JP2001156229A - Heat sink and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink which can enhance heat-exchange efficiency and can be easily formed at low cost. SOLUTION: Heat-exchanging fins 3, integrated with a block 2 made of a material with high thermal conductivity, are formed in parallel with each other. Several slots 4 are made in the block 2 so that they are in parallel with each other. The slots 4 are filled with two-phase-condensation fluid 6, and both ends 5A of each slot 4 are blocked. The slots are straight, and the lengthwise direction X of the fins 3 is in parallel with the axial direction Y of the slots 4. The block 2, fins 3, and slots 4 can be easily formed by extrusion molding. The fluid 6 enables uniform, quick heat transfer along the slots 4, enhancing the heat-exchange efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight heat sink having improved heat conduction efficiency and a method for manufacturing the same.

[0002]

Conventionally, as a heat sink of this type, a heat sink having a block portion and a fin portion integrally formed by extruding a heat conductive metal such as aluminum is generally used.

However, in these heat sinks, there is a problem that the weight increases because the base portion is formed thick. This is because heat is easily radiated because the entire heat sink is made of a good heat conductive metal, so if the base part is formed thin, heat will be radiated before heat is diffused from the heat source to the entire base, so only the heat source periphery Is heated to a high temperature, and the temperature distribution in the base portion is biased, so that the heat exchange efficiency is deteriorated. On the other hand, even when the base portion is formed thick, the heat capacity is increased by the thickness of the base, so that the temperature of the base does not easily decrease, and there is a problem in terms of heat radiation.

On the other hand, for example, FIG. 2 of Japanese Patent Application Laid-Open No. 6-221738 discloses a roll-bonded heat pipe formed by rolling and pressing to a thickness of about 1.6 mm. Has a configuration in which the radiation fins are brazed only in the radiation portion without providing the radiation fins, and the working fluid passages are provided in a lattice shape between the heat absorption portion and the radiation portion.

[0005] However, it is troublesome to braze the radiation fins to the roll-bonded heat pipe in a state where the heat conduction is good, which has been a factor of cost increase.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a heat sink which can be made light in weight and which can improve the heat exchange efficiency. Another object of the present invention is to provide a heat sink that can be formed more easily and at a lower cost, and a method of manufacturing the same.

[0007]

According to a first aspect of the present invention, there is provided a heat sink comprising a block made of a good heat conductor and heat exchange fins formed integrally and in parallel with each other on the surface of the block. A plurality of holes are respectively formed in parallel inside, and a two-phase condensable working fluid is sealed in the holes, and both ends of the holes are closed.

According to the first aspect of the present invention, when the heat of the heat source is transferred and radiated to the outside, the heat released from the heat source is quickly transferred to the entire block by the working fluid sealed in the block. The heat is radiated from the entire fin formed integrally with the block. Conversely, when the external heat is absorbed and transferred to the cold heat source, the heat absorbed from the entire fins is transferred to the cold heat source by the working fluid of the entire block.

According to a second aspect of the present invention, in the heat sink according to the first aspect, the hole is formed in a shape of a straight fine hole, and an axial direction of the hole and a longitudinal direction of the fin are formed in parallel. Things.

According to the configuration of the second aspect, the fin and the heat pipe having the hole formed by extrusion or the like can be easily integrally formed.

Further, according to a third aspect of the present invention, there is provided a method for manufacturing a heat sink, comprising: a block made of a good heat and heat conductor; and heat exchange fins formed integrally and in parallel with each other on the surface of the block. A plurality of holes are formed inside each of which are parallel to each other, and a two-phase condensable working fluid is sealed in the holes, and a heat sink formed by closing both ends of the holes is formed by extruding a block body. With the block, the hole whose axial direction is linear and the fin whose longitudinal direction is linear are formed so as to be parallel to each other.

According to the third aspect of the present invention, the block main body is extruded and formed so that the hole having a straight axis and the fin having a straight longitudinal direction can be formed in parallel.

[0013]

Hereinafter, embodiments of the present invention will be described.
Description will be given based on the drawings. FIGS. 1 to 4 show a first embodiment, in which a heat sink 1 is a thin plate-shaped block 2 made of aluminum or an aluminum alloy, which is a good conductor, and is formed integrally with the block 2. It is composed of a plurality of fins 3. In the embodiment, the fins 3 are arranged at a plurality of intervals on the upper surface, which is the surface of the block 2. In the inside of the block 2, a plurality of pores 4 are formed in a rectangular cross section.
Since these blocks 2, fins 3 and pores 4 are formed integrally by extrusion, not only the fins 3 and pores 4 but also the fins 3 and pores 4 are linear. And the longitudinal direction X of the fins 3
And the axis Y of the pores 4 are formed in parallel. Also,
The cross-sectional area of the pores 4, that is, the passage area of the working fluid 6, which will be described later, is formed, for example, in a range of 0.5 square mm to 2 square mm and is thin. Then, the end of the block 2 in the extrusion direction is crushed and further sealed by welding or the like.
The ends of the pores 4 are connected. In the embodiment, as shown in FIG. 3, the end side of the partition wall 5 of the pore 4 is removed, and the end 5A which is located at almost half of the removed end side is crushed and sealed by welding or the like. The ends of the adjacent pores 4 are connected to each other by a communication portion 5B formed by the other half. And in this pore 4,
A two-layer condensable working fluid 6 such as Freon substitute is sealed. Although the pores 4 are formed at regular intervals, the gaps between some of the pores 4 are configured to be wide, and the attachment portions 7 are formed with screw holes 7A. Using the screw holes 7A, a thermo module T serving as a heat source or a cold heat source is held between the block 2 and the heat transfer plate 9 by screws 8. The side surface 2A of the block 2 and the side surface 3A of the outermost fin 3 are provided on the same plane.

Further, as described above, the block 2, the fins 3, and the pores 4 are integrally formed by extrusion molding, and as shown in FIG.
Die 11 having holes 10 corresponding to fins 3
A semi-molten aluminum or aluminum alloy 12 is inserted into the dies 11 and pressurized, and the dies 11 are formed to flow out of the gaps of the dies 11 to produce a product having a constant cross section. Then, FIG.
The working fluid 6 is sealed as shown in FIG.

Next, the operation of this embodiment will be described.
First, the case where the surface of the thermo module T in contact with the block 2 is on the heat dissipation side, that is, the case where the thermo module T operates as a heat source for the heat sink 1 will be described. Conduction to the contact part of the block 2. The heat conducted to the contact portion of the block 2 causes the block 2
The working fluid 6 sealed in the inner pores 4 evaporates, and at this time, the latent heat of vaporization is taken from the block 2. The vaporized working fluid 6 moves quickly along the pores 4 to the entire inside of the block 2 by the pores 4. Then, the vaporized working fluid 6 condenses in the pores 4, but releases latent heat at this time, and heat is transmitted to the block 2. Thus, the heat released from the thermomodule T is
It moves uniformly and quickly over the entire block 2. The heat transferred to the entire block 2 is transferred to the fins 3
Will be dissipated. At this time, since the block 2 and the fins 3 are formed integrally, heat is satisfactorily conducted from the block 2 to the fins 3. Then, heat is radiated to the external space in the fins 3. By performing the above operations continuously, the heat released from the heat radiation surface of the thermomodule T is radiated from the fins 3.

Next, when the surface of the thermo module T in contact with the block 2 is on the cooling side, that is, when the thermo module T
When the heat is absorbed by the thermo module T from a contact portion between the heat absorbing surface of the thermo module T and the block 2, the heat sink 1 operates as a cold heat source. The latent heat is removed from the working fluid 6 existing as a gas and condenses. Furthermore, the working fluid 6 that has moved from the surroundings condenses, and the condensed working fluid 6 moves along the inside of the pores 4 along the pores 4 and moves quickly throughout the block 2. The condensed working fluid 6 is supplied to the heat sink 1
Is taken as vaporization latent heat and vaporized in the pores 4. In this manner, heat is uniformly and quickly transferred from the entire heat sink 1 to the thermo module T so as to compensate for the heat absorbed from the thermo module T. At this time, since the block 2 and the fin 3 of the heat sink 1 are integrally formed, heat is satisfactorily conducted from the fin 3 to the block 2. Then, the heat of the fins 3 is deprived and the temperature decreases, so that the heat of the outside air is absorbed from the fins 3. By performing the above operations continuously, the heat absorbed from the fins 3 moves to the heat absorbing surface of the thermomodule T.

As described above, in the above embodiment, in the heat sink including the plate-like block 2 made of a good heat conductor and the heat exchange fins 3 formed integrally and in parallel with the surface of the block 2, A plurality of pores 4 are formed in parallel inside 2, a two-phase condensable working fluid 6 is sealed in the pores 4, and both ends 5 A of the pores 4 are closed and formed. When the heat of the thermo module T, which is a heat source, is transferred and radiated to the outside, the heat released from the thermo module T is quickly moved along the pores 4 by the working fluid 6 sealed in the block 2 as a whole. And the heat is radiated from the entire fins 3 formed integrally with the block 2. On the contrary, the thermo module T which is a cold heat source by absorbing external heat
Is transferred to the thermo module T by the working fluid 6 in the entire block 2
Therefore, even if the block 2 is made thin, the heat is efficiently and uniformly transferred along the pores 4 by the working fluid 6, so that the heat exchange efficiency can be improved and the heat sink 1 can be further improved. Thus, the entire product using the heat sink 1 can be reduced in size and weight.

Further, the pores 4 are formed straight, and the longitudinal direction X of the fins 3 and the axial direction Y of the pores 4 are formed in parallel, so that the shape can be extruded. The blocks 2, fins 3, and pores 4 can be easily formed by extrusion molding or the like.

Further, in the manufacturing method, together with the block 2, the aluminum or aluminum alloy 12 is so formed that the pores 4 whose axial direction Y is linear and the fins 3 whose longitudinal direction X is linear are parallel. Since the heat is extruded by the die 11 and the heat is transferred uniformly and quickly along the pores 4 by the working fluid 6, it is possible to provide the heat sink 1 which can improve the heat exchange efficiency. In addition, it can be manufactured accurately and at low cost by extrusion molding.

Next, another embodiment of the present invention will be described. The same parts as those in the first embodiment are denoted by the same reference numerals,
A detailed description thereof will be omitted.

FIG. 5 shows a second embodiment.
Are protruded outward from the side surfaces 3B of the outermost fins 3 to form a mounting portion 7B in which a screw hole (not shown) is formed by the protruding portion.

As described above, in the second embodiment, the heat sink 1 can be mounted with good stability by forming the mounting portions 7B on both sides of the block 2 so as to protrude. In addition, the entire product using the heat sink 1 can be reduced in size and weight, and can be formed into a shape that can be extruded. In addition, the manufacturing method can accurately and inexpensively manufacture by extrusion. it can.

FIG. 6 shows a third embodiment in which fins 3 are provided on the upper and lower surfaces of one of the pores 4 in the block 2 in the axial direction Y.
And the block 2 is provided with a protruding portion 2C.
Thus, by providing the projecting portion 2C on the block 2 and attaching a thermo module (not shown) to the projecting portion 2C, it is possible to ensure a large number of fins 3 and a large total area of the fins 3. Further, similarly to the first embodiment, the heat sink 1 and the entire product using the heat sink 1 can be reduced in size and weight, and can be formed into a shape that can be extruded or the like. Extrusion allows accurate and inexpensive manufacture.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the invention. For example, the fin 3D is provided on the upper surface of the block 2 in which the pores 4 are formed as in the fourth embodiment shown in FIG. 7, and the longitudinal direction X ′ of the fins 3D and the axial direction Y of the pores 4 are provided.
Are arranged so as to intersect, and in the example, are orthogonal to each other, and in the above embodiment, the thermo module T is sandwiched between the block 2 and the heat transfer plate 9. It may be configured to be provided integrally with the heating plate 9.

[0025]

According to a first aspect of the present invention, there is provided a heat sink comprising a block made of a good conductor and heat exchange fins formed integrally and in parallel with each other on the surface of the block. A plurality of holes are formed in parallel, a two-phase condensable working fluid is sealed in the holes, and both ends of the holes are closed. A heat sink capable of improving heat exchange efficiency and reducing weight can be provided.

The heat sink according to the second aspect of the present invention comprises:
Claim 1 wherein the pores are formed into straight pores,
Since the longitudinal direction of the fin and the axial direction of the hole are formed in parallel to each other and can be formed by extrusion or the like, the heat sink can be formed easily and at low cost.

Further, the method of manufacturing a heat sink according to the third aspect of the present invention is a method of manufacturing a heat sink, comprising: a block made of a good heat conductor; and heat exchange fins formed integrally and in parallel with each other on the surface of the block. A heat sink formed by forming a plurality of holes in parallel, sealing a two-phase condensable working fluid in the holes, and closing both ends of the holes. The block body is formed by extruding the block body so that the hole and the longitudinal direction of the fin are parallel to each other, and it is possible to improve the heat exchange efficiency with excellent fluidity by aligning the working fluid along the hole, It is possible to easily and inexpensively form a heat sink capable of reducing the weight.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a first embodiment of the present invention.

FIG. 3 is a plan sectional view showing the first embodiment of the present invention.

FIG. 4 is a perspective view illustrating a manufacturing process according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing a second embodiment of the present invention.

FIG. 6 is a perspective view showing a third embodiment of the present invention.

FIG. 7 is a perspective view showing a fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 heat sink 2 block 3 fin 4 pore (hole) 6 working fluid X longitudinal direction Y axis direction

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 7/20 H01L 23/46 BF Term (Reference) 3L044 AA03 BA06 CA13 DA02 EA03 KA04 5E322 AA01 AB01 AB11 DB09 DC02 FA01 5F036 AA01 BA08 BB05 BB41 BB44 BB60 BD01

Claims (3)

[Claims] A heat sink comprising a block made of a good conductor and heat exchange fins formed integrally and in parallel on the surface of the block, a plurality of holes are formed inside the block in parallel with each other. A heat sink characterized in that a two-phase condensable working fluid is sealed in a hole and both ends of the hole are closed. 2. The heat sink according to claim 1, wherein the hole is formed in a shape of a straight fine hole, and a longitudinal direction of the fin and an axial direction of the hole are formed in parallel. 3. A block made of a good heat conductor and heat exchange fins formed integrally and in parallel with each other on the surface of the block, and a plurality of holes are respectively formed inside the block in parallel with each other. A heat sink formed by enclosing a two-phase condensable working fluid and closing both ends of the hole, the hole and the fin having a linear shape in the axial direction and the fin having a linear shape in the longitudinal direction together with the block. Wherein the block body is extruded so as to be parallel.