CN1665021A - Heat sink and method for making same - Google Patents

Abstract

The present invention provides a heat dissipation device, which includes a base, a plurality of heat dissipation fins formed on the base and at least one heat pipe formed inside the base, wherein the base includes a bottom plate that is interlocked and welded together and A cover plate, a plurality of heat dissipation fins are formed on the cover plate; at least one groove is formed on at least one fastening surface of the cover plate and the bottom plate. heat pipe in the seat. The invention also relates to a preparation method of the heat sink. The heat dissipation device provided by the invention has a structure in which a heat collecting pipe and a heat dissipation fin are integrated, thereby improving the heat dissipation efficiency of the heat dissipation device and reducing the volume of the heat dissipation device, and is suitable for heat dissipation of integrated circuit electronic devices.

Description

Cooling device and its preparation method

【Technical field】

The invention relates to a heat dissipation device and a preparation method thereof, in particular to a heat dissipation device including a heat pipe and a preparation method thereof.

【Background technique】

In recent years, with the rapid development of electronic technology, the high frequency and high speed of electronic devices and the density and miniaturization of integrated circuits have caused a sharp increase in the heat generation of electronic devices per unit volume. Therefore, heat dissipation devices are attached to electronic components to keep electronic components working. The heat generated is conducted to the air to ensure stable operation of electronic components.

For the existing structure of heat dissipation devices used to assist electronic components to dissipate heat, reference may be made to US Patent No. 4,884,331 issued on December 5, 1989. In the heat dissipation device, a plurality of heat dissipation fins are protruded on the top surface of the base. During operation, the base is attached to the surface of the electronic component to conduct heat, and then the heat is dissipated through the heat dissipation fins. However, even if the base is made of metal materials with strong thermal conductivity such as copper or aluminum, it is gradually difficult to meet the heat dissipation requirements of current high-frequency and high-speed electronic components. Therefore, the heat conduction and heat dissipation efficiency of the heat sink still needs to be improved.

In addition, Chinese Patent No. 99243628 published on July 26, 2000 discloses a heat dissipation device using heat pipes for heat conduction. Please refer to FIG. The heat dissipation fins 11 and the heat conduction blocks 12 are respectively bonded to both ends of the heat pipe 10 by sintering, and the three are bonded as one. During operation, the heat conduction block 12 is attached to the electronic component (not shown in the figure), and the heat emitted by the electronic component is conducted to the heat pipe 10 by the heat conduction block 12, and then conducted to the heat dissipation fin 11 through the heat pipe 10, and then dissipated by the heat dissipation fin 11 to the in the air. The heat conduction efficiency of the heat pipe 10 is hundreds of times higher than that of metal copper, so the heat dissipation efficiency of the heat dissipation device 1 can be improved.

However, this heat pipe type cooling device is composed of three parts, and the cooling fins 11 and the heat conduction block 12 are respectively connected to the two ends of the heat pipe 10, so that the three parts are scattered in space, so that the cooling device has a large volume, which is not conducive to Integrated circuit density and miniaturization.

In view of this, it is very necessary for the present invention to provide a heat dissipation device with high heat dissipation efficiency and small volume.

【Content of invention】

In order to overcome the problems of low heat dissipation efficiency and large volume of the heat dissipation device in the prior art, which are not conducive to the density and miniaturization of integrated circuits, the present invention provides a small volume heat dissipation device using heat pipes for heat conduction.

To achieve the above object, the present invention provides a heat dissipation device, which includes a base, a plurality of heat dissipation fins formed on the base, and at least one heat pipe formed inside the base. The base includes a bottom plate and a cover plate that are fastened and welded together. The heat dissipation fins are formed on the cover plate; at least one groove is formed on the fastening surface of at least one of the cover plate and the bottom plate. After being closed, the groove is fastened to form a heat pipe enclosed in the base.

The heat dissipation device provided by the present invention and its preparation method include the following steps: providing a metal base, the base includes a base plate and a cover plate, the base plate and the cover plate can be fastened and welded to form an integral body; the base plate and the cover plate At least one groove is formed on the fastening surface of the plate, and one end of the groove is sealed inside the base; the bottom plate and the cover plate are welded and buckled together, and the groove forms a pipe body with one end sealed; the inside of the pipe is evacuated, and then Inject an appropriate amount of heat pipe into the tube as the working fluid, and seal the tube body so that the working fluid is sealed in the tube; form a plurality of heat dissipation fins on the base cover plate; wherein the plurality of heat dissipation fins can also be pre-installed on the cover plate Formed or integrally formed with the cover plate.

Compared with the prior art, the heat sink provided by the present invention has the following advantages: the heat pipe is formed inside the base, which can reduce the volume of the heat sink; at the same time, the high thermal conductivity of the heat pipe is used to improve the heat conduction efficiency of the heat sink; thus it is suitable for high-end integrated circuits. Thermal efficiency, high density and miniaturization requirements.

【Description of drawings】

FIG. 1 is a schematic diagram of a heat dissipation device in the prior art;

FIG. 2 is an exploded schematic diagram of the structure of the heat sink in Embodiment 1 of the present invention;

Fig. 3 is a schematic diagram of the structural combination of the heat dissipation device according to Embodiment 1 of the present invention;

4 is a schematic cross-sectional view along the I-I direction of the heat dissipation device according to Embodiment 1 of the present invention;

5 is a schematic cross-sectional view of a heat sink according to Embodiment 2 of the present invention;

6 is a schematic cross-sectional view of a heat dissipation device according to Embodiment 3 of the present invention;

7 is a schematic cross-sectional view of a heat sink according to Embodiment 4 of the present invention;

Fig. 8 is a flow chart of the manufacturing method of the heat sink provided by the present invention.

【Detailed ways】

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Referring to FIG. 3, the heat dissipation device 20 according to Embodiment 1 of the present invention includes a base 21, a plurality of heat dissipation fins 22 formed on the base 21, and at least one heat pipe (not shown) formed inside the base. The base 21 includes a cover 24 and a bottom 25 .

Please refer to FIG. 2 and FIG. 4 together. The heat dissipation device 20 includes a base 21 , a plurality of heat dissipation fins 22 and heat pipes 23 formed inside the base. The base 21 includes a cover plate 24 and a bottom plate 25, and a plurality of cooling fins 22 are formed on the cover plate 24; the fastening surfaces of the cover plate 24 and the bottom plate 25 respectively have a plurality of corresponding grooves 26 and grooves. Groove 27, wherein the grooves 26 and 27 are 0.1 to 1 mm deep and 10 to 100 microns wide. After the cover plate 24 and the bottom plate 25 are fastened, the groove 26 and the groove 27 are connected and fastened to form a closed base. The heat pipe 23 inside the seat 21.

Referring to FIG. 5 , the heat dissipation device 30 provided by Embodiment 2 of the present invention includes a base 31 , a plurality of heat dissipation fins 32 and heat pipes 33 formed inside the base. The base 31 includes a cover plate 34 and a bottom plate 35, and a plurality of cooling fins 32 are formed on the cover plate 34; the fastening surfaces of the cover plate 34 and the bottom plate 35 respectively have a plurality of dislocated grooves 36 and grooves 37, wherein the grooves 36 and 37 are 0.1 to 1 mm deep and 10 to 100 microns wide. After the cover plate 34 and the bottom plate 35 are fastened together, the groove 36 and the groove 37 are dislocated and fastened to form a closed groove on the base 31. Internal heat pipe 33 .

Referring to FIG. 6 , the heat dissipation device 40 provided by Embodiment 3 of the present invention includes a base 41 , a plurality of heat dissipation fins 42 and heat pipes 43 formed inside the base. The base 41 includes a cover plate 44 and a bottom plate 45, and a plurality of cooling fins 42 are formed on the cover plate 44; there are a plurality of grooves 46 on the fastening surface of the bottom plate 45 and the cover plate 44, wherein the grooves The groove 46 is 0.1-1 mm deep and 10-100 microns wide. After the cover plate 44 is fastened with the bottom plate 45 , the groove 46 is fastened with the fastened surface of the cover plate 44 to form a heat pipe 43 enclosed in the base 41 . Of course, a plurality of grooves can also be formed on the fastening surface of the cover plate 44 , and then heat pipes can be formed by fastening with the bottom plate 45 .

In the heat dissipation devices provided by Embodiments 1 to 3 of the present invention, the heat pipes are all formed by buckling small grooves, and the pipe is a capillary tube. Therefore, there is no need to install a capillary wick inside the heat pipe. The heat pipe body can also be a pipe with a larger size:

Referring to FIG. 7 , the heat dissipation device 50 provided by Embodiment 4 of the present invention includes a base 51 , a plurality of heat dissipation fins 52 and heat pipes 53 formed inside the base. The base 51 includes a cover plate 54 and a bottom plate 55, and a plurality of cooling fins 52 are formed on the cover plate 54; the fastening surfaces of the cover plate 54 and the bottom plate 55 respectively have a plurality of grooves 56, 57, wherein the Grooves 56 and 57 are 2 to 8 mm deep and 5 to 15 mm wide. The groove bottoms of the grooves 56 and 57 have micro-grooves 58 and 59. The micro-grooves 58 and 59 are 0.1 to 1 mm deep and 10 to 10 mm wide. 100 microns, after the cover plate 54 is fastened with the bottom plate 55 , the grooves 56 and 57 are connected and fastened to form a heat pipe 53 enclosed inside the base 51 .

The pipe body of the heat pipe 53 is a pipe with a larger size. The radial section of the pipe formed by the bottom of the grooves 56 and 57 can be a standard circle, ellipse, rectangle, square or triangle, and the figure shows a rectangle. The micro-grooves 58 and 59 on the inner wall of the pipe are capillary structures, which constitute the capillary liquid-absorbing core of the heat pipe 53 .

Please refer to Figure 8, that is, the method for preparing a heat sink provided by the present invention includes the following steps:

A metal base is provided, the base includes a base plate and a cover plate, the base plate and the cover plate can be fastened and welded to form an integral body, and the metal includes copper;

At least one groove is formed on the fastening surface of the bottom plate and the cover plate, and one end of the groove is sealed inside the base. The groove can be formed by LIGA process or stamping method, and the groove formed by stamping method is relatively large in size. After the size trench is formed, continue to form smaller micro-grooves at the bottom of the trench by means of LIGA process, etc.;

The bottom plate and the cover plate are welded and fastened, and the groove forms a hollow pipe body with one end sealed in the base. The welding method includes soldering;

Vacuum the inside of the tube, then inject an appropriate amount of heat pipe into the tube as the working fluid, and seal the tube to seal the working fluid in the tube. The working fluid generally includes pure water, ammonia, methanol, acetone, heptane and other liquids. The injection volume is generally 50-80% of the tube volume;

A plurality of heat dissipation fins are formed on the cover plate of the base, and the heat dissipation fins can be integrally formed with the cover plate of the base by stamping or other methods, or can be pre-formed on the cover plate by welding or the like.

Compared with the prior art, the heat pipe of the heat sink provided by the present invention is formed inside the base, and the volume of the heat sink is reduced. At the same time, the high thermal conductivity of the heat pipe is used to improve the heat conduction efficiency of the heat sink, so that it is suitable for high heat conduction efficiency in integrated circuits. High density and miniaturization requirements.

The above description is only a preferred embodiment of the present invention, and all equivalent modifications or changes made by those familiar with the technology of this case according to the spirit of the invention of this case should be included in the following patent claims.

Claims (10)

1. A heat dissipation device comprising a base and a plurality of heat dissipation fins formed on the base, characterized in that at least one heat pipe is also formed in the base. 2. The heat dissipation device according to claim 1, wherein the base includes a cover plate and a bottom plate that are fastened and welded together, and at least one of the cover plate and the bottom plate is formed on a fastening surface. There is at least one groove, and the heat pipe is formed by the groove closed in the base after the cover plate and the bottom plate are snapped together. 3. The heat dissipation device according to claim 2, wherein the groove is 0.1-2 mm deep and 10-100 microns wide. 4. The heat dissipation device according to claim 1, wherein the groove is 2-8 mm deep and 5-30 mm wide. 5. The heat dissipation device according to claim 4, characterized in that micro-grooves are engraved on the bottom of the groove. 6. The heat dissipation device according to claim 5, characterized in that the micro-grooves are 0.1-2 mm deep and 10-100 microns wide. 7. The method for preparing a heat sink as claimed in claim 1, characterized in that the method comprises the following steps: providing a metal base, the base includes a base plate and a cover plate, the base plate and the cover plate can be fastened and welded to each other form a whole At least one groove is formed on the fastening surface of the bottom plate and the cover plate, and one end of the groove is sealed in the base; The bottom plate and the cover plate are welded and fastened, and the groove forms a hollow pipe body with one end sealed in the base; Vacuum the inside of the tube, then inject an appropriate amount of heat pipe into the tube as the working fluid, and seal the tube; A plurality of cooling fins are formed on the base cover plate. 8. The manufacturing method of the heat sink as claimed in claim 7, wherein the groove can be formed by X-ray deep electroforming process or stamping. 9 . The method for manufacturing a heat sink as claimed in claim 7 , wherein after the groove is formed by stamping, it further comprises forming a micro-groove at the bottom of the groove by using an X-ray deep electroforming process. 10 . The method of manufacturing a heat sink as claimed in claim 7 , wherein the heat sink fins are integrally formed with the base. 11 .

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