JP6447275B2 - Radiation fins and heat sinks and modules equipped with them - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a heat dissipation fin using a porous metal capable of improving heat transfer from a heat generating body or heat transfer to a heat absorbing body, and a heat sink and module including the heat sink. .

  In recent years, high performance and miniaturization of devices and equipment have progressed, and accordingly, the heat generation density of devices and equipment has increased.

  Generally, an element such as a semiconductor device in an apparatus or equipment cannot maintain its performance when a predetermined temperature is exceeded. Further, in some cases, it may be damaged. For this reason, temperature management by cooling or the like is required, and a technique for efficiently cooling elements such as semiconductor devices that generate a large amount of heat is strongly demanded as processing performance improves.

  As such a technique, for example, in the following Patent Document 1, heat radiation fins made of foam metal are arranged between a plurality of flat heat transfer tubes communicating with upper and lower headers, and air (20 ° C.) and refrigerant ( A heat exchanger for cooling that performs heat exchange with cold water (5 ° C., 10 ° C.) is described. Patent Document 2 describes an example in which the shape of the pin-type fin provided on the heat sink is a streamline shape with respect to the flow direction of the cooling water.

JP 2005-326136 A JP 2002-185175 A

  In the above-described prior art, the streamline-shaped fins described in Patent Document 2 are described as having the same shape on the upstream side and the downstream side in the flow direction of the refrigerant fluid. The shape is elliptical. However, in the elliptical shape described in Patent Document 2, in consideration of the pressure loss of the refrigerant fluid, it is not possible to reduce the contraction loss at the inlet, the friction loss at the surface, and the pressure loss due to the expansion of the outlet. Problem arises.

  That is, Patent Documents 1 and 2 do not clearly describe a structure for reducing the fluid resistance of the radiating fin and improving the heat transfer performance, and do not refer to the shape of the radiating fin in consideration of the manufacturing method. Furthermore, there is a problem that no consideration is given to a method of integrating the radiation fin base that makes good contact with an element such as a semiconductor device and the radiation fin itself.

  An object of the present invention is to provide a radiating fin capable of reducing fluid resistance and improving heat transfer performance, and a heat sink and module on which the radiating fin is mounted.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present invention includes a plurality of means for solving the above-mentioned problems, and as an example, a heat dissipating fin having a porous metal structure composed of a fine wire made of metal and a cavity, The fine wire has a portion in which the shape of each wire cross section is a streamline having a direction along a direction in which a fluid flows as a longitudinal direction.

  According to the present invention, fluid resistance can be reduced and heat transfer performance can be improved.

It is a side view of the heat sink which joined the porous metal in one embodiment of the present invention to the smooth board. It is AA sectional drawing of the heat sink shown in FIG. It is a partial cross section figure for the fine wire material of the heat sink in other embodiment of this invention. It is a partial cross section figure for the fine wire material of the heat sink in other embodiment of this invention. It is a partial cross section figure for the fine wire material of the heat sink in other embodiment of this invention. It is a side view of the thermoelectric conversion module in one embodiment of the present invention.

Embodiments of a heat dissipating fin using the porous metal of the present invention, a heat sink mounted with the fin, and a module will be described with reference to FIGS.
FIG. 1 is a side view of a heat sink in which porous metal is bonded to a smooth plate in one embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIGS. FIG. 6 is a side view of a thermoelectric conversion module according to an embodiment of the present invention.

  In FIG. 1, the heat sink 40 of the present embodiment targets air or water as a cooling medium, and reduces heat resistance and improves heat transfer performance, thereby transferring heat from a heating element to heat absorption body. It is a heat sink that can improve heat transfer. As shown in FIG. 1, the heat sink 40 includes a smooth plate 10 that is a base made of metal, and heat radiating fins 23 mounted on the smooth plate 10 through metal bonds.

  Among these, as shown in FIG. 1, the radiating fin 23 lowers the temperature of the fluid flowing into the radiating fin 23 and the fine wire 20 made of metal and the cavity so that the fluid with the lowered temperature flows out to the outside. It has a structure of a porous metal 22 composed of a portion 21. As a result, the portion where heat is transferred is transferred through the fine wire 20. The fluid 30 flows through the portion of the cavity 21 that is the surface of the fine wire 20. When the temperature of the fluid 30 is higher than the temperature of the fine wire 20, heat is transferred from the fine wire 20 to the fluid 30. On the other hand, when the temperature of the fluid 30 is lower than the temperature of the fine wire 20, heat is transferred from the fluid 30 to the fine wire 20. Thereby, heat transfer between the fine wire 20 and the fluid 30 can be performed.

  FIG. 2 shows an AA cross section of FIG. 1 which is a portion of the fine wire 20. In FIG. 2, the hollow portion 21 is omitted and only the fine wire 20 is illustrated.

  In FIG. 2, the fine wire 20 has a grid arrangement. As shown in FIG. 2, the fine wire 20 has a streamlined portion having a cross-sectional shape whose longitudinal direction is a direction along the direction in which the fluid 30 flows. That is, the fine wire 20 has a curved shape at the front surface portion where the fluid 30 strikes the flow direction of the fluid 30, and has a long and narrow shape at the rear surface portion so that the flow of the fluid 30 is not easily separated. The cross-sectional length 202 along the fluid flow direction is longer than the cross-sectional length 203 perpendicular to the fluid flow direction. With such a shape, it is possible to reduce the pressure loss due to the restriction at the front surface when passing through the fine wire 20. Moreover, the heat transfer area of the fine wire 20 can be expanded, and heat transfer performance can be improved.

  Further, the smooth plate 10 is joined to the fine metal material 20 through a metal bond on the porous metal 22 side. The side opposite to the porous metal 22 side of the smooth plate 10 is a module side that is joined to the module when used as a heat sink, and has a smooth surface in order to increase the heat conduction efficiency with the module.

  The material of the smooth plate 10 is the same material as the fine wire 20 of the porous metal 22. However, the same material is not necessarily required, and a metal plate having a melting point higher than that of the metal constituting the fine wire 20 or a plate made of a material having high thermal conductivity can be used.

  FIG. 3 shows an example of another embodiment of the AA cross section of FIG. Also in FIG. 3, the hollow part 21 is abbreviate | omitted similarly to FIG. 2, and only the fine wire 20 is described.

  In FIG. 3, the fine wires 20 are in a staggered arrangement. Similar to the embodiment of FIG. 2, the fine wire 20 of the embodiment of FIG. 3 has a curved shape at the front surface portion against which the fluid 30 hits, and a long shape at the rear surface portion so that the flow of the fluid 30 is not easily separated. Further, the cross-sectional length 202 along the fluid flow direction is longer than the cross-sectional length 203 perpendicular to the fluid flow direction.

  Even with such a cross-sectional shape and arrangement, it is possible to reduce the pressure loss due to the restriction at the front surface when passing through the fine wire 20. Moreover, the heat transfer area of the fine wire 20 can be expanded, and heat transfer performance can be improved.

  FIG. 4 shows an example of still another embodiment of the AA cross section of FIG. Also in FIG. 4, the hollow part 21 is abbreviate | omitted similarly to FIG. 2, and only the fine wire 20 is described.

  In FIG. 4, the fine wire 20 has a grid arrangement. This embodiment differs from the embodiment of FIG. 2 in that the space 201 is provided inside the fine wire 20. Although this will be described in detail later, during the heating step for forming the porous metal 22, the resin of the substrate disappears, and the space 201 is not filled with the metal. Further, a liquid refrigerant is injected into the space 201 and sealed. By enclosing the refrigerant, the heat conduction efficiency due to the phase change of the liquid refrigerant is further improved, and the heat transfer performance can be further improved.

  FIG. 5 shows an example of still another embodiment of the AA cross section of FIG. Also in FIG. 5, the hollow part 21 is abbreviate | omitted similarly to FIG. 2, and only the fine wire 20 is described.

  FIG. 6 shows an embodiment in which the heat sink 40 of the radiation fin 23 using the porous metal 22 is mounted on the thermoelectric conversion module 50.

  In FIG. 6, a thermoelectric conversion module 50 is a module that directly converts thermal energy into electrical energy. A P-type thermoelectric element and an N-type thermoelectric element are arranged, and when a temperature difference is generated between both ends, a current flows. On one surface of the thermoelectric conversion module 50, the heat sink 40 of the heat radiating fin 23 using the porous metal 22 is attached via a heat transfer elastomer such as a heat conductive grease 60. On the other side of the thermoelectric conversion module 50, a cooling / heating source 70 such as a water cooling jacket of a water cooling system is attached.

  For example, heat energy is directly converted into electric energy by using high-temperature exhaust gas generated from an automobile or the like and a low-temperature part of a radiator water cooling system such as an automobile. A cooling system can be configured by attaching the heat sink 40 of the heat dissipating fins 23 using the porous metal 22 to the high-temperature exhaust gas generated from an automobile or the like and the cold source 70 on the low-temperature part side of the radiator water cooling system of the automobile or the like. .

  According to the configuration of the present invention, the heat dissipating fin using the porous metal and the module on which the heat dissipating fin is formed by applying the metal powder to the base resin when the fin is formed using the porous metal for the heat dissipating fin. Then, it is allowed to stand at a high temperature to blow off the resin of the base material and solidify the metal. Further, when the metal is solidified, the metal-shaped front surface portion is changed to a curved surface and the rear surface portion is changed to a long and thin shape by a method such as gas blowing. Furthermore, when joining with the metal plate which is a base, when solidifying said metal, a porous metal fin and a base metal plate are integrated.

  With these, it is possible to attach a heat dissipating fin using porous metal to an element such as a semiconductor device via a heat transfer member such as a heat conducting grease, and from a heat dissipating fin from an element such as a semiconductor device or vice versa. Heat can be transferred well to elements such as semiconductor devices. In addition, the fluid resistance of the porous metal heat dissipating fins can be reduced, and the driving energy required for a fan, a pump, etc. required for flowing a fluid such as air or water as a refrigerant can be reduced. Further, by miniaturizing the radiating fins, the heat transfer rate is improved, and further, by making the radiating fins streamlined, the separation of the refrigerant flow by the projections of the radiating fins is eliminated. As a result, there is no stagnation region of the refrigerant flow after peeling, and the entire heat radiating fin can be used as a heat transfer area, and high performance of the heat radiating fin using the porous metal and the module on which the heat radiating fin is mounted can be achieved. .

  In addition, this invention is not restricted to said embodiment, A various deformation | transformation and application are possible. The above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the configurations described.

  For example, although a thermoelectric conversion module is illustrated as a module, the module can be a general electronic component that requires heat exchange. Moreover, the radiation fin of this invention can be used also for heat exchangers, such as an air conditioner.

10 ... smooth plate,
20 ... fine wire,
21 ... Cavity,
22 ... porous metal,
23 ... radiating fins,
30 ... Fluid,
40 ... heat sink,
50 ... Thermoelectric conversion module,
60 ... heat conduction grease,
70 ... cold source,
201 ... space part,
202 ... cross-sectional length along the fluid flow direction,
203: Section length perpendicular to the fluid flow direction.

Claims (6)

A heat dissipating fin having a porous metal structure composed of a fine wire made of metal and a cavity,
The said fine wire has the part which the shape of each wire rod cross section becomes a streamline which makes the direction along the direction where a fluid flows into a longitudinal direction. The radiation fin characterized by the above-mentioned. The radiating fin according to claim 1,
The said fine wire has a space part in the inside. The radiation fin characterized by the above-mentioned. The radiating fin according to claim 1,
In the fine wire, the cross-sectional shape of each wire is such that the cross-sectional length along the fluid flow direction is longer than the cross-sectional length perpendicular to the fluid flow direction. The radiating fin according to claim 2,
The space fin is sealed with a liquid refrigerant. A smooth plate made of metal;
A heat sink comprising: the heat dissipating fin according to claim 1 mounted on the smooth plate through a metal bond. A module on which the heat sink according to claim 5 is mounted.

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