JP5177294B2 - Electrochemical display element - Google Patents

Description

  The present invention relates to an electrochemical display element.

  In recent years, a display element having excellent visibility and low power consumption has been demanded. A display element that modulates light emitted from a self-luminous or self-luminous material such as a CRT, PDP, or LCD that is generally used at present has a problem that it is bright and easy to see but consumes a large amount of power.

  From the viewpoint of reducing power consumption, it is desirable to have a function (memory property) for holding display contents without a power source, and further, a low driving voltage is desired. As a display element having such characteristics, an electrochromic display element (hereinafter also referred to as an ECD element) using a reversible change of a light absorption state due to a redox reaction on the surface of an electrode film, a metal or a metal in a chemical structure In recent years, development of electrochemical display elements such as an electrodeposition display element (hereinafter also referred to as an ED element) that utilizes the deposition of a metal on the surface of an electrode film and the dissolution in an electrolytic solution from an electrolyte containing a compound having the above-mentioned has been actively carried out. Has been done. The display principle of both ECD elements and ED elements is based on the use of oxidation-reduction reactions on the surface of the electrode film and changes in light absorption by the reactants alone. Such a member is unnecessary, and is a display element that is very advantageous for cost reduction and process saving.

  However, such an electrochemical display element applies a voltage between a pair of electrode films, and moves a charge such as an oxidation reaction or a reduction reaction on the surface of each electrode film, that is, a current flows, thereby causing a display state to change. This is a current-driven display element to be switched. For this reason, a voltage drop occurs according to the resistance component of the path from the feeding electrode (feeding terminal portion) for applying a voltage to the electrode film until the current flows to the display medium, and the voltage applied to the display medium depending on the display position. There is a problem that the values are different and the display density is uneven.

  This display density unevenness becomes prominent when the area of the display area of the display element is increased, and the current flow path becomes longer. Further, a transparent conductive film typified by ITO (tin-doped indium oxide) formed on the surface of the transparent substrate on the observation side of the display element has a higher resistance value than a metal electrode film, and display density unevenness appears remarkably.

  In light control glass using an electrochromic layer, in order to suppress density unevenness, Patent Document 1 discloses that a low resistance electrode portion of copper is provided on the end portion of the element substrate surface and the upper and lower transparent conductive layers located inside. Thus, a configuration for reducing the resistance value of a path through which a current flows is disclosed.

  However, the configuration described in Patent Document 1 can be applied to a light-control glass that collectively colors and decolors the entire sealed electrochromic material, but a plurality of electrodes are formed in the display region. It is difficult to apply to a display element such as a segment type or a dot matrix type.

  That is, a segment type or dot matrix type display element requires an extraction electrode for individually applying a voltage to a plurality of patterned electrodes. For this reason, when providing the low resistance electrode part of patent document 1, the area | region for providing an extraction electrode separately from this low resistance electrode part is needed. Therefore, the area outside the display area (hereinafter also referred to as a non-display area or a frame) is increased, resulting in a problem that the display element becomes larger and hinders the downsizing of the device on which the display element is mounted.

  Therefore, in order to secure a region where the extraction electrode is provided without widening the frame, Patent Document 2 discloses the following configuration.

  The liquid crystal display device disclosed in Patent Document 2 includes a conductive sealing material positioned outside and a non-conductive sealing material positioned inside the conductive sealing material as a sealing material that seals liquid crystal between two substrates. Conductive particles are mixed in the conductive sealing material, and when the conductive particles come into contact between the substrates, the common electrode on the upper substrate and the lead-out wiring on the lower substrate are electrically connected. As a result, the frame can be made narrower than the conventional configuration in which the routing wiring is arranged outside the sealing material.

JP-A-6-167724 JP 2003-98532 A

  However, since the configuration described in Patent Document 2 performs electrical connection only with conductive particles mixed in the conductive sealing material, there is a problem that the electrical resistance cannot be sufficiently reduced. It was.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a highly reliable electrochemical display element that suppresses display density unevenness without inhibiting narrowing of the frame.

  The above object is achieved by the invention described below.

1. A transparent conductive substrate having a transparent conductive film formed on the surface of the transparent substrate;
An electrode substrate disposed opposite to the transparent conductive substrate and having an electrode film;
An electrolyte layer formed between the transparent conductive film and the electrode film;
An electrochemical display element having an annular shape around the electrolyte layer and a seal member for sealing the electrolyte layer,
An electrochemical display element comprising a conductive member electrically connected to the transparent conductive film and covered with the seal member.

  According to the present invention, by providing a conductive member that is electrically connected to the periphery of the transparent conductive film, the resistance component of the path until the current flows from the power supply electrode (power supply terminal portion) to the display medium (electrolyte layer) is reduced. The voltage drop in the path due to the resistance component can be reduced. Thereby, display density unevenness can be suppressed. Further, since the conductive member is covered with the seal member, it does not touch the outside air and the electrolyte layer. Thereby, corrosion and deterioration of a conductive member can be suppressed and reliability can be improved.

It is a cross-sectional schematic diagram which shows schematic structure of the electrochemical display element which concerns on Embodiment 1 of this invention. It is a cross-sectional schematic diagram which shows schematic structure of the electrochemical display element which concerns on Embodiment 2 of this invention. It is a schematic diagram which shows the manufacturing process of the electrochemical display element which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the manufacturing process of the electrochemical display element which concerns on Embodiment 2 of this invention.

Hereinafter, an electrochemical display element according to an embodiment of the present invention will be described based on the drawings. The present invention is not limited to the embodiment. Further, in all the following drawings, the ratio of dimensions of each component is appropriately changed in order to make the drawings easy to see. In the following description, “transparent” indicates that the transmittance in the visible light region (wavelength 400 nm to 700 nm) is about 70% or more.
(Embodiment 1)
The configuration of the electrochemical display element according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view illustrating a schematic configuration of an electrochemical display element 1 according to the first embodiment.

  As shown in FIG. 1, the main part of the electrochemical display element 1 includes a transparent conductive substrate 2, an electrode substrate 3, an electrolyte layer 6, a conductive member 8, a seal member 9, and the like.

  The transparent conductive substrate 2 includes a transparent substrate 201, a transparent conductive film 203 formed on the surface of the transparent substrate 201, and the like.

  As the transparent substrate 201, a substrate made of a hard material used in an electronic device such as soda lime glass, non-alkali glass, or quartz, or a substrate made of a flexible plastic can be used. Examples of the plastic material include polyethylene terephthalate (PET), triacetyl cellulose (TAC), cellulose acetate propionate (CAP), polycarbonate (PC), polyethersulfone (PES), polyethylene naphthalate (PEN), and polyimide. (PI) or the like can be used, and in order to enhance the characteristics of the substrate composed of these plastic materials, it is preferable to use a surface whose surface is subjected to a known surface coating or surface treatment.

  The transparent conductive film 203 is formed by sputtering an inorganic oxide such as tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), or polystyrene sulfonate-doped polyethylene dioxy. A conductive polymer typified by thiophene (PEDOT / PSS) can be formed using various wet coating methods.

  The electrode substrate 3 includes a substrate 301 and an electrode film 303 formed on the surface of the substrate 301. The electrochemical display element 1 has an active matrix structure, and the electrode substrate 3 includes a plurality of thin film transistors (not shown) arranged in a matrix on the surface, and a plurality of thin film transistors formed corresponding to the plurality of thin film transistors. Pixel electrodes (not shown). The plurality of pixel electrodes are formed by the electrode film 303. As this electrode substrate 3, for example, a TFT substrate disclosed in International Publication No. WO2006 / 129429 can be adopted.

  The substrate 301 can be a transparent substrate such as glass or PET, and the substrate 301 is not necessarily transparent, and a substrate such as stainless foil or polyimide can also be used.

  As the electrode film 303, in the case of an ECD element, an electrode having a tin oxide layer doped with antimony on an ITO electrode can be used. In the case of an ED element, a metal electrode such as a silver electrode or a silver palladium electrode can be used.

  In the electrochemical display element 1, the transparent conductive substrate 2 is arranged on the observation side, the electrode substrate 3 is arranged on the non-observation side, and the transparent conductive film 203 of the transparent conductive substrate 2 and the electrode film 303 of the electrode substrate 3 face each other. Has been placed.

In the case of an ECD element, an electrolyte layer 6 having an electrochromic dye is provided between the transparent conductive film 203 and the electrode film 303, and both positive and negative polarities are provided between the counter electrodes (the transparent conductive film 203 and the electrode film 303). By applying this voltage, an oxidation-reduction reaction of the electrochromic dye is performed on the surface of the observation-side electrode (transparent conductive film 203), and the electrochromic coloring state can be switched reversibly. In order to increase the whiteness of the electrolyte layer 6 in a transparent state, metal oxide fine particles such as TiO ₂ and ZnO are dispersed in the electrolyte layer 6 or the metal oxide fine particles are used with a binder such as a water-soluble polymer. The porous scattering layer 5 may be provided.

In the case of an ED element, an electrolyte layer 6 having silver or a compound containing silver in the chemical structure is provided between the transparent conductive film 203 and the electrode film 303, and a counter electrode (transparent conductive film 203, electrode film) 303), a positive and negative polarity voltage is applied between the two electrodes, whereby a silver oxidation-reduction reaction is performed on the surfaces of both electrodes, and the surface of the transparent conductive film 203 has a reduced black silver state and an oxidized transparent silver. Can be switched reversibly. In this case, as in the case of the ECD element, in order to increase the whiteness of the electrolyte layer 6 in a transparent state, metal oxide fine particles such as TiO ₂ and ZnO are dispersed in the electrolyte layer 6 or the metal A scattering layer 5 in which oxide fine particles are made porous using a binder such as a water-soluble polymer may be provided. Moreover, you may use another metal instead of silver.

  Here, details of the ECD material, the ED material, the electrolyte, and the like will be described.

[ECD material]
The electrochromic dye used in the electrochemical display element 1 is a compound that changes the light absorption state by accepting electrons, and an organic compound or a metal complex can be used. As the organic compound, a pyridine compound, a conductive polymer, and a styryl compound can be used. Can be used. Moreover, when using a leuco type | mold pigment | dye, you may use together a color developer or a decoloring agent as needed.

These materials may be applied directly to the surface of the electrode, or in order to more efficiently accept and receive electrons, an oxide semiconductor nanostructure typified by TiO ₂ is formed on the electrode, The electrochromic material may be coated and impregnated by a method such as an ink jet method.

[ED material]
Examples of the silver or silver-containing compound used in the electrochemical display element 1 include compounds such as silver oxide, silver sulfide, metallic silver, silver colloidal particles, silver halide, silver complex compounds, and silver ions. There are no particular limitations on the phase state species such as solid state, solubilized state in liquid, and gas state, and neutral, anionic, and cationic charged state species.

  The silver ion concentration contained in the electrolyte layer 6 is preferably 0.2 mol / kg ≦ [Ag] ≦ 2 mol / kg. When the silver ion concentration is less than 0.2 mol / kg, a dilute silver solution is obtained, and the driving speed is delayed. When the silver ion concentration is more than 2 mol / kg, the solubility is deteriorated, and precipitation is likely to occur during low-temperature storage.

〔Electrolytes〕
The electrolyte is usually a substance that dissolves in a solvent such as water and the solution exhibits ion conductivity. In the present embodiment, the electrolyte contains a metal or a compound other than the electrolyte. It does not matter.

  For the electrolyte layer 6 provided between the transparent conductive film 203 and the electrode film 303, an organic solvent, an ionic liquid, a redox active substance, a supporting electrolyte, a complexing agent, a white scattering material, a polymer compound, or the like is appropriately selected. Composed. Hereinafter, each component of the electrolyte layer 6 will be described.

(Organic solvent)
As the organic solvent used for the electrolyte layer 6, an organic solvent having a boiling point in the range of 120 to 300 ° C. that can remain in the electrolyte layer 6 without causing volatilization after the electrolyte layer 6 is formed can be used. For example, propylene carbonate, ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, butylene carbonate, γ-butyl lactone, tetramethyl urea, sulfolane, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, 2- ( N-methyl) -2-pyrrolidinone, hexamethylphosphortriamide, N-methylpropionamide, N, N-dimethylacetamide, N-methylacetamide, N, N-dimethylformamide, N-methylformamide, butyronitrile, propionitrile , Acetonitrile, acetylacetone, 4-methyl-2-pentanone, 2-butanol, 1-butanol, 2-propanol, 1-propanol, acetic anhydride, ethyl acetate, ethyl propionate , Dimethoxyethane, diethoxy furan, tetrahydrofuran, ethylene glycol, diethylene glycol, can be used triethylene glycol monobutyl ether.

  Among the above organic solvents, cyclic carboxylic acid esters such as propylene carbonate, ethylene carbonate, and γ-butyrolactone are more preferable.

(Polymer compound)
In order to increase the viscosity of the electrolyte layer 6, a polymer compound is used as a binder. Although it does not specifically limit as a high molecular compound, For example, it selects from a high molecular compound, such as a butyral resin, polyvinyl alcohol, polyethyleneglycol, and a poly vinylidene fluoride, suitably in view of the characteristic of a display element, the viscosity of an electrolyte, etc., and uses it. be able to.

(Metal oxide fine particles)
In order to increase the whiteness by scattering, an inorganic metal oxide is used. Examples of the inorganic metal oxide include titanium dioxide (anatase type or rutile type), barium sulfate, calcium carbonate, aluminum oxide, zinc oxide, magnesium oxide, zinc hydroxide, magnesium hydroxide, magnesium phosphate, hydrogen phosphate. Magnesium, alkaline earth metal salts, talc, kaolin, zeolite, acidic clay, glass and the like can be used.

(Spacer)
The spacer 7 is a spherical fine particle for regulating the gap between the counter electrodes (the transparent conductive film 203 and the electrode film 303). As the spacer 7, for example, a fine sphere made of glass, acrylic resin, silica, or the like used for a liquid crystal display or the like can be used. The average particle diameter of the spacer 7 is preferably in the range of 10 μm or more and 50 μm or less in order to improve the whiteness due to the dispersion stability in the electrolyte layer 6 and the scattering effect of the metal oxide fine particles dispersed in the electrolyte layer 6.

  Returning to FIG. 1, the conductive member 8 has a trapezoidal cross-sectional shape and is formed in an annular shape on the outer peripheral edge of the display area A of the transparent conductive film 203. The cross-sectional shape is not limited to a trapezoid, and may be other polygons, arcs, or the like, for example.

  The conductive member 8 is provided at an end portion of the transparent substrate 201, and a drive voltage from an external drive circuit (not shown) is applied to the conductive member 8 from the power supply terminal portion 203 a forming a part of the transparent conductive film 203 through the transparent conductive film 203. The resistance component of the path until the current flows through the electrolyte layer 6 is reduced, and the voltage drop of the path due to the resistance component is reduced. Thereby, variation in the voltage value applied to the transparent conductive film 203 depending on the display position can be suppressed, and display density unevenness can be suppressed.

  The conductive member 8 is a method in which copper, silver, gold, platinum, aluminum, chromium, nickel, tantalum, and alloys thereof are formed using a sputtering method or a vacuum evaporation method, and then patterned using a photolithography method. Alternatively, it can be formed using a method of patterning simultaneously with film formation by performing masking film formation during film formation.

  In addition, since the conductive member 8 is formed on the surface of the transparent conductive film 203 formed on the transparent substrate 201, the conductive member 8 may be patterned using an electrolytic plating method using the transparent conductive film 203 and a resist pattern. it can. In this case, the material of the conductive member 8 is preferably copper, silver, gold, platinum, nickel, chromium or the like that can be electroplated.

  In addition, the conductive member 8 can be formed using a printing method such as screen printing or an inkjet method, although the resistance value is larger than that of the vacuum film forming method. In this case, since the surface of the transparent conductive film 203 can be directly patterned in a non-vacuum, cost can be reduced.

  As a paste material in the case of using screen printing, a mixture in which the aforementioned metal and alloy fine particles, a binder resin, an organic solvent and the like are mixed can be used. As the binder resin, acrylic resin, epoxy resin, polyester resin, phenol resin, silicone resin, polyolefin resin, and polyimide resin can be used. The organic solvent is not particularly limited as long as it does not react with the metal fine particles and dissolves the binder resin material.

  The seal member 9 is formed in an annular shape around the periphery of the electrolyte layer 6, and seals the electrolyte layer 6, thereby leaking the electrolyte solution 61 that forms the electrolyte layer 6 and from outside air that affects the performance of the electrolyte layer 6. In addition to preventing intrusion of moisture, oxygen and the like, the transparent conductive substrate 2 and the electrode substrate 3 are bonded together.

  Further, since the seal member 9 is configured to cover the conductive member 8, that is, the seal member 9 and the conductive member 8 are arranged so as to overlap each other at substantially the same position, a narrow frame can be achieved.

In addition, since the conductive member 8 is covered with the seal member 9, it does not touch the outside air and the electrolyte layer 6. Thereby, corrosion and deterioration of the conductive member 8 can be suppressed, and reliability can be improved.
(Embodiment 2)
A configuration of an electrochemical display element according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view illustrating a schematic configuration of the electrochemical display element 1 according to the second embodiment. Since the basic configuration of the electrochemical display element 1 according to the second embodiment is substantially the same as that of the first embodiment, the description thereof will be omitted, and the arrangement and the like of the conductive member 8 different from the first embodiment will be described.

  A feeding electrode 305 for applying a voltage to the transparent conductive film 203 formed on the transparent conductive substrate 2 is formed in an annular shape on the outer periphery of the display area A of the substrate 301 of the electrode substrate 3. An annular shape is formed on the surface of the electrode 305.

  The seal member 9 is formed in an annular shape around the periphery of the electrolyte layer 6, and conductive particles 901 are dispersed therein. The conductive member 8 is electrically connected to the transparent conductive film 203 of the transparent conductive substrate 2 through the conductive particles 901. The materials and forming methods of the conductive member 8 and the seal member 9 are substantially the same as those in the first embodiment.

  The conductive particles 901 may be metal particles composed only of metal, or may be particles in which insulating particles of an inorganic material or an organic material are coated with a metal by a method such as a plating method. In particular, as the conductive particles, particles obtained by metal-coating insulating particles of an organic material are preferable because they can be easily manufactured.

  As insulating particles of organic materials, particles of polyethylene resin, polypropylene resin, polystyrene resin, acrylic resin, etc. can be used, and as metals for coating materials, copper, silver, gold, platinum, aluminum, chromium, nickel, Tantalum, palladium, etc. can be used. In particular, gold, nickel, and palladium are suitable as the metal for coating by a plating method.

  The particle diameter of the conductive particles 901 needs to be smaller than the distance between the transparent substrate 2 and the electrode substrate 3, for example, in the range of 1 to 20 μm, and more preferably in the range of 2 to 10 μm. In the case of particles coated with a metal, it is preferable to coat the metal with a thickness in the range of 0.1 to 1 μm. Furthermore, the conductive particles 901 may be mixed in the range of 0.1 to 5% by mass with respect to the material of the seal member 9, and more preferably in the range of 0.5 to 3% by mass.

  Even in such a configuration, as in the case of the first embodiment, the conductive member 8 causes the current to flow from the power supply terminal portion 305 a forming a part of the power supply electrode 305 to the electrolyte layer 6 through the transparent conductive film 203. The resistance component of the path can be reduced, and the voltage drop of the path due to the resistance component can be reduced. Thereby, variation in the voltage value applied to the transparent conductive film 203 depending on the display position can be suppressed, and display density unevenness can be suppressed.

  Similarly, since the seal member 9 is configured to cover the conductive member 8, that is, the seal member 9 and the conductive member 8 are arranged so as to overlap each other at substantially the same position, a narrow frame can be achieved. In addition, since the conductive member 8 is covered with the seal member 9, it does not touch the outside air and the electrolyte layer 6. Thereby, corrosion and deterioration of the conductive member 8 can be suppressed, and reliability can be improved.

  Further, by providing a power supply electrode 305 for the transparent conductive film 203 on the electrode substrate 3 side where a power supply electrode (not shown) for the electrode film 303 is provided, wiring from an external drive circuit (not shown) can be connected to one substrate ( It can be concentrated on the electrode substrate 3). Thereby, wiring can be simplified.

  Hereinafter, examples of the electrochemical display element 1 according to the embodiment of the present invention will be described.

Example 1
In FIG. 3, the outline | summary of the manufacturing process of the electrochemical display element 1 by Example 1 is shown. 3A to 3F, the left diagram is a schematic cross-sectional view, and the right diagram is a schematic plan view. The present example is a manufacturing example of the electrochemical display element 1 according to the first embodiment.

  First, an ITO film having a thickness of 110 nm is formed on the surface of a glass substrate (FIG. 3A: transparent substrate 201) using a sputtering method (FIG. 3A: transparent conductive film 203). 2 was produced. At this time, a power supply terminal portion 203a to which a drive voltage from an external drive circuit is applied was formed at a part of the left end of the transparent conductive film 203 (FIG. 3 (f2)).

  Subsequently, Dotite FA-401CA (made by Fujikura Kasei Co., Ltd.), which is a conductive paste, is screen-printed on the surface of the outer peripheral edge of the display area A of the transparent conductive film 203 with a thickness of 15 μm and the cross-sectional shape is trapezoidal. The conductive film 8 was formed in a ring shape (FIG. 3 (b1)). At this time, micropearl GS-230 (manufactured by Sekisui Chemical Co., Ltd.), which is a 0.4 mass% spacer material, was previously mixed with Doutite FA-401CA. In addition, the conductive member 8 was provided with an injection port 8a for injecting an electrolyte solution 61 described later (FIG. 3 (b2)).

  Subsequently, the transparent conductive substrate 2 on which the conductive member 8 was formed was subjected to a heat treatment at 150 ° C. for 30 minutes to dry the solvent, thereby forming the conductive member 8 as a low-resistance conductive resin wiring.

  Next, a plurality of thin film transistors arranged in a matrix not shown on the surface of a glass substrate (FIG. 3C: substrate 301), and a silver palladium electrode having a thickness of 100 nm as a plurality of pixel electrodes corresponding to the plurality of thin film transistors (FIG. 3C: electrode film 303) was formed, and an electrode substrate 3 having an active matrix structure was manufactured.

  Subsequently, an admixture obtained by dispersing 20% by mass of titanium oxide with an ultrasonic disperser in an isopropanol solution containing 2% by mass of polyvinyl alcohol (average polymerization degree 3500, saponification degree 87%) on the surface of the electrode film 303. The scattering layer 5 having a thickness of 20 μm was formed by applying to each cell and drying by heating (FIG. 3D).

  Subsequently, on the surface of the outer peripheral edge of the display area A of the substrate 301 on which the scattering layer 5 is formed, in the annular shape substantially the same as the conductive member 8 formed on the transparent conductive substrate 2 described above, thermosetting using a dispenser method Type epoxy sealant Structbond XN-21S (Mitsui Chemicals) was applied to form a seal member 9 (FIG. 3 (e1)).

  Subsequently, spacer material Micropearl SP-210 (manufactured by Sekisui Chemical Co., Ltd.) was disposed on the surface of the scattering layer 5 (FIGS. 3 (e1) and 3 (e2): spacer 7).

  Next, after aligning the transparent conductive film 203 of the transparent conductive substrate 2 and the electrode film 303 of the electrode substrate 3 so as to face each other, the cells are superposed and subjected to heat treatment at 150 ° C. for one hour in a pressurized state. (Fig. 3 (f1)).

  Next, an electrolytic solution 61 was prepared. As the electrolytic solution 61, 25 g of propylene carbonate / ethylene carbonate (mass ratio 7/3), 1.0 g of silver p-toluenesulfonate, 1.5 g of 3,6-dithia-1,8-octanediol, After 10 mg of mercaptotriazole was added and completely dissolved, 1.5 g of polyethylene glycol (average molecular weight 500,000) was added and the mixture was stirred while heating to 120 ° C.

  Subsequently, after the prepared electrolytic solution 61 was injected into the cell from the injection port 8a of the conductive member 8 by using a vacuum injection method, the injection port 8a was passed through the ultraviolet curable sealant Photolek A-720-180 (FIG. 3 ( f2): The electrolyte layer 6 was formed by sealing with the sealing member 801), and the electrochemical display element 1 was completed (FIG. 3 (f1)).

  A drive signal (drive voltage) is applied to the electrochemical display element 1 manufactured in this way to the power supply terminal portion 203a of the transparent conductive substrate 2 and the power supply terminal portion of the thin film transistor (not shown) of the electrode substrate 3 shown in FIG. Although the display operation was performed, it was confirmed that a good image with very little display density unevenness was obtained from the center to the periphery of the display area A.

  In addition, as a constant temperature and humidity test, the sample was left in a bath at 60 ° C. and 90% relative humidity for 240 hours, and the display images before and after the test were compared. No display density unevenness due to the accompanying increase in resistance value was observed, and it was confirmed that high reliability was ensured.

(Example 2)
In FIG. 4, the outline | summary of the manufacturing process of the electrochemical display element 1 by Example 2 is shown. 4A to 4F, the left diagram is a schematic sectional view, and the right diagram is a schematic plan view. This example is a manufacturing example of the electrochemical display element 1 according to the second embodiment.

  First, an ITO film having a thickness of 110 nm is formed on the surface of a glass substrate (FIG. 4A: transparent substrate 201) using a sputtering method (FIG. 4A: transparent conductive film 203). 2 was produced.

  Subsequently, on the surface of the outer peripheral edge of the display area A of the transparent conductive film 203, a UV-curing / thermo-curing sealant Worldlock No. 717 was applied in an annular shape to form a seal member 9 (FIG. 4 (b1), FIG. 4 (b2)). At this time, World Lock No. In 717, 1.5% by mass of conductive particle Micropearl AU-205 (manufactured by Sekisui Chemical Co., Ltd.) having a particle size of 5.0 μm and having a conductive plating layer formed on the surface in advance was mixed (FIG. 4). (B1): Conductive particles 901).

  Next, a plurality of thin film transistors arranged in a matrix not shown on the surface of a glass substrate (FIG. 4C: substrate 301), and a silver palladium electrode having a thickness of 100 nm as a plurality of pixel electrodes corresponding to the plurality of thin film transistors. (FIG. 4C: electrode film 303) was formed, and an electrode substrate 3 having an active matrix structure was manufactured. At this time, a silver palladium electrode for the transparent conductive film 203 (FIG. 4C: power supply electrode 305) was simultaneously formed in an annular shape on the surface of the outer peripheral edge of the display area A of the substrate 301. The electrode film 303 and the power supply electrode 305 were formed by forming a silver-palladium electrode 100 nm on the surface of the substrate 301 using a sputtering method and then patterning using a photolithography method. Further, except for the through hole of the pixel electrode (not shown) in the display area A of the electrode substrate 3 and the power supply terminal portion of the thin film transistor, the thin film transistor was covered with an insulating film.

  Subsequently, a conductive paste, Dotite FA-401CA (manufactured by Fujikura Kasei Co., Ltd.) having a thickness of 25 μm and a cross-sectional shape of a trapezoidal shape is formed on the surface of the power supply electrode 305 using a screen printing method. Was formed (FIG. 4D).

  Subsequently, the electrode substrate 3 on which the conductive member 8 was formed was subjected to a heat treatment at 150 ° C. for 30 minutes to dry the solvent, thereby forming the conductive member 8 as a low-resistance conductive resin wiring.

  Next, an electrolytic solution 61 was prepared. As the electrolytic solution 61, 0.2 g of polyethylene oxide having an average molecular weight of 200,000 as a polymer binder and 1.0% of titanium dioxide CR-90 (manufactured by Ishihara Sangyo Co., Ltd.) as inorganic oxide fine particles in 1.0 g of dimethyl sulfoxide. 48 g, 0.04 g of silver p-toluenesulfonate as a redox active substance and 0.08 g of 2-mercaptobenzimidazole as an additive were added and dissolved by heating. In addition, 0.5 mass% of spherical particle micropearl GS-230 (manufactured by Sekisui Chemical Co., Ltd.) having a diameter of 30 μm was dispersed in the electrolytic solution 61 as a gap control material for defining the thickness of the cell.

  Next, the prepared electrolytic solution 61 was applied in a dot pattern on the surface of the electrode film 303 of the electrode substrate 3 using a dispenser method. (FIG. 4 (e1), FIG. 4 (e2)).

  Next, the transparent conductive substrate 2 on which the sealing member 9 is formed and the electrode substrate 3 on which the electrolytic solution 61 is applied are introduced into a vacuum chamber that is a bonding apparatus, and the transparent conductive substrate 203 of the transparent conductive substrate 2 After aligning the electrode substrate 303 with the electrode film 303 facing each other, the electrolyte layer 6 was formed by sealing the electrolyte solution 61 by reducing the pressure and bonding (FIG. 4 (f1)). At this time, the conductive member 8 was electrically connected to the transparent conductive film 203 of the transparent conductive substrate 2 via the conductive particles 901 mixed in the seal member 9.

Subsequently, after bonding, the sealing member 9 was taken out of the vacuum chamber and irradiated with ultraviolet rays from the transparent conductive substrate 2 side at an illuminance of 100 mW / cm ² for 30 seconds to cure the sealing member 9 with ultraviolet rays. After the ultraviolet curing, heat treatment was performed at 120 ° C. for 30 minutes to thermally cure the seal member 9, thereby completing the electrochemical display element 1 (FIG. 4 (f1)).

  The electrochemical display element 1 manufactured in this way is connected to the power supply terminal portion 305a for the transparent conductive film 203 formed on the electrode substrate 3 and the power supply terminal portion of the thin film transistor (not shown) of the electrode substrate 3 shown in FIG. Although a display operation was performed by applying a drive signal (drive voltage), a good image with very little display density unevenness can be obtained from the center of the display area A to the periphery as in the case of the first embodiment. Was confirmed.

  In addition, as a constant temperature and humidity test, the sample was left in a bath at 60 ° C. and 90% relative humidity for 240 hours, and the display images before and after the test were compared. No display density unevenness due to the accompanying increase in resistance value was observed, and it was confirmed that high reliability was ensured.

  Thus, in the electrochemical display element 1 according to the embodiment of the present invention, the transparent conductive film 203 is formed in an annular shape facing the outer peripheral edge of the display region A, and is electrically connected to the transparent conductive film 203. The conductive member 8 is provided, and the conductive member 8 is covered with a seal member 9 that seals the electrolyte layer 6.

  By providing the annular conductive member 8 that is electrically connected to the periphery of the transparent conductive film 203, current flows from the power supply electrode (power supply terminal portion 203a, power supply terminal portion 305a) to the display medium (electrolyte layer 6). The resistance component of the path can be reduced, and the voltage drop of the path due to the resistance component can be reduced. Thereby, display density unevenness can be suppressed.

  In addition, the conductive member 8 and the seal member 9 are arranged in parallel so that the conductive member 8 is covered with the seal member 9, that is, the two members are arranged so as to overlap each other at substantially the same position. Therefore, it is possible to narrow the frame.

  In addition, since the conductive member 8 is covered with the seal member 9, it does not touch the outside air and the electrolyte layer 6. Thereby, corrosion and deterioration of the conductive member 8 can be suppressed, and reliability can be improved.

  Further, by using the electrochemical display element 1 as a display element 1 having an active matrix structure with a large screen, display density unevenness can be suppressed even when the display area is enlarged.

DESCRIPTION OF SYMBOLS 1 Electrochemical display element 2 Transparent conductive substrate 201 Transparent substrate 203 Transparent conductive film 203a Feeding terminal part 3 Electrode substrate 301 Substrate 303 Electrode film (pixel electrode)
305 Power supply electrode 305a Power supply terminal portion 5 Scattering layer 6 Electrolyte layer 61 Electrolytic solution 7 Spacer 8 Conductive member 801 Sealing member 9 Seal member 901 Conductive particle

Claims (4)

A transparent conductive substrate having a transparent conductive film formed on the surface of the transparent substrate;
An electrode substrate disposed opposite to the transparent conductive substrate and having an electrode film and a feeding electrode for the transparent conductive film ;
An electrolyte layer formed between the transparent conductive film and the electrode film;
A seal member that is formed annularly around the electrolyte layer and seals the electrolyte layer;
A conductive member covered with the seal member;
An electrochemical display element comprising:
The conductive member is formed on the feeding electrode,
In the sealing member, conductive particles having a particle size equal to the interval between the conductive member and the transparent electrode substrate are dispersed,
The electrochemical display element, wherein the conductive member is electrically connected to the transparent conductive film of the transparent conductive substrate through the conductive particles dispersed in the seal member. The electrochemical display element according to claim 1, wherein the conductive particles are particles obtained by metal-coating insulating particles made of an organic material. The electrochemical display element according to claim 1, wherein the conductive particles are mixed in a ratio of 0.5 to 3 mass% with respect to a material of the seal member. The electrochemical display element has an active matrix structure,
The electrode substrate is
A plurality of thin film transistors arranged in a matrix on the surface of the substrate;
Wherein the electrode film, an electrochemical display device according to any one of claims 1 to 3, wherein a plurality of pixel electrodes are formed corresponding to the plurality of thin film transistors.