JPH08148855A - Cabinet for electronic equipment - Google Patents

Abstract

PURPOSE: To enable a circuit substrate packaged in a case body having good appearance, in thin, light weight yet high strength to be grounded by a method wherein core material contained in a bonding synthetic layer laminated on one surface of a metallic sheet while a conductive filler is contained in a thermoplastic resin integrally molded with an inner mechanism part. CONSTITUTION: A bonding sheet comprising core material made of nickel fiber cloth impregnated with polystyrene base heat sensitive bonding agent is laminated with aluminum sheets 1 to be thermal pressed for manufacturing a laminated sheet. Next, a case body is manufactured by press machining with a bonding agent layer 2 turned inside. Next, containing this case body in an injection molding metallic mold having a cavity in the same shape as an inner mechanism 3 to be formed, the inner mechanism part 3 is formed by injection molding step using ABS resin blended with a copper fiber. Finally, a part packaging circuit substrate packaged with a circuit part 5 is arranged in the central part clad with the case bodies on upper and lower both surfaces so that a circuit substrate 4 may be metallic screwed 6, 7 on the boss of the inner mechanism part 3 to assemble the case body for fixing and grounding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casing for electronic equipment which is lightweight, has an excellent design, and can be grounded to a circuit board inside the casing.

[0002]

2. Description of the Related Art Conventionally, a housing for housing electronic equipment has been
A molded body that is molded by injection molding of a thermoplastic resin and has a design appearance and an internal mechanism portion that mounts an electronic circuit board or the like is used. However, in recent years, the density of electronic devices has been remarkably increased, and it is required that the housings for these electronic devices are thin, small and lightweight. In addition, since various electronic devices have been widely used, electromagnetic waves emitted from the electronic devices may interfere with other electronic devices in the vicinity, such as a TV, or conversely, may interfere with other electronic devices in the vicinity. There is a risk of malfunction due to interference from the electromagnetic waves that are generated.

In order to reduce the size and weight of such electronic equipment, prevent interference with other electronic equipment due to electromagnetic waves, and prevent malfunction of other electronic equipment due to electromagnetic waves, it has greater mechanical strength than resin and electromagnetic wave shielding properties. A metal plate having an adhesive resin layer has begun to be used as a housing. That is, as shown in FIG. 1, a laminated plate having an adhesive layer 2 on one surface of a metal plate 1 is formed into a predetermined casing outer shell shape by press working so that the adhesive layer 2 is on the inside, The outer shell molded body is mounted in an injection molding die, the internal mechanism portion 3 such as the spacer 3a and the protruding base 3b is integrally formed, the circuit component 5 is mounted on the circuit board 4, and the circuit board 4 is screwed. It is a housing for electronic equipment which is attached to the projecting stand 3b by 7 and is further integrated by the screws 6 for connecting the divided pieces.

[0004]

However, in the case of the above-mentioned housing, if the shield layer of the electronic circuit board 4 is grounded to the metal outer shell 1 in order to reduce the noise of the electronic equipment, the internal An adhesive layer 2 which is an insulator is interposed between the mechanism section 3 and the metal outer shell 1.
It is necessary to perform work such as scraping off the metal to expose the inner surface of the metal outer shell 1. In order to avoid this work, it is conceivable to connect the ground lead wire 8 of the electronic circuit board 4 to the outer surface of the metal outer shell 1 as shown in FIG. Extending to the outer surface of No. 1 is not preferable in appearance. In addition, as shown in FIG. 3, an inner flange 9 is provided at the opening edge of each divided piece on the split surface of the two-part configuration of the housing, and the metal outer shell is positioned on the upper surface of this inner flange 9, If the ground lead wire 8 is connected, the above-mentioned appearance problem is solved. However, in this case, since the inner flange portion 9 has an undercut shape as a molded body, there is a drawback that the processing is troublesome and the cost is high.

In order to improve these, a conductive filler is blended in the thermoplastic resin constituting the internal mechanism, and the conductive filler is added in the adhesive layer by injection pressure without using a core material in the adhesive layer. We have proposed a method of grounding by inserting the circuit board into the internal mechanical part by connecting the circuit board to the internal mechanical part by connecting the circuit board to the internal mechanical part by bringing the circuit board into contact with the metallic external shell. However, if the injection pressure is high when molding the internal mechanism,
The adhesive layer may flow due to the pressure of the resin, resulting in poor adhesion.In the molding of thin-walled parts that require high pressure for filling or molding of resin with poor fluidity, increase the multipoint gate and resin temperature, etc. There is a drawback that a special method of must be used.

The present invention has been made to solve the above drawbacks, and is thin, lightweight, and lightweight in a housing in which a metal outer shell and an internal mechanical portion made of synthetic resin are integrated through an adhesive layer. An object of the present invention is to provide a housing for an electronic device, which has high strength, does not require any special processing or method, is excellent in design, and can ground a circuit board mounted in the housing.

[0007]

As a result of earnest studies to achieve the above object, the present inventor has found that a thermoplastic material in which an adhesive synthetic resin layer contains a core material to integrally form an internal mechanism portion. It was found that the above object can be achieved by incorporating a conductive filler in the resin, and the present invention has been completed.

That is, according to the present invention, a laminated plate in which an adhesive synthetic resin layer is provided on one surface of a metal plate is formed into a casing outer shell shape so that the adhesive synthetic resin layer is on the inside. A housing for an electronic device in which an internal mechanism portion is integrally formed of a thermoplastic resin, wherein the adhesive synthetic resin layer includes a core material, and the thermoplastic resin is a conductive filler. It is a housing for electronic equipment, characterized by containing.

The present invention will be described below.

The electronic equipment using the housing of the present invention includes office automation equipment such as word processors and personal computers, small televisions, portable information equipment such as pagers, IC cards and PCs.
It generally refers to devices including semiconductor devices, such as card-shaped devices such as cards and calculators.

The laminated plate constituting the molded outer shell of the present invention is a metal plate provided with an adhesive synthetic resin layer on one surface. As the metal plate, a plate-like body having a thickness of 0.1 to 2.0 mm and made of stainless steel, aluminum, zinc alloy, magnesium alloy or the like which is lightweight and has excellent workability can be used.

As the synthetic resin of the adhesive synthetic resin layer, a polyolefin-based resin, an acrylic resin, an epoxy resin, which has excellent adhesiveness with the above-mentioned metal plate and also has good adhesiveness with the thermoplastic resin constituting the internal mechanism portion, A vinyl acetate resin can be used. For example, when the thermoplastic resin forming the internal mechanism section is polystyrene resin or ABS resin, a polyolefin-based, acrylic-based, or epoxy-based synthetic resin is used, and the thermoplastic resin forming the internal mechanism section is a polypropylene resin. When used, an acrylic or vinyl acetate synthetic resin can be used. This adhesive synthetic resin layer contains a core material such as a non-woven fabric or a woven fabric. By including the core material, it is possible to prevent the adhesive layer from flowing due to the pressure of the resin, resulting in poor adhesion.
The method for forming the adhesive synthetic resin layer on one surface of the metal plate is not particularly limited, and any method may be used. For example, an extrusion laminating method, a method of sticking with a hot press, a hot roll or the like can be used. It is particularly desirable that the core material has conductivity. The material of the conductive core material is iron, copper, copper alloy, aluminum, metallic fiber such as nickel, glass fiber or organic fiber having a metal layer on the surface,
Or a carbon fiber etc. are mentioned.

Examples of the thermoplastic resin constituting the internal mechanism portion include thermoplastic elastomer, polystyrene, ABS resin, polypropylene resin, modified polyphenylene oxide resin and the like. Examples of the conductive filler to be added to this thermoplastic resin include fibrous, powdery or flake carbon, iron, copper, copper alloys, aluminum and nickel.

As a method of manufacturing the housing, the laminated plate is formed into a shell shape of the housing by pressing or the like so that the adhesive synthetic resin layer is on the inside. Next, the outer shell of the housing is mounted in an injection molding die, a thermoplastic resin containing a conductive filler is injection-molded on the adhesive synthetic resin layer, and the internal mechanism is integrally formed. The body can be manufactured. The housing thus obtained is used in combination with the housing on the other side manufactured in the same manner. That is, place the component mounting circuit boards on the both sides of the circuit board in the center, cover the upper and lower surfaces with the case, and fix the circuit board to the boss of the internal mechanism with metal screws. Thus, the housing is assembled and fixed, and the circuit board is grounded.

[0015]

The electronic device casing of the present invention includes an adhesive synthetic resin layer, a core material, and a thermoplastic resin mixed with a conductive filler, so that the inside of the casing can be processed without any special processing. It has succeeded in grounding the circuit board mounted on. That is, the conductive filling material breaks through the adhesive synthetic resin layer by the injection molding pressure when integrally forming the internal mechanical portion with the thermoplastic resin, and the internal mechanical portion and the metal outer shell are electrically connected to each other, and the circuit board The circuit board can be grounded by attaching a metal screw to the internal mechanism part, while the core material is included, and the adhesive synthetic resin layer is washed away by the pressure of the resin, resulting in poor adhesion. Is to prevent.

[0016]

EXAMPLES Next, examples of the present invention will be described.

A wire diameter of 50μ on a 0.6 mm thick aluminum plate
An adhesive sheet made by impregnating NP608 (a product name of Sony Chemical Co., Ltd.), a polystyrene-based heat-sensitive adhesive, with a core material of a woven fabric of nickel fiber of m 3 is stacked and temporarily bonded using a heat press to form a laminated plate. Obtained. This was put into a press mold so that the adhesive layer was on the inner side, and pressed to obtain an outer shell molded body. This molded body is put into an injection molding die having a cavity having the same shape as the internal mechanism portion to be formed, and then an ABS resin containing a copper fiber, EC-2300 (trade name, manufactured by Toshiba Chemical Co., Ltd.) is injection molded. Then, the inside of the cavity was filled to form an internal mechanism portion to manufacture a housing for electronic equipment.

Comparative Example 1 A casing for electronic equipment was manufactured in the same manner as in Example except that an ABS resin containing no copper fiber was used instead of the ABS resin containing copper fiber.

Comparative Example 2 In the Example, an adhesive sheet was used in which a core material of a woven cloth of nickel fiber having a wire diameter of 50 μm was impregnated with a polystyrene-based heat-sensitive adhesive NP-608 (manufactured by Sony Chemical Co., Ltd.). Instead, a polystyrene-based heat-sensitive adhesive NP-605 in which a non-woven fabric made of organic fiber is impregnated.
A housing for electronic equipment was manufactured in the same manner as in the example except that (Sony Chemical Co., Ltd., trade name) was used.

Table 1 shows that metal screws are set on the bosses of the electronic device casings manufactured in Examples and Comparative Examples 1 and 2, and the resistance values of the screws and the aluminum plate of the outer shell are measured. there were. Since the electronic device casing of the present invention is electrically connected, the effect of the present invention can be confirmed.

[0021]

[Table 1]

[0022]

As is clear from the above description and Table 1, the electronic device casing of the present invention is thin, lightweight, has high strength, does not require any special processing, and is excellent in design, The circuit board mounted in can be grounded.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating an electronic device casing related to the present invention.

FIG. 2 is a cross-sectional view for explaining an example of a conventional circuit board grounding mode.

FIG. 3 is an explanatory sectional view for explaining another example of the conventional circuit board grounding mode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal plate 2 Adhesive synthetic resin layer 3 Internal mechanism part 3a Spacer 3b Projection stand 4 Circuit board 5 Circuit component 6 Dividing piece connecting screw 7 Screw 8 Ground lead wire 9 Inner flange

Claims (1)

[Claims] 1. A laminate plate in which an adhesive synthetic resin layer is provided on one surface of a metal plate is formed into a casing outer shell shape with the adhesive synthetic resin layer inside, and a thermoplastic resin is formed on the synthetic resin layer. In an electronic device casing in which the internal mechanism is integrally formed, the adhesive synthetic resin layer includes a core material, and the thermoplastic resin includes a conductive filler. The electronic device casing is characterized by: