JPH0660023U - Shield flat wire - Google Patents

Abstract

(57) [Abstract] [Purpose] Between the shield tape layer and the ground wire by electrically connecting the ground wire and the shield tape layer integrally joined to the drain wire via the drain wire. Ground resistance is low and stable,
It is an object of the present invention to obtain a shielded flat electric wire that has an extremely large effect in preventing electrical noise from the outside or nearby components. [Constitution] The shielded flat electric wire 8 includes a plurality of conductors 1.
The desired conductor 1 among them is the ground wire 2, and the drain wire 3 is soldered to one or both of the exposed terminals 2a so that the drain wire 3 fits in the connector hole together with the other conductor.
This drain wire 3 bonded integrally and then soldered is wired on the insulating layer 4 and fixed on the same layer 4 with a metal foil tape 5 having a two-layer structure of a metal foil and an adhesive. , A shield tape layer 6 consisting of a plastic film on one side and a metal foil partially coated with an adhesive on the other side
Is wound around the insulating layer 4 with the adhesive surface inside and the metal foil surface directly contacting the drain wire 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a shielded flat electric wire used for wiring in electronic equipment such as a calculator, a printer, a copying machine, and a stereo. More specifically, it relates to the improvement of the electrical connection between the ground wire and the shield tape layer in the shield flat electric wire.

[0002]

[Prior art]

 Recently, flat wires have been frequently used as interface transmission lines for electronic devices, replacing the conventionally used twisted wires and coaxial wires. However, compared with the above-mentioned twisted wire, coaxial wire, etc., these flat electric wires have the drawback that electric noise from the outside or nearby parts cannot be prevented because they are not shielded to prevent noise. Therefore, especially for applications where noise prevention is required, it is usual to provide a shield layer and a ground wire on these flat electric wires to electrically connect them and use them as shielded flat electric wires capable of preventing noise.

Prior arts therefor include, for example, FIGS. 5 and 6 (Publication No. 3-55206), FIG. 7, FIG. 8 (Publication 3-55206), and FIG. 9 (Publication No. 2-5952). 1), FIG. 10 (JP-A-4-30598), and the like.

To put it in detail, FIG. 5 and FIG. 6 are a perspective view of a shielded flat electric wire and a schematic cross-sectional view taken along the line VI-VI showing one of such electrical connection methods, at intervals. In a flat electric wire including insulating layers 14a and 14b in which both ends of the conductor 12 are exposed and plastic films are laminated above and below the plurality of tape-shaped conductors 12 arranged in parallel, the conductor 12 can be identified from among the plurality of conductors 12 described above. Of the upper conductor 13a is folded back onto the insulating layer 14a, the grounding metal foil 15 is connected to the folded back conductor 13a, and the grounding metal foil 15 is further covered. A shield tape layer 16 is provided on the insulating layers 14a and 14b. Reference numeral 17 in the drawing is a reinforcing tape layer for facilitating attachment to a connector or the like.

That is, in this example, two flat conductors are overlapped as the ground wire 13, and one of the flat conductors 13 a is bent and brought into contact with the shield tape layer 16, so that the shield tape layer 16 and the ground wire 13 are connected to each other. That is, a flat electric wire 11 with a shield that is electrically connected to is formed.

Next, FIG. 7 and FIG. 8 show a top view of another embodiment of a conventional shield flat electric wire and a schematic sectional view of the line VIII-VIII. In the drawing, reference numeral 21 denotes a flat electric wire of this example, in which two ends of the conductors are exposed from above and below a plurality of tape-shaped conductors 22 arranged in parallel at intervals, and two plastic films 23a and 23b such as a polyester film are formed. It is composed of a laminated insulating layer 23. Furthermore, a reinforcing tape layer 24 is provided on the lower surface of the exposed conductor 22 for facilitating attachment to a connector or the like, and a polyester film, a metal foil, and an adhesive layer 3 are provided on the insulating layer 23. A shield tape 25 having a layered structure is wound with the adhesive layer inside. Reference numeral 26 is a grounding lead wire, one end of which is locally removed the adhesive layer on the inner surface of the shield tape 25 and is connected to the exposed metal foil by soldering or the like, and the other end of which is crimped. Has been installed.

Further, FIG. 9 shows a flat electric wire in which a common insulating layer 34 is coated on a plurality of rectangular conductors 33 forming a ground wire 32 and / or a signal wire arranged in parallel at intervals. This is an example of a shield flat electric wire in which a shield layer 31 with an insulating film 35 is provided on the outer layer of the layer 34 with the shield layer inside, and the ground wire 32 and the shield layer 31 are directly metallically connected by spot welding. .

FIG. 10 is a schematic sectional view of a shielded flat electric wire showing still another aspect of the electrical connection system. As shown in the figure, in this example, the conductor 43 and the ground wire 42 coexisting are stripped of the insulation 44, and the shield layer 41 and the ground layer 42 are electrically connected to each other with a conductive adhesive 45 interposed therebetween. It forms a connected flat electric wire with shield.

[0009]

[Problems to be solved by the device]

 However, these shielded flat electric wires, for example, in the ones of FIGS. 5 and 6 and FIG. 10, the shield layer and the ground wire are electrically connected to each other by contact (superposition) with an intervening conductor, or Since it is made of a conductive adhesive, there is a problem in that the ground resistance value between the shield wire and the ground wire varies, and as a result, the shield effect varies. For example, in the shielded flat electric wire shown in FIGS. 5 and 6, the ground resistance varies from 50 mΩ to 200 mΩ.

Further, in FIGS. 7 and 8, since the grounding lead wire 26 is attached, the number of steps for connecting the grounding lead wire 26 to the device when the user attaches this cable to the device Is required. Further, the man-hours required to wind the shield tape 25 on the insulating layer 23 of the flat electric wire and the man-hours required to attach the earth treatment lead wire 26 to the flat electric wire are large, and the finished thickness of the entire flat electric wire is large. There was a problem that it impaired the flexibility of.

Further, in FIG. 9, since the ground wire 32 and the shield layer 31 are directly connected by spot welding, heat during welding often damages the conductor 33 and the insulating layer 34, which are signal wires. It has a problem that it is difficult to use.

An object of the present invention is to obtain a shielded flat electric wire which can solve all of the above problems at once.

[0013]

Means for Solving the Problems A shielded flat electric wire according to the present invention comprises a plurality of tape-shaped conductors arranged in parallel at intervals and two insulating layers made of a plastic film above and below the film layer on the lower surface. With or without the conductor, both ends of the conductor are exposed and laminated, and a reinforcing tape layer for facilitating attachment to the connector is attached directly or through the film layer to the lower surface of the exposed conductor. In the flat wire provided, the desired conductor of the above conductors is used as the ground wire, and the drain wire is soldered to one or both exposed ends of the conductor so that the thickness fits in the connector hole together with other conductors. This drain wire soldered to the ground wire and then soldered to the ground wire is laid on the insulating layer to form a two-layer structure of a metal foil and an adhesive layer. It is fixed on the insulating layer with a metal foil tape, and the shield tape layer is composed of a metal foil with a plastic film on one side and an adhesive partially coated on the other side, with the adhesive layer inside and the metal foil drained. The ground wire and the shield tape layer are completely electrically connected through the drain wire by being wound on the insulating layer so as to be in direct contact with the wire and finishing by pressing if necessary. By obtaining a shielded flat wire, all of the above problems have been solved.

[0014]

[Action]

 In the shield flat electric wire of this invention, the ground wire integrally joined to the shield tape layer and the drain wire is completely connected electrically through the drain wire, so that the shield tape layer and the ground wire are connected together. It has a low ground resistance value, is stable, and has the function of extremely effectively shielding electrical noise from the outside or nearby components.

[0015]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 is a perspective view of an embodiment of a shield flat electric wire according to the present invention, FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1, FIG. 3 is a perspective view of another example of the shield flat electric wire according to the present invention, 4 is a sectional view taken along line IV-IV in FIG. In the drawings, 8 is a shielded flat electric wire of the present invention, which has an insulating layer 4 composed of two plastic films 4a and 4b of PET, polyimide or the like having a thickness of 0.05 mm to 0.1 mm and having a space therebetween. The upper and lower surfaces of the plurality of tape-shaped conductors 1 arranged in parallel with each other, with or without the lower film layer 4b (Figs. 3 and 4) (Figs. 1 and 2), both ends 1a of the conductor. It is constructed by exposing and laminating.

The shielded flat electric wire 8 of the present invention, as shown in each figure, selects a desired conductor 1 (single or plural) from the above-mentioned plurality of tape-shaped conductors, and makes this a ground wire 2, One (Figs. 3 and 4) or both ends 2a (Figs. 1 and 2) are integrally joined by soldering without damaging the conductor 1 or the insulating layer 4 in the vicinity of the drain wire 3. ing.

In this case, the conductor 1 used is a solder-plated rectangular copper wire having a width of about 0.3 mm to 1.0 mm and a thickness of 0.05 mm to 0.1 mm on the drain wire 3 to be soldered. A flat copper wire having a thickness of approximately 0.05 mm to 0.1 mm and plated with solder (plating thickness 1 μm to 5 μm) is preferably used. The reason why the drain wire 3 is thickly plated is to make the soldering joint more complete. For example, if the plating thickness is 1 μm or less, the soldering becomes incomplete, which is not preferable.

Further, as shown in the figure, a reinforcing tape layer 7 made of a polyimide film, a PET film or the like for facilitating mounting is provided on the conductor exposed portion 1a which is an insertion / removal portion into / from the insertion / removal type connector hole. It is provided on the lower surface of the film directly or through the film 4b, and its thickness is selected to be in the range of approximately 0.10 mm to 0.20 mm. The reason for this is that the reinforcing tape layer 7 itself has a thickness of 0.20 mm or more because it is inserted into the connector hole together with the exposed conductor portion 1a and the ground wire terminal portion 2a to which the drain wire 3 is soldered. However, depending on the connector hole gap used, insertion may not be possible. If the thickness is 0.10 mm or less, it has the function itself as the reinforcing tape layer 7 that it is too thin and facilitates insertion and removal. Because I don't get it.

Further, it should be noted that in the present invention, the total thickness (2a + 3a) of the ground wire terminal portion 2a and the drain wire terminal portion 3a soldered to the ground wire terminal portion 2a and the thickness of the conductor 1 are both. It is designed to fit comfortably in the spring holes of the connector at the same time.

As an example, in the case of using an insertable / extractable (bane type) connector having an insertion hole gap of 0.30 mm ± 0.05 mm, 0.17 mm thick reinforcing tape layers 7 and 0. A conductor 1 having a thickness of 10 mm and a drain wire 3 having a thickness of 0.05 mm are used. According to this, the total thickness (2a + 3a) of the ground wire terminal 2a and the drain wire terminal 3a soldered thereto is 0. 32 mm, on the other hand, the total thickness of the conductor terminal portion 1a and the reinforcing tape layer 7 is 0.27 mm, both of which are within the permissible range of the connector hole gap (0.25 mm to 0.35 mm), and are easily inserted simultaneously. Is possible. Further, according to this method, even if the spring allowable gap of the connector hole is small, it can be easily dealt with by appropriately selecting the thickness of the drain wire 3 and the thickness of the reinforcing tape layer 7.

In the present invention, especially when the use of the thin conductor 1 is required in order to increase the flexibility of the shield flat electric wire 8, the lower surface insulation is performed to prevent the conductor exposed portion 2a from being bent or bent. Only the upper insulating layer 4a is peeled off leaving the layer 4b to expose both ends of the conductor 1 (FIGS. 3 and 4). In this case as well, the thicknesses of the drain wire 3 and the reinforcing tape layer 7 are appropriately selected. It can be easily handled by combining them.

On the other hand, the drain wire 3 soldered to the ground wire 2 and integrally joined is wired on the insulating layer 4, and the metal foil tape 5 having a two-layer structure of a metal foil and an adhesive layer is used to form the insulating layer. Fixed on 4. In this case, the metal foil tape 5 has a thickness of 8 to 50 μm, and one having aluminum foil or copper foil coated with an adhesive is used. Further, the pressure-sensitive adhesive does not necessarily have to be electrically conductive, and may be an ordinary solvent-type, water-based emulsion-type or hot-melt-type pressure-sensitive adhesive.

Next, a shield tape layer 6 made of a metal foil tape having a three-layer structure having a plastic film layer on one surface and a partially coated adhesive layer on the other side, with the adhesive surface inside, and the metal foil The surface is wound on the insulating layer 4 under a slight tension so that the surface of the drain wire 3 is in direct contact with the drain wire 3 fixed on the insulating layer 4a, and if necessary, it is finished by pressing.

Here, as the metal foil forming the shield tape layer 6, an aluminum foil or a copper foil having a thickness of approximately 5 μm to 15 μm is used. Further, as the plastic film provided on one surface of the metal foil, a polyester film, a polyimide film or the like having a thickness of 5 μm to 15 μm is used. In addition, the adhesive applied to the other surface of the metal foil does not necessarily need to use a conductive adhesive, and an adhesive appropriately selected from ordinary solvent type, aqueous emulsion type and hot melt type adhesives. Is partially coated. The reason why the partial coating is performed is that the shield tape layer 6 is brought into direct contact with the drain wire 3 and the shield tape layer 6 is provided with flexibility. Furthermore, the total thickness of the shield tape layer 6 is preferably 10 μm to 30 μm (0.01 mm to 0.03 mm). This is because if the thickness is 30 μm or more, the thickness of the shield tape layer 6 is too large when wrapped around the insulating layer and lacks flexibility, and if it is 10 μm or less, a sufficient shielding effect cannot be obtained.

In the thus-obtained shield flat electric wire 8 of the present invention, the ground wire 2 integrally joined to the drain wire 3 and the shield tape layer 6 are electrically connected completely via the drain wire 3. Therefore, the ground resistance value between the shield tape layer 6 and the ground line 2 is stably maintained at 0 to 10 mΩ. In addition, when the connector 1 is attached to the plug-in / out connector, the conductor 1, the ground wire 2, and the drain wire 3 can be directly connected to the connector, so that the grounding process via the connector can be easily performed.

In addition to the above, according to the present invention, the conductor is a foil, an extremely thin tape can be used for both the insulating layer 4 and the shield tape layer 6, and the finished thickness of the main body can be suppressed to 0.3 mm or less. As a result, the flat electric wire 8 is highly flexible, and the thickness and material of the metal foil can be easily selected, and the flat electric wire 8 has excellent shielding characteristics.

[0027]

[Experimental example]

 The shielded flat wire (No. 1, No. 2) of the present invention shown in FIGS. 1, 2 and 3 and 4 and the shielded wire of the reference example of FIGS. 5 and 6 were prepared under the conditions shown in Table 1.

[0028]

[Table 1]

The evaluation results of the samples prepared above are shown in Table 2.

[0030]

[Table 2]

As can be seen from Table 2, the shield tape of the present invention has a thin finished thickness of 0.3 mm or less and is excellent in flexibility. When the thickness of the insertion / extraction part is 0.295 ± 0.045mm, which is 0.30 ± 0.05mm of the effective hole of the connector hole, and there is no difficulty in connector insertion / extraction, within the effective range of the hole gap. It was Regarding the ground resistance value between the shield layers, the ground resistance was 0 to 8 mΩ, which was extremely low and had stable performance.

[0032]

[Effect of device]

 The shielded flat wire of the present invention is thin and highly flexible and easy to use.At the end of the shielded flat wire, the ground wire and the shielded tape layer integrally joined to the drain wire are electrically connected via the drain wire. By connecting the cable to the cable completely, the ground resistance between the shield layer and the ground wire is low, and a stable shielded flat wire can be obtained, which is extremely effective in preventing electrical noise from the outside and nearby parts. .

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the shield flat electric wire of the present invention.

2 is a cross-sectional view taken along the line II-II in FIG.

FIG. 3 is a perspective view showing another example of the shielded flat electric wire of the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a perspective view showing a conventional example of a shield flat electric wire.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is a plan view showing another example of a conventional shield flat electric wire.

8 is a cross-sectional view taken along the line VIII-VIII of FIG.

FIG. 9 is a cross-sectional view showing still another example of a conventional shield flat electric wire.

FIG. 10 is a transverse cross-sectional view showing still another example of the conventional shield flat electric wire.

[Explanation of symbols]

 1 conductor 1a conductor end portion 2 ground wire 2a ground wire end portion 3 drain wire 3a drain wire end portion 4 insulating layer 4a upper plastic film 4b lower plastic film 5 metal foil tape 6 shield tape layer 7 reinforcing tape layer 8 shield flat electric wire

Claims (2)

[Scope of utility model registration request] 1. A plurality of tape-shaped conductors, which are arranged in parallel at intervals, are provided with an insulating layer made of two plastic films on both sides of the conductor, with or without the lower film layer. A flat electric wire, which is exposed and laminated, and a reinforcing tape layer for facilitating attachment to a connector is provided on the lower surface of the exposed conductor, either directly or through a film layer. , A desired conductor is used as a ground wire, and a drain wire is soldered to one or both of the exposed ends of the ground wire so that the drain wire and the other conductor can be accommodated in the connector hole integrally.
Then, this soldered drain wire is wired on the insulating layer and fixed on the same layer with a metal foil tape consisting of a two-layer structure of metal foil and adhesive, while a plastic film is on one side and an adhesive on the other A shield tape layer made of a partially coated metal foil is wound around an insulating layer such that the adhesive surface is on the inside and the metal foil is in direct contact with the drain wire. A shielded flat electric wire, wherein the layer is a flat electric wire which is electrically connected through a drain wire. 2. The shield flat electric wire according to claim 1, wherein a ground resistance value between the ground wire electrically connected via a drain wire and the shield tape layer is stably maintained at 0 to 10 mΩ.