JP2009181849A - Organic el panel and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent progression and expansion of a non-light-emitting part (black frame and dark spot) of an organic EL panel. <P>SOLUTION: In the organic EL panel in which one or a plurality of organic EL elements (2) are formed on a substrate (1) and the substrate and a sealing member (3) to seal the organic EL element are pasted together, so as to cover the whole organic EL element, a first inorganic protection layer (70) and a second inorganic protection layer (71) are formed. On the second protection layer (71), a sheet-type desiccant (5) is arranged, and a space layer (S) is formed between the sheet-type desiccant and the organic EL element. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic EL panel and a method for manufacturing the same.

  An organic EL panel includes an organic EL element as a light emitting element. For example, a display screen of a mobile phone, a monitor screen of a vehicle-mounted or household electronic device, an information display screen of a personal computer or a television receiver, a lighting panel for advertisement As various display devices used in, etc., as various light sources used in scanners, printers, etc., as illumination devices used in general illumination, backlights of liquid crystal display devices, etc., or as an optical communication device using a photoelectric conversion function A self-luminous panel that can be used for various purposes.

Since the organic EL element has a property that the light emission characteristic deteriorates when exposed to moisture in the atmosphere, the organic EL element is sealed to block the organic EL element from the atmosphere in order to operate the organic EL panel stably for a long time. Structure is indispensable. As a sealing structure of an organic EL panel, a metal or glass sealing member and a substrate on which an organic EL element is formed are bonded together to form a sealing space surrounding the organic EL element, and the sealing space A structure (hollow sealing structure) in which a desiccant is disposed inside has been generally adopted. However, in consideration of further thinning and strength improvement of the panel, the organic EL element on the substrate is directly sealed without any space. The solid sealing structure covered with is being studied (see Patent Document 1 below).
JP 2007-5107 A

  As a proposal of a highly feasible solid sealing structure, a sealing adhesive is formed so as to cover the entire organic EL element on the substrate, and the substrate and the sealing member are not spaced through the sealing adhesive. A structure of bonding can be considered. In this sealing structure, moisture can be prevented from entering from the front or back surface of the organic EL panel by the substrate and the sealing member, but the sealing member and the substrate are interposed between the sealing member and the substrate via a sealing adhesive. Since it is bonded, it is inevitable that moisture enters the panel through the sealing adhesive. For this reason, when an organic EL panel having such a sealing structure is operated for a long time, it has been confirmed that a non-light-emitting portion called a black frame from the periphery of the panel proceeds toward the center of the panel. .

  In addition, non-light-emitting parts called dark spots (black spots) are generated at film defects due to adhesion of foreign substances, etc., and dark spots grow by long-time operation, and non-light-emitting parts scattered in the light-emitting parts are enlarged. This phenomenon has been confirmed.

  In order to avoid this black frame and dark spots, it is conceivable to provide a protective film for blocking deterioration factors in the solid sealing structure or to provide a desiccant inside the sealing structure.

  As the protective film described above, it is effective to cover the organic EL element with an inorganic material layer. In order to form a film of inorganic material without damaging the organic EL element, a protective film is gradually formed while controlling the energy of molecules incident on the substrate, but it sufficiently blocks the deterioration factors. In order to obtain a complete film, a considerable thickness (on the order of μm) is required. Therefore, it takes a long time to form a film, and there is a problem that high productivity cannot be obtained.

  In addition, when a desiccant is provided inside the sealing structure, moisture that is not adsorbed by the desiccant reaches the organic EL element via the sealing adhesive when the desiccant is dispersed in the sealing adhesive. Therefore, it is effective to concentrate the desiccant as close as possible to the organic EL element and cover the organic EL element with a layer of the desiccant as much as possible. For that purpose, a structure using a sheet-like desiccant, covering the whole organic EL element with this sheet-like desiccant, and bonding the substrate and the sealing member through the sealing adhesive formed thereon can be considered. .

  When such a structure is adopted, the surface of the sheet-like desiccant is covered with the sealing adhesive, so that the sheet-like desiccant can exhibit the adsorption function. Deterioration that occurs only from deterioration factors such as moisture that reaches the surface of the agent, does not enter the sealing adhesive from the outside and reaches the surface of the sheet desiccant, or deterioration that occurs from the inside of the sealing adhesive An adsorption function cannot be effectively exhibited for factors (those contained in outgas).

  Accordingly, there may be a deterioration factor that bypasses the sheet-like desiccant and reaches the organic EL element without reaching the surface of the sheet-like desiccant, and the organic EL element is covered with the sheet-like desiccant. Even when the structure is adopted, there is a problem that the growth of black frames and dark spots (non-light emitting portions) cannot be effectively prevented.

  Further, it has been confirmed that the sheet-like desiccant undergoes a volume change when absorbing moisture and expands in the thickness direction, and this volume change reduces the adhesive strength between the substrate and the sealing member, and causes the adhesion to float. If this occurs, the above-described black frame progresses at an extreme speed.

  This invention makes it an example of a subject to cope with such a problem. That is, in an organic EL panel adopting a solid sealing structure, by using a protective film and a desiccant in combination, the protective film is made as thin as possible to improve productivity, and the progress of the non-light emitting portion is effectively performed. Prolonging the lifespan of the display, maintaining the display quality by thinning and high strength, and improving the heat dissipation by adopting a solid sealing structure to prevent the panel from extending its life, maintaining the display quality of the panel It is an object of the present invention to be able to provide an organic EL panel that can be used.

In order to achieve such an object, the organic EL panel and the manufacturing method thereof according to the present invention include at least the configurations according to the following independent claims.
[Claim 1] An organic EL panel in which a plurality or a single organic EL element is formed on a substrate, and the substrate and a sealing member are bonded together with a sealing adhesive covering the organic EL element, The organic EL element includes a first electrode layer formed directly or via another layer on the substrate, an organic layer including an organic light emitting layer formed on the first electrode layer, and an organic layer on the organic layer. A first protective layer made of an inorganic material in contact with the second electrode layer, and is laminated on the first protective layer so as to cover the entire organic EL element. Forming a protective layer having a second protective layer made of an inorganic material, disposing a sheet-like desiccant on the protective layer so as to cover the entire organic EL element, An organic EL panel comprising a space layer formed between organic EL elements.

  [Claim 6] A method of manufacturing an organic EL panel in which a plurality or a single organic EL element is formed on a substrate, and the substrate and the sealing member are bonded together with a sealing adhesive covering the organic EL element. Forming an organic EL element on the substrate; forming a first protective layer made of an inorganic material in contact with the second electrode layer so as to cover the entire organic EL element; A step of forming a second protective layer made of an inorganic material on one protective layer, a step of fixing a sheet-like desiccant to a base material to form a sheet-like drying member, the substrate and the sealing member, In the state where the sheet-like drying member is disposed so as to cover the whole of the organic EL element, and the space layer is formed between the sheet-like desiccant and the organic EL element, the substrate and the sealing member And a step of bonding together A method of manufacturing an organic EL panel.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view for explaining the structure of an organic EL panel according to an embodiment of the present invention (FIG. 1 (a) is a conceptual diagram showing a cross-sectional structure, and FIG. 1 (b) is a conceptual diagram showing a cross section of an end portion). is there. The organic EL panel is formed by forming a plurality or a single organic EL element 2 on a substrate 1 and bonding the substrate 1 and a sealing member 3 with a sealing adhesive 4 covering the organic EL element 2. .

  The structure of the organic EL element 2 includes a first electrode layer 21 formed on the substrate 1 directly or via another layer, an organic layer 22 including a light emitting layer formed on the first electrode layer 21, And a second electrode layer 23 formed on the organic layer 22. In the illustrated example, the first electrode layer 21 is formed in a stripe shape on the substrate 1, and the light emitting portion (pixel) is partitioned by the insulating film 24 thereon, and the first electrode layer in the partitioned light emitting portion is formed. An organic layer 22 including a light emitting layer is formed on 21. A partition wall 25 is formed on the insulating film 24, and a second electrode layer 23 is formed in a stripe shape on the organic layer 22 along the partition wall 25 so as to intersect the first electrode layer 21. One organic EL element 2 is formed at the intersection of the first electrode layer 21 and the second electrode layer 23.

  For such organic EL element 2 shown as an example, a protective layer 7 made of an inorganic material is formed so as to cover the entire organic EL element 2, and a sheet-like desiccant 5 ( A sheet-like drying member 50) including the sheet-like desiccant 5 is disposed. As the sheet-like desiccant 5, a sheet-like desiccant formed by dispersing a desiccant component in a binder resin can be used.

  And when the organic EL panel which concerns on embodiment of this invention arrange | positions the sheet-like desiccant 5 between the board | substrate 1 and the sealing member 3, the space layer S is provided between the sheet-like desiccant 5 and an organic EL element. Forming.

  As shown in FIG. 1A, the protective layer 7 is provided so as to cover the entire organic EL element 2. By providing the protective layer 7 so as to cover the entire organic EL element 2, the barrier performance of the deterioration factor with respect to the organic EL element 2 can be enhanced. Further, by providing the protective layer 7, it can be avoided that the adhesive layer 6 or 53 for fixing the sheet-like desiccant 5 or the sheet-like drying member 50 has a direct adverse effect on the organic EL element 2. it can. As the protective layer 7, an inorganic protective layer made of an inorganic material is employed.

  The protective layer 7 has a two-layer structure as shown in FIG. That is, the protective layer 7 includes a first inorganic protective layer 70 in contact with the second electrode 23 and a second inorganic protective layer 71 laminated on the first inorganic protective layer 70. In this embodiment, a first inorganic protective layer 70 made of an inorganic material and a second inorganic protective layer 71 made of an inorganic material are sequentially laminated so as to cover the outermost edge E24 of the insulating film 24 made of an organic material. Accordingly, first, an insulating interface between the inorganic materials by the substrate 1 made of an inorganic material such as glass and the first inorganic protective layer 70 can be formed outside the outermost edge E24. Thereby, the progress of the black frame caused by the deterioration factor entering from the edge of the substrate 1 can be suppressed, and the growth of dark spots can be suppressed by completely covering the organic EL element 2.

  Since the protective layer 7 has a two-layer structure, the first inorganic protective layer 70 in contact with the second electrode 23 of the organic EL element 2 has low kinetic energy of molecules incident on the substrate, and damages the organic EL element 2. The second inorganic protective layer 71 can be formed by sputtering that is not applied, and a dense layer can be formed by sputtering with a relatively high deposition rate. Accordingly, the protective layer 7 having a high deterioration factor blocking property can be formed without damaging the organic EL element 2 while increasing the film forming speed of the entire protective layer 7. In addition, since the protective layer 7 can be thinned by combination with the sheet-like desiccant 5, this also shortens the entire film formation time and improves the productivity of the organic EL panel.

  And the sheet-like desiccant 5 is arrange | positioned so that the 2nd inorganic protective layer 71 may be covered, and the space layer S is formed between the adhesive bond layers 6 which fix the sheet-like desiccant 5. For example, the space layer S has a function of capturing deterioration factors such as moisture that has entered or generated between the substrate 1 and the sealing member 3. By exposing the surface of the sheet-like desiccant 5 on the organic EL element 2 side to the space layer S, the deterioration factor that has entered the space layer S is quickly adsorbed to the sheet-like desiccant 5, and sheet-like drying is performed. The adsorption function of the agent 5 can be expanded from the surface of the sheet-like desiccant 5 into the space layer S.

  According to this, since the space layer S can effectively capture a deterioration factor such as moisture that tends to adversely affect the organic EL element 2 and can be quickly adsorbed by the sheet-like desiccant 5, the organic EL panel In this case, it is possible to effectively prevent the progress of the non-light emitting portion (black frame or dark spot), and it is possible to extend the life of the panel while maintaining good display quality. In addition, by adopting such a sealing structure, it is possible to form a thin and high-strength organic EL panel as compared with the case where a hollow sealing structure is employed.

  The space layer S has a function of absorbing the expansion of the sheet-like desiccant 5 that occurs in the thickness direction of the organic EL panel with respect to the volume change that occurs when the sheet-like desiccant 5 absorbs moisture. As a result, even when the sheet-like desiccant 5 expands in the thickness direction, no trouble occurs in the adhesion between the substrate 1 and the sealing member 3, and abrupt progress of the black frame due to poor adhesion is prevented in advance. be able to.

  The space layer S may be formed in any way. For example, as shown in FIG. 1, the adhesive layer 6 for fixing the sheet-like desiccant 5 is used as the organic EL element 2 of the sheet-like desiccant 5. By partially forming on the side surface, the space layer S can be formed in a portion where the adhesive layer 6 is not present. According to this, the space layer S can be formed using a process for fixing the sheet-like desiccant 5 without any particular process. The form in which the adhesive layer 6 is partially formed on the surface of the sheet-like desiccant 5 is a space layer S in a portion without the adhesive layer 6 such as a dot shape (dot shape), a short side shape, a row shape, or a spiral shape. What is necessary is just to be formed.

  FIG. 2 is an explanatory view showing the structure of the sheet-like drying member 50 including the sheet-like desiccant 5 (FIG. 2A is a longitudinal sectional view showing the sheet-like drying member, and FIG. 2B is a rear view). is there. The sheet-like drying member 50 is obtained by fixing the sheet-like desiccant 5 to the base material 52 via the adhesive layer 51, and the base material 52 has an adhesive layer 53 for fixing to the protective layer 7. Is formed. In this example, the space layer S is formed in a portion without the adhesive layer 53 by partially forming the adhesive layer 53.

  As shown in FIG. 2B, in this example, the adhesive layer 53 is formed in the form of dots on the surface of the substrate 52. In order to partially form the adhesive layer 53, the space layer S is not only formed in a dot shape as shown, but also in a portion without the adhesive layer 53 such as a short side shape, a row shape, or a spiral shape. Anything can be used. In order for the space layer S to absorb the expansion in the thickness direction of the sheet-like desiccant 5, it is necessary to employ a flexible material as the base material 52. As an example, a ductile fluorinated ethylene resin (PTFE) is suitable.

  FIG. 3 is an explanatory view showing another structural example of the sheet-like drying member 50 including the sheet-like desiccant 5 (FIG. 3A is a longitudinal sectional view showing the sheet-like drying member, and FIG. 3B is the same). XX sectional view). As shown in FIG. 5A, the sheet-like drying member 50 is obtained by fixing the sheet-like desiccant 5 to the base material 52 via the adhesive layer 51, as in the example described above. Is formed with an adhesive layer 53 for fixing to the protective layer 7. In this example, the space layer S is formed inside a sheet-like drying member 50 in which the sheet-like desiccant 5 is fixed to the base material 52, and the adhesive layer 51 for fixing the sheet-like desiccant 5 is partially formed. It is formed in the part without the adhesive bond layer 51 by forming it automatically.

  FIG. 2B is a cross-sectional view taken along the line XX in FIG. 1A. In this example, the adhesive layer 51 is formed in the form of dots on the surface of the sheet-like desiccant layer 5. In order to partially form the adhesive layer 51 on the surface of the sheet-like desiccant 5, the adhesive layer 51 is not only formed in a dot shape in this way, but also in a short side shape, a row shape, a spiral shape, or the like. What is necessary is just to form the space layer S in the part which does not exist.

  In such an embodiment, since the space layer S can be formed in advance in the sheet-like drying member 50, the tact time in the bonding process of the organic EL panel can be shortened. Further, when the adhesive layer 51 is formed in a dot shape, a continuous space layer S can be formed on the entire surface of the sheet-like desiccant 5, so that the adsorption function of the sheet-like desiccant 5 can be more effectively performed. Can be improved.

In the embodiment shown in FIG. 4, a sealing structure similar to the example shown in FIG. 1 is applied to an organic EL panel driven by an active matrix. 4 denote the same parts as those in FIG. 1, and a repetitive description thereof will be omitted. In this example, a driving element 8 (TFT element or the like) is formed on the substrate 1, and a planarizing film 80 made of an inorganic material such as SiO ₂ is formed thereon. The driving element 8 and the first electrode layer 21 are connected by a connection wiring 81. And the sheet-like desiccant 5 is arrange | positioned so that the 2nd inorganic protective layer 71 may be covered, and the space layer S is formed between the adhesive bond layers 6 which fix the sheet-like desiccant 5.

  In this example as well, the deterioration factor that enters the interface between the adhesive layer 6 and the second inorganic protective layer 71 is captured by the space layer S, and is effectively applied to the surface of the sheet-like desiccant 5 in the same manner as described above. Since it is adsorbed, it is possible to effectively prevent the deterioration factor from entering the organic EL element. Further, even when the sheet-like desiccant 5 expands in the thickness direction, the volume change is absorbed by the space layer S, so that there is no problem in the adhesion between the substrate 1 and the sealing member 3. Here, instead of fixing the sheet-like desiccant 5 directly on the second inorganic protective layer 71 via the adhesive layer 6, a space layer S was formed inside as in the example shown in FIG. The sheet-like drying member 50 may be adhered on the second inorganic protective layer 71.

  5 and 6 are explanatory views (process flows) illustrating a method for manufacturing an organic EL panel according to an embodiment of the present invention. The example shown in FIG. 5 is a manufacturing method in the case of forming the space layer S between the sheet-like desiccant 5 or the sheet-like drying member 50 and the protective layer 7, and the example shown in FIG. In this manufacturing method, the space layer S is formed inside the drying member 50.

  In the example shown in FIG. 5, on the substrate 1 side, a step of forming an organic EL element on the substrate 1 (organic EL element formation step: S10), a step of forming the protective layer 7 (protective layer formation step: S11), and protection The step of placing and fixing the sheet-like desiccant 5 on the organic EL element via the layer 7 to form the space layer S (sheet-like desiccant placement and fixing (space layer formation) step: S12) is performed, In the sealing member 3, the process (sealing adhesive formation process: S20) of forming the sealing adhesive 4 for bonding to the sealing member 3 is performed, and after that, the board | substrate 1, the sealing member 3, and The process of bonding (bonding process: S30) is performed.

  On the other hand, in the example shown in FIG. 6, on the substrate 1 side, a step of forming an organic EL element on the substrate 1 (organic EL element forming step: S10), a step of forming the protective layer 7 (protective layer forming step: S11). And the step of forming the space layer S inside the sheet-like drying member 50 (sheet-like drying member forming step (space layer formation): S40) is performed on the sheet-like drying member 50 side, and then the substrate 1 , The step of placing and fixing the sheet-shaped drying member 50 on the organic EL element through the protective layer 7 (sheet-shaped drying member placement and fixing step: S13) is performed. A step of forming the sealing adhesive 4 for bonding (sealing adhesive forming step: S20) is performed, and then the step of bonding the substrate 1 and the sealing member 3 (bonding step: S30). Is done.

  Each step will be described in more detail with specific examples.

Organic EL element formation process S10;
First, if necessary, the substrate 1 is polished, washed, surface-covered, and the like to prepare for forming the first electrode layer 21. When an organic EL panel performs passive matrix driving, the first electrode layer 21 is formed directly on the substrate 1. However, when active matrix driving is performed, the organic EL panel is formed on the substrate 1 on which driving elements such as TFTs are formed. Then, another layer such as a planarizing film is coated, and the first electrode layer 21 is formed through the layer. The substrate 1 can be formed of glass or the like in the case of an inorganic material, and can be formed of plastic or the like in the case of an organic material. In order to adopt the bottom emission method in which light is extracted from the substrate 1 side, it is necessary to form the substrate 1 with a transparent member.

  The first electrode layer 21 is formed by forming a thin film by a film forming technique such as vapor deposition or sputtering, and then forming a predetermined pattern by a pattern forming technique such as photolithography. The material of the first electrode 21 is made of a conductive material, and a transparent electrode such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide) is used in order to adopt a bottom emission method in which light is extracted from the substrate 1 side. . Specifically, a transparent electrode material such as ITO or IZO is formed on the entire surface with a substantially constant film thickness by various film forming methods such as a sputtering film forming method on a substrate 1 such as glass. Thereafter, the first electrode layer 21 and the lead wiring (wiring for inputting a light emission / non-light emission control signal of the organic EL element 2 from an external circuit) are patterned.

  Next, an insulating film 24 is formed. As a forming procedure, first, an insulating film material such as a polyimide precursor or a novolac resin is formed on the entire surface of the substrate 1 on which the first electrode layer 21 is formed by a coating method such as a spin coating method. Thereafter, the insulating film 24 is patterned in a lattice shape so that the light emitting portion is opened on the first electrode layer 21.

  Thereafter, an organic layer 22 including an organic light emitting layer is formed on the first electrode layer 21 in the light emitting section partitioned by the insulating film 24. The organic layer 22 can be formed by a vacuum evaporation method. The organic layer 22 includes a hole injection layer, a hole transport layer, an electron block layer, and the like formed from the anode side to the light emitting layer, and an electron injection layer and an electron transport layer formed from the cathode side to the light emitting layer. , A hole blocking layer and the like are formed. Each of these functional layers is appropriately selected as necessary, and not all layers are necessarily required.

  An example of forming the organic layer 22 when the first electrode layer 21 is an anode and the second electrode layer 23 is a cathode is shown below.

  A hole injection layer such as copper phthalocyanine (CuPc) is formed on the first electrode layer 21, and, for example, NPB (N, N-di (naphtalence) -N, N-dipheneyl-benzidene) is formed on the hole. A film is formed as a transport layer. The hole transport layer has a function of transporting holes injected from the first electrode layer 21 to the light emitting layer. The hole transport layer may be a single layer or a stack of two or more layers. In addition, the hole transport layer is not formed by a single material, but a single layer may be formed by a plurality of materials, and a guest material having a high charge donating (accepting) property may be formed on a host material having a high charge transport capability. Doping may be performed. In addition, the hole transport layer is formed in the opening, to the top of the first insulating film 3 that forms the opening, and to the top of the first insulating film 3 formed on the outermost edge.

Next, a light emitting layer is formed on the hole transport layer. As an example, red (R), green (G), and blue (B) light-emitting layers are formed in respective film formation regions by using a resistance heating vapor deposition method using a coating mask. As the red (R), an organic material that emits red light such as a styryl pigment such as DCM1 (4- (dicyanomethylene) -2-methyl-6- (4′-dimethylaminostyryl) -4H-pyran) is used. An organic material that emits green light such as an aluminum quinolinol complex (Alq ₃ ) is used as green (G). As the blue (B), an organic material emitting blue light such as a distyryl derivative or a triazole derivative is used. Of course, other materials or a host-guest layer structure may be used, and the emission form may be a fluorescent material or a phosphorescent material.

The electron transport layer formed on the light emitting layer is formed by using various materials such as an aluminum quinolinol complex (Alq ₃ ) by various film forming methods such as resistance heating vapor deposition. The electron transport layer has a function of transporting electrons injected from the second electrode layer 23 to the light emitting layer. This electron transport layer may have a multilayer structure in which only one layer is stacked or two or more layers are stacked. In addition, the electron transport layer may be formed of a plurality of materials instead of a single material, and a guest material having a high charge donating (accepting) property may be formed on a host material having a high charge transport capability. It may be formed by doping.

  For example, the second electrode layer 23 is patterned in a stripe shape along a direction orthogonal to the pattern of the first electrode layer 21. At this time, since pattern formation by wet etching cannot be performed, patterning using a film formation mask is performed. When the partition 25 is formed on the insulating film 24, the pattern of the second electrode layer 23 can be formed using the partition 25 as a mask pattern. When the second electrode 23 functions as a cathode, a material having a work function lower than that of the anode is used so as to have an electron injection function. For example, when ITO is used as the anode, it is preferable to use aluminum (Al) or a magnesium alloy (Mg—Ag). However, since Al has a low electron injection capability, it is preferable to provide an electron injection layer such as LiF between Al and the electron transport layer.

Protective layer forming step S11;
An example of forming the protective layer 7 having a two-layer structure will be described. First, the first inorganic protective layer 70 is formed so as to cover the outermost edge portion of the insulating film 24. When the substrate 1 is formed of an inorganic material such as glass, the first inorganic protective layer 70 is made of inorganic materials such as magnesium oxide (MgO), molybdenum oxide (MoO ₃ ), tin oxide (SnO ₂ ), monoxide. It can be formed of a metal oxide such as silicon (SiO) or aluminum oxide (Al ₂ O ₃ ), a metal nitride such as silicon nitride, or a metal oxynitride so that the second electrode layer 23 is not damaged. In order to achieve this, it is formed by a vacuum deposition method, a CVD method or the like. The first inorganic protective layer 70 is formed so that at least the formation range of the insulating film 24 is completely covered and the outer end portion is in contact with the substrate 1. As a result, when the first inorganic protective layer 70 is covered with the sealing adhesive 4, the contact interface between the first inorganic protective layer 70 and the substrate 1 has a blocking function to block deterioration factors such as moisture. It will be.

  Next, the second inorganic protective layer 71 is formed on the first inorganic protective layer 70. As a material of the second inorganic protective layer 71, various metals such as Al and metal oxides such as IZO, which have a barrier property against deterioration factors such as moisture, are used. The second inorganic protective layer 71 can also be formed by a vacuum deposition method in the same manner as the organic layer 22, the second electrode layer 23, and the first inorganic protective layer 70, but preferably a dense film is formed by sputtering. It is desirable to do. The formation range of the second inorganic protective layer 71 is wider than the formation range of the insulating film 27.

Sheet desiccant placement / fixation (space layer formation) step S12;
As the sheet-like desiccant 5, a sheet desiccant component dispersed in a binder resin can be used. The binder resin is not particularly limited as long as it does not interfere with the moisture adsorption action of the desiccant component. Preferably, a material having a high gas permeability (that is, a material having a low barrier property, a gas permeable resin, etc.) is used. . Examples of materials include polymer materials such as polyolefin-based, polyacryl-based, polyacrylonitrile-based, polyamide-based, polyester-based, epoxy-based, polycarbonate-based, and polyfluorinated-based materials. Among these, polyfluorinated resins are preferable, and more specifically, polytetrafluoroethylene is preferable.

The desiccant component is not particularly limited as long as it has a function capable of adsorbing at least moisture, but in particular, a compound capable of chemically adsorbing moisture and maintaining a solid state even when moisture is adsorbed is preferable. Examples of such compounds include metal oxides, metal inorganic acid salts and organic acid salts, and it is particularly preferable to use at least one of alkaline earth metal oxides and sulfates. Examples of the alkaline earth metal include calcium oxide (CaO), barium oxide (BaO), and magnesium oxide (MgO). Examples of the sulfate include lithium sulfate (Li ₂ SO ₄ ), sodium sulfate (Na ₂ SO ₄ ), calcium sulfate (CaSO ₄ ), magnesium sulfate (MgSO ₄ ), cobalt sulfate (CoSO ₄ ), and gallium sulfate (Ga). ₂ (SO ₄ ) ₃ ), titanium sulfate (Ti (SO ₄ ) ₂ ), nickel sulfate (NiSO ₄ ), and the like. In addition, an organic material having hygroscopicity can also be used.

  In the formation of the sheet-like desiccant 5, the total amount of the binder resin and the desiccant component is 100% by weight, the binder resin is 5 to 90% by weight, and the desiccant component is about 10 to 95%. Preferably, the binder resin is about 20 to 80% by weight and the desiccant component is about 20 to 80% by weight. And binder resin and a desiccant component are mixed uniformly. In this case, the dry component is preferably blended after sufficiently drying in advance. If necessary, the binder resin may be mixed after being heated and melted. As a molding method of the sheet-like desiccant 5, for example, granulation by a rolling granulator, a biaxial granulator, or the like can be applied in addition to press molding including hot press molding and extrusion molding. The stretching process to form a sheet may be performed according to a known method, and may be any one of uniaxial stretching and biaxial stretching.

  In order to arrange and fix such a sheet-like desiccant 5, an adhesive layer 6 is partially formed on one surface of the sheet-like desiccant 5. The formation pattern of the adhesive layer 6 can be a dot (dot), a line, a spiral, or the like, and the portion where the adhesive layer 6 is not formed corresponds to the space layer S. The thickness of the adhesive layer 6 is set to a thickness that can sufficiently secure the space layer S.

  Further, as shown in FIG. 2, an adhesive layer 51 is formed on one surface of the sheet-like desiccant 5, and the sheet-like desiccant 5 is fixed to the base material 52 via the adhesive layer 51. The member 50 is formed. As the substrate 52, fluorinated ethylene resin (PTFE) or the like is used. In this case, the adhesive layer 53 is partially formed on one surface of the substrate 2, and the sheet-like drying member 50 is bonded and fixed on the protective layer 7 while forming the space layer S.

Sheet-shaped drying member formation (space layer S) process S40;
As shown in FIG. 3, a sheet-shaped drying member 50 having a space layer S therein is formed using the sheet-shaped desiccant 5 described above. As shown in FIG. 3A, the sheet-like drying member 50 is obtained by fixing the sheet-like desiccant 5 to the base material 52 via the adhesive layer 51, and the base material 52 has the adhesive layer 53. Is formed. In order to form this sheet-like drying member 50, first, a partial adhesive layer 51 such as a dot shape is formed on one surface of a substrate 52 made of PET (polyethylene terephthalate) or the like, and the other surface is entirely formed. An adhesive layer 53 is formed. As the adhesive layers 51 and 53, for example, an acrylic adhesive can be used. And the sheet-like desiccant 5 mentioned above is affixed on the one surface of the base material 52 through the adhesive bond layer 51. FIG. Thereby, the sheet-like drying member 50 in which the space layer S is formed in a portion where the adhesive layer 51 does not exist is obtained.

Sheet-like drying member arrangement / fixing step S13;
The sheet-like drying member 50 on which the space layer S is formed is disposed on the organic EL element, and is bonded and fixed by the adhesive layer 53. The sheet-shaped drying member 50 is disposed so as to cover the entire organic EL element, and is disposed so as to cover the entire protective layer 7.

Sealing adhesive forming step S20, bonding step S30;
A sealing adhesive 4 for sealing is formed on one surface of the sealing member 3, and the substrate 1 and the sealing member 3 are bonded to each other with the sheet-like desiccant 5 or the sheet-like desiccating member 50 interposed therebetween, and the organic EL element Sealing is performed between the substrate 1 and the sealing member 3. As the sealing adhesive 4, an ultraviolet curable or thermosetting epoxy resin or the like can be used. For example, the sealing adhesive 4 is attached to the sealing member 3 by a laminating method. After the substrate 1 and the sealing member 3 are bonded together via the sealing adhesive 4, the sealing adhesive 4 is cured by ultraviolet irradiation or heat treatment.

[Example]
Using PTFE as a binder resin and calcium oxide (CaO) as a desiccant component, a mixture of these in a weight ratio of 65:35 was processed into a sheet shape to form a sheet-like desiccant 5 having a thickness of about 70 μm. . An adhesive layer 51 made of an acrylic adhesive is formed in a dot shape on one surface of a base material 52 made of PET, and an adhesive layer 53 made of an acrylic adhesive is formed on the entire surface of the other surface of the base material 52. After forming, this was affixed on the sheet-like desiccant 5, and the sheet-like drying member 50 was formed.

After forming an ITO film as the first electrode layer 21 on the glass substrate 1 and patterning it in a stripe shape, an insulating film 24 made of polyimide is formed on the first electrode 21 so as to open a light emitting portion, As the organic layer 22, copper phthalocyanine (CuPc) is 30 nm as a hole injection layer, NPB is 30 nm as a hole transport layer, Alq ₃ doped with 0.6% by weight of coumarin as a light emitting layer is 30 nm, and Alq ₃ is an electron transport layer. ₃ is 30 nm, Li ₂ O is 1 nm as an electron injection layer, and these are formed by vacuum deposition, respectively. As the second electrode layer 23, an Al film is formed in a stripe shape so as to intersect the first electrode layer 21. A film was formed to form an organic EL element.

Then, a first inorganic protective layer 70 having a thickness of 100 nm is deposited by vapor deposition of a mixed layer of MgO and MoO ₃ so as to cover the outermost edge of the formed organic EL element, and a second inorganic protective layer 71 having a thickness of 300 nm is formed by sputtering IZO. Was formed as the protective layer 7. A protective layer 7 composed of a first inorganic protective layer 70 and a second inorganic protective layer 71 was formed. The above-mentioned sheet-like dry member 50 is bonded and fixed on the protective layer 7 through the adhesive layer 53, and the sealing adhesive 4 made of a thermosetting epoxy resin is laminated on the glass sealing member 3. The substrate 1 and the sealing member 3 were bonded together with a sealing adhesive 4 interposed therebetween.

  In contrast to the example of the organic EL panel formed in this way, the organic EL panel in which the adhesive layer 51 in the sheet-like drying member 50 is formed not on the entire surface but in the form of dots (that is, having no space layer S, Other than that, the same organic EL panel as in Example was formed as Comparative Example 1.

  In addition to the organic EL panel example described above, an organic EL panel that does not form a sheet-like desiccant (has a protective layer 7 formed so as to cover the outermost part of the organic EL element, and is sealed and adhered thereon. An organic EL panel in which the substrate 1 and the sealing member 3 were bonded together with the agent 4 interposed therebetween was used as Comparative Example 2.

  Moreover, the organic EL panel which does not form the protective layer 7 (an organic EL panel sealed only with the sealing adhesive 4 covering the organic EL element and the sealing member 3) is compared with the organic EL panel example described above. Example 3 was used.

The organic EL panels of Examples and Comparative Examples 1 to 3 were stored under conditions of high temperature and high humidity (60 ° C., 90%), and the progress of the non-light emitting part (black frame) formed in the light emitting part and the light emitting part G The growth rate of dark spots formed was observed. The results are summarized in (Table 1: Formation status of non-light-emitting portions in Examples and Comparative Examples).

  FIG. 7 is an explanatory diagram showing the effect of this embodiment. As shown in the figure, the progress of the non-light emitting portion (black frame) is formed from the end of the light emitting portion G toward the center with the light emitting portion G closest to the end 1E of the substrate 1 as a target. The width w of the non-light emitting part (black frame) bf is measured.

  The start time of occurrence of the non-light-emitting portion (black frame) bf is approximately 200 h in Comparative Example 3, whereas the progress of the non-light-emitting portion (black frame) bf in the Example, Comparative Example 1 and Comparative Example 2 exceeds 1500 h. Was not confirmed.

  After the progress of the non-light-emitting portion (black frame) bf is confirmed in the embodiment of the present invention, the speed of the non-light-emitting portion (black frame) bf is slower in the embodiment of the present invention than in the comparative example 3. Was confirmed. In Comparative Example 1, there is a sample in which the progress of the non-light-emitting portion (black frame) bf is slow, but there is a sample whose progress speed is high as in Comparative Example 3 without being suppressed, and the non-light-emitting portion (black frame) bf The stability of the progress inhibition effect was low.

  Further, there was a difference in the growth rate of dark spots formed in the light emitting part G. In the example, a dark spot having a diameter of about 10 μm started to light after 950 h and expanded after 950 h, and was about 18 μm even after 1930 h. The enlargement speed is about 0.6 μm / 100 h. On the other hand, in Comparative Example 2, the dark spot having a diameter of about 11 μm was enlarged with the passage of time at 490 h and became about 48 μm after 1930 h. The start of the enlarging time was early, and the enlarging speed was about 2.5 μm / 100 h, which is about 4 times that of the example.

  The Example of this invention has confirmed that there existed a difference with respect to Comparative Examples 1, 2, and 3 by the point that the suppression effect becomes high with both a black frame and a dark spot.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing (the figure (a) is a conceptual diagram which shows a cross-section, and the conceptual diagram which shows the cross section of the edge part of the same figure (b)) explaining the structure of the organic electroluminescent panel concerning one Embodiment of this invention. FIG. 2 is an explanatory view showing the structure of a sheet-like drying member containing a sheet-like desiccant (FIG. 2A is a longitudinal sectional view showing the sheet-like drying member, and FIG. 2B is a rear view). Explanatory drawing which showed the other structural example of the sheet-like drying member containing a sheet-like desiccant (the figure (a) is a longitudinal cross-sectional view which shows a sheet-like drying member, the figure (b) is the XX sectional drawing) It is explanatory drawing which shows the organic electroluminescent panel which concerns on other embodiment of this invention. It is explanatory drawing (process flow) which shows the manufacturing method of the organic electroluminescent panel which concerns on embodiment of this invention. It is explanatory drawing (process flow) which shows the manufacturing method of the organic electroluminescent panel which concerns on embodiment of this invention. It is explanatory drawing which shows the effect of the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Organic EL element, 3 ... Sealing member, 4 ... Sealing adhesive agent,
DESCRIPTION OF SYMBOLS 5 ... Sheet-like desiccant, 6 ... Adhesive layer, 7 ... Protective layer, 70 ... 1st inorganic protective layer, 71 ... 2nd inorganic protective layer, S ... Spatial layer, 50 ... Sheet-like drying member

Claims (9)

An organic EL panel in which a plurality or single organic EL elements are formed on a substrate, and the substrate and the sealing member are bonded together with a sealing adhesive covering the organic EL elements,
The organic EL element includes a first electrode layer formed directly or via another layer on the substrate, an organic layer including an organic light emitting layer formed on the first electrode layer, and an organic layer on the organic layer. A second electrode layer formed on
A first protective layer made of an inorganic material in contact with the second electrode layer and a second protective layer made of an inorganic material laminated on the first protective layer so as to cover the entire organic EL element Forming a protective layer,
A sheet-like desiccant is disposed on the protective layer so as to cover the entire organic EL element,
An organic EL panel, wherein a space layer is formed between the sheet-like desiccant and the organic EL element.   The organic EL panel according to claim 1, wherein the first protective layer is a layer formed by vapor deposition, and the second protective layer is a layer formed by sputtering.   The said space layer is formed in the part which does not have this adhesive bond layer by forming in part the adhesive bond layer for fixing the said sheet-like desiccant. Organic EL panel.   The organic EL panel according to claim 3, wherein the space layer is formed inside a sheet-shaped drying member in which the sheet-shaped desiccant is fixed to a base material.   The organic EL panel according to claim 3 or 4, wherein the adhesive layer for fixing the sheet-like desiccant is formed in a dot shape. A method for producing an organic EL panel in which a plurality or a single organic EL element is formed on a substrate, and the substrate and a sealing member are bonded together with a sealing adhesive covering the organic EL element,
Forming an organic EL element on the substrate;
Forming a first protective layer made of an inorganic material in contact with the second electrode layer so as to cover the entire organic EL element;
Forming a second protective layer made of an inorganic material on the first protective layer;
Fixing the sheet-like desiccant to the base material to form a sheet-like drying member;
In a state where the sheet-like drying member is disposed between the substrate and the sealing member so as to cover the entire organic EL element, and a space layer is formed between the sheet-like desiccant and the organic EL element. And a step of bonding the substrate and the sealing member together.   The space layer is formed in a portion without the adhesive layer by partially forming an adhesive layer for fixing the sheet-like drying member on the second protective layer. Item 7. A method for producing an organic EL panel according to Item 6.   The sheet-like desiccant and the base material are bonded together so that an adhesive layer for fixing the sheet-like desiccant is partially formed and the space layer is formed in a portion without the adhesive layer. The method for producing an organic EL panel according to claim 6, wherein the sheet-like drying member is formed.   9. The organic EL panel according to claim 6, wherein the step of forming the first protective layer is performed by vapor deposition, and the step of forming the second protective layer is performed by sputtering. Production method.

Images