JP4470935B2 - Multi-core coaxial cable and manufacturing method thereof - Google Patents

Description

  The present invention relates to a multi-core coaxial cable having a plurality of coaxial cables arranged in parallel and a method for manufacturing the same.

  In recent years, with the widespread use of notebook computers, mobile phones, small video cameras, etc., in addition to the reduction in size and weight of these electronic devices, higher speed and higher image quality are required. To meet these requirements, extremely thin coaxial cables are used for connecting the machine body and the liquid crystal display, and wiring within equipment. Also, for ease of wiring, multiple coaxial cables are integrated together. A harness-shaped multi-core cable is used.

  A coaxial cable used for a multi-core cable is configured by sequentially arranging a central conductor, an insulator, an outer conductor, and a jacket from the inside in a coaxial shape. The center conductor is formed by twisting a copper alloy wire, for example, and the outer surface thereof is covered with an insulating material such as a resin to form an insulator. The outer conductor disposed on the outer peripheral surface of the insulator is formed, for example, by spirally winding a copper alloy wire in a horizontal manner, and an outer cover is formed on the outer surface thereof.

  A multi-core cable is formed by integrating a plurality of such coaxial cables, and the terminal portion of the multi-core cable is connected and fixed to a connector terminal, a substrate or the like having a predetermined pitch by conductive adhesion such as soldering. As such a multi-core cable, the one shown in FIG. 7 is known (see, for example, Patent Document 1).

As shown in FIG. 7, in the multi-core cable 100, a plurality of coaxial cables 101 are arranged in parallel. In the terminal portion of each coaxial cable 101, the outer conductor 102, the insulator 104, and the center conductor 105 are sequentially exposed by cutting out the jacket 102. Then, a common ground bar 106 is integrated by soldering at least on the upper and lower surfaces of the outer conductor 103 of the plurality of coaxial cables 101 by terminal processing. The terminal-processed multi-core cable 100 is connected and fixed to the connected member 107 by soldering. That is, the center conductor 105 of each coaxial cable 101 is soldered to the connected member 107 with the solder S1, and both ends of the ground bar 106 are soldered to the ground pattern of the connected member 107 with the solder S2.
JP 2005-180922 A

  By the way, as described above, electronic devices such as notebook computers, mobile phones, and small video cameras have been improved in performance, and the amount of information to be processed has increased. The multi-core cable 100 used in such an electronic device is also required to be mounted with high density, and the number of cores per multi-core cable, that is, the number of coaxial cables 101 tends to increase.

  However, when further increasing the number of cores of such a multi-core cable, simply grounding at both ends of the ground bar 106 changes the ground potential depending on the position of the coaxial cable, resulting in unstable ground performance and noise removal. There was a possibility that the effect would be insufficient.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a multi-core coaxial cable capable of ensuring stable and sufficient grounding performance even when multi-core is achieved, and a method for manufacturing the same. There is to do.

In order to achieve the above-described object, a multi-core coaxial cable, which is the first feature of the present invention, has a plurality of coaxial cables arranged in parallel, and a center conductor, an insulator, and an outer conductor are stepped at their end portions. A ground bar which is sequentially exposed to each of the outer conductors via a conductive material, a connection terminal connected to the center conductor, and the ground bar which covers and is electrically connected to the ground bar. A connection terminal to which the central conductor of at least one coaxial cable set in advance for grounding among the plurality of coaxial cables is connected to the shell and the ground bar is electrically connected. a shall be electrically connected to the center conductor of the coaxial cable of the ground via the shell and.

  In the multi-core coaxial cable configured as described above, the outer cover is removed, and the ground bar is fixed to the outer conductor of the plurality of coaxial cables in which the outer conductor, the insulator, and the central conductor are sequentially exposed stepwise. Fix the position between the coaxial cables. The ground bar is covered with the shell and is electrically connected to the shell. The shell is connected to the ground circuit when the multi-core coaxial cable is connected to another device or circuit. Then, the outer conductor of the multi-core coaxial cable is grounded via the shell and the ground bar. Further, at least one of a plurality of coaxial cables constituting the multi-core coaxial cable is set in advance for grounding, and the connection terminal connected to the central conductor of the coaxial cable is electrically connected to the shell. . When the multi-core coaxial cable is connected to another device or circuit, the connection terminal connected to the ground central conductor is connected to the ground circuit. Thereby, the ground bar is grounded via the connection terminal of the coaxial cable set for the shell and the ground. In other words, the ground bar is grounded at other than both ends. As a result, stable and sufficient grounding performance can be ensured even when the number of cores of the multi-core cable increases and the width increases.

  Further, in the multi-core coaxial cable according to the present invention, in addition to the first feature of the present invention, a claw piece provided on the shell is electrically connected to a connection terminal connected to a center conductor of the ground coaxial cable. Having a second feature that is connected electrically.

  In the multi-core coaxial cable configured as described above, a claw piece is formed on the shell, and this claw piece is electrically connected to a connection terminal connected to the ground coaxial cable. As a result, the ground bar can be grounded at the position of the ground coaxial cable.

The manufacturing method of multiple-core coaxial cable which is the third aspect of the present invention, Resshi parallel a plurality of coaxial cables, the terminal portions of each said coaxial cable, the outer conductor, insulator and center conductor stage Each of the outer conductors is fixed with a conductive adhesive material, a connection terminal is connected to each of the central conductors, and a shell is covered so as to cover the ground bar. The ground bar and the ground coaxial cable are connected by electrically connecting a connection terminal connected to a central conductor of a coaxial cable used for grounding among the plurality of coaxial cables and fixing the shell. The center conductor is electrically connected through the shell .

  According to the manufacturing method of the multi-core coaxial cable configured as described above, the multi-core coaxial cable can be manufactured.

  In the third feature of the present invention, the multi-core coaxial cable manufacturing method according to the present invention is characterized in that a claw piece is provided on the shell and connected to a central conductor of the ground coaxial cable and the claw piece. And those having a fourth feature which is performed by electrically connecting the two.

  In the manufacturing method of the multi-core coaxial cable configured as described above, a claw piece is provided on the shell corresponding to the position of the coaxial cable set in advance for the ground, and connected to the central conductor of the ground coaxial cable. The connected terminal and the claw piece of the shell are electrically connected. Thereby, the center conductor of the ground coaxial cable can be grounded via the claw piece of the shell.

  According to the present invention, at least one of the plurality of coaxial cables constituting the multi-core coaxial cable is set in advance for grounding, and the connection terminal and the shell connected to the central conductor of the coaxial cable are connected to each other. Connect electrically. When this multi-core coaxial cable is connected to other equipment or circuits, the connection terminal connected to the center conductor for grounding is connected to the ground circuit. It will be grounded through a coaxial cable. In other words, since the ground bar can be grounded via the ground coaxial cable even at the end, the stable and sufficient grounding performance is ensured even when the number of cores of the multi-core cable increases and the width increases. The effect that it can do is acquired.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.
1 is a plan view of the vicinity of the end of the multi-core cable of the present invention, FIG. 2 is a cross-sectional view taken along II-II in FIG. 1, FIG. 3 is a cross-sectional view taken along III-III in FIG. FIG. 5A and FIG. 5B are enlarged sectional views showing a connection portion between the shell and the connection terminal.

  As shown in FIG. 1, in the multi-core coaxial cable 10 according to the embodiment of the present invention, a plurality of (for example, 40) coaxial cables 11 are arranged in parallel. As the coaxial cable 11, for example, an extremely small diameter (AWG (American Wire Gauge) 40, 42, 44, 46, etc.) can be used. Each coaxial cable 11 has a center conductor 12 in the center and an insulator 13 on the outside thereof. The central conductor 15 is generally a twisted wire made of a copper wire because it is flexible and resistant to bending, but a single wire may be used. Further, an outer conductor 14 is provided outside the insulator 13, and the outer side is covered with a jacket 15.

In each coaxial cable 11, the center conductor 12, the insulator 13, and the outer conductor 14 are sequentially exposed in a step shape at each terminal portion. For example, the outer conductor 14 can be exposed by cutting and peeling the outer cover 15 with a CO2 laser, and the insulator 13 can be exposed by cutting and peeling the outer conductor 14 with a YAG laser. Further, the central conductor 12 can be exposed by cutting and peeling the insulator 13 with a CO2 laser.
Each coaxial cable 11 is provided with a ground bar 16 made of a metal plate such as a copper plate, which is positioned at a predetermined pitch and fixed to each outer conductor 14 via a conductive adhesive material (not shown). ing. Examples of the conductive adhesive material include soldering (pulse heat), ACF, and a conductive adhesive material.
The ground bar 16 is preferably provided with locking means formed by a plurality of continuous recesses (not shown) for arranging the coaxial cables 11 at a predetermined pitch. In addition, as shown in FIG. 2, the ground bar 16 has a pair of ground bars facing each other, and the external conductor 14 is sandwiched between the ground bars 16 and 16 so that the external conductor 14 is securely held. desirable. Each ground bar 16 is connected to both ends by solder 16a.

As shown in FIGS. 1 and 2, each exposed central conductor 12 is independently connected to a connection terminal 31 provided integrally with the connector housing 30. The central conductor 12 can be connected to the connection terminal 31 by, for example, soldering (pulse heat), ACF, conductive adhesive, or the like.
A shell 20 covering the ground bar 16 is attached to the connector housing 30 by caulking at the end portion of the multi-core cable 10, and the shell 20 is electrically connected to the ground bar 16 via a conductive adhesive (not shown). Connected. Note that the shell 20 and the ground bar 16 may be connected, for example, by providing a plurality of contact portions projecting downward on the shell 20 so that the contact portions partially contact the ground bar 16. It is desirable to bond with. Examples of the conductive adhesive material include soldering (pulse heat), ACF, and conductive adhesive as described above.

  In the present embodiment, as shown in FIGS. 1 and 2, one coaxial cable 11 </ b> A among a plurality of coaxial cables 11 is set in advance for grounding, and a connection terminal 31 connected to the central conductor 12 is provided. It is electrically connected to the shell 20. Specifically, as shown in FIGS. 2 and 4, the shell 20 is provided with a claw piece 21 extending downward from the front surface 20a of the shell 20 at a position corresponding to the ground coaxial cable 11A. The claw piece 21 is in contact with the connection terminal 31 connected to the center conductor 12 of the ground coaxial cable 11A.

  As shown in FIG. 1, when one coaxial cable 11 </ b> A is used for the ground among the coaxial cables 11, the ground coaxial cable 11 </ b> A is arranged at the center so that the distance from both ends of the ground bar 16 is substantially the same. It is desirable to do. When a plurality of ground coaxial cables 11A are disposed, it is desirable that the ground coaxial cables 11A be disposed at positions where the width of the ground bar 16 is substantially equally divided.

Returning to the connection structure between the shell 20 and the connection terminal 31, as shown in FIG. 5A, the length at which the connection terminal 31 protrudes from the front surface 20 a of the shell 20 at the contact portion between the claw piece 21 and the connection terminal 31. It is desirable that the corner A formed by the connection terminal 31 and the claw piece 21 is soldered to be securely connected. Alternatively, as shown in FIG. 5B, the claw piece 21 penetrates the notch provided in the connection terminal 31, and the corner B formed by the claw piece 21 and the connection terminal 31 that penetrates is formed. You may make it solder.
On the other hand, as shown in FIG. 3, since the claw piece 21 is not provided on the front surface 20a of the shell 20 at the position of the coaxial cable 11 that is a signal line, the shell 20 and the connection terminal 31 are not electrically connected. It is in.

As described above, according to the multi-core coaxial cable 10 described above, the ground bar 16 is fixed to the outer conductor 14 of the coaxial cable 11 at the terminal portion of the plurality of coaxial cables 11. Thereby, the mutual position of the coaxial cable 11 having an extremely small diameter is fixed at a predetermined pitch. In addition, the outer conductor 14 of the coaxial cable 11 is electrically connected to the ground bar 16. When the shell 20 is connected to the ground circuit, the ground bar 16 is grounded via the shell 20 and the connection terminal 31 at the position of the ground coaxial cable 11A. It can be grounded near the center where the coaxial cable 11A is located.
By increasing the number of grounding points in this way, even if the number of cores of the multi-core cable 10 is increased and the width is increased, for example, the grounding potential of the ground bar 16 is brought close to zero potential and stable and sufficient grounding performance is achieved. Can be secured. In the 40-core multi-core cable, the ground bar 16 has a ground resistance of 10 to 25 mmΩ at each portion in the longitudinal direction, and is 10 to 15 mmΩ.

  In addition, if the claw piece 21 is provided in the shell 20 corresponding to the position of the coaxial cable 11A set in advance as a ground as in the above-described embodiment, the intermediate portion of the ground bar 16 can be easily grounded.

  Further, in the above-described embodiment, the shell 20 and the connection terminal 31 are made non-conductive without providing the claw piece 21 at the position of the coaxial cable 11 other than the position of the ground coaxial cable 11A. As described above, the length of the tip of the connection terminal 31 may be shortened so that it does not reach the front surface 20 a of the shell 20. In this case, the front surface 20a of the shell 20 is extended downward to the height of the connection terminal 31 over the entire width so that the claw piece 21 is not provided. At the position of the ground coaxial cable 11A, the connection terminal 31 is lengthened and brought into contact with the front surface 20a of the shell 20 to establish conduction.

  In the above-described embodiment, the claw piece 21 is provided on the shell 20 and brought into contact with the connection terminal 31 for grounding. However, the shell 20 and the connection terminal 31 are electrically connected with a conductive wire and grounded. You can also. In this case, the vacant coaxial cable 11 can be used for the ground later without setting the position of the ground coaxial cable 11A in advance.

  As described above, in the multi-core coaxial cable and the manufacturing method thereof according to the present invention, at least one of the plurality of coaxial cables constituting the multi-core coaxial cable is set in advance as a ground, and this coaxial cable is used. The connection terminal connected to the central conductor of the metal and the shell are electrically connected. In addition, when the multi-core coaxial cable is connected to another device or circuit, the connection terminal connected to the center conductor for grounding is connected to the ground circuit. As a result, the ground bar is grounded via the shell and the connection terminal, so that the ground bar can be grounded at both ends in the longitudinal direction and the central portion where the ground coaxial cable 11A is located. Even if the number of cores increases and the width becomes wider, stable and sufficient grounding performance can be ensured.

It is a top view near the edge part of the multi-core coaxial cable of this invention. It is sectional drawing of the II-II position in FIG. It is sectional drawing of the III-III position in FIG. It is the front view seen from the IV direction in FIG. (A) And (B) is an expanded sectional view which shows the connection part of a shell and a connection terminal. It is sectional drawing of the coaxial cable position in general parts other than the coaxial cable for grounds. It is a top view which shows the conventional multi-core coaxial cable.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Multi-core coaxial cable 11 Coaxial cable 11A Coaxial cable for ground 12 Center conductor 13 Insulator 14 External conductor 16 Ground bar 20 Shell 21 Claw piece 31 Connection terminal

Claims (4)

A plurality of coaxial cables are arranged in parallel, and a center conductor, an insulator, and an outer conductor are sequentially exposed stepwise at their end portions, and a ground bar fixed to each of the outer conductors via a conductive material, and the center A connection terminal connected to the conductor, and a shell that covers the ground bar and is electrically connected to the ground bar,
Of the plurality of coaxial cables, a connection terminal to which the central conductor of at least one coaxial cable set in advance as a ground is connected and the shell are electrically connected, and the ground bar and the ground are connected . multi-core coaxial cable and the center conductor of the coaxial cable, characterized in Rukoto are electrically connected through the shell.   The multi-core coaxial cable according to claim 1, wherein a claw piece provided on the shell is electrically connected to a connection terminal connected to a central conductor of the ground coaxial cable. Resshi parallel a plurality of coaxial cables, the terminal portions of each said coaxial cable, the outer conductor, the insulator and center conductor are sequentially exposed stepwise, through the conductive adhesive material ground bar to each of said outer conductor Fixing, connecting a connection terminal to each center conductor, covering the ground bar, covering the shell, electrically connecting the ground bar and the shell, and for grounding of the plurality of coaxial cables A connection terminal connected to a central conductor of a coaxial cable to be used and the shell are electrically connected to electrically connect the ground bar and the central conductor of the ground coaxial cable via the shell. A manufacturing method of a multi-core coaxial cable.   4. The method of manufacturing a multi-core cable according to claim 3, wherein a claw piece is provided on the shell, and a connection terminal connected to a central conductor of the ground coaxial cable is electrically connected to the claw piece. .

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