JPH09134623A - Flat cable with shield and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat cable which can be manufactured in few manhours while keeping stable product accuracy and whose shielding layer is perfectly insulated and protected. SOLUTION: First of all, a linear conductor is wired on a base film 11, and a prescribed conductor circuit 13 and an earth circuit 14 outside of it are formed, and a shielding layer 21 is formed by applying conductive paint so as to contact with a projecting part 14a of this earth circuit 14. Next, a laminate film is formed by sticking a cover lay film 12 to this, and mutually continuously arranged circuit part 10 and shielding part 20 are formed by cutting them in a prescribed shape so that an end part of a shielding layer 21 is not exposed including the conductor circuit 13, the earth circuit 14 and the shielding layer 21. The shielding part 20 is superposed on the obverse and reverse of the circuit part 10 by folding back the shielding part 20, and a flat cable having a shield is manufactured by sticking the circuit part 10 and the shielding part 20 together by a double coated tape 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shielded flat cable with a shield and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a shielded flat cable with an electromagnetic shield,
For example, there is one described in JP-A-4-33211. As shown in FIG. 16, the shielded flat cable 50 includes a plurality of flat conductors 51 forming a conductor circuit and a flat conductor 52 forming an earth circuit sandwiched between two insulating films 53 and the earth circuit. Of the flat conductor 52 as a film is exposed on the surface of the insulating film 53, and a sheath layer 54 formed of an insulating film having an electromagnetic shield layer on the insulating film 53 is formed so as to come into contact with the exposed flat conductor 52. It is coated.

In the shielded flat cable 50 thus provided with the electromagnetic shield, the ends of the electromagnetic shield layer are exposed on both sides of the shielded flat cable 50. The parts come into contact with the housing of the device or other conductive circuits, which causes malfunction.

Therefore, in order to prevent the end of such an electromagnetic shield layer from being exposed, the insulating layer 6 as shown in FIG.
The cylindrical shield film 63 having the electromagnetic shield layer 65 on the inner surface of 4 is covered on the flat cable body 61 where the flat conductor 62 as the earth circuit as described above is exposed, and the shield film 63 is fixed to the flat cable body 61. However, the step of covering and fixing the tubular shield film 63 on the flat cable body 61 needs to be completely processed in a separate step.
Since such work often relies on manual work, there has been a problem that the number of man-hours increases, the manufacturing cost increases, and the product accuracy becomes unstable.

Therefore, an object of the present invention is to provide a shielded flat cable in which the shield layer is completely insulated and protected, and a manufacturing method thereof, which can be manufactured with a small number of steps while maintaining stable product accuracy. is there.

[0006]

In order to solve the above problems, the present invention forms a predetermined conductor circuit by wiring a linear conductor on a base film having an adhesive layer on the upper surface of an insulating film. At the same time, a linear conductor is laid outside the conductor circuit to form a ground circuit, and the base film is folded back outside the ground circuit so as to wrap around the conductor circuit portion formed on the base film. When, in the area corresponding to the conductor circuit on the base film,
A shield layer made of a conductive material electrically connected to the earth circuit is formed, and a cover lay film is laminated on the base film so as to sandwich the conductor circuit, the earth circuit and the shield layer to form a laminated film. Formed, this laminated film, the conductor circuit,
By including a ground circuit and a shield layer, and cutting into a predetermined shape so that the end of the shield layer is not exposed, a circuit part and a shield part that are connected to each other are formed, and the circuit part is wrapped, By folding back the shield part, the shield part is superposed on the front and back of the circuit part, and the circuit part and the shield part are bonded together by a predetermined adhesive means, whereby a shielded flat cable is manufactured. .

Further, a linear conductor is laid on a base film having an adhesive layer on the upper surface of the insulating film to form a predetermined conductor circuit, and the linear conductor is laid on the outside of the conductor circuit. When the base film is folded back outside the ground circuit so as to form a ground circuit and wrap around the conductor circuit portion formed on the base film,
A shield layer made of a conductive material electrically connected to the ground circuit is formed in a region of the base film corresponding to the conductor circuit, and the conductor circuit and the ground circuit portion are sandwiched except the shield layer. As described above, a coverlay film is partially adhered to the base film, the base film partially adhered to the coverlay film includes the conductor circuit, an earth circuit and a shield layer, and the shield layer is provided. By cutting into a predetermined shape so that the area including it is larger than the area of the shield layer, the conductor circuit and the ground circuit are sandwiched between the base film and the coverlay film, and the circuit film is interposed via the base film. A shield portion having the shield layer connected thereto is formed, and the shield portion is wrapped around the circuit portion. By folding back the shield part with the shield layer inside, the shield part is overlapped on the front and back of the circuit part, and the circuit part and the shield part are pasted together by a predetermined bonding means to form a shielded flat cable. It can also be manufactured.

Further, when forming the earth circuit, a linear conductor is laid on the base film so that a part of the earth circuit has a protruding portion protruding outward, and the earth circuit is protruded. A conductive paint may be applied on the base film to form a shield layer so as to contact the portion.

Further, a conductor foil is attached on the base film to form a shield layer so as to come into contact with the protrusion of the earth circuit, or the earth circuit is provided with no protrusion. It is also possible to form a shield layer by adhering a conductor foil having a protrusion that contacts only a part thereof onto the base film.

Further, when forming the earth circuit, wiring is arranged so that a part of the linear conductor forming the earth circuit is projected outward, and the linear conductor is formed in a mesh shape or folded back to be parallel. The shield layer may be formed by finely laying the wires.

An adhesive or a double-sided tape can be used as the adhering means.

[0012]

Embodiments will be described below with reference to the drawings. As shown in FIGS. 1 to 3, the shielded flat cable 1 includes an adhesive layer (not shown).
Between the base film 11 having an adhesive layer and the cover lay film 12 having an adhesive layer (not shown).
And both films 11 and 12 with the earth circuit 14 sandwiched therebetween.
It is composed of a circuit portion 10 in which the above is laminated and a shield portion 20 which is continuously provided on the circuit portion 10.

The conductor circuit 13 and the earth circuit 14 are
Each of the linear conductors is formed on the base film 11 by wiring, and the ground circuit 14 is formed.
Has a projecting portion 14a, a part of which protrudes, in a continuous portion of the circuit portion 10 and the shield portion 20.

The shield portion 20 is connected to the earth circuit 1
The shield layer 21 electrically connected to a part of 4 is sandwiched between the base film 11 and the coverlay film 12 and laminated, and the circuit part 1
0, a first shield portion 20a having substantially the same shape as the circuit portion 10, and a second shield portion 2 having substantially the same shape as the circuit portion 10 and continuously connected to the first shield portion 20a.
0b.

The shield layer 21 is the ground circuit 1
4 is formed by applying a conductive paint on the base film 11 so as to come into contact with the protruding portion 14a of No. 4, and the shield layer 21 does not have its end exposed.
It is completely sandwiched between the base film 11 and the coverlay film 12.

As shown in FIG. 2, the shielded flat cable 1 is superposed on the surface side of the circuit portion 10 by folding back the first shield portion 20a connected to the circuit portion 10 at the connecting portion. At the same time, as shown in FIG. 3, the second shield part 20b continuously provided to the first shield part 20a is folded back at the continuously provided part so that the second shield part 20b is superposed on the back surface side of the circuit part 10. The circuit section 10 and the first shield section 20a and the second shield section 20b are fixed to each other by a double-sided tape 30 as an adhesive means.

The shielded flat cable 1 configured as described above is manufactured as follows. First,
As shown in FIGS. 4A and 4B, the base film 11 having an adhesive layer (not shown) on the upper surface of the insulating synthetic resin film is set on a wiring device (not shown). Then, as shown in FIGS. 5 (a) and 5 (b), by laying a linear conductor on the base film 11 by the wiring device, the conductor circuit 13 and a protruding portion partially protruding to the outside are formed. A ground circuit 14 having 14a is formed.

Next, as shown in FIGS. 6 (a) and 6 (b),
The shield layer 21 is formed by applying a conductive paint on the base film 11 so as to contact the protruding portion 14a of the earth circuit 14. This shield layer 21
Is a first shield layer 21a forming the first shield part 20a and the first shield layer 2a.
1a and a second shield layer 21b which forms the second shield portion 20b and is continuous with 1a. Further, the first shield layer 21a and the second shield layer 21b have a size and shape that substantially cover the conductor circuit 13 and the ground circuit 14 in the region which will be the circuit portion 10 finally surrounded by the dashed line in the drawing. The first shield layer 21a is arranged so as to be line-symmetrical to the circuit unit 10 with respect to a two-dot chain line passing through the base end of the protruding portion 14a of the earth circuit 14, and the second shield layer 21a is provided. The layer 21b is the first shield layer 21a.
And the second shield layer 21b are arranged so as to be line-symmetrical to the first shield layer 21a with respect to a two-dot chain line passing through the connecting portion. That is, when the base film 11 is folded back along the two-dot chain line, as described above, the circuit portion 1 is finally obtained.
The first shield layer 21a and the second shield layer 21b are formed in regions corresponding to the conductor circuit 13 and the ground circuit 14 in the region of 0.

Next, as shown in FIGS. 7 (a) and 7 (b),
The cover lay film 12 is laminated on the base film 11 on which the conductor circuit 13, the earth circuit 14 and the shield layer 21 are formed to form a laminated film, and then the conductor circuit 13, the earth circuit 14 and the shield layer 21 are formed. By cutting the laminate film into a predetermined shape so as to include it, the circuit portion 10 and the shield portion 20 which are continuous with each other are formed (see FIGS. 8A and 8B). At this time, the circuit portion 10 and the first shield portion 20a and the second shield portion 20b have substantially the same width, and the first shield portion 20a and the second shield portion 20b have the same width.
It is necessary to cut into a shape slightly larger than the first shield layer 21a and the second shield layer 21b so that the ends of the shield layer 21a and the second shield layer 21b are not exposed.

Then, as shown in FIG.
After the cover lay film 12 at both ends of 0 is stripped off to expose the ends of the conductor circuit 13 and the ground circuit 14, the circuit section 10, the first shield section 20a, and the first section.
The first shield portion 20a is folded back at the connecting portion between the shield portion 20a and the second shield portion 20b, and the circuit portion 1
The second shield part 20b is superposed on the back side of the circuit part 10 on the front side of the
0 and the shield portion 20 are fixed to each other, the shielded flat cable 1 as shown in FIGS. 1 to 3 is completed.

The shielded flat cable 1 configured as described above is completely covered and protected by the base film 11 and the coverlay film 12 on which the ends of the shield layer 21 are laminated. No malfunction occurs due to the end of the shield layer 21 coming into contact with the housing of the device or another conductive circuit.

According to the manufacturing method as described above,
Since mechanical shield processing can be performed during the flat cable manufacturing process, the number of man-hours does not increase extremely and it is possible to automate a series of manufacturing processes, thus maintaining stable product accuracy. The effect is that you can do it.

10 to 12 show another embodiment. The difference between this embodiment and the above embodiment is that the shield portion 20 is not formed of a laminated film, that is, the coverlay film 12 is not attached on the base film 11. Since the other points are the same, the same components are designated by the same reference numerals and the description thereof will be omitted.

The manufacturing method will be described below.
It should be noted that the steps shown in FIGS. 4 to 6 in the above-described embodiment are the same in this embodiment, and thus the description thereof will be omitted. As shown in FIGS. 10A and 10B, the protruding portion of the ground circuit 14 is formed on the base film 11 on which the conductor circuit 13 and the ground circuit 14 are formed through the steps shown in FIGS. A coverlay film 12 is partially attached so as to cover only the circuit portion 10 except for 14a.

Next, as shown in FIGS. 11A and 11B, a base film in which a coverlay film 12 is partially attached so as to include the conductor circuit 13, the ground circuit 14 and the shield layer 21. By cutting 11 into a predetermined shape, the circuit portion 10 in which the conductor circuit 13 and the ground circuit 14 are sandwiched between the base film 11 and the coverlay film 12, and the base film 11 is formed on the circuit portion 10.
And a shield part 20 having the shield layer 21 connected to each other via the shield layer 21.

Then, as in the above-described embodiment, the coverlay film 12 at both ends of the circuit portion 10 is peeled off to expose the end portions of the conductor circuit 13 and the ground circuit 14, and then the circuit portion 10 and The first shield part 20a and the connecting part of the first shield part 20a and the second shield part 20b are folded back to expose the shield layer 21a of the first shield part 20a on the front surface side of the circuit part 10.
Exposed shield layer 21b of the second shield portion 20b
Is overlaid on the back side of the circuit section 10 and the double-sided tape 3
When the circuit portion 10 and the shield portion 20 are fixed at 0,
The shielded flat cable 2 as shown in 2 (a) and 2 (b) is completed.

The shielded flat cable 2 thus manufactured is the same as the shielded flat cable 1 described above.
Unlike the above, since the unnecessary cover lay film 12 is not attached to the shield portion 20, there is an effect that the overall thickness is reduced.

In each of the above-described embodiments, the shield layer 21 is formed by applying the conductive paint so as to contact the protruding portion 14a of the earth circuit 14, but the present invention is not limited to this. , For example, FIG.
As shown in (a), a conductor foil punched into a predetermined shape is attached onto the base film 11 so as to come into contact with the protruding portion 14a of the earth circuit 14, or as shown in FIG. Instead of providing a protrusion on the circuit 14, a protrusion 21c that contacts only part of the earth circuit.
It is also possible to form the shield layer 21 by laminating a conductor foil provided with on the base film 11.

Further, as shown in FIGS. 14 and 15, a part of the earth circuit 14 is laid out so as to extend to the region where the shield layer is formed, and the linear conductor of the extended portion is arranged within the region. The shield layer 21 can also be formed by finely wiring. In that case, FIG.
As shown in FIG. 5, a wiring pattern may be considered in which the linear conductors are laid in a mesh shape, or as shown in FIG. 15, the linear conductors are laid in parallel while being folded back.

As described above, when the shield layer 21 is formed by using a part of the earth circuit 14, the conductive paint and the conductor foil are not required, and the conductor circuit 13 and the earth circuit 1 are not required.
Since the shield layer 21 can be formed in the same process by the wiring device for forming 4, it is advantageous in terms of equipment and man-hours.

In each of the above-mentioned embodiments, the double-sided tape 30 is used as the adhesive means for fixing the circuit portion 10 and the shield portion 20, but the present invention is not limited to this, and for example, adhesive You may use agents etc.

[0032]

As described above, in the shielded flat cable of the present invention, since the end portion of the shield layer is completely covered and protected, the end portion of the shield layer is not covered with the casing of the device as in the conventional case. No malfunction occurs due to contact with other conductive circuits.

Further, according to the manufacturing method of the present invention, since the shield treatment can be mechanically performed during the manufacturing process of the flat cable, the number of man-hours does not extremely increase, and the series of manufacturing processes can be automated. As a result, it is possible to maintain stable product accuracy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment according to the present invention.

FIG. 2 is a sectional view taken along line XX of the above.

FIG. 3 is a cross-sectional view taken along line YY of the above.

FIG. 4 is a process drawing showing the manufacturing method of the above.

FIG. 5 is a process drawing showing the manufacturing method of the above.

FIG. 6 is a process drawing showing the manufacturing method of the above.

FIG. 7 is a process drawing showing the manufacturing method of the above.

FIG. 8 is a process drawing showing the manufacturing method of the above.

FIG. 9 is a process drawing showing the manufacturing method of the above.

FIG. 10 is a process drawing showing the manufacturing method of the other embodiment.

FIG. 11 is a process drawing showing the manufacturing method of the above.

FIG. 12 is a sectional view of the above.

FIG. 13 is a plan view showing another embodiment of the shield layer.

FIG. 14 is a plan view showing another embodiment of the shield layer.

FIG. 15 is a plan view showing another embodiment of the shield layer.

FIG. 16 is a perspective view showing a conventional example.

FIG. 17 is a perspective view showing another conventional example.

[Explanation of symbols]

 1, 2 Shielded flat cable 10 Circuit part 11 Base film 12 Coverlay film 13 Conductor circuit 14 Earth circuit 14a Projection part 20 Shield part 20a 1st shield part 20b 2nd shield part 21 Shield layer 21a 1st shield layer 21b 2nd Shield layer 21c Projection part 30 Double-sided tape

Claims (16)

[Claims] 1. A linear conductor is laid on a base film having an adhesive layer on the upper surface of an insulating film to form a predetermined conductor circuit, and a linear conductor is laid on the outside of the conductor circuit. A step of forming an earth circuit, and when the base film is folded back outside the earth circuit so as to wrap around the conductor circuit portion formed on the base film, it corresponds to the conductor circuit on the base film. A step of forming a shield layer made of a conductive material electrically connected to the ground circuit in the region; and a coverlay film attached on the base film so as to sandwich the conductor circuit, the ground circuit and the shield layer. A step of forming a laminated film together, the laminated film including the conductor circuit, the ground circuit and a shield layer, and a shield By cutting into a predetermined shape so that the end of the layer is not exposed, a step of forming a circuit part and a shield part that are connected to each other, and by folding the shield part so as to wrap the circuit part, A method of manufacturing a flat cable with a shield, comprising: stacking the shield part on the front and back of a circuit part and bonding the circuit part and the shield part together by a predetermined bonding means. 2. A linear conductor is laid on a base film having an adhesive layer on the upper surface of an insulating film to form a predetermined conductor circuit, and the linear conductor is laid on the outside of the conductor circuit. A step of forming an earth circuit, and when the base film is folded back outside the earth circuit so as to wrap around the conductor circuit portion formed on the base film, it corresponds to the conductor circuit on the base film. A step of forming a shield layer made of a conductive material electrically connected to the ground circuit in the region; and a portion on the base film so as to sandwich the conductor circuit and the ground circuit portion excluding the shield layer. The step of attaching the coverlay film to the conductor circuit, the ground circuit and the base film partially attached with the coverlay film. And a shield layer, and a circuit part in which the conductor circuit and the ground circuit are sandwiched between the base film and the coverlay film by cutting into a predetermined shape so that the region including the shield layer is larger than the region of the shield layer. And a step of forming a shield part having the shield layer connected to the circuit part via a base film, and by folding the shield part with the shield layer inside so as to wrap the circuit part. A method for manufacturing a shielded flat cable, comprising: stacking the shield part on the front and back of the circuit part, and bonding the circuit part and the shield part by a predetermined adhesive means. 3. When forming the ground circuit, a part of the ground circuit has a protrusion protruding outward.
3. A shield layer is formed by laying a linear conductor on the base film and applying a conductive paint on the base film so as to contact the protruding portion of the earth circuit. The method for manufacturing the shielded flat cable described in. 4. When forming the earth circuit, a part of the earth circuit has a protrusion protruding outward.
The wire conductor is laid on the base film, and a conductor foil is attached on the base film to form a shield layer so as to come into contact with the protruding portion of the ground circuit. Method for manufacturing the shielded flat cable described above. 5. The shielded flat according to claim 1, wherein a conductor foil having a protruding portion that comes into contact with only a part of the ground circuit is stuck on the base film to form a shield layer. Cable manufacturing method. 6. When forming the ground circuit, wiring is performed so that a part of the linear conductor that forms the ground circuit extends outward, and the linear conductor is finely wired. The method for manufacturing a shielded flat cable according to claim 1, wherein a shield layer is formed. 7. The method for producing a shielded flat cable according to claim 5, wherein the shield layer is formed by laying the linear conductors in a mesh shape. 8. The method for manufacturing a shielded flat cable according to claim 5, wherein the shield layer is formed by laying the linear conductors in parallel while folding them back. 9. The method for manufacturing a shielded flat cable according to claim 1, wherein an adhesive is used as the adhering means. 10. The method of manufacturing a shielded flat cable according to claim 1, wherein a double-sided tape is used as the bonding means. 11. A flat cable with a shield manufactured by the manufacturing method according to claim 1. 12. A flat cable with a shield manufactured by the manufacturing method according to claim 2. 13. A shielded flat cable manufactured by the manufacturing method according to claim 3. 14. A flat cable with a shield manufactured by the manufacturing method according to claim 4. 15. A flat cable with a shield manufactured by the manufacturing method according to claim 6. 16. A flat cable with a shield manufactured by the manufacturing method according to claim 7.