JP6575296B2 - Shielded cable and method of manufacturing shielded cable - Google Patents

Description

  The present invention relates to a shielded cable and a method for manufacturing a shielded cable.

  In recent years, with the improvement in performance of information processing equipment, it has become indispensable to increase the capacity and speed of wiring between equipment. For example, there is a shielded cable for differential signal transmission that can cope with large capacity and high speed.

  The shielded cable for differential signal transmission includes two insulated wires (signal wires) arranged in parallel to transmit differential signals and a drain arranged so as to contact both of the two insulated wires. And a shield tape is spirally wound around these wires (see, for example, Patent Document 1). Moreover, as a shield tape which comprises a shield cable, the metal foil resin tape on which the layer which consists of a metal (for example, copper foil) and the layer which consists of resin was laminated | stacked is used (for example, refer patent document 1).

JP 2014-130707 A

  Recently, the signal frequency of information processing devices is increasing, and some information processing devices are required to perform stable signal transmission in a band of 20 to 25 GHz. However, in the above-described conventional shielded cable, for example, a “suckout phenomenon” that is an abrupt attenuation region appearing in a high frequency band of 13 GHz or more may occur, and stable signal transmission in the high frequency band may not be performed.

  In order to suppress the sack-out phenomenon, it is considered effective not to cause poor conduction (electrical disconnection) on the surface of the shield tape (metal foil resin tape). However, for that reason, it should be avoided that the shield tape cannot be wound well or the flexibility (flexibility) of the shield cable after the tape is wound is lost.

  An object of the present invention is to provide a shielded cable and a method for manufacturing the shielded cable that can suppress a sack-out phenomenon in a high-frequency band and can perform a good winding of a shield tape.

According to one aspect of the invention,
Two electric wires and a drain wire arranged to contact both of the two electric wires;
A shield tape spirally wound around the two electric wires and the drain wire, and
The shield tape is configured by folding a band-shaped body having a metal layer in the band width direction, the fold portion of the fold is located on the outer peripheral side of the overlapping portion of the band-shaped bodies, and The shielded cable is provided in which the metal layer is wound in a quadruple manner at the overlapping portion, and the metal layer is in contact with the two electric wires and the drain wire over the entire length of the cable. Is done.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to suppress the sack-out phenomenon in a high frequency band about a shield cable, it becomes possible to wind a shield tape favorably.

It is sectional drawing which shows the schematic structural example of the shielded cable which concerns on 1st embodiment of this invention. It is explanatory drawing which shows the structural example of the shield tape which concerns on 1st embodiment of this invention. It is explanatory drawing which shows an example of the winding aspect of the shield tape which concerns on 1st embodiment of this invention. It is explanatory drawing which shows the example of 1 process of the manufacturing method of the shielded cable which concerns on 1st embodiment of this invention. It is explanatory drawing which shows the structural example of the shield tape which concerns on 2nd embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

<First embodiment of the present invention>
First, a first embodiment of the present invention will be described. Here, an LVDS (Low Voltage Differential Signaling) cable is taken as an example of the shielded cable. The LVDS cable is used as a shielded cable for differential signal transmission.

(1) Configuration of Shielded Cable FIG. 1 is a cross-sectional view illustrating a schematic configuration example of a shielded cable according to the first embodiment.
As illustrated, the shielded cable 1 includes a plurality of electric wires. As the plurality of electric wires, two insulated wires (signal wires) 10 arranged in parallel to transmit differential signals, and a drain wire 20 arranged so as to contact both of the two insulated wires 10 are used. There is. Furthermore, the shielded cable 1 includes a shield tape 30 that is wound around the insulated wire 10 and the drain wire 20.

(Insulated wire)
The insulated wire 10 includes a signal line conductor 11 and a solid insulation layer 12 formed around the signal line conductor 11.

  The signal line conductor 11 is composed of, for example, a stranded wire formed by twisting seven signal line strands. As a result, the bending resistance can be improved as compared with the case where the signal line conductor 11 is made of a single wire, and the surface area can be increased to reduce the influence of the skin effect due to the transmission of the high-frequency signal. .

  Examples of the material for the solid insulating layer 12 include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polytetrafluoroethylene (PTFE). A fluororesin is mentioned.

  In addition, since the foamed insulating layer is easily crushed by the drain wire 20 and easily deformed, it is preferable to employ a solid insulating layer that is difficult to deform as the insulating layer of the insulated wire 10.

(Drain wire)
The drain wire 20 is preferably formed by twisting a plurality of (for example, seven) ground wire strands. Thereby, the frictional force between the drain wire 20 and the insulated wire 10 can be increased, and the drain wire 20 can be prevented from being displaced from a predetermined position.

(Shield tape)
The shield tape 30 is wound around the insulated wire 10 and the drain wire 20 in order to electrically shield them. That is, the insulated wire 10 and the drain wire 20 are surrounded by the shielding tape 30 that is a shielding conductor.

  The shield tape 30 has a metal layer in order to function as a shield conductor. Specifically, the shield tape 30 is configured using, for example, a copper rolled foil that forms a metal layer. The copper rolled foil is used because copper is a metal with high electrical conductivity and spreadability. However, the metal layer is not necessarily limited to the copper rolled foil, and may be formed of a metal material such as aluminum, nickel, copper, or an alloy material containing these. Further, it is not necessarily a single layer, and a plurality of metal materials may be laminated.

  In this embodiment, the shield tape 30 is configured using only copper rolled foil. That is, the shield tape 30 in this embodiment is composed of only a metal layer.

Here, the configuration of the shield tape 30 will be described in more detail.
FIG. 2 is an explanatory diagram showing a configuration example of the shield tape according to the first embodiment.

  As shown in FIG. 2A, the shield tape 30 is configured using, for example, a strip 31 made of a rolled copper foil. As shown in FIGS. 2B and 2C, the shield tape 30 is configured by folding the band-like body 31 in the band width direction.

  “Fold in half in the band width direction” means that the fold part 32 is located in the vicinity of the center of the band-shaped body 31 in the band width direction, that is, the fold part 32 is in the longitudinal direction of the band-shaped body 31 (perpendicular to the band width direction). This means that the belt-like body 31 is folded in two so as to extend in the direction).

  Therefore, after the band-like body 31 is folded in half in the band width direction, as shown in FIG. 2 (c), a fold portion 32 that is folded in half on one side of both end edges extending along the longitudinal direction thereof. Is located, and the belt-like body edge 33 is located on the other side. The band-shaped body edge 33 may be formed by the edge of the band-shaped body 31 before being folded in half, or may be formed by cutting the copper rolled foil after being folded in half. May be.

  Thus, about the shield tape 30 comprised by folding the strip | belt-shaped body 31 which consists of copper rolled foil into the band width direction, it is preferable that the surfaces which oppose by the two fold are adhere | attached. In addition, about the adhesion method of surfaces, it does not specifically limit, What is necessary is just to perform using a well-known method.

  Further, the shield tape 30 having the above configuration is spirally wound around the insulated wire 10 and the drain wire 20 to constitute the shield cable 1.

  “Spirally wound” means that the shield tape 30 is spirally wound so that the shield tapes 30 formed by the strips 31 overlap each other.

Here, the state where the shield tape 30 is wound will be described in more detail.
Drawing 3 is an explanatory view showing an example of the winding mode of the shield tape concerning a first embodiment.

  As shown in the figure, the shield tape 30 has an overlapping portion 34 between the strips 31 constituting the shielding tape 30, and the folded portion 32 is located on the outer peripheral side in the overlapping portion 34. Are wound around the insulated wire 10 and the drain wire 20. Therefore, in the overlapping portion 34, the copper rolled foil (that is, the metal layer) forming the strip 31 is overlapped so as to be quadrupled. In this way, if the metal layers overlap each other in the overlapping portion 34, conduction between the metal layers is ensured, so that the frequency band in which sackout is generated can be shifted to the high frequency side.

  Note that the winding pitch when the shield tape 30 is overwrapped, the width direction dimension of the overlap portion 34, the width direction dimension of the shield tape 30 itself, the thickness of the strip 31 constituting the shield tape 30 (the thickness of the copper rolled foil) ) And the like are not particularly limited as long as the cable length, cable diameter, flexibility (flexibility) and the like of the shielded cable 1 are appropriately set.

(2) Manufacturing method of shielded cable The shielded cable 1 having the above-described configuration is manufactured by the procedure described below.
Drawing 4 is an explanatory view showing an example of one process of a manufacturing method of a shielded cable concerning a first embodiment.

  In manufacturing the shielded cable 1, a shield tape 30 is prepared in which a band-shaped body 31 made of a copper rolled foil is folded in the band width direction. As described above, when the shield tape 30 is formed by folding the belt-like body 31 in half, the strength can be improved as compared with the case where there is no fold portion 32 (in the case of a single layer structure). Moreover, since it is sufficient to fold the belt-like body 31 in half, unlike the case where only a part in the belt width direction is folded back, the belt-like body 31 can be easily configured even when it is made of a thin copper rolled foil. . The method for folding the belt-like body 31 in half is not particularly limited, and may be performed using a known method.

  Thereafter, the two insulated wires 10 are arranged in parallel, and the shield tape 30 is spirally wound around these in a state where the drain wire 20 is arranged so as to contact both of them. At this time, the winding of the shield tape 30 applies tension to the side of the folded fold portion 32 of the shield tape 30 (see the arrow in the figure), and the fold portions 32 of the strips 31 constituting the shield tape 30 are connected to each other. This is performed so as to be positioned on the outer peripheral side of the overlapping portion 34. That is, while applying tension to the side where the band-shaped body edge 33 is located, not the side where the strip-like body edge 33 is located, of the both end edges extending along the longitudinal direction of the shield tape 30, 30 windings are performed.

  The band-shaped body edge 33 may have a microcrack due to an influence of a cutting process or the like when the edge is formed. Therefore, when tension is applied to the belt-like body edge 33 side, there is a possibility that a crack will be generated from a microcrack due to the tension, and the shield tape 30 may be damaged. On the other hand, if tension is applied to the side of the fold portion 32 that is folded in half, there is no fear that a crack will be generated from a microcrack, and the strength improvement by the crease portion 32 can be achieved. 30 can be wound well.

(3) Effects According to the Present Embodiment According to the present embodiment, one or a plurality of effects described below are exhibited.

(A) In this embodiment, the shield tape 30 is comprised by the strip | belt body 31 which has copper rolling foil (metal layer). Therefore, when the shield tape 30 is spirally wound around the insulated wire 10 and the drain wire 20, the metal layers can be overlapped with each other, and the generation frequency band of the suckout is shifted to the high frequency side. be able to.

(B) In the present embodiment, the shield tape 30 is configured by folding the belt-like body 31 in half. Therefore, the strength of the shield tape 30 can be improved as compared with the case where there is no fold portion 32 (in the case of a single layer structure). Furthermore, since the belt-like body 31 only needs to be folded in two, unlike the case where only a part in the belt width direction is folded back, for example, even when the belt-like body 31 is made of a thin copper rolled foil, the shield tape 30 can be easily Can be configured.

(C) Further, in the present embodiment, since the double-folded fold portion 32 is located on the outer peripheral side of the overlapping portion 34, the shield is applied while applying tension mainly to the fold portion 32 side instead of the belt-like body edge 33 side. The tape 30 is wound. Moreover, since the copper rolled foil (that is, the metal layer) forming the strip 31 is quadruple in the overlapping portion 34, the state where the metal layer is doubled over the entire width direction of the shield tape 30 (that is, the strip) The shield tape 30 is wound in a state of being folded in half. Therefore, when the shield tape 30 is wound, the shield tape 30 is not damaged due to the tension as in the case where tension is applied to the belt-like body edge 33, and the crease portion 32 is not damaged. Since the strength can be improved as compared with the case where there is no (single layer structure) or the case where only a part is folded, the shield tape 30 can be wound well.

(D) Moreover, in this embodiment, the strip | belt-shaped body 31 which comprises the shield tape 30 is comprised only from copper rolled foil (metal layer). Therefore, even if the belt-like body 31 is folded in half or the belt-like bodies 31 are overlapped with each other, conduction is surely ensured, and the generation frequency band of the sac-out is, for example, 25 GHz or more as described later. Can be shifted.

(E) Further, as described in the present embodiment, when the opposing surfaces are bonded by folding the shield tape 30 in two, the surfaces do not deviate from each other. To be able to do it.

<Second embodiment of the present invention>
Next, a second embodiment of the present invention will be described. Here, differences from the above-described first embodiment will be mainly described, and description of the same parts as in the first embodiment will be omitted.

(4) Configuration of Shield Tape In this embodiment, the configuration of the shield tape 30 is different from that in the first embodiment described above.
FIG. 5 is an explanatory diagram showing a configuration example of the shield tape according to the second embodiment.

  The shield tape 30 in the present embodiment is configured to have a metal layer in order to function as a shield conductor, but is not configured only from the metal layer as in the first embodiment. It is configured using a laminate 35 as shown in FIG. The stacked body 35 is formed by laminating a metal layer 35a and an insulating layer 35b to form a strip-shaped body.

  The metal layer 35a is formed of, for example, copper rolled foil, and the copper rolled foil is attached to the insulating layer 35b. However, the metal layer 35a is not necessarily limited to the copper rolled foil, and may be formed of a metal material such as aluminum, nickel, copper, or an alloy material containing these. Further, it is not always necessary that a foil-like material is attached, and it may be formed by a vapor deposition layer, a plating layer, or the like. Further, it is not necessarily a single layer, and a plurality of metal materials may be laminated.

  The insulating layer 35b is formed using, for example, a film-like resin material such as polyethylene or polyethylene terephthalate (PET) as a base material.

  As shown in FIGS. 5 (b) and 5 (c), such a band-shaped body made of the laminated body 35 is folded in half in the band width direction to form the shield tape 30. At this time, the belt-like body made of the laminated body 35 is folded in half so that the insulating layer 35b is located inside. As a result, after the belt-like body made of the laminate 35 is folded in half, the metal layer 35a is exposed on the surface as shown in FIG. 5 (c).

  When the shielding tape 30 configured as described above is spirally wound around the insulated wire 10 and the drain wire 20, the stacked body (band-shaped body) is formed so that the metal layers 35 a are in contact with each other at the overlapping portion 34 of the overlapping winding. ) 35 and the metal layers 35a overlap each other with the insulating layer 35b interposed therebetween.

(5) Effect concerning this embodiment According to this embodiment, in addition to the effect in 1st embodiment mentioned above, there exists the effect shown below.

(F) In this embodiment, since the laminated body (band-like body) 35 includes the insulating layer 35b in addition to the metal layer 35a, the shield tape 30 configured using the laminated body (band-like body) 35 is used. Thus, the shield tape 30 can be wound well. In addition, since the insulating layer 35b is located inside the half-fold, the metal layer 35a is located outside (the front side), and when the shield tape 30 is spirally wound, the metal layer 35a They will overlap each other. Therefore, even if the belt-like body 31 is folded in half or the belt-like bodies 31 are overlapped with each other, continuity is surely ensured, and the generation frequency band of the suckout is set to, for example, 20 GHz or more as described later. Can be shifted.

  Next, examples of the present invention will be specifically described. However, the present invention is not limited to the contents of the following examples.

Example 1
First, Example 1 corresponding to the first embodiment described above will be described.
In Example 1, a rolled copper foil having a thickness of 0.005 to 0.008 mm was folded in half in the band width direction to form a shield tape having a width direction dimension of 5 to 10 mm. That is, a shield tape made of 100% metal was formed. In this way, by forming the shield tape by folding the copper rolled foil in half, the strength can be improved without impairing the flexibility (flexibility) of the tape itself, and when only a part in the band width direction is folded back. It was confirmed that it can be easily formed as compared.

  Then, the formed shield tape was spirally wound around the twinax cable having the drain wire (that is, the two insulated wires 10 and the drain wire 20 in the first embodiment) to form an LVDS cable. At this time, it was confirmed that the shield tape could be satisfactorily wound by applying tension to the side of the folded fold part and winding the fold part so that the side of the fold part was positioned on the outer peripheral side of the overlapping portion.

  In the LVDS cable configured as described above, shield tapes made of 100% metal overlap each other over the entire length of the cable, and the shield tape is in contact with the drain wire. With such a configuration, it was confirmed that the frequency band of sac-out was shifted to 25 GHz or more. That is, it was confirmed that an LVDS cable that does not cause a sackout in a high frequency band up to 25 GHz can be obtained.

(Example 2)
Next, Example 2 corresponding to the above-described second embodiment will be described.
In Example 2, a belt-like laminate formed by forming a copper thin film having a thickness of 0.001 to 0.008 mm on one surface of a film-like PET material having a thickness of 0.002 to 0.005 mm is folded in half in the belt width direction. Thus, a shield tape having a width direction dimension of 5 to 10 mm was formed. At this time, the belt-shaped laminate was folded in half so that the film-like PET material was positioned inside, thereby forming a shield tape having the entire surface made of a copper thin film. Thus, it was confirmed that the strength such as the tensile strength can be improved by forming the shield tape using the belt-like laminate including the film-like PET material as compared with the case of 100% metal. In addition, by forming the shield tape by folding the belt-shaped laminated body in half, the strength can be improved without impairing the flexibility (flexibility) of the tape itself, and compared with the case where only a part of the belt width direction is folded back. It was confirmed that it can be easily formed.

  Then, the formed shield tape was spirally wound around a twinax cable having a drain wire in the same manner as in Example 1 to constitute an LVDS cable. At this time, it was confirmed that the shield tape could be satisfactorily wound by applying tension to the side of the folded fold part and winding the fold part so that the side of the fold part was positioned on the outer peripheral side of the overlapping portion.

  The LVDS cable configured as described above is exposed on the tape surface over the entire length of the cable, but the copper thin films overlap each other, and the copper thin film is in contact with the drain wire. With such a configuration, it was confirmed that the generation frequency band of sackout was shifted to 20 GHz or more. That is, it was confirmed that an LVDS cable that does not cause a sackout in a high frequency band up to 20 GHz can be obtained.

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

[Appendix 1]
According to one aspect of the invention,
Multiple wires,
A shield tape spirally wound around the plurality of electric wires, and
The shield tape is configured by folding a band-shaped body having a metal layer in the band width direction, the fold portion of the fold is located on the outer peripheral side of the overlapping portion of the band-shaped bodies, and A shielded cable is provided in which the metal layers are overlapped so as to be quadrupled at the overlapping portion.

[Appendix 2]
The shielded cable according to appendix 1, preferably,
The said strip | belt shape is comprised only from the said metal layer.

[Appendix 3]
The shielded cable according to appendix 1, preferably,
The belt-like body is constituted by a laminated body of the metal layer and the insulating layer, and is configured such that the insulating layer is located inside the bifold.

[Appendix 4]
The shielded cable according to any one of appendices 1 to 3, preferably,
The shield tape is bonded to the opposing surfaces by the two-fold.

[Appendix 5]
According to another aspect of the invention,
A method of manufacturing a shielded cable in which a shield tape is spirally wound around a plurality of electric wires,
As the shield tape, a belt-shaped body having a metal layer is prepared by being folded in half in the band width direction,
The shield tape so that the end of the fold fold side is positioned on the outer peripheral side of the overlapping portion of the strips while applying tension to the end of the fold fold side of the shield tape. A method of manufacturing a shielded cable in which a wire is spirally wound around the plurality of electric wires is provided.

[Appendix 6]
A method for manufacturing a shielded cable according to appendix 5, preferably,
The said strip | belt shape is comprised only from the said metal layer.

[Appendix 7]
A method for manufacturing a shielded cable according to appendix 5, preferably,
The belt-like body is constituted by a laminated body of the metal layer and the insulating layer, and is configured such that the insulating layer is located inside the bifold.

  DESCRIPTION OF SYMBOLS 1 ... Shield cable, 10 ... Insulated electric wire (signal wire), 20 ... Drain wire, 30 ... Shield tape, 31 ... Strip | belt-shaped body, 32 ... Folded part, 33 ... Edge of strip | belt-shaped body, 34 ... Overlapping part, 35 ... Laminated body (Band), 35a ... metal layer, 35b ... insulating layer

Claims (5)

Two electric wires and a drain wire arranged to contact both of the two electric wires;
A shield tape spirally wound around the two electric wires and the drain wire, and
The shield tape is configured by folding a band-shaped body having a metal layer in the band width direction, the fold portion of the fold is located on the outer peripheral side of the overlapping portion of the band-shaped bodies, and The shielded cable, wherein the metal layers are overlapped and wound so as to form a quadruple at the overlapping portion, and the metal layers are in contact with the two electric wires and the drain wires over the entire length of the cable. The shielded cable according to claim 1, wherein the belt-like body is composed only of the metal layer. 2. The shielded cable according to claim 1, wherein the belt-like body is configured by a laminated body of the metal layer and the insulating layer, and the insulating layer is positioned inside the bifold. The shield cable according to any one of claims 1 to 3, wherein surfaces of the shield tape facing each other are bonded to each other by the bifold. A method of manufacturing a shielded cable in which a shield tape is spirally wound around a drain wire arranged so as to come into contact with both two wires and the two wires ,
As the shield tape, a belt-shaped body having a metal layer is prepared by being folded in half in the band width direction,
While applying tension to the side of the two-fold fold portion in the shield tape, the fold portion is located on the outer peripheral side of the overlapping portion between the strips , and the metal layer is quadrupled at the overlapping portion, Manufacturing a shielded cable in which the shield tape is spirally wound around the two electric wires and the drain wire so that the metal layer contacts the two electric wires and the drain wire over the entire length of the cable Method.

Images