JP2021153201A - Electromagnetic wave shield tape, method for manufacturing the same, and electromagnetic wave shield cable - Google Patents

Abstract

To reduce problems in manufacturing of shield cables.SOLUTION: There is provided an electromagnetic wave shield tape which includes a metal layer and a resin layer and has Toyo value of 0.06 or less.SELECTED DRAWING: None

Description

The present invention relates to an electromagnetic wave shielded tape, a method for manufacturing the same, and an electromagnetic wave shielded cable. Specifically, the present invention relates to an electromagnetic wave shielded tape in which a specific warp is suppressed, a method for manufacturing the same, and an electromagnetic wave shielded cable.

In recent years, interest in global environmental issues has been increasing worldwide, and environmentally friendly vehicles equipped with secondary batteries such as electric vehicles and hybrid vehicles are becoming widespread. In many of these automobiles, a method is adopted in which the direct current generated from the mounted secondary battery is converted into an alternating current via an inverter, and then the necessary electric power is supplied to the alternating current motor to obtain a driving force. Electromagnetic waves are generated due to the switching operation of the inverter. Since electromagnetic waves interfere with reception of in-vehicle audio equipment and wireless equipment, measures have been taken to shield the electromagnetic waves by housing the inverter or the inverter together with the battery or motor in a metal case (Japanese Patent Laid-Open No. 2003). -285002 publication).

Countermeasures by this electromagnetic wave shield are also taken for electric wires. A typical structure of an electromagnetic wave shielded cable is shown in FIG. Wrap the electromagnetic wave shield tape around multiple cables. More specifically, the cable is arranged so that the longitudinal direction of the cable and the longitudinal direction of the electromagnetic wave shielding tape are parallel to each other. Then, the electromagnetic wave shield tape is wound so that the electromagnetic wave shield tape forms a cylinder about the longitudinal direction. Then, both edges of the electromagnetic wave shield tape are joined. Further, the electromagnetic wave shield tape is a laminated body, and includes at least a metal layer and a resin layer. Normally, the electromagnetic wave shielding tape is wrapped so that the resin layer is on the outside (and the metal layer is on the inside).

Japanese Unexamined Patent Publication No. 2003-285002

In the process as described above, when the shielded cable is formed, the desired shape cannot be obtained, which often causes problems related to productivity or quality. Therefore, an object of the present invention is to provide a shield tape capable of stably obtaining a desired cylindrical shape in a process of processing into a cylindrical shape.

As a result of diligent research by the present inventor, it has been found that there is a problem in the warped state of the shield tape as a cause of not obtaining the desired shape. More specifically, the warp of the shield tape was in the direction opposite to the winding direction (upward in FIG. 2). It has been found that when the tape is wound in such a state, the joint portions on both edges of the tape do not join, resulting in problems related to productivity or quality. Then, it was found that such a defect can be reduced by adjusting the state of this warp.

Based on the above findings, the present invention is specified in one aspect as follows.
(Invention 1)
An electromagnetic wave shield tape that has a metal layer and a resin layer and has a Toyo of 0.06 or less.
(Invention 2)
The electromagnetic wave shielding tape of Invention 1 having a curl of 0.4 or less.
(Invention 3)
Electromagnetic wave shielding tape of invention 1 or 2 for covering electric wires.
(Invention 4)
The metal layer
It has a Cu layer or a Cu alloy layer, or
A Cu layer or a Cu alloy layer and a Sn layer or a Sn alloy layer are provided.
The electromagnetic wave shielding tape according to any one of Inventions 1 to 3.
(Invention 5)
The cable coated with the electromagnetic wave shielding tape according to any one of Inventions 1 to 4.
(Invention 6)
The method for manufacturing an electromagnetic wave shielding tape according to any one of Inventions 1 to 4.
Including the process of laminating the metal foil and the resin film
The method in which the tension ratio (tension of the metal foil / tension of the resin film) is 3.0 or less in the laminating step.

In one aspect, the present invention suppresses Toyo to 0.06 or less. As a result, it is possible to suppress a problem that occurs when the electromagnetic wave shielding tape is wrapped around the cable.

In another aspect, the electromagnetic wave shielding tape of the present invention has a curl of 0.4 or less. This makes it easy to wrap the electromagnetic wave shielding tape around the cable.

Represents a state in which a cable is covered with a shield tape (conventional technique). Indicates the state in which Toyo is generated in the shield tape. Indicates the method of measuring the value of Toyo.

Hereinafter, specific embodiments for carrying out the present invention will be described. The following description is for facilitating the understanding of the present invention. That is, it is not intended to limit the scope of the present invention.

1. 1. Definition "Toyo" refers to the value measured by the following procedure in the present specification.
Place the shield tape on the horizontal surface plate. If the length of the shield tape is short, both terminals in the longitudinal direction may be lifted from the disc surface due to the influence of curl. Therefore, the length of the shield tape in the longitudinal direction is set to the length at which the non-lifting region exists. The contour curve of the shield tape is measured in the width direction of the shield tape, and the difference between the maximum value and the minimum value of the contour curve is measured (see the arrow in FIG. 3). Then, the ratio of the difference to the tape width (value of difference (mm) / tape width (mm)) is defined as "Toyo". The contour curve is measured by a commercially available non-contact coordinate measuring machine.

The Toyo value of the shield tape provided with the metal layer and the resin layer is a positive value when the resin layer side is concave (the metal layer side is convex, A in FIG. 3), and the metal layer side is concave (the resin layer side is convex, FIG. 3). The case of B) of is a negative value.

When the toyo is a negative value, the shield tape becomes a cylinder with the plated surface inside due to the deformation that reduces the diameter of the circle including the contour of the toyo, so that it can be easily processed. The present invention includes, in one embodiment, a shield tape in which Toyo has a negative value or a zero value.

On the other hand, when Toyo has a positive value, it is not always easy to process because it includes deformation that increases the diameter of the circle including the contour of Toyo. The present invention is, in one embodiment, a shield tape having a positive toyo that is difficult to process into a cylinder, and is a shield tape that suppresses the positive toyo.

"Curl" refers to a value measured by the following procedure in the present specification.
Place the shield tape on the horizontal surface plate. The length of the shield tape in the longitudinal direction is 50 mm. The contour curve of the shield tape is measured in the longitudinal direction of the shield tape, and the difference between the maximum value and the minimum value of the curve is measured. Then, the value of the ratio of the difference to the length in the tape longitudinal direction (difference (mm) / tape length (mm)) is defined as "curl". The contour curve is measured by a commercially available non-contact coordinate measuring machine. The rules for whether the curl value is positive or negative are the same as for Toyo. That is, the case where the resin layer side is concave (the metal layer side is convex, A in FIG. 3) is a positive value, and the case where the metal layer side is concave (the resin layer side is convex, B in FIG. 3) is a negative value.

2. Configuration of Shielded Tapes In one embodiment, the present invention includes shielded tapes. The shield tape includes at least a metal layer and a resin layer.

2-1. Metal layer The metal layer is not particularly limited, but is preferably a metal that blocks electromagnetic waves. For example, pure copper foil, copper alloy foil, pure aluminum foil, aluminum alloy foil and the like can be mentioned. Examples of the copper alloy include, but are not limited to, tough pitch copper, oxygen-free copper, Ag-containing copper, Sn-containing copper, P-containing copper and the like. Further, the copper foil may be an electrolytic copper foil or a rolled copper foil.

The thickness of the metal layer is not particularly limited, but is typically 5 to 35 μm.

2-2. Resin layer The resin layer is not particularly limited, but is preferably one having good consistency and adhesiveness with the electric wire covering member. For example, PET (polyethylene terephthalate) and the like can be mentioned without particular limitation. The thickness of the resin layer is not particularly limited, but is typically 10 to 30 μm.

2-3. Bonding layer When joining the resin layer and the metal layer, a thermoplastic adhesive or the like may be used. Further, after laminating the resin and the metal foil, the bonding layer is formed by pressing and heating if necessary. Further, by applying appropriate pressure and heat, the resin and the metal foil can be laminated without using an adhesive.

2-4. Plating layer The metal layer has a Sn layer or various alloy layers (particularly Sn alloy layers, for example, Ni—Sn alloy, Ag—Sn alloy, etc.) on the surface opposite to the surface bonded to the resin layer. An alloy consisting of an element A composed of Sn or In and one or more element B elements selected from the group of Ag, Ni, Fe, and Co) may be provided. The Sn layer or Sn alloy layer has advantages such as excellent corrosion resistance, good solderability, and low contact resistance. The thickness of the Sn layer or various alloy layers is not particularly limited, but is typically 0.1 to 2.0 μm. The means for providing the Sn layer or various alloy layers having the above thickness is not particularly limited, but plating can be typically performed.

2-5. AC layer The resin layer may be further provided with an AC (anchor coat) layer on a surface opposite to the surface bonded to the metal layer.

2-6. Shape In one embodiment, the electromagnetic wave shielding tape of the present invention is provided in the form of a coiled final product.

The width size is not particularly limited, but may be typically 5 mm to 15 mm (eg: 11.5 mm) as long as it is used for manufacturing a shielded cable, for example. Further, the thickness may be typically 20 to 50 μm.

Further, in one embodiment, the electromagnetic wave shielding tape of the present invention has a toyo of 0.06 or less, preferably 0.03 or less. The lower limit is not particularly limited, but is typically 0 or more.

Further, in one embodiment, the electromagnetic wave shielding tape of the present invention has a curl of 0.4 or less, preferably 0.2 or less. The lower limit is not particularly limited, but is typically 0 or more.

3. 3. Manufacturing Method In one embodiment, the present invention includes a method for manufacturing an electromagnetic wave shielding tape. The manufacturing method includes a step of laminating a metal foil and a resin film. Hereinafter, an exemplary manufacturing process will be described.

(1) Metal foil First, a metal foil for forming a metal layer can be prepared. For example, in the case of Cu foil, rolled copper foil may be provided. The rolled copper foil may be degreased and / or annealed, if necessary.

(2) Resin film and laminating process Next, a resin film for forming a resin layer can be prepared. Typically, a film composed of the resin material (for example, PET) of the above-mentioned example may be used.

Then, the metal foil and the resin film described above may be laminated. As described above, an adhesive may be used between the metal foil and the resin film. It is preferable to laminate the metal foil and the resin film while applying tension to the resin film.

The magnitude of the tension applied to the metal foil is not particularly limited, but is preferably 40% to 60% when the maximum tension that can be applied to the metal foil is 100%. On the other hand, the magnitude of the tension applied to the resin film is not particularly limited, but is preferably 20% to 80% when the maximum tension that can be applied to the resin film is 100%. Here, the maximum tension refers to the maximum tension at which neither slip scratches, wrinkles nor breaks occur.

When applying tension to the metal foil and the resin film, what is important is the ratio of the tension applied to both. In the prior art, it has been adjusted so as to be as flat as possible after laminating. This is to make it easier to handle in the plating process performed after the laminating process. However, the AC agent changes from a liquid to a solid due to the treatment with the AC agent (coating, heat treatment, etc.) performed after the plating step. Due to the change in volume in the process of the change and the influence of the tension during the laminating process, the laminated body after the treatment with the AC agent becomes not flat.

Therefore, in the present invention, the ratio of the tension applied to the metal foil and the resin film is adjusted in advance so that the shape is not flat during the laminating process. More specifically, the tension ratio is adjusted so that the deformation is opposite to the deformation caused by the treatment with the AC agent. Thereby, the deformation caused by the treatment with the AC agent can be offset. As a result, after the treatment with the AC agent, a flatter state can be approached or a flat state can be realized.

To explain a more detailed principle, tension is applied in the longitudinal direction of the metal foil and the resin film. As a result, the size of the metal foil and the resin film in the width direction is reduced, and conversely, the size in the longitudinal direction is increased. After laminating, when released from tension, the metal leaf and resin film try to return to their original shape. As a result, it tries to extend in the width direction. By adjusting the force to extend in the width direction with each of the metal foil and the resin film, the toyo after lamination is adjusted.

Based on the above principle, the ratio of tension applied to the metal foil and the resin film is preferably adjusted as follows. As the tension here, the unit tension (kgf / mm ² ) is used.
Tension ratio (metal leaf tension / resin film tension) ≤ 3.0
If it exceeds 3.0, the toyo of the shield tape becomes large. As a result, defects occur more frequently when the shield is wound around the cable.

More preferably, the ratio of tension applied to the metal foil and the resin film can be adjusted as follows.
0.5 ≤ tension ratio (metal leaf tension / resin film tension) ≤ 1.5

(3) Sn plating and various alloy plating Since the Sn layer or various alloy layers are provided, electroplating can be performed. The plating method can be performed by a known method. For example, Sn can be provided on the anode and the laminate can be installed on the cathode side.

(4) AC coating The AC agent can be applied to the resin layer side to perform heat treatment and / or drying treatment. As a result, the liquid AC agent changes to a solid state.

(5) Microslit processing Microslit processing can be performed to further process the laminate obtained in the above step into a desired width. For example, when the width of the above-mentioned laminated body is about 600 mm, microslit processing can be performed so that the width becomes 5 mm to 15 mm (example: 11.5 mm).

(6) Straightening Roll One or more shapes that apply bending stress to the shield tape based on the principle of roller leveler generally used for shape straightening of cold-rolled metal strips in any step of the above-mentioned manufacturing process. A straightening roll may be provided. For example, at the time of AC coating, the work piece may be wound around a shape straightening roll. Curling can be suppressed by adjusting the diameter of the shape-correcting roll, the tension acting on the shield tape, or both. More specifically, for example, under a certain tension, when the roll diameter is small, the shield tape is strongly curled (the bending stress is large), so that a large curl is developed on the shield tape. On the contrary, when the roll diameter is large, a small curl is developed because the bending is loose (the bending stress is small). Then, curl does not appear at all above a certain roll diameter. When the maximum roll diameter at which curl appears is 100%, the roll diameter is preferably 80% or less, and more preferably 70% or less. If it exceeds 80%, the curl is difficult to control because the bending is loose (the bending stress is small). The lower limit is not particularly limited, but is typically 40% or more. By adjusting the roll diameter in the range of 40 to 80%, the amount of curl of the shield tape can be controlled.

4. Utilization of Electromagnetic Wave Shielding Tape The electromagnetic wave shielding tape obtained by the above method can be used, for example, for manufacturing an electromagnetic wave shielded cable. For example, it can be arranged so that the longitudinal direction of the cable and the longitudinal direction of the electromagnetic wave shielding tape are parallel to each other. Then, the tape-shaped electromagnetic wave shielding material can be wound so that the electromagnetic wave shielding tape forms a cylinder about the longitudinal direction. Furthermore, both edges of the electromagnetic wave shielding tape can be joined.

First, a pure Cu rolled copper foil and a PET film were prepared. The copper foil and the PET film were laminated using a laminating machine. At that time, the tension applied to the copper foil and the PET film was adjusted so as to meet the conditions shown in Table 1.

Then, the work piece was connected to the cathode and electroplated. More specifically, the Sn plating or Sn alloy plating shown in Table 1 was applied.

After plating, an AC agent was applied to the PET film side, and then a dry heat treatment was performed. Then, the roll was wound with the shape correction roll shown in Table 1.

Then, microslit processing was performed so as to have a width of 11.5 mm. After processing, the shield tape was cut to a length of 50 mm. Then, Toyo and Karl were measured.

Finally, a shielded cable was manufactured using the obtained shielded tape. In the manufacture of shielded cables, the frequency of quality defects or line outages caused by the shielded tape not forming a predetermined cylindrical shape was investigated. Converted to processing per 10000 m, those with defects of 1.0 times or more are poor in productivity, those with defects of 0.5 times or more and less than 1.0 times are good in productivity, and defects are 0. When it was 0 times or more and less than 0.5 times, the productivity was judged to be the best.

The results are shown in Table 1. In Comparative Examples 1 to 3, the ratio of the tension between the copper foil and the PET film was inappropriate, so that the toyo became large. Further, comparing the 14th embodiment with the other examples, in the 14th embodiment, the diameter of the shape correction roll is large, so that the curl is large and the productivity of the shielded cable is inferior to that of the other examples. became.

In the present specification, the description of "or" or "or" includes the case where only one of the options is satisfied or the case where all the options are satisfied. For example, the description of "A or B" and "A or B" includes both the case where A is satisfied and B is not satisfied, the case where B is satisfied and A is not satisfied, and the case where A is satisfied and B is satisfied. Intended to be.

The specific embodiments of the present invention have been described above. The above-described embodiment is merely a specific example of the present invention, and the present invention is not limited to the above-described embodiment. For example, the technical features disclosed in one of the above embodiments can be provided to other embodiments. Further, for a specific method, it is possible to replace some steps with the order of other steps, and an additional step may be added between the two specific steps. The scope of the present invention is defined by the claims.

10 Electric wire 20 Shielding material

Claims (6)

An electromagnetic wave shielding tape comprising a metal layer and a resin layer, the metal layer being composed of a metal foil and a plating layer, and having a toyo of 0.06 or less. The electromagnetic wave shielding tape according to claim 1, which has a curl of 0.4 or less. The electromagnetic wave shielding tape according to claim 1 or 2, which is used for covering electric wires. The metal layer
A Cu layer or a Cu alloy layer and a Sn layer or a Sn alloy layer are provided.
The electromagnetic wave shielding tape according to any one of claims 1 to 3. A cable coated with the electromagnetic wave shielding tape according to any one of claims 1 to 4. The method for manufacturing an electromagnetic wave shielding tape according to any one of claims 1 to 4.
Including the process of laminating the metal foil and the resin film
The method in which the tension ratio (tension of the metal foil / tension of the resin film) is 3.0 or less in the laminating step.

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