JP2744566B2 - Radiator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiator for cooling a high heat generating element mounted on a printed circuit board.

[0002]

2. Description of the Related Art In recent years, as the mounting density of semiconductor elements has increased, the amount of heat generated by the semiconductor elements has increased, and a radiator shown in FIG. 7 has been proposed as a technique for efficiently cooling such high heat generating elements. ing.

This radiator is formed of a material having excellent heat conductivity, and has a heat sink 2 having a plurality of radiating fins 1, 1,... Protruding from an upper surface thereof, and a cooling fan 3 provided above the heat sink 2. Is done.

In this conventional example, the heat sink 2 which has absorbed the heat generated by the high heat generating element is provided with the cooling fan 3.
Will be forced air cooling.

[0005]

However, in the above-mentioned conventional example, the cooling fan 3 has a configuration in which the fan 7 is rotated by a motor 6 disposed at the center, and
Since the motor 6 has a large area for projecting the cooling air onto the delivery surface, the cooling air generating capability is not always high, and it is necessary to improve the number of revolutions of the motor 6 in order to exert a desired cooling effect. However, it has a drawback of causing noise and the like.

Further, as described above, since the motor 6 is disposed at the center of the cooling fan 3, the amount of cooling air is reduced at the center of the heat sink 2, which generates the largest amount of heat, and the cooling efficiency is never increased. It had the disadvantage of not being expensive.

The present invention has been made to solve the above-mentioned drawbacks, and has as its object to provide a radiator having good cooling efficiency.

[0008]

According to the present invention, there is provided a heat sink having a plurality of pin-shaped heat radiation fins as shown in FIG. And a cooling fan 3 fixed above the heat sink 2, and the heat radiating fin base end surface 4 of the heat sink 2 is achieved by providing a radiator having a concave surface which becomes lower toward the center.

[0009]

The radiator according to the present invention has a cooling fan 3 mounted on an upper portion of a heat sink 2 and spot cools the heat sink 2 by cooling air from the cooling fan 3.

The heat sink 2 is provided with a plurality of pin-shaped radiating fins 1, 1,...
It is formed in a concave surface that becomes lower toward the center. As a result, the protruding height of the adjacent radiating fins 1 from the radiating fin base end surface 4 becomes higher on the inner side of the heat sink 2, and a difference in pressure loss occurs between the two. Due to this difference in pressure loss, the cooling air sent from the cooling fan 3 is brought to the center of the heat sink 2, and the center of the heat sink 2 having a high calorific value is efficiently cooled.

Further, since the thickness of the heat sink 2 is small at the center, heat radiation is promoted, and the thickness increases toward the outer periphery, so that the heat conductivity is improved and the conduction cooling efficiency is improved. improves.

According to the second aspect of the present invention, the radiating fins 1 of the heat sink 2 extend along the radiating fin base end surfaces 4.
The cross-sectional shape is formed into a rectangular pin shape,
Be aligned. The cross-sectional area of each of the radiating fins 1, 1... Is reduced toward the distal end, so that the cooling air sent from the cooling fan 3 easily reaches the radiating fin base end surface 4 of the heat sink 2.

As a result, when the cooling fans 3 having the same airflow are used, the effective airflow is increased . Ma
In addition, the radiation fin 1 has a rectangular cross section.
In addition, for example, a vertical and horizontal groove on the surface of the aluminum block
Radiation fins can be formed simply by cutting
Therefore, the manufacturing cost can be reduced.

According to a third aspect of the present invention, the radiating fins are provided.
1 occupies every other grid of the matrix and is staggered
It is arranged in. To provide the radiation fins 1 thinned out
Reduces the pressure loss of the cooling air and increases the effective air flow
And the cooling air hits all the radiating fins 1
It will be cool. Grease not occupied by the radiation fins 1
Auxiliary fin with a smaller cross-sectional area than the radiation fin
The pressure loss of the cooling air is minimized,
In addition, the heat radiation surface increases.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a first embodiment of the present invention. In this embodiment, the radiator is a heat sink 2 made of a material having good heat conductivity such as an aluminum material.
And a cooling fan 3.

The cooling fan 3 drives the fan 7 to rotate by a motor 6 disposed at the center and sends cooling air downward, and is mounted on the heat sink 2 by appropriate means (not shown).

On the other hand, the heat sink 2 is formed by projecting a plurality of pin-shaped radiating fins 1, 1,... On an upper surface, and uses a heat conductive compound or an adhesive to form a heat sink surface of a high heat generating element. Joined to . Each radiation fin
1 is a cross section of the heat radiation fin 1 cut along a surface along the base end surface.
The shape is rectangular, and it is arranged vertically and horizontally.
You.

In this embodiment, the radiating fin base end face 4 of the heat sink 2 is formed so as to extend along a V-shape whose center line is the lowest point, and has a concave surface which becomes lower toward the center line. ing.

In the illustrated embodiment, the radiating fin base end surface 4 is inclined downward toward the center line along the V-shape. However, the present invention is not limited to this. It is also possible to form it so that it becomes lower toward the center point.

FIG. 2A shows a modification of the above-described embodiment. In this modification, a one-character partition plate 8 is provided on the center line of the heat sink 2. This partition plate 8
Are used to suppress interference of cooling air from both ends, and at the same time, also serve as the radiation fins 1.

Further, as shown in FIG. 2 (b), by providing an L-shaped radiating fin / guide plate 9 at the center, the surrounding cooling air can be collected mainly. FIG. 3 shows a second embodiment of the present invention. In this embodiment, the heat radiation fins 1 of the heat sink 2 are formed in a pointed shape with two opposing side walls as inclined surfaces.

This embodiment improves the cooling efficiency by making it easier for the cooling air from the cooling fan 3 to reach the radiating fin base end face 4, and the cross-sectional area becomes smaller toward the tip. However, in order to promote the introduction of the cooling air to the radiation fin base end surface 4, at least the total area of the distal end of the radiation fin 1 is set to 20% of the total area. It is desirable to set it to a percentage or less.

In the above-described embodiment, the inclined surfaces face in the same direction. However, forming the inclined surface toward the center of the heat sink 2 is a desirable modification. The shape is rectangular,
Various shapes such as a circle may be used.

FIG. 4 shows a third embodiment of the present invention. In the embodiment described below, the effective air flow of the cooling fan 3 is increased by minimizing the pressure loss of the cooling air sent from the cooling fan 3. Are arranged in a zigzag pattern occupying every other grid of the matrix.

FIG. 5 shows a fourth embodiment of the present invention. This embodiment is different from the third embodiment described above in that the radiation fins 1
By disposing the auxiliary fins 5 having a small cross-sectional area on the grid not occupied by the above, the heat radiation area can be improved without increasing the pressure loss of the cooling air.

In this embodiment, as shown in FIG. 6, when the radiating fins 1 are arranged on the outer peripheral grid in the same manner as the normal heat sink 2, the cooling air does not contribute to the cooling. Is prevented from passing through the heat sink 2 at the same time, and the cooling efficiency can be further improved.

[0027]

As described above, according to the radiator according to the present invention, the cooling air from the cooling fins having limited power can be effectively used, so that the cooling efficiency can be improved. In addition, since it is not necessary to use a cooling fin having a large power, generation of noise can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a modification of FIG.

3A and 3B are diagrams showing a second embodiment of the present invention, wherein FIG. 3A is a cross-sectional view and FIG. 3B is a plan view.

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

FIG. 5 is a view showing a fourth embodiment of the present invention, wherein (a) is a side view and (b) is a plan view.

FIG. 6 is a diagram showing a modification of FIG. 5;

FIG. 7 is a diagram showing a conventional example, where (a) is a side view,
(B) is a plan view.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 radiating fin 2 heat sink 3 cooling fan 4 radiating fin base end face 5 auxiliary fin

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H05K 7/20 H01L 23/36

Claims (3)

(57) [Claims] 1. A heat sink having a plurality of pin-shaped heat radiation fins, and a cooling fan fixed above the heat sink, wherein the heat radiation fin base end surface of the heat sink has a concave surface that becomes lower toward the center. Radiator formed. 2. A cross-sectional shape along a base end surface of a radiation fin is rectangular.
A plurality of pin-like radiating fins aligns vertically and horizontally erected in
A heat sink, and a cooling fan fixed above the heat sink, wherein the radiating fins of the heat sink have a smaller cross-sectional area toward a tip. 3. A heat sink having a plurality of pin-shaped heat dissipating fins, and a cooling fan fixed above the heat sink, wherein the heat dissipating fins occupy every other grid in a matrix and are staggered. On a grid that is arranged in a shape and is not occupied by the radiation fins,
Auxiliary fins with smaller cross-sectional area than radiation fins
The radiator.