U.S. patent application number 12/554284 was filed with the patent office on 2010-03-11 for fin, thermal module, and method for assembling the same.
This patent application is currently assigned to Pegatron Corporation. Invention is credited to YU WEI CHANG, CHAO TSAI CHUNG.
Application Number | 20100059207 12/554284 |
Document ID | / |
Family ID | 41798202 |
Filed Date | 2010-03-11 |
United States Patent
Application |
20100059207 |
Kind Code |
A1 |
CHANG; YU WEI ; et
al. |
March 11, 2010 |
FIN, THERMAL MODULE, AND METHOD FOR ASSEMBLING THE SAME
Abstract
This invention provides a method for assembling the thermal
module. According to the invention, the fin can be combined with a
heat pipe and a joint material to form the thermal module. The fin
includes a main body having a through hole and an feeding hole
communicating with each other. The heat pipe passes through the
through hole. The joint material is injected into the feeding hole
to fill a clearance between the heat pipe and the inner wall of the
through hole. In addition, when the fin is combined with the heat
pipe, the feeding hole is above the through hole, the joint
material flows downward along the clearance, and the clearance
gradually narrows along a flowing direction of the joint
material.
Inventors: |
CHANG; YU WEI; (Taipei City,
TW) ; CHUNG; CHAO TSAI; (Taipei City, TW) |
Correspondence
Address: |
MORRIS MANNING MARTIN LLP
3343 PEACHTREE ROAD, NE, 1600 ATLANTA FINANCIAL CENTER
ATLANTA
GA
30326
US
|
Assignee: |
Pegatron Corporation
Taipei City
TW
|
Family ID: |
41798202 |
Appl. No.: |
12/554284 |
Filed: |
September 4, 2009 |
Current U.S.
Class: |
165/104.26 ;
165/185; 29/890.03; 29/890.043 |
Current CPC
Class: |
Y10T 29/49373 20150115;
F28F 1/30 20130101; Y10T 29/4935 20150115; F28F 2275/04 20130101;
F28D 15/02 20130101; F28F 2275/025 20130101 |
Class at
Publication: |
165/104.26 ;
165/185; 29/890.03; 29/890.043 |
International
Class: |
F28D 15/04 20060101
F28D015/04; F28F 7/00 20060101 F28F007/00; B21D 53/08 20060101
B21D053/08 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 5, 2008 |
TW |
097134173 |
Claims
1. A cooling fin combined with a heat pipe and a joint material,
the cooling fin comprising: a main body having a through hole and
an feeding hole, the heat pipe passing through the through hole,
the feeding hole communicating with the through hole, the joint
material injected into the feeding hole to fill a clearance between
the heat pipe and the inner wall of the through hole; wherein when
the cooling fin is combined with the heat pipe, the feeding hole is
above the through hole, the joint material flows downward along the
clearance, and the clearance gradually narrows along a flowing
direction of the joint material.
2. The cooling fin according to claim 1, wherein a cross-section of
the heat pipe is flat.
3. The cooling fin according to claim 1, wherein the through hole
has a first end portion and a second end portion, and the feeding
hole is located at a vertical line connecting the first end portion
and the second end portion.
4. The cooling fin according to claim 1, wherein the through hole
has a first end portion and a second end portion, and an angle
between a central line of the feeding hole and a vertical line
connecting the first end portion and the second end portion is
between 0 to 45 degrees.
5. The cooling fin according to claim 1, wherein a width of the
feeding hole is equal to that of the through hole.
6. The cooling fin according to claim 1, wherein the joint material
is solder paste.
7. A thermal module comprising: a heat pipe; a joint material; and
a plurality of cooling fins, each cooling fin including a main
body, the main body having a through hole and an feeding hole, the
heat pipe passing through the through hole, the feeding hole
communicating with the through hole, the joint material injected
into the feeding hole to fill a clearance between the heat pipe and
the inner wall of the through hole; wherein when the thermal module
is assembled, the feeding hole is located above the through hole,
the joint material flows downward along the clearance, and the
clearance gradually narrows along a flowing direction of the joint
material.
8. The thermal module according to claim 7, wherein a cross-section
of the heat pipe is flat.
9. The thermal module according to claim 7, wherein the through
hole has a first end portion and a second end portion, and the
feeding hole is located at a vertical line connecting the first end
portion and the second end portion.
10. The thermal module according to claim 7, wherein the through
hole has a first end portion and a second end portion, and an angle
between a central line of the feeding hole and a vertical line
connecting the first end portion and the second end portion is
between 0 to 45 degrees.
11. The thermal module according to claim 7, wherein a width of the
feeding hole is equal to that of the through hole.
12. The thermal module according to claim 7, wherein the joint
material is solder paste.
13. The thermal module according to claim 7, further comprising: a
fixture base including a groove for containing the heat pipe and
fastening the heat pipe to approach a heating element.
14. A method for assembling a thermal module to combine a fin with
a heat pipe and a joint material, the method comprising the
following steps of: making a plurality of fins, each fin having a
through hole and an feeding hole communicating with each other;
making the heat pipe pass through the through holes of the fins and
making the feeding hole above the through hole; injecting the joint
material into the feeding hole to fill a clearance between the heat
pipe and the inner wall of the through hole; and making the joint
material flow downward along the clearance, the clearance gradually
narrowing along the flowing direction.
15. The method according to claim 14, wherein the fins are disposed
via a holding device to keep the feeding hole above the through
hole.
16. The method according to claim 14, wherein in the step of making
the joint material flow downward along the clearance, the method
further comprises the steps of: heating the joint material to melt
the joint material; and cooling the joint material to solidify the
joint material to tightly combine the cooling fins and the heat
pipe after the joint material flows downward along the clearance to
the bottom of the through hole.
17. The method according to claim 16, wherein the joint material is
solder paste.
18. The method according to claim 14, wherein the through hole has
a first end portion and a second end portion, and the feeding hole
is located at a vertical line connecting the first end portion and
the second end portion.
19. The method according to claim 14, wherein the through hole has
a first end portion and a second end portion, and an angle between
a central line of the feeding hole and a vertical line connecting
the first end portion and the second end portion is between 0 to 45
degrees.
20. The method according to claim 14, wherein a width of the
feeding hole is equal to that of the through hole.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Non-provisional application claims priority under 35
U.S.C. .sctn.119(a) on Patent Application No(s). 097134173 filed in
Taiwan, Republic of China on Sep. 5, 2008, the entire contents of
which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a cooling fin, a thermal module
including the cooling fin, and a method for assembling the thermal
module.
[0004] 2. Description of the Related Art
[0005] In past, only a central processing unit needs a thermal
module to keep an operating temperature and stability of the
central processing unit. With improvement of operating performance
of other electronic elements, such as a graphic chip, a north
bridge chip, a south bridge chip, a light-emitting diode and so on,
the thermal module becomes more and more important for preserving
stability of the electronic elements and the electronic devices
having the electronic elements.
[0006] For manufacturing light, slim, and powerful electronic
device, a plurality of electronic elements is assembled on a
circuit board with a limited area, which results in a high heat
flux of heat dissipation. Therefore, the thermal module becomes
more and more important.
[0007] A conventional thermal module generally includes a plurality
of fins and one or more heat pipes passing through the fins. FIG. 1
is a three-dimensional schematic diagram showing a thermal module
in the prior art. In FIG. 1, a thermal module 7 includes a
plurality of fins 70 and a heat pipe 72. When the thermal module 7
is made, a through hole 700 whose size and shape are the same with
the cross-section of the heat pipe 72 is formed on each of the fins
70 in advance. Then, solder paste 74 is spread on the heat pipe 72,
and the heat pipe 72 passes through the through holes 700 one by
one.
[0008] However, the heat pipe 72 may squeeze the solder paste 74
out when inserting the heat pipe 72 into the through holes 700.
Thus, the solder paste 74 overflows onto other positions of the
fins 70 around the through holes 700. Therefore, the overflowed
solder paste 74 needs to be cleaned manually. Thus, additional
labor is needed, and the solder paste 74 is wasted. Further, the
distribution of the solder paste 74 is non-uniform, deteriorating
the heat dissipation.
[0009] Therefore, a patent No. 568261 in Republic of China provides
a novel thermal module. FIG. 2A is a three-dimensional schematic
diagram showing the thermal module. FIG. 2B is a sectional
schematic diagram showing the thermal module in FIG. 2A along a
line O-O. In FIG. 2A and FIG. 2B, each fin 90 of a thermal module 9
has a through hole 900 as mentioned above, and the heat pipe 92
passes through the through holes 900 to combine the fins 90 in
series. The difference between this patent and FIG. 1 is that a
small solder paste feeding hole 902 is formed above the through
hole 900 of the fin 90.
[0010] When the thermal module 9 is made, the heat pipe 92 first
passes through the through holes 900 of the fins 90 one by one.
Then, solder paste 94 is injected into the solder paste feeding
holes 902. Next, the solder paste 94 is heated to be melted, such
that the solder paste 94 flows and fills a clearance between the
heat pipe 92 and the through holes 900 via capillary action.
Afterwards, the solder paste 94 is cooled and solidified to finish
making the thermal module 9.
[0011] However, practical applications show that the clearance
between the heat pipe 92 and the through hole 900 cannot be fully
filled by the patent No. 568261 in Republic of China. FIG. 2C and
FIG. 2D are sectional schematic diagrams showing the thermal module
in FIG. 2A along the line O-O in practical applications. In the
mentioned manufacture process, the solder paste 94 could not flow
to the edge of the through hole 900 opposite to the solder paste
feeding hole 902. Therefore, the soldering of the fins 90 and the
heat pipe 92 is not solid enough, and the solder paste 94 may not
flow downward and may deposit at the solder paste adding hole 902.
In addition, the non-uniform distribution of the solder paste 94
may also deteriorate the heat dissipation.
BRIEF SUMMARY OF THE INVENTION
[0012] One objective of this invention is to provide a cooling fin
and a method for assembling the thermal module. Particularly, the
invention can uniformly spread the solder material to the clearance
between the heat pipe and the fins of the thermal module. The
soldering quality and the heat transfer performance can be well
improved, thus to improve the prior art.
[0013] According to a first embodiment of the invention, the
cooling fin can be combined with a heat pipe and a joint material.
The cooling fin includes a main body. The main body has a through
hole and a feeding hole. The heat pipe passes through the through
hole. The feeding hole communicates with the through hole. The
joint material is injected into the feeding hole to fill the
clearance between the heat pipe and the inner wall of the through
hole.
[0014] According to a second embodiment of the invention, the
thermal module includes a heat pipe, a joint material, and a
plurality of fins. As mentioned above, each fin includes a main
body having a through hole and an feeding hole. The heat pipe
passes through the through hole. The feeding hole communicates with
the through hole. The joint material is injected into the feeding
hole to fill the clearance between the heat pipe and the inner wall
of the through hole.
[0015] Particularly, when assembling the thermal module, the
feeding hole is located above the through hole, the joint material
flows downward along the clearance, and the clearance gradually
narrows along a flowing direction of the joint material.
[0016] According to a third embodiment of the invention, a method
for assembling the thermal module is provided to combine a cooling
fin with a heat pipe and a joint material. The method includes the
following steps. A plurality of fins is made. As mentioned above,
each fin has a through hole and a feeding hole communicating with
each other.
[0017] Then, the heat pipe is made to pass through the through
holes of the fins, and the feeding hole is made to be above the
through hole. A clearance between the heat pipe and the inner wall
of the through hole gradually narrows downward. Finally, the joint
material is injected into the feeding hole to fill the clearance
between the heat pipe and the inner wall of the through hole, thus
to allow the joint material to flow downward along the
clearance.
[0018] These and other features, aspects, and advantages of the
present invention will become better understood with regard to the
following description, appended claims, and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a three-dimensional schematic diagram showing a
thermal module according to the prior art;
[0020] FIG. 2A is a three-dimensional schematic diagram showing a
thermal module according to the prior art;
[0021] FIGS. 2B to 2D are sectional schematic diagrams showing the
thermal module in FIG. 2A along a line O-O;
[0022] FIGS. 3A to 3C are schematic diagrams showing a fin
according to one embodiment of the invention;
[0023] FIG. 4 is a flowchart showing a method for assembling a
thermal module according to one embodiment of the invention;
[0024] FIGS. 5A to 5E are schematic diagrams showing the thermal
module in each step in FIG. 4;
[0025] FIG. 6A is a schematic diagram showing a fin and a heat pipe
in FIG. 5E along a direction F;
[0026] FIG. 6B is a schematic diagram showing a fluid located
between two gradually approaching walls;
[0027] FIG. 7A is a three-dimensional schematic diagram showing a
thermal module according to one embodiment of the invention;
and
[0028] FIG. 7B is a sectional schematic diagram showing the thermal
module in FIG. 7A along a line P-P.
DETAILED DESCRIPTION OF THE INVENTION
[0029] This invention provides a cooling fin, a thermal module
including the cooling fin, and a method for assembling the thermal
module.
[0030] According to one embodiment of the invention, the cooling
fin can be combined with a heat pipe and a joint material, thus to
form the thermal module. FIGS. 3A to 3B are schematic diagrams
showing a fin according to one embodiment of the invention. Please
refer to FIGS. 3A to 3C.
[0031] In FIGS. 3A to 3C, a main body 100 of a cooling fin 10 is
flat, and the main body 100 has a through hole 102 and an feeding
hole 104. The through hole 102 can be used for the heat pipe (not
shown) to pass through. The feeding hole 104 communicates with the
through hole 102. When the cooling fin 10 is combined with the heat
pipe, the feeding hole 104 is above the through hole 102, and the
joint material (not shown) is injected into the feeding hole 104 to
fill a clearance between the heat pipe and the inner wall of the
through hole 102. In addition, the through hole 102 has a first end
portion 102a and a second end portion 102b opposite to each other.
The feeding hole 104 extends from the first end portion 102a for
containing the joint material (not shown). In one practical
application, the joint material may be solder paste or other
suitable materials.
[0032] In FIG. 3A, in one embodiment, the feeding hole 104 can be
regarded as a extension portion of the through hole 102. Therefore,
the feeding hole 104 is located at a vertical line L connecting the
first end portion 102a and the second end portion 102b. Further, a
width of the widest portion of the feeding hole 104 is equal to
that of the widest portion of the through hole 102.
[0033] In FIG. 3B, in one embodiment, the feeding hole 104 is also
located at a vertical line L connecting the first end portion 102a
and the second end portion 102b. However, in this embodiment, a
width of the widest portion of the feeding hole 104 is smaller than
that of the widest portion of the through hole 102.
[0034] In FIG. 3C, in one embodiment, an angle between a central
line C of the feeding hole 104 and a vertical line L connecting the
first end portion 102a and the second end portion 102b is about 45
degrees. In one practical application, the feeding hole 104 may
extend from a suitable position of the first end portion 102a, such
that the angle between the central line and the vertical line L
connecting the first end portion 102a and the second end portion
102b may be between 0 to 45 degrees (such as 10, 20, or 30
degrees).
[0035] In addition, in one practical application, the shape of the
feeding hole 104 can be adjusted according to needs, and it is not
limited thereto. For example, the shape of the feeding hole 104 may
be adjusted according to a used joint material, a needed moving
speed of the joint material, needed capillary force and so on.
[0036] In one practical application, the main body 100 can further
include a structure for helping heat dissipation or fastening, such
as a bend, a protrusion, a recess, a fastening hole and so on. In
addition, the appearance of the main body 100 can be changed and
adjusted according to situations, and it is not limited to FIGS. 3A
to 3C.
[0037] FIG. 4 is a flowchart showing a method for assembling a
thermal module according to one embodiment of the invention. FIGS.
5A to 5E are schematic diagrams showing the thermal module in each
step in FIG. 4. Please refer to FIG. 4 and FIGS. 5A to 5E together.
To clearly describe this embodiment of the invention, only one
cooling fin is shown from FIGS. 5A to 5E. In one practical
application, the number of the cooling fin may increase or decrease
according to needs. In FIG. 4, the method for assembling the
thermal module includes the following steps.
[0038] In step S50, a heat pipe 12 and a cooling fin 10 as shown in
FIG. 5A are made. The cross-section of the heat pipe 12 is flat. In
one practical application, the cross-section of the heat pipe 12
may have other shapes. In addition, as described above, a main body
100 of the cooling fin 10 has a through hole 102 and an feeding
hole 104. The through hole 102 has a first end portion 102a and a
second end portion 102b opposite to each other, and the feeding
hole 104 extends from the first end portion 102a.
[0039] In this embodiment, the feeding hole 104 of the made fin 10
is the same as that in FIG. 3B. However, in one practical
application, the cooling fin having the feeding hole 104 as shown
in FIG. 3A and FIG. 3C or having other suitable feeding holes may
be made.
[0040] In step S52, the cooling fin 10 is sleeved on the heat pipe
12 via the through hole 102 as shown in FIG. 5B.
[0041] In step S54, the joint material 14 is injected into the
feeding hole 104 (as shown in FIG. 5C). In one practical
application, the joint material 14 may be solder paste or other
suitable materials. In addition, in FIG. 5C, the joint material 14
is a bar-shaped solid. However, in one practical application, the
joint material 14 may be a pasty solid or have other forms.
[0042] In step S56, the cooling fin 10 is disposed to keep the
feeding hole 104 above the through hole 102 (as shown in FIG. 5D).
Particularly, a clearance between the heat pipe 12 and the inner
wall of the through hole 102 gradually narrows downward. In one
practical application, the cooling fin 10 may be disposed via a
suitable holding device (not shown) to keep the above state. In
addition, if the joint material 14 is a pasty material or other
materials having high liquidity, the cooling fin 10 can be disposed
as shown in FIG. 5D in step S52 or S54.
[0043] Finally, in step S58, the joint material 14 is made to flow
downward along the clearance to tightly combine the cooling fin 10
and the heat pipe 12.
[0044] In one practical application, when the joint material is
solder paste, step S58 can further include the following steps. The
solder paste is heated to be melted. Further, after the solder
paste flows downward along the clearance and reaches the bottom of
the through hole, the solder paste is cooled to tightly combine the
cooling fin and the heat pipe.
[0045] In the method according to the embodiment of the invention,
the joint material flows downward and is uniformly distributed to
the clearance between the heat pipe and the through hole via
capillarity and gravity. In addition, the cooling fin is disposed
to keep the feeding hole above the through hole. When the joint
material flows from the first end portion of the through hole to
the second end portion of the through hole along the clearance
between the heat pipe and the through hole, the clearance between
the heat pipe and a wall of the second end portion gradually
narrows. Therefore, the capillary force can exist all the time,
which is help for the joint material to fully fill the clearance
between the heat pipe and the through hole.
[0046] To further describe the relation between gradually narrowing
of the clearance and the capillary force, please refer to FIG. 6A
and FIG. 6B. FIG. 6A is a schematic diagram showing the cooling fin
10 and the heat pipe 12 in FIG. 5E along a direction F. FIG. 6B is
a schematic diagram showing a fluid 20 located between two
gradually approaching walls 30, 32.
[0047] In FIG. 6A, the clearance between the heat pipe 12 and the
through hole 102 gradually narrows along arrow directions at the
second end portion 102b of through hole 102. In addition, in FIG.
6B, it is supposed that an angle between the two walls 30, 32 is
.alpha., the contact angle between a liquid extending line of the
fluid 20 and the two walls 30, 32 is .theta., a curvature radius of
the fluid 20 and an air interface at a lower side is R, and a
distance between contacting points of the fluid 20 and the walls
30, 32 is H.
[0048] According to the following formula, in FIG. 6B, the
capillary force .DELTA.P is inversely proportional to the curvature
radius R, where, .sigma. is surface tension.
.DELTA.P=2.sigma. cos .theta./R.
Further, as the clearance between the two walls 30, 32 gradually
narrows, the following relation can be achieved according to
.alpha., .theta., and H.
R = H / 2 cos ( .theta. - .alpha. ) R .varies. H ##EQU00001##
[0049] In other words, the curvature radius R is directly
proportional to the distance H. When the distance between the walls
30, 32 becomes smaller, the H becomes smaller, and the R also
becomes smaller. Therefore, the .DELTA.P becomes greater. As the
clearance between the heat pipe and the through hole gradually
narrows, the capillary force exists all the time, thus to allow the
joint material to be capable of successfully filling the clearance
between the heat pipe and the through hole.
[0050] FIG. 7A is a three-dimensional schematic diagram showing a
thermal module according to one embodiment of the invention. FIG.
7B is a sectional schematic diagram showing the thermal module in
FIG. 7A along a line P-P. Please refer to FIG. 7A and FIG. 7B
together.
[0051] In FIG. 7A, a thermal module 1 includes a plurality of
cooling fins 10 as mentioned above, a heat pipe 12, and a joint
material 14. In addition, in this embodiment, the thermal module 1
further includes a fixture base 16 having a groove 160 for
containing the heat pipe 12. In one practical application, the heat
pipe 12 may be attached to or be fastened to the groove 160 via a
fastening element.
[0052] In one practical application, the fixture base 16 is made of
a material with a better heat dissipation effect (such as copper,
alumina, alloy, or other suitable materials). The fixture base 16
can be fixed around a heating element (not shown) to allow the heat
pipe 12 to approach the heating element, thus to quickly dissipate
the heat generated by the heating element.
[0053] In FIG. 7B, according to the thermal module 1 assembled with
the cooling fin 10 via the method provided by the embodiment of the
invention, the joint material 14 can be uniformly distributed to
the clearance between the through hole 102 and the heat pipe 12,
and it does not deposit or overflow. The clearance between the
through hole 102 and the heat pipe 12 in the figure is enlarged on
purpose for showing clearly. In one practical application, the
clearance may be adjusted according to needs and may conform to
demands or standards on manufacture.
[0054] In one practical application, the thermal module can be
applied to an electronic device such as a computer, a display, a
light and so on for dissipating heat of a heating element in the
electronic device such as a processor, a display chip, a graphic
chip, a light-emitting diode and so on. In addition, the thermal
module can include a plurality of heat pipes, or it can be combined
with a fan, a heat dissipation plaster, a cooling fin, or other
suitable elements for improving the heat dissipation effect.
[0055] To sum up, the joint material can be uniformly distributed
to the clearance between the edge of the through hole and the heat
pipe via the feeding hole and disposing the cooling fin to keep the
feeding hole above the through hole during manufacture, thereby
tightly combining the cooling fin and the heat pipe and improving
the heat dissipation effect. In addition, according to the method
provided by the embodiment of the invention, the situation that the
joint material deposits or overflows in the prior art can be
avoided.
[0056] Although the present invention has been described in
considerable detail with reference to certain preferred embodiments
thereof, the disclosure is not for limiting the scope of the
invention. Persons having ordinary skill in the art may make
various modifications and changes without departing from the scope
and spirit of the invention. Therefore, the scope of the appended
claims should not be limited to the description of the preferred
embodiments described above.
* * * * *