JP2005183184A - Manufacturing method of organic el display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an organic EL display device which is excellent in display characteristics. <P>SOLUTION: The manufacturing method of the organic EL display device includes a step S101 to form an anode interconnection 1 on a substrate 11, a step S103 to form a partition 10 on the substrate 11, a step S104 to apply a liquid material to the substrate 11, and a step to form a cathode interconnection 5 on the substrate 11. The liquid material is applied so that an applying quantity at the nearby region of the outer periphery of a display region which intersects with an extended direction of the partition 10 may be larger than the applying quantity at the central region of the display region where the anode interconnection 1 intersects with the cathode interconnection 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an organic EL (Electro Luminescence) display device, and more particularly to a method for manufacturing an organic EL display device in which an organic light emitting layer is formed using a liquid material.

  In recent years, organic EL display devices using organic EL elements have been actively developed. An organic EL display device has a wider viewing angle than a liquid crystal display device, has a high response speed, and is expected as a next-generation display device because of the variety of light-emitting properties of organic substances. In an organic EL element used in an organic EL display device, an anode is formed on a substrate, and a thin-film organic compound is laminated on the anode to form an organic light emitting layer. A cathode is formed on the organic compound layer so as to face the anode formed on the substrate. An organic EL element is a current-driven display element that emits light when a current is supplied to an organic compound layer disposed between an anode and a cathode. Hereinafter, a thin film of an organic compound to be laminated is referred to as an organic thin film layer. A display pixel is a portion where an anode, a plurality of organic thin film layers, and a cathode are stacked.

  When an organic compound is stacked on an electrode provided on a substrate, an organic thin film layer may be formed by vacuum evaporation of an organic material. However, when an organic material is deposited, if the surface of the electrode serving as the base of the organic thin film layer has foreign matters attached, protrusions, or depressions, the organic thin film layer may not be in a desired state due to the influence.

  As a method for solving this problem, a technique for forming a desired organic thin film layer by dispersing or dissolving an organic material to be an organic thin film layer in a liquid and coating it as a solution to cover foreign matters, protrusions, depressions, etc. A wet coating method, hereinafter simply referred to as a coating method) is known. For example, Patent Document 1 describes that at least one of the organic thin film layers is formed by a coating method.

  Examples of the coating method include an offset printing method, a relief printing method, and a mask spray method. In the offset printing method and the relief printing method, a layer of a solution in which an organic material is dispersed or dissolved in a solvent (hereinafter referred to as an organic material solution or simply a solution) is formed only in a predetermined region. In the mask spray method, a glass mask, a metal mask, or the like having an opening that matches a desired region is disposed, and a solution in which an organic material is dispersed or dissolved is ejected. In this case, the solution is dispersed in a gaseous medium such as nitrogen, or the solution is atomized using a two-fluid nozzle or the like.

  In the organic EL display device, an isolation structure (hereinafter referred to as a partition) is provided so that the cathode wiring provided on the organic thin film layer is isolated. Such a configuration is described in Patent Document 1, for example. FIG. 9 is a cross-sectional view showing an example of a partition wall described in Patent Document 1. An anode wiring 101 is provided on the substrate 111, and then a partition wall 100 is provided. The partition wall 100 is formed, for example, so that the cross section increases as the distance from the substrate 111 increases. Such a structure of the partition wall 100 is called an inverted taper structure or an overhang structure.

  By making the partition wall 100 have an inversely tapered structure, the cathode wiring can be more reliably separated. When each organic thin film layer (hole injection transport layer 102, light emitting layer 103, electron injection transport layer 104) is formed by a coating method or the like in a state where the partition wall 100 is provided, the organic thin film layer is separated by the partition wall 100. As a result, Between each partition 100, the organic light emitting layer comprised from each organic thin film layer is formed. Thereafter, the cathode wiring 105 is formed by a vapor deposition method or the like. The cathode wiring 105 is also separated by the partition wall 100, and a patterned cathode wiring 105 is formed.

  In some cases, an insulating film having an opening is formed over the anode wiring, and a position to be a display pixel is determined by the position of the opening. FIG. 10 is an explanatory diagram showing a configuration example in the case where an insulating film having an opening is provided in the configuration described in Patent Document 1. In FIG. FIG. 10A is a schematic view showing a state where the substrate is observed from the side where the electrodes are arranged, and FIG. 10B is a cross-sectional view taken along line AA ′ of FIG. FIG. 10A also shows components that are hidden by cathode wiring or the like provided in the upper layer.

  In the example shown in FIG. 10, the anode wiring 101 and the cathode connection wiring 121 connected to the cathode wiring 105 are first formed on the substrate 111. Subsequently, an insulating film 122 having an opening 123 is formed. The opening 123 is provided at a position where the anode wiring 101 and the cathode wiring 105 intersect. A partition wall 100 is formed so as to be orthogonal to the anode wiring 101. Subsequently, a solution of an organic material is applied or evaporated to form the organic thin film layer 124.

  Although a plurality of layers are formed as the organic thin film layer, in FIG. 10B, the plurality of layers are collectively shown as the organic thin film layer 124. The concentration of the organic material is adjusted so that the organic thin film layer is formed with a certain thickness in the region where the organic thin film layer is to be formed. After the organic thin film layer 124 is formed, the cathode wiring 105 is deposited on the organic thin film layer. The partition wall 100 separates the organic thin film layer 124 and the cathode wiring 105, whereby the organic thin film layer 124 is formed between the partition walls, and the patterned cathode wiring 105 is formed.

  After forming the cathode wiring 105, an organic thin film layer made of a polymer or the like may be formed on the cathode wiring 105 in order to protect the organic EL element. This organic thin film layer (not shown) is also formed by a coating method or the like. In addition, another substrate (not shown) is disposed so as to face the surface of the substrate 111 on which electrodes and the like are disposed. In this substrate, a sealing material (not shown) is applied to the outer periphery of the region of the substrate 111 facing the organic EL element. With this sealing material, the substrate 111 and another substrate are bonded. The organic EL element is kept from being exposed to moisture and oxygen by being sealed with a substrate and a sealing material.

  However, when an organic material solution is applied after the partition wall 100 is formed, there arises a problem that the applied solution spreads along the partition wall 100. For example, in the example illustrated in FIG. 10, the solution spreads along a portion where the side surface of the partition wall 100 and the insulating film 122 intersect. This is because a phenomenon similar to the capillary action is caused by the space near the portion where the side surface of the partition wall 100 and the surface of the insulating film 122 intersect. In particular, when the partition wall 100 is formed so as to have an inverted taper structure in order to reliably separate the cathode wiring 105 and the like, the space near the intersection of the side surface of the partition wall 100 and the surface of the insulating film 122 becomes narrower, and the solution is more concentrated. It becomes easy to spread.

  FIG. 11 is an explanatory diagram showing a state in which the organic material solution has spread along the partition walls. In FIG. 11, the partition wall 100 and the organic material solution 125 are shown, and the other components are not shown. In FIG. 11, reference numeral 126 denotes an application region of the solution 125, and shows a range where the applied solution 125 should stay without spreading. That is, it is ideal that the solution 125 does not spread more than the application region 126. However, as already described, the solution 125 spreads along the partition wall 100. As a result, as shown in FIG. 11, the solution spreads more than the application region 126. For this reason, the concentration and the like of the solution 125 are adjusted so as to obtain a certain thickness, but the solution 125 spreads along the partition wall 100, so that it becomes difficult to achieve a desired thickness.

  FIG. 12 is an explanatory view showing a method of applying a solution of an organic material by a mask spray method which is an example of an application method. FIG. 12A is a cross-sectional view of the substrate 111 showing how the organic material solution 125 is ejected by the spray nozzle 131, and FIG. 12B shows how the spray nozzle 131 proceeds while ejecting the solution 125. It is the schematic diagram observed from the side which spouts.

  In FIG. 12, the solution 125 is ejected from the spray nozzle 131 onto the substrate 111 through the mask 132. As shown in FIG. 12B, the mask 132 is a mask having the shape of the application region 126 in FIG. 11 as an opening. The spray nozzle 131 reciprocally moves the opening in the y direction at a predetermined speed and moves in the x direction at a predetermined interval (pitch) in accordance with the arrow in the figure, and the entire opening, that is, the entire application region 126. The solution 125 is jetted out.

  As shown in FIG. 12A, the solution 125 ejected from the spray nozzle 131 is applied on the substrate 111 in a hemispherical application amount. The spray nozzle 131 moves at a pitch such that the hemispherical shapes overlap, and ejects the solution 125 without gaps. Here, the ejection amount of the solution 125, the moving speed of the spray nozzle 121, the pitch, and the like are constant, and the application amount of the solution 125 in the application region 126 is a uniform amount as indicated by 133.

  FIG. 13 is a graph showing the relationship between the coating amount of the organic material solution and the film thickness of the organic thin film layer. The graph of FIG. 13 shows the film thickness in the vicinity of the outer periphery where the solution in the application region 126 spreads. The horizontal axis of the graph indicates the position in the x direction in the coating region 126, the vertical axis indicates the coating amount and film thickness of the solution 125, 133 in the graph indicates the coating amount of the solution 125, and 134 indicates the film thickness of the organic thin film layer. Yes. Note that the values of the coating amount and the film thickness are schematically shown for explanation. As shown in the figure, even when the solution 125 is applied in a uniform application amount, the solution in the vicinity of the outer periphery of the application region 126 spreads further outward. The thinner it becomes.

As described above, since the film thickness of the organic thin film layer is uneven, there is a problem that uneven light emission occurs when each display pixel emits light.
Japanese Patent Laid-Open No. 2001-351799 (paragraphs 0012-0017, FIGS. 1 and 2)

  As described above, the conventional organic EL display device has a problem in that the liquid material serving as the organic layer flows out of the display area, thereby causing uneven light emission due to uneven film thickness, resulting in deterioration in display quality. .

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a method for manufacturing an organic EL display device having excellent display characteristics.

  The method of manufacturing an organic EL display device according to the present invention includes a step of forming a first electrode (for example, anode wiring 1 in the present embodiment) on a substrate, and a partition on the substrate on which the first electrode is formed. Forming a liquid material on the substrate on which the partition wall is formed, forming an organic compound layer, and isolating the partition on the substrate on which the organic compound layer is formed. Forming the second electrode (for example, the cathode wiring 5 in the present embodiment), and the step of forming the organic compound layer includes a step of forming a center in a display region where the first electrode and the second electrode intersect. The liquid material is applied so that the application amount in the vicinity of the outer periphery of the display region intersecting the extending direction of the partition wall is larger than the application amount in the region. Thereby, an organic EL display device with excellent display characteristics can be manufactured. The area where the application amount is increased may be a part of the outer periphery of the display area. For example, the partition wall extends in one direction, one side of the outer periphery of the display area may increase the application amount, the other side of the outer periphery of the display area may be the same application amount as the central area, You may increase the application quantity of one side of the said display area outer periphery, and the other side.

  In the method for manufacturing an organic EL display device described above, the step of forming the organic compound layer may include applying the liquid material in an application amount so that the film thickness of the organic compound layer is substantially uniform in the display region. Good. Thereby, the uniformity of the film thickness of the organic compound layer can be improved, and an organic EL display device with reduced occurrence of display unevenness can be manufactured.

  In the manufacturing method of the organic EL display device described above, the step of forming the organic compound layer may include applying the liquid material in an application amount so as to supplement the amount of the liquid material flowing out of the display area. Good. Thereby, the uniformity of the film thickness of the organic compound layer can be improved, and an organic EL display device with reduced occurrence of display unevenness can be manufactured.

  In the method for manufacturing an organic EL display device according to the present invention, a step of forming a first electrode on a substrate, a step of forming a partition on the substrate on which the first electrode is formed, and the partition are formed. Applying a liquid material onto the substrate, forming an organic compound layer, and forming a second electrode on the substrate on which the organic compound layer is formed so as to be isolated by the partition; In the step of forming the organic compound layer, in the display region where the first electrode and the second electrode intersect, the liquid material is formed in the display region so that the film thickness of the organic compound layer is substantially uniform. The amount of the liquid material that flows out to the outside is supplemented, and the liquid material is applied in a non-uniform coating amount in the display area. Thereby, the uniformity of the film thickness of the organic compound layer can be improved, and an organic EL display device with reduced occurrence of display unevenness can be manufactured.

  In the method for manufacturing an organic EL display device described above, the step of forming the organic compound layer includes moving a liquid material ejecting unit (for example, a spray nozzle) that ejects the liquid material relative to the substrate, and The application amount of the liquid material may be controlled by changing the relatively moving speed of the liquid material ejection unit. Thereby, the liquid material can be applied in a desired application amount, and an organic EL display device with excellent display characteristics can be manufactured.

  In the manufacturing method of the organic EL display device described above, the step of forming the organic compound layer includes a step of moving a liquid material ejecting unit that ejects the liquid material relative to the substrate, and a step of ejecting the liquid material. Moving relative to the substrate at a predetermined pitch in a direction substantially perpendicular to the relatively moving direction, and changing the pitch to control the coating amount of the liquid material. May be. Thereby, the liquid material can be applied in a desired application amount, and an organic EL display device with excellent display characteristics can be manufactured.

  In the method of manufacturing an organic EL display device described above, the step of forming the organic compound layer includes moving a liquid material ejecting unit that ejects the liquid material relative to the substrate, and moving the liquid material ejecting unit from the liquid material ejecting unit. The application amount of the liquid material may be controlled by changing the ejection amount of the liquid material. Thereby, the liquid material can be applied in a desired application amount, and an organic EL display device with excellent display characteristics can be manufactured.

  In the method for manufacturing an organic EL display device described above, the step of forming the organic compound layer includes applying the liquid material by bringing a halftone dot provided on a plate into close contact with the substrate, and changing a density of the halftone dots. Thus, the application amount of the liquid material may be controlled. Thereby, the liquid material can be applied in a desired application amount, and an organic EL display device with excellent display characteristics can be manufactured.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the organic electroluminescent display apparatus excellent in the display characteristic can be provided.

  Hereinafter, embodiments to which the present invention can be applied will be described. The following description is to describe the embodiment of the present invention, and the present invention is not limited to the following embodiment. For clarity of explanation, the following description and drawings are omitted as appropriate. Moreover, those skilled in the art can easily change, add, and convert each element of the following embodiments within the scope of the present invention.

  An element substrate on which an organic EL light emitting element of the organic EL display device according to the present embodiment is formed will be described with reference to FIG. FIG. 1 is a plan view showing the configuration of the element substrate 110 of the organic EL display device. Reference numeral 1 denotes an anode wiring, 5 denotes a cathode wiring, 10 denotes a partition, 11 denotes a substrate, 21 denotes a cathode connection wiring, 22 denotes an insulating film, 23 denotes an opening, 24 denotes a display area indicated by a broken line, and 25 denotes a contact hole.

  A plurality of anode wirings 1 and cathode connection wirings 21 connected to the cathodes are formed on the substrate 11 so as to be in contact with the surface of the substrate 11. The plurality of anode wirings 1 are formed in parallel. The cathode connection wirings 21 are formed corresponding to the number of the cathode wirings 5 and are formed perpendicular to the respective anode wirings 1. The anode wiring 1 and the cathode connection wiring 21 are formed of a transparent conductive film such as ITO, for example. An insulating film 22 is formed on the substrate on which the anode wiring 1 and the cathode connection wiring 21 are formed. The film thickness of the insulating film 22 is 0.7 μm, for example. The insulating film 22 is provided with an opening 23 at a position where the anode wiring 1 and the cathode wiring 5 intersect (that is, a position where a display pixel is formed). The display area 24 includes a plurality of display pixels, and the display area 24 performs image display by controlling the light emission amount of the organic light emitting layer in accordance with a drive signal from a drive circuit (not shown). The size of the display area 24 is, for example, 3 cm long and 4 cm wide.

  On the insulating film 22, an organic light emitting layer composed of a plurality of organic thin film layers (organic compound layers) and the cathode wiring 5 are sequentially laminated. Therefore, the organic light emitting layer is sandwiched between the cathode wiring 5 and the anode wiring 1. However, in FIG. 1, illustration of the organic light emitting layer is omitted. In addition, before the organic light emitting layer is formed, an isolation structure (hereinafter referred to as a partition wall 10) for separating adjacent cathode wirings 5 is provided. The barrier rib 10 is formed in a desired pattern before the cathode wiring 5 is formed by vapor deposition or the like. For example, as shown in FIG. 1, a plurality of partition walls 10 orthogonal to the anode wiring 1 are formed on the anode wiring 1 in order to form a plurality of cathode wirings 5 orthogonal to the anode wiring 1. The partition wall 10 preferably has an inverted taper structure. That is, it is preferable that the cross-section is formed so as to be separated from the substrate 11. Thereby, the side wall and the rising portion of the partition wall 10 are shadowed by vapor deposition, and the cathode wiring 5 can be divided. The partition wall 10 can be formed with a height of 3.4 μm and a width of 10 μm, for example.

  At least one of the organic thin film layers forming the organic light emitting layer is formed by applying a liquid organic light emitting layer material that is a solution of an organic material. In the present embodiment, the organic material solution is not applied as a uniform application amount in the display region 24. For example, the organic material solution is applied to the portion where the organic material solution flows out by the partition 10 more than the other portions. Apply the solution. Thereby, it is possible to prevent the film thickness from decreasing due to the outflow of the organic material solution, and to make the film thickness of the organic thin film layer in the display pixel constant. Therefore, occurrence of display unevenness can be prevented. The application of the organic material solution will be described in detail later.

  Then, the organic thin film material is concentrated, dried and cured to form an organic thin film layer. As a result, an organic thin film layer having a uniform thickness is formed in the display region 24. The organic thin film layer is separated by each partition wall 10.

  After the partition wall 10 is formed, a metal material or the like that becomes the cathode wiring 5 is deposited from above the organic thin film layer. A plurality of cathode wirings 5 can be formed by separating the cathode pattern by the partition wall 10 having a reverse taper structure. The cathode wiring 5 divided by the partition 10 is formed perpendicular to the anode wiring 1. Thereby, an organic light emitting layer is disposed between the cathode wiring 5 and the anode wiring 1 at the intersection of the cathode wiring 5 and the anode wiring 1.

  A contact hole 25 is formed in the insulating film 22 to connect the cathode connection wiring 21 and the cathode wiring 5 to the outside of the display region 24. The contact hole 25 is formed at a location where the cathode wiring 5 and the cathode connection wiring 21 overlap. Thereby, an electric current can be sent through the organic thin film layer sandwiched between the anode wiring 1 and the cathode wiring 5 in the opening 23, and the organic light emitting layer emits light.

  Next, a method for applying the organic material described above will be described with reference to FIGS. FIG. 2 is a graph showing the relationship between the coating amount of the organic material solution according to the present embodiment and the film thickness of the organic thin film layer, and FIG. 3 is a method of coating the organic material solution by the mask spray method according to the present embodiment. FIG. 4 is an explanatory view showing a method of applying an organic material solution by the ink jet method according to this embodiment, and FIG. 5 is a method of applying an organic material solution by the printing method according to this embodiment. It is explanatory drawing which shows.

  The relationship between the coating amount of the organic material solution and the film thickness of the organic thin film layer on the cathode connection wiring 21 side of the display region 24 shown in FIG. It becomes a graph. The horizontal axis of the graph indicates the position in the x direction in the display region 24, the vertical axis of the graph indicates the coating amount and film thickness of the solution, 201 in the graph indicates the film thickness of the organic thin film layer, and 202 indicates the coating amount of the solution. Yes.

  In the present embodiment, as in the application amount 202, the portion where the solution flows out is applied with a larger amount of the solution than the portion where the solution does not flow out, according to the amount of the solution flowing out. Here, the portion where the solution flows out is in the vicinity of the outer periphery of the display region 24 on the side where the cathode connection wiring 21 is connected between the partition walls 10 extending outward of the display region 24. By applying the solution so as to replenish the amount of the solution flowing out, a larger amount of the solution flows out to the outside of the display area 24 as in the film thickness indicated by 201, but the inside of the display area 24. In, a substantially constant film thickness can be obtained.

  In the figure, the application amount of the solution is increased in the vicinity of the left end portion of the display area 24, but the application amount can be increased in the same manner for the portion where the solution of the other organic material flows out. For example, when the cathode connection wiring 21 is formed on both the left and right sides in the figure, the coating amount can be increased in the vicinity of both the left and right ends of the display region 24. Moreover, you may increase the application quantity of a solution about all the parts from which the solution of an organic material flows out, and you may increase the application quantity of a solution about some of the parts from which a solution flows out.

  The coating amount of the solution is determined, for example, by measuring the film thickness when the solution is applied by the conventional method as shown in FIG. 13 in advance, and by the film thickness ratio between the portion where the solution does not flow out and the portion where the solution flows out , You can decide how much to increase. For example, when the film thickness of the portion where the solution does not flow out is 30 nm and the film thickness of the portion where the solution flows out is 10 nm, the coating amount is about three times larger than the portion where the solution does not flow out. It can be. In this case, it is preferable to consider not only the film thickness ratio but also the amount of solution flowing out.

  Note that the coating amount may be increased to such an extent that unevenness in light emission can be reduced without increasing the coating amount until the film thickness becomes substantially uniform.

  Thus, as a specific example for applying the organic material solution, there is a method of applying the mask spray method shown in FIG. FIG. 3A is a cross-sectional view of the substrate 11 showing a state in which an organic material solution is ejected by the spray nozzle 301, and FIG. 3B shows a state in which the spray nozzle 301 advances while ejecting the solution. It is the schematic diagram observed from the side to do.

  In FIG. 3, an organic material solution is ejected from the spray nozzle 301 onto the substrate 11 through the mask 302. The spray nozzle 301 is, for example, a fluid nozzle that supplies a gas such as nitrogen in which a solution is dispersed and ejects the solution in a mist form. As shown in FIG. 3B, the mask 302 is a mask whose opening is the shape of the display region 24, and is, for example, a metal mask or a glass mask. The spray nozzle 301 reciprocates the opening of the mask 302 at a predetermined speed in the y direction and moves at a predetermined interval (pitch) in the x direction according to the arrow in the figure, and the entire opening, that is, the display area 24. Spout the solution over the whole.

  As shown in FIG. 3A, the solution ejected from the spray nozzle 301 is applied in a hemispherical shape. This hemispherical shape schematically shows the application amount of the solution. That is, the center of the applied part has the largest application amount, and the application amount decreases as the distance from the center increases. The spray nozzle 301 moves at such a pitch that the hemispherical shapes overlap, and ejects the solution without any gaps.

  In the present embodiment, the application amount of the solution is controlled by changing the pitch and speed at which the spray nozzle 301 moves, the distance from the substrate 11, the ejection amount, and the like, and the application amount indicated by 202 is used. By narrowing the pitch at which the spray nozzle 301 moves, the amount of application per unit area can be increased.

  For example, the pitch of a portion where the coating amount is constant (for example, the vicinity of the display region 24 from the center of the drawing to the right end portion, the same applies hereinafter) is 4 mm, and the portion with a large coating amount (for example, the vicinity of the left end portion of the display region 24 The same applies hereinafter) may be 2 mm. Moreover, the application amount per unit area can be increased by slowing the moving speed of the spray nozzle 301. For example, the speed of the portion where the coating amount is constant may be 160 mm / s, and the speed of the portion where the coating amount is large may be 100 mm / s. Furthermore, the application amount can be increased by narrowing the distance between the spray nozzle 301 and the substrate 11. In addition, the application amount can be increased by increasing the gas supply amount to the spray nozzle 301.

  As another example for applying a solution of an organic material, there is an application method by an ink jet method shown in FIG. In FIG. 4, an organic material solution is ejected from the inkjet head 401 onto the substrate 11. In the ink jet method, since the solution does not scatter unlike the mask spray method, a mask is unnecessary. The ink jet head 401 includes, for example, a piezoelectric element. By applying a voltage to the piezoelectric element, an ink composition (here, a solution of an organic material) is ejected in units of dots.

  In the present embodiment, the application amount of the solution is controlled by changing the ejection amount, concentration, and the like of the solution from the ink jet head 401 to obtain the application amount indicated by 202. It is possible to increase the number of times the voltage is applied to the piezoelectric elements of the inkjet head 401 and increase the amount of solution applied per unit area. For example, the number of dots in a portion where the coating amount is constant may be 10 dots, and the number of dots in a portion where the coating amount is large may be 30 dots.

  Furthermore, as another example for applying a solution of an organic material, there is an application method by a printing method shown in FIG. In FIG. 5, the solution is injected into the halftone dots 502 that are the concave portions of the plate 501, and the halftone dots 502 are brought into close contact with the substrate 11 by pressing the plate 501, and the solution is applied. The plate 501 is made of, for example, an ultraviolet curable resin, and is formed by photolithography so that the halftone dots 502 have a predetermined interval and density. The plate 501 has an intaglio shape, but may alternatively have a relief plate or a flat plate shape.

  In the present embodiment, the application amount of the solution is controlled by changing the dot density and the like, and the application amount indicated by 202 is set. By narrowing the interval between the halftone dots 502 and increasing the halftone dot density, the application amount of the solution can be increased. For example, the interval between halftone dots in a portion where the coating amount is constant may be 30 μm, and the interval between halftone dots in a portion where the coating amount is large may be 15 μm.

  In the above-described coating method, the coating amount may be changed by other methods. For example, the application amount may be increased by applying the same portion again. Furthermore, application may be performed by changing the application amount by other application methods other than the above-described application methods.

  Next, a method for manufacturing the organic EL display device according to the present embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing an example of a method for manufacturing the organic EL display device according to the present embodiment.

  First, the anode wiring 1 and the cathode connection wiring 21 are formed on the substrate 11 (step S101). As the substrate 11, for example, a transparent substrate such as a glass substrate is used. The anode wiring 1 and the cathode connection wiring 21 are formed by forming an ITO film on the substrate 11 and etching the ITO film. ITO can be formed on the entire surface of the glass substrate with good uniformity by sputtering or vapor deposition. An ITO pattern is formed by photolithography and etching. This ITO pattern becomes the anode. A phenol novolac resin is used as the resist, and exposure development is performed. Etching may be either wet etching or dry etching. For example, ITO can be patterned using a mixed aqueous solution of hydrochloric acid and nitric acid. As the resist stripping material, for example, monoethanolamine can be used.

  The cathode connection wiring 21 may be made of a low resistance metal material such as Al or an Al alloy. For example, after patterning the ITO to be the anode wiring 1, Al or the like is formed by sputtering or vapor deposition. Alternatively, the anode wiring 1 may be formed after the cathode connection wiring 21 is formed. Then, the Al connection film 21 can be formed by patterning the Al film by photolithography and etching. Thereby, the wiring resistance of the cathode connection wiring 21 can be reduced.

  Furthermore, the configuration of the cathode connection wiring 21 may be a multilayer configuration of ITO and a metal material. For example, a metal thin film of 400 to 500 nm of Mo or Mo alloy may be formed on a 150 nm ITO layer. Thereby, wiring resistance and contact resistance can be reduced.

  Next, an insulating film 22 is formed on the surface of the substrate 11 provided with the anode wiring 1 and the cathode connection wiring 21 (step S102). For example, a photosensitive polyimide solution is applied by spin coating. The thickness of the insulating film 22 may be set to 0.7 μm, for example. After the layer of the insulating film 22 is patterned by a photolithography process, the insulating film 22 is cured, the insulating film at a position to be a display pixel is removed, and an opening 23 is provided. The intersection between the cathode wiring 5 and the anode wiring 1 formed in step S105, which will be described later, is a position where a display pixel is formed. At the same time, a contact hole 25 between the cathode wiring 5 and the cathode connection wiring 21 is formed. For example, the opening 23 can be formed with a size of about 300 μm × 300 μm.

  Subsequently, a partition wall 10 is formed on the surface of the insulating film (polyimide layer) 22 so that the cathode wiring 5 can be separated and disposed (step S103). The partition wall 10 is formed by applying a photosensitive resin such as a novolac resin or an acrylic resin film on the insulating film 22. For example, the partition wall 10 is formed by spin coating a photosensitive resin, patterning in a photolithography process, and photoreacting. It is desirable to use a negative type photosensitive resin so that the partition 10 has a reverse taper structure.

  When a negative photosensitive resin is used, when light is irradiated from above, the photoreaction becomes insufficient at deeper locations. As a result, when viewed from above, the cross-sectional area of the cured portion has a structure that is narrower on the lower side than on the upper side. This means that it has an inverted taper structure. With this structure, the cathode wiring 5 can be separated from each other because the portion that is shaded when viewed from the vapor deposition source during vapor deposition of the cathode does not reach the vapor deposition. Further, in order to modify the surface of the ITO layer in the opening 23, oxygen plasma or ultraviolet light may be irradiated. For example, the height of the partition wall 10 can be 3.4 μm.

  Thereafter, an organic thin film layer is stacked (step S104). The solution is applied by the above-described organic material solution application method. For example, when using a mask spray method, first, a metal mask having an opening is attached to a glass substrate. At this time, it arrange | positions so that the display area 24 which should provide the opening part of a metal mask and a liquid organic thin film layer may overlap. Moreover, it attaches so that the space of predetermined distance, for example, 60 micrometers, may be vacant between a metal mask and a glass substrate. Then, an ethyl benzoate solution in which 0.5% (percentage by mass) of polyvinyl carbazole is dissolved is applied by a mask spray method.

  FIG. 7 is a cross-sectional view showing the structure of the element substrate 110 at the end of the display area 24. 7 shows a cross-sectional structure in a direction parallel to the cathode wiring 5, and shows a cross-sectional structure corresponding to the portion indicated by AA ′ in FIG. 7, the same reference numerals as those in FIG. 1 indicate the same elements as those shown in FIG. 1, and the description thereof will be omitted.

  In FIG. 7, reference numeral 27 denotes an organic material solution. The organic material solution 27 is applied to the entire display region 24 from above the insulating film 22 through a metal mask. The application end of the organic material solution 27 is at the same position as the display area 24. By applying the organic material solution application method, a larger amount of solution is applied to a portion where the solution flows out than a portion where the solution does not flow out, so that the film thickness of the solution becomes almost constant inside the display region 24. . Further, outside the display area 24, the solution spreads along the partition wall 10 and flows out to the vicinity of the contact hole 25.

  Then, the organic material solution 27 is hardened by being concentrated and dried to form a hole injection layer which is an organic thin film layer. Subsequently, α-NPD (N, N′-di (naphthalen-1-yl) -N, N′-diphenyl-benzidine) is deposited on the upper layer of the hole injection layer to form a hole transport layer having a thickness of 40 nm. Form. Further, Alq (tris (8-hydroxynato) aluminum) serving as the host compound of the light emitting layer and coumarin 6 serving as the fluorescent dye of the guest compound are simultaneously vapor deposited on the upper layer to form a light emitting layer having a thickness of 60 nm. Form. Subsequently, LiF is deposited on the light emitting layer to form a cathode interface layer having a thickness of 0.5 nm.

  Thereafter, a metal material such as aluminum is vapor-deposited to form, for example, a cathode wiring 5 having a film thickness of 100 nm (step S105). As a result, the aluminum film is separated by the barrier ribs 10, and the cathode wiring 5 that intersects the anode wiring 1 can be formed between the barrier ribs. FIG. 8 is a cross-sectional view showing the structure of the element substrate 110 at the end of the display area 24. 8 shows a cross-sectional structure in a direction parallel to the cathode wiring 5, and shows a cross-sectional structure corresponding to the portion indicated by AA ′ in FIG. 8, the same reference numerals as those in FIG. 1 designate the same elements as those shown in FIG. 1, and the description thereof will be omitted.

  In FIG. 8, 28 is an organic light emitting layer formed from a plurality of organic thin film layers. The organic light emitting layer 28 is formed on the insulating film 22 and is in contact with the anode wiring 1 through the opening 23. On the organic light emitting layer 28, the cathode wiring 5 is disposed. The portion of the organic light emitting layer 28 in contact with the anode wiring 1 through the opening 23 emits light by the current flowing through the cathode and the anode. In the present embodiment, the cathode connection wiring 21 has a two-layer structure of an ITO layer and a metal layer. Via the contact hole 25 formed in the insulating film 22 outside the display area 24, the cathode wiring 5 provided in the display area 24 and the cathode connection wiring 21 communicating outside the display area 24 are electrically connected.

  Next, in order to seal the organic EL light emitting element formed by the above-mentioned process, a process for manufacturing a sealing counter substrate will be described. First. A glass substrate different from the element substrate is prepared. The glass substrate is processed to form a water catching material storage for storing the water catching material. The water catching material storage part applies a resist to the glass substrate and exposes a part of the substrate by exposure and development. The exposed part is formed by etching to form a water catching material storage part.

  After arranging a water catching material such as calcium oxide in the water catching material storage part, the two substrates are overlapped and bonded (step S106). Specifically, a sealing material is applied to the surface of the counter substrate on which the water catching material storage unit is provided using a dispenser. For example, an epoxy-based ultraviolet curable resin can be used as the sealing material. The sealing material is applied to the entire outer periphery of the region facing the organic EL element. After the two substrates are aligned and face each other, the sealing material is cured by irradiating ultraviolet rays, and the substrates are bonded to each other. Thereafter, in order to further accelerate the curing of the sealing material, for example, heat treatment is performed in a clean oven at 80 ° C. for 1 hour. As a result, the sealing material and the pair of substrates separate the substrate where the organic EL element is present from the outside of the substrate. By disposing the water catching material, it is possible to prevent the organic EL element from being deteriorated due to moisture remaining or entering the sealed space.

  Unnecessary portions near the outer periphery of the substrate are cut and removed, a signal electrode driver is connected to the anode wiring 1, and a scanning electrode driver is connected to the cathode connection wiring. A terminal portion connected to each wiring is formed at the substrate end. An anisotropic conductive film (ACF) is attached to this terminal portion, and a TCP (Tape Carrier Package) provided with a drive circuit is connected. Specifically, ACF is temporarily crimped to the terminal portion. Next, the TCP with the built-in drive circuit is finally bonded to the terminal portion. Thereby, a drive circuit is mounted. This organic EL display panel is attached to the housing, and the organic EL display device is completed.

  According to such a method for manufacturing an organic EL display device, by applying a solution of an organic material to be an organic EL element with a substantially constant film thickness, unevenness of the film thickness of the organic thin film layer is reduced, and the organic EL display device When the is driven, unevenness in light emission of each display pixel can be reduced.

It is a top view which shows schematic structure of the element substrate in the organic electroluminescence display concerning this embodiment. It is a graph which shows the relationship between the application quantity of a solution, and a film thickness in the coating method of the organic material solution of the organic electroluminescence display concerning this embodiment. It is sectional drawing and the top view for demonstrating the coating method of the organic material solution of the organic electroluminescent display apparatus concerning this embodiment. It is sectional drawing for demonstrating the coating method of the organic material solution of the organic electroluminescence display concerning this embodiment. It is sectional drawing for demonstrating the coating method of the organic material solution of the organic electroluminescence display concerning this embodiment. It is a flowchart for demonstrating the manufacturing method of the organic electroluminescent display apparatus concerning this embodiment. It is an expanded sectional view which shows the structure of the element substrate edge part after the organic material solution application | coating of the organic electroluminescence display concerning this embodiment. It is an expanded sectional view which shows the structure of the element substrate edge part after cathode wiring formation of the organic electroluminescent display apparatus concerning this embodiment. It is sectional drawing which shows the structure of the element substrate of the conventional organic electroluminescence display. It is a figure which shows the structure of the element substrate of the conventional organic EL display apparatus. It is a figure which shows the state which the solution of the organic material spread along the partition. It is sectional drawing and the top view for demonstrating the coating method of the conventional organic material solution. It is a graph which shows the relationship between the application quantity of a solution and the film thickness in the coating method of the conventional organic material solution.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anode wiring 5 Cathode wiring 10 Partition 11 Substrate 21 Cathode connection wiring 22 Insulating film 23 Opening 24 Display area 25 Contact hole 26 Application area

Claims (8)

Forming a first electrode on a substrate;
Forming a partition wall on the substrate on which the first electrode is formed;
Applying a liquid material on the substrate on which the partition walls are formed to form an organic compound layer;
Forming a second electrode on the substrate on which the organic compound layer is formed so as to be isolated by the partition;
The step of forming the organic compound layer includes:
The coating amount in the vicinity region of the outer periphery of the display region intersecting the extending direction of the partition wall is larger than the coating amount in the central region in the display region where the first electrode and the second electrode intersect. A method of manufacturing an organic EL display device in which the liquid material is applied. The step of forming the organic compound layer includes:
2. The method of manufacturing an organic EL display device according to claim 1, wherein the liquid material is applied in an application amount such that the film thickness of the organic compound layer is substantially uniform in the display region. The step of forming the organic compound layer includes:
2. The method of manufacturing an organic EL display device according to claim 1, wherein the liquid material is applied in an application amount so as to supplement the amount of the liquid material flowing out of the display area. Forming a first electrode on a substrate;
Forming a partition wall on the substrate on which the first electrode is formed;
Applying a liquid material on the substrate on which the partition walls are formed to form an organic compound layer;
Forming a second electrode on the substrate on which the organic compound layer is formed so as to be isolated by the partition;
The step of forming the organic compound layer includes:
In the display area where the first electrode and the second electrode cross each other, the amount of the liquid material flowing out of the display area is supplemented so that the film thickness of the organic compound layer is substantially uniform. A method for manufacturing an organic EL display device, wherein the liquid material is applied in a non-uniform coating amount in the display region. The step of forming the organic compound layer includes:
The liquid material ejecting means for ejecting the liquid material is moved relative to the substrate, and the coating speed of the liquid material is controlled by changing the relative moving speed of the liquid material ejecting means. 5. The method for manufacturing an organic EL display device according to claim 1, 2, 3 or 4. The step of forming the organic compound layer includes:
Moving the liquid material jetting means for jetting the liquid material relative to the substrate;
A step of moving the liquid material ejecting means relative to the substrate at a predetermined pitch in a direction substantially orthogonal to the direction of relative movement.
5. The method of manufacturing an organic EL display device according to claim 1, wherein the application amount of the liquid material is controlled by changing the pitch. The step of forming the organic compound layer includes:
The liquid material ejecting means for ejecting the liquid material is moved relative to the substrate, and the amount of the liquid material ejected from the liquid material ejecting means is changed to control the application amount of the liquid material. 5. The method for manufacturing an organic EL display device according to claim 1, 2, 3 or 4. The step of forming the organic compound layer includes:
The liquid material is applied by bringing the halftone dots provided on the plate into close contact with the substrate,
5. The method of manufacturing an organic EL display device according to claim 1, wherein the application amount of the liquid material is controlled by changing the density of the halftone dots.

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