JP2015053215A - 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: An organic electroluminescent display device comprises: a plurality of pixel electrodes 18; an insulation layer 22 provided on a region between pixel electrodes 18 adjacent to each other so as to place on edges of each of pixel electrodes 18; an organic electroluminescent film 30 containing a common layer 32 continuously covering a plurality of pixel electrodes 18 and the insulation film 22; and a common electrode 38 provided on the organic electroluminescent film 30. The insulation film 22 has a recessed and protruded upper surface consisting of a plurality of recesses 24 and a plurality of protrusions 26. The common layer 32 has a recessed and protruded upper step part 34 where each protrusions 26 is placed, and a lower step part 36 where each recesses 24 is placed. The upper step part 34 and the lower step part 36 are arranged to be vertically sifted from each other, and at least parts of them in its thickness direction are discontinuous to partially thin the common layer 32, thereby its electric resistance is enhanced.

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 for forming a light emitting layer is provided so as to be continuous as a whole. Alternatively, in order to obtain light emission of a plurality of colors in a plurality of pixels, an organic film for forming a light emitting layer is separated for each pixel, but a hole injection layer, an electron injection layer, a hole transport layer, or an electron transport layer For example, an organic film is continuously provided. In any case, at least one organic film is continuously provided over adjacent pixels.

JP 2010-212177 A JP 2006-140145 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 Documents 1 and 2 disclose that the surface of a partition wall (or insulating film) is roughened, but there is no description of an organic film formed thereon, so the problem of current leakage is not solved.

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

  (1) An organic electroluminescence display device according to the present invention includes a substrate, a plurality of pixel electrodes provided on the substrate, and adjacent pixel electrodes so as to be placed on end portions of the pixel electrodes. An organic electroluminescent film provided on the substrate so as to include an insulating layer provided in the region, a common layer continuously covering the plurality of pixel electrodes and the insulating layer, and an organic electroluminescent film on the organic electroluminescent film A common electrode provided, the insulating layer has a concavo-convex upper surface comprising a plurality of concave portions and a plurality of convex portions, and the common layer is an upper stage portion mounted on each convex portion of the concavo-convex shape And the lower step portion placed on each concave portion, the upper step portion and the lower step portion are shifted from each other up and down, and at least part of the thickness direction is discontinuous, thereby reducing the thickness of the common layer. Partially thin and power Characterized in that by increasing the resistance. According to the present invention, the electrical resistance is increased by partially reducing the thickness of the common layer above the region between the adjacent pixel electrodes. This can prevent current from leaking between adjacent pixels through the common layer.

  (2) In the organic electroluminescence display device described in (1), the upper stage part and the lower stage part may be characterized in that a part of the thickness direction is continuous.

  (3) In the organic electroluminescence display device described in (1), the upper stage part and the lower stage part may be separated.

  (4) In the organic electroluminescence display device according to any one of (1) to (3), the bottom surfaces of the plurality of recesses are arranged along one plane, and the top surfaces of the plurality of projections May be arranged along one other plane.

  (5) In the organic electroluminescence display device according to any one of (1) to (3), bottom surfaces of the plurality of concave portions are arranged along one convex curved surface, and the plurality of convex portions are arranged. The upper surface may be arranged along one other convex curved surface.

  (6) In the organic electroluminescence display device according to any one of (1) to (5), the plurality of pixel electrodes are arranged in a vertical direction and a horizontal direction, and a planar shape of each of the pixel electrodes Has a long axis and a short axis, and is long in one direction. The pixel electrodes adjacent to each other in the vertical direction are adjacent to each other in the short direction along the short axis, and are adjacent to each other in the horizontal direction. In the pixel electrode, long sides along the long axis are adjacent to each other, and the plurality of concave portions and the plurality of convex portions of the insulating layer are adjacent to each other while avoiding a region between the adjacent short sides. It may be formed in a region between the long sides.

  (7) The manufacturing method of the organic electroluminescence display device according to the present invention includes a step of preparing a substrate provided with a plurality of pixel electrodes, and the pixels adjacent to each other so as to be placed on end portions of the pixel electrodes. Forming an insulating layer in a region between the electrodes; forming an organic electroluminescence film on the substrate so as to include a common layer continuously covering the plurality of pixel electrodes and the insulating layer; Forming a common electrode on the organic electroluminescence film, wherein the insulating layer is formed to have a concavo-convex shape composed of a plurality of concave portions and a plurality of convex portions, and the common layer includes the common layer It is formed so as to have an upper step portion that is placed on each convex portion of the concavo-convex shape and a lower step portion that is placed on each concave portion, and the upper step portion and the lower step portion are positioned so as to be displaced from each other vertically, and at least a part of the thickness direction is between By it becomes continuous, characterized in that by increasing the electric resistance by reducing the thickness of the common layer partially. According to the present invention, the electrical resistance is increased by partially reducing the thickness of the common layer above the region between the adjacent pixel electrodes. This can prevent current from leaking between adjacent pixels through the common layer.

  (8) In the method of manufacturing an organic electroluminescence display device according to (7), the step of forming the insulating layer having the top surface of the concavo-convex shape includes a step of providing an insulating material, and a step of forming the insulating material by nanoimprinting. A step of applying the uneven shape.

  (9) In the method of manufacturing an organic electroluminescence display device according to (8), in the step of forming the insulating layer having the upper surface of the uneven shape, the insulating material is covered with the plurality of pixel electrodes. The insulating material may be partially removed from at least the central portion of each pixel electrode after the step of providing and forming the uneven shape.

  (10) In the method of manufacturing an organic electroluminescence display device described in (9), the insulating material may be partially removed by at least one of photolithography and dry etching.

  (11) In the method of manufacturing an organic electroluminescence display device according to (9), in the step of applying the uneven shape, the insulating material is formed at least above the central portion of each pixel electrode by the nanoimprint. It may be characterized in that it is recessed to reduce the thickness.

  (12) In the method of manufacturing an organic electroluminescence display device described in (11), the insulating material may be partially removed by dry etching.

1 is a perspective view of an organic electroluminescence display device according to a first 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 top view which shows the arrangement | sequence of several pixel electrodes. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the organic electroluminescent display apparatus which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the modification of 2nd Embodiment.

  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 a first 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.

  FIG. 3 is a plan view showing the arrangement of the plurality of pixel electrodes 18. The plurality of pixel electrodes 18 are arranged in the vertical direction and the horizontal direction. The planar shape of each pixel electrode 18 has a long axis and a short axis and is long in one direction. The pixel electrodes 18 adjacent to each other in the vertical direction have adjacent short sides along the short axis. The pixel electrodes 18 adjacent to each other in the horizontal direction are adjacent to each other along the long axis. The pixel electrode 18 is electrically connected to a wiring (not shown) of the circuit layer 16 through a contact 20.

  As shown in FIG. 2, an insulating layer 22 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 22 surrounds the peripheral edge of each pixel electrode 18. In other words, the insulating layer 22 has an opening 22a that exposes the central portion of the pixel electrode 18 (see FIG. 3).

  The insulating layer 22 has a concavo-convex upper surface composed of a plurality of concave portions 24 and a plurality of convex portions 26. The uneven shape is formed on a convex curved surface. Therefore, the bottom surfaces of the plurality of concave portions 24 are arranged along one convex curved surface, and the top surfaces of the plurality of convex portions 26 are arranged along one other convex curved surface. As shown in FIG. 3, the plurality of concave portions 24 and the plurality of convex portions 26 of the insulating layer 22 are formed in a region 28 between adjacent long sides, avoiding a region between adjacent short sides.

  An organic electroluminescence film 30 is provided on the first substrate 10. The organic electroluminescence film 30 is placed on the plurality of pixel electrodes 18 and the insulating layer 22. Although not shown, the organic electroluminescence film 30 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 30 includes a common layer 32 that continuously covers the plurality of pixel electrodes 18 and the insulating layer 22. In the example of FIG. 2, the entire organic electroluminescence film 30 is the common layer 32. Alternatively, at least one layer (excluding at least one layer) of the organic electroluminescence film 30 including a plurality of layers is the common layer 32 (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 30 having a tandem structure including two or more light emitting layers, even if the charge generation layer for supplying electrons and holes arranged between adjacent light emitting layers is the common layer 32. Good.

  The common layer 32 has an upper step portion 34 placed on each convex portion 26 of the concavo-convex shape of the insulating layer 22 and a lower step portion 36 placed on each concave portion 24. The upper step portion 34 and the lower step portion 36 are positioned so as to be shifted vertically from each other. The upper step portion 34 and the lower step portion 36 are partially continuous in the thickness direction, but form steps because at least some of the thickness direction are discontinuous in the horizontal direction. By forming the upper step 34 and the lower step 36, the thickness of the common layer 32 is partially reduced, and the electric resistance of the common layer 32 is increased.

  A common electrode 38 is provided on the organic electroluminescence film 30. The common electrode 38 is a cathode. By applying a voltage to the pixel electrode 18 and the common electrode 38, holes and electrons are injected from each into the organic electroluminescence film 30. The injected holes and electrons combine in the light emitting layer to emit light. Since the insulating layer 22 is interposed between the end of the pixel electrode 18 and the common electrode 38, a short circuit between them is prevented.

  According to the present embodiment, the electric resistance is increased by partially reducing the thickness of the common layer 32 above the region between the adjacent pixel electrodes 18. Thereby, it is possible to prevent current from leaking between adjacent pixels through the common layer 32.

  A sealing film 40 is provided on the common electrode 38. The sealing film 40 seals the organic electroluminescence film 30 so as to shield it from moisture. A filling layer 42 is provided on the sealing film 40.

  The second substrate 44 is disposed so as to face the first substrate 10 with a gap. A color filter layer 46 is provided on the surface of the second substrate 44 on the first substrate 10 side. The color filter layer 46 includes a black matrix 48 and a colored layer 50. Since the light emitting layer (not shown) of the organic electroluminescence film 30 described above emits a single color (for example, white), in this embodiment, the color filter layer 46 is provided to enable full color display. When the organic electroluminescence film 30 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 50 is unnecessary. A filling layer 42 is provided between the first substrate 10 and the second substrate 44.

  4-7 is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus which concerns on the 1st Embodiment of this invention.

  As shown in FIG. 4, a first substrate 10 provided with a plurality of pixel electrodes 18 is prepared, and an insulating material 52 is provided so as to cover the plurality of pixel electrodes 18.

  As shown in FIG. 5, an uneven shape is formed in the insulating material 52. For example, the insulating material 52 is provided with an uneven shape by nanoimprinting. Specifically, the nano stamper 54 having fine irregularities is pressed against the insulating material 52 to transfer the pattern. In the thermal nanoimprint, a thermoplastic resin is used as the insulating material 52, and the unevenness of the nano stamper 54 is press-transferred to the resin softened by heating to the glass transition temperature or higher.

  As shown in FIG. 6, the insulating material 52 is partially removed from at least the central part of each pixel electrode 18. The partial removal of the insulating material 52 is performed by at least one of photolithography and dry etching. When photolithography is applied, as shown in FIG. 6, the remaining insulating material 52 has a convex curved upper surface. Thus, the insulating layer 22 is formed in the region between the adjacent pixel electrodes 18 so as to be placed on the end portions of the respective pixel electrodes 18. The insulating layer 22 has a concavo-convex upper surface composed of a plurality of concave portions 24 and a plurality of convex portions 26.

  As shown in FIG. 7, an organic electroluminescence film 30 is formed on the first substrate 10 so as to include a common layer 32 that continuously covers the plurality of pixel electrodes 18 and the insulating layer 22. Since the organic electroluminescence film 30 is formed by vapor deposition, it has a shape according to the surface shape of the base. Specifically, the common layer 32 described above is formed so as to have an upper step portion 34 placed on each convex portion 26 of the concavo-convex shape of the insulating layer 22 and a lower step portion 36 placed on each concave portion 24. The upper step portion 34 and the lower step portion 36 are positioned so as to be shifted vertically from each other. The upper step portion 34 and the lower step portion 36 are at least partially discontinuous in the thickness direction. Then, the common electrode 38 is formed on the organic electroluminescence film 30.

  According to the present embodiment, the electric resistance is increased by partially reducing the thickness of the common layer 32 above the region between the adjacent pixel electrodes 18. Thereby, it is possible to prevent current from leaking between adjacent pixels through the common layer 32.

  FIG. 8 is a cross-sectional view showing an organic electroluminescence display device according to the second embodiment of the present invention. In the present embodiment, the uneven shape of the insulating layer 122 is formed on a plane. That is, the bottom surfaces of the plurality of recesses 124 are arranged along one plane, and the top surfaces of the plurality of projections 126 are arranged along another one plane. A plurality of sealing films 140 (first sealing film 156, second sealing film 158, and third sealing film 160) are provided on the common electrode 138 to block the organic electroluminescence film 130 from moisture. It is sealed like this. Other configurations correspond to the contents described in the above embodiment.

  9 to 10 are views for explaining a method of manufacturing the organic electroluminescence display device according to the second embodiment of the present invention.

  As shown in FIG. 9, the insulating material 152 formed so as to cover the plurality of pixel electrodes 118 is provided with an uneven shape by nanoimprinting. Specifically, the nano stamper 154 having fine unevenness is pressed against the insulating material 152 to transfer the pattern. In the optical nanoimprint, a photo-curing resin is used for the insulating material 152, the unevenness of the nano stamper 154 is press-transferred to the resin, and the resin is cured by irradiating ultraviolet rays.

  In addition, the thickness of the insulating material 152 is reduced by nanoimprinting by recessing the insulating material 152 at least above the center of each pixel electrode 118. Specifically, the nano stamper 154 has a protruding region corresponding to a position where the insulating material 152 can be depressed. The nano stamper 154 has irregularities in a relatively recessed area.

  Then, the insulating material 152 is partially removed from at least the central portion of each pixel electrode 118 (see FIG. 8). Note that the partial removal of the insulating material 152 is performed by dry etching.

  As shown in FIG. 10, an organic electroluminescence film 130 is formed. As shown in FIG. 8, a common electrode 138 is formed on the organic electroluminescence film 130, and a plurality of sealing films 140 (first sealing film 156, second sealing film 158 and third sealing film are formed). 160). The contents described in the first embodiment correspond to the subsequent processes.

  FIG. 11 is a diagram illustrating a modification of the second embodiment. Also in this example, the common layer 232 of the organic electroluminescence film 230 has an upper step portion 234 that rests on the convex portion 226 of the insulating layer 222 and a lower step portion 236 that rests on the concave portion 224, but the upper step portion 234 and the lower step portion 236 are separated. Yes. That is, the upper step 234 and the lower step 236 are positioned so as to be displaced from each other vertically, and the entire thickness direction is discontinuous. If the common layer 232 is formed thin, the upper step portion 234 and the lower step portion 236 are thus separated.

  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 Contact, 22 Insulating layer, 22a Opening 22a, 24 Recessed part, 26 Convex part, 28 area | region, 30 Electroluminescent film | membrane, 32 Common layer, 34 Upper part, 36 Lower part, 38 Common electrode, 40 Sealing film, 42 Filling layer, 44 Second substrate, 46 Color filter layer, 48 Black matrix, 50 Colored layer, 52 Insulating material, 54 Nano stamper, 118 Pixel electrode, 122 insulating layer, 124 concave portion, 126 convex portion, 130 electroluminescence film, 134 upper stage portion, 136 lower stage portion, 138 common electrode, 140 sealing film, 152 insulating material, 154 nano stamper, 156 first sealing film, 158 Second sealing film, 160 Third sealing film, 222 Marginal, 224 recess, 226 protrusion, 230 organic electroluminescent layer, 232 a common layer, 234 upper portion, 236 lower portion.

Claims (12)

A substrate,
A plurality of pixel electrodes provided on the substrate;
An insulating layer provided in a region between adjacent pixel electrodes so as to be placed on an end of each pixel electrode;
An organic electroluminescence film provided on the substrate so as to include a common layer continuously covering the plurality of pixel electrodes and the insulating layer;
A common electrode provided on the organic electroluminescence film;
Have
The insulating layer has a concavo-convex upper surface composed of a plurality of concave portions and a plurality of convex portions,
The common layer has an upper stage portion that is placed on each convex portion of the uneven shape and a lower stage portion that is placed on each concave portion,
The upper step portion and the lower step portion are shifted from each other vertically and at least part of the thickness direction is discontinuous, thereby partially reducing the thickness of the common layer and increasing the electrical resistance. An organic electroluminescence display device characterized by comprising: The organic electroluminescence display device according to claim 1,
The organic electroluminescence display device, wherein the upper stage part and the lower stage part are partially continuous in the thickness direction. The organic electroluminescence display device according to claim 1,
The organic electroluminescence display device, wherein the upper stage part and the lower stage part are separated. The organic electroluminescence display device according to any one of claims 1 to 3,
The bottom surfaces of the plurality of recesses are arranged along one plane,
The organic electroluminescence display device, wherein upper surfaces of the plurality of convex portions are arranged along another plane. The organic electroluminescence display device according to any one of claims 1 to 3,
The bottom surfaces of the plurality of recesses are arranged along one convex curved surface,
An organic electroluminescence display device, wherein upper surfaces of the plurality of convex portions are arranged along another convex curved surface. In the organic electroluminescence display device according to any one of claims 1 to 5,
The plurality of pixel electrodes are arranged in a vertical direction and a horizontal direction,
The planar shape of each of the pixel electrodes has a long axis and a short axis, and is long in one direction.
The pixel electrodes adjacent to each other in the vertical direction are adjacent to each other along the short axis,
The pixel electrodes adjacent to each other in the horizontal direction are adjacent to each other along the long axis,
The plurality of concave portions and the plurality of convex portions of the insulating layer are formed in a region between the adjacent long sides, avoiding a region between the adjacent short sides. Luminescence display device. Preparing a substrate provided with a plurality of pixel electrodes;
Forming an insulating layer in a region between adjacent pixel electrodes so as to be placed on an end of each of the pixel electrodes;
Forming an organic electroluminescence film on the substrate so as to include a common layer continuously covering the plurality of pixel electrodes and the insulating layer;
Forming a common electrode on the organic electroluminescence film;
Including
The insulating layer is formed so as to have a concavo-convex shape composed of a plurality of concave portions and a plurality of convex portions,
The common layer is formed so as to have an upper step portion placed on each convex portion of the uneven shape and a lower step portion placed on each concave portion,
The upper step portion and the lower step portion are shifted from each other vertically and at least part of the thickness direction is discontinuous, thereby partially reducing the thickness of the common layer and increasing the electrical resistance. A method for producing an organic electroluminescence display device. In the manufacturing method of the organic electroluminescent display device according to claim 7,
The step of forming the insulating layer having the top surface of the uneven shape,
Providing an insulating material;
Applying the uneven shape to the insulating material by nanoimprint;
The manufacturing method of the organic electroluminescent display apparatus characterized by including. In the manufacturing method of the organic electroluminescent display device according to claim 8,
In the step of forming the insulating layer having the top surface of the uneven shape,
Providing the insulating material so as to cover the plurality of pixel electrodes;
A method of manufacturing an organic electroluminescence display device, wherein the insulating material is partially removed from at least a central portion of each of the pixel electrodes after the step of forming the concavo-convex shape. In the manufacturing method of the organic electroluminescent display device according to claim 9,
The method for manufacturing an organic electroluminescence display device, wherein the partial removal of the insulating material is performed by at least one of photolithography and dry etching. In the manufacturing method of the organic electroluminescent display device according to claim 9,
The method for producing an organic electroluminescence display device, wherein in the step of forming the concavo-convex shape, the insulating material is recessed at least above the central portion of each pixel electrode by the nanoimprint to reduce the thickness. . In the manufacturing method of the organic electroluminescent display device according to claim 11,
The method for manufacturing an organic electroluminescence display device, wherein the partial removal of the insulating material is performed by dry etching.

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