U.S. patent application number 16/802641 was filed with the patent office on 2021-09-02 for cooling of server high-power devices using double-base primary and secondary heat sinks.
The applicant listed for this patent is Cisco Technology, Inc.. Invention is credited to Rakesh Bhatia, Mark Hong Chen.
Application Number | 20210274685 16/802641 |
Document ID | / |
Family ID | 1000004717264 |
Filed Date | 2021-09-02 |
United States Patent
Application |
20210274685 |
Kind Code |
A1 |
Bhatia; Rakesh ; et
al. |
September 2, 2021 |
COOLING OF SERVER HIGH-POWER DEVICES USING DOUBLE-BASE PRIMARY AND
SECONDARY HEAT SINKS
Abstract
A cooling system includes a primary heat sink including a
primary top base plate, a primary bottom base plate and a primary
fin pack including a plurality of fins, where the primary fin pack
is disposed between the primary top base plate and the primary
bottom base plate. The cooling system further includes secondary
heat sink including a secondary top base plate, a secondary bottom
base plate and a secondary fin pack including a plurality of fins,
where the secondary fin pack is disposed between the secondary top
base plate and the secondary bottom base plate. A heat pipe extends
between the primary top base plate and the primary bottom base
plate, where the heat pipe further extends from the primary heat
sink and couples with the secondary heat sink.
Inventors: |
Bhatia; Rakesh; (San Jose,
CA) ; Hong Chen; Mark; (Palo Alto, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cisco Technology, Inc. |
San Jose |
CA |
US |
|
|
Family ID: |
1000004717264 |
Appl. No.: |
16/802641 |
Filed: |
February 27, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05K 7/20727 20130101;
H05K 1/0203 20130101; H05K 7/20809 20130101; H05K 7/20154 20130101;
H05K 7/20336 20130101 |
International
Class: |
H05K 7/20 20060101
H05K007/20; H05K 1/02 20060101 H05K001/02 |
Claims
1. (canceled)
2. The cooling system of claim 4, further comprising a plurality of
secondary heat sinks coupled with the primary heat sink.
3. The cooling system of claim 6, wherein a top portion of the heat
pipe extends between the primary top base plate and a top side of
the primary fin pack, and a bottom portion of the heat pipe extends
between the primary bottom base plate and a bottom side of the
primary fin pack.
4. A cooling system comprising: a primary heat sink comprising a
primary top base plate, a primary bottom base plate and a primary
fin pack comprising a plurality of fins, wherein the primary fin
pack is disposed between the primary top base plate and the primary
bottom base plate; a secondary heat sink comprising a secondary top
base plate, a secondary bottom base plate and a secondary fin pack
comprising a plurality of fins, wherein the secondary fin pack is
disposed between the secondary top base plate and the secondary
bottom base plate; and a plurality of heat pipes extending between
the primary top base plate and the primary bottom base plate so as
to couple the primary heat sink with the secondary heat sink, the
plurality of heat pipes comprising: a first heat pipe extending
from the primary top base plate to the primary bottom base plate
and further from the primary bottom base plate to the secondary
bottom base plate; and a second heat pipe extending from the
primary bottom base plate to the primary top base plate and further
from the primary top base plate to the secondary top base
plate.
5. The cooling system of claim 4, wherein a length dimension of the
fins for the secondary fin pack is less than a length dimension of
the fins for the primary fin pack, and each length dimension is
defined in a direction of airflow through the primary fin pack and
the secondary fin pack.
6. A cooling system comprising: a primary heat sink comprising a
primary top base plate, a primary bottom base plate and a primary
fin pack comprising a plurality of fins, wherein the primary fin
pack is disposed between the primary top base plate and the primary
bottom base plate; a secondary heat sink comprising a secondary top
base plate, a secondary bottom base plate and a secondary fin pack
comprising a plurality of fins, wherein the secondary fin pack is
disposed between the secondary top base plate and the secondary
bottom base plate; and a heat pipe that extends between the primary
top base plate and the primary bottom base plate, wherein the heat
pipe further extends from the primary heat sink and couples with
the secondary heat sink; wherein each of the primary top base plate
and the primary bottom base plate includes a cut-out section, and
the cooling system further comprises a primary top block plate
connected with the primary top base plate at the cut-out section,
and a primary bottom block plate connected with the primary bottom
base plate at the cut-out section.
7. The cooling system of claim 6, wherein each of the primary top
block plate and the primary bottom block plate has a different
thermal conductivity in relation to each of the primary top base
plate and the primary bottom base plate.
8-9. (canceled)
10. A cooling system comprising: a primary heat sink comprising a
primary top base plate, a primary bottom base plate and a primary
fin pack comprising a plurality of fins, wherein the primary fin
pack is disposed between the primary top base plate and the primary
bottom base plate; a first secondary heat sink comprising a first
secondary top base plate, a first secondary bottom base plate and a
first secondary fin pack comprising a plurality of fins, wherein
the first secondary fin pack is disposed between the first
secondary top base plate and the first secondary bottom base plate;
a second secondary heat sink comprising a second secondary top base
plate, a second secondary bottom base plate and a second secondary
fin pack comprising a plurality of fins, wherein the second
secondary fin pack is disposed between the second secondary top
base plate and the second secondary bottom base plate; and a
plurality of heat pipes, the plurality of heat pipes comprising: a
first heat pipe that extends between the primary top base plate and
the primary bottom base plate and further extends from the primary
heat sink to couple with the first secondary heat sink; and a
second heat pipe that extends between the primary top base plate
and the primary bottom base plate and further extends from the
primary heat sink to couple with the second secondary heat sink;
wherein: a top portion of each of the first heat pipe and the
second heat pipe extends between the primary top base plate and a
top side of the primary fin pack, and a bottom portion of each of
the first heat pipe and the second heat pipe extends between the
primary bottom base plate and a bottom side of the primary fin
pack; the first heat pipe extends from the primary top base plate
to the primary bottom base plate and further from the primary
bottom base plate to the first secondary bottom base plate; and the
second heat pipe extends from the primary top base plate to the
primary bottom base plate and further from the primary bottom base
plate to the second secondary bottom base plate.
11. The cooling system of claim 10, further comprising: a third
heat pipe that extends from the primary bottom base plate to the
primary top base plate and further from the primary top base plate
to the first secondary top base plate; and a fourth heat pipe that
extends from the primary bottom base plate to the primary top base
plate and further from the primary top base plate to the second
secondary top base plate.
12. The cooling system of claim 10, wherein a length dimension of
the fins for each of the first secondary fin pack and the second
secondary fin pack is less than a length dimension of the fins for
the primary fin pack, and each length dimension is defined in a
direction of airflow through the primary fin pack, the first
secondary fin pack and the second secondary fin pack.
13. The cooling system of claim 10, wherein each of the primary top
base plate and the primary bottom base plate includes a cut-out
section, and the cooling system further comprises a primary top
block plate connected with the primary top base plate at the
cut-out section, and a primary bottom block plate connected with
the primary bottom base plate at the cut-out section.
14. The cooling system of claim 13, wherein each of the primary top
block plate and the primary bottom block plate has a different
thermal conductivity in relation to each of the primary top base
plate and the primary bottom base plate.
15. An apparatus comprising: a printed circuit board (PCB); a heat
generating component integrated with the PCB; and the cooling
system of claim 4.
16. The apparatus of claim 15, further comprising: one or more fans
disposed along the PCB so as to direct a flow of air through each
of the primary fin pack and the secondary fin pack.
17. The apparatus of claim 15, wherein the cooling system further
comprises a plurality of secondary heat sinks disposed along the
PCB and coupled with the primary heat sink.
18. (canceled)
19. The apparatus of claim 15, wherein the heat generating
component comprises a processor.
20. The apparatus of claim 15, wherein the apparatus comprises a
server that houses the PCB and the cooling system.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to heat sink structures for
providing cooling to electronic devices.
BACKGROUND
[0002] Typical high-power devices used on servers or other
computing devices, such as a CPU (central processing unit), a GPU
(graphics processing unit) or another integrated circuit component,
require a significant amount of power (e.g., in a range of about
300 Watts), and the trend for power consumption of such components
has been ever increasing. This in turn results in an ever
increasing heat dissipation by these components. In order to
properly cool the high-power components and maintain temperatures
under rated thermal specifications, heat sinks for air cooling are
deployed on the printed circuit board (PCB) of a device. It is
ideal to provide heat sink structures that effectively cool and
dissipate heat such high-power devices and further are arranged to
minimize the footprint on the PCB.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a view in perspective of an example embodiment of
an electronic device including a cooling system.
[0004] FIG. 2 is a top view in plan of the electronic device with
cooling system of FIG. 1.
[0005] FIG. 3A is a front view in perspective of the primary and
secondary double-base heat sinks of the cooling system of FIG.
1.
[0006] FIG. 3B is a rear view in perspective of the primary and
secondary double-base heat sinks of the cooling system of FIG.
1.
[0007] FIG. 4 is an exploded view in perspective of the primary and
secondary double-base heat sinks of the cooling system of FIG.
1.
DESCRIPTION OF EXAMPLE EMBODIMENTS
Overview
[0008] In an embodiment, a cooling system comprises a primary heat
sink comprising a primary top base plate, a primary bottom base
plate and a primary fin pack comprising a plurality of fins, where
the primary fin pack is disposed between the primary top base plate
and the primary bottom base plate. The cooling system also
comprises a secondary heat sink comprising a secondary top base
plate, a secondary bottom base plate and a secondary fin pack
comprising a plurality of fins, wherein the secondary fin pack is
disposed between the secondary top base plate and the secondary
bottom base plate. In addition, the cooling system comprises a heat
pipe that extends between the primary top base plate and the
primary bottom base plate, wherein the heat pipe further extends
from the primary heat sink and couples with the secondary heat
sink.
[0009] In another embodiment, a cooling system comprises a primary
heat sink comprising a primary top base plate, a primary bottom
base plate and a primary fin pack comprising a plurality of fins,
where the primary fin pack is disposed between the primary top base
plate and the primary bottom base plate. The cooling system further
comprises a first secondary heat sink and a second secondary heat
sink. The first secondary heat sink comprises a first secondary top
base plate, a first secondary bottom base plate and a first
secondary fin pack comprising a plurality of fins, where the first
secondary fin pack is disposed between the first secondary top base
plate and the first secondary bottom base plate. The second
secondary heat sink comprises a second secondary top base plate, a
second secondary bottom base plate and a second secondary fin pack
comprising a plurality of fins, where the second secondary fin pack
is disposed between the second secondary top base plate and the
second secondary bottom base plate. The cooling system further
comprises a plurality of heat pipes, where the plurality of heat
pipes comprises a first heat pipe and a second heat pipe. The first
heat pipe extends between the primary top base plate and the
primary bottom base plate and further extends from the primary heat
sink to couple with the first secondary heat sink. The second heat
pipe extends between the primary top base plate and the primary
bottom base plate and further extends from the primary heat sink to
couple with the second secondary heat sink.
[0010] In a further embodiment, an apparatus comprises a printed
circuit board (PCB), a heat generating component integrated with
the PCB, and a cooling system. The cooling system comprises a
primary heat sink disposed along the PCB and comprising a primary
top base plate, a primary bottom base plate and a primary fin pack
comprising a plurality of fins, where the primary fin pack is
disposed between the primary top base plate and the primary bottom
base plate, wherein the primary heat sink is disposed over the heat
generating component, a secondary heat sink disposed along the PCB
comprising a secondary top base plate, a secondary bottom base
plate and a secondary fin pack comprising a plurality of fins,
where the secondary fin pack is disposed between the secondary top
base plate and the secondary bottom base plate, and a heat pipe
that extends between the primary top base plate and the primary
bottom base plate, wherein the heat pipe further extends from the
primary heat sink and couples with the secondary heat sink.
EXAMPLE EMBODIMENTS
[0011] As described herein, a cooling system for cooling a
component of an electronic device comprises a primary heat sink and
at least one secondary heat sink thermally coupled with the primary
heat sink via at least one heat pipe. Each of the primary and
secondary heat sinks includes a double base, or a top base and a
bottom base, with a plurality of cooling fins disposed between the
top and bottom bases. Heat pipes also extend between the top and
bottom bases for each heat sink to facilitate transfer of heat
between top and bottom locations of each heat sink. The
configuration of the cooling system as described herein, in which a
double-base primary heat sink is thermally coupled with one or more
double-base secondary heat sinks, improves cooling fin efficiency
and facilitates improved energy efficiency by allowing cooling fans
associated with the cooling system to operate at slower fan speeds
during cooling operations.
[0012] The cooling system is useful for electronic devices, such as
network devices including server systems that include semiconductor
chips (e.g., CPUs (Central Processing Units), GPUs (Graphics
Processing Units), or semiconductor devices), which typically
require heat sinks to dissipate thermal energy generated by the
chips. Operational power for such devices can be about 300 Watts,
and the trend has been for power to be ever increasing with newer
technological designs. Example embodiments of electronic devices
with which the cooling system can be implemented include any number
of network devices in communication via any number of nodes (e.g.,
routers, switches, gateways, controllers, edge devices, access
devices, aggregation devices, core nodes, intermediate nodes, or
other network devices), which facilitate passage of data within the
network. One or more of the network devices may comprise one or
more fans and heat sinks as described herein to provide cooling to
electronic components (e.g., processors, such as CPUs or GPUs, or
other semiconductor devices) of the network device (e.g., server,
router, switch, or other network device). The network device may
further include any combination of memory, processors, power supply
units, and network interfaces.
[0013] As network systems speeds and power requirements increase,
the emission from electronic components increases along with a need
for improved cooling. In order to properly cool the high power
components and maintain their temperatures under rated thermal
specifications, heat sinks are implemented for use with air cooling
from fans. As the height of a heat sink increases, the fin
thickness (i.e., thicker material forming the elongated fins)
typically also increases to improve fin efficiency. However,
increasing fin thickness results in fewer fins to prevent air
pressure losses arising from lower air gaps from becoming too large
for system fans to drive air through the fins. To ensure improved
fin efficiency and minimize fin thickness, an alternative design is
desired. The cooling system as described herein provides a
configuration that achieves improved fin efficiency with minimized
fin thickness.
[0014] Referring to FIGS. 1-4, an example embodiment is depicted of
a cooling system including double-base primary and secondary heat
sinks implemented with an electronic device to provide cooling to
one or more components of the electronic device during operations
of the device. As shown in FIGS. 1 and 2, an electronic device 10,
e.g., a network or other electronic device such as a rack server,
includes a generally rectangular chassis or housing 12. Disposed
within the housing 12 are various components, including a printed
circuit board (PCB) with various integrated circuit and/or other
components integrated within layers of the PCB and/or disposed at a
top surface of the PCB. The components integrated with the PCB can
include, e.g., transistors, capacitors, resistors, inductors, etc.
Conductive traces can be embedded within the layers and/or
deposited on the PCB, where the conductive traces connect
components with each other. In particular, the PCB includes one or
more processors 20, such as CPUs and/or GPUs, which control
operations of the device 10. Disposed at one end near a front side
of the housing 12 is one or more hard drives 30.
[0015] Centrally located within the housing 12 of the device 10 is
a cooling system 100 that comprises a plurality or array of cooling
fans 110 and heat sinks disposed at a location forward and
downstream (i.e., in a direction of cooling air flow from the fans,
shown as arrows labeled D in FIGS. 1 and 2) from the cooling fans
110. One or more sets of heat sinks can be disposed directly over
and/or adjacent to one or more heat generating components of the
PCB (e.g., directly over processors 20, shown generally as phantom
lines in FIG. 2). In particular, each set of heat sinks includes a
primary heat sink 150 and a pair of secondary heat sinks 160 each
of which is separately and independently connected or thermally
coupled with the primary heat sink 150 (e.g., via one or more heat
pipes) as described herein. The heat sinks transfer heat generated
by the electronic components to which the heat sinks are proximate
or adjacent so as to effectively cool the components during
operations of the device 10 in order to ensure effective
performance of the device 10. The heat sinks and cooling fans can
be secured with the PCB in any suitable manner via any suitable
types of fasteners (e.g., threaded fasteners).
[0016] As shown in FIGS. 1 and 2, the device 10 includes two sets
of heat sinks, where the primary heat sink 150 of each set is
disposed directly above a component (e.g., a processor 20), and
with secondary heat sinks 160 associated with each primary heat
sink 150 being disposed behind the primary heat sink 150 to which
it is thermally coupled. Each secondary heat sink 160 is further
disposed between the primary heat sink 150 to which it is thermally
coupled and the array of cooling fans 110, with the array of
cooling fans 110 being disposed directly behind the secondary heat
sinks 160 along the PCB. It is noted that an electronic device can
include any suitable number of sets of heat sinks (e.g., one or
more sets) as well as any suitable number of cooling fans,
depending upon a specific architecture of a PCB and the number
and/or types of components that require cooling during operations
of the device.
[0017] Each of the heat sinks includes two bases (i.e., each heat
sink comprises a double-base heat sink) in the form of an upper or
top base plate and a lower or bottom base plate, with the top and
bottom base plates being generally parallel with each other. The
bottom base plates of the heat sinks can include, e.g., threaded
fasteners or any other suitable engagement structure to secure the
heat sinks to the PCB of the device 10. It is noted that the terms
upper, top, lower, bottom, front, forward, rear and the like in
relation to the bases and other components as described herein are
relative terms dependent upon the orientation of the heat sinks and
device to which the heat sinks are secured and should not be
interpreted in a limiting manner.
[0018] Referring to FIGS. 3A, 3B and 4, the primary heat sink 150
includes a generally rectangular top base plate 202, a generally
rectangular bottom base plate 206 spaced from the top base plate
202, and a set of fins or a fin pack 200 disposed between the top
base plate 202 and the bottom base plate 206. Similarly, each
secondary heat sink 160 includes a top base plate, a bottom base
plate spaced from the top base plate, and a set of fins or fin pack
disposed between the top and bottom base plates. In particular, one
secondary heat sink 160 includes a generally rectangular top base
plate 302A, a generally rectangular bottom base plate 306A, and a
fin pack 300A disposed between the top base plate 302A and bottom
base plate 306A, while another secondary heat sink 160 includes a
generally rectangular top base plate 302B, a generally rectangular
bottom base plate 306B, and a fin pack 300B disposed between the
top base plate 302B and bottom base plate 306B.
[0019] The top and bottom base plates for each of the primary and
secondary heat sinks can be formed of a metal or other material
having a suitable thermal conductivity. In an example embodiment,
each of the top and bottom base plates for the primary and
secondary heat sinks are formed of aluminum. Each secondary heat
sink 160 that is thermally coupled with a primary heat sink 150 has
one or more overall dimensions (length, height and/or width
dimensions) that are smaller in relation to the overall dimensions
(length, height, width dimensions) of the primary heat sink. In an
example embodiment, the length dimensions for the fin packs and the
fins of the secondary heat sinks are less than the length
dimensions for the fin pack and the fins of the primary heat sink
thermally coupled with the secondary heat sinks (where each length
dimension is defined as the direction of air flow through the heat
sinks). In addition, the fin pack width dimension for each
secondary heat sink is also smaller in relation to the fin pack
width dimension for the primary sink thermally coupled with the
secondary heat sinks.
[0020] Each of the top and bottom base plates of the primary heat
sink 150 further includes a block plate that is integrated with the
base plate (e.g., provided as a separate plate that fits within a
cut-out section, opening or window of each base plate). For
example, the top base plate 202 of the primary heat sink 150
includes a generally rectangular top block plate 204 that fits
within an opening or cut-out section of and connects with the top
base plate 202, while the bottom base plate 206 includes a
generally rectangular bottom block plate 208 that fits within an
opening or cut-out section of and connects with the bottom base
plate 206. Each block plate is also formed of a metal or other
material having a suitable thermal conductivity, where the thermal
conductivity of the block plate can differ from the thermal
conductivity of the base plate to which it is connected. For
example, each block plate can have a greater thermal conductivity
compared to the thermal conductivity of the base plate to which the
block plate is connected. In an example embodiment, each block
plate of the primary heat sink is formed of copper, while each base
plate of the primary heat sink is formed of aluminum. As can be
seen, e.g., in FIG. 2, the cooling system 100 is arranged on the
PCB of the electronic device 10 such that the bottom block plate
208 of a primary heat sink 150 lies directly over (and in closest
proximity to) the component (e.g., processor 20) to be cooled.
[0021] The fin pack 200 for the primary heat sink 150 includes a
plurality of fins, and the fin pack 300A, 300B for each secondary
heat sink 160 includes a plurality of fins, where the fins comprise
thin conductive plates that are arranged in parallel with each
other and with their lengths oriented in-line or generally parallel
with a direction of airflow provided by the cooling fans located
behind the heat sinks. The fins for each fin pack are constructed
of a metal (e.g., aluminum) or other material having a suitable
thermal conductivity to provide effective heat transfer
performance. Each fin for the fin packs of the primary and
secondary heat sinks is very thin, having a thickness that is less
than about 0.50 millimeter (mm), preferably no greater than about
0.30 mm. In an example embodiment, each fin for the fin pack 200 of
the primary heat sink has a thickness of about 0.25 mm, while each
fin for the fin pack 300A and the fin pack 300B of the secondary
heat sinks has a thickness of about 0.20 mm.
[0022] The primary heat sink 150 includes a plurality of heat
pipes, each heat pipe having a curved or looped configuration that
allows the heat pipe to extend between the top base plate 202 and
the bottom base plate 206, where the heat pipes also extend to the
secondary heat sinks 160 in the manner as described herein. The
heat pipes are constructed of a metal (e.g., copper) or any other
material having a suitable thermal conductivity to enable heat
transfer along the heat pipes in the manner described herein. The
heat pipes are hollow and can include any suitable coolant or
working fluid sealed within the heat pipes to facilitate effective
heat transfer between different portions of the heat sinks via the
heat pipes. In addition, the heat pipes can have any suitable
transverse cross-sectional shapes (e.g., circular, oval/elliptical,
rectangular, etc.) as well as any suitable cross-sectional
dimensions. In an example embodiment, each heat pipe has a
cross-sectional dimension (e.g., diameter) in the range of less
than about 10 mm (e.g., about 6 mm).
[0023] Referring to FIGS. 3A, 3B and 4, a first heat pipe 250A and
a second heat pipe 250B have a general U-shape and originate at a
location at a top side of the fin pack 200, where the first and
second heat pipes are spaced apart and extend generally parallel to
each other from a location near a rear side and along the top side
of the fin pack 200 and below the top base plate 202 (i.e., top
portions of the first and second heat pipes are disposed between
the fin pack top side and the top base plate). The top base plate
202 can include channels or grooves along its bottom surface that
are suitably dimensioned to receive and retain the first and second
heat pipes so that the first and second heat pipes can sufficiently
contact the top base plate and the top edges of fins within the fin
pack 200 while the top block plate 204 also contacts the top edges
of the fins within the fin pack 200. The first heat pipe 250A and
the second heat pipe 250B further extend in a continuous manner
forward and along the top side, where each heat pipe then bends so
as to extend along the front side of the fin pack 200. Along the
front side of the fin pack 200 (as shown in FIG. 3A), the first
heat pipe 250A and the second heat pipe 250B bow slightly outward
and away from each other as they extend from the top base plate 202
to the bottom base plate 206. The first and second heat pipes bend
around the front side to a bottom side of the fin pack 200 and
continue to extend along the fin pack bottom side and above the
bottom base plate 206 (i.e., bottom portions of the first and
second heat pipes are disposed between the fin pack bottom side and
the bottom base plate). Similar to the top base plate 202, the
bottom base plate 206 can include channels or grooves along its top
surface that are suitably dimensioned to receive and retain the
first and second heat pipes so that the first and second heat pipes
can sufficiently contact the bottom base plate and the bottom edges
of fins within the fin pack 200 while the bottom base plate also
maintains contact with the bottom edges of the fins within the fin
pack 200.
[0024] The first and second heat pipes further extend along the
bottom side and from the front side to the rear side of the fin
pack 200. The first heat pipe 250A continues extending beyond the
rear side and away from the fin pack 200 (as shown in FIG. 3B) to
connect with the fin pack 300A of a secondary heat sink 160, while
the second heat pipe 250B continues extending beyond the rear side
and away from the fin pack 200 to connect with the fin pack 300B of
a secondary heat sink 160. The first and second heat pipes bend
outward and away from each other as they approach and connect with
a corresponding secondary heat sink 160 (thus thermally coupling
the primary and secondary heat sinks), where the first heat pipe
250A extends along a bottom side of fin pack 300A and above bottom
base plate 306A (i.e., the first heat pipe 250A is between the fin
pack bottom side and the bottom base plate 306A) and the second
heat pipe 250B extends along a bottom side of fin pack 300B and
above bottom base plate 306B (i.e., the second heat pipe 250B is
between the fin pack bottom side and the bottom base plate 306B).
The bottom base plates 306A, 306B for each fin pack 300A, 300B can
also include channels or grooves along their top surfaces that are
suitably dimensioned to receive and retain the first and second
heat pipes so that the first and second heat pipes can sufficiently
contact the bottom base plates and bottom edges of the fin packs
300A, 300B while the bottom base plates of the secondary heat sinks
also maintain contact with the bottom edges of their corresponding
fin packs.
[0025] A third heat pipe 260A and a fourth heat pipe 260B have
similar shapes but extend in an opposite manner in relation to the
first and second heat pipes. In particular, each of the third heat
pipe 260A and the fourth heat pipe 260B has a general U-shape and
originates at a location at the bottom side of the fin pack 200,
where the third and fourth heat pipes are aligned close together
and extend generally parallel to each other from a location near a
rear side and along the bottom side of the fin pack 200 and above
the bottom base plate 206 (i.e., bottom portions of the third and
fourth heat pipes are disposed between the fin pack bottom side and
the bottom base plate). The third and fourth heat pipes are further
located along the space between the first and second heat pipes at
the bottom side of the fin pack 200, where the third and fourth
heat pipes also extend along the bottom block plate 208. As with
the first and second heat pipes, the bottom base plate 206 (and
also the bottom block plate 208) can include channels or grooves
along its top surface that are suitably dimensioned to receive and
retain the third and fourth heat pipes so that the third and fourth
heat pipes can sufficiently contact the bottom base plate (and
bottom block plate) and the bottom edges of fins within the fin
pack 200 while the bottom base plate (and bottom block plate)
maintains contact with the bottom edges of the fins within the fin
pack 200. The third heat pipe 260A and the fourth heat pipe 260B
further extend in a continuous manner forward and along the bottom
side of the fin pack 200, where each heat pipe then bends so as to
extend along the front side of the fin pack 200. Along the front
side of the fin pack 200 (as shown in FIG. 3A), the third heat pipe
260A and the fourth heat pipe 260B bow slightly outward and away
from each other as they extend from the bottom base plate 206 to
the top base plate 202. The third and fourth heat pipes are further
located between the first and second heat pipes along the front
side of the fin pack 200. The third and fourth heat pipes 260A,
260B bend around the front side to the top side of the fin pack 200
and continue to extend along the fin pack top side and above the
bottom base plate 206 (i.e., top portions of the third and fourth
heat pipes are disposed between the fin pack top side and the top
base plate). The third and fourth heat pipes are also located
between the first and second heat pipes at the top side of the fin
pack 200, where the third and fourth heat pipes further extend
beneath the top block plate 204. The top base plate 202 (and top
block plate 204) can include channels or grooves along its bottom
surface that are suitably dimensioned to receive and retain the
third and fourth heat pipes so that the third and fourth heat pipes
can sufficiently contact the top base plate (and top block plate)
and the top edges of fins within the fin pack 200 while the top
base plate (and top block plate) maintains contact with the top
edges of the fins within the fin pack 200.
[0026] The third and fourth heat pipes further extend along the top
side and from the front side to the rear side of the fin pack 200.
The third heat pipe 260A continues extending beyond the rear side
and away from the fin pack 200 to the fin pack 300A (as shown in
FIG. 3B) of the corresponding secondary heat sink 160, while the
fourth heat pipe 260B continues extending beyond the rear side and
away from the fin pack 200 to the fin pack 300B of the
corresponding secondary heat sink 160. The third and fourth heat
pipes bend outward and away from each other as they approach and
connect with their corresponding secondary heat sink 160 (so as to
thermally couple the primary heat sink with each secondary heat
sink), where the third heat pipe 260A extends along a top side of
fin pack 300A and beneath top base plate 302A (i.e., the third heat
pipe 260A is between the fin pack top side and the top base plate
302A) and the fourth heat pipe 260B extends along the top side of
fin pack 300B and beneath top base plate 302B (i.e., the fourth
heat pipe 260B is between the fin pack top side and the top base
plate 302B). The top base plates 302A, 302B for each fin pack 300A,
300B can also include channels or grooves along their bottom
surfaces that are suitably dimensioned to receive and retain the
third and fourth heat pipes so that the third and fourth heat pipes
can sufficiently contact the top base plates and top edges of the
fin packs 300A, 300B while each of the top base plate 302A and the
top base plate 302B also maintains contact with the top edges of
its corresponding fin pack 300A or fin pack 300B.
[0027] Each of the first heat pipe 250A, second heat pipe 250B,
third heat pipe 260A and fourth heat pipe 260B extends in a
direction along the top and bottom sides of the primary heat sink
150 that is in-line or generally parallel with the lengthwise
direction of the fins (i.e., in-line or generally parallel to the
direction of air flow) for fin pack 200 of the primary heat sink
150. The same heat pipes also extend in a direction along the top
side or the bottom side of the corresponding secondary heat sink
160 that is transverse (e.g., perpendicular) with the lengthwise
direction of the fins (i.e., transverse or perpendicular to the
direction of air flow) for fin packs 300A, 300B. The directions of
the heat pipes as well as the location of the heat pipes within the
channels of the base plates (and top block plates) helps to
minimize the width dimensions of the heat sinks as well as to
minimize or prevent removal of cut-out portions of slices of the
fins for the fin packs when the heat pipes traverse the top and
bottom sides of the fin packs. The heat pipes are also oriented so
that the primary heat sink includes the same number of heat pipes
extending along its top and bottom base plates (e.g., the primary
heat sink 150 in the example embodiment includes four heat pipes
extending along its top and bottom base plates, and each secondary
heat sink 160 in the example embodiment includes two heat pipes
extending along its top and bottom base plates).
[0028] During operations of the device 10, the cooling fans 110 are
operated provide a flow of air at a selected flow rate along the
direction shown by arrows labeled as D (as shown in FIGS. 1 and 2)
toward secondary heat sinks 160 and primary heat sink 150 for each
set of heat sinks in the cooling system 100, where the airflow
passes through the lengthwise dimension of the fin packs 300A,
300B, 200. The cooling fans 110 can be operated based upon an
indication (e.g., one or more measured temperatures obtained by one
or more temperature sensors provided at selected locations along
the PCB) that cooling is required for one or more components of the
device, such as processors 20.
[0029] The heat pipes operate to transport and dissipate thermal
energy from the top and bottom base plates of the primary heat sink
150 and the secondary heat sinks 160 toward a central location of
the fin packs. The top and bottom base plates also conduct heat
from the top and bottom sides of the heat sinks toward a central
location of the fins in the fin packs. The airflow provided by the
cooling fans 110 is directed first through the fins of fin packs
300A, 300B and then through fin pack 200 (since primary heat sink
150 is located forward the secondary heat sinks 160 and the cooling
fans 110 and thus downstream in the direction of airflow from the
cooling fans) to effectively draw heat away from the heat sinks and
the PCB components being cooled. The combined use of a primary heat
sink with one or more (e.g., two) secondary heat sinks, where each
heat sink includes a double base (i.e., an upper/top and
lower/bottom base plate), also provides a more efficient
dissipation of thermal energy from high power devices on the PCB
(e.g., components such as CPUs and GPUs). This in turn allows the
cooling fans that provide a flow of air through the fin packs of
the heat sinks to operate at lower speeds thus reducing the amount
of power required to operate the cooling system and enhancing the
overall energy efficiency of the device in which the cooling system
is implemented. The configuration of double base primary and
secondary heat sinks also allows for reducing the thickness of the
cooling fins, which further enhances the thermal performance of the
cooling system.
[0030] The cooling system including primary and secondary double
base heat sinks is not limited to the example embodiment described
herein but can include any suitable modifications for a particular
configuration with an electronic device. For example, the cooling
system can include any suitable number of cooling fans to provide
cooling air to the heat sinks. The primary heat sink can include
one or more secondary heat sinks thermally coupled with the primary
heat sink (via one or more heat pipes). Any selected number of heat
pipes (one or more) can be provided for each heat sink, where each
heat pipe can bend so as to traverse or extend between the top base
plate and the bottom base plate and further extend between a
primary heat sink and a secondary heat sink. Each heat sink can
have any suitable length, width and height dimensions configured to
provide adequate cooling for a particular application (e.g.,
cooling of one or more components for an electronic device), and
each fin pack can include any suitable number of cooling fins
having any suitable length, width and thickness dimensions for a
particular application.
[0031] Thus, in an example embodiment, a cooling system comprises a
primary heat sink comprising a primary top base plate, a primary
bottom base plate and a primary fin pack comprising a plurality of
fins, wherein the primary fin pack is disposed between the primary
top base plate and the primary bottom base plate. The cooling
system also comprises a secondary heat sink comprising a secondary
top base plate, a secondary bottom base plate and a secondary fin
pack comprising a plurality of fins, wherein the secondary fin pack
is disposed between the secondary top base plate and the secondary
bottom base plate. In addition, the cooling system comprises a heat
pipe that extends between the primary top base plate and the
primary bottom base plate, where the heat pipe further extends from
the primary heat sink and couples with the secondary heat sink.
[0032] The cooling system can further comprise a plurality of
secondary heat sinks coupled with the primary heat sink. A top
portion of the heat pipe can extend between the primary top base
plate and a top side of the primary fin pack, and a bottom portion
of the heat pipe can extend between the primary bottom base plate
and a bottom side of the primary fin pack.
[0033] The cooling system can further comprise a plurality of heat
pipes extending between the primary top base plate and the primary
bottom base plate, where the plurality of heat pipes comprise a
first heat pipe extending from the primary top base plate to the
primary bottom base plate and further from the primary bottom base
plate to the secondary bottom base plate, and a second heat pipe
extending from the primary bottom base plate to the primary top
base plate and further from the primary top base plate to the
secondary top base plate.
[0034] A length dimension of the fins for the secondary fin pack of
the cooling system can be less than a length dimension of the fins
for the primary fin pack, where each length dimension is defined in
a direction of airflow through the primary fin pack and the
secondary fin pack.
[0035] Each of the primary top base plate and the primary bottom
base plate of the cooling system can include a cut-out section, and
the cooling system can further comprise a primary top block plate
connected with the primary top base plate at the cut-out section,
and a primary bottom block plate connected with the primary bottom
base plate at the cut-out section. Each of the primary top block
plate and the primary bottom block plate can have a different
thermal conductivity in relation to each of the primary top base
plate and the primary bottom base plate.
[0036] In another embodiment, a cooling system comprises a primary
heat sink comprising a primary top base plate, a primary bottom
base plate and a primary fin pack comprising a plurality of fins,
wherein the primary fin pack is disposed between the primary top
base plate and the primary bottom base plate. The cooling system
further comprises a first secondary heat sink comprising a first
secondary top base plate, a first secondary bottom base plate and a
first secondary fin pack comprising a plurality of fins, where the
first secondary fin pack is disposed between the first secondary
top base plate and the first secondary bottom base plate. In
addition, the cooling system comprises a second secondary heat sink
comprising a second secondary top base plate, a second secondary
bottom base plate and a second secondary fin pack comprising a
plurality of fins, where the second secondary fin pack is disposed
between the second secondary top base plate and the second
secondary bottom base plate. Further, the cooling system comprises
a plurality of heat pipes, where the plurality of heat pipes
comprises a first heat pipe that extends between the primary top
base plate and the primary bottom base plate and further extends
from the primary heat sink to couple with the first secondary heat
sink, and a second heat pipe that extends between the primary top
base plate and the primary bottom base plate and further extends
from the primary heat sink to couple with the second secondary heat
sink.
[0037] A top portion of each of the first heat pipe and the second
heat pipe of the cooling system can extend between the primary top
base plate and a top side of the primary fin pack, and a bottom
portion of each of the first heat pipe and the second heat pipe of
the cooling system can extend between the primary bottom base plate
and a bottom side of the primary fin pack. The first heat pipe can
extend from the primary top base plate to the primary bottom base
plate and further from the primary bottom base plate to the first
secondary bottom base plate, and the second heat pipe can extend
from the primary top base plate to the primary bottom base plate
and further from the primary bottom base plate to the second
secondary bottom base plate.
[0038] The cooling system can further comprise a third heat pipe
that extends from the primary bottom base plate to the primary top
base plate and further from the primary top base plate to the first
secondary top base plate, and a fourth heat pipe that extends from
the primary bottom base plate to the primary top base plate and
further from the primary top base plate to the second secondary top
base plate.
[0039] A length dimension of the fins for each of the first
secondary fin pack and the second secondary fin pack of the cooling
system can be less than a length dimension of the fins for the
primary fin pack, where each length dimension is defined in a
direction of airflow through the primary fin pack, the first
secondary fin pack and the second secondary fin pack.
[0040] Each of the primary top base plate and the primary bottom
base plate of the cooling system can include a cut-out section, and
the cooling system can further comprise a primary top block plate
connected with the primary top base plate at the cut-out section,
and a primary bottom block plate connected with the primary bottom
base plate at the cut-out section. Each of the primary top block
plate and the primary bottom block plate can have a different
thermal conductivity in relation to each of the primary top base
plate and the primary bottom base plate.
[0041] In a further embodiment, an apparatus comprises a printed
circuit board (PCB), a heat generating component integrated with
the PCB, and a cooling system. The cooling system comprises a
primary heat sink disposed along the PCB and comprising a primary
top base plate, a primary bottom base plate and a primary fin pack
comprising a plurality of fins, where the primary fin pack is
disposed between the primary top base plate and the primary bottom
base plate, wherein the primary heat sink is disposed over the heat
generating component. The cooling system further comprises a
secondary heat sink disposed along the PCB comprising a secondary
top base plate, a secondary bottom base plate and a secondary fin
pack comprising a plurality of fins, wherein the secondary fin pack
is disposed between the secondary top base plate and the secondary
bottom base plate. In addition, the cooling system comprises a heat
pipe that extends between the primary top base plate and the
primary bottom base plate, where the heat pipe further extends from
the primary heat sink and couples with the secondary heat sink.
[0042] The apparatus can further comprise one or more fans disposed
along the PCB so as to direct a flow of air through each of the
primary fin pack and the secondary fin pack.
[0043] The cooling system of the apparatus can further comprise a
plurality of secondary heat sinks disposed along the PCB and
coupled with the primary heat sink.
[0044] The cooling system of the apparatus can also further
comprise a plurality of heat pipes extending between the primary
top base plate and the primary bottom base plate, where the
plurality of heat pipes comprises a first heat pipe extending from
the primary top base plate to the primary bottom base plate and
further from the primary bottom base plate to the secondary bottom
base plate, and a second heat pipe extending from the primary
bottom base plate to the primary top base plate and further from
the primary top base plate to the secondary top base plate.
[0045] The heat generating component of the apparatus can comprise
a processor.
[0046] In addition, the apparatus can comprise a server that houses
the PCB and the cooling system.
[0047] The above description is intended by way of example only.
The descriptions of the various embodiments have been presented for
purposes of illustration, but are not intended to be exhaustive or
limited to the embodiments disclosed. Many modifications and
variations will be apparent to those of ordinary skill in the art
without departing from the scope and spirit of the described
embodiments. The terminology used herein was chosen to best explain
the principles of the embodiments, the practical application or
technical improvement over technologies found in the marketplace,
or to enable others of ordinary skill in the art to understand the
embodiments disclosed herein.
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