JP2007065260A - Method for manufacturing electrophoretic device, electrophoretic device, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique formanufacturing an electrophoretic device excellent in durability by suppressing air from remaining in gaps between pixel electrodes when contacting a mixed solution of microcapsules and a binder. <P>SOLUTION: In the method for manufacture the electrophoretic device, a process to form the pixel electrodes (13a) comprises: a step to form a resist layer (62) on a surface being the electrophoretic layer side surface of a first substrate and to provide an aperture sections on the resist layer according to a pattern for forming the pixel electrodes; a step to form a conductive layer (13a) on the opening sections of the resist layer (62) with electroless plating; and a step to remove the resist layer (62) is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophoresis device manufacturing method, an electrophoresis device, and an electronic apparatus.

  Conventionally, an electrophoretic layer including electrophoretic particles and an electrophoretic dispersion medium is arranged between a pair of electrodes formed on each substrate, and a voltage is applied between the electrodes to change the distribution state of the electrophoretic particles. There are known electrophoretic devices that utilize this fact.

  As an embodiment of such an electrophoresis apparatus, Japanese Patent Application Laid-Open No. 1-86116 (Patent Document 1) discloses a liquid in which electrophoretic particles and an electrophoretic dispersion medium are enclosed in a microcapsule, and the microcapsule and a binder are mixed. There is disclosed a microcapsule type electrophoresis apparatus in which an electrode is disposed between electrodes. Japanese Patent Laying-Open No. 2004-4714 (Patent Document 2) discloses a microcapsule type electrophoresis apparatus manufactured using a flexible substrate that can be applied to electronic paper or the like. When electrophoretic particles and electrophoretic dispersion medium are encapsulated in microcapsules, the movement of the electrophoretic particles is moderately restricted, so that even if flexibility is given to the electrophoretic device, aggregation, aggregation, and uneven distribution of the electrophoretic particles occur. Hateful.

In these electrophoretic devices, at least one of the electrodes is formed on a substrate using a transparent conductive material. The other electrode is formed in accordance with a predetermined pattern as a pixel electrode by a method of printing a conductive material such as carbon paste or a method of etching a metal foil such as a rolled copper foil.
JP-A-1-86116 JP 2004-4714 A

  The pixel electrode formed by printing a conductive material or etching a metal foil generally has a thickness of several tens to several hundreds of micrometers for printing, and about 35 μm for a metal foil. For this reason, a recess (gap) having the depth of the pixel electrode is formed between the pixel electrodes. If the microcapsule / binder mixed solution is brought into contact with the microcapsule, the diameter of the microcapsule is larger than the width of the gap, so that the mixed solution cannot enter every corner of the gap and air may remain at the bottom of the gap. is there. This air expands at a high temperature, causing peeling between the microcapsule and the pixel electrode, and lowers the durability reliability of the electrophoretic device.

  Therefore, the present invention provides a technique for manufacturing an electrophoretic device having excellent durability by suppressing air from remaining in a gap between pixel electrodes when a mixed liquid of microcapsules and a binder is brought into contact. With the goal.

  In order to solve the above-described problems, a first aspect of the method for manufacturing an electrophoresis apparatus according to the present invention is such that an electrophoresis layer is disposed between a first substrate and a second substrate, and electrophoresis of the first substrate is performed. A method of manufacturing an electrophoretic device in which a pixel electrode is formed on a layer side surface and a transparent electrode layer is formed on a surface of the second substrate on an electrophoretic layer side, the step of forming the pixel electrode comprising: Forming a resist layer on a surface on the electrophoretic layer side of the first substrate, and providing an opening in the resist layer according to a pattern for forming the pixel electrode; and electroless plating on the opening of the resist layer The method includes a step of forming a conductive layer by a method and a step of removing the resist layer.

  According to the electroless plating method, the pixel electrode can be formed very thin, for example, about 1 to 10 μm. Accordingly, the gap between the pixel electrodes becomes sufficiently shallow, and air hardly remains between the pixel electrodes when the mixed liquid of the microcapsules and the binder is brought into contact.

  In order to solve the above-described problem, a second aspect of the method for manufacturing an electrophoresis apparatus according to the present invention is an electrophoretic layer disposed between a first substrate and a second substrate. A method of manufacturing an electrophoretic device, wherein a pixel electrode is formed on a surface on an electrophoretic layer side and a transparent electrode layer is formed on a surface on the electrophoretic layer side of the second substrate, wherein the pixel electrode is formed Forming a plating nucleus layer on the surface of the first substrate on the electrophoretic layer side, forming a resist layer on the plating nucleus layer, and forming the pixel electrode according to a pattern to form the pixel electrode A step of forming an opening in the resist layer, a step of forming a conductive layer in the opening of the resist layer by an electrolytic plating method, and a step of removing the plating core layer in regions other than the resist layer and the pattern. It is characterized by that.

  Also by the electrolytic plating method, the pixel electrode can be formed very thin, for example, about 1 to 10 μm. Accordingly, the gap between the pixel electrodes becomes sufficiently shallow, and air hardly remains between the pixel electrodes when the mixed liquid of the microcapsules and the binder is brought into contact.

  In addition, the method for manufacturing an electrophoretic device according to the present invention preferably further includes a step of forming a protective layer on the conductive layer after the step of forming the pixel electrode. The protective layer can contribute to the oxidation prevention of the electrode. The protective layer can be a thin film formed of gold or a solder material, but a gold thin film formed by a plating method is preferable in terms of thickness.

  In addition, the method for manufacturing an electrophoretic device according to the present invention preferably includes a step of forming an insulating film on the first substrate so as to fill the space between the pixel electrodes after the step of forming the pixel electrodes. By forming an insulating film between the pixel electrodes, the gap between the pixel electrodes can be further reduced, and when the microcapsules and the binder are brought into contact with each other, air remains in the gap more efficiently. It becomes possible to suppress.

  According to the present invention, an electrophoretic layer is disposed between the first substrate and the second substrate, a pixel electrode is formed on the surface of the first substrate on the electrophoretic layer side, and the electrophoretic layer of the second substrate There is also provided an electrophoretic device in which a transparent electrode layer is formed on a side surface, wherein the pixel electrode has a thickness of 10 μm or less. Such an electrophoresis apparatus is manufactured, for example, by the above-described method for manufacturing an electrophoresis apparatus according to the present invention. According to such a configuration, when a microcapsule or a binder is brought into contact with the surface on which the pixel electrode is formed, air hardly remains between the pixel electrodes, so that the electrophoresis apparatus is excellent in durability.

  In the electrophoretic device according to the present invention, it is also preferable that a protective layer made of a gold thin film is formed on the pixel electrode, whereby the pixel electrode can be protected from oxidation or the like. It is also preferable that an insulating film is formed so as to fill the space between the pixel electrodes.

  The configuration of the electrophoresis apparatus according to the present invention is particularly effective in the case of a microcapsule type electrophoresis apparatus. As described above, in the microcapsule type electrophoresis apparatus, air is likely to remain in the gap between the pixel electrodes. However, according to the configuration of the electrophoresis apparatus according to the present invention, the gap is sufficiently shallow. This is because the mixed liquid with the binder enters into every corner of the gap and the residual air can be suppressed.

  In addition, when a flexible material is used for the first substrate and the second substrate, the electrophoretic device is excellent in flexibility and can be applied to electronic paper or the like.

  The present invention also provides an electronic apparatus including the above-described electrophoresis apparatus as a display unit. Here, the “electronic device” includes all devices including a display unit that uses display by an electrophoretic material, and includes a display device, a television device, an electronic paper, a clock, a calculator, a mobile phone, a portable information terminal, and the like. Including. Also, things that deviate from the concept of “equipment”, for example, flexible paper / film-like objects, belonging to real estate such as wall surfaces to which these objects are attached, moving objects such as vehicles, flying objects, ships, etc. Including those belonging to.

Embodiments according to the present invention will be described below with reference to the drawings.
<First Embodiment>
(Electrophoresis device)
FIG. 1 shows a cross section of an electrophoresis apparatus 1 according to the first embodiment of the present invention. FIG. 2 schematically shows a plane of the electrophoresis apparatus 1, and a cross section in the AA ′ direction in FIG. 2 corresponds to FIG. 1. Corresponding parts in both figures are given the same reference numerals. As shown in each drawing, the electrophoretic display device 1 is roughly divided into a flexible printed wiring circuit (electrically connected to the first substrate 10, the electrophoretic dispersion liquid layer 20, the second substrate 30, and an external circuit ( FPC) substrate 40.

  The first substrate 10 has a configuration in which a thin film semiconductor circuit layer 12 is formed on a flexible substrate 11 as an insulating base substrate for forming an electric circuit. On the first substrate 10, a pixel electrode 13a is formed. Is formed. The thickness of the first substrate 10 is preferably 25 μm or more from the viewpoint of physical strength of the substrate when forming a thin film circuit, and is 200 μm or less from the viewpoint of ensuring the flexibility of the substrate. It is desirable.

  The flexible substrate 11 is, for example, a polycarbonate substrate having a film thickness of 200 μm. A semiconductor circuit layer 12 is laminated (bonded) on the flexible substrate 11 via an adhesive layer 11a made of, for example, a UV (ultraviolet) curable adhesive. In the case where the thin film semiconductor circuit layer 12 is formed on such a flexible substrate 11, for example, it is introduced in JP-A-10-125931, JP-A-11-26733, JP-A-2004-327836, etc. The thin film element transfer technology that has been used can be used. In these documents, a thin film semiconductor circuit is formed on a heat resistant substrate (glass substrate), and then the thin film semiconductor circuit layer including the thin film semiconductor circuit is peeled off from the heat resistant substrate and transferred entirely or partially onto the resin substrate. A thin film circuit transfer technique is disclosed.

  In addition, when using the board | substrate 11 which does not have flexibility for the 1st board | substrate 10, the pixel electrode 13a is directly attached on the board | substrate 10 with which the semiconductor circuit layer 12 was formed irrespective of the above transfer techniques. It can also be formed.

  Here, as the flexible substrate 11, a resin material excellent in lightness, flexibility, elasticity and the like can be used. For example, any of a thermoplastic resin and a thermosetting resin may be used. For example, polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, cyclic polyolefin, modified polyolefin, polyvinyl chloride, Vinylidene chloride, polystyrene, polyamide, polyimide, polyamideimide, polycarbonate, poly- (4-methylpentene-1), ionomer, acrylic resin, polymethylmethacrylate, acrylic-styrene copolymer, butadiene-styrene copolymer, polyol Polyester such as copolymer (EVOH), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PCT), polyether, polyether ketone (PEEK), poly -Terimide, polyacetal, polyphenylene oxide, modified polyphenylene oxide, polyarylate, aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, polyvinylidene fluoride, other fluorine resins, styrene, polyolefin, polyvinyl chloride, polyurethane, Various thermoplastic elastomers such as fluoro rubber and chlorinated polyethylene, epoxy resin, phenol resin, urea resin, melamine resin, non-corrosive polyester, silicone resin, polyurethane, etc., or copolymers and blends mainly composed of these , Polymer alloys, and the like, and one or more of these can be used in combination (for example, as a laminate of two or more layers). The thickness of the flexible substrate 11 is about 1 to 500 μm, and more preferably about 25 to 200 μm from the viewpoint of mechanical strength and flexibility.

  The thin film semiconductor circuit layer 12 includes a row decoder 51 and a column decoder 52 (see FIG. 2) for selecting a plurality of wiring groups, pixel electrode groups, pixel driving circuits, connection terminals, and driving pixels arranged in the row direction and the column direction, respectively. Etc. are configured. The pixel drive circuit includes a circuit element such as a thin film transistor (TFT).

  The material used as the adhesive layer between the flexible substrate 11 and the thin film semiconductor circuit layer 12 is, for example, a photo-curing adhesive such as a reactive curable adhesive, a thermosetting adhesive, or an ultraviolet curable adhesive, Various curable adhesives such as anaerobic curable adhesive can be used. In particular, it is preferable to use a photocurable adhesive from the viewpoint of reducing the cycle time of the process. As said photocurable material, an epoxy type, an acrylate type, and a silicone type photocurable material can be used, for example. The thickness of the adhesive layer is about 1 μm to 1 mm, more preferably about 10 to 100 μm.

  The display area unit 13 includes a plurality of pixel electrodes (drive electrodes) 13a arranged in a matrix, and displays an image (two-dimensional information). On the first substrate 10, pixel electrodes 13a are provided corresponding to the respective pixels.

  The connection electrode 14 is for electrically connecting the transparent electrode layer 32 of the second substrate 30 and the circuit wiring of the first substrate 10, and is connected to the outer peripheral portion of the thin film semiconductor circuit layer 12 (the outer periphery of the display region portion 13). ).

  The electrophoretic layer 20 is formed on the display area portion 13 of the first substrate 10 and over the outer peripheral area thereof. The formation region 16 of the electrophoretic layer 20 is indicated by a matte surface in FIG. The electrophoretic layer 20 includes a large number of microcapsules 21 fixed by a binder 22. The microcapsule 21 contains an electrophoretic dispersion medium and electrophoretic particles. The electrophoretic particles have a property of moving in the electrophoretic dispersion medium according to an applied voltage, and one type (one color) or more of electrophoretic particles are used. The thickness of the electrophoretic layer 20 is, for example, about 50 μm to 75 μm. The electrophoretic layer 20 is obtained by mixing the above-described microcapsule 21 in a binder 22 together with a desired dielectric constant modifier, and using a roll coater on the substrate with the obtained resin composition (emulsion or organic solvent solution). It can be formed by a known coating method such as a method using a roll laminator, a method by screen printing, or a spray method.

  Here, as shown in FIG. 9, in the conventional electrophoresis apparatus 1 ′, since the pixel electrode 13a ′ is formed to a thickness of several tens of μm or more, a gap 13b ′ formed between the pixel electrodes 13a ′ is also formed. The depth was several tens of μm or more. Therefore, when the microcapsule 21 and the binder 22 are supplied onto the pixel electrode 13a ′, the microcapsule 21 blocks the gap 13b ′ before the binder 22 enters the gap 13b ′, or the gap 13b is caused by the viscosity of the binder. The phenomenon of not reaching every corner of 'occurred, and air A sometimes remained in the gap 13b'.

  On the other hand, as shown in FIG. 1, the pixel electrode 13a of the electrophoresis apparatus 1 according to the present invention is extremely thin, for example, about 1 to 10 μm, preferably about 1 to 5 μm. With such a configuration, the gap 13b formed between the pixel electrodes 13a is extremely shallow, about several μm, so that the binder 22 penetrates into every corner of the gap 13b and no air remains in the gap 13b.

  Here, as the electrophoretic dispersion medium, for example, alcohol solvents such as water, methanol, ethanol, isopropanol, butanol, octanol, and methyl cellosolve, various esters such as ethyl acetate and butyl acetate, acetone, methyl ethyl ketone, and methyl isobutyl Ketones such as ketones, aliphatic hydrocarbons such as pentane, hexane and octane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, aromatic hydrocarbons such as benzene, toluene, xylene and hexylbenzene, methylene chloride, chloroform, A compound obtained by blending a surfactant or the like with a halogenated hydrocarbon such as carbon tetrachloride or 1,2-dichloroethane, a carboxylate or other various oils alone or a mixture thereof can be used.

  As described above, the electrophoretic particles are particles (polymer or colloid) having a property of moving to a desired electrode side by performing electrophoresis based on a potential difference in an electrophoretic dispersion medium. For example, black pigments such as aniline black and carbon black, white pigments such as titanium dioxide, zinc white, antimony trioxide, aluminum oxide, azo pigments such as monoazo, disazo, polyazo, isoindolinone, yellow lead, yellow iron oxide , Yellow pigments such as cadmium yellow, titanium yellow and antimony, red pigments such as quinacridone red and chrome vermillion, phthalocyanine blue and indanthrene blue, anthraquinone dyes, blue pigments such as bitumen, ultramarine blue and cobalt blue, phthalocyanine green, etc. Green pigments and the like. These particles may be used alone or in combination of two or more. Furthermore, these pigments include electrolytes, surfactants, metal soaps, resins, rubbers, oils, varnishes, charge control agents composed of particles such as compounds, or dispersing agents such as titanium coupling agents, lubricants, as necessary. Stabilizers and the like can be added.

  As a material constituting the microcapsule 21, it is preferable to use a flexible material such as a gum arabic / gelatin compound or a urethane compound. The microcapsule 21 can be formed using a known microencapsulation method such as an interfacial polymerization method, an insolubilization reaction method, a phase separation method, or an interfacial precipitation method. Further, the microcapsules 21 are preferably substantially uniform in size in order to exhibit an excellent display function. The microcapsule 21 having a substantially uniform size can be obtained by using, for example, filtration or specific gravity differential class. The size of the microcapsule 21 is usually about 30 to 60 μm.

The binder 22 is not particularly limited as long as it has good affinity with the microcapsule 21, excellent adhesion with the electrode, and has insulating properties. As this binder 22, the thing illustrated below can be used similarly to the insulating synthetic resin base material mentioned above. For example, polyethylene, chlorinated polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polypropylene, ABS resin, methyl methacrylate resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride -Vinylidene chloride copolymer, vinyl chloride acrylate copolymer, vinyl chloride-methacrylic acid copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol-vinyl chloride copolymer, propylene-vinyl chloride copolymer Thermoplastic resins such as coalescence, vinylidene chloride resin, vinyl acetate resin, polyvinyl alcohol, polyvinyl formal, and cellulose resin. Polyamide resin, polyacetal, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyphenylene oxide, polysulfone, polyamideimide, polyaminobismaleimide, polyethersulfone, polyphenylenesulfone, polyarylate, grafted polyfinylene ether, polyetheretherketone, poly Polymers such as etherimide. Fluorine such as polytetrafluoroethylene, polyfluoroethylenepropylene, tetrafluoroethylene-perfluoroalkoxyethylene copolymer, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, polytrifluoroethylene chloride, fluororubber Resin. Silicon resins such as silicone resin and silicon rubber. As other binder materials, methacrylic acid-styrene copolymer, polybutylene, methyl methacrylate-butadiene-styrene copolymer, and the like can be used. The binder material preferably has substantially the same dielectric constant of the electrophoretic display liquid and that of the dispersant as described in, for example, JP-A-10-149118. The transparent electrode layer 32 is formed on a thin film film (transparent insulating synthetic resin base material) 31 so as to cover the electrophoretic layer 20. As for the thickness of the 2nd board | substrate 30, 10-200 micrometers is desirable, More preferably, it is 25-75 micrometers.

  The thin film 31 plays a role of sealing and protecting the electrophoretic layer 20 and is configured using, for example, a polyethylene terephthalate (PET) film. As the thin film 31, various materials can be used as long as the flexible substrate 11 is an insulating transparent material. The thickness of the thin film 31 is preferably thinner than the thickness of the flexible substrate 11. More preferably, it is about half or less of the thickness of the flexible substrate 11.

  The transparent electrode layer 32 is configured using a transparent conductive film such as an indium oxide film (ITO film) doped with tin, for example. The area of the transparent electrode layer 32 is indicated by hatching in FIG. 2 and is the same area as the second substrate 30. The circuit wiring of the first substrate 10 and the transparent electrode layer 32 of the second substrate 30 are connected outside the formation region 16 of the electrophoretic layer 20. Specifically, the transparent electrode layer 32 and the connection electrode (terminal) 14 of the thin film semiconductor circuit layer 12 are connected via the conductive connection body 23.

  As the transparent conductive film constituting the transparent electrode layer 32, for example, in addition to the ITO film described above, a tin oxide film doped with fluorine (FTO film), a zinc oxide film doped with antimony, and indium were doped. Examples thereof include a zinc oxide film and a zinc oxide film doped with aluminum. The method for forming the transparent electrode on the thin film 31 is not particularly limited. For example, a sputtering method, an electron beam method, an ion plating method, a vacuum deposition method, a chemical vapor deposition method (CVD method), or the like is employed. can do.

The flexible printed circuit (FPC) substrate 40 is for electrical connection with an external circuit, and is connected to the outer periphery of the first substrate 10. This connection is performed by bonding the connection electrode (connection terminal) 42 of the FPC board 40 and the connection electrode (connection terminal) 15 of the first board 10 via an anisotropic conductive film (ACF) 43. .
(Method for manufacturing electrophoresis apparatus)
Next, a method for manufacturing an electrophoretic display device according to the present invention will be described with reference to FIGS. In both figures, parts corresponding to those in FIG.

  First, as shown in FIG. 3A, the second substrate 30 is produced by forming a transparent electrode layer 32 on a thin film 31 that is a transparent insulating material. In the present embodiment, a polyethylene terephthalate (PET) film is employed as the thin film 31. The transparent electrode layer 32 is formed by forming an ITO film, which is one of the transparent conductive films, on the PET film by a sputtering method or the like.

  Next, as illustrated in FIG. 3B, the electrophoretic layer 20 is formed on the transparent electrode layer 32 of the second substrate 30. For example, using a roll coater, the mixed liquid of the microcapsule 21 and the binder 22 is uniformly applied to the upper surface of the transparent electrode layer 32, and then dried at 80 ° C. for 20 minutes. As a result, an electrophoretic display sheet having a thickness of about 100 μm obtained by forming the electrophoretic layer 20 on the second substrate 30 is obtained.

  On the other hand, the first substrate 10 is manufactured by a process separate from the electrophoretic display sheet. As shown in FIG. 4A, first, the pixel electrode 13a is formed on the first substrate 10. As described above, in this step, the pixel electrode 13a may be formed directly on the substrate 10 on which the thin film semiconductor circuit layer 12 is formed, or the thin film semiconductor circuit 12 and the pixel electrode 13a are formed on the heat resistant substrate, and thereafter The thin film semiconductor circuit layer 12 and the pixel electrode 13a may be transferred onto the substrate 11.

  In the present embodiment, a flexible resin substrate having a low heat resistant temperature is used as the substrate 11. In general, in the formation of a thin film semiconductor circuit on a resin substrate having a low heat-resistant temperature, it is possible to use a semiconductor manufacturing technique of a low temperature process, but the performance of the semiconductor film is low, and thus the performance of the TFT is also low. Therefore, in the present embodiment, the latter thin film element transfer technique is used.

  That is, a thin film semiconductor circuit layer 12 in which a polysilicon semiconductor film is formed on a heat resistant substrate such as a quartz glass substrate (not shown) via a release layer, and a circuit for a matrix display such as a thin film transistor (TFT) and a signal wiring is formed. Form. In the present embodiment, the surface of the thin film semiconductor circuit layer 12 corresponds to the “surface on the electrophoretic layer side of the first substrate”. Therefore, the pixel electrode 13a is formed on the thin film semiconductor circuit layer 12 by an electroless plating method or an electrolytic plating method described later. A temporary transfer substrate (not shown) is bonded onto the thin film semiconductor circuit layer 12 with a water-soluble adhesive, and the release layer is broken by light irradiation or the like to transfer the thin film semiconductor circuit 12 to the temporary transfer substrate side. Next, the thin film semiconductor circuit 12 of the temporary transfer substrate is bonded to the flexible resin substrate 11 with a non-soluble adhesive. The flexible substrate 11 is, for example, a polycarbonate substrate having a film thickness of 200 μm. Further, the water-soluble adhesive between the temporary transfer substrate and the thin film first substrate is dissolved and removed to separate the temporary transfer substrate. In this manner, the thin film semiconductor circuit 12 in which the electrode wiring 13, the connection electrode 14, the connection terminal 15, the pixel electrode 13 a, and the like are formed on the flexible substrate 11 from the temporary transfer substrate is peeled and transferred. A substrate 10 is formed.

  As described above, the method for manufacturing an electrophoretic device according to the present invention is characterized in that the pixel electrode 13a group is formed extremely thin using a plating method. Therefore, a method for forming the pixel electrode 13a group will be described in detail with reference to FIGS. FIG. 5 shows a formation method by a so-called full additive method using an electroless plating method.

  First, as shown in FIG. 5A, a thin film semiconductor circuit 12 that will form a surface that will later become the electrophoretic layer side of the first substrate is formed on a quartz glass substrate 60. Subsequently, a plating resist is formed on the thin film semiconductor circuit 12, and exposure and development are performed to form a plating resist 62 having an opening in a region where the pixel electrode 13a is to be formed.

  Next, a catalyst layer (not shown) is formed on the surface of the thin film semiconductor circuit 12 and the resist 62 as necessary. Formation of the catalyst layer can be performed according to the methods disclosed in JP-A-6-61619, JP-A-11-314310, JP-A-2000-40896, and the like. As the catalyst, for example, noble metals such as gold, silver and palladium can be used. As a method for forming the catalyst layer, for example, a method of applying a paint containing a catalyst, a method of contacting a catalyst metal salt solution, a method of attaching catalyst metal particles, or the like can be used.

  After the formation of the catalyst layer, the substrate 60 is immersed in an electroless plating solution, thereby forming a conductive layer that becomes the pixel electrode 13a as shown in FIG. As the electroless plating solution, for example, copper sulfate 8 to 10 g / l, EDTA 25 to 35 g / l, formalin 2 to 5 ml / l, sodium hydroxide 2 to 5 g / l and a stabilizer or a surfactant added thereto are used. be able to. Formation of the conductive layer by electroless plating can be controlled to about 1 to 10 μm, preferably about 1 to 5 μm because the thickness of the layer can be controlled by adjusting the composition of the plating solution and the plating time.

  Next, as shown in FIG. 5C, in this embodiment, a gold thin film 64 is formed as a protective layer on the pixel electrode 13a by a plating method. The protective layer can be formed of a solder material or the like. However, when a gold thin film is formed by a plating method, the protective layer is extremely thin, for example, a protective layer of 1 μm or less can be formed.

  Subsequently, as shown in FIG. 5D, by removing the plating resist 62, the pixel electrode 13a is completed. According to the above method, a pixel electrode having a thickness of 10 μm or less including the thickness of the protective layer can be formed, and the binder 22 can easily enter every corner of the gap 13b.

  The thin film semiconductor circuit 12 and the pixel electrode 13a thus formed are peeled and transferred onto the resin substrate 11 by the transfer technique described above, whereby the first substrate 10 is formed. Since the first substrate 10 can form the pixel electrode 10a with a thickness of, for example, 10 μm or less, the depth of the gap 13b between the pixel electrodes 13a can also be, for example, 10 μm or less.

  On the other hand, FIG. 6 shows a forming method using a so-called semi-additive method using an electrolytic plating method. In the case of the semi-additive method, first, as shown in FIG. 6A, the thin film semiconductor circuit 12 that will later constitute the surface that will become the electrophoretic layer side of the first substrate is formed on the quartz glass substrate 70. Subsequently, a plating nucleus layer 71 made of chromium, nickel, copper or the like is formed on the thin film semiconductor circuit layer 12 to a thickness of about 50 nm to 100 nm by a method such as sputtering. Next, as in the case of the full additive method, a plating resist is formed on the plating nucleus layer 71, and exposure and development are performed to form a plating resist 72 having an opening in a region where the pixel electrode 13 a is to be formed. Form a film. Next, as shown in FIG. 6B, a conductive layer to be the pixel electrode 13a is formed by electrolytic plating in a region on the thin film semiconductor circuit layer 12 where the plating resist 72 is not formed. Further, as in the case of the above-described full additive method, as shown in FIG. 6C, a gold thin film 74 is formed on the conductive layer as a protective layer by a plating method, and shown in FIG. As described above, the pixel electrode 13a is completed by removing the plating resist 72 and the plating nucleus layer 71 in the region where the conductive layer is not formed. The thin film semiconductor circuit 12 and the pixel electrode 13a thus formed are peeled and transferred onto the resin substrate 11 by the transfer technique described above, whereby the first substrate 10 is formed. Also by this method, a pixel electrode having a thickness of 10 μm or less including the protective layer and the plating nucleus layer can be formed, and the binder 22 can be filled in the gap 13b so that air does not enter.

  Next, returning to FIG. 4, a method for manufacturing the electrophoresis apparatus will be described. As shown in FIG. 4B, a flexible printed circuit (FPC) substrate 40 for connecting to an external circuit is connected to the first substrate 10. The FPC board 40 is a flexible substrate 41 in which an insulating layer, a metal thin film wiring layer, and an insulating layer are laminated, and a connection electrode 42 connected to the wiring layer is exposed at an end thereof. Connection between the FPC board 40 and the first board 10 is performed by interposing an anisotropic conductive film (ACF) 43 between the connection electrode 42 of the FPC board 40 and the connection terminal 15 of the first board 10. For example, the first substrate 10 and the FPC substrate 40 are connected by sandwiching the anisotropic conductive film 43 at a pressure of 0.6 MPa at 80 ° C. and using an adhesive for the anisotropic conductive film 43.

  Next, as shown in FIG. 4C, a conductive connector is formed on the connection electrode 14 for energization with the transparent electrode layer 32 (see FIG. 4D) provided on the first substrate 10. 23 is arranged. The conductive connection body 23 can be arranged by, for example, a droplet discharge method or an offset printing method.

Next, as shown in FIG. 4D, the first substrate 10 and the electrophoretic display sheet (the electrophoretic layer 20 and the second substrate 30) are bonded together. Specifically, first, the electrophoretic display sheet and the first substrate 10 are opposed to each other so that the electrophoretic layer 20 is positioned in the display region portion 13 (see FIG. 1) on the first substrate 10. To do. Then, laminating is performed by a vacuum laminator, and the first substrate 10, the electrophoretic display layer 20, and the common electrode substrate 30 are bonded together to manufacture the electrophoretic display device 1. Lamination may be performed, for example, at 90 ° C. and a pressure of 0.8 MPa in a reduced pressure atmosphere.
<Second Embodiment>
(Electrophoresis device)
FIG. 7 shows a cross section of the electrophoresis apparatus 2 according to the second embodiment of the present invention. In the electrophoretic device 2, as shown in FIG. 7, an insulating film 18 is formed on the substrate 10 so as to fill in between the thinly formed pixel electrodes 13 a. Thereby, the step between the pixel electrode 13a and the thin film semiconductor circuit 12 is eliminated, the gap is almost eliminated, and when the microcapsule 21 and the binder 22 are brought into contact with each other, the possibility that a gap is generated in the gap is greatly reduced. Can do.

  In the conventional electrophoresis apparatus 1 ′ shown in FIG. 9, since the gap 13 b ′ is formed deeply, there is a high possibility that bubbles are involved in the step of filling the gap 13 b ′ with an insulating member to form an insulating film. However, in the electrophoretic device 2, since the pixel electrode is very thin, for example, formed to be 10 μm or less, the possibility of such a problem is low.

The electrophoretic device 2 can be obtained, for example, by forming an insulating film 18 between the pixel electrodes 13a after the process shown in FIG. 5D or FIG. 6D. Examples of the material of the insulating film 18 include polymers such as polyimide, polyurethane, polymethyl methacrylate, polyethylene, and polyvinyl acetate, resin materials such as silicon resin, epoxy resin, and fluororesin, and metals such as silicon oxide and aluminum oxide. An oxide etc. can be mentioned. In addition, as a method of forming the insulating film 18, in the case of using a polymer or a resin as a material, a method of polymerizing and curing by heating, UV irradiation or the like after applying a precursor such as a monomer or an oligomer, or applying a solution Then, a method of volatilizing the solvent can be used. When a metal oxide is used as a material, a vapor phase formation method such as sputtering or vapor deposition, or a liquid phase formation method using a sol-gel reaction can be used.
(Electronics)
Next, a specific example of an electronic apparatus to which the above-described electrophoresis apparatus according to the present invention is applied will be described with reference to FIG. FIG. 8A is a perspective view illustrating an electronic book which is an example of the electronic apparatus. The electronic book 1000 includes a book-shaped frame 1001, a cover 1002 provided to be rotatable (openable and closable) with respect to the frame 1001, an operation unit 1003, and the electrophoresis apparatus according to the present embodiment. The display unit 1004 is provided. FIG. 8A is a perspective view illustrating an electronic book which is an example of the electronic apparatus. The electronic book 1000 includes a book-shaped frame 1001, a cover 502 that can be rotated (openable and closable) with respect to the frame 1001, an operation unit 1003, and the electrophoresis apparatus according to the present embodiment. The display unit 1004 is provided. FIG. 8B is a perspective view illustrating a wrist watch that is an example of an electronic apparatus. The wristwatch 1100 includes a display unit 1101 configured by the electrophoresis apparatus according to the present embodiment. FIG. 8C is a perspective view illustrating electronic paper which is an example of the electronic apparatus. The electronic paper 1200 includes a main body 1201 formed of a rewritable sheet having the same texture and flexibility as paper, and a display unit 1202 configured by the electrophoresis apparatus according to the present embodiment. The range of electronic devices to which the electrophoretic device can be applied is not limited to this, and includes a wide range of devices that utilize changes in visual color tone accompanying the movement of charged particles. For example, in addition to the above-described devices, those belonging to real estate such as wall surfaces to which an electrophoretic film is bonded, and those belonging to moving bodies such as vehicles, flying objects, and ships are also applicable.

  In addition, this invention is not limited to the content of embodiment mentioned above, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the method for manufacturing an electrophoretic device described above, when a heat-resistant glass substrate or the like is used as the substrate 11, the thin film semiconductor circuit 12 and the pixel electrode 13a are formed directly on the substrate 10 without using a transfer technique. May be. Further, an insulating film may be formed on the first substrate 10 so as to fill the space between the pixel electrodes 13a, thereby eliminating the step between the pixel electrode 13a and the surface of the substrate 10 and minimizing the influence of the gap. It can be. Further, in the case where display is simple and a semiconductor circuit is unnecessary, a substrate 10 in which only the pixel electrode 13a and wiring are formed on the flexible substrate 11 may be used.

1 is a schematic cross-sectional view of an electrophoresis apparatus according to a first embodiment of the present invention. 1 is a schematic plan view of an electrophoresis apparatus according to the present invention. It is process drawing explaining the manufacturing method of an electrophoretic display sheet. It is process drawing explaining the manufacturing method of an electrophoresis apparatus. It is process drawing explaining the formation process of a pixel electrode. It is process drawing explaining the formation process of a pixel electrode. It is a schematic sectional drawing of the electrophoresis apparatus which concerns on the 2nd Embodiment of this invention. It is a perspective view explaining the specific example of the electronic device to which the electrophoresis apparatus is applied. It is a schematic sectional drawing of the electrophoresis apparatus which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... 1st board | substrate, 11 ... Flexible substrate, 12 ... Thin film semiconductor circuit, 13a ... Pixel electrode, 13b ... Gap, 16 ... Electrophoresis layer formation area, 18 ... Insulating film, 20 ... Electrophoresis layer, 21 ... Micro Capsule, 22 ... Binder, 30 ... Second substrate, 31 ... Thin film, 32 ... Transparent electrode layer, 40 ... Flexible printed circuit (FPC) substrate, 60, 70 ... Glass substrate, 62, 72 ... Plating resist, 64, 74 ... gold thin film, 71 ... plating core layer

Claims (11)

An electrophoretic layer is disposed between the first substrate and the second substrate, a pixel electrode is formed on the surface of the first substrate on the electrophoretic layer side, and a transparent electrode is formed on the surface of the second substrate on the electrophoretic layer side A method of manufacturing an electrophoresis apparatus in which a layer is formed,
Forming the pixel electrode comprises:
Forming a resist layer on the surface of the first substrate on the electrophoretic layer side, and providing an opening in the resist layer according to a pattern in which the pixel electrode is to be formed;
Forming a conductive layer in the opening of the resist layer by an electroless plating method;
And a step of removing the resist layer. An electrophoretic layer is disposed between the first substrate and the second substrate, a pixel electrode is formed on the surface of the first substrate on the electrophoretic layer side, and a transparent electrode is formed on the surface of the second substrate on the electrophoretic layer side A method of manufacturing an electrophoresis apparatus in which a layer is formed,
Forming the pixel electrode comprises:
Forming a plating nucleus layer on a surface of the first substrate on the electrophoretic layer side;
Forming a resist layer on the plating nucleus layer, and providing an opening in the resist layer according to a pattern to form the pixel electrode;
Forming a conductive layer on the opening of the resist layer by electrolytic plating;
Removing the plating nucleus layer in a region other than the resist layer and the pattern.   The method for manufacturing an electrophoretic device according to claim 1, further comprising a step of forming a protective layer on the conductive layer after the step of forming the pixel electrode.   The method for manufacturing an electrophoretic device according to claim 3, wherein the step of forming the protective layer includes a step of forming a gold thin film on the conductive layer by a plating method.   5. The electrophoretic device according to claim 1, further comprising a step of forming an insulating film on the first substrate so as to fill a space between the pixel electrodes after the step of forming the pixel electrodes. Manufacturing method. An electrophoretic layer is disposed between the first substrate and the second substrate, a pixel electrode is formed on the surface of the first substrate on the electrophoretic layer side, and a transparent electrode is formed on the surface of the second substrate on the electrophoretic layer side An electrophoretic device in which a layer is formed,
An electrophoretic device, wherein the pixel electrode has a thickness of 10 μm or less.   The electrophoretic device according to claim 6, wherein a protective layer made of a gold thin film is formed on the pixel electrode.   The electrophoretic device according to claim 6, wherein an insulating film is formed on the first substrate so as to fill the space between the pixel electrodes.   The electrophoretic device according to claim 6, wherein the electrophoretic layer includes microcapsules enclosing electrophoretic particles and an electrophoretic dispersion medium, and a binder.   The electrophoresis apparatus according to claim 6, wherein the first substrate and the second substrate have flexibility.   An electronic apparatus comprising the electrophoresis device according to claim 6.

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