U.S. patent application number 10/425491 was filed with the patent office on 2004-10-28 for stack up assembly.
Invention is credited to Harris, Shaun L..
Application Number | 20040212961 10/425491 |
Document ID | / |
Family ID | 33131495 |
Filed Date | 2004-10-28 |
United States Patent
Application |
20040212961 |
Kind Code |
A1 |
Harris, Shaun L. |
October 28, 2004 |
STACK UP ASSEMBLY
Abstract
A first printed circuit board is built including one or more
openings configured to correspond to heat-generating devices
attached to a second printed circuit board. The first and second
printed circuit boards are aligned with each other and a heat sink,
such that the heat sink is thermally coupled with heat-generating
electronic devices on both the first and second printed circuit
boards. Optionally, the first and second printed circuit boards may
be electrically coupled with each other through an electrical
connector. Also optionally, heat-generating devices may be
mechanically and electrically coupled with the second printed
circuit board through interposers configured (upon assembly) to
raise the heat-generating devices through the openings in the first
printed circuit board to contact a heat sink.
Inventors: |
Harris, Shaun L.; (McKinney,
TX) |
Correspondence
Address: |
HEWLETT-PACKARD DEVELOPMENT COMPANY
Intellectual Property Administration
P.O Box 272400
Fort Collins
CO
80527-2400
US
|
Family ID: |
33131495 |
Appl. No.: |
10/425491 |
Filed: |
April 28, 2003 |
Current U.S.
Class: |
361/697 ;
257/E23.09; 257/E23.101; 257/E23.104 |
Current CPC
Class: |
H05K 1/0204 20130101;
H05K 1/021 20130101; H05K 1/0203 20130101; H05K 2201/066 20130101;
H01L 2924/0002 20130101; H05K 1/144 20130101; H01L 2924/0002
20130101; H01L 23/3675 20130101; H01L 23/433 20130101; H01L 2924/00
20130101; H01L 23/36 20130101; H05K 2201/042 20130101 |
Class at
Publication: |
361/697 |
International
Class: |
H05K 007/20 |
Claims
1. An assembly, comprising: a first printed circuit board having a
first opening and including a first heat-generating device; a
second printed circuit board; a second heat-generating device
mechanically and electrically coupled with said second printed
circuit board, and substantially aligned with said first opening in
said first printed circuit board; and a heat sink having a first
protrusion configured to extend through the first opening in said
first printed circuit board, wherein said heat sink makes thermal
contact with said first heat-generating device on said first
printed circuit board, and wherein said heat sink first protrusion
makes thermal contact with said second heat-generating device on
said second printed circuit board.
2. The assembly of claim 1, wherein said first heat-generating
device is an ASIC.
3. The assembly of claim 1, wherein said first heat-generating
device is a microprocessor.
4. The assembly of claim 1, wherein said first heat-generating
device is a FET.
5. The assembly of claim 1, wherein said second heat-generating
device is an ASIC.
6. The assembly of claim 1, wherein said second heat-generating
device is a microprocessor.
7. The assembly of claim 1, wherein said second heat-generating
device is a FET.
8. The assembly of claim 1, wherein said first printed circuit
board including a first heat-generating device is a power
module.
9. The assembly of claim 1, wherein said second printed circuit
board including a second heat-generating device is a power
module.
10. The assembly of claim 1, wherein said first printed circuit
board is a voltage regulation module (VRM) circuit board.
11. The assembly of claim 1, wherein said second printed circuit
board is a voltage regulation module (VRM) circuit board.
12. The assembly of claim 1, further comprising: an electrical
connector configured to electrically couple said first printed
circuit board to said second printed circuit board.
13. The assembly of claim 1, wherein said first printed circuit
board also has a second opening.
14. The assembly of claim 13, further comprising: a third
heat-generating device mechanically and electrically coupled with
said second printed circuit board, and substantially aligned with
said second opening in said first printed circuit board.
15. The assembly of claim 14, wherein said heat sink also has a
second protrusion configured to extend through the second opening
in said first printed circuit board, wherein said heat sink second
protrusion makes thermal contact with said third heat-generating
device on said second printed circuit board
16. The assembly of claim 15, wherein said third heat-generating
device is an ASIC.
17. The assembly of claim 15, wherein said third heat-generating
device 2 is a microprocessor.
18. The assembly of claim 15, wherein said third heat-generating
device is a FET.
19. The assembly of claim 15, further comprising: an electrical
connector configured to electrically couple said first printed
circuit board to said second printed circuit board.
20-59 (Canceled).
60. A method for the construction of an assembly, comprising the
steps of: a) providing a first printed circuit board including a
first heat-generating device and having a first opening; b)
providing a second printed circuit board; c) mechanically and
electrically coupling a second heat-generating device to the second
printed circuit board in a location corresponding to the first
opening in the first printed circuit board; d) providing a heat
sink having a first protrusion configured to extend through the
first opening in the first printed circuit board and make thermal
contact with the second heat-generating device on the second
printed circuit board; e) mechanically coupling the first printed
circuit board with the second printed circuit board such that the
second heat-generating device on the second printed circuit board
is substantially aligned under the first opening in the first
printed circuit board; and f) mechanically coupling the heat sink
to the first and second printed circuit boards such that the first
protrusion of the heat sink extends through the first opening in
the first printed circuit board and makes thermal contact with the
second heat-generating device on the second printed circuit board,
and the heat sink makes thermal contact with the first
heat-generating device on the first printed circuit board.
61. The method of claim 60, wherein the first heat-generating
device is an ASIC.
62. The method of claim 60, wherein the first heat-generating
device is a microprocessor.
63. The method of claim 60, wherein the first heat-generating
device is a FET.
64. The method of claim 60, wherein the second heat-generating
device is an ASIC.
65. The method of claim 60, wherein the second heat-generating
device is a microprocessor.
66. The method of claim 60, wherein the second heat-generating
device is a FET.
67. The method of claim 60, wherein the first printed circuit board
including a first heat-generating device is a power module.
68. The method of claim 60, wherein the second printed circuit
board including a second heat-generating device is a power
module.
69. The method of claim 60, wherein the first printed circuit board
is a voltage regulation module (VRM) circuit board.
70. The method of claim 60, wherein the second printed circuit
board is a voltage regulation module (VRM) circuit board.
71. The method of claim 60, further comprising the step of: g)
electrically coupling the first printed circuit board to the second
printed circuit board through an electrical connector.
72. The method of claim 60, wherein the first printed circuit board
also has a second opening.
73. The method of claim 72, further comprising the step of: g)
mechanically and electrically coupling a third heat-generating
device to the second printed circuit board in a location
corresponding to the second opening in the first printed circuit
board.
74. The method of claim 73, wherein said heat sink also has a
second protrusion configured to extend through the second opening
in the first printed circuit board and make thermal contact with
the third heat-generating device on the second printed circuit
board.
75. The method of claim 74, wherein the third heat-generating
device is an ASIC.
76. The method of claim 74, wherein the third heat-generating
device is a microprocessor.
77. The method of claim 74, wherein the third heat-generating
device is a FET.
78. The method of claim 74, further comprising the step of: g)
electrically coupling the first printed circuit board to the second
printed circuit board through an electrical connector.
79-97. (cancelled).
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of heat
sinks and more specifically to the field of heat sinks configured
to conduct heat from heat-generating devices on two different
printed circuit boards.
BACKGROUND OF THE INVENTION
[0002] Modern electronics have benefited from the ability to
fabricate devices on a smaller and smaller scale. As the ability to
shrink devices has improved, so has their performance.
Unfortunately, this improvement in performance is accompanied by an
increase in power as well as power density in devices, resulting in
large amounts of heat. In order to maintain the reliability of
these devices, the industry must find new methods to remove this
heat efficiently.
[0003] Many current systems include a plurality of printed circuit
boards. These boards may each include a plurality of
heat-generating devices requiring cooling to remain within their
operating temperatures. Some commonly available current systems
configure the printed circuit boards such that they are parallel
with each other and then force airflow across the printed circuit
boards, thus cooling the heat-generating devices attached to the
printed circuit boards. The individual heat-generating devices may
include heat sinks to make more efficient use of the heat transfer
properties of the airflow. However, as devices shrink in size and
heat generation increases, standard techniques such as individual
heat sinks and wide gaps between parallel printed circuit boards
are no longer sufficient to provide the compact size required of
many devices today.
[0004] Some printed circuit boards and their devices are configured
to allow the use of a single heat sink across a plurality of
individual heat-generating devices. This allows the use of larger
heat sinks that are more efficient and cheaper and easier to
manufacture than a plurality of individual heat sinks. Often, two
printed circuit boards contain devices with functions that must be
closely mated for optimal performance. For example, a power module
board is most effective when it is as close as possible to the
printed circuit board including the ASICs or microprocessors to
which the power module board is supplying power. This closeness
reduces voltage drops along the, now shortened, interconnect
between the power module and the ASICs or microprocessors.
Typically, devices on both the power module board and the
microprocessor printed circuit board require heat sinks to
efficiently dissipate the heat generated by the heat-generating
devices on those boards. One technique involves placing the power
module board and the printed circuit board back-to-back with their
heat sinks facing outwards from the two boards. However, this
technique results in a system requiring two airflows over the two
sets of heat sinks for efficient cooling. This requirement causes
the overall volume of the completed device to increase, along with
the cost of providing two airflows. Similarly, when a single
printed circuit board is used and the power module is placed on the
opposing side of the printed circuit board, two sets of heat sinks
and two airflows are still required. Other configurations may place
the power module components on the same side of a single printed
circuit board with the other components, reducing the airflows
required to one. However, this configuration may not allow the
shortest possible power supply connections to the ASICs,
microprocessors, or other devices.
SUMMARY OF THE INVENTION
[0005] A first printed circuit board is built including one or more
openings configured to correspond to heat-generating devices
attached to a second printed circuit board. The first and second
printed circuit boards are aligned with each other and a heat sink,
such that the heat sink is thermally coupled with heat-generating
devices on both the first and second printed circuit boards. Within
the scope of the present invention the heat sink may be a heat
spreader, cold plate, refrigeration (evaporative cooling) plate,
heat pipe or any other device configured to remove heat from the
heat-generating devices. Optionally, the first and second printed
circuit boards may be electrically coupled with each other through
an electrical connector. Also optionally, heat-generating devices
may be mechanically and electrically coupled with the second
printed circuit board through interposers configured (upon
assembly) to raise the heat-generating electronic devices through
the openings in the first printed circuit board to contact a heat
sink.
[0006] Other aspects and advantages of the present invention will
become apparent from the following detailed description, taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1A is a top view of an example embodiment of a first
printed circuit board including heat-generating devices according
to the present invention.
[0008] FIG. 1B is a cross-sectional view of the example embodiment
of a first printed circuit board from FIG. 1A along section line
A-A.
[0009] FIG. 2A is a top view of an example embodiment of a second
printed circuit board including heat-generating devices according
to the present invention.
[0010] FIG. 2B is a cross-sectional view of the example embodiment
of a second printed circuit board from FIG. 2A along section line
B-B.
[0011] FIG. 3A is a cross-sectional view of an example stack up
assembly before assembly of the example embodiments of first and
second printed circuit boards from FIGS. 1 and 2 along with an
example embodiment of a heat sink according to the present
invention.
[0012] FIG. 3B is a cross-sectional view of an example stack up
assembly after complete assembly of the example embodiments of
first and second printed circuit boards from FIGS. 1 and 2 along
with an example embodiment of a heat sink according to the present
invention.
[0013] FIG. 4A is a top view of an example embodiment of a second
printed circuit board including heat-generating devices according
to the present invention.
[0014] FIG. 4B is a cross-sectional view of the example embodiment
of a second printed circuit board from FIG. 4A along section line
C-C.
[0015] FIG. 5A is a cross-sectional view of an example stack up
assembly before assembly of the example embodiments of first and
second printed circuit boards from FIGS. 1 and 4 along with an
example embodiment of a heat sink according to the present
invention.
[0016] FIG. 5B is a cross-sectional view of an example stack up
assembly after complete assembly of the example embodiments of
first and second printed circuit boards from FIGS. 1 and 4 along
with an example embodiment of a heat sink according to the present
invention.
[0017] FIG. 6 is a flow chart of an example method for the
construction of a stack up including first and second printed
circuit boards cooled by a single heat sink according to the
present invention.
[0018] FIG. 7 is a flow chart of an example method for the
construction of a stack up including first and second printed
circuit boards cooled by a single heat sink according to the
present invention.
[0019] FIG. 8 is a flow chart of an example method for the
construction of a stack up including first and second printed
circuit boards cooled by a single heat sink according to the
present invention.
[0020] FIG. 9 is a flow chart of an example method for the
construction of a stack up including first and second printed
circuit boards cooled by a single heat sink according to the
present invention.
DETAILED DESCRIPTION
[0021] FIG. 1A is a top view of an example embodiment of a first
printed circuit board including heat-generating electronic devices
according to the present invention. In this example embodiment of
the present invention a first printed circuit board 100 including a
first opening 102, a second opening 104, a third opening 106, and a
fourth opening 108 is provided. Other embodiments of the present
inventions may include any number of openings as needed for a
particular implementation of the present invention. Also included
on this first printed circuit board 100 are a number of first
heat-generating devices 110. The terminology "first heat-generating
devices" is used to distinguish these heat-generating devices on
the first printed circuit board from those present on the second
printed circuit board discussed below. As shown in FIGS. 5A and 5B,
an upper surface of the first heat-generating devices may be
substantially coplanar with (or even above) an upper surface of the
heat-generating devices on the second printed circuit board. While
this example embodiment of the present invention included five
first heat-generating devices 110, other embodiments may include
any number of first heat-generating devices 110 as needed for a
particular implementation of the present invention. These first
heat-generating devices 110 may include electronic power circuits,
application specific integrated circuits (ASICs), microprocessors,
discrete electronic devices such as field effect transistors
(FETs), other types of transistors, or other heat-generating
electronic devices as needed for a particular implementation of the
present invention. In some embodiments of the present invention
this first printed circuit board 100 may be a power module circuit
board, a voltage regulation module (VRM) circuit board, or any
other type of device as needed for a particular implementation of
the present invention.
[0022] FIG. 1B is a cross-sectional view of the example embodiment
of a first printed circuit board from FIG. 1A along section line
A-A. In this example embodiment of the present invention, the first
printed circuit board 100 is shown with a first opening 102, and a
second opening 104. Also shown in this cross-sectional view is one
of the upper heat-generating electronic devices 110 from FIG.
1A.
[0023] FIG. 2A is a top view of an example embodiment of a second
printed circuit board including heat-generating devices according
to the present invention. In this example embodiment of the present
invention a second printed circuit board 200 is provided including
a second heat-generating device 202, a third heat-generating device
204, a fourth heat-generating device 206, and a fifth
heat-generating device 208. Other embodiments of the present
invention may include any number of heat-generating devices as
needed for a particular implementation of the invention. These
heat-generating devices 202, 204, 206, and 208 may include
electronic power circuits, application specific integrated circuits
(ASICs), microprocessors, discrete electronic devices such as field
effect transistors (FETs), other types of transistors, or other
heat-generating devices as needed for a particular implementation
of the present invention. Also included on this second printed
circuit board 200 are a number of other devices 210 that may or may
not generate heat, along with a plurality of discrete devices 212,
(such as resistors, capacitors, transistors, and diodes, for
example) that also may or may not generate heat. Those of skill in
the art will recognize that any of the printed circuit boards may
include discrete devices 212, or other heat-generating devices that
are not directly coupled with the heat sink.
[0024] FIG. 2B is a cross-sectional view of the example embodiment
of a second printed circuit board from FIG. 2A along section line
B-B. In this example embodiment of the present invention, the
second printed circuit board 200 is shown with a second
heat-generating device 202, a third heat-generating device 204, and
two discrete devices 212.
[0025] FIG. 3A is a cross-sectional view of an example stack up
assembly before assembly of the example embodiments of first and
second printed circuit boards from FIGS. 1 and 2 along with an
example embodiment of a heat sink according to the present
invention. This example embodiment of a stack up according to the
present invention includes the first printed circuit board 100 from
FIG. 1, the second printed circuit board 200 from FIG. 2, along
with an example embodiment of a heat sink 300 according to the
present invention. Those of skill in the art will recognize that a
wide variety of thermal devices may be used as a heat sink 300.
While a standard finned heat sink 300 is shown in FIGS. 3A and 3B,
other example embodiments of the present invention may use heat
spreaders, cold plates, refrigeration (evaporative cooling) plates,
heat pipes, or other thermal devices in place of the finned heat
sink shown in these figures. This cross-sectional view of an
example stack up shows the first printed circuit board 100 from
FIG. 1B and the second printed circuit board 200 from FIG. 2B. In
this example embodiment of the present invention, the first printed
circuit board 100 is shown with a first opening 102, and a second
opening 104. Also shown in this cross-sectional view is one of the
first heat-generating devices 110 from FIG. 1A. In this example
embodiment of the present invention, the second printed circuit
board 200 is shown with a second heat-generating device 202, a
third heat-generating device 204, and two discrete devices 212.
Note that the heat sink 300 includes a first protrusion 302, and a
second protrusion 304 configured to pass through the first opening
102 and the second opening 104 of the first printed circuit board
100 and make contact with the second heat-generating device 202 and
the third heat-generating device 204 on the second printed circuit
board 200. Those of skill in the art will recognize that there is
no requirement that the bottom surfaces of the first protrusion 302
and the second protrusion 304 be co-planar. Note that in some
embodiments of the present invention, the heat sink 300 may be a
thermal plate, a vapor plate, a heat pipe, or any other thermal
device capable of removing heat from the heat-generating devices on
the first and second printed circuit boards.
[0026] FIG. 3B is a cross-sectional view of an example stack up
assembly after complete assembly of the example embodiments of
first and second printed circuit boards from FIGS. 1 and 2 along
with an example embodiment of a heat sink according to the present
invention. After the example stack up shown in FIG. 3A is
assembled, the first printed circuit board 100 is mechanically and
electrically coupled with the second printed circuit board 200
through one or more electrical connectors 306. These electrical
connectors 306 may be configured to set the distance between the
first and second printed circuit boards 100, and 200 such that the
heat sink 300 makes thermal contact with the first heat-generating
devices 110 on the first printed circuit board 100 along with the
heat-generating devices 202, and 204 on the second printed circuit
board 200. The discrete devices 212 attached to the second printed
circuit board 200 in this example embodiment of the present
invention are not thermally coupled to the heat sink. Those of
skill in the art will recognize that these discrete devices 212 may
not require cooling through the heat sink 300 if their heat output
is low. Also, there may be some cooling of these devices 212 by air
flowing between the first and second printed circuit boards 100,
and 200. While this example stack up of the present invention shows
two openings 102, and 104 in the first printed circuit board 100
and two heat-generating devices 202, and 204 attached to the second
printed circuit board 200, those of skill in the art will recognize
that any number of openings in the first printed circuit board 100
may be used to provide heat sink access to any number of heat
generating devices on the second printed circuit board 200.
[0027] FIG. 4A is a top view of an example embodiment of a second
printed circuit board including heat-generating devices according
to the present invention. This example embodiment of the present
invention is similar to that shown in FIGS. 2A and 2B. However, in
this example embodiment of the present invention, the
heat-generating devices 402, 404, 406, and 408 are packaged in pin
grid array (PGA) packages and supported by interposers 414 attached
to the second printed circuit board 400. In this example embodiment
of the present invention a second printed circuit board 400 is
provided including a second heat-generating device 402, a third
heat-generating device 404, a fourth heat-generating device 406,
and a fifth heat-generating device 408. These heat-generating
devices 402, 404, 406, and 408 are mechanically and electrically
coupled with the second printed circuit board 400 through
interposers 414 that are shown in FIG. 4B. Other embodiments of the
present invention may include any number of heat-generating devices
as needed for a particular implementation of the invention. These
heat-generating devices 402, 404, 406, and 408 may include
electronic power circuits, application specific integrated circuits
(ASICs), microprocessors, transistors, discrete devices, or other
heat-generating electronic devices as needed for a particular
implementation of the present invention. Also included on this
second printed circuit board 400 are a number of other devices 410
that may or may not generate heat, along with a plurality of
discrete devices 412, (such as resistors, capacitors, transistors,
and diodes, for example) that also may or may not generate
heat.
[0028] FIG. 4B is a cross-sectional view of the example embodiment
of a second printed circuit board from FIG. 4A along section line
C-C. In this example embodiment of the present invention, the
second printed circuit board 400 is shown with a second
heat-generating device 402, a third heat-generating device 404, and
two discrete devices 412. The second and third heat-generating
devices 402, and 404 are mechanically and electrically coupled to
the second printed circuit board 400 through interposers 414. Note
that in some example embodiments of the present invention the
interposers 414 may also include a socket configured to allow
insertion and removal of the heat-generating devices 402, and
404.
[0029] FIG. 5A is a cross-sectional view of an example stack up
assembly before assembly of the example embodiments of first and
second printed circuit boards from FIGS. 1 and 4 along with an
example embodiment of a heat sink according to the present
invention. This example embodiment of a stack up according to the
present invention includes the first printed circuit board 100 from
FIG. 1, the second printed circuit board 400 from FIG. 4, along
with an example embodiment of a heat sink 500 according to the
present invention. This cross-sectional view of an example stack up
shows the first printed circuit board 100 from FIG. 1B and the
second printed circuit board 400 from FIG. 4B. In this example
embodiment of the present invention, the first printed circuit
board 100 is shown with a first opening 102, and a second opening
104. Also shown in this cross-sectional view is one of the first
heat-generating devices 110 from FIG. 1A. In this example
embodiment of the present invention, the second printed circuit
board 400 is shown with a second heat-generating device 402, a
third heat-generating device 404, two discrete devices 412, and two
interposers 414 supporting the second and third heat-generating
devices 402, and 404. Note that the heat sink 500 includes a flat
bottom unlike the heat sink 300 shown in FIG. 3.
[0030] FIG. 5B is a cross-sectional view of an example stack up
assembly after complete assembly of the example embodiments of
first and second printed circuit boards from FIGS. 1 and 4 along
with an example embodiment of a heat sink according to the present
invention. After the example stack up shown in FIG. 5A is
assembled, the first printed circuit board 100 is mechanically and
electrically coupled with the second printed circuit board 400
through one or more electrical connectors 502. These electrical
connectors 502 may be configured to set the distance between the
first and second printed circuit boards 100, and 400 such that the
heat sink 500 makes thermal contact with the first heat-generating
devices 110 on the first printed circuit board 100 along with the
heat-generating devices 402, and 404 on the second printed circuit
board 400. Note that the interposers 414 mechanically and
electrically coupling the heat-generating devices 402, and 404 to
the second printed circuit board 400 are configured to position the
heat-generating devices such that their top surfaces are
substantially co-planar with each other and the heat-generating
devices 104 attached to the first printed circuit board 100. This
allows the use of a single heat sink 500 with a substantially
planar bottom surface to contact all of the heat-generating devices
104, 402, and 404 on the first and second printed circuit boards
100, and 200 that the designer desires to be thermally coupled to
the heat sink 500. The discrete devices 412 attached to the second
printed circuit board 400 in this example embodiment of the present
invention are not thermally coupled to the heat sink. Those of
skill in the art will recognize that these discrete devices 412 may
not require cooling through the heat sink 500 if their heat output
is low. Also, there may be some cooling of these devices 412 by air
flowing between the first and second printed circuit boards 100,
and 400. While this example stack up of the present invention shows
two openings 102, and 104 in the first printed circuit board 100
and two heat-generating devices 402, and 404 attached to the second
printed circuit board 400, those of skill in the art will recognize
that any number of openings in the first printed circuit board 100
may be used to provide heat sink access to any number of heat
generating devices on the second printed circuit board 400.
[0031] FIG. 6 is a flow chart of an example method for the
construction of a stack up including first and second printed
circuit boards cooled by a single heat sink according to the
present invention. In a step 602, a first printed circuit board
including a first heat-generating device and having a first opening
is provided. In a step 604, a second printed circuit board is
provided. In a step 606, a second heat-generating device is
electrically and mechanically coupled to the second printed circuit
board. In a step 608, the first and second printed circuit boards
are mechanically coupled. In an optional step 610, the first and
second printed circuit boards are electrically coupled through an
electrical connector. In a step 612, a heat sink having a first
protrusion is provided. In a step 614, the heat sink is
mechanically coupled to the first and second printed circuit
boards. In a step 616, the heat sink is thermally coupled to the
first heat-generating device and the second heat-generating
device.
[0032] FIG. 7 is a flow chart of an example method for the
construction of a stack up including first and second printed
circuit boards cooled by a single heat sink according to the
present invention. In a step 702, a first printed circuit board
including a first heat-generating device and having first and
second openings is provided. In a step 704, a second printed
circuit board is provided. In a step 706, a second heat-generating
device is electrically and mechanically coupled to the second
printed circuit board. In a step 708, a third heat-generating
device is electrically and mechanically coupled to the second
printed circuit board. In a step 710, the first and second printed
circuit boards are mechanically coupled. In an optional step 712,
the first and second printed circuit boards are electrically
coupled through an electrical connector. In a step 714, a heat sink
having a first and second protrusion is provided. In a step 716,
the heat sink is mechanically coupled to the first and second
printed circuit boards. In a step 718, the heat sink is thermally
coupled to the first, second, and third heat-generating
devices.
[0033] FIG. 8 is a flow chart of an example method for the
construction of a stack up including first and second printed
circuit boards cooled by a single heat sink according to the
present invention. In a step 802, a first printed circuit board
including a first heat-generating device and having a first opening
is provided. In a step 804, a second printed circuit board is
provided. In a step 806, a first interposer is electrically and
mechanically coupled to the second printed circuit board. In a step
808, a second heat-generating device is electrically and
mechanically coupled to the first interposer. In a step 810, the
first and second printed circuit boards are mechanically coupled.
In an optional step 812, the first and second printed circuit
boards are electrically coupled through an electrical connector. In
a step 814, a heat sink is provided. In a step 816, the heat sink
is mechanically coupled to the first and second printed circuit
boards. In a step 818, the heat sink is thermally coupled to the
first and second heat-generating devices.
[0034] FIG. 9 is a flow chart of an example method for the
construction of a stack up including first and second printed
circuit boards cooled by a single heat sink according to the
present invention. In a step 902, a first printed circuit board
including a first heat-generating device and having first and
second openings is provided. In a step 904, a second printed
circuit board is provided. In a step 906, a first interposer is
electrically and mechanically coupled to the second printed circuit
board. In a step 908, a second interposer is electrically and
mechanically coupled to the second printed circuit board. In a step
910, a second heat-generating device is electrically and
mechanically coupled to the first interposer. In a step 912, a
third heat-generating device is electrically and mechanically
coupled to the second interposer. In a step 914, the first and
second printed circuit boards are mechanically coupled. In an
optional step 916, the first and second printed circuit boards are
electrically coupled through an electrical connector. In a step
918, a heat sink is provided. In a step 920, the heat sink is
mechanically coupled to the first and second printed circuit
boards. In a step 922, the heat sink is thermally coupled to the
first, second, and third heat-generating devices.
[0035] The foregoing description of the present invention has been
presented for purposes of illustration and description. It is not
intended to be exhaustive or to limit the invention to the precise
form disclosed, and other modifications and variations may be
possible in light of the above teachings. The embodiments were
chosen and described in order to best explain the principles of the
invention and its practical application to thereby enable others
skilled in the art to best utilize the invention in various
embodiments and various modifications as are suited to the
particular use contemplated. It is intended that the appended
claims be construed to include other alternative embodiments of the
invention except insofar as limited by the prior art.
* * * * *