JP4143088B2 - Coaxial cable, manufacturing method thereof, and multicore cable using the same - Google Patents

Description

  The present invention is a coaxial cable that has high strength and high conductivity, is less likely to cause a decrease in strength even in operations that give a thermal load such as foaming extrusion work, soldering work, etc., and has excellent heat resistance And a manufacturing method thereof and a multicore cable using the same.

  High-strength and high-conductivity copper alloys are generally used as conductor materials used in bending-resistant cables for electronic devices (for example, robot cables) and bending-resistant cables for medical devices (for example, probe cables). Is used.

  Currently, copper alloy wires manufactured at a mass production level include Cu-Sn alloy wires and Cu-Sn-In alloy wires that can be continuously cast and rolled and are excellent in economic efficiency, and for electronic equipment, and It is widely used as a conductor material for flexible cables for medical equipment. Other copper alloy wires are also applied to various fields according to product costs and various characteristics of copper alloy wires.

With recent downsizing and weight reduction of electronic devices and miniaturization of medical devices, the conductors of electric wires used for these devices are strongly demanded to be reduced in diameter, and conductors having a diameter of 0.03 mm or less are required. It is becoming. In particular, with the advancement of the ultrasonic endoscope head, the ultrasonic endoscope cable tends to be more multi-core (200 to 260 cores), while reducing patient pain. There is an increasing demand for reducing the diameter of the head portion. The demand for reducing the diameter is also remarkable in a curl cable or the like used when performing an intravascular operation for approaching a predetermined affected area from within a blood vessel.
In recent years, there has been a strong demand for the development of a conductor material that has both high strength characteristics and high conductivity characteristics for the purpose of improving flex resistance and increasing transmission capacity, as well as the need for smaller diameters.

  The aforementioned Cu—Sn alloy wire and Cu—Sn—In alloy wire are made of a copper alloy obtained by adding Sn to tough pitch copper as a base metal. However, in order to increase the strength of the Cu—Sn alloy wire, it is necessary to increase the amount of Sn added. As a result, the electrical conductivity decreases, and it is difficult to achieve both strength and electrical conductivity. .

  On the other hand, in recent years, a Cu—Ag alloy has attracted attention as a copper alloy having both strength and electrical conductivity. Cu-Ag alloy with excellent tensile strength and electrical conductivity is, for example, a lot obtained by casting (1) a Cu-Ag alloy containing 1.0 to 15% by weight of silver in copper. (2) Heat treatment is performed at a temperature of 400 to 500 ° C. for 1 to 30 hours, and then (3) cold working with a reduction in area of 95% or more is performed (Patent Document 1). reference).

Moreover, 0.1 to 1.0% by weight of silver is added to pure copper to form a Cu-Ag alloy, which is made into a strand having 0.01 to 0.08 mm and a tensile strength of 600 MPa or more. After the number of wires is twisted together, the twisted wire is subjected to heat treatment to remove strain at the time of twisted wire to form an ultrafine copper alloy twisted wire (see Patent Document 2).
JP 2001-40439 A JP 2001-234309 A

  In low-capacity coaxial cables, a foamed insulator having a melting point of about 300 ° C. is used as an outer layer of an ultrafine copper alloy wire by extrusion coating. In this extrusion operation, the insulation heat and extrusion during coating are used. The mechanical properties of the ultrafine copper alloy wire, particularly the tensile strength, is lowered by the heat (300 to 380 ° C.) of the machine head. Furthermore, in the terminal processing, the tensile strength of the terminal portion ultrafine copper alloy wire is remarkably reduced by soldering iron heat of about 300 to 350 ° C. due to the soldering operation. Therefore, after foaming extrusion or soldering, it may be difficult to achieve both electrical and mechanical properties. Especially, the mechanical reliability of the cable and cable end processing part is greatly impaired due to the decrease in tensile strength. May be.

  In addition, for example, an ultra-fine wire having a wire diameter of 0.025 mm or less is used for a probe cable for an ultrasonic diagnostic apparatus or an ultrasonic endoscope cable, so that an electric resistance corresponding to such a conductor size is a problem. It becomes. Specifically, in accordance with the AWG (American Wire Gauge) standard, an ultrafine copper alloy stranded wire that truly achieves both a reduction in diameter and electrical characteristics is required. The relationship between the AWG standard and the twisted wire structure (number of twists / wire diameter) is 42 AWG (7 / 0.025), 43 AWG (7 / 0.023), 44 AWG (7 / 0.020), 45 AWG (7/0. 018), 46 AWG (7 / 0.016), 48 AWG (7 / 0.013), and 50 AWG (7 / 0.010).

  However, although the Cu-Ag alloy described in Patent Document 1 has both tensile strength and electrical conductivity, as a technique for this purpose, heat treatment is performed at a specific temperature for a long time (1 to 30 hours). Inefficient and expensive. In addition, no mention is made of measures for reducing strength due to thermal history when a thermal load such as extrusion work is applied, and no measures are taken. Furthermore, no mention is made of electrical resistance corresponding to a very thin conductor size.

  On the other hand, in the ultrafine copper alloy stranded wire of Patent Document 2, although silver is described as an additive element of the copper alloy, the addition amount is as small as 0.1 to 1.0% by weight, and improvement in tensile strength cannot be expected. . In addition, this ultra-fine copper alloy stranded wire has an elongation characteristic of 5% or more mainly for the purpose of improving the bending characteristics in the plastic strain region, but the tensile strength is inevitably lowered in the characteristics that emphasize elongation. End up. For this reason, it is particularly strong for the use of electronic equipment cables or medical equipment cables in which extra fine wires having a wire diameter of 0.025 mm or less are used, such as probe cables for ultrasonic diagnostic equipment and ultrasonic endoscope cables. There is a problem that it is insufficient and the flexibility is not sufficient.

  Therefore, the object of the present invention is to solve the above-mentioned problems, to achieve both high strength characteristics and low resistance characteristics (high conductivity), and to be strong even under a thermal load during foaming extrusion work or terminal soldering work. It is an object of the present invention to provide a coaxial cable having high heat resistance, a method for manufacturing the same, and a multicore cable using the same.

  In order to achieve the above object, the coaxial cable of the present invention contains 1 to 3% by weight of silver (Ag), and the balance of copper (Cu) and inevitable impurities is 0.010 to 0.025 mm. A plurality of copper alloy wires are twisted to form a copper alloy stranded wire, the copper alloy stranded wire has a tensile strength of 850 MPa or more, an electrical conductivity of 85% IACS or more, and foams on the outer periphery of the copper alloy stranded wire. An insulator is covered, and a plurality of conductor wires are spirally wound along the longitudinal direction of the copper alloy stranded wire to form an outer conductor, and a jacket layer is coated on the surface of the outer conductor. It is characterized by that.

  The copper alloy stranded wire is heat-treated, and it is preferable that the decrease rate of the electrical resistance after the heat treatment is 6% or more and the decrease rate of the tensile strength after the heat treatment is 20% or less.

  A plating layer of tin (Sn), silver (Ag), or nickel (Ni) can be formed on the surface of the copper alloy wire.

The copper alloy wire is a coaxial cable having a wire diameter of more than 0.021 mm and 0.025 mm or less, an electric resistance of 7500 Ω / km or less, a capacitance of 30 to 80 pF / m,
A coaxial cable having a wire diameter of more than 0.018 mm and not more than 0.022 mm, wherein the copper alloy wire has an electric resistance of 10,000 Ω / km or less, a capacitance of 30 to 80 pF / m,
The copper alloy wire is a coaxial cable having a wire diameter of more than 0.016 mm and 0.020 mm or less, an electrical resistance of 13000 Ω / km or less, a capacitance of 30 to 80 pF / m,
A coaxial cable having a wire diameter of more than 0.014 mm and not more than 0.018 mm, wherein the copper alloy wire has an electrical resistance of 15500 Ω / km or less, a capacitance of 30 to 80 pF / m,
A coaxial cable having a wire diameter of more than 0.013 mm and not more than 0.017 mm, wherein the copper alloy wire has an electric resistance of 17000 Ω / km or less, a capacitance of 30 to 80 pF / m,
A coaxial cable having a wire diameter of the copper alloy wire exceeding 0.011 mm and 0.015 mm or less, having an electric resistance of 23500 Ω / km or less, a capacitance of 30 to 80 pF / m,
A coaxial cable having a wire diameter of more than 0.008 mm and not more than 0.012 mm, wherein the copper alloy wire has an electric resistance of 40000 Ω / km or less, a capacitance of 30 to 80 pF / m,
Coaxial cable.

  Moreover, in order to achieve the said objective, the manufacturing method of the coaxial cable of this invention adds 1 to 3 weight% of silver to pure copper, produces | generates a copper alloy, performs wire drawing, and a wire diameter is 0.010. After producing a 0.025 mm ultrafine copper alloy wire, a plurality of the ultrafine copper alloy wires are twisted together to form an ultrafine copper alloy twisted wire, and after heat treatment at a temperature of 300 to 500 ° C. for 0.2 to 5 seconds, A skin layer is formed on the outer periphery of the copper alloy stranded wire after coating with a foam insulator having a thickness of 0.28 mm or less, and a plurality of conductor wires are further provided along the longitudinal direction of the copper alloy stranded wire on the outer periphery. After forming the outer conductor by spirally winding, a jacket layer is coated on the surface of the outer conductor.

  Furthermore, a plurality of the coaxial cables can be twisted around the tension member or the outer periphery of the center interposition to form a multicore cable.

  A plurality of coaxial cable units formed by bundling a plurality of coaxial cables on the tension member or the outer periphery of the center may be twisted to form a multicore cable.

  A plurality of coaxial cables may be arranged in parallel at a constant pitch to form a multicore cable.

  According to the present invention, both high strength characteristics and low resistance characteristics (high conductivity) are compatible, and the strength is not easily lowered even under a thermal load in a foam extrusion operation or a soldering operation of a terminal portion. Thus, it is possible to provide a coaxial cable and a multi-core cable that have both characteristics.

(coaxial cable)
FIG. 1 shows a cross-sectional view of the coaxial cable of this embodiment.
The coaxial cable 10 has a foamed insulator 5 coated on the outer periphery of a copper alloy stranded wire (inner conductor) 3 in which seven copper alloy wires 1 are stranded, and a plurality of outer peripherals of a skin layer 6 formed on the outer periphery thereof. A conductor wire 7 is spirally wound along the longitudinal direction of a copper alloy stranded wire (inner conductor) 3 to form an outer conductor 8, and a jacket layer 9 is coated on the surface thereof.

(Copper alloy wire)
The copper alloy wire 1 is a Cu-Ag alloy wire having a wire diameter of 0.025 to 0.010 mm and containing 1 to 3% by weight, preferably 1.5 to 2.5% by weight of silver. Is.
The reason why the silver content is set to 1 to 3% by weight is that an improvement in strength cannot be expected if it is less than 1% by weight, and if it exceeds 3% by weight, the conductivity is lowered although the strength is improved. Furthermore, by setting the silver content in the range of 1.5 to 2.5% by weight, the performance having the most compatible strength characteristics and conductivity characteristics can be obtained.

  Note that a tin (Sn), silver (Ag), or nickel (Ni) plating layer may be formed on the surface of the copper alloy wire 1.

(Inner conductor)
The internal conductor is composed of a copper alloy twisted wire 3 in which seven copper alloy wires 1 are twisted together, and has a tensile strength of 850 MPa or more and a conductivity of 85% IACS or more. The tensile strength of 850 MPa or more and the electrical conductivity of 85% IACS or more are considered to satisfy various characteristics such as flexibility, electrical resistance, and flexibility in the above range when considering use for a cable for medical equipment. This is because these characteristics cannot be satisfied outside the above range.
Moreover, this copper alloy twisted wire 3 is heat-treated, the reduction rate of the electrical resistance after the heat treatment is 6% or more, and the reduction rate of the tensile strength after the heat treatment is within 20%. . When the rate of decrease in electrical resistance after heat treatment is less than 6% and the rate of decrease in tensile strength after heat treatment exceeds 20%, disconnection is likely to occur in foam extrusion manufacturing operations and terminal portion soldering operations, and high It becomes difficult to achieve both strength characteristics and low resistance characteristics (high conductivity).

Furthermore, the electrical resistance of the copper alloy twisted wire 3 has the following relationship with the wire diameter of the copper alloy wire 1.
(1) When the wire diameter of the copper alloy wire 1 exceeds 0.021 mm and is 0.025 mm or less, the electric resistance is 7500 Ω / km or less.
(2) When the wire diameter of the copper alloy wire 1 exceeds 0.018 mm and is 0.022 mm or less, the electric resistance is 10,000 Ω / km or less.
(3) When the wire diameter of the copper alloy wire 1 exceeds 0.016 mm and is 0.020 mm or less, the electric resistance is 13000 Ω / km or less.
(4) When the wire diameter of the copper alloy wire 1 exceeds 0.014 mm and is 0.018 mm or less, the electric resistance is 15500 Ω / km or less.
(5) When the wire diameter of the copper alloy wire 1 exceeds 0.013 mm and is 0.017 mm or less, the electric resistance is 17000 Ω / km or less.
(6) When the wire diameter of the copper alloy wire 1 exceeds 0.011 mm and is 0.015 mm or less, the electric resistance is 23500 Ω / km or less.
(7) When the wire diameter of the copper alloy wire 1 exceeds 0.008 mm and is 0.012 mm or less, the electric resistance is 40000 Ω / km or less.
The reason why the electric resistance is limited for each size is to make the diameter reduction and the electric characteristics truly compatible in accordance with the AWG (American Wire Gauge) standard.

(Foam insulation)
As the foam insulator 5, for example, tetrafluoroethylene / perfluoropropyl vinyl ether copolymer (PFA) for foam extrusion can be used. The foamed insulator 5 is formed on the outer periphery of the copper alloy stranded wire 3 with a thickness of 0.28 mm or less. The reason why the thickness is 0.28 mm or less is to make the capacitance 30 pF / m or more in a coaxial cable of 43 AWG to 50 AWG.

(Skin layer)
The skin layer 6 is formed by winding a PET tape, or a tetrafluoroethylene / perfluoropropyl vinyl ether copolymer (PFA), a tetrafluoroethylene / hexafluoropropylene copolymer (FEP), or ethylene / tetrafluoride. An ethylene copolymer (ETFE) can be provided by extrusion coating or the like.

(Outer conductor)
The external conductor 8 (loss winding shield) has a large number (for example, 30 to 60) of conductor wires 7 such as Sn-plated copper wire, Sn-plated copper alloy wire, silver-plated copper wire, and silver-plated copper alloy wire. It is formed by spiral winding at a pitch.

(Jacket layer)
The jacket layer 9 is formed by winding a PET tape, or a tetrafluoroethylene / perfluoropropyl vinyl ether copolymer (PFA), a tetrafluoroethylene / hexafluoropropylene copolymer (FEP), or ethylene / tetrafluoride. An ethylene copolymer (ETFE) or the like can be provided by extrusion coating.

(Capacitance of coaxial cable)
The capacitance of the coaxial cable 10 exceeds 0.016 mm when the wire diameter of the copper alloy wire 1 exceeds 0.021 mm and is 0.025 mm or less, and exceeds 0.018 mm and 0.022 mm or less. In the case of 0.020 mm or less, in the case of over 0.014 mm and 0.018 mm or less, in the case of over 0.013 mm and 0.017 mm or less, in the case of over 0.011 mm and 0.015 mm or less, 0.008 mm In the case of exceeding 0.012 mm and exceeding 30 to 80 pF / m, the capacity is low.

(Multi-core cable: using four coaxial cables)
In FIG. 2, sectional drawing of the multi-core cable of this embodiment is shown.
This multi-core cable 20 has four coaxial cables 10 shown in FIG. 1 arranged concentrically on the outer periphery of a tension member 21 (or centrally interposed), twisted together and wound with a bind tape 23, and further shielded on the outside. 25 and a sheath 27 are provided.
The winding thickness of the bind tape 23 is 0.05 mm, for example. Further, as the shield 25, for example, a shield with an Sn-plated annealed copper wire braid having a thickness of 0.05 mm is used. The shield 25 may be a horizontal winding shield. The sheath 27 is formed by winding a PET tape or, for example, tetrafluoroethylene / perfluoropropyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), ethylene / tetra It can be provided by extrusion coating with a fluorinated ethylene copolymer (ETFE).
Although FIG. 2 shows a structure in which the coaxial cable 10 is arranged in one layer on the concentric circle and twisted, two or more layers of the coaxial cable 10 may be arranged and twisted.

(Multi-core cable: using four coaxial cable units)
In FIG. 3, sectional drawing of the multi-core cable of other embodiment is shown.
In this multi-core cable 30, a plurality of coaxial cables 10 shown in FIG. 1 are bundled to form a coaxial cable unit 31, and a plurality of coaxial cable units 31 are gathered and twisted around the outer periphery of a tension member 21 (or centrally interposed). A bind tape 23 is wound, and a shield 25 and a sheath 27 are provided outside the bind tape 23.

(Multi-core cable: Multi-core ribbon cable)
FIG. 4 shows a cross-sectional view of a multicore cable according to another embodiment.
This multi-core cable 40 is a multi-core ribbon cable in which a plurality of coaxial cables 10 shown in FIG. 1 are arranged in parallel at a constant pitch, and adhesive tape 41 is attached to both sides of the parallel body.

(Production method)
Next, the manufacturing method of the copper alloy wire used in this embodiment and a copper alloy twisted wire is demonstrated.
First, 1 to 3% by weight, preferably 1.5 to 2.5% by weight of silver is added to pure copper to produce a copper alloy. Thereafter, wire drawing is performed, or heat treatment is performed in the middle to produce an ultrafine wire having a wire diameter of 0.025 to 0.010 mm. In this case, tin (Sn), silver (Ag), or nickel (Ni) plating is applied to the intermediate wire diameter so that the wire diameter is finally 0.025 to 0.010 mm. May be.

Next, a heat treatment under specific conditions is performed on the obtained ultrafine copper alloy wire single wire or a predetermined number, for example, 7 twisted wires to obtain an ultrafine copper alloy twisted wire. The heat treatment is performed by running in a heating furnace heated to 300 to 500 ° C. for 0.2 to 5 seconds, preferably 0.5 to 1.5 seconds.
The heat treatment conditions were 300 to 500 ° C. and 0.2 to 5 seconds. The heat treatment temperature was less than 300 ° C. and the heat treatment time was less than 0.2 seconds. This is because the desired characteristic cannot be obtained with a small increase. Further, when the heat treatment temperature exceeds 500 ° C. and the heat treatment time exceeds 5 seconds, the electrical conductivity is greatly increased, but the tensile strength is remarkably lowered, and desired characteristics cannot be obtained. Further, by performing the heat treatment preferably in the range of 0.5 to 1.5 seconds, it is possible to obtain performance with the most compatible tensile strength and electrical conductivity.

  The copper alloy wire and the copper alloy twisted wire obtained by performing the above treatment have a wire diameter of 0.025 to 0.010 mm and 1 to 3% by weight of silver, preferably 1.5 to 2.5. It can be contained by weight%, the tensile strength can be 850 MPa or more, and the conductivity can be 85% IACS or more.

(Effect of this embodiment)
According to the present embodiment, the ultra-thin wire having a final wire diameter of 0.025 mm or less is compatible with both high strength characteristics and low resistance characteristics (high conductivity), and thermal in foaming extrusion work or terminal soldering work. Even under a heavy load, the strength is hardly lowered, and an ultrafine copper alloy wire and an ultrafine copper alloy twisted wire having high heat resistance can be obtained.
Therefore, if these ultrafine copper alloy wires and ultrafine copper alloy stranded wires are used to manufacture coaxial cables, etc., performances of miniaturization, diameter reduction, weight reduction, high bending resistance, and high transmission are required. It can be suitably used for cables for electronic devices and medical devices.

(Production of 43AWG coaxial cable)

  2.0% by weight of silver was added to oxygen-free copper, heated and dissolved in a graphite crucible fixed in a vacuum chamber, and then continuously cast using a graphite mold to produce a drawn wire with a diameter of 8 mm. Then, after wire drawing, intermediate annealing and wire drawing, Ag plating is performed so that the final element wire thickness is 1 μm, wire drawing is performed to a wire diameter of 0.023 mm, and an ultrafine copper alloy wire is formed. Obtained. Seven of these 0.023 mm Ag-plated copper alloy wires (Cu-2% Ag) were prepared and twisted at a pitch of 1.1 mm to produce a stranded wire having an outer diameter of 0.069 mm. Then, the obtained stranded wire was heat-treated for 5.0 seconds in a heat treatment furnace heated to 350 ° C. to obtain an ultrafine copper alloy stranded wire.

  With respect to this ultrafine copper alloy stranded wire, the tensile strength and electrical resistance before and after the heat treatment and the electrical conductivity after the heat treatment were measured, and the change rate of the tensile strength and the electrical resistance was calculated. The rate of change was calculated as [(value before heat treatment−value after heat treatment) / value before heat treatment] × 100%. The results are shown in Table 1.

  Furthermore, the outer periphery of this stranded wire was extrusion-coated with a foamed PFA resin having a thickness of 0.07 mm to form an internal insulator having bubbles with an outer diameter of 0.210 mm. A skin layer made of a PET tape having a thickness of 0.01 mm is formed on the outer periphery of the internal insulator, and a Cu—In—Sn alloy wire (0.19 weight) having a strand diameter of 0.025 mm is formed on the outer periphery of the skin layer. % Sn, 0.20 wt% In) is wound horizontally to form an outer conductor, a jacket made of 0.015 mm thick PET tape is formed on the outer periphery of the outer conductor, and a coaxial cable having an outer diameter of 0.310 mm Got.

(Production of 43AWG coaxial cable)

  The same process as in the manufacturing method of Example 1 was performed except that a heat treatment was performed at 450 ° C. for 1.5 seconds.

(Production of 43AWG coaxial cable)

  The same process as in the manufacturing method of Example 1 was performed except that a heat treatment was performed at 500 ° C. for 0.4 seconds.

(Production of 44AWG coaxial cable)

  2.0% by weight of silver was added to oxygen-free copper, heated and dissolved in a graphite crucible fixed in a vacuum chamber, and then continuously cast using a graphite mold to produce a drawn wire with a diameter of 8 mm. After that, after wire drawing, intermediate annealing, wire drawing, Ag plating is performed so that the final wire thickness is 0.9 μm, wire drawing is performed to a wire diameter of 0.020 mm, and ultrafine copper alloy Got a line. Seven pieces of this 0.020 mm Ag-plated copper alloy wire (Cu-2% Ag) were prepared and twisted at a pitch of 1.0 mm to produce a stranded wire having an outer diameter of 0.06 mm. Then, the obtained stranded wire was heat-treated for 5.0 seconds in a heat treatment furnace heated to 350 ° C. to obtain an ultrafine copper alloy stranded wire.

  With respect to this ultrafine copper alloy stranded wire, the tensile strength and electrical resistance before and after the heat treatment and the electrical conductivity after the heat treatment were measured in the same manner as in Example 1, and the change rate of the tensile strength and electrical resistance was calculated. The results are shown in Table 1.

  Further, a 0.06 mm thick foamed PFA resin was extrusion coated on the outer periphery of the stranded wire to form an internal insulator having bubbles with an outer diameter of 0.180 mm. A skin layer made of a PET tape having a thickness of 0.01 mm is formed on the outer periphery of the internal insulator, and a Cu—In—Sn alloy wire (0.19 weight) having a strand diameter of 0.025 mm is formed on the outer periphery of the skin layer. % Sn, 0.20 wt% In) is wound horizontally to form an outer conductor, a jacket made of PET tape having a thickness of 0.015 mm is formed on the outer periphery of the outer conductor, and a coaxial cable having an outer diameter of 0.280 mm Got.

(Production of 44AWG coaxial cable)

  The same treatment as in the production method of Example 4 was performed except that a heat treatment was performed at 450 ° C. for 1.5 seconds.

(Production of 44AWG coaxial cable)

  The same process as in the manufacturing method of Example 4 was performed except that a heat treatment was performed at 500 ° C. for 0.4 seconds.

(Production of 45AWG coaxial cable)

  2.0% by weight of silver was added to oxygen-free copper, heated and dissolved in a graphite crucible fixed in a vacuum chamber, and then continuously cast using a graphite mold to produce a drawn wire with a diameter of 8 mm. After that, after wire drawing, intermediate annealing, wire drawing, Ag plating is performed so that the final wire thickness is 0.8 μm, wire drawing is performed to a wire diameter of 0.018 mm, and ultrafine copper alloy Got a line. Seven pieces of this 0.018 mm Ag-plated copper alloy wire (Cu-2% Ag) were prepared and twisted at a pitch of 0.8 mm to produce a stranded wire having an outer diameter of 0.054 mm. Then, the obtained stranded wire was heat-treated for 5.0 seconds in a heat treatment furnace heated to 350 ° C. to obtain an ultrafine copper alloy stranded wire.

  With respect to this ultrafine copper alloy stranded wire, the tensile strength and electrical resistance before and after the heat treatment and the electrical conductivity after the heat treatment were measured in the same manner as in Example 1, and the change rate of the tensile strength and electrical resistance was calculated. The results are shown in Table 1.

  Further, a PFA resin having a thickness of 0.05 mm was extrusion coated on the outer periphery of the stranded wire to form an internal insulator having bubbles having an outer diameter of 0.154 mm. A skin layer made of a PET tape having a thickness of 0.01 mm is formed on the outer periphery of the inner insulator, and a Cu—In—Sn alloy wire (0.19 weight) having a strand diameter of 0.020 mm is formed on the outer periphery of the skin layer. % Sn, 0.20 wt% In) is formed into a lateral conductor to form an outer conductor, a jacket made of 0.015 mm thick PET tape is formed on the outer circumference of the outer conductor, and a coaxial cable having an outer diameter of 0.244 mm. Got.

(Production of 45AWG coaxial cable)

  The same process as in the manufacturing method of Example 7 was performed except that a heat treatment was performed at 450 ° C. for 1.5 seconds.

(Production of 45AWG coaxial cable)

  The same treatment as in the manufacturing method of Example 7 was performed except that a heat treatment was performed at 500 ° C. for 0.4 seconds.

(Production of 46AWG coaxial cable)

  2.0% by weight of silver was added to oxygen-free copper, heated and dissolved in a graphite crucible fixed in a vacuum chamber, and then continuously cast using a graphite mold to produce a drawn wire with a diameter of 8 mm. After that, after wire drawing, intermediate annealing, wire drawing, Ag plating is performed so that the final wire thickness is 0.7 μm, wire drawing is performed to a wire diameter of 0.016 mm, and ultrafine copper alloy Got a line. Seven pieces of this 0.016 mm Ag-plated copper alloy wire (Cu-2% Ag) were prepared and twisted at a pitch of 0.8 mm to produce a stranded wire having an outer diameter of 0.048 mm. Then, the obtained stranded wire was heat-treated for 5.0 seconds in a heat treatment furnace heated to 350 ° C. to obtain an ultrafine copper alloy stranded wire.

  With respect to this ultrafine copper alloy stranded wire, the tensile strength and electrical resistance before and after the heat treatment and the electrical conductivity after the heat treatment were measured in the same manner as in Example 1, and the change rate of the tensile strength and electrical resistance was calculated. The results are shown in Table 1.

  Furthermore, the outer periphery of this stranded wire was extrusion-coated with a foamed PFA resin having a thickness of 0.04 mm to form an internal insulator having bubbles with an outer diameter of 0.128 mm. A skin layer made of a PET tape having a thickness of 0.01 mm is formed on the outer periphery of the inner insulator, and a Cu—In—Sn alloy wire (0.19 weight) having a strand diameter of 0.020 mm is formed on the outer periphery of the skin layer. % Sn, 0.20 wt% In) is wound horizontally to form an outer conductor, a jacket made of 0.015 mm thick PET tape is formed on the outer circumference of the outer conductor, and a coaxial cable having an outer diameter of 0.218 mm Got.

(Production of 46AWG coaxial cable)

  The same process as in the manufacturing method of Example 10 was performed except that a heat treatment was performed at 450 ° C. for 1.5 seconds.

(Production of 46AWG coaxial cable)

  The same process as in the manufacturing method of Example 10 was performed except that a heat treatment was performed at 500 ° C. for 0.4 seconds.

(Production of 47AWG coaxial cable)

  2.0% by weight of silver was added to oxygen-free copper, heated and dissolved in a graphite crucible fixed in a vacuum chamber, and then continuously cast using a graphite mold to produce a drawn wire with a diameter of 8 mm. Then, after wire drawing, intermediate annealing and wire drawing, Ag plating is performed so that the final element wire thickness is 0.6 μm, wire drawing is performed to a wire diameter of 0.015 mm, and ultrafine copper alloy Got a line. Seven pieces of this 0.015 mm Ag-plated copper alloy wire (Cu-2% Ag) were prepared and twisted at a pitch of 0.8 mm to produce a stranded wire having an outer diameter of 0.045 mm. Then, the obtained stranded wire was heat-treated for 5.0 seconds in a heat treatment furnace heated to 350 ° C. to obtain an ultrafine copper alloy stranded wire.

  With respect to this ultrafine copper alloy stranded wire, the tensile strength and electrical resistance before and after the heat treatment and the electrical conductivity after the heat treatment were measured in the same manner as in Example 1, and the change rate of the tensile strength and electrical resistance was calculated. The results are shown in Table 1.

  Furthermore, the outer periphery of this stranded wire was extrusion-coated with a foamed PFA resin having a thickness of 0.035 mm to form an internal insulator having bubbles with an outer diameter of 0.115 mm. A skin layer made of a PET tape having a thickness of 0.01 mm is formed on the outer periphery of the inner insulator, and a Cu—In—Sn alloy wire (0.19 weight) having a strand diameter of 0.020 mm is formed on the outer periphery of the skin layer. % Sn, 0.20% by weight In) is formed on the outer conductor to form an outer conductor, a jacket made of PET tape having a thickness of 0.015 mm is formed on the outer periphery of the outer conductor, and a coaxial cable having an outer diameter of 0.205 mm. Got.

(Production of 47AWG coaxial cable)

  The same treatment as in the manufacturing method of Example 13 was performed, except that a heat treatment was performed at 450 ° C. for 1.5 seconds.

(Production of 47AWG coaxial cable)

  The same treatment as in the manufacturing method of Example 13 was performed, except that a heat treatment was performed at 500 ° C. for 0.4 seconds.

(Preparation of 48AWG coaxial cable)

  2.0% by weight of silver was added to oxygen-free copper, heated and dissolved in a graphite crucible fixed in a vacuum chamber, and then continuously cast using a graphite mold to produce a drawn wire with a diameter of 8 mm. After that, after wire drawing, intermediate annealing, wire drawing, Ag plating is performed so that the final wire thickness is 0.5 μm, wire drawing is performed to a wire diameter of 0.013 mm, and ultrafine copper alloy Got a line. Seven pieces of this 0.013 mm Ag-plated copper alloy wire (Cu-2% Ag) were prepared and twisted at a pitch of 0.7 mm to produce a stranded wire having an outer diameter of 0.039 mm. Then, the obtained stranded wire was heat-treated for 5.0 seconds in a heat treatment furnace heated to 350 ° C. to obtain an ultrafine copper alloy stranded wire.

  With respect to this ultrafine copper alloy stranded wire, the tensile strength and electrical resistance before and after the heat treatment and the electrical conductivity after the heat treatment were measured in the same manner as in Example 1, and the change rate of the tensile strength and electrical resistance was calculated. The results are shown in Table 1.

  Further, an 0.03 mm thick foamed PFA resin was extrusion coated on the outer periphery of the stranded wire to form an internal insulator having bubbles with an outer diameter of 0.099 mm. A skin layer made of a PET tape having a thickness of 0.01 mm is formed on the outer periphery of the internal insulator, and a Cu—In—Sn alloy wire (0.19 weight) having a strand diameter of 0.016 mm is formed on the outer periphery of the skin layer. % Sn, 0.20 wt% In) is wound horizontally to form an outer conductor, a jacket made of 0.015 mm thick PET tape is formed around the outer conductor, and a coaxial cable having an outer diameter of 0.181 mm Got.

(Preparation of 48AWG coaxial cable)

  The same treatment as in the production method of Example 16 was performed, except that a heat treatment was performed at 450 ° C. for 1.5 seconds.

(Preparation of 48AWG coaxial cable)

  The same process as in the manufacturing method of Example 16 was performed except that a heat treatment was performed at 500 ° C. for 0.4 seconds.

(Preparation of 50AWG coaxial cable)

  2.0% by weight of silver was added to oxygen-free copper, heated and dissolved in a graphite crucible fixed in a vacuum chamber, and then continuously cast using a graphite mold to produce a drawn wire with a diameter of 8 mm. Then, after wire drawing, intermediate annealing, wire drawing, Ag plating is performed so that the final wire thickness is 0.4 μm, wire drawing is performed to a wire diameter of 0.010 mm, and ultrafine copper alloy Got a line. Seven pieces of this 0.010 mm Ag-plated copper alloy wire (Cu-2% Ag) were prepared and twisted at a pitch of 0.5 mm to produce a stranded wire having an outer diameter of 0.030 mm. Thereafter, the obtained ultrafine copper alloy stranded wire was heat-treated for 5.0 seconds in a heat treatment furnace heated to 350 ° C. to obtain an ultrafine copper alloy stranded wire.

  With respect to this ultrafine copper alloy stranded wire, the tensile strength and electrical resistance before and after the heat treatment and the electrical conductivity after the heat treatment were measured in the same manner as in Example 1, and the change rate of the tensile strength and electrical resistance was calculated. The results are shown in Table 1.

  Further, a 0.025 mm thick foamed PFA resin was extrusion coated on the outer periphery of the stranded wire to form an internal insulator having bubbles with an outer diameter of 0.08 mm. A skin layer made of a PET tape having a thickness of 0.01 mm is formed on the outer periphery of the internal insulator, and a Cu—In—Sn alloy wire (0.19 weight) having a strand diameter of 0.016 mm is formed on the outer periphery of the skin layer. % Sn, 0.20% by weight In) is formed on the outer conductor to form an outer conductor, a jacket made of PET tape having a thickness of 0.015 mm is formed on the outer periphery of the outer conductor, and a coaxial cable having an outer diameter of 0.162 mm. Got.

(Preparation of 50AWG coaxial cable)

  The same treatment as in the manufacturing method of Example 19 was performed, except that a heat treatment was performed at 450 ° C. for 1.5 seconds.

(Preparation of 50AWG coaxial cable)

The same treatment as in the manufacturing method of Example 19 was performed, except that a heat treatment was performed at 500 ° C. for 0.4 seconds.
[Comparative Example 1]
(Production of 43AWG coaxial cable)

The same treatment as in the manufacturing method of Example 1 was performed except that the heat treatment was not performed.
[Comparative Example 2]
(Production of 43AWG coaxial cable)

The same treatment as in the production method of Example 2 was performed except that the Ag addition concentration was 0.5% by weight.
[Comparative Example 3]
(Production of 43AWG coaxial cable)

The same treatment as in the production method of Example 2 was performed except that the Ag addition concentration was 3.5% by weight.
[Comparative Example 4]
(Production of 43AWG coaxial cable)

The same treatment as in the production method of Example 1 was performed except that a heat treatment was performed at 250 ° C. for 5.0 seconds.
[Comparative Example 5]
(Production of 43AWG coaxial cable)

The same process as in the manufacturing method of Example 1 was performed except that a heat treatment was performed at 600 ° C. for 0.2 seconds.
[Comparative Example 6]
(Production of 43AWG coaxial cable)

The same process as in the manufacturing method of Example 1 was performed except that a heat treatment was performed at 450 ° C. for 0.1 second.
[Comparative Example 7]
(Production of 43AWG coaxial cable)

The same processing as in the manufacturing method of Example 1 was performed, except that a heat treatment was performed at 450 ° C. for 6.0 seconds.
[Conventional example 1]
(Production of 43AWG coaxial cable)

The same treatment as in the manufacturing method of Example 1 was performed, except that the additive metal was changed to Ag, Sn was 0.3% by weight, and heat treatment was not performed.
[Conventional example 2]
(Production of 43AWG coaxial cable)

The same treatment as in the manufacturing method of Example 1 was performed except that the additive metal was changed to Ag and Sn was 0.3 wt%.
[Conventional Example 3]
(Production of 43AWG coaxial cable)

The same treatment as in the production method of Example 2 was performed except that the additive metal was changed to Ag and Sn was 0.3 wt%.
[Conventional example 4]
(Production of 43AWG coaxial cable)

The same treatment as in the production method of Example 3 was performed except that the additive metal was changed to Ag and Sn was 0.3 wt%.
[Comparative Example 8]
(Preparation of 42AWG coaxial cable)

  0.19 wt% Sn and 0.20 wt% In are added to oxygen-free copper, heated and dissolved in a graphite crucible fixed in a vacuum chamber, and then continuously cast using a graphite mold. A rough drawn wire of φ8 mm was prepared. Then, after wire drawing, intermediate annealing and wire drawing, Ag plating is performed so that the final wire has a thickness of 1.1 μm, wire drawing is performed to a wire diameter of 0.025 mm, and ultrafine copper An alloy wire was obtained. Seven pieces of this 0.025 mm Ag-plated Cu—In—Sn alloy wire (0.19 wt% Sn, 0.20 wt% In) were prepared, twisted at a pitch of 1.3 mm, and the outer diameter Produced a 0.075 mm stranded wire. Then, the obtained stranded wire was heat-treated for 5.0 seconds in a heat treatment furnace heated to 350 ° C. to obtain an ultrafine copper alloy stranded wire.

  With respect to this ultrafine copper alloy stranded wire, the tensile strength and electrical resistance before and after the heat treatment and the electrical conductivity after the heat treatment were measured in the same manner as in Example 1, and the change rate of the tensile strength and electrical resistance was calculated. The results are shown in Table 1.

In addition, a 0.08 mm thick foamed PFA resin was extrusion coated on the outer periphery of the stranded wire to form an internal insulator having bubbles with an outer diameter of 0.235 mm. A skin layer made of a PET tape having a thickness of 0.01 mm is formed on the outer periphery of the internal insulator, and a Cu—In—Sn alloy wire (0.19 weight) having a strand diameter of 0.025 mm is formed on the outer periphery of the skin layer. % Sn, 0.20 wt% In) is wound horizontally to form an outer conductor, a jacket made of 0.015 mm thick PET tape is formed around the outer conductor, and a coaxial cable having an outer diameter of 0.335 mm Got.
[Comparative Example 9]
(Preparation of 42AWG coaxial cable)

The same process as in the manufacturing method of Comparative Example 8 was performed except that a heat treatment was performed at 450 ° C. for 1.5 seconds.
[Comparative Example 10]
(Preparation of 42AWG coaxial cable)

The same treatment as that of the manufacturing method of Comparative Example 8 was performed except that a heat treatment was performed at 500 ° C. for 0.4 seconds.
[Comparative Example 11]
(Production of 44AWG coaxial cable)

The same treatment as in the production method of Example 4 was performed, except that 0.19 wt% tin and 0.19 wt% indium were added instead of silver.
[Comparative Example 12]
(Production of 44AWG coaxial cable)

The same treatment as that of the manufacturing method of Comparative Example 11 was performed except that a heat treatment was performed at 450 ° C. for 1.5 seconds.
[Comparative Example 13]
(Production of 44AWG coaxial cable)

The same process as in the manufacturing method of Comparative Example 11 was performed except that a heat treatment was performed at 500 ° C. for 0.4 seconds.
[Comparative Example 14]
(Production of 46AWG coaxial cable)

The same treatment as in the production method of Example 10 was performed, except that 0.19 wt% tin and 0.19 wt% indium were added instead of silver.
[Comparative Example 15]
(Production of 46AWG coaxial cable)

The same process as in the manufacturing method of Comparative Example 14 was performed except that a heat treatment was performed at 450 ° C. for 1.5 seconds.
[Comparative Example 16]
(Production of 46AWG coaxial cable)

The same treatment as that of the manufacturing method of Comparative Example 14 was performed except that a heat treatment was performed at 500 ° C. for 0.4 seconds.
[Comparative Example 17]
(Preparation of 48AWG coaxial cable)

The same treatment as in the production method of Example 16 was performed, except that 0.19 wt% tin and 0.19 wt% indium were added instead of silver.
[Comparative Example 18]
(Preparation of 48AWG coaxial cable)

The same process as in the manufacturing method of Comparative Example 17 was performed except that a heat treatment was performed at 450 ° C. for 1.5 seconds.
[Comparative Example 19]
(Preparation of 48AWG coaxial cable)

The same process as in the manufacturing method of Comparative Example 17 was performed except that a heat treatment was performed at 500 ° C. for 0.4 seconds.
[Comparative Example 20]
(Preparation of 50AWG coaxial cable)

The same treatment as in the production method of Example 19 was performed, except that 0.19 wt% tin and 0.19 wt% indium were added instead of silver.
[Comparative Example 21]
(Preparation of 50AWG coaxial cable)

The same process as in the manufacturing method of Comparative Example 20 was performed except that a heat treatment was performed at 450 ° C. for 1.5 seconds.
[Comparative Example 22]
(Preparation of 50AWG coaxial cable)

  The same process as the manufacturing method of the comparative example 20 was performed except the point which heat-processes at 500 degreeC for 0.4 second.

(Evaluation results of ultrafine copper alloy stranded wires of Examples 1 to 21, Comparative Examples 1 to 22, and Conventional Examples 1 to 4)
Table 1 shows the tensile strength and electrical resistance before and after the heat treatment, the electrical conductivity after the heat treatment, the tensile strength and the electricity for the ultrafine copper alloy stranded wires of Examples 1-21, Comparative Examples 1-22, and Conventional Examples 1-4. The result of resistance change rate is shown.

  As shown in Table 1, in the seven stranded wires of Examples 1 to 3 (43AWG), since the additive metal concentration and the heat treatment conditions were appropriate, the rate of decrease in tensile strength was 6.9 to 10.8%. The tensile strength after heating was 910 MPa, and the target tensile strength of 850 MPa or more could be cleared. In addition, the rate of decrease in electrical resistance is remarkable at 6.1 to 7.3% (electrical resistance change rate of 6% or more), the electrical resistance after heating is 6,450 Ω / km, and the electrical conductivity is as high as 85% or more. A conductive wire could be obtained.

  In contrast, the seven twisted wires of Conventional Examples 1 to 4 (43 AWG) of copper tin alloy wires have a tensile strength of less than 850 MPa, and the heat treatment of the present invention is similarly applied to conventional copper tin alloy wires. (Conventional Examples 2 to 4), the tensile strength is greatly reduced to 710 to 730 MPa, the decrease rate of the electric resistance is also 0.9% or less, and both the properties of the tensile strength and the conductivity are compatible. It was difficult.

  The conventional twisted strands of Cu—Sn—In alloy wires (see Comparative Examples 8 to 22) had a tensile strength of less than 850 MPa after heating, and a high-strength material could not be obtained.

In addition, since Comparative Example 1 was not heat-treated, although the tensile strength was high, the electrical resistance was as high as 6,870 Ω / km, and a highly conductive wire having a conductivity of 85% or more could not be obtained. .
In Comparative Example 2, since the addition concentration of silver is too low at 0.5% by weight, the tensile strength falls below the target value of 850 MPa, and the rate of decrease in electrical resistance is only 2%, and the tensile strength and It turns out that it is difficult to achieve both resistances.
In Comparative Example 3, since the additive concentration of silver was too large at 3.5% by weight, the reduction rate of the electrical resistance was only 1%, and it was found that it was difficult to achieve both tensile strength and electrical resistance.
In Comparative Example 4, since the heat treatment temperature was as low as 250 ° C., the rate of decrease in electrical resistance was only 0.5%, and it was found that it was difficult to achieve both tensile strength and electrical resistance.
In Comparative Example 5, since the heat treatment temperature was as high as 600 ° C., the rate of decrease in tensile strength was remarkably 27.3%, indicating that it was difficult to achieve both tensile strength and electrical resistance.
In Comparative Example 6, since the heat treatment time was as short as 0.1 seconds, the rate of decrease in electrical resistance was only 1%, and it was found that it was difficult to achieve both tensile strength and electrical resistance.
In Comparative Example 7, since the heat treatment time was as long as 6.0 seconds, the rate of decrease in tensile strength was 22.1%, which was as low as 810 MPa, and it was difficult to achieve both tensile strength and electrical resistance. I understood.

When Examples 1 to 21 and Comparative Examples 8 to 22 are compared, the stranded wires of Comparative Examples 8 to 22 have an electrical resistance decrease rate of about 0.8 to 3.2%, and thus all of them are electric. The wire has a high resistance value. In Comparative Examples 8 to 22, the target value of tensile strength was less than 850 MPa.
That is, from Table 1, when Cu-0.19% Sn-0.19% In alloy as in Comparative Examples 8 to 22 was used, the tensile strength was found in Example 1 regardless of the presence or absence of heat treatment. It is found that the electric resistance is lower than that of Examples 21 to 21 and higher than that of Examples 1 to 21.

Further, as described in the prior art, the conventional product uses a Cu-0.19% Sn-0.19% In alloy twisted wire that is not particularly heat-treated, and is not subjected to a separate heat treatment. Therefore, even if it has high electrical conductivity and high strength characteristics even at the stage of bare seven stranded wires, it is caused by heating (for example, 400 to 300 ° C., 1 second to 5 seconds) generated during the extrusion operation. As shown in the alloy twisted wires of Comparative Examples 8 to 22, it can be seen that the rate of decrease in electrical resistance is small and the tensile strength is lower than before heating.
On the other hand, the stranded wire of the example is preheated after the stranded wire processing, so there is no heat history due to heating that occurs during the extrusion processing, and the tensile strength and electrical resistance before and after the extrusion processing. It is possible to provide a coaxial cable in which there is no fluctuation in

  From the results of Table 1, the electrical characteristics of the coaxial cable of the example are equivalent to those of a conventional one-size thick coaxial cable (for example, the electrical characteristics and mechanical characteristics of the coaxial cables of the 43AWG, 45AWG, and 47AWG of the example) Is equivalent to the electrical and mechanical properties of conventional 42 AWG, 44 AWG, and 46 AWG coaxial cables). Therefore, by using an odd-sized coaxial line such as 43 AWG, 45 AWG, and 47 AWG, it is possible to prevent a sudden deterioration in electrical characteristics of the coaxial line while reducing the diameter of the coaxial cable.

(Evaluation results of coaxial cables of Examples 1 to 21, Comparative Examples 1 to 22, and Conventional Examples 1 to 4)
First, bending tests were performed on the coaxial cables of Examples 1 to 21, Comparative Examples 1 to 22, and Conventional Examples 1 to 4, and the bending life was evaluated. In the bending test, one end of a sample cable (coaxial cable) is fixed to a jig having a bending radius of 2 mm, and a sample is removed from the coaxial cable after a 50 gf or 20 gf weight is suspended from the other end depending on the size of the sample cable. This is a test to measure the number of times (life) until the inner conductor of the sample cable breaks by repeatedly bending it 90 ° left and right at a test speed of 30 times / minute in the longitudinal direction. A voltage of several volts is constantly applied to the sample. The lifetime was determined when the current value decreased by 20% compared to the start of the test. The numerical values in the following table represent the number of bendings until the end of the service life.

Moreover, about each coaxial cable of Examples 1-21, Comparative Examples 1-22, and Conventional Examples 1-4, an electrostatic capacitance, attenuation amount, and characteristic impedance were evaluated.
The capacitance was measured by connecting an LCR meter between the inner conductor and outer conductor of a 1 m sample cable (coaxial cable) and measuring the capacitance at 1 kHz. Further, between the inner conductor and the outer conductor at both ends of the 1 m sample cable, the coaxial cable for measurement (lead wire) was connected to the transmitting side and the receiving side of the network analyzer, and the attenuation at 10 MHz was measured. Before measuring the attenuation of the sample, calibration was performed to eliminate the influence of the measurement coaxial cable (lead wire). The characteristic impedance was measured at 10 MHz using a network analyzer.
Table 2 shows the evaluation results of these electrical characteristics and mechanical characteristics.

As shown in Table 2, the bending life of the coaxial cables of Examples 1 to 3 (43 AWG) is more than 20,900 times, whereas Comparative Examples 1 to 7 (43 AWG) and Conventional Examples 1 to 4 (43 AWG) Then, 19,600 times, 12,300 times, 18,200 times, 20,600 times, 12,400 times, 18,800 times, 9,300 times, 16,500 times, 12,400 times, 11,900 times, respectively. It is understood that the coaxial cable of Examples 1 to 3 has a long bending life and excellent bending characteristics.
Further, even when Examples 4 to 21 and Comparative Examples 11 to 22 having the same wire size are compared, the coaxial cable of the example has a longer bending life and excellent bending characteristics than the coaxial cable of the comparative example. I understand that.

  Moreover, from the result of Table 2, it has confirmed that the coaxial cable of Examples 1-21 was maintaining the same electrostatic capacitance and characteristic impedance compared with the coaxial cable of a comparative example and a prior art example. Regarding the attenuation when the frequency is 10 MHz, it was confirmed that the coaxial cable of the example maintained the same or better attenuation characteristics than the coaxial cable of the conventional example and the comparative example of the same wire size. .

In particular, Comparative Example 8 is a 42 AWG coaxial cable, but when compared with the coaxial cable of Example 1 to Example 3 in terms of flex life and attenuation, the flex life is longer in Examples 1 to 3 and attenuation. It can be evaluated that the amount is almost the same.
Moreover, referring to Table 1, when comparing the tensile strength and electrical resistance in the stranded wire state, the tensile strength is superior in Examples 1 to 3, and the electrical resistance is evaluated to be substantially equivalent. it can.
In other words, according to the present embodiment, even if the coaxial cable is reduced by one size according to the customer's request, etc., the electrical characteristics (center conductor resistance, attenuation) are equivalent to those of the one size thicker comparative example. A coaxial cable having a higher bending characteristic (tensile strength) than that of a comparatively thick one size can be provided. For this reason, when reducing the diameter of the coaxial cable, it is possible to suppress deterioration of electrical characteristics (electric resistance, attenuation) and mechanical characteristics (bending life) as much as possible.

[Other Embodiments]
In addition to silver as an additive element of the copper alloy of the present invention, it is also possible to add one or two metals selected from magnesium (Mg) and indium (In) in a total amount of 0.02 to 0.10% by weight. It is. Increasing the amount of additive elements leads to an increase in cost, but further enhancement of strength can be expected.

It is a cross-sectional view of the coaxial cable of one embodiment of the present invention. It is a cross-sectional view of the multicore cable of one embodiment of the present invention. It is a cross-sectional view of the multicore cable of one embodiment of the present invention. It is a cross-sectional view of the multicore cable of one embodiment of the present invention.

Explanation of symbols

1 Copper alloy wire 3 Copper alloy stranded wire (Internal conductor)
DESCRIPTION OF SYMBOLS 5 Foam insulator 6 Skin layer 7 Conductor wire 8 Outer conductor 9 Jacket layer 10 Coaxial cable 20, 30, 40 Multicore cable 21 Tension member 23 Binding tape 25 Shield 27 Sheath 31 Coaxial cable unit 41 Adhesive tape

Claims (14)

  A plurality of copper alloy wires containing 1 to 3% by weight of silver (Ag) and the balance of copper (Cu) and inevitable impurities and having a wire diameter of 0.010 to 0.025 mm are twisted together to form a copper alloy twisted wire. The copper alloy stranded wire has a tensile strength of 850 MPa or more, an electrical conductivity of 85% IACS or more, and the outer periphery of the copper alloy stranded wire is coated with a foamed insulator, and further, a plurality of A coaxial cable, wherein a conductor wire is spirally wound along a longitudinal direction of the copper alloy stranded wire to form an outer conductor, and a jacket layer is coated on a surface of the outer conductor.   The copper alloy stranded wire is heat-treated, the reduction rate of the electrical resistance after the heat treatment is 6% or more, and the reduction rate of the tensile strength after the heat treatment is 20% or less. The coaxial cable according to claim 1.   The coaxial cable according to claim 1, wherein a plating layer of tin (Sn), silver (Ag), or nickel (Ni) is formed on a surface of the copper alloy wire.   A coaxial cable having a wire diameter of more than 0.021 mm and not more than 0.025 mm, wherein the copper alloy wire has an electric resistance of 7500 Ω / km or less and a capacitance of 30 to 80 pF / m. The coaxial cable according to claim 1.   A coaxial cable having a wire diameter of more than 0.018 mm and not more than 0.022 mm, wherein the copper alloy wire has an electric resistance of 10,000 Ω / km or less and a capacitance of 30 to 80 pF / m. The coaxial cable according to claim 1.   A coaxial cable having a wire diameter of more than 0.016 mm and not more than 0.020 mm, wherein the copper alloy wire has an electric resistance of 13000 Ω / km or less and a capacitance of 30 to 80 pF / m. The coaxial cable according to claim 1.   A coaxial cable having a wire diameter of more than 0.014 mm and not more than 0.018 mm, wherein the copper alloy wire has an electric resistance of 15500 Ω / km or less and a capacitance of 30 to 80 pF / m. The coaxial cable according to claim 1.   A coaxial cable having a wire diameter of more than 0.013 mm and not more than 0.017 mm, wherein the copper alloy wire has an electric resistance of 17000 Ω / km or less and a capacitance of 30 to 80 pF / m. The coaxial cable according to claim 1.   A coaxial cable having a wire diameter of more than 0.011 mm and not more than 0.015 mm, wherein the copper alloy wire has an electric resistance of 23500 Ω / km or less and a capacitance of 30 to 80 pF / m. The coaxial cable according to claim 1.   A coaxial cable having a wire diameter of more than 0.008 mm and not more than 0.012 mm, wherein the copper alloy wire has an electric resistance of 40000 Ω / km or less and a capacitance of 30 to 80 pF / m. The coaxial cable according to claim 1.   A copper alloy is produced by adding 1 to 3% by weight of silver to pure copper, and after drawing to produce an ultrafine copper alloy wire having a wire diameter of 0.010 to 0.025 mm, a plurality of the ultrafine copper alloy wires are formed. This twisted wire is made into an ultrafine copper alloy stranded wire, subjected to heat treatment at a temperature of 300 to 500 ° C. for 0.2 to 5 seconds, and then the foamed insulator having a thickness of 0.28 mm or less on the outer periphery of the copper alloy stranded wire After forming a skin layer, on the outer periphery, a plurality of conductor wires are spirally wound along the longitudinal direction of the copper alloy twisted wire to form an outer conductor, and then the surface of the outer conductor is formed. A method of manufacturing a coaxial cable, characterized in that a jacket layer is covered.   A multi-core cable, wherein a plurality of the coaxial cables according to claim 1 are twisted around an outer periphery of a tension member or a central interposition.   A multi-core cable, wherein a plurality of coaxial cable units formed by bundling a plurality of coaxial cables according to claim 1 are twisted around an outer periphery of a tension member or a central interposition.   A multi-core cable comprising a plurality of coaxial cables according to claim 1 arranged in parallel at a constant pitch.

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