JP2008288411A - Heat dissipator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat dissipator capable of both suppressing a deflection amount of a body on heating, and improving a heat dissipation performance. <P>SOLUTION: The heat dissipator includes the metal plate-like body 30, and a plurality of plate-like fins 41 integrally formed with the body 30 and provided in erecting manner in parallel each other on the surface 30a of the body 30. A circuit board 21 is press contacted to the rear surface 30b of the body 30 and the dissipator discharges the heat of the circuit board 21. A first splitting part 42 and a second splitting part 43 of the dissipator formed in a hollow manner to each fin 41 from a front edge part to a base end part of a erecting direction and splitting the continuity of an extending direction of the fins 41. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radiator that radiates heat from a circuit board, and more particularly to a radiator that is optimal for radiating heat from a fan control unit such as an automobile.

  Conventionally, as a radiator for a fan control unit, a plate-like main body and a plurality of fins formed in a streak pattern on one side of the front and back of the main body are provided, and the side opposite to where the fins of the main body are formed There is known a heat radiator formed by metal extrusion so that the circuit board is brought into contact with the surface of the circuit board and heat of the circuit board is radiated from the fins through the main body (for example, see Patent Document 1). .

Also, a metal die-cast radiator that uses a plurality of protrusions instead of a plurality of fins as a heat dissipation portion is also known.
JP 2000-299965 A

However, in a radiator with a plurality of fins in the heat dissipating part, the fins that are heat dissipating parts have a shape that is continuous in one direction, so when heat is transferred to this fin, it expands in one direction. There is a problem that the fin and the main body are bent integrally, and when the amount of bending becomes large, there is a possibility that the circuit board is deformed and the circuit board is adversely affected.
On the other hand, since the heat dissipation part is not continuous in one direction, the die-cast one can suppress the amount of bending compared to the one with fins. When the value is made smaller, it is impossible to remove the mold, and there is a limit to the number of protrusions, and the heat dissipation performance is limited.

  The present invention has been made paying attention to the conventional problems as described above, and provides a radiator that can achieve both the suppression of the amount of deflection of the main body during heating and the improvement of the heat dissipation performance. With the goal.

  In order to achieve the above-described object, the invention described in claim 1 is a metal plate-like main body, a plate formed integrally with the main body, and a plurality of plates arranged upright on the surface of the main body. Each of the fins is configured to contact the back surface of the main body and dissipate heat from the circuit board. The heat sink is characterized in that it is formed in a concave shape and a split portion is formed that cuts off the continuity in the extending direction of the fin.

  The invention according to claim 2 is the heat radiator according to claim 1, wherein the divided portion is formed at two positions of each fin.

  According to a third aspect of the present invention, in the radiator according to the first or second aspect, the main body is formed in a substantially quadrangular planar shape, and each fin extends substantially parallel to one side of the main body. A fixing piece formed integrally with a fixing hole through which a screw for fixing the main body to the attached portion is formed at an edge of the main body in a direction in which the fin extends. It was set as the feature heat radiator.

In the radiator of the present invention, the heat of the circuit board is transmitted to the main body, and further transmitted to the plurality of fins, and then radiated from the fins to the outside.
In this way, by dissipating heat from a plurality of fins, it is possible to secure a surface area and to obtain high heat dissipating performance as compared with standing projections.

On the other hand, when the radiator is cast, the fin expands in the extending direction due to the heat remaining in this part, so that the fin extends in the extending direction, and only the surface of the main body extends due to the expansion of the fin. In such a case, wrinkles are generated on the back surface of the main body, the adhesion to the circuit board is deteriorated, and the heat dissipation performance is reduced.
On the other hand, in the present invention, since the fin is provided with the dividing portion, the expansion due to the thermal expansion of the fin does not continuously occur in the entire fin. Surface extension can be suppressed.
Therefore, it is possible to prevent wrinkles from occurring on the back surface of the main body, and to prevent a decrease in heat dissipation performance.

In addition, the thermal expansion of the fin and the bending of the main body caused by the above-described phenomenon also occur when the circuit board is dissipated. There is a risk of giving.
Also in this case, in the case where the fins are formed as in the present invention, it is possible to suppress the expansion of the fins as a whole and to prevent the main body from being bent. An adverse effect on the circuit board can be suppressed.

  As described above, in the present invention, it is possible to achieve both of ensuring high heat dissipation performance and suppressing the amount of bending of the main body during molding and overheating.

Furthermore, in the invention according to claim 2, since the divided portions are formed at two positions of each fin, the entire surface area of the fins is ensured and high heat dissipation performance is obtained as compared with the case where three or more divided portions are provided. That is, it is possible to achieve a good balance between ensuring that the expansion of the fin due to thermal expansion is prevented and preventing the main body from being bent.
That is, when three or more divided portions are formed, the amount of bending of the main body when the fin is extended can be suppressed, but the entire area of the fin is reduced and the heat dissipation performance is deteriorated. On the other hand, when the dividing portion is formed at one location of the fin, the heat dissipation performance can be ensured, but the deflection of the main body when the fin is extended increases. Therefore, ensuring the two performances can be achieved in a well-balanced manner by providing two divided portions.

In the invention of claim 3, when the fin expands due to thermal expansion, it expands in the direction of a pair of sides of the rectangular main body and tries to extend the main body in this direction. Since it is fixed to the attached portion, the extension of the main body is suppressed.
Therefore, the bending prevention performance of the main body is improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The heat radiator of this embodiment is formed integrally with a metal plate-like main body (30) and the main body (30), and stands in a state where a plurality of the main body (30) are arranged in parallel on the surface (30a) of the main body (30). A radiator having a plate-like fin (41) provided, the circuit board (21) being brought into contact with the back surface (30b) of the main body (30) and radiating heat from the circuit board (21). Each fin (41) is formed with a concave portion (42, 43) that is formed in a concave shape from the tip end in the standing direction toward the base end, and cuts off the continuity in the extending direction of the fin (41). It is a heat radiator characterized by being formed.

  Below, based on FIGS. 1-2, the heat radiator A of Example 1 of this invention is demonstrated.

As shown in FIG. 2, the radiator A is provided in the radiator device 10 of the vehicle.
The radiator device 10 includes a heat exchanger 11 and motors 14 and 14 that are disposed on the front surface of the heat exchanger 11 and supported by a shroud 12 that covers a part of the heat exchanger 11 via a support member 13. And a fan 15 rotated by the motor 14.

  The radiator A of the first embodiment is used for heat dissipation of the fan control unit 20 (see FIG. 1) that controls the rotation of the motors 14 and 14.

  That is, the radiator A is attached to the support member 13 and is integrally formed by casting with a metal having high thermal conductivity including aluminum, copper and the like, and as shown in FIG. 30, and a fin portion 40 erected from the surface 30 a of the main body 30.

The main body 30 has a pair of fixing pieces 31 and 31 projecting from a pair of opposing sides, and each fixing piece 31 is formed with a boss portion 31a and supported by the boss portion 31a. A fixing hole 31b through which a screw fixed to the member 13 is inserted is formed.
The fan control unit 20 is provided on the back surface 30 b of the main body 30.
A plurality of positioning projections 30 c for the fan control unit 20 are formed on the back surface 30 b of the main body 30.

  The fan control unit 20 includes a circuit board 21 made of metal such as aluminum, and a circuit (not shown) mounted on the surface 21a. The circuit includes an integrated circuit and a plurality of MOSs (not shown). (Metal Oxide Semiconductor) Transistors 22 and 22 are provided. And the back surface 21b of the circuit board 21 is adhere | attached with the adhesive agent which abbreviate | omitted illustration in the state contact | abutted to the back surface 30b of the main body 30 of the heat radiator A.

The fin portion 40 of the radiator A includes a plurality of plate-like fins 41 erected from the surface 30 a of the main body 30.
The fins 41 extend in the direction of the arrow X, which is parallel to the pair of sides of the main body 30, and a plurality of the fins 41 are arranged in parallel at a certain interval in the direction of the arrow Y.
The fin 41 is formed in a substantially trapezoidal cross-sectional shape that gradually narrows in the rising direction (arrow Z direction) so that the mold can be easily removed during molding.

Furthermore, in the fin part 40, the 1st division part 42 and the 2nd division part 43 which divide | segment the fin 41 as discontinuity in the extending direction which is the arrow X direction are formed in each fin 41. , Is divided into three in the extending direction.
These division parts 42 and 43 are formed over the entire height from the front end surface of the fin 41 to the base end. Incidentally, it is formed in the same shape as the first and second divided parts 242 and 243 of Example 2 described later shown in FIG.

  The second divided portion 43 is formed so as to overlap each other in the direction of the arrow Y in each fin 41, but the first divided portion 42 is formed in the two right fins 41a and 41a in the drawing. Absent. Further, in the drawing, the first divided portions 42 a, 42 a, 42 a of the left three fins 41 b, 41 b, 41 b are arranged at different positions in the arrow X direction than the other first divided portions 42.

  Further, in the fan control unit 20, the highly exothermic MOS transistors 22 and 22 are disposed across the three fins 41, 41a and 41a in the arrow Y direction as shown in the figure.

Next, the operation of the first embodiment will be described.
(Manufacturing)
The radiator A is formed by casting.
At this time, although it is gradually cooled immediately after the mold is opened, the fin 41 expands in the extending direction (arrow X direction) when thermally expanded by the remaining heat. As the fins 41 are extended, only the surface 30a side of the main body 30 is extended, so that the main body 30 may be bent in the direction indicated by the arrow W in FIG.

In this case, if the fin 41 is continuous over almost the entire length of the main body 30 in the arrow X direction, the extension amount is transmitted to both ends of the fin 41, and the extension amount on the surface 30a side of the main body 30 increases. The amount of bending of the main body 30 may increase, and wrinkles may occur on the back surface 30b of the main body 30. And when wrinkles arise, the adhesiveness with the circuit board 21 deteriorates and the heat dissipation performance is lowered.
On the other hand, in the heat radiator A of the first embodiment, since the fins 41 are provided with the divided portions 42 and 43, the extension amount due to the thermal expansion is not transmitted to both ends in the extending direction of the fins 41, and the main body 30 The amount of expansion on the surface 30a side of the sheet is suppressed.
Therefore, the occurrence of wrinkles on the back surface 30b of the main body 30 is suppressed, and deterioration of the adhesion with the circuit board 21 is also prevented.

(When installed)
When the radiator A is attached, the fan control unit 20 is directed toward the support member 13, while the fin portion 40 is fixed in a state of facing the air blowing direction indicated by an arrow WD in FIG. Screws (not shown) are inserted through the pieces 31 and 31 and fixed to the support member 13.

(When the radiator device 10 is in operation)
When the motors 14 and 14 are rotated, air is blown in the direction of the arrow WD in FIG. 2B, and heat exchange is performed in the heat exchanger 11.

  The rotation of the motors 14 and 14 is controlled by the fan control unit 20, and heat generation is generated by the fan control unit 20 along with this control, and heat generation is particularly remarkable in the MOS transistors 22 and 22.

  The heat of the fan control unit 20 is radiated from the front surface 21a side of the circuit board 21 into the air, and is transmitted from the back surface 21b of the circuit board 21 to the radiator A to be radiated.

  At this time, in the radiator A, the heat transferred to the back surface 30b of the main body 30 is radiated into the air from the plurality of fins 41, and thus the heat is radiated by the plurality of fins 41. Compared with the case of forming, a surface area is ensured and high heat dissipation performance is obtained.

  In addition, in the first embodiment, the portion where the MOS transistors 22 and 22 that generate the most heat are provided across the plurality of fins 41, 41, a, and 41a. Heat generation can be efficiently dissipated.

In addition, when heat is transmitted to the fins 41, the fins 41 extend in the extending direction (arrow X direction), but each fin 41 is divided by the divided portions 42 and 43, so that during the casting In the same manner as described above, the main body 30 is restrained from bending in the direction of the arrow W as compared with the case where the fins are continuous over the entire length.
Thereby, it is possible to suppress the circuit board 21 from being bent together with the main body 30, and it is possible to prevent the circuit board 21 from being adversely affected by the bending.

As described above, in the radiator A according to the first embodiment, since the plurality of fins 41 are erected on the main body 30, higher heat dissipation performance can be obtained as compared with the case where the protrusions are erected. In addition, in the experimental results of the heat dissipation performance, it was possible to obtain the same heat dissipation performance as that in which the fins were integrated over the entire length.
Furthermore, since the MOS transistors 22 and 22 that generate the most heat are disposed across a plurality (three) of the fins 41, 41a, and 41a, more efficient heat radiation is performed as compared with the case where they do not straddle the plurality of fins. Is called.

  In addition, since each fin 41 is provided with the first divided portion 42 and the second divided portion 43 and divided into three in the extending direction of the fin 41, the body 30 can be prevented from being bent during cooling after casting, This bending can suppress the generation of wrinkles on the back surface 30b of the main body 30, and also can suppress the expansion of the main body 30 due to the expansion of the fins 41 due to thermal expansion when the heat is released from the fan control unit 20. It is possible to suppress the circuit board 21 from being adversely affected such as a loss due to the bending.

  Next, a radiator B according to Example 2 of the embodiment of the present invention will be described with reference to FIG. Since the second embodiment is a modification of the first embodiment, only the difference will be described, and the description of the same configuration and operational effects as the first embodiment will be omitted.

In the second embodiment, in the radiator B, the extending direction of each fin 241 of the fin portion 240 is 90 degrees different from that of the first embodiment, and each fin 241 extends in the arrow Y direction. ing.
Moreover, in each fin 241, the 1st division part 242 and the 2nd division part 243 are provided in two places of the arrow Y direction which is an extending direction. In addition, these division parts 242 and 243 are formed continuously in a direction orthogonal to the extending direction of each fin 241.

  In the second embodiment, in addition to the function and effect of the first embodiment, when the radiator device 10 is operated, the expansion direction when each fin 241 is thermally expanded is screwed by the fixing piece 31, so The deformation of the main body 30 is suppressed, and an effect that the main body 30 is suppressed from being bent in the arrow W direction is obtained.

  As described above, the embodiment of the present invention and Examples 1 and 2 have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment and Examples 1 and 2, and the present invention is not limited thereto. Design changes that do not depart from the gist are included in the present invention.

  For example, in the first and second embodiments, an example in which the main body 30 is formed in a substantially quadrangular shape is shown. However, the main body may have a rectangular shape, a polygon other than a square, an ellipse, a circular shape, or the like. It may be formed in a shape different from the planar shape.

  Moreover, in Example 1, 2, although the example which extended the fins 41 and 241 to the arrow X direction and arrow Y direction which are substantially parallel with one side of the main body 30 was shown, it is not limited to this, For example, As shown in FIG. 4A, each fin 341 may be formed in an L shape, or each fin 441 may be formed obliquely as shown in FIG. Note that the fin 341 has a split portion 342, and the fin 441 has a split portion 442.

Moreover, in Example 1, 2, although the division part showed the example formed in two places of the extension direction of the fins 41,241, the number is not limited to two places but one place or three or more You may form in multiple places.
In addition, as in the example shown in FIG. 4, different numbers of division parts 342, 442 may be formed according to the length of the fins 341, 441. In addition, there may be one that does not form the dividing portions 342 and 442.

  In the first and second embodiments, the dividing portions 42, 43, 242, and 243 are formed over the entire height of the fins 41 and 241, but are recessed from the tip in the rising direction of the fin to the middle in the proximal direction. Even if it is formed into a shape, the desired effect can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the heat radiator A of Example 1 of the best form of this invention, (a) is a top view, (b) is a side view. It is a figure which shows the radiator apparatus 10 which installed the heat radiator A of Example 1, (a) is a front view, (b) has shown a part of longitudinal section. It is a figure which shows the heat radiator of Example 2, (a) is a top view, (b) is a side view. It is the schematic which shows the other example of embodiment of this invention, (a) (b) has each shown the top view.

Explanation of symbols

21 Circuit board 30 Main body 30a Front surface 30b Back surface 31 Fixing piece 31b Fixing hole 40 Fin part 41 Fin 42 First division part 43 Second division part 240 Fin part 241 Fin 242 First division part 243 Second division part 341 Fin 342 Dividing part 441 Fin 442 Dividing part A Radiator B Radiator

Claims (3)

A metal plate-shaped body,
Plate-shaped fins that are formed integrally with the main body, and are erected in a state where a plurality of the main body are arranged side by side,
With
A heat radiator that abuts the circuit board on the back surface of the main body and radiates heat from the circuit board,
A heat radiator, wherein each fin is formed in a concave shape from a tip end in a standing direction toward a base end portion, and a split portion is formed to cut off continuity in the extending direction of the fin.   The radiator according to claim 1, wherein the divided portion is formed at two locations of each fin. The main body is formed in a substantially quadrangular planar shape,
Each fin extends substantially parallel to one side of the main body,
A fixing piece in which a fixing hole through which a screw for fixing the main body to the attached portion is inserted is integrally formed at an edge of the main body in a direction in which the fin extends. The heat radiator according to claim 1 or claim 2.

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