JPH08204371A - Radiating structure of electronic component - Google Patents

Abstract

PURPOSE: To make a radiating structure with a small size in height on a printed circuit board, by changing a plane surface area of a heat sink adequately according to the amount of heat generated from an electronic component on the heat sink. CONSTITUTION: A heat sink 2 made of flat metallic plate is provided in parallel with and separated from a face of a printed circuit board 1. In this case, the heat sink 2 has a narrow leg part 2a formed in a body on an end part thereof. The flat metallic plate of the heat sink 2 has a structure that can be diminished or extended in size lengthwise or crosswise according to the amount of heating from an electronic component 3 like a semiconductor device. Then, the heat from electronic component 3 mounted on the heat sink 2 is radiated outside from the heat sink 2.

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 electronic parts, particularly a semiconductor, mounted on a printed circuit board which constitutes an electronic device.

[0002]

2. Description of the Related Art Conventionally, a heat sink made of a metal plate such as aluminum die casting is generally attached to a printed board as a heat radiation structure for preventing electronic parts attached to the printed board which constitute an electronic device from generating heat. The heat generated from the electronic component is dissipated into the air through the heat sink by closely fixing the electronic component to the heat sink with screws or the like.

Various structures of such a heat sink have been devised, and a heat dissipation structure corresponding to the amount of heat generated from electronic components used, for example, semiconductor elements such as thyristors, triacs, and MOS FETs is used. For example, the heat sink 10 shown in FIG. 8 is a heat sink having a structure in which a plurality of semiconductor elements that generate a large amount of heat can be arranged, and a substrate 10a for fixing the semiconductor elements and multiple layers on both sides of the substrate 10a with a predetermined space therebetween. It has a structure in which a raised heat radiating plate 10b is provided. Heat sink 1 having such a structure
0 is a substrate 1 with a space left from the printed substrate 11.
0a is arranged, and in order to further enhance the heat radiation effect, the lateral dimension (arrows X1, X2 directions) of the heat radiating plate 10b is increased, and the height dimension (arrow Y direction) is also increased. Was trying to raise.

[0004]

However, in the conventional heat dissipation structure as described above, since the area of the mounting portion to the printed circuit board 11 is large, the lateral dimension thereof is set in order to obtain a heat dissipation plate having a great heat dissipation effect. If the size is increased, the space for mounting other components on the printed circuit board is narrowed, and if the size of the heat dissipation plate in the height direction is increased, there is a problem in that the size and weight of the entire product cannot be reduced. Therefore, when a heat sink is used, there is a problem that a heat dissipation structure in which the dimension of the printed board in the height direction does not increase is solved.

[0005]

In order to solve the above problems, a heat dissipation structure of an electronic component according to the present invention is a printed board on which an electronic component is mounted, and a heat sink formed in a flat plate shape on the surface of the printed board. According to the heat sink, the surface area of the flat plate shape is appropriately changed according to the amount of heat generated by the electronic components mounted on the heat sink.

Further, the flat plate-shaped heat sink is formed in a corrugated plate shape; the flat plate-shaped heat sink is provided with a plurality of through holes; The flat plate-shaped heat sink is formed in the flat plate shape. The heat sink is a heat dissipation structure for electronic components formed in a plurality of groove shapes.

[0007]

With the above structure, the size of the flat-plate heat sink is set to the surface area corresponding to the amount of heat generated from the electronic component, and the heat sink is installed on the surface of the printed board.
There is a space in which air flows freely between the heat sink and the printed circuit board, and the heat absorbed by the heat sink can be dissipated into the air without providing a heat radiating plate in the height direction of the printed circuit board as in the prior art. Like

In addition, the flat plate surface has a corrugated plate shape, a through hole form, a groove form, and the like, or a combination thereof to increase the surface area of the flat plate to enhance the heat dissipation effect. Will be able to

[0009]

Embodiments of the heat dissipation structure of an electronic component according to the present invention, particularly the heat dissipation structure of a semiconductor element, will be described below in detail with reference to the drawings.

As shown in FIG. 1, the heat dissipation structure for an electronic component according to the first embodiment of the present invention is a flat metal plate parallel to the surface of the printed board 1 and separated from the surface by a space. The heat sink 2 formed of a plate is installed. For that purpose, the thin leg portion 2a is provided at an appropriate position on the end portion of the heat sink 2.
Are integrally formed. The length of the leg portion 2a regulates the distance between the printed board 1 and the heat sink 2, that is, the height of the heat radiation space. calculate. A female screw is previously cut at the electronic component mounting position on the surface of the heat sink 2.

The size of the flat plate-shaped metal plate forming the heat sink 2 has a structure in which the area is appropriately expanded or reduced in the horizontal or vertical direction according to the amount of heat generated by the electronic component 3 to be mounted, for example, a semiconductor element. ing.

The heat sink 2 having such a structure is placed at a predetermined position on the upper surface of the printed circuit board 1, and the lower ends of the legs 2a are fixed to the predetermined position of the printed circuit board 1 by soldering or caulking. As a result, the heat sink 2 becomes a heat radiating plate which is floated from the surface of the printed board 1 by the length of the leg 2 a and is fixed in parallel with the surface of the printed board 1. Since the fixed portion of each portion 2a to the printed board 1 has an extremely small area, it has almost no effect on other general parts of the printed board 1 such as resistors and capacitors.

Next, the screw holes 5 provided in the electronic component 3 are aligned with the female screws of the heat sink 2, and the mounting screws 4 are attached.
The electronic component 3 is fixed to the heat sink 2 by passing through the screw hole 5. In FIG. 1, the electronic component 3 is one, but it goes without saying that a plurality of electronic components 3 may be attached.

The heat generated from the electronic component 3 attached to the heat sink 2 as described above is generated by the heat sink 2
The heat is dissipated into the space via. Further, although general components such as resistors and capacitors are arranged on the upper surface of the printed board 1 below the heat sink 2, the heat sink 2 is not affected by heat. That is, the heat sink 2
The lower part can be widely used by general parts without any trouble.

In the semiconductor heat dissipation structure according to the second embodiment of the present invention, as shown in FIGS. 2 and 3, the heat sink 2B formed in a flat plate shape has a corrugated plate surface. The other points are the same as those in the above-mentioned first embodiment, and the description thereof will be omitted. With such a structure, compared to the simple flat plate shape described in the first embodiment, a larger heat radiation area to the space can be obtained, and in particular, as shown in FIG. A space is formed in the contact surface 3a for contacting the component 3, for example, a semiconductor, and the corrugated plate-shaped valley portion 2c. Therefore, the heat generated from the electronic component 3 is conducted and radiated through the peak portion 2d of the heat sink 2B, and the valley portion 2
It has a structure that radiates heat to the space c. In addition, since the corrugated plate is used, the surface area can be increased and the heat dissipation effect can be improved. The valley portion 2c may be filled with a filler.

As shown in FIGS. 4 and 5, the semiconductor heat radiation structure according to the third embodiment of the present invention has staggered through holes 2f, for example, a rectangular type, on the surface of a heat sink 2E formed in a flat plate shape. It has a structure with through holes. When the electronic component 3 is arranged on the heat sink 2E having such a structure, the contact surface 3a with the electronic component 3 can radiate heat to the lower side, that is, the printed circuit board side via the through hole 2f, and the electronic component 3 can be radiated. Even if the lower contact surface 3a is not hermetically sealed, the structure is such that heat can be dissipated from substantially the entire surface of the electronic component 3 in the space provided, so to speak. Further, since the through holes 2f are provided, the surface area of the flat plate can be increased even if it is a flat plate shape, and the heat dissipation effect can be improved accordingly.

As shown in FIGS. 6 and 7, the semiconductor heat dissipation structure according to the fourth embodiment of the present invention is a structure in which a plurality of grooves 2h are provided in a heat sink 2G formed in a flat plate shape. The electronic component 3 is arranged so as to straddle such a groove 2h. Then, a space for the groove 2h is formed on the contact surface 3a of the electronic component 3, and heat can be radiated from the contact surface 3a side. Further, similar to the second and third embodiments, the groove 2h is provided, so that the area in contact with air can be increased and the heat radiation effect can be enhanced.

In this way, the point is that the heat sinks 2, 2B, 2E, 2 formed in the flat plate shape as the heat absorbing body according to the heat generation amount of the electronic component 3 as the heat generating body, for example, the semiconductor.
By adopting a structure in which the area of the plane of G is freely changed, it is not necessary to provide a heat generating means in the height direction, and the size can be reduced. Therefore, it goes without saying that the heat dissipation means is realized by appropriately combining the above-described first to fourth embodiments, and the shape is not limited to the above-described shape.

[0019]

As described above, in the heat dissipation structure for electronic parts according to the present invention, a heat sink formed in a flat plate shape is provided on the surface of the printed board, and the generated heat capacity of the electronic parts arranged in the heat sink is provided. According to the above, by appropriately changing the surface area of the flat plate, it is possible to effectively use the surface area of the printed board, and the height is not increased in the height direction with respect to the printed board unlike the prior art. Even if it is miniaturized, to increase the heat dissipation effect, the surface area of a flat heat sink is increased, for example, the flat plate area is increased, the shape of a corrugated plate is formed, a through hole is provided, a groove is provided, etc. A flat plate corresponding to the amount of heat can be formed to efficiently absorb the heat and dissipate it in the air.

[Brief description of drawings]

FIG. 1 shows a first heat dissipation structure of an electronic component according to the present invention.
3 is a schematic perspective view of the embodiment of FIG.

FIG. 2 is a schematic perspective view of the second embodiment.

3 is an explanatory view showing an enlarged main part of FIG.

FIG. 4 is a schematic perspective view of the third embodiment.

5 is an explanatory view showing an enlarged main part of FIG.

FIG. 6 is a schematic perspective view of the fourth embodiment.

7 is an explanatory diagram showing an enlarged main part of FIG.

FIG. 8 is an explanatory diagram showing an example of a heat dissipation structure (heat sink) for an electronic component in the related art.

[Explanation of symbols]

 1 Printed Circuit Board 2 Heat Sink 2a Leg 2B Heat Sink 2c Valley Part 2d Mountain Part 2E Heat Sink 2f Groove 2G Heat Sink 3 Electronic Component (Semiconductor) 3a Contact Surface 4 Mounting Screw 5 Screw Hole

Claims (4)

[Claims] 1. A printed circuit board on which an electronic component is mounted, and a heat sink formed in a flat plate shape on the surface of the printed circuit board, wherein the heat sink corresponds to the amount of heat generated by the electronic component mounted on the heat sink. A heat dissipation structure for electronic parts, characterized in that the surface area of a flat plate is appropriately changed. 2. The heat dissipation structure for an electronic component according to claim 1, wherein the heat sink formed in the flat plate shape is formed in a corrugated plate shape. 3. The heat dissipation structure for an electronic component according to claim 1, wherein the heat sink formed in the flat plate shape is provided with a plurality of through holes. 4. The heat dissipation structure for an electronic component according to claim 1, 2 or 3, wherein the flat plate-shaped heat sink is formed in a plurality of groove shapes.