US20110315351A1

US20110315351A1 - Vapor chamber having composite supporting structure

Info

Publication number: US20110315351A1
Application number: US12/821,309
Authority: US
Inventors: George Anthony. Meyer, IV; Chien-Hung Sun; Chieh-Ping Chen; Yung-Tai Lu; Te-Hsuan Chin; Mei-Yu Chen
Original assignee: Celsia Technologies Taiwan Inc
Current assignee: Celsia Technologies Taiwan Inc
Priority date: 2010-06-23
Filing date: 2010-06-23
Publication date: 2011-12-29

Abstract

A vapor chamber having a composite supporting structure includes a flat sealed casing; a wick structure, a working fluid and a composite supporting structure. The composite supporting structure has a waved supporting rack and at least one supporting pillar. The waved supporting rack is configured to support upper and lower inner walls of the flat sealed casing. The waved supporting rack has plural separated channels for allowing vapor of the working fluid to flow through. Both ends of the at least one supporting pillar are respectively connected to the flat sealed casing or the wick structure. With this arrangement, compressive strength and tensile strength of the vapor chamber can be increased simultaneously without obstructing the circulation of liquid/vapor phases of the working fluid and reducing the thermal-conducting efficiency thereof.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a vapor chamber, and in particular to a vapor chamber having a composite supporting structure.
2. Description of Prior Art
With the advancement of science and technology, the power and performance of a modern electronic element have been increased significantly. As a result, a large amount of heat is generated during the operation of the electronic element. If the heat is not conducted to the outside but accumulated inside the electronic element, the temperature of the electronic element will rise to such an extent that its performance is affected and even the electronic element may suffer damage. Therefore, it is an important issue for the manufacturers in this field to develop effective heat-conducting members to solve the above problem. For example, a vapor chamber is a common heat-conducting member used nowadays.
The vapor chamber includes a flat sealed casing, a wick structure formed in the flat sealed casing, and a working fluid filled in the flat sealed casing. The flat sealed casing is formed with a heat-absorbing surface and a heat-releasing surface opposite to the heat-absorbing surface. The heat-absorbing surface is brought into thermal contact with an electronic heat-generating element. The liquid/vapor phase change of the working liquid inside the vapor chamber thermally conducts the heat generated by the electronic heat-generating element from the heat-absorbing surface to the heat-releasing surface.
Recently, since electronic products are made more and more compact, the thickness of the vapor chamber provided in the electronic product has to be reduced accordingly. However, the reduction in the thickness of the vapor chamber inevitably reduces the thickness of the flat sealed casing. As a result, the whole structural strength of the vapor chamber becomes insufficient due to the thinned casing. When the vapor chamber is evacuated vacuum, the external atmosphere will exert a compressive force onto the vapor chamber, thereby making the vapor chamber sunken. In another case, the portion of the vapor chamber to which an electronic heat-generating element is adhered will be sunk due to the compressive force exerted by the electronic heat-generating element on the vapor chamber.
Therefore, it is well known to provide a supporting structure within the vapor chamber. The supporting structure abuts an upper surface and a lower surface of an inner wall of the vapor chamber to increase the structural strength of the vapor chamber, thereby protecting the vapor chamber from getting sunken due to the external compressive force. If the area and volume of the supporting structure are too small, the effect of the supporting structure may be insufficient. However, if the area and volume of the supporting structure are too large, the supporting structure may obstruct the phase change between liquid and vapor phases of the working fluid and thus adversely affect the thermal-conducting effect of the vapor chamber.
On the other hand, in practice, since the working fluid in the vapor chamber is vaporized when heated, the volume of the vapor phase of the working fluid is significantly larger than that of the liquid phase of the working fluid. The volume expansion and the pressure increase of vapor will bulge the casing of the vapor chamber, which causes unevenness of the vapor chamber. Thus, it is an important issue to balance the compressive strength and the tensile strength of the vapor chamber.
Therefore, it is an important issue for the present inventor to solve the above problems.

SUMMARY OF THE INVENTION

The present invention is to provide a vapor chamber having a composite supporting structure, whereby compressive strength and tensile strength thereof can be increased simultaneously without obstructing the circulation of liquid/vapor phases of the working fluid and reducing the thermal-conducting efficiency thereof.
The present invention provides a vapor chamber having a composite supporting structure, comprising: a flat sealed casing; a wick structure arranged on inner walls of the flat sealed casing; a working fluid filled within the flat sealed casing; and a composite supporting structure mounted in the flat sealed casing, the composite supporting structure having a waved supporting rack and at least one supporting pillar.
In comparison with prior art, the present invention has advantages features as follows:
According to the present invention, since the waved supporting rack is configured to support an upper inner wall and a lower inner wall of the flat sealed casing, the waved supporting rack can increase the compressive strength of the vapor chamber. Thus, the vapor chamber may not be sunken due to the compressive force exerted by an electronic heat-generating element or during a vacuum evacuation process.
Furthermore, since the waved supporting rack has therein a plurality of separated channels for allowing the vapor of the working fluid to flow through, the waved supporting rack will not obstruct the circulation of liquid/vapor phases of the working fluid nor adversely affect the thermal-conducting efficiency of the vapor chamber.
Since the composite supporting structure of the present invention further has at least one supporting pillar, both ends of the supporting pillar are respectively connected to the flat sealed casing or the wick structure, the flat sealed casing can be prevented from bulging, thereby increasing the tensile strength of the vapor chamber.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention;

FIG. 2 is an assembled perspective view showing the first embodiment of the present invention;

FIG. 3 is an assembled cross-sectional view showing the first embodiment of the present invention showing that the surface of the flat sealed casing has not been pressed to form a recess thereon while its inner wall abutting against the supporting pillar;

FIG. 4 is an assembled cross-sectional view showing the first embodiment of the present invention showing that the surface of the flat sealed casing has been pressed to form a recess thereon while its inner wall abutting against the supporting pillar;

FIG. 5 is a perspective view showing the first embodiment of the present invention;

FIG. 6 is an assembled cross-sectional view showing the first embodiment of the present invention;

FIG. 7 is an assembled cross-sectional view showing a second embodiment of the present invention; and

FIG. 8 is an assembled cross-sectional view showing a third embodiment of the present invention; and

FIG. 9 is an assembled cross-sectional view showing a fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description and technical contents of the present invention will become apparent with the following detailed description accompanied with related drawings. It is noteworthy to point out that the drawings is provided for the illustration purpose only, but not intended for limiting the scope of the present invention.
Please refer to FIGS. 1 and 6. The present invention provides a vapor chamber 1 having a composite supporting structure (referred to as “vapor chamber 1” hereinafter), which is configured to allow for heat conduction and dissipation of an electronic heat-generating element (not shown).
As shown in FIG. 6, the vapor chamber 1 includes a flat sealed casing 10, a wick structure arranged on an inner surface of the flat sealed casing 10, a working fluid 30 (indicated by dotted lines) filled in the flat sealed casing 10, and a composite supporting structure 40 mounted in the flat sealed casing 10.
The flat sealed casing 10 is made of metallic materials of good thermal conductivity. The wick structure 20 is made by sintering metallic powders or metallic meshes. The interior of the wick structure 20 has a plurality of tiny pores to thereby generate a capillary action. The wick structure 20 is arranged on an inner wall of the flat sealed casing 10. The working fluid 30 is filled inside the flat sealed casing 10. With the circulation of liquid/vapor phases of the working fluid 30 in the flat sealed casing 10, the heat generated by the electronic heat-generating element (not shown) can be conducted to the outside continuously.
According to a first embodiment shown in FIG. 1, the flat sealed casing 10 of the vapor chamber 1 has a sealing side 11. After the wick structure 20 and the composite supporting structure 40 are disposed in the flat sealed casing 10, the sealing side 11 is sealed to completely seal the flat sealed casing 10. In addition, a filling/degassing tube 12 is provided to protrude from one side of the flat sealed casing 10, by which the working fluid 30 can be filled in the flat sealed casing 10 and then the flat sealed casing 10 is evacuated vacuum. Finally, the filling/degassing tube 12 is sealed.
In the present embodiment, the composite supporting structure 40 is accommodated in the flat sealed casing 11 and includes a waved supporting rack 41 and at least one supporting pillar 42 (seven shown in FIG. 1). The waved supporting rack 41 is positioned to correspond to the electronic heat-generating element (not shown) for supporting the upper surface and the lower surface of the inner wall of the vapor chamber 1. The waved supporting rack 41 is capable of providing a sufficient strength for protecting the flat sealed casing 10 from getting sunken due to a compressive force exerted thereon by the electronic heat-generating element or the external atmosphere.
The waved supporting rack 41 comprises at least two side plates 411 and a plurality of waved pieces 412 connected between the two side plates 411. Each of the waved pieces 412 is constituted of a plurality of wave-crest sections 4121 and a plurality of wave-recess sections 4122. The wave-crest sections 4121 of the any two adjacent waved pieces 412 are staggered to each other. Similarly, the wave-recess sections 4122 of any two adjacent waved pieces 412 are staggered to each other. Any two adjacent waved pieces 412 are separated from each other to form a separated channel 4123 there between. The wave-crest sections 4121 are located in a level higher than that of the top surface of the side plate 411, and the wave-recess sections 4122 are located in a level lower than that of the bottom surface of the side plate 411.
As shown in FIG. 4, both ends of the supporting pillars 42 are respectively connected to the wick structure 20, thereby protecting the flat sealed casing 10 from bulging. More specifically, the supporting pillar 42 is a metallic pillar of any suitable shape (such as circle, square, rectangle or oval shown in FIG. 1). The supporting pillars 42 may be arranged towards four corners inside the flat sealed casing 10 away from the waved supporting rack 41. By means of any one of a thermal fusion process at high temperature, sintering, brazing and soldering, the supporting pillars 42 can be tightly connected to the wick structure 20. In this way, even though the working fluid 30 inside the vapor chamber 1 is vaporized, the tight connection between the supporting pillar 42 and the wick structure 20 can prevent the flat sealed casing 10 from bulging due to the internal vapor pressure of the working fluid 30. Thus, the tensile strength of the vapor chamber 1 can be increased.
Please refer to FIGS. 4 and 5. Alternatively, a forming tool (not shown) is used to press the outer surface of the flat sealed casing 10 against which the supporting pillar 42 abuts, thereby forming a recess 13. In this way, a preload is exerted at this location to thereby further increasing the tensile strength of the vapor chamber 1.
Please refer to FIG. 7, which shows a second embodiment of the present invention. The difference between the present embodiment and the previous embodiment lies in that: a portion of the wick structure 20 arranged on the inner lower wall of the flat sealed casing 10 is first sintered. Then, the supporting pillars 42 are disposed in the flat sealed casing 10. Finally, the rest portion of the wick structure 20 arranged on the upper inner wall of the flat sealed casing 10 is subjected to a sintering process. As a result, the upper end of each of the supporting pillars 42 directly abuts against the upper inner wall of the flat sealed casing 10, and the wick structure 20 is connected to the supporting pillars 42 after a heat fusion process. In other words, both ends of the supporting pillar 42 are respectively connected to the upper inner wall of the flat sealed casing 10 and the wick structure 20.
Please refer to FIG. 8, which shows a third embodiment of the present invention. The difference between the present embodiment and the previous embodiment lies in that: the supporting pillars 42 are first disposed in the flat sealed casing 10. Then, the wick structure 20 arranged on the upper and lower inner walls of the flat sealed casing 10 are sintered, so that both ends of each of the supporting pillars 42 abut against the upper and lower inner walls of the flat sealed casing 10 respectively. After a heat fusion process, the wick structure 20 is connected to the side edges of the supporting pillar 42.
Please refer to FIG. 9, which shows a fourth embodiment of the present invention. The difference between the present embodiment and the previous embodiment lies in that: the waved supporting rack 41 occupies substantially the whole internal space of the flat sealed casing 10. The supporting pillar 42 is disposed in an opening 43 formed inside the waved supporting rack 41. Like the previous embodiments, the supporting pillar 42 can be connected to the flat sealed casing 10 or the wick structure 20. In this way, even though the working fluid 30 inside the vapor chamber 1 is vaporized, the tight connection between the supporting pillars 42 and the wick structure 20 can prevent the flat sealed casing 10 from bulging due to the volume expansion of the vapor-phase working fluid 30. Thus, the tensile strength of the vapor chamber 1 can be increased.
In comparison with prior art, the present invention has advantages features as follows:
According to the present invention, since the waved supporting rack 41 is configured to support an upper inner wall and a lower inner wall of the flat sealed casing 10, the waved supporting rack 41 can increase the compressive strength of the vapor chamber 1. Thus, the vapor chamber 1 may not be sunken due to the compressive force exerted thereon by the electronic heat-generating element or a vacuum evacuation process.
Furthermore, since the waved supporting rack 41 has therein a plurality of separated channels 4123 for allowing the vapor of the working fluid 30 to flow through, the waved supporting rack 41 will not obstruct the circulation of liquid/vapor phases of the working fluid 30 nor adversely affect the thermal-conducting efficiency.
Since the composite supporting structure 40 of the present invention further has at least one supporting pillar 42 with its both ends connected to the flat sealed casing 10 or the wick structure 20, the flat sealed casing 10 can be prevented from bulging, thereby increasing the tensile strength of the vapor chamber 1.
Although the present invention has been described with reference to the foregoing preferred embodiments, it will be understood that the invention is not limited to the details thereof. Various equivalent variations and modifications can still occur to those skilled in this art in view of the teachings of the present invention. Thus, all such variations and equivalent modifications are also embraced within the scope of the invention as defined in the appended claims.

Claims

1. A vapor chamber having a composite supporting structure, comprising:

a flat sealed casing;

a wick structure arranged on inner walls of the flat sealed casing;

a working fluid filled within the flat sealed casing; and

a composite supporting structure mounted in the flat sealed casing, the composite supporting structure having a waved supporting rack and at least one supporting pillar.

2. The vapor chamber having a composite supporting structure according to claim 1, wherein the waved supporting rack is configured to support an upper inner wall and a lower inner wall of the flat sealed casing, the waved supporting rack has a plurality of separated channels for allowing vapor of the working fluid to flow through.

3. The vapor chamber having a composite supporting structure according to claim 2, wherein the waved supporting rack comprises at least two side plates and a plurality of waved pieces connected between the two side plates, each of the waved pieces is constituted of a plurality of wave-crest sections and a plurality of wave-recess sections, the wave-crest sections of any two adjacent waved pieces are staggered to each other, the wave-recess sections are staggered to each other, the wave-crest sections are located in a level higher than that of a top surface of the side plate, and the wave-recess sections are located in a level lower than that of a bottom surface of the side plate, and the separated channels are formed between any two adjacent waved pieces.

4. The vapor chamber having a composite supporting structure according to claim 3, wherein both ends of the at least one supporting pillar are respectively connected to the upper inner wall and the lower inner wall of the flat sealed casing.

5. The vapor chamber having a composite supporting structure according to claim 3, wherein both ends of the at least one supporting pillar are respectively connected to the upper inner wall of the flat sealed casing and the wick structure.

6. The vapor chamber having a composite supporting structure according to claim 3, wherein both ends of the at least one supporting pillar are respectively connected to the lower inner wall of the flat sealed casing and the wick structure.

7. The vapor chamber having a composite supporting structure according to claim 3, wherein both ends of the at least one supporting pillar are respectively connected to the wick structure.

8. The vapor chamber having a composite supporting structure according to claim 3, wherein the at least one supporting pillar is made of metallic materials, the wick structure is made by sintering metallic powders, the wick structure is connected to the supporting pillar by any one of a heat fusion process at high temperature, sintering, brazing or soldering.

9. The vapor chamber having a composite supporting structure according to claim 3, wherein the at least one supporting pillar is disposed toward four corners inside the flat sealed casing and away from the waved supporting rack.

10. The vapor chamber having a composite supporting structure according to claim 3, wherein the at least one supporting pillar is disposed in an opening formed inside the waved supporting rack.

11. The vapor chamber having a composite supporting structure according to claim 3, wherein an outer upper surface of the flat sealed casing is formed with a recess corresponding to the at least one supporting pillar.