JP4185605B2 - EL display device and EL display device manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an EL display device, and more particularly to an EL display device capable of displaying an arbitrary character or pattern using an EL (Electro Luminescence) element.
[0002]
[Prior art]
An EL display device using an EL element as a light-emitting element has been attracting attention in recent years because it has a wide viewing angle and a thin display device can be obtained. Research is being conducted.
[0003]
A conventional EL display device will be described with reference to FIG. In order to manufacture such a conventional EL display device, first, as shown in FIG. 3A, an ITO (Indium Tin Oxide) film is formed on the entire surface of the glass substrate 102 to form a transparent electrode 103, A light emitting layer 104 is formed on the entire surface of the transparent electrode 103. The light emitting layer 104 is configured by dispersing phosphor particles such as ZnS in an organic polymer such as cyanoethylated cellulose, and the phosphor particles emit light when an alternating voltage is applied. Yes.
[0004]
Next, a high dielectric layer 105 is formed on the entire surface of the light emitting layer 104, and a metal foil 107 is formed on the entire surface.
Next, as shown in FIG. 3B, the metal foil 107 is etched into a desired shape to form the back electrode 106. Here, two back electrodes 106 ₁ and 106 ₂ that are not electrically connected to each other are formed.
[0005]
Then, one end of the AC power supply 110 is connected to both the back electrodes 106 ₁ and 106 ₂ , and the other end is connected to the transparent electrode 103. Through the above steps, the EL display device 101 is completed.
[0006]
In the EL display device 101 thus completed, when an AC voltage is applied between the transparent electrode 103 and the back electrode 106 by the AC power supply 110, a strong AC voltage is applied to the light emitting layer 104 on the region where the back electrode 106 is formed. On the other hand, since almost no AC voltage is applied to the light emitting layer 104 in the other region, only the light emitting layer 104 in the region where the back electrode 106 is formed can be caused to emit light partially.
[0007]
The light partially emitted from the light emitting layer 104 is irradiated to the transparent electrode 103 side and also to the high dielectric layer 105 side. The high dielectric layer 105 is configured by mixing an oxide such as BaTiO ₃ having a high dielectric property and a high reflectance in an organic polymer such as cyanoethylated cellulose, and the high dielectric layer 105 side. When the light is irradiated, the light is reflected by an oxide such as BaTiO ₃ and irradiated again to the transparent electrode 103 side through the light emitting layer 104, so that the light emission efficiency is improved.
[0008]
Since the EL display device 101 can emit light only in the region where the back electrode 106 is formed, by forming the back electrode 106 in a predetermined pattern to be displayed in advance, the predetermined region can be obtained. Can be emitted and displayed on the glass substrate 102 side.
[0009]
However, in order for a user using the EL display device 101 to display a desired character, figure, or the like, the user obtains the state shown in FIG. It is necessary to form the back electrode 106 by molding according to the figure.
[0010]
In order to form the metal foil 107 into a desired figure, a method of etching the metal foil 107 is generally used. However, in this case, the user must have equipment that can be etched. Thus, it has been impossible to easily obtain an EL display device capable of displaying a desired character, figure, or the like.
[0011]
Further, when a plurality of back electrodes 106 that are not electrically connected are arranged on the high dielectric layer 105 so as to display a discontinuous pattern, each back electrode 106 ₁ is displayed. , 106 ₂ , both the back electrodes 106 ₁ , 106 ₂ had to be connected to the AC power supply 110.
[0012]
[Problems to be solved by the invention]
The present invention has been created to solve the above-described disadvantages of the prior art, and it is an object of the present invention to provide an EL display device capable of simplifying the manufacturing process.
[0013]
[Means for Solving the Problems]
The invention according to claim 1 is an EL display device, comprising: a transparent substrate; a transparent electrode layer disposed on the transparent substrate; a light emitting layer disposed on the transparent electrode layer; and the light emitting layer. A plurality of scattered electrodes arranged in an island shape and electrically isolated from each other, an anisotropic conductive film disposed on a scattered electrode layer composed of the scattered electrodes, and the anisotropic conductive film and a placed back electrode layer, a portion of the scattered electrode is pressed the said connection to said back electrode layer and the electrically by the conductive particles in the anisotropic conductive film in, said back electrode layer, When a voltage is applied between the transparent electrode layer and the transparent electrode layer, the light emitting layer located between the scattered electrode electrically connected to the back electrode layer by the conductive particles emits light. characterized in that it is configured to.
[0014]
A second aspect of the present invention is the EL display device according to the first aspect, wherein a high dielectric layer is disposed between the light emitting layer and the scattered electrode layer.
[0015]
The invention according to claim 3 is an EL display device manufacturing method, comprising: forming a transparent electrode layer on a transparent substrate; forming a light emitting layer on the transparent electrode layer; and forming an island on the light emitting layer. A plurality of dispersed and electrically isolated electrodes, and the anisotropic conductive film formed by adhering the anisotropic conductive film and the back electrode layer are formed of the scattered electrodes. The step of adhering to the scattered electrode layer and the back electrode layer are partially pressed, and the scattered electrode at the pressed position is electrically connected to the back electrode layer with conductive particles in the anisotropic conductive film. An EL display device manufacturing method having a process.
According to a fourth aspect of the present invention, in the EL display device manufacturing method according to the third aspect, the method includes a step of forming a high dielectric layer on the light emitting layer, and the scattered electrode is formed on the high dielectric layer. This is a method for manufacturing an EL display device.
The invention according to claim 5 is the EL display device manufacturing method according to any one of claim 3 or claim 4, wherein the scattered electrode is formed by forming a conductive adhesive by screen printing. Is the method.
[0016]
The EL display device of the present invention has a scattered electrode layer and an anisotropic conductive film, and has a back electrode layer on the anisotropic conductive film. Since the anisotropic conductive film is configured by mixing conductive particles in the insulating adhesive resin, the pressed portion is partially pressed from the back electrode layer side toward the scattered electrode layer. The insulating adhesive resin is softened, and the conductive particles in the pressed part come into contact with the upper and lower scattered electrode layers and the back electrode layer, and the scattered electrode layer and the back electrode layer in the pressed part are electrically connected through the conductive particles. To do.
[0017]
The scattered electrode layers are arranged in an island shape, and the scattered electrode layers are electrically isolated from each other, so that the scattered electrode layer and the back electrode layer in the pressed portion are electrically connected, but the scattered electrode layers other than the pressed portion are dispersed. The electrode layer and the back electrode layer are not electrically connected.
[0018]
For this reason, when a voltage is applied between the transparent electrode layer and the back electrode layer, a voltage is applied to the light emitting layer in the pressed portion from the transparent electrode layer and the scattered electrode layer adjacent to the light emitting layer. A strong voltage sufficient to cause the layer to emit light is applied.
[0019]
On the other hand, since a voltage is not directly applied from the scattered electrode layer adjacent to the light emitting layer at a place other than the pressing part, only a very weak voltage is applied to the light emitting layer at this part. Light can be emitted.
[0020]
Therefore, the user of the EL display device applies a voltage only to the light-emitting layer in the desired region by pressing the anisotropic conductive film in the desired region from the back electrode layer toward the scattered electrode. Therefore, even if the user does not have an etching facility as in the prior art, an EL display device capable of emitting and displaying a desired region can be easily manufactured.
[0021]
In addition, if the scattered electrode layer in the predetermined region and the back electrode layer are electrically connected with the anisotropic conductive film, a voltage is applied to one place of the back electrode layer and a voltage is applied to the transparent electrode. By applying a voltage to the light emitting layer in a predetermined region, only the predetermined region can emit light. Therefore, even when displaying a plurality of patterns that are not electrically connected to each other, it is not necessary to form a plurality of back electrodes on the light-emitting layer and connect a power source to each back electrode as in the prior art. Therefore, it is possible to simplify the manufacturing process.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. First, a method for manufacturing the EL display device of this embodiment will be described.
[0023]
As shown in FIG. 1A, after forming an ITO film on the entire surface of the glass substrate 2 and forming the transparent electrode 3, a fluorescent substance such as ZnS in an organic polymer such as cyanoethylated cellulose. The light-emitting layer 4 is formed by applying the solution mixed with sliver onto the transparent electrode 3 and curing it.
[0024]
Next, as shown in FIG. 1B, a solution in which a powder of highly reflective inorganic oxide such as BaTiO ₃ is dispersed in an organic polymer such as cyanoethyl cellulose is applied to the surface of the light emitting layer 4. Then, the high dielectric layer 5 is formed. Next, the conductive electrode material mixed with carbon or the like is screen-printed on the surface of the high dielectric layer 5 to form the scattered electrode layer 7 scattered in an island shape.
[0025]
And as shown in FIG.1 (c), what adhered the anisotropic conductive film 11 on the back electrode layer 12 which consists of metal foil is prepared beforehand, and the anisotropic conductive film 11 side is the scattered electrode layer 7 side. The back electrode layer 12 is disposed so as to face the side, and the anisotropic conductive film 11 and the scattered electrode layer 7 are lightly bonded with a conductive adhesive.
[0026]
After that, the glass substrate 2 side is placed on a support base (not shown), a pressing member (not shown) is heated to 160 ° C. and brought into contact with the back electrode layer 12, and the back electrode layer 12 is scattered by the pressing members. Press in the direction of the electrode layer 7 for 30 seconds.
[0027]
On the surface of the pressing member, a convex portion is formed in accordance with a desired shape to be displayed in advance, and the anisotropic conductive film 11 is partially formed by pressing from the back electrode layer 12 toward the scattered electrode layer 7. Pressed.
[0028]
The anisotropic conductive film 11 is configured by mixing conductive particles 8 in the insulating resin 9, and when pressed, the insulating resin 9 in the pressed portion is softened, and the structure shown in FIG. As shown in the figure, the conductive particles 8 in the pressed portion are in contact with the upper and lower scattered electrode layers 7 and the back electrode layer 12, and the upper and lower scattered electrode layers 7 and the back electrode layer 12 are conducted through the conductive particles 8. 2A is a plan view of the EL display device 1 as seen from the glass substrate 2 side, and FIG. 1D is a cross-sectional view taken along line AA in FIG. Reference numerals 13 _{1 to} 13 _{3 in} FIG. 2A indicate pressing portions of the anisotropic conductive film 11 pressed by the convex portions.
Thereafter, an AC power supply 10 is connected to the transparent electrode 2 and the back electrode layer 12 to complete the EL display device 1 shown in FIG.
[0029]
When an AC voltage of 100 V and 400 Hz is applied from the AC power source 10 between the back electrode layer 12 of the EL display device 1 thus completed and the transparent electrode 3, the pressing portions 13 _{1 to} 13 _{3 of the} anisotropic conductive film 11 are applied. The light emitting layer 4 is applied with a voltage strong enough to allow the light emitting layer 4 to emit light. On the other hand, the light emitting layer 4 emits light to light emitting layers other than the pressed portions 13 _{1 to} 13 ₃ of the anisotropic conductive film. A voltage that is too weak to be applied is applied.
Therefore, as shown in FIG. 2B, only the light emitting layers 14 _{1 to} 14 ₃ of the pressing portions 13 _{1 to} 13 ₃ of the anisotropic conductive film 11 can emit light.
[0030]
As described above, in the EL display device 1 according to this embodiment, the user of the EL display device 1 partially presses the anisotropic conductive film 11 from the back electrode layer 12 toward the scattered electrode layer 7. Therefore, since the light emitting layer 4 in a desired region can be made to emit light, it is not necessary for the user to form a back electrode by etching the metal foil. An EL display device capable of emitting and displaying a desired region can be manufactured.
[0031]
Moreover, since a voltage is applied to the transparent electrode 3 and a voltage is applied to one place of the back electrode layer 12, an AC voltage can be applied only to the light emitting layer 4 in a desired region to emit light. Even in the case of displaying a plurality of regions that are not electrically connected, it is possible to manufacture a plurality of back electrodes on a high dielectric layer as in the past, and it is not necessary to connect a power source to each back electrode. It becomes possible to simplify the process.
[0032]
In the present embodiment, an organic polymer such as cyanoethylated cellulose mixed with a fluorescent substance such as ZnS is used as the light emitting layer 4, but the present invention is not limited to this, and other light emitting elements are used. A body, for example, an organic EL having a property of emitting light when a DC voltage is applied may be used.
[0033]
【The invention's effect】
An EL display device capable of emitting and displaying a desired region can be manufactured by a simple manufacturing process.
[Brief description of the drawings]
FIG. 1A is a first cross-sectional view illustrating a manufacturing process of an EL display device of the present invention.
(b): Second cross-sectional view illustrating the manufacturing process of the EL display device of the present invention
(c): Third sectional view for explaining the manufacturing process of the EL display device of the present invention.
(d): Fourth sectional view for explaining the manufacturing process of the EL display device of the present invention. [FIG. 2] (a): View of the EL display device of the present invention as seen from the display surface.
(b): A diagram for explaining a state in which the EL display device of the present invention performs light emission display. FIG. 3 (a): a first sectional view for explaining a manufacturing process of a conventional EL display device.
(b): Second sectional view for explaining the manufacturing process of the conventional EL display device
DESCRIPTION OF SYMBOLS 1 ... EL display device 2 ... Glass substrate 3 ... Transparent electrode 4 ... Light emitting layer 5 ... High dielectric material layer 7 ... Scattering electrode layer 8 ... Insulating resin 9 ... Conductive particle 10 ... AC power supply 11 ... Anisotropic conductive film 12 ... Back surface Electrode layer

Claims (5)

A transparent substrate;
A transparent electrode layer disposed on the transparent substrate;
A light emitting layer disposed on the transparent electrode layer;
A plurality of scattered electrodes arranged in islands on the light emitting layer and electrically isolated from each other ;
An anisotropic conductive film disposed on a scattered electrode layer comprising the scattered electrodes ;
Having a back electrode layer disposed on the anisotropic conductive film ,
A part of the scattered electrode is electrically connected to the back electrode layer by the conductive particles in the pressed anisotropic conductive film;
When a voltage is applied between the back electrode layer and the transparent electrode layer, the scattered electrode electrically connected to the back electrode layer by the conductive particles and the transparent electrode layer are positioned between the transparent electrode layer and the transparent electrode layer. An EL display device, wherein the light emitting layer is configured to emit light . The EL display device according to claim 1, wherein a high dielectric layer is disposed between the light emitting layer and the scattered electrode layer. Forming a transparent electrode layer on the transparent substrate;
Forming a light emitting layer on the transparent electrode layer;
A step of disposing a plurality of scattered electrodes arranged in an island shape and electrically isolated on the light emitting layer;
Bonding the anisotropic conductive film of the film in which the anisotropic conductive film and the back electrode layer are bonded to the scattered electrode layer composed of the scattered electrodes;
And a step of partially pressing the back electrode layer and electrically connecting the scattered electrode at the pressed position to the back electrode layer with conductive particles in the anisotropic conductive film. . Forming a high dielectric layer on the light emitting layer;
The EL display device manufacturing method according to claim 3, wherein the scattered electrodes are formed on the high dielectric layer. The EL display device manufacturing method according to claim 3, wherein the scattered electrodes are formed by forming a conductive adhesive by screen printing.

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