US20100243212A1

US20100243212A1 - Non-flat vapor chamber with stiffening plate

Info

Publication number: US20100243212A1
Application number: US12/411,727
Authority: US
Inventors: George Anthony Meyer, IV; Chien-Hung Sun; Chieh-Ping Chen
Original assignee: Celsia Technologies Taiwan Inc
Current assignee: Celsia Technologies Taiwan Inc
Priority date: 2009-03-26
Filing date: 2009-03-26
Publication date: 2010-09-30

Abstract

A non-flat vapor chamber includes a casing, a capillary tissue, a stiffening plate, a support structure and a working fluid. The casing includes a lower case plate and an upper case plate sealed with the lower case plate. The lower case plate has a partial area protruded downward to form a chamber and a retaining portion formed within the chamber. A capillary tissue is installed on internal walls of the upper and lower case plates. The stiffening plate with a through hole is installed onto the retaining portion, and the casing contains a support structure. Upper and lower ends of the support structure abut the capillary tissue and the stiffening plate. A working fluid is filled into the casing, such that a support action is provided by pressing the stiffening plate at the retaining portion for stiffening the upper case plate of a vacuumed vapor chamber.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a vapor chamber, and more particularly to a non-flat vapor chamber with a stiffening plate.
2. Description of Prior Art
Vapor chamber has been used extensively in electronic devices, and the vapor chamber is generally attached onto heat generating components of a printed circuit board for dissipating waste heat produced by the heat generating components, so that the electronic components can be operated at a normal working temperature without the risk of being burned or damaged. However, a printed circuit board includes various different electronic components, and these components are installed with a height difference with respect to a distal surface of the printed circuit board instead of being installed flatly on the surface, and a general flat vapor chamber cannot be applied to such non-flat surface.
Therefore, a non-flat vapor chamber was introduced, wherein a protrusion is formed on the surface of the vapor chamber, and a containing space corresponding to the protrusion is formed inside the vapor chamber, and the protrusion is aligned precisely with the heat generating components of the printed circuit board to overcome the aforementioned problem. If no support body is installed in the vapor chamber and at a position corresponding to the protrusion, then the external case plate of the vapor chamber and the capillary tissue in the vapor chamber will be depressed and collapsed, after the interior of the vapor chamber is vacuumed and used for a long time. Therefore, the non-flat vapor chamber generally includes an upper case plate, a lower case plate, a working fluid, a capillary tissue and a support body, and the aforementioned protrusion is usually formed at the lower case plate.
The manufacturing procedure of the aforementioned non-flat vapor chambers is described as follows. Firstly, a protrusion is formed on the lower case plate, and a capillary tissue is attached onto internal walls of the upper and lower case plates, and both ends of the support body abut the capillary tissue, and a portion of the support body is contained in a containing space for abutting the internal walls of the upper and lower case plates, and the upper and lower case plates are engaged with each other and form a crevice between the upper and lower case plates, and then a working fluid is filled, and finally the interior of the vapor chamber is vacuumed and the crevice is sealed to complete the manufacture of the non-flat vapor chamber.
However, the non-flat vapor chambers of this sort still have the following problems in the actual manufacturing process. Since the support body is generally comprised of a plurality of cylindrical bodies, and the cross-sectional area of the cylindrical bodies is much smaller than the area of the lower case plate of the vapor chamber, and a portion of cylindrical bodies are contained in a containing space formed inside the protrusion and abutted against the upper and lower case plates and the capillary tissue. If the interior of the vapor chamber is vacuumed, the upper and lower case plates will be depressed the pressure, and marks of the plurality of cylindrical bodies will be formed on the surface of the vapor chamber since the cross-sectional area of the cylindrical bodies is much smaller than the surface area of the vapor chamber. A larger pressure is exerted onto the surface of the vapor chamber and the marks of the cylindrical bodies are formed on the surface of the vapor chamber. Therefore, the surface of the vapor chamber cannot be maintained as a flat surface or attached closely with the heat generating component, and the thermal conduction performance is lowered.
If the dimensions and the periphery of the cylindrical bodies are increased, the issue of forming marks on the surface of the vapor chamber can be solved, but such arrangement will occupy much of the internal space of the vapor chamber and lower the thermal conduction performance.
In view of the shortcomings of the prior art, the inventor of the present invention based on years of experience in the related industry to develop a non-flat vapor chamber with a stiffening plate in accordance with the present invention to overcome the shortcomings of the prior art.

SUMMARY OF THE INVENTION

It is a primary objective of the present invention to provide a non-flat vapor chamber with a stiffening plate, wherein a supporting force is provided by pressing a stiffening plate at a retaining portion, such that an upper case plate corresponding to the position of the stiffening plate will not be depressed by the vacuumed vapor chamber to assure a flat surface of the vapor chamber and the desired thermal conduction performance of the vapor chamber.
To achieve the foregoing objective, the present invention provides a non-flat vapor chamber comprising a casing, a capillary tissue, a stiffening plate, a support structure and a working fluid, wherein the casing includes a lower case plate and an upper case plate sealed with the lower case plate, and a partial area of the lower case plate is protruded downward to form a chamber therein, and a retaining portion is formed around the chamber, and the capillary tissue is disposed on internal walls of the upper and lower case plates, and the stiffening plate with a plurality of through holes is disposed on the retaining portion, and the support structure is contained in the casing, and upper and lower ends of the support structure are coupled to the capillary tissue and the stiffening plate respectively, and the working fluid is filled into the casing.
Compared with the prior art, the present invention overcomes the uneven surface drawback of the conventional vapor chamber caused by the internal support body of the vapor chamber by using the stiffening plate and the retaining portion, so that the surface of a vacuumed non-flat vapor chamber will not be depressed or marked to assure a flat surface of the vapor chamber. In addition, the stiffening plate does not occupy any of the thermal conducting space in the vapor chamber, and the design of having a through hole on the stiffening plate prevents the working fluid in the vapor chamber from being blocked by the stiffening plate to assure the expected thermal conduction performance of the vapor chamber. The structure of the stiffening plate and the retaining portion allows the vapor chamber of the invention to use the support structure of a conventional vapor chamber, and thus it is not necessary to redesign the support structure for manufacturing the non-flat vapor chamber of the present invention, so as to save the product development time. With the design of the non-flat vapor chamber of the invention, the internal volume can be increased to improve the heat dissipation performance.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded view of a lower case plate and a stiffening plate of the present invention;

FIG. 2 is an exploded view of the present invention;

FIG. 3 is a perspective view of the present invention;

FIG. 4 is a cross-sectional view of Section 4-4 of FIG. 3;

FIG. 5 is a bottom view of a stiffening plate in accordance with another preferred embodiment of the present invention;

FIG. 6 is a bottom view of a stiffening plate in accordance with a further preferred embodiment of the present invention; and

FIG. 7 is an exploded view of another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The technical characteristics, features and advantages of the present invention will become apparent in the following detailed description of preferred embodiments with reference to the accompanying drawings, and the preferred embodiments are used for illustrating the present invention only, but not intended to limit the scope of the invention.
With reference to FIGS. 1 and 2 for an exploded view of a lower case plate and a stiffening plate and an exploded view of the present invention respectively, the present invention provides a non-flat vapor chamber with a stiffening plate 1, comprising a casing 10, a capillary tissue 20, a stiffening plate 30, a support structure 40 and a working fluid 50.
The casing 10 includes a lower case plate 11 and an upper case plate 12 sealed and coupled to the lower case plate 11, wherein a cavity b is formed between the upper case plate 12 and the lower case plate 11, and a partial area of the lower case plate 11 is protruded downward to form a chamber 111 therein, and a retaining portion 112 is formed and enclosed by the periphery of the chamber 111. In this preferred embodiment, the retaining portion 112 is formed at a plurality of corner plates 1121 of the lower case plate 11, and the corner plates 1121 are disposed at the four corners of the chamber 111 respectively, but the invention is not limited to such arrangement only, and the corner plates 1121 may be designed at two opposite corners only. The capillary tissue 20 is disposed on internal walls of the upper case plate 12 and the lower case plate 11.
The stiffening plate 30 is installed on the retaining portion 112 and has a plurality of through holes 31. In addition, the stiffening plate 30 is in a rectangular shape and has a protruding edge 32 extended separately from the corners of the stiffening plate 30, such that a gap d is formed between the lateral side of the stiffening plate 30 and the internal wall of the lower case plate 11 for providing a buffer distance between the stiffening plate 30 and the lower case plate 11 to prevent the volume of the stiffening plate 30 from being expanded by high temperature, compressing with the lower case plate 11 or damaging the vapor chamber 1.
The support structure 40 is contained in the casing 10, and upper and lower ends of the support structure 40 are coupled with the capillary tissue 20 and the stiffening plate 30 respectively, and a working fluid 50 (as shown in FIG. 4) is filled into the casing 10.
With reference to FIGS. 3 and 4 for a perspective view of the present invention and a cross-sectional view of Section 4-4 of FIG. 3 respectively, the invention further comprises a filling and degassing tube 60, an upper case plate 12 and a lower case plate 11, both having a notch 113, 121, and the notches 113, 121 constitute an orifice c for passing the filling and degassing tube 60. The filling and degassing tube 60 is provided for vacuuming the interior of the vapor chamber 1 and filling the working fluid 50.
In FIG. 4, the stiffening plate 30 installed at the retaining portion 112 can provide a supporting force to the support structure 40 if the interior of the vapor chamber 1 is vacuumed, so that the upper case plate 12 and the lower case plate 11 will not be depressed by the vacuum pressure. In addition, the stiffening plate 30 is supported at the bottom of the support structure 40, and thus the support structure 40 will not be damaged by insufficient supporting force. With the chamber 111, the internal volume of the vapor chamber 1 can be increased to improve the heat dissipation performance of the vapor chamber 1.
With reference to FIG. 5 for a bottom view of a stiffening plate in accordance with another preferred embodiment of the present invention and FIG. 6 for a bottom view of a stiffening plate in accordance with a further preferred embodiment of the present invention, the through holes 31 of the two preferred embodiments are in a rectangular bar shape and a circular shape respectively, but not limited to such arrangement only. The through hole 31 is provided for allowing the working fluid 50 to flow between the lower case plate 11 and the lower case plate 12 without any hindrance.
With reference to FIG. 7 for an exploded view of another preferred embodiment of the present invention, the retaining portion 112 is formed on a surrounding wall 1122 of the lower case plate 11, wherein the surrounding wall 1122 can provide a better supporting force than the corner plate 1121, since the support area is situated at the periphery of the stiffening plate 30.
In summation of the description above, the present invention overcome the shortcomings of the prior art, and complies with the requirements of patent application and is thus duly filed for patent application. While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.

Claims

1. A non-flat vapor chamber comprising:

a casing, including a lower case plate and an upper case plate sealed with the lower case plate, and partial area of the lower case plate being protruded downward to form a chamber therein, and a retaining portion being formed around the chamber;

a capillary tissue, disposed on internal walls of the upper and lower case plates;

a stiffening plate, disposed on the retaining portion, and having a plurality of through holes;

a support structure, contained in the casing, and having upper and lower ends coupled to the capillary tissue and the stiffening plate respectively; and

a working fluid, filled into the casing.

2. The non-flat vapor chamber of claim 1, wherein the retaining portion is formed at the lower case plate and disposed separately at a plurality of corner plates at corners of the chamber.

3. The non-flat vapor chamber of claim 1, wherein the retaining portion is formed on a surrounding wall of the lower case plate.

4. The non-flat vapor chamber of claim 1, wherein the retaining portion and the lower case plate have internal surfaces constituting a height difference, such that a distal surface of the stiffening plate is aligned evenly with the internal surface of the lower case plate.

5. The non-flat vapor chamber of claim 1, wherein the through hole is in a rectangular-bar shape.

6. The non-flat vapor chamber of claim 1, wherein the through hole is in a circular shape.

7. The non-flat vapor chamber of claim 1, wherein the stiffening plate is substantially in a rectangular shape, having a protruding edge extended from the corners of the stiffening plate, such that a gap is formed between a lateral side of the stiffening plate and the internal wall of the lower case plate.

8. The non-flat vapor chamber of claim 1, further comprising a filling and degassing tube, and the upper and lower case plates having a notch each, and the notches constituting an orifice for passing the filling and degassing tube.