JP2014038802A - Cable for differential signal transmission and cable for multicore differential signal transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable for differential signal transmission and a cable for multicore differential signal transmission in which generation of a gap between an insulator that clads a pair of conductor wires that transmit a differential signal and a shield tape conductor, and a gap at an overlapping part of the shield tape conductor wound to be overlapped can be suppressed.SOLUTION: A cable 10 for differential signal transmission includes: an insulation electric wire 2 in which first and second conductor wires 21 and 22 are cladded by an insulator 20; a shield tape conductor 3 wound at an outer peripheral side of the insulation electric wire 2; and first and second resin tapes 4 and 5 wound at an outer peripheral side of the shield tape conductor 3. The shield tape conductor 3 is wound longitudinally reinforcingly in a longer direction of the insulation electric wire 2 so that both end parts of the same in a crosswise direction mutually overlap, the first resin tape 4 is wound longitudinally reinforcingly in a longer direction of the shield tape conductor 3 so as to be in contact with an outer peripheral surface of the shield tape conductor 3, and the second resin tape 5 wound spirally so as to be in contact with an outer peripheral surface of the first resin tape 4.

Description

  The present invention relates to a differential signal transmission cable having a pair of conducting wires for transmitting differential signals, and a multi-core differential signal transmission cable including a plurality of differential signal transmission cables.

  Conventionally, a differential signal transmission cable in which a pair of conductive wires for transmitting a differential signal is covered with an insulator is known. Among such differential signal transmission cables, there is one in which a conductive shield tape is wound around the outer peripheral side of an insulator in order to suppress signal attenuation particularly in a high frequency band (see, for example, Patent Document 1).

  The differential signal transmission cable described in Patent Document 1 has a pair of conductors coated with an insulator, and a shield tape is vertically wound around the outer periphery of the insulator. A double tape made of a polymer for pressing the shield tape is spirally wound around the outer periphery of the shield tape. The double tape is wound so that the spiral winding directions in the circumferential direction with respect to the central axis of the shield tape are opposite to each other.

US Pat. No. 7,790,981

  In the differential signal transmission cable configured as described above, when an unintended gap is generated between the insulator and the shield tape, a skew or a high frequency band (for example, a difference in signal propagation delay time between the pair of conductors) There is a case where a sac-out that is a sudden signal attenuation at 10 Gbps or more occurs, and the signal cannot be normally received on the receiving side. In addition, when the shield tape is overlapped and wound so that both ends in the width direction of the shield tape overlap, the characteristics change due to the generation of a gap between both ends of the overlap portion, and skew and suck-out may occur. May occur.

  The present inventors have found that when a double tape is spirally wound around the outer periphery of the shield tape, a gap may be generated between the insulator and the shield tape and / or in the overlapping portion of the shield tape. And the knowledge that generation | occurrence | production of these clearance gaps can be suppressed by changing the winding structure of these tapes was acquired.

  The present invention has been made on the basis of this finding, and the gap between the insulator covering the pair of conductors transmitting the differential signal and the shield tape conductor, and the overlapping portion of the overlapped shield tape conductor. It is an object of the present invention to provide a differential signal transmission cable and a multi-core differential signal transmission cable that can suppress the occurrence of noise.

  In order to solve the above-mentioned problems, the present invention comprises an insulated wire formed by covering a pair of conducting wires for transmitting a differential signal with an insulator, and a strip-shaped member having a conductive metal layer, and the insulated wire A shield tape conductor wound on the outer peripheral side of the shield tape, and first and second resin tapes wound on the outer peripheral side of the shield tape conductor, the shield tape conductor having overlapping widthwise ends. The first resin tape is vertically attached along the longitudinal direction of the shield tape conductor in contact with the outer circumferential surface of the shield tape conductor, and the first resin tape is attached along the longitudinal direction of the shield tape conductor. The second resin tape provides a differential signal transmission cable that is spirally wound in contact with the outer peripheral surface of the first resin tape.

  An adhesive layer is formed on each of the outer peripheral side of the first resin tape and the inner peripheral side of the second resin tape, and the first resin tape and the second resin tape are connected to the adhesive layer. It is good to be joined to each other.

  Further, the first resin tape is vertically attached so that both end portions in the width direction overlap each other, and an overlapping portion where the both end portions of the shield tape conductor overlap each other and the both end portions of the first resin tape are It is preferable that the overlapped overlapping portion is arranged so as to be shifted in the circumferential direction of the insulated wire.

  In order to solve the above problems, the present invention provides a multicore cable comprising a plurality of the differential signal transmission cables described above, wherein the plurality of differential signal transmission cables are collectively shielded. Provide a cable for differential signal transmission.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the clearance gap between the insulator and shield tape conductor which coat | cover a pair of conducting wire which transmits a differential signal, and the overlap part of the shield tape conductor wound by overwrapping can be suppressed.

1 is a cross-sectional view showing a cross-sectional structure of a differential signal transmission cable according to an embodiment of the present invention and a multicore differential signal transmission cable including a plurality of differential signal transmission cables. The structure of the cable for differential signal transmission which concerns on this Embodiment is shown, (a) shows one side of the cable 10 for differential signal transmission, (b) shows the side opposite to (a), respectively. . FIG. 2 is a cross-sectional view taken along line AA in FIG. It is the schematic which shows the manufacturing process of the cable for differential signal transmission, (a) is the process of carrying out the lengthwise winding of the shield tape conductor, (b) is the process of lengthwise winding the first resin tape (c) ) Shows a step of spirally winding the second resin tape, respectively.

[Embodiment]
FIG. 1 is a sectional view showing a sectional structure of a differential signal transmission cable according to an embodiment of the present invention and a multi-core differential signal transmission cable including a plurality of differential signal transmission cables.

  The multi-core differential signal transmission cable 100 bundles a plurality of differential signal transmission cables 10 (eight in the example shown in FIG. 1), and bundles the bundled differential signal transmission cables 10 together. The shield conductor 12 is shielded, the outer periphery of the shield conductor 12 is further covered with a braided wire 13, and the plurality of differential signal transmission cables 10, the shield conductor 12, and the braided wire 13 are made of an insulating material. It is configured to be accommodated in a jacket 14.

  In the example shown in FIG. 1, two differential signal transmission cables 10 are arranged at the center of the multicore differential signal transmission cable 100, and the two differential signal transmission cables 10 are twisted yarns or the like. It is accommodated in a cylindrical interposition 11 made of foamed polyolefin or the like. The other six differential signal transmission cables 10 are arranged at substantially equal intervals outside the intervening 11.

(Configuration of differential signal transmission cable 10)
2A and 2B show the configuration of the differential signal transmission cable 10 according to the present embodiment, in which FIG. 2A is a side view of the differential signal transmission cable 10 and FIG. 2B is opposite to the side surface shown in FIG. Each side is shown.

  The differential signal transmission cable 10 is composed of an insulated wire 2 in which first and second conductive wires 21 and 22 for transmitting a differential signal are covered with an insulator 20, and a belt-like member having a conductive metal layer. The shield tape conductor 3 wound on the outer peripheral side of the insulated wire 2 and the first and second resin tapes 4 and 5 wound on the outer peripheral side of the shield tape conductor 3 are provided. 2 shows a state in which a part of the shield tape conductor 3 and the first and second resin tapes 4 and 5 are removed and the inside thereof is exposed for explanation.

  The insulated wire 2 includes a first conducting wire 21 and a second conducting wire 22 made of a conductive metal such as copper arranged in parallel to each other, and the first conducting wire 21 and the second conducting wire 22 are collectively disposed as an insulator. 20 is covered. The outer edge of the insulator 20 in the cross section orthogonal to the central axis C of the insulated wire 2 has an elliptical shape. As the material of the insulator 20, for example, foamed polyethylene, foamed Teflon, or a Teflon-based material (Teflon is a registered trademark) such as tetrafluoroethylene / hexafluoropropylene copolymer (FEP) can be used.

  The shield tape conductor 3 is wound side by side along the longitudinal direction of the insulated wire 2 such that both end portions in the width direction overlap each other in the overlapping portion 3a. Here, the longitudinal winding means that the shield tape conductor 3 is arranged so that the longitudinal direction of the shield tape conductor 3 and the longitudinal direction of the insulated wire 2 are parallel, and the shield tape conductor 3 is arranged in the circumferential direction of the insulated wire 2. It is said to be bent along. The overlapping portion 3 a is formed to extend in parallel with the central axis C of the insulated wire 2.

  The first resin tape 4 is wound side by side along the longitudinal direction of the shield tape conductor 3 in contact with the outer peripheral surface of the shield tape conductor 3. That is, the first resin tape 4 is disposed so that the longitudinal direction thereof is parallel to the longitudinal direction of the shield tape conductor 3, and is bent and wound along the circumferential direction of the shield tape conductor 3. Further, the first resin tape 4 is wound side by side so that both end portions in the width direction overlap each other in the overlapping portion 4a. The overlapping portion 4 a is formed so as to extend in parallel with the central axis C of the insulated wire 2.

  The overlapping portion 3 a of the shield tape conductor 3 and the overlapping portion 4 a of the first resin tape 4 are arranged so as to be shifted in the circumferential direction of the insulated wire 2. In the present embodiment, the overlapping portion 4a is formed at a position where the central axis C of the insulated wire 2 is sandwiched between the overlapping portion 3a. That is, the overlapping portion 3a and the overlapping portion 4a are disposed at positions that are point-symmetric with respect to the central axis C in a cross section orthogonal to the central axis C.

  The second resin tape 5 is spirally wound in contact with the outer peripheral surface of the first resin tape 4. That is, the second resin tape 5 is insulated while its longitudinal direction is inclined with respect to the longitudinal direction of the shield tape conductor 3 and the first resin tape 4 and swivels along the outer peripheral surface of the first resin tape 4. It is wound so as to advance in a direction parallel to the central axis C of the electric wire 2.

  The 2nd resin tape 5 is spirally wound so that the both ends of the width direction may mutually overlap in the overlap part 5a. The direction of the spiral winding is a direction along the winding direction of the first resin tape 4 in the overlapping portion 4 a of the first resin tape 4. That is, the second resin tape 5 extends from the one end surface on the lower side (shield tape conductor 3 side) of the overlapping portion 4a of the first resin tape 4 shown by a broken line in FIG. It is wound toward the end face.

Figure 3 shows the A-A line cross section of FIG. 2, (a) is an overall view, (b) the _{B 1} an enlarged view of part (a), (c) is a _{B 2} an enlarged view of part (a) is there. In FIG. 3, the thicknesses of the shield tape conductor 3, the first resin tape 4, and the second resin tape 5 are exaggerated for explanation.

  The shield tape conductor 3 includes a resin layer 30 made of a flexible insulating resin such as PET (polyethylene terephthalate), and a conductive metal such as copper or aluminum provided on one surface of the resin layer 30. The metal layer 31 is made of a laminate. The resin layer 30 is disposed closer to the insulated wire 2 than the metal layer 31, and the surface 30 a of the resin layer 30 (the inner peripheral surface of the shield tape conductor 3) is in contact with the outer peripheral surface 20 a of the insulator 20. The thickness of the resin layer 30 is, for example, 6 μm or less, and the thickness of the metal layer 31 is, for example, 9 μm or less.

  The first resin tape 4 has, for example, a resin layer 40 made of a flexible insulating resin such as PET, and an adhesive layer 41 including an adhesive formed by being laminated on the resin layer 40. It is configured. The adhesive layer 41 is disposed on the outer peripheral side of the differential signal transmission cable 10 with respect to the resin layer 40. The thickness of the resin layer 40 is, for example, 4 to 12 μm. The thickness of the resin layer 40 is from 4 to 12 μm so as to securely press the shield tape conductor 3 so that no gap is generated between one end and the other end in the width direction of the shield tape conductor 3 in the overlapping portion 3a. It is desirable to select appropriately.

  The surface 40a of the resin layer 40 (the inner peripheral surface of the first resin tape 4) is in contact with the surface 31a of the metal layer 31 of the shield tape conductor 3 (the outer peripheral surface of the shield tape conductor 3). In the overlapping portion 4a of the first resin tape 4, the adhesive layer 41 on one end of the first resin tape 4 on the lower side (shield tape conductor 3 side) and the upper (second) The resin layer 40 on the other end of the first resin tape 4 on the resin tape 5 side) is joined.

  The second resin tape 5 includes, for example, a resin layer 50 made of a flexible insulating resin such as PET, and an adhesive layer 51 including an adhesive formed by being laminated on the resin layer 50. It is configured. The adhesive layer 51 is disposed on the inner peripheral side of the differential signal transmission cable 10 with respect to the resin layer 50. The thickness of the resin layer 50 is, for example, 4 to 12 μm.

  The surface 51a of the adhesive layer 51 (the inner peripheral surface of the second resin tape 5) is in contact with the surface 41a of the adhesive layer 41 of the first resin tape 4 (the outer peripheral surface of the first resin tape 4) and is bonded to each other. Has been. That is, the first resin tape 4 and the second resin tape 5 are joined to each other by the adhesive layers 41 and 51 provided on the outer peripheral side of the first resin tape 4 and the inner peripheral side of the second resin tape 5. Has been.

  In the overlapping portion 5a of the second resin tape 5, the adhesive layer 51 at one end of the second resin tape 5 on the upper side (the outer peripheral side of the differential signal transmission cable 10), The resin layer 50 at the other end of the second resin tape 5 on the lower side (first resin tape 4 side) is joined.

  The differential signal transmission cable 10 configured as described above transmits a differential signal through the first and second conducting wires 21 and 22. That is, in communication using the differential signal transmission cable 10, signals having opposite phases are output to the first conducting wire 21 and the second conducting wire 22 on the transmitting side, and the first conducting wire 21 and the receiving side are connected to the first conducting wire 21. A signal transmitted based on the potential difference from the second conductor 22 is received (decoded). The shield tape conductor 3 functions to suppress the occurrence of signal skew and suck-out using the first and second conductive wires 21 and 22 as transmission media.

(Manufacturing method of the differential signal transmission cable 10)
Next, a method for manufacturing the differential signal transmission cable 10 will be described.

  4A and 4B are schematic views showing a manufacturing process of the differential signal transmission cable 10, wherein FIG. 4A shows a process of vertically winding the shield tape conductor 3 on the outer peripheral side of the insulated wire 2, and FIG. (C) shows a step of spirally winding the second resin tape 5 around the outer peripheral side of the first resin tape 4.

  When longitudinally winding the shield tape conductor 3 around the outer periphery of the insulated wire 2, the shield tape conductor 3 is disposed in parallel with the insulated wire 2 as shown in FIG. The shield tape conductor 3 is vertically wound around so as to cover the outer peripheral surface 20 a of 20.

  Next, as shown in FIG. 4B, the first resin tape 4 is vertically wound around the outer peripheral side of the shield tape conductor 3. In this step, the first resin tape 4 is covered so as to cover at least the overlapping portion 3a of the shield tape conductor 3, and the first resin tape 4 is placed along the outer peripheral surface of the shield tape conductor 3 so as to be vertically attached. .

  Next, as shown in FIG. 4C, the second resin tape 5 is spirally wound around the outer peripheral side of the first resin tape 4. The second resin tape 5 is spirally wound in a state where a predetermined tension is applied in the longitudinal direction. Thereby, the 1st resin tape 4 and the 2nd resin tape 5 are joined firmly.

  In the cross section perpendicular to the central axis C of the insulated wire 2, the winding direction of the longitudinal auxiliary winding in the overlapping portion 3 a of the shield tape conductor 3, the winding direction of the vertical auxiliary winding in the overlapping portion 4 a of the first resin tape 4, and the second The winding direction of the spiral winding of the resin tape 5 is the same direction (the direction of arrow D in FIG. 4C).

(Operation and effect of the embodiment)
According to the present embodiment, there are the following operations and effects.

(1) Since the first resin tape 4 is vertically wound around the shield tape conductor 3 and the second resin tape 5 is spirally wound around the outer periphery thereof, the insulation 20 of the insulated wire 2 and the shield tape conductor 3 are It is possible to suppress the occurrence of gaps in the gaps and in the overlapping portion 3a of the shield tape conductor 3. That is, for example, when a double tape is spirally wound in opposite directions on the outer peripheral side of the shield tape as in the differential signal transmission cable described in Patent Document 1, the tension of the tape at the time of this spiral winding However, in this embodiment, the first resin tape 4 is wound around the shield tape conductor 3 in a vertical manner. Therefore, the tension when spirally winding the second resin tape 5 does not act directly on the shield tape conductor 3. That is, since the second resin tape 5 is spirally wound in a state where the entire shield tape conductor 3 is covered with the first resin tape 4, the influence of the tension when the second resin tape 5 is spirally wound is affected. Alleviated and the generation of a gap on the inner peripheral side of the shield tape conductor 3 due to the swinging of the insulated wire 2 is suppressed.

(2) Since the first resin tape 4 and the second resin tape 5 are wound so that the adhesive layers 41 and 51 face each other, the first resin tape 4 and the second resin tape 5 Are firmly joined. As a result, loosening of the shield tape conductor 3 can be suppressed, and signal skew can be suppressed.

(3) Since the overlapping portion 3a of the shield tape conductor 3 and the overlapping portion 4a of the first resin tape 4 are arranged so as to be shifted in the circumferential direction with respect to the central axis C of the insulated wire 2, it is used for differential signal transmission. Unevenness on the outer peripheral surface of the cable 10 is suppressed. As a result, the design is improved and, for example, when a plurality of differential signal transmission cables 10 are bundled as the multicore differential signal transmission cable 100, the difference in the multicore differential signal transmission cable 100 is increased. The movement of the moving signal transmission cables 10 is facilitated. Moreover, since the overlapping part 3a of the shield tape conductor 3 is covered with the continuous inner surface of the first resin tape 4, the generation of a gap in the overlapping part 3a can be reliably suppressed.

(4) The winding direction of the longitudinal auxiliary winding in the overlapping portion 4 a of the first resin tape 4 and the winding direction of the spiral winding of the second resin tape 5 are the same in the circumferential direction with respect to the central axis C of the insulated wire 2. Therefore, compared with the case where this direction is reverse, when the 2nd resin tape 5 is spirally wound, the both ends of the 1st resin tape 4 in the overlap part 4a of the 1st resin tape 4 will shift | deviate. This can be suppressed. That is, since the second resin tape 5 is wound from one end that is the lower side (inner side) to the other end that is the upper side (outer side) in the overlapping portion 4a, the other end portion is It is pressed against one end, and the generation of a gap in the overlapping portion 4a is suppressed.

  While the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. In addition, it should be noted that not all the combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

  The present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications without departing from the spirit thereof. For example, in the above-described embodiment, the case where the first conductor 21 and the second conductor 22 are collectively covered with the insulator 20 has been described. However, the present invention is not limited thereto, and the insulation covering the first conductor 21 is performed. The body and the insulator covering the second conductor 22 may be separate. Further, the number of differential signal transmission cables included in the multicore differential signal transmission cable 100 is not particularly limited.

DESCRIPTION OF SYMBOLS 2 ... Insulated electric wire, 3 ... Shield tape conductor, 3a ... Overlapping part, 4 ... 1st resin tape, 4a ... Overlapping part, 5 ... 2nd resin tape, 10 ... Differential signal transmission cable, 11 ... Interposition, DESCRIPTION OF SYMBOLS 12 ... Shield conductor, 13 ... Braided wire, 14 ... Jacket, 20 ... Insulator, 20a ... Outer peripheral surface, 21 ... First conducting wire, 22 ... Second conducting wire, 30 ... Resin layer, 30a ... Surface, 31 ... Metal Layer, 31a ... surface, 40, 50 ... resin layer, 41, 51 ... adhesive layer, 40a, 41a, 51a ... surface, 100 ... multi-core differential signal transmission cable, C ... central axis

Claims (4)

An insulated wire formed by covering a pair of conducting wires for transmitting a differential signal with an insulator;
A shield tape conductor made of a strip-shaped member having a conductive metal layer, wound around the outer peripheral side of the insulated wire, and
A first and a second resin tape wound around the outer periphery of the shield tape conductor;
The shield tape conductor is longitudinally wound along the longitudinal direction of the insulated wire so that both ends in the width direction overlap.
The first resin tape is vertically wound along the longitudinal direction of the shield tape conductor in contact with the outer peripheral surface of the shield tape conductor,
The differential signal transmission cable, wherein the second resin tape is spirally wound in contact with the outer peripheral surface of the first resin tape. An adhesive layer is formed on each of the outer peripheral side of the first resin tape and the inner peripheral side of the second resin tape,
The first resin tape and the second resin tape are joined together by the adhesive layer;
The differential signal transmission cable according to claim 1. The first resin tape is vertically attached so that both ends in the width direction overlap each other,
The overlapping portion where the both end portions of the shield tape conductor overlap each other and the overlapping portion where the both end portions of the first resin tape overlap are arranged so as to be shifted in the circumferential direction of the insulated wire,
The differential signal transmission cable according to claim 1 or 2. A plurality of differential signal transmission cables according to any one of claims 1 to 3,
A multi-core differential signal transmission cable formed by collectively shielding the plurality of differential signal transmission cables.

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