JP5835274B2 - Connecting member and flat cable with connecting member - Google Patents

Description

  The present invention relates to a connecting member connected to a flat cable and a flat cable with a connecting member.

  In Patent Document 1, a pair of insulating films are bonded from both sides of an array surface in which a plurality of conductors are arranged in a plane, and a connection member is bonded to a conductor as a connection electrode protruding from the pair of insulating films. A flat cable is described.

JP2013-020949A

  As a conductor included in the flat cable, it is conceivable to use a coaxial wire capable of high frequency. However, in the configuration of the connecting member described in Patent Document 1, it is difficult to use the connecting member as a connecting member connected to a flat cable including the coaxial cable because a portion for dropping the ground of the coaxial cable cannot be formed on the connecting member. .

  An object of the present invention is to provide a connection member that is connected to a flat cable, and is capable of providing a high-frequency connection member and a flat cable with the connection member at low cost.

The connecting member of the present invention is
A first insulating film;
A second insulating film affixed on the first insulating film;
A plurality of rectangular conductors attached on at least the second insulating film or the first insulating film in a parallel state; and
A ground bar extending in a parallel direction of the plurality of flat conductors in a state separated from one end in the length direction of the plurality of flat conductors;
With
The ground bar is conductively connected to at least one of the plurality of flat conductors.

  According to the connecting member of the present invention, it is possible to provide a connecting member connected to a flat cable including a coaxial cable capable of supporting high frequency at low cost.

It is a top view which shows an example of embodiment of the connection member which concerns on this invention, and a flat cable. It is sectional drawing which shows the state in which the connection member shown in FIG. 1 was connected to the flat cable. It is a figure which shows the manufacturing method of the connection member which concerns on the modification of this invention. It is a figure which shows the manufacturing method of the connection member shown in FIG. It is a figure which shows the example of the other manufacturing method of the connection member shown in FIG. It is a figure which shows the other modification of the connection member which concerns on this invention. It is a figure which shows the further another modification of the connection member which concerns on this invention. It is a figure which shows another modification of the connection member which concerns on this invention. It is a figure which shows another modification of the connection member which concerns on this invention.

[Description of Embodiment of Present Invention]
First, the contents of the embodiments of the present invention will be listed and described.
The connection member according to the embodiment of the present invention is
(1) a first insulating film;
A second insulating film affixed on the first insulating film;
A plurality of rectangular conductors attached in parallel on at least the second insulating film or the first insulating film; and
A ground bar extending in a parallel direction of the plurality of flat conductors in a state separated from one end in the length direction of the plurality of flat conductors;
With
The ground bar is conductively connected to at least one of the plurality of flat conductors.
According to this configuration, it is not necessary to form a connection member with an expensive flexible printed circuit board or the like, and it is possible to provide a connection member connected to a flat cable including a coaxial cable capable of supporting high frequencies at a low cost with a simple configuration. it can.

(2) In the one end part in the length direction of the first insulating film, the first insulating film is exposed without the second insulating film being pasted on the first insulating film,
It is preferable that the ground bar is disposed in a portion where the first insulating film is exposed.
According to this configuration, it is possible to reliably prevent conduction between a plurality of flat conductors other than the flat conductor that is conductively connected to the ground bar and the ground bar.

(3) The length of the flat conductor not connected to the ground bar is preferably shorter than the length of the flat conductor conductively connected to the ground bar.
According to this configuration, the position of the flat conductor connected to the ground bar among the plurality of flat conductors of the connecting member can be freely set.

(4) In at least a portion along the parallel direction of the plurality of flat conductors, the first insulating film is exposed without the second insulating film being pasted on the first insulating film,
At least one rectangular conductor among the plurality of rectangular conductors is disposed on the exposed portion of the first insulating film,
The rectangular conductor disposed in the portion where the first insulating film is exposed is preferably conductively connected to the ground bar.
According to this configuration, it is easy to discriminate between the flat conductor serving as the signal line portion and the flat conductors at both ends serving as the ground line portion, and to improve the connection workability between the flat conductor serving as the ground line portion and the ground bar. Can do.

Moreover, the flat cable with a connection member according to the embodiment of the present invention is
(5) A flat cable with a connecting member in which a flat cable is connected to the connecting member according to any one of (1) to (4),
The flat cable is
Around the center conductor, an insulator, an outer conductor, and a jacket are sequentially laminated in a coaxial manner, and a plurality of coaxials in which the center conductor, the insulator, and the outer conductor are sequentially exposed from one end side of the flat cable. Electric wires,
A third insulating film bonded from both sides of the arrangement surface of the plurality of coaxial electric wires arranged in a plane, and
The number of the coaxial wires is less than the number of rectangular conductors of the connection member,
Each central conductor is conductively connected to each of the rectangular conductors, and each external conductor is conductively connected to the ground bar of the connection member.
According to this configuration, a flat cable with a connecting member including a conductor capable of high frequency, such as a coaxial cable, can be provided at low cost.

[Details of the embodiment of the present invention]
Hereinafter, examples of embodiments of a connecting member and a flat cable according to the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of an end portion of a connection member and a flat cable according to the present embodiment, and FIG. 2 is a cross-sectional view showing a state in which the connection member is connected to the flat cable.

  The flat cable 1 according to the present embodiment is a cable used for electrically connecting a pair of external devices or for in-device wiring. As shown in FIG. 1, the flat cable 1 includes a plurality of (e.g., eight) coaxial wires 2 and a pair of insulating films 3 (an example of a third insulating film).

  The coaxial wire 2 is, for example, an electric wire in which a center conductor 5, an insulator 6, an outer conductor 7, and an outer jacket 8 are laminated in this order from the center in the radial direction. The plurality of coaxial electric wires 2 are arranged in a plane at a predetermined pitch.

The insulating film 3 is formed from a resin such as polyethylene terephthalate, polyester, or polyimide. The insulating film 3 is provided with adhesive layers made of a polyester-based adhesive, a flame-retardant polyvinyl chloride-based insulating adhesive, a flame-retardant polyolefin, or the like on the surfaces facing each other.
The pair of insulating films 3 are bonded to each other by sandwiching a plurality of coaxial electric wires 2 arranged in a planar shape from both sides of the arrangement surface with the surfaces of the adhesive layer facing each other.

  At the end in the longitudinal direction of the flat cable 1, the insulating film 3 is removed by a predetermined length, and a part of the coaxial cable 2 is exposed. The portion exposed from the end portion of the flat cable 1 is referred to as a connection portion 11 for convenience. In the connection portion 11, each coaxial cable 2 has a central conductor 5, an insulator 6, an external conductor 7, and a jacket 8 exposed in order from the tip side. The exposed center conductor 5 is a connection electrode 12.

  The connection member 20 according to the present embodiment includes a reinforcing film 21 (an example of a first insulating film), an insulating film 22 (an example of a second insulating film), a plurality of rectangular conductors 23, and a ground bar 24. Yes.

As the reinforcing film 21, for example, a film made of polyethylene terephthalate is used.
The insulating film 22 is provided on at least a part of the upper surface of the reinforcing film 21, and is made of, for example, a film made of polyethylene terephthalate that is thinner than the reinforcing film 21. The thickness of the connecting member 20 is adjusted by changing the thicknesses of the reinforcing film 21 and the insulating film 22 depending on a connection partner such as a connector. For example, the thickness of the reinforcing film 21 is 0.1 to 0.5 mm, and the thickness of the insulating film 22 is 0.01 to 0.5 mm. In this example, the reinforcing film 21 and the insulating film 22 are arranged such that one end portions in the length direction of the flat conductors 23 arranged on the insulating film 22 are shifted. On the other hand, the reinforcing film 21 and the insulating film 22 are arranged in a line at the other end in the length direction of the flat conductor 23 and both ends in the parallel direction of the flat conductor 23. Thereby, a portion 21 </ b> A where the insulating film 22 is not attached is exposed along the parallel direction of the plurality of flat conductors 23 on the reinforcing film 21.

  The plurality of flat conductors 23 are arranged on the upper surface of the insulating film 22 with substantially the same width and the same pitch as the connection electrodes 12 of the connection portion 11. These flat conductors 23 are made of a rolled copper foil of copper or copper alloy, and the surface thereof is plated with gold. The length of each flat conductor 23 is substantially the same as the length of the insulating film 22 in the short direction. As the rectangular conductor 23, one plated with tin, gold, silver or the like is used. The rectangular conductor 23 used for grounding and the rectangular conductor 23 used for signaling may be different in size, plating, and the like.

  The ground bar 24 extends in the parallel direction of the plurality of flat conductors 23 while being separated from one end of the flat conductor 23 in the length direction, and is disposed in a portion 21A on the reinforcing film 21 where the insulating film 22 is not pasted. ing. Both ends of the ground bar 24 are electrically connected by solder 15 to the rectangular conductors 23 at both ends of the plurality of flat conductors 23 arranged on the upper surface of the insulating film 22. The flat conductor 23 connected to the ground bar is either connected to the coaxial cable 2 or not connected.

  As shown in FIG. 2, the flat cable 1 and the connecting member 20 are connected to each other at the end in the longitudinal direction of the flat cable 1. Specifically, the connecting portion 11 of the flat cable 1 is superimposed on the connecting member 20, and the central conductor 5 that is the connecting electrode exposed from the coaxial cable 2 and the flat conductor 23 of the connecting member 20 are conductively connected by solder. Yes. Further, the outer conductor 7 exposed from the coaxial cable 2 and the ground bar 24 of the connection member 20 are conductively connected by solder. The distance between the ground bar 24 and the flat conductor 23 and the distance between the outer conductor 7 and the central conductor 5 in the connection portion 11 of the coaxial cable 2 are set such that the outer conductor 7 is connected to the ground bar 24 and the central conductor 5 is connected to the flat conductor 23. It is adjusted so that it can be connected at the same time.

  In recent years, a wiring material having a high shielding effect has been required to achieve high-speed signal transmission. In order to cope with such high-speed signal transmission, it is preferable to use a flat cable having a coaxial cable. However, in the conventional configuration of the connecting member for the flexible flat cable, it is difficult to use the connecting member as a connecting member for a flat cable provided with a coaxial cable because a portion for dropping the ground of the coaxial cable cannot be formed on the connecting member. Moreover, although it was possible to use a flexible printed circuit board etc. as a connection member, it was expensive.

  On the other hand, the connection member 20 according to the present embodiment includes at least one flat conductor 23 among a plurality of flat conductors 23 arranged in parallel on the insulating film 22 and a plurality of flat conductors 23 arranged on the reinforcing film 21. A ground bar 24 extending in the direction is conductively connected. With such a simple configuration, a portion where the ground of the coaxial cable 2 of the flat cable 1 is dropped can be formed in the connecting member 20. Therefore, it is not necessary to form a connection member with an expensive flexible printed circuit board or the like, and the connection member 20 that is conductively connected to the coaxial cable 2 of the flat cable 1 can be provided at low cost. Moreover, the flat cable 1 with the connection member 20 can be provided at low cost by connecting such a connection member 20 to the flat cable 1 provided with the coaxial cable 2 capable of supporting high frequencies.

  In addition, according to the connection member 20 according to the present embodiment, the reinforcing film 21 is exposed without being attached to the insulating film 22 at one end in the length direction of the plurality of flat conductors 23 of the reinforcing film 21, and this reinforcing A ground bar 24 is disposed in a portion 21A where the film 21 is exposed. Accordingly, unintentional conduction between the flat conductors 23 other than the flat conductor 23A conductively connected to the ground bar 24 and the ground bar 24 can be reliably prevented with a simple configuration. Further, the step between the central conductor 5 and the outer conductor 7 in the connection portion 11 of the coaxial cable 2 can be partially absorbed.

  While the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. In addition, the number, position, shape, and the like of the constituent members described above are not limited to the above-described embodiments, and can be changed to a number, position, shape, and the like that are suitable for carrying out the present invention.

  In the connection member 20 described in the above embodiment, the plurality of flat conductors 23 have substantially the same length, but the present invention is not limited to this example. For example, a connecting member 20A as shown in FIG. 4 may be used. A manufacturing method of the connecting member 20A will be described with reference to FIGS.

  First, as shown in FIG. 3, a plurality of flat conductors 23 are pasted on a long insulating film 22. Then, the long insulating film 22 to which the flat conductor 23 is attached is cut into an appropriate size.

  Next, as shown in FIG. 4A, in the cut insulating film 22, the ground bar 24 is placed on the one end side of the flat conductor 23 other than the flat conductor 23A connected to the ground bar 24. The portion to be cut is cut out together with the insulating film 22 of the portion to which the flat conductor 23 is attached. Accordingly, the length of the rectangular conductor 23 not connected to the ground bar 24 is shorter than the length of the rectangular conductor 23A conductively connected to the ground bar 24.

  Next, as shown in FIG. 4B, the insulating film 22 to which such a flat conductor 23 is attached is attached to the reinforcing film 21. And solder paste S is apply | coated to the part to which the ground bar 24 on the rectangular conductor 23A is connected. Similarly, the solder paste S is applied to the portion where the central conductor 5 of the coaxial cable 2 is connected on the flat conductors 23 and 23A.

Finally, as shown in FIG. 4C, the flat cable 1 and the connecting member 20A are connected. Specifically, the rectangular conductor 23A and the ground bar 24 are heated and soldered by, for example, a heater or a laser. Then, the outer conductor 7 of the coaxial cable 2 is soldered on the ground bar 24, and the central conductor 5 of the coaxial cable 2 is soldered on the flat conductors 23 and 23A.
As shown in FIG. 4C, a ground bar 24 may be further soldered on the outer conductor 7.

  In this modification, the rectangular conductor 23 not connected to the ground bar 24 and the insulating film so that the length of the flat conductor 23 not connected to the ground bar 24 is shorter than the length of the flat conductor 23A conductively connected to the ground bar 24. A part of 22 is cut off. According to this configuration, the position of the rectangular conductor 23A connected to the ground bar 24 among the plurality of rectangular conductors 23 of the connecting member 20A can be freely set.

  In FIG. 4A, the flat conductor 23 and one end side portion of the insulating film 22 are cut off on one side surface (the lower surface in FIG. 4A) along the longitudinal direction of the insulating film 22. However, the method of cutting the flat conductor 23 and the insulating film 22 is not limited to this example. For example, as shown in FIG. 5A, in the flat conductors 23 other than the flat conductor 23A (the flat conductor 23A arranged on the leftmost side in FIG. 5) connected to the ground bar 24, A method may be employed in which both end portions are left and a portion other than the both end portions and where the ground bar 24 is placed is cut together with the insulating film 22. Thereafter, as shown in FIG. 5B, by attaching the insulating film 22 to which such a flat conductor 23 is attached to the reinforcing film 21, the flat conductor that is not connected to the ground bar 24 as in FIG. A connecting member 20A1 having a length 23 shorter than the length of the flat conductor 23A conductively connected to the ground bar 24 can be produced.

In the above-described embodiment, the plurality of flat rectangular conductors 23 are all arranged on the insulating film 22, but the present invention is not limited to this example. For example, like the connecting member 20B shown in FIGS. 6A and 6B, at least a part of the parallel conductors 23 on the reinforcing film 21 in the parallel direction is reinforced without the insulating film 22 being attached. The film 21 may be exposed. In this example, flat conductors 23A at both ends of a plurality of flat conductors 23 are arranged on a portion 21B where the reinforcing film 21 is exposed, and the ground bars 24 provided on the reinforcing film 21 are provided with these flat conductors 23A. Are electrically conductively connected to both ends. In addition, in order to match the upper surfaces in the height direction of the plurality of flat conductors 23 arranged on the insulating film 22 and the flat conductors 23A on both ends, the flat conductors 23A on both ends are formed on the insulating film 22 with the thickness of the insulating film 22. It is preferable that the thickness of the flat conductor 23 is a total thickness.
According to this configuration, the rectangular conductor 23 on the insulating film 22 serving as the signal line portion and the flat conductors 23A at both ends serving as the ground line portion can be easily distinguished, and the connection workability between the rectangular conductor 23A and the ground bar 24 is facilitated. Can be improved.
Also in this example, the flat conductor 23A, which is used as a ground terminal by directly bonding the ground bar 24 on the reinforcing film 21, and the ground bar 24 may be electrically connected by a conductive adhesive, metal foil, or the like.

  Further, as in the connecting member 20C shown in FIG. 7, a conductive substrate 25 made of copper is attached to the lower surface of the reinforcing film 21, and the conductive substrate 25 and the rectangular conductors 23A at both ends serving as the ground wire portions have a substantially C cross section. It is good also as a structure electrically conductively connected by the character-shaped ground member 24A. According to this configuration, the high-frequency transmission characteristics of the connecting member 20C can be improved by providing the conductive substrate 25 made of copper.

  Further, like the connecting member 20D shown in FIG. 8, both ends of the ground bar 24 are arranged on the rectangular conductors 23A at both ends, and holes are provided in the portions of the ground bar 24 arranged on the rectangular conductors 23A. A configuration in which the rectangular conductor 23A and the ground bar 24 are conductively connected by embedding the conductive adhesive 26 may be employed.

Furthermore, as shown in FIG. 9, in the reinforcing film 21, a portion 21 </ b> C where the insulating film 22 is not attached and the reinforcing film 21 is exposed is provided also in the central portion in the parallel direction of the plurality of flat conductors 23. Also good. In this example, three flat conductors 23A serving as ground line portions are arranged at both ends and a central exposed portion 21C of the reinforcing film 21, and these flat conductors 23A are arranged in the parallel direction of the plurality of flat conductors 23. It is conductively connected to a single ground bar 24 extending along. In this example, since the ground portion is also grounded, the ground potential is more stable and preferable.
Thus, in the connection member 20E, the rectangular conductors 23A that become the ground line portions can be freely arranged.

  In the above embodiment, the ground bar 24 is disposed in the portion 21A where the insulating film 22 on the reinforcing film 21 is not pasted, but the insulating film 22 is attached to the entire upper surface of the reinforcing film 21, The ground bar 24 may also be arranged on the upper surface of the insulating film 22. In this case, the ground bar 24 is separated from one end in the length direction of the flat conductor 23 in order to prevent unintentional conduction between the flat conductor 23 and the ground bar 24 other than the flat conductor 23 (23A) conductively connected to the ground bar 24. It is necessary to arrange it in the state where

  In the above embodiment, the flat cable 1 has the same number of the coaxial electric wires 2 as the flat conductors 23 provided in the connecting member 20, but the number of the coaxial electric wires 2 is larger than the number of the rectangular conductors 23 of the connecting member 20. It may be less. That is, the coaxial cable 2 is conductively connected only to the rectangular conductor 23 that is not connected to the ground bar 24 among the plurality of rectangular conductors 23, and the coaxial cable 2 is not connected to the rectangular conductor 23 (23A) that is conductively connected to the ground bar 24. A configuration may be adopted.

1: Flat cable 2: Coaxial wire 3: Insulating film (an example of a third insulating film)
5: Center conductor 6: Insulator 7: External conductor 8: Outer sheath 11: Connection portion 15, 26: Solder 20, 20A, 20B, 20C, 20D: Connection member 21: Reinforcing film (an example of a first insulating film)
21A: Exposed portion of the reinforcing film 22: Insulating film (an example of a second insulating film)
23, 23A: Flat conductor 24: Ground bar

Claims (4)

A connecting member comprising a first insulating film, a second insulating film, a plurality of flat conductors, and a ground bar;
The second insulating film is affixed on the first insulating film,
The plurality of flat conductors are affixed on the second insulating film in a parallel state,
The first insulating film is partially exposed without the second insulating film being applied,
The ground bar is disposed in a portion where the first insulating film is exposed apart from the plurality of flat conductors,
The ground bar is a connection member that is conductively connected to at least one of the plurality of flat conductors. The connecting member according to claim 1 , wherein a length of the flat conductor not connected to the ground bar is shorter than a length of the flat conductor conductively connected to the ground bar . In at least a part along the parallel direction of the plurality of flat conductors, the first insulating film is exposed without the second insulating film being pasted on the first insulating film,
At least one rectangular conductor among the plurality of rectangular conductors is disposed on the exposed portion of the first insulating film,
The connecting member according to claim 1 or 2 , wherein the flat conductor disposed in the portion where the first insulating film is exposed is conductively connected to the ground bar . A flat cable with a connecting member in which a flat cable is connected to the connecting member according to any one of claims 1 to 3,
  The flat cable is
    Around the center conductor, an insulator, an outer conductor, and a jacket are sequentially laminated in a coaxial manner, and a plurality of coaxials in which the center conductor, the insulator, and the outer conductor are sequentially exposed from one end side of the flat cable. Electric wires,
    A third insulating film bonded to the arrangement surface of the plurality of coaxial electric wires arranged in a plane,
  The number of the coaxial wires is less than the number of rectangular conductors of the connection member,
  A flat cable with a connecting member, wherein each central conductor is conductively connected to each of the rectangular conductors, and each external conductor is conductively connected to the ground bar of the connecting member.

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