JP2015053214A - Organic electroluminescent display device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent current leakage between pixels adjacent to each other.SOLUTION: A substrate is prepared in which a plurality of pixel electrodes 18 are provided. An organic electroluminescent film 22 is formed so as to contain a common layer 24 continuously covering a plurality of pixel electrodes 18. A common electrode 28 is formed on the organic electroluminescent film 22. The common layer 24 is irradiated with energy rays in an upper part of a region between pixel electrodes 18 adjacent to each other avoiding an upper part of a plurality of pixel electrodes 18. The conductivity of the common layer 24 decreases in the upper part of the region between pixel electrodes 18 adjacent to each other due to the irradiation of the energy rays.

Description

  The present invention relates to an organic electroluminescence display device and a manufacturing method thereof.

  An organic electroluminescence display device has a structure in which an organic film is sandwiched between an anode and a cathode. Usually, a plurality of organic films are laminated, and one layer is a light emitting layer. In order to obtain light emission of one color (for example, white) in a plurality of pixels, an organic film serving as a light emitting layer is provided so as to be entirely continuous. Alternatively, in order to obtain light emission of a plurality of colors in a plurality of pixels, an organic film serving as a light emitting layer is separated for each pixel, but becomes a hole injection layer, an electron injection layer, a hole transport layer, or an electron transport layer. The organic film is provided continuously. In any case, at least one organic film is continuously provided over adjacent pixels.

JP 2009-88320 A

  In a high-quality display device, adjacent pixels have come close to each other due to pixel miniaturization. Therefore, current may leak from the electrode of any pixel to the adjacent pixel through the continuous organic film. There is a problem in that adjacent pixels emit light due to current leakage.

  Patent Document 1 discloses a method for preventing current leakage, but relates to prevention of current leakage between an anode and a cathode in one pixel, which is different from the problem to be solved by the present invention.

  An object of the present invention is to prevent current leakage between adjacent pixels.

  (1) An organic electroluminescence display device manufacturing method according to the present invention includes a step of preparing a substrate provided with a plurality of pixel electrodes, and an organic layer so as to include a common layer continuously covering the plurality of pixel electrodes. A step of forming an electroluminescence film, a step of forming a common electrode on the organic electroluminescence film, and above the plurality of pixel electrodes, above a region between the adjacent pixel electrodes, Irradiating the common layer with energy rays, and reducing the conductivity of the common layer above the region between the adjacent pixel electrodes by irradiation with the energy rays. To do. According to the present invention, since the common layer of the organic electroluminescence film has a low conductivity above the region between the adjacent pixel electrodes, current leakage between the adjacent pixels can be prevented.

  (2) In the method of manufacturing an organic electroluminescence display device according to (1), an insulating layer is formed in the region between adjacent pixel electrodes so as to be placed on the end portions of the pixel electrodes. The method may further include a step of forming the organic electroluminescence film on the insulating layer.

  (3) In the manufacturing method of the organic electroluminescence display device described in (1) or (2), the energy beam may be irradiated to the common layer before the common electrode is formed.

  (4) In the method of manufacturing an organic electroluminescence display device according to (1) or (2), after the common electrode is formed, the energy beam is irradiated to the common layer through the common electrode. This may be a feature.

  (5) In the method of manufacturing an organic electroluminescence display device according to (1) or (2), the method further includes a step of forming a sealing film on the common electrode, and after forming the sealing film, The energy beam may be irradiated to the common layer through the sealing film and the common electrode.

  (6) In the method of manufacturing an organic electroluminescence display device according to any one of (1) to (5), the energy beam is irradiated through a mask, and the mask is above the plurality of pixel electrodes. In this case, a pattern may be provided in which the energy rays are prevented from passing and the energy rays are allowed to pass above the region between the adjacent pixel electrodes.

  (7) In the method of manufacturing an organic electroluminescence display device according to any one of (1) to (5), a mask layer that prevents passage of the energy beam is formed above the organic electroluminescence film. A step of irradiating the energy rays through the pattern of the mask layer, the pattern of the mask layer preventing the passage of the energy rays above the plurality of pixel electrodes; The energy rays may be passed above the region in between.

  (8) An organic electroluminescence display device according to the present invention is provided on the substrate so as to include a substrate, a plurality of pixel electrodes provided on the substrate, and a common layer continuously covering the plurality of pixel electrodes. An organic electroluminescence film, and a common electrode provided on the organic electroluminescence film, wherein the common layer has a plurality of pixel electrodes above a region between adjacent pixel electrodes. It has the low electroconductive part whose electrical conductivity is lower than the part above this. According to the present invention, since the common layer of the organic electroluminescence film has a low conductivity above the region between the adjacent pixel electrodes, it prevents current leakage between the adjacent pixels. Can do.

1 is a perspective view of an organic electroluminescence display device according to an embodiment of the present invention. It is the schematic of the II-II sectional view of the organic electroluminescent display apparatus shown in FIG. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the modification 1 of embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the modification 2 of embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the modification 3 of embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the modification 4 of embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an organic electroluminescence display device according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a cross section taken along line II-II of the organic electroluminescence display device shown in FIG.

  As shown in FIG. 1, the organic electroluminescence display device has a light-transmitting first substrate 10 made of glass or the like. The first substrate 10 has an image display area for image display. An integrated circuit chip 12 for driving an element for displaying an image is mounted on the first substrate 10. A flexible wiring substrate 14 is connected to the first substrate 10 for electrical connection with the outside.

  As shown in FIG. 2, a circuit layer 16 is provided on the first substrate 10. The circuit layer 16 includes a wiring, a thin film transistor, an insulating film, and the like (not shown). A plurality of pixel electrodes 18 are provided on the first substrate 10 (on the circuit layer 16 in the example of FIG. 2). The pixel electrode 18 is an anode. An insulating layer 20 is provided in a region between adjacent pixel electrodes 18 so as to be placed on an end portion of each pixel electrode 18. The insulating layer 20 surrounds the periphery of each pixel electrode 18.

  An organic electroluminescence film 22 is provided on the first substrate 10. The organic electroluminescence film 22 is placed on the plurality of pixel electrodes 18 and the insulating layer 20. Although not shown, the organic electroluminescence film 22 includes a plurality of layers, includes at least a light emitting layer, and further includes at least one of an electron transport layer, a hole transport layer, an electron injection layer, and a hole injection layer. The light emitting layer is configured to emit only light of one color (for example, white).

  The organic electroluminescence film 22 includes a common layer 24 that continuously covers the plurality of pixel electrodes 18. In the example of FIG. 2, the entire organic electroluminescence film 22 is the common layer 24. Alternatively, at least one layer (excluding at least one layer) of the organic electroluminescence film 22 including a plurality of layers is the common layer 24 (for example, an electron injection layer), and the remaining layers including at least one layer are provided for each pixel electrode 18. It may be a cut layer. In the organic electroluminescence film having a tandem structure including two or more light emitting layers, a charge generation layer for supplying electrons and holes arranged between adjacent light emitting layers may be a common layer.

  The common layer 24 includes a low conductive portion 26 having a lower conductivity than a portion above the plurality of pixel electrodes 18 above a region between adjacent pixel electrodes 18. The presence of the low conductive portion 26 makes it difficult for carriers (electrons or holes) to flow in the spreading direction of the common layer 24. Since the low conductive portion 26 is on the insulating layer 20, the carrier flow in the spreading direction of the common layer 24 is prevented above the insulating layer 20. On the other hand, in the portion above the plurality of pixel electrodes 18 of the common layer 24 (portion excluding the low conductive portion 26), current flows in the thickness direction and the spreading direction of the common layer 24.

  A common electrode 28 is provided on the organic electroluminescence film 22. The common electrode 28 is a cathode. By applying a voltage to the pixel electrode 18 and the common electrode 28, holes and electrons are injected into the organic electroluminescence film 22 from each. The injected holes and electrons combine in the light emitting layer to emit light. Since the insulating layer 20 is interposed between the end portion of the pixel electrode 18 and the common electrode 28, a short circuit between them is prevented.

  According to the present embodiment, the common layer 24 of the organic electroluminescence film 22 has a low conductivity above the region between the adjacent pixel electrodes 18, so that current leakage between the adjacent pixels is performed. Can be prevented. Therefore, the pixel adjacent to the pixel through which the current flows is prevented from emitting light.

  A sealing film 42 is provided on the common electrode 28. The sealing film 42 seals the organic electroluminescence film 22 so as to shield it from moisture. A filling layer 38 is provided on the sealing film 42.

  The second substrate 30 is disposed so as to face the first substrate 10 with a gap. A color filter layer 32 is provided on the surface of the second substrate 30 on the first substrate 10 side. The color filter layer 32 includes a black matrix 34 and a colored layer 36. Since the light emitting layer (not shown) of the organic electroluminescence film 22 emits a single color (for example, white), the color filter layer 32 is provided in the present embodiment to enable full color display. When the organic electroluminescence film 22 includes a plurality of light emitting layers that emit different colors (for example, red, green, and blue), the light emitting layer emits light of a plurality of colors, and thus the colored layer 36 is unnecessary. A filling layer 38 is provided between the first substrate 10 and the second substrate 30.

  FIG. 3 is a view for explaining a method of manufacturing the organic electroluminescence display device according to the embodiment of the present invention.

  In the present embodiment, a first substrate 10 provided with a plurality of pixel electrodes 18 is prepared. An insulating layer 20 is formed in a region between adjacent pixel electrodes 18 so as to be placed on the end of each pixel electrode 18. The organic electroluminescence film 22 is formed so as to include a common layer 24 that continuously covers the plurality of pixel electrodes 18. The organic electroluminescence film 22 is formed on the insulating layer 20. The organic electroluminescence film 22 is formed by vapor deposition or sputtering.

  Then, the common layer 24 is irradiated with energy rays (ultraviolet rays, electron beams, infrared rays, etc.). The energy rays are irradiated above the area (insulating layer 20) between the adjacent pixel electrodes 18 while avoiding the area above the plurality of pixel electrodes 18. The conductivity of the common layer 24 is lowered above the region between the adjacent pixel electrodes 18 by irradiation with energy rays. Thereby, the low conductive portion 26 is formed in the common layer 24.

  The energy rays are irradiated through the mask 40. The mask 40 has a pattern including ribs and openings. The pattern prevents the energy rays from passing above the plurality of pixel electrodes 18 and allows the energy rays to pass above the region between the adjacent pixel electrodes 18. Alternatively, if laser scanning using a laser beam is applied, the mask 40 is unnecessary.

  Subsequently, as shown in FIG. 2, the common electrode 28 is formed on the organic electroluminescence film 22. The common electrode 28 is formed after the common layer 24 is irradiated with energy rays. Since the energy beam is irradiated before the formation of the common electrode 28, the loss of the irradiation energy is small.

  According to the present embodiment, the common layer 24 of the organic electroluminescence film 22 has a low conductivity above the region between the adjacent pixel electrodes 18, thereby preventing current leakage between the adjacent pixels. be able to.

  FIG. 4 is a diagram for explaining a method for manufacturing an organic electroluminescence display device according to Modification 1 of the embodiment of the present invention. In this example, after forming the common electrode 28, the common layer 24 is irradiated with energy rays. The energy ray passes through the common electrode 28.

  FIG. 5 is a diagram for explaining a method of manufacturing the organic electroluminescence display device according to the second modification of the embodiment of the present invention. In this example, the sealing film 42 is formed on the common electrode 28. Then, after forming the sealing film 42, energy rays are applied to the common layer 24 through the sealing film 42 and the common electrode 28. According to this, foreign substances can be prevented from being mixed by the sealing film 42.

  FIG. 6 is a diagram for explaining a method for manufacturing an organic electroluminescence display device according to Modification 3 of the embodiment of the present invention. In this example, the sealing film 42 is formed on the common electrode 28, and the mask layer 44 is formed on the sealing film 42 (above the organic electroluminescence film 22). The mask layer 44 is made of, for example, titanium oxide and is made of a material that prevents the passage of energy rays. Energy rays are irradiated through the pattern of the mask layer 44. The pattern of the mask layer 44 prevents the energy rays from passing above the plurality of pixel electrodes 18 and allows the energy rays to pass above the region between the adjacent pixel electrodes 18.

  FIG. 7 is a diagram for explaining a method for manufacturing an organic electroluminescence display device according to Modification 4 of the embodiment of the present invention. In this example, the mask layer 44 is formed on the common electrode 28 (above the organic electroluminescence film 22), and the sealing film 42 is formed on the mask layer 44. The mask layer 44 is made of, for example, titanium oxide, and prevents the passage of energy rays. Energy rays are irradiated through the pattern of the sealing film 42 and the mask layer 44. The pattern of the mask layer 44 prevents the energy rays from passing above the plurality of pixel electrodes 18 and allows the energy rays to pass above the region between the adjacent pixel electrodes 18.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the configuration described in the embodiment can be replaced with substantially the same configuration, a configuration that exhibits the same operational effects, or a configuration that can achieve the same purpose.

  DESCRIPTION OF SYMBOLS 10 1st board | substrate, 12 Integrated circuit chip, 14 Flexible wiring board, 16 Circuit layer, 18 Pixel electrode, 20 Insulating layer, 22 Electroluminescent film, 24 Common layer, 26 Low conductive part, 28 Common electrode, 30 2nd board | substrate, 32 color filter layers, 34 black matrix, 36 colored layer, 38 filling layer, 40 mask, 42 sealing film, 44 mask layer.

Claims (8)

Preparing a substrate provided with a plurality of pixel electrodes;
Forming an organic electroluminescence film so as to include a common layer continuously covering the plurality of pixel electrodes;
Forming a common electrode on the organic electroluminescence film;
Irradiating the common layer with energy rays above the area between the adjacent pixel electrodes, avoiding the upper part of the plurality of pixel electrodes;
Including
A method of manufacturing an organic electroluminescence display device, wherein the conductivity of the common layer is lowered above the region between adjacent pixel electrodes by irradiation with the energy beam. In the manufacturing method of the organic electroluminescent display device according to claim 1,
Further including a step of forming an insulating layer in the region between adjacent pixel electrodes so as to be placed on an end of each pixel electrode;
A method for manufacturing an organic electroluminescence display device, comprising forming the organic electroluminescence film on the insulating layer. In the manufacturing method of the organic electroluminescent display apparatus described in Claim 1 or 2,
Before forming the common electrode, the energy layer is irradiated with the energy beam before the common electrode is formed. In the manufacturing method of the organic electroluminescent display apparatus described in Claim 1 or 2,
A method for manufacturing an organic electroluminescence display device, comprising: forming the common electrode; and irradiating the energy layer with the energy beam through the common electrode. In the manufacturing method of the organic electroluminescent display apparatus described in Claim 1 or 2,
Further comprising forming a sealing film on the common electrode;
After forming the sealing film, the energy ray is applied to the common layer through the sealing film and the common electrode, and the method for manufacturing the organic electroluminescence display device. In the manufacturing method of the organic electroluminescent display device according to any one of claims 1 to 5,
Irradiating the energy rays through a mask;
The mask has a pattern in which the energy rays are blocked above the plurality of pixel electrodes and the energy rays are allowed to pass above the region between the adjacent pixel electrodes. Manufacturing method of luminescence display device. In the manufacturing method of the organic electroluminescent display device according to any one of claims 1 to 5,
Forming a mask layer on the organic electroluminescence film to prevent passage of the energy rays;
Irradiating the energy rays through the pattern of the mask layer;
The organic layer characterized in that the pattern of the mask layer prevents the energy beam from passing above the plurality of pixel electrodes and allows the energy beam to pass above the region between the adjacent pixel electrodes. A method for manufacturing an electroluminescence display device. A substrate,
A plurality of pixel electrodes provided on the substrate;
An organic electroluminescence film provided on the substrate so as to include a common layer continuously covering the plurality of pixel electrodes;
A common electrode provided on the organic electroluminescence film;
Have
The organic electroluminescence display device, wherein the common layer has a low conductive portion having a lower conductivity than a portion above the plurality of pixel electrodes above a region between adjacent pixel electrodes.

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