JP2005183078A - Organic el display device and manufacturing method of same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a an organic EL display device with excellent display characteristics and a manufacturing method of the same. <P>SOLUTION: The organic EL display device is provided with a base plate 11, positive electrode wirings 1, insulation films 22 each with an opening formed, barrier ribs 10 formed on the insulation films 22 and inside the openings of the same, organic compound layers formed in the openings of the insulation films 22, negative electrode wirings 5 formed inside the openings of the insulation films 22. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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

  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. 8 is a cross-sectional view showing an example of a partition wall described in Patent Document 1. As shown in FIG. FIG. 8 shows a part extracted from the substrate in the organic EL display device. 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. 9 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.9 (a) is a schematic diagram which shows the condition which observed the board | substrate from the side by which an electrode is arrange | positioned, FIG.9 (b) is sectional drawing in AA 'of Fig.9 (a). Here, the end portion of the substrate 111 shown in FIG. 9B and the end portion of the substrate 111 shown in FIG. 9A are the same. FIG. 9A also shows components that are hidden by cathode wiring or the like provided in the upper layer.

  In the example shown in FIG. 9, first, the anode wiring 101 and the cathode connection wiring 121 connected to the cathode wiring 105 are 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, the organic thin film layer 124 is formed by solution application or vapor deposition of an organic material.

  Although a plurality of layers are formed as the organic thin film layer, in FIG. 9B, 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.

  In the state where the partition wall 100 is formed, the peripheral portion of the opening 123 has a configuration shown in FIG. FIG. 10 shows a part extracted from the substrate 111 shown in FIG. FIG. 10A is a schematic diagram showing an enlarged view of a state in which the substrate 111 is observed from the side where the partition wall 100 is formed, and FIG. 10B is a cross-sectional view taken along line BB ′ of FIG. FIG.

  In FIG. 10, an anode wiring 101, an insulating film 122 having an opening 123, and a partition wall 100 are formed on a substrate 111. The partition wall 100 is formed to have a reverse taper structure as described above, and the insulating film 122 is formed to have a forward taper structure whose cross section becomes narrower as the distance from the substrate 111 is opposite to the reverse taper structure. Has been. The insulating film 122 is provided in a lattice shape so as to form the opening 123.

  An example of forming the organic thin film layer and the cathode wiring on the substrate on which the partition wall shown in FIG. 10 is formed will be described with reference to FIGS. FIGS. 11 to 13 show a part extracted from the substrate 111 shown in FIG. 9, and are cross-sectional views taken along line B-B ′ of FIG.

  First, for the description of the insulating film, the example shown in FIG. 11 is different from the configuration shown in FIG. In this example, the organic thin film layer and the cathode wiring 105 are formed on the substrate 111 on which only the anode wiring 101 and the partition wall 100 are formed. That is, no insulating film is formed on the substrate 11. Moreover, the organic thin film layer is only the vapor-deposited organic film 128 formed by vapor-depositing an organic material.

  The vapor-deposited organic film 128 and the cathode wiring 105 are formed on the anode wiring 101 and separated by the partition wall 100 as shown in the figure. Since the partition wall 100 has an inverted taper structure, the side surface portion of the partition wall 100 becomes a shadow during deposition and the amount deposited is reduced. For this reason, the film thickness of the vapor-deposited organic film 128 and the cathode wiring 105 becomes thinner as it approaches the side surface of the partition wall 100. The cathode wiring 105 is substantially in contact with the insulating film 122 at a portion where the side surface of the partition wall 100 and the surface of the anode wiring 101 intersect (dashed line portion in the figure). Accordingly, there is a problem that the cathode wiring 105 and the anode wiring 101 are easily short-circuited in this portion.

  In order to solve this problem, an insulating film as shown in FIG. 10 is provided. In the example shown in FIG. 12, the organic thin film layer and the cathode wiring 105 are formed on the substrate 111 on which the anode wiring 101, the insulating film 122, and the partition wall 100 shown in FIG. 10 are formed. In this example, the organic thin film layer is only the deposited organic film 128 as in FIG. The vapor-deposited organic film 128 and the cathode wiring 105 are formed on the anode wiring 101 and the insulating film 122 and separated by the partition wall 100 as shown in the figure.

  The deposited organic film 128 and the cathode wiring 105 are formed in a shape corresponding to the forward taper structure of the insulating film 122, and the film thickness decreases as the side of the partition wall 100 is approached, as in FIG. The cathode wiring 105 is almost in contact with the insulating film 122. As described above, even if the deposited organic film 128 and the cathode wiring 105 are thin, the cathode wiring 105 and the anode wiring 101 are not short-circuited because the insulating film 122 is formed on the anode wiring 101.

  Further, as described above, one layer of the organic thin film layer may be formed using a solution of an organic material. In the example shown in FIG. 13, the organic thin film layer 124 and the cathode wiring 105 are formed on the substrate 111 on which the anode wiring 101, the insulating film 122, and the partition wall 100 shown in FIG. 10 are formed. In this example, the organic thin film layer 124 includes a coating organic film 127 formed by applying a solution of an organic material and a vapor deposition organic film 128. The coated organic film 127, the deposited organic film 128, and the cathode wiring 105 are formed on the anode wiring 101 and the insulating film 122 and separated by the partition wall 100 as shown in the figure.

  11 and 12, the deposited organic film 128 and the cathode wiring 105 become thinner as they approach the side surface of the partition wall 100, whereas the coated organic film 127 forms the side surface of the partition wall 100 and the insulating film 122. At the part where the surfaces intersect, the film thickness suddenly becomes thicker than other parts. This is because, when an organic material solution is applied, a phenomenon similar to a capillary phenomenon occurs due to a space near a portion where the side surface of the partition wall 100 and the surface of the insulating film 122 intersect, and the solution is sucked. Conceivable. The sucked solution spreads along a 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. 14 is an explanatory diagram showing a state in which the organic material solution has spread along the partition walls. In FIG. 14, the partition wall 100 and the organic material solution 125 are shown, and other components are not shown. In FIG. 14, reference numeral 126 denotes an application region of the solution 125, which indicates 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. 14, the solution spreads more than the application region 126.

  The concentration and the like of the solution 125 are adjusted so that a constant thickness can be obtained, but the solution 125 spreads along the partition wall 100, so that it becomes difficult to achieve a desired thickness. In particular, since the solution in the vicinity of the outer peripheral portion of the application region 126 spreads outward, the thickness of the organic thin film layer becomes thinner as the outer peripheral portion of the application region 126 is reached. As described above, since the thickness of the organic thin film layer is uneven, there is a problem that uneven light emission occurs when each display pixel emits light.

  Further, when the solution applied from the display area flows out, unevenness of the film thickness in the pixel due to the flow of the solution occurs, and unevenness of the light emission luminance occurs in the pixel. In particular, this tendency appears remarkably in the pixels in the outer peripheral portion of the display area.

On the other hand, since the opening of the insulating film emits light and becomes a pixel, the portion of the insulating film is a portion that does not emit light. Therefore, there is a problem in that the ratio of the light emitting area of the pixel (the aperture ratio or the light emitting area ratio) is poor by providing the insulating film as compared with the case without the insulating film.
Japanese Patent Laid-Open No. 2001-351799 (paragraphs 0012-0017, FIGS. 1 and 2)

  As described above, in the conventional organic EL display device, when the liquid material serving as the organic layer flows out of the display region, the light emission unevenness is caused due to the film thickness unevenness, the display quality is deteriorated, and the aperture ratio is also reduced. There was a problem of being bad.

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

  The organic EL display device according to the present invention includes a substrate, a first electrode formed on the substrate, an insulating film formed to have an opening on the first electrode, and the first electrode. A partition extending to intersect the electrode and formed on the insulating film and in the opening of the insulating film; and an organic layer formed on the substrate on which the partition is formed in the opening of the insulating film And a second electrode formed by sandwiching the organic compound layer between the first electrode in the opening of the insulating film and separated by the partition wall. Thereby, display characteristics can be improved. Note that “on the substrate”, “on the electrode”, “on the insulating film”, etc. are not limited to being directly on the substrate or the like, and other layers may be interposed on the substrate or the like. included. The same applies to the following.

  In the above-described organic EL display device, the insulating film may extend in a direction parallel to the first electrode. Thereby, unevenness in light emission can be reduced.

  In the organic EL display device described above, the insulating film may be formed so as to cover both ends of the first electrode. Thereby, a short circuit between the cathode wiring and the anode wiring can be prevented.

  In the organic EL display device described above, the partition may be formed directly on the first electrode in the opening of the insulating film. Thereby, unevenness in light emission can be reduced.

  In the organic EL display device described above, the display pixel portion where the first electrode and the second electrode intersect may be displayed in a region between the opposing insulating film and the opposing partition. Thereby, an aperture ratio can be improved.

  In the organic EL display device described above, the organic compound layer may be a coating film. Thereby, the outflow of the solution of the organic material can be suppressed, and light emission unevenness can be reduced.

  In the organic EL display device described above, the organic compound layer may include 5% by weight or more of a polymer organic material having a weight average molecular weight of 1000 or more in the hole injection layer. Thereby, the outflow of the solution of the organic material can be suppressed, and light emission unevenness can be reduced.

  In the above-described organic EL display device, a vapor-deposited organic compound layer that is a vapor-deposited film may be further provided between the organic compound layer and the second electrode.

  An organic EL display device according to the present invention includes a substrate, a first electrode formed on the substrate, and extends so as to intersect the first electrode, and is formed directly on the first electrode. And the organic compound layer formed on the first electrode on the substrate on which the partition is formed and the organic compound layer separated from the first electrode by the partition. And a second electrode formed so as to be sandwiched therebetween. Thereby, display characteristics can be improved.

  In the organic EL display device described above, the organic compound layer may be a coating film. Thereby, the outflow of the solution of the organic material can be suppressed, and light emission unevenness can be reduced.

  The method of manufacturing an organic EL display device according to the present invention includes a step of forming a first electrode on a substrate and a step of forming an insulating film on the substrate on which the first electrode is formed so as to have an opening. Forming a partition on the insulating film and in the opening of the insulating film so as to cross and extend on the substrate on which the insulating film is formed; and Applying a liquid material on the substrate on which the partition wall is formed in the opening to form an organic compound layer; and isolating the insulating film on the substrate on which the organic compound layer is formed by the partition wall Forming a second electrode so as to sandwich the organic compound layer with the first electrode in the opening. Thereby, an organic EL display device with excellent display characteristics can be manufactured.

  The method for manufacturing an organic EL display device according to the present invention includes a step of forming a first electrode on a substrate, and a crossing and extending of the first electrode on the substrate on which the first electrode is formed. Forming a partition directly on the first electrode, applying a liquid material on the substrate on which the partition is formed, and forming an organic compound layer on the first electrode And forming a second electrode on the substrate on which the organic compound layer is formed, separated by the partition and sandwiching the organic compound layer with the first electrode. is there. Thereby, an organic EL display device with excellent display characteristics can be manufactured.

  The manufacturing method of the organic EL display device further includes a step of forming a vapor-deposited organic compound layer by vapor deposition between the organic compound layer and the second electrode.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the organic electroluminescence display which was excellent in the display characteristic, and an organic electroluminescence display 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 and simplified as appropriate. Further, 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. 1 is an anode wiring, 5 is a cathode wiring, 10 is a partition, 11 is a substrate, 21 is a cathode connection wiring, 22 is an insulating film, 23 is a display pixel portion, 24 is a display area indicated by a broken line, and 25 is 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. In the present embodiment, a plurality of insulating films 22 are formed in a direction parallel to the anode wiring 1. In addition, the insulating film 22 is formed so as to cover both ends of each anode wiring 1 and covers the steps at both ends of the anode wiring 1 to prevent a short circuit between the cathode wiring 5 and the anode wiring 1.

  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 separated. The partition wall 10 can be formed with a height of 3.4 μm and a width of 10 μm, for example.

  In the present embodiment, the display pixel portion 23 at a position where the anode wiring 1 and the cathode wiring 5 intersect each other is a region between the insulating films 22 and between the partition walls 10. The display area 24 includes a plurality of display pixel units 23. Each display pixel unit 23 controls the light emission amount of the organic light emitting layer in accordance with a drive signal from a drive circuit (not shown). Display. The configuration around the display pixel unit 23 will be described in detail later.

  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 which is a solution of an organic material, and concentrating and curing the organic thin film material. 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, in the display pixel part 23, an electric current can be sent through the organic thin film layer sandwiched between the anode wiring 1 and the cathode wiring 5, and the organic light emitting layer emits light.

  Next, the configuration of the insulating film according to the present embodiment and the organic thin film layer formed in this configuration will be described with reference to FIGS.

  In a state where the partition wall 10 is formed on the substrate 11, the peripheral portion of the display pixel portion 23 has a configuration shown in FIG. FIG. 2 shows a part extracted from the substrate 11 shown in FIG. FIG. 2A is a schematic diagram showing an enlarged view of the situation where the substrate 10 is observed from the side where the partition wall 10 is formed, and FIG. 2B is a cross-sectional view taken along the line BB ′ of FIG. FIG.

  In FIG. 2, the anode wiring 1 is formed on the substrate 11, and the insulating film 22 or the partition 10 is formed thereon. In the present embodiment, the insulating film 22 is formed only in the direction parallel to the anode wiring 1. For this reason, the partition 10 is formed directly on the anode wiring 1 in a portion where the partition 10 and the insulating film 22 do not intersect, for example, B-B ′ in FIG. Further, in the portion where the partition wall 10 and the insulating film 22 intersect, the insulating film 22 is formed on the anode wiring 1, and the partition wall 10 is formed thereon.

  Thus, by forming the insulating film 22 only in the direction parallel to the anode wiring 1, the display pixel portion 23 becomes a region between the partition walls 10, compared with the case where a conventional grid-like insulating film is formed. The aperture ratio can be improved.

  A state in which the organic thin film layer 28 and the cathode wiring 5 are formed on the substrate 11 is shown in FIG. FIG. 3 shows a part extracted from the substrate 11 shown in FIG. 1, and is a cross-sectional view taken along line B-B ′ of FIG.

  In FIG. 3, the organic thin film layer 28 and the cathode wiring 5 are formed on the substrate 11 on which the anode wiring 1 and the partition 10 shown in FIG. 2 are formed. Here, the organic thin film layer 28 includes a coated organic film 26 formed by applying a solution of an organic material and a deposited organic film 27 formed by vapor-depositing an organic material. The coated organic film 26, the deposited organic film 27, and the cathode wiring 5 are formed on the anode wiring 1 and separated by the partition 10 as shown in the figure.

  The coating organic film 26 is thicker than the other portions because the solution of the organic material is sucked by a phenomenon similar to the capillary phenomenon at the portion where the side surface of the partition wall 10 and the surface of the anode wiring 1 intersect. In the present embodiment, since the partition wall 10 is formed directly on the anode wiring 1, more solution is sucked up, and further, the outflow of the sucked-up solution can be suppressed. Thereby, the film thickness nonuniformity of the coating organic film 26 can be reduced.

  Further, since the vapor-deposited organic film 27 and the cathode wiring 5 are shaded during vapor deposition by the barrier ribs 10 at the side portions of the barrier ribs 10, the film thickness is reduced. As described above, even if the vapor-deposited organic film 27 and the cathode wiring 5 are thin, the coated organic film 27 is formed on the anode wiring 1, thereby preventing a short circuit between the cathode wiring 5 and the anode wiring 1. be able to. In particular, since the film thickness of the coated organic film 27 is thicker than other portions at the portion where the side surface of the partition wall 10 where the short circuit is likely to occur and the surface of the anode wiring 1 intersect, the short circuit can be prevented more reliably.

  Next, a method for manufacturing the organic EL display device according to the present embodiment will be described with reference to FIG. FIG. 4 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 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, it is cured and removed so that the insulating film remains only in the direction parallel to the anode wiring 1.

  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). 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 polyvinyl carbazole having an average molecular weight of 5000 of 0.5% (mass percentage) is dissolved is applied by a mask spray method.

  FIG. 5 is a cross-sectional view showing the structure of the element substrate 110 at the end of the display region 24. FIG. 5 shows a cross-sectional structure in a direction parallel to the cathode wiring 5, shows a part extracted from the substrate 11 shown in FIG. 1, and shows a portion indicated by AA ′ in FIG. 1. The corresponding cross-sectional structure. 5, 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. 5, 29 indicates an organic material solution, and the organic material solution 29 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 29 is at the same position as the display area 24. Since the insulating film 22 is formed only in the direction parallel to the anode wiring 1 as described above, the outflow of the solution can be suppressed, so that the film thickness of the solution becomes almost constant inside the display region 24. Therefore, light emission unevenness can be reduced. 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.

  In the above-described example, the organic material solution is applied by spraying. However, other wet application methods are used in which the organic material to be the organic thin film layer is dispersed or dissolved in a liquid and applied as a solution. be able to. For example, an offset printing method, a relief printing method, an ink jet coating method, or the like that forms a layer of a solution in which an organic material is dispersed or dissolved in a solvent only in a predetermined region can be used.

  Then, the organic material solution 29 is hardened by concentrating and drying 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. 6 is a cross-sectional view showing the structure of the element substrate 110 at the end of the display area 24. FIG. 6 shows a cross-sectional structure in a direction parallel to the cathode wiring 5, shows a part extracted from the substrate 11 shown in FIG. 1, and shows a portion indicated by AA ′ in FIG. 1. The corresponding cross-sectional structure. 6, 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. 6, reference numeral 28 denotes an organic light emitting layer formed of 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 in the display pixel portion 23. On the organic light emitting layer 28, the cathode wiring 5 is disposed. In the display pixel portion 23, the organic light emitting layer 28 in a portion in contact with the anode wiring 1 emits light by a 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 forming the insulating film only in the direction parallel to the anode wiring, the outflow of the organic material solution is suppressed, and the unevenness of the film thickness of the organic thin film layer is reduced. In addition, when the organic EL display device is driven, light emission unevenness of each display pixel can be reduced. Further, since there is no insulating film in the direction parallel to the partition wall, the aperture ratio can be improved. Furthermore, a short circuit between the cathode wiring and the anode wiring can be prevented by forming one layer of the organic thin film layer by applying an organic material solution.

  Table 1 shows a comparison of the short-circuit between the cathode wiring and the anode wiring, the aperture ratio, and the film thickness unevenness of the coated organic film in the organic EL display device according to this embodiment and the conventional organic EL display device. As described above, the organic EL display device according to the present embodiment shown in FIG. 3 prevents the short circuit between the cathode wiring and the anode wiring by the coated organic film, and the insulating film is insulated only in the direction parallel to the anode wiring. Since the film has a higher aperture ratio than a lattice-shaped film and suppresses the outflow of the organic material solution, the film thickness unevenness of the coated organic film is reduced.

  In the conventional organic EL display device shown in FIG. 11, the cathode wiring and the anode wiring are easily short-circuited as compared with the present embodiment. In the conventional organic EL display device shown in FIG. The aperture ratio is low due to the lattice-like insulating film. Moreover, in the conventional example of FIG.11 and FIG.12, since the organic thin film layer is only a vapor deposition organic film, the unevenness | corrugation on the surface of an anode wiring cannot be covered. In the conventional organic EL display device shown in FIG. 13, since the aperture ratio is lower due to the lattice-like insulating film and the organic material solution flows out as compared with the present embodiment, the display unevenness due to the uneven film thickness of the coated organic film. Occurs.

  In the above example, the insulating film is formed only in the direction parallel to the anode wiring. However, the present invention is not limited to this, and the insulating film is also formed in a direction parallel to the partition wall in a part of the display region or the display pixel portion. May be formed. For example, an insulating film may not be provided under the partition in a portion where the organic material solution easily flows out, and an insulating film may be provided under the partition in a portion where the solution does not easily flow out. Furthermore, no insulating film may be formed in the display region.

  Next, Example 1 in which the luminance of the organic EL display device is measured will be described with reference to FIG. FIG. 7 is a distribution diagram showing the measurement results of luminance in the display area of the organic EL display device. FIG. 7A shows the luminance of the organic EL display device having the conventional lattice-like insulating film shown in FIG. 13, and FIG. 7B shows the direction parallel to the anode wiring according to the present invention shown in FIG. Only the brightness | luminance of the organic electroluminescence display which has an insulating film is shown. The right side of the figure is the side where the cathode connection wiring is formed, and the organic material solution flows out to the right outside.

  In measuring the luminance, a circuit that performs low gradation control by a PWM (Pulse Width Modulation) method was used for the drive circuits of both organic EL display devices.

As shown in FIG. 7A, in the conventional organic EL display device, the luminance increased from the center of the display region to the right end. About 1.5 cd / ^{m 2} in the center of the display area is about 2.4 cd / ^{m 2} at the right end. In particular, the luminance in the vicinity of the right end is a remarkably high value. This is because the organic material solution flows out and the film thickness unevenness occurs in the organic thin film layer.

As shown in FIG. 7B, in the organic EL display device according to the present invention, the luminance is higher at the right end than at the center of the display region. About 1.5 cd / ^{m 2} in the center of the display area is about 2.0 cd / ^{m 2} at the right end. Further, as shown in FIG. 7A, the luminance does not increase remarkably in the vicinity of the right end, and the luminance is almost uniform from the center to the right end. This indicates that the outflow of the organic material solution is suppressed, and the film thickness unevenness of the organic thin film layer is reduced.

  Further, in the organic EL display device according to the present invention, a current test for 1000 hours was performed, but no short circuit between the cathode wiring and the anode wiring occurred. This indicates that a short circuit is prevented by the coated organic film.

It is a top view which shows schematic structure of the element substrate of the organic electroluminescence display concerning this embodiment. It is an enlarged schematic diagram which shows the structure of the display pixel part after the partition formation of the organic electroluminescent display apparatus concerning this embodiment. It is an expanded sectional view which shows the structure of the display pixel part after cathode wiring formation of the organic electroluminescent display apparatus 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 a distribution map which shows the measurement result of the brightness | luminance of the organic electroluminescence display 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 an enlarged schematic diagram which shows the structure of the display pixel part after the partition formation of the conventional organic EL display apparatus. It is an expanded sectional view which shows the structure of the display pixel part after cathode wiring formation of the conventional organic electroluminescence display. It is an expanded sectional view which shows the structure of the display pixel part after cathode wiring formation of the conventional organic electroluminescence display. It is an expanded sectional view which shows the structure of the display pixel part after cathode wiring formation of the conventional organic electroluminescence display. It is a figure which shows the state which the solution of the organic material spread along the partition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anode wiring 5 Cathode wiring 10 Partition 11 Board | substrate 21 Cathode connection wiring 22 Insulating film 23 Display pixel part 24 Display area 25 Contact hole 110 Element substrate

Claims (13)

A substrate,
A first electrode formed on the substrate;
An insulating film formed on the first electrode so as to have an opening;
A partition wall extending to intersect the first electrode and formed on the insulating film and in the opening of the insulating film;
An organic compound layer formed on the substrate in which the partition wall is formed in the opening of the insulating film;
A second electrode formed by sandwiching the organic compound layer between the first electrode in the opening of the insulating film and separated by the partition;
An organic EL display device.   The organic EL display device according to claim 1, wherein the insulating film extends in a direction parallel to the first electrode.   The organic EL display device according to claim 1, wherein the insulating film is formed so as to cover both ends of the first electrode.   The organic EL display device according to claim 1, wherein the partition is formed directly on the first electrode in the opening of the insulating film.   5. The organic EL display according to claim 2, wherein the display pixel portion where the first electrode and the second electrode intersect is displayed in a region between the facing insulating film and the facing partition. 6. apparatus.   The organic EL display device according to claim 1, wherein the organic compound layer is a coating film.   7. The organic EL display device according to claim 1, wherein the organic compound layer includes 5% by weight or more of a polymer organic material having a weight average molecular weight of 1000 or more in the hole injection layer. .   The organic EL display device according to claim 6, further comprising a vapor-deposited organic compound layer that is a vapor-deposited film between the organic compound layer and the second electrode. A substrate,
A first electrode formed on the substrate;
A partition wall extending to intersect the first electrode and formed directly on the first electrode;
On the substrate on which the partition wall is formed, an organic compound layer formed on the first electrode;
A second electrode isolated by the partition and formed so as to sandwich the organic compound layer with the first electrode;
An organic EL display device.   The organic EL display device according to claim 9, wherein the organic compound layer is a coating film. Forming a first electrode on a substrate;
Forming an insulating film on the substrate on which the first electrode is formed so as to have an opening;
Forming a partition on the insulating film and in the opening of the insulating film so as to cross and extend on the substrate on which the insulating film is formed;
Applying a liquid material on the substrate on which the partition wall is formed in the opening of the insulating film to form an organic compound layer;
Forming a second electrode on the substrate on which the organic compound layer is formed, separated by the partition and sandwiching the organic compound layer with the first electrode in the opening of the insulating film; When,
A method for manufacturing an organic EL display device comprising: Forming a first electrode on a substrate;
Forming a partition directly on the first electrode on the substrate on which the first electrode is formed so as to intersect and extend the first electrode;
Applying a liquid material on the substrate on which the partition walls are formed, and forming an organic compound layer on the first electrode;
Forming a second electrode on the substrate on which the organic compound layer is formed, separated by the partition and sandwiching the organic compound layer with the first electrode;
A method for manufacturing an organic EL display device comprising:   The method for manufacturing an organic EL display device according to claim 11, further comprising a step of forming a vapor-deposited organic compound layer by vapor deposition between the organic compound layer and the second electrode.

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