Electrical connector, connection assembly, and cable

Abstract

To provide an electrical connector, a connection assembly, and a cable that can improve communication performance.SOLUTION: An electrical connector includes: a cable having a plurality of conductors, including a plurality of signal lines and a plurality of ground lines and arranged in parallel with one another, and a coating portion that covers the plurality of conductors so that the tips of the conductors are exposed; and a plurality of terminals that are arranged in parallel along the parallel direction of the plurality of conductors so as to face the tips of the plurality of ground lines, respectively, and electrically connect each of the plurality of ground lines to ground. In a cross section of the plurality of conductors in a plane perpendicular to the central axes of the plurality of conductors, only the plurality of ground lines out of the plurality of signal lines and the plurality of ground lines each include a first flat portion on the surface, and each of the plurality of terminals includes a connection portion connected to the first flat portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to electrical connectors, connection assemblies and cables. [Background technology]

[0002] Patent Documents 1 and 2 disclose flat cables including a plurality of conductors and a covering covering the conductors. In the flat cable described in Patent Document 1, the tip end of each of the plurality of conductors is exposed from the covering. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-49971 [Patent Document 2] Patent Publication No. 2021-34283 Summary of the Invention [Problem to be solved by the invention]

[0004] In flat cables such as those described above, crosstalk between multiple conductors can be a problem. For example, in the flat cable described in Patent Document 1, crosstalk can occur at the ends of multiple conductors, where part of the electromagnetic waves generated by a signal transmitted through one signal line travels through an air layer and travels to another signal line. This crosstalk can degrade communication performance. The shape of the conductor itself can also affect communication performance. For example, when a circular ground wire is used, as in the flat cable described in Patent Document 2, the cross-sectional area of the ground wire itself cannot be ensured sufficiently, which tends to increase electrical resistance. In this case, it is difficult to improve communication performance.

[0005] The present disclosure provides electrical connectors, connection assemblies, and cables that can improve communication performance. [Means for solving the problem]

[0006] The electrical connector of the present disclosure includes a cable having a plurality of conductors, including a plurality of signal lines and a plurality of ground lines, arranged in parallel with one another, and a coating portion that covers the plurality of conductors so that the tips of the conductors are exposed, and a plurality of terminals that are arranged in parallel along the parallel direction of the plurality of conductors so as to face the tips of the plurality of ground lines, and electrically connect each of the plurality of ground lines to ground, wherein in a cross section of the plurality of conductors in a plane perpendicular to the central axes of the plurality of conductors, only a plurality of the plurality of ground lines out of the plurality of signal lines and a plurality of ground lines each include a first flat portion on the surface, and each of the plurality of terminals includes a connection portion connected to the first flat portion. [Effects of the Invention]

[0007] The electrical connectors, connection assemblies, and cables of the present disclosure can improve communication performance. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a connection assembly according to one embodiment. [Figure 2] FIG. 2 is a side view of the connection assembly of FIG. [Figure 3] FIG. 3 is a cross-sectional view of the connection assembly taken along line III-III of FIG. [Figure 4] FIG. 4 is a cross-sectional view of the connection assembly taken along line IV-IV of FIG. [Figure 5] Part (a) of FIG. 5 is a cross-sectional view showing a cable included in a connection assembly according to Modification 1, and part (b) of FIG. 5 is a cross-sectional view showing a cable included in a connection assembly according to Modification 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiments of the present disclosure] First, the contents of the embodiments of the present disclosure will be listed and described.

[0010] (1) The electrical connector of the present disclosure comprises a cable having a plurality of conductors, including a plurality of signal lines and a plurality of ground lines, arranged in parallel with one another, and a coating portion covering the plurality of conductors so that the tips of the conductors are exposed; and a plurality of terminals arranged in parallel along the parallel direction of the plurality of conductors so as to face the tips of the plurality of ground lines, respectively, and electrically connecting each of the plurality of ground lines to ground, wherein, in a cross section of the plurality of conductors in a plane perpendicular to the central axes of the plurality of conductors, only a plurality of the plurality of ground lines among the plurality of signal lines and a plurality of ground lines each include a first flat portion on the surface, and each of the plurality of terminals includes a connection portion connected to the first flat portion.

[0011] The electrical connector includes a plurality of terminals arranged parallel to the parallel direction of the conductors so as to face the respective tips of the ground wires, and electrically connecting each of the ground wires to ground. In this case, crosstalk, in which part of the electromagnetic waves generated by a signal transmitted through a signal wire sneaks through an air gap and reaches other signal wires, can be suppressed. Furthermore, in a cross-section of the conductors taken along a plane perpendicular to the central axes of the conductors, only a few of the signal wires and the ground wires include a first flat portion on their surfaces. Each of the terminals includes a connection portion connected to the first flat portion. When the ground wire includes the first flat portion on its surface, the bonding strength between the ground wire and the terminal can be improved, thereby stably connecting the ground wires to ground via the terminals. Furthermore, when the ground wire includes the first flat portion on its surface, the cross-sectional area of the ground wire can be increased compared to when the ground wire does not include the first flat portion on its surface (e.g., a circular ground wire), thereby suppressing an increase in electrical resistance. Furthermore, when the signal wire does not include the first flat portion on its surface, corners are prevented from forming on the surface of the signal wire, thereby suppressing degradation of high-frequency characteristics due to the skin effect. Therefore, the above-described electrical connector can improve the communication performance of signals propagating through signal lines and the like.

[0012] (2) In the electrical connector described in (1) above, the multiple signal lines may include a first signal line and a second signal line adjacent to each other, and the multiple ground lines may include a first ground line and a second ground line arranged on either side of the first signal line and the second signal line in a parallel direction and electrically connected to each other via multiple terminals. In this case, the first signal line and the second signal line may form a differential signal line. As a result, the currents flowing through the first signal line and the second signal line are in opposite phases, so that, for example, a portion of the electromagnetic wave sneaking from the first signal line to the first ground line and a portion of the electromagnetic wave sneaking from the second signal line to the second ground line can cancel each other out. As a result, the communication performance of signals propagating through the signal lines, etc. can be further improved.

[0013] (3) The electrical connector according to (1) or (2) above may further include a conductor member disposed on or inside the coating and connected to ground, and the multiple ground lines may be connected to the conductor member via multiple terminals. In this case, the multiple terminals may be connected to the conductor member and integrated to stabilize the ground. This reduces the effects of crosstalk and improves the communication performance of signals propagating through signal lines, etc.

[0014] (4) In the electrical connector described in any one of (1) to (3), each of the ground wires may further include a second flat portion on its surface, facing away from the first flat portion along a direction perpendicular to the parallel direction, in a cross section of the conductors in a plane perpendicular to the central axes of the conductors. For example, when the electrical connector is disposed on a main surface of a circuit board, connecting the second flat portion of each of the ground wires to an electrode on the main surface can improve the bonding strength between the ground wire and the terminal at the first flat portion and also improve the bonding strength between the ground wire and the circuit board electrode at the second flat portion. This stabilizes the electrical connection between the terminal, the ground wire, and the circuit board electrode.

[0015] (5) In the electrical connector according to any one of (1) to (4), each of the ground wires may further include a third flat portion and a fourth flat portion on its surface, facing opposite each other along the parallel direction, in a cross section of the conductors taken along a plane perpendicular to the central axes of the conductors. In this case, the spacing between adjacent ground wires can be made constant, which can reduce impedance fluctuations compared to a case where the ground wires include curved surfaces on their surfaces that bulge out on both sides of the parallel direction. As a result, signal degradation due to impedance fluctuations can be reduced.

[0016] (6) In the electrical connector described in any one of (1) to (5), in a cross section of the multiple conductors on a plane perpendicular to the central axis of the multiple conductors, when the direction perpendicular to the parallel direction is defined as the vertical direction, the width of the ground wire along the vertical direction may be larger than the width of the ground wire along the parallel direction. When the cross section of the ground wire extends vertically in this manner, the ground wire can effectively shield electromagnetic waves that sneak from one signal line to another signal line across the ground wire. This reduces crosstalk between the signal lines. Furthermore, when the cross section of the ground wire extends vertically in this manner, the cross-sectional area of the ground wire can be increased, thereby suppressing increases in electrical resistance. As a result, the communication performance of signals propagating through signal lines, etc. can be further improved.

[0017] (7) In the electrical connector according to any one of (1) to (6), the shape of each of the plurality of signal lines may be circular in cross section of the plurality of conductors in a plane perpendicular to the central axis of the plurality of conductors, which can more effectively suppress deterioration of high frequency characteristics of the plurality of signal lines due to the skin effect.

[0018] (8) A connection assembly according to one aspect of the present disclosure may include the electrical connector according to any one of (1) to (7) above, and a substrate having a plurality of electrodes connected to a plurality of conductors, the substrate having the electrical connector attached thereto, thereby achieving the effect of (1) above.

[0019] (9) A cable according to one embodiment of the present disclosure includes a plurality of conductors, including a plurality of signal lines and a plurality of ground lines, arranged in parallel with one another, and a coating that covers the plurality of conductors so that the tips of the conductors are exposed. In a cross section of the plurality of conductors in a plane perpendicular to the central axes of the conductors, only the plurality of ground lines among the plurality of signal lines and the plurality of ground lines each include a first flat portion on the surface.

[0020] In the above-described cable, in a cross section of the multiple conductors taken along a plane perpendicular to the central axes of the multiple conductors, only the multiple signal lines and the multiple ground lines include a first flat portion on their surfaces. In this case, when connecting the ground lines to the ground via another conductor, the first flat portion of the ground line is used as a connecting portion with the other conductor, thereby improving the joining strength between the ground line and the other conductor. This allows the multiple ground lines to be stably connected to the ground via the other conductor. Furthermore, when the ground lines include the first flat portion on their surfaces, the cross-sectional area of the ground line can be increased compared to when the ground line does not include the first flat portion on its surface (e.g., a circular ground line), thereby suppressing an increase in electrical resistance. Furthermore, since the signal lines do not include the first flat portion on their surfaces, corners are prevented from forming on the surface of the signal lines, thereby suppressing degradation of high-frequency characteristics due to the skin effect. Therefore, the above-described cable improves the communication performance of signals propagating through the signal lines and the like.

[0021] (10) In the cable described in (9) above, the multiple signal lines may include a first signal line and a second signal line adjacent to each other, and the multiple ground lines may include a first ground line and a second ground line electrically connected to each other and positioned to sandwich the first signal line and the second signal line in a parallel direction. In this case, the first signal line and the second signal line can form a differential signal line, so that currents flowing through the first signal line and the second signal line are opposite in phase. In this case, when the first ground line and the second ground line are connected to the ground, for example, a portion of the electromagnetic wave sneaking from the first signal line to the first ground line and a portion of the electromagnetic wave sneaking from the second signal line to the second ground line can cancel each other out. This reduces the influence of noise caused by the first signal line and the second signal line, thereby further improving the communication performance of signals propagating through the multiple signal lines. [Details of the embodiments of the present disclosure]

[0022] Specific examples of the electrical connector, connection assembly, and cable of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. In the following description, the same elements in the description of the drawings will be given the same reference numerals, and duplicate explanations will be omitted as appropriate.

[0023] FIG. 1 is a perspective view showing a connection assembly according to one embodiment. FIG. 2 is a side view showing the connection assembly of FIG. 1. As shown in FIGS. 1 and 2, connection assembly 100 includes an electrical connector 1 and a substrate 10. Electrical connector 1 has a cable 2, a plurality of terminals 3, and a ground bar 4 (conductor member). Hereinafter, the width direction of cable 2 is defined as the X direction (parallel direction), the height direction of cable 2 is defined as the Y direction (vertical direction), and the direction perpendicular to the X and Y directions is defined as the Z direction.

[0024] The substrate 10 has a main surface 10a and a plurality of electrodes 9. The main surface 10a extends along the X and Z directions. The electrical connector 1 is disposed facing the main surface 10a in the Y direction and mounted on the main surface 10a. The plurality of electrodes 9 are provided on the main surface 10a so as to be aligned along the X direction. Each of the plurality of electrodes 9 faces a plurality of conductors 5 of the cable 2 along the Y direction. The plurality of electrodes 9 are connected to the plurality of conductors 5, respectively. The plurality of electrodes 9 include, for example, a plurality of signal electrodes 91 and a plurality of ground electrodes 92. Each of the plurality of signal electrodes 91 is an electrode used as a signal line. Each of the plurality of ground electrodes 92 is an electrode used as a ground line. In this specification, "connection" includes both a mode in which two elements are directly connected and a mode in which two elements are indirectly connected via another element.

[0025] The cable 2 is, for example, a flexible flat cable (FFC). The cable 2 has a plurality of conductors 5 and a covering 6. Each of the plurality of conductors 5 is a member for transmitting power or an electrical signal, and is, for example, an electric wire made of a metal such as copper. The plurality of conductors 5 each extend along the Z direction and are lined up along the X direction.

[0026] 1, the multiple conductors 5 include, for example, a signal line 7A (first signal line), a signal line 7B (second signal line), a signal line 7C, a signal line 7D, a ground line 8A (first ground line), a ground line 8B (second ground line), and a ground line 8C. The signal line 7A and the signal line 7B are adjacent to each other along the X direction. The ground lines 8A and 8B are arranged on either side of the signal line 7A and the signal line 7B in the X direction. The signal line 7C and the signal line 7D are adjacent to each other along the X direction. The ground lines 8B and 8C are arranged on either side of the signal line 7C and the signal line 7D in the X direction. Currents of opposite phases flow through the two adjacent signal lines 7A and 7B, and signals are transmitted by differential transmission, in which signals are transmitted using the potential difference between the two signal lines 7A and 7B. Similarly, two adjacent signal lines 7C and 7D carry currents of opposite phases, and transmit signals by differential transmission, which transmits signals using the potential difference between the two signal lines 7C and 7D.

[0027] 1, the ground line 8A, signal line 7A, signal line 7B, ground line 8B, signal line 7C, signal line 7D, and ground line 8C are arranged in this order along the X direction. In this way, the cable 2 has a GSSG (Ground Signal Signal Ground) structure formed by the ground line 8A, signal line 7A, signal line 7B, and ground line 8B, and another GSSG structure formed by the ground line 8B, signal line 7C, signal line 7D, and ground line 8C.

[0028] In the following description, when the signal lines 7A to 7D are not to be distinguished from one another, the signal lines 7A to 7D are simply referred to as "signal lines 7." Similarly, when the ground lines 8A to 8C are not to be distinguished from one another, the ground lines 8A to 8C are simply referred to as "ground lines 8." The arrangement of the signal lines 7 and the ground lines 8 is not limited to the example described above, and other arrangements are also possible.

[0029] As shown in FIGS. 1 and 2 , the covering 6 covers the conductors 5 so that the tip ends 51 of the conductors 5 are exposed. The covering 6 has an end face 61 and a surface 62. The end face 61 is an end face located at the tip of the covering 6 in the Z direction and extends along the X and Y directions. The tip ends 51 of the conductors 5 protrude from the end face 61 in the Z direction. The surface 62 extends to surround the conductors 5. The surface 62 includes a first surface 62a and a second surface 62b aligned along the Y direction. The first surface 62a and the second surface 62b extend along the X and Z directions. The second surface 62b faces the main surface 10a of the substrate 10 in the Z direction. For example, the second surface 62b may contact the main surface 10a of the substrate 10.

[0030] Tips 51 of the multiple conductors 5 protruding from the end face 61 of the covering 6 bend in the Z direction and extend to the multiple electrodes 9 on the main surface 10a of the substrate 10. As shown in Fig. 2, for example, the tips 51 extend from the end face 61 along the Z direction, and then extend in a direction inclined with respect to the Z direction toward the electrodes 9 on the main surface 10a.

[0031] The tip portion 51 has, for example, a first portion 51a, a second portion 51b, and a connecting portion 51c. The first portion 51a extends from the end surface 61 of the covering portion 6 along the Z direction. The connecting portion 51c forms a bend with respect to the first portion 51a and, for example, extends in a direction inclined with respect to both the Y direction and the Z direction when viewed along the X direction. The second portion 51b extends from the connecting portion 51c to the tip surface of the conductor 5. The second portion 51b extends from the connecting portion 51c along the Z direction and is connected to the electrode 9 of the substrate 10.

[0032] FIG. 3 is a cross-sectional view of the connection assembly taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional view of the connection assembly taken along line IV-IV in FIG. 2. As shown in FIG. 4, the coating 6 includes an insulating portion 6a and a shielding layer 6b surrounding the insulating portion 6a. The insulating portion 6a extends along the Z direction. A plurality of signal lines 7 and a plurality of ground lines 8 are disposed inside the insulating portion 6a. The shielding layer 6b is disposed so as to surround the insulating portion 6a, centered in the Z direction. The shielding layer 6b may be made of, for example, a metal (e.g., copper or aluminum foil). As an example, the shielding layer 6b is aluminum tape. The shielding layer 6b is electrically connected to ground. The surface of the shielding layer 6b constitutes the surface 62 of the coating 6, including the first surface 62a and the second surface 62b. By disposing such a shielding layer 6b on the cable 2, the influence of noise from outside the cable 2 is suppressed.

[0033] As shown in FIGS. 1 and 3, the ground bar 4 is located on the opposite side of the cable 2 from the substrate 10 in the Y direction. The ground bar 4 is disposed, for example, on the first surface 62a of the coating 6. The ground bar 4 is, for example, a plate-shaped conductor member extending along the X and Z directions. When viewed along the Y direction, the ground bar 4 has a rectangular shape with the X direction as its longitudinal direction. The ground bar 4 is in contact with the first surface 62a of the coating 6 and is electrically connected to the shielding layer 6b. The ground bar 4 may be disposed inside the coating 6 (for example, inside the insulating portion 6a).

[0034] The multiple terminals 3 are arranged in parallel along the X direction so as to face the respective tips 51 of the multiple ground lines 8. The multiple terminals 3 electrically connect each of the multiple ground lines 8 to the ground via the ground bar 4. As shown in FIG. 1 , the multiple terminals 3 include terminals 3A, 3B, and 3C. For example, terminals 3A, 3B, and 3C face ground lines 8A, 8B, and 8C, respectively, along the Y direction and are electrically connected to ground lines 8A, 8B, and 8C, respectively. Hereinafter, when the terminals 3A to 3C are described without distinguishing between them, each of terminals 3A to 3C will be simply referred to as "terminal 3."

[0035] As shown in FIG. 2 , each of the multiple terminals 3 has a tip portion 31 and a connecting portion 32. The tip portion 31 of the terminal 3 includes a connection surface 31a (connecting portion) connected to the first portion 51a of the tip portion 51 of the ground wire 8. The connection surface 31a is, for example, a flat surface extending along the X and Z directions. The connecting portion 32 connects the tip portion 31 to the ground bar 4. When viewed along the X direction, the connecting portion 32 extends in a direction inclined with respect to both the Y and Z directions. The connecting portion 32 is connected to the ground bar 4. Therefore, the multiple terminals 3 are integrated with the ground bar 4. Therefore, the ground wires 8 are electrically connected to each other via the multiple terminals 3 and the ground bar 4. In this way, each of the multiple ground wires 8 is electrically connected to ground via the multiple terminals 3 and the ground bar 4. As a result, the shielding layer 6b, the multiple terminals 3, and the multiple ground wires 8 share a common electrical connection to ground, thereby stabilizing the impedance of the electrical connector 1.

[0036] 3 shows a cross section of the connection assembly 100 taken on a plane perpendicular to the central axis C5 of the multiple conductors 5. As shown in FIG. 3, in the cross section of the multiple conductors 5 taken on a plane perpendicular to the central axis C5 (hereinafter referred to as "conductor cross section"), only the multiple ground wires 8 out of the multiple signal wires 7 and the multiple ground wires 8 each include a first flat portion 8a at least on a surface 81. The surface 81 may be a side surface of the outer surface of the conductors 5 that extends from the tip end surface of the conductors 5 along the extension direction of the conductors 5.

[0037] The central axis C5 is an axis passing through the center of the conductor 5. The conductor cross section in a plane perpendicular to the central axis C5 is a conductor cross section obtained by cutting an arbitrary position along the extension direction of the central axis C5 of the conductor 5 with a plane perpendicular to the central axis C5. The arbitrary position along the extension direction of the central axis C5 of the conductor 5 may be, for example, any of the first portion 51a, the second portion 51b, and the connecting portion 51c, or may be any portion of the conductor 5 inside the coating 6.

[0038] The signal lines 7 do not have flat portions on the surface 81 in the conductor cross section. As an example, the shape of each of the signal lines 7 is circular in the conductor cross section. In contrast, the ground lines 8 include, for example, a first flat portion 8a, a second flat portion 8b, a third flat portion 8c, and a fourth flat portion 8d on the surface 81 in the conductor cross section. The ground lines 8 each have a rectangular shape in the conductor cross section. The first flat portion 8a, the second flat portion 8b, the third flat portion 8c, and the fourth flat portion 8d are formed continuously, for example, from the tip surface of the conductor 5 to the other end surface on the opposite side. In other words, the first flat portion 8a, the second flat portion 8b, the third flat portion 8c, and the fourth flat portion 8d are formed throughout the extension direction of the conductor 5 (i.e., the direction in which the central axis C5 extends). The first flat portion 8a, the second flat portion 8b, the third flat portion 8c, and the fourth flat portion 8d may be formed only in a partial region in the extension direction of the conductor 5 (for example, part or all of the tip portion 51).

[0039] The first flat portion 8a and the second flat portion 8b are, for example, flat surfaces that intersect with the Y direction and face opposite directions along the Y direction. As an example, the first flat portion 8a and the second flat portion 8b extend along the X direction and the Z direction, respectively, and are arranged parallel to each other along the Y direction. The first flat portion 8a faces the ground bar 4 or the terminals 3 in the Y direction. The first flat portion 8a is connected to the connection surface 31a, for example, via solder. The second flat portion 8b faces the electrodes 9 on the main surface 10a of the substrate 10 in the Y direction. The second flat portion 8b is connected to the connection surface 31a, for example, via solder. The connection between the connection surface 31a and the first flat portion 8a and the connection between the electrodes 9 and the second flat portion 8b are not limited to solder connection, and may be other connection methods such as crimping or welding (e.g., laser welding or thermal welding). The first flat portion 8a may be in direct contact with the connection surface 31a without soldering. The second flat portion 8b may be in direct contact with the electrode 9 without using solder. For example, the second flat portion 8b may be connected to the electrode 9 by a pressing member that presses the plurality of conductors 5 toward the substrate 10.

[0040] The third flat portion 8c and the fourth flat portion 8d are, for example, flat surfaces that intersect with the X direction and face opposite directions along the X direction. As an example, the first flat portion 8a and the second flat portion 8b extend along the Y direction and the Z direction, respectively, and are arranged parallel to each other along the X direction. The distance between the first flat portion 8a and the second flat portion 8b along the Y direction is the same as the distance between the third flat portion 8c and the fourth flat portion 8d along the X direction. In other words, in the conductor cross section, the width of the ground line 8 in the Y direction is the same as the width of the ground line 8 in the X direction.

[0041] "The ground line 8 has a first flat portion on the surface 81 in the conductor cross section" means that the surface 81 of the ground line 8 is represented by at least one straight line portion in the conductor cross section. For example, as described above, the surface 81 of the ground line 8 may be represented by only one or more straight line portions in the conductor cross section. Also, for example, the surface 81 of the ground line 8 may be represented by both straight lines and curved lines in the conductor cross section. Furthermore, "the signal line 7 does not have a flat portion on the surface 81 in the conductor cross section" means that the surface 81 of the signal line 7 is represented by only curved lines in the conductor cross section.

[0042] Next, the effects obtained by the electrical connector 1, the connection assembly 100, and the cable 2 according to this embodiment will be described.

[0043] The electrical connector 1 of this embodiment includes a plurality of terminals 3 arranged in parallel along the X direction so as to face the respective tips 51 of the ground wires 8, and electrically connecting each of the ground wires 8 to the ground. In this case, crosstalk, in which a portion of an electromagnetic wave generated by a signal transmitted to a signal line 7 is transmitted to another signal line 7 through an air gap, can be suppressed. For example, when a portion of an electromagnetic wave generated by a signal transmitted to signal line 7B propagates around the opposite side of the substrate 10 from ground line 8B, it is blocked by terminal 3B (see FIG. 1 ). Therefore, a portion of the electromagnetic wave generated by the signal transmitted to signal line 7B cannot propagate to signal line 7C. Furthermore, in the conductor cross section, only the plurality of ground wires 8 among the plurality of signal wires 7 and the plurality of ground wires 8 each include a first flat portion 8a on their surface 81. Each of the plurality of terminals 3 includes a connection surface 31a connected to the first flat portion 8a. When the ground wire 8 includes the first flat portion 8a on the surface 81, the bonding strength between the ground wire 8 and the terminal 3 can be improved, allowing multiple ground wires 8 to be stably connected to the ground via multiple terminals 3. For example, solder or the terminal 3 can be stably arranged on the first flat portion 8a, allowing the first flat portion 8a to be stably physically contacted with the terminal 3 or stably connected to the connection surface 31a of the terminal 3 via solder. In addition, when the ground wire 8 includes the first flat portion 8a on the surface 81, the cross-sectional area of the ground wire 8 can be increased, thereby suppressing an increase in electrical resistance, compared to when the ground wire 8 does not include the first flat portion 8a on the surface 81 (e.g., a circular ground wire). Furthermore, since the signal wire 7 does not include a flat portion on the surface 81, corners are prevented from being formed on the surface 81 of the signal wire 7, thereby suppressing degradation of high-frequency characteristics due to the skin effect. Therefore, the above-mentioned electrical connector 1 can improve the communication performance of signals propagating through the signal wire 7, etc.

[0044] As in this embodiment, the multiple signal lines 7 may include signal lines 7A and 7B adjacent to each other, and the multiple ground lines 8 may include ground lines 8A and 8B arranged on either side of signal lines 7A and 7B in the X direction and electrically connected to each other via multiple terminals 3. In this case, signal lines 7A and 7B can form differential signal lines. This allows currents flowing through signal lines 7A and 7B to be in opposite phases, so that, for example, a portion of an electromagnetic wave sneaking from signal line 7A to ground line 8A and a portion of an electromagnetic wave sneaking from signal line 7B to ground line 8B can cancel each other out. For example, if a portion of an electromagnetic wave generated by a signal transmitted through signal line 7A reaches ground line 8A and a portion of an electromagnetic wave generated by a signal transmitted through signal line 7B reaches ground line 8B, the two electromagnetic waves cancel each other out at the multiple terminals 3 (and ground bar 4). In addition, when the ground bar 4 is disposed on the surface 62 or inside the covering 6, the distance between the ground bar 4 and the conductors 5 is shorter than when the ground bar 4 is disposed somewhere other than the cable 2. This allows the two electromagnetic waves to cancel each other out more effectively. As a result, the communication performance of signals propagating through the signal line 7 and the like can be further improved.

[0045] As in this embodiment, the ground bar 4 is disposed on the surface 62 or inside the coating 6 and connected to the ground, and the multiple ground wires 8 may be connected to the ground bar 4 via multiple terminals 3. In this case, the multiple terminals 3 are connected to and integrated with the ground bar 4, thereby stabilizing the ground. This reduces the effects of crosstalk and improves the communication performance of signals propagating through the signal lines 7 and the like. Furthermore, in this embodiment, the shielding layer 6b of the coating 6 is connected to and integrated with the ground bar 4, thereby further stabilizing the ground.

[0046] Furthermore, when the ground bar 4 is disposed on the surface 62 of the coating 6, the ground bar 4 can block part of the electromagnetic waves generated by a signal transmitted through the signal line 7 from leaking into other signal lines 7. For example, the ground bar 4 can block part of the electromagnetic waves generated by a signal transmitted through the signal line 7B from leaking into the signal line 7C (see FIG. 1). This makes it possible to more effectively suppress crosstalk, which is the leakage of part of the electromagnetic waves generated by a signal transmitted through the signal line 7 into the other signal lines 7.

[0047] As in this embodiment, each of the multiple ground wires 8 may include, in the conductor cross section, a second flat portion 8b on the surface 81 that faces the opposite side to the first flat portion 8a along the Y direction. For example, when the electrical connector 1 is disposed on the main surface 10a of the substrate 10, connecting the second flat portion 8b of each of the multiple ground wires 8 to the electrode 9 on the main surface 10a can improve the bonding strength between the ground wire 8 and the terminal 3 at the first flat portion 8a and also improve the bonding strength between the ground wire 8 and the electrode 9 of the substrate 10 at the second flat portion 8b. This stabilizes the electrical connection between the terminal 3, the ground wire 8, and the electrode 9 of the substrate 10.

[0048] As in this embodiment, each of the multiple ground wires 8 may include, in the conductor cross section, a third flat portion 8c and a fourth flat portion 8d on the surface 81 that face opposite each other along the X direction. In this case, the spacing between adjacent ground wires 8 can be made constant, which can suppress impedance fluctuations, compared to when the ground wire 8 includes, for example, curved surfaces on the surface 81 that bulge out on both sides in the X direction. As a result, signal degradation due to impedance fluctuations can be suppressed.

[0049] As in the present embodiment, the shape of each of the multiple signal lines 7 may be circular in conductor cross section, which can more effectively suppress the degradation of high-frequency characteristics in the multiple signal lines 7 due to the skin effect.

[0050] The electrical connector, connection assembly, and cable of the present disclosure are not limited to the above-described embodiments, and various other modifications are possible.

[0051] In the above embodiment, the width of the ground line 8 along the Y direction in the conductor cross section is the same as the width of the ground line 8 along the X direction, but this is not limiting.

[0052] Part (a) of FIG. 5 is a cross-sectional view showing a cable included in the connection assembly according to Variation 1. As shown in Part (a) of FIG. 5, in the conductor cross section, the width of the ground wire 8 along the Y direction may be larger than the width of the ground wire 8 along the X direction. In other words, the distance along the X direction between the third flat portion 8c and the fourth flat portion 8d may be larger than the distance along the Y direction between the first flat portion 8a and the second flat portion 8b. In other words, the ground wire 8 may extend along the Y direction in the conductor cross section. The width of the ground wire 8 along the Y direction may be larger than the width of the signal line 7 along the Y direction, for example. When the cross section of the ground wire 8 extends in the Y direction in this manner, the ground wire 8 can effectively shield electromagnetic waves that sneak from one signal line 7 to the other signal line 7 across the ground wire 8. This reduces crosstalk between these signal lines 7. Furthermore, when the cross section of the ground wire 8 extends in the Y direction in this manner, the cross-sectional area of the ground wire 8 can be increased, thereby suppressing an increase in electrical resistance. As a result, the communication performance of signals propagating through the signal line 7 and the like can be further improved.

[0053] Part (b) of Fig. 5 is a cross-sectional view showing a cable included in the connection assembly according to Variation 2. As shown in Part (b) of Fig. 5, in the conductor cross section, corners formed between the first flat portion 8a and the third flat portion 8c, between the third flat portion 8c and the second flat portion 8b, between the second flat portion 8b and the fourth flat portion 8d, or between the fourth flat portion 8d and the first flat portion 8a may be flattened or rounded. In this case, the cross-sectional area of the ground wire 8 can be adjusted in the conductor cross section, and the impedance of the electrical connector 1 can be adjusted.

[0054] In the above embodiment, the tip portions 51 of the multiple conductors 5 extend along the Z direction and then bend relative to the XZ plane to extend to the multiple electrodes 9 on the main surface 10a of the substrate 10, but the tip portions 51 may extend from the end face 61 to the electrodes 9. For example, the tip portions 51 may extend only along the Z direction.

[0055] In the above embodiment, the ground bar 4 is disposed on the surface 62 of the cover 6 or inside the cover 6, but is not limited to this. For example, the ground bar 4 may be disposed on another member such as the main surface 10a of the substrate 10.

[0056] In the above embodiment, the electrical connector 1 has the ground bar 4 separate from the shielding layer 6b. However, the ground bar 4 may be formed by the shielding layer 6b itself, or may be integrated with the shielding layer 6b. In this case, the connecting portion 32 of the terminal 3 is electrically connected to the shielding layer 6b as a conductive member. [Explanation of symbols]

[0057] 100...Connection assembly 10...Substrate 10a…main surface 1...Electrical connector 2...Cable 3...Terminal 3A…Terminal 3B…Terminal 3C…Terminal 31...Tip 31a...Connection surface (connection part) 32...Connection part 4...Ground bar (conductor component) 5...Conductor 51...Tip 51a...first part 51b…Second part 51c...Connection part 6...Covering part 6a...insulation part 6b...Shield layer 61...End face 62…Surface 62a...front page 62b…Second side 7...Signal line 7A…Signal line (first signal line) 7B…Signal line (second signal line) 7C…Signal line 7D…Signal line 8...Ground wire 8A...Ground wire (first ground wire) 8B...Ground wire (second ground wire) 8C...Ground wire 81…Surface 8a…first flat part 8b…Second flat part 8c…Third flat part 8d…Fourth flat part 9...Electrode 91...Signal electrode 92...Ground electrode C5…Central axis

Claims

1. a cable having a plurality of conductors arranged in parallel, including a plurality of signal lines and a plurality of ground lines, and a covering that covers the plurality of conductors so that tip ends of the plurality of conductors are exposed; a plurality of terminals arranged in parallel along the parallel direction of the conductors so as to face the tip ends of the ground wires, respectively, and electrically connecting the ground wires to ground; Equipped with in a cross section of the plurality of conductors taken along a plane perpendicular to central axes of the plurality of conductors, only the plurality of ground lines out of the plurality of signal lines and the plurality of ground lines each include a first flat portion on a surface, An electrical connector, wherein each of the plurality of terminals includes a connection portion connected to the first flat portion.

2. the plurality of signal lines include a first signal line and a second signal line adjacent to each other, 2. The electrical connector according to claim 1, wherein the plurality of ground wires include a first ground wire and a second ground wire that are arranged at positions sandwiching the first signal wire and the second signal wire in the parallel direction and are electrically connected to each other via the plurality of terminals.

3. a conductor member disposed on or inside the covering and connected to the ground; the plurality of ground lines are connected to the conductor member via the plurality of terminals; 3. The electrical connector according to claim 1 or 2.

4. each of the plurality of ground lines further includes, on the surface in the cross section, a second flat portion facing in a direction opposite to the first flat portion along a vertical direction perpendicular to the parallel direction; 3. The electrical connector according to claim 1 or 2.

5. each of the plurality of ground wires further includes, on the surface in the cross section, a third flat portion and a fourth flat portion facing opposite to each other along the parallel direction; 3. The electrical connector according to claim 1 or 2.

6. In the cross section, when a direction perpendicular to the parallel direction is defined as a vertical direction, a width of the ground line along the vertical direction is larger than a width of the ground line along the parallel direction.

3. The electrical connector according to claim 1 or 2.

7. Each of the plurality of signal lines has a circular cross section.

3. The electrical connector according to claim 1 or 2.

8. The electrical connector according to claim 1 or 2; a substrate having a plurality of electrodes connected to the plurality of conductors, respectively, and on which the electrical connector is attached; A connection assembly comprising:

9. a plurality of conductors including a plurality of signal lines and a plurality of ground lines arranged in parallel with each other; a covering portion that covers the plurality of conductors so that tip portions of the plurality of conductors are exposed; Equipped with a cable, in which, in a cross section of the plurality of conductors taken on a plane perpendicular to central axes of the plurality of conductors, only the plurality of ground wires out of the plurality of signal wires and the plurality of ground wires each include a first flat portion on a surface.

10. the plurality of signal lines include a first signal line and a second signal line adjacent to each other, the plurality of ground lines include a first ground line and a second ground line that are arranged at positions sandwiching the first signal line and the second signal line in a parallel direction of the plurality of conductors and are electrically connected to each other, 10. The cable of claim 9.

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