JP2008098106A - Manufacturing method of organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an organic EL element for patterning an organic EL layer by using a photolithographic method providing the organic EL element with excellent lifetime characteristics. <P>SOLUTION: The organic EL layer, a protective layer, and a photoresist layer are laminated in this order in patterning the organic EL layer by using the photolithographic method. After the patterning, the photoresist layer and protective layer are stripped in this order. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic electroluminescence (hereinafter, electroluminescence may be abbreviated as EL) element using a photolithography method.

  In the EL element, holes and electrons injected from two opposing electrodes are combined in the light emitting layer, and the fluorescent material in the light emitting layer is excited by the energy to emit light of a color corresponding to the fluorescent material. Therefore, it has been attracting attention as a self-luminous planar display element. Among them, an organic EL element using an organic substance as a light emitting material has high luminous efficiency, such as being able to realize high luminance light emission even when an applied voltage is less than 10 V, and can emit light with a simple element structure. It is expected to be applied to advertisements that display these patterns in light emission and other simple display displays at low cost.

  In general, in manufacturing a display using an organic EL element, a light emitting layer and the like are patterned. As a patterning method of the light emitting layer, a method of evaporating a light emitting material through a shadow mask, a method of separately coating by an ink jet method, a photolithography method, and the like have been proposed.

  Among these methods, the photolithography method does not require a vacuum facility or the like having a highly accurate alignment mechanism as compared with the patterning method by vapor deposition, so that an organic EL element is manufactured relatively easily and inexpensively. be able to. In addition, the photolithography method is preferable in that it does not perform a pretreatment or the like on a structure or a substrate that assists patterning, as compared with a patterning method using an inkjet method. Furthermore, from the relationship with the ejection accuracy of the inkjet head, the photolithography method is more advantageous for the formation of a higher definition pattern.

  When patterning an organic EL layer by photolithography, when applying a photoresist on the organic EL layer, the organic material used for the organic EL layer is not only a photoresist solvent but also a photoresist developer, a peeling It is required to be insoluble in the liquid and the rinse liquid. However, since the organic material generally used for the organic EL layer is soluble in many solvents, it is difficult to form a photoresist layer by applying a photoresist on the organic EL layer.

  Therefore, for example, an anode, an organic EL layer, a cathode, and a protective layer are formed on the entire surface of the substrate, a photoresist layer is formed on the protective layer, this photoresist layer is patterned into a desired shape, and then reactive. A method of patterning an organic EL layer by successively etching the cathode, the protective layer, and the organic EL layer where the photoresist layer has been removed by ion etching (RIE) is disclosed (see Patent Document 1). . However, in order to pattern the three-color light emitting layer using this method, a cathode and a protective layer are vacuum-deposited on the organic EL layer, and then the cathode, the protective layer, and the organic EL layer are etched to form a photoresist. Since the process of removing the layer is repeated, there is a problem that the process is very complicated and the manufacturing cost increases.

  In addition, a method for insolubilizing an organic material forming an organic EL layer by curing and crosslinking is proposed. For example, in Patent Document 2, an organic material containing a thermosetting resin is used for the light emitting layer and the hole transporting layer, and the organic material containing the thermosetting resin is applied and then heat-cured to insolubilize. A method is disclosed. According to this method, a photoresist layer can be easily formed on the light emitting layer or the hole transport layer.

In this method, a light emitting material or a hole transporting material mixed with a thermosetting resin is used for the light emitting layer or the hole transporting layer. At this time, for example, the mixing ratio of the thermosetting resin and the hole transporting material is set to 4: 6. In such a mixing ratio, the ratio of the hole transporting material is actually too low, and the hole injection and transport characteristics are remarkably deteriorated.
In general, when a polymer-based light-emitting material is used for the light-emitting layer, it is important to purify the polymer-based light-emitting material in order to increase the light emission efficiency and the lifetime. For this reason, when a polymer light-emitting material and a photosensitive resin are mixed, a reaction initiator, ions as a reactant, or the like may act as impurities to cause deterioration of characteristics. For these reasons, Patent Document 2 describes that a thermosetting resin having no impurities is effective. However, even a thermosetting resin may act as an impurity.

  Further, in Patent Document 2, after the first color light emitting layer is patterned by dry etching, the photoresist layer is once peeled off, the thermosetting resin is completely cured, and the surface of the first color light emitting layer is exposed. A method of forming a light emitting layer for the second color is disclosed. In this method, the surface of the light emitting layer of the first color is exposed to damage by being subjected to dry etching for patterning the light emitting layer of the second color. Therefore, there is a problem that the injection efficiency of holes and electrons is remarkably lowered.

  In addition, by appropriately adjusting the solubility of a photoresist solvent, a photoresist developer, a stripping solution, etc. with respect to the organic material used for the organic EL layer, a photoresist layer is formed on the organic EL layer, and organic A method for patterning an EL layer has been proposed (see Patent Document 3). In this method, first, a photoresist layer is formed on the light emitting layer of the first color, patterned into a desired shape, and the light emitting layer of the first color in the portion where the photoresist layer has been removed is etched. Then, without removing the photoresist layer, a light emitting layer of the second color is formed, a photoresist layer is further formed on the light emitting layer of the second color, patterned into a desired shape, and the portion where the photoresist layer is removed The second color light emitting layer is etched. And after repeating such a process and patterning the light emitting layer of multiple colors, each photoresist layer is removed.

  According to this method, even when the second color light emitting layer is formed, the photoresist layer remains on the first color light emitting layer, and the first color light emitting layer is applied to form the second color light emitting layer. Since it is protected from dry etching for patterning the liquid and the light emitting layer of the second color, damage can be reduced. In this method, a photoresist is directly applied on the organic EL layer.

JP-A-9-293589 JP 2001-237075 A JP 2004-6231 A

  However, when a photoresist is applied directly on the organic EL layer, the life characteristics and the like may be deteriorated. This is because the photoresist component is slightly adhered to the surface of the organic EL layer even after the photoresist layer is peeled off, and it is considered that this small amount of the photoresist component has some influence on the lifetime characteristics and the like.

  The present invention has been made in view of the above problems, and provides a method for manufacturing an organic EL element in which an organic EL layer is patterned using a photolithography method, and provides a method for manufacturing an organic EL element having excellent lifetime characteristics. The main purpose is to do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have focused on the residue of the photoresist component as a cause of deteriorating the life characteristics when the photoresist is directly applied on the organic EL layer. In general, a photoresist contains a resin as a main component, a photosensitive agent, and various additives for improving coating properties and the like. Further, the resin as the main component has been devised such as lowering the molecular weight in order to improve developability and peelability. When such a photoresist is applied directly on the organic EL layer, a slight amount of the photoresist component remains on the surface of the organic EL layer even after the photoresist layer is peeled off. May be adversely affected. Therefore, the present inventors improve the life characteristics and the like by forming a protective layer on the organic EL layer before applying the photoresist so that the organic EL layer and the photoresist are not in direct contact with each other. The present invention was completed.

  That is, the present invention includes an organic EL layer forming step of forming at least one organic EL layer on a substrate on which an electrode layer is formed, a protective layer forming step of forming a protective layer on the organic EL layer, A photoresist layer forming step of applying a photoresist on the protective layer to form a photoresist layer, and a photoresist layer patterning step of patterning the photoresist layer by pattern exposure and development of the photoresist layer And an organic EL layer patterning step of patterning the organic EL layer by removing the protective layer and the organic EL layer in a portion where the photoresist layer is removed, and the remaining photoresist layer and the protective layer. And a peeling step for peeling the layers in this order.

  According to the present invention, since the protective layer is formed on the organic EL layer and the photoresist layer and the protective layer are peeled in this order, the organic EL layer can be prevented from being exposed to the photoresist component. Therefore, it is possible to obtain a long-life organic EL element.

  In the said invention, it is preferable to form at least a light emitting layer as said organic EL layer in the said organic EL layer formation process. This is because, as described above, the organic EL layer including the light emitting layer can be prevented from being exposed to the photoresist component, so that the lifetime can be further increased.

  In addition, the present invention provides a first organic EL layer forming step of forming a first organic EL layer including at least a first light emitting layer on a substrate on which an electrode layer is formed, and a first organic EL layer on the first organic EL layer. A first protective layer forming step of forming a protective layer; a first photoresist layer forming step of applying a photoresist on the first protective layer to form a first photoresist layer; and the first photoresist layer. A first photoresist layer patterning step of patterning the first photoresist layer so that the first photoresist layer in the first light emitting region remains by pattern exposure and development, and the first photoresist layer A first organic EL layer patterning step of patterning the first organic EL layer by removing the removed first protective layer and the first organic EL layer, and the first A second organic EL layer forming step of forming a second organic EL layer including at least a second light emitting layer on a substrate on which the EL layer, the first protective layer, and the first photoresist layer are formed in a pattern; A second protective layer forming step for forming a second protective layer on the second organic EL layer; and a second photoresist layer for forming a second photoresist layer by applying a photoresist on the second protective layer A second photoresist layer for patterning the second photoresist layer so that the second photoresist layer in the second light-emitting region remains by pattern exposure and development of the second photoresist layer; Patterning the second organic EL layer by removing the second protective layer and the second organic EL layer in a patterning step and the portion where the second photoresist layer is removed A second organic EL layer patterning step, the first organic EL layer, the first protective layer, and the first photoresist layer are formed in a pattern, and the second organic EL layer, the second protective layer, and A third organic EL layer forming step of forming a third organic EL layer including at least a third light emitting layer on the substrate on which the second photoresist layer is formed in a pattern; and a second organic EL layer on the third organic EL layer. A third protective layer forming step for forming three protective layers; a third photoresist layer forming step for forming a third photoresist layer by applying a photoresist on the third protective layer; and the third photoresist layer. A third photoresist layer patterning step of patterning the third photoresist layer so that the third photoresist layer in the third light emitting region remains by pattern exposure and development And a third organic EL layer patterning step of patterning the third organic EL layer by removing the third protective layer and the third organic EL layer in a portion where the third photoresist layer is removed, A peeling step of peeling the remaining first photoresist layer, the second photoresist layer and the third photoresist layer, and the first protective layer, the second protective layer and the third protective layer in this order; The manufacturing method of the organic EL element characterized by having.

According to the present invention, since each protective layer is formed on each organic EL layer, a photoresist is not directly applied on each organic EL layer. Further, when patterning the second organic EL layer, the second organic EL layer and the second protective layer are formed on the patterned first organic EL layer and the first protective layer, and the second protective layer. Since the photoresist is applied thereon, the first organic EL layer does not come into contact with the second photoresist layer. Furthermore, when the third organic EL layer is patterned, similarly, the first organic EL layer and the second organic EL layer do not come into contact with the third photoresist layer. Moreover, since each photoresist layer and each protective layer are peeled in this order, each organic EL layer can be prevented from being exposed to the photoresist component.
Further, as described above, when the second organic EL layer is patterned, the second organic EL layer and the second protective layer are formed on the patterned first organic EL layer and the first protective layer. Therefore, damage to the first organic EL layer during etching of the second organic EL layer can be reduced. Similarly, when patterning the third organic EL layer, it is possible to reduce damage to the first organic EL layer and the second organic EL layer when the third organic EL layer is etched.
Therefore, it is possible to obtain a long-life organic EL element.

  In the above invention, the first organic EL layer, the first protective layer, and the first photoresist layer are insoluble in a solvent used for forming the second organic EL layer and the third organic EL layer, and The second organic EL layer, the second protective layer, and the second photoresist layer are preferably insoluble in the solvent used for forming the third organic EL layer. This is because each layer can be laminated stably.

  In the present invention, each of the protective layers contains at least one selected from the group consisting of a water-soluble cellulose derivative, a modified cellulose derivative soluble in an organic solvent, a water-soluble polyvinyl alcohol derivative, and a fluoropolymer material. Is preferred. This is because when the protective layer is formed using such a material, the organic EL layer, the protective layer, and the photoresist layer can be stably stacked.

  Furthermore, in this invention, the said peeling process may have the process of peeling only each said photoresist layer, and the process of peeling only each said protective layer. This is because the surface of the organic EL layer can be effectively prevented from being exposed to the photoresist component by separately removing the photoresist layer and the protective layer.

  Further, the peeling step may be a step of gradually peeling the photoresist layers and the protective layers from an upper layer using a stripping solution that dissolves the photoresist layers and the protective layers. Such a process is preferable in terms of reduction in the number of processes and cost reduction.

  Furthermore, in this invention, it is preferable to perform the washing | cleaning process which wash | cleans the outermost surface of each said organic EL layer after the said peeling process. This is because the photoresist component remaining on the surface of the organic EL layer can be effectively removed.

  Moreover, you may perform the plasma processing process which plasma-processes the outermost surface of each said organic EL layer after the said peeling process. In this case as well, the photoresist component remaining on the surface of the organic EL layer can be effectively removed.

  In the present invention, a protective layer is formed on the organic EL layer, and the photoresist layer and the protective layer are peeled in this order, so that the organic EL layer can be prevented from being exposed to the photoresist component, and the long-life An organic EL element can be obtained.

  Hereinafter, the manufacturing method of the organic EL element of this invention is demonstrated in detail. The method for producing an organic EL device of the present invention has two modes: a case where a monochromatic light emitting layer is formed in a pattern, and a case where a three color light emitting layer is formed in a pattern. Hereinafter, each aspect will be described.

I. 1st aspect The 1st aspect of the manufacturing method of the organic EL element of this invention is the organic EL layer formation process which forms at least 1 layer of organic EL layer on the board | substrate with which the electrode layer was formed, On the said organic EL layer A protective layer forming step for forming a protective layer, a photoresist is applied on the protective layer, a photoresist layer forming step for forming a photoresist layer, a pattern exposure of the photoresist layer, and development, A photoresist layer patterning step for patterning the photoresist layer, and an organic EL layer patterning step for patterning the organic EL layer by removing the protective layer and the organic EL layer in a portion where the photoresist layer has been removed. And a peeling step for peeling off the remaining photoresist layer and the protective layer in this order. It is.

The manufacturing method of the organic EL element of this aspect is demonstrated referring drawings.
FIG. 1 is a process diagram showing an example of a method for producing an organic EL element of this embodiment. First, the electrode layer 2 is formed in a pattern on the substrate 1, the insulating layer 3 is formed between the patterns of the electrode layer 2, and the hole injection layer 4 and the light emitting layer 5 are formed on the electrode layer 2 and the insulating layer 3. To form an organic EL layer 6 (FIG. 1A, organic EL layer forming step). Subsequently, the protective layer 7 is formed on the light emitting layer 5 (FIG.1 (b), protective layer formation process).
Next, a positive photoresist is applied on the protective layer 7 to form a photoresist layer 8 (FIG. 1C, a photoresist layer forming step). Next, the photoresist layer 8 is subjected to pattern exposure through a photomask 11 so that at least the photoresist layer 8 in the light emitting region 10 remains, and then developed with a photoresist developer and washed to obtain a patterned photo resist. A resist layer 8 ′ is formed (FIGS. 1D and 1E, a photoresist layer patterning step).
Next, by removing the portions of the protective layer 7, the light emitting layer 5 and the hole injection layer 4 exposed by removing the photoresist layer, the patterned protective layer 7 ′, the light emitting layer 5 ′ and the hole injection layer 4 are removed. 'Is formed (FIG. 1 (f), organic EL layer patterning step).
Next, the uppermost layer of the photoresist layer 8 'is peeled off, and further the protective layer 7' is peeled off (FIGS. 1 (g) and (h), peeling step).
Finally, the counter electrode layer 9 is formed on the light emitting layer 5 ′ (FIG. 1 (i), counter electrode layer forming step).

  In this embodiment, since a protective layer is formed on the organic EL layer to be patterned, a photoresist is not directly applied on the organic EL layer. Moreover, since the photoresist layer and the protective layer are peeled in this order after the patterning of the organic EL layer, the opportunity for the photoresist component to contact the organic EL layer can be reduced. That is, the protective layer can prevent the photoresist component from coming into contact with the organic EL layer. Accordingly, it is possible to avoid a decrease in the light emission characteristics and the like of the organic EL layer due to the photoresist component, and it is possible to obtain an organic EL element having excellent light emission characteristics and the like.

Moreover, in the peeling process shown in FIG. 1, the photoresist layer is first peeled and then the protective layer is peeled. In this case, only the photoresist layer can be removed by using a photoresist stripping solution that dissolves the photoresist layer but does not dissolve the protective layer and the organic EL layer. Subsequently, only the protective layer can be removed by using a protective layer peeling solution that dissolves the protective layer but does not dissolve the organic EL layer. In such a stripping step, the photoresist layer and the protective layer can be stripped so that the photoresist component does not contact the organic EL layer at all. Thereby, the organic EL layer surface can be prevented from being contaminated by a photoresist component, for example, a photosensitizer, an additive, a resin, and the like, and the lifetime can be further increased.
Hereinafter, each process of the manufacturing method of the organic EL element of this aspect is demonstrated.

1. Organic EL layer forming step The organic EL layer forming step in this embodiment is a step of forming at least one organic EL layer on the substrate on which the electrode layer is formed.
Hereinafter, the organic EL layer, the electrode layer, and the substrate will be described.

(1) Organic EL layer The organic EL layer in this embodiment is composed of one or more organic layers. That is, the organic EL layer is a layer having a layer configuration of one or more organic layers. Usually, when an organic EL layer is formed by a wet method, it is difficult to stack a large number of layers in relation to the solvent, so that one or two organic layers are often formed. It is possible to further increase the number of layers by devising organic materials so as to have different solubility in water or by combining vacuum deposition methods.

  Especially, it is preferable that an organic EL layer contains a light emitting layer at least. That is, it is preferable to form at least a light emitting layer as the organic EL layer. In this case, it is possible to prevent the light emitting layer from being contaminated by the photoresist component, so that the lifetime can be further increased.

  Examples of the organic layer constituting the organic EL layer other than the light emitting layer include a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. This hole transport layer is often integrated with the hole injection layer by imparting a hole transport function to the hole injection layer. In addition, as an organic layer constituting the organic EL layer, holes or electrons such as a hole blocking layer and an electron blocking layer are prevented from penetrating, and further, exciton diffusion is prevented and excitons are placed in the light emitting layer. By confining, a layer for increasing the recombination efficiency can be cited.

  The organic EL layer may have a general configuration, and only the light emitting layer, hole injection layer / light emitting layer, hole injection layer / light emitting layer / electron injection layer, hole injection layer / hole blocking layer. / Light emitting layer / electron injection layer, hole injection layer / light emitting layer / electron transport layer, and the like can be exemplified.

  When laminating a plurality of organic layers, for example, after patterning the light-emitting layer or the hole injection layer and the light-emitting layer by a photolithography method, the electron transport layer, the electron injection layer, etc. are vacuumed on the patterned light-emitting layer. You may form in a pattern form by a vapor deposition method. Further, for example, after the hole injection layer is formed in a pattern by a vacuum deposition method, a light emitting layer may be formed on the pattern hole injection layer and patterned by a photolithography method. Furthermore, for example, after patterning the hole injection layer by a photolithography method, a light emitting layer or the like may be formed in a pattern shape by a vacuum evaporation method on the pattern hole injection layer.

  When forming a hole injection layer and a light emitting layer as an organic EL layer, after forming the hole injection layer and the light emitting layer on the entire surface of the substrate, the hole injection layer and the light emitting layer are patterned by a photolithography method. Alternatively, only the light emitting layer may be patterned by a photolithography method. In particular, when the conductivity of the hole injection layer is high, the hole injection layer and the light emitting layer are preferably patterned by a photolithography method in order to maintain the diode characteristics of the device and prevent crosstalk. On the other hand, when the resistance of the hole injection layer is high, the hole injection layer may be patterned or not patterned.

Here, the solubility of the membrane is generally defined by the solubility when the solid components in the membrane are dissolved in a solvent (100 × weight of dissolved solid content / (weight of dissolved solid content + solvent amount)). . In such a definition, when the solubility is less than 0.1%, it is often determined that the solubility is insoluble or insoluble. However, even when a solvent that is determined to be hardly soluble or insoluble in the above definition is used, when the film is immersed in the solvent, the film dissolves and film loss occurs.
In particular, in the organic EL element, the film thickness of the organic EL layer is very thin, and generally the film thickness of one organic layer constituting the organic EL layer is 100 nm or less. For this reason, even when the film is immersed in a solvent whose solubility is 0.1% or less in the above definition and is hardly soluble or insoluble, the thickness is easily reduced if the film thickness is about 100 nm. End up.

Therefore, in the present invention, regarding the solubility of the film, a film is formed on the substrate and sufficiently dried, and the film is immersed in a solvent at 25 ° C. for 1 minute, and then the film thickness before and after the immersion is measured. Depending on the difference (film thickness before immersion-film thickness after immersion), it was defined as follows.
When the film loss is 5 nm or less / min ... Insoluble When the film loss is more than 5 nm / min to 20 nm or less / min ... Difficultly soluble When the film loss is more than 20 nm / min ... Soluble The solubility of the film About a definition, it applies not only to an organic electroluminescent layer but to a protective layer, a photoresist layer, etc.

In the present invention, in order to form a protective layer on the organic EL layer, among the organic layers constituting the organic EL layer, the uppermost organic layer is composed of a solvent for the protective layer-forming coating liquid described later and the protective layer. It is preferably insoluble in the stripping solution. That is, the solubility of the uppermost organic layer among the organic layers constituting the organic EL layer is 5 nm or less / min with respect to the solvent of the protective layer-forming coating solution and the protective layer peeling solution. preferable.
Hereinafter, the light emitting layer, the hole injection layer, the electron transport layer, and the electron injection layer will be described.

(I) Light emitting layer The light emitting material used for the light emitting layer in this embodiment is not particularly limited as long as it includes a material that emits fluorescence and emits light. The light emitting function and the hole transport function or the electron transport function are not particularly limited. It may also serve as.

  In the case of forming a protective layer on the light emitting layer, the light emitting material is preferably insoluble in the solvent for the protective layer forming coating liquid described below and the protective layer stripping solution, and further insoluble in the photoresist stripping solution. More preferably. That is, the solubility of the light emitting layer is preferably 5 nm or less / min with respect to the solvent of the protective layer forming coating solution and the stripping solution of the protective layer, and further 5 nm or less with respect to the photoresist stripping solution. / Min is more preferable.

  Examples of the light-emitting material include a dye-based light-emitting material, a metal complex-based light-emitting material, and a polymer-based light-emitting material.

  Examples of dye-based luminescent materials include cyclopentamine derivatives, tetraphenylbutadiene derivatives, triphenylamine derivatives, oxadiazol derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, silole derivatives, thiophene ring compounds. Pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, oxadiazole dimers, pyrazoline dimers, and the like.

  Examples of the metal complex light emitting material include an aluminum quinolinol complex, a benzoquinolinol beryllium complex, a benzoxazole zinc complex, a benzothiazole zinc complex, an azomethyl zinc complex, a porphyrin zinc complex, a europium complex, or a central metal such as Al, Zn, Examples thereof include a metal complex having a rare earth metal such as Be or the like or Tb, Eu or Dy, and having a oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline structure or the like as a ligand.

  Examples of the polymer-based light emitting material include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and the like, or the above-described dye-based light emitting materials and metal complexes. Examples include those obtained by polymerizing a system light emitting material.

  As will be described later, in the case of forming a light emitting layer by applying a light emitting layer forming coating solution, the light emitting material is used from the viewpoint of utilizing the advantage that the light emitting layer can be accurately patterned by a photolithography method. As the above, it is preferable to use the polymer light emitting material.

  Further, various additives can be added to the light emitting material. For example, a doping agent may be added to the light emitting material for the purpose of improving the light emission efficiency and changing the light emission wavelength. Examples of such doping agents include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazoline derivatives, decacyclene, phenoxazone, quinoxaline derivatives, carbazole derivatives, fluorene derivatives. Can be mentioned.

  As a method for forming the light emitting layer, a method of applying a light emitting layer forming coating solution containing the above light emitting material or the like, or a vacuum deposition method or the like can be used. Among these, from the viewpoint of reducing manufacturing costs, a method of applying a light emitting layer forming coating solution is preferable.

  In this embodiment, when a hole injection layer to be described later is formed and the light emitting layer is formed by applying a light emitting layer forming coating solution on the hole injection layer, the light emitting layer is formed. In this case, in order to prevent the material for forming the hole injection layer and the coating solution for forming the light emitting layer from being mixed or dissolved, and to maintain the original light emitting characteristics of the light emitting material, the coating for forming the light emitting layer is used. It is preferable to use a solvent that does not dissolve the hole injection layer in the working solution. Specifically, the solvent used for the light emitting layer forming coating solution preferably has a solubility of the hole injection layer of 5 nm or less / min.

  For example, when a material for forming a hole injection layer described later is dissolved in a polar solvent such as an aqueous solvent, dimethylformamide (DMF), dimethyl sulfoxide (DIMSO), or alcohol, examples of the solvent include benzene and toluene. , Xylene isomers and mixtures thereof, aromatic solvents such as mesitylene, tetralin, p-cymene, cumene, ethylbenzene, diethylbenzene, butylbenzene, chlorobenzene, dichlorobenzene isomers and mixtures thereof; anisole, phenetole , Ether solvents such as butylphenyl ether, tetrahydrofuran, 2-butanone, 1,4-dioxane, diethyl ether, diisopropyl ether, diphenyl ether, dibenzyl ether, diglyme; dichloromethane, 1,1-dic Roetan, 1,2-dichloroethane, trichlorethylene, tetrachlorethylene, chloroform, carbon tetrachloride, chlorobenzene-based solvents such as 1-chloronaphthalene; and cyclohexanone are preferably used. These solvents may be used alone or in combination of two or more.

  Examples of the application method of the light emitting layer forming coating liquid include a dip coating method, a roll coating method, a blade coating method, a spin coating method, a micro gravure coating method, a gravure coating method, a bar coating method, and a wire bar coating method. , Casting method, flexographic printing method and the like.

  You may dry after application | coating of the said light emitting layer forming coating liquid.

  The light emitting layer in this embodiment does not contain a curing agent, and no curing / crosslinking treatment is performed when the light emitting layer is formed. For this reason, the light emitting layer after drying remains soluble in the solvent of the light emitting layer forming coating solution.

  The thickness of the light emitting layer is not particularly limited as long as it can provide a function of emitting light by providing a recombination field between electrons and holes, and specifically 10 nm to 500 nm. Can be about.

(Ii) Hole Injecting Layer The hole injecting layer in this embodiment is provided between the anode and the light emitting layer so that holes can be easily injected into the light emitting layer.

  The material used for the hole injection layer is not particularly limited as long as it is a material having a hole injection property that can stabilize the injection of holes into the light emitting layer. Examples of the material having hole injecting properties include arylamines, phthalocyanines, vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide, titanium oxide and other oxides, amorphous carbon, polyaniline, polythiophene, polyphenylene vinylene, and these. Examples thereof include conductive polymers such as derivatives. Specifically, arylamines include bis (N- (1-naphthyl-N-phenyl) benzidine (α-NPD), 4,4,4-tris (3-methylphenylphenylamino) triphenylamine (MTDATA). And the like, and examples of the polythiophene derivative include poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT / PSS).

  Further, a curable resin may be used for the hole injection layer. Further, an inorganic oxide sol-gel film may be used as the hole injection layer. This is because a hole injection layer insoluble in the solvent can be obtained. In addition, since it describes in detail in the below-mentioned 2nd aspect about the hole injection layer insoluble in a solvent, description here is abbreviate | omitted.

  When the light emitting layer is formed by applying the light emitting layer forming coating solution on the hole injecting layer, the material for forming the hole injecting layer is insoluble in the solvent of the light emitting layer forming coating solution. It is preferable. That is, the solubility of the hole injection layer is preferably 5 nm or less / min with respect to the solvent of the light emitting layer forming coating solution.

  As a method for forming the hole injection layer, a method of applying a coating liquid for forming a hole injection layer containing the above materials, a vacuum deposition method, or the like can be used. Among these, from the viewpoint of reducing manufacturing costs, a method of applying a hole injection layer forming coating solution is preferable.

  The solvent used in the hole injection layer forming coating solution is not particularly limited as long as the above materials are dispersed or dissolved, for example, alcohols such as water, methanol, and ethanol, or Examples include dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone. These solvents may be used alone or in combination of two or more.

  Examples of the coating method for forming the hole injection layer forming liquid include dip coating, roll coating, blade coating, spin coating, micro gravure coating, gravure coating, bar coating, and wire bar. Examples thereof include a coating method, a casting method, and a flexographic printing method.

  In addition, the thickness of the hole injection layer is not particularly limited as long as the thickness of the hole injection layer is sufficiently exhibited. Specifically, the thickness of the hole injection layer can be about 0.5 nm to 1000 nm. It is preferable to be within a range of ˜500 nm.

(Iii) Electron Transport Layer The electron transport layer in this embodiment is provided between the cathode and the light emitting layer so that electrons can be easily transported to the light emitting layer.

The material used for the electron transport layer is not particularly limited as long as it can transport the electrons injected from the cathode into the light emitting layer. For example, oxadiazoles, triazoles, bathocuproin, Examples thereof include phenanthrolines such as bathophenanthroline, and aluminum quinolinol complexes such as tris (8-quinolinolato) aluminum complex (Alq ₃ ).

  As a method for forming the electron transport layer, a method of applying an electron transport layer forming coating solution containing the above materials or the like, a vacuum deposition method, or the like can be used. Usually, a vacuum deposition method is used.

  The thickness of the electron transport layer is not particularly limited as long as the thickness of the electron transport layer is sufficiently exerted.

(Iv) Electron Injection Layer The electron injection layer in this embodiment is provided between the cathode and the light emitting layer so that electrons can be easily injected into the light emitting layer.

  The material used for the electron injection layer is not particularly limited as long as it can stabilize the injection of electrons into the light emitting layer. For example, an alkali metal such as an aluminum lithium alloy, lithium, or cesium is used. Alkaline metal halides such as lithium fluoride and cesium fluoride; alkaline earth metals such as strontium and calcium; alkaline earth metals such as magnesium fluoride, strontium fluoride, calcium fluoride, and barium fluoride And oxides such as magnesium oxide, strontium oxide, and aluminum oxide. Examples of the material used for the electron injection layer include sodium polymethyl methacrylate polystyrene sulfonate.

  As a method for forming the electron injection layer, a method for applying a coating solution for forming an electron injection layer containing the above materials or the like, a vacuum deposition method, or the like can be used. Usually, a vacuum deposition method is used.

  The thickness of the electron injection layer is not particularly limited as long as the thickness of the electron injection layer is sufficiently exhibited.

(2) Electrode layer The electrode layer used in this embodiment may be an anode or a cathode. In general, when an organic EL element is produced, it is preferable that the electrode layer is an anode because the organic EL element can be stably produced by laminating from the anode side.

  For the anode, a conductive material having a large work function is preferably used so that holes can be easily injected. On the other hand, a conductive material having a small work function is preferably used for the cathode so that electrons can be easily injected. As the conductive material, a metal material is generally used, but an organic substance or an inorganic compound may be used. In addition, a plurality of materials may be mixed and used for the electrode layer.

  For example, in the case of the bottom emission type in the organic EL element shown in FIG. 1 (i), the electrode layer preferably has transparency. As a conductive material having transparency, In—Zn—O (IZO), In—Sn—O (ITO), ZnO—Al, Zn—Sn—O, and the like can be exemplified as preferable examples. Further, for example, in the case of the top emission type in the organic EL element shown in FIG. 1 (i), the electrode layer is not required to be transparent. In this case, a metal can be used as the conductive material, and specifically, Au, Ta, W, Pt, Ni, Pd, Cr, Al alloy, Ni alloy, Cr alloy, or the like can be given.

  Whether the electrode layer is an anode or a cathode, the resistance is preferably relatively small.

  As a method for forming the electrode layer, a general electrode forming method can be used, and examples thereof include a sputtering method, an ion plating method, and a vacuum deposition method. An example of the patterning method for the electrode layer is a photolithography method.

(3) Substrate The substrate used in this embodiment is not particularly limited. For example, in the case of the bottom emission type in the organic EL element shown in FIG. 1 (i), the substrate preferably has transparency. On the other hand, for example, when the top emission type is used in the organic EL element shown in FIG. 1I, the substrate is not required to have transparency.
For the transparent substrate, for example, an inorganic material such as glass, a transparent resin, or the like can be used.

  The transparent resin is not particularly limited as long as it can be formed into a film shape, but preferably has high transparency, relatively high solvent resistance and heat resistance. Specific examples of such transparent resins include polyethersulfone, polyethylene terephthalate (PET), polycarbonate (PC), polyetheretherketone (PEEK), polyvinyl fluoride (PFV), polyacrylate (PA), polypropylene ( PP), polyethylene (PE), amorphous polyolefin, or fluorine resin.

2. Protective layer forming step The protective layer forming step in this embodiment is a step of forming a protective layer on the organic EL layer.

In the present invention, since the photoresist layer is formed on the protective layer, the protective layer is preferably insoluble or hardly soluble in the photoresist solvent. That is, the solubility of the protective layer is preferably 20 nm or less / min with respect to the photoresist solvent, and more preferably 5 nm or less / min.
On the other hand, when the protective layer is soluble in the photoresist solvent, it is possible to prevent the photoresist component from reaching the surface of the organic EL layer by making the protective layer relatively thick. In this case, a layer that is insoluble or hardly soluble in the photoresist solvent and does not contain the photoresist component may be formed on the protective layer.

The protective layer is preferably insoluble or hardly soluble in the photoresist developer. That is, the solubility of the protective layer is preferably 20 nm or less / min, and more preferably 5 nm or less / min with respect to the photoresist developer. This is because the photoresist layer can be stably patterned and a high-resolution display can be manufactured.
On the other hand, even when the protective layer is soluble in the photoresist developer, there is no particular problem because the area of the exposed portion of the protective layer exposed to the photoresist developer is relatively small.

Furthermore, the protective layer is preferably insoluble or hardly soluble in the photoresist stripping solution. That is, the solubility of the protective layer is preferably 20 nm or less / min, and more preferably 5 nm or less / min with respect to the photoresist stripping solution. In this case, it is possible to separate the photoresist layer and the protective layer separately in a later-described peeling step, and further reduce the chance that the surface of the organic EL layer contacts the photoresist component.
On the other hand, the protective layer may be soluble in a photoresist stripping solution. In this case, the photoresist layer and the protective layer can be gradually peeled off from the upper layer in the peeling step, which is preferable in terms of reduction in the number of steps and cost reduction.

  The material for forming such a protective layer is not particularly limited as long as it satisfies the above-described properties, and any of inorganic materials and organic materials can be used. Examples of the organic material forming the protective layer include a water-soluble cellulose derivative, a modified cellulose derivative in which the water-soluble cellulose derivative is soluble in an organic solvent, a water-soluble polyvinyl alcohol derivative, and a fluorine-based polymer material. Specifically, hydroxypropylmethylcellulose, hydroxypropylmethylcellulose acetate phthalate, acetylcellulose, and tetrafluoroethylene are preferably used as a material for forming the protective layer. In addition, a sol-gel film of an inorganic oxide can be used as a protective layer made of an inorganic material.

  In particular, the hole injection layer, the light emitting layer, and the protective layer are laminated in this order, and each layer is formed by applying each coating solution, and the following solvent is used for forming the hole injection layer and the light emitting layer. When the following photoresist and photoresist solvent are used for forming the photoresist layer, the above materials are preferably used for the protective layer. Here, as a solvent of the coating solution for forming the hole injection layer, a polar solvent such as an aqueous solvent, dimethylformamide (DMF), dimethyl sulfoxide (DIMSO) or alcohol is used, and as a solvent of the coating solution for forming the light emitting layer, Aromatic solvents such as xylene, toluene, anisole, mesitylene, tetralin, p-cymene, cumene, ethylbenzene, diethylbenzene, butylbenzene, chlorobenzene, cyclohexylbenzene, or tetrahydrofuran, 2-butanone, 1,4-dioxane, diethyl ether Ether solvent such as, a common novolac positive photoresist is used as a photoresist, and as a solvent, ketones, cellosolv acetates such as propylene glycol monomethyl ether acetate, ethers, etc. Cellosolves, a case of using the ethyl lactate.

  The thickness of the protective layer is appropriately selected depending on the type of the protective layer. For example, when the protective layer is insoluble or hardly soluble in the photoresist solvent, the thickness of the protective layer is preferably 0.01 μm or more. For example, when the protective layer is soluble in a photoresist solvent, the thickness of the protective layer is preferably 0.1 μm or more. The upper limit value of the thickness of the protective layer is preferably about 1 μm.

  As a method for forming the protective layer, a method of applying a protective layer-forming coating solution containing the above-described material is used.

  It is preferable that the solvent used for the coating liquid for forming the protective layer is a solvent that does not dissolve the uppermost organic layer among the organic layers constituting the organic EL layer. Specifically, the solvent used for the protective layer-forming coating solution preferably has a solubility of the uppermost organic layer of 5 nm or less / min. For example, when the hole injection layer and the light emitting layer are formed as the organic EL layer, and the protective layer is formed on the light emitting layer, the solvent is preferably one that does not dissolve the light emitting layer. In this case, the solvent may dissolve the hole injection layer or may not dissolve it.

  Specifically, the solvent includes ester solvents such as methyl acetate and ethyl acetate; cellosolv solvents such as ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, and butyl cellosolve acetate; dimethylformamide (DMF), dimethyl sulfoxide (DIMSO), Examples thereof include polar solvents such as alcohol and γ-butyrolactone. These solvents may be used alone or in combination of two or more.

  Moreover, even if the coating liquid for protective layer formation contains the solvent which melt | dissolves the uppermost organic layer, the uppermost organic layer should just be hardly soluble in the solvent. That is, any solvent can be used as long as the solubility of the uppermost organic layer is 20 nm or less / min.

  Examples of the method for applying the protective layer-forming coating solution include dip coating, roll coating, blade coating, spin coating, micro gravure coating, gravure coating, bar coating, and wire bar coating. , Casting method, flexographic printing method and the like.

3. Photoresist Layer Forming Step The photoresist layer forming step in this embodiment is a step of forming a photoresist layer by applying a photoresist on the protective layer.

  The photoresist used in this embodiment may be either a positive type or a negative type. Among these, considering the ease of peeling off the photoresist, a positive photoresist is preferable. As a photoresist, a general thing can be used, For example, a novolak-type resin, rubber | gum + bis azide-type resin etc. can be mentioned.

  The photoresist solvent used for the photoresist includes a material for forming the protective layer in order to prevent the protective layer and the photoresist from being mixed or dissolved when the photoresist is applied on the protective layer. It is preferable that it does not dissolve. Specifically, the photoresist solvent preferably has a protective layer solubility of 5 nm or less / min.

  Specifically, examples of the photoresist solvent include ketones such as acetone and methyl ethyl ketone; cellosolve acetates such as propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate; Cellosolves such as propylene glycol monoethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; alcohols such as methanol, ethanol, 1-butanol, 2-butanol and cyclohexanol; ethyl acetate and butyl acetate And ester solvents such as cyclohexane and decalin. These may be used alone or in combination of two or more.

  The method for applying the photoresist is not particularly limited as long as it can be applied to the entire surface of the substrate. For example, the spin coating method, the casting method, the dip coating method, the bar coating method, and the blade coating method. Roll coating method, gravure coating method, spray coating method, flexographic printing method and the like are used.

  The film thickness of the photoresist layer is not particularly limited, but when the protective layer and the organic EL layer are dry-etched in the organic EL layer patterning step described later, the thickness is within a range of 0.1 μm to 10 μm. It is preferable that it exists, More preferably, it exists in the range of 0.5 micrometer-5 micrometers. This is because if the thickness of the photoresist layer is in the above range, dry etching with high processing accuracy can be performed while maintaining the resist function.

4). Photoresist Layer Patterning Step The photoresist layer patterning step in this embodiment is a step of patterning the photoresist layer so that the photoresist layer in the light emitting region remains by pattern exposure and development of the photoresist layer.

  As a method for pattern exposure of the photoresist layer, for example, a general method such as a method of exposing through a photomask or a laser drawing method can be used.

  At the time of pattern exposure, when a positive photoresist is used, exposure is performed so that at least the light emitting region is a non-exposed region, and when a negative photoresist is used, at least the light emitting region is an exposed region. To expose.

  The photoresist developer used in this embodiment is not particularly limited as long as it does not dissolve the material forming the protective layer. Specifically, the photoresist developer preferably has a protective layer solubility of 5 nm or less / min. As such a photoresist developer, a generally used organic alkaline developer can be used. Further, as the photoresist developer, an inorganic alkaline developer or an aqueous solution capable of developing the first photoresist layer can be used.

  Moreover, it is preferable to wash with water after developing the photoresist layer.

5. Organic EL Layer Patterning Step The organic EL layer patterning step in this embodiment is a step of patterning the organic EL layer by removing the portion of the protective layer and the organic EL layer from which the photoresist layer has been removed.

  As a method for removing the protective layer and the organic EL layer, both wet etching using a solvent that dissolves the protective layer and the organic EL layer, and dry etching can be used. Among these, dry etching is preferable because color mixing or the like hardly occurs and high-definition patterning is possible.

  In wet etching, the protective layer and the organic EL layer are removed by dissolving the protective layer and the organic EL layer using a solvent that can dissolve the protective layer and the organic EL layer without dissolving the photoresist layer. To do. Examples of the solvent that can be used in this case include the solvents used in the above-described light emitting layer forming coating solution, hole injection layer forming coating solution, protective layer forming coating solution, and the like.

  In wet etching, the protective layer and the organic EL layer may be removed in an ultrasonic bath. By using an ultrasonic bath, for example, it is possible to prevent the line width of the light emitting layer pattern from being narrowed or to prevent the light emitting material or the like from flowing out of the light emitting layer, thereby enabling highly accurate patterning. . Further, it is also preferable in that high-precision patterning can be performed in a short time.

  The ultrasonic conditions used for this ultrasonic bath are preferably at an oscillation frequency of 25 ° C. and 20 to 100 KHz, and 0.1 to 60 seconds. This is because such a condition enables high-precision patterning in a short time.

  In dry etching, the thickness of the photoresist layer is considerably thicker than that of the protective layer and the organic EL layer. Therefore, by performing dry etching on the entire substrate, the portion where the photoresist layer is removed is protected. The layer and the organic EL layer can be removed. If dry etching is used, the edge of etching can be made sharper, so that it can be made narrower than the film thickness non-uniformity region existing at the edge of the pattern of the protective layer and the organic EL layer. High-definition patterning is possible.

  As a dry etching method, for example, atmospheric pressure plasma etching, reactive ion etching (RIE), plasma etching using an inert gas, etching using a laser, an ion beam, or the like can be used.

  In reactive ion etching, an organic film undergoes a chemical reaction to become a compound having a low molecular weight, which is removed by vaporization and evaporation. For this reason, when reactive ion etching is used, etching accuracy is high and processing in a short time is possible.

  In addition, when atmospheric pressure plasma etching is used, a vacuum apparatus is not required, and the processing time and cost can be reduced. Atmospheric pressure plasma etching utilizes the fact that organic substances are oxidatively decomposed by oxygen in the atmosphere that has been turned into plasma. At this time, the gas composition of the reaction atmosphere may be arbitrarily adjusted by gas replacement and circulation.

  Further, in dry etching, oxygen alone or a gas containing oxygen may be used. This is because by using oxygen alone or a gas containing oxygen, the organic film can be decomposed and removed by an oxidation reaction, and unnecessary organic substances can be removed.

6). Stripping Step The stripping step in this embodiment is a step of stripping the remaining photoresist layer and protective layer in this order.

As illustrated in FIGS. 1F to 1H, the peeling process may include a process of peeling only the photoresist layer 8 ′ and a process of peeling only the protective layer 7 ′. As illustrated in FIGS. 2 (f) and 2 (g), the photoresist layer 8 ′ and the protective layer 7 ′ are gradually peeled from the upper layer using a stripping solution that dissolves the photoresist layer and the protective layer. May be.
When the peeling step includes a step of peeling only the photoresist layer and a step of peeling only the protective layer, the photoresist layer and the protective layer are peeled separately, so that the surface of the organic EL layer touches the photoresist component. There is nothing at all. For this reason, a lifetime characteristic can be improved effectively.
In addition, when the peeling process is a process of gradually peeling the photoresist layer and the protective layer from the upper layer using a stripping solution that dissolves the photoresist layer and the protective layer, in terms of reducing the number of steps and reducing the cost. preferable. In this case, since the dissolution gradually proceeds from the upper surface side of the photoresist layer having a large contact area with the stripping solution, the photoresist layer and the protective layer are substantially removed in this order. For this reason, the opportunity for the organic EL layer surface to be exposed to the photoresist component can be reduced.

  When the peeling step includes a step of peeling only the photoresist layer and a step of peeling only the protective layer, as a method of peeling the photoresist layer, a method of immersing the substrate in a photoresist stripping solution, a photoresist peeling A method of jetting the liquid onto the substrate in the form of a shower can be used.

  The photoresist stripping solution is not particularly limited as long as it can dissolve the photoresist layer without dissolving the protective layer and the organic EL layer, and a material for forming the photoresist and the protective layer to be used. Depending on the combination of these, etc., it is appropriately selected. Specifically, in the photoresist stripping solution, the solubility of the photoresist layer is more than 20 nm / min, and the solubility of the protective layer and the organic EL layer is each 20 nm or less / min, especially 5 nm or less / min. preferable.

  As such a photoresist stripping solution, the above-described photoresist solvent can be used. When a positive photoresist is used, a photoresist developer can be used as the photoresist stripping solution. Further, as the photoresist stripping solution, a strong alkaline aqueous solution, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, or a mixture thereof, and a commercially available photoresist stripping solution may be used.

  Moreover, as a method of peeling a protective layer, the method of immersing a board | substrate in a protective layer peeling liquid, the method of ejecting a protective layer peeling liquid to a board | substrate in shower shape, etc. can be used.

  The protective layer remover is not particularly limited as long as it can dissolve the protective layer without dissolving the organic EL layer, and depends on the combination of the photoresist used and the material forming the protective layer, etc. It is different and is appropriately selected. Specifically, the protective layer stripping solution preferably has a solubility of the protective layer of more than 20 nm / min and a solubility of the organic EL layer of 20 nm or less / min, especially 5 nm or less / min.

  As such a protective layer peeling liquid, the solvent of the protective layer forming coating liquid described above can be used.

  For example, when a novolak resin is used as the photoresist and hydroxypropylmethylcellulose acetate phthalate is used as the protective layer, a ketone solvent such as methyl isobutyl ketone is preferably used as the photoresist stripping solution. It is preferable to use an ester solvent such as ethyl acetate as the liquid.

  Further, when the peeling step is a step of gradually peeling the photoresist layer and the protective layer from the upper layer using a peeling solution for dissolving the photoresist layer and the protective layer, as a method for peeling the photoresist layer and the protective layer For example, a method of immersing the substrate in the stripping solution, a method of spraying the stripping solution on the substrate in a shower shape, or the like can be used.

  The stripping solution is not particularly limited as long as it can dissolve the photoresist layer and the protective layer without dissolving the organic EL layer, and a combination of materials used to form the photoresist and the protective layer to be used. It is different depending on etc., and is appropriately selected. Specifically, the stripping solution preferably has a solubility of the photoresist layer and the protective layer of more than 20 nm / min, and the solubility of the organic EL layer is 20 nm or less / min, particularly 5 nm or less / min.

  As such a stripping solution, the above-mentioned photoresist stripping solution and protective layer stripping solution can be used. Specifically, examples of the stripper include ester solvents such as ethyl acetate and ether solvents such as propylene glycol monomethyl ether acetate.

7). Cleaning Step In this embodiment, it is preferable to perform a cleaning step for cleaning the outermost surface of the organic EL layer after the peeling step. This is because components remaining on the surface of the organic EL layer can be removed.

In this step, the outermost surface of the organic EL layer is cleaned using a cleaning liquid. As the cleaning liquid, a solvent that dissolves the photoresist layer and the protective layer and does not dissolve the organic EL layer can be used. In this case, the residual component on the outermost surface of the organic EL layer can be effectively removed. Specifically, in the cleaning liquid, the solubility of the photoresist layer and the protective layer is preferably more than 20 nm / min, and the solubility of the organic EL layer is preferably 5 nm or less / min.
As such a cleaning solution, the above-described photoresist stripping solution, protective layer stripping solution and stripping solution can be used. Specifically, propylene glycol monomethyl ether acetate, γ-butyrolactone, methyl acetate, ethyl acetate, butyl acetate, methyl isobutyl ketone and the like are preferably used as the cleaning liquid.

In addition, as the cleaning liquid, a solvent that dissolves the uppermost organic layer among the organic layers constituting the outermost surface of the organic EL layer, that is, the organic EL layer can be used. In this case, the outermost surface of the organic EL layer contaminated with residual components can be removed. Specifically, in the cleaning liquid, the solubility of the uppermost organic layer is preferably more than 20 nm / min.
As such a cleaning liquid, a solvent for the above-described light emitting layer forming coating liquid, a solvent for the hole injecting layer forming coating liquid, or the like can be used.

  At this time, it is preferable to adjust the cleaning so that the thickness of the uppermost organic layer to be removed is 20 nm or less, particularly 10 nm or less. If the thickness of the uppermost organic layer to be removed exceeds the above range, it is very difficult to remove only the outermost surface of the organic EL layer, and the uppermost organic layer may be missing or mixed. Because.

In order to set the thickness of the uppermost organic layer to be removed within the above range, a solvent that dissolves only the uppermost organic layer and a solvent in which the uppermost organic layer is insoluble or hardly soluble are mixed as a cleaning solution. It is preferable to use what was done. That is, as a cleaning liquid, a mixture of a solvent having a solubility of the uppermost organic layer of more than 20 nm / min and a solvent having a solubility of the uppermost organic layer of 20 nm or less / min, especially 5 nm or less / min. Is preferably used.
Examples of the solvent in which the uppermost organic layer is insoluble or hardly soluble include propylene glycol monomethyl ether acetate, γ-butyrolactone, methyl acetate, ethyl acetate, butyl acetate, and methyl isobutyl ketone.

  Further, in order to make the thickness of the uppermost organic layer to be removed within the above range, cleaning may be performed over a relatively long time using a solvent in which the uppermost organic layer is hardly soluble as a cleaning liquid. .

8). Plasma processing step In this embodiment, a plasma processing step of performing plasma processing on the outermost surface of the organic EL layer may be performed after the peeling step. This is because components remaining on the surface of the organic EL layer can be removed.

  As the introduced gas used in the plasma treatment, a generally used gas can be used. Especially, it is preferable that it is a gas which removes only the outermost surface of an organic EL layer and has little influence on an organic EL layer. Examples of such a gas include a gas containing fluorine or a fluorine compound, a gas containing chlorine or a chlorine compound, oxygen, argon, nitrogen, and the like. Two or more kinds of mixed gases may be used as the introduction gas.

  The conditions for the plasma treatment are appropriately selected depending on the type of introduced gas used. For example, when argon is used as the introduced gas, the plasma processing can be performed with a power of 200 W, a pressure in the chamber of 10 mTorr, a gas flow rate of 10 sccm, and a processing time of about 30 seconds.

9. Other Steps In this embodiment, usually, a counter electrode layer forming step for forming a counter electrode layer on the organic EL layer is performed after the peeling step. When the cleaning process or the plasma processing process is performed, the counter electrode layer forming process is performed after the cleaning process or the plasma processing process.

  The counter electrode layer is an electrode having a charge opposite to that of the electrode layer, and may be an anode or a cathode. Generally, when manufacturing an organic EL element, it is preferable that the counter electrode layer is a cathode because the organic EL element can be more stably produced from the anode side.

  For example, when the top emission type is used in the organic EL element shown in FIG. 1I, the counter electrode layer preferably has transparency. Further, for example, in the case of the bottom emission type in the organic EL element shown in FIG. 1 (i), the counter electrode layer does not require transparency.

  Note that the material for forming the counter electrode layer and the method for forming the counter electrode layer are the same as those of the electrode layer described in the section of the organic EL layer forming step, and thus description thereof is omitted here.

  Moreover, in this aspect, you may perform the insulating layer formation process which forms an insulating layer on a board | substrate. By forming the insulating layer, a short circuit of the organic EL element can be suppressed and the organic EL element that emits light stably can be obtained.

Examples of the material used for the insulating layer include a photocurable resin.
Further, the film thickness of the insulating layer can be set to about 0.1 μm to 10 μm. Especially, when patterning a light emitting layer by dry etching, it is preferable that it is the thickness of the grade that dry etching tolerance is expressed.

  As a method for forming the insulating layer, a general method for forming an insulating layer can be used. When forming the insulating layer, the insulating layer may be formed in advance in a pattern so that the light emitting region becomes an opening.

II. 2nd aspect The 2nd aspect of the manufacturing method of the organic EL element of this invention is a 1st organic EL layer formation process of forming the 1st organic EL layer containing at least a 1st light emitting layer on the board | substrate with which the electrode layer was formed. A first protective layer forming step for forming a first protective layer on the first organic EL layer; and a first photoresist for applying a photoresist on the first protective layer to form a first photoresist layer. A layer forming step, and pattern exposure of the first photoresist layer and development to pattern the first photoresist layer so that the first photoresist layer in the first light emitting region remains. A layer patterning step, and a first pattern for patterning the first organic EL layer by removing the first protective layer and the first organic EL layer in a portion where the first photoresist layer is removed. And a second organic EL layer including at least a second light emitting layer on a substrate on which the first organic EL layer, the first protective layer, and the first photoresist layer are formed in a pattern. A second organic EL layer forming step to be formed; a second protective layer forming step of forming a second protective layer on the second organic EL layer; and a photoresist applied on the second protective layer; A second photoresist layer forming step for forming a resist layer; and pattern exposure of the second photoresist layer and development to develop the second photoresist layer so that the second photoresist layer in the second light emitting region remains. A second photoresist layer patterning step of patterning the resist layer, and removing the second protective layer and the second organic EL layer in a portion where the second photoresist layer is removed. A second organic EL layer patterning step of patterning the second organic EL layer, the first organic EL layer, the first protective layer, and the first photoresist layer are formed in a pattern, and the second organic EL layer is further patterned. A third organic EL layer forming step of forming a third organic EL layer including at least a third light emitting layer on the substrate on which the EL layer, the second protective layer, and the second photoresist layer are formed in a pattern; A third protective layer forming step of forming a third protective layer on the third organic EL layer; and a third photoresist layer forming of applying a photoresist on the third protective layer to form a third photoresist layer Patterning the third photoresist layer and developing the pattern, and patterning the third photoresist layer so that the third photoresist layer in the third light emitting region remains. A third photoresist layer patterning step, and a third patterning of the third organic EL layer by removing the third protective layer and the third organic EL layer in a portion where the third photoresist layer is removed; Organic EL layer patterning step, remaining first photoresist layer, second photoresist layer and third photoresist layer, and first protective layer, second protective layer and third protective layer It has the peeling process which peels in this order, It is characterized by the above-mentioned.

The manufacturing method of the organic EL element of this aspect is demonstrated referring drawings.
3-5 is process drawing which shows an example of the manufacturing method of the organic EL element of this aspect. First, the electrode layer 2 is formed in a pattern on the substrate 1, the insulating layer 3 is formed between the patterns of the electrode layer 2, and the first hole injection layer 4a and the first hole injection layer 4a are formed on the electrode layer 2 and the insulating layer 3. One light emitting layer 5a is formed to be a first organic EL layer 6a (FIG. 3A, first organic EL layer forming step). Next, the first protective layer 7a is formed on the first light emitting layer 5a (FIG. 3B, first protective layer forming step). Next, a positive photoresist is applied on the first protective layer 7a to form the first photoresist layer 8a (FIG. 3C, first photoresist layer forming step). Next, the first photoresist layer 8a is subjected to pattern exposure through the photomask 11 so that at least the first photoresist layer 8a in the first light emitting region 10a remains, and then developed and washed with a photoresist developer. Thus, a patterned first photoresist layer 8a 'is formed (FIGS. 3D and 3E, first photoresist layer patterning step). Next, by removing the portions of the first protective layer 7a, the first light emitting layer 5a and the first hole injection layer 4a exposed by the removal of the first photoresist layer, the patterned first protective layer 7a ′, First light emitting layer 5a 'and first hole injection layer 4' are formed (FIG. 3F, first organic EL layer patterning step).

  Next, the second hole injection is performed on the substrate 1 on which the patterned first photoresist layer 8a ′, the first protective layer 7a ′, the first light emitting layer 5a ′, and the first hole injection layer 4a ′ are formed. The layer 4b and the second light emitting layer 5b are formed to form the second organic EL layer 6b (FIG. 3G, second organic EL layer forming step). Next, the second protective layer 7b is formed on the second light emitting layer 5b (FIG. 3H, second protective layer forming step). Next, a positive photoresist is applied on the second protective layer 7b to form a second photoresist layer 8b (FIG. 4A, second photoresist layer forming step). Next, the second photoresist layer 8b is subjected to pattern exposure through the photomask 11 so that at least the second photoresist layer 8b in the second light emitting region 10b remains, and then developed and washed with a photoresist developer. Thus, a patterned second photoresist layer 8b 'is formed (FIGS. 4B and 4C, second photoresist layer patterning step). Next, by removing the second protective layer 7b, the second light emitting layer 5b, and the second hole injection layer 4b exposed by removing the second photoresist layer, the patterned second protective layer 7b ′, The second light emitting layer 5b ′ and the second hole injection layer b ′ are formed (FIG. 4D, second organic EL layer patterning step).

  Next, the patterned first photoresist layer 8a ′, the first protective layer 7a ′, the first light emitting layer 5a ′ and the first hole injection layer 4a ′, and the patterned second photoresist layer 8b ′, The third hole injection layer 4c and the third light emitting layer 5c are formed on the substrate 1 on which the second protective layer 7b ', the second light emitting layer 5b', and the second hole injection layer 4b 'are formed, and the third organic The EL layer 6c is formed (FIG. 4E, third organic EL layer forming step). Next, a third protective layer 7c is formed on the third light emitting layer 5c (FIG. 4F, third protective layer forming step). Next, a positive photoresist is applied on the third protective layer 7c to form a third photoresist layer 8c (FIG. 4G, third photoresist layer forming step). Next, the third photoresist layer 8c is pattern-exposed through the photomask 11 so that at least the third photoresist layer 8c in the third light emitting region 10c remains, and then developed and washed with a photoresist developer. Thus, a patterned third photoresist layer 8c ′ is formed (FIGS. 5A and 5B, a third photoresist layer patterning step). Next, by removing the portions of the third protective layer 7c, the third light emitting layer 5c, and the third hole injection layer 4c exposed by the removal of the third photoresist layer, the patterned third protective layer 7c ′, A third light emitting layer 5c ′ and a third hole injection layer 4c ′ are formed (FIG. 5C, second organic EL layer patterning step).

Next, the first photoresist layer 8a ′, the second photoresist layer 8b ′, and the third photoresist layer 8c ′, which are positioned at the uppermost layer, are peeled, and the first protective layer 7a ′, the second protective layer 7b ′, and the first 3 The protective layer 7c ′ is peeled off (FIG. 5D, peeling step).
Finally, the counter electrode layer 9 is formed on the first light emitting layer 5a ′, the second light emitting layer 5b ′, and the third light emitting layer 5c ′ (FIG. 5E, counter electrode layer forming step).

  In this aspect, since each protective layer is formed on each organic EL layer to be patterned before forming each photoresist layer, the photoresist is not directly applied on each organic EL layer. Further, when patterning the second organic EL layer, the second organic EL layer and the second protective layer are formed on the patterned first organic EL layer and the first protective layer, and the second protective layer. Since the photoresist is applied thereon, the first organic EL layer does not come into contact with the second photoresist layer. Furthermore, when the third organic EL layer is patterned, similarly, the first organic EL layer and the second organic EL layer do not come into contact with the third photoresist layer. Moreover, after patterning all the organic EL layers, each photoresist layer and each protective layer are peeled in this order, so that the surface of each patterned organic EL layer is a photoresist component, for example, a photosensitive agent, an additive, a resin. It is possible to suppress exposure to the like. For this reason, it can prevent that a photoresist component contacts each organic EL layer by each protective layer. Accordingly, it is possible to avoid a decrease in life characteristics due to the photoresist component.

Further, as described above, when the second organic EL layer is patterned, the second organic EL layer and the second protective layer are formed on the patterned first organic EL layer and the first protective layer. Therefore, damage to the first organic EL layer when removing the second organic EL layer can be reduced. Similarly, when patterning the third organic EL layer, it is possible to reduce damage to the first organic EL layer and the second organic EL layer when the third organic EL layer is removed.
Therefore, it is possible to obtain a long-life organic EL element.

  Further, in the second photoresist layer patterning step, the second photoresist layer is patterned so that the second photoresist layer in the second light emitting region remains, so that the second photoresist layer is patterned on the patterned first organic EL layer. No photoresist layer remains. That is, the photoresist layer laminated on the patterned first organic EL layer is only the first photoresist layer. Further, the portion of the second organic EL layer exposed by the removal of the second photoresist layer is also removed in the second organic EL layer patterning step, so that the second organic EL layer is formed on the first organic EL layer. Does not remain. Therefore, it is possible to avoid a state in which an extra layer is stacked on the patterned first organic EL layer. As a result, it is possible to eliminate film thickness unevenness caused by stacking a plurality of layers.

  Further, only the first photoresist layer and the first protective layer that are peeled off in the peeling step are laminated on the first organic EL layer, and the first photoresist layer and the first protective layer are After each organic EL layer patterning step, it will be positioned in the uppermost layer. Therefore, the first photoresist layer and the first protective layer can be easily and quickly peeled off.

The first photoresist layer patterning step, the first organic EL layer patterning step, the second photoresist layer patterning step, the second organic EL layer patterning step, the third photoresist layer patterning step, the third organic EL layer patterning step, and The peeling process is the same as the photoresist layer patterning process, the organic EL layer patterning process, and the peeling process of the first aspect, and a description thereof will be omitted here.
Hereafter, each process other than the above of the manufacturing method of the organic EL element of this aspect is demonstrated.

1. First Organic EL Layer Forming Step The first organic EL layer forming step in this aspect is a step of forming a first organic EL layer including at least a first light emitting layer on a substrate on which an electrode layer is formed.

  In this embodiment, the light emitting layer of a plurality of colors can be formed in a pattern by patterning a plurality of times using a photolithography method. Therefore, different types of light emitting materials are used in the first, second, and third organic EL layer forming steps. At this time, it is preferable to form the light emitting layer by applying a light emitting layer forming coating solution from the viewpoint of reducing the manufacturing cost.

  In the case where the first organic EL layer is composed of the first hole injection layer and the first light emitting layer, in the second organic EL layer forming step described later, the first organic EL layer, the first protective layer, and When the second hole injection layer is formed by applying a coating solution for forming a second hole injection layer on the substrate on which the first photoresist layer is formed in a pattern, the first hole injection is performed. The layer is preferably insoluble in the solvent of the second hole injection layer forming coating solution. That is, the solubility of the first hole injection layer is preferably 5 nm or less / min with respect to the solvent of the second hole injection layer forming coating solution. Thus, when the second hole injection layer is formed, even if the solvent of the second hole injection layer forming coating solution contacts the edge of the pattern of the first hole injection layer, the first positive injection layer is formed. This is because the hole injection layer is not dissolved, so that the second hole injection layer can be stably laminated.

  In order to make the first hole injection layer insoluble in the solvent of the second hole injection layer forming coating solution, the first hole injection layer is cured with heat or radiation energy. Can be used. This is because the first hole injection layer insoluble in the solvent of the coating solution for forming the second hole injection layer can be obtained by curing the curable binder by heating or irradiation with actinic radiation.

At this time, as a material for forming the first hole injection layer, a mixture of a curable binder and a material having a hole injection property, or a hydroxyl group (—OH) or a carboxyl group (—COOH) in the molecule is used. A water-soluble or water-dispersible conductive material having an insolubilization treatment can be used.
In the latter case, for example, poly (3,4-alkenedioxythiophene) / polystyrene, which is very effective as a material for forming a hole injection layer in an organic EL device having a light emitting layer using a polymer light emitting material. Conductive polymer materials composed of sulfonate (PEDOT / PSS) and their derivatives are generally not insolubilized after heat drying. However, by mixing a photoinitiator or the like described in Applied physics letter, Vol 81, (2002) with the conductive polymer material, it can be cured by ultraviolet irradiation.

  The curable binder is not particularly limited as long as it is cured by the action of heat or radiation energy, and examples thereof include a sol-gel reaction liquid, a photocurable resin, and a thermosetting resin. Note that the sol-gel reaction liquid refers to a reaction liquid that gels after curing.

  Especially, it is preferable that a sclerosing | hardenable binder contains organopolysiloxane. This is because organopolysiloxane is highly versatile and easily available. In addition, the organopolysiloxane has an advantage that it is easy to handle because it does not require special reaction conditions and the crosslinking reaction of the organopolysiloxane can be advanced by a simple method.

  As said organopolysiloxane, what was described in Unexamined-Japanese-Patent No. 2000-249821 etc. can be used, for example.

The first hole injection layer forming coating solution is prepared by dispersing or dissolving the curable binder and the material having hole injection properties in a solvent. For example, when the curable binder contains an organopolysiloxane, an alcohol such as ethanol or isopropanol is preferably used as the solvent.
Examples of the coating method of the first hole injection layer forming coating solution include spin coating, spray coating, dip coating, roll coating, and bead coating.

The first hole injection layer can be formed by subjecting a coating film obtained by applying the first hole injection layer forming coating solution to a curing treatment.
Examples of the curing treatment include application of thermal energy or irradiation with radiation. Application of thermal energy may be performed at a temperature of about 80 to 250 ° C, preferably about 100 to 200 ° C. Thereby, a silane coupling reaction can be advanced and a 1st positive hole injection layer can be bridge | crosslinked and hardened.

  In addition, in order to make the first hole injection layer insoluble in the solvent of the coating solution for forming the second hole injection layer, the first hole injection layer is dissolved by the action of heat or radiation energy. A material that changes may be used, or materials having different solubility may be used for the first hole injection layer and the second hole injection layer.

  Here, the change in the solubility of the material means that the polarity of the solvent in which the main component of the material is dissolved or dispersed is changed. When a layer containing a material whose solubility is changed by the action of heat or radiation energy is changed by changing the solubility of the material by applying thermal energy or irradiating with radiation, it is used to form the layer. The solvent of the applied coating solution and the solvent in which the layer after application of heat energy or radiation is dissolved have different polarities.

  The extent to which the solubility of the material changes is that the first hole injection layer after application of thermal energy or irradiation is substantially dissolved in the solvent used in the first hole injection layer forming coating solution. It is sufficient if it is not mixed. Specifically, the solubility of the first hole injection layer after application of thermal energy or irradiation is 5 nm or less / min with respect to the solvent used in the first hole injection layer forming coating solution. Can be used as an index.

  As a material whose solubility is changed by the action of heat or radiation energy used for the first hole injection layer, for example, a part or all of the hydrophilic group of the hydrophilic organic material is converted into a lipophilic group And a part or all of the lipophilic group that returns to the hydrophilic group by the action of heat or radiation energy is preferably used.

  In the above materials, it is not necessary that all the hydrophilic groups of the hydrophilic organic material are converted into lipophilic groups. The ratio at which the hydrophilic group is converted to the lipophilic group may be a level that can maintain solubility at a desired concentration or higher in a general non-aqueous organic solvent. Specifically, the hydrophilic organic material that dissolves or disperses in water or an alcohol-based solvent is dissolved to 0.5% by mass or more in a general non-aqueous solvent such as toluene, xylene, ethyl acetate, or cyclohexanone. The hydrophilic group is preferably converted to a lipophilic group.

  Further, in the above material, it is not necessary for all of the lipophilic groups to return to the hydrophilic groups. The ratio of the lipophilic group returning to the hydrophilic group may be such that the first hole injection layer does not dissolve in the solvent of the second hole injection layer forming coating solution. Specifically, the lipophilic group is hydrophilic to such an extent that a material that dissolves 0.5% by mass or more in toluene, xylene, ethyl acetate, cyclohexanone, etc. becomes insoluble or hardly soluble in toluene, xylene, ethyl acetate, cyclohexanone, etc. It is preferable to return to the sex group. At this time, it is not necessary to completely return to the original hydrophilic organic material.

The hydrophilic organic material may have any hydrophilic group and can be dispersed or dissolved in water. For example, polyalkylthiophene derivatives, polyaniline derivatives, arylamines such as triphenylamine and triphenyldiamine, etc. Is mentioned. The polyalkylthiophene derivative and the polyaniline derivative may be doped with an acid such as polystyrene sulfonic acid.
Moreover, as a hydrophilic group, the sulfonic acid group, carboxylic acid group, and hydroxyl group which do not contain a salt are preferable from the ease of conversion reaction.

  The hydrophilic organic material used for the first hole injecting and transporting layer includes polystyrene sulfonic acid, polythiophene sulfonic acid, or derivatives thereof from the viewpoint of durability against conversion treatment, ease of purification, and cost. preferable.

  As a method of converting a hydrophilic group in a hydrophilic organic material into a lipophilic group, a part or all of the lipophilic group returns to the hydrophilic group by the action of heat or radiation energy, and therefore a method utilizing a protective reaction. Preferably there is. Here, the protective reaction refers to a reaction in which a hydrophilic group is derivatized and a protective group is temporarily introduced into the hydrophilic group. The protection reaction is preferably esterification, acetylation, tosylation, triphenylmethylation, alkylsilylation, or alkylcarbonylation.

  As a specific protection reaction, at least a part of the sulfonic acid group or carboxylic acid group is converted into a sulfochloride group or a carbonyl chloride group by a chlorinating agent such as phosphorus pentoxide or thionyl chloride, and converted into these chlorides. The method of esterifying by making alcohols, such as methanol and ethanol, react is mentioned.

  Thus, the material in which a part or all of the hydrophilic group of the hydrophilic organic material is converted into a lipophilic group has its solubility changed from hydrophilic to lipophilic because a protective group is introduced into the hydrophilic group. .

The first hole injection layer forming coating solution is prepared by dispersing or dissolving a material in which a part or all of the hydrophilic group of the hydrophilic organic material is converted into a lipophilic group in a solvent. Can do. At this time, a solvent that can disperse or dissolve a lipophilic material is used. Examples of such a solvent include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, acetone, ethyl acetate and the like.
In addition, the concentration of the material in which part or all of the hydrophilic groups of the hydrophilic organic material are converted to lipophilic groups in the first hole injection layer forming coating solution varies depending on the component or composition of the material. Although it is a thing, it is normally set at 0.1 mass% or more, Preferably it is about 1 mass%-5 mass%.

  The first hole injection layer changes the solubility of the coating film by applying thermal energy or irradiating the coating film obtained by applying the first hole injection layer forming coating solution. Can be obtained. You may dry after application | coating of the said 1st positive hole injection layer formation coating liquid. The solubility of the coating film after application of the first hole injection layer forming coating solution is oleophilic.

  When this coating film is applied with thermal energy or irradiated with radiation, the protective group introduced by the above protective reaction is eliminated and volatilized. Specifically, when an esterified sulfonic acid group or carboxylic acid group is given thermal energy or irradiated with radiation, the ester bond is decomposed, and the sulfonic acid group or carboxylic acid group in a free or salt state is restored. The

  When the protecting group is eliminated, the solubility of the membrane changes from lipophilic to hydrophilic. Thus, the film | membrane which became hydrophilic becomes immiscible with the solvent used for the coating liquid for 1st positive hole injection layer formation. That is, the first hole injection layer after application of thermal energy or irradiation with radiation is insoluble in the solvent of the first hole injection layer forming coating solution.

  For example, the heat energy may be applied by heating at about 200 to 220 ° C. for about 60 to 90 minutes. This heat treatment may be performed simultaneously with the drying after the application of the first hole injection layer forming coating solution.

Moreover, as a radiation, an ultraviolet-ray and an electron beam are mentioned, for example. The irradiation condition of the ultraviolet rays can be set, for example, at about 200 to 250 mJ / cm ² (wavelength: 400 nm or less). Moreover, as irradiation conditions of an electron beam, it can set, for example at 500 kV or more and 35 mA.

  The first organic EL layer is composed of a first hole injection layer and a first light emitting layer, and is formed on the second hole injection layer in a second organic EL layer formation step described later. When the second light emitting layer is formed by applying the second light emitting layer forming coating solution, the first light emitting layer is insoluble and difficult to dissolve in the solvent of the second light emitting layer forming coating solution. It may be either dissolved or soluble. Before forming the second light-emitting layer, the first light-emitting layer is covered with the second hole injection layer. Therefore, even if the first light-emitting layer is soluble in the solvent of the second light-emitting layer forming coating solution, the solvent It is because it does not contact and does not melt.

  Furthermore, in the case where the first organic EL layer is composed of the first hole injection layer and the first light emitting layer, the first organic EL layer and the first protection are formed in the third organic EL layer forming step described later. When the third hole injection layer is formed by applying the third hole injection layer forming coating liquid on the substrate on which the layer and the first photoresist layer are formed in a pattern, The hole injection layer is preferably insoluble in the solvent of the third hole injection layer forming coating solution.

  In addition, about making the 1st hole injection layer insoluble with respect to the solvent of the coating liquid for 3rd hole injection layer formation, the 1st hole injection layer mentioned above is formed in 2nd hole injection layer. This is the same as the case where the coating liquid is insoluble in the solvent of the coating liquid.

  The first organic EL layer is composed of a first hole injection layer and a first light emitting layer, and is formed on the third hole injection layer in a third organic EL layer formation step described later. When the third light emitting layer is formed by applying the third light emitting layer forming coating solution, the first light emitting layer is insoluble and difficult to dissolve in the solvent of the third light emitting layer forming coating solution. It may be either dissolved or soluble.

  In addition, since it is the same as that of what was described in the term of the organic EL layer forming process of the said 1st aspect about the other point of a 1st organic EL layer forming process, description here is abbreviate | omitted.

2. First protective layer forming step The first protective layer forming step in this aspect is a step of forming the first protective layer on the first organic EL layer.

  In the second organic EL layer forming step described later, a second hole injection layer forming coating solution is formed on the substrate on which the first organic EL layer, the first protective layer, and the first photoresist layer are formed in a pattern. When the second hole injection layer is formed by coating, the first protective layer is preferably insoluble in the solvent of the second hole injection layer forming coating solution. That is, the solubility of the first protective layer is preferably 5 nm or less / min with respect to the solvent of the second hole injection layer forming coating solution. Accordingly, even when the solvent of the second hole injection layer forming coating solution contacts the end of the pattern of the first protective layer when forming the second hole injection layer, the first protective layer is This is because the second hole injection layer can be stably laminated because it is not dissolved.

  In order to make the first protective layer insoluble in the solvent of the coating solution for forming the second hole injection layer, materials having different solubility may be used for the first protective layer and the second hole injection layer. .

  Furthermore, when the second protective layer is formed by applying a second protective layer-forming coating solution on the second organic EL layer in the second protective layer forming step described later, the first protective layer is Any of insoluble, hardly soluble and soluble in the solvent of the second protective layer forming coating solution may be used. Before forming the second protective layer, the first protective layer is covered with the second organic EL layer, so even if it is soluble in the solvent of the second protective layer forming coating solution, This is because they do not come into contact and do not dissolve.

  In addition, since it is the same as that of what was described in the term of the protective layer formation process of the said 1st aspect about the other point of a 1st protective layer formation process, description here is abbreviate | omitted.

3. First photoresist layer forming step The first photoresist layer forming step in this aspect is a step of applying a photoresist on the first protective layer to form a first photoresist layer.
In this embodiment, the first, second, and third types are used for the photoresist layer, but all are used for convenience, and all may be the same photoresist layer.

  In the second organic EL layer forming step described later, a second hole injection layer forming coating solution is formed on the substrate on which the first organic EL layer, the first protective layer, and the first photoresist layer are formed in a pattern. When the second hole injection layer is formed by coating, the first photoresist layer is preferably insoluble in the solvent of the second hole injection layer forming coating solution. That is, the solubility of the first photoresist layer is preferably 5 nm or less / min with respect to the solvent of the second hole injection layer forming coating solution. Accordingly, when the second hole injection layer is formed, even if the solvent of the second hole injection layer forming coating solution contacts the first photoresist layer, the first photoresist layer is not dissolved. This is because the second hole injection layer can be laminated stably.

  In order to make the first photoresist layer insoluble in the solvent of the coating solution for forming the second hole injection layer, materials having different solubility are used for the first photoresist layer and the second hole injection layer. That's fine.

  Furthermore, the first photoresist layer may be insoluble, hardly soluble or soluble in the photoresist solvent used in the second photoresist layer forming step. Before the second photoresist layer is formed, the first photoresist layer is covered with the second organic EL layer and the second protective layer, so that it is soluble in the solvent of the second protective layer forming coating solution. Even if it exists, it is because it does not come into contact with the solvent and does not dissolve.

  Since the other points of the first photoresist layer forming step are the same as those described in the section of the photoresist layer forming step of the first aspect, description thereof is omitted here.

4). Second organic EL layer forming step The second organic EL layer forming step in this aspect includes at least second light emission on the substrate on which the first organic EL layer, the first protective layer, and the first photoresist layer are formed in a pattern. This is a step of forming a second organic EL layer including a layer.

  A second hole injection layer is formed by applying a coating solution for forming a second hole injection layer on a substrate on which the first organic EL layer, the first protective layer, and the first photoresist layer are formed in a pattern. When formed, the solvent of the second hole injection layer forming coating solution is preferably one that does not dissolve the first organic EL layer, the first protective layer, and the first photoresist layer. That is, it is preferable that the solubility of the first organic EL layer, the first protective layer, and the first photoresist layer in the solvent of the second hole injection layer forming coating solution is 5 nm / min or less, respectively. This is because when the second hole injection layer is formed, the solvent of the second hole injection layer forming coating solution comes into contact with the first organic EL layer, the first protective layer, and the first photoresist layer. Because. Specifically, during the formation of the second hole injection layer, the solvent of the second hole injection layer forming coating solution is used as the edge of the pattern of the first organic EL layer and the first protective layer, and , Contacting the surface and edge of the pattern of the first photoresist layer.

  In the above case, the solvent of the second hole injection layer forming coating solution is compared with the area in contact with the surface and the edge of the pattern of the first photoresist layer. The area contacting the edge of the pattern is very small. Therefore, when the second hole injection layer is stably laminated, or when the minimum dimension value of one pixel is smaller than 100 μm, the solvent of the second hole injection layer forming coating solution is It is very effective not to dissolve the first organic EL layer and the first protective layer.

  Further, the second light emitting layer is formed by applying a second light emitting layer forming coating solution on the substrate on which the first organic EL layer, the first protective layer and the first photoresist layer are formed in a pattern. In that case, the solvent of the second light emitting layer forming coating solution is preferably one that does not dissolve the first photoresist layer. That is, the solvent of the second light emitting layer forming coating solution preferably has a solubility of the first photoresist layer of 5 nm or less / min.

  For example, when a general novolak positive photoresist is used for the first photoresist layer, the solvent is a light emitting layer forming coating solution described in the section of the organic EL layer forming step of the first aspect. The solvent used for is preferably used.

  In the case where the second organic EL layer is composed of a second hole injection layer and a second light emitting layer, in the third organic EL layer forming step described later, the second organic EL layer, the second protective layer, and In the case where the second hole injection layer is formed by applying a coating solution for forming a second hole injection layer on the substrate on which the second photoresist layer is formed in a pattern, the second hole injection is performed. The layer is preferably insoluble in the solvent of the third hole injection layer forming coating solution.

  In addition, about making the 2nd positive hole injection layer insoluble with respect to the solvent of the coating liquid for 3rd positive hole injection layer formation, the 1st positive hole injection layer mentioned above is 2nd positive hole injection layer formation. Since it is the same as the case where it is made insoluble with respect to the solvent of the coating liquid for coating, description here is abbreviate | omitted.

  The second organic EL layer is composed of a second hole injection layer and a second light emitting layer, and is formed on the third hole injection layer in a third organic EL layer formation step to be described later. When the third light emitting layer is formed by applying the third light emitting layer forming coating solution, the second light emitting layer is insoluble or difficult to dissolve in the solvent of the third light emitting layer forming coating solution. It may be either dissolved or soluble. Before the third light emitting layer is formed, the second light emitting layer is covered with the third hole injection layer, so that even if it is soluble in the solvent of the third light emitting layer forming coating solution, the solvent It is because it does not contact and does not melt.

  In addition, the other points of the second organic EL layer forming step are the same as those described in the section of the organic EL layer forming step of the first aspect, and thus description thereof is omitted here.

5. Second protective layer forming step The second protective layer forming step in this aspect is a step of forming the second protective layer on the second organic EL layer.

  When the second protective layer is formed by applying the second protective layer-forming coating liquid on the second organic EL layer, the solvent of the second protective layer-forming coating liquid is the first organic EL. The layer, the first protective layer, and the first photoresist layer may or may not dissolve. Before forming the second protective layer, the first organic EL layer, the first protective layer, and the first photoresist layer are covered with the second organic EL layer, so that the second protective layer forming coating solution is used as a solvent. This is because even if it is soluble, it does not come into contact with the solvent and does not dissolve.

  Further, in the third organic EL layer forming step described later, a third hole injection layer forming coating is formed on the substrate on which the second organic EL layer, the second protective layer, and the second photoresist layer are formed in a pattern. In the case where the third hole injection layer is formed by applying a working solution, the second protective layer is preferably insoluble in the solvent of the third hole injection layer forming coating solution. That is, the solubility of the second protective layer is preferably 5 nm or less / min with respect to the solvent of the third hole injection layer forming coating solution. As a result, even when the solvent of the third hole injection layer forming coating solution comes into contact with the end of the pattern of the second protective layer during the formation of the third hole injection layer, the second protective layer is This is because the third hole injection layer can be stably laminated because it is not dissolved.

  In order to make the second protective layer insoluble in the solvent of the third hole injection layer forming coating solution, materials having different solubility may be used for the second protective layer and the third hole injection layer. .

  Furthermore, in the case where the third protective layer is formed by applying a third protective layer-forming coating solution on the third organic EL layer in the third protective layer forming step described later, the second protective layer is Any of insoluble, hardly soluble and soluble in the solvent of the third protective layer forming coating solution may be used. Before forming the third protective layer, the second protective layer is covered with the third organic EL layer, so even if it is soluble in the solvent of the third protective layer-forming coating solution, This is because they do not come into contact and do not dissolve.

  In addition, since it is the same as that of what was described in the term of the protective layer formation process of the said 1st aspect about the other point of a 2nd protective layer formation process, description here is abbreviate | omitted.

6). Second Photoresist Layer Formation Step The second photoresist layer formation step in this aspect is a step of applying a photoresist on the second protective layer to form a second photoresist layer.

  The photoresist solvent used in this step may or may not dissolve the first organic EL layer, the first protective layer, and the first photoresist layer. Before forming the second photoresist layer, the first organic EL layer, the first protective layer, and the first photoresist layer are covered with the second organic EL layer and the second protective layer. This is because even if soluble, it does not come into contact with the solvent and does not dissolve.

  Further, in the third organic EL layer forming step described later, a third hole injection layer forming coating is formed on the substrate on which the second organic EL layer, the second protective layer, and the second photoresist layer are formed in a pattern. In the case where the third hole injection layer is formed by applying a working liquid, the second photoresist layer is preferably insoluble in the solvent of the third hole injection layer forming coating liquid. That is, the solubility of the second photoresist layer is preferably 5 nm or less / min with respect to the solvent of the third hole injection layer forming coating solution. Accordingly, when the third hole injection layer is formed, even if the solvent of the third hole injection layer forming coating solution contacts the second photoresist layer, the second photoresist layer is not dissolved. This is because the third hole injection layer can be laminated stably.

  In order to make the second photoresist layer insoluble in the solvent of the third hole injection layer forming coating solution, materials having different solubility are used for the second photoresist layer and the third hole injection layer. That's fine.

  Further, the second photoresist layer may be insoluble, hardly soluble or soluble in the photoresist solvent used in the third photoresist layer forming step. Before the third photoresist layer is formed, the second photoresist layer is covered with the third organic EL layer and the third protective layer, so that it is soluble in the solvent of the third protective layer forming coating solution. Even if it exists, it is because it does not come into contact with the solvent and does not dissolve.

  Since the other points of the second photoresist layer forming step are the same as those described in the section of the photoresist layer forming step of the first aspect, description thereof is omitted here.

7). Third Organic EL Layer Forming Step In the third organic EL layer forming step in this embodiment, the first organic EL layer, the first protective layer, and the first photoresist layer are formed in a pattern, and the second organic EL layer, 2 is a step of forming a third organic EL layer including at least a third light-emitting layer on a substrate on which a protective layer and a second photoresist layer are formed in a pattern.

  On the substrate on which the first organic EL layer, the first protective layer, and the first photoresist layer are formed in a pattern, and the second organic EL layer, the second protective layer, and the second photoresist layer are further formed in a pattern. When the third hole injection layer is formed by applying the third hole injection layer forming coating liquid, the solvent of the third hole injection layer forming coating liquid is the first organic EL layer. The first protective layer, the first photoresist layer, the second organic EL layer, the second protective layer, and the second photoresist layer are preferably not dissolved. That is, the solvent of the coating solution for forming the second hole injection layer is the first organic EL layer, the first protective layer, the first photoresist layer, the second organic EL layer, the second protective layer, and the second photoresist layer. It is preferable that the solubility of each is 5 nm or less / min.

  In addition, about the other point of a 3rd organic EL layer formation process, since it is the same as that of what was described in the term of the organic EL layer formation process of the said 1st aspect, description here is abbreviate | omitted.

8). Third protective layer forming step The third protective layer forming step in the present invention is a step of forming a third protective layer on the third organic EL layer.

  When the third protective layer is formed by applying the third protective layer-forming coating liquid on the third organic EL layer, the solvent of the third protective layer-forming coating liquid is the first organic EL. The layer, the first protective layer, the first photoresist layer, the second organic EL layer, the second protective layer, and the second photoresist layer may be dissolved or not dissolved. Before forming the second protective layer, the first organic EL layer, the first protective layer, the first photoresist layer, the second organic EL layer, the second protective layer, and the second photoresist layer are covered with the third organic EL layer. Therefore, even if it is soluble in the solvent of the third protective layer forming coating solution, it does not come into contact with the solvent and does not dissolve.

  In addition, since it is the same as that of what was described in the term of the protective layer formation process of the said 1st aspect about the other point of a 3rd protective layer formation process, description here is abbreviate | omitted.

9. Third Photoresist Layer Forming Step The third photoresist layer forming step in the present invention is a step of forming a third photoresist layer by applying a photoresist on the third protective layer.

  The photoresist solvent used in this step dissolves the first organic EL layer, the first protective layer, the first photoresist layer, the second organic EL layer, the second protective layer, and the second photoresist layer. May not dissolve well. Before forming the second photoresist layer, the first organic EL layer, the first protective layer, the first photoresist layer, the second organic EL layer, the second protective layer, and the second photoresist layer are composed of the third organic EL layer and Because it is covered with the third protective layer, even if it is soluble in the photoresist solvent, it does not come into contact with the solvent and does not dissolve.

  Since the other points of the third photoresist layer forming step are the same as those described in the section of the photoresist layer forming step of the first aspect, description thereof is omitted here.

10. Other Steps In this aspect, a cleaning step for cleaning the outermost surface of each organic EL layer may be performed after the peeling step. Moreover, you may perform the plasma processing process which plasma-processes the outermost surface of each organic EL layer after a peeling process.
Note that the cleaning process and the plasma treatment process are the same as those described in the section of the first aspect, and thus the description thereof is omitted here.

Furthermore, in this aspect, the counter electrode layer formation process which forms a counter electrode layer on each organic EL layer normally is performed after the said peeling process.
Since the counter electrode layer forming step is the same as that described in the first aspect, description thereof is omitted here.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be specifically described using examples and comparative examples.

[Example 1]
(Formation of electrode layer and insulating layer)
A substrate on which an indium tin oxide (ITO) film having a width of 85 μm and a pitch of 100 μm was formed as an electrode layer on a transparent glass substrate was prepared. A positive photoresist (OFPR-800, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to the entire surface of this substrate by a spin coating method and dried to form an insulating film having a thickness of 1 μm. Next, using a photomask (chrome line width (light-shielding part) 70 μm, opening width (transmission part) 30 μm) designed so that the light emitting region becomes an opening, the end of the ITO film is covered. Ultraviolet irradiation was performed with an alignment exposure machine. Next, the exposed portion of the insulating film is removed with a photoresist developer (manufactured by Tokyo Ohka Kogyo Co., Ltd., NMD-3), and then heat-treated on a hot plate at 230 ° C. for 1 hour to completely heat and cure the insulating film. An insulating layer was formed.

(Formation of organic EL layer)
An aqueous solution of poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT / PSS) (Startron's Baytron P CH-8000) and a γ-glycid having a glycidic group (-CHOCH ₂ ) as an organic functional group 10% by weight of xylpropyltrimethoxysilane (TSL8350 manufactured by Toshiba Silicone Co., Ltd.) was added to the PEDOT / PSS solid content to prepare a coating solution for forming a hole injection layer. This hole injection layer forming coating solution was applied to the entire surface of the substrate on which the insulating layer had been formed by a spin coating method and dried by heating to form a hole injection layer having a thickness of 100 nm.

  Next, a 1 wt% toluene solution of a polyfluorene derivative exhibiting red luminescence (American Dye Source, ADS100RE) was prepared to obtain a light emitting layer forming coating solution. This light emitting layer forming coating solution was applied to the entire surface of the hole injection layer by a spin coating method and dried by heating to form a light emitting layer having a thickness of 100 nm. Thereby, an organic EL layer was formed.

(Formation of protective layer)
Cellulose acetate (manufactured by Daicel Chemical Industries) is dissolved in a mixed solvent of methyl acetate and methanol (methyl acetate: methanol = 9: 1) to prepare a 2 wt% mixed solution of cellulose acetate, and a protective layer forming coating solution did. The protective layer-forming coating solution was applied to the entire surface of the light emitting layer by a spin coating method and dried by heating to form a protective layer having a thickness of 0.1 μm.

(Formation of photoresist layer)
A positive photoresist (OFPR-800, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on the entire surface of the protective layer by a spin coating method and dried to form a 1 μm-thick photoresist layer.

(Organic EL layer patterning)
Using a photomask (line width (light-shielding part) 85 μm, space width (transmission part) 15 μm) designed so that the light-emitting region becomes a light-shielding part, ultraviolet irradiation was performed by an alignment exposure machine. Subsequently, the photoresist layer of the exposed part was removed with a resist developer (manufactured by Tokyo Ohka Co., Ltd., NMD-3). Thereafter, dry etching was performed with a vacuum plasma apparatus to completely remove the organic EL layer and the protective layer where the photoresist layer was removed.

(Removal of photoresist layer and protective layer)
Next, the remaining photoresist layer and the protective layer of the unexposed portion are immersed in ethyl acetate at room temperature for 20 minutes, and then the front and back surfaces of the substrate are thoroughly washed again with ethyl acetate, and the photoresist component and the protective layer The photoresist layer and the protective layer were completely removed.

(Formation of counter electrode layer)
Next, on the exposed organic EL layer, calcium was vapor-deposited with a thickness of 1000 mm, and silver was further vapor-deposited with a thickness of 2000 mm as an oxidation protective layer to form a counter electrode layer.
Furthermore, using a glass substrate coated with a thermosetting adhesive as a sealing plate, the sealing plate was bonded in a glove box substituted with nitrogen gas so that the organic EL layer was completely sealed. , Heated at 80 ° C. for 1 hour and completely sealed.

[Example 2]
In Example 1, an organic EL device was produced in the same manner as in Example 1 except that the substrate was immersed in γ-butyrolactone for 5 minutes after removing the photoresist layer and the protective layer.

[Example 3]
In Example 1, an organic EL device was produced in the same manner as in Example 1 except that the photoresist layer and the protective layer were removed as described below.
The photoresist layer with the unexposed portion remaining is immersed in methyl isobutyl ketone at room temperature for 10 minutes, and then the front and back surfaces of the substrate are thoroughly washed again with methyl isobutyl ketone, and the photoresist components are thoroughly washed away. Only the layer was completely removed. Next, in a separate chamber, the remaining protective layer of the unexposed portion was immersed in ethyl acetate at room temperature for 10 minutes to completely remove only the protective layer.

[Example 4]
In Example 1, an organic EL device was produced in the same manner as in Example 1 except that the photoresist layer and the protective layer were removed as described below.
The photoresist layer with the unexposed portion remaining is immersed in methyl isobutyl ketone at room temperature for 10 minutes, and then the front and back surfaces of the substrate are thoroughly washed again with methyl isobutyl ketone, and the photoresist components are thoroughly washed away. Only the layer was completely removed. Next, in a separate chamber, the remaining protective layer of the unexposed portion was immersed in ethyl acetate at room temperature for 10 minutes to completely remove only the protective layer. Next, after removing the photoresist layer and the protective layer, the substrate was immersed in γ-butyrolactone for 5 minutes.

[Example 5]
(Formation of electrode layer and insulating layer)
A substrate on which an indium tin oxide (ITO) film having a width of 85 μm and a pitch of 100 μm was formed as an electrode layer on a transparent glass substrate was prepared. A positive photoresist (OFPR-800, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to the entire surface of this substrate by a spin coating method and dried to form an insulating film having a thickness of 1 μm. Next, using a photomask (chrome line width (light-shielding part) 70 μm, opening width (transmission part) 30 μm) designed so that the light emitting region becomes an opening, the end of the ITO film is covered. Ultraviolet irradiation was performed with an alignment exposure machine. Next, the exposed portion of the insulating film is removed with a photoresist developer (manufactured by Tokyo Ohka Kogyo Co., Ltd., NMD-3), and then heat-treated on a hot plate at 230 ° C. for 1 hour to completely heat and cure the insulating film. An insulating layer was formed.

(Formation of first organic EL layer)
An aqueous solution of poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT / PSS) (Startron's Baytron P CH-8000) and a γ-glycid having a glycidic group (-CHOCH ₂ ) as an organic functional group 10% by weight of xylpropyltrimethoxysilane (TSL8350 manufactured by Toshiba Silicone Co., Ltd.) was added to the PEDOT / PSS solid content to prepare a coating solution for forming a hole injection layer. This hole injection layer forming coating solution was applied to the entire surface of the substrate on which the insulating layer had been formed by spin coating, and dried by heating to form a first hole injection layer having a thickness of 100 nm.

  Next, a 1 wt% toluene solution of a polyfluorene derivative exhibiting red luminescence (American Dye Source, ADS100RE) was prepared to obtain a red luminescent layer forming coating solution. This red light emitting layer forming coating solution was applied to the entire surface of the first hole injection layer by a spin coating method and dried by heating to form a first light emitting layer having a thickness of 100 nm. Thereby, the first organic EL layer was formed.

(Formation of first protective layer)
Cellulose acetate (manufactured by Daicel Chemical Industries) is dissolved in a mixed solvent of methyl acetate and methanol (methyl acetate: methanol = 9: 1) to prepare a 2 wt% mixed solution of cellulose acetate, and a protective layer forming coating solution did. This protective layer-forming coating solution was applied to the entire surface of the first light-emitting layer by a spin coating method and dried by heating to form a first protective layer having a thickness of 0.1 μm.

(Formation of first photoresist layer)
A positive photoresist (OFPR-800, manufactured by Tokyo Ohka Co., Ltd.) was applied on the entire surface of the first protective layer by a spin coating method and dried to form a first photoresist layer having a thickness of 1 μm.

(Patterning of the first organic EL layer)
The photomask (line width (light-shielding part) 85 μm, space width (transmission part) 215 μm) designed so that the first light-emitting region becomes a light-shielding part was irradiated with ultraviolet rays by an alignment exposure machine. Next, the first photoresist layer in the exposed portion was removed with a resist developer (manufactured by Tokyo Ohka Co., Ltd., NMD-3). Thereafter, dry etching was performed by a vacuum plasma apparatus, and the first organic EL layer and the first protective layer in a portion where the first photoresist layer was removed were completely removed.

(Formation of second organic EL layer)
Next, without removing the remaining first photoresist layer, the hole injection layer-forming coating solution is applied to the entire surface of the substrate by a spin coating method, dried by heating, and a 100 nm-thickness first coating layer is formed. A two-hole injection layer was formed.

  Next, a 1 wt% toluene solution of a polyfluorene derivative (American Dye Source, ADS132GE) exhibiting green light emission was prepared to obtain a green light emitting layer forming coating solution. The green light emitting layer forming coating solution was applied to the entire surface of the second hole injection layer by a spin coating method and dried by heating to form a second light emitting layer having a thickness of 100 nm. As a result, a second organic EL layer was formed.

(Formation of second protective layer)
The protective layer-forming coating solution was applied to the entire surface of the second light emitting layer by a spin coating method and dried by heating to form a second protective layer having a thickness of 0.1 μm.

(Formation of second photoresist layer)
A positive photoresist (OFPR-800, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on the entire surface of the second protective layer by a spin coating method and dried to form a second photoresist layer having a thickness of 1 μm.

(Patterning of second organic EL layer)
The photomask (line width (light-shielding part) 85 μm, space width (transmission part) 215 μm) designed so that the second light-emitting region becomes a light-shielding part was irradiated with ultraviolet rays by an alignment exposure machine. Next, the second photoresist layer in the exposed portion was removed with a resist developer (manufactured by Tokyo Ohka Kogyo Co., Ltd., NMD-3). Thereafter, dry etching was performed with a vacuum plasma apparatus to completely remove the second organic EL layer and the second protective layer in the portion where the second photoresist layer was removed.

(Formation of third organic EL layer)
Next, without removing the remaining first photoresist layer and second photoresist layer, the hole injection layer forming coating solution is applied to the entire surface of the substrate by a spin coating method and dried by heating. A third hole injection layer having a thickness of 100 nm was formed.

  Next, a 1 wt% toluene solution of a polyfluorene derivative exhibiting blue luminescence (American Dye Source, ADS135BE) was prepared to obtain a coating solution for forming a blue luminescent layer. The blue light-emitting layer forming coating solution was applied to the entire surface of the third hole injection layer by a spin coating method and dried by heating to form a third light-emitting layer having a thickness of 100 nm. Thereby, the third organic EL layer was formed.

(Formation of third protective layer)
The protective layer-forming coating solution was applied to the entire surface of the third light emitting layer by a spin coating method and dried by heating to form a third protective layer having a thickness of 0.1 μm.

(Formation of third photoresist layer)
A positive photoresist (OFPR-800, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on the entire surface of the third protective layer by a spin coating method and dried to form a third photoresist layer having a thickness of 1 μm.

(Patterning of third organic EL layer)
The photomask (line width (light-shielding part) 85 μm, space width (transmission part) 215 μm) designed so that the third light-emitting region becomes a light-shielding part was irradiated with ultraviolet rays by an alignment exposure machine. Next, the third photoresist layer in the exposed portion was removed with a resist developer (manufactured by Tokyo Ohka Co., Ltd., NMD-3). Thereafter, dry etching was performed with a vacuum plasma apparatus to completely remove the third organic EL layer and the third protective layer in the portion where the third photoresist layer was removed.

(Removal of photoresist layer and protective layer)
Next, each photoresist layer and each protective layer in which an unexposed portion remains are immersed in ethyl acetate at room temperature for 20 minutes, and then the front and back surfaces of the substrate are thoroughly washed again with ethyl acetate, And each protective layer was thoroughly washed away, and each photoresist layer and each protective layer were completely removed.

(Formation of counter electrode layer)
Next, on the exposed organic EL layer, calcium was vapor-deposited with a thickness of 1000 mm, and silver was further vapor-deposited with a thickness of 2000 mm as an oxidation protective layer to form a counter electrode layer.
Furthermore, using a glass substrate coated with a thermosetting adhesive as a sealing plate, the sealing plate was bonded in a glove box substituted with nitrogen gas so that the organic EL layer was completely sealed. , Heated at 80 ° C. for 1 hour and completely sealed.

[Example 6]
In Example 5, an organic EL device was produced in the same manner as in Example 5 except that after removing each photoresist layer and each protective layer, the substrate was immersed in γ-butyrolactone for 5 minutes.

[Example 7]
In Example 5, an organic EL device was produced in the same manner as in Example 5 except that each photoresist layer and each protective layer were removed as described below.
Each photoresist layer in which the unexposed portion remains is immersed in methyl isobutyl ketone at room temperature for 10 minutes, and then, again, the front and back surfaces of the substrate are thoroughly washed with methyl isobutyl ketone, and the photoresist components are thoroughly washed away. Only the photoresist layer was completely removed. Next, in a separate chamber, each of the protective layers remaining in the unexposed part was immersed in ethyl acetate at room temperature for 10 minutes, and only each protective layer was completely removed.

[Example 8]
In Example 5, an organic EL device was produced in the same manner as in Example 5 except that each photoresist layer and each protective layer were removed as described below.
Each photoresist layer in which the unexposed portion remains is immersed in methyl isobutyl ketone at room temperature for 10 minutes, and then, again, the front and back surfaces of the substrate are thoroughly washed with methyl isobutyl ketone, and the photoresist components are thoroughly washed away. Only the photoresist layer was completely removed. Next, in a separate chamber, each of the protective layers remaining in the unexposed part was immersed in ethyl acetate at room temperature for 10 minutes, and only each protective layer was completely removed. Next, after removing each photoresist layer and each protective layer, the substrate was immersed in γ-butyrolactone for 5 minutes.

[Comparative Example 1]
In Example 1, an organic EL device was produced in the same manner as in Example 1 except that the protective layer was not formed.

[Comparative Example 2]
In Example 5, the organic EL element was produced like Example 5 except not having formed each protective layer.

[Evaluation of device life]
For the organic EL elements of Examples 1 to 8 and Comparative Examples 1 and 2, with the ITO electrode side as the positive electrode and the metal electrode side as the negative electrode, connected to a source meter and applied with a direct current, the same brightness in each example The current value was confirmed. Thereafter, the luminance was measured while changing the voltage so as to maintain the current value. The results are shown in Table 1 below.

It is process drawing which shows an example of the manufacturing method of the organic EL element of this invention. It is process drawing which shows the other example of the manufacturing method of the organic EL element of this invention. It is process drawing which shows the other example of the manufacturing method of the organic EL element of this invention. It is process drawing which shows the other example of the manufacturing method of the organic EL element of this invention. It is process drawing which shows the other example of the manufacturing method of the organic EL element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Electrode layer 3 ... Insulating layer 4, 4 '... Hole injection layer 5, 5' ... Light emitting layer 6 ... Organic EL layer 7, 7 '... Protective layer 8, 8' ... Photoresist layer 9 ... Opposite Electrode layer 10 ... Light emitting region

Claims (9)

An organic electroluminescence layer forming step of forming at least one organic electroluminescence layer on the substrate on which the electrode layer is formed;
A protective layer forming step of forming a protective layer on the organic electroluminescence layer;
A photoresist layer forming step of applying a photoresist on the protective layer to form a photoresist layer;
A photoresist layer patterning step of patterning the photoresist layer by pattern exposing and developing the photoresist layer; and
An organic electroluminescence layer patterning step of patterning the organic electroluminescence layer by removing the protective layer and the organic electroluminescence layer in a portion where the photoresist layer is removed;
A method for producing an organic electroluminescent element, comprising: a peeling step of peeling the remaining photoresist layer and the protective layer in this order.   The method for producing an organic electroluminescent element according to claim 1, wherein at least a light emitting layer is formed as the organic electroluminescent layer in the organic electroluminescent layer forming step. A first organic electroluminescence layer forming step of forming a first organic electroluminescence layer including at least a first light emitting layer on the substrate on which the electrode layer is formed;
A first protective layer forming step of forming a first protective layer on the first organic electroluminescence layer;
A first photoresist layer forming step of applying a photoresist on the first protective layer to form a first photoresist layer;
A first photoresist layer patterning step of patterning the first photoresist layer so that the first photoresist layer in the first light emitting region remains by pattern exposure and development of the first photoresist layer;
A first organic electroluminescence layer patterning step of patterning the first organic electroluminescence layer by removing the first protective layer and the first organic electroluminescence layer in a portion where the first photoresist layer is removed; ,
A second organic layer that forms a second organic electroluminescent layer including at least a second light emitting layer on a substrate on which the first organic electroluminescent layer, the first protective layer, and the first photoresist layer are formed in a pattern. An electroluminescence layer forming step;
A second protective layer forming step of forming a second protective layer on the second organic electroluminescence layer;
A second photoresist layer forming step of applying a photoresist on the second protective layer to form a second photoresist layer;
A second photoresist layer patterning step of patterning the second photoresist layer so that the second photoresist layer in the second light emitting region remains by pattern-exposing and developing the second photoresist layer;
A second organic electroluminescence layer patterning step of patterning the second organic electroluminescence layer by removing the second protective layer and the second organic electroluminescence layer in a portion where the second photoresist layer is removed; ,
The first organic electroluminescence layer, the first protective layer, and the first photoresist layer are formed in a pattern, and the second organic electroluminescence layer, the second protective layer, and the second photoresist layer are patterned. A third organic electroluminescence layer forming step of forming a third organic electroluminescence layer including at least a third light emitting layer on the substrate formed in a shape;
A third protective layer forming step of forming a third protective layer on the third organic electroluminescence layer;
A third photoresist layer forming step of applying a photoresist on the third protective layer to form a third photoresist layer;
A third photoresist layer patterning step of patterning the third photoresist layer so that the third photoresist layer in the third light emitting region remains by pattern exposure and development of the third photoresist layer;
A third organic electroluminescence layer patterning step of patterning the third organic electroluminescence layer by removing the third protective layer and the third organic electroluminescence layer in a portion where the third photoresist layer is removed; ,
A stripping step of stripping the remaining first photoresist layer, the second photoresist layer, and the third photoresist layer, and the first protective layer, the second protective layer, and the third protective layer in this order; The manufacturing method of the organic electroluminescent element characterized by having.   The first organic electroluminescent layer, the first protective layer, and the first photoresist layer are insoluble in a solvent used for forming the second organic electroluminescent layer and the third organic electroluminescent layer, and The organic electroluminescence device according to claim 3, wherein the organic electroluminescence layer, the second protective layer, and the second photoresist layer are insoluble in a solvent used for forming the third organic electroluminescence layer. Manufacturing method.   Each of the protective layers contains at least one selected from the group consisting of a water-soluble cellulose derivative, a modified cellulose derivative soluble in an organic solvent, a water-soluble polyvinyl alcohol derivative, and a fluorine-based polymer material. The manufacturing method of the organic electroluminescent element in any one of Claim 1- Claim 4.   The organic electro of any one of claims 1 to 5, wherein the peeling step includes a step of peeling only each of the photoresist layers and a step of peeling only each of the protective layers. Manufacturing method of luminescence element.   The stripping step is a step of gradually stripping each photoresist layer and each protective layer from an upper layer using a stripping solution that dissolves each photoresist layer and each protective layer. The manufacturing method of the organic electroluminescent element in any one of Claim 1- Claim 5.   The method for producing an organic electroluminescent element according to any one of claims 1 to 7, wherein a cleaning step of cleaning the outermost surface of each organic electroluminescent layer is performed after the peeling step.   The method for producing an organic electroluminescence element according to any one of claims 1 to 7, wherein a plasma treatment step of performing a plasma treatment on an outermost surface of each organic electroluminescence layer is performed after the peeling step.

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