JPH0760957B2 - Electromagnetic shield casing - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a casing that can house electric / electronic devices and can be shielded from electromagnetic waves.

[Conventional technology and its problems]

Conventionally, as a casing having an electromagnetic wave shielding property,
Applying paint mixed with conductive powder to the surface of synthetic resin, or applying metal plating or metal deposition to form a conductive coating on the surface, or kneading conductive filler such as metal powder or carbon fiber. There is something to keep in mind.

Among the above, the method of forming a conductive coating, since it is necessary to perform the coating forming treatment one by one after molding the casing, the workability is poor, the cost is high, and the coating peels off during handling. There is an easy problem.

On the other hand, the latter has a problem that the physical properties of the synthetic resin are deteriorated by the filler and sufficient electromagnetic wave shielding properties cannot be obtained.

In addition to the above, there are also those using a metal plate or metal foil,
Although it has an excellent electromagnetic wave shielding property, it is difficult to process it into a complicated shape and has no electrical insulation property, so that there is a problem that an accident such as a short circuit occurs.

An object of the present invention is to solve the above problems, and to provide a casing made of a material having good electric insulation and electromagnetic wave shielding properties and capable of being processed into a complicated shape.

[Means for achieving the purpose]

In order to achieve the above object, in the present invention, on both sides of the aluminum foil, the base material laminated with the heat-shrinkable synthetic resin film via the intermittent adhesive layer, after heat shrinking,
A thermoplastic synthetic resin layer was provided on at least one side of this base material, and this was molded to form an electromagnetic wave shielding casing.

[Action]

Since the aluminum foil is used as described above, it has excellent electromagnetic wave shielding properties, and since many fine wrinkles are formed in advance on the aluminum foil, the wrinkles absorb the spread during molding and the foil breaks. Instead, it can be formed into a complicated shape.

〔Example〕

First, the base material containing the aluminum foil will be described with reference to FIGS. 1 to 5.

As shown in FIG. 1, the base material 1 is an aluminum foil 2,
The heat-shrinkable synthetic resin films 4, 4'are laminated via the intermittent adhesive layers 3, 3 '.

The heat-shrinkable synthetic resin film 4, 4'is made of a resin such as polyethylene, polypropylene, vinyl chloride, polystyrene, polyester, ethylene-vinyl acetate copolymer, and has a shrinkage ratio as large as possible, for example, about 50%. It is preferably used. In addition, this film 4, 4 '
May be a laminate of two or more kinds of films as well as a single substance.

The intermittent adhesion layers 3 and 3'may be formed by a means capable of adhering the aluminum foil 2 and the films 4 and 4 '. In addition to the adhesive, the characteristics of the films 4 and 4'are used. Alternatively, heat fusion or ultrasonic fusion may be used. The pattern of the adhesive layer 3 may be linear as shown in FIG. 2 (a), dot-like as shown in (b), or lattice-like as shown in (c). Any pattern may be used as long as it has the intermittent portion 5 without being provided in the. A resin layer that flows by heating may be present in the intermittent portion 5.

As shown in FIG. 3, a printing or coloring layer 6 can be provided on the surface of the aluminum foil 2. Furthermore, the fourth
As shown in the figure, a plurality of aluminum foils 2 may be attached and used. In the figure, 7 is an adhesive layer.

When the substrate 1 as described above is heated, the films 4, 4'shrink as shown in FIG. On the other hand, aluminum foil 2
Is bonded to the films 4 and 4'through the intermittent bonding layer 3, so that the films 4 and 4'are drawn to the respective intermittent portions 5 as the films 4 and 4'shrink, and fine wrinkles are formed.

In this way, the thermoplastic synthetic resin layer 8 is provided on one surface of the base material 1 having fine wrinkles, and the molding sheet 10 as shown in FIG. 6 is formed.

In order to stack the base material 1 and the resin layer 8 on each other, in addition to extrusion, thermocompression bonding, etc., an adhesive described later may be used.

As shown in FIG. 7, the resin layer 8 may be provided on both sides of the base material 1.

Further, as shown in Fig. 8, the resin layer 8 may be a laminated body of two kinds of synthetic resin layers 8'and 8 ". Of course, a laminated body of two or more layers can also be used. In the figure, 9 and 9 are
It is an adhesive layer for bonding the base material 1 and the resin layer 8. In this case, if the adhesive surface of the base material 1 and the adhesive surface of the resin layer 8 are, for example, a vinyl type, a vinyl type or a urethane type may be used, and if a polypropylene type, a polyurethane type adhesive may be used. preferable. In any case, it is preferable to use an adhesive that strengthens the adhesion between the two and leaves some thermoplasticity.

Such a sheet 10 is molded to form a casing as shown in FIG. 9, for example. In the figure, A is an electronic component, 20
Is the substrate.

The shape of the casing is arbitrary. Round, oval,
Any shape such as a polygon may be used.

〔effect〕

According to this invention, as described above, a heat-shrinkable film is attached to an aluminum foil, and the heat-shrinkable film is heat-shrinked to form fine wrinkles on the aluminum foil, which is provided with a thermoplastic synthetic resin layer. Since the casing is formed, even if the sheet is spread by molding, the wrinkles of the aluminum foil absorb the elongation, breakage does not occur, it can be molded into a complicated shape, and the excellent electromagnetic wave that the aluminum foil has The shielding property is maintained as it is, and since both sides of the aluminum foil are covered with synthetic resin, it has electrical insulation properties, there is no fear of corrosion of the foil, and the electromagnetic shielding property may be impaired during handling. The effect of not having it can be improved.

[Brief description of drawings]

1, 3, and 4 are cross-sectional views showing some examples of base materials used for molding sheets, FIG. 2 is a plan view showing a pattern of an adhesive layer, and FIG. 6 is a sectional view showing some examples of the molding sheet, and FIG. 9 is a sectional view of the casing. 1 ... Base material, 2 ... Aluminum foil, 3, 3 '... Intermittent adhesive layer, 4, 4' ... Heat-shrinkable synthetic resin film, 5
...... Intermittent part, 8 ...... thermoplastic synthetic resin layer, 10 ...... molding sheet, 20 ...... substrate.

Front page continuation (72) Inventor Mamoru Kamata 1-25 Toyo Aluminum Co., Ltd., 4-25, Minamikyutaro-cho, Higashi-ku, Osaka-shi, Osaka

Claims (1)

[Claims] 1. A heat-shrinkable synthetic resin film is laminated on both sides of an aluminum foil via an intermittent adhesive layer, and a thermoplastic synthetic resin layer is provided on at least one surface of a substrate heat-shrinked. , Electromagnetic wave shield casing formed from this sheet.