed by the plasma ion plating method has a good surface property because it can form a smooth film, and is preferable for applications such as for organic EL.

  As long resin substrates, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), Examples thereof include flexible resin substrates such as cellulose triacetate (TAC) and cellulose acetate propionate (CAP).

  In particular, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone and the like are mentioned as preferable substrates, and a thickness of 50 μm to 400 μm is preferable.

  A preferred example of the flexible belt-like substrate S on which the transparent conductive film is formed is that on which an ITO film is formed with a thickness of 10 nm to 500 nm on these resin films.

  Further, it may be a resin film provided with an undercoat layer, a hard coat layer, or the like, and a transparent conductive film is applied to a resin substrate having a gas barrier film made of a material with low moisture permeability such as a silicon oxide layer or silicon oxynitride. Those formed are preferred.

  In particular, the gas barrier film is preferably formed on both surfaces of the resin film. This is because moisture does not penetrate into the substrate even in wet processes such as etching and washing described later.

  Since there is little water permeation into the substrate when wet, deterioration due to moisture permeation or outgassing from the substrate can be prevented after pattern formation, especially after forming an organic EL element or the like.

  These gas barrier layers are also preferably formed by a dry process such as sputtering, plasma CVD, or ion plating.

  Compared with the plasma CVD method and ion plating method that require introduction of raw materials necessary for thin film formation as gas components, the sputtering method has less restrictions on the target material, and even a high melting point material is a relatively thin film. Since it can be formed, it is particularly preferable to use a sputtering method which is a vacuum process. As a target, a barrier film to be formed, for example, a material that is the same as a constituent material such as silicon oxide or silicon oxynitride, or a material that has the same configuration as the constituent material by reaction with the sputtering gas, a sputtering gas is introduced, and a voltage is applied. In a vacuum environment with a predetermined gas pressure, plasma is generated and sputtering is performed to form a gas barrier film on the substrate. For example, an RF magnetron sputtering apparatus or the like is used.

  Further, an atmospheric pressure plasma CVD method may be used. For example, a polyethylene terephthalate film having a thickness of 200 μm is used as a substrate, a gas barrier film (thickness 70 nm) made of silicon oxide is formed on the substrate by atmospheric pressure plasma CVD, tetraethoxysilane is used as a thin film forming gas, a discharge gas (nitrogen), Further, it can be formed by mixing with an additive gas (oxygen) or the like and exciting it with a high frequency power source.

  The process using the rotary screen printing shown in FIG. 4 will be described in detail.

  On the transparent conductive film of the flexible strip-shaped substrate S fed out from the roll 1 of the flexible strip-shaped substrate S on which the transparent conductive film is formed, first, a resist solution is continuously patterned and printed in a patterning step. Is done. 2 schematically shows a rotary screen printing machine.

  Continuous printing can be performed endlessly by preparing the rotary screen in advance so as to enable patterning printing so as to form a necessary conductive film pattern on the transparent conductive film. Continuous printing is possible by using rotary screen printing.

  Next, the resist solution is continuously baked (dried) (not shown in the figure) and enters a curing step. The curing process is a heating process and is heated by a known heating device 3.

  In the case of a resist solution for etching ITO, for example, SPR081 of Kansai Paint, heat curing (also simply referred to as heat curing) may be performed at 120 ° C. for 20 minutes.

  In the present invention, since the resist solution is previously printed on the transparent conductive film of the flexible belt-like substrate S, there is no need for a photomask or pattern exposure by optical scanning. Further, there is no need for a development step, which is an operation for removing uncured resist other than the exposed pattern portion by development, and for removing a solvent and moisture due to development in the resist.

  In the present invention, the resist may be simply heat-cured after printing. Further, there is no need for pre-baking or the like.

  After post-baking (drying) after heat-curing (thermo-curing) (not shown in the figure), the etching process is continued.

  In the etching process, the exposed portion of the transparent conductive film where the resist pattern is not formed is etched.

  As an etching method, there are wet etching, dry etching, electrolytic etching, etc., but wet etching is preferable for performing continuously.

  As an etching solution for the ITO film used for wet etching, a hydrochloric acid aqueous solution, a hydrochloric acid ferric chloride aqueous solution, or the like is typical.

  In the etching step (also simply referred to as etching) in FIG. 4, wet etching is performed by introducing a substrate on which a resist is formed in an etching solution tank.

  In the figure, a state in which a flexible belt-like substrate S is introduced into an etching solution tank and the substrate S is transported through the tank.

  The number of the accumulator rolls in the liquid is one here, but the number of rolls is adjusted by the required etching time to adjust the immersion time in the liquid.

  Through this process, the ITO film in the portion where the resist is not formed is removed by etching.

  After the etching, washing with water is performed to discharge the acidic etching solution. In order to increase the permeability, it may be washed with water containing an activator, and then further washed with water for further washing.

  A shower may be used. For example, after washing by a water-washing shower process and a water-washing treatment process, a resist stripping process is started, preferably through a draining and drying process.

  The resist stripping process is a resist removing process, whereby a transparent conductive film such as ITO in a region protected by the resist is exposed, and a transparent conductive film pattern is formed.

  In the resist stripping process, a solvent, alkali, or the like is used as a stripping solution. In the case of an acid etching solution or the above resist, a caustic soda aqueous solution (about 1% to 3% by weight) is used at a temperature of about 40 ° C. Can be peeled off.

  Further, an alkaline stripping solution containing a glycol solvent, 2-aminoethanol as a component, or the like can also be used. In any case, it is preferable to use a stripping solution that does not affect the substrate or the transparent conductive film.

  Further, as the resist stripping step, a dry process such as ashing performed in a gas phase can be used. In the dry process, the resist can be removed by ashing with ozone or plasma in a gas phase.

  An ashing device is a photo-excited ashing device that introduces a gas such as ozone or oxygen into an ashing chamber, irradiates the gas or substrate with light such as ultraviolet rays, and peels it off by a chemical reaction between the gas and the photoresist. There is a plasma ashing apparatus that converts plasma into high-frequency plasma and uses the plasma.

  After the resist stripping step, water washing, that is, a water washing treatment step similar to that after etching or a water washing shower step or the like is performed, followed by dehydration treatment such as draining and drying. After the dehydration process, the substrate S having the patterned transparent conductive layer is taken up by the take-up roll 4.

  FIG. 5 is a schematic process diagram and a block diagram of the transparent conductive film pattern forming method of the present invention using screen printing of a resist solution.

  More specifically, FIG. 5 shows that a transparent conductive film that is continuously conveyed is formed when a resist solution (for example, an etching resist SPR081 manufactured by Kansai Paint) is used by using screen printing as a printing means. The schematic process figure and block diagram about the pattern formation method of the transparent conductive film of this invention which pattern-forms on a elongate board | substrate are shown.

  In FIG. 5, 20 schematically shows a screen printer. Ink (resist liquid in this case) is placed on one end of the screen (plate) inside (opposite the substrate), and the squeegee is reciprocated to push the ink under the screen and transfer it onto the substrate placed at the bottom of the screen. In the figure, the screen (plate), squeegee and ink are schematically shown.

  Since printing is performed by reciprocation of the squeegee, the substrate is kept stationary under the screen during this time. Therefore, screen printing is performed by intermittently transporting the flexible belt-like substrate.

  Therefore, in order to consistently and continuously form a transparent conductive film pattern, accumulating mechanisms 21 and 22 composed of a plurality of rolls are provided before and after the patterning process by printing (accumulation process), and the resist solution is arranged by screen printing. Absorbs the stagnation of conveyance during the process

  In FIG. 5, an accumulating mechanism 21 before the patterning process, an accumulating mechanism 22 after the curing process heated by the known heating device 3 after the patterning process, and two accumulating mechanisms are provided.

  Thus, when entering the accumulator mechanism 21 or when leaving the accumulator mechanism 22, the flexible belt-like substrate is apparently continuously conveyed.

  The subsequent etching steps can be performed consistently and continuously, and the steps can be assembled in the same manner as shown in FIG.

  Therefore, the step of arranging the resist solution in a pattern by screen printing on the flexible belt-like substrate on which the transparent conductive film to be continuously conveyed is formed and the curing step of curing the resist solution are intermittently performed. However, by providing an accumulator mechanism before and after this, this intermittent process and a continuous process such as an etching process, a resist stripping process, a water washing process, a dehydration process, etc. are continuously connected. Can be performed continuously.

  FIG. 6 is a schematic process diagram and a block diagram of the transparent conductive film pattern forming method of the present invention using screen printing of an etchant solution.

  More specifically, FIG. 6 shows a case where a transparent conductive film transported continuously is formed by using screen printing as a printing means and using an etchant liquid (for example, Etch liquid HiperEch04S Type 10 manufactured by Merck). The schematic process figure and block diagram about the pattern formation method of the transparent conductive film of this invention which pattern-forms on a elongate board | substrate are shown.

  Except that the etching is changed from wet etching to thermal etching and the resist stripping process is eliminated, the process is the same as the process using resist printing screen printing.

  According to these methods, flexible strip-like substrates can be continuously produced by a roll-to-roll method, so that the production efficiency can be improved, and resist pre-baking can be performed in comparison with the photolithography method which has been the mainstream in the past. In addition, there is an advantage that patterning can be performed by a simple method without the need for post-baking after development, a mask for pattern exposure, and an apparatus for scanning exposure.

  FIG. 7 is a schematic diagram illustrating an example of an organic EL structure forming process.

  The organic EL structure forming step 52 includes an organic layer forming step 53 including an organic light emitting layer and a second electrode forming step 54. In the organic layer forming step 53 including an organic light emitting layer, the hole transport layer is formed. And a step of forming an organic light emitting layer, and the second electrode forming step 54 includes a step of forming an electron injection layer and a second electrode layer.

  The organic layer forming step 53 including an organic light emitting layer includes a supply unit 301 for supplying a strip-shaped substrate, a cleaning surface modification processing unit 302 for the strip-shaped substrate, a first application / drying unit 303, and a first heating. A processing unit 304, a second static elimination processing unit 305, and a second application / drying unit 306 are included.

  In the supply part 301, the strip | belt-shaped base material 301b in which the 1st electrode was formed on the strip | belt-shaped base material is wound up by the winding core, and is supplied as the roll-shaped base material 301a.

  The cleaning surface modification processing unit 302 cleans and modifies the surface of the first electrode on the strip-shaped substrate 301b sent from the supply unit 301 before applying the hole transport layer forming coating solution. Quality processing means 302a and first charge removal processing means 302b.

  The first coating / drying unit 303 includes a backup roll 303a that holds the belt-shaped substrate 301b, and a coating liquid for forming a hole transport layer on the belt-shaped substrate 301b that is held by the backup roll 303a. A first wet coater 303b that coats a portion of the substrate, and a first drying device 303c that removes the solvent of the organic light-emitting layer formed on the first electrode on the belt-like substrate 301b. Yes. Reference numeral 304 denotes a first heat treatment unit.

  Reference numeral 305 denotes a second charge removal processing means for removing charge from the formed hole transport layer.

  The second application / drying unit 306 includes a first accumulator unit 306a, a pattern application unit 306b, a drying unit 306c, a heat processing unit 306d, a charge removal processing unit 306e, a second accumulator unit 306f, and a recovery unit 306g. have.

  The first accumulator unit 306a adjusts the difference in transport speed between the first coating / drying unit 303 and the second coating / drying unit 306 by moving the roll 306a1a in the vertical direction (the arrow direction in the drawing). The roll 306a1a can be added according to the speed difference.

  The pattern coating unit 306b applies a pattern of applying a coating solution for forming a light emitting layer on the hole transport layer in accordance with the pattern of the first electrode on the hole transport layer under atmospheric pressure conditions. A wet pattern forming and coating apparatus 306b1.

  The light emitting layer drying unit 306c has a function of removing the solvent in the light emitting layer under atmospheric pressure conditions, and has the same configuration as the first drying device 303c. The holding base 306b2 is not particularly limited as long as the belt-like base material can be fixed while maintaining flatness. For example, the holding base 306b2 is preferably fixed by an adsorption method.

  When coating is performed by the wet pattern formation coating apparatus 306b1 in the pattern coating unit 306b, pattern alignment is applied to a belt-shaped substrate alignment mark (not shown) on which a hole transport layer transported from the previous step is formed. The belt-like base material on which the hole transport layer is formed is adsorbed and fixed on the holding table, and the wet pattern formation coating device 306b1 is aligned according to the alignment mark. The light emitting layer forming coating solution is applied onto the electrode in accordance with the pattern of the first electrode except for a part of the lead portion of the first electrode formed by patterning.

  The neutralization processing unit 306e has a function of performing neutralization of the band-shaped base material on which the light emitting layer is formed and preventing a failure due to static electricity in the next process, and can be disposed as necessary. .

  The neutralization processing unit 306e preferably uses the same neutralization processing unit as the neutralization processing unit used in the first application / drying unit 303.

  The second accumulator unit 306f is arranged to adjust the difference in conveyance speed between the pattern application / drying unit 306 and the collection unit 306g by moving the roll 306f1 in the vertical direction (the arrow direction in the figure). The rolls can be added according to the speed difference.

  The second accumulator unit 306f has the same configuration as the first accumulator unit 306a. In the recovery part 306g, it is preferable that the strip-shaped base material 301f on which the light emitting layer is formed is cooled to room temperature with a cooling device (not shown) and then wound up.

  The second electrode forming step 54 includes a material supply unit 401, an electron injection layer forming unit 402, a second electrode forming unit 403, and a second winding unit 404. Up to 404 is performed continuously under reduced pressure conditions.

  In the supply section 401, a winding core produced in the organic layer (including the organic light emitting layer) forming step 53 and having a first electrode, a hole transport layer, and an organic light emitting layer formed on a belt-like substrate. The roll-shaped strip-shaped base material 301f wound up is supplied.

  An electron injection layer 301g is formed by the electron injection layer forming unit 402 on the organic light emitting layer of the band-shaped substrate 301f having the organic light emitting layer unwound from the supply unit 401. Reference numeral 402a denotes a vapor deposition apparatus, and 402b denotes an evaporation source container.

  In the second electrode formation part 403, the second electrode 301h is formed on the electron injection layer 301g formed in the electron injection layer formation part 402. Reference numeral 403a denotes a vapor deposition apparatus, and reference numeral 403b denotes an evaporation source container. The strip-shaped base material 301i formed by the second electrode forming portion 403 in a state where the second electrode 301h is orthogonal to the first electrode is wound around the winding core by the collecting portion 404 to become a roll-shaped strip-shaped base material C301j.

  The organic electronics structure is formed as described above. In the present invention, the organic layer (including an organic light emitting layer in the case of an organic EL element) is preferably formed by patterning as described below. .

  That is, a mode in which an organic layer is continuously formed on the first electrode and then a step of removing the organic layer between each organic electronics element structure is provided before the second electrode is disposed is a preferable mode. .

  As a method for forming a very thin thin film (organic light emitting layer) containing a phosphorescent (or fluorescent) organic compound contained in the organic layer, vapor deposition or the like may be used, but the wet process may be formed under atmospheric pressure. Therefore, the operation is simple and preferable from the viewpoint of cost.

  In addition, since the coating solution is prepared into a thin film, there is a feature that unevenness is difficult to be generated even in a large area, which is very advantageous in terms of cost and manufacturing technology. In particular, it can be said that lighting applications are very advantageous in terms of cost and manufacturing technology.

  Further, as a precise and rapid patterning method of the organic layer in the wet process, a method of wiping and removing a continuously formed organic layer in a pattern or a method of removing by a laser is preferably used.

  That is, a part of the continuous organic layer (including the organic light emitting layer) on the organic electronic structure on the belt-like substrate is selectively and continuously removed with a solvent or a laser to form a clearly patterned organic layer. Is preferred. When the organic layer is a multilayer, it may be removed for each layer or a plurality of layers may be removed simultaneously.

  When the step of removing the organic layer is performed, the step of providing the second electrode as described above is performed after this step.

  Another possible method is to remove the organic layer after forming the second electrode.

  FIG. 8 is a schematic diagram illustrating an example of the sealing layer forming step 55 and the cutting step 56.

  The sealing layer forming process 55 includes a bonding process 57 and a curing process 58.

  In the bonding step 57, the sealing member 16B having the adhesive layer 16A is pressure-bonded to the belt-like substrate 11 with a roller to form the sealing layer 16 made of the sealing member 16B on the organic EL structure.

  In this step, a part of the electrode lead portion (for example, 12b and 14b in FIG. 2) that is not covered with the sealing member is formed.

  As the adhesive used for the adhesive layer, a thermosetting adhesive that is cured by heating by an epoxy-based, acrylic-based, acrylic urethane-based heating means, or an ultraviolet curable adhesive that is cured by ultraviolet irradiation of an ultraviolet irradiation means. Although it can be used, a thermosetting adhesive is preferably used.

  In the curing step 58, the adhesive layer 16A is cured by heating with the heating means 58A, and the sealing layer 16 is fixed to the upper surface of the organic EL structure. When the adhesive is of a type using ultraviolet curing, it is cured by irradiating with UV light.

  The curing step 58 may be before the cutting step described later as shown in FIG. 5 or may be after the cutting step, but after the cutting step in terms of manufacturing efficiency, This is a preferred embodiment.

  The cutting step 56 is a step of obtaining each organic EL element by cutting the belt-like base material on which the sealing layer 16 is formed at a predetermined position.

  The cutting step 56 includes a cutting unit 61A, and the strip substrate 11 is cut by the cutting unit 61A in the cutting step 56 to obtain an organic EL element.

  The obtained organic EL element has a 1st electrode, a positive hole transport layer, an organic light emitting layer, a 2nd electrode layer, an electron injection layer, and a sealing layer on a base material.

  The cutting means 61A, a guillotine cutter that moves up and down, or a circular rotary cutter that suppresses vibration may be used.

  The cutting position is performed along a cutting line A that cuts in the width direction shown in FIG. In this case, the distance t between the cutting line A and the lead portions 12b and 14b of the first electrode and the second electrode is preferably 1 mm or more from the viewpoint of gas barrier properties of the adhesive layer and prevention of electrode short-circuit. What is cut along the cutting line is each organic EL element.

  Hereinafter, although an example is given and the concrete effect of the present invention is shown, the mode of the present invention is not limited to these. The structural formulas of the compounds used in the examples are shown below.

Example 1
<< Substrate No. on which the first electrode is formed Preparation of 1 >>
Example 1 of Japanese Patent Laid-Open No. 2007-83644 in which a gas barrier film is formed on a polyethylene naphthalate film (a film made by Teijin DuPont, hereinafter abbreviated as PEN) having a thickness of 100 μm, a width of 200 mm, and a length of 500 m Prepared with reference to the method described in 1.).

In addition, an alignment mark is provided on the belt-like base material in advance to indicate the position where the first electrode is formed, and a 120 nm thick ITO (indium tin oxide) is sputtered under a vacuum environment condition of 5 × 10 ⁻¹ Pa. To form a band-shaped substrate with a first electrode. A first electrode having a size of 10 mm × 10 mm was continuously formed at regular intervals and wound up by the following first electrode forming method (patterning method).

(First electrode formation method (patterning method))
Using a known screen printing machine, a resist solution (Kansai Paint: SPR081) is printed on the first electrode forming portion to a thickness of 20 μm using a screen plate of mesh 325, dried at 120 ° C. for 20 minutes, and then an etching solution (salt chloride). After etching at room temperature for 1 minute with 9.5% hydrochloric acid containing cupric), the resist was peeled off at room temperature for 2 minutes with a resist stripping solution (1% sodium hydroxide solution), then washed with water and dried to form the first electrode. .

<< Substrate No. on which the first electrode is formed Preparation of 2 >>
Base No. 1 was prepared in the same manner except that the following method was used as the first electrode forming method. 2 was produced.

(First electrode formation method (patterning method))
Using a known screen printer, an etchant solution (Merck: HiperEtch04S Type 10) is printed to a thickness of 20 μm using a screen plate of mesh 325 in addition to the first electrode forming part, and is thermally etched at 100 ° C. for 5 minutes, then washed with water and dried. The first electrode was formed.

<< Substrate No. on which the first electrode is formed Preparation of No. 3 >>
Base No. 1 was prepared in the same manner except that the following photolithographic method known as the first electrode forming method was used. 3 was produced.

(Known photolithography method)
A positive photoresist (“MICROPOSIT SRC-300A” manufactured by Shipley Far East) is applied to the first electrode formation surface of the base material, and a mask is used to perform temporary drying, exposure, development, and curing according to a photolithography process. The first electrode pattern was formed by etching the first electrode with an acid and removing the resist.

<< Substrate No. on which the first electrode is formed Preparation of No. 4 >>
Base No. 1 was prepared in the same manner except that the mesh 250 was used for the screen plate. 4 was produced.

<< Substrate No. on which the first electrode is formed Preparation of No. 5 >>
Base No. 2 was prepared in the same manner except that the mesh 250 was used for the screen plate. 5 was produced.

<< Substrate No. on which the first electrode is formed Preparation of No. 6 >>
Base No. 1 was prepared in the same manner except that the mesh 200 was used for the screen plate. 6 was produced.

<< Substrate No. on which the first electrode is formed 7 Preparation >>
Base No. 2 was prepared in the same manner except that the mesh 200 was used for the screen plate. 7 was produced.

  The obtained base material No. 1 on which the first electrode was formed was obtained. 1-No. The linearity (also referred to as linearity) of the edge part of each first electrode 7 and the angle (θ degree) of the edge part were measured using the method described below.

(Evaluation of linearity (linearity) of edge part of first electrode)
The base material No. Evaluation of the linearity of the edge part of the 1st 1-7 electrode is the 1st electrode (10 mm x length) which has the shape which changed the angle of the shape shown by FIG. A pattern having a thickness of 150 mm was formed), and the difference between the maximum value and the minimum value when the width direction was measured at 10 locations was evaluated as an index of the linearity (linearity) of the edge portion. In the present invention, the linearity of the edge portion of the first electrode is preferably 100 μm or less.

(Measurement of the edge angle (θ degrees) of the first electrode)
Subsequently, the base material No. The angle was measured on the inclined surface of the edge cross section of each of the first electrodes 1 to 7 and evaluated as an index of the edge portion shape.

  FIG. 9 shows an enlarged schematic diagram in the case where the edge portion of the first electrode has an inclined surface shape. In the figure, 201c indicates an inclined surface formed by patterning.

  θ represents the angle of the inclined surface 201c with respect to the plane 201a of the first electrode 201 (the surface facing the second electrode when an organic EL element is formed).

  The angle θ is preferably in the range of 0 to 80 degrees from the viewpoint of effectively preventing the occurrence of leakage current, and more preferably adjusted in the range of 30 to 75 degrees in the present invention. It is preferable.

  Substrate No. on which the first electrode produced above was formed. The linearity (linearity) and the edge angle (θ degrees) of the edge portions of the first electrodes 1 to 7 are shown together with the evaluation results of the organic EL elements 101 to 107 described later.

<< Formation of organic EL elements >>
Each of the prepared base materials with the first electrode No. 1-7 on the first hole transport layer, the second hole transport layer, the organic light emitting layer, the electron transport layer, the cathode buffer layer (electron injection layer), the second electrode, and the sealing member by the method shown below. The organic EL elements 101 to 107 were respectively formed in order.

(First hole transport layer formation)
A solution obtained by diluting polyethylene dioxythiophene / polystyrene sulfonate (PEDOT / PSS, Baytron P AI 4083 manufactured by Bayer) with pure water at 65% and methanol at 5% is used as a coating solution for forming the first hole transport layer. The entire surface (excluding 10 mm at both ends) was applied using an extrusion coater so that the thickness after drying was 30 nm. After coating, drying and heat treatment were performed to form a first hole transport layer.

(Application conditions)
The coating conditions for the coating solution for forming the first hole transport layer are as follows: the temperature is 25 ° C., the dew point is −20 ° C. or less in an N ₂ gas environment at atmospheric pressure, and the cleanliness class is 5 or less (as defined in JIS B 9920). )

(Pattern of the first hole transport layer: removal step 1)
The substrate on which the first hole transport layer is formed is irradiated with microwaves (2.45 GHz) to detect the position of the first electrode as a thermal pattern, and this is used as a positioning mark. Unnecessary portions on the extraction electrode portion and around the first electrode were removed by a known patterning technique such as a method of wiping off with a solvent or a method of removing with a laser.

  Next, as described below, the second hole transport layer, the organic light emitting layer, and the electron transport layer were sequentially formed by repeating coating, drying, and winding using an extrusion coating machine. The conveyance speed was 3 m / min.

(Second hole transport layer)
Under a nitrogen atmosphere, a solution of 50 mg of the hole transport material 1 dissolved in 10 ml of toluene was formed into a film by an extrusion coating method. After drying, ultraviolet light was irradiated for 180 seconds in a nitrogen atmosphere to carry out photopolymerization and crosslinking to form a second hole transport layer having a thickness of about 20 nm.

(Organic light emitting layer)
A toluene solution containing 1% by mass and 0.1% by mass of PVK and dopant 4, respectively, was formed on the second hole transport layer by an extrusion coating method. It dried at 120 degreeC and was set as the organic light emitting layer with a film thickness of about 50 nm.

(Electron transport layer)
A 1-butanol solution containing 0.5% by mass of the electron transport material 1 was similarly formed on the light emitting layer by an extrusion coating method. It dried at 60 degreeC and was set as the electron carrying layer with a film thickness of about 15 nm.

Similarly, the coating conditions were as follows: the temperature was 25 ° C., the N ₂ gas environment having a dew point temperature of −20 ° C. or lower, the atmospheric pressure, and the cleanliness class 5 or lower (JIS B 9920).

(Patterning of organic layer (organic light emitting layer): removal step 2)
The wound base material (PEN) on which the first hole transport layer is formed is supplied, and positioning is performed using a microwave sensor using the first electrode pattern formed on the PEN as a positioning mark. In addition, unnecessary portions on the extraction electrode portion of the first electrode and around the first electrode (first hole transport layer) were removed by a known patterning technique such as a method of wiping off with a solvent or a method of removing with a laser. .

  Next, a cathode buffer layer (electron injection layer), a second electrode, and a sealing member with an adhesive are sequentially formed on the organic layer under the following conditions to form a sealing layer, which is cut and further subjected to heat treatment. Then, an organic EL element was produced.

(Formation of cathode buffer layer (electron injection layer))
According to the position of the anode attached to the roll-shaped PEN on which the patterned organic layer is formed, a vacuum of 5 × 10 ⁻⁴ Pa is applied on the electron transport layer and a portion excluding the lead portion of the first electrode by a vapor deposition apparatus. A mask pattern deposition film was formed using LiF under environmental conditions, and a cathode buffer layer (electron injection layer) having a thickness of 0.5 nm was laminated.

(Formation of second electrode)
Subsequently, likewise according to the size of the first electrode on the cathode buffer layer (electron injection layer), as the lead portions of the second electrode is disposed on the side opposite to the lead portion of the first electrode, 5 × 10 ^{- A} mask pattern was formed by vapor deposition using aluminum under a vacuum of ⁴ Pa, and a second electrode made of an aluminum layer having a thickness of 100 nm was laminated to form an organic electronics structure (organic EL structure).

(Sealing layer formation (bonding of sealing members))
Next, the alignment mark attached to the band-shaped base material having the organic electronics structure is detected, and as shown in FIG. 2, except for a part of the lead portion of the first electrode and the second electrode according to the position of the alignment mark. A band-shaped sealing member 16 having an adhesive layer was bonded.

  For the bonding of the strip-shaped sealing member 16A, an apparatus shown in FIG. 6 was used, and as the strip-shaped sealing member, a film obtained by laminating a barrier layer of aluminum foil 30 μm on PET 50 μm was used.

  Further, a thermosetting adhesive having a melting point of 120 ° C. was used as the adhesive for the adhesive layer 16B, and the layer thickness was 30 μm.

(Cutting)
Next, in a state where a plurality of organic EL elements that are produced are continuously connected, the alignment mark is detected in the size of the individual organic EL element, and cut according to the position of the alignment mark. Was made.

  About the produced organic EL101-107, the leakage current characteristic was evaluated with the test method shown below.

(Evaluation method of leakage current characteristics)
Using a constant voltage power source, a reverse voltage (reverse bias) of 5 V was applied for 5 seconds, and the current flowing through the device at that time was measured. The maximum current value was taken as the leakage current. Moreover, the following rank evaluation was performed for evaluation.

Evaluation rank of leakage current A: Maximum current value is less than 1 × 10 ⁻⁸ A ○: Maximum current value is 1 × 10 ⁻⁸ A or more and less than 1 × 10 ⁻⁶ A Δ: Maximum current value is 1 × 10 ⁻⁶ A or more and less than 1 × 10 ⁻⁴ A ×: The maximum current value is 1 × 10 ⁻⁴ A or more. The results obtained for 101-107 are shown below.

Organic EL substrate Linearity Edge shape Leak Remarks Element No. No. (Μm) (degree) Current 101 1 50 45 ◎ Present invention 102 2 75 35 ○ Present invention 103 3 10 90 × Comparative example 104 4 75 55 ○ Present invention 105 5 100 40 ○ Present invention 106 6 125 60 Δ Present invention 107 7 150 50 Δ Present Invention From the above results, it can be seen that the method for producing an organic EL element of the present invention has less leakage current than that using the first electrode formed by photolithography.

  This is because the edge in the case of photolithography is a right angle, whereas the edge of the present invention has a chamfered shape, and it is difficult to form burrs at the edge portion, so it is determined that there is little leakage current. .

  It can also be seen that the leakage current increases when the edge linearity of the first electrode deteriorates.

  This is because if the edge linearity is poor, the shape of the edge portion becomes unstable, and burrs are formed in the portion where the chamfering of the edge portion is small.

DESCRIPTION OF SYMBOLS 1 Roll 2 Rotary screen printing machine 3 Heating apparatus 4 Winding roll 10 Organic EL element 11 Base material 12 1st electrode 13 Organic layer (An organic light emitting layer is included.)
14 Second electrode 15 Adhesive layer 16 Sealing layer 16A Adhesive layer 16B Band-shaped sealing member 20 Screen printer 21, 22 Accumulation mechanism 51 First electrode forming step 52 Organic EL structure forming step 53 Organic layer forming step 55 Sealing Layer forming step 56 Cutting step A Cutting line S Flexible strip-shaped substrate on which a transparent conductive film is formed t Distance between the cutting line A and the lead portion of the first electrode or the second electrode

Claims (6)

Fabrication of an organic electroluminescence device comprising a first electrode patterned on a substrate, an organic layer including an organic light emitting layer disposed on the first electrode, and a second electrode disposed on the organic layer In the method
An organic electroluminescence element comprising: a step of providing a material for forming the first electrode on the substrate; and a step of forming the first electrode by patterning using printing of a resist solution or an etchant solution. Manufacturing method.   The method for manufacturing an organic electroluminescent element according to claim 1, wherein the substrate is a flexible strip-shaped substrate.   The method for producing an organic electroluminescence element according to claim 1, wherein the printing is screen printing.   The method for producing an organic electroluminescent element according to claim 1, wherein the linearity of the edge portion of the first electrode is 100 μm or less.   5. The method of manufacturing an organic electroluminescent element according to claim 1, wherein an angle θ of the edge portion of the first electrode is 30 degrees to 75 degrees.   An organic electroluminescent device produced by the method for producing an organic electroluminescent device according to claim 1.

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