JP2010282943A - Extrafine-wire pair-stranded cable with shield - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extrafine-wire pair-stranded cable with a shield, the cable keeping the shield of the pair-stranded cable in a round shape, excellent in shielding properties and elasticity with light weight, and capable of being easily manufactured. <P>SOLUTION: The extrafine-wire pair-stranded cable with a shield is equipped with: a linear body made of low-dielectric-constant resin existing in the center part; two conductive linear bodies in contact with the linear body in the center part but not in contact with each other; and a plurality of low-dielectric-constant-resin linear bodies in contact with the linear body in the center part. The two conductive linear bodies and the plurality of low-dielectric-constant-resin linear bodies are in contact with each other and are twisted so as to surround the one low-dielectric-constant-resin linear body. An insulation coating layer of low dielectric constant is provided at an outer periphery of a whole body consisting of the two conductive linear bodies and the plurality of low-dielectric-constant-resin linear bodies, and a plating shield is formed at an outer periphery of the insulation coating layer. Further, a protection coating layer is formed at an outer periphery of the shield. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a shielded ultrafine wire-paired cable, and more particularly to a shielded ultrafine wire-paired cable that is excellent in shielding properties, excellent in bending resistance, and can be easily manufactured at a light weight.

  The reason why noise is mixed in the signal is that electromagnetic waves reach the conducting wire carrying the signal from the outside. When the line of magnetic force across the conductor increases or decreases, a force called electromotive force is generated. This electromotive force causes an extra current to flow through the pair of wires, which becomes noise mixed in the signal to be transmitted.

  One method for preventing noise is a shield that covers a conductor with a conductor so that electromagnetic waves from outside do not enter (see, for example, Patent Documents 1 and 2). The electromotive force is generated outside the conductor pair and escaped.

  On the other hand, the twisted cable counteracts the influence of electromagnetic waves by twisting together a pair of conducting wires (see, for example, Patent Document 3). When the lead wire is rotated halfway, the influence of electromagnetic waves works in the opposite direction to the part before half rotation. If the conductor is twisted, it cancels out the electromotive force generated at the position where the position is slightly shifted, so that no extra current flows and noise is less likely to occur.

  Further, the twisted cable has an effect of preventing a phenomenon called “crosstalk” in which electromagnetic waves generated from adjacent signal lines become noise sources. Crosstalk is caused by the generation of magnetic field lines around the current flowing through the conductor. However, if the pair of conducting wires is twisted together, the direction of the generated magnetic field lines is reversed every half rotation and cancels out, so that the magnetic field lines that go out decrease. As a result, crosstalk is less likely to occur.

  There has also been proposed a technique for further suppressing noise generation by further providing a shield around a twisted cable (for example, see Patent Document 4).

JP 2001-195924 A JP 2008-004275 A Japanese Patent No. 3918067 Japanese translation of PCT publication No. 2003-508882

  However, when the twisted cable is shielded, the shield becomes elliptical along the twist. As described above, when the shield is in an elliptical state along the twist, there is a disadvantage that the attenuation amount with respect to the high-frequency signal is increased.

  An object of the present invention is to provide a high-frequency shielded ultrafine wire pair-twisted cable that can keep a shield of a twisted cable in a circular shape, has excellent shielding properties and bend resistance, and can be easily manufactured at a light weight. It is in.

  The inventors of the present invention achieve the above object by concentrically twisting two conductive linear bodies and a plurality of low dielectric constant resin linear bodies around a central low dielectric constant resin linear body. It was found that this was achieved, and the present invention was completed.

  That is, the shielded ultrafine wire pair stranded cable of the present invention is in contact with one low dielectric constant resin linear body (1) existing in the central portion and the central linear body (1). There are two conductive linear bodies (2) that are not in contact with each other and a plurality of low dielectric constant resin linear bodies (3) that are in contact with the central linear body (1). The two conductive linear bodies (2) and the plurality of low dielectric constant resin linear bodies (3) are in contact with each other and the one low dielectric constant resin linear body (1 ) Surrounding the two conductive linear bodies (2) and the plurality of low dielectric constant resin linear bodies (3). The insulating coating layer (4) is provided, the outer periphery of the insulating coating layer is provided with a plating shield (5), and the outer periphery of the shield is provided with a protective coating layer (6). And wherein the door.

  The shielded ultrafine wire-twisted cable of the present invention can keep the shield of the twisted cable in a circular shape, has excellent shielding properties and excellent bending resistance, and can be easily manufactured with a light weight.

It is a schematic sectional drawing of the shielded extra fine wire pair twisted cable of this invention. It is a schematic explanatory drawing only of the linear body part for demonstrating the shielded extra fine wire pair twisted cable of this invention. It is a schematic sectional drawing which shows another aspect of the shielded extra fine wire pair twisted cable of this invention. It is a schematic sectional drawing which shows another aspect of the ultrafine wire pair twisted cable with a shield of this invention.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of a shielded ultrafine wire pair stranded cable of the present invention, and FIG. 2 is a schematic explanatory view showing only a linear body portion of the shielded ultrafine wire pair stranded cable shown in FIG. . In the shielded ultrafine wire pair twisted cable of the embodiment of the present invention shown in FIG. 1, one low dielectric constant resin linear body (1) existing in the central portion, and the central linear body (1) Two conductive linear bodies (2) that are in contact but not in contact with each other, and four low dielectric constant resin linear bodies that are in contact with the central linear body (1) As shown in FIG. 2, the two conductive linear bodies (2) and the four low dielectric constant resin linear bodies (3) are in contact with each other. The two conductive linear bodies (2) and the plurality of low dielectric constant resins that are twisted in a concentric manner so as to surround the linear body (1) of the low dielectric constant resin An insulating coating layer (4) having a low dielectric constant is provided on the entire outer periphery of the linear body (3), and a plating shield (5) is provided on the outer periphery of the insulating coating layer. Protective coating layer (6) is provided on the outer periphery of the de.

  The shielded ultrafine wire-paired cable of the present invention has two conductive linear bodies and four low dielectric constant resin linear bodies around the linear body of the low dielectric constant resin as shown in FIG. 2 are arranged, or two conductive linear bodies and three low dielectric constant resin linear bodies are illustrated around the central linear body of the low dielectric constant resin. 4, two conductive linear bodies and six low dielectric constant resin linear bodies are shown in FIG. 4 around the central linear body of the low dielectric constant resin. It may be arranged like this, and more linear bodies of low dielectric constant resin may be used.

  As the linear body of the low dielectric constant resin constituting the shielded ultrafine wire pair stranded cable of the present invention, for example, a linear body made of a fluorine-based resin can be used. Examples of the fluorine resin include ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene perfluoroalkoxyethylene copolymer (PFA), and fluoroethylene hexafluoropropylene copolymer (FEP). This is the most excellent in terms of bending resistance.

  The material of the conductive linear body constituting the shielded ultrafine wire-paired cable of the present invention is not particularly limited as long as it has high conductivity, for example, copper, silver or an alloy thereof, a tin-containing copper alloy, Examples thereof include a chromium-zirconium-containing copper alloy, an in-situ metal fiber reinforced copper alloy, and the like, and an internal conductor made of the in-situ metal fiber reinforced copper alloy is particularly preferable in terms of bending resistance. Moreover, the electroconductive linear body which plated silver, gold | metal | money, tin, etc. on the surface of the electroconductive linear body which consists of these materials can be used, and what plated gold | metal | money and silver is preferable at the electroconductive point. The conductive linear body may be composed of a single wire, or may be a twist of a plurality of single wires (for example, 7 or 19 wires).

  Here, the in-situ metal fiber reinforced copper alloy conductive linear body (conductive wire) is a copper matrix reinforced with metal fibers, and particularly in-situ, that is, in the process of forming the wire. The wire which formed the metal fiber in. For example, it refers to a wire containing in-situ formed fibrous silver having a maximum diameter of 2.5 μm or less and an average diameter of 1.0 μm or less in a copper matrix.

  For example, the in-situ metal fiber reinforced copper alloy conductor is formed by swaging an alloy material having a silver content of 1 to 25% by mass and the balance being substantially copper, if necessary, and then performing the first cooling. By performing a wire drawing process, followed by a solution treatment, and then performing a second cold wire drawing process, fibrous silver is formed in-situ in the copper matrix to obtain a wire, and at least one wire is formed. It is obtained by forming a conducting wire using this. The alloy material is not limited to the above-described alloy. For example, an alloy having a silver content of 1 to 25% by mass, a zirconium content of 0.01 to 8% by mass, and the balance being substantially copper. Materials can also be used.

  In the shielded ultrafine wire-paired cable of the present invention, for example, as shown in FIG. 2, two conductive linear bodies (2) and four low dielectric constant resin linear bodies (3) are mutually connected. It is in contact with each other and is twisted in a concentric state surrounding a single low dielectric constant resin linear body (1). Such a twisted body and a method for producing the twisted body are well known, and the present invention In S, it may be S twist or Z twist, and those twisted together by a well-known method are used.

  In the shielded ultrafine wire-paired cable of the present invention, the whole of the two conductive linear bodies (2) twisted together and the plurality of low dielectric constant resin linear bodies (3) (hereinafter, twisted together) An insulating coating layer (4) having a low dielectric constant is provided on the outer periphery of the body). Examples of the insulating coating layer include a coating layer made of a polyester resin, a fluorine resin, a polystyrene resin, a polyolefin resin, or the like, and enamel coating. However, fluororesin or polyethylene is preferred from the viewpoint of low dielectric constant, preferable for diameter reduction, and bending resistance.

  In the shielded ultrafine wire pair stranded cable of the present invention, it is preferable to provide an insulating coating layer made of a polymer alloy of polyamide and ABS resin. As a polymer alloy of the polyamide and the ABS resin (hereinafter abbreviated as a polymer alloy), a polymer alloy can be formed if an insulating coating layer having a predetermined thickness can be formed on the outer periphery of the twisted body by extrusion molding. There are no particular limitations on the types and blending ratios of the polyamide and the ABS resin. However, ASTM D1238, temperature: 220 ± 0.2 ° C., load: 2160 g, sample: about 10 g of pellets in order to easily form an insulation coating layer having a predetermined thickness on the outer periphery of the twisted body by extrusion molding. Test apparatus: Melt indexer, Orifice: Melt flow rate (MFR) measured under the condition of 0.9φ × 8 L (mm) is preferably 10 g / 10 min or more (in the present invention, all MFR is this Measured under the conditions). The upper limit of MFR is not limited in terms of the possibility of extrusion molding, but is about 60 g / 10 min in consideration of available polyamide, ABS resin, polymer alloy, and the like. Therefore, in the present invention, the MFR of the polymer alloy is preferably about 10 to 60 g / 10 min.

  When the insulating coating layer is formed, for example, by extrusion in the horizontal direction, it is preferable to use a polymer alloy having a relatively low fluidity, for example, a polymer alloy having an MFR of 30 g / 10 min or less, and an MFR of 20 g / It is more preferable to use a polymer alloy of 10 min or less. On the other hand, when a highly fluid polymer alloy is used, when the insulating coating layer is formed by extrusion in the horizontal direction, the thickness of the insulating coating layer partially changes in the outer peripheral direction due to resin sagging. Since there exists a possibility, it is desirable to form an insulation coating layer by the extrusion molding to the perpendicular direction downward direction. In this case, it is preferable to use a polymer alloy having a high fluidity, for example, a polymer alloy having an MFR of 20 to 60 g / 10 min, more preferably a polymer alloy having an MFR of 25 to 50 g / 10 min, and an MFR of 30. Most preferably, a polymer alloy of ˜40 g / 10 min is used. However, when manufacturing a shielded ultrafine wire pair twisted cable with an outer diameter of 300 μm or less, the resin of the insulating coating layer itself becomes light, so even if the insulating coating layer is formed by extrusion in the horizontal direction, the resin There is no possibility that the thickness of the insulating coating layer partially changes in the outer peripheral direction due to sagging.

  As the polyamide constituting the polymer alloy, polyamides formed from diamines and dicarboxylic acids and copolymers thereof can be used. For example, nylon 66, polyhexamethylene sebacamide (nylon 6 · 10), polyhexamethylene dodecanamide (nylon 6 · 12), polydodecamethylene dodecanamide (nylon 1212), polymetaxylylene adipamide (nylon) MXD6), polytetramethylene adipamide (nylon 46), and mixtures and copolymers thereof can be used. Further, a ring-opening polymer of cyclic lactam, a polycondensate of aminocarboxylic acid, and a copolymer comprising these components, specifically, nylon 6, poly-ω-undecanamide (nylon 11), poly-ω-dodecanamide. (Nylon 12) and other aliphatic polyamide resins and copolymers thereof, and copolymers with polyamides comprising diamines and dicarboxylic acids, specifically nylon 6T / 6, nylon 6T / 11, nylon 6T / 12, Nylon 6T / 6I / 12, nylon 6T / 6I / 610/12, etc., and mixtures thereof can also be used.

  As the ABS resin constituting the polymer alloy, various types and grades of ABS resin are commercially available. Therefore, the polymer alloy is appropriately selected and used so that the MFR of the polymer alloy falls within the above range. Generally, since the MFR of polyamide is low, an ABS resin having a relatively high MFR is used.

  In the shielded ultrafine wire-twisted cable of the present invention, the insulating coating layer may be used alone as the above polymer alloy. For this polymer alloy, for example, various resins, specifically polystyrene (PS) , Polycarbonate (PC) or the like may be used.

  In the shielded ultrafine wire pair stranded cable of the present invention, a plating shield (5) is provided on the outer periphery of the insulating coating layer.

  In order to enhance the adhesion strength of the thin film shield layer formed by electroless plating, the polymer alloy constituting the insulating coating layer preferably contains a water-soluble substance, a surfactant, a coagulant, a phosphorus compound, and the like.

  The above water-soluble substance means a substance that is soluble in water regardless of solubility. As such water-soluble substances, polysaccharides such as starch, dextrin, pullulan, hyaluronic acid, carboxymethylcellulose, methylcellulose, ethylcellulose or salts thereof; propylene glycol, ethylene glycol, diethylene glycol, neopentyl glycol, butanediol, pentanediol, Polyhydric alcohols such as polyoxyethylene glycol, polyoxypropylene glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, glycerin; polyvinyl alcohol, polyacrylic acid, polymaleic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, acrylic acid Maleic anhydride copolymer, maleic anhydride-diisobutylene copolymer, maleic anhydride-acetic acid Nirukoporima, naphthalene sulfonate formalin condensates and their salts. Among these, those that are soluble in water but low in solubility are preferred, specifically, those having a water solubility (25 ° C.) of 300 g / 100 g or less are preferred, and those having a solubility of 100 g / 100 g or less are more preferred. The thing of 10 g / 100g or less is still more preferable. Examples of such water-soluble substances include pentaerythritol (7.2 g / 100 g) and dipentaerythritol (0.1 g / 100 g or less). The content ratio of the polymer alloy and the water-soluble substance is preferably 0.01 to 50 parts by mass, more preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of the polymer alloy. Preferably, it is 0.01-15 mass parts.

  As the surfactant, any of an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant can be used. These surfactants include fatty acid salts, rosinates, alkyl sulfates, alkyl benzene sulfonates, alkyl diphenyl ether sulfonates, polyoxyethylene alkyl ether sulfates, sulfosuccinic acid diester salts, α-olefin sulfate esters, α -Anionic surfactants such as olefin sulfonates; Cationic surfactants such as mono- or dialkylamines or polyoxyethylene adducts thereof, mono- or di-long-chain alkyl quaternary ammonium salts; alkyl glucosides, polyoxyethylene alkyl ethers , Polyoxyethylene alkyl phenyl ether, sucrose fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene propylene bromide Nonionic surfactants such as lac copolymer, fatty acid monoglyceride and amine oxide; amphoteric surfactants such as carbobetaine, sulfobetaine and hydroxysulfobetaine. The content ratio of the surfactant in the polymer alloy is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the polymer alloy. Preferably, it is 0.01-2 mass parts.

  As phosphorus compounds, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, tris (o- or p-phenylphenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl Diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, di (isopropylphenyl) phenyl phosphate, o-phenylphenyl crecresyl phosphate, tris (2,6-dimethylphenyl) phosphate, tetraphenyl-m-phenylene diphosphate, tetraphenyl- p-phenylene diphosphate, phenyl resorcinol polyphosphate, bisphenol A-bis (diphenyl phosphate), bisphenol A. Condensation phosphates such as polyphenyl phosphate, dipyrrocatechol high-positive phosphate; diphenyl (2-ethylhexyl) phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, diphenyl neopentyl phosphate, Fatty acids and aromatic phosphates such as orthophosphates such as pentaerythritol diphenyldiphosphate and ethylpyrocatechol phosphate; melamine polyphosphate, tripolyphosphate, pyrophosphate, orthophosphate, hexametaphosphate, phytic acid, etc. Phosphoric acid compounds of these, or alkali metal salts or alkanolamine salts thereof, and the like. One or two or more selected from these phosphorous compounds It can be used. Furthermore, as phosphorus compounds other than the above, phosphorus compounds that are used as known flame retardants and antioxidants for resins can be used. As described above, in the present invention, phosphorus compounds that are widely used as flame retardants and antioxidants can be used, but these phosphorus compounds are used as a plating layer for the polymer alloy insulating coating layer. It functions as a component that increases the adhesion strength.

  When manufacturing the shielded ultrafine wire pair stranded cable of the present invention, a degreasing treatment is performed as necessary. The degreasing treatment can be performed using, for example, an aqueous surfactant solution containing an alkali such as sodium hydroxide or sodium carbonate or an acid such as sulfuric acid or carbonic acid.

  Conventionally, when plating an ABS resin molded body, an etching process for roughening the ABS resin molded body after the degreasing treatment has been essential in order to increase the adhesion strength between the ABS resin molded body and the plating layer. For example, after the degreasing treatment, it is necessary to perform etching treatment at 65 to 70 ° C. for 10 to 15 minutes using a chromic acid bath (mixed solution of chromium trioxide and sulfuric acid), and hexavalent chromate ions that are toxic to wastewater. Was included. For this reason, the process of neutralizing and precipitating after reducing the hexavalent chromate ion to the trivalent ion is indispensable, and there has been a problem during wastewater treatment. In this way, it is desirable not to perform an etching process using a chromium bath in consideration of the safety at the time of work in the field and the environmental impact of wastewater, but in that case, in that case, the molded product obtained from the ABS resin is not processed. There is a problem that the adhesion strength of the plating layer cannot be increased.

  When the insulating coating layer is made of a polymer alloy of polyamide and ABS resin, the polyamide component is etched by etching the surface of the insulating coating layer with hydrochloric acid, phosphoric acid, sulfuric acid or organic acid. When the polymer alloy contains a water-soluble substance, the water-soluble substance is soluted in the etching process, and the surface of the insulating coating layer becomes porous, and the adhesion strength of the plating layer is further improved. It is preferable to use those acids having a low concentration (preferably less than 4 N, more preferably 3.5 N or less, and still more preferably 3.0 N or less). Such an etching process can improve the adhesion strength of the plating layer, and also has an excellent effect that the safety during work is higher and the waste liquid process is easier than when a high concentration acid is used. Is obtained.

  After the etching treatment step with the acid, for example, a water washing step, a step of treating with a catalyst application liquid, a water washing step, a step of treating with an activating liquid (activation step), and a water washing step can be performed. In addition, the process with a catalyst provision liquid and the process with an activation liquid can be performed simultaneously.

  The treatment with the catalyst-imparting solution is performed, for example, by immersing in a 35% hydrochloric acid solution (10 to 20 mg / L) of tin chloride (20 to 40 g / L) at room temperature for about 1 to 5 minutes. The treatment with the activation solution is performed by immersing in a 35% hydrochloric acid solution (3 to 5 m / L) of palladium chloride (0.1 to 0.3 g / L) at room temperature for about 1 to 2 minutes.

  Thereafter, electroless plating is performed once or twice as necessary to form a thin film shield layer. As the plating bath, one containing nickel, copper, cobalt, nickel-cobalt alloy, silver, gold or the like and a reducing agent such as formalin or hypophosphite can be used. The pH and temperature of the plating bath are selected according to the type of plating bath used. When the plating process is further performed after the electroless plating, an electroplating process using copper or the like can be added after the activation process using acid or alkali.

  In the shielded ultrafine wire pair stranded cable of the present invention, a protective coating layer (sheath) is provided outside the thin film shield layer. Examples of the material for the protective coating layer include fluorine resins, olefin resins, polyesters, polyurethanes, ABS resins, and polyimides. By using polyurethane as the material of the protective coating layer, for example, during the laser processing when exposing the internal conductor from the end of the shielded ultrafine wire-twisted cable, the surface of the protective coating layer is burned (discolored). It can be effectively prevented.

  As a method for forming a protective coating layer made of polyurethane, for example, dipping or the like can be mentioned. In the present invention, a thin film shield layer is formed on the outer periphery through a die from a polyurethane tank containing polyurethane. It is preferable to form by the so-called die finishing that draws out the covered electric wire. In addition, for example, by forming the protective coating layer by pulling out the covered electric wire in the vertical direction, it is easy to set the dice at the center of the axis of the internal conductor, and the protective coating layer is formed with a substantially uniform film thickness by die finishing. can do.

  In the shielded ultrafine wire-paired cable of the present invention, the insulating coating layer made of a polymer alloy of polyamide and ABS resin is preferably formed to be relatively thin, for example, 90 μm or less, more preferably 30 μm or less. It is preferable that The reason is that if the insulation coating layer is formed relatively thick, when the cable is bent, the surface of the cable (insulation coating layer) is whitened, and the cable is likely to break from the whitened portion. is there.

  In the shielded ultrafine wire pair stranded cable of the present invention, it is preferable to form a metal plating layer as the thin film shield layer. Examples of the metal plating layer include copper, silver, nickel, gold, tin, and the like, or composite plating or alloy plating thereof. Furthermore, the thickness of the metal plating layer is preferably 4 μm or less, more preferably 2 μm or less. If it is thicker than this, there may be a problem in bending resistance.

  In the shielded ultrafine wire-twisted cable of the present invention, the thickness of the insulating coating layer is preferably 90 μm or less, the thickness of the thin film shielding layer is preferably 4 μm or less, the thickness of the insulating coating layer is 30 μm or less, and More preferably, the thickness of the thin film shield layer is 2 μm or less. This increases the bending resistance of the insulating coating layer and the thin film shield layer, respectively, and as a result, the bending resistance of the cable can be further increased.

Example 1
Two stranded wires having an outer diameter of 0.048 mm and seven galvanized silver alloy wires having a diameter of 0.016 mm twisted in a state where six wires are arranged around one center, and a diameter of 0.2 mm. Five FEP filaments of 05 mm were twisted together in the arrangement shown in FIGS. 1 and 2 to produce a twisted body having an outer diameter of about 0.15 mm. A polymer alloy (polyamide and ABS resin) with an MFR of 40 g / 10 min is used as the material of the insulating coating layer, and the outer diameter is 0.20 mm using an extrusion molding device (the standard thickness of the insulating coating layer is 0.025 mm). A coated electric wire was manufactured. The outer peripheral surface of the coated electric wire thus formed is etched with hydrochloric acid, provided with a catalyst, activated, and the outer peripheral surface is coated with a thin film shield layer (0.002 mm thick) made of copper by electroless plating. A metal plating layer) was formed. A shielded extra-fine wire-twisted cable with an outer diameter of approximately 0.224 mm, with a protective coating layer (standard thickness is 0.01 mm) made of polyurethane by die finishing on the outer periphery of the coated electric wire on which the thin-film shield layer is formed Got. The characteristic impedance of the obtained shielded ultrafine wire-paired cable was 64Ω, and the transmission loss (60 MHz) was 3.9 dB.

DESCRIPTION OF SYMBOLS 1 Linear body of low dielectric constant resin which exists in center part 2 Conductive linear body 3 Linear body of low dielectric constant resin 4 Low dielectric constant insulating coating layer 5 Plating shield 6 Protective coating layer

Claims (4)

  A shielded extra-fine wire-twisted cable, which is in contact with one linear body (1) of low dielectric constant resin existing in the center, but in contact with the linear body (1) in the center. Two conductive linear bodies (2) that are not, and a plurality of low dielectric constant resin linear bodies (3) in contact with the central linear body (1), Two conductive linear bodies (2) and the plurality of low dielectric constant resin linear bodies (3) are in contact with each other to surround the single low dielectric constant resin linear body (1). The two conductive linear bodies (2) and the plurality of low dielectric constant resin linear bodies (3) that are twisted together have a low dielectric constant on the outer periphery. An insulating coating layer (4) is provided, a plating shield (5) is provided on the outer periphery of the insulating coating layer, and a protective coating layer (6) is provided on the outer periphery of the shield. Shielded filament pair twisted cable characterized.   The shielded ultrafine wire pair stranded cable according to claim 1, wherein the linear bodies (1) and (3) of the low dielectric constant resin are made of a fluorine-based polymer.   The shielded ultrafine wire-twisted cable according to claim 1 or 2, wherein the conductive linear body (2) comprises a stranded wire.   The thickness of the linear body (1) at the center, the thickness of the conductive linear body (2), and the thickness of the plurality of linear bodies (3) being twisted are the same and twisted together. The total number of the plurality of linear bodies (3) is 4, and there are two linear bodies (3) twisted together between the conductive linear bodies (2). The shielded extra fine wire twisted cable according to 1, 2 or 3.

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