JP3988027B2 - Flat cable and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flat cable and a manufacturing method thereof.
[0002]
[Prior art]
A tape electric wire in which a conductor is covered with an insulating tape is widely used in various technical fields including electronic equipment because it can be thinned.
[0003]
This flat cable is formed as follows. First, as shown in FIG. 4, the continuous forming apparatus 1 is used to continuously supply upper and lower insulating tapes 2 and 3 and a plurality of conductors 5 arranged and supported on the support roller 4 at a predetermined pitch. The insulating tape conductor 30 is formed by passing between the pair of rotating rollers 6 and 7 and thermocompression bonding. Then, immediately before the insulating tape conductor 30 is wound by the roll 32, the remaining portions of both side portions 31 in the longitudinal direction of the insulating tape conductor 30 are removed by the cutters 33 and 34. Here, cut portions 8 are formed at a predetermined interval on the insulating tape 2 on the upper surface, and the conductor 5 is exposed at this portion.
[0004]
Then, as shown in an enlarged view of the main part of the flat cable in FIG. 5, after the insulating tape conductor 32 wound around the roll 32 is developed, the flat cable is formed by sequentially punching out. At this time, by making the punched portion an intermediate portion of the cut portion 8, the conductor 5 is exposed at both ends, and the exposed conductor region is used to prevent breakage of the exposed conductor and to reinforce the end portion of the flat cable. A reinforcing plate (11) is attached to the back side of the. Usually, this insulating tape has a constant width and is of a straight type.
[0005]
By the way, in recent years, along with the miniaturization of elements, the miniaturization of pitch is also progressing, and recently, a conductor pitch of 0.3 mm or less has been required.
[0006]
When the pitch becomes narrow in this way, the width W of the terminal portion needs to be within a predetermined range in order to connect the terminal with the connector. For example, in the case of an insulating conductor tape having a conductor pitch of 0.3 mm, the distance W1 from the outermost conductor 5 to the outside of the insulating tape 3 is usually required to be about 0.2 mm from the connector fitting property. Yes.
[0007]
[Problems to be solved by the invention]
However, if a straight-type flat cable structure as described above having a narrow pitch is used, there is a problem that it is not possible to obtain electrical characteristics satisfying standards such as underwater withstand voltage.
As described above, the conventional straight type tape structure cannot obtain sufficient electrical characteristics, so it is difficult to satisfy the connector specification of a narrow pitch type of about 0.3 mm, and it matches the dimensional tolerance for the narrow pitch connector. It was impossible to produce an FFC.
[0008]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a fine-pitch flat cable satisfying electrical characteristics, particularly underwater withstand voltage characteristics.
[0009]
[Means for Solving the Problems]
Therefore, the flat cable according to the present invention includes a covering portion including a plurality of conductors arranged at an arrangement pitch of 0.3 mm or less and an insulating tape that integrally fixes the conductors so as to be sandwiched from both sides. at least longitudinal one of the insulating tape in the direction one end constitutes a terminal portion which is peeled by a predetermined length, each end from the end in the width direction of the insulating tape in the cover portion of the part as the distance in the guide member or closest to the part becomes wider than the distance from said each end portion in the width direction of the insulating tape in the guide member or closest to the respective end portions of the terminal portion The distance from each end in the width direction of the insulating tape in the terminal portion to the conductor closest to each end is not less than 0.17 mm and does not exceed 0.25 mm. The distance from each end in the width direction of the insulating tape to the conductor closest to each end is 0.25 mm or more. The distance from each end of the insulating tape in the width direction of the insulating tape to the conductor closest to each end is currently set to 0.2 ± 0.03 mm or less as a standard . It has preferred, the terminal portion is provided with a reinforcing plate, the reinforcing plate is characterized by being formed so as to overlap a portion of the cover portion.
In the method of the present invention, a plurality of conductors arranged at an arrangement pitch of 0.3 mm or less are integrally fixed with an insulating tape so as to be sandwiched from both sides, and the conductors are arranged on one side every predetermined length. A step of forming a flat cable having an exposed portion that is exposed to the wire, a cutting step of cutting the exposed portion into a predetermined length so that the exposed portion becomes a terminal portion, and cutting the end portion in the width direction of the insulating tape. formed to look contains a reducing condensation step of Genchijimi the width of the insulating tape at both ends of the width direction of the terminal portion, each end from the end in the width direction of the insulating tape in the terminal portion The distance to the conductor closest to the portion is not less than 0.17 mm and does not exceed 0.25 mm, and the insulating tape in the covering portion where both sides of the conductor are sandwiched by the insulating tape From each end in the width direction The distance to the conductor closest to each end is 0.25 mm or more .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment)
Hereinafter, a flat cable according to an embodiment of the present invention will be described.
As shown in FIG. 1 and FIG. 3 (FIG. 3 is a cross-sectional view of FIG. 1), this flat cable is made of a tin-plated annealed copper foil 5 having a width W = 0.20 mm and a thickness t = 0.035 mm. Covering part 200 sandwiched between insulating tapes 2 and 3 made of PET resin through an adhesive layer made of a flame-retardant adhesive (thickness 0.03 mm) and covered on both sides with insulating tapes 2 and 3 The distance W2 between the insulating tapes on the side portion of the terminal portion is formed to be larger than the distance W1 between the insulating tapes on the side portion of the terminal portion 100 where one surface is exposed.
[0011]
That is, in the covering portion, the distance W2 from the end portion of the outermost conductor 5 to the outer end of the insulating tape is such that the end portion of the outermost conductor 5 in the terminal portion 100 extends from the outer end of the insulating tape. It is formed to be larger than the distance W1.
[0012]
A reinforcing plate 11 made of PET resin (polyethylene terephthalate) is provided on the back surface of the insulating tape 3 on the back surface side of the terminal portion 10. This is because it is used as a reference in the width direction and the thickness direction during insertion into the connector and fitting into the terminal.
[0013]
Next, a method for manufacturing the flat cable will be described.
First, by using the continuous forming apparatus 1 shown in FIG. 4, a pair of upper and lower insulating tapes 2 and 3 and a plurality of conductors 5 arranged and supported at a predetermined pitch on the support roller 4 are continuously supplied to a pair of The insulating tape conductor 30 is formed by passing between the rotating rollers 6 and 7 and thermocompression bonding. Then, immediately before the insulating tape conductor 30 is wound by the roll 32, the remaining portions of the both side portions 31 in the longitudinal direction of the insulating tape conductor 30 are removed by the cutters 33 and 34, and the winding is formed. Here, cut portions 8 are formed at predetermined intervals on the insulating tape 2 on the upper surface, and the conductor 5 is exposed at this portion. (Fig. 2 (a))
[0014]
And after unfolding the insulating tape conductor 30 wound up by the roll 32, as shown in FIG.2 (b) by punching out sequentially, a flat cable is formed. At this time, by making the punched portion an intermediate portion of the cut portion 8, the conductor 5 is exposed at both ends, and the exposed conductor region is used to prevent breakage of the exposed conductor and to reinforce the end portion of the flat cable. A reinforcing plate (11) is attached to the back side of the plate.
[0015]
And as shown in FIG.2 (c), in the terminal part 100 in which this reinforcement board (11) exists, distance W1 = 0.2mm from the edge part of the conductor 5 of the outermost part to the outer end of an insulating tape, The insulating tape at the terminal portion is reduced in width so that the distance W2 from the end of the outermost conductor 5 in the covering portion 200 to the outer end of the insulating tape is equal to or greater than 0.25 mm.
[0016]
This step of reducing the width can be easily performed by cutting with a cutter. Further, the width may be reduced by punching.
[0017]
Further, when cutting with a cutter, by cutting in the region where the reinforcing plate 11 exists, it is possible to suppress the occurrence of cutting flash and to obtain a good cut surface.
[0018]
The covering part at the center of the flat cable with a length of about 3m thus formed is immersed in water for about 2m for 1 hour, and AC1000V is applied between the conductor and water for 1 minute, and then the presence or absence of dielectric breakdown is confirmed. As a result, all 10 samples were free from dielectric breakdown, and good characteristics could be maintained.
[0019]
(Comparative example)
Next, as a comparative example, the insulating tape is wound with a cutter at the time of winding so that the distance W2 from the end of the outermost conductor 5 to the outer end of the insulating tape is 0.2 mm for both the covering portion and the terminal portion. The whole was excised.
[0020]
The covering portion at the center of the flat cable having a length of about 3 m formed as described above was immersed in water for about 1 m over about 2 m as in the previous embodiment, and AC 1000 V was applied between the conductor and water for 1 minute. Thereafter, the presence or absence of dielectric breakdown was confirmed. As a result, 5 out of 10 samples caused dielectric breakdown.
[0021]
As is clear from these comparisons, according to the present invention, it is possible to obtain a highly reliable flat cable that satisfies both electrical characteristics and connector fitting properties.
[0022]
In the conventional straight type tape structure, it was difficult to satisfy the connector specification of a narrow pitch type of 0.3 mm or less. However, according to the present invention, the insulating tape width is increased in the covering portion. FFCs that match the dimensional tolerances for narrow pitch connectors can be manufactured.
[0023]
Thus, in the flat cable of the present invention, in the terminal portion, the width of the insulating tape from the outermost conductor is minimized to satisfy the connector fitting property, and the insulating tape in the region other than the terminal portion is used. It is characterized by being wide enough to satisfy the electrical characteristics.
[0024]
Furthermore, in the above-described embodiment, the margin width is adjusted and reduced after punching (cutting) at the terminal portion. However, the margin width may be adjusted prior to cutting. Good.
[0025]
In the above-described embodiment, the 0.3 mm pitch flat cable has been described. However, the present invention can also be applied to a fine pitch of 0.3 mm or less.
[0026]
Moreover, in the said embodiment, although tin plating soft copper foil was used as a conductor, conductors, such as a tin plating phosphor bronze foil and copper foil, are applicable, without being limited to this.
[0027]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain a highly reliable flat cable excellent in electrical characteristics and connector fitting property even in a narrow pitch flat cable.
[Brief description of the drawings]
FIG. 1 is a top view showing a flat cable according to an embodiment of the present invention.
2 is a diagram showing a manufacturing process of a flat cable according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a flat cable according to an embodiment of the present invention. FIG. It is.
FIG. 5 is a top view showing a conventional flat cable.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 2, 3 Insulating tape 4 Support roller 5 Conductor 6, 7 Rotating roller 30 Insulating tape conductor

Claims (3)

Including a covering portion composed of a plurality of conductors arranged at an arrangement pitch of 0.3 mm or less and an insulating tape that integrally fixes the conductors so as to be sandwiched from both sides;
One end of the insulating tape at least one end in the longitudinal direction of the covering portion constitutes a terminal portion separated by a predetermined length,
The distance from each end portion in the width direction of the insulating tape in the covering portion to the conductor closest to the respective end portion is determined from each end portion in the width direction of the insulating tape in the end portion to each end. Configured to be wider than the distance to the conductor closest to the part,
The distance from each end portion in the width direction of the insulating tape in the terminal portion to the conductor closest to each end portion is not less than 0.17 mm and does not exceed 0.25 mm,
A flat cable characterized in that a distance from each end portion in the width direction of the insulating tape in the covering portion to the conductor closest to each end portion is 0.25 mm or more. The flat cable according to claim 1, wherein the terminal portion includes a reinforcing plate on the insulating tape side, and the reinforcing plate is formed so as to overlap a part of the covering portion. A plurality of conductors arranged at an arrangement pitch of 0.3 mm or less are integrally fixed with an insulating tape so as to be sandwiched from both sides, and the exposed portion is exposed on one surface every predetermined length. Forming the flat cable, a cutting step of cutting to a predetermined length so that the exposed portion becomes a terminal portion, and forming the end portion in the width direction of the insulating tape to form the end portion A reduction step of reducing the width of the insulating tape at both ends in the width direction of
The distance from each end in the width direction of the insulating tape in the terminal portion to the conductor closest to each end is 0.17 mm or more and does not exceed 0.25 mm, and the conductor The distance from each end in the width direction of the insulating tape to the conductor closest to each end in the covering portion sandwiched between the both sides of the insulating tape is 0.25 mm or more, To manufacture a flat cable.

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