JP2007200645A - Organic electro-luminescence panel and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an organic EL (electro-luminescence) panel in which performance of an organic EL element is not deteriorated when a sealing member is adhered through adhesives for manufacturing the organic EL panel to be sealed by adhesion-sealing, and to provide the organic EL panel. <P>SOLUTION: The organic EL element has on a substrate a first electrode, an organic EL layer formed on the first electrode including at least one organic compound layer containing a light emitting layer, and a second electrode. These elements are adhesion-sealed with the sealing member through an adhesives layer. The second electrode has a multilayer configuration having at least two layers and it is formed in at least two steps of lamination. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing an organic electroluminescence panel (hereinafter also referred to as an organic EL panel) and an organic EL panel produced by this production method.

  In recent years, organic EL elements using organic substances have been promising for use as solid light-emitting inexpensive, large-area full-color display elements and writing light source arrays, and active research and development have been promoted. The organic EL element includes a first electrode (anode or cathode) formed on a substrate, an organic compound layer (single layer portion or multilayer portion) containing an organic light emitting material laminated thereon, that is, a light emitting layer, It is a thin film type element having a second electrode (cathode or anode) laminated on the light emitting layer. When a voltage is applied to such an organic EL element, electrons are injected from the cathode and holes are injected from the anode into the organic compound layer. It is known that light is obtained by releasing energy as light when the electrons and holes recombine in the light emitting layer and the energy level returns from the conduction band to the valence band.

  As described above, since the organic EL element is a thin film type element, when an organic EL panel in which one or a plurality of organic EL elements are formed on a substrate is used as a surface light source such as a backlight, a surface light source. It is possible to easily make a device equipped with In addition, when a display device is configured using an organic EL panel in which a predetermined number of organic EL elements as pixels are formed on a substrate as a display panel, the liquid crystal display device has high visibility and no viewing angle dependency. There are benefits that cannot be obtained.

  By the way, organic substances such as organic light emitting materials used in organic EL elements are weak against moisture and oxygen, and their performance deteriorates. Also, the characteristics of electrodes deteriorate rapidly in the atmosphere due to oxidation. In general, a sealing layer is provided as the uppermost layer.

  Many studies have been made on the organic EL element sealing method so far, and it is roughly classified into two methods, a casing type sealing method and a close contact type sealing method.

  The casing type sealing method is to seal an organic EL element by placing it in a case and blocking the outside, and filling the case with a predetermined gas or fluid for sealing together with the organic EL element. Is the method. The close-contact type sealing method is to seal by sealing the surface of an organic EL element formed on the substrate (behind the element when viewed from the substrate side) with an adhesive such as a glass plate. Is the method.

  In the case of the casing type sealing method, there is a problem that it cannot be made thin, requires a process for filling the case with a sealing gas or fluid, and is unsuitable for mass production. Therefore, a close-contact type sealing method has become the mainstream because it can be made thin, mass production is relatively easy, and a high sealing effect can be easily obtained.

As a sealing method of the adhesion type adhesive, for example, Japanese Unexamined 4-212284 discloses, GeO as described in JP-A-5-182759 Patent Publication, on the protective film made of an inorganic compound such as SiO _2, Light A method of fixing a glass substrate via a curable resin or the like is known. In JP 2001-307871 A, a barrier layer and a sealing film including a sealant layer made of a thermoplastic adhesive resin having a melt flow rate of 5 g / 10 min or more and 20 g / 10 min or less as defined in JIS K 7210 are tightly sealed. Organic EL elements are known.

However, in these methods, when the adhesive and the photo-curing resin are cured, the volume shrinks and thus a residual stress is generated. This residual stress is caused by the organic EL element to be sealed and the adhesive or photo-curing resin. Even if there is a film of GeO, SiO ₂ or the like between them, if the film thickness is as small as μm, it is transmitted to the organic EL. Since the residual stress is particularly strong at a portion having a small radius of curvature, the residual stress propagated to the organic EL element is concentrated on the end portion of the organic EL element. As a result, it is known that the electrode end of the element is crushed, and the anode and cathode come into contact with each other, causing a short circuit. This is a close-contact type sealing method using an adhesive and a photocurable resin. Measures for mitigating residual stress when an adhesive or a photocurable resin is cured have been studied. For example, a method is known in which a fluid stress relaxation layer is provided between an organic EL element and an adhesive, and a sealing material is fixed with the adhesive (see, for example, Patent Document 1). As an adhesive layer on the organic EL element, the adhesive shrinkage of the adhesive on the organic EL element side is set to two layers by using an adhesive smaller than the shrinkage ratio of the adhesive on the sealing material side to cure the adhesive. A method is known in which a sealing material is fixed with an adhesive so that the light emitting element is not affected by stress due to shrinkage (see, for example, Patent Document 2).

  The close-contact type sealing methods described in Patent Document 1 and Patent Document 2 enable relatively easy mass production and support a thin organic EL element having a high sealing effect. Damages to the light-emitting element due to (surface adhesion on the organic electroluminescence element) are occasionally observed, and the response is insufficient. In addition, the installation of a new functional layer such as a stress relaxation layer or a plurality of adhesives is one of the factors that complicates the process and does not increase the production efficiency.

From such a situation, when manufacturing an organic EL panel in which an organic electroluminescence element (hereinafter also referred to as an organic EL element) is sealed by an adhesion type sealing method in which a sealing material is fixed via an adhesive, an organic EL panel is manufactured. Development of an organic EL panel manufacturing method and an organic EL panel that do not cause deterioration in the performance of the element is desired. In the present invention, a state where the first electrode, the organic layer, and the second electrode are formed on the substrate is referred to as an organic EL element, and a state in which the first electrode, the organic layer, and the second electrode are tightly sealed with a sealing member is referred to as an organic EL panel.
Japanese Patent Laid-Open No. 8-124777 JP 2003-109750 A

  The present invention has been made in view of the above circumstances, and its purpose is to produce an organic EL element when manufacturing an organic EL panel sealed by an adhesion type sealing method in which a sealing material is fixed through an adhesive. It is providing the manufacturing method of an organic electroluminescent panel and an organic electroluminescent panel which do not produce the performance degradation of this.

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

  1. An organic electroluminescence element having a first electrode, an organic electroluminescence layer having at least one organic compound layer including a light emitting layer formed on the first electrode, and a second electrode is bonded to the substrate. In the method of manufacturing an organic electroluminescence panel having an adhesive sealing structure with a sealing member through an agent layer, the second electrode has a multilayer structure having at least two layers and is laminated and formed at least twice. A method for producing an organic electroluminescence panel, comprising:

  2. 2. The method of manufacturing an organic electroluminescence panel according to 1 above, wherein the formation of the second electrode is a vapor deposition method.

  3. When the second electrode is laminated and formed at least twice, the positional relationship between the substrate on which the second electrode is formed and the vapor deposition source of the material of the second electrode is different each time it is laminated, The manufacturing method of the organic electroluminescent panel of said 1 or 2 to do.

  4). 4. The method according to any one of the above items 1 to 3, wherein when the second electrode is stacked and formed at least twice, the deposition rate of each layer is changed (relative to the deposition rate of the lower layer). Manufacturing method of organic electroluminescence panel.

  5. The total thickness of the second electrode is 100 nm or more and 2 μm or less, and the thickness of each layer forming the second electrode is 10 nm or more. 5. Manufacturing method of organic electroluminescence panel.

  6). 5. The method of manufacturing an organic electroluminescence panel according to any one of 1 to 4, wherein at least one layer of the second electrode is formed of a material different from that of the other layers.

  7). 7. The method for manufacturing an organic electroluminescence panel according to 6, wherein the different material is an organic compound.

  8). 8. The organic electro of any one of 1 to 7, wherein the substrate and / or the sealing member is a flexible sealing member having a resin base material and a gas barrier layer. Manufacturing method of luminescence panel.

  9. 8. The method for producing an organic electroluminescence panel according to any one of 1 to 7, wherein the substrate and / or the sealing member is a glass plate.

  10. 8. The method for manufacturing an organic electroluminescence panel according to any one of 1 to 7, wherein the substrate and / or the sealing member is a metal sheet.

  11. 11. The method for producing an organic electroluminescence panel according to any one of 1 to 10, wherein the adhesive layer is provided on a sealing member.

  12 The method for producing an organic electroluminescence panel according to any one of 1 to 11, wherein the adhesive layer is provided on a light emitting portion of the organic electroluminescence element and on a peripheral surface of the light emitting portion.

  13. An organic electroluminescence element having a first electrode, an organic electroluminescence layer having at least one organic compound layer including a light emitting layer formed on the first electrode, and a second electrode is bonded to the substrate. An organic electroluminescence panel having an adhesive sealing structure with a sealing member through an agent layer, wherein the second electrode has a multilayer structure, and is formed by being laminated at least twice. Electroluminescence panel.

  14 14. The organic electroluminescence panel as set forth in 13, wherein the second electrode is formed by a vapor deposition method.

  15. 15. The organic electroluminescence panel as described in 13 or 14 above, wherein the total thickness of the second electrode is 100 nm or more and 2 μm or less, and the thickness of each layer forming the second electrode is 10 nm or more. .

  16. 16. The organic electroluminescence panel according to any one of 13 to 15, wherein at least one layer of the second electrode is formed of a material different from that of the other layers.

  17. 17. The organic electroluminescence panel as described in 16 above, wherein the different material is an organic compound.

  18. 18. The organic electro of any one of 13 to 17, wherein the substrate and / or the sealing member is a flexible sealing member having a resin base material and a gas barrier layer. Luminescence panel.

  19. 18. The organic electroluminescence panel according to any one of 13 to 17, wherein the substrate and / or the sealing member is a glass plate.

  20. 18. The organic electroluminescence panel according to any one of 13 to 17, wherein the substrate and / or the sealing member is a metal sheet.

  21. 21. The organic electroluminescence panel according to any one of 13 to 20, wherein the adhesive layer is provided on a sealing member.

  22. The organic electroluminescence panel according to any one of 13 to 21, wherein the adhesive layer is provided on a light emitting portion of the organic electroluminescence element and a peripheral surface of the light emitting portion.

  Provided are an organic EL panel manufacturing method and an organic EL panel that do not cause deterioration in performance of an organic EL element when an encapsulant is fixed with an adhesive in order to manufacture an organic EL panel sealed by a close-contact type sealing method It was possible to produce high-quality thin and light organic EL panels.

  The embodiment of the present invention will be described with reference to FIGS. 1 to 8, but the present invention is not limited to this.

  FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of an organic EL panel.

  In the figure, 1 indicates an organic EL panel. The organic EL panel 1 includes a first electrode 102, a hole transport layer (hole injection layer) 103, an organic compound layer (light emitting layer) 104, an electron injection layer 105, and a second electrode 106 on a substrate 101. And an adhesive layer 107 and a sealing member 108 in this order. In the organic EL panel shown in this figure, a hole injection layer (not shown) may be provided between the first electrode 102 and the hole transport layer 103. Further, an electron transport layer (not shown) may be provided between the second electrode 106, the organic compound layer (light emitting layer) 104, and the electron injection layer 105. It is preferable that the substrate 101 and / or the sealing member 108 is a flexible sealing member, a glass plate, or a metal sheet having a resin base material and a gas barrier layer.

  The layer configuration of the organic EL panel shown in this figure shows an example, but the following configurations can be cited as the layer configuration of other typical organic EL elements.

(1) Substrate / first electrode (anode) / light emitting layer / electron transport layer / second electrode (cathode) / sealing member (2) substrate / first electrode (anode) / hole transport layer / light emitting layer / positive Hole blocking layer / electron transport layer / second electrode (cathode) / sealing member (3) substrate / first electrode (anode) / hole transport layer (hole injection layer) / light emitting layer / hole blocking layer / electron Transport layer / cathode buffer layer (electron injection layer) / second electrode (cathode) / sealing member (4) substrate / first electrode (anode) / anode buffer layer (hole injection layer) / hole transport layer / light emission Layer / hole blocking layer / electron transport layer / cathode buffer layer (electron injection layer) / second electrode (cathode) / sealing member In the case of an organic EL panel, the first electrode (anode) 102 side is usually the observation side The first electrode (anode) 102 includes ITO (mixture of tin oxide and indium oxide), IZO (mixture of zinc oxide and indium oxide). ZnO, SnO ₂ , In ₂ O _{3 and the} like are known. Among them, the ITO electrode has a high light transmittance of 90% or more and a low sheet resistance value of 10Ω / □ or less, and is also used as a transparent electrode for liquid crystal displays and solar cells. Further, the IZO electrode has an advantage that a predetermined low resistance value can be obtained without heating the substrate at the time of formation, and the film surface is smoother than the ITO electrode.

  As shown in FIG. 1, the present invention cures an adhesive when manufacturing an organic EL panel in which at least one organic EL element formed on a substrate is closely sealed with an adhesive using a sealing member. The present invention relates to an organic EL panel manufacturing method and an organic EL panel manufactured so that a light emitting element is not affected by stress due to shrinkage.

  FIG. 2 is an enlarged schematic sectional view of a portion indicated by T in FIG.

  The sealing member 108 is a flexible sealing member having a resin base material 108a and a gas barrier layer 108b. The resin base material 108a may be a single body or a laminate, and can be appropriately selected as necessary. The gas barrier layer 108b may be a single body or a laminate, and can be appropriately selected as necessary. The sealing member 108 is bonded to the second electrode 106 and the peripheral surface of the second electrode via the adhesive layer 107.

  This figure shows a case where a flexible sealing member having a resin base material 108a and a gas barrier layer 108b is used as the sealing member 108, but other sealing members 108 include a glass plate, a metal, and the like. Sheets can be used.

  The second electrode 106 has a multilayer structure including at least a first layer 106a (a layer in contact with the adhesive layer 107) and a second layer 106b (a layer in contact with the electron injection layer 105). It is preferable that the second layer 106b is made of a different material. The material for forming the first layer 106a is preferably a metal or a metal compound, and the material for forming the second layer 106b is preferably a metal, a metal compound or an organic compound.

  Examples of the organic compound include organic compounds that form an organic electroluminescent layer. The organic compound forming the organic electroluminescent layer will be described later. The organic electroluminescence layer refers to a layer constituting the base 101 to the electron injection layer 105 in FIG.

As the metal or metal compound, a material having a small work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Suitable are a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, a lithium / aluminum mixture, aluminum and the like.

  The total thickness of the second electrode 106 is preferably 100 nm or more and 2 μm or less in consideration of adhesion, resistance value, film formation time, and the like, and the first layer 106 a and the second layer 106 b forming the second electrode 106. The thickness of each is preferably 10 nm or more in consideration of adhesion, resistance value, and the like.

The second electrode 106 is stacked by being formed by a vapor deposition method at least twice. The method of laminating the second electrode 106 will be described with reference to FIGS. 4 to 6. As shown in this figure, the following effects can be obtained by laminating and forming the second electrode at least twice. It is done.
1) Propagation of residual stress due to curing shrinkage of the adhesive is suppressed by the interface between the first layer and the second layer constituting the second electrode, and damage to the organic EL element is reduced.
2) Propagation of the bonding pressure stress of the sealing member is suppressed by the interface between the first layer and the second layer constituting the second electrode, and damage to the light emitting element is reduced.
3) Film formation defects (pinholes) can be suppressed by forming the second electrode in multiple times.
4) Since film formation defects (pinholes) are suppressed, invasion of outgas generated during curing of the adhesive is suppressed, and damage to the organic EL element is reduced.
5) Chemical corrosion (corrosion propagation) of the second electrode due to outgas or the like generated during curing of the adhesive is suppressed by the interface between the first layer and the second layer constituting the second electrode, and the light emitting device Damage is reduced.
Further, when the second electrode is laminated and formed at least twice, for example, the first layer 106a is formed of a metal or a metal compound, and the second layer 106b is formed of a metal, a metal compound, or an organic compound. The following effects can be given.
1) The interface between the first layer and the second layer constituting the second electrode is more emphasized, propagation of each damage is further suppressed, and damage to the organic EL element is reduced.
2) When the material of the second layer is an organic compound, by using the same material as that constituting the organic electroluminescence layer, the film forming apparatus (vapor phase deposition apparatus) can be shared, and the apparatus can be simplified and miniaturized. I can plan.

  FIG. 3 is a schematic view of a method for producing an organic EL element using a single substrate.

  In the figure, 2 indicates a manufacturing apparatus. Reference numeral 201 denotes a supply unit that supplies the single-wafer substrate 201a to the process. Reference numeral 202 denotes a substrate cleaning apparatus for cleaning the surface of the single-wafer substrate 201a in order to improve the vapor deposition property before the first electrode is vapor-deposited on the surface of the single-wafer substrate 201a supplied from the supply unit 201. . Reference numeral 203 denotes a first electrode forming vapor deposition apparatus for forming the first electrode a on the single wafer substrate 201a after the cleaning process. Reference numeral 204 denotes a hole transport layer forming vapor deposition apparatus for forming the hole transport layer b on the first electrode a of the single substrate 201a on which the first electrode a is formed. Reference numeral 205 denotes a light emitting layer forming vapor deposition apparatus for forming a light emitting layer c on the hole transport layer b of the single wafer substrate 201a on which the hole transport layer b is formed. Reference numeral 206 denotes an electron injection layer forming vapor deposition apparatus for forming an electron injection layer d on the light emitting layer c of the single substrate 201a on which the light emitting layer c is formed. Reference numeral 207a denotes a first electrode forming vapor deposition apparatus for a first layer for forming a first layer e of a second electrode having at least two layers on the electron injection layer d of the single wafer substrate 201a on which the electron injection layer d is formed. Reference numeral 207b denotes a second electrode forming vapor deposition apparatus for second layer for forming the second layer f on the first layer e of the second electrode. Reference numeral 208 denotes a recovery unit that recovers the organic EL element 4. The first electrode formation vapor deposition apparatus 203 to the second layer second electrode formation vapor deposition apparatus 207b have the same configuration. The configurations of the second electrode forming vapor deposition apparatus for the first layer and the second electrode forming vapor deposition apparatus for the second layer will be described in detail with reference to FIG.

  The deposition rate of the second electrode forming vapor deposition apparatus 207b for the second layer is in consideration of the suppression of film formation defects (pinholes) with respect to the deposition rate by the second electrode forming vapor deposition apparatus 207a for the first layer. However, it is preferable to change it. The change rate of the deposition rate is preferably 10% or more and 1000% or less in consideration of the film formation time and the temperature increase of the organic EL element due to film formation.

  In addition, since this figure shows the case where the second electrode is formed of two layers, the case where two vapor deposition apparatuses are provided is shown, but the number of vapor deposition apparatuses constitutes the second electrode. Depending on the number of layers to be arranged, it is possible to arrange them. Also in this case, it is preferable to change the deposition rate of each layer to 10% or more and 1000% or less with respect to the deposition rate of the lower layer. In addition, when the material constituting the second electrode is the same, it is possible to use the same vapor deposition apparatus without providing a vapor deposition apparatus for each layer. It is preferable in terms of

  FIG. 4 is a schematic view of the vapor deposition apparatus for forming the second electrode first layer for forming the first layer of the second electrode shown in FIG. FIG. 4A is an enlarged schematic diagram of the vapor deposition apparatus for forming the second electrode first layer shown in FIG. FIG. 4B is a schematic block diagram showing the relationship between each part and each means constituting the vapor deposition apparatus for forming the second electrode first layer.

  In the figure, reference numeral 207a denotes a vapor deposition apparatus for forming the second electrode first layer. The second electrode first layer forming vapor deposition apparatus 207a includes a vapor deposition chamber A, a substrate holding means B, a mask arranging means C, a raw material evaporation means D, and a control means E. Note that the raw material evaporation means D is placed outside the normal line of the edge of the deposited film formation region.

A1 indicates an exhaust port provided in the vapor deposition chamber A, and is connected to an exhaust means (not shown) which is a decompression means. The vacuum degree is set to the vapor deposition chamber A via the main valve A2. . The degree of vacuum in the vapor deposition chamber A can be appropriately set as necessary. A3 shows a vacuum degree meter which is a measuring means for measuring the vacuum degree of the vapor deposition chamber A. There is no limitation in particular as a vacuum measuring meter, For example, an ionization vacuum gauge and a Pirani vacuum gauge are mentioned. A4 indicates an inert gas inlet, and an inert gas such as N ₂ , Ar, Ne, or He is introduced as an atmospheric gas via a gas inlet valve A5 as necessary.

  The substrate holding means B has a substrate holding member B1, a temperature measuring means B2, and a temperature control mechanism B3, and the temperature can be controlled by the temperature control mechanism B3. A plurality of the substrates 201a (see FIG. 3) on which the electron injection layer d (see FIG. 3) held by the substrate holding member B1 is formed may be arranged, or arranged at any position of the substrate holding member B1. It is also possible. The substrate holding member B1 is not particularly limited as long as the planarity of the substrate can be held and held, and examples thereof include stainless steel and aluminum.

  The temperature measuring unit B2 measures the temperature of the substrate 201a (see FIG. 3) on which the electron injection layer d (see FIG. 3) disposed on the substrate holding member B1 is formed, and feeds back the result to the control unit E. It is like. By controlling the temperature control mechanism B3 that circulates the heat medium to the substrate holding member B1 according to the fed back information, the temperature of the substrate can be kept constant while the raw material is being deposited on the substrate. Yes. There is no limitation in particular as temperature measurement means B2, For example, a thermocouple, a temperature sensor, etc. are mentioned.

  B4 indicates a rotating means for rotating the substrate holding member B1. The rotating means is not particularly limited, and may be, for example, a rotary motor or a belt via a pulley. This figure shows the case of a rotary motor. The substrate holding member B1 may be rotated or fixed, but it is preferable to rotate in consideration of film formation uniformity.

  The mask placement means C includes a mask placement member C1, a temperature measurement means C4, and a temperature control mechanism C5, and the temperature control mechanism C5 can control the temperature. The temperature measuring means C4 is preferably the same as the temperature measuring means B2 arranged on the substrate holding member B1.

  C3 indicates a mask arranged on the mask arrangement member C1. The mask placement member C1 is not particularly limited as long as the planarity of the mask C3 can be maintained and placed, and examples thereof include stainless steel, aluminum, copper, and the like. The mask arrangement member C1 is attached to the substrate holding member B1.

  A6 shows a shielding plate of a raw material deposition control means for controlling the deposition of the raw material (the first layer forming raw material constituting the second electrode) on the substrate 201a formed up to the electron injection layer d (see FIG. 3). . The shielding plate A6 may be of any type, but as a function, the vapor deposition on the substrate 201a (see FIG. 3) on which the electron injection layer d (see FIG. 3) is formed by completely closing is completely performed. It is preferable to use a type that can be prevented. Note that the shielding plate shown in this figure is of an open / close type and can be controlled to open / close. A7 shows the drive means of shielding board A6.

  The temperature control mechanism B3 includes a medium temperature control means (not shown) that can be heated and cooled, and a medium that can be heated and cooled, the substrate holding member B1 of the substrate holding means B, and the mask arrangement member C1 of the mask arrangement means C. Circulation means (not shown) for circulation to the medium and circulation amount control means (not shown) for the circulation amount of the medium. By circulating the medium controlled to a predetermined temperature to the substrate holding member B1 and the mask arrangement member C3 by the temperature control mechanism B3, the layers up to the electron injection layer d (see FIG. 3) arranged on the substrate holding member B1 are formed. The substrate 201a (see FIG. 3) and the mask C3 arranged on the mask arrangement member C1 can be set to a predetermined temperature.

  Examples of the medium include synthetic organic heat medium oil. Examples of the medium temperature control means include a combination of a heater and a chiller. Examples of the circulation amount control means include a combination of a flow meter and a pump.

  The raw material evaporation means D is disposed in the lower part of the vapor deposition chamber A corresponding to the outside of the normal line of the edge of the deposited film formation region, and includes a raw material container D1 having heating means (not shown), Raw material temperature measuring means D3 for measuring the temperature of raw material (raw material for forming the first layer of the second electrode) D2, current supply part D4 for heating the raw material container D1, and opening of the opening D5 of the raw material container D1 And an aperture ratio control means lid D6 for controlling the ratio. The shape of the raw material container D1 is not particularly limited, and examples thereof include a line type and a spot type, and the number to be arranged can be appropriately selected depending on the size of the substrate 201a. The heating means for the material container D1 is not particularly limited, and examples thereof include a sputtering method and a resistance heating method. This figure shows the resistance heating method. The lid D6 may have any shape, and may not have a shape that covers all the mouths of the raw material evaporation means. The lid D6 is preferably a controllable movable lid in order to obtain a stable deposited film surface until the raw material D2 reaches a set temperature. D7 indicates a moving means for moving the lid D6.

  It is preferable to feed back the result of the raw material temperature measuring means D3 to the control means E, and perform control processing so as to maintain the set temperature by performing arithmetic processing on the set temperature previously input to the control means E. By combining these controls with the control of the movable lid D6, it is possible to perform control such that the lid is opened when the set temperature is reached.

  The raw material (raw material for forming the first layer of the second electrode) D2 in the raw material container D1 is a metal or a metal compound. The relationship between each part and each means constituting the second electrode forming vapor deposition apparatus 207a for the first layer will be described with reference to a schematic block diagram shown in FIG. Information on the temperature of the substrate 201a on which the electron injection layer d (see FIG. 3) held by the substrate holding means B measured by the substrate temperature measuring means B2 is input to the CPU of the control means E. The information input to the control means E performs a calculation process with the preset temperature previously input to the memory, and a temperature control mechanism B3 disposed in the substrate holding means B for circulating the heat medium adjusted to a predetermined temperature. It is possible to control the circulation amount of the medium and the temperature of the medium.

  Information on the temperature of the mask C3 held by the mask placement member C1 measured by the mask temperature measuring means C4 is input to the CPU of the control means E. The information input to the control means E performs a calculation process with the preset temperature input in advance in the memory, and a temperature control mechanism C5 that circulates the medium adjusted to a predetermined temperature disposed in the mask placement member C1. It is possible to control and control the circulation amount of the heat medium and the temperature of the heat medium. At this time, the circulation amount of the medium by the temperature control mechanism C5 and the temperature of the medium are set according to the temperature history of the substrate 201a (see FIG. 3) on which the electron injection layer d (see FIG. 3) is formed. It is a method to control.

  The result of the raw material D2 in the raw material container D1 measured by the raw material temperature measuring means D3 is fed back to the control means E, and the arithmetic processing is performed on the set temperature input in advance to the control means E, and the result is arranged in the raw material container D1 The temperature of the raw material D2 can be controlled to be constant by adjusting the current of the current supply unit D4 of the heating means (not shown). By maintaining the temperature of the raw material D2 at a specified temperature, a substantially constant temperature of the raw material is vapor-deposited on the substrate 201a (see FIG. 3) on which the electron injection layer d (see FIG. 3) has been formed. The formation of the first layer of two electrodes becomes possible.

  Information regarding the amount of the raw material D2 in the raw material container D1 converted according to time is input to the CPU of the control means E. The information input to the control means E performs the calculation process with the amount of the raw material D2 in the raw material container D1 previously input to the memory, operates the moving means (attached illustration) D7, and moves the lid D6 of the raw material container D1. It is possible to change the aperture ratio. For example, the opening ratio is 100% when the amount of the raw material D2 in the raw material container D1 is 100%, and 50% when the amount of the raw material D2 in the raw material container D1 is 50%.

  By keeping the deposition rate of the raw material D2 substantially constant, the top of the electron injection layer d (see FIG. 3) of the substrate 201a (see FIG. 3) formed up to the electron injection layer d (see FIG. 3) is formed. In addition, it is possible to form the first layer of the second electrode stably by depositing a certain material D2 in a vapor phase.

  Information on the temperature of the raw material D2 in the raw material container D1 measured by the raw material temperature measuring means D3 is input to the CPU of the control means E. The information input to the control means E performs a calculation process with the raw material deposition start temperature input in advance in the memory, and operates the driving means A7 to open and close the shielding plate A6. It is possible to prevent vapor deposition on the substrate 201a (see FIG. 3) on which even the unstable electron injection layer d (see FIG. 3) is formed. For example, after at least 30 seconds have elapsed since the difference between the raw material deposition start temperature inputted in advance and the temperature of the raw material D2 in the raw material container D1 measured by the raw material temperature measuring means D3 becomes −10 to + 10 ° C., the shielding plate It is preferable to open and close when it reaches 20 ° C or higher.

  The temperature measurement result of the raw material D2 is fed back to the temperature control mechanism B3 of the substrate 201a (see FIG. 3) on which the electron injection layer d (see FIG. 3) is formed and the temperature control mechanism C5 of the mask C3. Of course, it can be used to determine the heating start timing of the substrate 201a (see FIG. 3) on which the electron injection layer d (see FIG. 3) is formed and the mask C3.

  FIG. 5 is a schematic view of the second electrode second layer forming vapor deposition apparatus for forming the second layer of the second electrode shown in FIG.

  In the drawing, reference numeral 207b denotes a vapor deposition apparatus for forming a second electrode and a second layer.

  D 'indicates a raw material evaporation means. The raw material evaporation means D ′ measures the temperature of the raw material container D′ 1 having heating means (not shown) and the raw material (the second layer forming raw material for the second electrode) D′ 2 in the raw material container D′ 1. Raw material temperature measuring means D'3, a current supply part D'4 for heating the raw material container D'1, and an opening ratio control means for controlling the opening ratio of the opening D'5 of the raw material container D'1. And a lid D′ 6. D'7 indicates a moving means for moving the lid D'6. Other symbols are the same as those in FIG. The configuration and control of the raw material evaporation means D ′ are the same as those of the raw material evaporation means D shown in FIG. The raw material (raw material for forming the second layer of the second electrode) D′ 2 in the raw material container D′ 1 is preferably a metal, a metal compound, or the same organic compound as the organic compound constituting the electroluminescent layer. The metal and the metal compound are preferably the same metal and metal compound as the first layer forming raw material of the second electrode.

  The second electrode / second layer forming vapor deposition apparatus 207b has the same configuration except that the position of the material evaporation means D ′ is different from that of the second electrode / first layer forming vapor deposition apparatus 207a shown in FIG. Since the control method is the same, description of each part is omitted.

  The position of the material container D′ 1 of the material evaporation means D ′ is preferably different from the position of the material container D1 of the material evaporation means D of the vapor deposition apparatus 207a for forming the second electrode first layer shown in FIG. The positions of the raw material container D1 and the raw material container D′ 1 will be described with reference to FIG.

  6 is a schematic diagram showing the positional relationship between the raw material evaporation means shown in FIG. 4 and the raw material evaporation means shown in FIG.

  This figure shows the second electrode when the second electrode composed of the first layer and the second layer is formed on the electron injection layer d of the single wafer substrate 201a on which the electron injection layer d shown in FIG. 3 is formed. The positional relationship between the raw material container D1 of the first layer forming vapor deposition apparatus 207a and the raw material container D'1 of the second electrode second layer forming vapor deposition apparatus 207b is shown.

  In the present invention, when the second electrode is laminated and formed at least twice, the positional relationship between the substrate on which the second electrode is formed and the vapor deposition source of the material of the second electrode is different every time it is laminated. As shown in this figure, the positional relationship between the raw material container D1 and the raw material container D′ 1 is referred to.

  In the figure, O indicates the center point of the deposited film formation region. θ1 represents an angle formed by a line connecting the center of the raw material container D1 and the deposition center point O and a line connecting the center of the raw material container D′ 1 and the deposition center point O.

  The angle θ1 is preferably 1 ° to 120 ° in consideration of coverage (suppression of pinholes), deposited material efficiency, and the like.

When the second electrode is laminated and formed at least twice, the positional relationship between the raw material container D1 for forming the first layer and the raw material container D′ 1 for forming the second layer is as shown in FIG. The following effects can be given.
1) Suppression of film formation defects (pinholes) is further improved, propagation of each damage is further suppressed, and damage to the organic EL element is reduced.

  FIG. 7 is a schematic view of a manufacturing process of an organic EL element that is tightly sealed with a sealing member. The manufacturing process shown in the figure shows a case where an adhesive is disposed on the sealing member.

  In the figure, 3 indicates a manufacturing process. In the manufacturing process 3, the first supply process 301 of the sealing member 301a, the second supply process 302 of the organic EL element 302a, the adhesive arrangement process 303, the sealing member 301a and the organic EL element 302a are bonded to each other. It has the bonding process 304 and the collection | recovery process 305 bonded through. The organic EL element 302a is manufactured by a method using the vapor deposition apparatus shown in FIGS. 3 to 6, and the second electrode has a first layer made of metal, a metal compound, and a second layer made of metal, metal. It has a two-layer structure formed from a compound or an organic compound.

  The first supply step 301 is a supply robot 301c having a storage box 301b of a single-sealed sealing member 301a cut to the size of the organic EL element 302a and a suction plate 301c1 for taking out the sealing member 301a from the storage box 301b. have. The supply robot 301c can move in the vertical direction (arrow A direction in the figure), move in the horizontal direction (arrow B direction in the figure), and rotate (arrow C direction in the figure).

  The sealing member 301 a taken out from the storage box 301 b by the supply robot 301 c is placed on the placing table 307. The mounting table 307 preferably has suction means (not shown) for mounting and fixing the sealing member 301a. Further, it is possible to move in the X-axis and Y-axis directions and change the angle for alignment when the adhesive is placed on the sealing member 301a in the adhesive placement step 303. After the sealing member 301a is placed and fixed on the mounting table 307, it is sent to the adhesive placement step 303 by the moving means. The mounting table 307 can be sequentially moved from the first supply process 301 to the bonding process 304 along the guide rail 308 by a moving means (not shown). When the mounting table 307 is moved to each process by the moving means, each process is provided with a detection device (not illustrated) that detects an alignment mark (not illustrated) attached to the mounting table 307. It is controlled so as to stop at a specified position in the main body according to the information shown in the figure. The type of the detection device (not shown) is not particularly limited, and examples thereof include image recognition means using a CCD camera.

  The arrangement process 303 includes an adhesive arrangement device 303a. As the arrangement device 303a, the adhesive to be used may be a melt type or a sheet type, so that it can correspond to the type of the adhesive. For example, when the adhesive is a melt type, a photocuring and thermosetting sealing agent having a reactive vinyl group of an acrylic acid oligomer, a methacrylic acid oligomer, a moisture curing type sealing agent such as 2-cyanoacrylate, Examples thereof include epoxy-based heat and chemical curing type (two-component mixed) sealing agents, cationic curing type ultraviolet curing epoxy resin sealing agents, and the like. Among these, it is preferable to apply a cationic curing type ultraviolet curable epoxy resin sealant by screen printing in consideration of production efficiency and film thickness stability.

In the case of a sheet-like type, a sheet-like sealing agent and a thermoplastic resin are exemplified. The sheet-like sealant refers to a sealant that is non-flowable at room temperature (about 25 ° C.) and exhibits fluidity in the range of 50 ° C. to 100 ° C. when heated and is formed into a sheet shape. Examples of the sealant to be used include a photocurable resin mainly composed of a compound having an ethylenic double bond at the molecular end or side chain and a photopolymerization initiator. As the thermoplastic resin, a thermoplastic resin having a melt flow rate of JIS K 7210 specified in a range of 5 to 20 g / 10 min is preferable, and a thermoplastic resin of 6 to 15 g / 10 min or less is more preferably used. The thermoplastic resin is not particularly limited as long as it satisfies the above numerical values. For example, low-density polyethylene (LDPE), HDPE, which is a polymer film described in Toray Research Center, Inc., a new development of functional packaging materials. , Linear low density polyethylene (LLDPE), medium density polyethylene, unstretched polypropylene (CPP), OPP, ONy, PET, cellophane, polyvinyl alcohol (PVA), stretched vinylon (OV), ethylene-vinyl acetate copolymer (EVOH) ), Ethylene-propylene copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, vinylidene chloride (PVDC), and the like can be used. Among these thermoplastic resins, LDPE, LLDPE produced using LDPE, LLDPE and a metallocene catalyst, or a thermoplastic resin using a mixture of LDPE, LLDPE and HDPE films is preferably used. Various arrangement methods can be used, for example, wet lamination method, dry lamination method, hot melt lamination method, extrusion lamination method, and thermal lamination method. Thickness of adhesive to be arranged Is preferably 5 to 100 μm in consideration of curing reaction time, influence on the organic layer, moisture permeation from the edge, etc. for both the melt type and the sheet type.

  After arrange | positioning an adhesive agent to a sealing member, it moves to the bonding process 304 by the moving means (not shown) to the washing | cleaning process 306c in the state mounted in the mounting base.

  The second supply process 302 includes a supply robot 302c including a shelf-type storage box 302b for the organic EL elements 302a and two extraction arms 302c1 for extracting the organic EL elements 302a from the shelf-type storage box 302b. The take-out arm 302c1c moves in the horizontal direction (arrow D direction in the figure) and holds the organic EL element on the mounting table 309 in order to hold both ends of the organic EL element 302a stored and stored in the shelf-type storage box 302b. In order to place 202a and to take out the organic EL element 302a housed in the lower stage from the upper stage of the shelf type storage box 302b, it is possible to move in the vertical direction (arrow E direction in the figure). The organic EL element 302a taken out from the shelf-type storage box 302b by the supply robot 302c is placed on the placement table 309 and sent to the bonding step 304 by the moving means. The surface of the organic EL element 302a stored in the shelf-type storage box 302b (the surface on which the sealing material is bonded) is facing downward. The mounting table 309 holds the four end sides of the organic EL element 302a, and the center part is a cavity to avoid the surface of the organic EL element 302a (the surface of the second electrode) from damage due to contact.

The bonding step 304 includes a supply robot 304a, a bonding device 304b, and a curing processing device 304c. The supply robot 304a has the same mechanism and function as the supply robot 302c, and moves in the vertical direction (arrow F direction in the figure), moves in the horizontal direction (arrow G direction in the figure), and rotates (in the figure). Movement in the direction of arrow H) is possible. In the bonding step 304, the second electrode side of the organic EL element 302a mounted on the mounting table 309 is applied to the surface of the adhesive 301a1 of the sealing member 301a mounted on the mounting table 307 by the supply robot 304a. Overlap, and thereafter, pressure bonding is performed by the bonding apparatus 304b and processing is performed by the curing processing apparatus 304c, whereby the adhesion sealing of the organic EL element 302a by the sealing member 301a is completed, and an organic EL panel is manufactured. After the close sealing has been completed, it is recovered in the recovery step 305. Incidentally, the surface pressure at the time of bonding by the bonding apparatus 304b, the flexible sealing member bonded condensable, damage or the like of the organic EL element is ^{considered, 0.5 × 10 4 Pa~9.8 × 10} 4 Pa is preferred. It is preferable to perform bonding by the bonding apparatus 304b in a reduced pressure environment of 1 Pa to 30 kPa in consideration of air bubbles.

  The curing processing device 304c can be changed according to the type of adhesive used. For example, when the adhesive is a thermosetting type, it becomes a curing processing apparatus having a heating device, and when it is an ultraviolet curing type, it becomes a curing processing apparatus having an ultraviolet irradiation device. Depending on the curing time and tact of the selected adhesive, the curing processing device 304c can be used as a temporary curing device and a main curing device. In addition, although the case where the bonding apparatus 304b and the hardening processing apparatus 304c are isolate | separated is shown in this figure, it is also possible to give the function of the hardening processing apparatus 304c to the bonding apparatus 304b. From the viewpoint of life reduction due to deterioration of the organic EL element, it is important that the water concentration and the oxygen concentration are low until the above-described curing processing by the curing processing device 304c. It is preferable to carry out below.

  FIG. 8 is a schematic view of another manufacturing process of an organic EL element that is tightly sealed with a sealing member. The manufacturing process shown in this figure shows a case where an adhesive is disposed on the organic EL element.

  In the figure, 4 indicates a manufacturing process. In the manufacturing process 4, the second supply process 401 of the organic EL element 401a, the first supply process 402 of the sealing member 402a, the adhesive disposing process 403, the organic EL element 401a and the sealing member 402a are bonded to each other. It has the bonding process 404 and the collection | recovery process 405 which bond via. The organic EL element 401 a is manufactured by a method using the vapor deposition apparatus shown in FIGS. 3 to 6, and the second electrode has a first layer made of metal, a metal compound, and a second layer made of metal, metal. It has a two-layer structure in which a compound or an organic compound is formed.

  The second supply process 401 includes a supply robot 401c including a shelf-type storage box 401b for the organic EL elements 401a and two extraction arms 401c1 for extracting the organic EL elements 401a from the shelf-type storage box 401b. The take-out arm 401c1c moves in the horizontal direction (in the direction of arrow I in the figure) and holds the organic EL element on the mounting table 407 in order to hold both ends of the organic EL element 401a stored and stored in the shelf-type storage box 401b. In order to place 401a and to take out the organic EL element 401a housed in the lower stage from the upper stage of the shelf-type storage box 401b, it is possible to move in the vertical direction (direction of arrow J in the figure). The organic EL element 401a taken out from the shelf-type storage box 401b by the supply robot 401c is mounted and fixed on the mounting table 407 with the surface (the surface of the second electrode) facing upward, and then moved by a moving means (not shown). Along the guide rail 408, the adhesive is sent to the adhesive placement step 403 by the moving means. The surface of the organic EL element 401a stored in the shelf-type storage box 401b (the surface of the second electrode) is facing upward. The mounting table 407 has the same mechanism and function as the mounting table 307 shown in FIG.

  The placement step 403 includes an adhesive placement device 403a. The placement device 403a is the same as the placement device 303a shown in FIG. 7, and the same adhesive is used. After the adhesive is disposed on the organic EL element 401a, the adhesive is moved to the bonding step 404 along the moving guide rail 408 by a moving means (not shown) while being mounted on the mounting table.

  The first supply process 402 is a supply robot 402c including a storage box 402b of a single-sealed sealing member 402a cut to the size of the organic EL element 401a, and a suction plate 402c1 for taking out the sealing member 402a from the storage box 402b. have. The supply robot 402c has the same mechanism and function as the supply robot 301c shown in FIG. The sealing member 402a taken out from the storage box 402b by the supply robot 402c is placed on the placing table 409 and sent to the bonding step 404 by the moving means. The mounting table 409 preferably has the same structure as the mounting table 307 shown in FIG.

The bonding step 404 includes a supply robot 404a, a bonding device 404b, and a curing processing device 404c. The supply robot 404a has the same mechanism and function as the supply robot 304a shown in FIG. In the bonding step 404, the sealing member 402a mounted on the mounting table 409 is superimposed on the adhesive surface 401a1 of the organic EL element 401a mounted on the mounting table 407 by the supply robot 404a. Then, the adhesion | attachment sealing of the organic EL element 401a by the sealing member 402a is complete | finished by crimping | bonding with the bonding apparatus 404b and processing with the hardening processing apparatus 404c, and an organic EL panel is manufactured. After the close sealing is completed, it is recovered in the recovery step 405. Incidentally, the surface pressure at the time of bonding by the bonding apparatus 404b, the flexible sealing member bonded condensable, damage or the like of the organic EL element is ^{considered, 0.5 × 10 4 Pa~9.8 × 10} 4 Pa is preferred. It is preferable to perform bonding by the bonding apparatus 304b in a reduced pressure environment of 1 Pa to 30 kPa in consideration of air bubbles.

The curing processing device 404c can be changed according to the type of adhesive used. For example, when the adhesive is a thermosetting type, it becomes a curing processing apparatus having a heating device, and when it is an ultraviolet curing type, it becomes a curing processing apparatus having an ultraviolet irradiation device. Depending on the curing time and tact of the selected adhesive, the curing processing device 404c can be used as a temporary curing device and a main curing device. In addition, although the case where the bonding apparatus 404b and the hardening processing apparatus 404c are isolate | separated is shown in this figure, it is also possible to give the function of the hardening processing apparatus 404c to the bonding apparatus 404b. From the viewpoint of reducing the lifetime due to the deterioration of the organic EL element, it is important that the water concentration and the oxygen concentration are low until the above-described curing treatment by the curing treatment apparatus 404c. Preferably, the environment has a moisture concentration of 10 ppm or less and an oxygen concentration of 10 ppm or less. It is preferable to carry out below.
Using the manufacturing apparatus shown in FIG. 7 and FIG. 8, the organic EL element having the second electrode having at least two layers in the multilayer structure is sealed with a sealing member via an adhesive by the method shown in FIG. 3 to FIG. 6. The following effects can be obtained by stopping.
1) Propagation of residual stress due to curing shrinkage of the adhesive is suppressed by the interface between the first layer and the second layer constituting the second electrode, and damage to the light emitting element is reduced.
2) Propagation of the bonding pressure stress of the sealing member is suppressed by the interface between the first layer and the second layer constituting the second electrode, and damage to the light emitting element is reduced.
3) Film formation defects (pinholes) can be suppressed by forming the second electrode in multiple times.
4) Since film formation defects (pinholes) are suppressed, invasion of outgas generated when the adhesive is cured is suppressed, and damage to the light emitting element is reduced.
5) Cathode chemical corrosion (corrosion propagation) due to outgas generated during curing of the adhesive is suppressed by the interface between the first layer and the second layer constituting the second electrode, and damage to the light emitting element. Is reduced.
6) Damage to the light emitting element can be suppressed without installing a new functional layer such as a stress relaxation layer or an adhesive layer, and the process can be simplified and downsized.
7) Production efficiency is improved.

  Hereinafter, the materials forming the substrate, the gas barrier layer, the first electrode, the hole transport layer, the light emitting layer, the electron transport layer, the sealing layer and the like constituting the organic EL element according to the present invention will be described.

  Examples of the substrate according to the present invention include a single wafer substrate and a strip-shaped flexible substrate. Examples of the single-wafer substrate include a transparent glass plate, a metal sheet, and a sheet-like transparent resin film. The same glass as the sealing member can be used as the transparent glass plate. As the metal sheet, the same metal sheet as the sealing member can be used. Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones, poly Cycloolefin resins such as ether imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Apel (trade name, manufactured by Mitsui Chemicals) Can be mentioned. A transparent resin film is mentioned as a strip | belt-shaped flexible board | substrate, The same resin film as a single wafer board | substrate can be used.

When a transparent resin film is used as the substrate, a gas barrier film is preferably formed on the surface of the resin film as necessary. Examples of the gas barrier film include an inorganic film, an organic film, or a hybrid film of both. As a characteristic of the gas barrier film, the water vapor permeability is preferably 0.01 g / m ² · day · atm or less. Furthermore, a high barrier film having an oxygen permeability of 10 ⁻³ ml / m ² / day or less and a water vapor permeability of 10 ⁻⁵ g / m ² / day or less is preferable.

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

As the first electrode, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such an electrode substance include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ .ZnO) capable of forming a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when the pattern accuracy is not required (about 100 μm or more) ), A pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. When light emission is extracted from the anode, the transmittance is desirably greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

  A hole injection layer (anode buffer layer) may be present between the first electrode and the light emitting layer or the hole transport layer. The hole injection layer is a layer provided between the electrode and the organic layer in order to lower the driving voltage and improve the luminance of light emission. “The organic EL element and the forefront of industrialization (November 30, 1998, NTS) The details are described in the second volume, Chapter 2, “Electrode Materials” (pages 123 to 166) of “The Company”. Examples of the material used for the anode buffer layer (hole injection layer) include materials described in JP-A No. 2000-160328.

  The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers. The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound. Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two of those described in US Pat. No. 5,061,569. Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, it is preferable to use these materials because a light-emitting element with higher efficiency can be obtained.

  Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. This hole transport layer may have a single layer structure composed of one or more of the above materials. A hole transport layer having a high p property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like. It is preferable to use such a hole transport layer having a high p property because an organic EL element with lower power consumption can be produced.

  According to the present invention, the light emitting layer refers to a blue light emitting layer, a green light emitting layer, and a red light emitting layer. There is no restriction | limiting in particular as a lamination order in the case of laminating | stacking a light emitting layer, You may have a nonluminous intermediate | middle layer between each light emitting layer. In the light emitting layer according to the present invention, it is preferable that at least one blue light emitting layer is provided at a position closest to the anode among all the light emitting layers. Also, when four or more light emitting layers are provided, for example, blue light emitting layer / green light emitting layer / red light emitting layer / blue light emitting layer, blue light emitting layer / green light emitting layer / red light emitting layer / blue light emitting from the order close to the anode. Layered / green light emitting layer, blue light emitting layer / green light emitting layer / red light emitting layer / blue light emitting layer / green light emitting layer / red light emitting layer, etc. It is preferable for improving luminance stability. A white element can be manufactured by forming a light emitting layer in multiple layers.

  The total thickness of the light emitting layer is not particularly limited, but is usually selected in the range of 2 nm to 5 μm, preferably 2 to 200 nm in consideration of the uniformity of the film and the voltage required for light emission. Furthermore, it is preferable that it exists in the range of 10-20 nm. A film thickness of 20 nm or less is preferable because it has the effect of improving the stability of the emission color with respect to the driving current as well as the voltage surface. The film thickness of each light emitting layer is preferably selected in the range of 2 to 100 nm, and more preferably in the range of 2 to 20 nm. Although there is no restriction | limiting in particular about the film thickness relationship of each light emitting layer of blue, green, and red, It is preferable that the blue light emitting layer (the sum total when there are two or more layers) is the thickest among three light emitting layers.

  The light emitting layer includes at least three layers having different emission spectra, each having an emission maximum wavelength in the range of 430 to 480 nm, 510 to 550 nm, and 600 to 640 nm. If it is three or more layers, there will be no restriction | limiting in particular. When there are more than four layers, there may be a plurality of layers having the same emission spectrum. A layer having an emission maximum wavelength in the range of 430 to 480 nm is referred to as a blue light emitting layer, a layer in the range of 510 to 550 nm is referred to as a green light emitting layer, and a layer in the range of 600 to 640 nm is referred to as a red light emitting layer. Moreover, in the range which maintains the said maximum wavelength, you may mix a several luminescent compound in each light emitting layer. For example, the blue light emitting layer may be used by mixing a blue light emitting compound having a maximum wavelength of 430 to 480 nm and a green light emitting compound having the same wavelength of 510 to 550 nm.

  The organic light emitting material used as the material of the light emitting layer is (a) charge injection function, that is, holes can be injected from the anode or hole injection layer when an electric field is applied, and electrons are injected from the cathode or electron injection layer. (B) a transport function, that is, a function that moves injected holes and electrons by the force of an electric field, and (c) a light emission function, that is, a recombination field of electrons and holes. However, there is no particular limitation as long as it has the three functions of connecting these to light emission. For example, fluorescent whitening agents such as benzothiazole, benzimidazole, and benzoxazole, and styrylbenzene compounds can be used. Specific examples of the above-mentioned optical brightener include 2,5-bis (5,7-di-t-pentyl-2-benzoxazolyl) -1,3,4-thiadiazole in the benzoxazole series, 4 , 4′-bis (5,7-t-pentyl-2-benzoxazolyl) stilbene, 4,4′-bis [5,7-di- (2-methyl-2-butyl) -2-benzoxa Zoolyl] stilbene, 2,5-bis (5,7-di-t-pentyl-2-benzoxazolyl) thiophene, 2,5-bis [5-α, α-dimethylbenzyl-2-benzoxazoli Ru] thiophene, 2,5-bis [5,7-di- (2-methyl-2-butyl) -2-benzoxazolyl] -3,4-diphenylthiophene, 2,5-bis (5-methyl) -2-benzoxazolyl) thiophene, 4,4′-bis (2 -Benzoxazolyl) biphenyl, 5-methyl-2- [2- [4- (5-methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazole, 2- [2- (4-chlorophenyl) vinyl Naphtho [1,2-d] oxazole and the like. Examples of the benzothiazole type include 2,2 ′-(p-phenylenedivinylene) -bisbenzothiazole, and examples of the benzimidazole type include 2- [2- [4- (2-benzimidazolyl) phenyl] vinyl] benzimidazole. 2- [2- (4-carboxyphenyl) vinyl] benzimidazole and the like. In addition, other useful compounds are listed in Chemistry of Synthetic Soybean (1971), pages 628-637 and 640.

  Specific examples of the styrylbenzene compound include 1,4-bis (2-methylstyryl) benzene, 1,4-bis (3-methylstyryl) benzene, 1,4-bis (4-methylstyryl). ) Benzene, distyrylbenzene, 1,4-bis (2-ethylstyryl) benzene, 1,4-bis (3-methylstyryl) benzene, 1,4-bis (2-methylstyryl) -2-methylbenzene, 1,4-bis (2-methylstyryl) -2-ethylbenzene and the like can be mentioned.

  Further, in addition to the above-described optical brightener and styrylbenzene compound, for example, 12-phthaloperinone, 1,4-diphenyl-1,3-butadiene, 1,1,4,4-tetraphenyl-1,3- Butadiene, naphthalimide derivatives, perylene derivatives, oxadiazole derivatives, aldazine derivatives, pyrazirine derivatives, cyclopentadiene derivatives, pyrrolopyrrole derivatives, styrylamine derivatives, coumarin compounds, international publications WO 90/13148 and Appl. Phys. Lett. , Vol 58, 18, P1982 (1991), and aromatic dimethylidin compounds. Specific examples of the aromatic dimethylidin compounds include 1,4-phenylene dimethylidin, 4,4′-phenylene dimethylidin, 2,5-xylylene dimethylidin, 2,6-naphthylene dimethylidin, 1,4-biphenylenedimethylidin, 1,4-p-terephenylenedimethylidin, 4,4′-bis (2,2-di-t-butylphenylvinyl) biphenyl, 4,4′-bis (2 , 2-diphenylvinyl) biphenyl and the like, and derivatives thereof. Specific examples of the compound represented by the general formula (I) include bis (2-methyl-8-quinolinolato) (p-phenylphenolate) aluminum (III), bis (2-methyl-8-quinolinolato). ) (1-naphtholate) aluminum (III) and the like.

  In addition, a compound in which the above-described organic light-emitting material is used as a host and the host is doped with a strong fluorescent dye from blue to green, for example, coumarin-based or the same fluorescent dye as the host, is also suitable as the organic light-emitting material. When the above-described compound is used as the organic light-emitting material, blue to green light emission (the emission color varies depending on the type of dopant) can be obtained with high efficiency. Specific examples of the host that is the material of the compound include organic light-emitting materials having a distyrylarylene skeleton (particularly preferably, 4,4′-bis (2,2-diphenylvinyl) biphenyl). Specific examples of the dopant of the material are diphenylaminovinylarylene (particularly preferably, for example, N, N-diphenylaminobiphenylbenzene and 4,4′-bis [2- [4- (N, N-di- -P-tolyl) phenyl] vinyl] biphenyl).

  The light emitting layer preferably contains a known host compound and a known phosphorescent compound (also referred to as a phosphorescent compound) in order to increase the light emission efficiency of the light emitting layer. The host compound is a compound contained in the light-emitting layer, the mass ratio in the layer is 20% or more, and the phosphorescence quantum yield of phosphorescence emission is 0.1 at room temperature (25 ° C.). Is defined as less than a compound. The phosphorescence quantum yield is preferably less than 0.01. A plurality of host compounds may be used in combination. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. In addition, by using a plurality of phosphorescent compounds, it is possible to mix different light emission, thereby obtaining an arbitrary emission color. White light emission is possible by adjusting the kind of phosphorescent compound and the amount of doping, and can also be applied to illumination and backlight.

  As these host compounds, compounds having a hole transporting ability and an electron transporting ability, preventing emission light from being increased in wavelength, and having a high Tg (glass transition temperature) are preferable. Known host compounds include, for example, JP-A Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, and 2002-334786. Gazette, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227 2002-231453, 2003-3165, 2002-234888, 2003-27048, 2002-255934, 2002-260861, 2002-280183, Examples thereof include compounds described in 2002-299060, 2002-302516, 2002-305083, 2002-305084, 2002-308837 and the like.

  In the case of having a plurality of light emitting layers, it is preferable that 50% by mass or more of the host compound in each layer is the same compound because it is easy to obtain a uniform film property over the entire organic layer. It is more preferable that the light emission energy is 2.9 eV or more because it is advantageous in efficiently suppressing energy transfer from the dopant and obtaining high luminance. Phosphorescence emission energy means the peak energy of the 0-0 band of phosphorescence emission when the photoluminescence of a deposited film of 100 nm is measured on a substrate with a host compound.

  The host compound has a phosphorescence emission energy of 2.9 eV or more and a Tg of 90 ° C. or more in consideration of deterioration of the organic EL device over time (decrease in luminance and film properties), market needs as a light source, and the like. Preferably there is. That is, in order to satisfy both luminance and durability, it is preferable that phosphorescence emission energy is 2.9 eV or more and Tg is 90 ° C. or more. Tg is more preferably 100 ° C. or higher.

  A phosphorescent compound (phosphorescent compound) is a compound in which light emission from an excited triplet is observed, is a compound that emits phosphorescence at room temperature (25 ° C.), and has a phosphorescence quantum yield of 25. The compound is 0.01 or more at ° C. When used in combination with the host compound described above, an organic EL device with higher luminous efficiency can be obtained.

  The phosphorescent compound according to the present invention preferably has a phosphorescence quantum yield of 0.1 or more. The phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 version, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence quantum yield used in the present invention only needs to achieve the phosphorescence quantum yield in any solvent.

  There are two types of light emission of the phosphorescent compound in principle. One is the recombination of the carrier on the host compound to which the carrier is transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent compound. The energy transfer type, in which light emission from the phosphorescent compound is obtained by moving to the phosphorescent compound, and the other is that the phosphorescent compound becomes a carrier trap, resulting in recombination of the carriers on the phosphorescent compound and from the phosphorescent compound. Although it is a carrier trap type in which light emission can be obtained, in any case, it is a condition that the excited state energy of the phosphorescent compound is lower than the excited state energy of the host compound.

  The phosphorescent compound can be appropriately selected from known compounds used for the light emitting layer of the organic EL device. The phosphorescent compound is preferably a complex compound containing a group 8-10 metal in the periodic table of elements, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex compound), rare earth Of these, iridium compounds are the most preferred.

  In the present invention, the phosphorescence emission maximum wavelength of the phosphorescent compound is not particularly limited, and can be obtained in principle by selecting a central metal, a ligand, a ligand substituent, and the like. The emission wavelength can be changed.

  The light emission color of the organic EL device according to the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with a luminance meter CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates.

The white element referred to in the present invention means that the chromaticity in the CIE1931 color system at 1000 cd / m ² is X = 0.33 ± 0.07 when the front luminance at 2 ° C. viewing angle is measured by the above method. It is in the region of Y = 0.33 ± 0.07.

  The electron injection layer is made of a material having a function of transporting electrons and is included in the electron transport layer in a broad sense. The electron injection layer is a layer provided between the electrode and the organic layer for lowering the driving voltage and improving the luminance of the light emission. “Organic EL element and its forefront of industrialization (NST 30, November 30, 1998) Issue) ”, Chapter 2, Chapter 2,“ Electrode Materials ”(pages 123-166). The details of the electron injection layer (cathode buffer layer) are also described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

  In addition, as an electron transport material (also serving as a hole blocking material) used for the electron transport layer adjacent to the light emitting layer side, it is sufficient if it has a function of transmitting electrons injected from the cathode to the light emitting layer. As a material, any one of conventionally known compounds can be selected and used. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodisides. Examples include methane and anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivatives, thiadiazole derivatives in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and quinoxaline derivatives having a quinoxaline ring known as an electron-withdrawing group can also be used as the electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  Also, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum. Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. Distyrylpyrazine derivatives can also be used as electron transport materials, and inorganic semiconductors such as n-type-Si and n-type-SiC are also used as electron transport materials in the same manner as the hole injection layer and hole transport layer. I can do it. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  An electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like. It is preferable to use such an electron transport layer having a high n property because an element with lower power consumption can be manufactured.

As the second electrode, a material having a work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Suitable are a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, a lithium / aluminum mixture, aluminum and the like. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. In order to transmit the emitted light, if either one of the first electrode (anode) or the second electrode (cathode) of the organic EL element is transparent or translucent, the emission luminance is advantageously improved.

Moreover, after producing the metal with a thickness of 1 to 20 nm on the second electrode, the conductive transparent material mentioned in the description of the first electrode is produced thereon, so that a transparent or translucent second electrode ( A cathode) can be manufactured, and by applying this, an element in which both the first electrode (anode) and the second electrode (cathode) are transmissive can be manufactured.

  The external extraction efficiency at room temperature of light emission of the organic EL device according to the present invention is preferably 1% or more, more preferably 5% or more. Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor may be used in combination. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

  The organic EL device according to the present invention is preferably used in combination with the following method in order to efficiently extract light generated in the light emitting layer. The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1), and only about 15% to 20% of the light generated in the light emitting layer can be extracted. It is generally said that there is no. This is because the light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the element, or the transparent electrode or light emitting layer and the transparent substrate This is because the light undergoes total reflection between them, the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the side of the device.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435). A method for improving efficiency by providing a substrate with a light condensing property (JP-A-63-314795). A method of forming a reflective surface on the side surface of an element (Japanese Patent Laid-Open No. 1-220394). A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between a substrate and a light emitter (Japanese Patent Laid-Open No. 62-172691). A method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter (Japanese Patent Laid-Open No. 2001-202827). There is a method of forming a diffraction grating between any one of the substrate, the transparent electrode layer, and the light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951).

  When a low refractive index medium is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower. . Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less. The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate. The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method is generated from the light emitting layer by utilizing the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Of the light, the light that cannot go out due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (inside a transparent substrate or transparent electrode) , Trying to extract light out. The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. The light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated. At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium. The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

  Furthermore, the organic EL device according to the present invention can be processed to provide, for example, a structure on a microlens array on the light extraction side of the substrate in order to efficiently extract the light generated in the light emitting layer, or so-called collection. By combining with the light sheet, the luminance in the specific direction can be increased by condensing light in a specific direction, for example, the front direction with respect to the element light emitting surface. As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 μm to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, the substrate may be formed with a triangle stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded, and the pitch is randomly changed. The shape may be other shapes. Moreover, in order to control the light emission angle from a light emitting element, you may use a light-diffusion plate and a film together with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

When using a flexible sealing member for the sealing member concerning this invention, the flexible sealing member of the multilayer structure which has a resin layer and a gas barrier layer is preferable. As the characteristics of the gas barrier layer, the water vapor transmission rate is 0.01 g / m ² · in consideration of crystallization of the organic layer, generation of dark spots due to peeling of the second electrode, and extension of the lifetime of the organic EL element. It is preferably not more than day. The water vapor transmission rate is a value measured mainly by the MOCON method by a method based on the JIS K7129B method (1992).

The oxygen permeability is 0.01 ml / m ² · day · atm or less in consideration of generation of dark spots due to crystallization of the organic layer, peeling of the second electrode, etc., and extension of the lifetime of the organic EL element. It is preferable. The oxygen permeability is a value measured mainly by the MOCON method by a method based on JIS K7126B method (1987).

  The thickness of the flexible sealing member to be used is preferably 10 to 300 μm in consideration of handleability during production, tensile strength, stress cracking resistance of the gas barrier layer, and the like. Thickness shows the average value which measured 10 each in the vertical direction and the width direction using the micrometer.

  The amount of moisture measured according to ASTM D570 when sealing the flexible sealing member is the generation of dark spots due to crystallization of the organic layer due to moisture brought in by the flexible sealing member, peeling of the second electrode, etc. In consideration of extending the life of the organic EL element and the like, 1.0% or less is preferable.

  The resin base material 108a constituting the flexible sealing member according to the present invention is not particularly limited. For example, ethylene tetrafluoroethyl copolymer (ETFE), high density polyethylene (HDPE), stretched polypropylene (0PP) , Polystyrene (PS), polymethyl methacrylate (PMMA), stretched nylon (ONy), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyimide, polyether styrene (PES), etc. for general packaging The thermoplastic resin film material used for the film can be used. As these thermoplastic resin films, a multilayer film produced by coextrusion with a different film, a multilayer film produced by bonding with different stretching angles, etc. can be used as required. Further, it is naturally possible to combine the density and molecular weight distribution of the film used to obtain the required physical properties.

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

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

  The thickness of the glass plate to be used is preferably 0.1 mm to 2.0 mm in consideration of handling at the time of production, thinning of the panel, and the like. Thickness shows the average value which measured 10 each in the vertical direction and the width direction using the micrometer. The glass is not particularly limited, and examples thereof include silicate glass, alkali silicate glass, lead alkali glass, soda lime glass, potassium lime glass, barium glass, borosilicate glass, and phosphate glass.

  The thickness of the metal sheet to be used is preferably 20 μm to 2 mm in consideration of handling at the time of manufacture and thinning of the panel. Thickness shows the average value which measured 10 each in the vertical direction and the width direction using the micrometer. There is no limitation in particular as a metal, For example, metal materials, such as aluminum, copper, and nickel, alloy materials, such as stainless steel and an aluminum alloy, etc. are mentioned.

  Hereinafter, although an example is given and the concrete effect of the present invention is shown, the mode of the present invention is not limited to this.

Example 1
<Production of organic EL element>
With the manufacturing apparatus shown in FIG. 3, the size of one dot in which the first electrode, the hole transport layer, the light emitting layer, the electron transport layer, and the second electrode are formed in this order on the substrate is 2 mm × An organic EL element composed of 2 mm and a total of 70 dots (light emitting area) of 7 dots × 10 dots was prepared by the method described below.

(Preparation of substrate)
A soda-lime glass having a thickness of 1.1 mm, a width of 40 mm, and a length of 60 mm was prepared as a substrate. In addition, the surface of the soda-lime glass used was a silica-coated glass for protection from acid and alkali.

(Formation of the first electrode)
The prepared glass substrate was cleaned by irradiation at a distance of 12 mm with an irradiation intensity of 15 mW / cm ² using a low-pressure mercury lamp having a wavelength of 184.2 nm. Thereafter, using a vapor deposition apparatus, indium tin oxide (ITO) is used under a vacuum of 5 × 10 ⁻⁴ Pa, and the deposited film formation region (first electrode formation region) of the prepared glass substrate A 1-electrode forming vapor deposition apparatus was used to form 7 rows of patterned first electrodes having a width of 2 mm, a length of 58 mm, a spacing of 2 mm, a thickness of 150 nm.

(Formation of hole transport layer)
A glass substrate on which the first electrode is formed is used, and N is used as a hole transport layer forming material on the first electrode except for an end portion for forming an external extraction electrode of the first electrode formed on the glass substrate. , N′-diphenyl-N, N′-m-tolyl 4,4′-diamino-1,1′-biphenyl (hereinafter referred to as TPD) and hole transport under a vacuum of 5 × 10 ⁻⁴ Pa A hole transport layer was formed by vapor deposition (vapor deposition) using a layer forming vapor deposition apparatus. The thickness of the hole transport layer was 50 nm.

(Formation of light emitting layer)
Using a glass substrate on which a hole transport layer is formed, using Alq ₃ as a light emitting layer forming material on the hole transport layer, and forming a light emitting layer by vapor deposition under a vacuum of 5 × 10 ⁻⁴ Pa The light emitting layer was formed by vapor deposition with an apparatus. The thickness of the light emitting layer was 50 nm.

(Formation of electron injection layer)
Using a glass substrate on which a light emitting layer is formed, using LiF as a material for forming an electron injection layer in a region where a hole transport layer including the light emitting layer is formed, under a vacuum of 5 × 10 ⁻⁴ Pa LiF was vapor-deposited with an electron injection layer forming vapor deposition apparatus to form an electron injection layer. The thickness of the electron injection layer was 0.5 nm.

(Formation of second electrode)
A glass substrate on which an electron injection layer is formed is used, and as shown in Table 1, a second electrode composed of multiple layers is formed on the electron injection layer with a second electrode formation vapor deposition apparatus at 5 × 10 ⁻⁴ Pa. The organic EL element No. 1 was deposited and formed under vacuum. 1-1 to 1-13. The formed second electrode had a width of 2 mm, a length of 38 mm, an interval of 2 mm, a thickness of 150 nm, and a 10-row pattern.

  Each organic EL element No. Table 2 shows materials used for the second electrodes 1-1 to 1-13.

  Each organic EL element No. Table 3 shows the deposition rate of each layer of the second electrode 1-1 to 1-13, the amount of change in the deposition rate, and the positional relationship of the raw material containers in the vapor deposition apparatus. The amount of change in the deposition rate indicates the rate of change (%) relative to the lower layer rate.

(Preparation of flexible sealing member)
A flexible sealing member having a configuration of PET 120 μm / SiO 30 nm / SiN 100 nm was prepared. The water vapor permeability of the prepared flexible sealing member measured by the MOCON method mainly in accordance with JIS K7129B method (1992) was 0.01 g / m ² · day. The oxygen permeability measured mainly by the MOCON method by a method based on JIS K7126B method (1987) was 0.01 ml / m ² · day · atm.

<Adhesive sealing of organic EL element by flexible sealing member>
(Arrangement of adhesive on flexible sealing member)
Using the manufacturing process shown in FIG. 7, an ultraviolet curable liquid sealant (manufactured by ThreeBond 3124C, manufactured by Three Bond Co., Ltd.) was used, and the film was placed at a thickness of 50 μm by screen printing using an adhesive placement device.

<Bonding with organic EL elements>
Each prepared organic EL element No. 1-1 to 1-13 are bonded to the prepared flexible sealing member in the bonding step of the manufacturing apparatus shown in FIG. 3, and the pressing force is 0.1 in a reduced pressure environment of 1 × 10 ⁻² Pa. An organic EL panel that was pressure-bonded at 1 MPa and cured and sealed tightly by irradiation with ultraviolet light having a main wavelength of 365 nm from the flexible sealing member side (90 msec at 100 mW / cm ² ) was prepared. 101-113.
(Evaluation)
Each prepared sample No. Table 4 shows the results of tests 101 to 113 and the occurrence rate of dark spots (spot-shaped non-light-emitting portions) tested by the following test method and evaluated according to the evaluation rank shown below.

Test method for the rate of occurrence of dark spots (spot-shaped non-light-emitting parts) Using a constant voltage power supply, 5V DC is applied to one dot of the organic EL panel, and the presence or absence of dark spots is visually observed using a loupe (magnification 8 times). Observed. Measurement was performed for all 70 dots (light emitting area), and the dark spot generation ratio was calculated from the number of dots where dark spots were generated.

Evaluation rank of occurrence ratio of dark spots (spot-like non-light-emitting portions) A: Occurrence rate 0% (no occurrence of dark spots)
○: Occurrence rate 1% or more and less than 5% △: Occurrence rate 5% or more and less than 10% ×: Occurrence rate 10% or more

  The effectiveness of the present invention was confirmed.

Example 2
<Adhesive sealing of organic EL element by flexible sealing member>
With the manufacturing apparatus shown in FIG. When forming the first layer and the second layer of the second electrode after forming the electron injection layer using the same material as 1-2, the second electrode forming vapor deposition apparatus for the first layer shown in FIG. The relationship between the position of the raw material container and the position of the raw material container of the second electrode forming vapor deposition apparatus for the second layer shown in FIG. 5 was changed as shown in Table 5 to produce an organic EL device. Thereafter, the same flexible sealing member as in Example 1 was used, the same adhesive as in Example 1 was placed under the same conditions, and then bonded to each organic EL element produced under the same conditions, and the adhesive sealing was performed. An organic EL panel was prepared and sample No. 201-205.

  The positional relationship between the first layer raw material container and the second layer raw material container includes a line connecting the center of the first layer raw material container and the deposition center point, and the center of the second raw material container and the deposition center point. Indicates the angle formed by the line connecting.

The thickness of the first layer was 0.15 μm, and the thickness of the second layer was 0.15 μm. The degree of vacuum during deposition of the first layer was 5 × 10 ⁻⁴ Pa, and the deposition rate was 0.2 nm / sec. The degree of vacuum during the deposition of the second layer was 5 × 10 ⁻⁴ Pa, the deposition rate was 0.2 nm / sec, and the amount of change in the deposition rate relative to the deposition rate of the first layer was 0%.
(Evaluation)
Each prepared sample No. Table 5 shows the results of evaluating the occurrence ratio of dark spots (spot-like non-light emitting portions) in 201 to 205 by the same test method as in Example 1 and evaluating according to the same evaluation rank as in Example 1.

  Sample No. 205 showed a good result in the evaluation rank of the dark spot generation ratio, but other sample Nos. Compared with 201-204, the tendency for the amount of the material used for film-forming to increase (the tendency for deposition material efficiency to become low) was recognized. The effectiveness of the present invention was confirmed.

Example 3
<Adhesive sealing of organic EL element by flexible sealing member>
With the manufacturing apparatus shown in FIG. After forming up to the electron injection layer using the same material as 1-2, when forming the first layer and the second layer of the second electrode, the second electrode forming vapor deposition for the first layer shown in FIG. The organic EL device was manufactured by changing the deposition rate of the second layer by the second electrode forming vapor deposition apparatus for the second layer shown in FIG. 5 as shown in Table 6 with respect to the deposition speed of the first layer by the apparatus. . Thereafter, the same flexible sealing member as in Example 1 was used, the same adhesive as in Example 1 was placed under the same conditions, and then bonded to each organic EL element produced under the same conditions, and the adhesive sealing was performed. An organic EL device was prepared and sample No. 301 to 308.

Both the position of the material container of the second electrode forming vapor deposition apparatus for the first layer and the position of the material container of the second electrode forming vapor deposition apparatus for the first layer are both on the normal line (center position) of the deposition region center point. The positional relationship between the first layer raw material container and the second layer raw material container was 0 °. The thickness of the first layer was 0.15 μm, and the thickness of the second layer was 0.15 μm.
(Evaluation)
Each prepared sample No. Table 6 shows the results of evaluating the occurrence ratio of dark spots (spot-shaped non-light emitting portions) 301 to 308 by the same test method as in Example 1 and evaluating according to the same evaluation rank as in Example 1.

  Sample No. 308 showed good results in the evaluation rank of the dark spot generation ratio, but it was recognized that the luminance of light emission decreased due to the temperature increase of the organic EL element during the deposition of the second electrode. The effectiveness of the present invention was confirmed.

Example 4
<Adhesive sealing of organic EL element by flexible sealing member>
With the manufacturing apparatus shown in FIG. Table 7 shows the thicknesses of the first layer and the second layer when forming the first layer and the second layer of the second electrode after forming the electron injection layer using the same material as 1-2. In this manner, an organic EL element was produced. Thereafter, the same flexible sealing member as in Example 1 was used, the same adhesive as in Example 1 was placed under the same conditions, and then bonded to each organic EL element produced under the same conditions, and the adhesive sealing was performed. An organic EL element manufactured as described above was prepared. 401 to 414.

  Both the position of the material container of the second electrode forming vapor deposition apparatus for the first layer and the position of the material container of the second electrode forming vapor deposition apparatus for the first layer are both on the normal line (center position) of the deposition region center point. The positional relationship between the first layer raw material container and the second layer raw material container was 0 °.

The degree of vacuum during deposition of the first layer and the second layer was 5 × 10 ⁻⁴ Pa, the deposition rate was 0.2 nm / sec, and the amount of change in the deposition rate was 0%.
(Evaluation)
Each prepared sample No. Table 7 shows the results of the evaluation of the occurrence ratio of dark spots (spot-shaped non-light-emitting portions) 401 to 414 by the same test method as in Example 1 and according to the same evaluation rank as in Example 1.

  The effectiveness of the present invention was confirmed.

It is a schematic sectional drawing which shows an example of the laminated constitution of an organic EL element. It is an expansion schematic sectional drawing of the part shown by T of FIG. It is a schematic diagram of the manufacturing method of the organic EL element which uses a single substrate. It is the schematic of the vapor deposition apparatus for 2nd electrode 1st layer formation for the 1st layer formation of the 2nd electrode shown by FIG. It is the schematic of the vapor deposition apparatus for 2nd electrode 2nd layer formation for 2nd layer formation of the 2nd electrode shown by FIG. It is a schematic diagram which shows the positional relationship of the raw material evaporation means shown in FIG. 4, and the raw material evaporation means shown in FIG. It is a schematic diagram of the manufacturing process of the organic EL element tightly sealed by the sealing member. It is a schematic diagram of the other manufacturing process of the organic EL element tightly sealed by the sealing member.

Explanation of symbols

1 Organic EL Panel 101 Substrate 102 First Electrode 103 Hole Transport Layer (Hole Injection Layer)
104 Organic compound layer (light emitting layer)
DESCRIPTION OF SYMBOLS 105 Electron injection layer 106 2nd electrode 106a 1st layer 106b 2nd layer 107 Adhesive layer 108, 301a Sealing member 2 Manufacturing apparatus 207a 2nd electrode formation vapor deposition apparatus for 1st layers 207b 2nd electrode for 2nd layers Formation vapor deposition apparatus D1, D'1 Raw material container D2 First layer forming raw material D'2 Second layer forming raw material 3, 4 Manufacturing process 301, 402 First supply process 302, 401 Second supply process 302a, 401a Organic EL elements 303, 403 Arrangement process 304, 404 Bonding process 305, 405 Recovery process

Claims (22)

An organic electroluminescence element having a first electrode, an organic electroluminescence layer having at least one organic compound layer including a light emitting layer formed on the first electrode, and a second electrode is bonded to the substrate. In the method of manufacturing an organic electroluminescence panel having an adhesive sealing structure with a sealing member through an agent layer, the second electrode has a multilayer structure having at least two layers and is laminated and formed at least twice. A method for producing an organic electroluminescence panel, comprising: 2. The method of manufacturing an organic electroluminescence panel according to claim 1, wherein the formation of the second electrode is a vapor deposition method. When the second electrode is laminated and formed at least twice, the positional relationship between the substrate on which the second electrode is formed and the vapor deposition source of the material of the second electrode is different each time it is laminated, The manufacturing method of the organic electroluminescent panel of Claim 1 or 2. The deposition rate of each layer is changed (relative to the deposition rate of the lower layer) when the second electrode is laminated and formed at least twice. Manufacturing method of organic electroluminescence panel. The total thickness of the second electrode is 100 nm or more and 2 μm or less, and the thickness of each layer forming the second electrode is 10 nm or more. The manufacturing method of the organic electroluminescent panel of description. 5. The method of manufacturing an organic electroluminescence panel according to claim 1, wherein at least one layer of the second electrode is made of a material different from that of the other layers. The method of manufacturing an organic electroluminescence panel according to claim 6, wherein the different material is an organic compound. The organic material according to any one of claims 1 to 7, wherein the substrate and / or the sealing member is a flexible sealing member having a resin base material and a gas barrier layer. Manufacturing method of electroluminescence panel. The method for manufacturing an organic electroluminescence panel according to any one of claims 1 to 7, wherein the substrate and / or the sealing member is a glass plate. The method for manufacturing an organic electroluminescence panel according to claim 1, wherein the substrate and / or the sealing member is a metal sheet. The method of manufacturing an organic electroluminescence panel according to claim 1, wherein the adhesive layer is provided on a sealing member. The method for producing an organic electroluminescence panel according to any one of claims 1 to 11, wherein the adhesive layer is provided on a light emitting portion of an organic electroluminescence element and a peripheral surface of the light emitting portion. . An organic electroluminescence element having a first electrode, an organic electroluminescence layer having at least one organic compound layer including a light emitting layer formed on the first electrode, and a second electrode is bonded to the substrate. An organic electroluminescence panel having an adhesive sealing structure with a sealing member through an agent layer, wherein the second electrode has a multilayer structure, and is formed by being laminated at least twice. Electroluminescence panel. 14. The organic electroluminescence panel according to claim 13, wherein the second electrode is formed by a vapor deposition method. 15. The organic electroluminescence according to claim 13, wherein the total thickness of the second electrode is 100 nm or more and 2 μm or less, and the thickness of each layer forming the second electrode is 10 nm or more. panel. The organic electroluminescence panel according to any one of claims 13 to 15, wherein at least one layer of the second electrode is formed of a material different from that of the other layers. The organic electroluminescence panel according to claim 16, wherein the different material is an organic compound. The organic substrate according to any one of claims 13 to 17, wherein the substrate and / or the sealing member is a flexible sealing member having a resin base material and a gas barrier layer. Electroluminescence panel. The organic electroluminescence panel according to any one of claims 13 to 17, wherein the substrate and / or the sealing member is a glass plate. The organic electroluminescence panel according to any one of claims 13 to 17, wherein the substrate and / or the sealing member is a metal sheet. The organic electroluminescence panel according to any one of claims 13 to 20, wherein the adhesive layer is provided on a sealing member. The organic electroluminescence panel according to any one of claims 13 to 21, wherein the adhesive layer is provided on a light emitting portion of the organic electroluminescence element and on a peripheral surface of the light emitting portion.

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