JP2010160906A - Organic electroluminescent apparatus, method for manufacturing the same, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL which can more reliably prevent an organic EL element from degrading due to water or other components, to provide a method for manufacturing an organic EL apparatus, and to provide an electronic device including the organic EL apparatus. <P>SOLUTION: In the organic EL apparatus 100 and the method for manufacturing the same, a photocurable resin-buffering film 621 in a lower layer side and a thermosetting resin-buffering film 622 in an upper layer side are layered between a first inorganic sealing film 61 and a second inorganic sealing film 63. Since the thermosetting resin-buffering film 622 is excellent in ability for flattening, any crack or pinhole does not occur in the second inorganic sealing film 63. In addition, since there is no process of heating when the photocurable resin-buffering film 621 is formed, no organic constituent of photocurable resin enters through the crack or pinhole of the first inorganic sealing film 61. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence, a method for producing an organic electroluminescence device, and an electronic apparatus including the organic electroluminescence device.

  The organic electroluminescence device includes an organic electroluminescence element in which a first electrode layer, an organic functional layer, and a second electrode layer are stacked on an element substrate, and emits light for the purpose of enhancing the electron injection effect at a low voltage. In some cases, an electron injection layer mainly composed of alkali metal or alkaline earth metal is disposed between the functional layer and the cathode layer. Since the organic functional layer, the cathode layer, and the electron injection layer used in such an organic electroluminescence element are very active, they easily react with moisture and oxygen gas existing in the atmosphere and are easily deteriorated. When such deterioration occurs, a non-light-emitting portion called a dark spot is generated.

Therefore, the surface of the element substrate on which the organic electroluminescent element is formed is covered with a thermosetting or photocurable organic buffer film, and then covered with an inorganic sealing film made of a silicon nitride film or a silicon oxynitride film. A configuration has been proposed (see Patent Document 1).
Japanese Patent Laid-Open No. 2005-85488

  However, even when the sealing structure described in Patent Document 1 is adopted, there is a problem that the organic electroluminescence element cannot be completely prevented from being deteriorated by moisture or oxygen gas.

  Here, the inventor of the present application adds an inorganic sealing film made of a silicon nitride film or a silicon oxynitride film to the lower layer side of the organic buffer film, so that the organic electroluminescence element is deteriorated by moisture or oxygen gas. It is proposed to prevent it reliably. However, as a result of various studies by the inventor of the present application, there is a problem that even when such a three-layer structure is adopted, an organic electroluminescence device that does not reach the target life is generated.

  In view of the above problems, an object of the present invention is to provide an organic electroluminescence device capable of more reliably preventing the organic electroluminescence element from being deteriorated by contact with moisture and other components, and a method for producing an organic electroluminescence device And an electronic device including the organic electroluminescence device.

  In order to solve the above problems, the inventor of the present application added an inorganic sealing film made of a silicon nitride film or a silicon oxynitride film on the lower layer side of the organic buffer film, but the organic electroluminescence element does not contain moisture or oxygen gas. After investigating the reason why it was not possible to reliably prevent deterioration, the following knowledge was obtained. First, in the configuration in which the inorganic sealing layer on the lower layer side, the photocurable organic buffer film, and the inorganic sealing layer on the upper layer side are stacked, the planarization ability of the photocurable organic buffer film is low. We obtained new knowledge that cracks and pinholes occurred in the inorganic sealing layer, and that moisture and oxygen penetrated from the cracks and pinholes. In addition, when a thermosetting organic buffer film is used instead of the photocurable organic buffer film, the organic component contained in the thermosetting resin is inorganicly sealed on the lower layer side when heating for curing is performed. New knowledge was obtained that the organic functional layer was dissolved by intrusion from cracks and pinholes in the layer.

  The present invention has been achieved based on the above findings, and in an organic electroluminescence device to which the present invention is applied, a first electrode layer, an organic functional layer, and a second electrode layer are laminated on an element substrate. An organic electroluminescent element, a first inorganic sealing film covering the organic electroluminescent element, a photocurable resin buffer film covering the first inorganic sealing film, and a thermosetting covering the photocurable resin buffer film It has a resin buffer film and a second inorganic sealing film that covers the thermosetting resin buffer film.

  Moreover, the manufacturing method of the organic electroluminescent apparatus to which this invention is applied is the organic electroluminescent element which laminates | stacks a 1st electrode layer, an organic functional layer, and a 2nd electrode layer on an element substrate, and forms an organic electroluminescent element. After applying the photocurable resin so as to cover the forming step, the first inorganic sealing film forming step for forming the first inorganic sealing film covering the organic electroluminescent element, and the first inorganic sealing film, A photocurable resin buffer film forming step for forming a photocurable resin buffer film by curing, and after applying a thermosetting resin so as to cover the photocurable resin buffer film, the photocurable resin buffer film is cured and thermoset resin buffered It has a thermosetting resin buffer film forming step for forming a film, and a second inorganic sealing film forming step for forming a second inorganic sealing film covering the thermosetting resin buffer film.

  In the organic electroluminescence device to which the present invention is applied and the manufacturing method thereof, between the first inorganic sealing film and the second inorganic sealing film, the lower-layer side photocurable resin buffer film and the upper-layer side thermosetting are provided. A resin buffer film is laminated. Among the resins constituting the buffer film, the thermosetting resin has an excellent ability to flatten the surface because the viscosity is reduced during heating. For this reason, since the second inorganic sealing film is formed on the surface flattened by the thermosetting resin buffer film, no cracks or pinholes are generated. Therefore, it is possible to reliably prevent moisture and oxygen from entering from the second inorganic sealing layer on the upper layer side. Moreover, since the photocurable resin which comprises the organic buffer film of a lower layer does not have the process of heating, a viscosity does not fall until it hardens | cures. For this reason, the photocurable resin has a lower ability to flatten the surface than the thermosetting resin, but the organic component used for the photocurable resin was formed in the first inorganic sealing layer on the lower layer side. No intrusion through cracks or pinholes. Therefore, according to the present invention, it is possible to prevent the organic electroluminescent element from being deteriorated by moisture or oxygen gas without causing deterioration of the organic electroluminescent element due to the organic component used in the organic buffer film. it can. Therefore, the reliability of the organic electroluminescence device can be greatly improved.

  In the method for manufacturing an organic electroluminescence device according to the present invention, the photocurable resin preferably has a viscosity of 1 Pa · s or more until it is cured after being applied. With such a viscosity, even if cracks or pinholes are generated in the first inorganic sealing layer on the lower layer side, the organic component contained in the photocurable resin enters from the cracks or pinholes in the first inorganic sealing layer. There is nothing to do.

  Here, from the viewpoint of preventing the photocurable resin buffer film from becoming too thick, the viscosity of the photocurable resin is preferably 8 Pa · s or less at the time of application. Therefore, in this invention, it is preferable that the viscosity of photocurable resin is 1-8 Pa.s at the time of application | coating. Also, from the viewpoint of preventing the thermosetting resin buffer film from becoming too thick, the viscosity of the thermosetting resin is preferably 8 Pa · s or less at the time of application, similar to the photocurable resin. . In addition, although there is no minimum in the viscosity of a thermosetting resin buffer film, from the viewpoint of apply | coating to a predetermined area | region, it is preferable that it is 0.5 Pa.s or more also at the time of a heating.

  In the present invention, it is preferable that both the first inorganic sealing film and the second inorganic sealing film are either a silicon nitride film or a silicon oxynitride film. If the first inorganic sealing film and the second inorganic sealing film are a silicon nitride film and a silicon oxynitride film, entry of moisture and oxygen can be reliably prevented. Here, when the silicon nitride film and the silicon oxynitride film are formed on a surface with irregularities or steps, there is a drawback that cracks and pinholes are likely to occur. However, in the present invention, the second inorganic sealing on the upper layer side Since the film is formed on the surface flattened by the thermosetting resin buffer film, no cracks or pinholes are generated. Also, since the first inorganic sealing film on the lower layer side is formed on a surface with irregularities and steps, cracks and pinholes are likely to occur, but the resin sealing laminated on the first inorganic sealing film Since the film is a photocurable resin buffer film, the organic component does not enter from cracks or pinholes in the first inorganic sealing layer.

  In the present invention, the photocurable resin buffer film and the thermosetting resin buffer film can both adopt an epoxy resin layer.

  An organic electroluminescence device to which the present invention is applied is used as a display unit, a light source device, or the like in an electronic device.

  Embodiments of the present invention will be described below. In the drawings to be referred to in the following description, the scales of the layers and the members are different from each other in order to make the layers and the members large enough to be recognized on the drawings.

(overall structure)
FIG. 1 is an equivalent circuit diagram showing an electrical configuration of an organic electroluminescence (hereinafter referred to as EL) apparatus to which the present invention is applied. In the organic EL device 100 shown in FIG. 1, on the element substrate 10, a plurality of scanning lines 3a, a plurality of data lines 6a extending in a direction intersecting the scanning lines 3a, and a scanning line 3a are provided. And a plurality of power supply lines 3e extending in parallel. In the element substrate 10, a plurality of pixels 100a are arranged in a matrix in a rectangular pixel region 10a (light emitting region). A data line driving circuit 101 is connected to the data line 6a, and a scanning line driving circuit 104 is connected to the scanning line 3a. Each pixel region 10a holds a switching thin film transistor 30b to which a scanning signal is supplied to the gate electrode via the scanning line 3a, and a pixel signal supplied from the data line 6a via the switching thin film transistor 30b. The storage capacitor 70 to be driven, the driving thin film transistor 30c to which the pixel signal held by the storage capacitor 70 is supplied to the gate electrode, and the power supply line 3e when electrically connected to the power supply line 3e through the thin film transistor 30c. A first electrode layer 81 (anode layer) into which a driving current flows and an organic EL element 80 in which an organic functional layer is sandwiched between the first electrode layer 81 and the cathode layer are formed.

  According to this configuration, when the scanning line 3a is driven and the switching thin film transistor 30b is turned on, the potential of the data line 6a at that time is held in the holding capacitor 70, and according to the charge held in the holding capacitor 70, The on / off state of the driving thin film transistor 30c is determined. Then, a current flows from the power supply line 3e to the first electrode layer 81 via the channel of the driving thin film transistor 30c, and further a current flows to the counter electrode layer via the organic functional layer. As a result, the organic EL element 80 emits light according to the amount of current flowing therethrough.

  In the organic EL device 100 configured as described above, each of the plurality of pixels 100a corresponds to red (R), green (G), and blue (B), and red (R), green (G), and blue (B). The three pixels 100a constitute one pixel. In this embodiment, the organic EL element 80 emits white light or mixed color light of red (R), green (G), and blue (B), and the pixel 100a is red (R), green (G), blue ( Which of B) corresponds is defined by a color filter layer described later.

  In the configuration shown in FIG. 1, the power supply line 3e is parallel to the scanning line 3a. However, a configuration in which the power supply line 3e is parallel to the data line 6a may be adopted. In the configuration shown in FIG. 1, the storage capacitor 70 is configured using the power supply line 3e. However, the storage capacitor 70 may be configured by forming a capacitance line separately from the power supply line 3e. Good.

(Specific configuration of organic EL device)
2A and 2B are a plan view of the organic EL device to which the present invention is applied, as viewed from the sealing substrate side together with the respective components, and a JJ ′ cross-sectional view thereof. . In addition, illustration of a color filter layer etc. is abbreviate | omitted in FIG.2 (b). 2A and 2B, the organic EL device 100 of this embodiment includes an element substrate 10 and a sealing substrate 20 that functions as a color filter layer substrate and a sealing function. In FIG. 10, the sealing substrate 20 is disposed so as to overlap the surface side on which the plurality of organic EL elements 80 are formed.

  The element substrate 10 and the sealing substrate 20 are bonded together by the first sealing material layer 91 and the second sealing material layer 92. Although the detailed configuration of the first sealing material layer 91 and the second sealing material layer 92 will be described later, the first sealing material layer 91 is shown by a region where dots are densely attached in FIG. A frame is formed along a peripheral region 10c surrounding the pixel region 10a. On the other hand, the second sealing material layer 92 is formed over the entire area surrounded by the first sealing material layer 91, as shown by the area where dots are sparsely attached in FIG. Yes.

  Further, a sealing film 60 is formed in the pixel region 10 a where the organic EL elements 80 are arranged on the element substrate 10 so as to cover the organic EL elements 80. The detailed configuration of the sealing film 60 will be described later.

  In the element substrate 10, a terminal 102 is formed in an overhang region from the sealing substrate 20. Further, in the element substrate 10, the data line driving circuit 101 and the scanning line driving circuit 104 (described with reference to FIG. 1) are used by using the peripheral region 10c or a region sandwiched between the pixel region 10a and the peripheral region 10c. (Not shown) is formed.

(Configuration of organic EL element)
FIG. 3 is a cross-sectional view schematically showing a cross-sectional configuration of an organic EL device to which the present invention is applied. FIG. 3 shows only three organic EL elements corresponding to red (R), green (G), and blue (B) as organic EL elements.

  As shown in FIG. 3, the element substrate 10 includes a support substrate 10d made of a quartz substrate, a glass substrate, a ceramic substrate, a metal substrate, or the like. Insulating films 11, 12, 13, 14, and 15 are formed on the surface of the support substrate 10 d, and an organic EL element 80 is formed on the insulating film 15. In this embodiment, the insulating films 11, 12, 13, and 15 are formed of a silicon oxide film, a silicon nitride film, or the like, and the insulating film 14 is a flat film made of a thick photosensitive resin having a thickness of 1.5 to 2.0 μm. It is formed as a chemical film. The insulating film 11 is a base insulating layer, and although not shown, the thin film transistors 30b and 30c, the storage capacitor 70, and the like described with reference to FIG. 1 using the layers of the insulating films 11, 12, 13, and 14 are used. Various wirings and driving circuits are formed. In addition, the conductive films formed between the different layers are electrically connected to each other by using the contact holes formed in the insulating films 12, 13, 14, and 15.

  The organic EL device 100 of the present embodiment is a top emission type, and as shown by an arrow L1, light is extracted from the side where the organic EL element 80 is formed as viewed from the support substrate 10d. In addition to a transparent substrate such as, an opaque substrate such as ceramics such as alumina or stainless steel can be used. In addition, a light reflection layer 41 made of aluminum, silver, or an alloy thereof is formed between the insulating films 14 and 15, and light emitted from the organic EL element 80 toward the support substrate 10d is reflected on the light reflection layer. By reflecting at 41, light can be emitted. When the organic EL device 100 is configured as a bottom emission type, light is extracted from the support substrate 10d side, and therefore a transparent substrate such as glass is used as the support substrate 10d.

  In the element substrate 10, a first electrode layer 81 (anode / pixel electrode) made of an ITO film or the like is formed in an island shape above the insulating film 15, and the organic EL element 80 is formed above the first electrode layer 81. A thick partition wall 51 made of a photosensitive resin or the like having an opening for defining the light emitting portion is formed.

  An organic functional layer 82 and a second electrode layer 83 (cathode) are laminated on the upper layer of the first electrode layer 81, and the organic EL element is formed by the first electrode layer 81, the organic functional layer 82, and the second electrode layer 83. 80 is formed. In this embodiment, the organic functional layer 82 and the second electrode layer 83 are formed over the entire surface of the pixel region 10a including the region where the partition walls 51 are formed.

In this embodiment, the organic functional layer 82 includes a hole injection layer made of a triarylamine (ATP) multimer, a TPD (triphenyldiamine) -based hole transport layer, a styrylamine-based material containing an anthracene-based dopant or a rubrene-based dopant. A light-emitting layer made of (host) and an electron injection layer made of aluminum quinolinol (Alq ₃ ) are laminated in this order, and a second electrode layer 83 made of a thin-film metal such as MgAg is formed thereon. Yes. In addition, an electron injection buffer layer made of LiF may be formed between the organic functional layer 82 and the second electrode layer 83. Among these materials, each layer constituting the organic functional layer 82 and the electron injection buffer layer can be sequentially formed by a vacuum evaporation method using a heating boat (crucible). Further, the metal material constituting the second electrode layer 83 and the like can be formed by a vacuum deposition method, and the oxide material such as ITO constituting the first electrode layer 81 can be formed by an ECR plasma sputtering method or a plasma gun type ion plating. It can be formed by a high-density plasma film forming method such as a method or a magnetron sputtering method.

  In this embodiment, the organic EL element 80 emits white light or mixed color light of red (R), green (G), and blue (B). For this reason, in the organic EL device 100, the red (R), green (G), and blue (B) color filter layers 22 (R) and (B) formed at positions facing the organic EL element 80 in the sealing substrate 20 ( Full color display is performed by performing color conversion according to G) and (B). That is, the sealing substrate 20 is made of a transparent substrate 20d made of a plastic substrate such as polyethylene terephthalate, acrylic resin, polycarbonate, polyolefin, or a glass substrate, and red (R), green (G), blue (B ) Color filter layers 22 (R), (G), (B), and color filter layers 22 (R), (G), (B) to prevent light leakage between the light shielding layers 23 (black matrix) Layer), a light-transmitting planarizing film 24, a light-transmitting gas barrier layer 25 made of a silicon oxynitride layer, and the like are formed in this order. In this embodiment, the color filter layers 22 (R), (G), and (B), the light shielding layer 23, the planarization film 24, and the gas barrier layer 25 are formed only in a region that overlaps the pixel region 10 a in the sealing substrate 20. It is not formed in the peripheral region 10c. For this reason, the support substrate 20 d is exposed in the peripheral region 10 c of the sealing substrate 20.

  The color filter layers 22 (R), (G), and (B) are layers in which pigments or dyes are mixed in the transparent binder layer, and red (R), green (G), and blue (B) are used. However, light blue or light cyan may be added depending on the purpose. The thickness of the color filter layers 22 (R), (G), and (B) is preferably as thin as possible in consideration of the light transmittance, and is formed in a range of 0.1 to 1.5 μm. It may be different depending on the corresponding color. The light shielding layer 23 is made of a resin containing a black pigment, and the thickness thereof is thicker than the color filter layers 22 (R), (G), and (B), and a film thickness of about 1 to 2 μm is preferable. The above film thickness may be sufficient. The sealing substrate 20 may be provided with functional layers such as an ultraviolet blocking / absorbing layer that prevents the incidence of ultraviolet rays, a light reflection preventing layer, and a heat dissipation layer.

(Sealing structure)
In the organic EL device 100 configured as described above, the organic functional layer 82, the second electrode layer 83 used as the cathode, the electron injection layer, and the like are easily deteriorated by moisture, and such deterioration causes deterioration of the electron injection effect. , A non-light-emitting portion called a dark spot is generated. Therefore, in this embodiment, a configuration in which the sealing substrate 20 is bonded to the element substrate 10 and a configuration in which the sealing film 60 described below is formed on the element substrate 10 are used in combination.

  First, on the element substrate 10, the sealing film 60 is formed on the second electrode layer 83 over a region wider than the pixel region 10 a. In this embodiment, as the sealing film 60, a first inorganic sealing film 61 laminated on the second electrode layer 83 and an organic buffer film 62 made of a resin layer laminated on the first inorganic sealing film 61. In addition, a laminated film including a second inorganic sealing film 63 laminated on the organic buffer film 62 is used. As the first inorganic sealing film 61 and the second inorganic sealing film 63, in addition to silicon compounds such as silicon nitride, silicon oxynitride, and silicon oxide, aluminum such as aluminum nitride, aluminum oxynitride, and aluminum oxide (such as alumina) is used. A compound, a tantalum compound such as tantalum oxide, a titanium compound such as titanium oxide, or the like can be used. Such an inorganic material has an advantage that it has excellent adhesion with an ITO film or the like constituting the second electrode layer 83. Further, the first inorganic sealing film 61 and the second inorganic sealing film 63 may have a structure in which a plurality of the above inorganic films are stacked.

In this embodiment, the first inorganic sealing film 61 and the second inorganic sealing film 63 are formed by a high-density plasma vapor deposition method using a high-density plasma source, such as a plasma gun ion plating, ECR plasma sputtering, or ECR plasma. It is composed of silicon nitride (SiN _x ) or silicon oxynitride (SiO _x N _y ) formed by CVD, surface wave plasma CVD, ICP-CVD, etc., and such a thin film is formed at a low temperature. However, it functions as a high-density gas barrier layer that reliably blocks moisture. In addition, it is preferable that the thickness of the 1st inorganic sealing film 61 and the 2nd inorganic sealing film 63 is 10-500 nm. If the thickness of the first inorganic sealing film 61 and the second inorganic sealing film 63 is less than 10 nm, there may be a portion that partially penetrates due to a film defect or film thickness variation. The gas barrier properties may be impaired. On the other hand, if the thickness of the first inorganic sealing film 61 and the second inorganic sealing film 63 exceeds 500 nm, there is a possibility that cracking due to stress may occur.

  The organic buffer film 62 is composed of a resin layer, and planarizes surface irregularities caused by the partition walls 51 and wirings, and prevents the second inorganic sealing film 63 from generating cracks and pinholes. Is functioning as

  As the organic buffer film 62, in this embodiment, a lower-layer photocurable resin buffer film 621 that covers the first inorganic sealing film 61 and an upper-layer thermosetting resin buffer film that covers the photocurable resin buffer film 621. A laminated film with 622 is used. In this embodiment, various kinds of photo-curable resins can be used for the photo-curable resin buffer film 621. In this embodiment, a photo-curable epoxy resin is used. In addition, various thermosetting resins can be used for the thermosetting resin buffer film 622. In this embodiment, a thermosetting epoxy resin is used.

  More specifically, an epoxy adhesive that is cured by ultraviolet rays is used for the photocurable resin buffer film 621, and the epoxy adhesive is preferably an epoxy monomer / oligomer having an epoxy group and a molecular weight of 3000 or less. (Definition of monomer: molecular weight 1000 or less, definition of oligomer: molecular weight 1000 to 3000) is used. More specifically, the first sealing material layer 91 includes, for example, bisphenol A type epoxy oligomer, bisphenol F type epoxy oligomer, phenol novolac type epoxy oligomer, 3,4-epoxycyclohexenylmethyl-3 ′, 4′- Epoxycyclohexenecarboxylate, ε-caprolactone-modified 3,4-epoxycyclohexylmethyl 3 ′, 4′-epoxycyclohexanecarboxylate, etc. are used alone or in combination. Moreover, as a curing agent that reacts with an epoxy monomer / oligomer, a photoreactive type that causes a cationic polymerization reaction such as diazonium salt, diphenyliodonium salt, triphenylsulfonium salt, sulfonate ester, iron arene complex, silanol / aluminum complex, etc. An initiator is added, and a cationic polymerization reaction is caused mainly by ultraviolet irradiation.

  In addition, as the thermosetting epoxy adhesive constituting the thermosetting resin buffer film 622, an organic compound material having excellent fluidity and having no volatile component such as a solvent is used. An epoxy mono-oligomer having a molecular weight of 3000 or less, more preferably an epoxy monomer having a molecular weight of 1000 or less is used. For example, thermosetting epoxy adhesives include hard bisphenol A type epoxy monomers, bisphenol F type epoxy monomers, novolac type phenol epoxy monomers, 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexene carboxylate. , Ε-caprolactone-modified 3,4-epoxycyclohexylmethyl 3 ′, 4′-epoxycyclohexanecarboxylate and the like may be used alone or in combination. Further, as the curing agent that reacts with the epoxy monomer, an addition polymerization type that forms a tough and excellent heat-resistant cured film is good, and amines such as aromatic amine, diethylenetriamine, triethylenetetramine, and polyetherdiamine, Methyl-1,2,3,6-tetrahydrophthalic anhydride, methyl-3,6-undomethylene-1,2,3,6-tetrahydrophthalic anhydride, 1,2,4,5-benzenetetracarboxylic dianhydride Products, acid anhydride curing agents such as 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, dicyandiamide and the like. These are mixed with a reaction initiator such as aromatic amino alcohol, alcohol, mercaptan, tertiary amine catalyst or silane coupling agent.

  Here, the thermosetting resin buffer film 622 exhibits a function of flattening a surface on which the second inorganic sealing film 63 is formed, and cracks and pinholes are generated in the second inorganic sealing film 63. To prevent. In the photocurable resin buffer film 621, an organic component contained in the thermosetting resin used for the thermosetting resin buffer film 622 enters the organic EL element 80 side from a crack or pinhole of the first inorganic sealing film 61. To prevent. The detailed function of the photocurable resin buffer film 621 will be described in the description of the manufacturing process described later.

  In the present embodiment, the first inorganic sealing film 61 (high-density gas barrier layer) and the second inorganic sealing film 63 (high-density gas barrier layer) constituting the sealing film 60 are the pixel region 10a and the region near the pixel region 10a. And on the entire surface of the element substrate 10 including all of the peripheral region 10c far from the pixel region 10a. On the other hand, the organic buffer film 62 is thickly formed only in the pixel region 10a and the vicinity region of the pixel region 10a, and is not formed in the peripheral region 10c far from the pixel region 10a. The insulating films 14 and 15 are generally formed only in the pixel region 10a.

  Next, in this embodiment, as shown in FIGS. 2A, 2B, and 3, between the element substrate 10 and the sealing substrate 20, the first sealing material layer 91 is disposed along the peripheral region 10c. Is formed in a rectangular frame shape. In addition, between the element substrate 10 and the sealing substrate 20, a translucent second sealing material layer 92 is formed over the entire region surrounded by the peripheral region 10 c, and the element substrate 10 and the sealing substrate 20 are formed. Is bonded by the first sealing material layer 91 and the second sealing material layer 92. As the first sealing material layer 91 and the second sealing material layer 92, a resin-based adhesive such as urethane, acrylic, epoxy, or polyolefin can be used. In this embodiment, an epoxy-based adhesive that is cured by ultraviolet rays is used for the first sealing material layer 91 as in the case of the photocurable resin buffer film 621. In addition, a thermosetting epoxy adhesive is used for the second sealing material layer 92 as in the case of the thermosetting resin buffer film 622.

(Production method)
With reference to FIG. 4, the principal part of the manufacturing method of the organic electroluminescent apparatus 100 of this form is demonstrated. FIG. 4 is a process cross-sectional view illustrating a state from the formation of the organic EL element 80 on the element substrate 10 to the formation of the sealing film 60 in the manufacturing process of the organic EL device 100 to which the present invention is applied. FIG. 5 is an explanatory diagram showing a change in viscosity until the thermosetting resin used for the thermosetting resin buffer film 622 is cured in the manufacturing process of the organic EL device 100 to which the present invention is applied.

  In manufacturing the organic EL device 100 of this embodiment, in addition to a method of bonding the element substrate 10 and the sealing substrate 20 in a single size, a large-sized substrate that can take a large number of the element substrate 10 and the sealing substrate 20 is used. In some cases, a method of bonding in a state and then cutting the large substrate into a single product size may be employed. Regardless of the size, the element substrate 10 will be described because the basic configuration is the same regardless of which method is employed.

  First, as shown in FIG. 4A, in the organic EL element formation step, the first electrode layer 81, the organic functional layer 82, and the second electrode layer 83 are stacked on the pixel region 10a of the element substrate 10 to form an organic layer. The EL element 80 is formed.

Next, in the first inorganic sealing layer forming step shown in FIG. 4B, silicon nitride (SiN _x ) is formed by plasma gun ion plating, ECR plasma sputtering, ECR plasma CVD, surface wave plasma CVD, ICP-CVD, or the like. ) Or silicon oxynitride (SiO _x N _y ) or the like, a first inorganic sealing film 61 (high-density gas barrier layer) is formed. At that time, since the first inorganic sealing film 61 is formed on a surface with unevenness and steps, cracks and pinholes are likely to occur.

  Next, in the photocurable encapsulating resin layer forming step shown in FIG. 4C, a photocurable resin 621a (ultraviolet curable epoxy-based resin) is formed by dispenser drawing, screen printing, ink jet using a micropiezo head, or the like. (Resin) is applied and then irradiated with ultraviolet rays to cure the photo-curable resin 621a. As a result, a photocurable resin buffer film 621 is formed so as to cover the first inorganic sealing film 61. The application and curing of the photocurable resin 621a is performed in an inert gas atmosphere such as nitrogen. Here, the curing process of the photocurable resin 621a is performed at room temperature. For this reason, since the viscosity reduction does not occur in the photocurable resin 621a, the ability to flatten the surface is low. Instead, since the viscosity decrease does not occur in the photocurable resin 621a, even when cracks or pinholes are generated in the first inorganic sealing film 61, the organic component contained in the photocurable resin 621a is the first inorganic. It does not enter the organic EL element 80 side from cracks or pinholes in the sealing film 61.

  Here, the photocurable resin 621a preferably has a viscosity of 1 Pa · s or more until it is cured after being applied. With such a viscosity, even if cracks or pinholes are generated in the first inorganic sealing film 61 on the lower layer side, the organic component contained in the photocurable resin 621a is cracked or pinned in the first inorganic sealing film 61. There is no intrusion from the hole. From the viewpoint of preventing the photocurable resin buffer film 621 from becoming too thick, the viscosity of the photocurable resin 621a is preferably 8 Pa · s or less at the time of application. Further, the photocurable resin 621a is preferably dehydrated to a moisture content of 0.1 wt% (1000 ppm) or less.

  Next, in the thermosetting sealing resin layer forming step shown in FIG. 4D, a thermosetting resin 622a (ultraviolet curable epoxy type) is formed by dispenser drawing, a screen printing method, an inkjet method using a micropiezo head, or the like. (Resin) is applied and then heated to cure the thermosetting resin 622a. As a result, a thermosetting resin buffer film 622 is formed so as to cover the photocurable resin buffer film 621, and an organic buffer film 62 composed of the photocurable resin buffer film 621 and the thermosetting resin buffer film 622 is formed. Is done. The application and curing of the thermosetting resin 622a is performed in an inert gas atmosphere such as nitrogen.

  Here, in the curing step of the thermosetting resin 622a, for example, baking (heating) is performed at a temperature of about 90 ° C. At that time, as shown in FIG. 5, the thermosetting resin 622a softens the organic component, temporarily reduces the viscosity of the coating liquid, and gives a minimum value. Further heating causes the organic component to cure, so that the viscosity of the coating liquid increases, and the organic component is cured when the viscosity of the coating liquid reaches a predetermined value or more. Therefore, the thermosetting resin buffer film 622 is excellent in the ability to flatten the surface. On the other hand, when the viscosity of the thermosetting resin 622a is reduced to 1 Pa · s or less, the organic component tends to penetrate into the lower layer side, but the photocurable resin buffer film 621 is formed on the lower layer side of the thermosetting resin 622a. Is formed. For this reason, the organic component contained in the thermosetting resin 622a does not enter the organic EL element 80 side from the crack or pinhole of the first inorganic sealing film 61.

  From the viewpoint of preventing the thermosetting resin buffer film 622 from becoming too thick, the viscosity of the thermosetting resin 622a is 8 Pa · s or less at the time of application, as with the photocurable resin 621a. It is preferable. Note that there is no lower limit on the viscosity of the thermosetting resin 622a, but from the viewpoint of application to a predetermined region, it is preferably 0.5 Pa · s or more even during heating. The thermosetting resin 622a is preferably dehydrated to a moisture content of 0.1 wt% (1000 ppm) or less.

Next, in the second inorganic sealing layer forming step shown in FIG. 4E, silicon nitride (SiN _x ) is formed by plasma gun ion plating, ECR plasma sputtering, ECR plasma CVD, surface wave plasma CVD, ICP-CVD, or the like. ) Or silicon oxynitride (SiO _x N _y ) or the like, a second inorganic sealing film 63 (high density gas barrier layer) is formed. At that time, since the second inorganic sealing film 63 is formed on the surface flattened by the thermosetting resin buffer film 622 of the organic buffer film 62, cracks and pinholes are hardly generated.

  Thereafter, the element substrate 10 and the sealing substrate 20 are bonded together by the first sealing material layer 91 and the second sealing material layer 92 as shown in FIGS.

  In such a bonding process, a photo-curing property for forming the first sealing material layer 91 on the peripheral region 10c of the element substrate 10 by a dispenser drawing, a screen printing method, an inkjet method using a micro piezo head, or the like. An epoxy resin material (first sealing material) is applied.

  Next, the second sealing material layer 92 is formed in the region surrounded by the photocurable first sealing material on the element substrate 10 by a dispenser drawing, a screen printing method, an ink jet method using a micro piezo head, or the like. A thermosetting epoxy resin material (second sealing material) is applied.

  Next, in the overlapping step, the element substrate 10 and the sealing substrate 20 are overlapped so as to sandwich the sealing material therebetween. At that time, the sealing substrate 20 is pressurized toward the element substrate 10 with a force of about 600 N, and this state is maintained for about 200 seconds. In such an overlapping process, the first sealing material contacts the sealing substrate 20 and the inside is sealed, and then the second sealing material develops between the element substrate 10 and the sealing substrate 20. This superposition process is performed in a reduced pressure atmosphere with a vacuum degree of about 1 Pa.

  Next, when the pressure is returned to the normal pressure, the state is the same as when the pressure is increased by the atmospheric pressure. Therefore, the second sealing material is developed to every corner between the element substrate 10 and the sealing substrate 20, and the second The filling property of the sealing material is improved. At that time, the first sealing material functions as a bank for the second sealing material. For this reason, even if it will be in the same state as it was pressurized by atmospheric pressure when returning from a pressure reduction state to a normal pressure, the 2nd sea material will be blocked by the 1st seal material, and will not flow outside.

  Next, in the curing step, the first sealing material layer is selectively cured by irradiating the first sealing material with ultraviolet rays from the element substrate 10 and / or the sealing substrate 20 side. 91 is formed. Next, the element substrate 10 and the sealing substrate 20 bonded together by the first sealing material layer 91 are heated at 60 to 100 ° C. in a state where the element substrate 10 and the sealing substrate 20 are disposed on the hot plate. The second sealing material is cured while spreading the second sealing material to every corner, and the second sealing material layer 92 is formed. In this manner, the element substrate 10 and the sealing substrate 20 are bonded to each other by the first sealing material layer 91 and the second sealing material layer 92.

  In the organic EL device 100 configured as described above, the second sealing material layer 92 is cured. Therefore, convection does not occur in the second sealing material layer 92 when left at a high temperature, so that the second inorganic sealing film 63 of the sealing film 60 is not damaged, and the second sealing material layer 92 is 60 functions as a protective film for the second inorganic sealing film 63. Here, the thickness of the second sealing material layer 92 is 1 to 5 μm, and the thinner the pixel is, the better. In addition, fillers such as clay minerals, silica balls, and resin balls that are contained in a large amount in general adhesives cause damage to the second inorganic sealing film 63 of the sealing film 60, and thus the first It is preferable that such a filler is not blended in the sealing material layer 91 and the second sealing material layer 92. In particular, the second sealing material layer is in contact with the sealing film 60 and considering light transmittance. It is preferable that no filler is blended.

(Main effects of this form)
As described above, in the organic EL device 100 and the manufacturing method thereof according to the present embodiment, between the first inorganic sealing film 61 and the second inorganic sealing film 63, the photocurable resin buffer film 621 and the thermosetting resin. A resin buffer film 622 is laminated. Among the resins constituting the organic buffer film 62, the thermosetting resin 622a for forming the upper-layer thermosetting resin buffer film 622 is excellent in the ability to flatten the surface because the viscosity decreases during heating. ing. For this reason, since the 2nd inorganic sealing film 63 is formed on the surface planarized by the thermosetting resin buffer film 622, a crack and a pinhole do not generate | occur | produce. Accordingly, it is possible to reliably prevent moisture and oxygen from entering from the second inorganic sealing film 63 on the upper layer side.

  Further, when the photocurable resin buffer film 621 constituting the lower layer side of the organic buffer film 62 is formed, there is no step of heating, so that the viscosity of the photocurable resin 621a does not decrease until it is cured. Therefore, the photocurable resin 621a has a lower ability to flatten the surface than the thermosetting resin 622a, but the organic component used for the photocurable resin 621a is the first inorganic sealing film 61 on the lower layer side. Intrusion through cracks and pinholes formed in Therefore, according to the present invention, it is possible to prevent the organic EL element 80 from being deteriorated by moisture or oxygen gas without causing deterioration of the organic EL 80 due to the organic component used in the organic buffer film 62. . Therefore, the reliability of the organic EL device 100 can be significantly improved.

[Other embodiments]
In the above embodiment, the case where the color filter layers 22 (R), (G), and (B) are provided on the sealing substrate 20 in the top emission type organic EL device 100 has been described as an example. The present invention may be applied to an organic EL device that itself emits light of each color. In the above-described embodiment, the organic EL device 100 for color display has been described as an example. However, when used as an optical head of a copying machine, the organic EL device 100 for monochrome can be used. The present invention may be applied to.

  In the above embodiment, a plurality of organic EL elements 80 are formed in the pixel region 10a. However, as in the case where the organic EL device 100 is used as a light source device, one organic EL element is provided in the light emitting region. The present invention may be applied when the element 80 is formed.

  In the above embodiment, the top emission type organic EL device 100 has been described as an example. However, the present invention may be applied to a bottom emission type organic EL device.

  In the above embodiment, the sealing substrate 20, the first sealing material layer 91, and the second sealing material layer 92 are used for sealing. However, the sealing substrate 20, the first sealing material layer 91, and the second sealing material 20 are used. The present invention may be applied to the case where sealing is performed only with the sealing film 60 without performing sealing with the sealing material layer 92. Further, the present invention may be applied when the sealing substrate 20 is bonded to the element substrate 10 with one kind of sealing material layer.

  In the above embodiment, an example in which the organic functional layer 82 is formed on the entire surface of the pixel region 10a has been described. However, after the organic functional layer is selectively applied to the region surrounded by the partition wall 51 by an inkjet method or the like, the fixing is performed. Thus, a hole injection layer made of 3,4-polyethylenediosithiophene / polystyrene sulfonic acid (PEDOT / PA · S) or the like and an organic functional layer made of a light emitting layer are formed on the first electrode layer 81. The present invention may be applied to a manufactured organic EL device. In this case, the light emitting layer is made of, for example, a polyfluorene derivative, a polyphenylene derivative, a polyvinyl carbazole, a polythiophene derivative, or a polymer material thereof. -It is composed of a material doped with diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, quinacridone and the like. Further, as the light emitting layer, a π-conjugated polymer material in which double-bonded π electrons are non-polarized on the polymer chain is also a conductive polymer, so that it is excellent in light emitting performance, and thus is preferably used. . In particular, a compound having a fluorene skeleton in the molecule, that is, a polyfluorene compound is more preferably used. In addition to such materials, it is also possible to use a composition comprising a conjugated polymer organic compound precursor and at least one fluorescent dye for changing light emission characteristics.

[Example of mounting on electronic devices]
With reference to FIG. 6, an electronic apparatus in which the organic EL device 100 according to the above-described embodiment is mounted will be described. FIG. 6 is an explanatory diagram of an electronic apparatus using the organic EL device to which the present invention is applied.

  FIG. 6A shows a configuration of a mobile personal computer including the organic EL device 100. The personal computer 2000 includes an organic EL device 100 as a display unit and a main body 2010. The main body 2010 is provided with a power switch 2001 and a keyboard 2002. FIG. 6B shows the configuration of a mobile phone provided with the organic EL device 100. The cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and the organic EL device 100 as a display unit. By operating the scroll button 3002, the screen displayed on the organic EL device 100 is scrolled. FIG. 6C shows the configuration of a personal digital assistant (PDA) to which the organic EL device 100 is applied. The information portable terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the organic EL device 100 as a display unit. When the power switch 4002 is operated, various types of information such as an address book and a schedule book are displayed on the organic EL device 100. Electronic devices to which the organic EL device 100 is applied include those shown in FIGS. 6A to 6C, a digital still camera, a liquid crystal television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation system. Examples thereof include a device, a pager, an electronic notebook, a calculator, a word processor, a workstation, a videophone, a POS terminal, and a device equipped with a touch panel. And the organic electroluminescent apparatus 100 mentioned above is applicable as a display part of these various electronic devices.

1 is an equivalent circuit diagram showing an electrical configuration of an organic EL device to which the present invention is applied. (A), (b) is the top view which looked at the planar structure of the organic electroluminescent apparatus to which this invention was applied from the sealing substrate side with each component, respectively, and its JJ 'sectional drawing. It is sectional drawing which shows typically the cross-sectional structure of the organic electroluminescent apparatus to which this invention is applied. In the manufacturing process of the organic electroluminescent apparatus to which this invention is applied, after forming an organic electroluminescent element in an element substrate, it is process sectional drawing which shows a mode until it forms a sealing film. It is explanatory drawing which shows a viscosity change until the thermosetting resin used for the thermosetting resin buffer film hardens | cures in the manufacturing process of the organic electroluminescent apparatus to which this invention is applied. It is explanatory drawing of the electronic device using the organic electroluminescent apparatus to which this invention is applied.

10..Element substrate, 10a..Pixel region, 10c..Peripheral region, 60..Sealing film, 61..First inorganic sealing film, 62..Organic buffer film, 63..Second inorganic sealing Film, 80 ... Organic EL element, 81 ... First electrode layer, 82 ... Organic functional layer, 83 ... Second electrode layer, 100 ... Organic EL device, 100a ... Pixel, 621 ... Photocurable Resin buffer film, 622 ... Thermosetting resin buffer film

Claims (8)

On the element substrate,
An organic electroluminescence element in which a first electrode layer, an organic functional layer, and a second electrode layer are laminated;
A first inorganic sealing film covering the organic electroluminescence element;
A photocurable resin buffer film covering the first inorganic sealing film;
A thermosetting resin buffer film covering the photocurable resin buffer film;
A second inorganic sealing film covering the thermosetting resin buffer film;
An organic electroluminescence device characterized by comprising:   2. The organic electroluminescence device according to claim 1, wherein each of the first inorganic sealing film and the second inorganic sealing film is one of a silicon nitride film and a silicon oxynitride film.   3. The organic electroluminescence device according to claim 1, wherein each of the photocurable resin buffer film and the thermosetting resin buffer film is an epoxy resin. An organic electroluminescent element forming step of forming an organic electroluminescent element by laminating the first electrode layer, the organic functional layer, and the second electrode layer on the element substrate;
A first inorganic sealing film forming step of forming a first inorganic sealing film covering the organic electroluminescence element;
A photocurable resin buffer film forming step of forming a photocurable resin buffer film by applying a photocurable resin so as to cover the first inorganic sealing film;
A thermosetting resin buffer film forming step of forming a thermosetting resin buffer film by applying a thermosetting resin so as to cover the photocurable resin buffer film;
A second inorganic sealing film forming step of forming a second inorganic sealing film covering the thermosetting resin buffer film;
The manufacturing method of the organic electroluminescent apparatus characterized by having.   5. The method of manufacturing an organic electroluminescence device according to claim 4, wherein the photocurable resin has a viscosity of 1 Pa · s or more until the photocurable resin is cured after being applied.   6. The organic electroluminescence according to claim 4, wherein each of the first inorganic sealing film and the second inorganic sealing film is one of a silicon nitride film and a silicon oxynitride film. Device manufacturing method.   The method for producing an organic electroluminescent device according to claim 4, wherein both the photocurable resin and the thermosetting resin are epoxy resins.   An electronic apparatus comprising the organic electroluminescence device according to any one of claims 1 to 3.

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