Communication cable and communication cable assembly

Abstract

To provide a communication cable and a communication cable assembly for which a reversible plug capable of being inserted into a receptacle even if front and rear of the plug are inverse can be used, and by which a communicable distance can be made longer for a cable diameter.SOLUTION: A communication cable 1 has: two first differential pair 2A, 2B which transmits high-speed differential signal; and a configuration channel wire 6 for detecting the direction of front and rear of a plug, where the first differential pair has the two first differential pair 2A, 2B only.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to communication cables and communication cable assemblies. [Background technology]

[0002] In recent years, transmission cables that can reduce costs and improve transmission characteristics have been proposed (see, for example, Patent Document 1).

[0003] Various standards have been established for the USB (Universal Serial Bus) interface standard, and the maximum transfer speed has been improved. For example, USB1.0 and USB1.1 are 12Mbps, USB2.0 is 480Mbps, USB3.0 is 5Gbps, USB3.1 is 10Gbps, and USB3.2 is 20Gbps. Meanwhile, while Type-A and Type-B connectors were specified, the reversible Type-C connector has been specified since USB3.1.

[0004] In addition, USB cables are now capable of handling a variety of communications using a single cable, which has resulted in more complex core configurations and an increase in the number of cores. For example, 4 cores are recommended for USB 2.0, 8 cores for USB 3.0, and 15 cores for USB Type-C.

[0005] The transmission cable described in Patent Document 1 is a transmission cable that complies with the USB Type-C standard, and is a 17-core cable including eight coaxial lines (for 10 Gbps transmission), four signal lines (a first SBU line, a second SBU line, a CC line, and a Vconn line), one power line, two ground lines, and a pair of twisted pairs. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-10747 A Summary of the Invention [Problem to be solved by the invention]

[0007] Transmission cables conforming to the conventional USB Type-C standard are the mainstream in many countries as charging cables for smartphones. Furthermore, there is a trend to adopt the USB Type-C standard as power cables and communication cables not only for smartphones but also for PCs and other communication and imaging devices. This is not to standardize the characteristics of the cables, but is thought to be to standardize the plugs (mating parts) of the connectors and the receptacles of the devices to be connected to increase convenience. On the other hand, the USB Type-C standard specifies the specifications for both the cable and the connector. The cable outer diameter (cable diameter) is also restricted due to the constraints on the board size of the USB-compliant connector. As a result, the conductor cross-sectional area of ​​each core wire cannot be increased, and there is a problem that communication quality deteriorates when the cable length is long.

[0008] An object of the present invention is to provide a communication cable and a communication cable assembly that can use a reversible plug that can be inserted into a receptacle upside down and that can increase the communication distance relative to the cable diameter. [Means for solving the problem]

[0009] [1] A device including two first differential pairs for transmitting high-speed differential signals and a configuration channel line for detecting the front and back orientation of a plug; The first differential pair does not include any other first differential pairs than the two first differential pairs. Communication cable. [2] The communication cable described in [1], wherein the signal lines constituting the first differential pair have a central conductor and an insulating layer covering the conductor, and the ratio of the conductor diameter to the cable diameter is 0.06 or more. [3] The communication cable according to [2], wherein the ratio of the communication distance of the high-speed differential signal to the cable diameter is 800 or more. [4] Further comprising a second differential pair for transmitting a low-speed differential signal, a power line, and a ground line; The communication cable according to [1] above, having 9 or more and 14 or less core wires. [5] The communication cable described in [4] above, further comprising a power line for the circuit in the plug. [6] The communication cable according to any one of [1] to [5] above; The plug; a connector board that electrically connects a terminal of the communication cable and the plug; A communication cable assembly comprising: Effect of the Invention

[0010] According to the present invention, a reversible plug that can be inserted into a receptacle upside down can be used, and the communication distance can be increased relative to the cable diameter. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a plan view showing an example of a communication cable assembly according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view illustrating an example of the communication cable illustrated in FIG. [Diagram 3] FIG. 3 shows a connector board compatible with a cable compliant with the USB Type-C standard, where (a) is a plan view of the connector board seen from the front side, and (b) is a plan view of the connector board seen from the back side. [Figure 4] FIG. 4 shows an example of a connector board according to the first embodiment, where (a) is a plan view of the connector board as seen from the front side, and (b) is a plan view of the connector board as seen from the back side. [Diagram 5] Figure 5 shows a diagram for explaining how the first differential pair is connected to the connector board shown in Figure 4, where (a) is a plan view of the connector board seen from the front side, and (b) is a plan view of the connector board seen from the back side. [Figure 6] FIG. 6 is a cross-sectional view showing an example of a communication cable according to the second embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view showing an example of a communication cable according to a third embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view showing an example of a communication cable according to a fourth embodiment of the present invention. [Figure 9] 9A and 9B are diagrams for explaining how the first differential pair is connected to the connector board shown in FIG. 4, where (a) is a plan view of the connector board seen from the front side, and (b) is a plan view of the connector board seen from the back side. [Figure 10] FIG. 10 is a cross-sectional view showing an example of a communication cable according to a fifth embodiment of the present invention. [Figure 11A] FIG. 11A is a diagram showing the attenuation characteristics when the cable length is 3 m. [Figure 11B] FIG. 11B is a diagram showing attenuation characteristics according to cable lengths corresponding to the respective communication distances. [Figure 12A] 12A(a) and 12A(b) are diagrams showing schematic examples of the arrangement of core wires. [Figure 12B] 12B(c) to (e) are diagrams showing schematic examples of the arrangement of the core wires. [Figure 12C] 12C(f) to (k) are diagrams showing schematic examples of the arrangement of core wires. [Figure 12D] 12D(l) to (q) are diagrams showing schematic examples of the arrangement of core wires. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each drawing, components having substantially the same functions are designated by the same reference numerals, and duplicated explanations will be omitted.

[0013] [First embodiment] 1 is a plan view showing an example of a communication cable assembly according to a first embodiment of the present invention. The communication cable assembly 100 includes a communication cable 1 of a predetermined length within a communication distance, a first plug connector (hereinafter abbreviated as "first connector") 110A connected to one end of the communication cable 1, and a second plug connector (hereinafter abbreviated as "second connector") 110B connected to the other end of the communication cable 1.

[0014] The communication cable 1 is a 9-core cable with fewer cores than the cable compliant with the USB Type-C standard. That is, a cable compliant with the USB Type-C standard has four pairs of high-frequency signal lines (SSTX1 line, SSRX1 line, SSTX2 line, SSRX2 line), but the communication cable 1 limits the high-frequency signal lines to two pairs (for example, (SSTX1 line, SSRX1 line)).

[0015] Furthermore, while a cable compliant with the USB Type-C standard has signal lines (SBU1 line, SBU2 line) for an alternate mode (HDMI (registered trademark), DisplayPort, etc.), this communication cable 1 does not have an alternate mode, in other words, does not include signal lines (SBU1 line, SBU2 line) or is specialized for USB signals. Note that signal lines (SBU1 line, SBU2 line) may be added as necessary.

[0016] With the above configuration, the number of core wires can be reduced, and when the cable diameter is the same as in the past, the conductor diameter of the SSTX1 wire and the SSRX1 wire can be increased, and the communication distance can be increased. That is, the communication distance relative to the cable diameter can be increased. Furthermore, by leaving the CC wire compliant with the USB Type-C standard, a reversible plug that can be inserted into a connector compliant with the USB Type-C standard, that is, a receptacle, can be adopted. Furthermore, since the number of core wires can be reduced, the core wires can be made thick, and as described later, advantages in the selection of the material of the resin layer and advantages in manufacturing can be obtained. Note that, in order to enjoy the convenience of the unification of connectors compliant with the USB Type-C standard, it is sufficient that at least the shape and structure of the fitting part of the connector are consistent with the shape and structure of the fitting part of the USB Type-C standard of the device to be connected, and the shape and structure of the connector board and cable other than the fitting part of the connector do not have to comply with the USB Type-C standard. Furthermore, since the cable length can be increased without deteriorating the communication quality and the weight can be reduced, it can also be used, for example, in in-vehicle devices.

[0017] The first connector 110A is connected to, for example, a receptacle provided in a computer, and includes a resin housing 111A, a plug 112A provided so as to be exposed from the housing 111A, and a connector board 200 disposed within the housing 111A. The connector board 200A of the first connector 110A electrically connects the plug 112A to one end of the communication cable 1.

[0018] The second connector 110B is connected to, for example, a receptacle provided in a peripheral device, and uses the same connector as the first connector 110A, as shown in Fig. 1(a). That is, the second connector 110B includes a resin housing 111A, a plug 112A provided so as to be exposed from the housing 111A, and a connector board 200A disposed within the housing 111A. The connector board 200A of the second connector 110B electrically connects the plug 112A to the other end of the communication cable 1.

[0019] In this embodiment, as shown in Fig. 1(a), the first connector 110A and the second connector 110B use the same connector, but as shown in Fig. 1(b), different connectors may be used. For example, the second connector 110B includes a resin housing 111B equipped with a screw for preventing the connector from coming off, a plug 112B provided so as to be exposed from the housing 111B, and a connector board 200A arranged in the housing 111B. In this embodiment, the connector board 200A of the first connector 110A and the connector board 200A of the second connector 110B use the same board, but different boards may be used.

[0020] (Communication cable configuration) FIG. 2 is a cross-sectional view showing an example of the communication cable 1 shown in FIG. 1. This communication cable 1 has two first differential pairs 2A, 2B for transmitting high-speed differential signals (for example, 5 Gbps to 20 Gbps), a second differential pair 3 for transmitting low-speed differential signals (for example, 480 Mbps), a power line 4 (Vbus line), a ground line 5, and a configuration channel line (hereinafter referred to as "CC line") 6 for detecting the front and back orientation of a plug conforming to the USB Type-C standard, and is a 9-core cable in which the first differential pair does not include any other than the two first differential pairs 2A, 2B. Note that the communication cable 1 is not limited to a 9-core cable, and may be a cable with 10 or more cores and 14 or less cores. By making it 14 or less cores, it is possible to differentiate from the recommended number of cores (15 cores) in USB Type-C. Also, the CC line 6 may not conform to the USB Type-C standard.

[0021] Among the signal lines 2a to 2d constituting the first differential pair 2A, 2B, two adjacent signal lines 2a, 2b constitute the first differential pair, and the other two adjacent signal lines 2c, 2d constitute the second differential pair. The pair of signal lines 2a, 2b are twisted together with the drain wire 10 and collectively covered by the shield layer 11. This constitutes a first twinax cable. The other pair of signal lines 2a, 2b are also twisted together with the drain wire 10 and collectively covered by the shield layer 11, thereby constituting a second twinax cable. The communication cable 1 using the twinax cable for the first differential pair 2A, 2B is hereinafter also referred to as a twinax type communication cable. Note that the twinax cable may be of a type that is not twisted. The drain wire 10 is, for example, a twisted wire made by twisting a plurality of metal wires together. The signal lines 2a to 2d are an example of signal lines that form a first differential pair.

[0022] The signal lines 2a to 2d each include a conductor 21 and an insulating layer 22 that covers the conductor 21. The conductor 21 is, for example, a twisted wire formed by twisting together a plurality of metal wires. The insulating layer 22 is made of a resin material (for example, cross-linked polyethylene). The conductor 21 is an example of a central conductor.

[0023] The shield layer 11 includes an inner shield layer 11a provided on the inside and formed by winding a conductive tape (e.g., a tape laminated with aluminum and polyester), and an outer shield layer 11b provided on the outside of the inner shield layer 11a and formed by winding a resin tape (e.g., a polyester tape).

[0024] The second differential pair 3 is formed by twisting two signal lines 3a, 3b together. The signal lines 3a, 3b each include a conductor 31 and an insulating layer 32 that covers the conductor 31. The conductor 31 is, for example, a twisted wire formed by twisting together a plurality of metal wires. The insulating layer 32 is made of a resin material (for example, cross-linked polyethylene).

[0025] The power line 4 includes a conductor 41 and an insulating layer 42 that covers the conductor 41. The conductor 41 is, for example, a twisted wire formed by twisting together a plurality of metal wires. The insulating layer 42 is made of a resin material (for example, cross-linked polyethylene).

[0026] The ground wire 5 includes a conductor 51 and an insulating layer 52 that covers the conductor 51. The conductor 51 is, for example, a twisted wire formed by twisting together a plurality of metal wires. The insulating layer 52 is made of a resin material (for example, cross-linked polyethylene). The ground wire 5 may be a bare wire that does not have an insulating layer on its outer periphery.

[0027] The CC wire 6 includes a conductor 61 and an insulating layer 52 that covers the conductor 61. The conductor 61 is, for example, a stranded wire formed by twisting together a plurality of metal wires. The insulating layer 62 is made of a resin material (for example, polyvinyl chloride).

[0028] The first differential pair 2A, 2B, the second differential pair 3, the power line 4, the ground line 5, and the CC line 6 are covered with a shielding layer 12 together with the intervening string 13, and the outside of the shielding layer 12 is covered with a sheath 7. The sheath 7 is made of a resin material (e.g., polyvinyl chloride) having a thickness of about 0.6 to 0.9 mm. The intervening string 13 is made of a fibrous material (e.g., cotton, silk, etc.). The intervening string 13 is an example of an inclusion.

[0029] The shield layer 12 comprises an inner shield layer 12a provided on the inside and formed by winding a conductive tape (e.g., a tape laminated with aluminum and polyester), and an outer shield layer 12b provided on the outside of the inner shield layer 12a and formed from a metal braid (e.g., a tin-plated soft copper wire braid).

[0030] (Connector board configuration) Fig. 3 shows a connector board 200B compatible with a cable compliant with the USB Type-C standard, where (a) is a plan view of the connector board 200B seen from the front side, and (b) is a plan view of the connector board 200B seen from the back side. Fig. 4 shows an example of a connector board 200A according to this embodiment, where (a) is a plan view of the connector board 200A seen from the front side, and (b) is a plan view of the connector board 200A seen from the back side. In Figs. 3 and 4, A indicates the plug side, B indicates the cable side, and C indicates the width direction of the connector board.

[0031] (Configuration of connector board compatible with cables compliant with the USB Type-C standard) Connector board 200B, which is compatible with cables compliant with the USB Type-C standard, is configured to be compatible with an 18-core cable, i.e., has 18 terminals (also called pads), as shown in FIG. 3, and has a base material 201 formed from an insulating material.

[0032] As shown in FIG. 3(a), on the surface 201a of the base material 201, there are formed a plug side surface terminal group 211 consisting of terminals 211a to 211l provided on the plug side A, terminals 221a, 221b provided midway between the plug side A and the cable side B, and a cable side surface terminal group 231 consisting of terminals 231a to 231i provided on the cable side B.

[0033] As shown in FIG. 3(b), on the back surface 201b of the base material 201, there are formed a plug side back surface terminal group 212 consisting of 212a to 212j provided on the plug side A, terminals 222a, 222b provided midway between the plug side A and the cable side B, and a cable side back surface terminal group 232 consisting of terminals 232a to 232i provided on the cable side B.

[0034] The terminals 231a to 231i of the cable side front surface terminal group 231 are formed at a pitch of 0.9 to 1.0 mm, and the terminals 232a to 232i of the cable side back surface terminal group 232 are formed at a pitch of 0.9 to 1.0 mm. In other words, the minimum pitch of the terminals in the width direction C of the connector board 200B is 0.9 mm.

[0035] (Configuration of the Connector Board According to the Present Embodiment) The connector board 200A of this embodiment complies with the USB Type-C standard, but as shown in FIG. 4, is configured to be compatible with 9-core and 10-core cables, i.e., has 10 terminals (also called pads), and has a base material 201 made of an insulating material.

[0036] As shown in Fig. 4(a), a plug-side surface terminal group 211 consisting of terminals 211a to 211l provided on the plug side A, terminals 221a and 221b for a metal cover (not shown) of the plug 112A provided between the plug side A and the cable side B, and a cable-side surface terminal group 231 consisting of terminals 231a to 231f provided on the cable side B are formed on the surface 201a of the base material 201. The terminal 231f of the cable-side surface terminal group 231 is a shield terminal and has a rectangular shape whose longitudinal direction is the width direction C of the connector board 200A. The terminals 231a and 231b of the cable-side surface terminal group 231 are an example of a pair of surface terminals. The shield terminal 231f is an example of a surface shield terminal.

[0037] As shown in FIG. 4(b), the back surface 201b of the base material 201 is provided with a plug-side back surface terminal group 212 consisting of terminals 212a to 212j provided on the plug side A, terminals 222a and 222b for a metal cover (not shown) of the plug 112A provided between the plug side A and the cable side B, and a cable-side back surface terminal group 232 consisting of terminals 232a to 232f provided on the cable side B. The terminal 232f of the cable-side back surface terminal group 232 is a shield terminal and has a rectangular shape whose longitudinal direction is the width direction C of the connector board 200A. The front surface 201a and the back surface 201b are an example of one surface. The terminals 232a and 232b of the cable-side back surface terminal group 232 are an example of a pair of back surface terminals. The shield terminal 232f is an example of a back surface shield terminal.

[0038] The terminals 231a to 231e of the cable side front surface terminal group 231, excluding the shield terminal 231f, are formed at a pitch of 1.57 mm or more, and the terminals 232a to 232e of the cable side back surface terminal group 232, excluding the shield terminal 232f, are formed at a pitch of 1.2 to 2.0 mm. That is, the minimum pitch of the terminals in the width direction C of the connector board 200A is 1.2 mm.

[0039] According to the connector board 200A of the present embodiment, the minimum pitch of the terminals in the width direction C can be increased to 1.3 times or more the minimum pitch in the width direction C of the connector board 200B conforming to the USB Type-C standard. In addition, since the number of cores of the cable is reduced, the number of pads of the connector board 200A can also be reduced, and the pad width can be increased, for example, from 0.5 mm to 0.8 mm for the same dimensions and area as the connector board 200B conforming to the USB Type-C standard. With the above configuration, the connection work can be performed with the naked eye. In addition, the connection work of the communication cable 1 to the connector board 200A can be performed without using a jig (line arrangement part) that aligns and holds the end of the communication cable 1 to be connected.

[0040] (Manufacturing method of communication cable assembly) Next, an example of a method for manufacturing communication cable assembly 100 according to this embodiment will be described.

[0041] First, two first differential pairs 2A and 2B, a second differential pair 3, a power line 4, a ground line 5, a CC line 6, and an interposer 13 are prepared. For the first differential pair 2A and 2B, two signal lines 2a and 2b or two signal lines 2c and 2d and a drain line 10 are twisted together and a conductive tape is wound around the outer periphery to form an inner shield layer 11a, and a resin tape is wound around the outer periphery of the inner shield layer 11a to form an outer shield layer 11b. The second differential pair 3 is formed by twisting two signal lines 3a and 3b together.

[0042] Next, the two first differential pairs 2A and 2B, the second differential pair 3, the power line 4, the ground line 5, the CC line 6, and the interposer 13 are twisted together, and a conductive tape is wound around the outer periphery of these to form the inner shield layer 12a, and a metal braid is wound around the outer periphery of the inner shield layer 12a to form the outer shield layer 12b. Next, a sheath 7 is formed around the outer periphery of the shield layer 12 by extrusion molding using an extruder.

[0043] In this manner, the communication cable 1 is manufactured. Thereafter, the communication cable 1 is cut to a required length, and the ends are connected to the connector board 100A of the first connector 110A and the connector board 100A of the second connector 110B, thereby manufacturing the communication cable assembly 100 having the first connector 100A and the second connector 100B at both ends of the communication cable 1. The operation of connecting the first differential pair 2A, 2B to the connector board 100A will be described later.

[0044] (Connection of the first differential pair) Figure 5 shows a diagram for explaining how the signal lines 2a to 2d of the first differential pair 2A, 2B are connected to the connector board 100A shown in Figure 4, where (a) is a plan view of the connector board 100A seen from the front side, and (b) is a plan view of the connector board 100A seen from the back side.

[0045] When the conductors 21 of the signal lines 2a and 2b of the communication cable 1 according to the first embodiment are connected to the terminals 231a and 231b of the cable side surface terminal group 231 of the connector board 200B corresponding to the cable conforming to the USB Type-C standard shown in FIG. 3(a), the shield layer 11 must be peeled off, and the insulating layer 22 of the signal lines 2a and 2b must be peeled off, and the exposed conductors 21 must be connected to the terminals 231a and 231b with a narrow pitch. On the other hand, when the conductors 21 of the signal lines 2a and 2b are connected to the terminals 231a and 231b of the cable side surface terminal group 231 of the connector board 200A shown in FIG. 4(a), the pitch of the terminals 231a and 231b is wide, so that the connection work of the signal lines 2a and 2b can be easily performed. This is also true for the back surface 201b of the connector board 200A shown in FIG. 4(b). The drain wire 10 is drawn out from the shield layer 11 and connected to a metal cover (not shown) of the plug 112A.

[0046] (Effects of the First Embodiment) The communication cable assembly 100 according to the first embodiment has the following advantages. (a) The number of core wires can be reduced compared to the core wire configuration of cables compliant with the USB Type-C standard, which reduces manufacturing costs and enables weight reduction. (b) When the cable outer diameter is the same, the outer diameter of the core wire can be made thicker, improving various characteristics (communication performance, bending resistance (meaning the property of being less likely to break when repeatedly bent; the same applies below), and mechanical strength). In addition, since the conductor is made thicker, the risk of breakage due to injection pressure during molding is reduced, and the options for molding methods are expanded. In addition, when the cable outer diameter is the same, the core wires of the signal lines 2a, 2b, etc. can be made thicker, broadening the range of materials that can be selected for the insulating layer. For example, it is possible to select the constituent material from expensive nylon-based resins such as polyamide to inexpensive polyolefin-based resins such as polyethylene, and to shorten the molding time by changing the molding machine from a dedicated molding machine that performs low-pressure molding to a general-purpose molding machine that performs injection molding. (c) Since the communication distance of high-speed differential signals relative to the cable diameter can be increased, when the cable diameter is reduced (e.g., 3.7 mm), the weight of the communication cable can be reduced without shortening the communication distance. Also, when the cable diameter is kept at the same level as the conventional one (e.g., 6.8 mm), the conductors 21 of the first differential pair 2A, 2B can be made thicker, so the communication distance can be increased. (d) Since it has a CC wire 6, a reversible plug can be used that can be inserted into the receptacle upside down (upside down). (e) Since the pitch of the terminals 231a, 231b and the pitch of the terminals 232a, 232b of the connector board 200A are wide, the signal lines 2a to 2d that constitute the first differential pair 2A, 2B can be easily connected to the connector board 200A.

[0047] [Second embodiment] 6 is a cross-sectional view showing an example of a communication cable according to a second embodiment of the present invention. In the communication cable 1 of the first embodiment, the CC wire 6 is arranged between the power wire 4 and the ground wire 5, but in the communication cable 1 of this embodiment, the CC wire 6 is arranged at a position where it contacts the shield layer 11 covering the first differential pair 2B and the ground wire 5, and the conductor diameter of the conductors 21 of the signal lines 2a to 2d is reduced to reduce the cable diameter. The communication cable assembly 100 according to the second embodiment is manufactured in the same manner as in the first embodiment, and therefore a description thereof will be omitted.

[0048] According to the second embodiment, by appropriately selecting the outer diameters of the power line 4, the ground line 5, and the CC line 6, the outer diameter of the cable can be made smaller than that of the first embodiment without shortening the communication distance of the high-speed differential signal.

[0049] [Third embodiment] 7 is a cross-sectional view showing an example of a communication cable according to a third embodiment of the present invention. The communication cable 1 of the first embodiment is a 9-core cable, but the communication cable 1 of this embodiment is a 10-core cable obtained by adding a power line for a circuit in a plug (hereinafter referred to as a "Vconn line") that complies with the USB Type-C standard to the communication cable 1 of the first embodiment. The following mainly describes the differences from the first embodiment.

[0050] The communication cable 1 according to the third embodiment is a 10-core cable having two first differential pairs 2A and 2B, a second differential pair 3, a power line 4, a ground line 5, a CC line 6 conforming to the USB Type-C standard, and a Vconn line 8, similar to the first embodiment. Note that the communication cable 1 is not limited to a 10-core cable, and may be a cable with 11 or more cores. Also, the Vconn line 8 may not conform to the USB Type-C standard.

[0051] The Vconn line 8 includes a conductor 81 and an insulating layer 82 that covers the conductor 81. The conductor 81 is, for example, a stranded wire formed by twisting together a plurality of metal wires. The insulating layer 82 is made of a resin material (for example, polyvinyl chloride).

[0052] In the first embodiment, the CC line 6 is disposed between the power line 4 and the ground line 5, but in this embodiment, the power line 4 and the ground line 5 are disposed side by side, with the CC line 6 disposed on one side of them and the Vconn line 8 disposed on the other side. The CC line 6 and the Vconn line 8 are connected to an IC chip (eMarker) built into the plug. The communication cable assembly 100 according to the third embodiment is manufactured in the same manner as in the first embodiment, and therefore a description thereof will be omitted.

[0053] According to the third embodiment, the same effects as those of the first embodiment are achieved, and since the third embodiment is provided with a CC line 6 and a Vconn line 8, it is possible to connect the charger and the device with the communication cable 1 and quickly charge the device with power that complies with the USB PD (Power Delivery) standard.

[0054] [Fourth embodiment] 8 is a cross-sectional view showing an example of a communication cable according to a fourth embodiment of the present invention. In the communication cable 1 of the first embodiment, the first differential pair of signal lines 2a, 2b constituting the two first differential pairs 2A, 2B and the second differential pair of signal lines 2c, 2d are collectively shielded by a shield layer 11, respectively, but the communication cable 1 of this embodiment uses coaxial cables 9a-9d as the signal lines constituting the two first differential pairs 2A, 2B (also called a coaxial type communication cable). The following mainly describes the differences from the first embodiment.

[0055] In the communication cable 1 according to the fourth embodiment, the first differential pair 2A is configured by a first differential pair of a pair of coaxial wires 9a and 9b, the first differential pair 2B is configured by a second differential pair of a pair of coaxial wires 9c and 9d, these coaxial wires 9a to 9d are arranged on the outer periphery side, a CC line 6 and an intervening string 14 are arranged in the center, and the first differential pair 2A, 2B, the second differential pair 3, the power line 4, and the ground line 5 are covered with the intervening string 13 by a shield layer 12, and the outside of the shield layer 12 is covered with a sheath 7. The intervening string 14 is made of a resin material (for example, polyethylene). The coaxial wires 9a to 9d are an example of a signal line that configures the first differential pair. The intervening string 14 is an example of an inclusion.

[0056] The coaxial wires 9a to 9d each include a central conductor 91, an inner insulating layer 92 covering the central conductor 91, an outer conductor 93 formed on the outside of the inner insulating layer 92, and an outer insulating layer 94 covering the outer conductor 93. The central conductor 91 is, for example, a stranded wire formed by stranding a plurality of metal wires. The inner insulating layer 92 is made of a resin material (for example, cross-linked polyethylene). The outer conductor 93 is, for example, made of a metal braid or the like. The outer insulating layer 94 is made of a resin material (for example, polyvinyl chloride). The central conductor 91 is an example of a central conductor.

[0057] (Manufacturing method of communication cable assembly) Next, an example of a method for manufacturing the communication cable assembly 100 according to the fourth embodiment will be described.

[0058] First, two first differential pairs 2A and 2B, a second differential pair 3, a power line 4, a ground line 5, a CC line 6, and interposers 13 and 14 are prepared. Four coaxial lines 9a to 9d that constitute the first differential pair 2A and 2B are prepared. The second differential pair 3 is formed by twisting two signal lines 3a and 3b together.

[0059] Next, the two first differential pairs 2A, 2B, the second differential pair 3, the power line 4, the ground line 5, the CC line 6, and the interposers 13, 14 prepared are twisted together, and a conductive tape is wound around the outer periphery of these to form the inner shield layer 12a, and a metal braid is wound around the outer periphery of the inner shield layer 12a to form the outer shield layer 12b. Next, a sheath 7 is formed around the outer periphery of the shield layer 12 by extrusion molding using an extruder.

[0060] In this manner, the communication cable 1 is manufactured. Thereafter, the communication cable 1 is cut to a required length, and the ends are connected to the connector board 100A of the first connector 110A and the connector board 100A of the second connector 110B, thereby manufacturing a communication cable assembly 100 having the first connector 100A and the second connector 100B at both ends of the communication cable 1. The operation of connecting the coaxial lines 9a to 9d constituting the first differential pair 2A, 2B to the connector board 100A will be described later.

[0061] (Connection of the first differential pair) 9A and 9B are diagrams for explaining how the first differential pair is connected to the connector board shown in FIG. 4, where (a) is a plan view of the connector board seen from the front side, and (b) is a plan view of the connector board seen from the back side.

[0062] When connecting the central conductors 91 of the coaxial lines 9a and 9b of the communication cable 1 according to the fourth embodiment to the terminals 231a and 231b of the cable side surface terminal group 231 of the connector board 200B corresponding to the cable conforming to the USB Type-C standard shown in FIG. 3(a), the outer insulating layer 94 must be peeled off, and the inner insulating layer 92 of the coaxial lines 9a and 9b must be peeled off, and the exposed central conductors 91 must be connected to the terminals 231a and 231b having a narrow pitch. In addition, the outer conductor 93 must be drawn out as a single conductor and connected to a shield terminal (a metal cover of the plug 112A, not shown). On the other hand, when connecting the central conductors 91 of the coaxial lines 9a and 9b to the terminals 231a and 231b of the cable side surface terminal group 231 of the connector board 200A shown in FIG. 4(a), the pitch of the terminals 231a and 231b is wide, so that the connection work of the coaxial lines 9a and 9b can be easily performed. In addition, the outer peripheral surface can be connected to the shield terminal 231f without drawing out the exposed outer conductor 93 like a single conductor wire. This also applies to the back surface 201b of the connector board 200A shown in FIG. 4(b).

[0063] (Effects of the Fourth Embodiment) The communication cable 1 of the fourth embodiment has the same effects as the first embodiment, and since the coaxial wires 9a-9d are used as the signal lines constituting the first differential pair 2A, 2B, the outer insulating layers 94 of the coaxial wires 9a-9d can be peeled off to connect the outer circumferential surfaces of the exposed outer conductors 93 to the shield terminals 231f, 232f, facilitating the connection of the coaxial wires 9a-9d to the connector board 200A.

[0064] In addition, since the coaxial cables 9a to 9d are used as the first differential pairs 2A and 2B, the coaxial cables 9a to 9d are independent of each other, and therefore the characteristic change in the differential is very small, so that the bending resistance can be improved compared to the twinax type communication cable. This is clear from the results of the durability test below. That is, an 8-core coaxial type communication cable, which does not include the CC line 6 from the present embodiment, is attached to a cable bear (registered trademark), and a durability test is performed in which the cable is repeatedly moved and bent under predetermined conditions (movement distance: 1 m, bending speed: 30 times / min, bending radius (inner side): 75 mm). As a result, even if the moving bending exceeds 30 million times, the required characteristics can be maintained, although there is some damage to the sheath and some influence on the transmission characteristics. On the other hand, in the case of a twinax type communication cable having the same 8-core core structure, when the moving bending exceeds 100,000 times, mechanical damage causes a change in the transmission characteristics in the first differential pairs 2A and 2B, causing communication degradation.

[0065] [Fifth embodiment] Fig. 10 is a cross-sectional view showing an example of a communication cable according to a fifth embodiment of the present invention. The communication cable 1 according to this embodiment is obtained by adding a Vconn line 8 to the center of the communication cable 1 according to the fourth embodiment, and using two intermediate strings 14a, 14b made of a resin material (e.g., polyethylene). The intermediate strings 14a, 14b are examples of intermediate materials. Note that the communication cable assembly 100 according to the fifth embodiment is manufactured in the same manner as the fourth embodiment, and therefore a description thereof will be omitted.

[0066] The communication cable 1 according to the fifth embodiment has the same effects as the fourth embodiment, and includes the CC line 6 and the Vconn line 8, so that the charger and the device can be connected with the communication cable 1 to charge the device at high speed with power conforming to the USB PD (Power Delivery) standard. In addition, the coaxial lines 9a to 9d are used as the first differential pair 2A, 2B, so that the bending resistance can be improved. EXAMPLES

[0067] As described below, the communication performance (communication distance and attenuation characteristics) of Example 1 corresponding to the first embodiment, Example 2 corresponding to the second embodiment, and a comparative example were tested and evaluated.

[0068] (Test conditions for communication distance) A PC as a computer and a camera as a peripheral device were connected with a communication cable to be tested. The PC used was a ProBook 430 G5 manufactured by HP, and the camera used was a USB3.1 Gen1 uEye SE series manufactured by IDS. The communication cables to be tested were the following Example 1, Example 2, and Comparative Example. The configurations of these are shown in Table 1. In Table 1, T indicates tin-plated annealed copper wire, and AG indicates silver-plated annealed copper wire. In addition, in the Comparative Example, only electric wires comparable to Example 1 and Example 2 are shown in Table 1.

[0069] [Table 1]

[0070] In Example 1, a 9-core cable with a diameter of 6.8 mm was used, and AWG size 27 (conductor diameter 0.42 mm) was used as the conductors 21 of the signal lines 2a to 2d constituting the first differential pair 2A, 2B. The conductor diameter d with respect to the cable diameter D (d / D) was 0.062.

[0071] In Example 2, a 9-core cable with a diameter of 3.7 mm was used, and AWG size 32 (conductor diameter 0.24 mm) was used as the conductors 21 of the signal lines 2a to 2d constituting the first differential pair 2A, 2B. The conductor diameter d with respect to the cable diameter D (d / D) was 0.065.

[0072] In the comparative example, a 17-core cable with a diameter of 5.2 mm was used, and AWG size 30 (conductor diameter 0.3 mm) was used as the conductor of the signal line constituting the first differential pair. The ratio (d / D) of the conductor diameter d to the cable diameter D was 0.058. If the ratio (d / D) exceeds 0.07, the weight of the communication cable increases, so it can be said from Example 1, Example 2, and the comparative example that the ratio (d / D) is preferably 0.06 or more and 0.07 or less.

[0073] (Method of evaluating communication distance) The video captured by the camera was sent to a PC via the communication cable under test, and the communication performance (communication distance) was evaluated based on the presence or absence of freezing, dropping, noise, image discoloration, etc. during the 10-minute shooting period. If there were no problems with the video for 10 minutes, it was marked as ○, and if the video was not displayed on the PC, it was marked as ×. The evaluation results are shown in Table 2.

[0074] (Attenuation characteristics) Fig. 11A shows the attenuation characteristics when the cable length is 3 m. Fig. 11B shows the attenuation characteristics according to the cable length (used cable length) corresponding to each communication distance. Since the data transfer speed of the camera used is 5 Gbps, the attenuation characteristics were measured around 2.5 GHz.

[0075] The amount of attenuation when the communication cable length is 3 m is due to the AWG size of the communication cable, and as shown in Fig. 11A, the smaller the AWG size (the larger the conductor diameter), the smaller the amount of attenuation. That is, the amount of attenuation around a frequency of 2.5 GHz was 6 dB in Example 1, 11 dB in Example 2, and 8 dB in the comparative example. These attenuation values ​​are shown in Table 2.

[0076] As shown in Fig. 11B, the attenuation in the cable length corresponding to the communication distance is 13 dB at a frequency of about 2.5 GHz in the cases of Examples 1 and 2, which can be estimated as the communication limit. On the other hand, in the case of the comparative example, although it is small at 8 dB at a frequency of about 2.5 GHz, it is considered that the communication distance is the shortest at 3 m due to the power supply specifications by the power line 4 (Vbus line), the potential difference with GND, and other factors. The above attenuation values ​​are shown in Table 2.

[0077] [Table 2]

[0078] (Summary of evaluation) (1) In Example 1 (cable diameter 6.8 mm), the communication distance was doubled from 3 m to 6 m compared to the comparative example (cable diameter 5.2 mm). In Example 2 (cable diameter 3.7 mm), the communication performance was equivalent to that of the comparative example (cable diameter 5.2 mm), and the weight of the communication cable was reduced. (2) When the cable diameter is D and the communication distance is L, the communication distance L (L / D) relative to the cable diameter D as an evaluation value of communication performance was L / D = 6000 mm / 6.8 mm = 882 for Example 1, L / D = 3500 mm / 3.7 mm = 946 for Example 2, and L / D = 3000 mm / 5.2 mm = 577 for the comparative example. Therefore, it can be said that the communication distance L / D relative to the cable diameter is preferably 800 or more or 880 or more, and more preferably 900 or more or 940 or more.

[0079] (Example of core wire arrangement) Fig. 12(a) to (q) are diagrams showing schematic examples of the arrangement of core wires constituting the communication cable 1. Fig. 12(a) to (e) are diagrams showing the layout of core wires that do not require high bending resistance, and Fig. 12(f) to (q) are diagrams showing the layout of core wires that require high bending resistance. Fig. 12(a) corresponds to the first embodiment (Fig. 2), Fig. 12(c) corresponds to the third embodiment (Fig. 7), Fig. 12(i) corresponds to the fourth embodiment (Fig. 8), and Fig. 12(l) corresponds to the fifth embodiment (Fig. 10).

[0080] In the 9-core communication cable 1 in which twinax cables are used for the first differential pair 2A, 2B, the power line (core wire No. 7) and the ground line (core wire No. 8) are arranged on both sides of the CC line (core wire No. 9) as shown in FIG. 12(a) in the first embodiment, but they can also be arranged on both sides of the second differential pair 3 as shown in FIG. 12(b).

[0081] In the 10-core communication cable 1 using twinax cables for the first differential pair 2A, 2B, the CC line (core No. 9) and the Vconn line (core No. 10) are arranged on both sides of the power line (core No. 7) and the ground line (core No. 8) in the third embodiment as shown in Fig. 12(c), but they may be arranged on both sides of the second differential pair (core Nos. 5 and 6) as shown in Fig. 12(d). Also, as shown in Fig. 12(e), the power line (core No. 7) and the ground line (core No. 8) may be arranged on both sides of the second differential pair (core Nos. 5 and 6), and the CC line (core No. 9) and the Vconn line (core No. 10) may be arranged on the opposite side of the second differential pair (core Nos. 5 and 6).

[0082] In the 9-core communication cable 1 in which the coaxial wires 9a to 9d are used for the first differential pair 2A, 2B, the paired coaxial wires are adjacent to each other as shown in FIG. 12(i) in the fourth embodiment, but a power line (core wire No. 7) or a ground line (core wire No. 8) may be placed between them as shown in FIGS. 12(h) and (k).

[0083] In the 10-core communication cable 1 in which the coaxial wires 9a to 9d are used for the first differential pairs 2A, 2B, the paired coaxial wires are adjacent to each other as shown in FIG. 12(l) in the fifth embodiment, but a power line (core wire No. 7) or a ground line (core wire No. 8) may be placed between them as shown in FIGS. 12(n) and (q).

[0084] Although the embodiment of the present invention has been described above, the embodiment of the present invention is not limited to the above embodiment, and various modifications and implementations are possible. [Explanation of symbols]

[0085] 1...communication cable, 2A, 2B...first differential pair, 2a to 2d...signal lines, 3...second differential pair, 3a, 3b...signal lines, 4...power line, 5...ground line, 6...CC line, 7...sheath, 8...Vconn line, 9a to 9d...coaxial line, 10...drain line, 11...shield layer, 11a...inner shield layer, 11b...outer shield layer, 12...shield layer, 12a...inner shield layer, 12b...outer shield layer, 13...intervening cord, 21...conductor, 22...insulating layer, 31...conductor, 32...insulating layer, 41...conductor, 42...insulating layer, 51...conductor, 52...insulating layer, 61...conductor, 62...insulating layer, 81...conductor, 82...insulating layer, 91...center conductor, 92...inner insulating layer, 93...outer Conductor, 94...outer insulating layer, 100...communication cable assembly, 110A...first connector, 110B...second connector, 111A, 111B...housing, 112A, 112B...plug, 200A, 200B...connector board, 201...substrate, 201a...surface, 201b...back, 211...plug side surface terminal group, 211a to 211l, 221a, 221b...terminals, 212...plug side back terminal group, 212a to 212j, 222a, 222b...terminals, 231...cable side surface terminal group, 231a to 231e...terminals, 231f...shield terminal, 232...cable side back terminal group, 232a to 232e...terminals, 232f...shield terminal

Claims

1. The connector includes two first differential pairs for transmitting high-speed differential signals and a configuration channel line for detecting the front and back orientation of the plug; The first differential pair does not include any other first differential pairs than the two first differential pairs. Communication cable.

2. The signal lines constituting the first differential pair include a central conductor and an insulating layer covering the conductor, and a ratio of a conductor diameter of the conductor to a cable diameter is 0.06 or more.

2. The communication cable according to claim 1.

3. The ratio of the communication distance of the high-speed differential signal to the cable diameter is 800 or more.

3. The communication cable according to claim 2.

4. The signal processing circuit further includes a second differential pair for transmitting a low-speed differential signal, a power supply line, and a ground line, The number of cores is 9 or more and 14 or less.

2. The communication cable according to claim 1.

5. a power line for the circuit in the plug; 5. The communication cable according to claim 4.

6. A communication cable according to any one of claims 1 to 5; The plug; a connector board that electrically connects a terminal of the communication cable and the plug; A communication cable assembly comprising:

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