JPH0241147Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a conductive adhesive tape or sheet for shielding interference radio waves such as electromagnetic waves generated from electronic equipment and the like.

In recent years, the housings of televisions, radios, VTRs, and other electronic devices have increasingly been made of plastic because of their ease of manufacture and low cost. However, since the plastic housing does not have the ability to shield electromagnetic waves, the electromagnetic waves generated by the built-in electronic devices cause electromagnetic interference to surrounding electronic devices. In addition, internal ICs and electronic components may be subject to electromagnetic interference due to external electromagnetic waves. To prevent this, for example, the walls of plastic cases are coated with conductive paint, but not only does painting require a lot of work, but some of the walls have many heat dissipation holes. However, there are drawbacks such as the fact that it is extremely difficult to shield electromagnetic waves around the heat radiation holes.

This design has a ventilation hole of a predetermined size that can maintain electromagnetic wave shielding properties that penetrates a conductive substrate and a hot melt adhesive layer that is integrally provided on the surface of the conductive substrate. Even if there is a ventilation hole in the body, it can be easily thermocompressed to prevent radio wave interference caused by electromagnetic waves, etc., and the heat generated from electronic equipment etc. can be easily dissipated to the outside of the housing.

To explain an example below, the conductive substrate 1 having the ventilation hole 2 is made of a foil or thin film made of copper, copper alloy, iron, stainless steel or other iron alloy, aluminum, nickel or other conductive metal, conductive amorphous metal, etc. A sheet, a conductive plastic, etc., punched out with a mold or the like, with ventilation holes 2 of a predetermined size arranged in a predetermined arrangement, or a wire made of the above-mentioned conductive metal, conductive plastic, carbon, etc. Organized into a mesh of a predetermined size using tape material, etc.
There are also woven ones. The size of the holes 2, such as the above-mentioned ventilation holes or mesh holes, must be such that they can provide the ventilation necessary to release the heat generated by the electronic equipment to the outside of the case, and can also block the electromagnetic waves generated by the electronic equipment. Yes, the hole shape is round, oval,
Can be made into square or irregular shapes as appropriate, and its maximum opening size can be
It is approximately 0.5 to 10 mm. This maximum opening dimension is, for example, the hole diameter for a circular hole, the long axis for an oval hole,
For square holes, the length is approximately the length of the longest line that crosses the hole. If the maximum opening size is less than 0.5 mm, sufficient ventilation for heat dissipation will not be possible, and if it exceeds 10 mm, it will be difficult to obtain the effect of shielding electromagnetic waves.

One surface of the conductive substrate 1 has ethylene-
A hot melt adhesive layer 3 made of vinyl acetate copolymer, polyamide, polyester, ethylene-acrylic copolymer, synthetic rubber, or other thermoplastic or thermosetting adhesive is formed on the conductive substrate. It is provided so as not to block the pores 2. The adhesive layer 2 is provided on the entire surface of one surface of the base body, and if necessary, it can be provided in a desired part with an area 4 where the adhesive layer is not present (a fourth
~Figure 6). This is particularly effective when the vent hole is small.
The above-mentioned hot melt adhesive layer can be appropriately formed by a known method such as a nozzle method, a wheel method, a roller method, or a portable gun method depending on the adhesive. Furthermore, the hot melt adhesive layer 2 can be formed on both sides of the conductive substrate in the same manner as on the one side, if necessary.

In addition to the above, the conductive adhesive tape or sheet of the present invention includes foils or thin sheets of various conductive metals constituting the conductive substrate, conductive plastic sheets, wires of the conductive metal, carbon fiber, conductive A laminate is formed by providing a hot-melt adhesive layer on the back side or both front and back surfaces of a conductive fabric or a conductive non-woven fabric obtained by knitting and weaving plastic fibers, etc., and penetrating the laminate. The vent holes 2 of a predetermined size can be formed very easily by punching or the like in a predetermined arrangement.

The present invention has the above-mentioned structure, and can be easily pasted by applying the adhesive layer of the adhesive sheet to the inner surface of the plastic casing of the above-mentioned electronic devices, for example, and pressing it using a hot press or the like. It can be used to shield electromagnetic waves. and,
In particular, even if the casing has heat dissipation holes etc., if this adhesive sheet is pasted on the inner surface of the case, the heat dissipation holes will not be blocked since the sheet is equipped with ventilation holes. Since the ventilation and heat dissipation effects are not hindered in any way, and the size of the ventilation hole is as described above, sufficient electromagnetic wave shielding can be achieved.

In addition, since a hot melt adhesive is used for the adhesive layer, the bond is strong, and because there are heat radiation holes in the housing, the adhesive does not come into contact with the inner surface of the housing, leaving the adhesive exposed. Even if it is exposed to the environment, it will not get dirty or get dirty due to dirt or dust adhering to it like normal adhesives, and it will remain stable for a long period of time. It can perform heat dissipation and electromagnetic shielding. In addition, the conductive adhesive tape or sheet of the present invention can be used in areas with ventilation holes such as the housing, and can be used in combination with other areas, such as by applying conductive paint, and its structure is simple and easy to install. Can be done.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view;
2 is a sectional view taken along the - line in FIG. 1, FIG. 3 is a plan view showing a modified example, FIG. 4 is a plan view showing another modified example, and FIG. 5 is a sectional view taken along the - line in FIG. FIG. 6 is a sectional view taken along the line -- in FIG. 4. 1 is a conductive substrate, 2 is a ventilation hole, 3 is a hot melt adhesive layer, and 4 is an adhesive-free area.

Claims (1)

[Scope of utility model registration request] It has a substantially sheet-like conductive base, and its maximum opening size is 0.5 to 10 mm so that the conductive base has appropriate air permeability and electromagnetic wave shielding properties.
A conductive adhesive tape or sheet for shielding electromagnetic waves, which has a plurality of vent holes each having a size of 1, and a hot melt adhesive layer provided on at least one surface of the conductive substrate so as not to block the vent holes.