US20150176916A1

US20150176916A1 - Flat mesh wick structure of ultrathin heat pipe and ultrathin heat pipe having the same

Info

Publication number: US20150176916A1
Application number: US14/180,185
Authority: US
Inventors: Hao Pai
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-12-25
Filing date: 2014-02-13
Publication date: 2015-06-25
Also published as: TW201525398A; CN203672207U; CN104748596A

Abstract

A flat mesh wick structure of an ultrathin heat pipe and an ultrathin heat pipe having the same are provided in the present disclosure. The mesh wick structure is included of a plurality of braided wires, and each of the braided wires is included of a plurality of intercrossed segments arranged at interval and a plurality of connecting segments connected between the adjacent intercrossed segments, wherein the intercrossed segment of each braided wire is of a flat shape. The flat mesh wick structure is constituted thereby.

Description

BACKGROUND

The present disclosure is related to a screen mesh wick structure, and particularly a flat mesh wick structure of an ultrathin heat pipe and an ultrathin heat pipe having the same.

DESCRIPTION OF RELATED ART

The majority of current 3C electronic products are designed to be compact, and heat pipes arranged therein are accordingly compact. Therefore, ultrathin heat pipes (thickness less than 1.5 mm) are engineered for this requirement.
However, thin wick structures have to be arranged in the ultrathin heat pipe, as a result of the slim ultrathin heat pipe. Otherwise, the ultrathin heat pipe does not contain enough inner space to form a vapor channel. A related art ultrathin heat pipe shown in FIG. 1 includes a tube 1 a and a wick structure 2 a arranged in the tube 1 a. The tube 1 a includes a bottom wall 10 a, an upper wall 11 a arranged opposite to and at interval with the bottom wall 10 a, and two lateral walls 12 a connected between the bottom wall 10 a and the upper wall 11 a. The tube 1 a allows the wick structure 2 a arranged therein and attached on an internal surface of the bottom wall 10 a. If a thickness T of the tube 1 a is less than 0.4 mm, a height H of an inner space in the tube 1 a is approximately 0.2 mm (not counting thickness of the bottom wall 10 a and the upper wall 11 a, which are both approximately 0.1 mm). The related art heat pipe shown in FIG. 2 ordinarily includes pure copper mesh wick structures 2 d consisted of braided metal wires with diameter d of 0.05 mm. The total thickness of the braided mesh is approximately 0.11 mm, and is reached the state-of-art limitation of minimum thickness for braid mesh.
If the wick structure 2 a is arranged in the tube 1 a as a cylinder and attached on the internal surface of the tube, the tube 1 a will be choked by the wick structure 2 a, and there will be no redundant space to form a vapor channel allowing a vapored working fluid flowing therein. Therefore, the ultrathin heat pipe is not able to transfer heat.
If the wick structure 2 a is arranged in the tube 1 a and attached on both of the bottom wall 10 a and the upper wall 11 a, a vapor channel with a height (H-t) less than 0.1 mm is formed in the tube 1 a. That results to high flow drag and steep gradient of temperature, and only a poor heat transfer performance of the ultrathin heat pipe is achieved as well.
In views of this, in order to solve the above disadvantage, the present inventor studied related technology and provided a reasonable and effective solution in the present disclosure.

SUMMARY

A main purpose of the present disclosure is providing a flat mesh wick structure of ultrathin heat pipe and an ultrathin heat pipe having the same. A braded mesh wick structure is squeezed to form a flat shape, and the flat mesh wick structure is formed thereby. The flat mesh wick structure is applied to be arranged at bilateral or as a stake in the ultrathin heat pipe, and a wick transfer performance of the ultrathin heat pipe is thereby enhance.
Another purpose of the present disclosure is providing a flat mesh wick structure of ultrathin heat pipe and ultrathin heat pipe having the same. The flat mesh wick structure is able to enlarge contacting area with the internal surface of the tube. Compared with non-squeezed mesh wick structure having contact points with the internal surface of a flat tube, the flat mesh wick structure has contact plates with the internal surface of the flat tube is more fit with internal surface of the flat tube. Thereby, less thermal resistance and fewer apertures are produced between the flat mesh wick structure and the internal surface of the flat tube. Therefore, the flat mesh wick structure has better wicking performance than that conventional.
Another purpose of the present disclosure is providing a flat mesh wick structure of ultrathin heat pipe and ultrathin heat pipe having the same. Owning to be squeezed, the flat mesh wick structure is reinforced. Thereby, the flat mesh wick structure is liable to be located in the flat tube. In order to accomplish the above purpose, a flat mesh wick structure of an ultrathin heat pipe is provided in the present invention. The flat mesh wick structure is included of a plurality of braided wires. Each of the braided wire is included of a plurality of intercrossed segments arranged at interval and a plurality of connecting segments connected between the adjacent intercrossed segments. The intercrossed segment of each braided wire is of a flat shape.
In order to accomplish the above purpose, an ultrathin heat pipe is provided in the present invention. The ultrathin heat pipe is included of a flat tube and the flat mesh wick structure mentioned above. The flat tube is included a vapor channel therein, and the flat mesh wick structure is arranged in the vapor channel of the flat tube.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a sectional view showing a conventional mesh arranged in an ultrathin heat pipe.

FIG. 2 is a drawing of partial enlargement showing the mesh in FIG. 1.

FIG. 3 is a schematic diagram showing a part of the present disclosure.

FIG. 4 is a sectional view showing a part of the present disclosure.

FIG. 5 is a sectional view showing the present disclosure arranged in a flat tube.

FIG. 6 is a sectional view showing another embodiment of the present disclosure arranged in the flat tube.

DETAILED DESCRIPTION OF EMBODIMENT

Please refer to enclosed figures and specification of the present disclosure to understand features and technological content thereof. However, the figures and specification are not limitations of the present disclosure.
Please refer to FIGS. 3 and 4, these figures showing a schematic diagram and a sectional view of a part the present disclosure. A flat mesh wick structure of an ultrathin heat pipe and an ultrathin heat pipe having the same are disclosed in the present disclosure. The mesh wick structure (1) includes a plurality of braided wires (10, 10′) braided along two directions intercrossed with each other. In an embodiment of the present disclosure, first braided wires (10) are arranged along a first direction, second braided wires (10′) are arranged along a second direction, and the first and second braided wires (10, 10′) are braided intercrossed with each other. The braided wires (10, 10′) are preferably made of metal such as copper.
Each of the braided wires (10, 10′) is of a strip shape and includes a plurality of intercrossed segments (11, 11′) arranged at interval and a plurality of connecting segments (12, 12′) connected between the adjacent intercrossed segments (11, 11′). The braided wires (10, 10′) are braided to form the mesh wick structure (1), and then the mesh wick structure (1) is squeezed to form a flat external surface (110, 110′) on each intercrossed segment (11, 11′) of each braided wire (10, 10′). Please further refer to FIG. 4. In addition to the flat external surface (110, 110′) formed on each intercrossed segment (11, 11′) of each braided wires (10, 10′), a flat intercrossed surface (111, 111′) is formed on each intercrossed segment (11, 11′) intercrossed with each other between braided wires (10, 10′) intercrossed with each other. The intercrossed surfaces (111, 111′) are arranged opposite to the external surfaces (110, 110′), and the intercrossed surface (111, 111′) of each braided wires (10, 10′) are attached with each other. Therefore, the cross section of the intercrossed segment (11, 11′) of each braided wire (10, 10′) is of a flat shape. Thereby, an interval between the external surfaces (110, 110′) (a thickness (t) of the wick structure (1)) of the intercrossed segments (11, 11′) of the intercrossed squeezed braided wires (10, 10′) is reduced. In other words, the thickness (t) of the wick structure (1) is significantly reduced to be approximately less than 0.05 mm. The wick structure (1) could be squeezed by a plate mold or a roller to reduce the thickness thereof.
Thereby, the flat mesh wick structure of ultrathin heat pipe and the ultrathin heat pipe having the same of the present disclosure can be thus realized.
The above mesh wick structure (1) is arranged in a flat tube (2) of the ultrathin heat pipe. The flat tube (2) includes a bottom wall (20), an upper wall (21) opposite to the bottom wall (20) and arranged at interval with the bottom wall (20), and a two lateral walls (22) connected between the bottom wall (20) and the upper wall (21). A vapor channel (23) is formed in the flat tube (2) by the bottom wall (20), the upper wall (21) and the lateral walls (22). Because the mesh wick structure (1) is squeezed to be less the 0.05 mm and attached on an internal surface of the bottom wall (20), a redundant space with at least 0.15 mm height (h) can be reserved in the flat tube (2) while the thickness of the flat tube (2) is kept to be 0.4 mm. Therefore, an internal space of the vapor channel (23) with sufficient height is provided to allow vapor flows smoothly therein. Moreover, the vapor channel (23) can be formed with another mesh wick structure (not be shown in figures) being attached on the internal surface of the upper wall (21) or with the mesh wick structure (1) being arranged at a stack (not be shown in figures).
Furthermore, because the vapor channel (23) could be formed with a sufficient height, the mesh wick structure (1) can further be combined with another supporting or wick structure (such as sintered powder, mesh, fiber or the combinations thereof) as shown in FIG. 6. For example, one or more supporting wick structure (13) consisting of sintered powder could be arranged on the mesh wick structure (1). The supporting wick structure (13) is in contact with only a part of the mesh wick structure (1) and the upper wall (21), and a space is reserved at both sides thereof for vapor channel (23). The mesh wick structure (1) could be arranged at a part in the flat tube (2).
Therefore, the flat mesh wick structure of ultrathin heat pipe and the ultrathin heat pipe having the same of the present disclosure have at least below advantages resulting to a better performance of the ultrathin heat pipe.
1. The flat mesh wick structure is able to reserve sufficient space in the vapor channel 23 of the ultrathin heat pipe to allow the working fluid flowing therein or the arrangement of another wick structure therein.
2. There are more contact area formed between the mesh wick structure (1) and the flat tube (2) owning to the squeezed braided wires (10, 10′). Compared with the contact points between related art braided wires and the flat tube (2), the squeezed braided wires (10, 10′) can be attached on the flat tube (2) more compactly. Thereby, less thermal resistance and more capillary force are achieved in the ultrathin heat pipe.
3. The squeezed braided wire (10, 10′) is firmer than the non-squeezed one. Thereby, the mesh wick structure (1) is reinforced, and more easily arranged into the flat tube (2).
Although the present invention has been described with reference to the foregoing preferred embodiment, 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

What is claimed is:

1. A flat mesh wick structure of an ultrathin heat pipe, the flat mesh wick structure comprising:

a plurality of braided wires, each of the braided wires comprising a plurality of intercrossed segments arranged at interval and a plurality of connecting segments connected between the adjacent intercrossed segments;

wherein each intercrossed segment of each braided wire is of a flat shape.

2. The flat mesh wick structure of an ultrathin heat pipe according to claim 1, wherein a flat external surface is formed on the intercrossed segment of each braided wire.

3. The flat mesh wick structure of an ultrathin heat pipe according to claim 2, wherein a flat intercrossed surface is formed on the intercrossed segment of each braided wire, and the intercrossed surfaces are arranged opposite to the external surfaces.

4. The flat mesh wick structure of an ultrathin heat pipe according to claim 3, wherein the braided wires are respectively arranged along a first direction and a second direction to intercross with each other, and the intercrossed surfaces of any two intercrossed braided wires are attached to each other.

5. The flat mesh wick structure of an ultrathin heat pipe according to claim 4, wherein an interval between the external surfaces of two intercrossed braided wires is less than 0.05 mm.

6. An ultrathin heat pipe, comprising:

a flat tube having a vapor channel therein; and

a mesh wick structure arranged in the vapor channel of the flat tube and comprising a plurality of braided wires, each of the braided wires comprising a plurality of intercrossed segments arranged at interval and a plurality of connecting segments connected between the adjacent intercrossed segments;

wherein the intercrossed segment of each braided wire is of a flat shape.

7. The ultrathin heat pipe according to claim 6, wherein a flat external surface is formed on the intercrossed segment of each braided wire.

8. The ultrathin heat pipe according to claim 7, wherein a flat intercrossed surface is formed on the intercrossed segment of each braided wire, and the intercrossed surfaces are arranged opposite to the external surfaces.

9. The ultrathin heat pipe according to claim 8, wherein the braided wires are arranged along a first direction and a second direction to intercross with each other, and the intercrossed surfaces of any two intercrossed braided wires are attached to each other.

10. The ultrathin heat pipe according to claim 9, wherein the interval between the external surfaces of two intercrossed braided wires is less than 0.05 mm.

11. The ultrathin heat pipe according to claim 10, wherein the flat tube is comprised of a bottom wall, an upper wall arranged opposite to and at interval with the bottom wall, and two lateral walls connected between the bottom wall and the upper wall, the vapor channel is surrounded and formed thereby.

12. The ultrathin heat pipe according to claim 11, wherein the mesh wick structure is attached on an internal surface of the bottom wall.

13. The ultrathin heat pipe according to claim 12, wherein the mesh wick structure is comprised of at least one supporting wick structure, the supporting wick structure is arranged on the mesh wick structure, and the supporting wick structure is contacted only a part of the mesh wick structure and the upper wall.

14. The ultrathin heat pipe according to claim 13, wherein the supporting wick structure is made of at least one of the group consisted of sintered powder, mesh and fiber.

15. The ultrathin heat pipe according to claim 12, wherein only a part in the flat tube is occupied by the mesh wick structure.