JP2916088B2 - 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.

[0002]

2. Description of the Related Art A heat sink with a fan is used to cool a high heat generating element on a substrate such as an MPU in a spot manner. A heat sink with a fan is formed by mounting a fan device on a heat sink body made of a material having good thermal conductivity, such as aluminum, and is conventionally provided on the heat sink body to increase a cooling area and improve cooling performance. The radiating fins are provided at an equal pitch in consideration of the entire pressure loss and the like.

[0003]

On the other hand, in a heat sink with a fan whose size is restricted because it is directly mounted on a semiconductor element package, the space between the heat radiation fins is reduced and the surface area is increased to improve the cooling performance. Although it is very important to make the cooling fins narrow, the gap between the cooling fins is clogged with dust or the like in a short period of time, and there is a disadvantage that the cooling performance tends to be reduced.

An object of the present invention is to solve the above-mentioned drawbacks, and an object of the present invention is to provide a heat sink with a fan capable of maintaining stable cooling performance for a long period of time.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided the above-mentioned object, as shown in FIG. 1, which is mounted on a heating element and has a plurality of radiation fins 10, 10,. A heat sink body 20 and a fan device 30 mounted on the heat sink body 20.
This is achieved by providing different heat sinks with fans in the left and right regions with respect to a vertical line L hanging down from the center of the fan device 30 to each side of the heat sink body 20.

[0006]

In general, increasing the surface area of the radiating fins 10 is an effective means for improving the cooling performance. For this reason, the radiating fins 10 should be densely provided as long as the pressure loss does not cause a reduction in the cooling performance. Desirably, radiation fin 1
The gap between 0 and 10 is a passage of the cooling air, and if the space d between the radiating fins 10 is reduced, clogging due to dust and the like in the room will be caused.

On the other hand, as a result of an experiment conducted by the present inventor using a heat sink with a fan in which the fan device 30 is mounted on the rectangular heat sink main body 20, the distribution of the cooling air velocity at the peripheral edge of the heat sink main body 20 is biased. Was.

The present invention has been made in view of the fact that the unevenness of the cooling air velocity distribution at the peripheral edge of the heat sink body 20 may cause ubiquitous clogged portions. By changing the distance d between the heat radiation fins 10 according to the conditions, the occurrence of clogging is prevented, and
The cooling performance has also been improved.

That is, in the first aspect of the present invention,
Radiation fins 10 on the periphery of the heat sink body 20;
The distance d between the radiating fins 10 is different between the left and right regions with respect to a vertical line L hanging down from the center of the fan device 30 to each side of the heat sink body 20. By preventing the clogging, the clogging is prevented, and the heat exchange efficiency in a low wind speed region is improved.

Further, according to claim 2, a fan device 3 for sucking air from the side of the heat sink body 20 and exhausting the air upward.
Where 0 is used to provide the location of the wide and narrow area,
According to the third aspect, the arrangement of the wide and narrow area is provided when the fan device 30 that suctions air from above the heat sink body 20 and exhausts air to the side is used.

The heat sink body 20 according to claim 4,
In addition to the clogging at the periphery of the heat sink body 20, a structure for preventing clogging inside the heat sink body 20 is provided. That is, the radiation fins 10 are provided at the same intervals d, d,... In the area partitioned along the rotation direction of the rotary fan 31, and are different in different areas.

Further, in the fifth, sixth and seventh aspects, an efficient monitoring structure for cooling performance of a heat sink with a fan is provided.

[0013]

FIG. 1 shows an embodiment of the present invention. The heat sink with a fan includes a heat sink body 20 formed of a material having good heat conductivity such as aluminum, a fan device 30, and a cover member 50.

The heat sink body 20 is formed in a rectangular shape in a plan view, and has a plurality of radiating fins 1 on a peripheral portion except a central portion.
0, 10,... The fan device 30 mounted at the center of the heat sink body 20 is mounted with the shaft of the rotating fan 31 embedded in the heat sink body 20 in order to reduce the overall height of the heat sink with a fan, and is indicated by an arrow in FIG. As described above, the cooling air is rotated clockwise to generate cooling air flowing upward from below.

A cover member 50 is fixed to the heat sink body 20 on which the fan device 30 is mounted, with the back surface in contact with the upper end of the radiation fin 10. The cover member 50 is provided with a wind guide opening 51 at the center. By driving the fan device 30, cooling air is introduced from a side portion of the heat sink body 20, that is, a gap between the radiation fins 10, and the air flows from the wind guide opening 51. The hot air is discharged and cooled.

The radiating fin 10 is connected to the heat sink body 20.
The distance d between the radiating fins 10 and 10 is widened in the left region and narrowed in the right region with respect to the center when each side is viewed from the front. ing. The distance d between the heat radiation fins 10 in the wide and narrow areas is appropriately determined in consideration of the degree of pressure loss and the like, and is shown in FIGS. 2 and 3 by using a cotton linter (cotton) having a length of 1 mm or less and a thickness of 1.5 μm or less. Powder) was used as test dust, and from a result of an experiment in which a heat sink with a fan having a spacing d of 0.2 mm between the radiating fins 10 of 0.2 mm was continuously operated for 4 months, etc., the distance between the radiating fins 10 in the wide spacing region was determined. It is desirable that d be about 1 mm, and about half that in a narrowly spaced area.

FIG. 2 is a view showing a clogged state when the fan device 30 is used in which the rotating fan 31 rotates clockwise and exhausts air from the upper surface. FIG. 3 shows a state where the rotating fan 31 rotates clockwise. FIG. 4 is a diagram illustrating a clogged state when the fan device 30 that exhausts air from a lower surface is used, in which clogged portions are indicated by hatching in the figure. Further, in the drawings shown in FIG. 2 and subsequent figures, a state in which the cover member 50 is removed is shown.

Which of the two regions at the center of each side is the region where the space d between the radiating fins 10 is wide depends on the exhaust direction of the fan device 30 and the rotation of the rotating fan 31 in the fan device 30. The following can be determined in consideration of the direction. Now, when each side is viewed from the front in FIG. 1, the rotation direction of the rotating fan 31 passing through the back of each side is indicated by an arrow crossing each side (an arrow A in FIG. 1B). The arrangement of the wide and narrow area of the radiation fin 10 is uniquely determined by the direction of the arrow and the exhaust direction of the fan device 30, and when the fan device 30 that exhausts from the upper surface is used, the area on the escape side of the arrow is radiated. When the fan device 30 that exhausts air from the lower surface is used, the space d between the heat radiation fins 10 is set to be a narrow region. The entry side area is a wide interval area.

That is, in the case of using the fan device 30 that rotates counterclockwise and exhausts air from the lower surface, the arrangement of the wide and narrow space regions is exactly the same as that of the above-described embodiment.
When the rotation fan 31 rotates counterclockwise, or when the rotation direction of the rotation fan 31 is clockwise and the fan device 30 that exhausts air from the lower surface is used, the radiation fin 10
The distance d between them may be narrow in the left region and wide in the right region.

In the above embodiment, the heat radiation fins 10 are of a plate type having an elongated rectangular shape in plan view, but pin fins can also be used. In addition, the area where the heat radiation fins 10 are formed may be formed over the entire surface of the heat sink main body 20, other than being arranged only on the peripheral edge of the heat sink main body 20. Attached to the top of the

Further, in the above-described embodiment, each side is divided into two regions. However, each side is divided into three or more regions, and the distance d between the radiation fins 10 is gradually narrowed for each region. It is also possible to spread and spread.

That is, the present invention comprises a heat sink body 20 mounted on a heating element and provided with a plurality of radiating fins 10 on an upper surface, and a fan device 30 mounted on the heat sink body 20. The interval d between
The distribution of the spacing d between the radiation fins 10 between the regions divided along the rotation direction of the rotating fan 31 and the distribution of the cooling air passing through each region substantially coincides with the distribution of the cooling wind. It is also possible to configure as an attached heat sink.

FIGS. 4 and 5 show a second embodiment of the present invention.
This embodiment shows a structure for efficiently detecting clogging between the radiation fins 10 and 10, and the clogging detecting means 40 is mounted in a narrow interval region in the above-described embodiment. As the clogging detection means 40, a temperature sensor, a wind speed sensor, an optical sensor, or the like can be used.

Although FIGS. 4 and 5 show the case where the radiation fins 10 are formed at the same pitch over the entire surface, the present invention is also applicable to the embodiment shown in FIG. 1 (FIG. 6).
reference).

[0025]

As is apparent from the above description, according to the present invention, clogging of the gap between the radiation fins can be reliably prevented, and stable cooling performance can be secured for a long period of time. it can.

[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.

FIGS. 2A and 2B are explanatory diagrams showing experimental results, in which FIG.
(B) is a side view.

3A and 3B are explanatory diagrams showing other experimental results, in which FIG. 3A is a plan view and FIG. 3B is a side view.

FIG. 4 is a diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram showing a modification of FIG. 4;

FIG. 6 is a diagram showing another modification.

[Explanation of symbols]

 Reference Signs List 10 heat radiation fins 20 heat sink body 30 fan device 31 rotating fan 40 clogging detection means L perpendicular d interval

Continuation of the front page (56) References JP-A-7-58470 (JP, A) JP-A-5-280882 (JP, A) JP-A-63-238377 (JP, A) JP-A-4-25975 (JP) , U) Hikaru 2-91619 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05K 7/20 H01L 23/36 H01L 23/467

Claims (7)

(57) [Claims] 1. A heat sink body mounted on a heat generating element and having a plurality of heat dissipating fins on a top surface and having a rectangular shape in a plan view, and a fan device mounted on the heat sink body. A heat sink with a fan in which the intervals between the radiation fins are different in right and left regions with respect to a vertical line hanging down from the center of the fan device to each side of the heat sink body. 2. The fan device according to claim 1, wherein the fan unit is configured to take in air from a side of the heat sink body and exhaust the air upward. 2. The heat sink with a fan according to claim 1, wherein the heat sink is narrower than the opposite area. 3. The fan device according to claim 1, wherein the fan unit is configured to take in air from above the heat sink body and exhaust the air to the side, and the distance between the radiation fins with respect to the vertical line is defined as: The heat sink with a fan according to claim 1, wherein the heat sink is wider than the opposite side area. 4. A heat sink body mounted on the heating element and provided with a plurality of heat dissipating fins on an upper surface, and a fan device mounted on the heat sink body, wherein a distance between the heat dissipating fins is equal to a rotation of the rotating fan. A heat sink with a fan that is different for each area divided along the direction. 5. A heat sink body mounted on the heat generating element and having a plurality of heat dissipating fins on the upper surface and having a rectangular shape in plan view, a fan mounted on the heat sink body and sucking air from a side portion of the heat sink body and exhausting the air upward. Device, having clogging detection means attached to at least one edge of the heat sink body, wherein the clogging detection means borders a perpendicular line hanging down from the center of the fan device to each side of the heat sink body A heat sink with a fan arranged in the escape side area of the rotating fan. 6. A heat sink body mounted on the heat generating element and having a plurality of heat dissipating fins on its upper surface and having a rectangular shape in plan view, a fan mounted on the heat sink body and sucking air from above the heat sink body to exhaust air to the side. Device, having clogging detection means attached to at least one edge of the heat sink body, wherein the clogging detection means borders a perpendicular line hanging down from the center of the fan device to each side of the heat sink body A heat sink with a fan arranged in the entry area of the rotating fan. 7. A clogging detecting means is provided at an edge of a region where a space between the heat radiation fins is narrowed.
The heat sink with a fan according to 2, 3, or 4.