US20110220328A1

US20110220328A1 - Flexible heat pipe and manufacturing method thereof

Info

Publication number: US20110220328A1
Application number: US12/720,301
Authority: US
Inventors: Yu- Po HUANG; Tung-Jung Kuo
Original assignee: Kunshan Jue Chung Electronics Co Ltd
Current assignee: KUNSHAN JUE-CHUNG ELECTRONICS Co Ltd; Kunshan Jue Chung Electronics Co Ltd
Priority date: 2010-03-09
Filing date: 2010-03-09
Publication date: 2011-09-15

Abstract

In a flexible heat pipe and a manufacturing method thereof, the flexible heat pipe includes a first tube body, a second tube body arranged apart from the first tube body, a flexible section, a wick structure, and a working fluid. The flexible section includes an annular elastomer and a soft encapsulating layer. The annular elastomer connects the first tube body and the second tube body. The soft encapsulating layer is set around the annular elastomer. The capillary structure is settled inside the first tube body, the second tube body, and the annular elastomer. The working fluid is filled inside the first tube body, the second tube body, and the soft encapsulating layer. Then, the flexible heat pipe can be bent to any angle or in any direction according to practical demands.

Description

FIELD OF THE INVENTION

The present invention generally relates to heat pipes, in particular to a flexible heat pipe and a manufacturing method of the flexible heat pipe.

BACKGROUND OF THE INVENTION

As computer components such as a central processing unit (CPU) come with an increasingly higher computing speed, the heat generated by the components also becomes increasingly greater. Obviously, the use of a heat sink composed of a plurality of heat dissipating fins and a fan in the past no longer meets the requirement of the high-speed operation of the present CPUs. Therefore, some manufacturers developed a heat dissipating device that combines a heat pipe with heat dissipating fins to overcome the heat dissipation problem of the present CPUs. However, existing heat pipes still have a drawback of occupying much space, and thus it is a main subject for related manufacturers and developers to improve the conventional heat pipes.
In general, a conventional heat pipe comprises a metal tube body, a wick structure and a working fluid, wherein the metal tube body includes a sealed chamber, and the wick structure is installed on an internal wall of the metal tube body, and the working fluid is filled in the sealed chamber of the metal tube body, and a gas passage is formed on an internal side of the wick structure, and the wick structure includes a liquid passage.
When the foregoing heat pipe is used, the space limitation of the surrounding environment and the heat conduction at different positions are generally taken into consideration, and thus most of the conventional heat pipes are bent into an L-shape or a U-shape. However, the interior of the wick structure and the internal wall of the metal tube body of the bent heat pipe may be peeled of or fallen off easily, so that the heat conduction effect is reduced significantly. Furthermore, most of the foregoing heat pipes can be bent once only in the manufacturing process, and a second bend of the heat pipe may crack the metal tube body easily. Obviously, the conventional heat pipe requires further improvements.

SUMMARY OF THE INVENTION

Therefore, it is a primary objective of the present invention to provide a flexible heat pipe and its manufacturing method, and the flexible heat pipe can be bent to any angle or in any direction according to practical demands.
To achieve the foregoing objective, the present invention discloses a flexible heat pipe comprising a first tube body, a second tube body, a flexible section, a wick structure and a working fluid, wherein the second tube body is arranged apart from the first tube body, and the flexible section is interconnected to the first tube body and the second tube body, and the flexible section includes an annular elastomer and a soft encapsulating layer, and the annular elastomer is coupled to the first tube body and the second tube body, and the soft encapsulating layer is coupled to the first tube body and the second tube body and wrapped around the exterior of the annular elastomer; and the wick structure is disposed inside the first tube body, second tube body and the annular elastomer, and the working fluid is filled inside the first tube body, second tube body and the soft encapsulating layer.
To achieve the foregoing objective, the present invention provides a manufacturing method of a flexible heat pipe, and the manufacturing method comprises the steps of:
(a) providing a first tube body and a second tube body, both having a first wick structure;
(b) providing an annular elastomer with an end coupled to the first tube body;
(c) providing a second wick structure, passing the second wick structure into the annular elastomer and attaching the second wick to the first wick structure of the first tube body;
(d) coupling the second tube body to another end of the annular elastomer, and attaching the second wick structure to the first wick structure of the second tube body; and
(e) providing a soft encapsulating layer coupled to the first tube body and a second tube body and wrapped around the exterior of the annular elastomer.
The present invention further has the following effects. The invention uses the annular elastomer to support the soft encapsulating layer, so that the soft encapsulating layer will not sink or collapse easily. With each receiving section of the soft encapsulating layer sheathed onto each heat pipe tightly, a quick heat conduction effect can be achieved. Since the flexible material of the heat pipe allows the heat pipe to be adjusted and bent to any angle, the heat pipe will not be hardened easily and the integrity of its original structure will remain even after the pipe has been adjusted and bent repeatedly for many times.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a heat pipe in accordance with present invention;

FIG. 2 is a perspective view of a heat pipe in accordance with present invention;

FIG. 3 is a partial cross-sectional view of a heat pipe in accordance with present invention;

FIG. 4 is a cross-sectional view of a heat conducting module after being bent in accordance with present invention;

FIG. 5 is a flow chart of a manufacturing method of a heat pipe in accordance with the present invention; and

FIG. 6 is a schematic view of a heat pipe applied to an electronic heat-generating component in accordance with the present invention

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The technical characteristics and contents of the present invention will become apparent with the following detailed description accompanied with related drawings, and the drawings are provided for the purpose of illustrating the present invention only, but not intended for limiting the scope of the invention.
With reference to FIGS. 1 to 3, the present invention provides a flexible heat pipe comprising a first tube body 10, a second tube body 20, a flexible section 30, a wick structure 40 and a working fluid (not shown in the figure).
The second tube body 20 is arranged apart from the first tube body 10, and both of the first tube body 10 and the second tube body 20 are vertical tubes, and each tube body 10, 20 is made of a good thermal conducting material such as copper.
The flexible section 30 includes an annular elastomer 31 and a soft encapsulating layer 32, and the annular elastomer 31 can be bent in its axial direction, wherein the annular elastomer 31 of this preferred embodiment is a helical spring, but the invention is not limited to such arrangement only. The soft encapsulating layer 32 is disposed and wrapped around the external surface of the annular elastomer 31, wherein the soft encapsulating layer 32 of this preferred embodiment is a copper foil, but the invention is not limited to such arrangement only. The helical spring type elastomer 31 has a free length smaller than the axial length of the soft encapsulating layer 32, such that when the soft encapsulating layer 32 is wrapped around the exterior of the elastomer 31, a receiving section 321, 322 can be formed separately at both ends of the soft encapsulating layer 32 (as shown in FIG. 3) for coupling the first tube body 10 and the second tube body 20, and each tube body 10, 20 is coupled to the soft encapsulating layer 32 with a thermal contact.
The wick structure 40 is made of a metal mesh, a steel wire, or a fiber material, or sintered with a metal powder, wherein the wick structure 40 of this preferred embodiment includes a first wick structure 41, 42 installed in each tube body 10, 20 and a second wick structure 43 passed into the annular elastomer 31 and contacted with each first wick structure 41, 42.
The working fluid can be pure water filled inside each tube body 10, 20. Each tube body 10, 20 is vacuumed, such that a vapor-liquid phase change mechanism for conducting heat can be achieved.
With reference to FIG. 4, the flexible section 30 can be bent to any angle or in any direction according to actual demands of the heat pipe, wherein the annular elastomer 31 is provided for supporting the soft encapsulating layer 32, so that the soft encapsulating layer 32 will not sink or collapse easily. With the tight sheathing between each receiving section 321, 322 of the soft encapsulating layer 32 and each heat pipe 10, 20, a quick conduction effect can be achieved.
With reference to FIG. 5, a manufacturing method of a heat pipe in accordance with the present invention comprises the steps of:
(a) providing a first tube body 10 and a second tube body 20, both having a first wick structure 41, 42;
(b) providing an annular elastomer 31 with an end coupled to the first tube body 10;
(c) providing a second wick structure 43, passing the second wick structure 43 into the annular elastomer 31, and attaching the second wick structure 43 to a first wick structure 41 of the first tube body 10;
(d) coupling the second tube body 20 to another end of the annular elastomer 31, and attaching the second wick structure 43 to a first wick structure 42 of the second tube body 20; and
(e) providing a soft encapsulating layer 32 coupled to the first tube body 10 and a second tube body 20 and wrapped around the exterior of the annular elastomer 31.
It is noteworthy to point out that each tube body 10, 20 and the annular elastomer 31 in Steps (b) and (d) are coupled by a soldering method, and the soft encapsulating layer 32 and each tube body 10, 20 in Step (e) are coupled by the soldering method.
In addition, the manufacturing method of a heat pipe in accordance with the present invention further comprises a Step f) of filling a working fluid into the second tube body 20, and vacuuming and sealing the first tube body 10 and the second tube body 20.
With reference to FIG. 6, the heat pipe of the present invention can be combined with a fin module 6 for dissipating the heat generated by an electronic heat-generating component 8 (such as a CPU chip) installed on a mainboard 7. A heat plate 9 is attached onto a heat-generating surface of the electronic heat-generating component 8, such that the heat generated by the electronic heat-generating component 8 will be absorbed by the heat plate 9, and then the vapor-liquid phase change occurred at the first tube body 10 will conduct the heat to the soft encapsulating layer 32, and then conduct the heat from the soft encapsulating layer 32 to the second tube body 20, and the heat at the second tube body 20 will be dissipated to the outside by the fin module 6. Since the flexible section 30 can be adjusted and bent to any angle, the heat pipe will not be hardened easily and the integrity of its original structure will remain, even after the pipe has been adjusted and bent repeatedly for many times.
In summation of the description above, the flexible heat pipe and the method of manufacturing the flexible heat pipe definitely can achieve the expected using purposes and overcome the shortcomings of the prior art. In addition, the invention complies with the patent application requirements, 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 flexible heat pipe, comprising:

a first tube body;

a second tube body, arranged apart from the first tube body;

a flexible section, interconnected to the first tube body and the second tube body, and including an annular elastomer and a soft encapsulating layer, and the annular elastomer being coupled to the first tube body and the second tube body, and the soft encapsulating layer being coupled to the first tube body and the second tube body and installed around an exterior of the annular elastomer;

a wick structure, installed inside the first tube body, the second tube body and the annular elastomer; and

a working fluid, filled inside the first tube body, the second tube body and the soft encapsulating layer.

2. The flexible heat pipe of claim 1, wherein the first tube body and the second tube body are vertical tubes.

3. The flexible heat pipe of claim 2, wherein the annular elastomer is a helical spring.

4. The flexible heat pipe of claim 3, wherein the soft encapsulating layer is a copper foil.

5. The flexible heat pipe of claim 4, wherein the helical spring has a free length smaller than an axial length of the copper foil, such that a receiving section is formed separately at both ends of the copper foil for passing and receiving the first tube body and the second tube body respectively.

6. A manufacturing method of a flexible heat pipe, comprising the steps of:

(a) providing a first tube body and a second tube body, both having a first wick structure;

(b) providing an annular elastomer with an end coupled to the first tube body;

(c) providing a second wick structure, passing the second wick structure into the annular elastomer and attaching the second wick to the first wick structure of the first tube body;

(d) coupling the second tube body to another end of the annular elastomer, and attaching the second wick structure to the first wick structure of the second tube body; and

(e) providing a soft encapsulating layer coupled to the first tube body and the second tube body and wrapped around an exterior of the annular elastomer.

7. The manufacturing method of a flexible heat pipe as recited in claim 6, wherein the first tube body and the annular elastomer in the Step (b) are coupled by a soldering method.

8. The manufacturing method of a flexible heat pipe as recited in claim 6, wherein the second tube body and the annular elastomer in the Step (d) are coupled by a soldering method.

9. The manufacturing method of a flexible heat pipe as recited in claim 6, wherein the soft encapsulating layer and each tube body in the Step (e) are coupled by a soldering method.

10. The manufacturing method of a flexible heat pipe as recited in claim 6, further comprising a step (f) of filling a working fluid into the second tube body, and vacuuming and sealing the first tube body and the second tube body.