JP2011096378A - Organic el display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display device wherein two adjoining sub-pixels having the same colors can be vapor-deposited and formed by one mask opening part, and auxiliary wiring can be thereby disposed so as not to narrow a light emitting region as far as possible. <P>SOLUTION: A plurality of pixels 11 composed of organic light emitting elements in each of which a lower electrode 21, an organic compound layer containing at least a luminescent layer 25, and an upper electrode 27 are formed in order are arranged on a substrate 20. Each pixel 11 is composed of a plurality of sub-pixels SP having the same luminescent colors and different luminescent colors, and is formed so that the interval D2 between the adjoining sub-pixels having the different luminescent colors is wider than the interval D1 between the adjoining sub-pixels having the same luminescent colors. The auxiliary wiring 22 having a sheet resistance value lower than that of the upper electrode 27 is at least disposed between the adjoining sub-pixels having different luminescent colors. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic EL display device in which a plurality of pixels having different emission colors are arranged in the same plane.

  As a color display, an organic EL display device is known in which a plurality of pixels having different emission colors are arranged two-dimensionally in the same plane. In the case of manufacturing this type of organic EL display device, as a method for forming the organic compound layer, a vacuum evaporation method using an evaporation mask such as a photoresist mask is mainly used.

  However, if the pixels are reduced in order to perform high-definition display, the distance between the openings of the vapor deposition mask is also reduced, so that the mask strength is lowered and the alignment accuracy is deteriorated.

  As a technique for solving such a problem, for example, two subpixels having the same emission color are adjacent to each other among a plurality of pixels, and these two adjacent subpixels are continuously integrated. An organic EL panel has been proposed (see Patent Document 1). According to this technique, since two adjacent sub-pixels of the same color can be formed using one mask opening, the width of the non-opening of the mask can be widened, and a reduction in mask strength is prevented. Can do.

JP 2004-207126 A

  By the way, in the organic EL display device (panel) of Patent Document 1, the upper electrode positioned on the light extraction side must be a transparent or translucent material in the used film thickness. Therefore, a transparent conductive film such as ITO (Indium Tin Oxide) or IZO (Indium Zing Oxide) is used for the upper electrode. Here, since these ITO and IZO cannot sufficiently reduce the sheet resistance value as compared with metal materials such as Al and Ag, there is a problem that a voltage drop occurs in the display region and luminance becomes non-uniform.

  As a measure for preventing this problem, there is a method of reducing the resistance value of the upper electrode by arranging an auxiliary wiring made of a metal material having a low sheet resistance value such as Al at least in a region excluding the pixel.

  However, when such an auxiliary wiring is arranged, an arrangement space corresponding to the auxiliary wiring is required. Therefore, even if two adjacent sub-pixels of the same color are deposited and formed at one mask opening to widen the light emitting region as in Patent Document 1, it is difficult to make the most of the effect.

  Therefore, in view of the above problems, the present invention can form two adjacent subpixels of the same color by vapor deposition at one mask opening, and can arrange auxiliary wiring so as not to narrow the light emitting region as much as possible. An object is to provide an organic EL display device.

  The configuration of the present invention made to achieve the above object is as follows.

  That is, in the organic EL display device according to the present invention, a plurality of pixels composed of an organic light emitting element in which a lower electrode, an organic compound layer including at least a light emitting layer, and an upper electrode are sequentially formed on a substrate are arranged, and Each pixel consists of a plurality of sub-pixels of the same emission color and different emission colors, and the interval between adjacent sub-pixels of different emission color is formed wider than the interval between adjacent sub-pixels of the same emission color, The organic EL display device is characterized in that an auxiliary wiring having a sheet resistance value lower than that of the upper electrode is disposed at least between the adjacent sub-pixels of different emission colors.

  According to the present invention, the auxiliary wiring is provided between the sub-pixels of different luminescent colors, so that the distance between the adjacent sub-pixels of the same luminescent color is kept small, and the auxiliary wiring with a low sheet resistance value is used. The resistance value can be reduced. Therefore, the voltage drop of the upper electrode is suppressed, and in-plane luminance is uniformed and power consumption is reduced.

  In addition, it is possible to manufacture an organic EL display device with a high aperture ratio without impairing the effect of expanding the light emitting region by depositing the organic compound layer of the adjacent sub-pixel of the same color at one mask opening. .

1 is a schematic plan view illustrating a basic configuration of an organic EL display device according to the present invention. It is a top view which shows the planar structure of the organic electroluminescent display apparatus of 1st Embodiment. It is the sectional view on the AB line of FIG. It is a top view which shows the plane structure of the organic electroluminescence display of 2nd Embodiment. (A)-(c) is sectional drawing which shows the process after forming an organic compound layer until it forms an upper electrode, (c) It is the AB sectional view taken on the line of FIG. It is a top view which shows the planar structure of the organic electroluminescent display apparatus of 3rd Embodiment. FIG. 7 is a cross-sectional view taken along line AB in FIG. 6.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments. In the following embodiments, well-known or publicly known techniques in the technical field of the present invention are applied to portions that are not particularly described or illustrated.

[First Embodiment]
First, the configuration of the first embodiment of the organic EL display device according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic plan view showing a basic configuration of an organic EL display device according to the present invention. FIG. 2 is a plan view showing a planar configuration of the organic EL display device of the first embodiment, and FIG. 3 is a cross-sectional view taken along the line AB of FIG. In these figures, 11 is a subpixel, 13 is an organic compound layer, 20 is a substrate, 21 is a lower electrode, 22 is an auxiliary wiring, 23 is a bank, 24 is a hole injection layer and a hole transport layer, and 25 is a light emitting layer. , 26 are an electron transport layer and an electron injection layer, 27 is an upper electrode, and 28 is a sealing member.

  As shown in FIGS. 1 to 3, the organic EL display device of the present embodiment is a top emission type, and a lower electrode 21, an organic compound layer 13 including at least a light emitting layer 25, and an upper electrode 27 are provided on a substrate 20. A plurality of pixels composed of organic light emitting elements formed in sequence are arranged. Each pixel composed of an organic light emitting element includes a plurality of sub-pixels 11 having the same emission color and different emission colors, which will be specifically described below.

  A plurality of lower electrodes 21 and auxiliary wirings 22 made of metal or the like are formed on the substrate 20. The lower electrode 21 and the auxiliary wiring 22 are formed by simultaneous film formation and patterning in the same plane on the substrate 20. At this time, the auxiliary wiring 22 is formed in a portion between adjacent sub-pixels of the same emission color. Does not form. In the configuration example of FIG. 1, the auxiliary wiring 22 is formed along the longitudinal direction of the sub-pixel 11. However, the auxiliary wiring 22 may be formed in the lateral direction and arranged vertically and horizontally like a mesh.

  The lower electrode 21 and the auxiliary wiring 22 are preferably light-reflective and have a low sheet resistance value. For example, the lower electrode 21 and the auxiliary wiring 22 are preferably formed of a metal material such as Cr, Al, Ag, Au, or Pt. This is because the light extraction efficiency can be improved with a member having higher light reflectivity, and the voltage drop of the upper electrode 27 can be suppressed with a material having a lower sheet resistance value.

  A plurality of thin film transistors serving as switches for the plurality of lower electrodes 21 are formed on the substrate 20. Further, a drive circuit for driving a plurality of thin film transistors is formed, and a thin film transistor, a lower electrode 21 and a wiring electrically connected to the drive circuit are formed.

  Banks 23 are formed on the substrate 20. The bank 23 may be formed of an inorganic material or an organic material, or may be composed of an inorganic material layer and an organic material layer provided thereon. The bank 23 surrounds at least a part of each lower electrode 21 and rests on the end of each lower electrode 21. That is, a part (center portion) of the lower electrode 21 is exposed from the bank 23. Similarly, only the end portion of the auxiliary wiring 22 is covered with the bank 23, and the central portion is exposed.

  Above the lower electrode 21, for example, an organic compound layer 13 made of a low molecular organic material is formed by mask vapor deposition using a photoresist mask or the like. In the organic compound layer 13 of this embodiment, for example, a hole injection layer and a hole transport layer 24, a light emitting layer 25, an electron transport layer and an electron injection layer 26 are formed in this order. It is not limited. When the organic compound layer 13 is formed by vapor deposition, since at least a part of the auxiliary wiring 22 is covered with a vapor deposition mask such as a photoresist mask, the organic compound layer 13 is covered on the portion of the auxiliary wiring 22 covered with the mask. Layer 13 is not formed.

  For example, doping the hole injection material or the hole transport material with an organic light emitting material, or doping the electron injection material or the electron transport material with an organic light emitting material can widen the range of color selection. Furthermore, the organic compound layer 13 is preferably an amorphous film from the viewpoint of luminous efficiency. The light emitting layer 25 emits light upon receiving energy from an electric field or current. In the organic EL display device of this embodiment, a plurality of rows of light emitting layers 25 that emit light of each of three colors of R (red), G (green), and B (blue) are arranged in stripes (see FIG. 1). .

  Examples of organic light-emitting materials of each color include triarylamine derivatives, stilbene derivatives, polyarylenes, aromatic condensed polycyclic compounds, aromatic heterocyclic compounds, aromatic heterocyclic condensed ring compounds, metal complex compounds, and the like, and single oligos thereof. Can be used. However, it is not limited to these exemplary materials.

  The organic compound layer 13 may be a layer having a single function of hole injection, hole transport, electron injection, or electron transport, or may be a layer having a composite function.

  The film thickness of the organic compound layer 13 is preferably about 0.05 μm to 0.3 μm, and a more preferable film thickness range is about 0.05 to 0.15 μm.

  As the hole injection and transport material, for example, a phthalocyanine compound, a triarylamine compound, a conductive polymer, a perylene compound, an Eu complex, or the like can be used, but the material is not limited to the exemplified materials.

Examples of the electron injecting and transporting material include, for example, Alq ₃ in which an 8-hydroxyquinoline trimer is coordinated to aluminum, an azomethine zinc complex, a distyrylbiphenyl derivative system, and the like. It is not something.

  An upper electrode 27 is formed above the organic compound layer 13. The upper electrode 27 is made of a light transmissive material such as IZO, for example. In the organic EL display device of this embodiment, since the organic compound layer 13 does not cover the auxiliary wiring 22, the exposed portion of the auxiliary wiring 22 and the upper electrode 27 are electrically connected when the upper electrode 27 is formed. Connected. That is, there is a connection position between the upper electrode 27 and the auxiliary wiring 22 between adjacent sub-pixels of different colors (see FIG. 2).

  The organic EL display device of the present embodiment is covered with a sealing member 28, and for example, glass or the like is used as the sealing member 28. The sealing member 28 is for sealing a region (display region) in which a plurality of rows of light emitting layers 25 are arranged, and is attached to a peripheral region outside the display region. For example, an adhesive may be used as the sealing material for attaching the sealing member 28. A desiccant (not shown) is attached to the surface of the sealing member 28 on the sealing space side.

  As described above, the organic EL display device according to the present embodiment includes a plurality of rows of light emitting layers 25 having a light emission color of R, G, and B and a stripe arrangement. The light emitting layer 25 in each column includes a plurality of subpixels (corresponding to subpixels) SP that emit light by energy generated by an electric field or current. That is, each subpixel SP is a portion where an electric field is applied to the light emitting layer 25 between one lower electrode 21 and the upper electrode 27 (a portion facing a portion exposed from the bank 23 of one lower electrode 21). is there.

  As shown in FIG. 1, subpixels SP of the same color are arranged in the vertical direction (longitudinal direction of the subpixel SP). On the other hand, three-color RGB sub-pixels SP are arranged in the horizontal direction (short direction of the sub-pixels SP).

  There is a relationship of D1 <D2 between the distance D1 between adjacent sub-pixels of the same emission color and the interval D2 between adjacent sub-pixels of different emission color. Further, by forming two adjacent sub-pixels of the same color at one mask opening, the light emitting region can be enlarged. In addition, by connecting the auxiliary wiring 22 and the upper electrode 27 between adjacent sub-pixels of different colors, it is possible to achieve in-plane luminance uniformity and power consumption reduction.

  As described above, according to the first embodiment, it is possible to manufacture an organic EL display device having a wide light emitting region, uniform in-plane luminance, and low power consumption.

[Second Embodiment]
Next, the configuration of the organic EL display device according to the second embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a plan view showing a planar configuration of the organic EL display device of the second embodiment, and FIGS. 5A to 5C show the steps from the formation of the organic compound layer to the formation of the upper electrode. FIG. 5C is a cross-sectional view taken along the line AB of FIG. In addition, when there is no description in particular about the material used in 2nd Embodiment, production conditions, etc., the same thing as 1st Embodiment is used.

  As shown in FIGS. 4 and 5, in the organic EL display device of the second embodiment, a plurality of lower electrodes 21, auxiliary wirings 22, and auxiliary wires 22 are formed on the substrate 20 with the same material and shape as in the first embodiment. Banks 23 are formed.

  Above the lower electrode 21, for example, an organic compound layer 13 made of a low molecular organic material is formed by mask vapor deposition. In this embodiment, in order to simplify the vapor deposition process by reducing the fine mask, the hole injection layer and the hole transport layer 24, the electron transport layer and the electron injection layer 26 other than the R, G and B light emitting layers 25 are provided. It is formed over the entire display area. As for the light emitting layer 25, as in the first embodiment, the three colors R, G, and B are arranged in stripes (see FIG. 1). Therefore, the auxiliary wiring 22 is covered with a hole injection layer and a hole transport layer 24 and an electron transport layer and an electron injection layer 26 constituting the organic compound layer 13 (see FIG. 5A).

The removal of the organic compound layer 13 deposited on the auxiliary wiring 22 between adjacent sub-pixels of different colors is performed, for example, by laser ablation (see FIG. 5B). For the laser light 29, for example, an excimer laser having a wavelength of 248 nm is used. The laser beam 29 is used as a planar light source, and the substrate 20 is irradiated with a predetermined pattern through a mask that passes through the processed portion. The organic compound layer 13 is removed at an output of 100 mJ / cm ² per unit area. The number of irradiations may be removed by selecting the required number of irradiations according to the film thickness of the organic compound layer 13. An example of the laser irradiation position in the present embodiment is shown by a broken line in FIG. 4, but it may be on the auxiliary wiring 22 between adjacent sub-pixels of different colors, and is limited to the processing position and processing pitch shown in FIG. It is not something.

  An upper electrode 27 is formed above the organic compound layer 13. In this embodiment, the auxiliary wiring 22 and the upper electrode 27 are electrically connected (conducted) via a contact hole (electrical connection hole) 50 formed by laser processing. That is, there is a connection position between the upper electrode 27 and the auxiliary wiring 22 by the contact hole 50 between adjacent sub-pixels of different colors (see FIG. 4).

  The organic EL display device of this embodiment is covered with a sealing member 28 made of glass or the like, for example, as in the first embodiment (see FIG. 5C), and the sealing of the sealing member 28 is performed. A desiccant (not shown) is attached to the space side surface.

  There is a relationship of D1 <D2 between the interval D1 between adjacent sub-pixels of the same color and the interval D2 between adjacent sub-pixels of different colors. Further, by forming two adjacent sub-pixels of the same color at one mask opening, the light emitting region can be enlarged. In addition, by connecting the auxiliary wiring 22 and the upper electrode 27 between adjacent sub-pixels of different colors, it is possible to achieve in-plane luminance uniformity and power consumption reduction.

  As described above, the second embodiment basically has the same operational effects as the first embodiment. In particular, according to the organic EL display device of the second embodiment, the fine mask is reduced, and the organic compound layer 13 on the auxiliary wiring 22 is laser-removed, so that the vapor deposition process can be simplified.

[Third Embodiment]
Next, the configuration of the organic EL display device according to the third embodiment will be described with reference to FIGS. FIG. 6 is a plan view showing a planar configuration of the organic EL display device of the third embodiment, and FIG. 7 is a cross-sectional view taken along the line AB of FIG. In addition, when there is no description in particular about the material used in 3rd Embodiment, preparation conditions, etc., the same thing as 1st Embodiment is used.

  As shown in FIGS. 6 and 7, in the organic EL display device of the third embodiment, a plurality of lower electrodes 21 made of metal or the like are formed on a substrate 20. The lower electrode 21 has light reflectivity, and the portion corresponding to the adjacent sub-pixels of the same color has a narrow interval (D1), and the portion corresponding to the adjacent sub-pixels of different colors forms a wide sense (D2). ing.

  Banks 23 are formed on the substrate 20. The bank 23 surrounds at least a part of each lower electrode 21 and rests on the end of each lower electrode 21. That is, a part (center portion) of the lower electrode 21 is exposed from the bank 23.

  Above the lower electrode 21, for example, an organic compound layer 13 made of a low molecular organic material is formed by mask vapor deposition. In the organic EL display device of this embodiment, in order to simplify the vapor deposition process by reducing fine masks, the hole injection layer and hole transport layer 24 other than the R, G, and B light emitting layers 25, the electron transport layer, and the electrons An injection layer 26 is formed over the entire display area. As for the light emitting layer 25, as in the first embodiment, the three colors R, G, and B are arranged in stripes (see FIG. 1).

  Above the organic compound layer, for example, an upper electrode 27 having optical transparency such as IZO is formed. In the present embodiment, as shown in FIG. 6, the auxiliary wiring 30 is formed by mask vapor deposition in a portion corresponding to the area between the adjacent sub-pixels on the upper electrode 27. As in the first embodiment, the auxiliary wiring 30 is preferably formed of a material having a sheet resistance value lower than that of the upper electrode 27. For example, the auxiliary wiring 30 is made of a metal material such as Cr, Al, Ag, Au, or Pt. It is preferable to become. In this embodiment, since the auxiliary wiring 30 is formed on the upper electrode 27, the auxiliary wiring 30 and the upper electrode 27 are in direct contact with each other to ensure electrical connection. That is, there is a connection position between the upper electrode 27 and the auxiliary wiring 30 between adjacent sub-pixels of different colors (see FIG. 6).

  The organic EL display device of this embodiment is covered with a sealing member 28 made of glass or the like, for example, as in the first embodiment (see FIG. 5C), and the sealing of the sealing member 28 is performed. A desiccant (not shown) is attached to the space side surface.

  There is a relationship of D1 <D2 between the interval D1 between adjacent sub-pixels of the same color and the interval D2 between adjacent sub-pixels of different colors. Further, by forming two adjacent sub-pixels of the same color at one mask opening, the light emitting region can be enlarged. In addition, by connecting the auxiliary wiring 30 and the upper electrode 27 between adjacent sub-pixels of different colors, it is possible to achieve in-plane luminance uniformity and power consumption reduction.

  As described above, the third embodiment has basically the same functions and effects as those of the first embodiment. In particular, according to the organic EL display device of the third embodiment, the vapor deposition process can be simplified by reducing the fine mask. Further, since the auxiliary wiring 30 is formed on the upper electrode 27, the auxiliary wiring 22 and the upper electrode 27 are in direct contact with each other, and there is a specific effect that electrical connection between them can be ensured. Yes.

  The preferred embodiment of the present invention has been described above. However, this is merely an example for explaining the present invention, and various embodiments different from the above-described embodiment may be implemented without departing from the gist of the present invention. Can do.

  For example, in the second embodiment, the organic compound layer that has been volumed on the auxiliary wiring 22 is removed by laser, but the present invention is not limited to this, and the organic compound layer may be removed by other methods such as dry etching.

  11: Subpixel, 13: Organic compound layer, 20: Substrate, 21: Lower electrode, 22 (30): Auxiliary wiring, 25: Light emitting layer, 27: Upper electrode, 50: Electrical connection hole (contact hole)

Claims (6)

A plurality of pixels composed of an organic light emitting device in which a lower electrode, an organic compound layer including at least a light emitting layer, and an upper electrode are sequentially formed are arranged on a substrate, and each pixel has the same emission color and a different emission color. Consisting of multiple sub-pixels,
The interval between adjacent sub-pixels of different emission colors is formed wider than the interval between adjacent sub-pixels of the same emission color,
An organic EL display device, wherein an auxiliary wiring having a sheet resistance value lower than that of the upper electrode is disposed at least between the adjacent sub-pixels of different emission colors.   The organic EL display device according to claim 1, wherein the lower electrode has light reflectivity, and the upper electrode has light transmittance.   The auxiliary wiring is formed before the organic compound layer is formed, and after the organic compound layer is formed by covering at least a part of the auxiliary wiring with a mask, an exposed portion of the auxiliary wiring and the upper electrode are formed. The organic EL display device according to claim 1, wherein the organic EL display device is electrically connected.   The auxiliary wiring is formed before the organic compound layer is formed, the organic compound layer is formed so as to cover the auxiliary wiring, and at least a part of the organic compound layer on the auxiliary wiring is removed. 4. The organic EL display device according to claim 1, wherein an electrical connection hole for connecting the auxiliary wiring and the upper electrode is formed. 5.   5. The organic EL display device according to claim 3, wherein the auxiliary wiring is formed simultaneously with the lower electrode, and the auxiliary wiring and the lower electrode are in the same plane.   4. The organic EL display device according to claim 1, wherein the auxiliary wiring is formed by mask vapor deposition after the upper electrode is formed. 5.

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