JP2023038143A - Heating element and driving device - Google Patents

Abstract

[Problem] The object is to provide a heating element in which the electrode wiring pattern is formed in a space-saving manner, and which can rapidly generate heat in a localized area with low power. It is also an object to provide a drive device using said heating element. [Solution] The present invention provides a heating element comprising a substrate, a positive wiring electrode and a negative wiring electrode formed on said substrate and facing each other, and a resistor formed between the facing positive and negative wiring electrodes, wherein the positive and negative wiring electrodes have a slope angle of 70 degrees or more on the facing side and a recess on the upper surface. The present invention also provides a drive device in which a substrate is a flexible sheet (stretchable sheet) formed by laminating two or more sheets with different linear expansion coefficients, and in which cuts are made around the heating element. [Selected Figure] Figure 4

Description

The present invention relates to a heating element and a driving device using the heating element.

As a heat generating element, there is known a planar heat generating sheet formed by inserting or coating a resistor having a high volume resistivity, for example, mainly composed of carbon, between the positive electrode and the negative electrode of the wiring electrode pattern printed on the sheet. It is

Patent Document 1 discloses a planar heating element in which resistors are formed by printing and drying on a comb-shaped wiring electrode pattern formed by printing and drying, and the pitch between the positive and negative comb-shaped electrodes is different. It is disclosed that the temperature is adjusted according to user's preference by providing a plurality of heat-generating portions.

Japanese Patent No. 4449804

However, Patent Literature 1 does not disclose the recognition of the problem of forming a wiring pattern of electrodes in a space-saving manner and instantaneously generating heat in a local pinpoint portion of several square millimeters.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a heating element in which a wiring pattern of electrodes is formed in a space-saving manner, and which is capable of rapidly heating a local portion with a small electric power. A further object of the present invention is to provide a driving device using the heating element.

In order to solve the above-mentioned problems, one representative heating element of the present invention includes a base material, a positive wiring electrode and a negative wiring electrode formed on the base material and facing each other, and the positive electrode. and a resistor formed between opposing wiring electrodes of the positive electrode and the negative electrode, and the wiring electrodes of the positive electrode and the negative electrode have a slope angle of 70 degrees or more on the opposing side surfaces and have a concave portion on the upper surface. It is a heating element that

According to the present invention, the wiring pattern of the electrodes of the heating element can be formed in a space-saving manner, and it is possible to rapidly heat a local portion with a small electric power.
Problems, configurations, and effects other than those described above will be clarified by the description in the following embodiments.

FIG. 1 is a diagram showing a heating element 200 using conventional wiring electrodes. FIG. 2 is a cross-sectional view of the heating element 200 cut along the XZ plane including the X-X' axis. FIG. 3 is a photomicrograph of a cross-sectional shape of wiring printed by a conventional method. FIG. 4 is a diagram schematically showing a heating element 500 using wiring electrodes according to the present invention. FIG. 5 is a cross-sectional view of the heating element 500 cut along the XZ plane including the X-X' axis. FIG. 6 shows a cross-sectional shape of a wiring electrode formed by the present screen printing method. FIG. 7 is a plan view of a photograph taken by a laser microscope of wiring electrodes formed by the present screen printing method. FIG. 8 is a perspective view of a photograph taken by a laser microscope of wiring electrodes formed by the present screen printing method. FIG. 9 is a cross-sectional view of a photograph taken by a laser microscope of wiring electrodes formed by the present screen printing method. FIG. 10 is a schematic diagram showing the formula of Joule heat. FIG. 11 is a diagram showing an injection step in the present screen printing method. FIG. 12 is a diagram showing a sweeping step by a squeegee in the present screen printing method. FIG. 13 is a diagram showing recesses formed in screen mesh traces when the coating agent and printing method according to the present embodiment are used. FIG. 14 is a diagram showing recesses formed in screen mesh traces when the coating agent and the printing method according to the present embodiment are used. FIG. 15 is a diagram showing a heating element and a driving device according to the first embodiment; FIG. 16 is a plan view showing a heating element and a driving device according to the second embodiment; FIG. 17 is a comparison diagram of temperature rise graphs of a heating element with a wiring electrode pattern according to the present invention and a heating element with a conventional wiring electrode pattern. FIG. 18 is a plan view of an LED flicker 806 to which the second embodiment is applied. FIG. 19 is a plan view of a butterfly device 808 to which the second embodiment is applied. FIG. 20 is a plan view showing a heating element and driving device according to the third embodiment. FIG. 21 is a plan view showing a heating element and driving device according to the fourth embodiment. FIG. 22 is a longitudinal cross-sectional view of the balloon capillary tube 1200 according to the fifth embodiment. FIG. 23 is a schematic diagram of an example of the balloon drive unit 1203. As shown in FIG. FIG. 24 is a schematic diagram showing how the balloon driving unit 1203 is driven. FIG. 25 is a longitudinal cross-sectional view of a modification of the balloon capillary tube 1200 according to the fifth embodiment. FIG. 26 is a schematic diagram of a braille display device 1300 to which the fifth embodiment is applied.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited by this embodiment.
Moreover, in the description of the drawings, the same parts are denoted by the same reference numerals.

In the present disclosure, the directions indicated by the X-axis, Y-axis, and Z-axis on the drawings may be used to indicate directions.

In the present disclosure, unless otherwise specified, "top" means the Z-axis positive direction, "bottom" means the negative direction, and "height" means the length on the Z-axis.

In the present disclosure, unless otherwise specified, the substrate-side surface in contact with the wiring electrode is parallel to the XY plane. The “bottom surface” means the surface where the wiring electrodes are in contact with the substrate side (XY plane).

In the present disclosure, unless otherwise specified, a top view of the XY plane is a plan view. A view on the XZ plane is called a sectional view.

First, a conventional example will be described with reference to FIGS.
FIG. 1 is a diagram showing a heating element 200 using conventional wiring electrodes. In FIG. 1, the comb-shaped electrode portions of the positive wiring electrode 202 and the negative wiring electrode 203 are arranged on the substrate 301 so as to be mutually present in the X-axis direction. A heating element is formed by filling a resistor 204 (not shown) in the gap between these comb-shaped electrodes.

In addition, on the bottom surfaces where the positive wiring electrode 202 and the negative wiring electrode 203 are in contact with the substrate 301 , there are mutually parallel sides facing each other with the resistor 204 interposed therebetween (hereinafter referred to as “opposing parallel sides”). In FIG. 1, the opposing parallel sides are parallel to the Y-axis. In addition, in the positive electrode wiring electrode 202 or the negative electrode wiring electrode 203, the surfaces including the opposing parallel sides and facing each other with the resistor 204 interposed therebetween are referred to as "opposing side surfaces".

FIG. 2 is a cross-sectional view of the heating element 200 in FIG. 1 taken along the XZ plane including the X-X' axis. The X-X' axis is a straight line perpendicularly intersecting the opposing parallel sides at any position. The cross section of the positive wiring electrode 202 and the negative wiring electrode 203 has a semi-cylindrical shape and diverges from top to bottom. A distance 302 represents the minimum distance in the X direction between the facing side surface 206 on the positive wiring electrode 202 side and the facing side surface 207 on the negative wiring electrode 203 side, and a distance 303 represents the maximum distance.

FIG. 3 is a photomicrograph of a cross-sectional shape of wiring printed by a conventional method. As mentioned above, it is confirmed that the cross section takes a semicylindrical shape.

FIG. 4 is a diagram schematically showing a heating element 500 using wiring electrodes according to an embodiment of the present invention. 5 is a cross-sectional view of the heating element 500 in FIG. 4 taken along the XZ plane including the X-X' axis. In the following description, the same reference numerals are given to the same or equivalent components as in the above-described conventional example, and the description thereof will be simplified or omitted.

The positive wiring electrode 502 and the negative wiring electrode 503 of this embodiment have a substantially rectangular cross section and are formed in a state of standing substantially perpendicular to the substrate. A facing side surface 506 on the side of the positive wiring electrode 502 and a facing side surface 507 on the side of the negative wiring electrode 503 face each other substantially in parallel. Therefore, the spacing between opposing side surfaces 506 and 507 is substantially the same in the Z direction.

The structure of the wiring electrodes of the heating element of this embodiment will be described in detail below. The wiring electrodes in this embodiment are formed using a screen printing method (hereinafter referred to as "this screen printing method"), which will be described later. The present screen printing method is described in detail in the specification and drawings of Japanese Patent Application No. 2021-105169 (hereinafter referred to as "prior application"), which is a prior application filed by the present applicant.

FIG. 6 shows a cross-sectional shape of a wiring electrode formed by the present screen printing method. It corresponds to the cross-sectional shape of the positive wiring electrode 502 or the negative wiring electrode 503 schematically shown in FIG. A line segment connecting both ends X1 and X2 of the bottom surface of the wiring electrode in the X direction is called a "bottom", and its length is L1. Hereinafter, L1 is also referred to as "electrode width".

Let X3 be an inflection point (a point at which the inclination turns from an increase to a decrease) when tracing from X1 along the opposing side surface in the positive direction of the Z-axis. An inflection point obtained by the same method from X2 on the other opposite side surface of the wiring electrode is assumed to be X4. A line segment connecting X3 and X4 is called an "upper base" and its length is L2. The angle between the line segment connecting the inflection points X3 and X1 and the base is called the "slope angle" and is set to θ1. Although illustration is omitted, similarly, the slope angle formed by the line segment connecting X2 and X4 and the lower base is assumed to be θ2.
Also, hereinafter, the wiring electrode surface above the upper base is referred to as the upper surface.

Next, the details of the cross-sectional shape of the wiring electrode formed by the present screen printing method will be described with reference to FIGS.
7 to 9 show images of wiring electrodes formed by the present screen printing method with a screen printing plate having a plate groove width of 200 μm, a plate groove depth of 200 μm, and a pitch interval of the plate groove of 200 μm, and observed with a laser microscope manufactured by Keyence Corporation. It is a photograph.

FIG. 7 is a plan view of a photograph taken by a laser microscope of wiring electrodes formed by the present screen printing method. FIG. 8 is a perspective view of a photograph taken by a laser microscope of wiring electrodes formed by the present screen printing method. FIG. 9 is a cross-sectional view of a photograph taken by a laser microscope of wiring electrodes formed by the present screen printing method.

Table 1 shows the measurement results of the upper base (L2) and the lower base (L1). From the lower bottom values, it can be seen that the electrode width (L1) substantially matches the length of the plate groove width.

表２から明らかなように、本件スクリーン印刷法を用いて形成された配線電極の法面角度はアスペクト比０．５～４の範囲で７０度以上をとり略垂直であることが分かる。 Table 2 shows the measurement results of measuring the slope angle with respect to a plurality of combinations of plate groove width and plate groove depth. In Table 2, "left" means θ1, and "right" means θ2. The slope angle can be measured from the profile shape of the wiring electrode in the cross-sectional view of FIG.

As is clear from Table 2, the slope angle of the wiring electrodes formed by the present screen printing method is 70 degrees or more in the aspect ratio range of 0.5 to 4 and is substantially vertical.

As another feature of the cross-sectional shape of the wiring electrode formed by the present screen printing method, as can be seen from FIG. 6 or FIGS. This is based on the peculiar phenomenon that recesses are formed at screen mesh intersections according to the present screen printing method. This is because, as will be described later, during printing, the lubricant for avoiding cohesive failure of the electrodes oozes out from the coating agent onto the portions of the upper surfaces of the wiring electrodes that come into contact with the intersections of the screen mesh. In the cross-sectional shape of FIG. 6, the recess width l3, which is the distance between the vertices, has a value of 10 to 40 μm.

In the conventional screen printing method, as explained in FIGS. 1 to 3, the wiring electrodes have a semi-cylindrical shape and the upper surface is formed with a convex portion. I can say.

<Line width, pitch and aspect ratio of wiring electrodes>
The heating element and driving device in this embodiment are intended to generate heat and drive at a low voltage of approximately 5V with space-saving wiring. For the wiring electrodes for this purpose, the length of the electrode width (corresponding to L1 in FIG. 6) is 100 to 200 μm, the interval (pitch) between the electrodes is approximately equal to twice the electrode width, and the aspect ratio is (Ratio of height to width of electrode) is preferably 0.5-4.
Conventionally, when electrodes having a width of 200 μm are formed in parallel, a pitch width of 500 to 1,000 μm is required. Use of the wiring electrodes in this embodiment enables space saving.

ここで、Ｑ［Ｗ］：ジュール熱、Ｒ：抵抗［Ω］、Ｉ：電流［Ａ］、Ａ：断面積［ｍ^２］、σ：電気伝導率［Ｓ／ｍ］、Ｌ：長さ［ｍ］である。
したがってジュール熱Q［W］を大きくするには断面積Ａ［ｍ^２］または長さＬ［ｍ］を大きくすればよい。 <Action/effect>
Next, FIG. 10 is a schematic diagram for explaining the formula of Joule heat. Joule heat is represented by the following formula.

Here, Q [W]: Joule heat, R: Resistance [Ω], I: Current [A], A: Cross-sectional area [m ² ], σ: Electrical conductivity [S / m], L: Length [ m].
Therefore, in order to increase the Joule heat Q [W], the cross-sectional area A [m ² ] or the length L [m] should be increased.

1 to 3, the cross section of the wiring electrode formed by the conventional printing method has a semi-cylindrical shape. , and the heat generation efficiency is poor even from the Joule's formula.

Further, in the case of an electrode having a semi-cylindrical cross section, it is not possible to obtain a sufficient film thickness in the height direction, and it is not possible to obtain a printed wiring or a cross sectional area of the electrode sufficient to generate a desired amount of heat.
Therefore, conventionally, electrodes with a low aspect ratio and a wider line width of about 10 microns, which is the limit film thickness of screen printing, are printed as comb-teeth electrodes in which the positive electrode and the negative electrode are alternately arranged, and a resistor is formed there. there is With such specifications, if a large area is used, a large amount of heat can be secured, but a large amount of heat cannot be obtained in an area of several millimeters. When it is desired to increase the temperature rise rate of an area of several millimeters, it is necessary to apply a high voltage of several tens of volts, and a voltage of about 5 V hardly causes a temperature rise.

On the other hand, in the positive wiring electrode 502 and the negative wiring electrode 503 of the present invention, the opposed side surfaces 506 and 507 face each other substantially in parallel, so that the current flows relatively uniformly through the entire resistor, resulting in good heat generation efficiency. . Furthermore, since current widely flows over the entire cross-sectional area A [m2], Joule heat Q [W] can be increased.

The electrode width, pitch, aspect ratio, and driving voltage are related to each other. For example, even if the pitch is lengthened, if the aspect ratio is increased, the same amount of heat can be obtained at the same voltage. Therefore, by using the wiring electrode structure of this embodiment, it is possible to increase the degree of freedom in designing the heating element.
In addition, the electrode width, pitch, and aspect ratio are largely defined by the specifications of the screen printing plate actually used for manufacturing. It is also possible to manufacture one with twice the pitch) or with four times or more the aspect ratio.

The screen printing method used to form the wiring electrodes in this embodiment will be described below.

<Printing ink>
The positive electrode and negative electrode that can be used in the present embodiment are electrodes printed with a coating agent containing an additive incompatible with a mixture (main agent) of a filler and a binder and a main solvent, which is a solvent for the binder, as a printing ink. be.

Inorganic fillers and organic fillers can be used in the present embodiment as fillers that can be used for electrodes. Inorganic fillers are classified into metals and non-metals. Organic fillers are primarily polymeric compositions. Metals include noble metals and base metals. For example, noble metals include gold, silver, platinum, and palladium. Base metals include iron, copper, nickel, aluminum, lead, zinc, tin, tungsten, molybdenum, tantalum, magnesium, cobalt, Bismuth, cadmium, titanium, zirconium, antimony, manganese, beryllium, chromium, germanium, vanadium, gallium, hafnium, indium, niobium, rhenium, and thallium. Gold, silver and copper are particularly useful in this embodiment. Non-metals are elements other than the above metals. For example, in classification according to reactivity, reactive non-metals include hydrogen, carbon, nitrogen, oxygen, fluorine, phosphorus, sulfur, chlorine, bromine, selenium, iodine, Astatine, noble gases such as helium, neon, argon, krypton, xenon, and radon, and semimetals having chemical properties such as non-metals such as boron, silicon, germanium, arsenic, antimony, and tellurium.
However, inorganic fillers include substances in which multiple elements are chemically bonded, such as calcium carbonate, silica, carbon black, graphite, carbon nanotubes, alumina, aluminum nitride, boron nitride, beryllia, barium titanate, and lead zirconate titanate. , ferrite, CMC, titanium oxide, glass beads, magnesium oxide, hydrotalcite, MOS, barium sulfate, titanium oxide, zinc oxide, iron oxide, calcium oxide, magnesium oxide, zeolite, calcium oxide, magnesium oxide, and the like.

Polymer compounds, which are organic fillers, are linear high-molecular weight compounds formed by chemically bonding the inorganic fillers in a one-dimensional structure through chemical reactions such as addition polymerization, condensation polymerization, addition condensation, and covalent bonding. There are molecular compounds and network-like polymer compounds having a three-dimensional structure linked by covalent bonds.
Inorganic fillers used in electrodes are inorganic compounds in which copper, silver, silicon, etc. are chemically bonded to oxygen, hydrogen, carbon, etc., and are based on metal atoms that have electrical conductivity and thermal conductivity. In particular, those having a siloxane bond or the like are preferable.
The organic filler is a polymer having a urethane bond such as polyurethane, which is usually produced by polyaddition of a compound having an isocyanate group and a hydroxyl group, and is a urethane resin having a bond interposed by urethane (-NH.CO.O-), or Synthetic resins made of acrylate or methacrylate polymers, such as urethane rubber acrylic resin, and high-molecular compounds with amide bonds (the same bonds as proteins) are used.

The shape of the filler is spherical, flat, acicular, or polygonal, and the particle size is preferably from 0.1 μm to several tens of μm.

Binders that can be used for electrodes include thermosetting resins, photo-curing resins, and thermoplastic resins.

Thermosetting resins are in a state before chemical reactions such as addition polymerization, condensation polymerization, addition polymerization, and covalent bonding of the organic filler. ), such as phenolic resins, amino resins, unsaturated polyester resins, epoxy resins, and silicone rubbers.
Thermosetting resins have various reaction temperature ranges from normal temperature to high temperature, and react by addition polymerization, condensation polymerization, addition condensation, covalent bonding, and the like. For example, elastomers such as silicone rubber are mainly made of polyorganosiloxane (silicone polymer), which has a backbone (main chain) of siloxane bonds (Si-O-) in which silicon atoms and oxygen atoms are arranged alternately. (High Temperature Vulcanizing rubber), LTV (Low Temperature Vulcanizing rubber) and RTV (Room Temperature Vulcanizing rubber). The curing temperature for HTV is 140°C or higher, LTV is 40-140°C, and RTV is 0-40°C. They are often classified by type. In addition, it can be divided into a solid millable type (HCR; High Consistency Rubber) and a liquid type according to the properties before curing, and the liquid type includes LSR (Liquid Silicone Rubber) and RTV product groups. HCR uses linear gum with a degree of polymerization of 5000 to 10000, whereas liquid silicone rubber (LSR, RTV) mainly consists of linear polymers with a degree of polymerization of 100 to 2000. Furthermore, it can be classified into peroxide curing, addition reaction curing, and condensation reaction curing according to the crosslinking mechanism.
A photocurable resin is a resin that is polymerized and cured by light of a specific wavelength. In short, the binder is a thermosetting resin, a photosetting resin, a thermoplastic resin, or the like before chemical reaction or fixation or adhesion as described above.

Binders used in electrodes include thermoplastic polyurethane elastomers, which are block copolymers with urethane bonds, thermoplastic polyurethanes, thermosetting urethane elastomers, polyesters, acrylic rubber and polypropylene, and acrylics composed mainly of polyester. A resin having rubber elasticity and porosity, such as a system elastomer and a thermoplastic elastomer having a block copolymer of methyl methacrylate and butyl acrylate, can be applied.
More preferably, a material containing siloxane is used. Siloxane refers to a state in which silicon (Si) and oxygen (O) are alternately bonded to form a polymer, which is the main skeleton of silicone called siloxane bond. In particular, a silicone elastomer having a siloxane compound as a backbone is highly effective in making the flexible or stretchable characteristics of the electrode more effective.

The pattern wiring printing ink capable of forming the electrodes that can be used in the present embodiment is defined based on a concept completely different from that of printing inks used in general printing applications. A general printing ink is used by mixing a binder contained in the printing ink with one having a small difference in solubility parameter (hereinafter abbreviated as SP value). Since two components with a small SP value difference are easily mixed (highly soluble), it is possible to secure handling properties during printing, smoothness of the printed matter, adhesion to the printed matter, and the like.

However, in the present invention, unlike the general concept of printing ink, an additive having a large difference in SP value from the inorganic filler or organic filler and/or binder contained in the printing ink is used. As a result, in this embodiment, the filling pressure can cause the additive to ooze out as a lubricant.

As described above, when a silicone elastomer having a siloxane compound as a skeleton is used as a binder for printing ink, it is water-insoluble, so it is preferable to use a water-soluble solvent as an additive. Furthermore, since the elastomer has rubber elasticity and porosity, the porosity is infiltrated and impregnated with a water-soluble solvent. When such printing ink is used for printing, the impregnated additive oozes out due to the pressure and shear applied to the printing ink, forming a film on the interface between the plate and the printing ink, and lubricity as a lubricant. easy to express.

As an example of the composition of the printing ink used in this embodiment, a conductive material such as silver or carbon is used as a filler, a silicone polymer is used as a binder, and a main solvent (for example, a chain siloxane such as dimethylsiloxane or dodecamethylpentasiloxane) is used. , octadecamethylcyclononasiloxane) or normal undecane, or a solvent mainly composed of aliphatic hydrogen or the like as a main component, and additives are added. In this case, since the binder is water-insoluble, the additive should be water-soluble.

The printing ink used in the present embodiment will be described using a mixture of rubber (binder) and oil (additive) as an example. When rubber (binder) and oil (additive) are mixed, the rubber swells. This is a phenomenon in which oil enters between rubber molecules. If the oil (additive) mixes easily with the rubber (binder), it will swell. However, it will bleed out to the surface of the rubber under conditions such as compression.
In other words, when the binder of the printing ink is water-insoluble, adding a water-soluble solvent additive makes it difficult for substances with different polarities and substances with large differences in SP values to mix with each other. A state is formed in which the additive, which is a water-soluble solvent, seeps out onto the surface of the ink for printing.

When the binder of the printing ink is water-soluble, a water-insoluble solvent is used as an additive. Then, by the same mechanism as described above, the water-insoluble solvent seeps out onto the surface of the printing ink and acts as a lubricant.

A water-insoluble solvent and a water-soluble solvent can be used as the main solvent and additives used in the printing ink. In general, fillers and solvents contained in printing inks used in printing methods include compositions containing compounds represented by the following structural formula (1) (excluding monohydroxystearic acid). Available.
[Chemical 1]
R1-CH2-R2 (1)
(wherein R1 represents a monohydroxyalkyl group and R2 represents a carboxyl group (C(=O)OH) or an amide group (C(=O)NH2))

Specific examples of solvents include n-heptane (SP value: 7.3), 2-(2-ethoxyethoxy)ethyl acetate (SP value: 9.0), ethylene glycol monoethyl ether acetate (SP value: 8. 8), n-propanol (SP value: 11.8), 1,2,5,6-tetrahydrobenzyl alcohol (SP value: 11.3), diethylene glycol ethyl ether (SP value: 10.9), 3-methoxy butanol (SP value: 10.9), triacetin (SP value: 10.2), propylene glycol monomethyl ether (SP value: 10.2), cyclopentanone (SP value: 10.0), γ-butyrolactone (SP value: 9.9), cyclohexanone (SP value: 9.9), propylene glycol-n-propyl ether (SP value: 9.8), propylene glycol-n-butyl ether (SP value: 9.7), dipropylene Glycol methyl ether (SP value: 9.7), 1,4-butanediol diacetate (SP value: 9.6), 3-methoxybutyl acetate (SP value: 8.7), propylene glycol diacetate (SP value : 9.6), ethyl lactate acetate (SP value: 9.6), ε-caprolactone (SP value: 9.6), 1,3-butylene glycol diacetate (SP value: 9.5), dipropylene glycol -n-propyl ether (SP value: 9.5), 1,6-hexanediol diacetate (SP value: 9.5), dipropylene glycol-n-butyl ether (SP value: 9.4), tripropylene glycol Methyl ether (SP value: 9.4), tripropylene glycol-n-butyl ether (SP value: 9.3), undecane (SP value: 15.8), decane (SP value: 15.8), dodecane (SP value: 16.0), cyclohexanol acetate (SP value: 9.2), diethylene glycol monoethyl ether acetate (SP value: 9.0), ethylene glycol methyl ether acetate (SP value: 9.0), diethylene glycol monobutyl ether Acetate (SP value: 8.9), ethylene glycol monobutyl ether acetate (SP value: 8.9), methyl acetate (SP value: 8.8), ethyl acetate (SP value: 8.7), propylene glycol monomethyl ether Acetate (SP value: 8.7), n-propyl acetate (SP value: 8.7), dipropylene glycol methyl ether acetate (SP value : 8.7), 3-methoxybutanol acetate (SP value: 8.7), butyl acetate (SP value: 8.7), isopropyl acetate (SP value: 8.5), tetrahydrofuran (SP value: 8.3 ), dipropylene glycol methyl-n-butyl ether (SP value: 8.0), dipropylene glycol methyl-n-propyl ether (SP value: 8.0), dipropylene glycol dimethyl ether (SP value: 7.9), Propylene glycol methyl-n-butyl ether (SP value: 7.8), propylene glycol methyl-n-propyl ether (SP value: 7.8), dimethylsiloxane (SP value: 7.5) and the like can be mentioned.
In the present invention, the SP value is only used as a reference for the solvent to be selected, and what is important is the combination of judging whether it is water-insoluble or water-soluble and adding a solvent that is the complete opposite of the main solvent.

Regarding the definition of water-insoluble and water-soluble, the definition for water-soluble liquids of Class 4 dangerous goods is shown. Class 4 dangerous goods are flammable liquids. They are further divided into (a) those that dissolve in water (water-soluble) and (b) those that do not dissolve in water (water-insoluble).
These are defined in the ordinance as follows. The water-soluble liquid is a liquid that maintains a uniform appearance when mixed with the same volume of pure water at 1 atmosphere and 20°C. separates into two layers when mixed with If the specific gravity of the liquid is less than that of water, a water-insoluble layer will form above the water layer, and if the specific gravity of the liquid is greater than that of water, a water-insoluble layer will form below the water layer. In the case of water-soluble liquids, the mixture becomes uniform without layer separation. Some substances, such as diethyl ether, which is a special flammable substance, and ethyl acetate, which is a class 1 petroleum, are slightly soluble in water, but by definition they are classified as water-insoluble.

Therefore, when classified based on the above definition,
Water-soluble solvents include 2-(2-ethoxyethoxy)ethyl acetate (SP value: 9.0), ethylene glycol monoethyl ether acetate (SP value: 8.8), n-propanol (SP value: 11.8). , 1,2,5,6-tetrahydrobenzyl alcohol (SP value: 11.3), diethylene glycol ethyl ether (SP value: 10.9), 3-methoxybutanol (SP value: 10.9), propylene glycol monomethyl ether (SP value: 10.2), γ-butyrolactone (SP value: 9.9), propylene glycol-n-propyl ether (SP value: 9.8), dipropylene glycol methyl ether (SP value: 9.7) , ethyl lactate acetate (SP value: 9.6), ε-caprolactone (SP value: 9.6), tripropylene glycol methyl ether (SP value: 9.4), tripropylene glycol-n-butyl ether (SP value: 9.3), diethylene glycol monoethyl ether acetate (SP value: 9.0), ethylene glycol methyl ether acetate (SP value: 9.0), diethyl ether acetate (SP value: 9.0), tetrahydrofuran (SP value: 8 .3), dipropylene glycol methyl-n-butyl ether (SP value: 8.0), dipropylene glycol methyl-n-propyl ether (SP value: 8.0), dipropylene glycol dimethyl ether (SP value: 7.9 ), propylene glycol methyl-n-propyl ether (SP value: 7.8).

Water-insoluble solvents include undecane (SP value: 15.8), decane (SP value: 15.8), dodecane (SP value: 16.0), triacetin (SP value: 10.2), cyclopentanone ( SP value: 10.0), cyclohexanone (SP value: 9.9), propylene glycol-n-butyl ether (SP value: 9.7), 1,4-butanediol diacetate (SP value: 9.6), 3-methoxybutyl acetate (SP value: 8.7), propylene glycol diacetate (SP value: 9.6), 1,3-butylene glycol diacetate (SP value: 9.5), dipropylene glycol-n- Propyl ether (SP value: 9.5), 1,6-hexanediol diacetate (SP value: 9.5), dipropylene glycol-n-butyl ether (SP value: 9.4), cyclohexanol acetate (SP value : 9.2), diethylene glycol monobutyl ether acetate (SP value: 8.9), ethylene glycol monobutyl ether acetate (SP value: 8.9), methyl acetate (SP value: 8.8), ethyl acetate (SP value: 8.7), propylene glycol monomethyl ether acetate (SP value: 8.7), n-propyl acetate (SP value: 8.7), dipropylene glycol methyl ether acetate (SP value: 8.7), 3-methoxy Butanol acetate (SP value: 8.7), butyl acetate (SP value: 8.7), isopropyl acetate (SP value: 8.5), propylene glycol methyl-n-butyl ether (SP value: 7.8), dimethyl It is siloxane (SP value: 7.5).

When the total weight of the filler and binder contained in the printing ink used in this embodiment is 100 parts, the filler may be 50 to 99.9 parts. Specifically, a filler, a silver paste, a copper paste, or the like used for printing applications may be used as the main agent.

It is preferable to adjust the amount of additives in the printing ink in the range of 0.1 to 50 parts per 100 parts of the total weight of the filler and binder contained in the coating agent.

The printing ink used in this embodiment may contain a compatible solvent that has good affinity with the binder. The presence of a compatible solvent makes it possible to ensure the adhesion, electrical conductivity, electrical continuity, etc. between the mixture (main agent) of the inorganic filler or organic filler and the binder and the substrate to be printed. This is because the slipperiness can be obtained while maintaining those properties. If the addition amount is outside the above range, the chemical bonds of the main component elastomer or the like will be damaged or separated, resulting in physically fragile properties and making printing difficult. Even if it can be printed, it may lose its elastic force, or may lose its electrical conductivity and thermal conductivity significantly.

The printing ink used in the present embodiment has an effect that the lubricant in the coating material oozes out due to pressure applied to the printing ink during squeegee sweeping. Therefore, the peeling of the coating agent from the interface of the mask is facilitated, and the coating agent is transferred to the base material without causing cohesive failure, so that a wiring electrode having a substantially rectangular cross-sectional shape and an almost vertical opposing side surface can be obtained. .

<Flexible or stretchable seat>
A flexible sheet or stretchable sheet used as a base material for pattern printing according to the present invention will be described.

Flexible sheets or stretchable sheets that can be used in this embodiment include OPP (biaxially oriented polypropylene), CPP (unoriented polypropylene), HDPE (high density polyethylene), MDPE (medium density polyethylene), LDPE (low density polyethylene), L-LDPE (linear low-density polyethylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), O-NY (nylon), PA (polyamide), EVAC (EVA resin), PVC (polyvinyl chloride), SAN (AS resin), ABS (ABS resin), PMMA (methacrylic resin), PVAL (polyvinyl alcohol), PVDC (vinylidene chloride resin), PC (polycarbonate), POM (acetal resin), PBT (polybutylene terephthalate), PTFE (fluororesin), PF (phenol resin), MF (melamine resin), UF (urea resin), PUR (polyurethane), EP (epoxy resin), UP (unsaturated polyester resin), PS (polystyrene), KOP (poly vinylidene chloride-coated OPP), AL (aluminum foil), AOP (PVA-coated OPP/Torcello), PT, MST, K cellophane, VM (aluminum vapor deposition film, transparent vapor deposition film), co-extrusion film (co-extrusion) film), non-woven fabric, NR (natural rubber), IR (isoprene rubber), BR (butadiene rubber), SBR (styrene-butadiene rubber), IIR (butyl rubber), NBR (nitrile rubber), EPM, EP, EPDM (ethylene-propylene rubber) ), CR (chloroprene rubber), ACM, ANM (acrylic rubber), CSM (chlorosulfonated polyethylene rubber), PUR, U (urethane rubber), Si, Q, VMQ, SR (silicone rubber), FKM, FPM (fluorine rubber), EVA (ethylene-vinyl acetate rubber), CO, ECO (epichlorohydrin rubber), T (fluidized rubber), copper foil, etc., and can be used in the form of a laminated film of a single layer or two or more layers. In the following disclosure, when referring to a flexible sheet, it is possible to replace the flexible sheet with a stretchable sheet unless there is a special reason.

<Resistor>
Next, the resistor used in this embodiment will be described.

The resistor that can be used in the present embodiment is a resistor layer composed of a mixture of a filler and a binder and a solvent for the binder, which is dried, heat-cured, or light-cured, and is composed of a conductive organic adhesive. Examples of conductive organic adhesives that can be used include acrylic adhesives, epoxy adhesives, polyester adhesives, polyurethane adhesives, silicone adhesives, and polyimide adhesives.
As the conductivity-imparting agent, conductive particles such as carbon black particles and graphite particles can be blended, and carbon paste having PTC characteristics (positive temperature coefficient) is particularly preferable. As the application means, a doctor blade method, a screen printing method, a method of applying by spraying, or the like can be adopted.

PTC is an abbreviation for Positive Temperature Coefficient Thermal-Resistor. is called the "temperature coefficient". In other words, a substance with a high PTC has the property that when the temperature rises, it becomes difficult for electricity to flow, and when the temperature drops, it becomes easy for electricity to flow. And if this characteristic is used in a heater, when only a part of the heater becomes abnormally high temperature, it is possible to suppress heat generation only in that part and to suppress wasteful power consumption. Conversely, when the temperature is low, the resistance value is small and electricity flows easily, but when the temperature reaches a certain temperature, the resistance value rises sharply and electricity stops flowing. The temperature at this point is called the Curie point, and although the Curie point varies depending on the substance, the general operating range is about -50°C to 150°C. Therefore, even if the heating element of the present invention is incorporated into a flexible or stretchable sheet of an actuator, safety against ignition or the like is ensured.

<Insulating material>
The insulating coating material used in this embodiment will be described.

The insulating coating material that can be used in this embodiment is desirably composed of a material having sufficient heat resistance to prevent strength deterioration, deformation, melting, deterioration, burning, etc. during the desired usage time. For example, a sheet made of a polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene-terephthalate-isophthalate copolymer, polyarylate, etc., preferably a biaxially oriented sheet can be used. Alternatively, a fluororesin such as polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, or the like, a resin sheet made of a polyimide resin, or the like, an RTV silicone rubber, or the like can also be used.
A flame retardant may be added to these resins to impart flame retardancy. As the flame retardant, aluminum hydroxide, magnesium hydroxide, molybdenum oxide, diantimony trioxide and the like can be used.
These insulating films can be adhered to desired areas by methods such as heat sealing, dry lamination, and spray coating. Alternatively, a desired range can be coated by a printing method such as silk screen, gravure printing, flexographic printing, offset printing, or roll transfer printing.
As the resin binder of the ink to be used, for example, an acrylic resin, a polyester resin, a polyimide resin, a silicone resin, or the like can be used. Incidentally, the thickness of the insulating coating is preferably about 20 to 300 μm.
Next, an example for verifying the effect of this embodiment will be described.

<Printing of wiring electrodes>
A two-layer film consisting of a 200 μm-thick silicone elastomer film base material and a PET film laminated on the back side, and a stretchable silver paste “Dotite (registered trademark)” manufactured by Fujikura Kasei Co., Ltd. as an ink for printing electrode patterns. ) XA-9476” conductive ink (filler; silver binder; siloxane elastomer), ELASTOSIL (registered trademark) LR 3162 made by Asahi Kasei Wacker mainly composed of carbon as a resistor High resistance conductivity with a volume resistivity of 80 Ω cm An elastomer was prepared.

As an additive to the electrode pattern printing ink, we prepared 2-(2-ethoxyethoxy)ethyl acetate (a.k.a. diethylene glycol monoethyl ether acetate), a water-soluble solvent that is incompatible with the siloxane elastomer, and applied it to the electrode. It was mixed with an ink for pattern printing to obtain an ink for pattern printing imparted with slipperiness.
The screen printing method is adopted as the printing method, and the ink for pattern printing to which the screen printing plate is given the above-mentioned lubricity is filled in a dispenser syringe, and printing is performed while the needle of the dispenser is in contact with the screen printing plate. bottom.

FIG. 11 is a diagram showing an injection step in the present screen printing method. First, a nickel film having a thickness of 200 μm was bonded to a mesh made of metal such as nickel to prepare a screen printing plate 603 having openings of a printing pattern.
Next, a silicone elastomer film substrate 605 with a thickness of 200 μm was set on a printing stage, and a screen printing plate 603 made of a nickel film with a thickness of 200 μm was superimposed thereon so that the nickel film surface and the silicone elastomer film were in close contact with each other. .

Next, an arbitrary taper needle is attached to the lower end of the syringe 604 filled with the above-described pattern printing ink, and this taper needle is vertically applied from the metal mesh 602 side of the screen printing plate 603 with a constant pressure. By pressing, the tip opening of the tapered needle and the screen printing plate were brought into close contact without any gap. In this state, the supply pressure to the syringe 604 filled with the pattern printing ink was set at 300 kPa.

At the same time, the syringe 604 was moved in the Y-axis direction at a sweep speed of 20 mm/s over the screen plate on which the pattern to be printed was formed. After sweeping, the syringe 604 is separated from the metal mesh 602 by a fixed distance and shifted 1 mm in the X-axis direction. After that, the syringe 604 was brought into close contact with the metal mesh 602 again, and the syringe 604 was run in the Y-axis direction at a supply pressure of 300 kPa and a sweep speed of 20 mm/s. The supply pressure and sweep speed may be arbitrarily adjusted.

By repeating the running shift in the above manner, the ink for pattern printing was injected into the screen holes of the entire pattern to be printed. At this time, the supply pressure, sweep speed, shift length, etc. can be arbitrarily changed according to the printing conditions.

FIG. 12 is a diagram showing a sweeping step by a squeegee in the present screen printing method. When the syringe 604 has completely or partially filled the interspersed patterns to be filled, the squeegee 606 is tilted about 60 degrees with respect to the surface of the screen printing plate 603 and the metal mesh 602 in the Z-axis direction. Sweep with constant pressure in a direction and constant speed.

As a result, the cross-sectional shape of the groove formed on the screen printing plate 603 is transferred as it is, and the area of the substantially vertically steep opposing side surface with a substantially rectangular electrode width of about 100 μm and a height of about 200 μm with a large aspect ratio. Wide wiring pattern printing is possible.

<Concave>
Concave portions formed on the surface of the electrode when screen printing is performed using the printing ink described above will be described. 13 and 14 are diagrams showing recesses formed in screen mesh traces when the coating agent and printing method according to the present embodiment are used.

When the screen printing plate 610 shown in FIG. 13 is used, the pressure of the squeegee and the pressure of pushing back from the substrate 615 are generated at the interface H between the filled coating agent 611 and the openings 613 of the mask 612 and the screen mesh 614. A part of the additive in the coating material 611 oozes out to the surface as a lubricant, and the inner wall of the opening 613 of the mask 612, the base material 615, and the screen mesh 614 are coated with the lubricant.
This facilitates peeling of the coating agent 611 from the mask interface, and the coating agent 611 is transferred onto the substrate 615 without causing cohesive failure.

Further, when a dispenser is used as a pressure filling type pressurized container, for example, the coating agent leaked from the contact point between the screen printing plate 610 and the tip of the dispenser, or the coating agent leaked from the opening 613 of the mask. can be removed from the plate surface by sweeping with a squeegee and recovered. During sweeping with the squeegee, part of the additive in the coating material 611 oozes out as a lubricant to the crossing points with the screen mesh 614 , so that this part becomes recesses 616 .

As shown in FIG. 14, similar depressions 616 are also formed when using a screen printing plate 620 in which a metal mask 622 and a metal mesh 624 are bonded together. Hereinafter, the term "screen mesh" also includes metal mesh.

The screen mesh marks are traces that pass through the screen mesh and remain as unevenness on the surface at the intersections of the screen mesh in the printed pattern. When a conventional coating agent and conventional screen printing are used, cohesive failure occurs, and the above-described semi-cylindrical protrusions are formed in the screen mesh marks.

As a specific example, the case of using a screen plate having a mesh wire diameter of 16±2 μm and a length of one side of mesh openings of 60±2 μm will be described.

On the printed surface when the coating agent and printing method according to the present embodiment are used, the width of the screen mesh marks formed on the pattern surface is 15.8 μm, and the mesh wire diameter is 87.8% to 113%. The length of one side of the trace of the mesh opening was 63 μm, which was 101.6% to 108.6% of the length of one side of the mesh opening of the screen plate.

In addition, the screen mesh mark showed a value of 3.89 μm in the gap (height difference) between the mesh opening mark as the top (top surface) and the bottom.

From these results, in the screen printing method of the present invention, concave portions are generated when the width of mesh traces is 10 μm or more and 40 μm or less. Also, the opening marks can have a square shape with a side length of 20 μm or more and 210 μm or less. The term "square" as used herein includes not only cases where the lengths of adjacent sides are exactly the same, but also cases where the lengths of adjacent sides deviate by about ±10%. Also, the mesh portion of the screen plate may have a different shape such as parallel lines, and in this case as well, the traces of the portion corresponding to the mesh become recesses.

<Heat generating element and driving device using heat generating element>
A plurality of embodiments of the heating element and the driving device (actuator) using the heating element according to the present embodiment will be described below. However, it goes without saying that the present invention is not limited to these embodiments. In addition, in the description of the drawings, the same reference numerals are given to the same or equivalent components as those described above, and the description thereof will be simplified or omitted.

[First Embodiment]
FIG. 15 is a diagram showing a heating element and a driving device according to the first embodiment; Hereinafter, the contents of the first embodiment will be described according to the order of manufacture.
First, as the base material used in the first embodiment, two types of flexible or stretchable sheets 701 and 702 having different coefficients of linear expansion are bonded together.
Next, in this embodiment, the positive wiring electrode 703 is arranged in a form surrounded by the U-shaped negative wiring electrode 704 . Hereinafter, a wiring pattern in which one electrode is U-shaped and surrounds the other electrode inside the U-shaped wiring pattern is referred to as a "U-shaped wiring pattern". Further, the wiring electrode on the U-shaped side is called the "U-shaped side electrode", and the wiring electrode inside the "U-shaped side electrode" is called the "inner electrode". ).

Next, the resistor 204 is filled in the gap between the positive wiring electrode 703 and the negative wiring electrode 704 facing each other. After that, the positive wiring electrode 703 , the negative wiring electrode 704 and the resistor 204 are covered with an insulating coating material 705 .
As a result, the positive wiring electrode 703, the resistor 204, and the negative wiring electrode 704 are arranged on a plane, and a heat generating portion can be obtained in which these are sandwiched between the substrate and the insulating layer from above and below.
If it is desired to thermally isolate the heat-generating part from the surroundings, a cut 706 may be provided in the outer peripheral base material of the U-shaped negative electrode wiring electrode 704 .
In other words, it is possible to realize a form in which the heat generating portion protrudes as a cantilever in the area surrounded by the notch 706 .

Hereinafter, a divided area in which a structural unit in which a resistor is sandwiched between opposite side surfaces of positive and negative electrode wiring electrodes is continuously repeated in the direction perpendicular to the opposite parallel sides is referred to as a "heat generating unit". In that case, the wiring electrode pattern can be specified by the number of positive wiring electrodes and the number of negative wiring electrodes present in one heating unit (hereinafter, positive wiring electrodes or negative wiring electrodes may be simply referred to as positive electrodes or negative electrodes). .).

For example, in the wiring pattern (U-shaped wiring pattern) of the first embodiment, there is one heating unit, but the wiring pattern can be specified as a combination of one (odd number) positive electrode and two (even number) negative electrodes. .

When the wiring patterns are specified in this way, the combinations of wiring patterns include (a) a combination of an odd number of positive electrodes and an even number of negative electrodes, (b) a combination of an even number of positive electrodes and an odd number of negative electrodes, and (c) a combination of an even number of positive electrodes. There is a combination of an even number of negative electrodes, and (d) a combination of an odd number of positive electrodes and an odd number of negative electrodes.

A heating unit in which the wiring pattern of wiring electrodes takes a U-shaped wiring pattern is sometimes called a "U-shaped heating unit", and a driving body (actuator) based on the heating unit is sometimes called a "U-shaped actuator".

[Second embodiment]
FIG. 16 is a plan view showing a heating element and a driving device according to the second embodiment; This embodiment is the same as the first embodiment except that the number of electrodes in the wiring pattern is different. Constituent elements that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals, and descriptions thereof are simplified or omitted.

The wiring pattern 801 has a configuration in which three U-shaped heating units having a U-shaped wiring pattern are connected. Each U-shaped wiring pattern is composed of two positive wiring electrodes and three negative wiring electrodes. Similarly, each U-shaped wiring pattern in the wiring pattern 802 is composed of three positive wiring electrodes and four negative wiring electrodes.

In the wiring patterns 802 and 803, since each heating unit has three negative wiring electrodes connected in series, the negative electrode side is connected as a common negative electrode terminal 803, and the positive electrode side is connected to three independent positive electrode terminals 804a to 804c. It's becoming Therefore, by arbitrarily applying a voltage, it is possible to change the heat generation and the portion to be operated by input control of a sequencer or the like. In addition, the notch 805 allows each heating unit to act as an independent drive (U-shaped actuator). In addition, a terminal may be called a drive terminal.

By increasing the number of wiring electrodes, the amount of current flowing through one heating unit increases, and the amount of heat generated also increases. If possible, it is preferable that the line width of the wiring electrode arranged on the outermost side is made wider than the line width of the electrode having a smaller number of lines.

<Manufacturing method>
A manufacturing method of the second embodiment will be described. First, by the present screen printing method, a wiring pattern 801 in which three heat generating units each composed of two positive electrodes and three negative electrodes were connected was printed on a base material. Each electrode has a width of 200 .mu.m and a height of 153 .mu.m. Once in that state, it was calcined at 90° C. for 30 minutes and at 160° C. for 60 minutes.

As the base material, a flexible sheet 701 made of a PET film with a thickness of 100 μm (linear expansion coefficient: 6.5 (×10 −5 /° C.)) and a silicone elastomer film with a thickness of 200 μm (linear expansion coefficient: 40 (×10 −5/° C.)))), and flexible sheets having different linear elongations against heat, such as the flexible sheet 702, were pasted together to form a base material.

The flexible sheet 702 may be made of polyurethane (linear expansion coefficient: 20 (×10 −5 /° C.)) or polyvinylidene chloride (linear expansion coefficient: 19 (×10 −5 /° C.)) in addition to silicone. A film can also be adopted depending on the application and design. Moreover, in order to enhance the heat radiation effect, a metal sheet such as an aluminum foil or a copper foil may be added to bond two or more layers of sheets together. Alternatively, the metal sheet can be used instead of PET.

Next, as the resistor 204, ELASTOSIL (registered trademark) LR 3162 manufactured by Asahi Kasei Wacker Co., Ltd., a high-resistance conductive elastomer mainly composed of carbon and having a volume resistivity of 80 Ω·cm, is injected into the electrode gap between the two positive electrodes and the three negative electrodes. do. In this way, the resistor 204 was made into a shape in which three filled states of 6 mm length were connected by scraping the electrode height along the electrode length direction, and baked at 100° C. for 60 minutes.

Next, KER-4690 (A/B) manufactured by Shin-Etsu Chemical Co., Ltd. was coated as a flexible UV photosensitive insulating coating material 705 to a thickness of about 10 microns, and cured with UV light having a wavelength of 365 nm.

Similarly, the wiring pattern 802 shown in FIG. 16, in which three U-shaped heating units each having three positive electrodes and four negative electrodes are connected, was also subjected to UV curing treatment by the above method.

Next, in the wiring patterns 801 and 802, a total of four cuts 805 are made between and outside the three connected heat generating units with a cutter so as to penetrate to the back of the substrate, and the heat generating units are cut perpendicular to the cuts 805. Incisions 706 were made so as to separate the three head sides of each of them, and a heat generating element composed of three independent heat generating units was formed.

<Action/effect>
In order to observe the operation of one heating unit, the temperature rise when a DC voltage of 5 V was applied to the positive terminal 804a and the negative terminal 803 was monitored with a thermocouple fixed on the resistor 204 with polyimide tape.

FIG. 17 is a comparison diagram of temperature rise graphs of a heating element with a wiring electrode pattern according to the present invention and a heating element with a conventional wiring electrode pattern.
The heating element according to the present invention has wiring patterns 801 and 802, and the conventional heating element has the wiring pattern 801 printed by screen printing, which is used in conventional electrode printing.

As can be seen from FIG. 17, the temperatures of all the three heating elements formed this time did not rise once they reached a constant temperature. Therefore, it can be seen that this heating element has a PTC characteristic.

Further, in a comparison with the wiring pattern 801, the heating element formed by the present screen printing method, which has an electrode width of 200 μm, a height of 153 μm, and wiring electrodes with substantially vertical opposite sides, has a steep temperature rise of 60° C. at an application time of 10 seconds. , and the temperature after 120 seconds in the PTC characteristic was 76.9°C. The heating element exhibited a fairly slow temperature rise of 24.6° C. at an application time of 10 seconds, and the temperature remained at a low temperature of 26.4° C. after 120 seconds in PTC characteristics.

A comparison of the wiring patterns 801 and 802 showed almost the same sharp temperature rises of 60° C. and 60.1° C., respectively, at an application time of 10 seconds. However, the temperature after 120 seconds in the PTC characteristic was 76.9° C. for the wiring pattern 801 and 83° C. for the wiring pattern 802, resulting in a difference of about 6° C. It can be inferred that this difference is caused by the fact that the number of positive and negative electrodes is increased by one. In other words, the heating element of this embodiment can control the amount of heat generated by the PTC characteristic by changing the number of electrodes.

Furthermore, in the wiring pattern 802, an object was placed on the tip of the heating unit so that the operation could be observed, and when the positive electrode terminal 804a and the negative electrode terminal 803 were turned on and off by applying a DC voltage of 5 V, the operation was observed. Approximately 2 mm warped operation was confirmed with a stroke of . In this way, we were able to create an agile driving device (actuator) that generates warpage with bimetal-like motion.

[Application example 1 of the second embodiment]
FIG. 18 is a plan view of an LED flicker 806 to which the second embodiment is applied. Descriptions of components that are the same as or equivalent to those of the second embodiment will be simplified or omitted.

A terminal on one side of the LED chip 807 is adhered to the tip of the U-shaped actuator with a conductive adhesive, and the wiring of the opposite polarity (negative if positive) is in contact with the other terminal that is not adhered to the LED chip. , and cut around each U-shaped actuator. Wiring resistance may be adjusted so that a general LED rated current of 20 mA flows.

The heating element side is forcibly distorted upward by about 1 mm to create a state in which it is not connected to the opposite side. When the circuit is energized, the current does not flow to the LED at first, and the temperature of the heating element rises, forcing the part that is distorted by about 1 mm to warp downward and conduct to the wiring placed on the opposite side. As a result, a current flows in the opposite direction and the LED lights up. As a result, the amount of current flowing through the heating element decreases, the temperature of the heating element decreases, and the downward warp returns upward, cuts off the current to the LED, and extinguishes the light. As a result, the amount of current flowing to the heating element increases again, the downward warp increases, and the LED lights up. It becomes an automatic flasher (flicker) that automatically repeats this operation.

[Application example 2 of the second embodiment]
FIG. 19 is a plan view of a butterfly device 808 to which the second embodiment is applied. Descriptions of components that are the same as or equivalent to those of the second embodiment will be simplified or omitted.
By connecting a plurality of U-shaped actuators and arranging, for example, symmetrically cut blocks around the U-shaped actuators, each actuator can be operated independently. This makes it possible to flap its wings like a butterfly or a dragonfly, or walk like a centipede. Also, by incorporating variations in the wiring pattern, it is possible to add twist to each actuator, enabling more complicated flapping and walking movements.

[Third embodiment]
An embodiment of the present invention in which electrode patterns are arranged in a circle as an actuator that connects a plurality of U-shaped wiring patterns is shown.
In the present embodiment, arranging in a circle means that the longitudinal direction of the U-shaped wiring pattern is arranged at approximately equal intervals in the radial direction from the center of the circle toward the outer periphery, forming a circle as a whole. means that it is arranged as

In the first place, when 8 U-shaped wiring patterns are evenly arranged on a circle, if lead wires and terminals corresponding to the U-shaped side electrode and the inner electrode of each U-shaped wiring pattern are provided in a one-to-one correspondence, 8× Since 2=16 terminals are required, the number of terminals increases, and furthermore, there arises a problem that the positive or negative lead wire cannot be led out from the center of the pattern to the outside on one substrate.

FIG. 20 is a plan view showing a heating element and driving device according to the third embodiment.

The circular wiring pattern 1001 of this embodiment can be connected, for example, from the terminal 1001e to the connection portion 1001e (X) where the U-shaped side electrodes of the adjacent U-shaped wiring patterns are joined. Also, the terminal 1001f can be connected to the connection portion 1001f (X) where the inner electrodes of adjacent U-shaped wiring patterns are joined. Here, one of the two U-shaped electrodes joined to the connecting portion 1001e (X) is positioned clockwise, and one of the two inner electrodes joined to the connecting portion 1001f (X) is counterclockwise. Those positioned on one side of the circumference face each other to form a heat generating unit.

Similarly, of the two U-shaped electrodes joined to the connecting portion 1001g (X), the one positioned counterclockwise and the two inner electrodes joined to the connecting portion 1001f (X) Those located on one side of the clockwise direction face each other to form a heat generating unit.

In this manner, the specifications are such that the positive electrode and the negative electrode join hands in a circle while shifting the phases by one pair.
A resistor is inserted into the gap between the positive electrode and the negative electrode of each U-shaped wiring pattern to form a heating unit. An insulating coating material covers the wiring electrodes and resistors, and a U-shaped notch 706 is formed on the outer circumference of each U-shaped wiring pattern.

Next, a DC voltage of 5 V was applied to the terminal 1001e as the positive electrode and the terminal 1001f as the negative electrode.
In this case, only the resistor 1002ef generates heat. In order to heat only the resistor 1002fg on the U-shaped pattern that is adjacent in the clockwise direction, a DC voltage of 5 V is applied to the terminal 1001f as the negative electrode and the terminal 1001g as the positive electrode.

In this manner, when the 5 V application is shifted in the order of terminal 1001g positive electrode, terminal 1001h negative electrode, terminal 1001a positive electrode, terminal 1001b negative electrode, terminal 1001c positive electrode, terminal 1001d negative electrode, and terminal 1001e positive electrode, they are arranged in a circle. The U-shaped wiring pattern has become an actuator that warps the outer circumference of the circle clockwise one by one. Therefore, depending on the combination of the voltages applied to each of them, it can also be an actuator that can rotate in the opposite direction, bend in half, bend in 45-degree increments, and create any combination of bending patterns.

In this embodiment, a drive terminal of a first polarity (meaning positive or negative) is adjacent to a drive terminal of a second polarity having a different polarity (“adjacent” means drive terminals placed at both ends). including relationships between them). The driving terminals of the first polarity are connected to the wiring electrodes in the U-shaped wiring patterns of the clockwise and counterclockwise U-shaped heating units adjacent to each other, and the driving terminals of the second polarity are connected to each other. The clockwise wiring electrode and the second polarity are connected to the wiring electrodes in the U-shaped wiring patterns of the adjacent clockwise and counterclockwise U-shaped heating units, and are connected to the driving terminals of the first polarity. The counterclockwise wiring electrodes connected to the drive terminals of 1 and 2 constitute wiring electrodes facing each other in the same U-shaped wiring pattern.

[Fourth Embodiment]
In the third embodiment, the actuators are circular and have a pattern in which the outer side of the circle is bent at every phase of 45 degrees.

FIG. 21 is a plan view showing a heating element and driving device according to the fourth embodiment.

The circular wiring pattern 1101 has an appearance in which fan-shaped heat generating units each having a shape in which the center angle of a circle is substantially evenly divided (for example, approximately equal to six) are arranged in a circle. The wiring pattern in each heat generation unit is arranged such that positive and negative wiring electrodes are alternately arranged in a comb shape from near the center to near the outer periphery with a certain gap so as to follow the circular arc shape that is the outer periphery of the fan shape. (hereinafter referred to as "fan-shaped wiring pattern"). A resistor is inserted into the gap to form a heating unit (hereinafter referred to as a "fan-shaped heating unit"). Although an even number of heat generating units is desirable, the number is not limited to this.

According to this embodiment, for example, from the terminal 1101d, the positive electrodes of two heat generating units adjacent to each other can be connected to the connection portion 1101d (Y) near the maximum sectoral arc. Further, from the terminal 1101c, the negative electrodes of the two heat generating units adjacent to each other can be connected to the connecting portion 1101c (Y) near the maximum sectoral arc.

In this manner, one terminal is connected to the positive or negative wiring electrodes of the two heat generating units adjacent to each other through the connecting portion located near the maximum sectoral arc. For example, positive electrodes and negative electrodes such as a terminal 1101d positive electrode, a terminal 1101c negative electrode, a terminal 1101b positive electrode, a terminal 1101a negative electrode, a terminal 1101h positive electrode, a terminal 1101g negative electrode, a terminal 1101f positive electrode, and a terminal 1101e negative electrode are arranged alternately while being adjacent to each other. A resistor is inserted into the gap between the positive electrode and the negative electrode of each fan-shaped wiring pattern to form a heating unit. An insulating coating material covers the wiring electrodes and resistors, and there are radial cuts 1103 from the circle center.

Next, a DC voltage of 5V was applied to the terminal 1101d as the positive electrode and the terminal 1101c as the negative electrode.
In this case, only the resistor 1102cd on the fan-shaped pattern generates heat, and in order to heat only the resistor 1102bc on the fan-shaped pattern adjacent in the clockwise direction, a DC voltage of 5V is applied to the negative electrode of the terminal 1101c and the positive electrode of the terminal 1101b. will be applied.

In this manner, the terminals 1101b positive, 1101a negative, 1101h positive, 1101g negative, 1101f positive, 1101e negative, and 1101d positive are shifted in this order to form a circle. The fan-shaped block became an actuator that warps the inside of the circle clockwise one by one.

This is because the fan-shaped comb-shaped electrode is formed with a longer circular arc toward the outside of the circle, so the heat generation area of the resistor is large at that point, and the amount of strain on the outside where the heat value is larger than that at the center of the arc is large. This is because the central portion can largely warp starting from the heat generating portion on the outside.

Therefore, as in the third embodiment, depending on the combination of voltages applied to each, the actuator can rotate in the opposite direction, warp in half, warp in 45-degree increments, and create any combination of warping patterns.

In this embodiment, a drive terminal of a first polarity (meaning positive or negative) is adjacent to a drive terminal of a second polarity having a different polarity (“adjacent” means drive terminals placed at both ends). including relationships between them). The drive terminals of the first polarity are connected to the wiring electrodes in the fan-shaped wiring patterns of the clockwise and counterclockwise fan-shaped heating units adjacent to each other, and the drive terminals of the second polarity are adjacent to each other. It is connected to the wiring electrodes in the fan-shaped wiring patterns of the clockwise and counterclockwise fan-shaped heating units, and to the clockwise wiring electrode connected to the first polarity drive terminal and the second polarity drive terminal. The counterclockwise wiring electrodes to be connected constitute wiring electrodes facing each other in the same fan-shaped wiring pattern.

[Fifth embodiment]
The fifth embodiment differs from the above-described first to fourth embodiments in that the drive device is driven by the vapor pressure when the liquid is heated and vaporized by the heating element according to this embodiment. In the following description, the same reference numerals are given to components that are the same as or equivalent to those of the above-described embodiment, and the description thereof will be simplified or omitted.

An example of an application field of the present embodiment is a rewritable Braille display device. Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 2-160278, the movable iron core is moved up and down by the electromagnetic attraction force of the solenoid to display Braille, and as disclosed in Japanese Patent Application Laid-Open No. 10-74039, light It is known to display braille by using heat and expansion due to light supplied from a semiconductor laser light source. However, these have had problems in terms of the size and operating noise of the solenoid, the size of the assembly of the optical semiconductor laser light sources, and the price. On the other hand, according to the present embodiment, space-saving, low-cost driving without operation noise is possible, and application to a rewritable Braille display device, an angle adjusting device such as a polarizing plate, and the like is conceivable.

<Balloon Capillary>
FIG. 22 is a longitudinal cross-sectional view of the balloon capillary tube 1200 according to the fifth embodiment. The "balloon capillary tube 1200" comprises a balloon part 1201 and a capillary tube part 1202, and has a structure in which the end of the capillary part 1202 opposite to the balloon part 1201 is closed and sealed. It is filled with a low boiling point solvent that vaporizes or thermally expands at a low temperature. The low boiling point solvent is preferably an organic solvent such as ethanol, or a fluorine-based inert liquid that is safer and does not corrode. Note that the liquid is not shown in some cases for the sake of convenience.

<Material>
Materials that can be used for the balloon part or the capillary part in this embodiment include CPP (unstretched polypropylene), HDPE (high density polyethylene), MDPE (medium density polyethylene), LDPE (low density polyethylene), L-LDPE (linear low-density polyethylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), O-NY (nylon), PA (polyamide), EVAC (EVA resin), PVC (polyvinyl chloride), SAN (AS resin), ABS (ABS resin), PMMA (methacrylic resin), PVAL (polyvinyl alcohol), PVDC (vinylidene chloride resin), PC (polycarbonate), POM (acetal resin), PBT (polybutylene terephthalate), PTFE (fluororesin), PF ( phenol resin), MF (melamine resin), UF (urea resin), PUR (polyurethane), EP (epoxy resin), UP (unsaturated polyester resin), PS (polystyrene), KOP (polyvinylidene chloride coated OPP), AL (aluminum foil), A-OP (PVA coated OPP/Tohcello), PT, MST, K cellophane (cellophane), VM (aluminum vapor deposition film, transparent vapor deposition film), co-extrusion film (co-extrusion film), NR ( natural rubber), IR (isoprene rubber), BR (butadiene rubber), SBR (styrene-butadiene rubber), IIR (butyl rubber), NBR (nitrile rubber), EPM, EP, EPDM (ethylene-propylene rubber), CR (chloroprene rubber) , ACM, ANM (acrylic rubber), CSM (chlorosulfonated polyethylene rubber), PUR, U (urethane rubber), Si, Q, VMQ, SR (silicone rubber), FKM, FPM (fluororubber), EVA (ethylene vinyl acetate rubber), CO, ECO (epichlorohydrin rubber), T (polysulfide rubber), etc., and can be processed from single-layer or multi-layer films and tubes. In particular, if VM (aluminum vapor deposition film, transparent vapor deposition film) with gas barrier properties is used, it is possible to maintain the gas enclosed in the balloon for a long period of time. Elasticity and flexibility can be imparted by using these materials.

<Manufacturing method>
An example of a method for manufacturing the balloon capillary tube 1200 of this embodiment will be described.
Prepare a polyolefin heat-shrinkable tube with a diameter of about 1.2 mm, heat the entire tube moderately with a burner, shrink the entire tube to about 0.5 mm in diameter, and then iron one end of the tube at a high temperature. It was sandwiched and welded so that there would be no air leakage. The vicinity of the welded tube is pinpointed with a burner, melted, and compressed air is instantaneously sent from the other open end of the tube to expand the melted portion as a balloon portion 1201 having a diameter of 3 mm. (inflation method). At this time, the film of the balloon portion 1201 becomes thinner as it expands, and has a film thickness suitable for repeated expansion and contraction.

The "inflation method" is generally a type of extrusion molding, and is a method specialized for molding resin (plastic) bag-shaped films. Blow in cold air to expand it to a certain size and shape it into a bag. Besides single layers, it is also possible to form multilayer films by coextrusion.

Next, prepare a beaker filled with ethanol, immerse the above-processed tube in ethanol, and after confirming in particular that the other end of the opened tube is not exposed to the liquid surface, remove the beaker to a vacuum deaerator. It was placed inside the beaker, a vacuum state of 0.1 Mpa was created, and it was confirmed that all the air inside the tube inside the beaker was discharged outside the tube. Then, the tube was filled with ethanol by returning the vacuum state to the atmospheric pressure state.

Next, the tube filled with ethanol was taken out, and while the balloon portion 1201 was crushed with a clip, the opened other end of the tube was clamped with an iron heated at a high temperature and sealed to form a capillary portion 1202 . At this time, the balloon remains in a collapsed or deflated state.

<Balloon drive unit>
A balloon capillary tube 1200 is fixed to the heating unit according to the invention. The combination of one heating unit and a balloon capillary fixed thereto is referred to in this disclosure as a "balloon drive unit." FIG. 23 is a schematic diagram of an example of the balloon drive unit 1203. As shown in FIG. A heating unit 1204 having a positive wiring electrode 703, a negative wiring electrode 704, and a resistor 204 similar to those shown in FIG. Fixing is performed with a UV curable resin or the like. The base material 1205 is a resin base material. In this embodiment, the notches 1206 are provided for heat dissipation.

<How to drive>
A method of driving the balloon driving unit 1203 will be described. FIG. 24 is a schematic diagram showing how the balloon driving unit 1203 is driven. A heating unit 1204 composed of electrodes and resistors similar to those in the second embodiment was used except that a resin base material having a film thickness of 200 μm was used as the base material 1205 . The heating unit 1204 is fixed to the capillary tube part 1202 near the end of the capillary tube part 1202 opposite to the balloon part 1201 . Ethanol was used as liquid 1210 . Then, the operation when a voltage of 5 V was applied to the positive wiring electrode 703 and the negative wiring electrode 704 of the heating unit 1204 was observed.

FIG. 24(a) shows the state when the switch is opened and no voltage is applied to the positive wiring electrode 703 and the negative wiring electrode 704. FIG. The surface temperature of the heating unit 1204 is 22.5° C., and the liquid 1210 in the balloon capillary tube 1200 is completely filled.

FIG. 24(b) shows the state when the switch is closed and a voltage of 5 V is applied to the positive wiring electrode 703 and the negative wiring electrode 704. FIG. When the electric current flows through the heating unit 1204 for 10 seconds, the temperature of the heating element 701 reaches about 80° C., and the liquid 1210 (ethanol: boiling point is 78.37° C.) existing at the end of the capillary tube portion 1202 near it boils and vaporizes. By doing so, it becomes steam 1211 and expands inside the pipe. The vapor pressure of the vapor 1211 pushes the unvaporized liquid 1210 (ethanol) toward the balloon section 1201 . As a result, ethanol flowed into the deflated balloon portion 1201, and the balloon portion 1201, whose stress had been reduced due to the thinning of the polyolefin film due to the encapsulation of compressed air, was pushed outward and expanded.

FIG. 24(c) shows the state when the switch is opened again and no voltage is applied to the positive wiring electrode 703 and the negative wiring electrode 704. FIG. At this time, since the temperature of the heating unit 1204 is below the boiling point, the vapor 1211 is liquefied and the atmospheric pressure applied to the balloon portion 1201 causes the liquid 1210 (ethanol) in the balloon portion 1201 to flow back, and the balloon portion 1201 deflates again. It was confirmed.

<Action/effect>
According to the balloon drive unit 1203 according to the present embodiment, since heating is performed by the heating unit 1204 according to the present invention in the vicinity of the end of the capillary portion 1202, the local temperature reaches a high temperature instantaneously and the inside of the capillary portion 1202 is heated. Since it is possible to increase the internal pressure and inflate the balloon portion 1201, driving by inflating and deflating the balloon portion 1201 can be realized efficiently in a space-saving manner.
In addition, in this embodiment, instead of directly heating the balloon portion 1201 with a heating element, it is possible to perform remote control to heat the vicinity of the end of the capillary portion 1202 on the opposite side of the balloon portion 1201. Even if the balloon portion 1201 is touched, it is possible to prevent burns due to the heat of the isolated heating element.

<Modified example of the fifth embodiment>
In the balloon capillary tube 1200 of the fifth embodiment described above, the balloon part 1201 and the capillary tube part 1202 are integrally molded of resin, but part of the capillary tube part 1202 is made of a heat-resistant material such as iron, aluminum, or stainless steel. And it can be replaced by a metal tube with good thermal conductivity (hereinafter referred to as "metal capillary portion"). FIG. 25 is a longitudinal cross-sectional view of a modification of the balloon capillary tube 1200 according to the fifth embodiment. A balloon capillary tube 1200 of Modified Example 1 shown in FIG. Each member is fixed by a means such as fusion bonding, and the end of the second metal capillary portion 1213 on the side opposite to the balloon portion 1201 is covered with resin, filled, and fused and sealed. However, the fixing and sealing means are not limited to these.

<Manufacturing method>
An example of a method for manufacturing the balloon capillary tube 1200 of Modification 1 of the present embodiment will be described.
The tip of the first SUS tube (first metal capillary portion 1212) with an outer diameter of 1.27 mm is covered with a lid-shaped polyolefin resin with an inner diameter of 1.2 mm, melted with a burner, and the tip of the first SUS tube is capped.

Next, while heating the lid-shaped polyolefin resin and the first SUS pipe with a burner, compressed air is blown into the first SUS pipe from the open end, so that the lid-shaped polyolefin resin expands to form the balloon portion 1201. rice field.

Next, the first SUS tube is cut at a distance of 10 mm from the balloon, and a polyolefin tube (capillary tube portion 1202) is put over the cut first SUS tube and cut at a length of 500 mm. Then, a burner was applied to the covered portion to fuse at the fused portion 1214 .

Next, a second SUS tube (second metal capillary portion 1213) having a length of 5 mm was inserted into the end of the polyolefin tube that had not yet been fused, and the inserted portion was similarly hit with a burner to fuse at the fused portion 1215. I put it on.
Here, the first SUS tube and the second SUS tube were connected to both ends of the 500 mm polyolefin tube. Since the polyolefin tube is heat-shrinkable, if a burner is applied to the entire polyolefin tube to prevent holes, scorching, etc. from occurring, When the diameter of 1.2 mm shrinks to a diameter of 0.6 mm, the tube becomes more susceptible to capillary action.

Next, a beaker filled with ethanol is prepared, the above-mentioned object to be processed is immersed in ethanol, and after confirming that the open end of the second SUS tube is not exposed to the liquid surface, the beaker is vacuum degassed. The beaker was put into the apparatus, a vacuum state of 0.1 Mpa was created, and it was confirmed that all the air inside the object to be processed in the beaker was discharged to the outside. Next, by returning the vacuum state to the atmospheric pressure state, ethanol was filled in the object to be processed.

Next, the object to be processed filled with ethanol was taken out, and with the balloon portion 1201 crushed with a clip, the open end of the second SUS pipe was covered with an epoxy resin, the hole was filled and fused to seal at the sealing portion 1216 . .

<Action/effect>
In the balloon driving unit 1203 using the present modified example 1, the second metal capillary portion 1213 is heated. This has the effect of speeding up the thermal reactivity of the portion 1201 .
Further, by interposing the first metal capillary portion 1212 between the balloon portion 1201 and the capillary portion 1202, the formation and size adjustment of the balloon portion 1201 can be easily performed, and the manufacturing efficiency is improved.

A balloon capillary tube 1200 of Modified Example 2 shown in FIG. different. Further, the balloon capillary tube 1200 of Modified Example 3 shown in FIG. different from 1.

<Application example of the fifth embodiment>
FIG. 26 is a schematic diagram of a braille display device 1300 to which the fifth embodiment is applied. Descriptions of components that are the same as or equivalent to those of the first to fifth embodiments will be simplified or omitted.

A plurality of (12 in FIG. 26) U-shaped heat generating units are formed on one sheet-like base material 1205 . The wiring pattern formed on the substrate is the same as that of the second embodiment except that the number of electrodes is different. In addition, cutouts 1206 for heat dissipation are formed in the gaps between the U-shaped heat generating units. A second metal capillary portion 1213 made of, for example, a SUS tube is fixed on each U-shaped heat generating unit, and a capillary portion 1202 and a balloon portion 1201 are connected to form a balloon driving unit 1203 . However, it goes without saying that the balloon capillary tube 1200 can have the configuration of this embodiment or other modifications.

A balloon portion 1201 of each balloon capillary tube 1200 is incorporated in a board 1301 having a hole, and by touching the hole with a finger, expansion and contraction of the balloon portion 1201 are transmitted to a person as a tactile sensation. Since the board 1301 in which the balloon part 1201 is incorporated is separated from the heating element and can be driven by remote control, there is no fear of getting burned by touching the board. In addition, by imparting flexibility to the capillary portion 1202, flexibility can be imparted to the arrangement of the base material 1205 and the board 1301. FIG.

A plurality of substrates 1205 (three in FIG. 26) on which a plurality of balloon drive units 1203 are formed are stacked with a certain gap, and each balloon portion 1201 is incorporated in a predetermined location on a board 1301 to form an arbitrary dot. A Braille display of numbers can be formed. However, the substrates do not necessarily have to be overlapped, and may be arranged as appropriate according to the design.

<Action/effect>
Since the Braille display device according to this application example drives a local portion using a heating element capable of rapidly generating heat with low power and a balloon capillary tube, space can be saved. In addition, it is possible to increase the number of Braille dots in a given area, enabling more complex and advanced Braille expression. Needless to say, such applications are applicable not only to Braille display devices but also to other fields.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Various changes are possible in

For example, it goes without saying that the heating element/driving device can be designed by adjusting the electrode line width, pitch, aspect ratio, etc. of the wiring electrodes within the scope of the present invention.

The wiring pattern is not limited to a U-shaped wiring pattern or fan-shaped wiring pattern, and the number of positive electrodes and the number of negative electrodes of the heating unit can be any even or odd number.

DESCRIPTION OF SYMBOLS 200... Heat generating element 202... Positive wiring electrode 203... Negative wiring electrode 204... Resistor 206, 207... Opposite side surface 301... Base material 302... Spacing 303... Spacing
500: heating element 502: positive wiring electrode
503 Negative wiring electrode 506, 507 Opposing side 602 Metal mesh 603 Screen printing plate 604 Syringe 605 Base material 606 Squeegee 610, 620 Screen printing plate 611 Coating agent 612 Mask 613 Opening 614 Screen mesh 615 Base material 616 Recess 622 Metal mask 624 Metal mesh 701, 702 Flexible sheet 703 Positive wiring electrode 704 Negative wiring electrode 705 Insulating coating material 706 Notches 801, 802 Wiring pattern 803 Negative terminal 804a, 804b, 804c Positive terminal 805 Notch 806 LED flicker 807 LED chip 808 Butterfly device 1001 Circle wiring pattern
1001a to 1001h...Terminals 1001e(X), 1001f(X), 1001g(X)...Connecting portions
1002ef, 1002fg... resistor 1101... circular wiring patterns 1101a to 1101h... terminals
1101c (Y), 1101d (Y) ... connection part
1102bc, 1102cd... Resistor 1103... Notch 1200... Balloon capillary tube 1201... Balloon part 1202... Capillary tube part 1203... Balloon driving unit 1204... Heat generating unit 1205... Base material 1206... Notch 1210... Liquid 1211... Vapor, 1212 First metal capillary portion 1213 Second metal capillary portion 1214, 1215 Fusing portion 1216 Sealing portion 1300 Braille display device 1301 Board

Claims (11)

a base material, a positive electrode wiring electrode and a negative electrode wiring electrode formed on the base material and facing each other, and a resistor formed between the positive electrode and the negative electrode wiring electrode facing each other,
The positive and negative wiring electrodes have a slope angle of 70 degrees or more on the opposing side surfaces and have a recessed portion on the upper surface.
A heating element characterized by: 2. The heating element according to claim 1, wherein said wiring electrodes have an electrode width of 100 to 200 μm and a pitch of 1 to 2 times as long as said electrode width. 3. The heating element according to claim 1, wherein the wiring electrodes have an aspect ratio of 0.5-4. The heating element according to any one of claims 1 to 3, wherein the recess has a width of 10 to 40 µm. The base material is a flexible sheet formed by laminating two or more layers of sheets having different coefficients of linear expansion,
5. The driving device using the heating element according to claim 1, wherein the heating unit has a cutout around it. 6. The driving device according to claim 5, wherein the wiring pattern of the positive wiring electrode and the negative wiring electrode is a U-shaped wiring pattern. Multiple U-shaped heat generating units are arranged in a circle,
the driving terminals of the first polarity are connected to the wiring electrodes in the U-shaped wiring patterns of the clockwise and counterclockwise U-shaped heating units adjacent to each other;
A second polarity drive terminal having a different polarity is adjacent to the first polarity drive terminal,
the drive terminals of the second polarity are connected to the wiring electrodes in the U-shaped wiring patterns of the clockwise and counterclockwise U-shaped heating units adjacent to each other;
The clockwise wiring electrode connected to the drive terminal of the first polarity and the counterclockwise wiring electrode connected to the drive terminal of the second polarity are wiring electrodes facing each other in the same U-shaped wiring pattern. consists of
7. The driving device according to claim 6, characterized in that: The wiring pattern of the positive wiring electrode and the negative wiring electrode is a fan-shaped wiring pattern,
Multiple fan-shaped heat generating units are arranged in a circle,
the drive terminals of the first polarity are connected to the wiring electrodes in the fan-shaped wiring patterns of the clockwise and counterclockwise fan-shaped heating units adjacent to each other;
A second polarity drive terminal having a different polarity is adjacent to the first polarity drive terminal,
the drive terminals of the second polarity are connected to the wiring electrodes in the fan-shaped wiring patterns of the clockwise and counterclockwise fan-shaped heating units adjacent to each other;
The clockwise wiring electrode connected to the drive terminal of the first polarity and the counterclockwise wiring electrode connected to the drive terminal of the second polarity are wiring electrodes facing each other in the same fan-shaped wiring pattern. consists of
6. The driving device according to claim 5, characterized in that: a balloon capillary comprising a balloon portion and a capillary portion, wherein the end of the capillary portion opposite to the balloon portion is closed and sealed and filled with a low boiling point solvent;
5. The driving device using a heating element according to claim 1, wherein said balloon capillary tube is fixed so that an end portion of said capillary tube portion opposite to the balloon portion is in close contact with a heating unit. 10. The drive according to claim 9, wherein at least a portion of the end on the side of the balloon portion or a portion of the end on the side opposite to the balloon portion of the capillary portion is composed of a metal capillary portion made of metal. Device. 11. The structure of claim 9 or 10, characterized in that a plurality of said substrates each provided with a plurality of balloon drive units each comprising a combination of said heat generating unit and said balloon capillary tube fixed to said heat generating unit are arranged. The driving device according to any one of Claims 1 to 3.

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