U.S. patent application number 12/910292 was filed with the patent office on 2011-09-22 for modular heat sink and method for fabricating same.
Invention is credited to Eihab Baqui, Sharath KUMAR, Eran Plonski.
Application Number | 20110226458 12/910292 |
Document ID | / |
Family ID | 41254728 |
Filed Date | 2011-09-22 |
United States Patent
Application |
20110226458 |
Kind Code |
A1 |
Plonski; Eran ; et
al. |
September 22, 2011 |
MODULAR HEAT SINK AND METHOD FOR FABRICATING SAME
Abstract
There is described a method for fabricating a modular heat sink,
the method comprising: extruding N individual integral heat sink
segments using an extrusion process, each one of the N segments
corresponding to 1/N of the modular heat sink, N being an integer
greater than one; and assembling the N individual integral heat
sink segments together in order to obtain the modular heat
sink.
Inventors: |
Plonski; Eran; (Montreal,
CA) ; KUMAR; Sharath; (Laval, CA) ; Baqui;
Eihab; (Brossard, CA) |
Family ID: |
41254728 |
Appl. No.: |
12/910292 |
Filed: |
October 22, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/CA2009/000551 |
Apr 24, 2009 |
|
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12910292 |
|
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61048400 |
Apr 28, 2008 |
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Current U.S.
Class: |
165/185 ;
29/890.03 |
Current CPC
Class: |
F28F 21/084 20130101;
B23P 2700/10 20130101; B21C 23/10 20130101; F28F 1/42 20130101;
F28F 21/085 20130101; H01L 21/4882 20130101; F28F 2275/14 20130101;
B21C 23/14 20130101; F28F 3/02 20130101; H01L 23/367 20130101; F28F
1/422 20130101; H01L 2924/0002 20130101; F28F 1/16 20130101; H01L
2924/0002 20130101; F28D 2021/0029 20130101; H01L 2924/00 20130101;
Y10T 29/4935 20150115 |
Class at
Publication: |
165/185 ;
29/890.03 |
International
Class: |
F28F 7/00 20060101
F28F007/00; B21D 53/02 20060101 B21D053/02 |
Claims
1. A method for fabricating a modular heat sink, said method
comprising: extruding N individual integral heat sink segments
using an extrusion process, each one of said N segments
corresponding to 1/N of said modular heat sink. N being an integer
greater than one; and assembling said N individual integral heat
sink segments together in order to obtain said modular heat
sink.
2. The method as claimed in claim 1, wherein said extruding
comprises extruding N identical individual integral heat sink
segments.
3. The method as claimed in claim 1, wherein said extruding
comprises extruding at least two different individual integral heat
sink segments.
4. The method as claimed in claim 3, wherein said extruding
comprises extruding said at least two different individual integral
heat sink segments having a different shape.
5. The method as claimed in claim 3, wherein said extruding
comprises extruding said at least two different individual integral
heat sink segments from different materials.
6. The method as claimed in claim 1, wherein said assembling
comprises releasably connecting said N individual integral heat
sink segments together.
7. The method as claimed in claim 1, wherein said assembling
comprises permanently securing said N individual integral heat sink
segments together.
8. The method as claimed in claim 1, wherein said extruding
comprises extruding N connectable individual integral heat sink
segments, each having a male connector and a female connector
thereon, said female connector of each one of said N connectable
individual integral heat sink segments being adapted to receive
said male connector of another one of said N connectable individual
integral heat sink segments
9. The method as claimed in claim 8, wherein said extruding
comprises extruding four quadrants of a cylindrically shaped
modular heat sink.
10. The method as claimed in claim 1, wherein said extruding
comprises extruding said N individual integral heat sink segments
from one of aluminum and copper.
11. A modular heat sink comprising N extruded individual integral
heat sink segments connected together to form said modular heat
sink, each one of said N segments corresponding to 1/N of said
modular heat sink. N being an integer greater than one.
12. The modular heat sink as claimed in claim 11, wherein said N
extruded individual integral heat sink segments are identical.
13. The modular heat sink as claimed in claim 11, wherein at least
two of said N extruded individual integral heat sink segments are
different.
14. The modular heat sink as claimed in claim 13, wherein said at
least two of said N extruded individual integral heat sink segments
have a different shape.
15. The modular heat sink as claimed in claim 13, wherein at least
one of said N extruded individual integral heat sink segments is
made from a different material.
16. The modular heat sink as claimed in claim 11, wherein said N
extruded individual integral heat sink segments are releasably
connected together.
17. The modular heat sink as claimed in claim 11, wherein said N
extruded individual integral heat sink segments are permanently
secured together.
18. The modular heat sink as claimed in claim 11, wherein each one
of said N extruded individual integral heat sink segments comprises
a male connector and a female connector thereon, said male
connector of each of said N extruded individual integral heat sink
segments being received in said female connector of another one of
said N extruded individual integral heat sink segments.
19. The modular heat sink as claimed in claim 11, wherein said N
extruded individual integral heat sink segments are made of one of
aluminum and copper.
20. The modular heat sink as claimed in claim 11, wherein said N
extruded individual integral heat sink segments are four quadrants
of a cylindrically shaped modular heat sink.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation under 35 USC
.sctn.120 of International patent application no. PCT/CA2009/000551
filed Apr. 24, 2009 entitled MODULAR HEAT SINK AND METHOD FOR
FABRICATING SAME, which claims priority under 35 USC .sctn.119(e)
of Provisional Patent Application bearing Ser. No. 61/048,400,
filed on Apr. 28, 2008, the contents of which are hereby
incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to the field of heat
dissipation devices, also known as heat sinks.
BACKGROUND OF THE INVENTION
[0003] Devices such as electronic circuits and lighting systems
usually emit heat while functioning, and this emitted heat can be
harmful to the device. For example, an increased temperature can
shorten the lifetime of a lighting system and/or decrease its
brightness. As a result, cooling the lighting device is required to
ensure a long lifetime and/or a high brightness.
[0004] Heat sinks can be used to cool heat generating devices. A
heat sink cools the device by absorbing and dissipating generated
heat. A heat sink is made of a thermal conductive material and has
a specific shape which improves the transfer of heat, whereby the
shape is specifically determined by a need for greater surface
area. Extrusion techniques are usually used to fabricate heat sinks
as it is an efficient and cost-saving fabrication technique in
comparison to other fabrication processes such as casting or
machining. However, when using this fabrication process, the
dimensions of heat sinks are limited because of limitations
inherent to the extrusion process. Hence, it is not possible to
make heat sinks for large lighting systems when using the extrusion
process.
[0005] Therefore, there is a need for improvements to the methods
for fabricating heat sinks adapted to large heat generating
devices.
SUMMARY OF THE INVENTION
[0006] According to a broad aspect, there is provided a method for
fabricating a modular heat sink, the method comprising: extruding N
individual integral heat sink segments using an extrusion process,
each one of the N segments corresponding to 1/N of the modular heat
sink, N being an integer greater than one; and assembling the N
individual integral heat sink segments together in order to obtain
the modular heat sink.
[0007] According to a second broad aspect, there is provided a
modular heat sink comprising a N extruded individual integral heat
sink segments connected together to form the modular heat sink,
each one of the N segments corresponding to 1/N of the modular heat
sink, N being an integer greater than one.
[0008] The expression "heat sink segment" is to be understood as
any device made in a single piece and having heat sink properties.
A heat sink segment forms a heat sink when connected to at least
another heat sink segment. The characteristics of each heat sink
segment, such as the shape and dimensions for example, are defined
so that the heat sink segments form the heat sink when connected
together and can be fabricated by any adequate type of extrusion
process. The heat sink segments being part of the heat sink can be
identical. Alternatively, they can have different shapes and/or
dimensions and/or be made of different materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Further features and advantages of the present invention
will become apparent from the following detailed description, taken
in combination with the appended drawings, in which:
[0010] FIG. 1 illustrates a heat sink according to the prior
art;
[0011] FIG. 2 is a flow chart of a method for fabricating a modular
heat sink, in accordance with an embodiment;
[0012] FIG. 3 is a top view of a quadrant heat sink segment, in
accordance with an embodiment;
[0013] FIG. 4 is a top view of a cylindrical heat sink made of four
heat sink segments as shown in FIG. 2, in accordance with an
embodiment;
[0014] FIG. 5 is a perspective view of a cubic heat sink segment
having a single aperture, in accordance with an embodiment;
[0015] FIG. 6A is a perspective view of a heat sink formed of four
cubic heat sink segments as shown in FIG. 4, in accordance with an
embodiment;
[0016] FIG. 6B is a perspective view of a modular heat sink
comprising straps to maintain heat sink segments in position, in
accordance with an embodiment;
[0017] FIG. 7 is a perspective view of a cubic heat sink segment
having five apertures, in accordance with an embodiment;
[0018] FIG. 8 is a side view of a heat sink formed of two
rectangular heat sink segments to form a heat sink as illustrated
in FIG. 6, in accordance with an embodiment;
[0019] FIG. 9A is a top view of a cubic modular heat sink
comprising four apertures, in accordance with an embodiment;
and
[0020] FIG. 98 is a top view of a modular heat sink provided with
seven apertures, in accordance with an embodiment.
[0021] It will be noted that throughout the appended drawings, like
features are identified by like reference numerals.
DETAILED DESCRIPTION
[0022] FIG. 1 illustrates a heat sink 10 according to the prior
art. Heat sink 10 comprises a top and a bottom circular surface and
a lateral cylindrical surface. The heat sink 10 has a specific
shape in order to increase its total surface area that is in
contact with a cooling fluid such as air. The lateral surface of
the heat sink 10 is provided with fins 12. A central aperture 14
and lateral apertures 16 extend from the top surface to the bottom
surface. The fins 12, the central aperture 14 and the lateral
apertures 16 increase the total surface area of heat sink 10 that
is in contact with air, which allows the cooling of an electronic
device to be in physical contact with the heat sink 10.
[0023] According to the prior art, heat sinks are made in a single
piece. When heat conductive material such as aluminum or copper is
used to fabricate heat sinks by extrusion, the size of the heat
sink is limited because of the extrusion process. Extrusion can be
any adequate fabrication process which consists in pushing material
through a die of a desired profile shape. However, a large heat
sink fabricated following this process does not present good
mechanical properties such as rigidity. These poor mechanical
properties are inherent to the extrusion process.
[0024] A heat sink is designed in accordance with the
characteristics of the object to be cooled, a target temperature
for the object, the characteristics of the environment in which the
heat sink will be placed, etc. For example, if the modular heat
sink is to be used to cool an LED board comprising a plurality of
LEDs, the characteristics of the modular heat sink are chosen in
accordance with the dimensions of the LED board, the repartition of
the LEDs on the LED board, the heat generated by the LEDs, the
temperature of the environment in which the heat sink is to be
placed, a target temperature for the LED board, etc. The
characteristics of a heat sink comprises, but are not limited to,
the shape, the dimensions, the material properties such as rigidity
for example, and the like. If the characteristics of the heat sink
prevent the heat sink from being fabricated in a single piece by
extrusion, then the method illustrated in FIG. 2 can be used to
fabricate the heat sink.
[0025] FIG. 2 illustrates one embodiment of a method 20 for
fabricating a modular heat sink. The first step 22 consists in
extruding N individual integral heat sink segments using an
extrusion process. N is an integer greater than one so that at
least two individual integral heat sink segments are extruded. Each
one of the N segments corresponds to 1/N of the modular heat sink
to be fabricated. The second step 24 consists in assembling the N
individual integral heat sink segments together in order to obtain
the modular heat sink. In one embodiment, the assembling can
consist in releasably connecting the individual integral heat sink
segments together. In an alternate embodiment, the assembling can
consist in permanently and fixedly securing the individual integral
heat sink segments together.
[0026] In one embodiment, a heat sink is to be fabricated while
using an extrusion process and the heat sink is broken down into
two pieces, i.e. two individual integral heat sink segments, each
corresponding to one half of the heat sink. In another embodiment,
the heat sink is broken down into three pieces, i.e. three
individual integral heat sink segments, each corresponding to one
third of the heat sink. The breaking down of the heat sink is
performed with the desired number of individual integral heat sink
segments that can be fabricated in a single piece while using an
extrusion process.
[0027] In one embodiment, the heat sink to be fabricated is
symmetrical and the N individual integral heat sink segments are
substantially identical. In another embodiment, the N individual
integral heat sink segments are different while each one of the N
individual integral heat sink segments corresponds to 1/N of the
heat sink. The nature of the differences between the segments can
be material, shape, surface area, volume of material, etc.
[0028] It should be understood that any assembling means such as
male-female connectors, fasteners, adhesive, welding, etc, can be
used for releasably or permanently connecting the heat sink
segments together. In one embodiment, the heat sink segments are
fixedly secured together once connected. This can be achieved by
welding, permanent adhesive bonding, etc. In another embodiment, a
relative movement between the heat sink segments is possible once
connected together. In this case, the heat sink segments become
fixedly secured together once attached to the object to be cooled.
It should be understood that more than one assembling means can be
used for connecting the individual integral heat sink segments
together. For example, a combination of male/female connector and
adhesive bonding can be used.
[0029] In one embodiment, a heat sink having a shape similar to the
heat sink 10 is made in multiple steps. The heat sink is divided
into several heat sink segments, each one having dimensions adapted
to be fabricated while using the extrusion process. The different
heat sink segments are then assembled together to form a large heat
sink having a shape such as the shape of heat sink 10.
[0030] It should be understood that heat sinks having any shape can
be fabricated while using the process illustrated in FIG. 2. A
complete heat sink having a given shape is broken down into at
least two pieces or segments which are made in a single piece by
extrusion. The breaking down of the complete heat sink is made so
that each resulting individual heat sink segment can be fabricated
integrally. The different segments are then assembled together to
create the heat sink of the given shape.
[0031] FIG. 3 illustrates the top view of a heat sink segment 120
in accordance with an embodiment. The heat sink segment 120
corresponds to a quadrant of a cylindrical heat sink 150
illustrated in figure. The heat sink segment 120 is made of a
single piece of heat conductive material. The heat sink segment 120
is provided with fins 124 on one of its lateral surfaces. A central
aperture 126 extends from the top surface to the bottom surface
(not shown) of heat sink segment 120. The fins 124 and the aperture
126 allow the surface of heat sink segment 120 that is in contact
with the cooling fluid to be increased. The heat sink segment 120
is also provided with a circular recess 128 and a projecting end
130, which extend along a length of the heat sink segment 120. The
shape and dimensions of the circular recess 128 and the projecting
end 130 are adapted to form a male/female connector so that the
projecting end 130 of one heat sink segment 120 can fit into a
circular recess 128 of another heat sink segment 120. The heat sink
segment 120 is also provided with a round surface 132 opposite to
the lateral surface having fins 124 and a recess 134, 136 on the
other two lateral surfaces. The recess 134 is adjacent to the
circular recess 128 while the recess 136 is adjacent to the
projecting end 130.
[0032] The heat sink 150 is created by assembling four identical
heat sink segments 120 together, as illustrated in FIG. 4. The
projecting end 130 of one heat sink segment 120 fits into the
circular recess 128 of a next heat sink segment 120 like a tenon
fits into a mortise. This secures the four heat sink segments 120
together to give rise to the heat sink 150. The resulting heat sink
150 has a cylindrical shape and presents the fins 124 that extend
along its external lateral surface. The apertures 126 extend from
the top surface to the bottom surface of the heat sink 150. An
aperture 152 having the shape of a cross is formed by the round
surface 132 and the recesses 134 and 136 of each heat sink segment
120. The aperture 152 also extends from the top surface to the
bottom surface of the heat sink 150.
[0033] In one embodiment, each circular recess 128 is closed at one
end, thereby forming an abutting surface. Each projecting end 130
is inserted in its corresponding circular recess 128 via the open
end of the corresponding circular recess 128 and slides therein
until abutting against the closed end of the corresponding recess
128. In another embodiment, the circular recesses 128 are each
provided with an open end at their two extremities. In this case,
the heat sink segments 120 can have a longitudinal relative
movement. In order to fixedly secure the heat sink segments 120
together, any adequate type of mechanical fasteners such as screws,
bolts, etc, can be used. Alternatively, any adequate type of
adhesive can be used for securing the heat sink segments together.
In another embodiment, the heat sink segments 120 become fixedly
secured together once the heat sink 150 is attached to the object
to be cooled.
[0034] While FIGS. 3 and 4 refer to recesses 128 and projecting
ends 130 having a circular shape, it should be understood that they
can be provided with any shape that allows a heat sink segment to
fit and/or to slide into another heat sink segment in order to form
a heat sink. For example, a recess and a projecting end each having
a T-shape is also possible. Any adequate type of mechanical
male-female connectors can be used for connecting the heat sink
segments 120 together.
[0035] FIG. 5 illustrates one embodiment of a heat sink segment 160
which corresponds to a quadrant of a cubic heat sink 170
illustrated in FIG. 6A. The heat sink segment 160 is made of a
single heat conductive piece having a substantially cubic shape.
The heat sink segment 160 is provided with a round surface 164 and
an aperture 162 extending through from one face to an opposite face
of the heat sink segment 160.
[0036] FIG. 6A illustrates a heat sink 170 made of four identical
heat sink segments 160, in accordance with one embodiment. The four
heat sink segments 160 are secured to each other by adhesive
bonding 172 in order to form heat sink 170. The adhesive used to
secure the heat sink segments 160 together is chosen to be
resistant to the temperature of the heat sink 170. The resulting
heat sink 170 presents a central aperture 172 which is formed by
the round surface 164 of the heat sink segments 160, and four
apertures 162 extending from the front face to the rear face of the
heat sink 170.
[0037] It should be understood that any mechanical means can be
used to connect the single piece heat sink segments together to
form the modular heat sink. The mechanical means can be either
permanent or non-permanent. For example, the heat sink segments can
be designed so that they fit together and assembly results in the
modular heat sink. In another example, a permanent or non-permanent
adhesive can be used to connect the heat sink segments together.
The heat sink segments can also be welded together. FIG. 63
illustrates one embodiment of a heat sink 176 which uses straps 178
in order to maintain the assembly in position. The heat sink 176 is
made of four heat sink segments 160 and has the same shape and
dimensions as the heat sink 170, The straps 178 surround the heat
sink segments 60 and maintain them in position. A combination of
different assembling means, such as a combination of a male/female
connector and an adhesive bonding, can also be used.
[0038] FIG. 7 illustrates another example of a heat sink segment
180 that can be used to make a heat sink similar to heat sink 170.
The heat sink segment 180 is made in a single piece using usual
extrusion technique. The heat sink segment 180 is provided with a
central penetrating aperture 182 and four penetrating apertures
184. The heat sink segment 180 has a similar shape as heat sink 170
but its width is half the width of heat sink 170 and is therefore
not adapted for an adequate cooling.
[0039] FIG. 8 illustrates a side view of a heat sink 186, in
accordance with one embodiment. The heat sink 186 is made of two
identical heat sink segments 180 which are stacked together. The
two heat sink segments 180 are secured together by an adhesive
bonding 188. The heat sink 186 has the same shape and dimensions as
the heat sink 170. Alternatively, the heat sink segments 180 may be
connected together using any adequate type of connection means or
combination of connection means such as a male/female connector for
example.
[0040] While the previous embodiments refer to a modular heat sink
composed of N identical heat sink segments, it should be understood
that the N heat sink segments can have different shapes as long as
each one of the N heat sink segments corresponds to 1/N of the heat
sink, and can be made of different materials, such as copper.
[0041] FIG. 9A illustrates the top view of a modular heat sink 200
comprising four individual integral heat sink segments 202, 204,
206, 208. The four heat sink segments 202, 204, 206, 208 are
connected together by a releasable connection such as a
non-permanent adhesive bonding for example. Each heat sink segment
202, 204, 206, 208 is provided with an aperture 210, 212, 214, 216
which extends from the top face to the bottom face of the heat sink
segment 202, 204, 206, 208. The heat sink 200 can be used to cool a
heat generating device which generates heat uniformly along its
surface upon contact with the heat sink 200. If the heat generating
device is replaced by another device which generates heat
non-uniformly along its surface, such as a device that generates
more heat in a region in contact with the heat sink segment 204,
the heat sink 200 will no longer be adapted to cool the heat
generating device. If a standard heat sink made in a single piece
is used to adequately cool the device, a new heat sink adapted to
the new heat generating device has to be provided. If the heat sink
is the modular heat sink 200, only the heat sink segment 204 facing
the hottest region of the new device can be changed.
[0042] FIG. 9B illustrates the top view of a heat sink 220 which is
adapted to cool the new device which non-uniformly generates heat,
according to one embodiment. The heat sink 220 is similar to the
heat sink 200 but the heat sink segment 204 is replaced by the heat
sink segment 222 which is fabricated using the extrusion process.
The heat sink segment 222 is provided with four apertures 224 which
extend from the top surface to the bottom surface of the heat sink
segment 222. In comparison to the heat sink segment 204, the heat
sink segment 222 provides greater cooling since it is provided with
four apertures 224.
[0043] The heat sink 220 represents an example of a non-symmetrical
heat sink. The heat sink segments 202, 206, 208, and 222 are not
identical but each one of the heat sink segments 202, 206, 208, and
222 corresponds to 1/4 of the heat sink 220.
[0044] It should be understood that the heat sink segments 202-208
and 222 can be shaped so that the heat sinks 200 and 220 are
provided with fins such as fins 224 on their outer lateral
surface.
[0045] It should be understood that the modular heat sink can have
any shape and/or dimension. The heat sink segments constituting the
modular heat sink can also have any shape and/or dimensions as long
as they form the modular heat sink when they are assembled
together.
[0046] It should be understood that any material having good
thermal conductivity such as aluminum or copper can be used to
fabricate the heat sink segments.
[0047] It should be noted that modular heat sinks can be used to
cool any devices which generate heat, such as lighting systems,
electronic circuits, and the like.
[0048] The embodiments of the invention described above are
intended to be exemplary only. The scope of the invention is
therefore intended to be limited solely by the scope of the
appended claims.
* * * * *