JPH07312492A - Heat sink with fan - Google Patents

Abstract

PURPOSE:To provide a heat sink with fan in which high cooling performance is exhibited even when a sufficient suction space can not be ensured on the suction side. CONSTITUTION:The heat sink with fan comprises a heat sink body 20 where a plurality of pin-like heat dissipation fins 22, 22, ... are planted around a cooling fan loading region formed on a fixing board 21, a cover body 40 secured to the heat sink body 20 and defining a space for passing cooling wind between the heat dissipation fins 22, 22, ... together with the fixing board 21, and a cooling fan 50 disposed in the cooling fan loading region in order to introduce the cooling wind into the space through a cooling wind introduction port 41 of the cover body 40. The cover body 40 is disposed at such height as the upper part of the rotary blade 51 of the cooling fan 50 is exposed through the cooling wind introduction port 41. The exposed part of the rotary blade 51 is surrounded by a tubular restriction part 60 projecting from the circumferential fringe of a cooling wind introduction port 41.

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, as the degree of integration of semiconductor elements has improved, the amount of heat generated by semiconductor elements has tended to increase, and there is a demand for an efficient cooling structure for the semiconductor. And
In order to meet such a demand, attention is focused on a technique of spot-cooling a high heat generating element using a heat sink with a fan in which a small cooling fan is 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 made of a material having good thermal conductivity such as aluminum, and has a plurality of pin-shaped heat radiation fins 22, 22 on the upper surface of the fixing plate 21 to the high heat generating element 10 except the cooling fan mounting region. · The heat sink body 20 formed by projecting and the heat sink body 2
A cover body 40 that closes the upper surface of 0 to form a ventilation air space 30 for cooling air between the radiating fins 22, 22 ... And a cooling air introduction that is installed in the cooling fan installation area and is opened in the central portion of the cover body 40. The cooling fan 50 forcibly introducing the cooling air into the ventilation space 30 from the opening 41. Further, the cover body 40 is provided with a cylindrical throttle portion 60 projecting to the back surface of the peripheral edge of the cooling air introduction port 41, and improves the wind speed of the cooling air into the ventilation space 30 to improve the cooling efficiency. .

FIG. 12 shows another conventional example of a heat sink with a fan. In the conventional example shown in FIG. 12, the cooling fan 5
0 is incorporated in a casing 52 made of synthetic resin or the like, and is fixed to the upper surface of the heat sink body 20.

[0004]

On the other hand, when the above heat sink with fan is used to cool the high heat generating element 10 mounted in a small electronic device such as a book type personal computer, as shown in FIG. In many cases, the wall surface of the housing or the obstacle wall 70 such as another printed circuit board is arranged close to the suction port side of the cooling fan 50, and the cooling air is sufficiently supplied to the heat sink body 20 due to the increase in the pressure loss on the suction side. It had the drawback that it was not done at all.

Further, in each of the above-mentioned conventional examples, the cooling air is introduced from the cooling air introduction port 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 introduction port 41 is the highest. Despite the high heat exchange efficiency, heat exchange with the cover body 40 in the conventional example shown in FIG. 11, particularly with the throttle portion 60 is performed via the radiation fins 22, and in the conventional example shown in FIG. Since 52 is formed of a synthetic resin material or the like, it has a drawback that it does not sufficiently contribute to the improvement of cooling efficiency.

The present invention has been made to solve the above drawbacks, and a heat sink with a fan capable of exhibiting 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 effectively utilize the high-velocity cooling airflow in the cooling air introduction port 41 of the cooling air to further enhance the cooling efficiency.

[0008]

According to the present invention, the above-mentioned object is, as shown in FIG. 1, a fixing plate 21 for a high heat generating element 10.
A heat sink body 20 in which a plurality of pin-shaped heat radiation fins 22, 22 are provided upright around a cooling fan mounting area formed on the heat sink body 20 and a fixing plate 2 fixed to the heat sink body 20.
The cover body 40 that cooperates with the heat radiation fins 22, 22 to form a ventilation space 30 for the cooling air between the heat radiation fins 22 and 22 and the cooling fan mounting area, and the ventilation space 30 is provided from the cooling air introduction port 41 of the cover body 40. Cooling fan 50 that forcibly introduces cooling air into it
And the cover body 40 is arranged at a height where the upper part of the rotary blade 51 of the cooling fan 50 is exposed from the cooling air inlet 41, and the exposed part of the rotary blade 51 of the cooling fan 50 is This is achieved by providing a heat sink with a fan surrounded by a cylindrical narrowed portion 60 protruding from the peripheral edge of the cooling air inlet 41.

[0009]

In the present invention, the cover body 40 which forms the ventilation space 30 between the radiation fins 22, 22, ... It is arranged at a height exposed from 41, and a relatively wide intake space 71 is secured between the obstacle wall 70 on the inlet side of the assumed cooling fan 50 and the cover body 40. The exposed portion of the rotary vane 51 is surrounded by a cylindrical throttle portion 60 that projects from the peripheral edge of the cooling air introduction port 41 to increase the wind speed of the introduced cooling air into the ventilation space 30. Due to the increase of the introduced wind speed by the throttle portion 60 and the action of the intake space 71 secured on the upper surface of the cover body 40, the deterioration of the cooling performance when the obstacle wall 70 exists near the suction port of the cooling fan 50 is alleviated. . Further, since the installation space for the narrowed portion 60 is secured by lowering the fixing position of the cover body 40, the height dimension 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 increasing the pressure loss on the discharge side of the cooling fan 50. However, the cooling fan 50 is generally on the suction side. Of the obstacle wall 7 on the discharge side as compared with the performance deterioration due to the obstacle wall 70 of
Since the degree of performance deterioration due to 0 is low, if at least the area of the ventilation space 30 that is the same as the ventilation area of the cooling fan 50 is secured, deterioration of the cooling performance due to an increase in pressure loss will 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 project upward, and expect a cooling effect of the heat radiation fins 22 by the cooling air flowing through the intake space 71. be able to.

According to the third and fourth aspects of the invention, the rotation range of the rotary blades 51 of the cooling fan 50 is surrounded by the cylindrical throttle portion 60 made of a highly heat conductive material, and the heat absorbed by the heat sink body 20 is The heat is transferred to the throttle 60. The speed of the cooling air is the fastest at the throttle 60,
By forming the throttle portion 60 with a high thermal conductive material, the throttle portion 60 can be effectively used as a cooling element.

In the fifth aspect of the 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 blades 51. The casing 52 provided with the narrowed portion 60 is made of a material having good thermal conductivity and functions as a heat dissipation element.

In the invention according to claim 6, the throttle portion 60.
Plural concavo-convex stripes 61 are engraved on the inner peripheral wall surface of so that the heat exchange efficiency with the cooling air is further improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described 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 made of a material having good thermal conductivity such as aluminum, and has a high heat generating element 10.
A plurality of pin-shaped heat radiation fins 22, 22 ... Are projected from a fixing plate 21 fixed to the heat sink surface of the device by means such as adhesion. The radiating fins 22 are arranged in a grid pattern over the entire upper surface of the fixed plate 21 except for the cooling fan mounting area in the central portion. The height of the radiating fins 22 is determined so as to be substantially the same as the height of the cooling fan 50, which will be described later, in the installed state in order to make the overall thickness as thin as possible. In FIG. 1, reference numeral 11 indicates a lead of the high heat generating element 10.

The cooling fan 50 is incorporated in the cooling fan mounting region in a state in which the rotation shaft is rotatably supported by a bearing portion (not shown) formed on the fixed plate 21, and the rotary blades 51 are arranged as shown in FIG. As indicated by a broken line in FIG. 3, the cooling air is sucked from above and is blown toward the fixed plate 21.

The cover body 40 is made of a material having a high thermal conductivity such as aluminum and is arranged in parallel with the fixing plate 21 of the heat sink body 20 to form a ventilation space 30 for cooling air between the radiation fins 22, 22. The cover plate portion 42 and the throttle portion 60 projecting upward from the peripheral edge of the cooling air introduction port 41 opened in the central portion of the cover plate portion 42.
The throttle unit 60 is formed in a tubular shape surrounding the upper part of the rotating region of the rotating blades 51 of the cooling fan 50, and the upper end thereof is the upper end of the rotating blades 51 of the cooling fan 50 or the heat radiation fins 22 of the heat sink body 20. Almost coincides with the upper end of. Further, in order to position the upper end of the narrowed portion 60 at the above-mentioned position, the cover plate portion 42 is provided with insertion holes 42a, 42a, ... The cover body 40 is fixed by, for example, the radiation fins 2 arranged at the four corners.
2 is formed in a short size, and a cover plate portion 42 is fixed to the upper surface of the short size heat dissipation fin 22, or as shown in FIG.
It is possible to adopt various known methods such as mounting a retaining ring 43 such as a C ring, and further driving a retaining pin or the like into the heat radiation fin 22.

The installation height of the cover body 40, more specifically, the distance between the cover plate portion 42 and the fixed plate 21 of the heat sink body 20 affects the ease with which cooling air flows in the ventilation space 30. It is desirable to set the area of the space 30 to be equal to or larger than the ventilation area of the cooling fan 50 to prevent the pressure loss in the ventilation space 30 from becoming excessive. Also, as shown in FIG. Forming the rounded surface 62 at the lower boundary edge between the cover plate portion 60 and the cover plate portion 42 is also an effective modification for improving the introduction of the cooling air into the ventilation space 30.

When the heat dissipating fins 22, 22 ... Are penetrated 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, the structure in which the heat radiation fin 22 penetrates from the cover plate portion 42 is not essential, and there is a risk of interference with other parts around the heat sink body 20, especially on the upper surface of the heat sink body 20. In some cases, the radiation fins 22 may be provided only in the ventilation space 30.
Is also possible, and it is also possible to expose a part of the radiation fins 22 to the upper part of the cover body 40.

A second embodiment of the present invention is shown in FIGS. In the following description of the embodiments, the same components as those in the above-described embodiments are designated by the same reference numerals in the drawings and the description thereof will be omitted. The heat sink body 20 is made of a material having good thermal conductivity such as aluminum, and the cooling fan 50 is incorporated in a cooling fan mounting area provided in the center thereof. Further, a cover body 40 having a cooling air introduction port 41 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 heat radiation fins 22 and 2.
A ventilation space 30 for cooling air is formed between the two. Similar to the above-described embodiment, the cover body 40 is made of a highly heat-conductive material such as aluminum, and is screwed to the fixed block 22 ′ that also serves as the heat radiation fins 22 formed at the four corners of the heat sink body 20.

Further, the heat sink body 20 includes:
A diaphragm 60 is provided. The throttle portion 60 is made of a material having better thermal conductivity than the heat sink body 20, such as copper, and has a tubular shape surrounding the rotation range of the rotary blades 51 of the cooling fan 50. The narrowed portion 60 is provided with fixing protrusions 63, 63, ... At the lower end periphery, and the fixing protrusion 63 has a hole (not shown) provided in the fixing plate 21.
It is pressed into and fixed to the heat sink body 20. As means for fixing the throttle portion 60 to the heat sink body 20, it is possible to use well-known means such as brazing in addition to press fitting.

It should be noted that the inner peripheral wall surface of the throttle portion 60 is shown in FIG.
As shown in FIG. 7, when a plurality of concave-convex stripes 61, 61 ... Are engraved, the heat exchange efficiency with the cooling air flowing through the narrowed portion 60 can be further improved.

Further, in FIG. 5, the throttle portion 60 is fixed to the fixed plate 21 of the heat sink body 20 and is arranged from the upper surface of the fixed plate 21 to the upper part of the cooling fan 50, but the present invention is not limited to this, and as shown in FIG. In addition, it is possible to enclose only the upper part of the cooling fan 50. In this case, the narrowed portion 60 is formed in a ring shape and can be held and fixed on the stepped 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 press-fitted into a fitting portion formed by the rising wall 22b of the step portion 22a of the heat radiation fin 22.

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 fan unit 53 including a motor and rotating blades 51, and the fan unit 53. 20 and a casing 52 for fixing and supporting the same. The motor bearing portion 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, to suppress heat transfer from the heat sink body 20, and prevent shortening of life due to temperature rise. To be done.
On the other hand, the casing 52 is made of a material having excellent thermal conductivity such as copper and aluminum, and has a tubular throttle portion 60 surrounding the rotation range of the rotary blades 51 on the fan unit 53 side while holding the fan unit 53. And a fixing portion 52a to the heat sink body 20, and the diaphragm portion 60 has
A slit 64 into which the fixed blade 53a formed on the fan unit 53 side is fitted is formed. The casing 52 can be fixed to the heat sink body 20 by an appropriate means such as screwing or adhesion.

[0025]

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

Further, by positively utilizing the throttle portion as a heat dissipation element, it is possible to improve the overall cooling efficiency.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, in which (a) is a plan view,
(B) is a side view showing a part of the view.

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

FIG. 3 is an exploded perspective view of FIG.

FIG. 4 is a view showing a second embodiment of the present invention, (a) is a plan view and (b) is a side view showing a part of the view.

5A and 5B are views showing a heat sink body, FIG. 5A is a plan view, and FIG. 5B is a 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 a diaphragm unit.

FIG. 8 is a view showing a modified example of FIG. 4, (a) is a plan view,
(B) is a half sectional view of (a), and (c) is a sectional view taken along the line AA of (a).

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

FIG. 10 is an exploded view of FIG.

11A and 11B are views showing a conventional example, in which FIG. 11A is a plan view and FIG.
[Fig. 3] is a half sectional view of (a).

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

[Explanation of symbols]

 10 High Heat-generating Element 20 Heat Sink Body 21 Fixing Plate 22 Radiating Fin 30 Ventilation Space 40 Cover Body 41 Cooling Air Inlet 50 Cooling Fan 51 Rotating Blade 52 Casing 53 Fan Unit 60 Throttling Section 61 Concavo-convex Strip

Claims (6)

[Claims] 1. A heat sink body having a plurality of pin-shaped radiation 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 cooperates with the heat radiation fins (22, 22 ...) To form a ventilation space (30) for the cooling air, and a cooling air for the cover body (40) that is arranged in the cooling fan mounting area. A cooling fan (50) for forcibly introducing cooling air into the ventilation space (30) from the introduction port (41), and the cover body (40) is an upper part of the rotary blade (51) of the cooling fan (50). Is arranged at a height exposed from the cooling air inlet (41), and the exposed portion of the rotary blades (51) of the cooling fan (50) is projected from the peripheral edge of the cooling air inlet (41). A heat sink with a fan surrounded by a cylindrical throttle portion (60). 2. The heat sink with a fan according to claim 1, wherein the heat radiation fins (22, 22 ...) Of the heat sink body (20) penetrate the cover body (40) and project upward. 3. A heat sink with a fan, wherein a cooling fan (50) is attached to a heat sink body (20) fixed to a high heat generating element (10), wherein rotating blades (51) of the cooling fan (50) rotate. The range is a cylindrical throttle part (6
A heat sink with a fan which is surrounded by 0) and which transfers the amount of heat absorbed in the heat sink body (20) to the throttle portion (60). 4. A heat sink body having a plurality of pin-shaped radiation 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) which cooperates with the heat radiation fins (22, 22 ...) To form a ventilation space (30) for the cooling air, and a cover body (4) which is arranged in the cooling fan mounting area.
Ventilation space (3
0) and a cooling fan (50) forcibly introduced into the heat sink body (20), and the heat sink body (20) is made of a material having a better thermal conductivity than at least the heat sink body (20). A heat sink with a fan to which a cylindrical throttle portion (60) surrounding the rotation range of the rotary blade (51) is fixed. 5. A heat sink body (20) in which a plurality of heat radiation fins (22, 22 ...) Are erected on the upper surface of a fixing plate (21) to the high heat generating element (10), and an upper surface of the heat sink body (20). A fan unit (53) housed in a casing (52) fixed to the heat sink body (20), and a cooling fan (50) for sending cooling air to the heat sink body (20) side, the cooling fan (50) The casing (52) is made of a material having good heat conductivity, and the casing (52) is provided with a cylindrical throttle portion (60) surrounding the rotation range of the rotary blades (51). Heat sink with fan. 6. The heat sink with fan according to claim 1, wherein a plurality of concavo-convex stripes (61, 61 ...) Are engraved on the inner peripheral wall surface of the throttle portion (60).