JPH0823184A - Electronic circuit case provided with heat removing structure - Google Patents

Abstract

PURPOSE:To provide an electronic circuit case provided with a heat removing structure that is excellent in heat removing capability and thus enables heat removal in environments containing water or dust. CONSTITUTION:An electronic circuit case 1 is provided with heat removing structure: Outer fins 3 and inner fins 4 are formed outside and inside a circumferential wall 2, respectively; these fins 3, 4 are thermally coupled with each other. The inner fins 4 on the circumferential wall 2 of the electronic circuit case 1 are placed in proximity to heating elements 5, such as dropper resistors. The inner fins 4 absorb heat generated from a heating element 5. The absorbed heat is efficiently transmitted to the outer fins 3, through which the heat is removed by radiation or the like. In brief the inner fins absorb heat, and the outer fins radiate it. If electric parts involving heating are housed in a small space, as a result, heat is efficiently removed. This prevents excessive temperature rise within an electronic circuit case, and eliminates the influence of heat oh other parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit case containing a plurality of electronic elements, and more particularly to an electronic circuit case having a heat removal structure for radiating heat generated from the electronic elements and the like to the outside of the case.

[0002]

2. Description of the Related Art In an electric circuit used for electric equipment mounted on an automobile, etc., when an electronic part which generates heat such as a dropper resistance is housed in a small electronic circuit case, thermal influence on other parts is caused. It is necessary to efficiently radiate heat so as not to give heat to suppress an excessive rise in temperature inside the electronic circuit case. In a conventional electronic circuit case, when a large amount of heat such as a dropper resistance is stored in the case, many slits are provided in the electronic circuit case, and the electronic circuit case is operated by the action of natural convection of air. It was radiating heat to the outside.

As shown in FIG. 5, a conventional electronic circuit case 5 is used.
0 is a slit 5 provided in one side wall 50A of the electronic circuit having the dropper resistor 52 therein.
The low-temperature inflow air 53 outside the case is taken in from 1A. Then, the inflow air 53 enters the electronic circuit case 50, contacts the dropper resistor 52, and removes heat from the dropper resistor 52 to raise its own temperature. After this, the slit 5 of the ceiling wall 50B is used as the high temperature outflow air 54.
Flow out from 1B. In this way, the heat is removed from the heating element by the natural convection of air.

[0004]

However, in the conventional natural convection type electronic circuit case as described above, since the specific heat or heat capacity of air as a heat removing medium is small, a sufficient heat removing effect cannot be obtained. There was a problem. Furthermore, the configuration of the electronic circuit case having such many slits on the ceiling wall or the side wall is difficult to use in an environment where water and dust enter the electronic circuit case. Further, when the entire circuit is covered with a molding material or the like, the slit cannot be provided in the electronic circuit case, which makes it difficult to adopt the heat removal by natural convection as described above.

The object of the present invention is to solve the above-mentioned problems of the prior art. It has a high heat removal function and is capable of removing heat even in an environment where water and dust are present. An object of the present invention is to provide an electronic circuit case provided with.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic circuit case having a heat removal structure containing an electronic circuit having a heating element inside and outside the same peripheral wall constituting the electronic circuit case, respectively. This can be achieved by an electronic circuit case provided with a heat removal structure characterized in that fins are provided and both fins are thermally connected.

Further, the above object of the present invention is to provide an electronic circuit case having a heat removal structure containing an electronic circuit having a heating element, with fins provided inside and outside the same peripheral wall constituting the electronic circuit case, Achieved by an electronic circuit case having a heat removal structure characterized in that a gap between an inner fin of a peripheral wall of the electronic circuit case and a heating element is filled with a heat conductive material, and both fins are thermally connected. can do.

[0008]

In the electronic circuit case provided with the heat removal structure according to the present invention, fins are provided inside and outside the same peripheral wall constituting the electronic circuit case, and both fins are thermally connected. As a result, the fins inside the peripheral wall of the electronic circuit case effectively absorb the heat generated by the heating element inside the electronic circuit case, and the absorbed heat is effectively transmitted to the fins outside the peripheral wall of the electronic circuit case. Heat is removed from the outer fins. Therefore, the heat transfer between both fins is performed with low loss, so that high heat removal efficiency is realized.

Further, fins are provided inside and outside the same peripheral wall constituting the electronic circuit case, and a gap between the inner fin on the peripheral wall of the electronic circuit case and the heating element is filled with a heat conductive material. This is a configuration in which is thermally connected. With this, the heat from the heating element is transmitted to the inner fins with high efficiency by being conducted through the heat conducting material, and further improved heat removal efficiency can be realized.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an electronic circuit case having a heat removal structure of the present invention will be described below with reference to FIGS. FIG. 1 is a partial perspective view showing a first embodiment of an electronic circuit case having a heat removal structure of the present invention, and FIG. 2 is an explanatory view showing a heat removal state in FIG. As shown in FIG. 1, an electronic circuit case 1 having the heat removal structure of this embodiment is provided with outer fins 3 and inner fins 4 on the inside and outside of the peripheral wall 2, respectively, and these fins 3 and 4 are thermally connected. The configuration is as follows. The thermal connection between the fins 3 and 4 is realized by resin-molding the fins 3 and 4 with the same peripheral wall member, for example. The peripheral wall 2 of this electronic circuit case 1
The inner fins 4 are disposed as a pair of walls facing at least the heating element 5 from the lower surface of the peripheral wall near the heating element 5 such as a dropper resistor attached to the wiring board 8 by the soldering portion 9. Further, the outer fins 3 are provided so as to project from the outer wall 6 of the case at a position facing the inner fins 4 with the peripheral wall 2 therebetween. The material of the electronic circuit case 1 including both the fins 3 and 4 does not have to be resin, and can be formed of a metal alloy based on aluminum or the like.

As shown in FIG. 2, the inner fins 4 of the peripheral wall 2 of the electronic circuit case having the above-described structure transfer the heat generated from the heating element 5 in the electronic circuit case to the radiant heat transfer 11 or the convective heat transfer of the air inside the case. 12 efficiently absorbs heat (collects heat). The absorbed heat is efficiently transferred to the outer fins 3 by the low-loss heat transfer between the inner fins 4 and the outer fins 3 on the peripheral wall of the electronic circuit case, and the heat is removed from the outer fins 3 by the heat radiation 13 or the like. Is.

That is, the inner fins 4 on the peripheral wall of the electronic circuit case have a heat absorbing function, and the outer fins 3 on the same peripheral wall have a heat radiating function. As a result, a temperature gradient is formed from the relatively high temperature inner fin 4 to the relatively low temperature outer fin 3. As a result, heat can be efficiently transferred from the case inner side 7 to the case outer side 6 of the electronic circuit case, and thus a large heat removal effect can be obtained.
As a result, heat can be efficiently removed even when accommodating heat-generating electrical components in a narrow space, and it is possible to prevent excessive temperature rise in the electronic circuit case and avoid thermal effects on other components. can do.

A second embodiment of the electronic circuit case having the heat removal structure according to the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is a partial perspective view showing a second embodiment of an electronic circuit case having a heat removal structure according to the present invention, and FIG. 4 is an explanatory view of a heat removal state in FIG. As shown in FIG. 3, in the electronic circuit case 21 having the heat removal structure of the present embodiment, the inner fins 24 are provided inside the peripheral wall 22 which constitutes at least the heating element from the lower surface of the peripheral wall near the heating element 5 such as a dropper resistor. 5 are provided as a pair of walls that face each other with 5 in between. The outer fins 23 are provided outside the peripheral wall 22.
However, the inner fins 2 are separated by the peripheral wall 22 on the outside 26 of the case.
4 is provided so as to project at a position opposite to 4. This outer fin 2
3 and the inner fin 24 are thermally connected to each other, and this thermal connection is realized, for example, by resin-molding both fins 23 and 24 with the same peripheral wall member. In addition,
Similar to the first embodiment, the material of the electronic circuit case 21 does not have to be resin, and can be formed of a metal alloy based on aluminum or the like.

The inner fins 24 of the peripheral wall 22 of the electronic circuit case 21 have a sufficient depth to enclose the heating element 5 such as a dropper resistor. Further, the thermally conductive molding material 2 is provided in the space between the heating element 5 and the inner fin 24.
Fill 8. As the filling method, the heating element 5 mounted on the wiring board 8 by the soldering portion 9 is put in a predetermined mold, the molding material 28 is poured, and the mold material 28 is taken out from the mold before it is solidified and the predetermined position in the electronic circuit case 21. The heating element 5 is disposed between the predetermined inner fins 24 together with the molding material 28 by being attached to. Alternatively, the wiring board 8 may be attached to the electronic circuit case 21.
Alternatively, the molding material 28 may be attached at a predetermined position inside and the molding material 28 may be directly poured into the gap with the case inside 27 facing upward. Also,
As the molding material, an epoxy resin or a nylon resin, which has a large heat transfer coefficient and is excellent in other thermal characteristics, is suitable, but the molding material is not limited thereto.

Molding material 2 filled as shown in FIG.
8 efficiently transfers the heat generated from the heating element 5 to the inner fins 24 by the conduction heat transfer 29. This heat is effectively transmitted to the outer fins 23 by the low loss heat flow-through 30, and is removed from the outer fins 23 by the heat radiation 31 and the like. With this configuration, the heat transfer efficiency is improved, and the amount of heat absorbed from the heating element per unit time and unit area is increased. That is, the present embodiment remarkably improves the heat transfer from the heating element to the inner fins 24 of the electronic circuit case by using the molding material 28 having a larger heat transfer coefficient than air.

[0016]

As described above, in the electronic circuit case provided with the heat removal structure according to the present invention, fins are provided inside and outside the same peripheral wall constituting the electronic circuit case, and both fins are thermally provided. It is a structure connected to.
With this configuration, the inner fins on the peripheral wall of the electronic circuit case effectively absorb heat from the heating element in the electronic circuit case,
The absorbed heat is effectively transmitted to the outer fins of the peripheral wall of the electronic circuit case, and the heat is removed from the outer fins by heat radiation or the like. Furthermore, since heat transfer between both fins is performed with low loss, high heat removal efficiency can be realized, and temperature rise in the electronic circuit case can be effectively suppressed. Therefore, even when the heat-generating electrical components are stored in a narrow space, the heat can be efficiently removed, excessive temperature rise can be suppressed, and thermal influence on other components can be avoided. You can

Further, fins are provided inside and outside the same peripheral wall constituting the electronic circuit case, and a gap between the inner fin on the peripheral wall of the electronic circuit case and the heating element is filled with a heat conductive material. This is a configuration in which is thermally connected. With this configuration, the heat from the heating element is conducted through the heat conducting material and efficiently transmitted to the inner fins, and further improved heat removal efficiency can be realized.

Further, the heat is removed by the heat flow through the peripheral wall material of the electronic circuit case, and it is not due to the convection of air, so that it is not necessary to provide an opening such as a slit in the electronic circuit case. Therefore, since the electronic circuit case can be sealed, heat can be efficiently removed while ensuring water resistance and dust resistance.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing a first embodiment of an electronic circuit case having a heat removal structure according to the present invention.

FIG. 2 is an explanatory diagram showing a heat removal state in FIG.

FIG. 3 is a partial perspective view showing a second embodiment of an electronic circuit case having a heat removal structure according to the present invention.

FIG. 4 is an explanatory diagram showing a heat removal state in FIG.

FIG. 5 is a cross-sectional view showing a conventional heat removal structure.

[Explanation of symbols]

 1,21 Electronic Circuit Case with Heat Removal Structure 2,22 Peripheral Wall 3,23 Outer Fin 4,24 Inner Fin 5 Heater 6,26 Outer Case 7,27 Inside Case 8 Wiring Board 11 Radiant Heat Transfer 12 Convective Heat Transfer 13 , 31 Heat dissipation 14,30 Heat flow through 28 Mold material 29 Conductive heat transfer

Claims (2)

[Claims] 1. An electronic circuit case having a heat removal structure containing an electronic circuit having a heating element, wherein fins are provided inside and outside the same peripheral wall constituting the electronic circuit case, and both fins are thermally provided. An electronic circuit case having a heat removal structure characterized by being connected. 2. An electronic circuit case having a heat removal structure containing an electronic circuit having a heating element, wherein fins are provided on the inside and outside of the same peripheral wall forming the electronic circuit case, respectively. An electronic circuit case having a heat removal structure, characterized in that the gap between the inner fin and the heating element is filled with a heat conductive material, and the two fins are thermally connected.