U.S. patent application number 13/723118 was filed with the patent office on 2014-06-26 for heat dissipation device.
This patent application is currently assigned to ASIA VITAL COMPONENTS CO., LTD.. The applicant listed for this patent is ASIA VITAL COMPONENTS CO., LTD.. Invention is credited to Chih-Yeh Lin.
Application Number | 20140174704 13/723118 |
Document ID | / |
Family ID | 50973304 |
Filed Date | 2014-06-26 |
United States Patent
Application |
20140174704 |
Kind Code |
A1 |
Lin; Chih-Yeh |
June 26, 2014 |
HEAT DISSIPATION DEVICE
Abstract
A heat dissipation device includes a first board body and a
second board body. The first board body has a first face and a
second face. The second face is formed with a rough structure. The
second board body has a third face and a fourth face. The fourth
face is mated with the second face and covered by the second face.
The second and fourth faces together define a chamber. A working
fluid is filled in the chamber. The rough structure is coated with
a coating. By means of the rough structure and the coating, the
cost for the heat dissipation device is reduced and the thermal
resistance of the heat dissipation device is lowered.
Inventors: |
Lin; Chih-Yeh; (New Taipei
City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ASIA VITAL COMPONENTS CO., LTD. |
New Taipei City |
|
TW |
|
|
Assignee: |
ASIA VITAL COMPONENTS CO.,
LTD.
New Taipei City
TW
|
Family ID: |
50973304 |
Appl. No.: |
13/723118 |
Filed: |
December 20, 2012 |
Current U.S.
Class: |
165/185 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 23/427 20130101; F28D 15/0233 20130101; H01L 2924/00 20130101;
H01L 2924/0002 20130101 |
Class at
Publication: |
165/185 |
International
Class: |
F28F 99/00 20060101
F28F099/00 |
Claims
1. A heat dissipation device comprising: a first board body having
a first face and a second face, the second face being formed with a
rough structure; and a second board body having a third face and a
fourth face, the fourth face of the second board body being mated
with the second face of the first board body and covered by the
second face, the second and fourth faces together defining a
chamber, a working fluid being filled in the chamber.
2. The heat dissipation device as claimed in claim 1, wherein a
heat source is attached to the third face.
3. The heat dissipation device as claimed in claim 2, wherein the
rough structure of the second face or the fourth face is coated
with a coating.
4. The heat dissipation device as claimed in claim 3, wherein both
the rough structure of the second face and the fourth face are
coated with coatings.
5. The heat dissipation device as claimed in claim 4, wherein the
second face is partially or totally formed with the rough
structure.
6. The heat dissipation device as claimed in claim 5, wherein the
second face is partially formed with the rough structure and the
rough structure is positioned right above the heat source.
7. The heat dissipation device as claimed in claim 3, wherein the
coating is a hydrophilic coating or a hydrophobic coating.
8. The heat dissipation device as claimed in claim 1, wherein the
working fluid is selected from a group consisting of pure water,
methanol, acetone, coolant and ammonia.
9. The heat dissipation device as claimed in claim 6, wherein the
rough structure of the second face is a capillary structure with
micro-channels, the capillary structure being formed by means of
mechanical processing or etching.
10. The heat dissipation device as claimed in claim 9, wherein the
mechanical processing is stamping, marking or sculpturing.
11. The heat dissipation device as claimed in claim 1, wherein the
rough structure has a recessed/raised form, a waved form or a
saw-toothed form.
12. The heat dissipation device as claimed in claim 1, wherein the
second board body has a capillary structure formed on the fourth
face.
13. The heat dissipation device as claimed in claim 12, wherein the
capillary structure is selected from a group consisting of
channeled structure, sintered powder body and mesh body.
14. The heat dissipation device as claimed in claim 1, wherein at
least one support pillar is disposed in the chamber, two ends of
the support pillar being respectively connected to the second face
and the fourth face, a capillary structure being disposed on an
outer surface of the support pillar.
15. The heat dissipation device as claimed in claim 14, wherein the
capillary structure is selected from a group consisting of
channeled structure, sintered powder body and mesh body.
16. The heat dissipation device as claimed in claim 3, wherein the
coating is a dioxide silicon coating.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a heat
dissipation device, and more particularly to a heat dissipation
device, which is manufactured at lower cost and has greatly lowered
thermal resistance.
[0003] 2. Description of the Related Art
[0004] Along with the rapid advance of scientific and technologic
industries, electronic devices have more and more powerful
functions. For example, the operation speed of central processing
unit (CPU), chip set and electronic components of display unit has
become faster and faster. This leads to higher heat generated by
the electronic components per unit time. In case that the heat is
not dissipated in time, the operation of the entire electronic
device will be affected or even the electronic components will burn
out.
[0005] In general, the heat generated by the electronic components
is dissipated by means of cooling fan, heat sink or heat pipe. The
heat sink is in contact with a heat source. Via the heat pipe, the
heat generated by the heat source is transferred to a remote end
for dissipating the heat. Alternatively, the cooling fan can
forcedly guide airflow to carry away the heat of the heat sink.
With respect to a narrow space or a large-area heat source, a vapor
chamber is often selectively used as a heat conduction member for
dissipating the heat.
[0006] A conventional vapor chamber is composed of two board
materials mated with each other. The mating faces of the board
materials are formed with capillary structures (such as channeled
structures, mesh structures or sintered bodies or a combination
thereof). The board materials are mated with each other to define a
closed chamber in a vacuum state. A working fluid is filled in the
chamber. In order to increase the capillary limit, the board
materials are supported by coated copper pillars, sintered pillars
or foamed pillars as backflow passages. When the liquid working
fluid in the evaporation section of the vapor chamber is heated,
the liquid working fluid is evaporated into vapor phase. After the
vapor working fluid flows to the condensation section of the vapor
chamber, the vapor working fluid is condensed into liquid phase.
The liquid working fluid then flows back to the evaporation section
through the copper pillars. Accordingly, the working fluid is
circularly used. After the vapor working fluid in the condensation
section is condensed into liquid working fluid in the form of small
water beads, due to gravity or capillary attraction, the working
fluid can flow back to the evaporation section.
[0007] However, in the conventional vapor chamber, the backflow
speed of the working fluid is too slow. This often leads to vacant
combustion or poor thermal homogeneity. As a result, the working
fluid can be hardly effectively transformed between liquid phase
and vapor phase for heat exchange. In design, the capillary
attraction of the capillary structure to the liquid working fluid
can be increased to speed the backflow of the liquid working fluid.
In this case, the heat transfer performance of the vapor chamber
can be effectively enhanced. However, conventionally, the capillary
attraction and the fluid resistance are two design factors
conflicting with each other. In consideration of increase of the
capillary attraction, it is necessary to provide a capillary
structure with smaller voids. However, the smaller voids will apply
greater resistance against the fluid to hinder the working fluid
from flowing back to the evaporation section.
[0008] Reversely, in the case that it is considered to reduce the
fluid resistance, it is necessary to provide a capillary structure
with larger voids to facilitate backflow of the working fluid.
However, under such circumstance, the capillary attraction will be
decreased.
[0009] To overcome the above problem, a vapor chamber with complex
micro-structures is now available in the market. Such vapor chamber
includes a first capillary structure layer and a second capillary
structure layer. The first and second capillary structure layers
have different sizes of voids. However, the manufacturing processes
of both the conventional single-layer vapor chamber and the complex
vapor chamber are complicated and it is hard to thin the vapor
chambers. Moreover, it is hard to control the quality of the vapor
chambers. As a result, the cost is higher and the ratio of
defective products is increased.
[0010] According to the above, the conventional vapor chamber has
the following shortcomings:
[0011] 1. The cost is higher.
[0012] 2. The thermal homogeneity is poorer.
[0013] 3. The conventional vapor chamber has a considerable
thickness.
[0014] 4. The thermal resistance of the conventional vapor chamber
is higher.
SUMMARY OF THE INVENTION
[0015] It is therefore a primary object of the present invention to
provide a heat dissipation device, which is manufactured at greatly
lowered cost.
[0016] It is a further object of the present invention to provide
the above heat dissipation device, which has lower thermal
resistance.
[0017] It is still a further object of the present invention to
provide the above heat dissipation device, in which the
condensation section has better thermal homogeneity.
[0018] To achieve the above and other objects, the heat dissipation
device of the present invention includes a first board body and a
second board body. The first board body has a first face and a
second face. The second face is formed with (or provided with) a
rough structure. The second board body has a third face and a
fourth face. The fourth face of the second board body is mated with
the second face of the first board body and covered by the second
face. The second and fourth faces together define a chamber. A
working fluid is filled in the chamber. The rough structure of the
second face or the fourth face is coated with a coating.
Alternatively, both the rough structure of the second face and the
fourth face are coated with coatings.
[0019] In the above heat dissipation device, the second face is
partially or totally formed with the rough structure and the
coating coated on the rough structure is a dioxide silicon coating.
Also, the coating is a hydrophilic coating or a hydrophobic
coating. When the third face of the second board body absorbs heat,
the liquid working fluid is heated and evaporated into vapor
working fluid. Then, the vapor working fluid on the second face of
the first board body is condensed into liquid working fluid. By
means of the rough structure, the liquid working fluid is quickly
pulled to a section of the second face corresponding to the
position of the heat source. The collected liquid working fluid
then flows back to the fourth face of the second board body.
Accordingly, the rough structure can speed the backflow of the
liquid working fluid and lower the thermal resistance of the heat
dissipation device as well as enhance the thermal homogeneity
thereof. Also, the rough structure overcomes the problems of the
conventional vapor chamber that the manufacturing process is
complicated and the quality is hard to control. Therefore, the
ratio of defective products is greatly reduced and the
manufacturing cost is greatly lowered.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The structure and the technical means adopted by the present
invention to achieve the above and other objects can be best
understood by referring to the following detailed description of
the preferred embodiments and the accompanying drawings,
wherein:
[0021] FIG. 1A is a perspective exploded view of a first embodiment
of the present invention;
[0022] FIG. 1B is a perspective assembled view of the first
embodiment of the present invention;
[0023] FIG. 1C is a sectional view of the first embodiment of the
present invention;
[0024] FIG. 1D is an enlarged view of circled area of FIG. 1C;
[0025] FIG. 1E is a sectional view of the first embodiment of the
present invention in another aspect;
[0026] FIG. 1F is an enlarged view of circled area of FIG. 1E;
[0027] FIG. 2A is a sectional view of a second embodiment of the
present invention;
[0028] FIG. 2B is an enlarged view of circled area of FIG. 2A;
[0029] FIG. 3A is a sectional view of a third embodiment of the
present invention;
[0030] FIG. 3B is an enlarged view of circled area of FIG. 3A;
[0031] FIG. 4A is a sectional view of a fourth embodiment of the
present invention;
[0032] FIG. 4B is an enlarged view of circled area of FIG. 4A;
[0033] FIG. 5A is a sectional view of a fifth embodiment of the
present invention;
[0034] FIG. 5B is an enlarged view of circled area of FIG. 5A;
[0035] FIG. 6 is a perspective exploded view of a sixth embodiment
of the present invention; and
[0036] FIG. 7 is a perspective exploded view of a seventh
embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Please refer to FIGS. 1A, 1B, 1C, 1D, 1E and 1F. FIG. 1A is
a perspective exploded view of a first embodiment of the present
invention. FIG. 1B is a perspective assembled view of the first
embodiment of the present invention. FIG. 1C is a sectional view of
the first embodiment of the present invention. FIG. 1D is an
enlarged view of circled area of FIG. 1C. FIG. 1E is a sectional
view of the first embodiment of the present invention in another
aspect. FIG. 1F is an enlarged view of circled area of FIG. 1E.
According to the first embodiment, the heat dissipation device of
the present invention includes a first board body 10 and a second
board body 11. The first board body 10 has a first face 101 and a
second face 102 (condensation section). The second face 102 is
partially (FIGS. 1C and 1D) or totally (FIGS. 1E and 1F) formed
with (or provided with) a rough structure 1021. In the case that
the second face 102 is partially formed with the rough structure
1021, the rough structure 1021 is positioned right above a heat
source 2 (CPU, transistor or other heat generation object
(component)). The rough structure 1021 of the second face 102 is
coated with a coating 1022 of dioxide silicon.
[0038] In this embodiment, preferably, the rough structure 1021 of
the second face 102 is a capillary structure with micro-channels.
The capillary structure is formed by means of mechanical processing
(stamping, marking or sculpturing) or etching. The rough structure
1021 is a recessed/raised structure. The coating 1022 is a
hydrophilic coating or a hydrophobic coating. In this embodiment,
the coating 1022 is, but not limited to, a hydrophilic coating.
[0039] The second board body 11 has a third face 111 and a fourth
face 112 (evaporation section). The fourth face 112 of the second
board body 11 is mated with the second face 102 of the first board
body 10 and covered by the second face 102. The second and fourth
faces 102, 112 together define a chamber 113. The third face 111 is
in contact with the heat source 2.
[0040] A working fluid 12 is filled in the chamber 113. The working
fluid 12 is selected from a group consisting of pure water,
methanol, acetone, coolant and ammonia.
[0041] According to the above arrangement, the second face 102 is
partially or totally formed with the rough structure 1021 coated
with a hydrophilic or hydrophobic coating 1022. When the third face
111 of the second board body 11 in contact with the heat source 2
absorbs heat, the liquid working fluid 12 is heated and transformed
into vapor working fluid 12. Then, the vapor working fluid 12 on
the second face 102 of the first board body 10 is condensed into
liquid working fluid 12. By means of the rough structure 1021, the
liquid working fluid 12 is quickly collectively pulled to a section
(the hottest part of the condensation section) of the second face
102 corresponding to the position of the heat source 2. The
collected liquid working fluid 2 then flows back to the fourth face
112 of the second board body 11. Accordingly, the rough structure
1021 can speed the backflow of the liquid working fluid 2 and lower
the thermal resistance of the heat dissipation device 1 as well as
enhance the thermal homogeneity. Also, the rough structure 1021
overcomes the problems of the conventional vapor chamber that the
manufacturing process is complicated and the quality is hard to
control. Therefore, the ratio of defective products is greatly
reduced and the manufacturing cost is greatly lowered.
[0042] Please now refer to FIGS. 2A and 2B. FIG. 2A is a sectional
view of a second embodiment of the present invention. FIG. 2B is an
enlarged view of circled area of FIG. 2A. The second embodiment is
partially identical to the first embodiment in component and
relationship between the components and thus will not be repeatedly
described hereinafter. The second embodiment is mainly different
from the first embodiment in that the rough structure 1021 has a
waved form. The rough structure 1021 is coated with a coating 1022.
The rough structure 1021 can speed the backflow of the liquid
working fluid and enhance the thermal homogeneity as well as lower
the thermal resistance of the heat dissipation device and lower the
manufacturing cost.
[0043] Please now refer to FIGS. 3A and 3B. FIG. 3A is a sectional
view of a third embodiment of the present invention. FIG. 3B is an
enlarged view of circled area of FIG. 3A. The third embodiment is
partially identical to the first embodiment in component and
relationship between the components and thus will not be repeatedly
described hereinafter. The third embodiment is mainly different
from the first embodiment in that the rough structure 1021 has a
saw-toothed form. The rough structure 1021 is coated with a coating
1022. The rough structure 1021 can speed the backflow of the liquid
working fluid and enhance the thermal homogeneity as well as lower
the thermal resistance of the heat dissipation device and lower the
manufacturing cost.
[0044] Please now refer to FIGS. 4A and 4B. FIG. 4A is a sectional
view of a fourth embodiment of the present invention. FIG. 4B is an
enlarged view of circled area of FIG. 4A. The fourth embodiment is
partially identical to the first embodiment in component and
relationship between the components and thus will not be repeatedly
described hereinafter. The second embodiment is mainly different
from the first embodiment in that the coating 1022 is coated on the
fourth face 112 (evaporation section).
[0045] Please now refer to FIGS. 5A and 5B. FIG. 5A is a sectional
view of a fifth embodiment of the present invention. FIG. 5B is an
enlarged view of circled area of FIG. 5A. The fifth embodiment is
partially identical to the first embodiment in component and
relationship between the components and thus will not be repeatedly
described hereinafter. The fifth embodiment is mainly different
from the first embodiment in that both the rough structure 1021 of
the second face 102 and the fourth face 112 are coated with the
coatings 1022. This also can speed the backflow of the liquid
working fluid and enhance the thermal homogeneity as well as lower
the thermal resistance of the heat dissipation device and lower the
manufacturing cost.
[0046] Please now refer to FIG. 6, which is a perspective exploded
view of a sixth embodiment of the present invention. The sixth
embodiment is partially identical to the first embodiment in
component and relationship between the components and thus will not
be repeatedly described hereinafter. The sixth embodiment is mainly
different from the first embodiment in that the second board body
11 has a capillary structure 1121 formed on the fourth face 112.
The capillary structure 1121 is selected from a group consisting of
channeled structure, sintered powder body and mesh body. In this
embodiment, the capillary structure 1121 is, but not limited to, a
sintered powder body for illustration purposes only.
[0047] Please now refer to FIG. 7, which is a perspective exploded
view of a seventh embodiment of the present invention. The seventh
embodiment is partially identical to the first embodiment in
component and relationship between the components and thus will not
be repeatedly described hereinafter. Also referring to FIG. 1E, the
seventh embodiment is mainly different from the first embodiment in
that at least one support pillar 1131 is disposed in the chamber
113. Two ends of the support pillar 1131 are respectively connected
to the second face 102 (condensation section) and the fourth face
112 (evaporation section). In addition, a capillary structure 1131a
is disposed on an outer surface of the support pillar 1131. The
capillary structure 1131a is selected from a group consisting of
channeled structure, sintered powder body and mesh body. In this
embodiment, the capillary structure 1131a is, but not limited to, a
sintered powder body for illustration purposes only.
[0048] The rough structure 1021 (not shown) is tapered in height
from the center of the board body to the edges of the board
body.
[0049] According to the above embodiment, when the third face 111
of the second board body 11 absorbs heat, the liquid working fluid
12 is heated and transformed into vapor working fluid 12. Then, the
vapor working fluid 12 on the second face 102 of the first board
body 10 is condensed into liquid working fluid 12. Thanks to the
hydrophilicity of the coating 1022 and by means of the capillary
attraction of the capillary structure 1131a of the support pillar
1131, the liquid working fluid 12 is pulled from the condensation
section back to the evaporation section. Accordingly, the backflow
of the liquid working fluid is speeded and the thermal homogeneity
is enhanced. Also, the thermal resistance of the heat dissipation
device 1 is lowered.
[0050] In conclusion, in comparison with the conventional vapor
chamber, the present invention has the following advantages:
[0051] 1. The cost is lowered.
[0052] 2. The thermal homogeneity of the heat dissipation device is
enhanced.
[0053] 3. The thermal resistance of the heat dissipation device is
lowered.
[0054] The present invention has been described with the above
embodiments thereof and it is understood that many changes and
modifications in the above embodiments can be carried out without
departing from the scope and the spirit of the invention that is
intended to be limited only by the appended claims.
* * * * *