JPH0629669A - Casing for electronic apparatus - Google Patents

Abstract

PURPOSE:To realize high rigidity, small thickness, and light weight, by forming a base body of material whose rigidity is higher than synthetic resin parts. CONSTITUTION:As a base body 1, an Al plate is formed in a tray type by press machining, then inserted into a movable metal mold and clamped. Resin is injected and a mold is opened after cooling, thereby obtaining a cabinet wherein the base body 1 of Al and parts 2 of ABS resin are formed in a unified body. The base body 1 is composed of metal containing aluminum. The parts 2 of synthetic resin is composed of aromatic polyamide(PA), polybutyrlene terephthalate(PBT), and acrylonitril butadien styrene(ABS). Hence external load and shock are supported by the base body 1, and heat dissipation of an internal circuit and an equipment is improved by using material excellent in thermal conductivity as the base body 1. Electromagnetic shield also can be added. Function imparting parts 2 like a boss and a rib are composed of synthetic resin, and therefore can be easily formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an electronic device enclosure.

[0002]

2. Description of the Related Art Conventionally, synthetic resins such as ABS (acrylonitrile butadiene styrene) and polycarbonate have been used as materials for electronic devices. Generally, these synthetic resins are widely used for enclosures because they have high mechanical strength and low cost, but it is necessary to have an appropriate wall thickness in order to secure the strength. It got bigger.

Therefore, in order to improve the strength and reduce the weight of the casing, FRP (fiber reinforced plastic) is used in which reinforcing fibers such as glass fibers are mixed in a synthetic resin to improve the strength.

[0004]

[Problems to be Solved by the Invention] The conventional FRP has anisotropy in strength and is not excellent in thin-wall moldability. On the other hand, in recent years, as personal computers and telephones have become more sophisticated and portable, it has become an important technical issue to make the enclosure thinner and lighter and to make it stronger.

It is an object of the present invention to provide a high-strength, thin-walled, lightweight electronic device enclosure.

[0006]

[Means for Solving the Problems] 1)
A synthetic resin part is provided on the base body by in-mold molding, and the base body is an electronic device casing made of a material having a higher strength than the synthetic resin part, or 2) the base body is made of a metal containing aluminum, 1) The parts are made of aromatic polyamide (PA), polybutylene terephthalate (PBT), acrylonitrile butadiene styrene (ABS)
This is achieved by the electronic device enclosure described.

[0007]

In the present invention, the electronic device enclosure is made of a high-strength material and a synthetic resin. That is, a high-strength material is used as a base, and synthetic resin is used to integrally form protruding functional parts such as bosses and ribs by in-mold molding.

As a molding method, it is desirable to use pressure molding such as compression molding or transfer molding or injection molding. Since the electronic device enclosure of the present invention comprises a base body made of a high-strength material and a component made of a synthetic resin, both the high strength of the enclosure and the reduction in size and weight are achieved. External loads and shocks are supported by the base body, and the use of a material with good thermal conductivity for the base body improves the heat dissipation of the internal circuit and the device. Further, if a metal is used for the base, electromagnetic shielding property can be added. On the other hand, the function-added parts such as bosses and ribs can be easily formed because they are made of synthetic resin, and the function-added parts made of synthetic resin can be integrally molded by in-mold molding by pressure molding or injection molding. Therefore, the productivity of the box is good.

For this reason, it has become possible to easily obtain a high-strength, thin-walled, small-sized enclosure for electronic equipment which is excellent in heat dissipation and electromagnetic shielding.

[0010]

Embodiments FIGS. 1 (A) to 1 (C) are explanatory views of Embodiment 1 of the present invention. In FIG. 1 (A), the synthetic resin portion 2 is molded so as to cover one surface of the base 1. A plate-shaped aluminum (Al) plate was used as the substrate, and ABS resin was used as the synthetic resin part.

First, Al plate (300 mm × 300 mm × 0.5 mm)
Is molded into a dish by pressing. Then, as shown in FIG. 2, the Al plate is inserted into the movable mold and the mold is clamped.
Then, the resin is injected, and after cooling, the mold is opened to obtain a casing in which the Al substrate and the ABS resin component are integrally molded.

FIG. 1 (B) shows a case in which function-added parts such as bosses and ribs are provided in the housing. The manufacturing method is the same as in the case of FIG. FIG. 1 (C) is an example in which the surface coating portion of FIG. 1 (A) and the function-added component of FIG. 1 (B) are simultaneously molded. The manufacturing method in this case is basically the same as the above, but when resin parts are provided on both surfaces of the base in this way, it is preferable to provide through holes as shown in FIG. 3 in the base. Since the resin at the time of molding goes around to the back side of the substrate through this through hole to mold the component, the mold may have a normal structure. Also,
The installation position of the through hole basically matches the molding position of the function-added component.

Further, in the case where one side or both sides of the substrate are covered with resin, the resin component will be a short shot unless a proper number of through holes are provided at a proper position. Synthetic resin is ABS resin, case size is 320 mm × 320 m
In the case of m × 2.5 mm (base thickness 0.5 mm), the through holes can be arranged to cover the entire surface of the substrate in the arrangement example shown in FIG.

The description of FIGS. 2 to 4 will be given below.
2 (A) to 2 (C) are cross-sectional views illustrating the molding process of the example. In the figure, 1 is a base, 3 is a movable type, and 4 is a fixed type.

FIG. 2A shows a state before the mold is clamped, FIG. 2B shows a state where the resin 2 is molded after the mold is clamped, and FIG. 2C shows a state where the mold is opened. 3 (A) and 3 (B) are explanatory views of an embodiment in which a through hole is provided in the base.

FIG. 3 (A) is a plan view of the base body in which a through hole 5 is opened. FIG. 3 (B) shows the molding process after mold clamping. FIG. 4 is a plan view of a base body showing an arrangement example of through holes.

FIG. 5 is an explanatory view of the second embodiment of the present invention.
In this example, the moldability of a thin-walled casing was examined, and the molded product shown in the figure was molded as a molding model. Since this model assumes a state in which synthetic resin parts are coated on the outside of the housing of the base body, the wall thickness of the entire housing depends on how thin both the base body and the resin parts can be made.

The resin used in the examples is an aromatic polyamide (P
There are four types: A), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), ABS (high flow grade).

The results of molding are shown in Table 1.
Although the limit was 1 mm, the other three types had relatively good fluidity and could be formed to a wall thickness of 0.8 mm.

[Table 1] Next, the base material is stainless steel, aluminum, copper,
In the case of FRP, the wall thickness is 0.4, 0.5, 0.3, and
1.0 mm is required. Therefore, the total thickness of the enclosure is
It will be 1.1 to 1.8 mm.

When a substrate was made of each material with the above thickness, the weight of the substrate was as shown in Table 2. Strength, wall thickness,
Aluminum is suitable for the material of the substrate from the viewpoint of weight balance, but it may be appropriately selected depending on the required properties of the casing.

[0021]

[Table 2] Tensile strength Young's modulus Specific gravity Substrate thickness Substrate weight (kgf / mm ² ) (kgf / mm ² ) (g / mm ² ) (mm) (Kg) Stainless steel 50 to 90 10000 7.3 0.4 2.2 Aluminum 28 〜 50 7140 2.7 0.5 1.0 Copper 20〜30 11000 9.0 0.3 2.0 FRP 20 2000 1.4 1.4 1.1 If the resin part does not cover the surface of the substrate for decoration and protection, that is, only bosses and ribs are outsert on the substrate. The wall thickness of the case when molded by the method is 0.3 to 1.0 mm.

[0022]

According to the present invention, a high-strength, thin-walled, lightweight electronic device enclosure is obtained. In addition, by appropriately changing the material of the base, it is possible to create an enclosure having excellent heat dissipation and electromagnetic shielding properties.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a molding process of an example.

FIG. 3 is an explanatory diagram of an embodiment in which a through hole is provided in the base body.

FIG. 4 is a plan view of a base body showing an arrangement example of through holes.

FIG. 5 is an explanatory diagram of a second embodiment of the present invention.

[Explanation of symbols]

 1 Base 2 Synthetic Resin Parts 3 Movable 4 Fixed 5 Through Hole

Front Page Continuation (72) Koichi Kimura 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (2)

[Claims] 1. An enclosure for electronic equipment, characterized in that a synthetic resin part is provided on a base by in-mold molding, and the base is made of a material having a higher strength than that of the synthetic resin part. 2. The substrate is made of a metal containing aluminum, and the synthetic resin component is made of aromatic polyamide (PA), polybutylene terephthalate (PBT), acrylonitrile butadiene styrene (ABS). The electronic device enclosure according to 1.