JP3127096B2 - Heat sink - 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 radiating heat sink which is attached to a heat generating element (heat generating component) such as a semiconductor element and dissipates heat generated in the heat generating element to the outside air, and a method of manufacturing the same.

[0002]

2. Description of the Related Art This type of heat sink has a basic structure in which a heat radiating fin is provided on a base plate. In this manufacture, a heat radiating fin and a base plate are separately formed, and the two are integrally joined. Both methods are broadly divided into a method of integrally molding them with the same material.

As a method of integrally joining the radiation fin and the base plate as in the former, generally, brazing, soldering, fitting and fixing (such as crimping and press fitting), and mechanical joining (riveting and crimping) are used. Etc.), bonding using an adhesive (hot melt, adhesive having thermal conductivity), and the like (for example, JP-A-62-86842, JP-A-63-81838, and JP-A-2-58342). No.).

[0004] As a method of integrally molding the heat radiation fin and the base plate as in the latter, for example, a method of extruding the heat radiation fin and the base plate integrally, a method of cutting the heat radiation fin on the surface of the extruded die, or a method of multi-wire sawing (See, for example, Japanese Utility Model Application Laid-Open No. 63-50137 and Japanese Utility Model Application Laid-Open No. 62-10).
1236, JP-A-6-232300, JP-A-5-129485).

[0005]

However, in the method in which the radiation fin and the base plate are joined by brazing or pressure fixing, the thickness of the radiation fin is large and the pitch of the radiation fin is large. On the other hand, the number of radiation fins that can be joined cannot be set large. Therefore, the surface area of the radiation fin (radiation area)
Cannot be increased, and there is a limitation in improving the heat radiation efficiency. Also,
Equipment such as a jig is required for joining the heat radiation fins and the base plate, and the number of processing steps is large, and the manufacturing cost is high. Since the radiation fin and the base plate are joined together, contact thermal resistance is likely to occur, and the thermal conductivity is inferior to that of the radiation fin and the base plate formed integrally.

On the other hand, in the case of integral molding by cutting or grinding, a large amount of time is required for processing including the time for setting and resetting in a processing apparatus, and the productivity is low, and the method is not suitable for mass production. In addition, the equipment cost is high, and if the depreciation cost of the equipment is included, the cost is greatly increased. Even in the case of integral molding by extrusion, the thickness of the radiating fins is large and the pitch of the radiating fins is large as in the case of the joining method such as brazing or pressure fixing, so that the number of radiating fins per fixed area of the base plate is increased. And the heat radiation area and heat radiation characteristics are limited.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and it is possible to reduce the pitch of the radiating fins, increase the number of radiating fins attached to a fixed area of the base plate, and increase the radiating area. It is an object of the present invention to provide a heat sink and a method of manufacturing the heat sink, which can increase the efficiency.

Another object of the present invention is to provide a heat sink and a method of manufacturing the same, which can reduce the number of processing steps and the manufacturing cost by improving the thermal conductivity and eliminating the joining operation.

[0009]

A heat sink according to the present invention is obtained by insert-molding heat-radiating fins on a die-cast base plate.

The heat radiation fins may be provided in a plurality of rows of heat radiation fins arranged in parallel with a predetermined pitch in a large number of flat plates, so that the flow of air between the heat radiation fins can be made in both the vertical and horizontal directions. This is preferable in that the heat radiation efficiency can be further improved.

The radiation fins are arranged in a plurality of rows of radiation fins arranged in parallel with a predetermined pitch in a large number of flat plates, and the phases of the radiation fins are shifted from adjacent radiation fin rows. Turbulence in the flow of wind between,
This is preferable in that the boundary layer can be reduced and the heat radiation efficiency can be further improved.

The base of the radiating fin is insert-molded on one side of the base plate, and a mounting boss having a mounting hole for the heating element is integrally formed on the other surface of the base plate so as to be integrally formed. Above.

It is preferable that the base radiating fin of the base plate be rounded in order to improve the thermal conductivity from the base plate to the radiating fin.

[0014]

The radiating fins may be formed in a pin shape or a corrugated shape other than the flat fin shape.

[0016]

[Function] Since the heat radiation fins are insert-molded on the base plate, the heat radiation fins can be thinned and arranged at a fine pitch, so that the number of heat radiation fins attached to a fixed area of the base plate can be increased, and the heat radiation area can be increased accordingly. it can.

Since the radiation fins can be integrally formed at the same time as the base plate is formed, the joining operation of the two can be omitted. In addition, the heat conductivity can be improved by integrally forming the radiation fin and the base plate.

[0018]

【Example】

Embodiment 1 FIGS. 1A to 1D show a heat radiation heat sink according to Embodiment 1 of the present invention, wherein FIG. 1A is a plan view and FIG.
FIG. 3C is a side view, FIG. 3C is a front view, and FIG. 3D is an enlarged cross-sectional view taken along line AA in FIG.

In FIG. 1, reference numeral 1 denotes a heat-radiating heat sink formed by integrally insert-molding a base portion 3a of a heat-radiating fin 3 made of an aluminum alloy on one side of a base plate 2 made of an aluminum alloy die-cast. The radiating fins 3 are flat, and are arranged in a line in parallel with a predetermined pitch on one side of the base plate 2. The thickness of the radiation fin 3 is, for example, in the range of 0.2 to 0.3 mm. The pitch between the radiation fins 3 is, for example,
It is in the range of 1.0 to 1.5 mm.

FIG. 2 shows a process sequence of the method for manufacturing the heat sink. In FIG. 2A, the upper mold 4 is raised. In the lower die 5, grooves 6 are arranged in parallel with a predetermined pitch, and in the grooves 6, a radiating fin 3 made of an aluminum alloy is inserted by an insert robot 7 or the like, and a root portion 3a of which is shown in FIG.
As shown in (2), fix it so that it protrudes upward.

Next, as shown in FIG. 2B, the upper die 4 and the lower die 5 are clamped, and the aluminum alloy is melted in a base plate forming space 8 formed between the upper and lower dies 4.5. Inject under pressure. After cooling, the upper die 4 is raised as shown in FIG. 3 (c), and the protrusion pins 9 of the lower die 5 are pushed up to take out the heat radiation heat sink 1 in which the base plate 2 and the heat radiation fins 3 are integrally formed.

Embodiment 2 FIGS. 3 (a) to 3 (d) show a base plate 2 according to Embodiment 1 in which the base buried portion 12 of the radiation fin 3 is rounded. Thereby, the cross-sectional area of the base buried portion of the radiation fin 3 of the base plate 2 can be increased, and the thermal conductivity from the base plate 2 to the radiation fin 3 can be further improved.

Embodiment 3 FIGS. 4A to 4D show a heat radiation heat sink according to Embodiment 3 of the present invention. FIG. 4A is a plan view and FIG.
FIG. 3C is a side view, FIG. 3C is a front view, and FIG. 3D is an enlarged cross-sectional view taken along line AA in FIG.

In this embodiment, the plate-shaped heat radiation fins 3 are arranged in a predetermined pitch on the one surface of the base plate 2 in place of the above-described first embodiment in which the plate-shaped heat radiation fins 3 are insert-molded in a line at a predetermined pitch. The radiating fin rows 10 are provided in a plurality of rows. According to this, the radiation fin 3
-Since the flow of the wind is enabled in both the vertical direction Y and the horizontal direction X between the three, the heat radiation efficiency can be further improved, which is advantageous.

Fourth Embodiment In the third embodiment, the radiation fin rows 10.1 adjacent to each other are arranged.
The radiation fins 3 of the adjacent radiation fins 10 are replaced with each other as shown in FIGS. 5A to 5D.
-The three are not aligned correctly and are arranged in a shifted state. That is, the phases of the heat radiation fins 3 are shifted between the adjacent heat radiation fin rows 10.

When arranged in this manner, the radiation fins 3.3
In addition to allowing the flow of the wind in the vertical direction Y and the horizontal direction X between them, the wind can be turbulently flowed between the radiating fins 3 to further improve the heat radiation efficiency.

Embodiment 5 The heat radiation heat sink shown in FIGS. 6A to 6D is a radiation fin 3 formed in a pin shape having a circular or square cross section.
Are formed by insert molding on one surface of the base plate 2 in a predetermined pitch arrangement by the process shown in FIG.

Embodiment 6 In the heat radiation heat sink shown in FIGS. 7A to 7D, a heat radiation fin 3 formed in a corrugated shape is insert-molded on one surface of the base plate 2 in a predetermined pitch arrangement by the process shown in FIG. It was done. In this case, the folded portion on one side of the corrugated shape of the radiation fin 3 is insert-molded on the base plate 2 as the root portion 3a.

Embodiment 7 In the heat radiation heat sink shown in FIGS. 8A to 8E, the radiation fin 3 is insert-molded on one side of the base plate 2 by the process shown in FIG. In addition, a mounting boss 13 having a heating element mounting hole 11 is integrally formed by protruding. Of course, in this case, a pin-shaped projection for forming a heating element mounting hole and a concave portion for forming a mounting boss are provided on the inner surface of the lower mold 5 shown in FIG.

If the mounting boss 13 having the heat generating material mounting hole 11 is integrally formed with the base plate 2 as described above, the time required to post-process the mounting hole in the base plate 2 when actually mounting the heat generating material can be omitted. Efficient work of mounting the heating element.

The radiating fins 3 are made of copper having a higher thermal conductivity than an aluminum alloy, or are made of a metal material different from the base plate 2 and having a higher thermal conductivity, and are formed in a flat plate shape, a pin shape, or a corrugated shape. Shaped ones can also be used.

[0032]

As described above, in the heat radiation heat sink of the present invention, since the radiation fins are insert-molded on the die-cast base plate, the radiation fin pitch can be reduced, and the number of radiation fins per fixed area of the base plate can be increased accordingly. As a result, the heat radiation surface area can be increased, and the heat radiation efficiency can be improved. Since the radiation fin and the base plate are integrally formed, the thermal conductivity is improved, and the joining operation can be omitted, so that the number of processing steps and the manufacturing cost can be reduced. Also the root of the radiation fin
By adding a radius to the embedded part, base play
Increase the cross-sectional area of the root embedded part of the heat radiation fin
Can conduct heat from base plate to radiating fins
Properties can be further improved.

[0033]

[Brief description of the drawings]

FIGS. 1A and 1B show a heat radiation heat sink according to a first embodiment of the present invention. FIG. 1A is a plan view, FIG.
FIG. 3C is a front view, and FIG. 3D is an enlarged cross-sectional view taken along line AA in FIG.

FIG. 2 is a process diagram of a method for manufacturing a heat sink according to the present invention.

3A and 3B show a heat sink according to a second embodiment of the present invention. FIG. 3A is a plan view, FIG.
FIG. 3C is a front view, and FIG. 3D is an enlarged cross-sectional view taken along line AA in FIG.

4A and 4B show a heat radiation heat sink according to a third embodiment of the present invention. FIG. 4A is a plan view, FIG.
FIG. 3C is a front view, and FIG. 3D is an enlarged cross-sectional view taken along line AA in FIG.

5A and 5B show a heat sink according to a fourth embodiment of the present invention. FIG. 5A is a plan view, FIG.
FIG. 3C is a front view, and FIG. 3D is an enlarged cross-sectional view taken along line AA in FIG.

6A and 6B show a heat sink according to a fifth embodiment of the present invention. FIG. 6A is a plan view, FIG.
FIG. 3C is a front view, and FIG. 3D is an enlarged cross-sectional view taken along line AA in FIG.

7A and 7B show a heat radiation heat sink according to Embodiment 6 of the present invention. FIG. 7A is a plan view, FIG.
FIG. 3C is a front view, and FIG. 3D is an enlarged cross-sectional view taken along line AA in FIG.

8A and 8B show a heat sink according to a seventh embodiment of the present invention. FIG. 8A is a plan view, FIG.
FIG. 2C is a front view, FIG. 2D is a bottom view, and FIG.
FIG. 4 is an enlarged sectional view taken along line AA in FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 heat radiation heat sink 2 base plate 3 radiation fin 4 upper die 5 lower die 11 heat generating material mounting hole 13 mounting boss 12 root embedded part

Claims (3)

(57) [Claims] A heat radiation fin is insert-molded on a die-cast base plate , and said base plate is
A heat sink, characterized in that a radius is provided in a root embedded portion of the heat radiation fin. 2. A die-cast base plate.
The radiating fins are insert-molded, and a plurality of radiating fin rows in which a number of flat radiating fins are arranged in parallel at a predetermined pitch are provided in a plurality of rows.
A heat sink having a fin array . 3. A radiating fin is provided on one side of the base plate .
The base is insert molded and the other side of the base plate
The mounting boss with the heating element mounting hole is
Radiating heat sink characterized that you have been.