JPH11340384A - Heat sink and cooling structure using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pipe suitable for heat dissipating equipment which prevents damage of electric/electronic components which is to be caused by heat generation. SOLUTION: An upper block plate 30 and a lower block plate 30 are faced each other. Slit sheets 10 on which a plurality of slits 11 are formed are bonded to facing surfaces of the upper and the lower block plates 30. A plurality of parallel fin plates 20 are arranged between the upper and the lower block plates 30, inserting their end portions in the slits 11, and a heat sink is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink suitable for cooling electric and electronic parts such as semiconductor elements.

[0002]

2. Description of the Related Art Electric and electronic components such as semiconductor elements mounted on various devices such as personal computers and electric and electronic devices such as power equipment generate heat to some extent during use. If the electric / electronic component is excessively heated by this heat generation, its performance will be reduced or its life will be shortened. In addition, in recent years, the miniaturization of electric appliances represented by personal computers and the like has been progressing, and therefore, there has been an urgent need to develop excellent cooling technology for electric and electronic components mounted thereon.

Electric / electronic devices requiring cooling (hereinafter referred to as
As a method of cooling the component to be cooled, for example, an air-cooled type, that is, a fan or the like is attached to a housing of an electric device in which the cooling device is mounted, and the atmosphere in the housing is cooled, thereby excessively cooling the component to be cooled. There are ways to prevent the temperature from rising. Although this method is effective particularly for relatively large electric equipment, it is not suitable for small equipment. In recent years, in addition to the air-cooling method described above, a method of connecting a heat sink to a component to be cooled and dissipating heat via the heat sink has been widely used, and particularly, a heat pipe has been incorporated between the component and the component to be cooled. A cooling method using a heat sink has been developed to improve the heat dissipation effect. In addition, a technology has been developed in which an electric fan is used to blow the heat sinks and fins to achieve higher cooling efficiency.

[0004]

A heat sink has a function of absorbing heat from an object to be cooled (such as an electronic component) and dissipating the heat. As such,
For example, a typical example is a material in which a plurality of thin fin plates are raised almost perpendicularly to a block plate using a material having excellent thermal conductivity such as an aluminum material. Such a heat sink typically causes electronic components to contact the block plate portion, and dissipates the heat of the electronic components transmitted to the block plate to the atmosphere generally via the fin plate portion. Used in form.

When the fin plate has a relatively large thickness, the heat sink having the above-described shape can be integrally formed by extrusion, forging, or other casting methods. When the thickness is reduced to a certain extent, it becomes difficult to integrally form by extrusion, forging, casting, or the like. Also, when the height of the fin plate is large, or when the interval between the adjacent fin plates (fin pitch) is narrowed to some extent, the extrusion processing,
It becomes difficult to integrally form by forging, casting, or the like.

In such a case, a method has been adopted in which a block plate serving as an upper plate and a lower plate and a metal sheet serving as a fin plate are separately prepared from an aluminum material or the like, and these are joined by brazing or the like. According to such a manufacturing method, the metal sheet serving as the fin plate can be manufactured by rolling or the like, and the size of the fin plate and the pitch of the fins to be joined to the block plate can be freely adjusted.

[0007] However, it is not easy to join a large number of thin fin plates to the upper and lower block plates in a state where the thin fin plates are built almost vertically on the block plate. That is, when joining a plurality of fin plates together, the position of the fin plates often shifts. Of course, such problems can be prevented by joining a plurality of fin plates one by one at appropriate positions, but the manufacturing cost becomes too large and a practical method for mass production. is not.

[0008]

Means for Solving the Problems The present inventors propose a practical heat sink which is excellent in terms of manufacturing cost. In the heat sink of the present invention, an upper block plate and a lower block plate are opposed to each other, and a slit sheet having a plurality of slits formed on a surface facing the upper and lower block plates is joined. It has a structure in which the ends are inserted and arranged side by side between the upper and lower block plates.

The fin plate is preferably inserted into the slit so as to be fixed by a tightening spring mechanism. In addition, if at least a part of the fin plate is provided with a cut-and-raised portion that comes into contact with another adjacent fin plate, assembly becomes easy. If one or both of the slit sheet and the upper and lower block plates are formed of a brazing sheet, joining becomes easier.

When a metal material having excellent thermal conductivity such as copper or aluminum is applied to the block plate, it is desirable from the viewpoint of heat absorption and heat uniformity, and the aluminum material has an advantage that it is particularly lightweight. When at least one of the upper and lower block plates of the heat sink has a heat pipe structure, a higher heat uniformity can be realized as a heat sink, and heat radiation of a cooled component such as an electronic component to be cooled is more effective. Becomes In this case, if a convex portion corresponding to the height of the component to be cooled is provided on the heat absorbing surface of the heat pipe, the heat absorbing effect is further improved. It is also possible to adopt a structure in which a heat pipe is incorporated or attached to at least one of the upper block plate and the lower block plate of the heat sink. If the heat pipe has a built-in wick in the cavity constituting the heat pipe, the heat sink having the heat pipe is maintained upside down in extreme cases even when used upside down (top heat mode). The heat radiation effect can be enhanced by attaching a heat transfer block between the heat absorption surface and the heat radiation surface.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. 1 and 2 show a first embodiment of the present invention. FIG. 1 is an exploded explanatory view for explaining the structure of the heat sink of the present invention, and FIG. 2 is a schematic perspective view showing the heat sink of the present invention. In FIG. 1, reference numerals 30 and 30 denote an upper block plate and a lower block plate.
0 and 30 are arranged facing each other. Reference numeral 20 denotes a fin plate, and the plurality of fin plates 20 are arranged so as to be substantially perpendicular to the upper and lower block plates 30. A slit sheet 10 in which a slit 11 is formed at a predetermined position is joined to the upper and lower block plates 30 and 30 on opposite sides, and upper and lower ends of a fin plate 20 are inserted into the slit 11. 20 is configured.

Slit 1 for inserting fin plate 20
The width of 1 is slightly smaller than the thickness of the fin plate 20,
When the fin plate 20 is inserted, it is preferable that the two be fixed by a spring mechanism. By doing so, when joining the fin plate 20 and the slit sheet 10 or the block plate 30, the joining operation becomes easier. In addition, although not shown, if a support is provided between the upper and lower block plates 30 and 30 separately from the fin plate 20 to fix the upper and lower block plates 30 and 30, the fin plate 20 is not necessarily a slit sheet. It is not necessary to join to 10 or the block board 30.

By the way, the slit sheet 10 is omitted,
If the groove into which the fin plate 20 is inserted is formed directly on the surface of the block plate 30, the fin plate 20 can be inserted and held as in the case described above. Will increase. Therefore, the cost of the assembled heat sink increases. On the other hand, according to the present invention, since the slit sheet 10 is formed not through the groove but through the slit 11,
Although the material cost is slightly higher than in the case of forming the groove in the block plate 30, there is a remarkable difference as compared with the labor and the cost is advantageous. Therefore, the heat sink 5 can be provided at low cost.

Further, when forming a groove in the block plate 30, if the width of the groove becomes narrow, it becomes difficult to form the groove. Alternatively, also when the interval between the grooves is narrow, it is difficult to form the grooves. In the present invention, since the slits 10 are formed not through the grooves but through the slits 11, it is possible to form the slits with a narrow width and a slit with a small interval at a low cost as compared with the case of forming the grooves. Can be.

As described above, in the present invention, the heat sink 5 can be easily assembled by applying the slit sheet 10. When the heat sink 5 is made of an aluminum material, it is easy to join the block plate 30 and the slit sheet 10 by brazing. The fin plate 20 is joined to the slit sheet 10 and / or the block plate 30, and it is preferable to apply brazing also in this joining.

At the time of brazing, brazing may be performed by separately arranging a brazing material, but it is convenient to apply a brazing sheet to the slit sheet 10, for example.
The brazing sheet is an aluminum sheet provided with an aluminum material layer serving as a brazing material on one surface or both surfaces. For example, if a slit sheet 10 in which a brazing material is arranged on the surface side in contact with the block plate 30 is applied, the block plate 30 and the slit sheet 10 are joined by brazing, but the fin plate 20 is formed in the slit 11 at an appropriate depth. The fin plate 20 is also inserted into the block plate 3
Since it reaches the brazing material disposed on the surface side in contact with 0, the fin plate 20 can be joined to the slit sheet 10 simultaneously with the brazing of the block plate 30 and the slit sheet 10. As a matter of course, a brazing sheet having brazing material disposed on both sides may be applied as the slit sheet 10. In this case, the slit sheet 10
And the block plate 30 and the fin plate 20 are more securely joined.

Instead of using a brazing sheet as the slit sheet 10, a brazing sheet may be used as the block plate 30. In this case, if the fin plate 20 is inserted to a depth to reach the block plate 30,
The fin plate 20 can be joined to the block plate 30 simultaneously with the brazing of the block plate 30 and the slit sheet 10.

The heat sink 5 of the present invention (FIG. 2) assembled as described above is
In general, a use mode in which a heat-generating component to be cooled (hereinafter, referred to as a component to be cooled) 40 is attached to the zero portion. The contact between the component to be cooled 40 and the block plate 30 may be direct contact or contact with heat transfer grease or the like. Of course, in some cases, these may be joined by soldering or the like.

FIG. 3 shows a second embodiment of the present invention. The fin plate 20 is provided with a cut-and-raised portion 21 that comes into contact with another adjacent fin plate 20 so that the distance between the fin plates 20, 20 is increased. If the heat sink 5 is assembled by providing the cut-and-raised portion 21 as shown in FIG. 3 on all or a part of the plurality of fin plates 20 shown in FIG. As shown in the drawing, the cut-and-raised portion 21 can maintain the interval between the adjacent fin plates 20, so that assembly can be more easily achieved.

FIG. 5 shows a third embodiment of the present invention, in which the lower block plate 30 shown in FIG. 2 has a heat pipe structure. In FIG. 5, reference numeral 51 denotes a lower block plate (3
0) is a flat heat pipe with a heat pipe structure,
The heat pipe 51 includes a heat absorbing surface 52 and a heat radiating surface 53, and the component to be cooled 40 contacts the heat absorbing surface 52, and the heat radiating surface 5.
The fin plate 20 is joined to 3. Endothermic surface 5
The cavity 54 composed of the second and heat radiating surfaces 53 is maintained at a reduced pressure, and the working fluid is injected.

As described above, since the lower block plate (30) has a heat pipe structure, the heat generated from the component to be cooled 40 can be efficiently transferred from the radiating surface 53 to the fin plate 20.
The heat is dissipated. In FIG. 5, reference numeral 56 denotes a heat transfer block, and the heat transfer block 56 is provided in contact with the respective inner walls of the heat absorbing surface 52 and the heat radiating surface 53. The heat transfer block 56 has the effect of reducing the thermal resistance between the heat absorbing surface 52 and the heat radiating surface 53, and more efficiently transfers the heat generated from the cooled component 40 from the heat absorbing surface 52 to the heat radiating surface 53. The heat dissipation effect can be further improved.

In FIG. 5, reference numeral 57 denotes a wick. The wick 57 is arranged along the inner wall of the heat radiating surface 53 and extends to the inner wall of the heat absorbing surface 52 so as to follow the side wall of the heat transfer block 56.
The tip is disposed so as to contact the inner wall of the heat absorbing surface 52. With this arrangement, the wick 57 can be connected to the respective inner and side walls with a small thermal resistance. The tip of the wick 57 may be metal-joined to the inner wall of the heat absorbing surface 52. With metal bonding, the thermal resistance between them will be even lower.

In FIG. 5, a working fluid (not shown) is accommodated in the cavity 54 in an appropriate amount. As the working fluid, water,
Alternative Freon, Fluorinert, ammonia, alcohol,
Acetone or the like can be used. When selecting a working fluid, it is necessary to determine it in consideration of compatibility with the material constituting the heat pipe. In FIG. 5, reference numerals 61, 62, and 63 denote protrusions provided on the heat absorbing surface 52. The protrusions have sizes that can be selectively used depending on the heat generation capacity of the component to be cooled 40 as described later.
It has a height.

The projections 61, 62 provided on the heat absorbing surface 52
Is formed in such a size that the heat transfer block 56 and the wick 57 can be installed, and the arrangement of the heat transfer block 56 in the convex portion 63 is omitted. This is because in a place where the heat generation of the cooled component 40 is small, even if the heat transfer block 56 is omitted, the cooling effect can be sufficiently achieved only by the heat pipe function.

As shown in FIG. 5, the heat-absorbing surface 52 of the heat pipe 51 is mounted on the
When the components 4 are arranged to be cooled and the components to be cooled are operated, the temperatures of the components 42, 43, and 44 to be cooled increase. The heat of the components to be cooled 42 and 43 having a large amount of heat is transmitted from the heat absorbing surface 52 to the operation of the heat pipe and the heat transfer block 56 disposed at a position overlapping with the components to be cooled 42 and 43, and the heat of the heat pipe 51 is radiated. The heat is transmitted to the surface 53, and the heat is generally radiated to the outside through the fin plate 20, and the cooled component 4
2, 43 are cooled. The heat transfer block 56 is
And the wick 57 are provided so as to be in surface contact with each other, so that the evaporation area of the working fluid is enlarged, the heat transfer coefficient is further improved, and much heat can be radiated.

As shown in the figure, when used in a bottom heat mode (a mode in which the heat absorbing surface side is located below the heat radiating surface side), the working fluid in the heat pipe 51 is caused by gravity. By the reflux and the capillary action by the wick 57, the reflux of the working fluid is maintained, and the heat pipe 51 operates normally. On the other hand, depending on the use condition, the top heat mode (the mode in which the heat absorbing surface side is positioned higher than the heat radiating surface side) may be used due to a large inclination, but even in such a case, the wick 57 causes the capillary action. Thus, the reflux of the working fluid is maintained, and the parts to be cooled are cooled well. In particular, since the wick 57 is also in contact with or joined to the inner wall of the heat absorbing surface to which the component to be cooled 40 (41, 42, 43) is attached, the working fluid is more reliably returned.

The heat of the cooled component 44 having a small calorific value is transmitted from the heat absorbing surface 52 to the heat radiating surface 53 by the operation of the heat pipe, and the heat is radiated to the outside through the fin plate 20 and the cooled component 44 is cooled. . In addition, even in the case of the top heat mode, since heat is transmitted through the wall of the heat pipe, a small amount of heat can be radiated,
The cooled component 44 continues to be cooled.

FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, a heat pipe 71 is joined to the lower block plate 30 shown in FIG. The heat pipe 71 may be the flat heat pipe described with reference to FIG. 5, or may be a circular or elliptical heat pipe. The circular or elliptical heat pipe 71 is connected to the lower block plate 30.
In order to attach the heat pipe, the block board 30 may be embedded or a hole or a groove may be formed in the block plate and a heat pipe may be incorporated into the hole or the groove. Alternatively, the heat pipe may be simply attached to a block plate.

FIGS. 5 and 6 illustrate the embodiment in which the lower block plate 30 has a heat pipe function. However, the upper block plate 30 also has a heat pipe function and cools components to be cooled vertically. Needless to say, a cooling structure can be used.

[0030]

As described above, the heat sink of the present invention has advantages that it can be easily assembled, can be mass-produced, and can be provided at low cost. In addition, by combining the radiating fin plate and the heat pipe structure, the radiating effect is further improved, the radiated heat of the component to be cooled can be effectively performed, and the size of the electronic device incorporating the electronic component can be further reduced. It has an excellent effect such as that it becomes possible.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an assembling state showing a first embodiment of a heat sink of the present invention.

FIG. 2 is a schematic perspective view illustrating a heat sink according to a first embodiment of the present invention.

FIG. 3 is an explanatory view showing a heat sink according to a second embodiment of the present invention.

FIG. 4 is a partial explanatory view showing an assembled state of the fin plate shown in FIG. 3;

FIG. 5 is an explanatory sectional view showing a third embodiment of the heat sink of the present invention.

FIG. 6 is an explanatory sectional view showing a heat sink according to a fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 5 heat sink 10 slit sheet 11 slit 20 fin plate 21 cut-and-raised portion 30 block plate 40 heat-generating component 41-43 heat-generating component 51 heat pipe 52 heat-absorbing surface 53 heat-radiating surface 54 cavity 56 heat-transfer block 57 wick 61-63 convex 71 heat pipe

Claims (11)

[Claims] An upper block plate and a lower block plate are opposed to each other, and a slit sheet having a plurality of slits formed on a surface facing the upper and lower block plates is joined. A heat sink, wherein a heat sink is inserted between the upper and lower block plates. 2. The heat sink according to claim 1, wherein the fin plate is inserted into the slit to be fixed by a tightening spring mechanism. 3. The fin plate according to claim 1, wherein at least a part of the fin plate is provided with a cut-and-raised portion that comes into contact with another adjacent fin plate.
A heat sink according to claim 1. 4. The heat sink according to claim 1, wherein the slit sheet or the block plate is formed of a brazing sheet. 5. The heat sink according to claim 1, wherein at least one of the upper and lower block plates has a heat pipe structure. 6. The heat sink according to claim 5, wherein at least one convex portion is provided on the heat absorbing surface of the heat pipe structure. 7. The heat sink according to claim 1, wherein a heat pipe is incorporated or attached to at least one of the upper and lower block plates. 8. The heat sink according to claim 7, wherein the heat absorbing surface of the heat pipe has at least one protrusion. 9. The heat sink according to claim 5, wherein a wick is built in a cavity formed by the heat absorbing surface and the heat radiating surface of the heat pipe. 10. The heat sink according to claim 5, wherein at least one heat transfer block is inserted between the heat absorbing surface and the heat radiating surface of the heat pipe. 11. A heat sink according to claim 1, wherein the heat sink is disposed opposite to a substrate on which the component to be cooled is mounted, and the component to be cooled and the heat sink are thermally connected. Cooling structure using a heat sink.