US20100051239A1

US20100051239A1 - Dissipation module,flat heat column thereof and manufacturing method for flat heat column

Info

Publication number: US20100051239A1
Application number: US12/348,511
Authority: US
Inventors: Chi-Feng Lin; Ming-Te Chuang
Original assignee: Delta Electronics Inc
Current assignee: Delta Electronics Inc
Priority date: 2008-08-28
Filing date: 2009-01-05
Publication date: 2010-03-04
Also published as: TWI426859B; TW201010590A

Abstract

A manufacturing method for a flat heat column includes the steps of: providing a flat hollow tube, of which a first wick structure is disposed on the inner surface; providing at least one guiding device disposed within the flat heat tube for supporting the flat heat tube, wherein a second wick structure is disposed on the surface of the guiding device; connecting the first wick structure and the second wick structure for forming a continuous wick structure; and filling a working fluid and sealing both two ends of the flat hollow tube so as to form the flat heat column. A heat dissipation module and its flat heat column are also disclosed for applying to a heat element. The flat heat column can provide flowing path with optimum thermal conductive efficiency for the fluid therein.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 097132974 filed in Taiwan, Republic of China on Aug. 28, 2008, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention
The present invention relates to a heat dissipation module and in particular to a heat dissipation module having a guiding device disposed in a hollow tube and the guiding device has a wick structure.
2. Related Art
Accompanying the development of the technology, the number of transistors on a same unit area of the electronic device has been increasing, and this leads to an increase in heat energy while using the electronic device. The heat pipe is a simple but very effective heat dissipation device, and it has been widely applied on various electronic heat dissipation products. The heat pipe is used to transfer the energy by the latent heat produced as the working fluid is changing between the gas phase and the liquid phase. In the vaporization section, the working fluid takes away a great amount of heat energy from the heat source by the latent heat of vaporization; while in the condensation section, the working fluid condenses into the liquid and releases the heat energy. The working fluid reflows back to the vaporization section with capillary force provided by the wick structure and then the phase change would be performed again; hence continuously dissipate the heat from the heat source to a distant place.
The flat heat plate is a type of heat pipe. Since the flat heat plate is conventionally formed by welding an upper plate and a lower plate together, not only that the welding path is long and the welding reliability is low, but also that the wick structures on the upper and lower plates are not able to be continuously connected but merely connected by contacting. This would cause a decrease in capillary force as the working fluid passes, so as to slow down the reflow rate, hence affect the thermal conductivity.
Additionally, in the conventional method of welding the upper and the lower plates, since a lot of elements and a high level of mold/fixture technique are needed, the cost of the conventional method is relatively higher. Because of the limitation of their geometric shapes, the wick structure on the upper plate and the wick structure on the lower plate have to be sintered separately instead of being formed over a single step at the same time. Furthermore, different molds and fixtures have to be used for the flat heat plates with different lengths, so the cost of equipment is largely increased.

SUMMARY OF THE INVENTION

In view of the foregoing, the present invention is to provide a flat heat column, which has high reliability, low cost and high thermal conductive efficiency, and a manufacturing method thereof.
To achieve the above, the present invention is to provide a method for manufacturing a flat heat column, including the steps of providing a flat hollow tube having a continuous first wick structure disposed on an inner surface of the flat hollow tube; providing at least one guiding device disposed in the flat hollow tube and having a second wick structure disposed on a surface of the guiding device; connecting the first wick structure and the second wick structure to form a continuous wick structure; and filling a working fluid and sealing two ends of the flat hollow tube.
To achieve the above, the present invention is to provide a flat heat column, including a flat hollow tube, at least one guiding device and a working fluid. The flat hollow tube has a continuous first wick structure disposed on its inner surface. The guiding device is disposed in the flat hollow tube and has a second wick structure disposed on a surface of the guiding device. The working fluid is disposed in the sealed flat hollow tube. The first wick structure and the second wick structure form a continuous wick structure.
To achieve the above, the present invention is to provide a heat dissipation module according to a method for manufacturing a flat heat column of the present invention, rather than being conventionally formed by an upper plate and a lower plate. Thus, the reliability can be increased by reducing the number of welding paths, a guiding device can be disposed at any position in the flat hollow column, and a continuous wick structure can be formed by a wick structure on a condensation end and a wick structure on a vaporization end. This helps prevent a capillary force for a working fluid from being interrupted, in which the working fluid flows from the condensation end to the vaporization end through the guiding device, so as to increase the circulating flow rate of the working fluid, hence effectively enhance the heat dissipation efficiency. Compared to the conventional flat heat plate having a discontinuous wick structure, the structure and the method for manufacturing the flat heat column according to the present invention can provide a more preferable wick structure that makes the working fluid circulate quickly and enhances thermal conductivity.
In addition, a method is provided for manufacturing the flat heat column of the present invention allows an outer surface of the flat heat column formed by stamping instead of the flat heat plate that is formed in a complicated way such as welding or at high cost, the length of the flat heat column can be adjusted according to the requirements of different users, and the mold is cheap and can be shared. Thus, the manufacturing process of the present invention can be simplified. In general, the method for manufacturing the flat heat column of the present invention has the advantages of low cost and that the flat heat column can be easily changed to different shapes.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIGS. 1A and 1B are schematic illustrations of manufacturing processes of two flat heat columns according to the preferred embodiment of the present invention;

FIG. 2A is a cross-sectional view of the flat heat column in FIG. 1A turned up-side-down along a line A-A′, wherein the guiding device is a solid pillar;

FIG. 2B is a cross-sectional view of the flat heat column in FIG. 1A turned up-side-down along a line A-A′, wherein the guiding device and the second wick structure are integrally formed with the same material;

FIG. 3 is a cross-sectional view of the flat heat column in FIG. 1B turned up-side-down along a line B-B′;

FIG. 4 is a cross-sectional view of the flat heat column in FIG. 1B turned up-side-down along a line C-C′;

FIG. 5A is an exploded view of a heat dissipation module according to the preferred embodiment of the present invention;

FIG. 5B is a schematic illustration of a heat dissipation module according to a first embodiment of the present invention;

FIG. 5C is a schematic illustration of a heat dissipation module according to a second embodiment of the present invention; and

FIG. 6 is a schematic illustration of a heat dissipation module according to a third embodiment of the present 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.
FIGS. 1A and 1B are schematic illustrations of manufacturing processes of two flat heat columns according to the present invention. A method for manufacturing a flat heat column is illustrated as follows. With reference to FIGS. 1A and 1B, firstly, a flat hollow tube 2 that is provided is, for example, a circular tube 1 formed by stamping, and its cross-sectional shape is rectangular. The cross-sectional shape of the circular tube 1 can also be polygon, oblong, or long arc. The material of the tube is, for example, aluminum (Al), copper (Cu), titanium (Ti), molybdenum (Mo), or other metal with high thermal conductivity. It is to be noted that the flat hollow tube 2 can be not only formed by applying a stamping process to a circular tube 1 but also directly formed by stamping.
A continuous first wick structure 4 is formed by sintering in the flat hollow tube 2 and is disposed on the inner surface of the flat hollow tube 2. The first wick structure 4 is a porous structure and can be a metal spring shape, a groove shape, a pillar shape, a meshed shape, or formed with a metal powder. Next, a convex plate 3 (as shown in FIG. 1B) can be formed on a surface of the flat hollow tube 2 by stamping according to actual product requirements, and the surface having the convex plate 3 is the bottom surface of the flat heat column for contacting the heat source. Alternatively, the flat hollow tube does not need to have a convex plate 3 disposed thereon but directly contacts the heat source, as shown in FIG. 1A.
Next, at least one guiding device 5 is provided and a second wick structure 6 is formed on the surface of the guiding device 5 by sintering. The sintered guiding device 5 is then disposed in the flat hollow tube 2 and a second sintering is performed to connect the first wick structure 4 and the second wick structure 6 on the guiding device 5 to form a continuous wick structure, and a filling tube 7 is inserted into the side surface of the flat tube. After that, the two ends of the flat hollow tube 2 are sealed and the junction between the filling tube 7 and the flat hollow tube 2 are sealed, both by welding, melting, or mechanical-manufacturing-like method. After sealing, a working fluid is filled into the flat hollow tube 2 through the filling tube 7; the working fluid is, for example, inorganic compound, water, alkane, alcohol, liquid metal, ketone, freon, or organic compound. Lastly, through the filling tube 7 the flat hollow tube 2 is vacuumed to remove the non-condensable gas (NCG), and the filling tube 7 will then be sealed, such that the manufacturing of the flat heat columns 11A and 11B of the present invention can be completed.
FIG. 2A is a cross-sectional view of the flat heat column in FIG. 1A turned up-side-down along a line A-A′. The guiding device 5 can be a solid pillar and the second wick structure is disposed on the surface of the solid pillar. Alternatively, as shown in FIG. 2B, the guiding device 5 and the second wick structure 6 can be formed integrally with the same material, e.g. a porous structure in a metal spring shape, in a meshed shape, or formed with a metal powder. The identical or equivalent elements in each embodiment are denoted by the same reference numerals. Please refer to FIGS. 1A and 2B, the flat heat column 11A includes a flat hollow tube 2, at least one guiding device 5, and a working fluid W. The dot distributing in the flat hollow tube 2 means the working fluid W is in gas phase. The flat hollow tube 2 is an integrally-formed tube having a continuous first wick structure 4 disposed on its inner surface. The guiding device 5 is disposed in the flat hollow tube 2 and a second wick structure 6 is disposed on the surface of the guiding device 5. The working fluid W is disposed in the sealed flat hollow tube 2. The first wick structure 4 and the second wick structure 6 together form a continuous wick structure. Other than supporting the upper and lower plates of the flat heat column 11A, the guiding device 5 can further increase the reflow rate of the working fluid W so as to enhance the heat dissipation efficiency. The features or the illustrations of the elements denoted by the same reference numerals have been described above, thus the detailed description thereof will be omitted.
FIG. 3 is a cross-sectional view of the flat heat column in FIG. 1B turned up-side-down along a line B-B′. FIG. 4 is a cross-sectional view of the flat heat column in FIG. 1B turned up-side-down along a line C-C′. The identical or equivalent elements in each embodiment are denoted by the same reference numerals. With reference to FIGS. 1B, 3, and 4, the flat heat column 11B includes a flat hollow tube 2, at least one guiding device 5, and a working fluid W. The flat hollow tube 2 has at least one convex plate 3 and is integrally formed. In addition, the flat hollow tube 2 has a continuous first wick structure 4 disposed on its inner surface. The guiding device 5 is disposed in the flat hollow tube 2 and has a second wick structure 6 on its surface. The working fluid W is disposed in the sealed flat hollow tube 2, in which the first wick structure 4 and the second wick structure 6 together form a continuous wick structure. Other than supporting the upper and the lower plates of the flat heat column 11B, the guiding device 5 can further increase the reflow rate of the working fluid W so as to enhance the heat dissipation efficiency. The features or the illustrations of the elements denoted by the same numerals have been described above, thus the detailed description thereof will be omitted.
It has to be specifically illustrated that, as shown in FIG. 2A, the guiding device 5 can be a solid pillar and the second wick structure is disposed on the surface of the solid pillar. Alternatively, as shown in FIGS. 3 and 4, the guiding device 5 and the second wick structure 6 can be integrally formed with the same material, e.g. a porous structure in a metal spring shape, in a meshed shape, or formed with a metal powder. In addition, with reference to FIG. 4, at least one supporting part 24 (e.g. a high thermal conductive stick or a supporting part sintered with copper powder) can be further disposed inside each of the two ends of the flat hollow tube 2 next to the sealing portions 13, so that the flat hollow tube 2 can keep flat while sealing its two ends.
Please again refer to FIGS. 5A and 5C. As shown in FIG. 5A, the heat dissipation module 10 includes a fin 40, a flat heat column 11, and a fixing plate 50. The flat heat column 11 works just like the flat heat column 11B in FIG. 1B. The fixing plate 50 includes a bottom portion 51, at least two side portions 52, and at least two connecting portions 53. As shown in FIG. 5B, the bottom portion 51 and the side portions 52 form a accommodating space 55 for accommodating the flat heat column 11, and the fixing plate 50 has an opening 54 for accommodating the convex plate 3. Alternatively, as shown in FIG. 5C, the opening 54′ can accommodate a part of the flat heat column 11 and the convex plate 3. The fin 40 is connected to a side of the flat heat column 11 opposite to the convex plate 3 and fixedly connected to the connecting portion 53, such that the flat heat column 11 is held fixedly between the fin 40 and the fixing plate 50.
Please refer to FIG. 6, the heat dissipation module 10 includes a fin 40, a flat heat column 11, and a fixing plate 60. The flat heat column 11 is the sealed flat hollow tube filled with the working fluid. In the flat heat column 11, at least one guiding device is formed and connected to the two opposite inner surfaces of the flat hollow tube, such that the working fluid can reflow and circulate through the guiding device. At least two fixing plates 60 include a bottom portion 61 and a side portion 62. Two fixing plates 60 are disposed on the two opposite sides of the flat heat column 11, and lean against and press the flat heat column 11. A fin 40 is connected to a side of the flat heat column 11 opposite to the convex plate 3 and is fixedly connected to the bottom portion 61.
According to the method for manufacturing the flat heat column of the present invention, the flat heat column can be formed integrally from a circular tube, rather than being conventionally formed by an upper plate and a lower plate. Thus, the reliability of the flat heat column can be increased by reducing the number of welding paths, a guiding device can be disposed at any position in the flat heat column, and a continuous wick structure can be formed with the wick structure on a condensation end and the wick structure on a vaporization end. This helps prevent a capillary force for a working fluid from being interrupted, in which the working fluid flows from the condensation end to the vaporization end through the guiding device, so as to increase the circulating flow rate of the working fluid, hence effectively enhance the heat dissipation efficiency. Compared to the conventional flat heat plate having a discontinuous wick structure, the structure and the method for manufacturing the flat heat column according to the present invention can provide a more preferable wick structure that makes the working fluid circulate quickly and enhances thermal conductivity.
Moreover, the method for manufacturing the flat heat column of the present invention allows an outer surface of the flat heat column formed from a circular tube material by stamping instead of the flat heat plate that is formed in a complicated way or at high cost, the length of the flat heat column can be adjusted according to the requirements of different users, and the mold is cheap and can be shared. Thus, the manufacturing process of the present invention can be simplified. Generally, the method for manufacturing the flat heat column of the present invention has the advantages of low cost and that the flat heat column can be easily changed to different shapes.
Although the present 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 present invention.

Claims

1. A method for manufacturing a flat heat column, the method comprising steps of:

providing a flat hollow tube having a first wick structure disposed on an inner surface of the flat hollow tube;

providing at least one guiding device disposed within the flat heat column and having a second wick structure disposed on a surface of the guiding device;

connecting the first wick structure and the second wick structure to form a continuous wick structure; and

filling a working fluid and sealing two ends of the flat hollow tube.

2. The method according to claim 1, wherein the flat hollow tube is integrally formed as a single piece and formed by stamping, or the flat hollow tube is a circular tube.

3. The method according to claim 2, wherein at least one convex plate is further formed on a surface of the flat hollow tube.

4. The method according to claim 1, wherein the flat hollow tube is formed directly by stamping, and at least one convex plate is further formed on a surface of the flat hollow tube.

5. The method according to claim 1, wherein the first wick structure and the second wick structure are connected by sintering to form the continuous wick structure, or the first wick structure is a porous structure in a metal spring shape, in a meshed shape, or formed with a metal powder.

6. The method according to claim 1, wherein the guiding device is a solid pillar and the second wick structure is disposed on a surface of the solid pillar, or the guiding device and the second wick structure are integrally formed with the same material.

7. A flat heat column, comprising:

a flat hollow tube having a continuous first wick structure disposed on an inner surface of the flat hollow tube;

at least one guiding device disposed in the flat hollow tube and having a second wick structure disposed on a surface of the guiding device; and

a working fluid disposed in the sealed flat hollow tube, wherein the first wick structure and the second wick structure form a continuous wick structure.

8. The flat heat column according to claim 7, wherein the flat hollow tube is integrally formed as a single piece and formed by stamping, or the flat hollow tube is a circular tube.

9. The flat heat column according to claim 8, wherein at least one convex plate is further formed on a surface of the flat hollow tube.

10. The heat flat column according to claim 7, wherein the flat hollow tube is directly formed by stamping.

11. The flat heat column according to claim 10, wherein at least one convex plate is further formed on a surface of the flat hollow tube.

12. The flat heat column according to claim 7, wherein the first wick structure and the second wick structure are connected by sintering to form the continuous wick structure, or the first wick structure is a porous structure in a metal spring shape, in a meshed shape, or formed with a metal powder.

13. The flat heat column according to claim 7, wherein the guiding device is a solid pillar and the second wick structure is disposed on a surface of the solid pillar.

14. The flat heat column according to claim 7, wherein the guiding device and the second wick structure are integrally formed with the same material, and the guiding device and the second wick structure are porous structures in a metal spring shape, in a meshed shape, or formed with a metal powder.

15. The flat heat column according to claim 7, wherein the material of the flat hollow tube is aluminum, copper, titanium, molybdenum, or other metal with high thermal conductivity, or the cross-sectional shape of the flat hollow tube is polygon, oblong, or long arc.

16. The flat heat column according to claim 7, wherein a filling tube is further inserted into a side surface of the flat tube so that the working fluid is filled into the flat heat column through the filling tube, the working fluid is inorganic compound, water, alkane, alcohol, liquid metal, ketone, freon, or organic compound, or both two ends of the flat hollow tube are sealed by welding, melting, or mechanical-manufacturing-like way.

17. The flat heat column according to claim 7, wherein at least one supporting part is further disposed in the flat hollow tube such that the flat hollow tube keeps flat while sealing its two ends, and the supporting part is a high thermal conductive stick or formed with a sintered copper powder.

18. A heat dissipation module, comprising:

a flat heat column, comprising:

a flat hollow tube having a continuous first wick structure disposed on an inner surface of the flat hollow tube,

at least one guiding device disposed in the flat hollow tube and having a second wick structure disposed on a surface of the guiding device, and

a working fluid disposed in the sealed flat hollow tube; and

a fin connected to the flat heat column;

wherein the first wick structure and the second wick structure form a continuous wick structure.

19. The heat dissipation module according to claim 18, further comprising:

a fixing plate having a bottom portion, at least two side portions, and at least two connecting portions, wherein the bottom portion and the side portions form a accommodating space for accommodating the flat heat column, the bottom portion has an opening for accommodating a convex plate formed on a surface of the flat hollow tube, the fin is connected to a side of the flat heat column opposite to the convex plate and is fixedly connected to the connecting portions.

20. The heat dissipation module according to claim 18, further comprising:

at least two fixing plates, and each of the fixing plates having a bottom portion and a side portion, disposed oppositely on two sides of the flat heat column, and the side portion leaning against and pressing the flat heat column, wherein the fin is connected to a side of the heat flat column opposite to a convex plate formed on a surface of the flat hollow tube and is fixedly connected to the bottom portion of each of the fixing plates.