JP2014209493A - Method of manufacturing organic el device, and organic el device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an organic EL device, and an organic EL device, capable of suppressing separation caused by stress concentration to each layer end part and enhancing the reliability of the organic EL device, by alleviating the stress concentration even when using a roll-to-roll process.SOLUTION: A method of manufacturing an organic EL device includes: a substrate supply step of supplying a substrate 101 from a feeding roll to a take-up roll; a first electrode layer formation step of forming a first electrode layer 102 on the substrate 101; an organic EL layer formation step of forming the organic EL layer 103 on the first electrode layer 102; and a second electrode layer formation step of forming a second electrode layer 104 on the organic EL layer 103. The first electrode layer 102 is formed by using a shadow mask. At least a part of a lateral face of the first electrode layer 102 is a taper surface 102T inclined in an inner direction from a lower side to an upper side. An angle θ made by the taper surface 102T of the first electrode layer and the first electrode layer 102 side surface of the substrate 101 is 1° or less.

Description

  The present invention relates to an organic EL device manufacturing method and an organic EL device.

  In recent years, a method of forming an organic EL (electroluminescence) element on a narrow strip substrate by a roll-to-roll process is known (see, for example, Patent Document 1). The roll-to-roll process uses a flexible substrate as a base material, winds the substrate around a roll, rotates the roll, pulls out the substrate, and moves the electrode and organic EL layer on the substrate. This is a continuous production process in which organic EL devices are continuously produced by performing processing such as forming the substrate and winding the processed substrate around another roll again.

JP 2008-287996 A

  However, in an organic EL device formed by a roll-to-roll process, the use of a flexible substrate tends to cause peeling due to stress concentration at the end of each layer, which impairs the reliability of the organic EL device (organic There is a problem that the EL element is easily destroyed.

  The present invention has been made in view of the above problems, and even when a roll-to-roll process is used, the stress concentration at the end of each layer is reduced, resulting in the stress concentration. An object is to suppress peeling and increase the reliability of an organic EL device.

The method for producing the organic EL device of the present invention comprises:
A substrate supply process for supplying the substrate from the feed roll to the take-up roll;
A first electrode layer forming step of forming a first electrode layer on the substrate;
An organic EL layer forming step of forming an organic EL layer on the first electrode layer;
A second electrode layer forming step of forming a second electrode layer on the organic EL layer,
The first electrode layer is formed using a shadow mask, and at least a part of a side surface of the formed first electrode layer is a tapered surface inclined inward from the lower side to the upper side, The angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side is 1 ° or less.

In the organic EL device of the present invention, the first electrode layer, the organic EL layer, and the second electrode layer are laminated in this order on the flexible substrate,
The first electrode layer has a tapered surface in which at least a part of the side surface is inclined inward from the lower side toward the upper side, and the tapered surface of the first electrode layer and the first electrode layer of the substrate The angle formed by the side surface is 1 ° or less.

  According to the present invention, even when a roll-to-roll process is used, by reducing the stress concentration at the end of each layer, the peeling can be suppressed and the reliability of the organic EL device can be improved. it can. Furthermore, as a secondary effect of the present invention, it is also possible to suppress a decrease in yield due to a residue or the like generated by photolithography or the like.

FIG. 1 is a schematic cross-sectional view showing an example of the configuration of an organic EL device according to the present invention. FIG. 2 is a schematic cross-sectional view showing an example of the shape near the opening of a shadow mask used in the method for manufacturing an organic EL device of the present invention. FIG. 3 is a schematic cross-sectional view showing another example of the shape in the vicinity of the opening of the shadow mask used in the method for manufacturing the organic EL device of the present invention. FIG. 4 is a schematic cross-sectional view showing still another example of the shape in the vicinity of the opening of the shadow mask used in the method for manufacturing the organic EL device of the present invention. FIG. 5 is a diagram for explaining the arrangement of the substrate and the shadow mask in the first electrode layer forming step. FIG. 6 is a perspective view of the vicinity of the opening of the shadow mask in the first electrode layer forming step. FIG. 7 is a schematic cross-sectional view illustrating an example of the configuration of an organic EL device of a comparative example.

  In the method for producing an organic EL device of the present invention, the shadow mask used in the first electrode layer forming step is preferably a shadow mask in which the cross-sectional shape of the inner surface of the opening has a tapered shape or a multistage shape.

  In the shadow mask used in the first electrode layer forming step in the method for manufacturing an organic EL device of the present invention, the inner edge of the opening has a constant thickness, and the thickness is in the range of 5 to 500 μm. A mask is preferred.

  In the organic EL layer forming step in the method for producing an organic EL device of the present invention, the organic EL layer is preferably formed using a shadow mask for forming an organic EL layer.

  In the second electrode layer forming step in the method for manufacturing an organic EL device of the present invention, it is preferable that the second electrode layer is formed using a second electrode layer forming shadow mask.

  In the method for manufacturing an organic EL device of the present invention, the substrate has a width that is 10 to 100 mm, a length that is 10 to 2000 m, and a length that can be restored when the radius of curvature is 30 mm or more. It is preferable to use a strip-like substrate.

  Next, the present invention will be described in detail. However, the present invention is not limited by the following description.

  The organic EL device has a laminate in which a first electrode layer, an organic EL layer, and a second electrode layer are provided in this order on a substrate. One of the first electrode layer and the second electrode layer is an anode, and the other is a cathode. The organic EL device manufacturing method of the present invention is a method for manufacturing an organic EL device by a roll-to-roll process, the substrate supplying step of supplying a substrate from a feeding roll to a winding roll, Forming a first electrode layer on the substrate; forming an organic EL layer on the first electrode layer; forming a second electrode layer on the organic EL layer; And a second electrode layer forming step. The first electrode layer is formed using a shadow mask, and at least a part of a side surface of the formed first electrode layer is a tapered surface inclined in an inner direction from the lower side to the upper side. The angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side is 1 ° or less.

  Examples of the substrate include metal plates and metal foils such as aluminum (Al), copper (Cu), and stainless steel (SUS), polyethylene (PE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), and polyimide (PI). ), Methacrylic resin (PMMA), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), cycloolefin resin (COP), and other resin plates, flexible glass, and the like can be used. The present invention is not limited to these substrates, and other materials applicable to a roll-to-roll process can also be used. As the substrate, it is preferable to use a long belt-like substrate that can be restored with a width within a range of 10 to 100 mm, a length within a range of 10 to 2000 m, and a curvature radius of 30 mm or more. More preferably, it is a long belt-like substrate having a width in the range of 30 to 60 mm, a length in the range of 200 to 2000 m, and a recoverable radius of curvature of 10 mm or more.

  When a conductive substrate is used as the substrate, the formation surface of the organic EL element needs to ensure insulation. Therefore, when using a conductive substrate, it is necessary to provide an insulating layer over the conductive substrate. As the insulating layer, for example, an inorganic insulating layer, an organic insulating layer, a laminate of an inorganic insulating layer and an organic insulating layer, or the like can be used. The organic EL element may be formed on the insulating layer.

  The inorganic insulating layer preferably contains at least one of a metal and a metalloid. It is preferable that at least one of the metal and the metalloid is at least one selected from the group consisting of oxides, nitrides, carbides, oxynitrides, oxycarbides, nitride carbides, and oxynitride carbides. Examples of the metal include zinc, aluminum, titanium, copper, and magnesium. Examples of the semimetal include silicon, bismuth, and germanium.

  As the organic insulating layer, an insulating resin layer can be used. Since the conductive substrate may be heated to 150 to 300 ° C. in the manufacturing process, it is preferable to select a heat resistant resin having a glass transition temperature of 150 ° C. or higher. Specifically, acrylic resin, norbornene resin, epoxy resin, polyimide resin, polyamideimide resin, polyamide resin, polyester resin, polyarylate resin, polyurethane resin, polycarbonate resin, polyetherketone resin, polyphenylsulfone resin, and these resins And the like. Among these, the resin is preferably at least one selected from the group consisting of acrylic resins, norbornene resins, epoxy resins, and polyimide resins.

  As the first electrode layer, indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), indium zinc oxide (IZO (registered trademark)), gold, platinum, nickel, tungsten, copper and Metals such as aluminum, alkali metals such as lithium and cesium, alkaline earth metals such as magnesium and calcium, rare earth metals such as ytterbium, alloys such as aluminum-lithium alloys and magnesium-silver alloys, and the like can be used.

  In the method for manufacturing an organic EL device of the present invention, the first electrode layer is formed using a shadow mask. The first electrode layer can be formed by, for example, a sputtering method, a vapor deposition method, a CVD method, or the like. Examples of the shadow mask include those made of metal such as stainless steel (SUS), aluminum (Al), and copper (Cu), but are not limited thereto. The shadow mask preferably has a thickness of 10 to 2000 μm, more preferably 20 to 500 μm.

  The angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side is 1 ° or less, preferably in the range of 0.03 ° to 1 °, more preferably 0.1. It is in the range of ° to 1 °. In some cases, the angle of the end of the first electrode layer is not a film shape but a sea-island shape as in the examples described later. In this case, the angle is 20% to 80% of the thickness of the first electrode layer. Refers to the angle calculated from the slope between. When the angle is larger than 1 °, the thickness of the organic EL layer is locally reduced at the end portion of the first electrode layer, and the electric field is increased, which causes a problem that the element is easily destroyed. In addition, when a photolithography process is used for forming the first electrode layer, it is difficult to set the angle to 1 ° or less, and the cost is increased, and further, reliability is reduced due to a residue generated in the process. In the present invention, a shadow mask is used because of the problem of yield reduction.

  The angle formed by the tapered surface of the end portion of the first electrode layer and the surface of the substrate on the first electrode layer side can be adjusted by the thickness of the inner end portion of the opening of the shadow mask. When the thickness is reduced, the angle can be increased, and when the thickness is increased, the angle can be decreased. It can also be adjusted by the size of the gap between the substrate and the shadow mask when the first electrode layer is formed. When the gap is reduced, the angle can be increased, and when the gap is increased, the angle can be reduced. The thickness of the inner edge of the shadow mask opening may be changed by changing the thickness of the shadow mask itself, or by half-etching one side of the inner edge of the shadow mask opening on the side of the film forming source. Only the thickness of the inner end may be reduced. Examples of the cross-sectional shape of the inner side surface of the shadow mask opening are shown in FIGS.

  In the shadow mask of FIG. 2, since the thickness of the inner end of the opening is equal to the thickness of the other part, the strength of the shadow mask itself may be a problem when it is desired to reduce the thickness of the inner end of the opening. is there. When it is desired to reduce the thickness of the inner end of the opening, it is preferable that the sectional shape of the inner surface S of the opening is a multistage shape or a tapered shape, as in the shadow mask having the sectional shape of FIGS. In this case, the thickness in the vicinity of the opening is equal to that of the shadow mask in FIG. 2, but the thickness other than in the vicinity of the opening can be increased. As described above, it is preferable to use the shadow mask having the cross-sectional shape shown in FIGS. 3 and 4 because the strength of the shadow mask itself can be obtained. The thickness d of the inner end of the opening of the shadow mask is preferably in the range of 5 to 500 μm, more preferably in the range of 50 to 300 μm. When the thickness d is in the above range, it is preferable in that the strength in the vicinity of the opening is maintained. Further, the width L of the multi-stage or tapered shape forming portion is preferably in the range of d / 5 to 5d, and more preferably in the range of d / 3 to 3d. When the width L is in the above range, it is preferable because the pattern accuracy can be increased while maintaining the strength near the opening.

  As a method of providing a gap between the substrate and the shadow mask when forming the first electrode layer, a method of half-etching the surface on the substrate side in the vicinity of the opening of the shadow mask, and between the shadow mask and the substrate. There are a method of sandwiching a spacer, a method of applying a knurling process to a shadow mask or the substrate, a method of forming a pattern on the substrate by a photolithography method, and the like.

  FIG. 5 is an explanatory diagram of the arrangement of the substrate and the shadow mask in the first electrode layer forming step. FIG. 6 is a perspective view of the vicinity of the opening of the shadow mask in the first electrode layer forming step as seen from the film forming source side. As shown in FIGS. 5 and 6, a film forming source 150 is disposed so as to face the surface of the substrate 101 on the side on which the first electrode layer is formed. The film forming source 150 is a vapor deposition source, a sputter target, or the like that includes a material for forming the first electrode layer. A shadow mask 210 is disposed between the substrate 101 and the film forming source 150. The material for forming the first electrode layer is released from the film forming source 150, and the first electrode layer is formed on the substrate 101 in accordance with the shape of the opening of the shadow mask 210. In the figure, the substrate 101 and the shadow mask 210 are disposed in close contact with each other, but the present invention is not limited to this, and a gap (gap) may be provided between the substrate and the shadow mask.

  The organic EL layer has at least a hole transport layer, a light emitting layer, and an electron transport layer, and may have a hole injection layer, an electron injection layer, and the like as necessary. When the first electrode layer is an anode and the second electrode layer is a cathode, the organic EL layer is, for example, a hole injection layer or a hole transport layer from the first electrode layer toward the second electrode layer. The light emitting layer, the electron transport layer, and the electron injection layer are laminated in this order. On the other hand, when the first electrode layer is a cathode and the second electrode layer is an anode, the organic EL layer is, for example, a hole injection layer or a hole from the second electrode layer toward the first electrode layer. A transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are laminated in this order.

  The material for forming the hole transport layer is not particularly limited as long as the material has a hole transport function. Examples of the material for forming the hole transport layer include 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB) and 4,4′-bis [N- (3- And aromatic amine compounds such as methylphenyl) -N-phenylamino] biphenyl (TPD), carbazole derivatives such as 1,3-bis (N-carbazolyl) benzene, and polymer compounds. As the material for forming the hole transport layer, one kind may be used alone, or two or more kinds may be used in combination. The hole transport layer may have a multilayer structure of two or more layers.

  The material for forming the hole injection layer is not particularly limited. For example, HAT-CN (1, 4, 5, 8, 9, 12-hexaazatriphenylene hexacarbonitrile), vanadium oxide, niobium oxide, and tantalum oxide Metal oxides such as phthalocyanines, phthalocyanine compounds such as phthalocyanine, polymer compounds such as a mixture of 3,4-ethylenedioxythiophene and polystyrenesulfonic acid (PEDOT / PSS), and materials for forming the hole transport layer . The material for forming the hole injection layer may be used alone or in combination of two or more.

  The material for forming the light emitting layer is not particularly limited as long as it is a light emitting material. As a material for forming the light emitting layer, for example, a low molecular light emitting material such as a low molecular fluorescent light emitting material or a low molecular phosphorescent light emitting material can be used. Further, the material for forming the light emitting layer may have both a light emitting function and an electron transport function or a hole transport function.

Examples of the low-molecular light-emitting material include aromatic dimethylidene compounds such as 4,4′-bis (2,2′-diphenylvinyl) -biphenyl (DPVBi), 5-methyl-2- [2- [4- ( Oxadiazole compounds such as 5-methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazole, 3- (4-biphenylyl) -4-phenyl-5-t-butylphenyl-1,2,4- Triazole derivatives such as triazole, styrylbenzene compounds such as 1,4-bis (2-methylstyryl) benzene, azomethine zinc complexes and organometallic complexes such as tris (8-quinolinolato) aluminum (Alq ₃ ), naphthoquinone derivatives, And anthraquinone derivatives and fluorenone derivatives.

  Further, as a material for forming the light emitting layer, a host material doped with a light emitting dopant material may be used.

  As the host material, for example, the above-described low-molecular light-emitting materials can be used. Besides these, 1,3-bis (N-carbazolyl) benzene (mCP), 2,6-bis (N-carbazolyl) pyridine , 9,9-di (4-dicarbazole-benzyl) fluorene (CPF), 4,4′-bis (carbazol-9-yl) -9,9-dimethyl-fluorene (DMFL-CBP), etc. Can be used.

Examples of the dopant material include organic iridium complexes such as tris (2-phenylpyridyl) iridium (III) (Ir (ppy) ₃ ) and tris (1-phenylisoquinoline) iridium (III) (Ir (piq) ₃ ). Phosphorescent metal complexes such as styryl derivatives, perylene derivatives, and the like can be used.

  Furthermore, the material for forming the light emitting layer may include the above-described material for forming the hole transport layer, the material for forming the electron transport layer described later, various additives, and the like.

  The material for forming the electron transport layer is not particularly limited as long as the material has an electron transport function. Examples of the material for forming the electron transport layer include metal complexes such as bis (2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum (BAlq), 2- (4-biphenylyl) -5- (4- tert-butylphenyl) -1,3,4-oxadiazole (PBD) and 1,3-bis [5- (p-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] Examples thereof include heteroaromatic compounds such as benzene (OXD-7) and polymer compounds such as poly (2,5-pyridine-diyl) (PPy). The material for forming the electron transport layer may be used alone or in combination of two or more. The electron transport layer may have a multilayer structure of two or more layers.

The material for forming the electron injection layer is not particularly limited, and examples thereof include alkali metal compounds such as lithium fluoride (LiF) and cesium fluoride (CsF), alkaline earth metal compounds such as calcium fluoride (CaF ₂ ), Examples thereof include a material for forming the electron transport layer. The material for forming the electron injection layer may be used alone or in combination of two or more. The electron injection layer may have a multilayer structure of two or more layers.

  The formation method of each layer which comprises the said organic EL layer is not specifically limited, For example, a sputtering method, a vapor deposition method, the inkjet method, the coating method etc. are mention | raise | lifted. Examples of the patterning method of the organic EL layer include a shadow mask method and a photolithography method. From the viewpoint of damage to the organic EL layer, resist residue, the number of steps, etc., in the organic EL layer forming step, a shadow for forming the organic EL layer is used. It is preferably formed using a mask.

  Examples of the second electrode layer include indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), metals such as gold, platinum, nickel, tungsten, copper and aluminum, and alkali metals such as lithium and cesium. Further, alkaline earth metals such as magnesium and calcium, rare earth metals such as ytterbium, alloys such as aluminum-lithium alloys and magnesium-silver alloys, and the like can be used.

  The second electrode layer can be formed by, for example, a sputtering method, a vapor deposition method, a CVD method, or the like. Examples of the patterning method for the second electrode layer include a shadow mask method and a photolithography method. From the viewpoint of damage to the organic EL layer, a resist residue, the number of steps, and the like, in the second electrode layer forming step, the second electrode layer is formed. It is preferably formed using a layer forming shadow mask.

  FIG. 1 is a schematic cross-sectional view of an example of the configuration of the organic EL device of the present invention. As shown in the figure, in the organic EL device 100, a first electrode layer 102, an organic EL layer 103, and a second electrode layer 104 are laminated in this order on a substrate 101. At least a part of the side surface of the first electrode layer 102 is a tapered surface 102T that is inclined inward from the lower side toward the upper side. An angle θ formed by the tapered surface 102T and the surface of the substrate 101 on the first electrode layer 102 side is 1 ° or less. The organic EL device of the present invention can be produced by the method for producing an organic EL device of the present invention, but is not limited thereto.

  Next, examples of the present invention will be described together with comparative examples. The present invention is not limited or restricted by the following examples and comparative examples. In addition, various properties and physical properties in each example and each comparative example were measured and evaluated by the following methods.

(An angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side)
Since the end of the first electrode layer may have a sea-island shape instead of a film shape, the angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side is It calculated from the gradient between 20%-80% of 1 electrode layer thickness. The gradient was measured by observing the cross section of the organic EL device with a scanning electron microscope (trade name: JSM-6610) manufactured by JEOL Ltd.

(Leakage (element breakdown rate))
100 organic EL devices each having one 20 mm × 100 mm square light emitting part (element) were prepared, and 0.1 V / -8 V to 8 V between the first electrode layer and the second electrode layer of the organic EL device. The voltage application at intervals of sec was repeated 100 times. By this operation, the number of organic EL devices in which leakage occurred was counted, and the destruction rate of the element was evaluated according to the following evaluation criteria.
A: Device breakdown rate is 0 to 10%
B: Destruction ratio of the element exceeds 10% and 30% or less C: Destruction ratio of the element exceeds 30% and 100% or less

(Yield (number of dark spots))
5 V is applied between the first electrode layer and the second electrode layer of the organic EL device after performing the leak test, and the light emitting surface is optical microscope (Keyence Corporation digital microscope (trade name: VHX- 1000)), the number of dark spots having a diameter of 10 μm or more was counted, and the yield was evaluated according to the following evaluation criteria.
G: The number of dark spots per 1 cm ² is 0 to 1 NG: The number of dark spots per 1 cm ² is 2 or more

[Example 1]
As a substrate for producing an organic EL element, an insulating acrylic resin for organic EL (trade name “JEM-477” manufactured by JSR Corporation) is applied and dried as a planarizing layer on a SUS foil having a total length of 1000 m, a width of 30 mm, and a thickness of 50 μm. I prepared a cure. After performing the cleaning process and the heating process on the substrate, the cross-sectional shape of the inner surface of the opening is a multistage shape on the substrate in an atmosphere of a vacuum degree of 10 ⁻⁴ Pa or less, and the inside of the opening A shadow mask for forming a first electrode layer made of SUS having an end thickness d of 100 μm was adhered. In this state, Al was vapor-deposited as a first electrode layer at a rate of 1 l / sec (0.1 nm / sec) by a vacuum vapor deposition method so that the thickness became 100 nm. At this time, the angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side was 0.03 °. Thereafter, a shadow mask for forming an organic EL layer is adhered to the substrate, and HAT-CN (thickness 10 nm) / NPB (thickness 50 nm) / Alq ₃ (thickness 50 nm) / LiF (thickness 0.5 nm) is used as the organic EL layer. Vacuum deposition was performed at a rate of 1 liter / sec (0.1 nm / sec). Next, a shadow mask for forming the second electrode layer was adhered to the substrate, Al (thickness 1 nm) / Ag (thickness 19 nm) was vapor-deposited as the second electrode layer, an organic EL element was formed on the substrate, and wound up . Thereafter, unwinding in an inert gas atmosphere, cutting each element, and enabling terminal connection from the first electrode layer (anode) and the second electrode layer (cathode) in a state of covering the light emitting part, respectively. And sealing with a glass sealing plate in which an annular convex portion having a height of 0.4 mm and a width of 2 mm is projected from the peripheral portion of a plate-like body having a thickness of 1.1 mm. An EL device was obtained. For bonding the sealing plate, a two-component room temperature curing type epoxy adhesive (trade name “Quick 5” manufactured by Konishi Co., Ltd.) is applied to the periphery of the sealing plate, and a desiccant ( A product name “moisture getter sheet” manufactured by Dynic Co., Ltd. was attached.

[Example 2]
The thickness d of the inner end of the opening of the first electrode layer forming shadow mask is 50 μm, and the angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side is 0. An organic EL device of this example was obtained in the same manner as in Example 1 except that the angle was set to 06 °.

[Example 3]
The thickness d of the inner end of the opening of the first electrode layer forming shadow mask is 25 μm, and the angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side is 0. An organic EL device of this example was obtained in the same manner as in Example 1 except that the angle was 11 °.

[Example 4]
The thickness d of the inner end of the opening of the first electrode layer forming shadow mask is 10 μm, and the angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side is 0. An organic EL device of this example was obtained in the same manner as in Example 1 except that the angle was set to 29 °.

[Example 5]
The thickness d of the inner end of the opening of the first electrode layer forming shadow mask is 5 μm, and the angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side is 0. An organic EL device of this example was obtained in the same manner as in Example 1 except that the angle was 57 °.

[Example 6]
As the first electrode layer, IZO was deposited at a rate of 1 Å / sec (0.1 nm / sec) by a vacuum deposition method so as to have a thickness of 100 nm, and the tapered surface of the first electrode layer and the first layer of the substrate were deposited. An organic EL device of this example was obtained in the same manner as in Example 1 except that the angle formed by the surface on the one electrode layer side was 0.05 °.

[Example 7]
In the same manner as in Example 6, except that ITO was deposited as a first electrode layer by a vacuum deposition method at a rate of 1 ｓｅｃ / sec (0.1 nm / sec) so as to have a thickness of 100 nm. An organic EL device was obtained. The angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side was 0.05 °.

[Comparative Example 1]
Using a lift-off resist (trade name “FNPR-L3” manufactured by Fuji Pharmaceutical Co., Ltd.) on a substrate, a pattern is formed by a photolithography method, and an Al layer having a thickness of 100 nm is formed by a sputtering method. An organic EL device of this comparative example was obtained in the same manner as in Example 1 except that the first electrode layer was formed by lift-off. The angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side was 3 °.

[Comparative Example 2]
An organic layer of this comparative example was formed in the same manner as in Example 1 except that an Al layer having a thickness of 100 nm was formed on the substrate by sputtering and the first electrode layer was formed by etching Al by photolithography. An EL device was obtained. The angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side was 30 °.

[Comparative Example 3]
The organic layer of this comparative example is the same as in Example 1 except that an IZO layer having a thickness of 100 nm is formed on the substrate by sputtering and the first electrode layer is formed by etching IZO by photolithography. An EL device was obtained. The angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side was 40 °.

[Comparative Example 4]
An organic layer of this comparative example was formed in the same manner as in Example 1 except that an ITO layer having a thickness of 100 nm was formed on the substrate by sputtering and the first electrode layer was formed by etching ITO by photolithography. An EL device was obtained. The angle formed by the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side was 80 °.

[Evaluation]
About the organic EL device obtained by each Example and the comparative example, the leak (element destruction rate) and the yield (number of dark spots) were measured and evaluated. The results are shown in Table 1.

  As shown in Table 1, in the organic EL devices obtained in the examples, the occurrence of leak (element breakdown rate) and dark spots is small, and the stress concentration is reduced by reducing the stress concentration at the end of each layer. It can be seen that peeling caused by concentration is suppressed. On the other hand, in Comparative Examples 1 to 4 in which the angle exceeds 1 °, destruction of the element was observed. A schematic cross-sectional view of the configuration of the organic EL device 700 of the comparative example is shown in FIG. In FIG. 7, the same parts as those in FIG. As illustrated, in the organic EL device 700 of the comparative example, it is conceivable that the organic EL layer 103 is thinned by increasing the angle θ at the end of the first electrode layer 702. It is considered that the destruction of the element is caused by the thinning of the organic EL layer in addition to peeling caused by stress concentration at the end of each layer. Moreover, the generation | occurrence | production of the dark spot increased compared with the organic EL device obtained in the Example. This includes a step of removing unnecessary portions of the photoresist layer and the first electrode layer once formed in the lift-off step and the photoetching step, so that the residue of the photoresist and the electrode forming material remains on the substrate, It is thought to be caused by the residue. Comparing Examples and Comparative Examples, it can be seen that according to the present invention, a highly reliable organic EL device in which leakage (element breakdown rate) and yield (number of dark spots) are suppressed is obtained.

  According to the method for producing an organic EL device of the present invention, it is possible to continuously produce an organic EL device having excellent reliability. The organic EL device of the present invention can be used in various fields such as a lighting device and a display device, and its application is not limited.

100, 700 Organic EL (electroluminescence) device 101 Substrate 102, 702 First electrode layer 102T Tapered surface 103 Organic EL (electroluminescence) layer 104 Second electrode layer 110, 210, 310, 410 Shadow mask 150 Film forming source

Claims (7)

A substrate supply process for supplying the substrate from the feed roll to the take-up roll;
A first electrode layer forming step of forming a first electrode layer on the substrate;
An organic EL layer forming step of forming an organic EL layer on the first electrode layer;
A second electrode layer forming step of forming a second electrode layer on the organic EL layer,
The first electrode layer is formed using a shadow mask, and at least a part of a side surface of the formed first electrode layer is a tapered surface inclined inward from the lower side to the upper side,
The method of manufacturing an organic EL device, wherein an angle formed between the tapered surface of the first electrode layer and the surface of the substrate on the first electrode layer side is 1 ° or less. 2. The method of manufacturing an organic EL device according to claim 1, wherein the shadow mask used in the first electrode layer forming step is a shadow mask in which a cross-sectional shape of an inner surface of the opening has a tapered shape or a multistage shape. . The shadow mask used in the first electrode layer forming step is a shadow mask in which an inner end portion of an opening has a constant thickness and the thickness is in a range of 5 to 500 μm. 3. A method for producing an organic EL device according to 1 or 2. 4. The organic EL device according to claim 1, wherein in the organic EL layer forming step, the organic EL layer is formed using a shadow mask for forming an organic EL layer. 5. Production method. 5. The organic according to claim 1, wherein in the second electrode layer forming step, the second electrode layer is formed using a shadow mask for forming a second electrode layer. Manufacturing method of EL device. As the substrate, a long strip-shaped substrate having a width in a range of 10 to 100 mm and a length in a range of 10 to 2000 m and a radius of curvature of 30 mm or more is used. The manufacturing method of the organic EL device as described in any one of Claims 1-5. An organic EL device,
On the flexible substrate, the first electrode layer, the organic EL layer and the second electrode layer are laminated in this order,
The first electrode layer has a tapered surface in which at least a part of the side surface is inclined inward from the lower side toward the upper side, and the tapered surface of the first electrode layer and the first electrode layer of the substrate An organic EL device characterized in that an angle formed with the side surface is 1 ° or less.

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