KR100613954B1 - Coaxial cable, multicore cable, and electronics using them - Google Patents

Abstract

For coaxial cables, it is easy to remove external conductors for terminal processing, etc., excellent in insulation characteristics, and less noise is generated even when bending or turning. For this reason, it is coaxial by using one or more coaxial small wires provided with the outer conductor formed by winding the ribbon-shaped conductor which has a substantially rectangular cross section with four corners smoothly spirally around the insulator at an angle of 45 degrees or more. Use a cable. In addition, the moving shaft cable is arranged in a mechanically rotated or bent place to be an electronic device.

Description

Coaxial Cable, Multi-core Cable, and Electronic Device Using It {COAXIAL CABLE, MULTICORE CABLE, AND ELECTRONICS USING THEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single core coaxial wire, a coaxial cable or a multicore coaxial cable used for connecting a liquid crystal display inside a notebook personal computer or a sensor cable of a medical ultrasonic diagnostic apparatus, and an electronic device using the same. .

DESCRIPTION OF RELATED ART Conventionally, the coaxial cable which coat | covered the coaxial small wire which consists of a center conductor, an insulator, and an outer conductor is used. Such a coaxial cable includes a single core cable coated with one coaxial wire, a multicore cable coated with a common wire with a plurality of single core cables, and a multicore cable with a common sheath with a plurality of coaxial wires. As a method of arranging coaxial or single core cables in a multicore cable, there is a layered multicore cable intertwined with a flat multicore cable in which coaxial single wire or single core cables are arranged on a flat surface. Such a single or multi-core coaxial cable may be a composite cable in which a same type of cable is assembled and a different type of communication line or power line.

In a conventional coaxial cable, a laminated tape obtained by laminating a metal tape or an insulating film such as a metal tape and a polyester is generally used as an outer conductor (shield). For example, Japanese Unexamined Patent Application Publication No. 2-47726. Braids of metal tapes are known, as indicated in Japanese Patent No. 2-47728. This outer conductor has the advantage of not being decomposed in the case of metal tape braiding. On the other hand, there is a drawback that it takes time to remove the outer conductor for end treatment.

4 is a side view showing a conventional coaxial cable using braided metal tape. In Fig. 4, reference numeral 11 denotes a center conductor, 12 an insulator, 13 an outer conductor braided with a metal tape, and 14 an outer shell. As such a metal tape, a slit of a wide metal tape is usually used, but sharp edges such as curling and burr remain on the shear surface at the time of slit of the metal tape, and this part damages the insulator, In addition, the insulation breakdown voltage may decrease due to concentration of voltage there. This problem is especially acute in the case of thin coaxial cables having an insulation thickness of 0.15 mm or less.

In addition, when a conventional coaxial cable is placed in a device wiring in an electronic device, particularly in a moving part of a medical sensor cable which moves a cable whenever a rotation part or a medical treatment point corresponding to a monitor part and a main body part of a notebook computer is changed, When the coaxial cable moves, there is a problem that static noise is generated by friction between the insulator and the outer conductor.

[Initiation of invention]

The present invention has been obtained as a result of various studies on the confectionery, and can be applied to the coaxial cables of the various forms. The inventors used a ribbon-shaped conductor obtained by rolling and flattening a copper or copper alloy ring wire as an outer conductor, and wound the outer ribbon conductor on the insulator in a spiral shape to form an outer conductor. By constructing, it has been found that coaxial small wires and coaxial cables, which are flexible and have a low noise when performing mechanical movement and are rich in mechanical durability and have a small outer diameter, can be obtained. Reached.

First of all, the present invention is a coaxial line composed of a center conductor, an insulator, and an outer conductor, the thickness of the insulator being 0.15 mm or less, and as the outer conductor, a ribbon-shaped conductor obtained by rolling a flat line of copper or copper alloy by rolling, is used. It is a coaxial element wire characterized by winding the ribbon-shaped conductor spirally around the insulator.

Secondly, a coaxial element wire composed of a center conductor, an insulator, and an outer conductor, the insulator being formed in contact with the center conductor, and the thickness of the insulator is 0.03 mm or more and 0.15 mm or less in the smallest portion, and the outer conductor is 4 in cross section. It is made by winding one or more ribbon-shaped conductors of approximately rectangular shape with smooth corners in a spiral shape with one long side facing the insulator, and the winding angle with respect to the axis of the coaxial axis of the ribbon-shaped conductor is 45 ° or more. It is characterized by coaxial wire. Here, when the center conductor is a stranded line of a plurality of conductor lines, the thickness of the insulator is obtained as the thickness of the smallest portion by measuring the thickness of the insulator in the circumferential direction. Here, the ribbon conductor is made of a metal containing copper, and is characterized in that the ribbon is wound around the insulator with a tension of 30% or more of the tensile breaking tension of the ribbon conductor.

In addition, one coaxial wire may be coated with a single core coaxial cable.

Alternatively, a plurality of coaxial small wires may be assembled to form a multi-core cable coated with a common sheath. In addition, a common sheath may be coated on the single-core coaxial cable to form a multi-core cable.

Moreover, the said coaxial small wire, coaxial cable, or a multicore cable is arrange | positioned in the place which receives the mechanical rotation or bending of an electronic device.

The substantially rectangular ribbon-shaped conductor of the shape where the four corners of the cross section used here are smooth can be manufactured easily at low cost by rolling and flattening the round wire of copper or copper alloy. In the present invention, since the ribbon-shaped conductor does not have an acute edge on the outer circumference of the cross section, when wound outside as an outer conductor, there is no problem of damage to the insulator or voltage concentration, and such a substantially rectangular ribbon-shaped conductor Since the mechanical strength is high and not braided, it is easy to remove and easy to handle in terminal processing. In addition, the inventors have found that the noise generated in the coaxial cable due to the rotational bending of the placement portion in the electronic device is the static noise generated by the friction between the insulator and the external conductor. Since the outer conductor of the present invention is formed by winding one long side of the substantially rectangular shape of the ribbon-shaped conductor toward the insulator in a spiral shape, the outer surface of the ribbon-shaped conductor is coaxial with a large friction between the insulator and the insulator. Even when the cable is bent, the phenomenon that the ribbon-shaped conductor rubs the insulator is unlikely to occur, so that the electrostatic noise is prevented.

1 is a perspective view showing a single-core coaxial cable using a representative coaxial wire of the present invention

2 is a schematic diagram illustrating a method of winding a ribbon conductor according to the present invention.

Figure 3 is a schematic diagram showing a cross-sectional view of the flat cable as an example of the multi-core cable of the present invention

Figure 4 is a side view showing a conventional coaxial cable using braiding of metal tape

5 is a view showing a cross-sectional view of the ribbon-shaped conductor of the present invention in comparison with a circular line before rolling;

6 is a diagram illustrating a bending test of coaxial lines.

7 is a diagram illustrating a torsion test of coaxial wires.

Best Mode for Carrying Out the Invention

Hereinafter, the present invention will be described in detail with reference to the drawings. The coaxial small wire constituting the coaxial cable of the present invention basically has an insulator thickness of 0.15 mm or less, and the coaxial small wire can be configured with a narrow diameter, so that the wiring is particularly small in an electronic device requiring a small wiring space and miniaturization of the volume occupied by the wire. It is effective in coaxial cable and thin flat multi-core cable. In addition, a ribbon-shaped conductor obtained by rolling and flattening a copper or copper alloy ring wire as an outer conductor is used, and the ribbon-shaped conductor is wound around the insulator in a spiral shape to form a coaxial wire. 1 is a perspective view schematically showing a single-core coaxial cable using a representative coaxial wire of the present invention. 1, (1) is a center conductor such as copper or copper alloy, (2) is an insulator composed of PFA, polyester, polyimide film, etc., (3) is an outer conductor, and the cross section is approximately rectangular and has four corners. Consists of a ribbon-shaped conductor with a smooth cross section. This ribbon-shaped conductor can be manufactured by chamfering four corners of a rectangular conductor wire, etc. Moreover, it can roll and flatten the ring wire of copper or a copper alloy, and can manufacture it, and is advantageous in terms of manufacturing cost. The ribbon-shaped conductor is wound around the insulator 2 in a spiral shape to form an outer conductor 3.

(1) Thickness of insulators: Electronic devices such as notebook computers and medical sensors change their positions and angles by manpower, so they are increasingly required to be smaller and lighter. Coaxial cables used are also wired in narrow spaces. For this reason, thinning of coaxial cables is required. On the other hand, the deformation applied to the coaxial cable, especially the outer conductor, when the deformation is caused by the rotation or bending of the arrangement portion of the coaxial cable, the larger the outer diameter, the more noise is generated. For this reason, the thickness of the insulator of the coaxial small wire which comprises the coaxial small wire and coaxial cable of this invention is 0.15 mm or less, and needs to be thin. On the other hand, the thinner the insulator thickness is, the better it is.However, since it is subject to deformation due to bending and torsion repeatedly during use, the value that is extremely fine within the range of mechanical durability and flexibility, For example, about 0.03 mm or more is preferable.

(2) Outer conductor: As a ribbon-like conductor constituting the outer conductor, a rolled and flattened round wire made of a metal conductor such as copper or copper alloy is used, and the ribbon-shaped conductor is spirally wound on the insulator. External conductor. Thus, since the ribbon-shaped conductor is obtained by rolling a round wire, the four corners of the cross section have a smooth shape and take the shape of a substantially rectangular shape having no acute edges in the entire circumference. The outer conductor is constructed by winding one long side of the approximately rectangular shape of the ribbon conductor toward the insulator. As a result of the ribbon-shaped conductor having such a shape, it does not have an acute edge like that of the slit tape of the conventional method, and it is hard to cause breakage of the insulator or localization of voltage, and obtains stable breakdown voltage characteristics. Can be. In addition, by using the ribbon-shaped conductor without rolling the copper or copper alloy flattened by rolling the round wire, there is an advantage that it does not decompose only by winding even if it is not partially braided as in the conventional method. The tension when winding the ribbon-shaped conductors does not impair the properties of the insulator, and the wound ribbon-shaped conductors do not break when the coaxial wire or coaxial cable is bent or twisted, while maintaining the force to clamp the insulator at all times. It is necessary to be tension, and it is preferable that it is 30% or more and 80% or less of the breaking tension of a ribbon conductor. In addition, a layer of metal deposited on a thin tape under the outer conductor may be formed. In this case, the shielding effect can be improved and the dielectric breakdown voltage characteristic of the insulator can be improved.

The winding angle of the ribbon-shaped conductor is preferable in that it has flexibility if it is 45 ° or more, more preferably 60 ° or more, but too close to the right angle, productivity is extremely low and undesirable, so about 80 ° That's the limit. In addition, as the size of the outer conductor, the thickness is preferably 0.03 mm or less in order to reduce the outer diameter of the coaxial wire and the coaxial cable, and preferably 0.01 mm or more from the point of mechanical strength. In addition, the width of the ribbon-shaped conductor is preferably wider from the viewpoint of maintaining the characteristics as an outer conductor, and preferably 0.1 mm or more. The narrower one is cheaper in terms of the workability and cost of the outer winding. Since wrinkles hardly occur at the time of occurrence, 0.3 mm or less is preferable. In particular, in terms of electrical characteristics, mechanical properties, and manufacturability, the outer conductor may be manufactured by rolling a tapered conductor having a thickness of 0.025 mm and a width of 0.20 mm, or a round wire having an outer diameter of 0.05 mm. A tape-shaped conductor having a thickness of 0.012 mm and a width of 0.18 mm has excellent characteristics.

(3) Multi-core cable: In particular, in the case of the multi-core cable of the present invention, the outer conductor of the coaxial wire may be used to coaxially wire and to coat a common sheath. Since it is manufactured by rolling from a ring, it has a smooth surface without sharp edges etc. on the outer circumference, so that the insulator may be injured by the outer conductor even if the force from the side, the so-called side pressure, acts on the coaxial shaft by twisting or the like. There is no fear of lowering the breakdown voltage of the insulator, and the thinner and thinner the multicore cable can be realized while maintaining mechanical durability and electrical characteristics as a multicore cable.

This invention is demonstrated concretely by the following Example.

(Example 1)

In order to use it for an outer conductor, the ring wire which tin-plated the copper alloy of outer diameter 0.05mm which showed the cross-sectional shape in FIG. 5 (A) was rolled, and 0.012 mm of thickness and 0.18 mm which showed the cross-sectional shape in the same degree B. Long ribbon-shaped conductors were produced. As an insulator, a PFA (tetrafluoroethylene-per-fluoroalkylvinyl ether copolymer) resin is formed by a known extrusion coating method around a center conductor having an outer diameter of 0.09 mm (seven twists of tin-plated copper alloy wire having an outer diameter of 30 µm). After coating so as to form a circular outer shape having an outer diameter of 0.23 mm, as shown in Fig. 2 (A), the tape-shaped conductor has a tension of 60 gf / 1 piece and a pitch of 0.29 mm as shown in Fig. 2 (A). At intervals, the outer coil was wound in a spiral shape to form an angle of 68 ° with respect to the axis of the coaxial wire, thereby producing a coaxial wire.

The coaxial wire was subjected to a breakdown voltage test as its basic characteristic, a bending test as a dielectric property, a torsion test, and an electrostatic noise test when used in a rotating part and a bent part. At this time, the coaxial cable is manufactured by combining the coaxial strands in various forms. Therefore, the coaxial cable was evaluated in the state of the coaxial strands in order to evaluate in a state without the influence of the outer skin.

Withstand voltage test: Using 300 m coaxial wire, a DC voltage of 1000 V was applied between the center conductor and the outer conductor for 1 minute, and the presence of dielectric breakdown was examined. As a result, the breakdown voltage failure in which the insulating layer was broken was not recognized, and the characteristics as a good coaxial cable could be confirmed.

Mandrel Bending Test: The test method is schematically shown in FIG. The center portion of the coaxial wire 20 is sandwiched between two metal rods 22 of 5 mm in shape, and 50gf load 21 is mounted on the lower end, and the upper end is wound 90 ° on each side of the metal rod. Was performed. One round of right and left bending was performed once, and 1000 rounds of bending were performed at a rate of 30 times / minute. Thereafter, the same pressure resistance test was carried out, but the withstand pressure failure was not recognized, and excellent resistance to repeated bending was confirmed.

Torsion test: The test method is schematically shown in FIG. The upper end of the coaxial small wire 20 having a length of 20 cm is fixed to the upper fixing point 24, and a 50 gf load 23 is attached to the lower end and suspended vertically, and the load 23 is oriented about the central axis of the coaxial cable. To rotate 180 ° counterclockwise and counterclockwise respectively. After twisting in clockwise direction, counterclockwise direction, and each twisting once, and performing 1000 twists at a speed of 30 times / min, the same pressure resistance test was performed as above, but the pressure resistance failure was not recognized. Excellent resistance to could be confirmed.

Electrostatic Noise Characteristics: FIG. 7 schematically shows a test method. In addition, in order to evaluate the magnitude of the electrostatic noise when rapid deformation was applied, a 50-cm-long coaxial wire was horizontally laid, a 20-cm-long cotton thread was attached to the center, and a 20gf load was applied to the other end of the cotton thread. While the voltage between the center conductor of the coaxial line and the external conductor was measured by a voltmeter, the weight was dropped freely from the height of the coaxial line, and the electrostatic noise characteristic was measured as the maximum value of the voltage fluctuation. As a result of performing the same measurement 10 times, the maximum value of the voltage fluctuation which generate | occur | produced about this coaxial line was 2.5 kW at maximum. On the other hand, when the outer conductor of the coaxial wire was changed to the braid shown in Fig. 4 in the related art, and the same evaluation was performed, a voltage variation reaching a maximum value of 100 Hz was seen. From this result, the significant improvement effect of the electrostatic noise was confirmed by the use of this invention.

Next, as shown in FIG. 3, these 10 coaxial wires were arranged in parallel, and the adhesive tape with polyester tape was covered with the outer cover 6 to form a flat multicore cable. In addition, sheathed the coaxial wire to form a single core coaxial cable, and twisted 30 cores of the single core coaxial cable and put a common sheath on the outside to maintain a flexible and mechanical durability as a multicore cable. Got it. Also in the multicore cable obtained in this way, it was confirmed that the characteristics including the insulation characteristics were good.

(Example 2)

In Example 1, the ribbon-shaped conductor was wound around the outer surface with a butt wound as shown in Fig. 2 (B) in a spiral shape at a pitch of 0.18 mm and 75 ° with a design force of 55 gf / 1. . The withstand voltage characteristic, the bending characteristic, the torsion characteristic, and the electrostatic noise characteristic of this coaxial line were also favorable. Using this coaxial wire, a single core coaxial cable, a parallel multicore cable, and a multicore cable were produced in the same manner as in Example 1. The coaxial cable and the multicore cable thus obtained were confirmed to have good characteristics including insulation characteristics.

(Example 3)

In Example 1, as shown in Fig. 2 (c), the ribbon-shaped conductors were spirally formed at a pitch of 0.29 mm and 68 ° with a tension of 65 gf / 1 (delayed by two sheets in the same direction, respectively). Cold) wound outside to produce a coaxial wire. Moreover, as shown to FIG. 2 (D), the thing which wound the 2nd ribbon-shaped conductor in the reverse direction at the pitch of 0.29 mm and 68 degrees was also produced. The pressure resistance, bending characteristics, torsion characteristics and electrostatic noise characteristics of these coaxial wires were also good, and the shielding characteristics of the outer conductor layer were particularly excellent. Also in the same manner as in Example 1, a single core coaxial cable, a flat multicore cable, and a multicore cable were also produced for these coaxial small wires. The coaxial cable and the multicore cable thus obtained were confirmed to have good characteristics including insulation characteristics.

As described above, a substantially rectangular ribbon-shaped conductor having a smooth four corners in cross section is used as the outer conductor, and the ribbon-shaped conductor is wound around the insulator in a spiral shape to form an outer conductor so as to form an outer conductor. By using this coaxial wire, a narrow coaxial cable having flexibility and abundant mechanical durability can be obtained. A plurality of coaxial small wires or coaxial cables may be collected and coated to be used as a multicore cable. In addition, by arranging the coaxial cable or the multi-core cable thus obtained in the rotating part and the bending part of the electronic device, an electronic device having excellent insulation characteristics and a low electrostatic noise for a long time can be obtained, and high quality and high speed signal transmission in the device can be realized. Can be.

Claims (7)

delete As a coaxial wire consisting of a center conductor, an insulator and an outer conductor, The insulator is formed in contact with the center conductor and the thickness of the insulator is 0.03 mm or more and 0.15 mm or less in the smallest portion. The outer conductor is formed by winding one or a plurality of ribbon-shaped conductors of a substantially rectangular shape having four corners of a cross section in a spiral shape with one long side facing the insulator, and the thickness of the ribbon-shaped conductor is 0.01 mm or more. 0.03 mm or less, and the winding angle with respect to the axis of the coaxial axis of the said ribbon-shaped conductor is 45 degree or more, The coaxial element wire characterized by the above-mentioned. 3. The coaxial element wire according to claim 2, wherein the ribbon conductor is made of a metal containing copper and is wound around the insulator with a tension of at least 30% of the tensile strength at break of the ribbon conductor. An outer coaxial cable is coated on one coaxial element wire according to claim 2 or 3. A multi-core cable comprising a plurality of coaxial cables as described in claim 4 and coated with a common sheath. A multi-core cable comprising a plurality of coaxial wires according to claim 2 or 3 and coated with a common sheath. delete

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