JP2003258444A - Case for electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a case for an electronic device which does not need insert molding and by which the mounting strength of a ventilation film can be ensured. <P>SOLUTION: A lid 13 of the case 10 for an electronic device is provided with an air hole 17 covered with the ventilation film 20. The ventilation film 20 is composed of a water-repellent and oil repellent layer 21 made of PET or the like and a porous layer 22 made of PTFE or the like stacked on it and has the property of shutting out liquid but permitting the passage of a gas. A part 23 to be welded on which the water-repellent and oil-repellent layer 21 is not stacked is formed on the periphery of the porous layer 22. The ventilation film 20 is set by welding the edge of an annular welding part 18 provided on the rim of the air hole 17 of the lid 13 on the part 23 to be welded. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case for electronic equipment that houses electronic components such as a circuit board.

[0002]

2. Description of the Related Art Some electronic device cases of this type are hermetically sealed so that water and oil do not enter inside.
However, if the case is made completely airtight, when the temperature difference between the inside and outside of the case becomes large, the air inside may expand or contract, which may deform the case and damage the seal part. There is. Therefore, conventionally, as shown in FIG. 4, a vent hole 2 is provided in the case 1, and the vent hole 2 is covered with a vent film 3 having air permeability and waterproof / oil-proof property, so that the pressure difference between the inside and the outside can be reduced. At the same time, it is designed to prevent water and oil from entering from the outside.

However, in the above-mentioned one, since the gas permeable membrane 3 is disposed on the outer surface side of the case 1, the gas permeable membrane 3 may come into contact with foreign matter and be damaged. Therefore, Japanese Patent Laid-Open No. 2001-2001
In the one disclosed in 155814, FIG.
As shown in (C), the gas permeable membrane 4 is provided on the inner surface side of the case 5 to protect the gas permeable membrane 4.

Here, the breathable film 4 has a structure in which a porous layer 7 is laminated on a water / oil repellent layer 6, and the water / oil repellent layer 6 is formed.
Is formed of a nonwoven fabric made of a resin having water / oil repellency such as polyethylene terephthalate (PET), and the porous layer 7 is formed of a porous film made of a fluororesin or the like. Further, the breathable film 4 is arranged so that the water-repellent / oil-repellent layer 6 is on the outer surface side of the case 5, and the outer peripheral portion of the water-repellent / oil-repellent layer 6 is in close contact with the hole edge of the vent hole 8. It is installed. More specifically, insert molding is performed when the case 5 is manufactured, and the resin forming the water-repellent / oil-repellent layer 6 of the gas permeable film 4 and the resin forming the case 5 (PBT or the like) are melted with each other. The case 5 and the gas permeable membrane 4 are attached in an integrated state.

[0005]

However, the above-mentioned products have the problems that the mold structure is complicated and the number of manufacturing steps is increased due to the insert molding. On the other hand, as a manufacturing means other than the insert molding, the ventilation hole 8
It is conceivable to weld the hole edge portion of the water-repellent / oil-repellent layer 6 of the gas permeable membrane 4 to PE.
Since the resin such as T has poor adhesion to the resin such as PBT forming the case 5, the attachment strength of the gas permeable membrane 4 may be low. The present invention has been made in view of the above circumstances, and an object thereof is to provide an electronic device case that does not require insert molding and can secure the attachment strength of a gas permeable membrane.

[0006]

An electronic equipment case according to the invention of claim 1 for solving the above-mentioned problems is an electronic equipment case for accommodating electronic components in a hermetically sealed state, and is made of synthetic resin. In the case where the case main body is provided with a ventilation hole covered with a ventilation film, the ventilation film is
A porous layer is laminated on the oil-repellent layer, and the water-repellent / oil-repellent layer side is arranged inside the case body with the outer surface side facing the outer surface side of the case body. A welded portion in which the water-repellent / oil-repellent layer is not laminated is provided, and the welded portion provided at the edge of the vent hole in the case body is welded to the welded portion. It has characteristics.

A second aspect of the present invention is characterized in that, in the first aspect, a protective rib is formed on the inner surface side of the case main body so as to project around the gas permeable membrane.

[0008]

According to the invention of claim 1, since insert molding is unnecessary by using a simple means such as welding for attaching the gas permeable membrane, the mold structure is complicated or the number of manufacturing steps is reduced. You don't have to increase it. In addition, the attachment strength of the gas permeable membrane can be secured by welding the porous layer having a relatively high adhesiveness to the case body instead of the water / oil repellent layer having a low adhesiveness.

According to the second aspect of the present invention, the protective ribs prevent other components or the like from coming into contact with and damaging the gas permeable membrane when the components are transported or assembled.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the electronic device case 10 (hereinafter, referred to as “case”) of the present embodiment is covered with a box-shaped case base 12 that houses and holds a circuit board 11, and an upper surface opening of the case base 12. And a lid body 13 that opens. The case base 12 and the lid 13 (both correspond to the “case body” of the present invention)
For example, it is formed of a synthetic resin material such as polybutylene terephthalate (PBT) and polyphenylene sulfide (PPS). A cylindrical fitting portion 14 into which a mating connector (not shown) can be fitted is formed to project on the outer surface of the case base portion 12. Further, a terminal fitting 16 is embedded in the case base 12, and one end of the terminal fitting 16 projects into the tubular fitting portion 14 to connect with a mating terminal fitting provided in the mating connector. Is possible. The other end of the terminal fitting 16 is connected to the circuit on the circuit board 11 inside the case 10.

The lid 13 is covered with an opening on the upper surface of the case base 12 via a seal member (not shown), and is fixed to the case base 12 by screwing or the like, so that the inner space of the case 10 is closed. It is hermetically sealed. A circular ventilation hole 17 is provided through the upper surface of the lid body 13, and a circular ventilation film 20 is attached to the inside of the case 10 so as to cover the ventilation hole 17.

As shown in FIG. 2, the breathable film 20 has a water repellent property.
It has a structure in which a porous layer 22 is laminated on the oil repellent layer 21, and has a property of blocking passage of liquid but permitting passage of gas. The water / oil repellent layer 21 is formed of a nonwoven fabric made of a resin having water / oil repellency such as polyethylene terephthalate (PET). The porous layer 22 is formed of, for example, a porous film of polytetrafluoroethylene (PTFE) or the like. The outer diameter of the water / oil repellent layer 21 is made slightly larger than the inner diameter of the ventilation hole 17. Further, the outer diameter of the porous layer 22 is made slightly larger than the outer diameter of the water / oil repellent layer 21, so that the outer periphery of the porous layer 22 is covered with the water / oil repellent layer 21 not laminated. Welded part 2
3 is formed. On the other hand, the vent hole 1 in the lid 13
A welded portion 18 having a mountain-shaped cross section and annularly protruding toward the inside of the case 10 is formed at the edge of the hole 7. The breathable film 20 is arranged so that the water-repellent / oil-repellent layer 21 is on the outer surface side of the case 10, and the welded portion 18 is provided.
The gas permeable membrane 20 is attached by welding this portion by ultrasonic welding or the like in a state in which the tip end portion of the is adhered to the welded portion 23 of the porous layer 22 (see FIG. 3). Further, on the inner surface side of the lid body 13, an annular protective rib 19 is formed so as to project around the gas permeable membrane 20, and the gas permeable membrane 20 is accommodated in a recessed portion inside the protective rib 19. ing.

As described above, according to the present embodiment, since insert molding is unnecessary by using a simple means such as welding for attaching the gas permeable membrane 20, the mold structure is complicated or the number of manufacturing steps is increased. You don't have to. Further, the PTF having a relatively high adhesiveness to the lid 13 is not the water / oil repellent layer 21 made of PET or the like having a low adhesiveness.
Since the porous layer 22 such as E is welded, the attachment strength of the gas permeable membrane 20 can be secured.

Further, the protection ribs 19 prevent other parts or the like from coming into contact with and damaging the gas permeable membrane 20 when the parts are transported or assembled.

The present invention is not limited to the embodiments described above and illustrated in the drawings, and can be implemented with various modifications without departing from the scope of the invention.

[Brief description of drawings]

FIG. 1 is an overall cross-sectional view showing an electronic device case according to the present embodiment.

FIG. 2 is a partially enlarged cross-sectional view showing a state before attaching a breathable film.

FIG. 3 is a partially enlarged cross-sectional view showing a state in which a breathable membrane is attached.

FIG. 4 is a sectional view showing a conventional electronic device case.

5A is a perspective view showing another conventional electronic device case, FIG. 5B is a sectional view thereof, and FIG. 5C is a partially enlarged sectional view thereof.

[Explanation of symbols]

10 ... Electronic device case 11 ... Circuit board (electronic component) 12 ... Case base (case body) 13 ... Lid body (case body) 17 ... Vent 18 ... Welded part 19 ... Protective rib 20 ... Breathable membrane 21 ... Water / oil repellent layer 22 ... Porous layer 23 ... Welded part

Claims (2)

[Claims] 1. A case for electronic equipment for housing electronic parts in a hermetically sealed state, wherein a case body made of synthetic resin is provided with a vent hole covered with a vent film, wherein the vent film is The water-repellent / oil-repellent layer is laminated with a porous layer, and the water-repellent / oil-repellent layer is arranged inside the case body with the water-repellent / oil-repellent layer side facing the outer surface side of the case body. A welded portion in which the water-repellent / oil-repellent layer is not laminated is provided on an outer peripheral portion, and a welded portion provided at a hole edge portion of the vent hole in the case body is welded to the welded portion. A case for electronic equipment characterized by the above. 2. The electronic device case according to claim 1, wherein a protective rib is formed on the inner surface side of the case body so as to project around the gas permeable membrane.