U.S. patent application number 11/762996 was filed with the patent office on 2008-11-20 for heat spreader with vapor chamber and heat dissipation apparatus using the same.
This patent application is currently assigned to FOXCONN TECHNOLOGY CO., LTD.. Invention is credited to CHANG-SHEN CHANG, JUEI-KHAI LIU, HSIEN-SHENG PEI, CHAO-HAO WANG.
Application Number | 20080283222 11/762996 |
Document ID | / |
Family ID | 40026338 |
Filed Date | 2008-11-20 |
United States Patent
Application |
20080283222 |
Kind Code |
A1 |
CHANG; CHANG-SHEN ; et
al. |
November 20, 2008 |
HEAT SPREADER WITH VAPOR CHAMBER AND HEAT DISSIPATION APPARATUS
USING THE SAME
Abstract
A heat dissipation apparatus includes a heat sink (30) and a
heat spreader (10). The heat spreader includes a heating area (11)
and a cooling area (13), and defines a vapor chamber (16) therein.
A plurality of artery meshes (151) are arranged in the vapor
chamber and extend from the heating area towards the cooling area.
A working medium is contained in the artery meshes. The artery
meshes are located between wick structures (15a, 15b) attached to a
top cover (14) and a base plate (12) of the heat spreader,
respectively, and contact therewith.
Inventors: |
CHANG; CHANG-SHEN;
(Tu-Cheng, TW) ; WANG; CHAO-HAO; (Tu-Cheng,
TW) ; LIU; JUEI-KHAI; (Tu-Cheng, TW) ; PEI;
HSIEN-SHENG; (Tu-Cheng, TW) |
Correspondence
Address: |
PCE INDUSTRY, INC.;ATT. CHENG-JU CHIANG
458 E. LAMBERT ROAD
FULLERTON
CA
92835
US
|
Assignee: |
FOXCONN TECHNOLOGY CO.,
LTD.
Tu-Cheng
TW
|
Family ID: |
40026338 |
Appl. No.: |
11/762996 |
Filed: |
June 14, 2007 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
H01L 23/427 20130101;
H01L 2924/0002 20130101; H01L 2924/00 20130101; H01L 2924/0002
20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/04 20060101
F28D015/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 18, 2007 |
CN |
200710074369.7 |
Claims
1. A heat spreader comprising: a base plate; a top cover
hermetically covering the base plate; a vapor chamber defined
between the base plate and the top cover; wick structures disposed
in the vapor chamber; working medium contained in the wick
structures, wherein the wick structures comprise first and second
wicks respectively attached to a top face of the base plate and a
bottom face of the top cover; and a plurality of artery meshes
sandwiched between the first and the second wicks, the working
medium being also contained in the plurality of artery meshes.
2. The heat spreader as described in claim 1, wherein the plurality
of artery meshes are symmetrically disposed in the vapor
chamber.
3. The heat spreader as described in claim 1, wherein the plurality
of artery meshes comprise two artery meshes arranged at a middle
portion of the heat spreader, and four artery meshes extending from
a place near neighboring ends of the two artery meshes towards four
corners of the heat spreader, respectively.
4. The heat spreader as described in claim 1, wherein each of the
plurality of artery meshes is a hollow tube, a channel being
defined in a middle portion of the hollow tube and a plurality of
pores being defined in a wall of the hollow tube.
5. The heat spreader as described in claim 4, wherein a diameter of
each of the plurality of artery meshes equals to a distance between
the first and the second wicks.
6. The heat spreader as described in claim 4, wherein a diameter of
each of the plurality of artery meshes is in an approximate range
from 0.5 mm to 2 mm.
7. The heat spreader as described in claim 4, wherein each of the
plurality of artery meshes is woven from a plurality of wires
selected from copper wires, aluminum wires, stainless steel wires
and fiber wires.
8. The heat spreader as described in claim 7, wherein a diameter of
the wire is 0.05 mm, a thickness of the wall of each of the
plurality of artery meshes is 0.2 mm, and a diameter of the channel
is 1 mm.
9. The heat spreader as described in claim 1, wherein a thickness
of the heat spreader is in an approximate range from 0.5 mm to 2
mm.
10. The heat spreader as described in claim 1, wherein the first
and second wicks are selected from mesh, fiber, fine grooves,
sintered powder and carbon nanotube arrays.
11. A heat dissipation apparatus comprising: a heat sink; and a
heat spreader on which the heat sink is mounted, comprising a
heating area and a cooling area surrounding the heating area, and
defining a vapor chamber therein, a plurality of artery meshes
being arranged in the vapor chamber and extending from the heating
area outwardly towards the cooling area, wherein a working medium
is contained in the plurality of artery meshes.
12. The heat dissipation apparatus as described in claim 11,
further comprising first and second wicks disposed at top and
bottom portions of the heat spreader respectively, the plurality of
artery meshes being sandwiched between the first and the second
wicks.
13. The heat dissipation apparatus as described in claim 12,
wherein the first and second wicks are selected from mesh, fiber,
fine grooves, sintered powder and carbon nanotube arrays.
14. The heat dissipation apparatus as described in claim 11,
wherein each of the plurality of artery meshes is a hollow tube
woven from a plurality of wires selected from copper wires,
aluminum wires, stainless steel wires and fiber wires, a channel
being defined in a middle portion of the hollow tube and a
plurality of pores being defined in a wall of the hollow tube.
15. The heat dissipation apparatus as described in claim 14,
wherein a diameter of the wire is 0.05 mm, a thickness of the
sidewall of each of the plurality of artery meshes is 0.2 mm, and a
diameter of the channel is 1 mm.
16. The heat dissipation apparatus as described in claim 11,
wherein a diameter of each of the plurality of artery meshes is in
an approximate range from 0.5 mm to 2 mm.
17. The heat dissipation apparatus as described in claim 1, wherein
a thickness of the heat spreader is in an approximate range from
0.5 mm to 2 mm.
18. The heat dissipation apparatus as described in claim 11,
wherein the heat sink has a plurality of fins.
19. A heat dissipation apparatus, comprising: a heat spreader
having a base plate and a top cover hermetically connected to the
base plate, wherein wick structures are attached to a top face of
the base plate and a bottom face of the top cover, respectively, at
least an artillery mesh being located between the wick structures,
contacting therewith and extending from a place near a middle
portion of the heat spreader outward toward an edge of the heat
spreader, wherein the artillery mesh is in a form of a flexible
elongate hollow tube which is woven from a plurality of wires; and
a heat sink mounted on the top cover of the heat spreader and
thermally connecting therewith.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to heat spreaders, and more
particularly to a heat spreader having a vapor chamber for transfer
or dissipation of heat from a heat-generating component and a heat
dissipation apparatus using the same.
[0003] 2. Description of Related Art
[0004] Nowadays, heat spreaders are used in electronic products for
dissipating heat generated by electronic components such as CPUs.
Typically, the heat spreader includes a vacuum vessel defining
therein a vapor chamber, a wick structure provided in the chamber
and lining an inside wall of the vessel, and a working fluid
contained in the wick structure. The heat spreader is arranged to
have an intimate contact with the electronic component so as to
form a heating area at a middle portion of the heat spreader
corresponding to the electronic component and a cooling area at the
other portion of the heat spreader.
[0005] As the electronic component is maintained in thermal contact
with the heat spreader, the working fluid contained in the wick
structure corresponding to the heating area vaporizes. The vapor
then spreads to fill the chamber, and wherever the vapor comes into
contact with the cooling area of the vessel, it releases its latent
heat of vaporization and condenses. The condensate returns to the
heating area via a capillary force generated by the wick structure.
Thereafter, the condensate frequently vaporizes and condenses to
thereby remove the heat generated by the electronic component.
[0006] As progress continues to be made in electronics area, the
electronic components are made to be more powerful while occupying
a smaller size. Thus, the heating area needs to transfer more heat
to the cooling area of the heat spreader. In contrast, the heating
area of the heat spreader is decreased as the size of the
electronic component is decreased, and the cooling area of the heat
spreader is commensurately increased. Therefore, the heat flux
density between the heating and the cooling areas of the heat
spreader is increased. Accordingly, the wick structure needs to
have more powerful heat transfer capability. However, the wick
structure of the heat spreader selected from the conventional
types, such as mesh, fiber, fine grooves, and sintered powder,
cannot satisfy such requirement, which further limits the increase
for the heat transfer capability of the heat spreader. Therefore,
it is need to provide a heat spreader which contains a wick
structure having more powerful heat transfer capability.
SUMMARY OF THE INVENTION
[0007] The present invention relates, in one aspect, to a heat
spreader for transfer or dissipation of heat from a heat-generating
component and a heat dissipation apparatus using the same. The heat
dissipation apparatus includes a heat sink and a heat spreader. The
heat spreader includes a heating area and a cooling area, and
defines a vapor chamber therein. A plurality of artery meshes are
arranged in the vapor chamber and extend from the heating area
outwardly towards the cooling area. Wick structures are
respectively attached to a top surface of a base plate and a bottom
surface of a top cover of the heat spreader. The artery meshes are
sandwiched between the wick structures. A working medium is
contained in the artery meshes and the wick structures. In addition
to be transferred vertically upwardly to reach a heat sink on the
heat spreader by vaporization of the working medium, heat absorbed
by the heating area of the heat spreader can be transferred to the
cooling area horizontally via the artery meshes.
[0008] Other advantages and novel features of the present invention
will become more apparent from the following detailed description
of preferred embodiments when taken in conjunction with the
accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a cross-sectional view of a heat dissipation
apparatus in accordance with a preferred embodiment of the present
invention;
[0010] FIG. 2 is a cross-sectional view of a heat spreader of FIG.
1;
[0011] FIG. 3 is a top, cross-sectional view of the heat spreader
of FIG. 2, taken along line III-III thereof;
[0012] FIG. 4 is a partly enlarged view of an artery mesh of the
heat spreader of FIG. 3, in circle IV; and
[0013] FIG. 5 is an enlarged transverse view of the artery mesh of
FIG. 4, taken along line V-V thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to FIG. 1, a heat dissipation apparatus in
accordance with a preferred embodiment of the present invention is
shown. The heat dissipation apparatus is mounted on a heat
generating electronic component 20 such as a CPU (central
processing unit), a North Bridge chip, a GPU (graphic processing
unit) of a VGA card (video graphics array card) or an LED (light
emitting diode). The heat dissipation apparatus includes a heat
spreader 10 and a heat sink 30 mounted on the heat spreader 10.
[0015] The heat sink 30 is made of materials having high thermal
conductive capabilities such as copper or aluminum. The heat sink
30 includes a rectangular shaped bottom base 31 and a plurality of
fins 32 perpendicularly and upwardly extending from the bottom base
31. The bottom base 31 has an intimate contact with the heat
spreader 10 so as to absorb heat therefrom. The fins 32 dissipate
the heat absorbed from the heat spreader 10 to the surrounding
environment.
[0016] Referring to FIGS. 2 and 3, the heat spreader 10 has a flat
type configuration and is rectangular shaped when viewed from
above. The heat spreader 10 includes a rectangular shaped base
plate 12, a top cover 14 covering the base plate 12, and wick
structures 15 disposed in a sealed vapor chamber 16 defined between
the base plate 12 and the top cover 14. The base plate 12 and the
top cover 14 are made of the materials having high thermal
conductive capabilities, such as copper or aluminum. The top cover
14 includes a flat covering plate 141 parallel to the base plate
12, four sidewalls 142 perpendicularly and downwardly extending
from a periphery of the covering plate 141, and four joint plates
140 horizontally extending from free ends of the sidewalls 142. A
thickness of the heat spreader 10 is determined by a height of the
sidewall 142 and thicknesses of the base plate 12 and the covering
plate 141, and is preferably between about 2 and about 3.5
millimeters (mm). In this embodiment, the thickness of the heat
spreader 10 is 3 mm. The joint plates 140 are welded to a periphery
120 of the base plate 12 so as to form the sealed vapor chamber 16
between the base plate 12 and the top cover 14. The vapor chamber
16 of the heat spreader 10 is evacuated to form a vacuum and a
working medium is contained in the wick structures 15. The working
medium can be selected from a liquid such as water, alcohol, or
methanol, which has lower boiling point and is compatible with the
wick structures 15. In this embodiment, the working medium is
water.
[0017] The heat generating electronic component 20 is disposed
under and has an intimate contact with a central portion of the
base plate 12. A substantially rectangular shaped heating area 11
is formed at the central portion of the heat spreader 10, absorbing
heat from the heat generating electronic component 20. A cooling
area 13 is formed at the other portion of the heat spreader 10 and
surrounds the heating area 11, transferring the heat to the heat
sink 30 and dissipating the heat to the surrounding environment.
That is, the cooling area 13 directly dissipates the heat to the
surrounding environment at a bottom of the heat spreader 10, and
transfers the heat to the heat sink 30 at a top thereof.
[0018] The wick structures 15 includes first and second wicks 15a,
15b respectively attached to the base plate 12 and the covering
plate 141, and six artery meshes 151 sandwiched between the first
and the second wicks 15a, 15b. The first and the second wicks 15a,
15b are selected from mesh, fiber, fine grooves, sintered powder,
carbon nanotube arrays and composite of such wicks. The artery
meshes 151 are symmetrically disposed at two opposite sides of the
heating area 11. As viewed from above, the artery meshes 151
radially extend from the central portion (heating area 11) of the
heat spreader 10 towards a periphery (corners of the cooling area
13) thereof. Two of the artery meshes 151 are arranged at a middle
portion of heat spreader 10 and are in line with each other, and
the other four artery meshes 151 extend from corners of the heating
area 11 towards corners of the cooling area 13 of the heat spreader
10. That is, each of the artery mesh 151 has an inner end 1513
located at the heating area 11 of the heat spreader 10 and an outer
end 1514 located at the cooling area 13 thereof. Therefore, the
working medium can move horizontally between the heating and the
cooling areas 11, 13 of the heat spreader 10 via capillary forces
generated by the artery meshes 151.
[0019] Referring to FIGS. 4 and 5, the artery mesh 151 is a
flexible elongate hollow tube which is woven from a plurality of
metal wires such as copper wires, aluminum wires, or stainless
steel wires. Alternatively, the artery mesh 151 can also be woven
from a plurality of fiber wires. In this embodiment, the artery
mesh 151 is woven from a plurality of copper wires. A diameter of
the copper wire can be about 0.05 mm. A plurality of pores are
defined in a wall 1512 of the artery mesh 151. The pores
communicate the artery meshes 151 with the first and the second
wicks 15a, 15b so that the working medium can move between top and
bottom portions of the heat spreader 10. That is, the working
medium can move between the first and the second wicks 15a, 15b via
capillary forces generated by the artery meshes 151. The artery
mesh 151 has an annular cross section and a channel 1510 is defined
in a middle portion of the artery mesh 151. A diameter of the
channel 1510 is preferably from 0.5 mm to 2 mm. The diameter of the
channel 1510 is 1 mm in this embodiment. A diameter of an outer
surface of the artery mesh 151 substantially equals a distance
between the first and the second wicks 15a, 15b, so that the artery
mesh 151 has intimate contact with the first and the second wicks
15a, 15b. A thickness of the wall 1512 of the artery mesh 151 is
determined by the amount and the diameter of the wires. In this
embodiment, the thickness of the wall 1512 of the artery mesh 151
is about 0.2 mm.
[0020] In operation of the heat dissipation apparatus, the working
fluid contained in the second wick 15b corresponding to the heating
area 11 vaporizes due to the heat absorbed from the heat generating
electronic component 20. The vapor then spreads to fill the vapor
chamber 16, and wherever the vapor comes into contact with the
cooling area 13 of the heat spreader 10, it releases its latent
heat of vaporization and condenses. The vapor moves vertically
upwardly to transfer the heat to the heat sink 30. Furthermore, the
vapor moves horizontally along the channels 1510 of the artery
meshes 151 to transfer the heat to the cooling area 13 of the heat
spreader 10. The heat is therefore directly dissipated to the
surrounding environment at the bottom of the heat spreader 10 and
evenly transferred to the heat sink 30 at the top thereof, which
further dissipates the heat to the surrounding environment. The
condensate returns to the heating area 11 due to the capillary
forces generated by the artery meshes 151 and the first and the
second wicks 15a, 15b. Thereafter, the condensate continues to
vaporize and condense, thereby removing the heat generated by the
heat generating electronic component 20.
[0021] In the present heat spreader 10, the artery mesh 151 helps
the working medium at the cooling area 13 of the heat spreader 10
to move towards the heating area 11 thereof. That is, the artery
mesh 151 helps the working medium to horizontally move in the heat
spreader 10. This increases the heat transfer capability of the
heat spreader 10. Furthermore, the artery mesh 151 also helps the
working medium at the top portion of the heat spreader 10 to move
towards the bottom portion thereof. That is, the artery mesh 151
helps the working medium to perpendicularly move in the heat
spreader 10. This further increases the heat transfer capability of
the heat spreader 10.
[0022] It is to be understood, however, that even though numerous
characteristics and advantages of the present invention have been
set forth in the foregoing description, together with details of
the structure and function of the invention, the disclosure is
illustrative only, and changes may be made in detail, especially in
matters of shape, size, and arrangement of parts within the
principles of the invention to the full extent indicated by the
broad general meaning of the terms in which the appended claims are
expressed.
* * * * *