Fin and Heat Sink

Abstract

A fin is penetrated through by a heat pipe. The fin includes a fin body and a plurality of positioning protrusions. The fin body has an accommodating hole penetrated by the heat pipe. The positioning protrusions are formed at the circumference of the accommodating hole for holding against the heat pipe, so that a gap is provided between the heat pipe and the circumference of the accommodating hole.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 096147970 filed in Taiwan, Republic of China on Dec. 14, 2007, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates to a thermal conducting element and, in particular, to a fins assembly and a heat sink.

2. Related Art

According to the progress of technology, the integration of electronic devices has been continuously increased. Thus, the electronic apparatus generate more heat when it is working. Therefore, it is an important subject to increase the heat dissipating efficiency so as to maintain the operation stability of the electronic apparatus. In general, a heat sink, which includes a fins assembly and a heat pipe, is applied to solve this problem.

As shown in FIG. 1A, a conventional heat sink 1 includes a fins assembly 11 and a heat pipe 12. The fins assembly 11 is composed of a plurality of fins 111, which are connected with each other. The fins 111 form an accommodating hole 112 for accommodating the heat pipe 12. After disposing the solder paste between the fins assembly 11 and the heat pipe 12 and heating the solder paste, the fins assembly 11 and the heat pipe 12 can be relatively fixed by the solder paste. In general, there are two methods for disposing the solder paste between the fins assembly 11 and the heat pipe 12, which will be described hereinbelow.

The first method for disposing the solder paste between the fins assembly 11 and the heat pipe 12 is to inject the solder paste through an injection portion 112a (such as a hole) formed on the accommodating hole 112 after the heat pipe 12 is inserted into the accommodating hole 112. In detailed, an injection needle N is inserted into the injection portion 112a, and then the solder paste is injected and filled between the fins assembly 11 and the heat pipe 12. After that, the solder paste is heated so as to fix the fins assembly 11 and the heat pipe 12. However, due to the error caused by the manual operation or machines, the amount of the injected solder paste can not be precisely controlled and the thickness of the solder paste may be non-uniform. This will decrease the combination strength between the fins assembly 11 and the heat pipe 12, thereby affecting the heat dissipating efficiency. In addition, the configuration of the injection portion 112a decreases the total heat dissipating area of the fins assembly 11, and the process of injecting the solder paste may take a long time so as to increase the manufacturing cost.

As shown in FIG. 1B, the second method for disposing the solder paste, which does not need the injection portion 112a, is to dispose the solder paste 121 on the outer surface of the heat pipe 12 and then insert the heat pipe 12 into the accommodating hole 112 of the fins assembly 11. However, since no fixing mechanism is provided, a part of the solder paste 121 disposed on the heat pipe 12 may be scraped off by the accommodating hole 112 when inserting the heat pipe 12 into the accommodating hole 112. Moreover, the solder paste 121 may be pushed and overflow through the other end of the accommodating hole 112, so that it is necessary to remove the overflowed solder paste by manual. This also causes the non-uniformity of the solder paste and thus decreases the combination strength between the fins assembly 11 and the heat pipe 12.

Therefore, it is an important subject to provide a fin and a heat sink that can increase the reliability and throughput.

SUMMARY OF THE INVENTION

In view of the foregoing subject, an object of the invention is to provide a fin and a heat sink that can increase the reliability and decrease the manufacturing cost.

To achieve the above object, the invention discloses a fin, which is penetrated by a heat pipe. The fin includes a fin body and a plurality of positioning protrusions. The fin body has an accommodating hole, and the heat pipe penetrates through the accommodating hole. The positioning protrusions are formed at the circumference of the accommodating hole for holding against the heat pipe, so that a gap is provided between the heat pipe and the circumference of the accommodating hole.

In addition, the invention also discloses a heat sink including a fins assembly and a heat pipe. The fins assembly includes a plurality of fins connected with each other. Each fin includes a fin body and a plurality of positioning protrusions. The fin has an accommodating hole, and the positioning protrusions are formed at the circumference of the accommodating hole. The accommodating holes of the fin bodies are aligned with each other. The heat pipe penetrates through the accommodating holes and is held by the positioning protrusions, so that a gap is provided between the heat pipe and the circumferences of the accommodating holes.

As mentioned above, the fin and heat sink of the invention have the positioning protrusions disposed on the circumference of the accommodating hole for holding against the heat pipe. Thus, a gap can be provided between the heat pipe and the circumferences of the accommodating holes, thereby preventing the thermo-conductive medium disposed on the outer surface of the heat pipe from being scraped off or pushed out. Accordingly, the combination strength of the heat pipe and the fins can be controlled, so that the reliability of the product can be increased. In addition, since the thermo-conductive medium is not pushed out or scraped off, the action of removing the overflowed thermo-conductive medium is unnecessary, so that the manufacturing cost can be reduced. Moreover, the thermo-conductive medium is disposed on the outer surface of the heat pipe, so the process for disposing the solder paste can be speeded up, thereby increasing the throughput. In addition, the thermo-conductive medium disposed on the outer surface of the heat pipe can be more uniform so as to increase the combination strength of the heat pipe and the fins. Furthermore, since the injection hole of the fins assembly is unnecessary in this invention, the heat dissipating area of the fins can be increased.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more fully understood from the detailed description and accompanying drawings, which are given for illustration only, and thus are not limitative of the present invention, and wherein:

FIGS. 1A and 1B are schematic diagrams of disposing the solder paste on the conventional heat sink;

FIG. 2 is a schematic diagram showing a heat sink according to a preferred embodiment of the invention; and

FIG. 3 is a sectional diagram of the heat sink according to the preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.

FIG. 2 is a schematic diagram showing a heat sink 2 according to a preferred embodiment of the invention. The heat sink 2 includes a fins assembly 21 and a heat pipe 22. FIG. 3 is a sectional diagram of the heat sink 2, wherein the heat pipe 22 has penetrated through the accommodating holes 212 of the fins 211. The heat sink 2 will be described hereinbelow with reference to FIGS. 2 and 3.

The fins assembly 21 includes a plurality of fins 211 connected with each other. Each fin 211 includes a fin body F and a plurality of positioning protrusions 213. The fin body F has an accommodating hole 212, and the accommodating holes 212 of the fin bodies F are aligned with each other. The heat pipe 22 can penetrate through the accommodating holes 212. The positioning protrusions 213 are formed at the circumference of at least one of the accommodating holes 212. In the embodiment, the positioning protrusions 213 of the fins 211 are also aligned and disposed on a straight line. Alternatively, the positioning protrusions 213 can be randomly arranged.

In the embodiment, the accommodating hole 212 can be, for example but not limited to, circular, elliptical, flat or polygonal. Preferably, the shape of the heat pipe 22 must match the accommodating hole 212. In addition, the shape or aspect of the positioning protrusions 213 can be, for example but not limited to, a protruding point or a rib. The positioning protrusions 213 and the fin body F can be integrally formed by punching. Alternatively, the positioning protrusions 213 can be additional added elements. For example, the positioning protrusion 213 can be a protruding point or a rib, which is formed on the circumference of the accommodating hole 212 by wedging or adhering.

The heat pipe 22 penetrates through the accommodating holes 212 and is held by the positioning protrusions 213, so that a gap G can be provided between the heat pipe 22 and the circumferences of the accommodating holes 212. In the embodiment, a thermo-conductive medium 221 is disposed on at least one portion of an outer surface 222 of the heat pipe 22. The thermo-conductive medium 221 includes a solder paste, a thermal adhesive or other thermo-conductive material. In the embodiment, the thermo-conductive medium 221 can be formed on the outer surface 222 of the heat pipe 22 by screen printing, coating or adhering. The area of the thermo-conductive medium 221 can be determined according to the actual need. For example, the thermo-conductive medium 221 can be formed on the whole outer surface 222 or another surface opposite to the outer surface 222. In the embodiment, the thermo-conductive medium 221 is formed on the top and bottom surfaces of the heat pipe 22.

Since the positioning protrusions 213 are disposed on the circumference of the accommodating hole 212, the positioning protrusions 213 can thrust against the heat pipe 22, so that a gap G can be provided between the heat pipe 22 and the circumference of the accommodating hole 212. Due to the gap G, the thermo-conductive medium 221 will not be pushed out or scraped by the circumference of the accommodating hole 212 when inserting the heat pipe 22 into the accommodating hole 212. The gap G is preferably equal to or slightly larger than the thickness of the thermo-conductive medium 221. In the embodiment, the number of positioning protrusions 213 is not limited and must be two or more. The positioning protrusions 213 are disposed corresponding to the thermo-conductive medium 221. For example, the positioning protrusions 213 can be disposed on one side of the accommodating hole 212, which is adjacent to the thermo-conductive medium 221. In addition, the positioning protrusions 213 can be located on opposite sides of the accommodating hole 212 or symmetrically disposed on the circumference of the accommodating hole 212.

In addition, each fin body F may include at least one hollow portion 214, which is disposed adjacent to one of the positioning protrusions 213. In the embodiment, two hollow portions 214 are disposed adjacent to two sides of the positioning protrusions 213. The hollow portions 214 can make the punching process of forming the positioning protrusions 213 much easier. In addition, the hollow portions 214 can provide the structural flexibility for facilitating the positioning protrusions 213 to guide the heat pipe 22 into the accommodating hole 212.

In the embodiment, the heat pipe 22 has an enclosed chamber and a capillary structure disposed on the inner wall thereof. In addition, the heat pipe 22 contains a work fluid therein. One end of the heat pipe 22 is an evaporation end A, and the other end thereof is a condensation end B. The evaporation end A is in contact with a heat source (not shown). The work fluid located around the evaporation end A can absorb the heat and then be evaporated into the gas state. The gas-state work fluid flows toward the condensation end B due to the pressure difference. Then, the gas-state work fluid can release the latent heat around the condensation end B and be condensed into the liquid state. The condensed work fluid can flow back to the evaporation end A according to the capillarity of the capillary structure. This loop of the work fluid can achieve the heat dissipating effect. The fins assembly 21 can be disposed around the condensation end B for helping to dissipate the heat generated by the heat source. In the embodiment, the heat sink 2 can be applied to various kinds of electronic device, which can generate heat, such as the CPU chip, display chip or graphic chip of the notebook computer.

With reference to FIGS. 2 and 3 again, the invention also discloses a fin 211, which is cooperated with a heat pipe 22. The fin 211 includes a fin body F and a plurality of positioning protrusions 213. The fin body F has an accommodating hole 212, and the heat pipe 22 can penetrate through the accommodating hole 212. The positioning protrusions 213 are formed at the circumference of the accommodating hole 212 and hold against the heat pipe 22, so that a gap G can be provided between the heat pipe 22 and the circumference of the accommodating hole 212. The functions and features of the fin 211 are the same as those described above, so the detailed descriptions will be omitted.

To sum up, the fin and heat sink of the invention have the positioning protrusions disposed on the circumference of the accommodating hole for holding against the heat pipe. Thus, a gap can be provided between the heat pipe and the circumferences of the accommodating holes, thereby preventing the thermo-conductive medium disposed on the outer surface of the heat pipe from being scraped off or pushed out. Accordingly, the combination strength of the heat pipe and the fins can be controlled, so that the reliability of the product can be increased. In addition, since the thermo-conductive medium is not pushed out or scraped off, the action of removing the overflowed thermo-conductive medium is unnecessary, so that the manufacturing cost can be reduced. Moreover, the thermo-conductive medium is disposed on the outer surface of the heat pipe, so the process for disposing the solder paste can be speeded up, thereby increasing the throughput. In addition, the thermo-conductive medium disposed on the outer surface of the heat pipe can be more uniform so as to increase the combination strength of the heat pipe and the fins. Furthermore, since the injection hole of the fins assembly is unnecessary in this invention, the heat dissipating area of the fins can be increased.

Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.

Claims

1. A fin, which is cooperated with a heat pipe, comprising:

a fin body having an accommodating hole, wherein the heat pipe penetrates through the accommodating hole; and

a plurality of positioning protrusions formed at the circumference of the accommodating hole and holding against the heat pipe, so that a gap is provided between the heat pipe and the circumference of the accommodating hole.

2. The fin according to claim 1, wherein the accommodating hole is circular, elliptical, flat or polygonal.

3. The fin according to claim 1, wherein a thermo-conductive medium is disposed on at least a portion of an outer surface of the heat pipe.

4. The fin according to claim 3, wherein the thermo-conductive medium comprises a solder paste or a thermal adhesive.

5. The fin according to claim 3, wherein the positioning protrusions are located on one side of the accommodating hole adjacent to the thermo-conductive medium.

6. The fin according to claim 1, wherein the positioning protrusions are located on opposite sides of the accommodating hole.

7. The fin according to claim 1, wherein the positioning protrusions are symmetrically disposed on the circumference of the accommodating hole.

8. The fin according to claim 1, wherein each of the positioning protrusions comprises a protruding point or a rib.

9. The fin according to claim 1, wherein the fin body comprises at least one hollow portion disposed adjacent to one of the positioning protrusions.

10. A heat sink, comprising:

a fins assembly comprising a plurality of fins connected with each other, wherein each of the fins comprises a fin body having an accommodating hole and a plurality of positioning protrusions formed at the circumference of the accommodating hole, and the accommodating holes of the fin bodies are aligned with each other; and

a heat pipe penetrating through the accommodating holes and held by the positioning protrusions, so that a gap is provided between the heat pipe and the circumferences of the accommodating holes.

11. The heat sink according to claim 10, wherein the accommodating hole is circular, elliptical, flat or polygonal.

12. The heat sink according to claim 10, wherein a thermo-conductive medium is disposed on at least a portion of an outer surface of the heat pipe.

13. The heat sink according to claim 12, wherein the thermo-conductive medium comprises a solder paste or a thermal adhesive.

14. The heat sink according to claim 12, wherein the positioning protrusions are located on one side of the accommodating hole adjacent to the thermo-conductive medium.

15. The heat sink according to claim 10, wherein the positioning protrusions are located on opposite sides of the accommodating hole.

16. The heat sink according to claim 10, wherein the positioning protrusions are symmetrically disposed on the circumference of the accommodating hole.

17. The heat sink according to claim 10, wherein the positioning protrusions and the accommodating hole are integrally formed by punching.

18. The heat sink according to claim 10, wherein each of the positioning protrusions comprises a protruding point or a rib.

19. The heat sink according to claim 10, wherein the fin body comprises at least one hollow portion disposed adjacent to one of the positioning protrusions.