U.S. patent application number 16/039089 was filed with the patent office on 2018-11-08 for additive manufactured passive thermal enclosure.
The applicant listed for this patent is Microsoft Technology Licensing, LLC. Invention is credited to Andrew Douglas Delano, Lincoln Ghioni, Kurt Jenkins, Jeffrey Taylor Stellman.
Application Number | 20180321720 16/039089 |
Document ID | / |
Family ID | 60263008 |
Filed Date | 2018-11-08 |
United States Patent
Application |
20180321720 |
Kind Code |
A1 |
Jenkins; Kurt ; et
al. |
November 8, 2018 |
ADDITIVE MANUFACTURED PASSIVE THERMAL ENCLOSURE
Abstract
Thermal management devices and systems, and corresponding
manufacturing methods are described herein. A thermal management
device includes a plate having a first surface. The first surface
partially defines a chamber of the thermal management device. The
thermal management device also includes capillary features disposed
on the plate, and walls having a first end and a second end. The
walls are disposed on the plate and extend away from the first
surface of the plate, at the first end, to the second end. The
walls partially define the chamber of the thermal management
device. The thermal management device also includes a layer of
material disposed on the walls, at the second end of the wall. The
layer of material partially defines the chamber.
Inventors: |
Jenkins; Kurt; (Sammamish,
WA) ; Delano; Andrew Douglas; (Woodinville, WA)
; Ghioni; Lincoln; (Redmond, WA) ; Stellman;
Jeffrey Taylor; (Seattle, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Microsoft Technology Licensing, LLC |
Redmond |
WA |
US |
|
|
Family ID: |
60263008 |
Appl. No.: |
16/039089 |
Filed: |
July 18, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15336635 |
Oct 27, 2016 |
10054995 |
|
|
16039089 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28F 2255/18 20130101;
B23P 2700/09 20130101; H01L 21/4882 20130101; H01L 23/427 20130101;
H05K 7/20336 20130101; B23P 15/26 20130101; F28D 15/0233 20130101;
H01L 2023/4037 20130101; H01L 21/4871 20130101; G06F 1/203
20130101; G06F 1/206 20130101; B23K 26/342 20151001; B23K 2101/14
20180801; B33Y 80/00 20141201; G06F 2200/201 20130101; F28D
2020/0013 20130101; F28D 15/0283 20130101; B33Y 70/00 20141201;
B33Y 10/00 20141201; H01L 23/4275 20130101; F28D 15/046
20130101 |
International
Class: |
G06F 1/20 20060101
G06F001/20; B33Y 70/00 20150101 B33Y070/00; B33Y 80/00 20150101
B33Y080/00; B23K 26/342 20140101 B23K026/342; H01L 23/427 20060101
H01L023/427; B23P 15/26 20060101 B23P015/26; F28D 15/02 20060101
F28D015/02; H05K 7/20 20060101 H05K007/20; F28D 15/04 20060101
F28D015/04; B33Y 10/00 20150101 B33Y010/00 |
Claims
1. A thermal management device comprising: a plate having a first
surface, the first surface partially defining a chamber of the
thermal management device; capillary features disposed on or in the
plate; walls each having a first end and a second end, each of the
walls being disposed on the plate and extending away from the first
surface of the plate, at the first end, to the second end,
respectively, the walls partially defining the chamber of the
thermal management device; and a layer of material disposed on the
second ends of the walls, the layer of material partially defining
the chamber.
2. The thermal management device of claim 1, wherein the plate is
an enclosure plate of an electronic device.
3. The thermal management device of claim 2, wherein the chamber
covers a substantial portion of the first surface of the enclosure
plate.
4. The thermal management device of claim 2, wherein the plate is
mountable to an inner surface of a housing of the electronic
device.
5. The thermal management device of claim 1, wherein the plate, the
capillary features, the walls, and the layer of material are made
of a first material.
6. The thermal management device of claim 5, further comprising a
fluid, a second material, or the fluid and the second material
inside the chamber, the second material being different than the
first material.
7. The thermal management device of claim 1, wherein the layer of
material is a first layer of material, wherein the plate has a
second surface, the second surface being opposite the first
surface, and wherein the thermal management device further
comprises a second layer of material, the second layer of material
being disposed on the second surface of the plate.
8. The thermal management device of claim 7, wherein the second
layer of material is made of a wax.
9. The thermal management device of claim 7, wherein the second
layer of material covers less than all of the second surface of the
plate, and wherein the second layer of material is a thermal
insulator.
10. The thermal management device of claim 7, wherein the second
layer of material covers less than all of the second surface of the
plate, and wherein the thermal management device further comprises
a third layer of material, the third layer of material being
disposed on the second surface of the plate.
11. The thermal management device of claim 10, wherein the second
layer of material and the third layer of material are made of
different materials.
12. The thermal management device of claim 10, wherein the second
layer of material and the third layer of material are made of a
same material.
13. The thermal management device of claim 1, wherein at least one
of the walls extends in a non-perpendicular direction relative to
the plate.
14. The thermal management device of claim 1, wherein a height of
at least one of the walls varies along the plate, a shape of a
first portion of the thermal management device is different than a
shape of a second portion of the thermal management device, or a
combination thereof.
15. The thermal management device of claim 1, wherein a portion of
the capillary features extends from the first surface of the plate,
towards the layer of material, partially across the chamber.
16. The thermal management device of claim 1, wherein a portion of
the capillary features extends from the first surface of the plate
to the layer of material, across the chamber.
17. The thermal management device of claim 16, wherein the portion
of the capillary features is a first portion of the capillary
features, wherein a second portion of the capillary features
extends from the first surface of the plate to the layer of
material, across the chamber.
18. The thermal management device of claim 16, wherein the portion
of capillary features includes screen wick structures, open
channels, channels covered with screens, and annulus behind a
screen, an artery structure, a corrugated screen, or any
combination thereof.
19. The thermal management device of claim 1, wherein the plate is
a first plate, and wherein the layer of material is a second plate
disposed on the second ends of the walls.
20. The thermal management device of claim 19, wherein the first
plate and the second plate are made of different materials.
Description
PRIORITY
[0001] This application is a divisional application of U.S.
application Ser. No. 15/336,635, filed on Oct. 27, 2016, which is
hereby incorporated by reference in its entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] For a more complete understanding of the disclosure,
reference is made to the following detailed description and
accompanying drawing figures, in which like reference numerals may
be used to identify like elements in the figures.
[0003] FIG. 1 depicts a top view of a portion of a computing device
including an example of a passive thermal management system.
[0004] FIG. 2 depicts a cross section of a computing device
including the passive thermal management system of FIG. 1.
[0005] FIG. 3 depicts a cross section of a computing device
including another example of a passive thermal management
system.
[0006] FIG. 4 is a block diagram of a computing environment in
accordance with one example for implementation of the disclosed
methods or one or more electronic devices.
[0007] FIG. 5 is a flow diagram of a method for manufacturing a
thermal management device in accordance with one example.
[0008] While the disclosed devices, systems, and methods are
representative of embodiments in various forms, specific
embodiments are illustrated in the drawings (and are hereafter
described), with the understanding that the disclosure is intended
to be illustrative, and is not intended to limit the claim scope to
the specific embodiments described and illustrated herein
DETAILED DESCRIPTION
[0009] Current microprocessor design trends include designs having
an increase in power, a decrease in size, and an increase in speed.
This results in higher power in a smaller, faster microprocessor.
Another trend is towards lightweight and compact electronic
devices. As microprocessors become lighter, smaller, and more
powerful, the microprocessors also generate more heat in a smaller
space, making thermal management a greater concern than before.
[0010] The purpose of thermal management is to maintain the
temperature of a device within a moderate range. During operation,
electronic devices dissipate power as heat that is to be removed
from the device. Otherwise, the electronic device will get hotter
and hotter until the electronic device is unable to perform
effectively. When overheating, electronic devices run slowly. This
can lead to eventual device failure and reduced service life.
[0011] As computing devices get smaller (e.g., thinner), thermal
management becomes more of an issue. Heat may be dissipated from a
computing device using forced and natural convection, conduction,
and radiation as a way of cooling the computing device as a whole
and a processor operating within the computing device. Depending on
the thickness of the device, there may not be sufficient room
within the device for active thermal management components such as,
for example, fans. Passive thermal management may thus be relied on
to cool the device. For example, buoyancy driven convection (i.e.,
natural convection) and radiation to the surroundings may be relied
upon to cool the device. Assuming the size of a computing device,
and thus a surface area for radiative heat transfer, is fixed, and
a maximum temperature of an outside surface of the computing device
is fixed by user comfort and safety limits, optimized heat
rejection from the computing device, and thus a maximum steady
state power level for the computing device, is provided when the
maximum temperature of the outside surface of the computing device
is constantly maintained.
[0012] Disclosed herein are apparatuses, systems, and methods for
providing an isothermal surface of a computing device to maximize
passive heat transfer (e.g., in the presence of a buoyancy driven
flow) from the computing device. The improved passive heat transfer
from the electronic device may be provided by a constant
temperature process (e.g., condensation of a pure fluid such as
water) on or near the surface. For example, a phase change device
(e.g., a vapor chamber) that is thermally connected to a heat
generating component within the computing device may be positioned
adjacent to the surface. To minimize a distance between the surface
and the phase change device, the phase change device is formed on
an enclosure plate of the computing device. Walls and capillary
features of the phase change device are formed directly on the
enclosure plate with additive manufacturing (e.g.,
three-dimensional (3D) printing).
[0013] As an example, the improved heat dissipation from a
computing device may be implemented by a thermal management device
that includes a plate having a first surface. The first surface
partially defines a chamber of the thermal management device. The
thermal management device also includes capillary features disposed
on the plate, and walls having a first end and a second end. The
walls are disposed on the plate and extend away from the first
surface of the plate, at the first end, to the second end. The
walls partially define the chamber of the thermal management
device. The thermal management device also includes a layer of
material disposed on the walls, at the second end of the walls. The
layer of material partially defines the chamber.
[0014] Such heat dissipation apparatuses or systems have several
potential end-uses or applications, including any electronic device
having a passive or an active cooling component (e.g., fan). For
example, the heat dissipation apparatus may be incorporated into
personal computers, server computers, tablet or other handheld
computing devices, laptop or mobile computers, gaming devices,
communications devices such as mobile phones, multiprocessor
systems, microprocessor-based systems, set top boxes, programmable
consumer electronics, network PCs, minicomputers, mainframe
computers, or audio or video media players. In certain examples,
the heat dissipation apparatus may be incorporated within a
wearable electronic device, where the device may be worn on or
attached to a person's body or clothing. The wearable device may be
attached to a person's shirt or jacket; worn on a person's wrist,
ankle, waist, or head; or worn over their eyes or ears. Such
wearable devices may include a watch, heart-rate monitor, activity
tracker, or head-mounted display.
[0015] Using one or more of these features described in greater
detail below, improved heat dissipation may be provided for the
electronic device. With the improved heat dissipation feature, a
more powerful microprocessor may be installed for the electronic
device, a thinner electronic device may be designed, a higher
processing speed may be provided, the electronic device may be
operated at a higher power for a longer period of time, or any
combination thereof may be provided when compared to a similar
electronic device without one or more of the improved heat
dissipation features. In other words, the heat dissipation features
described herein may provide improved thermal management for an
electronic device such as a mobile phone, tablet computer, or
laptop computer.
[0016] FIG. 1 depicts a top view of a portion of a computing device
100 including an example of a passive thermal management system 102
that is supported by a housing 104. In FIG. 1, a portion of the
housing 104 is removed, and an interior of the housing 104 (e.g.,
largest cross-section of the housing) is shown. The computing
device 100 may be any number of computing devices including, for
example, a personal computer, a server computer, a tablet or other
handheld computing device, a laptop or mobile computer, a
communications device such as a mobile phone, a multiprocessor
system, a microprocessor-based system, a set top box, a
programmable consumer electronic device, a network PC, a
minicomputer, a mainframe computer, or an audio and/or video media
player. The passive thermal management system 102 is, for example,
at least partially additive manufactured.
[0017] The housing 104 supports at least the passive thermal
management system 102 and a heat generating electrical device 106.
The heat generating electrical device 106 may be any number of
electrically powered devices including, for example, a processor,
memory, a power supply, a graphics card, a hard drive, or other
electrically powered devices. The heat generating electrical device
106 (e.g., a processor) may be supported by the housing 104 via,
for example, a printed circuit board (PCB) 108 attached to and/or
supported by the housing 104. The processor 106 is in communication
with other electrical devices or components (not shown) of the
computing device 100 via the PCB 108, for example. The computing
device 100 may include a number of components not shown in FIG. 1
(e.g., a hard drive, a power supply, connectors).
[0018] The passive thermal management system 102 includes a phase
change device 110. In the example shown in FIG. 1, the phase change
device 110 is a vapor chamber. In other examples, the passive
thermal management system 102 includes one or more additional
and/or different phase change devices (e.g., one or more heat
pipes).
[0019] The vapor chamber 110 abuts or is adjacent to the processor
106. The passive thermal management system 102 may be installed in
a computing device where heat flux within the computing device does
not reach levels high enough to prevent a working fluid within the
vapor chamber 110 to return to a heat source (e.g., dry-out) such
as, for example, the processor 106 (e.g., an evaporator). The
working fluid may be any number of fluids including, for example,
ammonia, alcohol, ethanol, or water.
[0020] The vapor chamber 110 may be any number of sizes and/or
shapes. For example, as shown in FIG. 1, the vapor chamber 110 may
be a rectangular flat vapor chamber (e.g., with rounder corners).
The thickness of the vapor chamber 110 may be defined based on the
thickness of the computing device 100 in which the passive thermal
management system 102 is installed. A largest outer surface area of
the vapor chamber 110 may approximately match a surface area (e.g.,
a largest surface area) of an inner surface 112 of the housing 104.
In one example, the vapor chamber 110 is sized such that the
largest outer surface area of the vapor chamber 110 is as large as
will fit inside the housing 104. In other examples, the vapor
chamber 110 is smaller.
[0021] In one example, the computing device 100 includes an
enclosure plate (see FIG. 2). The enclosure plate is a plate
mounted to an inner surface of the housing 104 to provide
electromagnetic interference (EMI) shielding, structural support,
and/or thermal spreading. The enclosure plate may be made of any
number of materials including, for example, aluminum. For example,
the enclosure plate may be aluminum sheet stock. The enclosure
plate may be physically connected to the inner surface of the
housing 104 in any number of ways including, for example, with one
or more connectors. The one or more connectors may include tabs,
flanges, through holes, screws, nut/bolt combinations, another
connector, or any combination thereof.
[0022] In the prior art, a vapor chamber, for example, may be
physically and thermally connected to the enclosure plate with, for
example, adhesive and/or welds. The adhesive and/or welds increase
thermal resistance between the processor, for example, the
enclosure plate, and ultimately the housing. The additive
manufactured vapor chamber of the present examples removes a layer
of material (e.g., a top or a bottom of the vapor chamber of the
prior art) and thus a joint between layers of material that would
otherwise create thermal resistance, as chamber defining walls of
the vapor chamber are additive manufactured directly on the
enclosure plate. Such a configuration allows the thickness of the
computing device to be decreased and reduces the thermal resistance
between the processor 106, for example, and the housing 104. This
may improve heat transfer capabilities from the vapor chamber, for
example, to the housing, and ultimately out of the computing device
100.
[0023] FIG. 2 depicts a cross section of a computing device 200
including the passive thermal management system 102 of FIG. 1. The
computing device 200 also includes a PCB 202 supported within a
housing 204. The PCB 202 may be supported by and/or fixed to the
housing 204 in any number of ways including, for example, with
tabs, flanges, connectors, an adhesive, or any combination thereof.
The PCB 202 supports and is electrically connected to a heat
generating component 206 (e.g., a processor).
[0024] Heat is moved away from the processor 206, for example, and
out of the computing device 200 with the passive thermal management
system 102. The processor 206 includes a first side 208 (e.g., a
top or first surface), a second side 210 (e.g., a bottom or a
second surface), and at least one third side 212 that extends from
the first side 208 to the second side 210. The second side 210 of
the processor 206 abuts or is adjacent to the PCB 202. The first
side 208 of the processor 206 abuts or is adjacent to the vapor
chamber 110 of the passive thermal management system 102.
[0025] The vapor chamber 110 includes a first side 214 (e.g., a
top), a second side 216 (e.g., a bottom), and at least one third
side 218 that extends to the second side 216. In the example shown
in FIG. 2, the at least one third side 218 is offset relative to an
outer perimeter defined by the first side 214. In another example,
the at least one third side 218 extends from the first side 214 to
the second side 216. The second side 216 of the vapor chamber 110
abuts or is adjacent to the first side 208 of the processor 206.
The second side 216 of the vapor chamber 110 may be adjacent to the
first side 208 of the processor 206 in that one or more layers of
additional material may be disposed between the second side 216 of
the vapor chamber 110 and the first side 208 of the processor 206.
For example, one or more layers of thermal adhesive may be disposed
between the second side 216 of the vapor chamber 110 and the first
side 208 of the processor 206.
[0026] The first side 214 of the vapor chamber 110 abuts or is
adjacent to a surface (e.g., an inner surface 220) of the housing
204. The inner surface 220 of the housing 204 may be an inner
surface of the housing 204 opposite the first side 214 of the vapor
chamber 110. The inner surface 220 may cover a largest dimension of
the housing 204 and may be part of a backing layer (e.g., a bucket)
or a display module of the computing device 200. The first side 214
of the vapor chamber 110 may be adjacent to the inner surface 220
of the housing 204 in that one or more layers of material (e.g.,
layer of material 222) or air (e.g., a vacuum) is disposed between
the first side 214 of the vapor chamber 110 and the inner surface
220 of the housing 204. The layer of material 222 may be disposed
on the inner surface 220 of the housing 204 and/or on the first
side 214 of the vapor chamber 110. In the example shown in FIG. 2,
the layer of material 222 covers the entire inner surface 220 of
the housing 204. In another example, the layer of material 222
covers less than the entire inner surface 220 of the housing 204.
The first side 214 of the vapor chamber 110 may be substantially
the same shape and/or size as the inner surface 220 of the housing
204 in that, for example, the housing 204 has rounded corners and
the vapor chamber does not 110, or vice versa.
[0027] The layer of material 222 may be any number of materials
including, for example, a wax (e.g., a refined paraffin wax that
includes a binder). The binder eliminates flow after phase change.
Different paraffin waxes may be used for the layer of material 222
based on the particular computing device and, more specifically,
temperatures produced within the particular computing device.
Different paraffin waxes have different melt peaks, different
densities, and different latent heats of fusion. The paraffin wax
used, for example, may be selected such that the melt peak of the
paraffin wax matches a temperature at the vapor chamber 110 during
operation of the computing device 200 (e.g., at maximum steady
state power level and/or at a power level greater than the maximum
steady state power level). When a melting point is reached, the
paraffin wax begins to store heat during phase change. Depending on
the amount of wax applied to the vapor chamber 110 and/or the inner
surface 220 of the housing 204, for example, and the material used,
sufficient cooling of the computing device 200 (e.g., without
reducing power) may be provided for additional time, for example,
while the computing device 200 operates above steady state power.
With increased volume of the layer of material 222, the amount of
additional time the computing device 200, for example, may be
sufficiently cooled during higher than steady state power operation
also increases.
[0028] The vapor chamber 110 may be physically attached to the PCB
202, the housing 204 (e.g., the inner surface 220 of the housing
204), another surface within the computing device 200, or any
combination thereof in any number of ways. For example, the vapor
chamber 110 may be physically attached with tabs, flanges,
connectors, an adhesive, or any combination thereof. As shown in
the example of FIG. 2, the vapor chamber 110 may be physically
attached to the inner surface 220 of the housing 204 via one or
more (e.g., four or eight) posts including through-holes and
corresponding connectors (e.g., screws).
[0029] Part of the vapor chamber 110 is formed by an enclosure
plate 224 (e.g., a first plate). The enclosure plate 224 includes a
first side 226, a second side 228, and at least one third side 230
extending from the first side 226 to the second side 228. Computing
devices of the prior art typically include an enclosure plate 224
physically connected to the housing of the computing device to, for
example, structurally strengthen the computing device. The
enclosure plate 224 of the present examples acts as the first side
214 of the vapor chamber. The enclosure plate 224 may be made of
any number of thermally conductive materials including, for
example, aluminum, and may be any number of sizes based on, for
example, the size of the computing device into which the passive
thermal management system 102 is installed. For example, the
enclosure plate 224 may be an aluminum flat plate. In other
examples, the enclosure plate 224 is made of copper or another
material.
[0030] The vapor chamber 110 also includes walls 232 that are
additive manufactured directly on the second side 228 of the
enclosure plate 224. The walls 232 define a perimeter (e.g., a
length and a width) and a thickness of the vapor chamber 110. The
walls 232 may extend away from the second side 228 of the enclosure
plate 224, at a first end 234 of the walls 232, to a second end 236
of the walls 232. The walls 232 may extend away from the second
side 228 of the enclosure plate 224 in any number of directions
including, for example, in a direction perpendicular to the second
side 228 of the enclosure plate 224. In other examples, the walls
232 extend away from the second side 228 of the enclosure plate 224
in non-perpendicular directions relative to the second side 228 of
the enclosure plate 224 (see FIG. 3).
[0031] The walls 232 are made of any number of thermally conductive
materials including, for example, aluminum. In one example, the
walls 232 are made of the same material as the enclosure plate 224.
In another example, the walls 232 are made of a different material
than the enclosure plate 224 (e.g., different alloys of the same
metal or different metals).
[0032] The vapor chamber 110 also includes a layer of material 238
(e.g., a second plate, a sheet, or a foil). In one example, the
second plate 238 is made of the same material as the enclosure
plate 224 and/or the walls 232. In another example, the second
plate 238 is made of a different material than the enclosure plate
224 and/or the walls 232. The second plate 238 may be the same size
or a different size than the enclosure plate 224. The second plate
238 may have a length and a width based on the perimeter defined by
the walls 232 of the vapor chamber 110. The second plate 238 may be
any number of thicknesses. In one example, the thickness of the
second plate 238 is set based on the computing device (e.g., the
size of the computing device and/or the heat generated to be
removed) in which the vapor chamber is installed. In one example, a
plurality of second plates 238 are physically attached to the
second end 236 of the walls 232 (e.g., at different heights due to
walls 232 with non-uniform heights being additive manufactured on
the enclosure plate 224).
[0033] The second plate 238 is physically attached to the second
end 236 of the walls 232. The second plate 238 may be physically
attached to the second end 236 of the walls 232 in any number of
ways including, for example, with welding or diffusion bonding.
Other methods of physically attaching the second plate 238 to the
second end 236 of the walls 232 may be used.
[0034] The enclosure plate 224, the walls 232, and the second plate
238 at least partially define a chamber 240 (e.g., a vapor space)
of the vapor chamber 110. In one example, the chamber 240 covers a
substantial portion of the second side 228 of the enclosure plate
224 in that the perimeter defined by the walls 232 matches the
perimeter of the enclosure plate 224. The chamber 240 is filled
with a working fluid (e.g., water) and/or another material (e.g., a
wax). The internal structure of the vapor chamber 110 is important
for phase change performance. Features that affect phase change
performance include the vapor space 240 and capillary features 242.
The vapor space 240 is a path for evaporated working fluid to
travel to a condenser of the vapor chamber 110, and the capillary
features 242 are a pathway for condensed working fluid to return to
an evaporator of the vapor chamber 110.
[0035] The capillary features 242 may be formed on at least a
portion of the second side 228 of the enclosure plate 224, the
walls 232, an extension 244 through the chamber 240, and/or the
second plate 238. In the example shown in FIG. 2, a portion of the
capillary features 242 extend (e.g., at extension 244) from the
second side 228 of the enclosure plate 224 to the second plate 238.
The extension 244 is adjacent to (e.g., centered relative to) the
processor 206 to increase efficiency of the vapor chamber 110. The
extension 244 provides a path for liquid to be evaporated by, for
example, heat generated by the processor 206. The extension 244 may
extend all of the way across the chamber 240 and separate the
chamber 240 into a number of separate chambers, or the extension
240 may not extend all of the way across the vapor chamber 110. In
one example, a plurality of extensions 244 including capillary
features extend from the second side 228 of the enclosure plate 224
to the second plate 238, adjacent to the processor 206. As
examples, the capillary features 242 may include screen wick
structures, open channels, channels covered with screens, an
annulus behind a screen, an artery structure, a corrugated screen,
other structures, or any combination thereof. The capillary
features 242 may be additive manufactured on at least a portion of
the second side 228 of the enclosure plate 224, the walls 232,
and/or the second plate 238. In one example, at least some of the
capillary features 242 are chemically etched on at least a portion
of the second side 228 of the enclosure plate 224, the walls 232,
and/or the second plate 238. For example, capillary features 242
are chemically etched on the second plate 238 while additional
capillary features 242 are additive manufactured on the enclosure
plate 224, or the enclosure plate 224 and the walls 232.
[0036] Prior art manufacturing processes for thermal management
devices include stamping, extrusion, casting, and machining. Such
manufacturing processes, however, are constrained based on the
material being used and the device being manufactured. Thermal
management devices manufactured with these prior art processes are
constrained by associated tolerances.
[0037] Tolerances for additive manufactured thermal management
devices are smaller compared to the prior art manufacturing
processes. Accordingly, an additive manufactured vapor chamber of
one or more of the present examples may be any number of sizes
and/or shapes. In one example, the additive manufactured vapor
chamber is non-uniform in size and/or shape. Also, by 3D printing
directly on an enclosure plate (e.g., the enclosure plate 224),
different materials may be applied on different portions of the
enclosure plate to control thermal resistance between the vapor
chamber 110 and the housing 204 (e.g., an outer surface of the
housing 204), and thus the processor 206 and the housing 204. This
control of the thermal resistance aids in the provision of an
isothermal surface on the housing (e.g., the outer surface of the
housing 204).
[0038] FIG. 3 depicts a cross section of a computing device 300
including another example of a passive thermal management system
302. The passive thermal management system 302 includes a phase
change device 304 such as, for example, a vapor chamber. In another
example, the phase change device 304 is a heat pipe. Part of the
vapor chamber 304 is formed by an enclosure plate 306 (e.g., a
first plate). The enclosure plate 306 includes a first side 308, a
second side 310, and at least one third side 312 extending from the
first side 308 to the second side 310. The enclosure plate 306 may
be made of any number of thermally conductive materials including,
for example, aluminum, copper, or another material. For example,
the enclosure plate 306 may be an aluminum flat plate.
[0039] The vapor chamber 304 includes walls 314 that are additive
manufactured directly on the second side 310 of the enclosure plate
306. The walls 314 define a perimeter (e.g., a length and a width)
and a thickness of the vapor chamber 304. The perimeter may vary
along the thickness (e.g., the height) of the vapor chamber 304. In
other words, the walls 314 may extend away from the second side 310
of the enclosure plate 306 in a non-perpendicular direction
relative to the second side 310 of the enclosure plate 306. In the
example shown in FIG. 3, opposite walls 314 extend in directions
away from the second side 310 of the enclosure plate 306 and
towards each other. In other words, the walls 314 extend away from
the second side 310 of the enclosure plate 306 such that a
cross-section of the vapor chamber 304 is trapezoidal. The
trapezoidal shape of the vapor chamber 304 may provide for a
structurally strong vapor chamber. In one example, a vacuum is
pulled within the vapor chamber 304, and the trapezoidal shape may
help prevent the vapor chamber 304 from collapsing on itself when
the vacuum is pulled.
[0040] In the example shown in FIG. 3, a first portion of the walls
314a has a different height than a second portion of the walls
314b. By 3D printing the walls 314a directly onto the enclosure
plate 306, any number of shapes and/or sizes (e.g., non-uniform
shapes and/or sizes) may be provided for the vapor chamber 304. The
non-uniform shapes and/or sizes may accommodate for components
within a particular portion of the computing device 300 and/or may
aid in producing an isothermal surface on the computing device 300
based on locations and amounts of heat generation within the
computing device 300.
[0041] In the example shown in FIG. 3, a layer of material 316 is
disposed on the first side 308 of the enclosure plate 306. The
layer of material 316 may be disposed on the first side 308 of the
enclosure plate 306 in any number of ways including, for example,
with additive manufacturing (e.g., 3D printing). The layer of
material 316 may be any number of materials including, for example,
an insulating material such as a foam or a plastic. The layer of
material 316 may cover less than all of the first side 308 of the
enclosure plate 306. For example, the layer of material 316 may be
disposed on the first side 308 of the enclosure plate 306 above a
heat generating component 318 (e.g., a processor), such that a hot
spot is not formed on an outer surface 320 of the computing device
300. The size and placement of the layer of material 316 may be set
based on a temperature distribution on the outer surface 320 of the
computing device 300 during operation of the computing device 300.
In one example, the layer of material 316 covers the entire first
side 308 of the enclosure plate 306. In another example, one or
more additional layers of the same or a different material than the
layer of material 316 may be disposed on the vapor chamber 304
(e.g., the first side 308 of the enclosure plate 306). The layer of
material 316 or the layer of material 316 and the one or more
additional layers of material may provide thermal resistance
balancing towards the goal of an isothermal outer surface 320 of
the computing device 300. In one example, no layer of material is
disposed on the first side 308 of the enclosure plate 306. Instead,
a vacuum is formed between the first side 308 of the enclosure
plate 306 and the inner surface 220 of the computing device
300.
[0042] Other components and/or features may be disposed (e.g.,
additive manufactured) within and/or on the vapor chamber 304. For
example, fins of a heat sink, which provide an extended area for
heat rejection, may be additive manufactured on any number of
surfaces within and/or on the vapor chamber 304. In one example,
fins of a heat sink are additive manufactured on a surface 322 of a
second plate 324 inside the vapor chamber 304.
[0043] Heat sinks of the prior art may be physically attached
(e.g., soldered) to an outer surface of a phase change device
(e.g., a heat pipe or vapor chamber). The attachment region creates
an additional thermal resistance in a thermal management system,
thus reducing overall performance of the thermal management system.
Fin geometries for fins manufactured using processes of the prior
art are also limited to basic shapes. By 3D printing the heat sink,
the additional thermal resistance created by the attachment region
is removed, the heat sink is formable within a phase change device
(e.g., the vapor chamber 304), for example, and fin geometries are
less limited compared to the prior art.
[0044] Other features may be additive manufactured within the
thermal management system 302. For example, texturing may be
disposed on any number of surfaces within the thermal management
system 302. For example, texturing may be additive manufactured on
the first side 308 of the enclosure plate 306. The texturing may
aid in heat transfer from the vapor chamber 304 out of the
computing device 300.
[0045] In the present examples, the integration of a phase change
device (e.g., a vapor chamber) with an enclosure of an electronic
device reduces the height of components within the electronic
device, allowing a thinner electronic device to be produced or
providing space for other components within the electronic device.
For example, a thermal solution (e.g., including the vapor chamber)
may be lowered a number of millimeters within the electronic device
by forming the vapor chamber on the enclosure. Also, the
utilization of a largest surface area of the electronic device for
the thermal solution (e.g., covering substantially all of a largest
surface area of the electronic device) maximizes heat transfer, may
aid in the creation of an isothermal surface on the electronic
device, and may allow for the elimination of fans within the
electronic device, which reduces noise.
[0046] With reference to FIG. 4, a thermal management system, as
described above, may be incorporated within an exemplary computing
environment 400. The computing environment 400 may correspond with
one of a wide variety of computing devices, including, but not
limited to, personal computers (PCs), server computers, tablet and
other handheld computing devices, laptop or mobile computers,
communications devices such as mobile phones, multiprocessor
systems, microprocessor-based systems, set top boxes, programmable
consumer electronics, network PCs, minicomputers, mainframe
computers, or audio or video media players. The thermal management
system may be incorporated within a computing environment having an
active cooling source (e.g., fan). In another example, the thermal
management system may be incorporated within a computing
environment not having an active cooling source.
[0047] The computing environment 400 has sufficient computational
capability and system memory to enable basic computational
operations. In this example, the computing environment 400 includes
one or more processing units 402, which may be individually or
collectively referred to herein as a processor. The computing
environment 400 may also include one or more graphics processing
units (GPUs) 404. The processor 402 and/or the GPU 404 may include
integrated memory and/or be in communication with system memory
406. The processor 402 and/or the GPU 404 may be a specialized
microprocessor, such as a digital signal processor (DSP), a very
long instruction word (VLIW) processor, or other microcontroller,
or may be a general purpose central processing unit (CPU) having
one or more processing cores. The processor 402, the GPU 404, the
system memory 406, and/or any other components of the computing
environment 400 may be packaged or otherwise integrated as a system
on a chip (SoC), application-specific integrated circuit (ASIC), or
other integrated circuit or system.
[0048] The computing environment 400 may also include other
components, such as, for example, a communications interface 408.
One or more computer input devices 410 (e.g., pointing devices,
keyboards, audio input devices, video input devices, haptic input
devices, or devices for receiving wired or wireless data
transmissions) may be provided. The input devices 410 may include
one or more touch-sensitive surfaces, such as track pads. Various
output devices 412, including touchscreen or touch-sensitive
display(s) 414, may also be provided. The output devices 412 may
include a variety of different audio output devices, video output
devices, and/or devices for transmitting wired or wireless data
transmissions.
[0049] The computing environment 400 may also include a variety of
computer readable media for storage of information such as
computer-readable or computer-executable instructions, data
structures, program modules, or other data. Computer readable media
may be any available media accessible via storage devices 416 and
includes both volatile and nonvolatile media, whether in removable
storage 418 and/or non-removable storage 420. Computer readable
media may include computer storage media and communication media.
Computer storage media may include both volatile and nonvolatile,
removable and non-removable media implemented in any method or
technology for storage of information such as computer readable
instructions, data structures, program modules or other data.
Computer storage media includes, but is not limited to, RAM, ROM,
EEPROM, flash memory or other memory technology, CD-ROM, digital
versatile disks (DVD) or other optical disk storage, magnetic
cassettes, magnetic tape, magnetic disk storage or other magnetic
storage devices, or any other medium which may be used to store the
desired information and which may be accessed by the processing
units of the computing environment 400.
[0050] FIG. 5 shows a flowchart of one example of a method 500 for
manufacturing a thermal management device of a computing device.
The method 500 is implemented in the order shown, but other orders
may be used. Additional, different, or fewer acts may be provided.
Similar methods may be used for manufacturing a thermal management
device.
[0051] In act 502, walls of a phase change device are produced on a
first surface of a metal plate using additive manufacturing (e.g.,
3D printing). In one example, the walls of the phase change device
are additive manufactured directly on the first surface of the
metal plate. In another example, there are one or more intervening
layers of material between the metal plate and the walls. The metal
plate and the walls partially define a chamber of the phase change
device. In one example, the phase change device is a vapor chamber.
In another example, the phase change device is a heat pipe.
[0052] Additive manufacturing may include any number of methods of
manufacturing. For example, additive manufacturing may include 3D
printing, selective laser melting (SLM), direct metal laser
sintering (DMLS), directed energy deposition, electron beam
forming, electroforming, screen printing, another form of additive
manufacturing, or any combination thereof.
[0053] The 3D printing may include depositing layers of material
onto a power bed with inkjet printer heads. In one example, the 3D
printing is stencil 3D printing. Alternatively or additionally, the
3D printing may include an extrusion-based process, a
sintering-based process, or another process. In an extrusion-based
process, small beads of material are extruded, and the small beads
of material harden to form the layers. In a sintering-based
process, heat and/or pressure is used to compact and/or form the
layers (e.g., with a laser). The successive layers of material may
be deposited under computer control based on a 3D model to produce
an object (e.g., the vapor chamber).
[0054] The walls of the phase change device are additive
manufactured such that each of the walls has a first end and a
second end, and extends away from the first surface of the metal
plate, at the first end, to the second end. The walls of the phase
change device may be additive manufactured on the first surface of
the metal plate such that the walls extend away from the first
surface of the metal plate in any number of directions relative to
the first surface of the metal plate. In one example, the walls
extend away from the first surface of the metal plate in a
direction perpendicular to the first surface of the metal plate. In
another example, at least one of the walls extends away from the
first surface of the metal plate in a non-perpendicular direction
relative to the first surface of the metal plate.
[0055] The metal plate may be an enclosure plate of the computing
device. The enclosure plate provides EMI shielding, structural
support, and/or a thermal path for heat out of the computing
device. By, for example, 3D printing the walls directly on the
enclosure plate of the computing device, the computing device may
be thinner compared to a computing device of the prior art in which
a phase change device is positioned at a distance from or is
physically attached to the enclosure plate. The enclosure plate may
be made of any number of thermally and/or electrically conductive
materials including, for example, aluminum. In one example, the
phase change device is formed (e.g., additive manufactured) on
another surface within the computing device (e.g., an inner surface
of a housing of the computing device).
[0056] The walls of the phase change device may be additive
manufactured using any number of materials. For example, the walls
of the phase change device may be additive manufactured using
copper, aluminum, titanium, gold, another thermally conducting
material, or any combination thereof. As one example, the walls of
the phase change device are additive manufactured using two or more
materials (e.g., copper and aluminum). In one example, the walls of
the phase change device are additive manufactured using the same
material of which the enclosure plate is made (e.g., aluminum). In
another example, the walls of the phase change device are additive
manufactured using a material (e.g., copper) that is different than
the material of which the enclosure plate is made. The walls may be
any number of shapes and/or sizes. The size and/or shapes of the
walls may be uniform or non-uniform. For example, at least one of
the walls has a larger height compared to the other walls. In one
example, a single, circular wall is printed directly on the
enclosure plate.
[0057] In act 504, capillary features of the phase change device
are produced on the first surface of the metal plate using additive
manufacturing (e.g., 3D printing). As examples, the capillary
features may include screen wick structures, open channels,
channels covered with screens, an annulus behind a screen, an
artery structure, a corrugated screen, other structures, or any
combination thereof. In one example, the capillary features of the
phase change device are formed directly on the first surface of the
metal plate. In another example, there are one or more layers of
intervening layers of material between the metal plate and the
capillary features.
[0058] The capillary features may be additive manufactured using
any number of materials including, for example, copper, aluminum,
titanium, gold, another thermally conducting material, or any
combination thereof. In one example, the capillary features are
additive manufactured using two or more materials (e.g., copper and
aluminum). In one example, the capillary features are additive
manufactured using the same material as the enclosure plate and/or
the walls. In another example, the capillary features are additive
manufactured using a material different than the materials used for
the enclosure plate and/or the walls.
[0059] In one example, the capillary features are additive
manufactured on only the enclosure plate. In another example, the
capillary features are not formed on the enclosure plate. Instead,
the capillary features are additive manufactured along the height
of the walls or are additive manufactured integral with the walls.
In yet another example, the capillary features are additive
manufactured on the enclosure plate and with the walls. In one
example, the capillary features are additive manufactured on the
enclosure plate, and a portion of the capillary features are
additive manufactured such that the portion extends from the
enclosure plate to a layer of second material opposite the
enclosure plate. A cross-section of the portion may match a size
and a shape of a heat generating component supported within the
computing device.
[0060] In act 506, the chamber is filled with a fluid, a first
material, or the fluid and the first material. The fluid may be a
working fluid of the vapor chamber, for example. The working fluid
may be selected such that with a maximum heat flux within the
computing device, the working fluid does not dry-out. The working
fluid may be any number of fluids including, for example, ammonia,
alcohol, ethanol, or water.
[0061] In one example, the chamber is filled with another material.
For example, the chamber may be filled with, for example, a wax to
store thermal energy when the computing device is operated at a
high processing speed for an extended period of time. In other
words, the chamber may be filled with the wax to increase the
thermal capacitance of the thermal management system within the
computing device.
[0062] In act 508, the layer of a second material is physically
attached to the second end of the walls. The layer of the second
material may be a plate the same as or similar to the enclosure
plate (e.g., an aluminum plate). In one example, the layer of the
second material is a foil-like material (e.g., a foil). The size
and/or shape of the layer of the second material may match a
perimeter of the vapor chamber formed at the second end of the
walls. Capillary features may be additive manufactured on or
chemically etched in the layer of the second material.
Alternatively, the layer of the second material may not include any
capillary features.
[0063] In one example, the layer of the second material is
physically attached to the second end of the walls before the
chamber is filled with, for example, the working fluid. The walls
of the vapor chamber may be additive manufactured in act 502 to
include a port for filling the vapor chamber with the working
fluid. The port may be sealed (e.g., mechanically or with heat)
after the vapor chamber is filled with the working fluid.
[0064] The layer of the second material may be physically attached
to the second end of the walls in any number of ways. For example,
the layer of the second material is physically attached to the
second end of the walls with welding, diffusion bonding, or another
attachment method. In one example, a plurality of layers of
material (e.g., made of a same material or different materials) are
physically attached to different sections of the walls. For
example, different sections of the walls may have different
heights, and separate layers of material may be physically attached
to the different sections of the walls, respectively, using welding
or diffusion bonding.
[0065] In one example, the walls and the capillary features are
additive manufactured on the first surface of the metal plate with
a first material, and one or more layers of a second material are
additive manufactured on a second surface of the metal plate. The
metal plate may be a flat plate, and the second surface may be
opposite the first surface. The second material may be a thermally
insulating material (e.g., a foam or a plastic). The one or more
layers of the second material may cover less than all of the second
surface of the metal plate, and the one or more layers of the
second material may be positioned on the second surface of the
metal plate to control thermal resistance between a heat generating
component physically connected to the vapor chamber, for example,
and an outer surface of the computing device. For example, a layer
of thermally insulating material may be additive manufactured on
the second surface of the metal plate, in a location opposite where
the heat generating component of the computing device is to be
installed. The control of thermal resistance may aid in providing
an isothermal outer surface of the computing device. In one
example, the thermal resistance control aids in the minimization of
heat transfer to the outer surface of the computing device to avoid
hot spots on the outer surface of the computing device. For
example, if the phase change device (e.g., a surface area of the
phase change device) is small relative to the inner surface of the
housing of the computing device, a hot spot may otherwise form
without the thermally insulating material disposed on the second
surface of the metal plate and/or the inner surface of the housing
of the computing device.
[0066] In another example, at least one connector is additive
manufactured on the metal plate, as part of the walls, and/or on
the layer of the second material. The at least one connector may
include one or more flanges, tabs, through-holes, or other
connectors for physically attaching the vapor chamber, for example,
to a housing of the computing device and/or other components within
the computing device.
[0067] While the present claim scope has been described with
reference to specific examples, which are intended to be
illustrative only and not to be limiting of the claim scope, it
will be apparent to those of ordinary skill in the art that
changes, additions and/or deletions may be made to the disclosed
embodiments without departing from the spirit and scope of the
claims.
[0068] The foregoing description is given for clearness of
understanding only, and no unnecessary limitations should be
understood therefrom, as modifications within the scope of the
claims may be apparent to those having ordinary skill in the
art.
[0069] In a first embodiment, a thermal management device includes
a plate having a first surface. The first surface partially defines
a chamber of the thermal management device. The thermal management
device also includes capillary features disposed on or in the
plate. The thermal management device includes walls having a first
end and a second end. The walls are disposed on the plate and
extend away from the first surface of the plate, at the first end,
to the second end. The walls partially define the chamber of the
thermal management device. The thermal management device includes a
layer of material disposed on the second end of the walls. The
layer of material partially defines the chamber.
[0070] In a second embodiment, with reference to the first
embodiment, the plate is an enclosure plate of an electronic
device.
[0071] In a third embodiment, with reference to the second
embodiment, the chamber covers a substantial portion of the first
surface of the enclosure plate.
[0072] In a fourth embodiment, with reference to the first
embodiment, the plate, the capillary features, the walls, and the
layer of material are made of a first material.
[0073] In a fifth embodiment, with reference to the fourth
embodiment, the thermal management device further includes a fluid,
a second material, or the fluid and the second material inside the
chamber. The second material is different than the first
material.
[0074] In a sixth embodiment, with reference to the first
embodiment, the layer of material is a first layer of material. The
plate has a second surface. The second surface is opposite the
first surface. The thermal management device further includes a
second layer of material. The second layer of material is disposed
on the second surface of the plate.
[0075] In a seventh embodiment, with reference to the sixth
embodiment, the second layer of material covers less than all of
the second surface of the plate. The second layer of material is a
thermal insulator.
[0076] In an eighth embodiment, with reference to the first
embodiment, at least one of the walls extends in a
non-perpendicular direction relative to the plate.
[0077] In a ninth embodiment, with reference to the first
embodiment, a height of at least one of the walls varies along the
plate. A shape of a first portion of the thermal management device
is different than a shape of a second portion of the thermal
management device, or a combination thereof.
[0078] In a tenth embodiment, a computing device includes a heat
generating electronic component. The computing device also includes
a housing that supports the heat generating component. The housing
has an inner surface and an outer surface. The computing device
includes a thermal management device supported by the housing. The
thermal management device includes a plate having a first surface
and a second surface. The second surface of the plate faces the
inner surface of the housing. The plate partially defines a chamber
of the thermal management device. The thermal management device
also includes walls having a first end and a second end. The walls
are disposed on the plate and extend away from the first surface of
the plate, at the first end, to the second end. The walls partially
define the chamber of the thermal management device. The thermal
management device also includes a layer of first material disposed
on the second end of the walls. The layer of material partially
defines the chamber. The thermal management device includes a
fluid, a second material, or the fluid and the second material
disposed in the chamber.
[0079] In an eleventh embodiment, with reference to the tenth
embodiment, the second surface of the plate is substantially the
same shape and size as the inner surface of the housing.
[0080] In a twelfth embodiment, with reference to the tenth
embodiment, the plate and the walls are made of the first material
or a third material.
[0081] In a thirteenth embodiment, with reference to the tenth
embodiment, the computing device further includes a layer of third
material disposed between the second surface of the plate and the
inner surface of the housing. The layer of third material has a
first surface and a second surface. The first surface of the layer
of third material is in physical contact with the second surface of
the plate, and the second surface of the layer of third material is
in physical contact with the inner surface of the housing.
[0082] In a fourteenth embodiment, with reference to the thirteenth
embodiment, the layer of third material is made of wax.
[0083] In a fifteenth embodiment, with reference to the tenth
embodiment, the thermal management device further includes
capillary features disposed on the first surface of the plate.
[0084] In a sixteenth embodiment, with reference to the tenth
embodiment, the plate is an enclosure plate of the housing.
[0085] In a seventeenth embodiment, a method for manufacturing a
thermal management device includes additive manufacturing walls of
a phase change device on a first surface of a metal plate, such
that the wall has a first end and a second end, and extends away
from the first surface of the metal plate, at the first end, to the
second end. The metal plate and the walls partially define a
chamber. The method also includes additive manufacturing capillary
features on the first surface of the metal plate, filling the
chamber with a fluid, a first material, or the fluid and the first
material, and physically attaching a layer of second material to
the second end of the walls.
[0086] In an eighteenth embodiment, with reference to the
seventeenth embodiment, additive manufacturing the walls includes
3D printing the walls on the first surface of the metal plate using
the second material or a third material. The method also includes
3D printing a fourth material on a second surface of the metal
plate. The second surface of the metal plate is opposite the first
surface of the metal plate.
[0087] In a nineteenth embodiment, with reference to the
seventeenth embodiment, physically attaching the layer of second
material to the second end of the walls includes welding or
diffusion bonding the layer of second material onto the second end
of the walls.
[0088] In a twentieth embodiment, with reference to the seventeenth
embodiment, the method further includes 3D printing at least one
connector on the metal plate, the walls, the layer of second
material, or any combination thereof. The thermal management device
is connectable to an inner surface of a housing of an electronic
device via the at least one connector.
[0089] In connection with any one of the aforementioned
embodiments, the thermal management device or the method for
manufacturing the thermal management device may alternatively or
additionally include any combination of one or more of the previous
embodiments.
[0090] The foregoing description is given for clearness of
understanding only, and no unnecessary limitations should be
understood therefrom, as modifications within the scope of the
claims may be apparent to those having ordinary skill in the
art.
* * * * *