JP2674820B2 - Automatic flat cable manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a flat cable useful as an electric wiring material for automobiles and the like.

[Summary of the Invention]

The present invention, when producing a flat cable in which a conductor layer is sandwiched by a pair of insulating films having an adhesive layer, a conductor pattern punched into a desired shape including a straight line portion and a curved portion is supported by an adhesive film. By subjecting the flat cable to a post-process in this state, a flat cable having a complicated shape is manufactured with high productivity.

[Conventional technology]

Conventionally, a so-called vinyl chloride-coated wire obtained by coating a copper wire or the like with vinyl chloride has been mainly used as an electric wiring material for automobiles. In particular, electric wiring materials used for automobiles have a very large number of lines of 600 to 800, which is a considerable weight.

By the way, in recent automobiles, interior equipment such as a power window (automatic opening / closing window) and an electromagnetic door lock system is standard equipment, and accordingly, more electric wiring materials are required. For example, the number of lines is 1000
It is not uncommon for vehicles to exceed the line, and the weight of the electric wiring material is considerably heavy. These potential wiring members are usually arranged on door panels, ceilings, etc., but as the number of electric wiring members increases, it becomes difficult to store them in a compact size, and their workability has deteriorated. For example, wire harness assembly and the like are all done manually.

Therefore, a flat cable has been proposed to solve these problems. The above flat cable is
It is formed by sandwiching a plurality of conductor layers constituting a wiring circuit from a pair of insulating films having adhesive layers formed on both sides thereof. Therefore, unlike, for example, a vinyl chloride-coated wire formed by coating the outer surface of a copper wire with vinyl chloride, it is possible to collectively form a conductor layer having a desired wiring pattern on the same film. Since it can be made thin and there is no need to insulate each conductor layer, the weight is light and the conductor occupancy rate is high.

By the way, the above-mentioned flat cable is usually manufactured by interposing and laminating a plurality of conductor layers and a pair of insulating films on which an adhesive layer is formed at the same time between rollers which are arranged to face each other.

However, in automobiles, etc., it is required to have not only a linear shape but also a complicated shape including a curved line because it is arranged in a place such as the inside of a door, which cannot be dealt with by the above-mentioned laminating method. . For this reason, in the case of a complicated shape including straight lines and curved lines, it is considered that the conductor layer is formed into a desired conductor pattern shape by etching, but the thickness of the conductor layer is 70 μm to 150 μm especially for electric wiring materials for automobiles. Since a thick film is used, it is very difficult to form a pattern accurately by etching, and it is time-consuming and the number of steps is large, resulting in a high cost.

[Problems to be solved by the invention]

Therefore, the method of the present invention has been proposed in view of such conventional circumstances, and is intended to manufacture a flat cable having a complicated shape with high accuracy and at low cost and with high productivity.

[Means for solving the problem]

In order to achieve the above object, the method for producing an automobile flat cable according to the present invention comprises a step of laminating an adhesive film on a conductor layer having a thickness of 70 μm to 150 μm, and at least the conductor layer so that the adhesive film is not divided. A step of punching into a conductor pattern of a desired shape, a step of laminating a first insulating film having an adhesive layer on the punched conductor layer, and a step of peeling off the adhesive film except for the conductor pattern of the conductor layer It is characterized by including a step of removing unnecessary portions, a step of laminating a second insulating film having an adhesive layer on the copied conductor pattern, and a step of thermocompression-bonding these insulating films. is there.

[Action]

When punching a conductor layer laminated to an adhesive film into a conductor pattern of a desired shape, not completely punching up to the adhesive film, but at least punching so that only the conductor layer is cut.
The adhesive film is not divided. of course,
Since the punched conductor layer is also adhered by the adhesive film, the conductor pattern is not separated. Therefore, in this state, it can be transported to the next process, which is easy to handle.

Further, the punched conductor layer is laminated on an insulating film having an adhesive layer having a higher adhesive strength than that of the adhesive film. Therefore, when the adhesive film is peeled off, a conductor pattern having a desired shape is copied on the insulating film. On the other hand, unnecessary parts other than the conductor pattern of the conductor layer are copied on the peeled adhesive film.

〔Example〕

Hereinafter, specific examples of a method for manufacturing a flat cable to which the present invention is applied will be described with reference to the drawings.

To manufacture the flat cable of this embodiment, first,
As shown in FIG. 1, an adhesive film (2) is laminated on one surface of the conductor layer (1).

For the conductor layer (1), a metal foil having excellent conductivity can be used, and among them, a copper foil having more excellent conductivity is suitable. Further, regarding the thickness of the conductor layer (1), since the flat cable is used for an electric wiring material for automobiles in particular, the thickness is preferably about 50 to 150 μm.

In this example, the conductor layer (1) had a thickness of 100 μm.
A copper foil with a thickness of 500 mm was used.

As the adhesive film (2), a material such as a polyethylene terephthalate film coated with an adhesive or an adhesive can be used. The adhesive film (2) serves as a support for preventing the conductor pattern (1) from being separated from the adhesive film (2) when the conductor layer (1) is punched into a conductor pattern of a desired shape in a later step. Therefore, because of the clearance setting of the cutting edge at the time of punching and the strength of the waist as a support,
A 100 μm thick polyethylene terephthalate film is preferred. On the other hand, the adhesive applied on the polyethylene terephthalate film is also for temporarily fixing the conductor pattern punched in a later step so as not to separate, so that the peel strength is not so high and the adhesive An adhesive with high cohesive strength without transfer is desirable.

In this example, the adhesive film (2) is 38
A polyethylene terephthalate film (2a) with a thickness of μm and a width of 500 mm is used, on which an acrylic rubber adhesive (2a)
b) was applied to a thickness of 25 μm. Here, the above adhesive (2
For b), a peel strength of about 20 to 100 g was used.

To laminate the adhesive film (2) on one surface of the conductor layer (1), a roll laminator device composed of a pair of rollers (3) and (4) arranged to face each other as shown in FIG. 1 is used. . Here, the conductor layer (1)
And the adhesive film (2) at the same time on these rollers (3),
During (4), a linear pressure of 3 kg / cm and a speed of 4 to 5 m / sec were sent out, and 60 to
It was laminated by these rollers (3) and (4) by applying heat of 80 ° C.

Next, as shown in FIG. 2, the conductor layer (1) and the adhesive film (2) are laminated on the four corners of the laminate at the four steps of forming the conductor pattern and extracting the outer shape in the next step and the final step. Positioning holes (5a), (5b), (5c) for positioning the laminate of 1) and the adhesive film (2),
Drill (5d).

In this embodiment, the positioning holes (5a), (5b),
Although (5c) and (5d) are provided at the four corners of the laminate, only two holes may be provided on the diagonal line if the positioning can be reliably performed.

Next, as shown in FIG. 3, the conductor layer (1) is punched out to form a conductor pattern (6) having a desired shape including straight lines and curved lines.

To form the conductor pattern (6) by punching, for example, a mold having a plurality of cutting edges (7) arranged corresponding to the desired conductor pattern (6a) as shown in FIG. 4 is used. It When the conductor pattern (6a) is formed with the above mold, the cutting blade (7) is completely attached to the adhesive film (2).
Conductor pattern (6a) when cut so as to cut up to
Therefore, so-called half blanking is performed so that at least only the conductor layer (1) is cut.

As a result, the conductor pattern (6a) having a desired shape and the unnecessary portion (1a) other than the conductor pattern (6a) are formed.
The cut conductor pattern (6a) and the unnecessary portion (1a) are attached to the adhesive film (2) and are not separated. In addition, in this embodiment, positioning holes (5a), (5b), (5c), (5d) were formed in the four corners of the laminate of the conductor layer (1) and the adhesive film (2) in the previous step. Therefore, the conductor pattern (6) can be formed at a desired position.

Regarding the cutting position of the cutting blade (7), it is possible to cut to a position where the adhesive film (2) is not completely cut, but the adhesive film (2) is cut in a later step. Since it plays the role of a support for the conductor pattern (6), its limit is naturally limited. To form the conductor pattern (6),
In addition to the method using the above mold, for example, a Viku mold may be used.

Next, as shown in FIGS. 5 and 6, a first insulating film (9) having an adhesive layer (8) is laminated on the punched conductor layer (1).

As the first insulating film (9), a material having excellent insulating property and flexibility is suitable, and for example, a polyethylene terephthalate film or the like is desirable. Regarding the film thickness, 38-75 μm that satisfies both insulation and flexibility
The degree is preferred.

In this example, the first insulating film (9) was used.
A polyethylene terephthalate film having a thickness of 50 μm is used. Holes (10a), (10b), (10c) for forming terminal portions are formed at positions corresponding to the terminals of the conductor pattern (6a), and Positioning holes (5a), (5b), (5
Holes (11) are also provided at the positions corresponding to (c) and (5d).
A), (11b), (11c) and (11d) were drilled. In addition, another same material as this was produced and used as a second insulating film. Of course, these perforating processes are performed before laminating on the conductor layer (1).

On the other hand, as the adhesive layer (8) applied to the first insulating film (9), a thermosetting adhesive is suitable because heat is applied by a hot press or the like in a later step.
Further, the film thickness of the adhesive layer (8) is preferably 30 to 75 μm which satisfies both the adhesive force and the insulating property. In this example, a thermosetting adhesive having the following composition was used for the adhesive layer (8), and a flame retardant was added to this to obtain flame retardancy.

Thermosetting adhesive composition 100 parts by weight of saturated polyester resin (manufactured by Unitika Ltd .; trade name UE-3220) 70 parts by weight of aluminum hydroxide (manufactured by Showa Metal Co., Ltd .; trade name of Heidilite H42M) 30 parts by weight of antimony trioxide Tolylene diisocyanate 1 part by weight (manufactured by Nippon Polyurethane Company; trade name: Coronate L) 100 parts by weight of methyl ethyl ketone 100 parts by weight of toluene On the conductor layer (1), the first insulating film (9) having the adhesive layer (8) of the above composition is provided. To laminate to
Lamination was performed for 5 to 10 seconds by hot pressing at a temperature of 120 to 140 ° C and a pressure of 10 to 15 kg / cm ² .

The adhesive layer (8) is not limited to this, and may be, for example, a thermoplastic adhesive applied. Further, a thermosetting adhesive and a thermoplastic adhesive are sequentially applied on the insulating film. It may be a two-layer structure formed by In particular, if the two-layer structure is used, the thermosetting adhesive layer does not melt and flow out during thermocompression bonding, so insulation on the conductor layer is ensured and a flat cable with no unevenness in appearance is obtained. To be

Next, as shown in FIG. 7, the adhesive film (2)
Was removed to remove unnecessary portions (1a) other than the conductor pattern (6a) having a desired shape.

As a result, the desired conductor pattern (6a) is copied on the first insulating film (9). On the other hand, the unnecessary portion (1a) is peeled off together with the adhesive film (2). Here, since the adhesive (2b) having a relatively low peel strength is used for the adhesive film (2), the adhesive film (2) can be easily peeled from the first insulating film (9). Become.

Next, as shown in FIGS. 8 and 9, the above-mentioned second insulating film (12) produced simultaneously with the first insulating film (9) on the copied conductor pattern (6) of the desired shape. )
Laminate.

As a result, the conductor pattern (6) is sandwiched between the first insulating film (9) and the second insulating film (12). In addition, this second insulating film (1
Also in 2), since the terminal portion forming holes (not shown) are formed at the positions corresponding to the terminal portions of the conductor pattern (6), these terminal portion forming holes (10a), (10
Both surfaces of the conductor pattern (6) are exposed in b) and (10c).

The second insulating film (12) has the first
Thermosetting adhesive (13) applied to the insulating film (9)
Are similarly applied.

Next, as shown in FIG. 10, these insulating films (9) and (12) are thermocompression bonded.

In this embodiment, a hot press is used for thermocompression bonding, and
The temperature was 150 ° C, the pressure was 15 to 20 kg / cm ² , and the processing time was 60 minutes. As a result, the adhesive layers (8) and (13) of the first insulating film (9) and the second insulating film (12) are softened and melted, and the first insulating film (9) and the second insulating film (12) The insulating film (12) was bonded. Of course, conductor pattern (6)
Was also firmly sandwiched by the first insulating film (9) and the second insulating film (12).

Finally, the conductor pattern (6) sandwiched between the first insulating film (9) and the second insulating film (12).
The laminate is cut out so as to correspond to the shape of the conductor pattern (6).

As a result, as shown in FIG. 11, the flat cable (14) having the conductor pattern (6) exposed at the positions corresponding to the terminal portion forming holes (10a), (10b), (10c) is completed. The exposed portions of the conductor pattern (6) become the external terminals (15a), (15b), (15c). Further, also in this outer shape cutting process, the first insulating film (9) and the second insulating film (9)
Since the positioning holes are formed at each of the four corners of the insulating film (12), there is no fear that the outline extraction position cannot be accurately determined.

Flat cable obtained as above (14)
Unlike a so-called vinyl chloride coated wire in which a copper wire or the like is coated with vinyl chloride, has a high conductor occupancy rate, is thin, lightweight, and has flexibility. Therefore this flat cable (14)
By disposing as an electric wiring member inside a door of an automobile or the like, a large amount of electric wiring member can be stored in the same space as the conventional one. Also, especially the above flat cables (14)
Since it is thin and flexible, it can be stored compactly, and its wiring work can be performed easily. Therefore, the wiring work can be automated, and the cost can be significantly reduced in the component assembly process.

〔The invention's effect〕

As is clear from the above description, according to the aspect of the present invention, a flat cable having a complicated shape including a straight line and a curved line can be accurately manufactured at low cost without taking any complicated steps. .

Further, in the method of the present invention, at least the conductor layer is punched out so that the adhesive film is not divided when the conductor layer is punched and patterned, so that the punched conductor pattern is transported to the next step or the like. In addition, the handling property is excellent even in the peeling process of the adhesive film.

Further, the flat cable obtained by the method of the present invention has a complicated shape including straight lines and curved lines, is thin and lightweight, and has a high conductor occupancy. Therefore, if this flat cable is used as an electric wiring material for automobiles or the like, its industrial value is great.

[Brief description of the drawings]

1 to 11 each show a manufacturing process of a flat cable to which the present invention is applied, FIG. 1 is an enlarged sectional view of an essential part showing a process of laminating an adhesive film on a conductor layer, and FIG. 2 is a positioning diagram. It is a schematic perspective view which shows a hole processing process. FIG. 3 is a schematic perspective view showing a conductor pattern forming step, and FIG. 4 is an enlarged sectional view of an essential part showing an example of a punching method for forming the conductor pattern. FIG. 5 shows the first
FIG. 6 is an enlarged sectional view of an essential part showing the step of laminating the insulating film in FIG. 6, and FIG. 6 is a schematic perspective view thereof. FIG. 7 is an enlarged sectional view of an essential part showing the peeling process of the adhesive film. 8th
The figure is an enlarged cross-sectional view of an essential part showing the laminating step of the second insulating film, and FIG. 9 is a schematic perspective view thereof. Tenth
The figure is an enlarged cross-sectional view of an essential part showing a thermocompression bonding process. FIG. 11 is a plan view showing a flat cable having an outer shape. 1 ... Conductor layer 2 ... Adhesive film 6,6a ... Conductor pattern 9 ... First insulating film 12 ... Second insulating film 14 ... Flat cable

Claims (1)

(57) [Claims] 1. A step of laminating an adhesive film to a conductor layer having a thickness of 70 μm to 150 μm, a step of punching at least the conductor layer into a conductor pattern having a desired shape so as not to divide the adhesive film, and the punching. A step of laminating a first insulating film having an adhesive layer on the conductor layer; a step of peeling off the adhesive film to remove unnecessary portions other than the conductor pattern of the conductor layer; A method for producing a flat cable for an automobile, comprising: a step of laminating a second insulating film having an adhesive layer on the substrate; and a step of thermocompression-bonding these insulating films.