U.S. patent application number 15/191404 was filed with the patent office on 2016-10-20 for solid-state drive with passive heat transfer.
The applicant listed for this patent is Apple Inc.. Invention is credited to Ron A. HOPKINSON, Eric A. KNOPF, William F. LEGGETT, Jay S. NIGEN, Richard H. TAN, Derek J. YAP.
Application Number | 20160307819 15/191404 |
Document ID | / |
Family ID | 49715135 |
Filed Date | 2016-10-20 |
United States Patent
Application |
20160307819 |
Kind Code |
A1 |
NIGEN; Jay S. ; et
al. |
October 20, 2016 |
SOLID-STATE DRIVE WITH PASSIVE HEAT TRANSFER
Abstract
The disclosed embodiments relate to a system that facilitates
thermal conductance in a system that includes a module comprising a
circuit board with integrated circuits, such as a solid-state
drive. A thermal-coupling material between one side of the circuit
board and an adjacent baseplate is used to increase thermal
conduction between the circuit board and the baseplate.
Furthermore, the module may include another thermal-coupling
material between the baseplate and a housing that at least in part
surrounds the circuit board, thereby increasing thermal conduction
between the baseplate and the housing. In these ways, the baseplate
and/or the housing may be used as a heat-transfer surfaces or heat
spreaders that reduce hotspots associated with operation of the
integrated circuits.
Inventors: |
NIGEN; Jay S.; (Mountain
View, CA) ; HOPKINSON; Ron A.; (Campbell, CA)
; YAP; Derek J.; (San Carlos, CA) ; KNOPF; Eric
A.; (Mountain View, CA) ; LEGGETT; William F.;
(Cupertino, CA) ; TAN; Richard H.; (Fremont,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc. |
Cupertino |
CA |
US |
|
|
Family ID: |
49715135 |
Appl. No.: |
15/191404 |
Filed: |
June 23, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13683955 |
Nov 21, 2012 |
9408328 |
|
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15191404 |
|
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|
61657489 |
Jun 8, 2012 |
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61656747 |
Jun 7, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 23/3735 20130101;
G06F 1/20 20130101; H05K 1/0201 20130101; H01L 23/552 20130101;
H01L 21/4882 20130101; H05K 3/0061 20130101; H01L 2924/0002
20130101; H05K 1/141 20130101; H05K 2201/042 20130101; H05K 7/20436
20130101; H05K 7/205 20130101; H01L 2924/00 20130101; F28F 21/00
20130101; H01L 23/3737 20130101; H05K 2201/10159 20130101; H01L
2924/0002 20130101 |
International
Class: |
H01L 23/373 20060101
H01L023/373; H01L 21/48 20060101 H01L021/48; H01L 23/552 20060101
H01L023/552 |
Claims
1. A module, comprising: a first circuit board having an integrated
circuit disposed on a first surface of the first circuit board; and
a second circuit board separated by a gap from the first circuit
board; and a thermal-coupling material that: is positioned between
and thermally coupled to at least a portion of the first circuit
board and the second circuit board, wherein the thermal-coupling
material provides for thermal conductance between the first circuit
board and the second circuit board.
2. The module of claim 1, wherein the first surface faces the
second circuit board and the thermal-coupling material is thermally
coupled to at least a portion of the first surface.
3. The module of claim 2, wherein the thermal-coupling material is
thermally coupled to at least a portion of the integrated
circuit.
4. The module of claim 1, wherein the first surface faces the
second circuit board and at least a portion of the thermal-coupling
material at least partially envelopes the integrated circuit.
5. The module of claim 1, wherein a second surface of the first
circuit board faces the second circuit board and the
thermal-coupling material is thermally coupled to at least a
portion of the second surface.
6. The module of claim 5, wherein the first surface is on an
opposite side of the first circuit board from the second surface
and the first circuit board is configured to thermally transfer
heat from the first surface to the second surface.
7. The module of claim 1, wherein the integrated circuit includes
an electromagnetic interference shield.
8. The module of claim 1, wherein the first circuit board includes
a second surface on an opposite side of the first circuit board
from the first surface; and wherein the first circuit board
includes components disposed on the first surface and the second
surface, the components including the integrated circuit.
9. A portable electronic device, comprising: a first circuit board
having an integrated circuit disposed on a first surface of the
first circuit board; and a second circuit board separated by a gap
from the first circuit board; and a thermal-coupling material that:
is positioned between and thermally coupled to at least a portion
of the first circuit board and the second circuit board, wherein
the thermal-coupling material provides for thermal conductance
between the first circuit board and the second circuit board.
10. The portable electronic device of claim 9, wherein the first
surface faces the second circuit board and the thermal-coupling
material is thermally coupled to at least a portion of the first
surface.
11. The portable electronic device of claim 10, wherein the
thermal-coupling material is thermally coupled to at least a
portion of the integrated circuit.
12. The portable electronic device of claim 9, wherein the first
surface faces the second circuit board and at least a portion of
the thermal-coupling material at least partially envelopes the
integrated circuit.
13. The portable electronic device of claim 9, wherein a second
surface of the first circuit board faces the second circuit board
and the thermal-coupling material is thermally coupled to at least
a portion of the second surface.
14. The portable electronic device of claim 13, wherein the first
surface is on an opposite side of the first circuit board from the
second surface and the first circuit board is configured to
thermally transfer heat from the first surface to the second
surface.
15. The portable electronic device of claim 9, wherein the
integrated circuit includes an electromagnetic interference
shield.
16. The portable electronic device of claim 9, wherein the first
circuit board includes a second surface on an opposite side of the
first circuit board from the first surface; and wherein the first
circuit board includes components disposed on the first surface and
the second surface, the components including the integrated
circuit.
17. A method for transferring heat from an integrated circuit of a
first circuit board, the method comprising: transferring first heat
from the integrated circuit to a first surface of the first circuit
board; and transferring the first heat from the first circuit board
to a second circuit board using a thermal-coupling material
disposed between and thermally coupled to at least a portion of the
first circuit board and the second circuit board.
18. The method of claim 17, wherein the thermal-coupling material
is thermally coupled to the first surface.
19. The method of claim 17, wherein at least a portion of the
thermal-coupling material is thermally coupled to a second surface
of the first circuit board, the second surface on an opposite side
of the first circuit board from the first surface; and wherein the
method further comprises conducting the first heat from the first
surface to the second surface.
20. The method of claim 17, wherein the thermal-coupling material
is thermally coupled to at least a portion of the integrated
circuit; and wherein the method further comprises transferring
second heat from the integrated circuit to the second circuit
board.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/683,955 filed Nov. 21, 2012, which claims
the benefit of U.S. Provisional Application No. 61/657,489 filed
Jun. 8, 2012, and to U.S. Provisional Application No. 61/656,747
filed Jun. 7, 2012, the contents of each are incorporated by
reference herein in their entireties.
BACKGROUND
[0002] 1. Field
[0003] The described embodiments relate to techniques for cooling
integrated circuits.
[0004] 2. Related Art
[0005] A solid-state drive is a type of memory that stores
information on multiple integrated circuits. For example, the
integrated circuits may include a solid-state non-volatile memory,
such as flash memory chips or dynamic-random-access-memory (DRAM)
chips. Solid-state drives are increasingly popular because, unlike
hard-disk drives, they do not contain moving parts, and are
therefore more reliable, have reduced power consumption and
generate less noise.
[0006] However, flash memory chips, such as NAND flash devices, are
susceptible to memory wear after repeated program-erase cycles. In
particular, stored information can be lost if a specified maximum
number of program-erase cycles (such as 1,000,000 program-erase
cycles) is exceeded. This memory wear can be exacerbated by the
temperature increase associated with the heat generated during
operation of a flash memory chip.
[0007] More expensive, solid-state drives based on DRAM chips offer
reduced latency and are not susceptible to memory wear. However,
DRAM chips also generate heat during operation. The temperature
increase associated with this heat can adversely impact other
components in electronic devices that include solid-state
drives.
[0008] More generally, the computational performance of integrated
circuits has increased significantly in recent years. This
increased performance has been accompanied by an increase in power
consumption and associated heat generation. Furthermore, this
additional heat generation has made it harder to maintain
acceptable operational temperatures in these integrated
circuits.
[0009] Cooling integrated circuits that include
wireless-communication circuits (which are sometimes referred to as
`wireless-communication integrated circuits`) can be especially
challenging. This is because these integrated circuits are often
enclosed in electromagnetic-interference shields to reduce
interference.
[0010] Existing approaches to cooling a wireless-communication
integrated circuit often use an electromagnetic-interference shield
as a heat sink. Thus, a thermal-interface material is often
included between electromagnetic-interference shield and
wireless-communication integrated circuit to increase the thermal
conductance between them. However, there are limits to the thermal
power that can be conducted away from wireless-communication
integrated circuits via this thermal path, which can constrain the
performance of wireless-communication integrated circuits.
SUMMARY
[0011] Some of the described embodiments facilitate thermal
conductance in a system that includes a module with a circuit
board, having a top surface and a bottom surface, and integrated
circuits disposed on the top surface and the bottom surface.
Moreover, the module includes a baseplate, having a top surface and
a bottom surface, mechanically coupled to an edge of the circuit
board. Furthermore, a first thermal-coupling material is
mechanically coupled to the bottom surface of the circuit board and
the top surface of the baseplate. This first thermal-coupling
material increases a thermal conductance between the circuit board
and the baseplate.
[0012] Note that the integrated circuits may include memory, such
as flash memory.
[0013] Additionally, the first thermal-coupling material may
include a thermal pad and/or a thermal gel.
[0014] In some embodiments, the module includes a housing enclosing
the circuit board, the baseplate and the first thermal-coupling
material. Moreover, the module may include a second
thermal-coupling material mechanically coupled to the bottom
surface of the baseplate. This second thermal-coupling material may
include a thermal pad. Additionally, the housing may enclose the
circuit board, the baseplate, the first thermal-coupling material
and the second thermal-coupling material.
[0015] Furthermore, the baseplate may be made of metal.
[0016] Another embodiment provides a portable electronic device.
This portable electronic device may include an external housing and
the module. In the portable electronic device, the second thermal
material may be mechanically coupled to the bottom surface of the
baseplate and the external housing, and may increase a thermal
conductance between the baseplate and the external housing.
[0017] Another embodiment provides a method for transferring heat
from integrated circuits. During the method, heat is transferred
from the integrated circuits disposed on surfaces of a circuit
board to the baseplate mechanically coupled to the edge of the
circuit board using the first thermal-coupling material disposed
between the circuit board and the baseplate, where the first
thermal-coupling material increases the thermal conductance between
the circuit board and the baseplate. Then, heat is transferred from
the baseplate to the external housing of the portable electronic
device that includes the circuit board, the integrated circuits and
the baseplate using the second thermal-coupling material disposed
between the baseplate and the external housing, where the second
thermal-coupling material increases the thermal conductance between
the baseplate and the external housing.
[0018] Additional described embodiments facilitate thermal
conductance in a second module with a circuit board, having a top
surface and a bottom surface, and an integrated circuit disposed on
the top surface. Moreover, the second module includes a second
circuit board, having a top surface, mechanically coupled to the
circuit board. Furthermore, the bottom surface of the circuit board
is separated from the top surface of the second circuit board by a
gap, and a thermal-interface material in the gap between the bottom
surface of the circuit board and the top surface of the second
circuit board thermally couples the circuit board and the second
circuit board so that heat generated during operation of the
integrated circuit is conducted to the second circuit board.
[0019] In some embodiments, the second module includes an
electromagnetic-interference shield disposed on the top surface of
the circuit board and at least partially enclosing the integrated
circuit. For example, the circuit board may include a
wireless-communication circuit board.
[0020] Alternatively, the integrated circuit may include a
solid-state memory. For example, the circuit board may include a
solid-state drive.
[0021] Note that the thermal-interface material may include: a
foam, a thermal gel, a thermal pad, thermal grease, and/or an
elastomeric material.
[0022] In some embodiments, the second module includes components
disposed on the bottom surface of the circuit board, where a
surface of the thermal-interface material facing the bottom surface
of the circuit board includes pre-compressed regions so that a
contact area between the surface of the thermal-interface material
and the bottom surface of the circuit board is increased relative
to a thermal-interface material without the pre-compressed
regions.
[0023] Another embodiment provides a second portable electronic
device that includes the second module.
[0024] Another embodiment provides a second method for transferring
heat from an integrated circuit. During the second method, heat
generated by the integrated circuit disposed on the top surface of
the circuit board is transferred to the bottom surface of the
circuit board. Then, the heat is conducted to a top surface of the
second circuit board, which is thermally coupled to the circuit
board by the thermal-interface material. Note that the bottom
surface of the circuit board is separated from the top surface of
the second circuit board by the gap, and the thermal-interface
material is in the gap between the bottom surface of the circuit
board and the top surface of the second circuit board.
BRIEF DESCRIPTION OF THE FIGURES
[0025] FIG. 1 is a block diagram illustrating a side view of a
module in accordance with an embodiment of the present
disclosure.
[0026] FIG. 2 is a block diagram illustrating a side view of the
module of FIG. 1 in a portable electronic device in accordance with
an embodiment of the present disclosure.
[0027] FIG. 3 is a flowchart illustrating a method for transferring
heat from integrated circuits in accordance with an embodiment of
the present disclosure.
[0028] FIG. 4 is a block diagram illustrating a side view of a
module in accordance with an embodiment of the present
disclosure.
[0029] FIG. 5 is a block diagram illustrating a side view of the
module of FIG. 1 in a portable electronic device in accordance with
an embodiment of the present disclosure.
[0030] FIG. 6 is a flowchart illustrating a method for transferring
heat from an integrated circuit in accordance with an embodiment of
the present disclosure.
[0031] Note that like reference numerals refer to corresponding
parts throughout the drawings. Moreover, multiple instances of the
same part are designated by a common prefix separated from an
instance number by a dash.
DETAILED DESCRIPTION
[0032] FIG. 1 presents a block diagram illustrating a side view of
a module 100. This module includes a circuit board 110, having a
top surface 112 and a bottom surface 114, and integrated circuits
116 disposed on top surface 112 and bottom surface 114. For
example, integrated circuits 116 may include memory, such as flash
memory or dynamic-random-access memory (DRAM). Therefore, module
100 may include a solid-state drive. More generally, module 100 may
include another type of volatile or non-volatile computer-readable
memory.
[0033] Moreover, module 100 includes a baseplate 118, having a top
surface 120 and a bottom surface 122, mechanically coupled to an
edge 124 of circuit board 110. For example, baseplate 118 may be
made of metal. Furthermore, a thermal-coupling material 126 is
mechanically coupled to bottom surface 114 and top surface 120.
This thermal-coupling material may increase a thermal conductance
(defined as .kappa.A/L, where .kappa. is the thermal conductivity
of thermal-coupling material 126, A is a cross-sectional area, and
L is a thickness) between circuit board 110 and baseplate 118 so
that baseplate 118 can be used as a heat-transfer surface or heat
spreader for integrated circuits 116. For example, thermal-coupling
material 126 may include a thermal pad and/or a thermal gel. In an
exemplary embodiment, the thermal gel is Gel 30 (from Chomerics
North America of Woburn, Mass.) and/or the thermal pad is the Gap
Pad VO Ultra Soft (from The Bergquist Company of Chanhassen,
Minn.).
[0034] In some embodiments, module 100 includes an optional housing
130 (such as a housing made of metal or plastic) that at least
partially encloses circuit board 110, baseplate 118 and
thermal-coupling material 126. Moreover, module 100 may include
optional thermal-coupling material 128 mechanically coupled to
bottom surface 122. This optional thermal-coupling material may
include a thermal pad, such as the Gap Pad VO Ultra Soft. Note that
optional housing 130 may also partially enclose optional
thermal-coupling material 128.
[0035] Module 100 may be included in an electronic device, such as
a portable electronic device. This is shown in FIG. 2, which
presents a block diagram illustrating a side view of module 100
(FIG. 1) in a portable electronic device 200. In particular,
portable electronic device 200 may include an external housing 210
and module 100. In portable electronic device 200, thermal-coupling
material 128 may be mechanically coupled to bottom surface 122 and
external housing 210, and may increase a thermal conductance
between baseplate 118 and external housing 210 so that external
housing 210 can be used as a heat-transfer surface or heat spreader
for integrated circuits 116. In addition, thermal-coupling material
128 may provide additional thermal inertia or thermal mass to
circuit board 110 and integrated circuits 116. This thermal inertia
may reduce temperature increases of circuit board 110 and
integrated circuits 116 that occur during episodic operation of
integrated circuits 116, such as during read or write
operations.
[0036] By including thermal-coupling materials 126 and/or 128,
hotspots in portable electronic device 200 that are associated with
heat generated during operation of integrated circuits 116 may be
reduced or eliminated. For example, during operation of portable
electronic device 200, the maximum temperature associated with
integrated circuits 116 may be less than 55 C.
[0037] Portable electronic device 200 may include: one or more
program modules or sets of instructions stored in an optional
memory subsystem, such as module 100. These sets of instructions
may be executed by an optional processing subsystem (such as one or
more processors) on a motherboard (not shown). Note that the one or
more computer programs may constitute a computer-program mechanism.
Moreover, instructions in the various modules in the optional
memory subsystem may be implemented in: a high-level procedural
language, an object-oriented programming language, and/or in an
assembly or machine language. Furthermore, the programming language
may be compiled or interpreted, e.g., configurable or configured,
to be executed by the optional processing subsystem.
[0038] In some embodiments, functionality in these circuits,
components and devices may be implemented in one or more:
application-specific integrated circuits (ASICs),
field-programmable gate arrays (FPGAs), and/or one or more digital
signal processors (DSPs). Moreover, the circuits and components may
be implemented using any combination of analog and/or digital
circuitry, including: bipolar, PMOS and/or NMOS gates or
transistors. Furthermore, signals in these embodiments may include
digital signals that have approximately discrete values and/or
analog signals that have continuous values. Additionally,
components and circuits may be single-ended or differential, and
power supplies may be unipolar or bipolar.
[0039] Portable electronic device 200 may include one of a variety
of devices that can include memory, including: a laptop computer, a
media player (such as an MP3 player), an appliance, a
subnotebook/netbook, a tablet computer, a smartphone, a cellular
telephone, a network appliance, a personal digital assistant (PDA),
a toy, a controller, a digital signal processor, a game console, a
device controller, a computational engine within an appliance, a
consumer-electronic device, a portable computing device, a personal
organizer, and/or another electronic device.
[0040] While portable electronic device 200 was used as an
illustration in the preceding discussion, in other embodiments
module 100 is included in an electronic device, such as a server, a
desktop computer, a mainframe computer and/or a blade computer.
Moreover, alternative passive heat transfer components and/or
materials may be used in thermal-coupling material 126 and/or 128.
In some embodiments, circuit board 110 only includes integrated
circuits 116 on top surface 112 and/or thermal-coupling mechanism
126 is pre-stressed with cavities corresponding to components on
back surface 114 so that a contact area between thermal-coupling
mechanism 126 and back surface 114 is maximized. Furthermore, in
some embodiments there is a gap between optional thermal-coupling
material 128 and external housing 210 in FIG. 2, so that heat is
transferred to external housing 210 by radiation or conduction
through air in the gap.
[0041] Additionally, one or more of the components may not be
present in the FIGS. 1 and 2. In some embodiments, the preceding
embodiments include one or more additional components that are not
shown in FIGS. 1 and 2. Also, although separate components are
shown in FIGS. 1 and 2, in some embodiments some or all of a given
component can be integrated into one or more of the other
components and/or positions of components can be changed.
[0042] We now describe embodiments of a method that can be
performed using the preceding embodiments. FIG. 3 presents a
flowchart illustrating a method 300 for transferring heat from
integrated circuits, such as those in module 100 (FIG. 1). During
the method, heat is transferred from the integrated circuits
disposed on surfaces of a circuit board to a baseplate mechanically
coupled to an edge of the circuit board using a first
thermal-coupling material disposed between the circuit board and
the baseplate (operation 310), where the first thermal-coupling
material increases the thermal conductance between the circuit
board and the baseplate. Then, heat is transferred from the
baseplate to an external housing of a portable electronic device
(which includes the circuit board, the integrated circuits and the
baseplate) using a second thermal-coupling material disposed
between the baseplate and the external housing (operation 312),
where the second thermal-coupling material increases the thermal
conductance between the baseplate and the external housing.
[0043] In some embodiments of method 300, there may be additional
or fewer operations. Moreover, the order of the operations may be
changed, and/or two or more operations may be combined into a
single operation.
[0044] We now describe embodiments of thermal-management technique
for a wireless-communication integrated circuit. FIG. 4 presents a
block diagram illustrating a side view of a module 400. This module
includes a circuit board 410, having a top surface 412 and a bottom
surface 414, and at least an integrated circuit 416 disposed on top
surface 412. For example, integrated circuit 416 may include a
wireless-communication integrated circuit, and circuit board 410
may include a wireless-communication circuit board. Therefore, in
some embodiments integrated circuit 416 may be at least partially
enclosed by an optional electromagnetic-interference (EMI) shield
418. Alternatively, integrated circuit 416 may include a
solid-state memory, such as flash memory, dynamic-random-access
memory (DRAM) or, more generally, another type of volatile or
non-volatile computer-readable memory. Thus, circuit board 410 may
include a solid-state drive.
[0045] Moreover, module 400 includes a circuit board 420, having a
top surface 422, mechanically coupled to an edge 424 of circuit
board 410. Bottom surface 414 of circuit board 410 may be separated
from top surface 422 of circuit board 420 by a gap 426, and a
thermal-interface material 428 in gap 426 may thermally couple
circuit board 410 and circuit board 420 so that heat generated
during operation of integrated circuit 416 is conducted to circuit
board 420. The ground plane(s) and copper traces in circuit board
420 can then function as a heat sink for circuit board 110 and
integrated circuit 116. In addition, thermal-interface material 428
may provide additional thermal inertia or thermal mass to circuit
board 410 and integrated circuit 416. This thermal inertia may
reduce temperature increases of circuit board 410 and integrated
circuit 416 that occur during episodic operation of integrated
circuit 416, such as during read or write operations.
[0046] In particular, thermal-interface material 428 may increase a
thermal conductance (defined as .kappa.A/L, where .kappa. is the
thermal conductivity of thermal-interface material 428, A is a
cross-sectional area, and L is a thickness) between circuit board
410 and circuit board 420 so that circuit board 420 can be used as
a heat-transfer surface or heat spreader for integrated circuit
416. For example, thermal-interface material 428 may include: a
foam, a thermal gel, a thermal pad, thermal grease, and/or an
elastomeric material. In an exemplary embodiment, the thermal gel
is Gel 30 (from Chomerics North America of Woburn, Mass.) and/or
the thermal pad is the Gap Pad VO Ultra Soft (from The Bergquist
Company of Chanhassen, Minn.).
[0047] In an exemplary embodiment, circuit board 410 has a
thickness 430 of 0.8 mm, gap 426 has a thickness 432 of 1.6 mm, and
circuit board 420 has a thickness 440 of 1.0 mm. Moreover, during
operation, integrated circuit 416 may have a power consumption of
approximately 3.5 W.
[0048] In some embodiments, module 400 includes optional components
434 (such as capacitors) disposed on bottom surface 414 of circuit
board 410, where a surface 436 of thermal-interface material 428
facing bottom surface 414 includes optional pre-compressed regions
438 so that a contact area between surface 436 and bottom surface
414 is increased relative to a thermal-interface material without
optional pre-compressed regions 438. In addition, optional
pre-compressed regions 438 may ensure that the stress applied to
optional components 434 by thermal-interface material 428 does not
exceed a strain limit of circuit board 410, so that optional
components 434 do not detach from bottom surface 414.
[0049] Module 400 may be included in an electronic device, such as
a portable electronic device. This is shown in FIG. 5, which
presents a block diagram illustrating a side view of module 400
(FIG. 4) in a portable electronic device 500.
[0050] By including thermal-interface material 428, hotspots in
portable electronic device 500 that are associated with heat
generated during operation of integrated circuit 416 may be reduced
or eliminated. For example, during operation of portable electronic
device 500, the maximum temperature associated with integrated
circuit 416 may be less than 55 C.
[0051] Portable electronic device 500 may include: one or more
program modules or sets of instructions stored in an optional
memory subsystem, such as module 500. These sets of instructions
may be executed by an optional processing subsystem (such as one or
more processors) on a motherboard, such as circuit board 420. Note
that the one or more computer programs may constitute a
computer-program mechanism. Moreover, instructions in the various
modules in the optional memory subsystem may be implemented in: a
high-level procedural language, an object-oriented programming
language, and/or in an assembly or machine language. Furthermore,
the programming language may be compiled or interpreted, e.g.,
configurable or configured, to be executed by the optional
processing subsystem.
[0052] In some embodiments, functionality in these circuits,
components and devices may be implemented in one or more:
application-specific integrated circuits (ASICs),
field-programmable gate arrays (FPGAs), and/or one or more digital
signal processors (DSPs). Moreover, the circuits and components may
be implemented using any combination of analog and/or digital
circuitry, including: bipolar, PMOS and/or NMOS gates or
transistors. Furthermore, signals in these embodiments may include
digital signals that have approximately discrete values and/or
analog signals that have continuous values. Additionally,
components and circuits may be single-ended or differential, and
power supplies may be unipolar or bipolar.
[0053] Portable electronic device 500 may include one of a variety
of devices that can include memory, including: a laptop computer, a
media player (such as an MP3 player), an appliance, a
subnotebook/netbook, a tablet computer, a smartphone, a cellular
telephone, a network appliance, a personal digital assistant (PDA),
a toy, a controller, a digital signal processor, a game console, a
device controller, a computational engine within an appliance, a
consumer-electronic device, a portable computing device, a personal
organizer, and/or another electronic device.
[0054] While portable electronic device 500 was used as an
illustration in the preceding discussion, in other embodiments
module 400 is included in an electronic device, such as a server, a
desktop computer, a mainframe computer and/or a blade computer.
Furthermore, alternative passive heat transfer components and/or
materials may be used in thermal-interface material 528.
[0055] Additionally, one or more of the components may not be
present in FIGS. 4 and 5. In some embodiments, the preceding
embodiments include one or more additional components that are not
shown in FIGS. 4 and 5. Also, although separate components are
shown in FIGS. 4 and 5, in some embodiments some or all of a given
component can be integrated into one or more of the other
components and/or positions of components can be changed.
[0056] We now describe embodiments of a method that can be
performed using the embodiments in FIGS. 4 and 5. FIG. 6 presents a
flowchart illustrating a method 600 for transferring heat from an
integrated circuit, such as that in module 400 (FIG. 4). During the
method, heat generated by the integrated circuit disposed on the
top surface of the circuit board is transferred to the bottom
surface of the circuit board (operation 410). Then, the heat is
conducted to a top surface of the second circuit board, which is
thermally coupled to the circuit board by the thermal-interface
material (operation 412). Note that the bottom surface of the
circuit board is separated from the top surface of the second
circuit board by the gap, and the thermal-interface material is in
the gap between the bottom surface of the circuit board and the top
surface of the second circuit board.
[0057] In some embodiments of method 600, there may be additional
or fewer operations. Moreover, the order of the operations may be
changed, and/or two or more operations may be combined into a
single operation.
[0058] In the preceding description, we refer to `some
embodiments.` Note that `some embodiments` describes a subset of
all of the possible embodiments, but does not always specify the
same subset of embodiments.
[0059] The foregoing description is intended to enable any person
skilled in the art to make and use the disclosure, and is provided
in the context of a particular application and its requirements.
Moreover, the foregoing descriptions of embodiments of the present
disclosure have been presented for purposes of illustration and
description only. They are not intended to be exhaustive or to
limit the present disclosure to the forms disclosed. Accordingly,
many modifications and variations will be apparent to practitioners
skilled in the art, and the general principles defined herein may
be applied to other embodiments and applications without departing
from the spirit and scope of the present disclosure. Additionally,
the discussion of the preceding embodiments is not intended to
limit the present disclosure. Thus, the present disclosure is not
intended to be limited to the embodiments shown, but is to be
accorded the widest scope consistent with the principles and
features disclosed herein.
* * * * *