JP2022048924A - Coaxial cable and cable assembly - Google Patents

Abstract

To provide a coaxial cable and a cable assembly hardly causing lowering of a shield effect, and hardly causing abrupt attenuation in a predetermined frequency band.SOLUTION: A coaxial cable 1 is such that: a shield layer 4 has a laterally wound shield part 41 formed by winding a plurality of metal element wires 411 having plating layers 411b in the outermost layers around the periphery of an insulator 3, and a collective plating part 42 comprising hot-dip plating covering the periphery of the laterally wound shield part 41; the shield layer 4 has a connection part 43 in which the metal element wires 411 adjacent in the peripheral direction are connected by the collective plating part 42 in a separation part 45 in which the metal element wires 411 adjacent in the peripheral direction are separated from each other; and the shield layer 4 has an inner peripheral part 4b in which the plurality of metal element wires 411 are not covered by the collective plating part 42 and a plating layer 411b is exposed, and is provided with the connection part 43 between the adjacent inner peripheral parts 4b.SELECTED DRAWING: Figure 1

Description

The present invention relates to coaxial cables and cable assemblies.

Coaxial cables are used as internal wiring for image pickup devices used for automatic driving and electronic devices such as smartphones and tablet terminals, or as cables for high-frequency signal transmission used as wiring in machine tools such as industrial robots. ..

As a conventional coaxial cable, a tape member such as a copper tape in which a copper foil is provided on a resin layer is spirally wound around an insulator to form a shield layer (for example, Patent Document 1). reference).

Japanese Unexamined Patent Publication No. 2000-285747

However, the above-mentioned conventional coaxial cable has a problem that a phenomenon called suckout occurs in which a rapid attenuation occurs in a predetermined frequency band (for example, a band of several GHz such as 1.25 GHz).

On the other hand, for example, by plating the outer surface of the insulator to form a shield layer, it is possible to suppress the occurrence of suckout. However, when the coaxial cable is repeatedly bent, cracks and peeling from the outer surface of the insulator may occur in the shield layer made of plating. If the shield layer made of plating cracks or peels off from the outer surface of the insulator, the shielding effect is reduced. That is, the effect of shielding the noise generated in the coaxial cable by the shield layer is reduced.

Therefore, an object of the present invention is to provide a coaxial cable and a cable assembly in which a decrease in the shielding effect is unlikely to occur and a rapid attenuation is unlikely to occur in a predetermined frequency band.

The present invention includes a conductor, an insulator that covers the periphery of the conductor, a shield layer that covers the periphery of the insulator, and a sheath that covers the periphery of the shield layer, for the purpose of solving the above problems. The shield layer is a horizontal winding shield portion formed by spirally winding a plurality of metal strands having a plating layer on the outermost layer around the insulator, and hot-dip plating covering the periphery of the horizontal winding shield portion. The shield layer has a batch plating portion including, and in a separated portion where the metal strands adjacent to each other in the circumferential direction are separated from each other, the metal strands adjacent to each other in the circumferential direction are the batch plating portion. The shield layer has an inner peripheral portion in which the plurality of metal strands are not covered by the collective plating portion and the plating layer is exposed, and the shield layer is adjacent to each other. Provided is a coaxial cable in which the connecting portion is provided between the inner peripheral portions.

The present invention also provides a cable assembly comprising the coaxial cable and a terminal member integrally provided at at least one end of the coaxial cable, for the purpose of solving the above problems.

According to the present invention, it is possible to provide a coaxial cable and a cable assembly in which a decrease in the shielding effect is unlikely to occur and a rapid attenuation is unlikely to occur in a predetermined frequency band.

It is a figure which shows the coaxial cable which concerns on one Embodiment of this invention, (a) is the sectional view which shows the cross section perpendicular to the longitudinal direction, (b) is the main part enlarged view. It is a figure explaining the formation of the batch plating part. It is a photograph and an enlarged photograph thereof when the shield layer was peeled off and observed. (A) is a photograph showing the result of analyzing the region where silver is present in the peeled shield layer, and (b) is a photograph showing the result of analyzing the region where tin is present in the peeled shield layer. It is a graph which shows the evaluation result of a frequency characteristic. It is sectional drawing which shows the terminal part of the cable assembly which concerns on one Embodiment of this invention.

[Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(Overall configuration of coaxial cable 1)
1A and 1B are views showing a coaxial cable 1 according to the present embodiment, FIG. 1A is a cross-sectional view showing a cross section perpendicular to the longitudinal direction, and FIG. 1B is an enlarged view of a main part thereof.

As shown in FIGS. 1A and 1B, the coaxial cable 1 is provided so as to cover the conductor 2, the insulator 3 provided so as to cover the periphery of the conductor 2, and the insulator 3. It includes a shield layer 4 provided and a sheath 5 provided so as to cover the periphery of the shield layer 4.

The conductor 2 is composed of a stranded conductor in which a plurality of metal strands 21 are twisted together. In this embodiment, a conductor 2 obtained by twisting seven metal strands 21 made of annealed copper wire having an outer diameter of 0.023 mm is used. Not limited to this, as the conductor 2, a compression stranded conductor obtained by twisting the metal strands 21 and then compression-processing so that the cross-sectional shape perpendicular to the cable longitudinal direction becomes a circular shape can also be used. By using a compressed stranded conductor as the conductor 2, the conductivity is improved, good transmission characteristics can be obtained, and bendability can be maintained. Further, from the viewpoint of improving conductivity and mechanical strength, the metal wire 21 includes tin (Sn), silver (Ag), indium (In), titanium (Ti), magnesium (Mg), iron (Fe) and the like. It may be a copper alloy wire containing.

The insulator 3 is made of, for example, PFA, FEP (fluorinated ethylene / propylene hexafluoride copolymer) fluororesin, polyethylene, polypropylene or the like. The insulator 3 may be a foamed resin or may be made of a crosslinked resin in order to improve heat resistance. Further, the insulator 3 may have a multi-layer structure. For example, a first non-foaming layer made of non-foaming polyethylene is provided around the conductor 2, a foaming layer made of foamed polyethylene is provided around the first non-foaming layer, and a first non-foaming polyethylene is provided around the foaming layer. It is also possible to have a three-layer structure in which two non-foamed layers are provided. In the present embodiment, an insulator 3 made of PFA is formed by tube extrusion around the conductor 2. By forming the insulator 3 by extruding a tube, it becomes easy to peel off the insulator 3 from the conductor 2 at the time of terminal processing, and the terminal workability is improved.

The sheath 5 is made of, for example, a fluororesin such as PFA or FEP, polyvinyl chloride, crosslinked polyolefin or the like. In the present embodiment, the sheath 5 made of fluororesin is formed by tube extrusion.

(Shield layer 4)
In the coaxial cable 1 according to the present embodiment, the shield layer 4 includes a horizontal winding shield portion 41 in which a plurality of metal strands 411 are spirally wound around the insulator 3, and the entire circumference of the horizontal winding shield portion 41. It has a conductive batch plating portion 42 provided so as to collectively cover it.

In the present embodiment, the metal wire 411 is fixed by the collective plating portion 42. Therefore, in order to ensure the bendability of the coaxial cable 1, the metal wire 411 has a low yield strength that is easily plastically deformed. It is necessary to use a material made of various materials. More specifically, as the metal wire 411, it is preferable to use a metal wire having a tensile strength of 200 MPa or more and 380 Pa or less and an elongation of 7% or more and 20% or less.

In the present embodiment, as the metal strand 411, a silver-plated annealed copper wire having a plating layer 411b made of silver around the metal wire 411a made of annealed copper wire is used. The metal wire 411a is not limited to annealed copper wire, but may be a copper alloy wire, an aluminum wire, an aluminum alloy wire, or a wire having a low softening temperature in which a trace amount of a metal element (for example, titanium, magnesium, etc.) is added to pure copper. Can be used. Further, the metal constituting the plating layer 411b is not limited to silver, and may be, for example, tin or gold. However, in order to improve the electrical characteristics of the coaxial cable 1, it is desirable that the plating layer 411b has a high conductivity, and it is desirable to use a material having at least a higher conductivity than the batch plating portion 42. That is, it can be said that it is more preferable to use the plating layer 411b made of silver having high conductivity. Here, the horizontal winding shield portion 41 is formed by using 22 metal strands 411 made of silver-plated annealed copper wire having an outer diameter of 0.025 mm.

Further, in the present embodiment, as the batch plating portion 42 made of hot-dip plating, one made of tin is used. However, the present invention is not limited to this, and as the batch plating portion 42, for example, one made of silver, gold, copper, zinc or the like can be used. However, from the viewpoint of ease of manufacture, it can be said that it is more preferable to use the batch plating portion 42 made of tin.

FIG. 2 is a diagram illustrating the formation of the batch plating portion 42. First, prior to the formation of the batch plating portion 42, a plurality of metal strands 411 are twisted around the insulator 3 to form the horizontal winding shield portion 41. A cable substrate 101 in which a laterally wound shield portion 41 is formed around the insulator 3 is referred to as a cable substrate 101. When forming the batch plating portion 42, first, the drum 102a around which the cable substrate 101 is wound is set in the delivery device 102, and the cable substrate 101 is sent out from the delivery device 102. The cable substrate 101 delivered from the delivery device 102 is introduced into the flux tank 103, and the flux is applied to the periphery of the cable substrate 101 (that is, the periphery of the horizontal winding shield portion 41). The flux is for facilitating the simultaneous adhesion of molten tin to the entire circumference of the horizontal winding shield portion 41, and for example, a rosin-based flux or the like can be used. The cable substrate 101 that has passed through the flux tank 103 is introduced into the plating tank 104 that stores tin melted at a temperature of 250 ° C. or higher and lower than 300 ° C., and passes through the die 105. The tin remaining after passing through the die 105 is cooled to form the batch plating portion 42. That is, the batch plating portion 42 is a hot-dip plating layer formed by hot-dip plating. After that, the cable substrate 101 on which the batch plating portion 42 is formed is wound up by the winder 106. The linear velocity when the cable substrate 101 on which the horizontal winding shield portion 41 is formed is passed through the plating tank 104 is, for example, 40 m / min or more and 80 m / min or less, and more preferably 50 m / min or more and 70 m / min or less. It is as follows.

When forming the batch plating portion 42, the silver constituting the plating layer 411b of the portion in contact with the molten tin (that is, hot-dip plating) diffuses into the tin in the plating tank 104, and the metal strand 411 and the batch plating portion 42 (That is, the portion between the metal wire 411a and the batch plating portion 42 that is in contact with the surface of the metal wire 411), an intermetal compound 411c containing copper and tin is formed. When the present inventors performed EDX analysis (analysis by energy dispersive X-ray spectroscopy) using SEM (scanning electron microscope), the surface of the metal wire 411 (the metal wire 411 and the batch plating portion 42) It was confirmed that the intermetallic compound 411c composed of copper and tin was present in layers. That is, in the intermetallic compound 411c, the metal element (tin, etc.) constituting the batch plating portion 42 made of hot-dip plating and the metal element (copper, etc.) constituting the main component of the metal strand 411 undergo a metallic diffusion reaction. A compound layer is formed on the surface of the metal wire 411. The thickness of the layer of the intermetallic compound 411c is, for example, about 0.2 μm to 1.5 μm. It is considered that the intermetallic compound 411c contains silver constituting the plating layer 411b, but the silver content in the intermetallic compound 411c is so small that it is difficult to detect by EDX analysis.

The shield layer 4 has an intermetallic compound 411c formed between the metal wire 411 and the batch plating portion 42, so that the surface of the metal wire 411 is formed when the coaxial cable 1 is repeatedly bent or twisted. The batch plating portion 42 is less likely to come off, and a gap is less likely to occur between the metal wire 411 and the batch plating portion 42. As a result, in the coaxial cable 1, even if bending or twisting is applied, the horizontal winding shield portion 41 can be kept fixed by the collective plating portion 42 from the outside of the horizontal winding shield portion 41, and the shield layer 4 and the shield layer 4 can be maintained. The distance to the conductor 2 is less likely to change. Therefore, in the coaxial cable 1, it is possible to prevent the shielding effect from being lowered due to bending or twisting, and it is possible to prevent abrupt attenuation from occurring in a predetermined frequency band. The thickness of the layer of the intermetallic compound 411c is determined by observing the cross section of the coaxial cable 1 (the cross section perpendicular to the longitudinal direction of the coaxial cable 1) using, for example, an optical microscope or an electron microscope.

A plating layer 411b made of silver remains on the metal wire 411 in the portion that does not come into contact with the batch plating portion 42 (the metal wire 411 in the portion that does not come into contact with the tin melted during plating). That is, the plating layer 411b made of silver remains on the metal strand 411 at the inner side (insulator 3 side) in the cable radial direction. That is, in the shield layer 4 of the coaxial cable 1 according to the present embodiment, the plurality of metal strands 411 are covered by the batch plating portion 41 rather than the outer peripheral portion 4a in which the plurality of metal strands 411 are covered by the batch plating portion 4. The conductivity of the inner peripheral portion 4b where the plating layer 411b is exposed is high. In the transmission of high-frequency signals, the current is concentrated on the insulator 3 side of the shield layer 4, so that the plating layer 411b having high conductivity such as silver is present in the inner peripheral portion 4b of the shield layer 4, so that the shield layer is formed. It is possible to suppress the decrease in conductivity of 4 and maintain good damping characteristics. The conductivity of the tin plating constituting the batch plating portion 42 is 15% IACS, and the conductivity of the silver plating constituting the plating layer 411b is 108% IACS.

The outer peripheral portion 4a referred to here is a portion where the metal wire 411 comes into contact with the plating (tin or the like) melted during hot-dip plating (that is, a portion where the intermetallic compound 411c is formed). The inner peripheral portion 4b is a portion where the plating layer 411b made of silver plating or the like remains.

(Explanation of connecting portion 43)
The shield layer 4 has a separated portion 45 in which metal strands adjacent to each other in the circumferential direction are separated from each other. It is not necessary that all the metal strands 411 are separated from each other, and there may be a contact portion in which some of the metal strands 411 adjacent to each other in the circumferential direction are in contact with each other. The contact portion has a filling portion on the outer periphery of the horizontal winding shield portion 41 in which the metal strands 411 adjacent to each other in the circumferential direction are filled by the batch plating portion 42.

The shield layer 4 has a connecting portion 43 in which metal strands 411 adjacent to each other in the circumferential direction are connected by a batch plating portion 42. It is desirable that the batch plating portion 42 is provided so as to collectively cover the entire circumference of the lateral winding shield portion 41 in the circumferential direction and the axial direction, and to mechanically and electrically connect a plurality of metal strands 411. In the shield layer 4 of the coaxial cable 1 according to the present embodiment, a connecting portion 43 is provided between adjacent inner peripheral portions 4b. Since the periphery of the inner peripheral portion 4b is not covered by the collective plating portion 42, it is between the inner peripheral portions 4b of the adjacent metal strands 411 and between the outer surface of the insulator 3 and the collective plating portion 42 (connecting portion 43). ), There is an air layer 44 between the inner surface and the inner surface. With respect to the air layer 44, the inner surface of the connecting portion 43 facing the outer surface of the insulator 3 has a shape curved so as to be recessed toward the inner side of the connecting portion 43. By having such a curved shape, an air layer 44 having a predetermined size can be provided between the outer surface of the insulator 3 and the inner surface of the connecting portion 43, so that the shielding effect is less likely to deteriorate and the predetermined size is determined. It is possible to use the coaxial cable 1 in which abrupt attenuation is unlikely to occur in the frequency band (for example, the frequency band up to 26 GHz).

FIG. 3 is a photograph and an enlarged photograph thereof when the coaxial cable 1 is actually prototyped, the shield layer 4 is peeled off, and observed. As shown in FIG. 3, in the present embodiment, at least a part of the shield layer 4 constitutes the connecting portion 32 when viewed from the inside in the cable radial direction (direction from the surface of the insulator 3 toward the shield layer 4). The batch plating portion 42 and the plating layer 411b exposed at the inner peripheral portion 4b are alternately arranged in a direction perpendicular to the longitudinal direction of the metal wire 411. That is, when the shield layer 4 is viewed from the inside in the radial direction, the tin constituting the collective plating portion 42 and the silver constituting the plating layer 411b are alternately arranged in a striped pattern.

By having the connecting portion 43 between the adjacent inner peripheral portions 4b, for example, as compared with the case where all the metal strands 411 adjacent in the circumferential direction come into contact with each other, the batch plating portion 42 is subjected to bending or twisting. Is less likely to crack or peel off. That is, the connecting portion 43 in which the portions where the metal strands 441 are separated from each other are connected by the batch plating portion 42 is composed of only the batch plating portion 42 made of hot-dip plating that is more flexible than the metal strands 411. .. When bending or twisting is applied, the collective plating portion 42 of the connecting portion acts to stretch, and the flexibility of the entire shield layer 4 is improved. As a result, the batch plating portion 42 is less likely to crack or peel off when bent or twisted. The distance between the adjacent metal strands 411 in the circumferential direction is such that the shortest distance from the surface of one metal strand 411 to the other metal strand 411 is less than half the outer diameter of the metal strand 411. And, the above-mentioned action and effect can be easily obtained.

Further, the thickness W (the minimum linear distance from the inner surface to the outer surface of the collective plating portion 42 in the connecting portion 43) along the radial direction of the collective plating portion 42 in the connecting portion 43 is, for example, the outer diameter of the metal strand 411. When it is 30% (0.3 × d) or more of (diameter) d, cracking of the batch plating portion 42 is less likely to occur. In particular, when the thickness W of the batch plating portion 42 in the connecting portion 43 is the same as or larger than the outer diameter (diameter) d of the metal strands 411, the bonding strength between the metal strands 411 becomes large. Further, cracking is less likely to occur. Further, in the coaxial cable 1, since the collective plating portion 42 has the connecting portion 43 as described above, when the cable assembly is performed, the plurality of metal strands 411 constituting the horizontal winding shield portion 41 are combined with the collective plating portion 42. The shield layer 4 can be easily removed while spirally winding along the winding direction of the plurality of metal strands 411 in a state of being attached to the coaxial wire. The upper limit of the thickness W of the collective plating portion 42 in the connecting portion 43 may be, for example, 130% (1.3 × d) of the outer diameter d of the metal wire 411. The outer diameter d of the metal wire 411 is, for example, 0.02 mm to 0.10 mm. For the thickness W of the connecting portion 43 and the outer diameter d of the metal wire 411, for example, the cross section of the coaxial cable 1 (the cross section perpendicular to the longitudinal direction of the coaxial cable 1) is observed using an optical microscope or an electron microscope. It is required by that.

For example, if the shield layer 4 is composed of only the horizontal winding shield portion 41, a gap is generated between the metal strands 411 and the noise characteristics are deteriorated. Further, due to the influence of the gap generated between the metal strands 411, a phenomenon called suckout occurs in which abrupt attenuation occurs in a predetermined frequency band (for example, a band of 10 GHz to 25 GHz). As in the present embodiment, by providing the collective plating portion 42 made of hot-dip plating so as to cover the entire circumference of the horizontal winding shield portion 41, the gap between the metal strands 411 can be closed by the collective plating portion 42. , The shielding effect can be improved. This makes signal transmission loss less likely to occur. Further, by eliminating the gap between the metal strands 411, it is possible to suppress the occurrence of suckout.

Further, by providing the batch plating portion 42 so as to cover the periphery of the horizontal winding shield portion 41, the metal wire 411 is unwound when the sheath 5 is removed at the cable terminal portion to expose the shield layer 4 during terminal processing. It becomes difficult and it becomes possible to easily perform terminal processing. Furthermore, by providing the batch plating portion 42 so as to cover the periphery of the horizontal winding shield portion 41, it is possible to keep the impedance stable and constant in the longitudinal direction of the cable.

FIG. 4A is a photograph showing the result of analyzing the region where silver is present in the shield layer 4 peeled off from the insulator 3, and FIG. 4B is a photograph showing the region where tin is present in the peeled shield layer 4. It is a photograph showing the result of analysis. Both FIGS. 4A and 4B show a state in which the peeled shield layer 4 is observed from the inside in the radial direction of the cable, and the scales of both are the same. In FIG. 4A, the light-colored portion represents the region where silver (Ag) is present, and in FIG. 4B, the light-colored portion represents the region where tin (Sn) is present. Represents. Note that FIGS. 4 (a) and 4 (b) are obtained by elementally mapping the data obtained from EDX analysis using SEM.

As shown in FIGS. 4A and 4B, in the shield layer 4, tin (Sn) is present in the width of the region where silver (Ag) is present when viewed from the inside in the cable radial direction. It is larger than the width of the area. That is, in the present embodiment, the width of the plating layer 411b exposed at the inner peripheral portion 4b is larger than the width of the collective plating portion 42 constituting the connecting portion 43 when viewed from the inside in the radial direction of the cable. The width referred to here is the width in the arrangement direction (vertical direction of FIGS. 4A and 4B) of the plating layer 411b and the collective plating portion 42, and is a direction perpendicular to the longitudinal direction of the metal wire 411. The width of.

When a current (shielding current) flows from the insulator 3 side to the shield layer 4, the loss is smaller and the transmission characteristics are improved when this shield current flows to the plating layer 411b made of silver having high conductivity. .. Therefore, as in the present embodiment, by making the width of the plating layer 411b larger than the width of the collective plating portion 42 (connecting portion 43) when viewed from the inside in the cable radial direction, the shield current is transferred to the plating layer 411b. It becomes easier to flow and it becomes possible to improve the transmission characteristics. In particular, the wider the width of the plating layer 411b, the larger the region of the inner peripheral portion 4b, and the longer the distance from the insulator 3 to the inner surface of the batch plating portion 42 (connecting portion 43). The shield current is less likely to flow in 42, and the transmission characteristics are further improved.

(Characteristic evaluation of coaxial cable 1)
The coaxial cable 1 according to the present embodiment was produced and used as an example, and the frequency characteristics were evaluated. The cable length was 1 m. Further, in the coaxial cable 1 in the embodiment, a conductor 2 made by twisting seven metal strands 21 made of annealed copper wire having an outer diameter of 0.023 mm is used, and PFA (perfluoroalkoxyalkane) is used as the insulator 3. A tube-extruded one is used, and 22 metal strands 411 having an outer diameter of 0.025 mm (43 AWG) and silver plating on the surface are spirally wound as the horizontal winding shield portion 41, and the batch plating portion is used. As 42, hot-dip plating made of molten tin was used, and as the sheath 5, one made of fluororesin was used. In the evaluation of the frequency characteristic, the transmission characteristic S21 was measured using a network analyzer. The measurement range was 10 MHz to 30 GHz, and the output power was −8 dBm. The measurement results are shown in FIG.

As shown in FIG. 5, in the coaxial cable 1 of the embodiment, no rapid attenuation was observed up to 20 GHz or later (for example, up to 26 GHz), and it was confirmed that the suckout was suppressed. From the result of FIG. 5, it was confirmed that it was suck-out free in the frequency band of at least 25 GHz or less.

(Cable assembly)
Next, a cable assembly using the coaxial cable 1 will be described. FIG. 6 is a cross-sectional view showing a terminal portion of the cable assembly according to the present embodiment.

As shown in FIG. 6, the cable assembly 10 includes a coaxial cable 1 according to the present embodiment and a terminal member 11 integrally provided at at least one end of the coaxial cable 1.

The terminal member 11 is, for example, a connector, a sensor, a substrate mounted on the connector or the sensor, a substrate in an electronic device, or the like. FIG. 6 shows a case where the terminal member 11 is a substrate 11a. The substrate 11a is formed with a signal electrode 12 to which the conductor 2 is connected and a ground electrode 13 to which the shield layer 4 is connected. The substrate 11a is a printed circuit board on which a conductor pattern including a signal electrode 12 and a ground electrode 13 is printed on a base material 16 made of resin.

In the terminal portion of the coaxial cable 1, the sheath 5 having a predetermined length is removed from the terminal to expose the shield layer 4, and the exposed shield layer 4 and the terminal portion of the insulator 3 are removed to expose the conductor 2. Is exposed. The exposed conductor 2 is fixed to the signal electrode 12 by a connecting material 14 such as solder, and the conductor 2 is electrically connected to the signal electrode 12. Further, the exposed shield layer 4 is fixed to the ground electrode 13 by a connecting material 15 such as solder, and the shield layer 4 is electrically connected to the ground electrode 13. The conductor 2 and the shield layer 4 need not be connected by using connecting materials 14 and 15 such as solder. For example, the conductor 2 and the shield layer 4 are fixed to the fixing metal fittings by crimping or the like. Or the shield layer 4 may be connected. Further, when the terminal member 11 is a connector or a sensor, the conductor 2 or the shield layer 4 may be directly connected to the electrode or the element.

(Actions and effects of embodiments)
As described above, in the coaxial cable 1 according to the present embodiment, the shield layer 4 is the horizontal winding shield portion 41 in which a plurality of metal strands 411 are spirally wound so as to cover the periphery of the insulator 3. The shield layer 4 has a peripheral plating portion 42 made of hot-dip plating that covers the periphery of the horizontal winding shield portion 41, and the shield layer 4 is peripherally formed at a separated portion 45 in which metal strands 411 adjacent to each other in the circumferential direction are separated from each other. The shield layer 4 has a connecting portion 43 in which metal strands 411 adjacent to each other in the direction are connected to each other by a batch plating portion 42, and a plurality of metal strands 411 are not covered by the batch plating portion 42 in the shield layer 4. The plating layer 411b has an exposed inner peripheral portion 4b, and a connecting portion 43 is provided between adjacent inner peripheral portions 4b.

With this configuration, the shield layer 4 is connected to the entire circumference via the batch plating portion 42, and the gap between the metal strands 411 of the horizontal winding shield portion 41 can be closed by the batch plating portion 42. This makes it possible to improve noise characteristics and suppress the occurrence of suckout. That is, according to the present embodiment, it is possible to realize the coaxial cable 1 in which the shielding effect is unlikely to be lowered and the rapid attenuation is unlikely to occur in a predetermined frequency band (for example, a frequency band up to 26 GHz). Further, by providing the batch plating portion 42 so as to enter between the metal strands 411, the bonding strength between the metal strands 411 can be improved, and the batch plating portion 42 is less likely to be peeled off.

(Summary of embodiments)
Next, the technical idea grasped from the embodiment described above will be described with reference to the reference numerals and the like in the embodiment. However, the respective reference numerals and the like in the following description are not limited to the members and the like in which the components within the scope of the claims are specifically shown in the embodiment.

[1] The conductor (2), the insulator (3) that covers the periphery of the conductor (2), the shield layer (4) that covers the periphery of the insulator (3), and the periphery of the shield layer (4). The shield layer (4) has a plurality of metal strands (411) having a plating layer (411b) on the outermost layer in a spiral shape around the insulator (3). The shield layer (4) has a horizontal winding shield portion (41) configured by winding and a collective plating portion (42) made of hot-dip plating that covers the periphery of the horizontal winding shield portion (41). In the separated portion (45) where the metal strands (411) adjacent to each other in the circumferential direction are separated from each other, the metal strands (411) adjacent to each other in the circumferential direction are connected by the collective plating portion (42). In the shield layer (4), the plurality of metal strands (411) are not covered with the collective plating portion (42), and the plating layer (411b) is formed. A coaxial cable (1) having an exposed inner peripheral portion (4b) and having the connecting portion (43) between adjacent inner peripheral portions (4b).

[2] At least a part of the shield layer (4) is exposed at the collective plating portion (42) constituting the connecting portion (43) and the inner peripheral portion (4b) when viewed from the inside in the radial direction of the cable. The coaxial cable (1) according to [1], wherein the plating layers (411b) are alternately arranged in a direction perpendicular to the longitudinal direction of the metal wire (411).

[3] When viewed from the inside in the radial direction of the cable, the width of the plating layer (411b) exposed at the inner peripheral portion (4b) is larger than the width of the collective plating portion (42) constituting the connecting portion (43). The coaxial cable (1) according to [2], which is also large.

[4] The coaxial cable (1) according to any one of [1] to [3], wherein the conductivity of the plating layer (411b) is higher than that of the collective plating portion (42).

[5] The coaxial cable (1) according to any one of [1] to [4], wherein the plating layer (411b) is made of silver and the collective plating portion (42) is made of tin.

[6] The shield layer (4) has an outer peripheral portion (4a) in which the plurality of metal strands (411) are covered by the batch plating portion (42), and the outer peripheral portion (4a) is the plurality of. The coaxial cable (1) according to any one of [1] to [5], which has an intermetallic compound (411c) between the metal wire (411) and the collective plating portion (42).

[7] The coaxial cable (1) according to any one of [1] to [6], and the terminal member (11) integrally provided at at least one end of the coaxial cable (1). Cable assembly (10).

Although the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. It should also be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention. Further, the present invention can be appropriately modified and implemented without departing from the spirit of the present invention.

1 ... Coaxial cable 2 ... Conductor 3 ... Insulator 4 ... Shield layer 4a ... Outer peripheral part 4b ... Inner peripheral part 41 ... Horizontal winding shield part 411 ... Metal wire 411a ... Metal wire 411b ... Plating layer 411c ... Metallic compound 42 ... Batch plating part 4a ... Outer peripheral part 4b ... Inner peripheral part 43 ... Connecting part 45 ... Separation part 5 ... Sheath 10 ... Cable assembly 11 ... Terminal member

Claims (7)

With the conductor
The insulator that surrounds the conductor and
A shield layer that covers the periphery of the insulator and
A sheath that covers the periphery of the shield layer is provided.
The shield layer is made of a horizontal winding shield portion formed by spirally winding a plurality of metal strands having a plating layer on the outermost layer around the insulator, and melt plating covering the periphery of the horizontal winding shield portion. With a batch plating part,
The shield layer has a connecting portion in which the metal strands adjacent to each other in the circumferential direction are connected by the collective plating portion in a separated portion where the metal strands adjacent to each other in the circumferential direction are separated from each other.
Moreover, the shield layer has an inner peripheral portion in which the plurality of metal strands are not covered by the collective plating portion and the plating layer is exposed.
The connecting portion is provided between the adjacent inner peripheral portions.
coaxial cable. In at least a part of the shield layer, when viewed from the inside in the radial direction of the cable, the collective plating portion constituting the connecting portion and the plating layer exposed at the inner peripheral portion are formed in the longitudinal direction of the metal strand. Alternately arranged in the direction perpendicular to the opposite,
The coaxial cable according to claim 1. When viewed from the inside in the cable radial direction, the width of the plating layer exposed at the inner peripheral portion is larger than the width of the collective plating portion constituting the connecting portion.
The coaxial cable according to claim 2. The conductivity of the plating layer is higher than that of the batch plating portion.
The coaxial cable according to any one of claims 1 to 3. The plating layer is made of silver, and the batch plating portion is made of tin.
The coaxial cable according to any one of claims 1 to 4. The shield layer has an outer peripheral portion in which the plurality of metal strands are covered by the batch plating portion.
The outer peripheral portion has an intermetallic compound between the plurality of metal strands and the batch plating portion.
The coaxial cable according to any one of claims 1 to 5. The coaxial cable according to any one of claims 1 to 6 and the coaxial cable.
A terminal member integrally provided at at least one end of the coaxial cable.
Cable assembly.

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