JP2880646B2 - Heat sink with fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink with a fan. In recent years, with an increase in the degree of integration of semiconductor elements, the amount of heat generated by the semiconductor elements has been increasing, and an efficient cooling structure for the semiconductors has been demanded. And
In order to meet such a demand, attention has been paid to a method of spot cooling a high heat generating element using a heat sink with a fan having a small cooling fan mounted on a heat sink body.

[0002]

2. Description of the Related Art FIG. 11 shows a conventional heat sink with a fan. The heat sink with a fan is formed of a material having good thermal conductivity such as aluminum, and a plurality of pin-shaped radiating fins 22, 22. A heat sink body 20 formed by projecting the heat sink body 2
And a cover body 40 that closes the upper surface of the cooling fins to form a cooling air ventilation space 30 between the radiating fins 22, 22. A cooling fan 50 forcibly introducing cooling air into the ventilation space 30 through the opening 41. Further, the cover body 40 is provided with a cylindrical throttle portion 60 protruding from the peripheral back surface of the cooling air introduction port 41, thereby improving the speed of the cooling air flowing into the ventilation space 30 and improving the cooling efficiency. .

FIG. 12 shows another conventional heat sink with a fan. In the conventional example shown in FIG.
Numeral 0 is incorporated in a casing 52 made of a synthetic resin or the like, and is fixed to the upper surface of the heat sink body 20.

[0004]

On the other hand, when using the above-described heat sink with a fan to cool the high heat generating element 10 mounted on a small electronic device such as a book-type personal computer, as shown in FIG. In many cases, an obstacle wall 70 such as a housing or another printed circuit board is disposed close to the suction port side of the cooling fan 50, and the supply of cooling air to the heat sink body 20 is sufficient due to an increase in pressure loss on the suction side. However, there is a drawback that it is not carried out at the same time.

In each of the above-described conventional examples, the cooling air is introduced from the cooling air inlet 41 of the cover body 40 or the casing 52 to the heat sink body 20 side, and the wind speed near the cooling air inlet 41 is highest. In spite of the high heat exchange efficiency, heat exchange with the cover body 40, particularly the throttle portion 60 in the conventional example shown in FIG. 11 is performed through the radiating fins 22, and in the conventional example shown in FIG. 52 has a drawback that it is not sufficiently contributed to the improvement of the cooling efficiency because it is formed of a synthetic resin material or the like.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned drawbacks, and provides a heat sink with a fan which can exhibit high cooling performance even when a sufficient intake space cannot be secured on the intake side. The purpose is to provide.

Another object of the present invention is to improve the cooling efficiency by effectively utilizing a high-speed cooling airflow at a cooling air inlet 41 of the cooling air.

[0008]

According to the present invention, the above-mentioned object is achieved, as shown in FIG.
A heat sink body 20 having a plurality of pin-shaped radiating fins 22 erected around a cooling fan mounting area formed on the heat sink body 20 and a fixing plate 2
And a cover body 40 that forms a ventilation space 30 for cooling air between the radiation fins 22, 22... And a cooling fan mounting area. Cooling fan 50 forcibly introducing cooling air into the inside
The cover body 40 is disposed at a height at which the upper portion of the rotating blade 51 of the cooling fan 50 is exposed from the cooling air inlet 41, and the exposed portion of the rotating blade 51 of the cooling fan 50 has This is achieved by providing a heat sink with a fan that is surrounded by a cylindrical throttle portion 60 protruding from the periphery of the cooling air inlet 41.

[0009]

According to the present invention, as shown in detail in FIG. 2, the cover body 40 which forms the ventilation space 30 between the radiation fins 22, 22,. A relatively wide intake space 71 is secured between the cover 40 and the obstacle wall 70 on the suction port side of the cooling fan 50 which is assumed to be located at a height exposed from the cooling fan 41. The exposed portion of the rotary blade 51 is surrounded by a cylindrical throttle portion 60 protruding from the periphery of the cooling air inlet 41, and increases the speed of the cooling air introduced into the ventilation space 30. The increase in the introduced wind speed by the throttle unit 60 and the action of the intake space 71 secured on the upper surface of the cover body 40 alleviate the deterioration of the cooling performance when the obstacle wall 70 is present near the suction port of the cooling fan 50. . In addition, since the installation space of the throttle unit 60 is secured by lowering the fixing position of the cover body 40, the height H does not increase. Further, by fixing the cover body 40 close to the fixing plate 21, the area of the ventilation space 30 is reduced, which may be a cause of an increase in pressure loss on the discharge side of the cooling fan 50. Compared with the performance degradation due to the obstacle wall 70, the obstacle wall 7 on the discharge side.
Since the degree of performance deterioration due to zero is low, if at least the area of the ventilation space 30 equal to the ventilation area of the cooling fan 50 is secured, the deterioration of cooling performance due to an increase in pressure loss does not occur.

According to the second aspect of the present invention, the heat radiation fins 22 of the heat sink body 20 penetrate the cover body 40 and protrude upward, so that the cooling effect of the cooling air flowing through the intake space 71 can be expected. be able to.

According to the third and fourth aspects of the present invention, the rotation range of the rotary blades 51 of the cooling fan 50 is surrounded by a cylindrical throttle portion 60 formed of a high heat conductive material, and the amount of heat absorbed by the heat sink body 20 is The heat is transferred to the throttle unit 60. The wind speed of the cooling air becomes the fastest in the throttle unit 60,
By forming the constricted portion 60 from a high thermal conductive material, the constricted portion 60 can be effectively used as a cooling element.

According to the fifth aspect of the present invention, a configuration effective when the cooling fan 50 is mounted on the heat sink body 20 is proposed. That is, the casing 52 of the cooling fan 50 is formed with the cylindrical throttle portion 60 surrounding the rotation range of the rotary blade 51. The casing 52 provided with the throttle portion 60 is formed of a material having good heat conductivity, and functions as a heat dissipation element.

According to the sixth aspect of the present invention, the throttle section 60 is provided.
Are formed on the inner peripheral wall surface, and the efficiency of heat exchange with cooling air is further improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 3 show a first embodiment of the present invention. In this embodiment, the heat sink with a fan includes a heat sink body 20, a cooling fan 50 mounted on the heat sink body 20, and a cover body 40 fixed to the heat sink body 20.

The heat sink body 20 is formed of a material having good thermal conductivity such as aluminum,
A plurality of pin-shaped radiating fins 22, 22,... Protrude from a fixing plate 21 fixed to the heat sink surface by means such as bonding. The radiation fins 22 are arranged in a grid pattern over the entire upper surface of the fixed plate 21 except for the cooling fan mounting region at the center. The height of the radiating fins 22 is determined so as to substantially match the height of the cooling fan 50 to be described later in an installed state in order to make the overall thickness as thin as possible. In FIG. 1, reference numeral 11 denotes a lead of the high heating element 10.

The cooling fan 50 is incorporated in a cooling fan mounting area with a rotating shaft rotatably supported by a bearing (not shown) formed on the fixed plate 21. As shown by the broken line, the cooling air is sucked from above and driven to blow toward the fixed plate 21.

The cover body 40 is formed of a highly heat conductive material such as aluminum, and is disposed in parallel with the fixing plate 21 of the heat sink body 20 to form a ventilation space 30 for cooling air between the radiating fins 22. It comprises a cover plate portion 42 and a throttle portion 60 protruding upward from the periphery of the cooling air introduction port 41 formed at the center of the cover plate portion 42.
The throttle portion 60 is formed in a cylindrical shape surrounding the upper part of the rotation region of the rotating blade 51 of the cooling fan 50, and the upper end thereof is provided at the upper end of the rotating blade 51 of the cooling fan 50 or the radiation fin 22 of the heat sink body 20. Approximately coincides with the upper end of Further, through holes 42a, 42a,... Of the heat radiation fins 22 are formed in the cover plate portion 42 in order to position the upper end of the throttle portion 60 at the above-described position. The fixing of the cover body 40 is performed, for example, by radiating fins 2 arranged at four corners.
2 is formed in a short dimension, and the cover plate 42 is fixed to the upper surface of the short radiating fin 22 or, as shown in FIG.
Various well-known methods can be adopted, such as mounting a retaining ring 43 such as a C-ring, or driving a fin 22 into the radiating fin 22 with a retaining pin or the like.

The installation height of the cover body 40, more specifically, the distance between the cover plate portion 42 and the fixing plate 21 of the heat sink body 20 affects the flow of the cooling air in the ventilation space 30. It is desirable that the area of the space 30 is set to be equal to or greater than the ventilation area of the cooling fan 50 to prevent the pressure loss in the ventilation space 30 from becoming excessive, and as shown in FIG. Forming a round surface 62 at the lower boundary edge between the cover plate portion 60 and the cover plate portion 42 is also an effective modification to improve the introduction of the cooling air into the ventilation space 30.

When the radiation fins 22, 22,... Are made to penetrate upward from the cover plate portion 42, cooling of the cooling fins by suction air from the cooling fan 50 generated above the cover plate portion 42 can be expected. In addition, although a higher improvement in cooling efficiency can be obtained, a configuration in which the heat radiation fins 22 are penetrated from the cover plate portion 42 is not essential, and there is a risk of interference with other components on the periphery, especially on the upper surface of the heat sink body 20. In the case, the radiation fins 22 are only provided in the ventilation space 30.
May be provided, and a part of the radiation fins 22 may be exposed above the cover body 40.

FIGS. 4 to 6 show a second embodiment of the present invention. In the description of the embodiment described below, the same components as those in the above-described embodiment are denoted by the same reference numerals in the drawings, and description thereof will be omitted. The heat sink body 20 is formed of a material having good thermal conductivity such as aluminum, and the cooling fan 50 is incorporated in a cooling fan mounting area provided at the center thereof. A cover body 40 having a cooling air inlet 41 formed at the center is fixed to the upper surface of the heat sink body 20, and cooperates with the fixing plate 21 to dissipate the radiation fins 22, 2.
A ventilation space 30 for cooling air is formed between 2 and the like. The cover body 40 is formed of a high heat conductive material such as aluminum, and is screwed to a fixing block 22 ′ formed also at the four corners of the heat sink body 20 and also serving as the radiation fins 22, similarly to the above-described embodiment.

Further, the heat sink body 20 includes:
A throttle unit 60 is provided. The throttle portion 60 is formed of a material having better thermal conductivity than the heat sink body 20, for example, copper or the like, and has a cylindrical shape surrounding the rotation range of the rotating blades 51 of the cooling fan 50. The narrowed portion 60 is provided with fixing projections 63 on the lower peripheral edge, and the fixing projections 63 are formed in holes (not shown) provided in the fixing plate 21.
To be fixed to the heat sink body 20. As means for fixing the throttle portion 60 to the heat sink main body 20, it is possible to use well-known means such as brazing in addition to press-fitting.

FIG. 7 shows the inner peripheral wall surface of the throttle section 60.
As shown in (2), when a plurality of irregularities 61, 61,... Are engraved, the efficiency of heat exchange with the cooling air flowing through the throttle unit 60 can be further improved.

In FIG. 5, the throttle portion 60 is fixed to the fixing plate 21 of the heat sink body 20 and is disposed from the upper surface of the fixing plate 21 to the upper portion of the cooling fan 50. However, the present invention is not limited to this, and as shown in FIG. In addition, it is also possible to configure so as to surround only the upper part of the cooling fan 50. In this case, the squeezing portion 60 is formed in a ring shape, and can be held and fixed on the step portion 22a formed on the corresponding radiation fin 22, and an adhesive or the like can be used as a fixing means, Alternatively, it can be pressed into a fitting portion formed by the rising wall 22b of the step portion 22a of the heat radiation fin 22.

FIGS. 9 and 10 show a third embodiment of the present invention. This embodiment shows a modification that is effective when the cooling fan 50 is mounted on the heat sink body 20. The cooling fan 50 includes a motor, a fan unit 53 including a rotating blade 51, and And a casing 52 for fixing and supporting the casing on the casing 20. The bearing portion of the motor of the fan unit 53 is formed of a material having a lower thermal conductivity than the heat sink body 20, such as synthetic resin or iron, so that heat transfer from the heat sink body 20 is suppressed, and shortening of life due to temperature rise is prevented. Is done.
On the other hand, the casing 52 is formed of a material having excellent thermal conductivity, such as copper or aluminum, and has a cylindrical throttle portion 60 surrounding the rotation range of the rotary blade 51 on the fan unit 53 side while holding the fan unit 53. And a fixing portion 52a to the heat sink body 20.
A slit 64 is formed to fit the fixed wing 53a formed on the fan unit 53 side. The casing 52 can be fixed to the heat sink body 20 by any appropriate means such as screwing or bonding.

[0025]

As is apparent from the above description, according to the present invention, even if there is an obstacle wall near the suction port of the cooling fan, the cooling efficiency does not decrease and stable operation is achieved. Cooling performance can be exhibited.

In addition, the cooling efficiency of the whole can be improved by positively using the throttle as a heat radiation element.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of the present invention, wherein (a) is a plan view,
(B) is a side view showing a partly broken view.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is an exploded perspective view of FIG.

FIGS. 4A and 4B are views showing a second embodiment of the present invention, in which FIG. 4A is a plan view, and FIG.

5A and 5B are views showing a heat sink main body, wherein FIG. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along line AA of FIG.

FIG. 6 is an exploded perspective view of FIG.

FIG. 7 is a diagram showing a modified example of the diaphragm unit.

8A and 8B are views showing a modification of FIG. 4, wherein FIG.
(B) is a half sectional view of (a), and (c) is a sectional view taken along line AA of (a).

FIGS. 9A and 9B are views showing a third embodiment of the present invention, wherein FIG. 9A is a plan view and FIG. 9B is a half sectional view of FIG.

FIG. 10 is an exploded view of FIG. 9;

11A and 11B are views showing a conventional example, where FIG. 11A is a plan view and FIG.
2 is a half sectional view of FIG.

FIG. 12 is a view showing another conventional example, in which (a) is a plan view,
(B) is a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 High heat generation element 20 Heat sink main body 21 Fixing plate 22 Radiation fin 30 Ventilation space 40 Cover body 41 Cooling air introduction port 50 Cooling fan 51 Rotating blade 52 Casing 53 Fan unit 60 Restricted part 61 Concavo-convex stripe

Continuation of the front page (56) References JP-A-7-297758 (JP, A) JP-A-7-183678 (JP, A) JP-A-4-337699 (JP, A) JP-A-2-211700 (JP) , A) JI-56-134760 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05K 7/20 H01L 23/36 H01L 23/467

Claims (6)

(57) [Claims] 1. A heat sink body having a plurality of pin-shaped radiating fins (22, 22...) Standing around a cooling fan mounting area formed on a fixing plate (21) for a high heat generating element (10). 20) and a fixing plate (21) fixed to the heat sink body (20).
A cover body (40) that forms a ventilation space (30) for cooling air between the radiation fins (22, 22...) In cooperation with A cooling fan (50) for forcibly introducing cooling air from the inlet (41) into the ventilation space (30), wherein the cover body (40) is located above the rotating blades (51) of the cooling fan (50). Are arranged at a height exposed from the cooling air inlet (41), and the exposed portion of the rotating blade (51) of the cooling fan (50) protrudes from the periphery of the cooling air inlet (41). A heat sink with a fan surrounded by a cylindrical throttle (60). 2. The heat sink with a fan according to claim 1, wherein the radiation fins (22, 22...) Of the heat sink body (20) penetrate the cover body (40) and protrude upward. 3. A heat sink with a fan in which a cooling fan (50) is mounted on a heat sink body (20) fixed to a high heat generating element (10), wherein rotation of a rotating blade (51) of the cooling fan (50). The range is a cylindrical throttle (6) formed of a high heat conductive material.
A heat sink with a fan surrounded by the heat sink body (20) and transmitting heat absorbed by the heat sink body (20) to the throttle portion (60). 4. A heat sink body having a plurality of pin-shaped radiating fins (22, 22,...) Provided around a cooling fan mounting area formed on a fixing plate (21) for a high heat generating element (10). 20) and a fixing plate (21) fixed to the heat sink body (20).
A cover body (40) that forms a ventilation space (30) for cooling air between the radiation fins (22, 22...) In cooperation with the cooling fan,
0) through the cooling air inlet (41),
A cooling fan (50) forcibly introduced into the cooling fan (50), wherein the heat sink body (20) is made of a material having better heat conductivity than at least the heat sink body (20). A heat sink with a fan to which a cylindrical throttle (60) surrounding the rotation range of the rotating blade (51) is fixed. 5. A heat sink body (20) having a plurality of radiating fins (22, 22...) Erected on an upper surface of a fixing plate (21) for a high heat generating element (10), and an upper surface of the heat sink body (20). A cooling fan (50) formed to house a fan unit (53) in a casing (52) fixed to the cooling fan and blowing cooling air to the heat sink body (20) side; The casing (52) is formed of a material having good thermal conductivity, and the casing (52) is formed with a cylindrical throttle portion (60) surrounding the rotation range of the rotary blade (51). Heat sink with fan. 6. A heat sink with a fan according to claim 1, wherein a plurality of ridges (61, 61,...) Are engraved on an inner peripheral wall surface of said narrowed portion (60).