U.S. patent application number 10/753500 was filed with the patent office on 2005-07-14 for heat sink and method for manufacturing the same.
This patent application is currently assigned to Advanced Thermal Technologies. Invention is credited to Lee, Tzung-Lung, Lin, Ming-Chen.
Application Number | 20050150633 10/753500 |
Document ID | / |
Family ID | 34739199 |
Filed Date | 2005-07-14 |
United States Patent
Application |
20050150633 |
Kind Code |
A1 |
Lee, Tzung-Lung ; et
al. |
July 14, 2005 |
Heat sink and method for manufacturing the same
Abstract
A heat sink and a method for manufacturing a heat sink are
described. A plate-like base is manufactured with a plurality of
parallel grooves and a plurality of fins by an impact extrusion
process. A high temperature heat treatment is performed to soften
the plate-like base. The fins are positioned in corresponding
grooves and an equal force is applied to both ends of the
plate-like base so that the grooves are deformed and the fins are
fixedly positioned. The method is simpler and significantly cheaper
than that for conventional heat sinks.
Inventors: |
Lee, Tzung-Lung; (Taipei
City, TW) ; Lin, Ming-Chen; (Taipei City,
TW) |
Correspondence
Address: |
TROXELL LAW OFFICE PLLC
SUITE 1404
5205 LEESBURG PIKE
FALLS CHURCH
VA
22041
US
|
Assignee: |
Advanced Thermal
Technologies
|
Family ID: |
34739199 |
Appl. No.: |
10/753500 |
Filed: |
January 9, 2004 |
Current U.S.
Class: |
165/80.3 ;
257/E23.103 |
Current CPC
Class: |
H01L 21/4882 20130101;
F28F 13/00 20130101; H01L 2924/0002 20130101; H01L 2924/0002
20130101; H01L 2924/00 20130101; H01L 23/3672 20130101 |
Class at
Publication: |
165/080.3 |
International
Class: |
F28F 007/00 |
Claims
What is claimed is:
1. A heat sink, comprising: a plate-like base, having a plurality
of parallel grooves; and a plurality of fins, respectively
positioned in the parallel grooves.
2. The heat sink as claimed in claim 1, wherein the plate-like base
and the fins are made of aluminum.
3. The heat sink as claimed in claim 1, wherein the plate-like base
and the fins are made of copper.
4. The heat sink as claimed in claim 1, wherein the plate-like base
has a central segment and two flange segments, and the two flange
segments correspond to and extend from both ends of the central
segment.
5. The heat sink as claimed in claim 1, wherein the parallel
grooves are U-shaped.
6. The method of manufacturing a heat sink, the method comprising
the steps of: manufacturing a plate-like base with a plurality of
parallel grooves and a plurality of fins by an impact extrusion
process; positioning the fins to corresponding grooves and applying
an equal force to both ends of the plate-like base so that the
grooves are deformed and the fins are fixedly positioned.
7. The method as claimed in claim 6, wherein the plate-like base
and the fins are made of aluminum.
8. The method as claimed in claim 6, wherein the plate-like base
and the fins are respectively made of copper and aluminum.
9. The method as claimed in claim 6, wherein the plate-like base
and the fins are manufactured by powder metallurgy.
10. The method as claimed in claim 6, wherein the plate-like base
is subjected to a high temperature heat treatment to soften the
plate-like base.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat sink and a method
for manufacturing the same, and in particular to a heat sink and a
method for manufacturing a heat sink that is easily manufactured,
cheap and highly efficient in heat dissipation.
[0003] 2. Description of Related Art
[0004] Referring to FIGS. 1 and 2, a conventional heat sink 1 is
disclosed. The conventional heat sink 1 has a plate-like base 11
and a plurality of fins 12. The plate-like base 11 and plurality of
fins 12 are manufactured by an impact extrusion process and can be
made of copper. Then, thermal transfer adhesive is applied to the
bottom of the fins 12 which are equidistantly separated and
positioned on top surface of the plate-like base 11.
[0005] In addition, the plate-like base 11 and plurality of fins 12
can also be made of copper and aluminum, respectively. Compared
with the heat sink made of copper in the prior art, the heat sink
described above has less overall weight. However, when a plurality
of fins 12 is connected to the plate-like base 11, each fin 12 must
individually soldered to the top surface of the plate-like base 11
by solder 13.
[0006] No matter what the plate-like base 11 and a plurality of
fins 12 are made of, it is time-consuming and expensive to connect
the plate-like base 11 and a plurality of fins 12 by soldering.
[0007] Due to the desire for lightweight mobile electronic device,
when the heat sink has less weight, it is not prone breaking during
shipping. Although the conventional heat sink 1 is made of
lightweight aluminum instead of the heavier copper, the weight of
the conventional heat sink 1 cannot be decreased. However, the fins
12 are soldered to most of the area of the plate-like base 11 so
that the weight of the conventional heat sink 1 fails to be
significantly decreased.
[0008] Furthermore, the plate-like base 11 of the conventional heat
sink 1 abuts against a heat-generating component 21. A fan (not
shown) subsequently attached to the conventional heat sink 1
provides a cooling airflow. Because the fins 12 are equidistantly
separated and positioned on the top surface of the plate-like base
11, the cooling airflow contacts the plate-like base 11 of the
conventional heat sink 1. Then, part of the cooling airflow flows
between fins 12 and another part of the cooling airflow flows in
the opposite direction. Turbulent airflow thus occurs near the
contact area of the fins 12 and the plate-like base 11 and
generates a higher back pressure so that the fan provides less
airflow and efficiency of heat dissipation is adversely
impacted.
[0009] Thus, there is need to develop a heat sink and a method for
manufacturing a heat sink.
SUMMARY OF THE DISCLOSURE
[0010] It is an object of the present invention to provide a heat
sink and a method for manufacturing a heat sink that is easily
manufactured, cheap and highly efficient in heat dissipation.
[0011] It is another object of the present invention to provide a
method for manufacturing a heat sink made of different materials
and that is lighter and highly efficient in heat dissipation.
[0012] It is another object of the present invention to provide a
heat sink made of different materials and that is lighter and
highly efficient in heat dissipation.
[0013] It is an object of the present invention to provide a heat
sink and a method for manufacturing a heat sink. The method of the
present invention includes manufacturing a plate-like base with a
plurality of parallel grooves and a plurality of fins by an impact
extrusion process, performing a high temperature heat treatment to
soften the plate-like base, and positioning the fins to
corresponding grooves and applying an equal force to both ends of
the plate-like base so that the grooves are deformed and the fins
are fixedly positioned.
BRIEF DESCRIPTION OF DRAWINGS
[0014] The present invention can be fully understood from the
following detailed description and preferred embodiment with
reference to the accompanying drawings, in which:
[0015] FIG. 1 is a perspective view of a conventional heat
sink;
[0016] FIG. 2 is an enlarged partial view of the conventional heat
sink indicated by arrow A of FIG. 1;
[0017] FIG. 3 is an exploded view of a heat sink in accordance with
the present invention;
[0018] FIG. 4 is a perspective view of a heat sink in accordance
with the present invention;
[0019] FIG. 5 is an enlarged partial view of the heat sink
indicated by arrow A of FIG. 4;
[0020] FIG. 6 is a block diagram illustrating a heat sink according
to one embodiment of the present invention; and
[0021] FIG. 8 is a block diagram illustrating a heat sink according
to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] The following detailed description is of the best presently
contemplated modes of carrying out the invention. This description
is not to be taken in a limiting sense, but is made merely for the
purpose of illustrating general principles of embodiments of the
invention. The scope of the invention is best defined by the
appended claims.
[0023] FIGS. 3-5 illustrate a heat sink 3 in accordance with one
embodiment of the present invention. The heat sink 3 has a
plate-like base 31 and a plurality of fins 32 positioned on the
plate-like base 31. The plate-like base 31 has a central segment
311 and two flange segments 312. The two flange segments 312
correspond to and extend from both ends of the central segment 311
in the direction of arrow Y. The central segment 311 and the two
flange segments 312 have their corresponding top surfaces and
bottom surfaces. The top surfaces of the central segment 311 and
the two flange segments 312 are in the same plane, and the bottom
surfaces of the central segment 311 and the two flange segments 312
are also in the same plane. In addition, a length of the central
segment 311 in the direction of arrow X is greater than that of the
two flange segments 312. A plurality of parallel grooves 313 is
located in the central segment 311 and the two flange segments 312.
Further, each of the parallel grooves 313 is U-shaped and is
adapted to receive the fins 32.
[0024] Referring to FIGS. 3 and 4, the length of the fins 32 is
greater than that of the plate-like base 31 in the direction of
arrow X. Thus, middle portions 321 of the fins 32 are only in
contact with the plate-like base 31. However, two end portions 322
of the fins 32 are not in contact with the plate-like base 31, and
there are thermal transfer channels 323 between two neighboring
fins 31.
[0025] Thus, the central segment 311 of the plate-like base 31
abuts against a heat-generating component 42 of a circuit board 41.
The two flange segments 312 of the plate-like base 31 are not in
contact with two end portions 322 of the fins 32 so that the
circuit board 41 is not in contact with the fins 32. When the
heat-generating component 42 is in use, the central segment 311 of
the plate-like base 31 conducts heat generated by the
heat-generating component 42 and carries heat into the fins 32 of
the two flange segments 312 and the plate-like base 31. Heat is
thus vented away from the fins 32. To increase efficiency of heat
dissipation, a fan (not shown) can be installed on the heat sink 3
and cooling airflow flows in the directions indicated by arrows in
FIG. 4. After the cooling air is blowing at the fins 32, the
cooling air is blown along the thermal transfer channels 323
between the fins 32 and is directed toward the two end portions 322
of the fins 32. Further, a part of cooling airflow flows through
the bottom of the thermal transfer channels 323. Thus, a larger
back pressure does not result to lessen the cooling airflow of the
fan. The heat sink 3 of one embodiment of the present invention has
an improved efficiency of heat dissipation.
[0026] Referring to FIGS. 3 and 6, a method of manufacturing the
heat sink 3 is described as follows. In step 51, the plate-like
base 31 is formed on the heat sink 3 by an impact extrusion
process, and a plurality of parallel grooves 311 are formed by a
stamping process. The plate-like base 31 and the fins 32 can be
respectively made of copper and aluminum. In step 52, the
plate-like base 31 is placed in a high temperature furnace and the
temperature within the furnace is kept between 1000-1100.degree. C.
so that the plate-like base 31 is fully softened to relieve
residual stress. In step 53, the fins 32 are respectively
positioned into the parallel grooves 311 of the plate-like base 31
by a jig (not shown), and the plate-like base 31 is subjected to
compressive forces as shown in FIG. 5 so that the parallel grooves
311 are deformed to grasp the fins 32. The plate-like base 31 and
the fins 32 of the heat sink 3 are made of aluminum or copper.
[0027] Referring to FIG. 7, in Step 54, the plate-like base 31 is
manufactured by powder metallurgy and the fins 32 are manufactured
by an impact extrusion process. Because density of components made
by powder metallurgy is less than that of aluminum or copper, the
processing of softening the plate-like base 31 is shortened. Then,
in step 55, the fins 32 can be positioned in the parallel grooves
311 of the plate-like base 31 and the plate-like base 31 is
subjected to a compressive force.
[0028] Thus, advantages of the present invention are described in
the following:
[0029] 1. The manufacturing process is straightforward and has a
low cost. The plate-like base 31 is formed on the heat sink 3 by an
impact extrusion process, and a plurality of parallel grooves 311
is formed by a stamping process. The plate-like base 31 is placed
in a high temperature furnace. The fins 32 are respectively
positioned in the parallel grooves 311 of the plate-like base 31,
and the plate-like base 31 is subjected to compressive forces. The
parallel grooves 311 are deformed to grasp the fins 32. Thus,
compared with the conventional method, the present invention
provides a simplified method and is significantly cheaper.
[0030] 2. The heat sink according to present invention has improved
efficiency of heat dissipation. Since the parallel grooves 311 of
the plate-like base 31 of the present invention abut against the
heat-generating component 42, the two flange segments 312 of the
plate-like base 31 are not in contact with two end portions 322 of
the fins 32. Thus, there is a gap between the circuit board 41 and
the fins 32. When the heat-generating component 42 is in use, the
central segment 311 of the plate-like base 31 conducts heat
generated by the heat-generating component 42 and carries heat into
the fins 32 of the two flange segments 312 and the plate-like base
31. Heat is vented away from the fins 32 with the help of cooling
air (a fan can be installed on the heat sink 3 to increase
efficiency of heat dissipation). After the cooling air is blown
onto the fins 32, the cooling air is blown along the thermal
transfer channels 323 between the fins 32 and is directed toward
the two end portions 322 of the fins 32. Further, a part of cooling
airflow is flows through the bottom of the thermal transfer
channels 323. Thus, a larger back pressure does not result to
lessen the cooling airflow of the fan. The heat sink 3 of one
embodiment of the present invention has a better efficiency of heat
dissipation.
[0031] 3. The heat sink is lightweight.
[0032] According to the present invention, the plate-like base 31
and the fins 32 of the heat sink 3 are respectively made of copper
and aluminum. The present invention is able to meet the requirement
of a light-weight of mobile electronic device. When the heat sink
is lightweight, it is not prone to damage during
transportation.
[0033] 4. The material of which the plate-like base 31 and the fins
32 are made can be replaced if necessary.
[0034] 5. There is no limitation of separation and height of the
fins 32.
[0035] While the invention has been described with reference to the
preferred embodiments, the description is not intended to be
construed in a limiting sense. It is therefore contemplated that
the appended claims will cover any such modifications or
embodiments as may fall within the scope of the invention defined
by the following claims and their equivalents.
* * * * *