JP2023156555A - Cable assembly and connector - Google Patents

Abstract

To provide a cable assembly which enhances characteristic impedance, and to provide a connector.SOLUTION: In a cable assembly 1, a coaxial cable 2 consists of a central conductor 2a, a dielectric 2b, an external conductor 2c, and an outer cover 2d. A pair of ground bars 4A and 4B is connected with a grounding member of a plug connector. In the coaxial cable 2, a first exposure part 3a in which an outer peripheral surface of the central conductor 2a is exposed and a second exposure part 3b in which an outer peripheral surface of the external conductor 2c is exposed are formed by exposing the outer peripheral surfaces extending in an X axis direction in the order of the central conductor 2a, the external conductor 2c, and the outer cover 2d from one end in an extension direction. A plurality of coaxial cables 2 are arrayed in a direction crossing the X axis direction in a state where the first exposure part 3a and the second exposure part 3b are aligned in the extension direction, and the ground bars 4A and 4B hold the plurality of coaxial cables 2 therebetween in contact with the second exposure part 3b. The external conductor 2c prevents exposure of an outer peripheral surface of the dielectric 2b extending in the extension direction.SELECTED DRAWING: Figure 1

Description

FIELD OF THE INVENTION The present invention relates to cable assemblies and connectors.

Patent Document 1 discloses an electrical connector that integrates a plurality of coaxial cables and connects them to a board.

Japanese Patent Application Publication No. 2020-184475

The electrical connector disclosed in Patent Document 1 is required to further improve its characteristic impedance as the signal speed increases.

The present invention was made under the above circumstances, and an object of the present invention is to provide a cable assembly and a connector that can improve characteristic impedance.

In order to achieve the above object, a cable assembly according to a first aspect of the present invention includes:
A cable assembly that constitutes a connector that connects circuits,
A center conductor extending in one direction, a dielectric covering an outer circumferential surface extending in the extending direction of the central conductor, an outer conductor covering an outer circumferential surface extending in the extending direction of the dielectric, and an outer circumferential surface extending in the extending direction of the outer conductor. a plurality of cables consisting of an outer sheath that covers the
a pair of conductive ground bars connected to the ground member of the connector,
In the cable, in the extending direction, the outer circumferential surface of the central conductor, the outer conductor, and the outer sheath are exposed from one end in the order of extending in the extending direction, so that the outer circumferential surface of the central conductor is exposed. a first exposed portion and a second exposed portion to which an outer peripheral surface of the external conductor is exposed;
The plurality of cables are arranged in a direction intersecting the extending direction, with the first exposed portion and the second exposed portion being aligned with respect to the extending direction,
the pair of ground bars are in contact with the second exposed portion and sandwich the plurality of cables;
An outer circumferential surface of the dielectric extending in the extending direction is covered with the outer conductor and is not exposed.

The first ground bar of the pair of ground bars is
a first flat plate portion that contacts the second exposed portion;
a conductive wall part extending from the first flat plate part and partitioning between the first exposed parts of the adjacent cables;
A second ground bar of the pair of ground bars includes a second flat plate portion that is in contact with the second exposed portion and is disposed opposite to the first flat plate portion.
It may also be a thing.

The wall portion is
a ground connection portion extending from an outer edge of the first flat plate portion near one end of the cable between the first exposed portions of the adjacent cables and contacting a grounding member of the connector;
an overhanging solder portion extending along the ground connection portion from solder filled between the first flat plate portion and the second flat plate portion;
It may also be a thing.

The ground connection portion is
a bent portion extending from the outer edge and bent in opposite directions of the pair of ground bars;
a connecting portion extending from the tip of the bent portion along the first exposed portion and connecting to a grounding member of the connector;
Equipped with
It may also be a thing.

the first flat plate portion protrudes closer to one end of the cable than the second flat plate portion;
It may also be a thing.

The first flat plate part and the second flat plate part are arranged such that an outer edge near one end of the cable is close to a boundary between the first exposed part and the second exposed part.
It may also be a thing.

The cable assembly according to the second aspect of the present invention includes:
A cable assembly that constitutes a connector that connects circuits,
A center conductor extending in one direction, a dielectric covering an outer circumferential surface extending in the extending direction of the central conductor, an outer conductor covering an outer circumferential surface extending in the extending direction of the dielectric, and an outer circumferential surface extending in the extending direction of the outer conductor. a plurality of cables consisting of an outer sheath that covers the
a pair of conductive ground bars connected to the ground member of the connector,
In the cable, a first exposed portion in which the outer peripheral surface of the central conductor is exposed and a second exposed portion in which the outer peripheral surface of the outer conductor is exposed are formed in this order from one end in the extending direction,
The plurality of cables are arranged in a direction intersecting the extending direction, with the first exposed portion and the second exposed portion being aligned with respect to the extending direction,
the pair of ground bars are in contact with the second exposed portion and sandwich the plurality of cables;
One of the ground bars of the pair of ground bars is
a flat plate portion that contacts the second exposed portion;
An electrically conductive wall part that overhangs from the flat plate part and partitions between the first exposed parts of the adjacent cables is provided.

The connector according to the third aspect of the present invention is
A cable assembly according to the first or second aspect of the invention is provided.

According to the present invention, characteristic impedance can be improved.

(A) is a perspective view of a cable assembly according to Embodiment 1 of the present invention. (B) is an enlarged perspective view showing the inside of the rectangular frame in (A). FIG. 2 is a perspective view of a connector pair on which a cable assembly is mounted. FIG. 2 is an exploded perspective view of a plug connector on which a cable assembly is mounted. FIG. 2 is a perspective view showing a transmission line formed by a pair of connectors. (A) is a plan view of the connector pair. (B) is a sectional view taken along line VV in (A). (A) is a graph showing the characteristic impedance of a conventional connector pair. (B) is a graph showing the characteristic impedance of the connector pair of FIG. 2; (A) is a graph showing NEXT (Near End Crosstalk) characteristics of a conventional connector pair. (B) is a graph showing the NEXT characteristics of the connector pair in FIG. 2; (A) is a graph showing FEXT (Far End Crosstalk) characteristics of a conventional connector pair. (B) is a graph showing the FEXT characteristics of the connector pair of FIG. 2; (A) is a perspective view of a cable assembly according to Embodiment 2 of the present invention. (B) is an enlarged perspective view showing the inside of the rectangular frame in (A). (A) is a perspective view of a cable assembly according to Embodiment 3 of the present invention. (B) is an enlarged perspective view showing the inside of the rectangular frame in (A).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or equivalent parts are given the same reference numerals.

Embodiment 1
First, Embodiment 1 of the present invention will be described. The cable assembly and connector pair according to the first embodiment are used, for example, to connect circuits between substrates and to transmit a plurality of signals between the circuits.

[Cable assembly]
As shown in FIGS. 1A and 1B, the cable assembly 1 according to the first embodiment includes a plurality of coaxial cables 2 and a pair of ground bars 4A and 4B. Each of the plurality of coaxial cables 2 has the same diameter and the same type.

A plurality of coaxial cables 2 are arranged in a line. In the first embodiment, the direction in which the coaxial cables 2 extend is defined as the X-axis direction, and the direction in which the coaxial cables 2 are arranged is defined as the Y-axis direction. Further, a direction perpendicular to the above-mentioned extension direction and the above-mentioned arrangement direction is defined as the Z-axis direction.

[coaxial cable]
Two coaxial cables 2 form a set. A set of coaxial cables 2 transmit differential signals. In the cable assembly 1, a plurality of coaxial cables 2, specifically 13 sets, are arranged in the Y-axis direction. There is an interval of about one cable between each set of coaxial cables 2.

As shown in FIG. 1(B), the coaxial cable 2 includes a center conductor 2a extending in one direction (X-axis direction), a dielectric 2b covering the outer peripheral surface extending in the direction in which the center conductor 2a extends, and a dielectric 2b extending in the direction in which the center conductor 2a extends. The external conductor 2c covers the outer circumferential surface extending in the extending direction of the external conductor 2c, and the outer sheath 2d covers the outer circumferential surface extending in the extending direction of the outer conductor 2c. The outer conductor 2c is grounded as described later, and the center conductor 2a and the outer conductor 2c are insulated. The voltage level of the signal transmitted through the coaxial cable 2 is determined by the potential difference between the center conductor 2a and the outer conductor 2c. Therefore, the potential difference between the center conductors 2a of one set of coaxial cables 2 becomes the voltage level of the differential signal to be transmitted.

The radial periphery of the center conductor 2a is covered with an outer conductor 2c with a dielectric 2b in between. Therefore, the outer conductor 2c can reduce the level of electromagnetic wave mixing and leakage between the center conductor 2a and the outside.

In the coaxial cable 2, in the extending direction (X-axis direction), the outer peripheral surface extending in the extending direction is exposed from one end (-X side end) in the order of the central conductor 2a, the outer conductor 2c, and the outer sheath 2d. are doing. As a result, at one end of the coaxial cable 2, a first exposed portion 3a where the outer circumferential surface of the center conductor 2a is exposed and a second exposed portion 3b where the outer circumferential surface of the outer conductor 2c is exposed are formed.

The length of the first exposed portion 3a in the extending direction is the same for each coaxial cable 2, and is long enough for connection by soldering to a signal contact 31 of a plug connector 11, which will be described later. The length of the second exposed portion 3b in the extending direction is the same for each coaxial cable 2, and is equal to or greater than the width of ground bars 4A and 4B in the X-axis direction, which will be described later. The plurality of coaxial cables 2 are arranged in a direction intersecting the extending direction (Y-axis direction) with the first exposed portions 3a and the second exposed portions 3b aligned in the extending direction (X-axis direction).

The outer circumferential surface of the dielectric 2b extending in the extending direction is configured so as not to be exposed. In other words, in the coaxial cable 2, the end of the outer conductor 2c in the extending direction extends to the end of the dielectric 2b in the same direction. Thereby, as will be described later, it is possible to suppress the peak of the characteristic impedance that appears near the end of the coaxial cable 2 and improve the characteristic impedance.

[Grand Bar]
As shown in FIGS. 1(A) and 1(B), the ground bars 4A and 4B are rectangular and flat plates made of a conductive material (for example, metal) that extend in one direction (Y-axis direction). It is a member. The ground bars 4A, 4B do not necessarily have to be rectangular. The ground bars 4A, 4B only need to extend in the arrangement direction of the coaxial cables 2 and contact the second exposed portions 3b of all the coaxial cables 2.

The ground bar 4A as the first ground bar has its longitudinal direction in the Y-axis direction, and is in contact with the second exposed portion 3b, which is the outer circumferential surface of the plurality of external conductors 2c, from the +Z side (above) in the plate thickness direction. It will be placed in The ground bar 4B as a second ground bar has its longitudinal direction in the Y-axis direction, and contacts the second exposed portion 3b, which is the outer peripheral surface of the plurality of external conductors 2c, from the -Z side (lower side) in the thickness direction. placed in the state. The length of the ground bars 4A, 4B in the Y-axis direction is longer than the length of the array of the plurality of coaxial cables 2 in the Y-axis direction.

In this way, the pair of ground bars 4A and 4B contact the outer conductor 2c, that is, the second exposed portion 3b, and sandwich the plurality of coaxial cables 2 in the Z-axis direction.

More specifically, the ground bar 4A is a conductive ground connection portion that partitions between a flat plate portion 4a as a first flat portion that contacts the second exposed portion 3b and the first exposed portion 3a of the adjacent coaxial cable 2. 4b. The ground connection portion 4b extends along the direction in which the first exposed portion 3a extends (X-axis direction).

In this embodiment, this ground connection portion 4b constitutes a wall portion. The ground connection part 4b extends from the outer edge of the flat plate part 4a near one end (-X side) of the coaxial cable 2 between the first exposed parts 3a of the adjacent coaxial cables 2, and It extends along the current direction.

More specifically, the ground connection part 4b extends from the above-mentioned outer side of the flat plate part 4a, and has a bent part 4c where the pair of ground bars 4A and 4B are bent in opposite directions, and a coaxial line extending from the tip of the bent part 4c. A connecting portion 4d extending along the first exposed portion 3a of the cable 2.

The ground bar 4B as a second ground bar includes a flat plate portion 4e as a second flat plate portion that contacts the second exposed portion 3b. In this embodiment, the flat plate portion 4a of the ground bar 4A is formed to have a larger width in the X-axis direction than the flat plate portion 4e of the ground bar 4B. Also, the outer edge of the ground bar 4A closer to one end (-X end) of the coaxial cable 2 is set in the -X direction (the direction in which the value of X decreases) than the outer edge of the ground bar 4B on the same side (-X side). ) is overhanging. That is, the flat plate portion 4a protrudes toward one end (-X end) of the coaxial cable 2.

The gap formed between the flat plate part 4a of the ground bar 4A and the flat plate part 4e of the ground bar 4B is filled with solder to form a solder part 5. In this case, in the process of forming the solder portion 5, the solder filled between the flat plate portion 4a of the ground bar 4A and the flat plate portion 4e of the ground bar 4B is applied to the -Z side of the flat plate portion 4a of the ground bar 4A. It is guided by the surface and overhangs in the -X direction (the direction in which the value of X decreases). The overhanging solder is further guided to the ground connection part 4b and forms an overhang solder part 5a that finally adheres to the ground connection part 4b. Since the bent portion 4c is bent in the direction in which the pair of ground bars 4A and 4B face each other, an overhanging solder portion 5a is likely to be formed between the solder portion 5 and the bent portion 4c in the process of forming solder. ing. The overhanging solder portion 5a is formed at a portion that partitions the first exposed portions 3a of adjacent coaxial cables 2.

The wall according to the present embodiment is formed by a ground connecting portion 4b extending from the ground bar 4A and an overhanging solder portion 5a extending along the ground connecting portion 4b. The wall portion composed of the ground connection portion 4b and the overhanging solder portion 5a reduces crosstalk between the pair of coaxial cables 2 that transmit differential signals.

[Connector pair]
Cable assembly 1 is mounted on connector pair 10 shown in FIG. The connector pair 10 includes a plug connector 11 and a receptacle connector 12. The cable assembly 1 is mounted on a plug connector 11 as a connector, and the receptacle connector 12 is mounted on a board 13.

The plug connector 11 has an insertion portion 11a that projects toward the -X side, and the receptacle connector 12 has an insertion port 12a that opens toward the +X side. When the insertion part 11a of the plug connector 11 is inserted into the insertion port 12a and the plug connector 11 and receptacle connector 12 are fitted, the coaxial cable 2 of the cable assembly 1 mounted on the plug connector 11 and the board 13 are connected. are connected to the electric circuit (see FIG. 5(A)).

[Plug connector]
As shown in FIG. 3, the plug connector 11 includes the above-mentioned cable assembly 1, a plug structure 20 in which the main components of the plug connector 11 are formed, and a conductive cable disposed on the +Z side of the plug structure 20. It includes an upper shell 21 and a conductive cover 22 disposed on the +Z side of the upper shell 21. Cable assembly 1 is arranged between plug structure 20 and upper shell 21 .

The plug structure 20 includes a housing 30 made of an insulating member, a signal contact 31 of a conductor, a conductive ground contact 32 as a grounding member, and a conductive lower shell 33. There is. The housing 30 is a case of the plug connector 11. A signal contact 31 and a ground contact 32 are assembled into this housing 30 by press fitting or insert molding. The signal contacts 31 and the ground contacts 32 are arranged in the Y-axis direction.

In this arrangement, the signal contact 31 is arranged to contact the center conductor 2a of the coaxial cable 2 in the cable assembly 1, and the ground contact 32 is arranged to contact the ground connection 4b in the cable assembly 1. ing. In this embodiment, the ground contact 32 is one of the grounding members. As a result, the ground contacts 32 are arranged on both sides of the pair of signal contacts 31 in the Y-axis direction. The lower shell 33 is insulated from the signal contact 31 and is provided at a position where it contacts the ground bar 4B of the cable assembly 1. In this embodiment, the lower shell 33 also serves as one of the grounding members.

The upper shell 21 is provided at a position in contact with the ground bar 4A. Further, the upper shell 21 is also connected to the lower shell 33. The upper shell 21 also serves as one of the grounding members. By assembling the upper shell 21 and the lower shell 33, insertion holes into which rotation bars 22a of the cover 22, which will be described later, are rotatably inserted are formed at both ends of both in the Y-axis direction.

The cover 22 is formed to cover the plug structure 20, the cable assembly 1, and the upper shell 21. The cover 22 has a rotation bar 22a, and is connected to the lower shell 33 and the upper shell 21 so as to be rotatable around the Y axis, as shown in FIGS. 2 and 5(A). When plug connector 11 is inserted into receptacle connector 12, cover 22 is rotated in a direction away from upper shell 21, as shown in FIG. When the plug connector 11 is inserted into the receptacle connector 12, the cover 22 rotates in a direction approaching the upper shell 21 and covers the entire connector pair 10, as shown in FIG. 5(A). The cover 22 is also made of a conductive member and functions as an electromagnetic shield by coming into contact with the upper shell 21.

[Receptacle connector]
As shown in FIGS. 2, 4, and 5B, the receptacle connector 12 includes an insulating housing 40, a conductive signal contact 41, a conductive ground contact 42, and a conductive lower shell 43. and a conductive upper shell 44.

Housing 40 is a case of receptacle connector 12. The signal contacts 41 and the ground contacts 42 are arranged in the Y-axis direction on the housing 40, as shown in FIG. In this arrangement, the signal contacts 41 are placed in contact with the signal contacts 31 and are soldered to the signal electrodes 13a of the substrate 13. The ground contact 42 is placed in contact with the ground contact 32 and is soldered to the ground electrode 13b of the substrate 13.

The lower shell 43 is placed in contact with the lower shell 33, and the upper shell 44 is placed in contact with the upper shell 21. As shown in FIG. 2, the upper shell 44 has a board connection portion 44a that is grounded to the board 13.

[Transmission route]
The plug connector 11 and the receptacle connector 12 form a transmission line between the coaxial cable 2 and the board 13. As shown in FIG. 4, for example, the center conductor 2a of the coaxial cable 2, the signal contact 31, the signal contact 41, and the signal electrode 13a of the substrate 13 are connected in this order to form a signal transmission line. As mentioned above, in the cable assembly 1, the two coaxial cables 2 form a set to transmit differential signals, so the connector pair 10 also has two signal transmission cables for transmitting differential signals. transmission lines are formed as one set.

Further, as shown in FIG. 4, the outer conductor 2c of the coaxial cable 2, the ground bar 4A (flat plate part 4a and wall part (ground connection part 4b and overhanging solder part 5a)), the ground contact 32, the ground contact 42, the board 13 The grounding electrodes 13b are connected in this order to form a grounding transmission line. This grounding transmission line is formed between the above-mentioned pair of signal transmission transmission lines in the Y-axis direction.

Further, as shown in FIG. 5(B), the ground bar 4A is in contact with the upper shell 21, and the ground bar 4B is in contact with the lower shell 33. Further, the upper shell 21 of the plug connector 11 is in contact with the upper shell 44 of the receptacle connector 12, and the lower shell 33 of the plug connector 11 is in contact with the lower shell 43 of the receptacle connector 12. The upper shell 21 and lower shell 33 of the plug connector 11 are electrically connected. Further, the upper shell 44 and the lower shell 43 of the receptacle connector 12 are connected to the ground electrode 13b of the board 13 by soldering and are grounded. Therefore, these upper shells 21, 44 and lower shells 33, 43 form an electromagnetic shield that surrounds the above-mentioned signal transmission transmission line on all sides.

[Characteristic impedance]
Next, the operation (characteristics) of the connector pair 10 including the cable assembly 1 according to the embodiment of the present invention will be described. The cable assembly 1 described above affects the transmission characteristics of electrical signals in the connector pair 10. Below, evaluation of characteristic impedance in a signal transmission line when using the cable assembly 1 will be described. This evaluation can be performed by the TDR (Time Domain Reflectometry) method. Here, the rise time of the transmitted test signal is in the range of 20% to 80% of 15 ps.

FIG. 6A shows, as a comparative example of the cable assembly 1 according to the present embodiment, the characteristic impedance of a signal transmission line of a conventional connector pair in which the cable assembly 1 is not mounted. In this graph, the vertical axis represents characteristic impedance (Ω), and the horizontal axis represents time (S). The characteristic impedance of the conventional connector pair is determined when an electrical signal is transmitted from the signal electrode 13a of the substrate 13 to the center conductor 2a of the coaxial cable 2.

In the graph of FIG. 6A, range A indicates the characteristic impedance of the connector pair 10. Furthermore, range B indicates the characteristic impedance of the coaxial cable 2. The vicinity of the boundary between range A and range B represents the characteristic impedance of the portion where the first exposed portion 3a of the coaxial cable 2 and the signal contact 31 of the plug connector 11 are connected.

Since the characteristic impedance of the center conductor 2a of the coaxial cable 2 (range B in the graph of FIG. 6A) is approximately 100Ω, in order to match the characteristic impedance in the signal transmission line, the characteristic impedance of the connector pair 10 must also be 100Ω. It is desirable that the amount is within a certain range.

However, as shown in FIG. 6A, in a conventional connector pair that does not include the cable assembly 1, the boundary between range A and range B, that is, the center conductor 2a of the coaxial cable 2 and the signal contact 31, A large peak appears near the connection position. The magnitude of the peak is approximately 107.5Ω.

On the other hand, as shown in FIG. 6(B), in the connector pair 10 including the plug connector 11 and the receptacle connector 12 including the cable assembly 1 according to the first embodiment, the coaxial cable The peak that occurs at the position where the center conductor 2a of No. 2 and the signal contact 31 are connected can be reduced to about 102.5Ω. That is, in this portion, the specific impedance is suppressed to about 5Ω.

This extends the second exposed portion 3b where the outer conductor 2c is exposed to the vicinity of the first exposed portion 3a where the center conductor 2a is exposed, thereby maximizing the area where the center conductor 2a is evenly covered by the outer conductor 2c. This is thought to be due to matching the characteristic impedance.

[Crosstalk; NEXT]
Furthermore, the cable assembly 1 according to the present embodiment not only improves characteristic impedance but also reduces crosstalk. FIG. 7A shows NEXT (Near End Crosstalk, S1, S3) in a conventional connector pair that does not include the cable assembly 1 according to the first embodiment. As shown in FIG. 7(A), the resonant frequency of the connector pair without the cable assembly 1 is approximately 16 GHz.

On the other hand, in the connector pair 10 including the plug connector 11 and the receptacle connector 12 including the cable assembly 1 according to the first embodiment, the resonant frequency is 18 GHz in NEXT, as shown in FIG. 7(B). It has shifted to some degree. That is, in the connector pair 10, the resonant frequency is shifted to the higher side by about 2 GHz.

[Crosstalk; FEXT]
On the other hand, FIG. 8(A) shows FEXT (Far End Crosstalk: S1, 4) in a conventional connector pair that does not include the cable assembly 1 according to the first embodiment. There is. As shown in FIG. 8A, the conventional connector pair has a resonant frequency of about 16 GHz.

On the other hand, in the connector pair 10 including the plug connector 11 and the receptacle connector 12 including the cable assembly 1 according to the first embodiment, the resonance frequency is 18 GHz in FEXT, as shown in FIG. 8(B). It has shifted to some extent. That is, in the connector pair 10, the resonant frequency is shifted to the higher side by about 2 GHz.

In the cable assembly 1 according to the present embodiment, the first exposed portion of a set of coaxial cables 2 for transmitting differential signals is provided by a wall portion including a ground connection portion 4b and an overhanging solder portion 5a on the ground bar 4A. 3a is partitioned into groups. Therefore, the peak of the resonant frequency in crosstalk, for example, NEXT and FEXT, can be shifted higher. As a result, by using the connector pair 10, higher speed signal transmission is possible while reducing crosstalk.

Of the pair of ground bars 4A and 4B, the flat plate part 4e of the ground bar 4B, which is the second ground bar without a wall part, also connects one end of the coaxial cable 2, similar to the flat plate part 4a of the ground bar 4A. (-X end), specifically, it may protrude to the vicinity of the boundary between the first exposed portion 3a and the second exposed portion 3b. That is, the outer edges of the flat plate portions 4a and 4e closer to one end (−X end) of the coaxial cable 2 may be arranged close to the boundary thereof. Here, closeness means that the position (X position) of the outer edge in the extending direction is the same as or close to the X position of the boundary between the first exposed part 3a and the second exposed part 3b. More specifically, when the solder portion 5 is formed between the flat plate portion 4a and the flat plate portion 4e, the positions of the outer sides of the flat plate portions 4a and 4e are adjusted to the extent that the overhanging solder portion 5a is formed. This means bringing the first exposed portion 3a and the second exposed portion 3b closer to the boundary. In this case, it becomes possible to further reduce crosstalk by enlarging the overhanging solder portion 5a. In this case, care must be taken to prevent the overhanging solder portion 5a from coming into contact with the center conductor 2a.

Moreover, the ground connection part 4b may be connected to the ground bar 4B instead of the ground bar 4A. In this case, the ground bar 4B may protrude more in the −X direction (the direction in which the value of X decreases) than the ground bar 4A.

Also, a wall portion may be formed on both of the ground bars 4A and 4B. In this case, solder may enter between the ground connection portion of the ground bar 4A and the ground connection portion of the ground bar 4B to form an overhanging solder portion 5a.

Embodiment 2
Next, a second embodiment of the present invention will be described. As shown in FIG. 9, in the cable assembly 1 according to the present embodiment, the flat plate portion 4a of the ground bar 4A does not extend to the vicinity of the boundary between the first exposed portion 3a and the second exposed portion 3b. This is different from the first embodiment described above. In this embodiment, the overhanging solder portion 5a is not formed on the ground connection portion 4b.

Even in this case, the second exposed portion 3b where the outer conductor 2c is exposed is extended to the first exposed portion 3a where the center conductor 2a is exposed, and the area where the center conductor 2a is covered by the outer conductor 2c is moved around the first exposed portion 3a. Therefore, as in the connector pair 10 including the cable assembly 1 according to the first embodiment, as shown in FIG. 6(B), the peak of the characteristic impedance can be reduced.

Embodiment 3
Next, a third embodiment of the present invention will be described. As shown in FIGS. 10(A) and 10(B), the cable assembly 1 according to the present embodiment is different from the above embodiment in that it includes a ground connecting portion 6 instead of the ground connecting portion 4b. It is different from forms 1 and 2.

The ground connection portion 6 extends straight in the X-axis direction. The ground connection portion 6 has an L-shaped cross section when viewed from the X-axis direction, and has a size that can completely cover the first exposed portion 3a when viewed from the Y-axis direction. Thereby, crosstalk can be further reduced and the resonance frequencies of NEXT and FEXT can be shifted higher.

Note that, as shown in FIGS. 10(A) and 10(B), also in this embodiment, the solder portion 5 is formed between the flat plate portion 4a of the ground bar 4A and the flat plate portion 4e of the ground bar 4B. ing. Further, by slightly increasing the amount of solder, it is possible to form an overhanging solder portion also in the ground connection portion 6 according to this embodiment.

As described above in detail, according to the above embodiment, in the coaxial cable 2, the center conductor 2a is uniformly surrounded by the outer conductor 2c except for the first exposed portion 3a where the tip thereof needs to be exposed. Therefore, in the coaxial cable 2, it is possible to widen the section where the central conductor 2a and the outer conductor 2c have the same positional relationship. As a result, characteristic impedance can be improved.

Further, according to the embodiment described above, the conductive wall portion allows the transmission lines (the first exposed portions 3a of one set of coaxial cables 2) for transmitting differential signals to be connected in signal units (group units). It's partitioned off. This makes it possible to prevent crosstalk from one transmission line to another, thereby reducing crosstalk.

The shape of the ground connection portion 4b is not limited to that described above. The larger the size of the partition between the coaxial cables 2, like the ground connection part 6 shown in FIGS. 10(A) and 10(B), the more the crosstalk reduction effect can be enhanced.

Various shapes can be adopted for the shape of the ground connection portion, but in consideration of the formation of the overhanging solder portion 5a, a configuration may be adopted in which the overhanging solder portion 5a that is formed becomes larger. For example, the size of the overhanging solder portion 5a may be increased by decreasing the curvature of the bent portion 4c (see FIG. 1(B)).

In the above embodiment, only the configuration of one end of the coaxial cable 2 is described. However, the configuration of the other end of the coaxial cable 2 can also be the same configuration. The other end of the coaxial cable 2 can also be connected to another board by fitting the plug connector 11 that constitutes the cable assembly 1 and the receptacle connector 12 with the cable assembly 1.

The above embodiment describes the cable assembly 1, plug connector 11, and connector pair 10 that transmit differential signals. However, it is not limited to this. The present invention may also be applied to cable assemblies that transmit single-ended signals. In this case, a ground connection portion 4b is provided between two adjacent coaxial cables 2.

In the above embodiment, 13 sets of two coaxial cables 2 are provided. However, it is not limited to this. There is no limit to the number of coaxial cables 2.

This invention is capable of various embodiments and modifications without departing from the broad spirit and scope of this invention. Further, the embodiments described above are for explaining the present invention, and do not limit the scope of the present invention. That is, the scope of the invention is indicated by the claims rather than the embodiments. Various modifications made within the scope of the claims and the meaning of the invention equivalent thereto are considered to be within the scope of this invention.

The present invention can be applied to cable assemblies and connectors that combine a plurality of cables.

1 cable assembly, 2 coaxial cable (cable), 2a center conductor, 2b dielectric, 2c outer conductor, 2d jacket, 3a first exposed part, 3b second exposed part, 4A ground bar (first ground bar), 4B ground bar (second ground bar), 4a flat plate part (first flat plate part), 4b ground connection part, 4c bent part, 4d connection part, 4e flat plate part (second flat plate part), 5 solder part, 5a overhang solder part, 6 ground connection part, 10 connector pair, 11 plug connector, 11a insertion part, 12 receptacle connector, 12a insertion port, 13 board, 13a signal electrode, 13b ground electrode, 20 plug structure, 21 upper shell, 22 cover , 22a rotation bar, 30 housing, 31 signal contact, 32 ground contact, 33 lower shell, 40 housing, 41 signal contact, 42 ground contact, 43 lower shell, 44 upper shell, 44a board connection part

Claims (8)

A cable assembly that constitutes a connector that connects circuits,
A center conductor extending in one direction, a dielectric covering an outer circumferential surface extending in the extending direction of the central conductor, an outer conductor covering an outer circumferential surface extending in the extending direction of the dielectric, and an outer circumferential surface extending in the extending direction of the outer conductor. a plurality of cables consisting of an outer sheath that covers the
a pair of conductive ground bars connected to the ground member of the connector,
In the cable, in the extending direction, the outer circumferential surface of the central conductor, the outer conductor, and the outer sheath are exposed from one end in the order of extending in the extending direction, so that the outer circumferential surface of the central conductor is exposed. a first exposed portion and a second exposed portion to which an outer peripheral surface of the external conductor is exposed;
The plurality of cables are arranged in a direction intersecting the extending direction, with the first exposed portion and the second exposed portion being aligned with respect to the extending direction,
the pair of ground bars are in contact with the second exposed portion and sandwich the plurality of cables;
An outer circumferential surface of the dielectric extending in the extending direction is covered with the outer conductor and is not exposed.
cable assembly. The first ground bar of the pair of ground bars is
a first flat plate portion that contacts the second exposed portion;
a conductive wall part extending from the first flat plate part and partitioning between the first exposed parts of the adjacent cables;
A second ground bar of the pair of ground bars includes a second flat plate portion that is in contact with the second exposed portion and is disposed opposite to the first flat plate portion.
The cable assembly of claim 1. The wall portion is
a ground connection portion extending from an outer edge of the first flat plate portion near one end of the cable between the first exposed portions of the adjacent cables and contacting a grounding member of the connector;
an overhanging solder portion extending along the ground connection portion from solder filled between the first flat plate portion and the second flat plate portion;
A cable assembly according to claim 2. The ground connection portion is
a bent portion extending from the outer edge and bent in opposite directions of the pair of ground bars;
a connecting portion extending from the tip of the bent portion along the first exposed portion and connecting to a grounding member of the connector;
Equipped with
A cable assembly according to claim 3. the first flat plate portion protrudes closer to one end of the cable than the second flat plate portion;
A cable assembly according to claim 3. The first flat plate part and the second flat plate part are arranged such that an outer edge near one end of the cable is close to a boundary between the first exposed part and the second exposed part.
A cable assembly according to claim 3. A cable assembly that constitutes a connector that connects circuits,
A center conductor extending in one direction, a dielectric covering an outer circumferential surface extending in the extending direction of the central conductor, an outer conductor covering an outer circumferential surface extending in the extending direction of the dielectric, and an outer circumferential surface extending in the extending direction of the outer conductor. a plurality of cables consisting of an outer sheath that covers the
a pair of conductive ground bars connected to the ground member of the connector,
In the cable, a first exposed portion in which the outer peripheral surface of the central conductor is exposed and a second exposed portion in which the outer peripheral surface of the outer conductor is exposed are formed in this order from one end in the extending direction,
The plurality of cables are arranged in a direction intersecting the extending direction, with the first exposed portion and the second exposed portion being aligned with respect to the extending direction,
the pair of ground bars are in contact with the second exposed portion and sandwich the plurality of cables;
One of the ground bars of the pair of ground bars is
a flat plate portion that contacts the second exposed portion;
an electrically conductive wall part extending from the flat plate part and partitioning between the first exposed parts of the adjacent cables;
cable assembly. A connector comprising a cable assembly according to any one of claims 1 to 7.

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