US20080185128A1

US20080185128A1 - Flat Plate-Type Heat Pipe

Info

Publication number: US20080185128A1
Application number: US11/815,364
Authority: US
Inventors: Seok Hwan Moon; Gunn Hwang; Sang Choon KO; Sung Weon Kang; Chang Auck Choi
Original assignee: Individual
Current assignee: Electronics and Telecommunications Research Institute ETRI
Priority date: 2005-04-19
Filing date: 2006-01-10
Publication date: 2008-08-07
Also published as: WO2006112586A1; KR100631050B1; JP2008531966A; TWI297766B; TW200638016A

Abstract

Provided is a flat plate-type heat pipe formed of a flat pipe having a predetermined through-hole formed therein and a plurality of grooves extending from an inner surface of the through-hole in a longitudinal direction so that, while the interior of the heat pipe is in a vacuum state, heat in the heat pipe is discharged to the exterior due to a phase change of between liquid and gaseous states of working fluid and the working fluid flows by a capillary force produced from the plurality of grooves, whereby it is possible to obtain a strong capillary force and an excellent cooling effect while it is manufactured through a simple process.

Description

TECHNICAL FIELD

The present invention relates to a flat plate-type heat pipe and, more particularly, to a fine structure of flat plate-type heat pipe which is formed of a flat pipe having a predetermined through-hole formed therein and a plurality of grooves having at least one corner formed at an inner surface of the through-hole such that a liquid working fluid flows by a capillary force produced in the corners, whereby it is possible to improve thermal performance, to increase productivity by manufacturing the heat pipe using a simple process, and to employ to a compact and thin electronic device.

BACKGROUND ART

In general, chips and systems packaged in an electronic device have been highly integrated and miniaturized as semiconductor manufacturing technology is developed. According to the tendency, since heat density of components included in the electronic device is remarkably increased, it is required to employ a cooling system capable of effectively dissipating the heat density. Specially, since the electronic device is thinned together with the miniaturization thereof, the cooling system should be also miniaturized.
Conventional cooling systems such as a heat sink, fan, compact heat pipe of a circular cross-section having a diameter larger than 3mm, and so on are applicable to the miniaturized electronic device.
The heat sink has been widely used as a basic structure of a cooling means since it can be freely manufactured regardless of its size and thickness. However, when it is required for the heat sink to have a very small size, heat dissipation may be relatively decreased due to a reduction of a heat transfer area.
It is difficult for the fan to be manufactured in a small size, and therefore, reliability of the fan may be decreased.
The miniaturized heat pipe of a circular cross-section having a diameter larger than 3mm may be used to be adapted to a thin layer structure. However, since the miniaturized heat pipe is designed to have a circular cross-section, when it is pressed to be adapted to the miniaturized and thin electronic device, the heat transfer performance may be largely decreased due to a structure change of wick, and so on.
Therefore, a fine heat pipe having a diameter smaller than 3mm is required to be adapted to the miniaturized and thin electronic device.

DISCLOSURE OF INVENTION

TECHNICAL PROBLEM

The present invention is directed to a flat plate-type heat pipe formed of a flat pipe having a predetermined through-hole formed therein and a plurality of grooves having at least one corner formed at an inner surface of the through-hole so that a liquid working fluid flows by a capillary force produced in the corners, whereby it is possible to improve thermal performance, to increase productivity by manufacturing the heat pipe using a simple process, and to be adapted to a compact and thin electronic device.

TECHNICAL SOLUTION

One aspect of the present invention is to provide a fine structure of flat plate-type heat pipe formed of a flat pipe having a predetermined through-hole formed therein and a plurality of grooves extending from an inner surface of the through-hole in a longitudinal direction so that, while the interior of the heat pipe is in a vacuum state, heat in the heat pipe is discharged to the exterior due to a phase change of between liquid and gaseous states of working fluid, and the working fluid flows by a capillary force produced from the plurality of grooves.
In this process, preferably, the heat pipe further includes a separation layer for forming a plurality of flow paths in the through-hole.
Preferably, each of the plurality of grooves has at least one corner from which the capillary force is produced.

ADVANTAGEOUS EFFECTS

As can be seen from the foregoing, the flat plate-type heat pipe in accordance with the present invention is formed of a flat pipe having a predetermined through-hole formed therein and a plurality of grooves having at least one corner formed at an inner surface of the through-hole so that a liquid working fluid is flowed by a capillary force produced from the corner, whereby it is possible to obtain a strong capillary force through structural modification of the heat pipe itself, without installing a separate wick for flowing the liquid working fluid in the heat pipe, and to improve thermal performance, to increase productivity by manufacturing the heat pipe using a simple process, and to be adapted to a compact and thin electronic device.
In addition, in accordance with the present invention, it is possible to form a plurality of flow paths in one flat plate-type heat pipe by forming a plurality of separation layers in the flat plate-type heat pipe.
Further, in accordance with the present invention, it is very advantageous to more obtain an inner vapor flow space to improve heat transfer performance in comparison with the conventional heat pipe having the same thickness.
Although the present invention has been described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that a variety of modifications and variations may be made to the present invention without departing from the spirit or scope of the present invention defined in the appended claims, and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a first exemplary embodiment of the present invention;

FIG. 2 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a second exemplary embodiment of the present invention;

FIG. 3 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a third exemplary embodiment of the present invention;

FIG. 4 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a fourth exemplary embodiment of the present invention; and

FIG. 5 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a fifth exemplary embodiment of the present invention.

MODE FOR THE INVENTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. Like reference numerals designate like elements throughout the specification.
FIG. 1 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a first exemplary embodiment of the present invention.
Referring to FIG. 1, the flat plate-type heat pipe in accordance with the first embodiment of the present invention is formed of a body 100 having a flat plate shape.
Preferably, the flat body 100 is made of a metal pipe manufactured using an extrusion process.
In addition, the body 100 has a predetermined through-hole 105 through which a working fluid introduced from the exterior flows.
A plurality of grooves 110 having a rectangular section and extending in a longitudinal direction of the through-hole 105 are formed in an inner surface of the through-hole 105.
Corners 115 are formed at lower sides of the rectangular section grooves 110 to produce a capillary force such that the liquid working fluid flows.
Additionally, a plurality of separation layers 120 may be formed in the through-hole 105 to form a plurality of flow paths.
As described above, the flat plate-type heat pipe in accordance with the first embodiment of the present invention is capable of flowing the liquid working fluid using the capillary force produced at the corners 115 of the respective rectangular section grooves 110, without using the conventional wick functioning as a passageway allowing the liquid working fluid to be flowed (returned) from a condenser section to an evaporation section. That is, the corners 115 of the rectangular section grooves 110 can function as the conventional wick.
In addition, the flat plate-type heat pipe in accordance with the first embodiment of the present invention is capable of discharging inner heat to the exterior using a phase change between liquid and gaseous states of the liquid working fluid injected into the heat pipe in the state that the heat pipe is in a vacuum state.
FIG. 2 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a second exemplary embodiment of the present invention.
Referring to FIG. 2, the flat plate-type heat pipe in accordance with the second embodiment of the present invention is formed of a body 200 having a flat pipe shape, similar to that of the first embodiment.
The body 200 has a predetermined through-hole 205 through which a working fluid introduced from the exterior flows, and a plurality of grooves 210 having a V-shaped cross-section and extending in a longitudinal direction of the through-hole 205 are formed in an inner surface of the through-hole 205.
Corners 215 are formed at lower sides of the V-shaped grooves 210 to produce a capillary force such that the liquid working fluid flows.
Additionally, a plurality of separation layers 220 may be formed in the through-hole 205 to form a plurality of flow paths.
Meanwhile, since the flat plate-type heat pipe in accordance with the second embodiment of the present invention has the same function and effect as the first embodiment of the present invention, the description of the second embodiment will not be repeated.
FIG. 3 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a third exemplary embodiment of the present invention.
Referring to FIG. 3, the flat plate-type heat pipe in accordance with a third exemplary embodiment of the present invention is formed of a body 300 having a flat pipe shape, similar to that of the first embodiment of the present invention.
The body 300 has a predetermined through-hole 305 through which a working fluid introduced from the exterior flows, and a plurality of grooves 310 having a trapezoid or dovetail cross-section (
) with an upper width smaller than a lower width and extending in a longitudinal direction of the through-hole 305 are formed in an inner surface of the through-hole 305.
Corners 315 are formed at lower sides of the trapezoid or dovetail grooves 310 to produce a capillary force such that the liquid working fluid flows.
Additionally, a plurality of separation layers 320 may be formed in the through-hole 305 to form a plurality of flow paths.
Meanwhile, since the flat plate-type heat pipe in accordance with the third embodiment of the present invention has the same function and effect as the first embodiment of the present invention, the description of the third embodiment will not be repeated.
FIG. 4 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a fourth exemplary embodiment of the present invention.
Referring to FIG. 4, the flat plate-type heat pipe in accordance with the fourth embodiment of the present invention is formed of a body 400 having a flat pipe shape, similar to that of the first embodiment of the present invention.
The body 400 has a predetermined through-hole 405 through which a working fluid introduced from the exterior flows, and a plurality of grooves 410 having a “
”-shaped cross-section and extending in a longitudinal direction of the through-hole 405 are formed in an inner surface of the through-hole 405.
Sharp corners 415 are formed at lower sides of the “
”-shaped grooves 410 to produce a capillary force such that the liquid working fluid flows.
Additionally, a plurality of separation layers 420 may be formed in the through-hole 405 to form a plurality of flow paths.
Meanwhile, since the flat plate-type heat pipe in accordance with the fourth embodiment of the present invention has the same function and effect as the first embodiment of the present invention, the description of the fourth embodiment will not be repeated.
FIG. 5 is an enlarged perspective view of a flat plate-type heat pipe in accordance with a fifth exemplary embodiment of the present invention.
Referring to FIG. 5, the flat plate-type heat pipe in accordance with the fifth embodiment of the present invention is formed of a body 500 having a flat pipe shape, similar to that of the first embodiment of the present invention.
The body 500 has a predetermined through-hole 505 through which a working fluid introduced from the exterior flows, and a plurality of grooves 510 having a “
”-shaped cross-section and extending in a longitudinal direction of the through-hole 505 are formed in an inner surface of the through-hole 505.
Sharp corners 515 are formed at lower sides of the “
”-shaped grooves 510 to produce a capillary force such that the liquid working fluid flows.
Additionally, a plurality of separation layers 520 may be formed in the through-hole 505 to form a plurality of flow paths.
Meanwhile, since the flat plate-type heat pipe in accordance with the fifth embodiment of the present invention has the same function and effect as the first embodiment of the present invention, the description of the fifth embodiment will not be repeated.
As described above, since the flat plate-type heat pipe in accordance with the first to fifth embodiments of the present invention having a diameter smaller than 3mm has excellent heat dissipation and heat transfer performance, it can be effectively used as a cooling means for the small and thin electronic device.
While the grooves 110 to 510 adapted to the first to fifth embodiments of the present invention have the rectangular, V-shaped, trapezoid (
), “
” and “
” cross-sections, but not limited thereto, the grooves may be variously modified to have at least one corner.

Claims

1. A flat plate-type heat pipe including: a flat pipe having a predetermined through-hole formed therein; and a plurality of grooves extending from an inner surface of the through-hole in a longitudinal direction, wherein, while the interior of the heat pipe is in a vacuum state, heat in the heat pipe is discharged to the exterior due to a phase change of between liquid and gaseous states of working fluid, and the working fluid flows by a capillary force produced from the plurality of grooves.

2. The flat plate-type heat pipe according to claim 1, further comprising a separation layer for forming a plurality of flow paths in the through-hole.

3. The flat plate-type heat pipe according to claim 1, wherein each of the plurality of grooves has at least one corner from which the capillary force is produced.