JP2023183062A - flat cable - Google Patents

Abstract

To realize an even thinner flat cable.SOLUTION: A flat cable 1A of an embodiment has: a plurality of coaxial cables 10 which are arranged in parallel at a predetermined pitch; a plurality of connection members 20 which are arranged between adjacent coaxial cables 10, and extend along a longitudinal direction of the coaxial cables 10; and an outer cover 30 which covers the plurality of coaxial cables 10 and the connection members 20. The outer cover 30 is constituted of a first cover member 31 and a second cover member 32 which oppose to each other while sandwiching the coaxial cables 10 and the connection members 20. Each connection member 20 is fixed to the first cover member 31 and the second cover member 32, and each coaxial cable 10 is not fixed to the first cover member 31 and the second cover member 32.SELECTED DRAWING: Figure 2

Description

The present invention relates to a flat cable.

Flat cables are known that include a plurality of cores arranged in parallel. Examples of cores included in flat cables include coaxial cables and insulated wires. Flat cables are used, for example, as wiring materials for electronic devices such as mobile phones and notebook personal computers.

Patent No. 3603665

As devices in which flat cables are used become smaller and thinner, flat cables are required to be made even thinner.

An object of the present invention is to realize further thinning of the flat cable.

A flat cable according to one embodiment includes at least an insulator around a conductor, a plurality of cores arranged in parallel at a predetermined pitch, and a plurality of cores arranged between adjacent cores, and arranged in a longitudinal direction of the cores. a plurality of connecting members extending along the plurality of cores and an outer covering covering the plurality of cores and the connecting members. The outer covering includes a first covering member and a second covering member that face each other with the core and the connecting member interposed therebetween. Each of the connecting members is fixed to the first covering member and the second covering member, while each of the cores is not fixed to the first covering member and the second covering member.

According to the present invention, a thinner flat cable than before is provided.

FIG. 2 is a plan view showing a portion of a flat cable according to one embodiment. FIG. 2 is a schematic cross-sectional view of the flat cable shown in FIG. 1. FIG. 3 is an enlarged cross-sectional view of the coaxial cable shown in FIG. 2. FIG. 3 is an enlarged sectional view of the connecting member shown in FIG. 2. FIG. 2 is a schematic diagram showing a manufacturing process of the flat cable shown in FIG. 1. FIG. FIG. 7 is a schematic cross-sectional view of a flat cable according to another embodiment.

Hereinafter, one embodiment of the flat cable of the present invention will be described with reference to the drawings. Note that in all the drawings referred to to describe the embodiments, the same or substantially the same configurations and elements are denoted by the same reference numerals. In addition, as a general rule, the structure or elements that have been explained once will not be explained repeatedly.

(First embodiment)
<Overview of flat cable>
FIG. 1 is a plan view showing a part of a flat cable 1A according to this embodiment. More specifically, FIG. 1 is a plan view showing one end side of a flat cable 1A that has been subjected to terminal treatment. Moreover, FIG. 2 is a schematic cross-sectional view of the flat cable 1A. Note that the cross section shown in FIG. 2 is a cross section taken along line AA in FIG.

The flat cable 1A includes a plurality of coaxial cables 10 as cores, a plurality of connection members 20 arranged between adjacent coaxial cables 10, and an outer sheath 30 that covers the plurality of coaxial cables 10 and the connection members 20. have

More specifically, the flat cable 1A includes 36 coaxial cables 10 and 35 connecting members 20. Further, the outer sheathing 30 is composed of a first sheathing member 31 and a second sheathing member 32 that face each other with all the coaxial cables 10 and the connecting member 20 interposed therebetween. Note that all 36 coaxial cables 10 are signal coaxial cables. Therefore, each coaxial cable 10 is used as a signal line in a device in which the flat cable 1A is used.

Each connection member 20 is a rod-shaped or column-shaped member extending along the longitudinal direction of the coaxial cable 10. On the other hand, the first covering member 31 and the second covering member 32 are band-shaped or tape-shaped members that extend along the longitudinal direction of the coaxial cable 10 and the connecting member 20.

In the following description, the first covering member 31 may be referred to as the "lower covering member 31" and the second covering member 32 may be referred to as the "upper covering member 32." Furthermore, the direction in which the coaxial cables 10 are arranged is defined as the "width direction", and the direction in which the lower covering member 31 and the upper covering member 32 face each other is defined as the "height direction". However, such names and definitions are merely names and definitions for convenience of explanation.

According to the above definition, the width (W) of the flat cable 1A shown in FIG. 2 is, for example, 0.65 mm or more and 192 mm or less. Further, the height (H) of the flat cable 1A is, for example, 0.15 mm or more and 1.60 mm or less.

However, the width (W) of the flat cable 1A changes depending on the number of coaxial cables 10, the width of the connecting member 20, etc. Further, the height (H) of the flat cable 1A changes depending on the outer diameter of the coaxial cable 10 and the thickness of the lower covering member 31 or the upper covering member 32.

Each connecting member 20 shown in FIG. 2 is fixed to a lower covering member 31 and an upper covering member 32. As shown in FIG. On the other hand, each coaxial cable 10 is not fixed to the lower covering member 31 and the upper covering member 32. Furthermore, although the connecting member 20 and the coaxial cables 10 on both sides of the connecting member 20 are in contact with each other, they are not fixed.

<Coaxial cable>
FIG. 3A is an enlarged cross-sectional view of the coaxial cable 10. Each coaxial cable 10 has at least an insulator provided around the conductor. More specifically, each coaxial cable 10 has an inner conductor 11, an inner insulator 12, an outer conductor 13, and an outer insulator (sheath) 14.

The internal conductor 11 is formed by a plurality of (seven in this embodiment) metal wires 11a twisted together. As the metal wire 11a, a plated wire such as a tin-plated annealed copper wire, a tin-plated copper alloy wire, a silver-plated annealed copper wire, a silver-plated copper alloy wire, etc. is used. The outer diameter of each metal wire 11a is, for example, 0.01 mm or more and 0.5 mm or less, and the outer diameter of the inner conductor 11 is, for example, 0.03 mm or more and 0.15 mm or less.

The inner insulator 12 is made of fluororesin, foamed fluororesin, polyethylene, foamed polyethylene, polypropylene, foamed polypropylene, or the like. The thickness of the inner insulator 12 is, for example, 0.02 mm or more and 0.12 mm or less, and the outer diameter thereof is, for example, 0.07 mm or more and 0.38 mm or less. Note that the inner insulator 12 may be a single layer or a multilayer of two or more layers.

The outer conductor 13 is formed by a plurality of metal wires 13a wound laterally around the inner insulator 12. For example, a tin-plated annealed copper wire, a tin-plated copper alloy wire, a silver-plated annealed copper wire, a silver-plated copper alloy wire, or the like is used as the metal wire 13a. The outer diameter of each metal wire 13a is, for example, 0.017 mm or more and 0.032 mm or less.

The outer insulator 14 is made of polyvinyl chloride (PVC), fluororesin, or the like. The thickness of the outer insulator 14 is, for example, 0.022 mm or more and 0.045 mm or less, and the outer diameter thereof is, for example, 0.15 mm or more and 0.54 mm or less. That is, the outer diameter (d) of the coaxial cable 10 is, for example, 0.15 mm or more and 0.54 mm or less. Note that the outer insulator 14 may be formed of a tape member. Further, the outer insulator 14 may be omitted depending on the use of the flat cable 1A.

A plurality of coaxial cables 10 each having the above configuration are arranged in parallel at a predetermined pitch (P), as shown in FIG. Note that the pitch (P) shown in FIG. 2 is, for example, 0.15 mm or more and 5.54 mm or less.

<Connection member>
FIG. 3B is an enlarged cross-sectional view of the connecting member 20. Each connecting member 20 includes a base 21 , a first bonding portion 22 , and a second bonding portion 23 . The connecting member 20 is a member for connecting a first covering member 31 and a second covering member 32, which will be described later.

The base 21 has a rectangular cross-sectional shape. More specifically, the base 21 includes an upper surface 21a, a lower surface 21b, a right side surface 21c, and a left side surface 21d, and has, for example, a quadrilateral (rectangular in this embodiment) cross-sectional shape. The width of the base 21 is, for example, 0.10 mm or more and 2.00 mm or less, and the thickness of the base 21 is, for example, 0.05 mm or more and 0.54 mm or less.

The first adhesive part 22 is provided on the lower surface 21b of the base 21 and has viscosity or adhesive properties. The second adhesive part 23 is provided on the upper surface 21a of the base 21 and has viscosity or adhesive properties. The first adhesive part 22 is formed by, for example, double-sided tape applied to the lower surface 21b of the base 21 or an adhesive applied to the lower surface 21b. The second adhesive portion 23 is also formed, for example, by double-sided tape applied to the upper surface 21a of the base 21 or an adhesive applied to the upper surface 21a. As the adhesive for forming the first adhesive part 22 and the second adhesive part 23, for example, an acrylic adhesive, a urethane adhesive, a silicone adhesive, or the like is used. The width of the first adhesive part 22 and the second adhesive part 23 is the same as the width of the base 21 or smaller (narrower) than that. The thickness of the first adhesive part 22 and the second adhesive part 23 is, for example, 0.005 mm or more.

The connection member 20 has flexibility equal to or greater than that of the coaxial cable 10. Specifically, the base 21 of the connection member 20 is formed of the same material as the insulator (for example, the outer insulator 14) that constitutes the coaxial cable 10. That is, the base portion 21 is formed of polyvinyl chloride (PVC), fluororesin, or the like.

As can be seen from FIG. 3B, the base 21 is the main part of the connecting member 20. Therefore, the flexibility of the connecting member 20 depends exclusively on the flexibility of the base 21. Therefore, the connecting member 20 of this embodiment, in which the material of the base 21 and the material of the insulator (for example, the outer insulator 14) constituting the coaxial cable 10 are the same, has flexibility equal to or greater than that of the coaxial cable 10. have.

However, even if the material of the base 21 and the material of the insulator constituting the coaxial cable 10 are the same, depending on the structure and size of the coaxial cable 10, the flexibility of the coaxial cable 10 may exceed the flexibility of the base 21. It is possible.

However, in this embodiment, the cross-sectional areas of the base 21 and the coaxial cable 10 are substantially the same. Under such conditions, the flexibility of the base 21, which is made of the same material as the outermost layer of the coaxial cable 10, is greater than the flexibility of the coaxial cable 10 that includes the inner conductor 11 and the outer conductor 13. It is normal to exceed.

<External coating>
As described above, the outer covering 30 is composed of a first covering member 31 and a second covering member 32 that face each other. As shown in FIG. 2, the connecting member 20 is interposed between the first covering member 31 and the second covering member 32 that face each other. Further, one surface 22a of the first adhesive portion 22 of each connecting member 20 is fixed (adhered) to the inner surface 31a of the lower covering member 31. Further, one surface 23a of the second adhesive portion 23 of each connecting member 20 is fixed (adhered) to the inner surface 32a of the upper covering member 32. That is, one surface 22a of the first adhesive part 22 is a first bonding surface that is fixed (adhered) to the inner surface 31a of the lower covering member 31, and one surface 23a of the second adhesive part 23 is the inner surface of the upper covering member 32. This is a second bonding surface that is fixed (adhered) to 32a.

Therefore, in the following description, one surface 22a of the first bonding section 22 may be referred to as a "first bonding surface 22a", and one surface 23a of the second bonding section 23 may be referred to as a "second bonding surface 23a".

The first covering member 31 and the second covering member 32 are connected to each other by a plurality of connecting members 20 interposed therebetween to form the outer covering 30.

Here, the height (h) of the connection member 20 shown in FIG. 3B is the same as the outer diameter (d) of the coaxial cable 10 shown in FIG. 3A. That is, the height (h) of the connecting member 20 is, for example, 0.15 mm or more and 0.54 mm or less. As a result, as shown in FIG. 2, the inner surface 31a of the lower covering member 31 to which the first bonding surface 22a of the connecting member 20 is bonded comes into contact with the outer peripheral surface of the coaxial cable 10 without bonding. ing. Similarly, the inner surface 32a of the upper covering member 32 to which the second bonding surface 23a of the connecting member 20 is bonded is in contact with the outer peripheral surface of the coaxial cable 10 without being bonded.

However, as described above, the coaxial cable 10 is not fixed to the lower covering member 31 or the upper covering member 32. Therefore, when performing the terminal treatment of the flat cable 1A, the outer covering 30 can be easily removed. Further, the flexibility of the flat cable 1A is improved compared to the case where the coaxial cable 10 is fixed to the lower covering member 31 or the upper covering member 32.

As described above, the lower covering member 31 and the upper covering member 32 are connected to each other by the connecting member 20 interposed therebetween. Therefore, the inner surface 31a of the lower covering member 31 to which the first bonding surface 22a of the connecting member 20 is bonded is opposed to the inner surface 32a of the upper covering member 32 to which the second bonding surface 23a of the connecting member 20 is bonded. The spacing is the same or substantially the same as the height (h) of the connecting member 20. Since the height (h) of the connecting member 20 is the same as the outer diameter (d) of the coaxial cable 10, the facing distance between the inner surface 31a of the lower sheathing member 31 and the inner surface 32a of the upper sheathing member 32 is the same as that of the coaxial cable 10. The outer diameter (d) of No. 10 is also the same or substantially the same.

That is, the height (H) of the flat cable 1A is the height of the connection member 20 (=outer diameter of the coaxial cable 10)+thickness of the lower covering member 31+thickness of the upper covering member 32.

From another perspective, the height (H) of the flat cable 1A is lower than when an adhesive layer or adhesive tape is present between the coaxial cable 10 and the lower covering member 31 or the upper covering member 32. ing. In other words, the flat cable 1A is thinner than when an adhesive layer or adhesive tape is present between the coaxial cable 10 and the lower covering member 31 or the upper covering member 32.

<Manufacturing method>
Next, an example of a method for manufacturing the flat cable 1A will be described. As shown in FIG. 4(A), the connecting members 20 are arranged on the lower covering member 31 at predetermined intervals and fixed to the lower covering member 31. More specifically, the first bonding surface 22a of each connecting member 20 is bonded to the inner surface 31a of the lower covering member 31.

Thereafter, as shown in FIG. 4(B), the coaxial cable 10 is placed outside the connecting members 20 at both ends in the width direction and between the adjacent connecting members 20. Here, the interval (S) between adjacent connection members 20 is set in advance based on the pitch (P) of the coaxial cables 10. Specifically, the interval (S) is set to 0.15 mm or more and 0.60 mm or less. As a result, when the coaxial cables 10 are arranged between adjacent connection members 20, the coaxial cables 10 are lined up at a predetermined pitch (P).

From another perspective, the connection member 20 functions as a partition member that partitions the inner surface 31a of the lower covering member 31 on which the coaxial cable 10 is arranged. From another perspective, the connecting member 20 functions as a guide member that facilitates the work of arranging the coaxial cables 10 at a predetermined pitch (P).

Next, as shown in FIG. 4(C), the upper covering member 32 is placed over the coaxial cable 10 and the connecting member 20 to cover them. At the same time, the second bonding surface 23a of each connecting member 20 is adhered to the inner surface 32a of the upper covering member 32. Further, both widthwise ends of the lower covering member 31 and the upper covering member 32 are bonded to each other.

(Second embodiment)
Another embodiment of the flat cable of the present invention will be described. FIG. 5 is a schematic cross-sectional view of the flat cable 1B according to this embodiment. However, the flat cable 1B according to this embodiment has the same basic structure as the flat cable 1A according to the first embodiment. Therefore, a description of the same or substantially the same configuration as the flat cable 1A will be omitted, and only the differences from the flat cable 1A will be described.

As shown in FIG. 5, in the flat cable 1B, the height of the connecting member 20 is lower than the outer diameter of the coaxial cable 10. As a result, the outer covering 30 has irregularities.

More specifically, a plurality of recesses 40 extending along the coaxial cable 10 are formed in the lower covering member 31 and the upper covering member 32. The recesses 40 are formed above and below each connection member 20.

The flat cable 1B provided with the recess 40 as described above can be easily bent inward in the width direction or rolled up, compared to the flat cable 1A. Furthermore, since the volume of the connecting member 20 is reduced, it is expected that manufacturing costs will be reduced and flexibility will be improved.

The present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the gist thereof. For example, all or part of the plurality of coaxial cables 10 can be replaced with a power coaxial cable.

Further, there is also an embodiment in which a gap is provided between the connecting member 20 and the coaxial cables 10 on both sides of the connecting member 20. In such an embodiment, although the function of the connecting member 20 as a partition member or a guide member is reduced, the flexibility of the flat cable is further improved.

Furthermore, the core of the flat cable of the present invention is not limited to a coaxial cable. For example, all or part of the coaxial cable 10 in the above embodiment can be replaced with an insulated wire that does not include the outer conductor 13 or the outer insulator 14.

Note that the numerical values and materials described in this specification are merely examples, and can be changed as appropriate.

1A, 1B...Flat cable, 10...Coaxial cable (core), 11...Inner conductor, 11a...Metal wire, 12...Inner insulator, 13...Outer conductor, 13a...Metal wire, 14...Outer insulator, 20... Connection member, 21...Base, 21a...Top surface 21b...Bottom surface, 21c...Right side surface, 21d...Left side surface, 22...First bonding part, 22a...First bonding surface, 23...Second bonding part, 23a...Second bonding Surface, 30... External covering, 31... First covering member (lower covering member), 31a... Inner surface, 32... Second covering member (upper covering member), 32a... Inner surface, 40... Recessed portion, d... Outer diameter, P ...Pitch, S...Spacing, W...Width

Claims (8)

A plurality of cores having at least an insulator around the conductor and arranged in parallel at a predetermined pitch;
a plurality of connecting members arranged between the adjacent cores and extending along the longitudinal direction of the cores;
an outer covering covering the plurality of cores and the connecting member;
The outer covering is composed of a first covering member and a second covering member that face each other with the core and the connecting member in between,
Each of the connection members is fixed to the first sheathing member and the second sheathing member, while each of the cores is a flat cable that is not fixed to the first sheathing member and the second sheathing member. . The flat cable according to claim 1, wherein the connection member includes a first bonding surface bonded to the inner surface of the first covering member and a second bonding surface bonded to the inner surface of the second covering member. The flat cable according to claim 1, wherein the height of the connecting member and the outer diameter of the core are the same. The flat cable according to claim 1, wherein the height of the connecting member is lower than the outer diameter of the core. The connection member includes a base, a first adhesive part provided on one surface of the base and forming the first bonding surface, and a second adhesive part provided on the other surface of the base and forming the second bonding surface. The flat cable according to claim 2, further comprising an adhesive portion. 6. The flat cable according to claim 5, wherein the base of the connecting member is made of the same material as the insulator constituting the core. The flat cable according to claim 1, wherein the connecting member and the cores on both sides of the connecting member are in contact with each other. The flat cable according to claim 1, wherein a gap is provided between the connecting member and the cores on both sides of the connecting member.

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