JP2016162715A - Method of manufacturing organic el device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an organic EL device capable of improving display quality.SOLUTION: The method of manufacturing an organic EL device 100 comprises the steps of: forming an organic EL element 30 including a pixel electrode 31, a functional layer 32, and a counter electrode 33, on a substrate 11; forming a cathode protection layer 34a on the organic EL element 30; forming an organic buffer layer 34c on the cathode protection layer 34a; and forming a gas barrier layer 34d on the organic buffer layer 34c. The method also comprises a step of forming a cover layer 34b on the cathode protection layer 34a between the step of forming the cathode protection layer 34a and the step of forming the organic buffer layer 34c.SELECTED DRAWING: Figure 5

Description

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

  The organic EL (electroluminescence) device has a light emitting element in which a light emitting layer (functional layer) made of an organic light emitting material is sandwiched between an anode (pixel electrode) and a cathode (counter electrode). In the organic EL device, for example, a light emitting layer, a cathode, a cathode protective layer, an organic buffer layer, and a gas barrier layer are arranged in this order from the substrate side.

  For example, as described in Patent Document 1, the organic buffer layer is manufactured by arranging a screen mesh on the cathode protective layer on the substrate using a screen printing apparatus and pattern printing the coating material with a squeegee. (Transfer), and then the screen mesh is peeled off.

JP 2007-69548 A

  However, if the organic buffer layer is also made thinner as the entire organic EL device is made thinner in order to improve the luminance, a part of the printing device or transfer device (for example, a screen mesh in the screen printing device) becomes the cathode protective layer. Easy to touch. When contacted, damage such as a crack is applied to the cathode protective layer, and there is a problem that a component (for example, epoxy resin) from the organic buffer layer enters from the crack and the cathode formed in the lower layer deteriorates. As a result, there is a problem that a non-light emitting region occurs.

  An aspect of the present invention has been made to solve at least a part of the above problems, and can be realized as the following forms or application examples.

  Application Example 1 An organic EL device manufacturing method according to this application example includes a step of forming an organic EL element including a pixel electrode, a functional layer, and a counter electrode on a substrate, and cathode protection on the organic EL element. Forming an organic buffer layer on the cathode protective layer; and forming a gas barrier layer on the organic buffer layer; A step of forming a cover layer on the cathode protective layer is included between the step of forming the cathode protective layer and the step of forming the organic buffer layer.

  According to this application example, the cover layer is formed between the cathode protective layer and the organic buffer layer. Therefore, when forming the organic buffer layer, for example, even when a part of the device to be formed is in contact with the substrate, the cover is formed. Since the layer is formed, it is possible to suppress damage to the underlying cathode protective layer. Therefore, it is possible to prevent the cathode protective layer from cracking, as in the case where a part of the device directly contacts the cathode protective layer, and to prevent the counter electrode formed in the lower layer from deteriorating. Can do. As a result, it is possible to suppress the occurrence of a non-light emitting portion.

  Application Example 2 In the method of manufacturing the organic EL device according to the application example, it is preferable that the organic buffer layer is formed on the cover layer using a screen printing method. .

  According to this application example, even when the organic buffer layer is formed using the screen printing method, the cover layer is formed on the cathode protective layer in advance, so that a part of the screen printing apparatus is in contact with the substrate. However, it is possible to suppress damage to the cathode protective layer directly. Therefore, deterioration of the counter electrode can be suppressed.

  Application Example 3 In the method of manufacturing an organic EL device according to the application example, the step of forming the cover layer includes the step of forming an end portion of the cover layer outside the end portion of the display area in plan view, and the cathode. The cover layer is preferably formed so as to be inside the protective layer and the end portions of the gas barrier layer.

  According to this application example, since the end portion of the cover layer is formed so as to be outside the end portion of the display area in plan view, at least the display area (light emitting area) can be covered with the cover layer. Thus, when the screen printing method is used, the display region (light emitting area) can be protected by the cover layer even when the substrate is in contact with the substrate.

  Application Example 4 In the method for manufacturing an organic EL device according to the application example, the cover layer preferably has a thickness of 100 nm to 500 nm.

  According to this application example, by forming the cover layer so as to have the above film thickness, even when a part of the screen printing apparatus is in contact with the substrate, the cover layer can absorb the stress, It is possible to suppress damage to the lower cathode protective layer.

  Application Example 5 In the method for manufacturing an organic EL device according to the application example, the cover layer material is preferably an organic low molecular weight material.

  According to this application example, since the organic low molecular weight material is used for the cover layer, the cover layer serves as a cushion even when there is physical contact with the cover layer. It can suppress that damage is added to.

FIG. 2 is an equivalent circuit diagram illustrating an electrical configuration of the organic EL device according to the embodiment. 1 is a schematic plan view showing the configuration of an organic EL device. 1 is a schematic cross-sectional view showing the overall structure of an organic EL device. The flowchart which shows the manufacturing method of an organic electroluminescent apparatus. The schematic sectional drawing which shows a one part manufacturing process among the manufacturing methods of an organic electroluminescent apparatus. The schematic sectional drawing which shows the method of screen printing. The schematic sectional drawing which shows a one part manufacturing process among the manufacturing methods of an organic electroluminescent apparatus.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

  In the following forms, for example, “on the substrate” is described, and unless otherwise specified, when arranged so as to be in contact with the substrate, or disposed on the substrate via other components. Or a case where a part is disposed on the substrate and a part is disposed via another component.

<Organic EL device>
First, the organic EL device of the present embodiment will be described with reference to FIGS. FIG. 1 is an equivalent circuit diagram showing the electrical configuration of the organic EL device of the present embodiment, FIG. 2 is a schematic plan view showing the configuration of the organic EL device of the present embodiment, and FIG. 3 shows the overall structure of the organic EL device. It is a schematic sectional drawing.

  As shown in FIG. 1, the organic EL device 100 according to this embodiment includes a plurality of scanning lines 12 and a plurality of data lines 13 that intersect each other, and a plurality of power supply lines 14 that are parallel to each of the plurality of data lines 13. And have. It has a scanning line driving circuit 16 to which a plurality of scanning lines 12 are connected, and a data line driving circuit 15 to which a plurality of data lines 13 are connected. In addition, a plurality of sub-pixels 18 are arranged in a matrix corresponding to each intersection of the plurality of scanning lines 12 and the plurality of data lines 13.

  The sub pixel 18 includes an organic EL element 30 as a light emitting element and a pixel circuit 20 that controls driving of the organic EL element 30.

  The organic EL element 30 includes a pixel electrode 31, a counter electrode 33 as a common electrode, and a functional layer 32 as an organic light emitting layer provided between the pixel electrode 31 and the counter electrode 33. Such an organic EL element 30 can be electrically expressed as a diode. As will be described in detail later, the counter electrode 33 is formed as a common cathode across the plurality of sub-pixels 18.

  The pixel circuit 20 includes a switching transistor 21, a storage capacitor 22, and a driving transistor 23. The two transistors 21 and 23 can be configured using, for example, an n-channel or p-channel thin film transistor (TFT) or a MOS transistor.

  The gate of the switching transistor 21 is connected to the scanning line 12, one of the source or drain is connected to the data line 13, and the other of the source or drain is connected to the gate of the driving transistor 23.

  One of the source and drain of the driving transistor 23 is connected to the pixel electrode 31 of the organic EL element 30, and the other of the source and drain is connected to the power supply line 14. A storage capacitor 22 is connected between the gate of the driving transistor 23 and the power supply line 14.

  When the scanning line 12 is driven and the switching transistor 21 is turned on, the potential based on the image signal supplied from the data line 13 at that time is held in the storage capacitor 22 via the switching transistor 21.

  The on / off state of the driving transistor 23 is determined according to the potential of the storage capacitor 22, that is, the gate potential of the driving transistor 23. When the driving transistor 23 is turned on, a current corresponding to the gate potential flows from the power supply line 14 to the functional layer 32 sandwiched between the pixel electrode 31 and the counter electrode 33 via the driving transistor 23. The organic EL element 30 emits light according to the amount of current flowing through the functional layer 32.

  As shown in FIG. 2, the organic EL device 100 has an element substrate 10. The element substrate 10 is provided with a display area E0 (indicated by a one-dot chain line in the drawing) and a non-display area E3 outside the display area E0. The display area E0 has an actual display area E1 (indicated by a two-dot chain line in the figure) and a dummy area E2 surrounding the actual display area E1.

  In the actual display area E1, sub-pixels 18 as light-emitting pixels are arranged in a matrix. The sub-pixel 18 includes the organic EL element 30 as described above, and any one of blue (B), green (G), and red (R) in accordance with the operation of the switching transistor 21 and the driving transistor 23. The light emission of the color is obtained.

  In the present embodiment, the sub-pixels 18 that can emit light of the same color are arranged in the first direction, and the second direction in which the sub-pixels 18 that can emit light of different colors intersect (orthogonal) the first direction. The so-called stripe-type sub-pixels 18 are arranged in an array. Hereinafter, the first direction is referred to as the Y direction, and the second direction is referred to as the X direction. The arrangement of the sub-pixels 18 on the element substrate 10 is not limited to the stripe method, and may be a mosaic method or a delta method.

  The dummy area E2 is provided with a peripheral circuit mainly for causing the organic EL elements 30 of the sub-pixels 18 to emit light. For example, as shown in FIG. 2, a pair of scanning line driving circuits 16 are provided extending in the Y direction at positions sandwiching the actual display area E1 in the X direction. An inspection circuit 17 is provided between the pair of scanning line driving circuits 16 at a position along the actual display area E1.

  A flexible circuit board (FPC) 43 for electrical connection with an external drive circuit is connected to one side (the lower side in the figure) parallel to the X direction of the element substrate 10. A driving IC 44 connected to the peripheral circuit on the element substrate 10 side through the wiring of the FPC 43 is mounted on the FPC 43. The driving IC 44 includes the data line driving circuit 15 described above, and the data line 13 and the power supply line 14 on the element substrate 10 side are electrically connected to the driving IC 44 via the flexible circuit board 43.

  Between the display area E0 and the outer edge of the element substrate 10, that is, in the non-display area E3, for example, a wiring 29 for applying a potential to the counter electrode 33 of the organic EL element 30 of each subpixel 18 is formed. The wiring 29 is provided on the element substrate 10 so as to surround the display area E0 except for the side portion of the element substrate 10 to which the FPC 43 is connected.

  Next, the structure of the organic EL device will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view schematically showing the structure of the organic EL device. The organic EL device in the present embodiment is a so-called “top emission structure” organic EL device.

  As shown in FIG. 3, the organic EL device 100 is arranged such that the element substrate 10 and the counter substrate 41 face each other with an adhesive layer 42 interposed therebetween.

  Specifically, wiring, a driving transistor 23 (see FIG. 1), and the like are provided on a base material 11 as a substrate constituting the element substrate 10, a pixel electrode 31 is provided thereon, and an organic light emitting layer is further provided. A functional layer 32 is provided. The functional layer 32 is covered with a counter electrode 33 that functions as a cathode.

  The portion where the functional layer 32 is sandwiched between the pixel electrode 31 and the counter electrode 33 is the organic EL element 30.

  Further, a sealing layer 34 is formed on the counter electrode 33 over the counter electrode 33 and the entire substrate 11. On the sealing layer 34, a color filter 36 is formed so as to substantially overlap the region of the functional layer 32 in plan view. An adhesive layer 42 is provided on the color filter 36. A counter substrate 41 is disposed on the adhesive layer 42.

  Since the organic EL device 100 is a top emission type, the substrate 11 can be a transparent substrate such as glass or an opaque substrate such as silicon or ceramics.

  The wiring and the driving transistor 23 formed on the base material 11 are covered with an insulating layer 26. A contact hole (not shown) is formed in the insulating layer 26, and the pixel electrode 31 is electrically connected to the driving transistor 23. On the insulating layer 26, a planarizing insulating layer 27 in which a reflective layer 25 made of an aluminum alloy or the like is provided is formed.

  Light emitted from the functional layer 32 is reflected by the reflective layer 25 and transmitted through the color filter 36 and extracted from the counter substrate 41 side.

  On the planarization insulating layer 27, an organic EL element 30 including a pixel electrode 31, a functional layer 32, and a counter electrode 33 is formed. Further, an insulating pixel partition wall 28 is disposed so as to partition the organic EL element 30.

  The pixel electrode 31 is formed using a transparent conductive film such as ITO (Indium Tin Oxide). In the case where the reflective layer 25 is not provided for each subpixel 18, the pixel electrode 31 may be formed using aluminum having light reflectivity or an alloy thereof.

  The functional layer 32 is formed using a vapor phase process such as a vacuum deposition method or an ion plating method so as to be in contact with each pixel electrode 31.

  The functional layer 32 includes, for example, a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron transport layer. In the present embodiment, a functional layer 32 is formed by forming a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron transport layer on the pixel electrode 31 by using a vapor phase process and sequentially stacking them. Is formed. The layer configuration of the functional layer 32 is not limited to this, and may include an intermediate layer that controls the movement of holes and electrons that are carriers.

  The organic light emitting layer may be configured to obtain white light emission. For example, an organic light emitting layer capable of obtaining red light emission, an organic light emitting layer capable of obtaining green light emission, and an organic light emitting layer capable of obtaining blue light emission; It is possible to adopt a combination of the above.

  A counter electrode 33 is formed to cover the functional layer 32. The counter electrode 33 is formed, for example, by forming a film of an alloy of Mg and Ag with a thickness sufficient to obtain light transmissivity and light reflectivity. As a result, a plurality of organic EL elements 30 are completed.

  In addition, an optical resonator is configured between the reflective layer 25 and the counter electrode 33 for each of the sub-pixels 18R, 18G, and 18B by forming the counter electrode 33 in a state having light transmittance and light reflectivity. Also good.

  Next, a sealing layer 34 that covers the plurality of organic EL elements 30 is formed so that water, oxygen, and the like do not enter. The sealing layer 34 of the present embodiment is formed by laminating a cathode protective layer 34a, a cover layer 34b, an organic buffer layer 34c, and a gas barrier layer 34d in this order from the counter electrode 33 side.

The cathode protective layer 34a is preferably made of a silicon-based material having light permeability and excellent gas barrier properties, such as silicon oxynitride (SiON). Note that SiO ₂ may be used. The film thickness of the cathode protective layer 34a is, for example, about 200 nm.

  A cover layer 34b is disposed on the cathode protective layer 34a. The cover layer 34b is provided between the cathode protective layer 34a and the organic buffer layer 34c described later, so that when the organic buffer layer 34c is formed by a screen printing method, a part of a screen printing apparatus (for example, a screen) Even when the mesh, the screen printing plate 51 (see FIG. 6) is in contact with the element substrate 10, it is possible to prevent the cathode protective layer 34a from being damaged.

  Accordingly, even when the screen printing plate 51 (see FIG. 6) is in contact with the element substrate 10 in order to form the organic buffer layer 34c thin, the cover layer 34b serves as a cushion, so that the cathode protective layer 34a is hardly damaged. The deterioration of the counter electrode 33 can be suppressed. As a result, generation of a non-light emitting region can be suppressed. Furthermore, since the organic buffer layer 34c can be formed thin, the luminance can be improved.

  Examples of the material of the cover layer 34b include organic low molecular weight materials such as Alq3 (Tris (8-quinolinolato) aluminum). The thickness of the cover layer 34b is, for example, about 100 nm to 500 nm. Thus, by forming the cover layer 34b with an organic material with the above film thickness, even when a part of the screen printing apparatus is in contact with the element substrate 10, the cover layer 34b functions as a cushion. Therefore, the stress can be absorbed, and damage to the lower cathode protective layer 34a can be suppressed.

  Further, the cover layer 34b is formed such that the end portion of the cover layer 34b is outside the display region E0 (actual display region E1) in a plan view and inside the end portions of the cathode protective layer 34a and the gas barrier layer 34d. It is preferable to form so that it becomes.

  An organic buffer layer 34c is provided on the cover layer 34b. The organic buffer layer 34c is arranged so as to fill the uneven portion of the cathode protective layer 34a formed in an uneven shape due to the influence of the shape of the pixel partition wall 28, and the upper surface thereof is formed substantially flat. The organic buffer layer 34c has a function of relieving stress generated by warping or volume expansion of the element substrate 10 and preventing the cathode protective layer 34a from peeling from the pixel partition 28 having an unstable shape.

  In addition, since the upper surface of the organic buffer layer 34c is substantially planarized, the gas barrier layer 34d made of a hard film formed on the organic buffer layer 34c is also planarized. Therefore, there is no portion where stress is concentrated, and the occurrence of cracks in the gas barrier layer 34d is prevented. Further, the unevenness is filled by covering the pixel partition wall 28, which is effective in improving the film thickness uniformity of the black matrix 36a and the colored layers 36R, 36G, and 36B formed on the gas barrier layer 34d.

  The organic buffer layer 34c can be formed using, for example, an epoxy resin or a coating-type inorganic material (such as silicon oxide) that has excellent thermal stability. If the organic buffer layer 34c is applied and formed by screen printing, the surface of the organic buffer layer 34c can be planarized. That is, the organic buffer layer 34c can also function as a flattening layer that relieves unevenness on the surfaces of the cathode protective layer 34a and the cover layer 34b. The thickness of the organic buffer layer 34c is about 2 μm.

  The gas barrier layer 34d is for preventing oxygen and moisture from entering, and thereby, deterioration of the organic EL element 30 due to oxygen and moisture can be suppressed. As the gas barrier layer 34d, it is preferable to use a silicon-based material having optical transparency and excellent gas barrier properties, such as silicon oxynitride (SiON).

  A color filter 36 is formed on the gas barrier layer 34d. Specifically, each color coloring layer 36 (red color layer 36R, green color layer 36G, blue color layer 36B) constituting the color filter 36 and a black matrix 36a are formed between the color color layers.

  The black matrix 36a is, for example, a light shielding layer made of a resin mixed with a pigment such as carbon black. In order to perform appropriate color conversion, light between adjacent pixel regions of the colored layers 36R, 36G, and 36B described above is used. This is to prevent leakage.

  A counter substrate 41 is disposed on the color filter 36 with an adhesive layer 42 interposed therebetween. The counter substrate 41 is made of a transparent substrate such as glass. The adhesive layer 42 is made of, for example, a transparent resin material. Examples of the transparent resin material include urethane, acrylic, epoxy, and polyolefin resin materials.

  The adhesive layer 42 is filled in the organic EL device 100 surrounded by the sealing material 37 without any gap, and fixes the counter substrate 41 disposed opposite to the element substrate 10 and against mechanical shock from the outside. It has a buffer function and protects the organic EL element 30 and the gas barrier layer 34d.

  A sealing material 37 is provided in the peripheral portion between the element substrate 10 and the counter substrate 41. The sealing material 37 is made of, for example, an epoxy material that is cured by ultraviolet rays to improve the viscosity.

<Method for manufacturing organic EL device>
Next, a method for manufacturing the organic EL device of this embodiment will be described with reference to FIGS. FIG. 4 is a flowchart showing a method for manufacturing the organic EL device. 5 to 7 are schematic cross-sectional views illustrating some of the manufacturing steps in the method for manufacturing the organic EL device.

  As shown in FIG. 4, the manufacturing method of the organic EL device 100 of the present embodiment includes a cathode protective layer forming step (step S11), a cover layer forming step (step S12), and an organic buffer layer forming step (step S13). And a gas barrier layer forming step (step S14), a color filter forming step (step S15), and a bonding step (step S16). As a method for forming the driving transistor 23, the organic EL element 30, and the like on the substrate 11, a known method can be adopted.

  Therefore, in FIGS. 5A to 7G, the display of the configuration of the driving transistor 23 and the organic EL element 30 on the base material 11 is omitted. Hereinafter, the manufacturing method of the characteristic part of the present invention will be mainly described.

  First, as shown in FIG. 4, in step S <b> 11, the cathode protective layer 34 a is formed so as to cover the counter electrode 33. Specifically, as shown in FIG. 5A, a cathode protective layer 34a made of silicon oxynitride (SiON) or the like is formed on the element substrate 10 on which the counter electrode 33 is formed.

  Examples of the method for forming the cathode protective layer 34a include a vacuum deposition method and a sputtering method. The film thickness of the cathode protective layer 34a is, for example, about 200 nm.

  In step S12, the cover layer 34b is formed. Specifically, as shown in FIG. 5B, the cover layer 34b is formed on the cathode protective layer 34a by using, for example, a vacuum deposition method. As described above, examples of the material for the cover layer 34b include organic low-molecular materials such as Alq3. The film thickness of the cover layer 34b is, for example, about 100 nm to 500 nm.

  In step S13, the organic buffer layer 34c is formed. Specifically, as shown in FIG. 6, it is formed using a screen printing method. FIG. 6 is a schematic cross-sectional view showing a screen printing method.

  As shown in FIG. 6, on the element substrate 10, a screen printing plate 51 for selectively supplying a solution 34c1 to be the organic buffer layer 34c is disposed. On the screen printing plate 51, a squeegee 52 for spreading the solution 34c1 over the whole is disposed. The material of the screen printing plate 51 is, for example, stainless steel.

  The solution 34c1 includes a thermosetting epoxy resin having transparency and a solvent for the epoxy resin. The organic buffer layer 34c made of an epoxy resin is formed by applying the solution 34c1 by a screen printing method and drying it. Specifically, the solution 34c1 that has been screen-printed in a reduced-pressure atmosphere is cured by heating in the range of 60 ° C to 100 ° C. As described above, the thickness of the organic buffer layer 34c is, for example, about 2 μm.

  Specifically, the solution 34 c 1 is supplied onto the screen printing plate 51, and the solution 34 c 1 is stretched along the surface of the screen printing plate 51 with the squeegee 52, so that the opening 34 a is formed in the screen printing plate 51. The solution 34c1 falls and is applied onto the element substrate 10.

  Thereafter, the applied solution 34c1 is heated and cured. Thereby, an organic buffer layer 34c as shown in FIG. 5C is formed.

  At this time, since it is desired to reduce the film thickness of the organic buffer layer 34 c, the clearance (distance) between the screen printing plate 51 and the element substrate 10 is reduced, and the screen printing plate 51 may come into contact with the element substrate 10. In other words, the cathode protective layer 34a on the element substrate 10 and the screen printing plate 51 are in contact with each other. As a result, a crack occurs in the cathode protective layer 34a, and the component of the organic buffer layer 34c may enter through the crack and the counter electrode 33 may be deteriorated.

  In the present invention, since the cover layer 34b is formed on the cathode protective layer 34a, even when the screen printing plate 51 and the element substrate 10 come into contact with each other during screen printing, the contact impact is absorbed by the cover layer 34b. Thus, damage to the cathode protective layer 34a can be suppressed.

  In other words, when the organic buffer layer 34c is formed thin, even if the screen printing plate 51 comes into contact with the element substrate 10, the cover layer 34b serves as a cushion, so that the cathode protective layer 34a is hardly damaged, and the counter electrode 33 Can be prevented from deteriorating. As a result, it is possible to suppress the occurrence of a non-light emitting region where the organic EL element 30 does not emit light. Furthermore, since the organic buffer layer 34c can be formed thin, the luminance can be improved.

  In step S14, the gas barrier layer 34d is formed. Specifically, as shown in FIG. 7D, the gas barrier layer 34d is formed on the organic buffer layer 34c by using, for example, a vacuum deposition method or a sputtering method. The material of the gas barrier layer 34d is, for example, silicon oxynitride (SiON). The film thickness of the gas barrier layer 34d is, for example, approximately 200 nm to 400 nm.

  In addition, although the high gas barrier property is realizable by making the film thickness of the cathode protective layer 34a and the gas barrier layer 34d thick, on the other hand, it is easy to produce a crack by expansion | swelling and shrinkage | contraction. Therefore, it is preferable to control the film thickness to about 200 nm to 400 nm.

  In step S15, the color filter 36 is formed. Specifically, as shown in FIG. 7E, first, a black matrix 36a is formed on the gas barrier layer 34d. As a manufacturing method of the black matrix 36a, the material liquid of the black matrix 36a is applied to the surface of the gas barrier layer 34d by, for example, an inkjet method in an air atmosphere. Next, the material liquid of the black matrix 36a is dried and cured.

  Next, as shown in FIG. 7F, colored layers 36R, 36G, and 36B are formed on the element substrate 10 on which the black matrix 36a is formed. Specifically, the material liquid of each of the colored layers 36R, 36G, and 36B is applied by an ink jet method between the regions where the black matrix 36a on the surface of the gas barrier layer 34d is formed in an air atmosphere. Next, the element substrate 10 coated with the material liquid for the colored layers 36R, 36G, and 36B is dried and cured, so that the colored layers 36R, 36G, and 36B corresponding to the sub-pixels 18R, 18G, and 18B of the respective colors are formed. The color filter 36 is completed.

  In step S16, the element substrate 10 and the counter substrate 41 are bonded together. Specifically, as shown in FIG. 7G, first, the sealing material 37 is temporarily cured by irradiating the counter substrate 41 applied with the material liquid of the adhesive layer 42 and the sealing material 37 with ultraviolet rays.

  Next, the element substrate 10 and the counter substrate 41 are bonded and bonded together. Thereafter, the bonded organic EL device 100 is heated in the atmosphere. Thereby, the temporarily cured sealing material 37 and the adhesive layer 42 are thermally cured. Thus, the organic EL device 100 is completed.

  As described above in detail, according to the method for manufacturing the organic EL device 100 of the present embodiment, the following effects can be obtained.

  (1) According to the method for manufacturing the organic EL device 100 of the present embodiment, the cover layer 34b is formed between the cathode protective layer 34a and the organic buffer layer 34c, so that the organic buffer layer 34c is formed by screen printing. Even when a part of the screen printing apparatus (for example, the screen printing plate 51) is in contact with the element substrate 10 during the formation, the cover layer 34b can absorb the stress, and the cathode protective layer 34a underneath can be absorbed. Damage can be prevented from being added. Therefore, it becomes possible to prevent the cathode protective layer 34a from cracking, as in the case where the screen printing plate 51 is in direct contact with the cathode protective layer 34a, and the counter electrode 33 formed under the cathode protective layer 34a is deteriorated. Can be prevented. As a result, it is possible to suppress the occurrence of a non-light emitting portion.

  (2) According to the method for manufacturing the organic EL device 100 of the present embodiment, since the end of the cover layer 34b is formed so as to be outside the end of the display area in plan view, at least the display area (light emitting area) ) Can be covered with a cover layer 34b. Therefore, when the organic buffer layer 34c is formed by using the screen printing method, the display region (light emitting area) can be protected by the cover layer 34b even when a part of the screen printing apparatus is in contact with the element substrate 10. .

  (3) According to the method for manufacturing the organic EL device 100 of the present embodiment, when the organic buffer layer 34c is formed by the screen printing method, the clearance between the element substrate 10 and the screen printing plate 51 can be reduced. The film thickness of the organic buffer layer 34c can be reduced. Therefore, luminance can be improved.

  The aspect of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification. It is included in the range. Moreover, it can also implement with the following forms.

(Modification 1)
As described above, the method of forming the cover layer 34b is not limited to the formation of the organic low molecular weight material using the vacuum vapor deposition method, and any method other than the vacuum vapor deposition method may be used as long as a thin film can be formed. You may make it form.

(Modification 2)
As described above, the organic buffer layer 34c is formed using a screen printing method, but is not limited thereto, and other printing methods such as gravure printing may be used, or other transfer methods may be used. You may do it.

  DESCRIPTION OF SYMBOLS 10 ... Element board | substrate, 11 ... Base material as a board | substrate, 12 ... Scanning line, 13 ... Data line, 14 ... Power supply line, 15 ... Data line drive circuit, 16 ... Scanning line drive circuit, 17 ... Inspection circuit, 18 and 18R , 18G, 18B ... sub-pixel, 20 ... pixel circuit, 21 ... switching transistor, 22 ... storage capacitor, 23 ... driving transistor, 25 ... reflection layer, 26 ... insulating layer, 27 ... flattened insulating layer, 28 ... pixel Partition wall 29 ... Wiring 30 ... Organic EL element 31 ... Pixel electrode 32 ... Functional layer 33 ... Counter electrode 34 ... Sealing layer 34a ... Cathode protective layer 34b ... Cover layer 34c ... Organic buffer layer 34d ... Gas barrier layer, 36 ... Color filter, 36B ... Blue colored layer, 36G ... Green colored layer, 36R ... Red colored layer, 36a ... Black matrix, 37 ... Sealing material, 41 ... Counter substrate, 42 Adhesive layer, 43 ... flexible circuit board, 44 ... driving IC, 51 ... screen printing plate, 51a ... opening hole, 52 ... squeegee, 100: organic EL device.

Claims (5)

Forming an organic EL element including a pixel electrode, a functional layer, and a counter electrode on a substrate;
Forming a cathode protective layer on the organic EL element;
Forming an organic buffer layer on the cathode protective layer;
Forming a gas barrier layer on the organic buffer layer;
A method of manufacturing an organic EL device having
A method for producing an organic EL device, comprising a step of forming a cover layer on the cathode protective layer between the step of forming the cathode protective layer and the step of forming the organic buffer layer. It is a manufacturing method of the organic EL device according to claim 1,
The step of forming the organic buffer layer includes forming the organic buffer layer on the cover layer using a screen printing method. It is a manufacturing method of the organic EL device according to claim 1 or 2,
The step of forming the cover layer includes the step of forming the cover layer so that an end portion of the cover layer is outside the end portion of the display area and inside the end portions of the cathode protective layer and the gas barrier layer in a plan view. Forming an organic EL device. It is a manufacturing method of the organic EL device according to any one of claims 1 to 3,
The method of manufacturing an organic EL device, wherein the cover layer has a thickness of 100 nm to 500 nm. It is a manufacturing method of the organic EL device according to any one of claims 1 to 4,
The method of manufacturing an organic EL device, wherein the material of the cover layer is an organic low molecular weight material.

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