US20130213612A1

US20130213612A1 - Heat pipe heat dissipation structure

Info

Publication number: US20130213612A1
Application number: US13/402,507
Authority: US
Inventors: Chun-Ming Wu
Original assignee: Individual
Current assignee: Asia Vital Components Co Ltd
Priority date: 2012-02-22
Filing date: 2012-02-22
Publication date: 2013-08-22

Abstract

A heat pipe heat dissipation structure includes a main body and at least one first capillary structure. The main body has a first inner side, a second inner side, a third inner side, a fourth inner side and at least one chamber filled with a working fluid. The first capillary structure is disposed in the chamber. The first capillary structure includes a first section disposed on the first inner side and a second section extending from two sides of the first section along the adjacent third and fourth inner sides. The first section has a thickness larger than that of the second section. The heat pipe heat dissipation structure has better heat transfer efficiency.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates generally to a heat pipe heat dissipation structure, and more particularly to a heat pipe heat dissipation structure, which has better heat transfer efficiency and better anti-gravity ability and is able to reduce interface thermal resistance.
2. Description of the Related Art
There is a more and more obvious trend to miniaturization of all kinds of high-performance computers, intelligent electronic devices and other electrical equipments. To catch up this trend, the heat transfer components and heat dissipation components used in these devices have also been more and more miniaturized and thinned to meet the requirements of users.
It is known that heat pipe is a heat transfer component with excellent thermal conductivity. The thermal conductivity of the heat pipe is several times to several tens times the thermal conductivity of copper, aluminum or the like. Therefore, the heat pipe is used as a cooling component and applied to various electronic devices.
As to the configuration, the conventional heat pipes can be classified into heat pipes in the form of circular tubes, heat pipes with D-shaped cross sections and flat-plate heat pipes. The heat pipes are mainly used to conduct the heat generated by the heat sources in the electronic devices and cool the heat sources. Currently, in view of easy installation and larger contact area, flat-plate heat pipes are widely used for cooling the heat sources. Following the miniaturization of the cooling mechanism, various flat-plate heat pipes are widely applied to the electronic devices for conducting the heat generated by the heat-generating components.
The conventional heat pipe structure can be manufactured by means of many kinds of methods. For example, the heat pipe can be manufactured in such a manner that metal powder is filled into a hollow tubular body and sintered to form a capillary structure layer on the inner wall face of the tubular body. Then the tubular body is vacuumed and filled with a working fluid and then sealed. Alternatively, a metal-made mesh body is placed into the tubular body. The mesh capillary structure body will naturally outward stretch and expand to attach to the inner wall face of the tubular body to form a capillary structure layer. Then the tubular body is vacuumed and filled with a working fluid and then sealed. To meet the requirements for miniaturization and thinning of the electronic devices, the heat pipe needs to be manufactured with the form of a flat plate.
The flat-plate heat pipe can achieve object of thinning. However, this leads to another problem. That is, in the flat-plate heat pipe, the metal powder is sintered to form a capillary structure layer fully coated on the inner wall face of the heat pipe. When compressing the flat-plate heat pipe, the capillary structure, (that is, the sintered metal powder or mesh capillary structure body) in the flat-plate heat pipe on two sides of the compressed faces is likely to be squeezed and damaged. In this case, the capillary structure tends to peel off from the inner wall face of the flat-plate heat pipe. This will greatly deteriorate the heat transfer performance of the thin heat pipe or even make the thin heat pipe lose its function. Moreover, although the flat-plate heat pipe can conduct the heat, after thinned and flattened, the internal capillary structure of the flat-plate heat pipe will have insufficient capillary attraction. As a result, the working fluid will block the vapor passage. Furthermore, after thinned, the area of the flow passage inside the flat-plate heat pipe is reduced so that the capillary attraction is lowered. As a result, the maximum heat transfer amount is lowered. On one hand, this is mainly because after thinned, the internal capacity of the flat-plate heat pipe is reduced and on the other hand, this is because after flattened, the central section of the flat-plate heat pipe is recessed to narrow or even block the vapor passage.
To solve the above problems existing in the conventional heat pipe, some manufacturers in this field insert a core bar into the internal chamber of the flat-plate heat pipe. The core bar is formed with a specific axial cut. Metal powder is filled into the space defined by the cut and the inner wall face of the chamber. Then the metal powder is sintered to form a capillary structure at the central section of the chamber. Then the core bar is extracted out. Then the central section of the chamber is compressed and flattened. The capillary structure thermally contacts the plane parts of the inner wall face of the chamber. In addition, voids are formed on two sides of the capillary structure in the chamber to serve as the vapor passages. Accordingly, better vapor passage impedance is achievable. However, the cross-sectional area of the capillary structure is quite narrow so that the capillary attraction is lowered. As a result, the anti-gravity thermal efficiency and heat transfer efficiency are poor.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a heat pipe heat dissipation structure, which has better heat transfer efficiency.
A further object of the present invention is to provide the above heat pipe heat dissipation structure, which has better anti-gravity ability and is able to reduce interface thermal resistance.
A still further object of the present invention is to provide the above heat pipe heat dissipation structure, which is able to bear greater thermal power impact per unit area.
To achieve the above and other objects, the heat pipe heat dissipation structure of the present invention includes a main body and at least one first capillary structure. The main body has a first inner side, a second inner side opposite to the first inner side, a third inner side, a fourth inner side opposite to the third inner side and at least one chamber. A working fluid is filled in the chamber. The first capillary structure is disposed in the chamber. The first capillary structure includes a first section and a second section. The first section is formed on the first inner side. The second section extends from two sides of the first section along the adjacent third and fourth inner sides. The first section has a thickness larger than that of the second section. The first and second sections are respectively formed on the first, third and fourth inner sides of the main body. Accordingly, the vapor working fluid can fully freely flow within the chamber to advantageously achieve an excellent heat transfer efficiency, have better anti-gravity ability and reduce the pressure impedance. Moreover, the heat pipe heat dissipation structure is able to bear greater thermal power impact per unit area.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein:

FIG. 1 is a perspective view of a first embodiment of the heat pipe heat dissipation structure of the present invention;

FIG. 2 is a sectional view of the first embodiment of the heat pipe heat dissipation structure of the present invention;

FIG. 3A is a perspective view of a second embodiment of the heat pipe heat dissipation structure of the present invention, showing an application thereof;

FIG. 3B is a sectional view of the second embodiment of the heat pipe heat dissipation structure of the present invention, showing the application thereof;

FIG. 3C is a perspective view of the second embodiment of the heat pipe heat dissipation structure of the present invention, showing another application thereof;

FIG. 3D is a sectional view of the second embodiment of the heat pipe heat dissipation structure of the present invention, showing the other application thereof;

FIG. 4 is a sectional view of a third embodiment of the heat pipe heat dissipation structure of the present invention;

FIG. 5 is a sectional view of the third embodiment of the heat pipe heat dissipation structure of the present invention, showing the application thereof;

FIG. 6 is a sectional view of a fourth embodiment of the heat pipe heat dissipation structure of the present invention; and

FIG. 7 is a sectional view of a fifth embodiment of the heat pipe heat dissipation structure of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 1 and 2. FIG. 1 is a perspective view of a first embodiment of the heat pipe heat dissipation structure of the present invention. FIG. 2 is a sectional view of the first embodiment of the heat pipe heat dissipation structure of the present invention. According to the first embodiment, the heat pipe heat dissipation structure of the present invention includes a main body 1 and at least one first capillary structure 16. The main body 1 has a first inner side 11, a second inner side 12, a third inner side 13, a fourth inner side 14 and at least one chamber 15. The first inner side 11 is opposite to the second inner side 12, while the third inner side 13 is opposite to the fourth inner side 14. The first, second, third and fourth inner sides 11, 12, 13, 14 together define the chamber 15. A working fluid is filled in the chamber 15. The working fluid is selected from a group consisting of pure water, inorganic compound, alcohol, ketone, liquid metal, coolant and organic compound. The inner wall face of the chamber 15, (that is, the first, second, third and fourth inner sides 11, 12, 13, 14) is a smooth wall face.
The first capillary structure 16 is selected from a grouping consisting of a mesh body, a fiber body, a sintered powder body, a combination of mesh body and sintered powder body and a microstructure body. In this embodiment, the first capillary structure 16 is, but not limited to, a sintered powder body for illustration purposes only. The first capillary structure 16 is disposed in the chamber 15 and includes a first section 161 and a second section 162. The first section 161 is formed on the first inner side 11. The second section 162 extends from two sides of the first section 161 along the adjacent third and fourth inner sides 13, 14. The first section 161 has a thickness larger than that of the second section 162. That is, the first section 161 has a radial extension volume larger than that of the second section 162.
As aforesaid, the thickness of the first section 161 on the first inner side 11 is larger than the thickness of the second section 162 on the third and fourth inner sides 13, 14. Accordingly, an outer face of the first inner side 11 is able to absorb heat generated by a heat-generating component with larger power. In other words, the unit area of the first capillary structure 16 is larger so that the first capillary structure 16 is able to bear greater thermal power impact and transfer more amount of heat. The second inner side 12 is free from any capillary structure so as to reduce pressure impedance against flowing of the vapor working fluid 2 in the chamber 15 toward the second inner side 12 (as shown in FIG. 3B). Accordingly, the vapor-liquid circulation efficiency is greatly increased.
According to the above arrangement, the first and second sections 161, 162 of the first capillary structure 16 are respectively disposed on the first, third and fourth inner sides 11, 13, 14 in the chamber 15 and integrally connected with each other so as to increase heat transfer efficiency and reduce pressure impedance. Therefore, the vapor-liquid circulation efficiency is effectively enhanced.
Please now refer to FIGS. 3A and 3B and supplementally refer to FIG. 2. FIG. 3A is a perspective view of a second embodiment of the heat pipe heat dissipation structure of the present invention, showing an application thereof. FIG. 3B is a sectional view of the second embodiment of the heat pipe heat dissipation structure of the present invention, showing the application thereof. In the second embodiment, the heat pipe heat dissipation structure of the first embodiment is correspondingly attached to at least one heat-generating component 4 (such as central processor, graphic chip, south bridge and north bridge chips or other processing chip). That is, the outer face of the first inner side 11 of the main body 1 is attached to at least one heat-generating component 4 for conducting heat. The liquid working fluid 3 in the first and second sections 161, 162 of the first capillary structure 16 on the first, third and fourth inner sides 11, 13, 14 serve to rapidly absorb the heat to evaporate into vapor working fluid 2. The second inner side 12 is free from any capillary structure so that the vapor working fluid 2 can rapidly flow to the second inner side 12. After the vapor working fluid 2 is cooled and condensed into the liquid working fluid 3 on the second inner side 12, the liquid working fluid 3 will flow back to the first section 161 on the first inner side 11 and the second section 162 on the third and fourth inner sides 13, 14 under gravity to continue the vapor-liquid circulation. Accordingly, an excellent heat dissipation effect can be achieved.
Please now refer to FIGS. 3C and 3D. FIG. 3C is a perspective view of the second embodiment of the heat pipe heat dissipation structure of the present invention, showing another application thereof. FIG. 3D is a sectional view of the second embodiment of the heat pipe heat dissipation structure of the present invention, showing the other application thereof. At least one heat dissipation unit 5 is correspondingly connected with an outer face of the second inner side 12 of the main body 1. The heat dissipation unit 5 is selected from a group consisting of a heat sink, a radiating fin assembly and a water-cooled unit. The heat dissipation unit 5 serves to speed cooling of the vapor working fluid 2 flowing to the second inner side 12, whereby the vapor working fluid 2 can be more rapidly condensed into the liquid working fluid 3. Accordingly, the vapor-liquid circulation effect of the working fluid can be enhanced to achieve an excellent heat dissipation effect.
Please now refer to FIG. 4 and supplementally refer to FIG. 1. FIG. 4 is a sectional view of a third embodiment of the heat pipe heat dissipation structure of the present invention. The third embodiment is substantially identical to the first embodiment in structure, connection relationship and effect and thus will not be repeatedly described hereinafter. The third embodiment is different from the first embodiment in that the second inner side 12 of the main body 1 is divided into a capillary forming section 121 and at least one capillary-free section 122, which is free from any capillary structure. The capillary-free section 122 is positioned on two sides of the capillary forming section 121 in adjacency to the corresponding third and fourth inner sides 13, 14 respectively.
At least one swelling capillary section 17 is further disposed in the main body 1. The swelling capillary section 17 is selected from a grouping consisting of a mesh body, a fiber body, a sintered powder body, a combination of mesh body and sintered powder body and a microstructure body. The swelling capillary section 17 is disposed on the capillary forming section 121 of the second inner side 12 opposite to the first section 161.
The swelling capillary section 17 has a free end 171 extending from the capillary forming section 121 to connect with the opposite first section 161 of the first capillary structure 16. In this embodiment, the swelling capillary section 17 has, but not limited to, the form of a hill. In practice, alternatively, the swelling capillary section 17 can have a trapezoidal form, rectangular form or conic form.
The first capillary structure 16, the swelling capillary section 17 and the inner wall of the chamber 15 together define a first vapor passage 151 and a second vapor passage 152. The first vapor passage 151 is defined by the first, second and third inner sides 11, 12, 13, the first capillary structure 16 and the swelling capillary section 17. The second vapor passage 152 is defined by the first, second and fourth inner sides 11, 12, 14, the first capillary structure 16 and the swelling capillary section 17.
Please further refer to FIGS. 4 and 5. The outer face of the first inner side 11 of the main body 1 is attached to at least one heat-generating component 4 for conducting heat. When the heat-generating component 4 generates heat, the liquid working fluid 3 in the first and second sections 161, 162 on the first, third and fourth inner sides 11, 13, 14 rapidly absorb the heat to evaporate into vapor working fluid 2. As aforesaid, the capillary-free section 122 of the second inner side 12 corresponding to the first and second vapor passages 151, 152 is free from any capillary structure. Therefore, the vapor working fluid 2 can rapidly flow toward the capillary-free section 122 through the first and second vapor passages 151, 152. After the vapor working fluid 2 is cooled and condensed into the liquid working fluid 3 on the capillary-free section 122 of the second inner side 12, the liquid working fluid 3 flows back to the first section 161 on the first inner side 11 and the second section 162 on the third and fourth inner sides 13, 14 through the first and second vapor passages 151, 152 due to gravity or the capillary attraction of the swelling capillary section 17 to continue the vapor-liquid circulation. Accordingly, the heat transfer efficiency is increased and the pressure impedance is reduced to achieve an excellent heat dissipation effect.
Please now refer to FIG. 6, which is a sectional view of a fourth embodiment of the heat pipe heat dissipation structure of the present invention. The fourth embodiment is substantially identical to the third embodiment in structure, connection relationship and effect and thus will not be repeatedly described hereinafter. The fourth embodiment is different from the third embodiment in that the swelling capillary section 17 swells from the first section 161 of the first capillary structure 16. That is, the swelling capillary section 17 is disposed on the first section 161 opposite to the second inner side 12. In other words, the free end 171 of the swelling capillary section 17 extends from the first section 161 to connect with the opposite capillary forming section 121.
Please now refer to FIG. 7, which is a sectional view of a fifth embodiment of the heat pipe heat dissipation structure of the present invention. The fifth embodiment is substantially identical to the first embodiment in structure, connection relationship and effect and thus will not be repeatedly described hereinafter. The fifth embodiment is different from the first embodiment in that a second capillary structure 18 is further disposed on the inner wall face of the chamber 15. The second capillary structure 18 is formed on the first, second, third and fourth inner sides 11, 12, 13, 14 of the main body 1 and correspondingly connected with the first capillary structure 16. In practice, the second capillary structure 18 is selected from a group consisting of a mesh body, a fiber body, a sintered powder body, a combination of mesh body and sintered powder body and a structure formed with multiple micro-channels. In this embodiment, the second capillary structure 18 is, but not limited to, a structure formed with multiple micro-channels for illustration purposes only. In comparison with the conventional heat pipe, the present invention has the following advantages:

- 1. The maximum heat transfer efficiency is increased.
- 2. The present invention has better anti-gravity ability.
- 3. The present invention has smaller interface thermal resistance.
- 4. The unit area of the first capillary structure is larger so that the present invention can bear greater thermal power impact and transfer more amount of heat.

The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. It is understood that many changes and modifications of the above embodiments can be made without departing from the spirit of the present invention. The scope of the present invention is limited only by the appended claims.

Claims

What is claimed is:

1. A heat pipe heat dissipation structure comprising:

a main body having a first inner side, a second inner side opposite to the first inner side, a third inner side, a fourth inner side opposite to the third inner side and a chamber, a working fluid being filled in the chamber; and

at least one first capillary structure disposed in the chamber, the first capillary structure including a first section and a second section, the first section being formed on the first inner side, the second section extending from two sides of the first section along the adjacent third and fourth inner sides, the first section having a thickness larger than that of the second section.

2. The heat pipe heat dissipation structure as claimed in claim 1, wherein the first, second, third and fourth inner sides together define the chamber.

3. The heat pipe heat dissipation structure as claimed in claim 1, wherein the second inner side is divided into a capillary forming section and at least one capillary-free section, the capillary-free section being positioned on two sides of the capillary forming section in adjacency to the corresponding third and fourth inner sides respectively.

4. The heat pipe heat dissipation structure as claimed in claim 3, wherein at least one swelling capillary section is further disposed in the main body, the swelling capillary section being disposed on the capillary forming section of the second inner side opposite to the first section.

5. The heat pipe heat dissipation structure as claimed in claim 4, wherein the swelling capillary section has a free end extending from the capillary forming section to connect with the opposite first section.

6. The heat pipe heat dissipation structure as claimed in claim 5, wherein the inner wall of the chamber, the first capillary structure and the swelling capillary section together define a first vapor passage and a second vapor passage, the first vapor passage being defined by the first, second and third inner sides, the first capillary structure and the swelling capillary section, the second vapor passage being defined by the first, second and fourth inner sides, the first capillary structure and the swelling capillary section.

7. The heat pipe heat dissipation structure as claimed in claim 3, wherein at least one swelling capillary section is further disposed in the main body, the swelling capillary section being disposed on the first section opposite to the second inner side.

8. The heat pipe heat dissipation structure as claimed in claim 7, wherein the swelling capillary section has a free end extending from the first section to connect with the opposite capillary forming section.

9. The heat pipe heat dissipation structure as claimed in claim 8, wherein the inner wall of the chamber, the first capillary structure and the swelling capillary section together define a first vapor passage and a second vapor passage, the first vapor passage being defined by the first, second and third inner sides, the first capillary structure and the swelling capillary section, the second vapor passage being defined by the first, second and fourth inner sides, the first capillary structure and the swelling capillary section.

10. The heat pipe heat dissipation structure as claimed in claim 1, wherein an outer face of the first inner side of the main body is correspondingly attached to at least one heat-generating component for conducting heat, at least one heat dissipation unit being correspondingly connected with an outer face of the second inner side of the main body, the heat dissipation unit being selected from a group consisting of a heat sink, a radiating fin assembly and a water-cooled unit.

11. The heat pipe heat dissipation structure as claimed in claim 1, wherein the inner wall face of the chamber is a smooth wall face.

12. The heat pipe heat dissipation structure as claimed in claim 1, wherein a second capillary structure is further disposed on the inner wall face of the chamber, the second capillary structure being formed on the first, second, third and fourth inner sides and correspondingly connected with the first capillary structure.

13. The heat pipe heat dissipation structure as claimed in claim 1, wherein the first capillary structure is selected from a grouping consisting of a mesh body, a fiber body, a sintered powder body, a combination of mesh body and sintered powder body and a microstructure body.

14. The heat pipe heat dissipation structure as claimed in claim 4, wherein the swelling capillary section is selected from a grouping consisting of a mesh body, a fiber body, a sintered powder body, a combination of mesh body and sintered powder body and a microstructure body.

15. The heat pipe heat dissipation structure as claimed in claim 7, wherein the swelling capillary section is selected from a grouping consisting of a mesh body, a fiber body, a sintered powder body, a combination of mesh body and sintered powder body and a microstructure body.

16. The heat pipe heat dissipation structure as claimed in claim 12, wherein the second capillary structure is selected from a grouping consisting of a mesh body, a fiber body, a sintered powder body, a combination of mesh

17. The heat pipe heat dissipation structure as claimed in claim 1, wherein the first section has a radial extension volume larger than that of the second section.