JPH077196U - Conductive cloth tape - Google Patents

Abstract

(57) [Summary] [Structure] A cloth woven with short fibers is subjected to a metal plating electro-conductive treatment in a single layer made of a single metal or in a multilayer made of two or more kinds of metals. Or a conductive cloth tape whose both surfaces are coated with a non-conductive adhesive. [Effect] Since the conductive cloth tape of the present invention is made of cloth, it can expand and contract and can be stuck without any gaps. Can be stacked. Then, the shielding of the radiated electromagnetic waves can be easily processed into a highly effective state. In addition, it is possible to easily and highly effectively prevent static electricity from being charged and discharged in an insulative plastic housing made of plastic of an electronic device.
Further, since it is not necessary to use a conductive adhesive as an adhesive, it is economically advantageous.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a conductive cloth tape having an excellent electromagnetic wave shielding effect.

[0002]

[Prior art]

 Grounding treatment is indispensable in order to improve the effect of shielding radiated electromagnetic waves, preventing electrostatic charging, and preventing electrostatic discharge.

In particular, in the case of an electronic device, the shielding of the radiated electromagnetic wave does not prevent the radiated electromagnetic wave generated inside the electronic device from leaking to the outside of the device, or the external unnecessary interference electromagnetic wave from entering the inside of the device. In the case of an object, in order to prevent unnecessary electromagnetic waves from leaking to the outside from the building or room, or to prevent unwanted interference electromagnetic waves from entering the building or anechoic chamber from the outside, use conductors with an electromagnetic wave shielding effect on the ceiling and walls. It is necessary to energize the hexahedron of the floor in a planar manner to make the impedance between the parts equal.

In order to achieve this equivalence, even at the joints on the respective surfaces, and also at the joints to which conductors are bonded in order to secure the width of the respective surfaces, the contact resistances are joined in a planar manner. It is necessary to take measures that are as small as possible.

Further, of course, the gap through which electricity does not flow must be linearly less than 1/100 of the wavelength of the interference frequency. If the length is more than 1/100, resonance phenomenon or leakage of a single interference electromagnetic wave occurs.

Even in the shielding process of a digital signal cable, a conductor is spirally wound to shield electromagnetic waves. Similarly, the contact resistance of the spirally laminated conductor is very small. , It is necessary to stack them so that there are no gaps.

In order to cover the contact tape with no gap and to have a very small contact resistance as described above, a conductive tape having excellent workability, that is, when pasted, has a current-carrying effect in the direction of pasting and wrinkles A flexible material that does not generate is required.

To meet this need, the technology for showing the current-carrying effect in the direction in which the conductive tape is pasted is as shown in FIG. 1, in which the conductive adhesive is mixed with the conductive filler in the adhesive layer of the tape. , Coated on metal foil. Alternatively, as shown in FIG. 2, the metal foil is embossed, and a non-conductive adhesive is applied to the surface of the metal foil. It is brought into contact with the body to be coated to achieve the current-carrying effect.

[0009]

[Problems to be solved by the device]

 If such a conventional conductive tape is strongly pressed and adhered, there is a drawback that the electric current in the attaching direction is lost or reduced.

That is, when the tape is strongly pressed, the adhesive (non-conductive) is mixed around the embossed protrusions and the conductive filler to increase the contact resistance.

In addition, in the conventional conductive tape, a metal foil is used as a support that performs a current-carrying function in the lateral direction. However, since the metal foil is hard and cannot be expanded and contracted, the signal cable is not flexible. When a round and elongated object like the one is spirally wound or pasted on a rounded object and subjected to electromagnetic wave shielding processing, wrinkles are generated, resulting in a bad appearance and a gap that may cause electromagnetic wave leakage. There is a defect that can.

[0012]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention has been completed by discovering the following as a result of earnest research.

The surface of the cloth woven with the long fibers is smooth, but the surface of the cloth woven with the short fibers has a lot of short fiber ends, and is not good for evaluation of the cloth. However, when this short fiber cloth is plated, this fluff is also plated, and this becomes a conductive protrusion.

Since the conductive protrusions are part of the body of the cloth and are plated after the cloth is processed, the intersections of the warp threads and the weft threads are jointly plated, so Are one in one.

Since the fluff caused by the short fibers is made conductive by the metal plating in the electroconductive short fiber cloth subjected to the plating process without using the electroconductive adhesive, the electroconductive cloth tape is laminated. When applied, the conductive fluff protruding from the non-conductive adhesive layer fulfills the electricity flow between the conductive cloths.

It has been found that the grounding performance enhances the electromagnetic wave shielding effect by the effect that the impedance between the conductive cloth tapes that are laminated is made equal to each other.

That is, according to the present invention, a cloth woven with short fibers is subjected to a metal plating conductive treatment in a single layer made of a single metal or in a multilayer made of two or more kinds of metals, and further, one side of the cloth. Alternatively, the conductive cloth tape is characterized in that both surfaces are coated with a non-conductive adhesive.

The conductive cloth tape of the present invention is a cloth woven with short fibers, which is made of a single metal made of a metal having a high specific conductivity or relative magnetic permeability such as copper or nickel, or a single layer made of two or more kinds of metals. It is made by applying metal plating to two or more layers and processing conductive cloth, and applying non-conductive adhesive such as acrylic, acrylic / rosin mixed or silicone based on one or both sides. This is an application of the fluffing of metal-finished short fiber ends as conductive projections.

The cloth used in the present invention is characterized in that a cloth woven by short fibers is applied instead of long fibers. Satin weave is generally used for weaving with short fibers, but since this satin weave is densely woven and the dense state is metal-plated, the effect of shielding the electric field strength of electromagnetic waves is high. There is an effect.

Since the ends of the short fibers are fluffy, when they are metal-plated, they become strong conductive projections, which are eroded from the non-conductive adhesive layer applied to this cloth. As a result, the energizing function in the laminating direction during laminating is fulfilled.

[0021] A plain weave or a twill weave is generally used as a cloth made of long fibers. If a plain woven cloth made of long fibers is subjected to metal plating to achieve a high shielding effect against radiated electromagnetic waves, it is necessary to woven densely, resulting in high cost and hardness.

Since the twill weave, which is a woven type having high flexibility with long fibers, has a high aperture ratio, the effect of shielding the electric field strength and magnetic field strength of electromagnetic waves is correspondingly reduced. In addition, the cloth made of long fibers has fine fluffs like a down hair on the finished surface, but if an adhesive is applied to this surface, this fine downless hair cannot project the adhesive layer, Does not become a conductive protrusion.

According to the present invention, as shown in FIG. 1, as a pressure-sensitive adhesive for imparting tackiness to a conductive cloth tape, even if a conductive pressure-sensitive adhesive is not adopted, a short fiber fluff is used. Since 3 is made conductive by metal plating, when this conductive cloth tape is laminated and pasted, the conductive fluff 3 protruding from the non-conductive adhesive layer 2 carries out the electric conduction between the conductive cloths, which is shown in FIG. The same function as that of the conductive filler 6 mixed with the conductive adhesive 5 of the conductive tape shown in Fig. 3 and the embossed shape (projection) 9 of the embossed rolled copper foil 7 of the conductive tape shown in Fig. 3 is obtained. Fulfill

The grounding performance by the conductive fluff that is electrically integrated with the support of the conductive cloth tape is that when the conductive cloth tape is laminated, there is almost no contact resistance when the conductive cloth tape is energized. In this state, the impedance between the conductive cloth tapes that have been laminated is made equal and the electromagnetic wave shielding effect is enhanced.

Furthermore, the stretchability of the cloth allows the layers to be freely and freely laminated when the rounded surface or the spiral winding process is performed.

Further, it is possible to easily shield the radiated electromagnetic wave into a highly effective state. In addition, such a grounding effect can be easily and highly effectively applied to a process for preventing static electricity charging and discharging of a complicated insulating casing made of plastic of an electronic device.

[0027]

【Example】

 A cloth woven from acrylic short fibers is metal pretreated with an alkaline solution, electroless copper plating 15 g copper per square meter, and electroless nickel plating nickel square meters to prevent the oxidation of this copper. Weighed 3.5 grams per hit. The electrical characteristics of this conductive cloth are as follows. Surface electrical resistance of conductive cloth Warp direction: 0.1 ohm / square Weft direction: 0.3 ohm / square

A non-conductive pressure-sensitive adhesive was applied to the above-mentioned conductively processed cloth as shown in (A) below to prepare a conductive cloth tape of the present invention.

For comparison, as shown in (B) below, a nickel powder-mixed conductive adhesive was applied to prepare a conductive cloth tape for comparison.

(A) Application of non-conductive pressure-sensitive adhesive The pressure-sensitive adhesive mixed in the following weight ratio is wet-coated on the above conductive cloth to a thickness of 120 micrometer and dried at 100 degrees Celsius. It was placed in an oven for 3 minutes to dry. Acrylic adhesive (NV: 55%) ... 85% Toluene ... 15%

(B) Application of Conductive Adhesive Adhesive mixed in a weight ratio as follows was applied wet to the above conductive cloth to a thickness of 120 micrometer and dried in a drying oven at 100 degrees Celsius. And let it dry for 3 minutes. Acrylic adhesive (NV: 55%) ... 75% Toluene ... 19.5% Nickel powder (particle size: 10 μm) ... 5.5%

As shown in FIG. 4, the conductive cloth tapes coated with the above-mentioned (A) and (B) adhesives were laminated on each other (A) or (B), and electric resistance values were measured comparatively. The results are shown in Table 1.

In addition, the conductive tape processed by (A) and (B), which are different in the conductive processing of the pressure-sensitive adhesive, are stuck on a 15 cm square plastic board in the middle thereof, and in a state of 10 mm, (A) Or (B) Make a test piece by stacking two comrades and attach it to a shield box: TR17301 of Advantest Corporation. A comparative measurement of the electromagnetic wave shielding effect was performed.

Table 1 shows the measurement data of the electric field strength at each 100 MHz. In addition, the adhesive strength when applied was measured and compared by the method of JIS Z 0237, and the data are shown in Table 1.

[0035]

[Table 1]

As is clear from Table 1, the conductive cloth tape of the present invention has the same effect as the case where the conductive adhesive is used even if a non-conductive adhesive is used as the adhesive. It was found that the adhesive strength is high and the cost of the raw material of the adhesive is low only to the extent that the conductive filler is not mixed in.

[0037]

[Effect of device]

 Since the conductive cloth tape of the present invention is made of cloth, it can be stretched and can be stuck without any gaps, so that it can be stuck without any gaps when, for example, electromagnetic wave shielding processing of a rounded surface or a spiral winding.

Then, the shielding of the radiated electromagnetic waves can be easily processed into a highly effective state.

In addition, it is possible to easily and highly effectively prevent static electricity from charging or discharging an insulative housing made of plastic and having a complicated shape of an electronic device.

Furthermore, since it is not necessary to use a conductive adhesive as an adhesive, it is economically advantageous.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a conductive cloth tape of the present invention.

FIG. 2 is a cross-sectional view of a metal foil tape coated with a conductive adhesive.

FIG. 3 is a cross-sectional view of a tape made of embossed rolled copper foil.

FIG. 4 is a top view of a test piece for measuring the effect of energization when conductive cloth tapes are laminated.

[Explanation of symbols]

 1 conductive cloth 2, 8 non-conductive adhesive 3 fluffing 4 conductive metal foil 5 conductive adhesive 6 conductive filler 7 embossed rolled copper foil 9 embossed shape (projection) 10 conductive cloth tape

Claims (1)

[Scope of utility model registration request] 1. A cloth woven with short fibers is subjected to a metal plating conductive treatment in a single layer made of a single metal or in a multilayer made of two or more kinds of metals, and further, on one side or both sides of the cloth. A conductive cloth tape characterized by being coated with a non-conductive adhesive.