JPH054310Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a storage structure for storing a substrate having a heat sink in a case.

In general, electronic devices used in adverse environments, such as electronic devices for automobiles, are often housed in resin cases in order to protect the electronic devices from dust, dust, water droplets, and the like from the outside. Furthermore, when an electronic device includes a heat generating element such as a power transistor, it is also desirable to ensure sufficient heat dissipation in order to protect other elements from heat damage.

[Prior Art] FIGS. 4 and 5 are explanatory diagrams of a conventional storage structure. In FIG. 4, a board 2 is stored in a resin case 1 with an open bottom surface, A metal pedestal 3 is fixed with screws, leaving some openings on the sides to ensure heat dissipation. Further, in FIG. 5, a substrate 2 is housed in a resin case 1 whose lower surface is open, and the open surface is covered with a resin frame 4 that fits into the case 1.

[Problem that the invention attempts to solve]

Among the conventional configurations mentioned above, the structure shown in FIG.
Since there is an opening between the case 1 and the metal pedestal 2, there is a drawback that the dustproofness and dripproofness are poor.

On the other hand, the structure shown in FIG. 5 has better dustproof and drip-proof properties than the structure shown in FIG. 4 by closely fitting the case 1 and the resin frame 4. However, on the other hand, it has the disadvantage that heat dissipation becomes extremely poor.
That is, when a heat generating element such as a power transistor is mounted on the substrate 2, the heat generating element is attached to a heat sink 5 provided on the substrate 2 as shown in FIGS. 4 and 5, but in the structure shown in FIG. Because of its good properties, the heat from the heat sink is trapped inside the case and cannot be easily dissipated to the outside. For this reason, there is a drawback that the capacity and usage conditions of power transistors and the like are greatly restricted.

The structure shown in Fig. 4 is similar to the structure shown in Fig. 5 because it uses a metal pedestal 2 and leaves an opening.
The heat dissipation is better than the structure shown in the figure, but this is only a comparison with Fig. 5, and since all the heat dissipation of the heat sink 5 is done inside the case 1, there is a limit to its heat dissipation. be. Therefore, in either structure, the temperature of the heat sink 5 rises considerably,
A chip 6 such as a microcomputer that is susceptible to heat damage needs to be mounted as far away from the heat sink 5 as possible, which reduces the degree of freedom in arranging components on the board.

The present invention solves these conventional problems, and its purpose is to provide a substrate storage structure that is excellent in dust-proofing, drip-proofing, and heat dissipation.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention stores a board with a heat sink attached near the edge of the board in a case body so that the heat sink is located on the open side of the case, and The open surface is closed by a case lid having an opening that fits with the heat sink, the heat sink is fitted into the opening so as to be exposed from the inside to the outside, and the case lid is exposed at the opening of the case lid. The heat dissipation plate is fixed to a part of a metal frame for holding and fixing the case body in a predetermined position.

[Effect]

The open side of the case body is closed by fitting the opening of the case lid with the heat dissipation plate, ensuring sufficient dust-proof and drip-proof properties, and the heat dissipation plate comes in contact with the outside via the pedestal, allowing for sufficient heat dissipation. will be carried out.

〔Example〕

FIG. 1 is a partially cutaway side view of an embodiment of the present invention.

In the figure, a case body 10 made of resin has a horizontally opening structure with only the left end open, and a board 11 is housed therein.

A heat sink 13 is attached to the end of the substrate 11 with screws 12, and a heat generating element 14 such as a power transistor is fixed to the heat sink 13 with screws 15. The board 11 is inserted into the case body 10 so that the side to which the heat sink 13 is attached is on the open side of the case body 10, and the case body 10 is closed with a resin case lid 16 having an opening that fits with the heat sink 13. The open surface of is preferably sealed.

The claw portions 17a of the metal frame 17 are inserted into the guide portions 10a formed on the right side, front and back surfaces of the case body 10, and the screws 18 are used to secure the case body 10.
and the metal frame 17 are fixed. Metal frame 1
A part of 7 is bent so as to completely cover and contact the heat sink 13 exposed from the opening of the case lid 16, and the heat sink 13 and the metal frame 17 are fixed at this part with screws 19. has been done.

A bracket 20 is attached to the metal frame 17, and the case body 10 is attached to an automobile or the like using this bracket 20.

In this embodiment, the connector 21 is attached directly behind the heat sink 13 on the board 11. This allows the connector 21 to play the role of a heat shield,
This is to prevent the heat of the heat sink 13 from being directly transmitted to microcomputers and the like that are susceptible to heat damage.

FIG. 2 is an exploded view of FIG. 1, and the same reference numerals as in FIG. 1 indicate the same parts.

A guide part 10b for guiding the board 11 is provided on the inner surface of the case body 10, and the board 11 is slid along this guide part 10b, and is guided inside the case body 10 by this guide part 10b. is held in place.

After the board 11 on which the heat sink 13, the connector 21, the elements 22 such as a microcomputer, etc. are mounted is housed in the case body 10 as described above,
The open surface of the case body 10 is sealed by the case lid 16. The method of fixing the case lid 16a and the case body 10 is shown in the figure by providing a claw portion 16a on the case lid 16 and locking the claw portion 16 to protrusions (not shown) provided on the front and back surfaces of the case body. This is what we do.

After covering the case lid 16, next place the metal stand 17.
The claw portion 17a is inserted into the guide portion 10a of the case body 10, and both are fixed with the screw 18. In addition, the metal frame 17 and the heat sink 1 are connected by screws 19.
3 and fixed.

In the above embodiment, the case body 10 and the case lid 16 are made of resin, but they may be made of metal.

FIG. 3 is a side view of main parts of another embodiment of the present invention, and the same reference numerals as in FIG. 1 indicate the same parts. In this embodiment, a screw 1 for fixing a heat sink 13 to a substrate 11 is used.
2 is connected to the ground pattern formed on the substrate 11, and the heating element 14 is connected to the insulating plate 3.
It is attached to the heat sink 13 via 0.
With such a structure, the heat transfer path becomes the earth path as it is, and the bracket earth can be set without any special parts.

[Effect of idea]

As explained above, in this invention, the opening of the case lid and the heat sink are fitted together to close the open surface of the case body that houses the board, so it has excellent dustproof and drip-proof properties, and the heat sink is Since it makes contact with the outside via the metal frame, even if the case body is made of resin, the heat from the heat sink is not trapped inside the case and can be sufficiently dissipated to the outside, resulting in excellent heat dissipation. Furthermore, the heat radiation area includes not only the area of the heat sink but also the area of the pedestal, increasing the thermal capacity. As a result, it is possible to reduce the area of the heat sink, which has the effect of increasing the effective area on the substrate accordingly. Further, since the heat of the heat sink can be sufficiently radiated to the outside through the metal frame, sufficient heat can be radiated regardless of the material of the case, increasing the degree of freedom in case design. Furthermore, since the case lid is held down by a pedestal, the sealing performance of the case body can be further increased, and there is no need to use a special structure to prevent the case lid from coming off.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of an embodiment of the present invention, Fig. 2 is an exploded assembly view of Fig. 1, Fig. 3 is a side view of main parts of another embodiment of the present invention, and Fig. 4 is a side view of a main part of another embodiment of the invention. The figure is an explanatory diagram of a conventional storage structure, and FIG. 5 is an explanatory diagram of another conventional storage structure. In the figure, 10 is the case body, 11 is the board,
13 is a heat sink, 16 is a case lid, and 17 is a metal frame.

Claims (1)

[Claims for Utility Model Registration] A board with a heat sink attached near the edge of the board is housed in a case body so that the heat sink is positioned on the open side of the case, and the open side of the case body is placed on the open side of the case body. The case lid is closed by a case lid having an opening that fits with the heat sink, and the heat sink is fitted into the opening so as to be exposed from the inside to the outside, and the heat sink that appears in the opening of the case lid is closed. A storage structure for a board having a heat sink, characterized in that the structure is fixed to a part of a metal pedestal for holding and fixing the case body in a predetermined position.