JPH08139236A - Heat dissipation structure of heating element - Google Patents

Abstract

PURPOSE: To obtain cooling structure of a heat generation element so that the heat generation element stored in a case made of a material of low thermal conductivity can be cooled efficiently. CONSTITUTION: A cooling structure consists of a heat sink 2 attached to a heat generation element 1 and cooling the heat generation element 1, a case 3 for storing the heat sink 2 and fixing it by fixing means 5a and 5b, and a grease 6 filled between the storage case 3 and the heat sink 2 to improve contact between them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat dissipating structure for a heat generating element, such as a power transistor, for improving the heat dissipating of the heat generating element when the heat dissipating element is provided in a housing case having poor heat dissipation.

[0002]

2. Description of the Related Art Conventionally, as a means for radiating a heat generating element such as a power transistor inside an electronic device by natural heat radiation, a heat radiating element made of aluminum having a high heat conductivity is provided in the heat generating element to accommodate the heat generating element. Dissipate heat inside the storage case, or use aluminum as the material of the storage case to further improve heat dissipation efficiency, and directly fix the heating element to the storage case to dissipate heat to the outside of the storage case as a radiator. There were many structures. On the other hand, if there are environmental restrictions due to the place where the electronic device equipped with the heating element should be installed,
For example, when corrosion resistance and strength are required, a storage case made of aluminum, which has good heat dissipation performance but is poor in corrosion resistance and strength, is not suitable for use, and therefore, a stainless steel case has been used. Further, even when the airtightness is further required as an environmental constraint at the place where the electronic device is to be installed, a similar heat dissipation structure is often adopted.

[0003]

As described above, in the conventional heat dissipating structure for the heat generating element, the material of the storage case that also functions as a heat radiator due to the environmental restrictions of the place where the electronic device is to be installed. However, there is a problem in that the stainless steel material has to be used, and the heat conductivity of the stainless steel material is not high, so that the heat radiation efficiency is poor and the heat radiation means is difficult.
Further, in addition to the above restrictions, even when the airtightness is required, the stainless steel material had to be used as the material of the storage case. Therefore, the heat dissipated from the heat generating element is stored in the storage case for the same reason as above. There is also a problem that it becomes difficult to escape to the outside, and the temperature of the heating element further rises, which causes deterioration of the performance of the element.

The present invention has been made in order to solve the above-mentioned problems, and heat generation that can efficiently dissipate heat from a heating element housed in a housing case made of a material having a low thermal conductivity. The purpose is to obtain a heat dissipation structure for the device.

[0005]

According to the present invention, there is provided a heat dissipating structure for a heat generating element, wherein a heat dissipating plate is accommodated in a housing case, and the heat dissipating plate dissipates heat from the heat generating element evenly. The storage case is fixed by the fixing means, and the grease is interposed between the storage case and the heat dissipation plate to enhance the adhesion between the storage case and the heat dissipation plate.

[0006]

According to the heat dissipation structure of the heating element of the present invention,
The heat generated from the heat generating element is first transferred to the heat radiating plate that is in close contact with the heat generating element by heat conduction, then from the heat radiating plate to the grease, and then from this grease to the entire housing case. In this case, since the grease is interposed between the storage case and the heat dissipation plate, it is possible to enhance the adhesion between the storage case and the heat dissipation plate and reduce the contact thermal resistance. Therefore, heat can be efficiently conducted from the heat radiating plate to the entire housing case, and as a result, heat can be efficiently radiated from the heating element.

[0007]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. The present embodiment shows the heat dissipation structure of the heating element (power transistor) in the 4-wire electromagnetic flowmeter. FIG. 1 is a cross-sectional view showing a heat dissipation structure of a heating element according to an embodiment of the present invention. In the figure, 1 is a heating element such as a power transistor, and 2 is a plate-shaped heat dissipation plate made of aluminum having a high thermal conductivity. The heating element 1 is tightly fixed by a screw or the like (not shown) via grease (not shown). Although the heat dissipation plate 2 is formed in a flat plate shape in the present embodiment, it may be formed by bending so as to have a corrugated cross section, for example, in order to increase the heat transfer area. 3 is a stainless steel case formed in a box shape for accommodating the heat generating element 1 while ensuring corrosion resistance and strength, and 4 is an inner wall surface of the case 3 for fixing the heat dissipation plate 2 with screws (fixing means). ) A fixing surface 5c provided with a screw hole (fixing means) 5b having an appropriate depth so that the screw 5 can be fixed by the screw 5a.
It is wound around a and is arranged between the screw head of the screw 5a and the heat radiating plate 2, and by tightening the screw 5a, the heat radiating plate 2 is pressed against the fixing surface 4 side, and the spring 6 for evenly radiating heat is fixed. It is a grease having a large thermal conductivity which is interposed between the surface 4 and the heat dissipation plate 2 to enhance the adhesion between them and reduce the contact thermal resistance. The grease 6 is used by applying it to the fixed surface 4, but it has a property that it is soft immediately after application and is appropriately hardened thereafter.

Next, the operation and effect of this embodiment will be described. The heat generated from the heat generating element 1 is first transferred by heat conduction to the heat radiating plate 2 that is in close contact with the heat generating element 1 and then from the heat radiating plate 2 to the grease 6 and the fixing surface 4, and further to this fixed surface. It is transmitted from 4 to the entire storage case 3. In this case, since the grease 6 is interposed between the fixed surface 4 of the storage case 3 and the heat dissipation plate 2, the contact between the fixed surface 4 and the heat dissipation plate 2 is enhanced to reduce the contact thermal resistance. You can Therefore, heat is efficiently conducted from the heat sink 2 to the fixed surface 4, and as a result, the heat is stored in the storage case 3.
It can be efficiently diffused to the whole, and the entire storage case 3 can be radiated as a kind of radiator. That is, due to the environmental restrictions of the place where the electronic device should be installed, even if a stainless steel material having a low thermal conductivity is used as the material of the housing case 3 which also plays a role as a radiator, the heat dissipation of the heat generating element 1 is efficiently performed. It has the effect of being able to perform well. Moreover, since the heat dissipation of the heating element 1 can be efficiently performed in this way,
Even when the storage case 3 needs to be hermetically sealed, there is an effect that the temperature inside the storage case 3 and the heating element 1 can be prevented from further increasing in temperature, and the performance of the heating element 1 can be prevented from deteriorating.

Example 2. FIG. 2 is a cross-sectional view showing a heat dissipation structure of a heating element according to another embodiment of the present invention. In the drawing, reference numeral 7 denotes through holes provided in the heat dissipation plate 2 in an appropriate number, and all other members are the same as those in the first embodiment. Since it is the same as the one described above, the same reference numerals are given and the description thereof is omitted. The through holes 7 are for releasing air that may accumulate between the heat radiating plate 2 and the fixed surface 4 when the heat radiating plate 2 is fixed by applying the grease 6 to the fixed surface 4. Therefore, according to the configuration of the second embodiment, the air that causes the contact thermal resistance and inhibits the heat radiation can be removed from the through hole 7, and the heat radiation of the heating element 1 can be performed more efficiently. effective. Although the heat dissipation plate 2 is formed in a flat plate shape in the present embodiment as well, it may be formed by bending so as to have a corrugated cross section, for example, in order to increase the heat transfer area. The same as in Example 1.

Embodiment 3. FIG. 3 is a sectional view showing a heat dissipation structure of a heating element according to still another embodiment of the present invention. In the drawing, 8 is formed on the inner wall surface of the storage case 3 so that both ends of the heat dissipation plate 2 can be engaged and supported. It is a recessed part. Therefore, according to the configuration of the third embodiment, the screw 5a and the screw hole 5b for fixing the heat dissipation plate 2 to the storage case 3 are unnecessary, and the heat dissipation of the heat generating element 1 can be efficiently performed with a simpler structure. There is an effect that can be. The heat dissipation plate 2 in this embodiment may be provided with the through hole described in the second embodiment.

[0011]

As described above, according to the present invention, a heat radiating plate for closely fixing a heat generating element to radiate heat from the heat generating element, and a storage case for accommodating the heat radiating plate and fixing it by a fixing means, Since the grease is provided between the housing case and the heat dissipation plate to enhance the adhesion between the housing case and the heat dissipation plate, it is possible to efficiently dissipate heat from the heating element housed in the housing case made of a material having a low thermal conductivity. There is an effect that a heat dissipation structure of the heat generating element that can be performed is obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a heat dissipation structure of a heating element according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a heat dissipation structure of a heating element according to another embodiment of the present invention.

FIG. 3 is a partial sectional view showing a heat dissipation structure of a heating element according to still another embodiment of the present invention.

[Explanation of symbols]

 1 Heating Element 2 Heat Sink 3 Storage Case 4 Fixing Surface 5a Screw (Fixing Means) 5b Screw Hole (Fixing Means) 6 Grease

Claims (1)

[Claims] 1. A heat radiating plate for closely fixing a heat generating element to radiate heat from the heat generating element, a housing case for housing the heat radiating plate and fixing the heat radiating plate by fixing means, and a space between the housing case and the heat radiating plate. A heat-dissipating structure for a heat-generating element, which is provided with grease to enhance the adhesion between the two.