JPH08162787A - Heat sink with fan - Google Patents

Abstract

PURPOSE: To keep a cooling effect constantly for a long time in a heat sink with a fan. CONSTITUTION: A heat sink with a fan includes a heat-sink main body 20 having a rectangular shape when viewed from above with a plurality of radiating fins 10 on an upper face and mounted on a heating element, and a fan unit 30 mounted on the heat-sink main body 20. The distance (d) between the heat radiating fins 10 differs in right and left regions that are separated by a perpendicular line (L) from the center of the fan unit 30 to each side of the heat-sink main body 20.

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 for spot cooling a high heat generating element such as an MPU on a substrate. 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. Conventionally, the heat sink with a fan is provided on the heat sink body to increase a cooling area and improve cooling performance. The radiating fins are provided at equal pitches in consideration of the pressure loss of the whole.

[0003]

On the other hand, in a heat sink with a fan whose size is restricted because it is directly mounted on a semiconductor device package, it is necessary to narrow the gap between the radiation fins and increase the surface area to improve the cooling performance. Although it is very important for this purpose, if the gap between the cooling fins is narrowed, the gap between the cooling fins is clogged with dust or the like in a short period of time, and the cooling performance tends to deteriorate.

The present invention has been made to solve the above 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]

According to the present invention, the above-mentioned object is, as shown in FIG. 1, a rectangular shape in plan view which is mounted on a heating element and has a plurality of heat radiation fins 10, 10 ... Of the heat sink body 20 and a fan device 30 attached to the heat sink body 20, and the distance d between the heat radiating fins 10 and 10 at the edge of the heat sink body 20.
Can be achieved by providing different heat sinks with fans in the left and right regions with a vertical line L hanging from the center of the fan device 30 to each side of the heat sink body 20 as a boundary.

[0006]

In general, increasing the surface area of the radiating fins 10 is an effective means for improving the cooling performance. Therefore, the radiating fins 10 should be densely arranged to the extent that the pressure loss does not decrease the cooling performance. Desirable but radiation fin 1
The gap between 0 and 10 is a passage for cooling air, and if the gap d between the radiating fins 10 is narrowed, 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 a fan device 30 is mounted on a rectangular heat sink body 20, a bias in the distribution of the cooling wind velocity around the periphery of the heat sink body 20 was confirmed. It was

The present invention has been made paying attention to the fact that the uneven distribution of the cooling air velocity distribution around the periphery of the heat sink body 20 may cause the uneven distribution of the clogging points. By changing the distance d between the radiation fins 10 according to the above, the occurrence of clogging is prevented, and
The cooling performance is also improved.

That is, in the invention according to claim 1,
Radiating fins 10 on the edge of the heat sink body 20,
The interval d between the 10 is different in the left and right regions with a vertical line L hanging from the center of the fan device 30 to each side of the heat sink body 20 as a boundary, and the interval d between the radiation fins 10 in the high wind speed region is wide and low. By narrowing the area, clogging can be prevented and the heat exchange efficiency can be improved in the low wind speed region.

Further, in claim 2, the fan device 3 for inhaling air from the side of the heat sink body 20 and exhausting it upward.
The arrangement of wide and narrow areas is provided when 0 is used,
In the third aspect, the arrangement state of the wide and narrow regions is provided when the fan device 30 that takes in air from above the heat sink body 20 and exhausts it to the side is used.

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

Further, in claims 5, 6 and 7, there is provided an efficient structure for monitoring the cooling performance of a heat sink with a fan.

[0013]

EXAMPLE FIG. 1 shows an example of the present invention. The heat sink with a fan is composed of a heat sink body 20 formed of a material having a good thermal 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 at the peripheral edge portion except the central portion.
0, 10 ... are projected. The fan device 30 attached to the center of the heat sink body 20 is attached with the shaft portion of the rotary fan 31 embedded in the heat sink body 20 in order to reduce the overall height of the heat sink with fan, and is shown by an arrow in FIG. As described above, the cooling air that rotates clockwise is generated from the lower side to the upper side.

A cover member 50 is fixed to the heat sink body 20 to which the fan device 30 is attached, with the back surface thereof being in contact with the upper ends of the radiation fins 10. The cover member 50 is provided with an air guide opening 51 at the center, and by driving the fan device 30, cooling air is introduced from the side portions of the heat sink body 20, that is, the gaps between the heat radiating fins 10. It is discharged and the high temperature part is cooled.

The radiation fin 10 is composed of a heat sink body 20.
Of the heat dissipation fins 10 and 10 are widened in the left side region and narrowed in the right side region with respect to the center when viewed from the front side. ing. The distance d between the heat dissipating fins 10 in the wide and narrow region is appropriately determined in consideration of the degree of pressure loss and the like, but as shown in FIGS. 2 and 3, a cotton linter having a length of 1 mm or less and a thickness of 1.5 μm or less (cotton linter) is used. Powder) was used as a test dust, and the distance between the heat radiation fins 10 in the wide distance region was wide, based on the results of experiments in which a heat sink with a fan having a distance d between the heat radiation fins 10 of 0.2 mm was continuously operated for 4 months. It is desirable that d be about 1 mm, and about half that in a narrow interval region.

FIG. 2 is a diagram showing a clogging state when the fan device 30 in which the rotary fan 31 rotates clockwise and exhausts from the upper surface is used, and FIG. 3 shows the rotary fan 31 rotating clockwise. FIG. 3 is a diagram showing a clogged state when a fan device 30 exhausting air from the lower surface is used, and the clogged portions are shown 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 one of the regions divided into two at the center of each side has the wider space d between the heat radiation fins 10 is determined by the exhaust direction of the fan device 30 and the rotation of the rotary fan 31 in the fan device 30. It can be determined as follows in consideration of the direction. Now, when each side is viewed from the front side in FIG. 1, the rotation direction of the rotary fan 31 passing through the back side of each side is indicated by an arrow crossing each side (arrow A in FIG. 1B). The arrangement of the wide and narrow regions 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 exhausting from the upper surface is used, the escape side region of the arrow is radiated. The space d between the fins 10 is wide, whereas when the fan device 30 exhausting air from the lower surface is used, the escape side region of the arrow is defined as a region where the space d between the heat radiating fins 10 is narrow, 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 gap regions is exactly the same as that of the above embodiment,
When the rotating fan 31 rotates counterclockwise, or when the rotating fan 31 rotates clockwise and the fan device 30 that exhausts air from the lower surface is used, the heat dissipation fin 10 is used.
The distance d may be narrowed in the left side area and widened in the right side area.

In the above embodiments, the radiation fin 10 is shown as a plate type having an elongated rectangular shape in a plan view, but a pin shape can also be used. Further, the formation area of the heat dissipation fins 10 may be formed over the entire surface of the heat sink body 20 other than the area arranged only on the peripheral edge of the heat sink body 20, and in this case, the fan device 30 is formed by the fan device 30. Mounted on the top of the.

Further, in the above-mentioned embodiment, each side is divided into two regions, but it 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 expand and spread.

That is, the present invention has a heat sink body 20 mounted on a heating element and having a plurality of heat radiation fins 10 on its upper surface, and a fan device 30 mounted on the heat sink body 20. The distance d between
A fan that is different between regions divided along the rotation direction of the rotary fan 31 and has a distribution of the spacing d between the heat radiating fins 10 that is substantially the same as the distribution of the wind speed of the cooling air passing through each region. It is also possible to configure it as an attached heat sink.

A second embodiment of the present invention is shown in FIGS.
This embodiment shows a structure for efficiently detecting clogging between the radiating fins 10 and 10. The clogging detecting means 40 is attached to the region which is the narrowly spaced 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.

4 and 5, the radiation fins 10 are formed over the entire surface at equal pitches, but they can also be applied to the embodiment shown in FIG. 1 (FIG. 6).
reference).

[0025]

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

[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.

FIG. 2 is an explanatory view showing experimental results, (a) is a plan view,
(B) is a side view.

3A and 3B are explanatory views showing other experimental results, where 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.

FIG. 6 is a diagram showing another modification.

[Explanation of symbols]

 10 radiating fins 20 heat sink body 30 fan device 31 rotating fan 40 clogging detection means L vertical line d interval

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 23/467

Claims (7)

[Claims] 1. A heat sink body, which is mounted on a heating element and has a rectangular shape in plan view, having a plurality of heat radiation fins on its upper surface, and a fan device mounted on the heat sink body. A heat sink with a fan in which the space between the heat radiating fins differs in the left and right areas from the center of the fan unit to the vertical line that hangs from each side of the heat sink body. 2. The fan device is for inhaling air from a side portion of a heat sink body and exhausting air upward, and the space between the heat radiating fins at the perpendicular line is a boundary between the heat dissipating fins in the inlet side region. The fan-equipped heat sink according to claim 1, wherein the heat sink is narrower than the opposite side region. 3. The fan device is for inhaling air from above a heat sink body and exhausting to a side portion, and the space between the heat radiating fins on the side of the perpendicular line is in the admission side region of the rotary fan. The heat sink with a fan according to claim 1, wherein the heat sink is wider than the area on the opposite side. 4. A heat sink body mounted on a heat generating element and having a plurality of heat radiation fins on its upper surface, and a fan device mounted on the heat sink body, wherein the space between the heat radiation fins is the rotation of a 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 a heat generating element and having a plurality of heat radiation fins on its upper surface, the heat sink body having a rectangular shape in plan view, and a fan mounted on the heat sink body and sucking air from a side portion of the heat sink body and exhausting it upward. The device and a clogging detection unit attached to at least one edge portion of the heat sink body, wherein the clogging detection unit is a boundary line that extends from the center of the fan device to each side of the heat sink body. A heat sink with a fan located in the escape side area of the rotating fan. 6. A heat sink body mounted on a heat generating element and having a plurality of heat radiation fins and having a rectangular shape in plan view, and a fan mounted on the heat sink body and sucking air from above the heat sink body and exhausting to the side. The device and a clogging detection unit attached to at least one edge portion of the heat sink body, wherein the clogging detection unit is a boundary line that extends from the center of the fan device to each side of the heat sink body. A heat sink with a fan that is placed in the entry side area of the rotating fan. 7. A clogging detection means is provided at a peripheral edge of a region where a space between the heat radiation fins is narrowed.
A heat sink with a fan according to 2, 3, or 4.