U.S. patent application number 14/143377 was filed with the patent office on 2014-07-10 for vehicles, power electronics modules and cooling apparatuses with single-phase and two-phase surface enhancement features.
This patent application is currently assigned to PURDUE RESEARCH FOUNDATION. The applicant listed for this patent is Toyota Motor Engineering & Manufacturing North America, Inc.. Invention is credited to Ercan Mehmet Dede, Suresh V. Garimella, Shailesh N. Joshi, Matthew Joseph Rau.
Application Number | 20140192485 14/143377 |
Document ID | / |
Family ID | 50001632 |
Filed Date | 2014-07-10 |
United States Patent
Application |
20140192485 |
Kind Code |
A1 |
Rau; Matthew Joseph ; et
al. |
July 10, 2014 |
VEHICLES, POWER ELECTRONICS MODULES AND COOLING APPARATUSES WITH
SINGLE-PHASE AND TWO-PHASE SURFACE ENHANCEMENT FEATURES
Abstract
Jet-impingement, two-phase cooling apparatuses and power
electronics modules having a target surface with single- and
two-phase surface enhancement features are disclosed. In one
embodiment, a cooling apparatus includes a jet plate surface and a
target layer. The jet plate surface includes a jet orifice having a
jet orifice geometry, wherein the jet orifice is configured to
generate an impingement jet of a coolant fluid. The target layer
has a target surface, single-phase surface enhancement features,
and two-phase surface enhancement features. The target surface is
configured to receive the impingement jet, and the single-phase
surface enhancement features and the two-phase enhancement features
are arranged on the target surface according to the jet orifice
geometry. The single-phase surface enhancement features are
positioned on the target surface at regions associated with high
fluid velocity, and the two-phase surface enhancement features are
positioned on the target surface at regions associated with low
fluid velocity.
Inventors: |
Rau; Matthew Joseph;
(Lafayette, IN) ; Dede; Ercan Mehmet; (Ann Arbor,
MI) ; Joshi; Shailesh N.; (Ann Arbor, MI) ;
Garimella; Suresh V.; (West Lafayette, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Toyota Motor Engineering & Manufacturing North America,
Inc. |
Erlanger |
KY |
US |
|
|
Assignee: |
PURDUE RESEARCH FOUNDATION
West Lafayette
IN
Toyota Motor Engineering & Manufacturing North America,
Inc.
Erlanger
KY
|
Family ID: |
50001632 |
Appl. No.: |
14/143377 |
Filed: |
December 30, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13734710 |
Jan 4, 2013 |
8643173 |
|
|
14143377 |
|
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Current U.S.
Class: |
361/700 ;
165/168 |
Current CPC
Class: |
H05K 7/20845 20130101;
H05K 7/2029 20130101; H01L 23/4735 20130101; H01L 2924/0002
20130101; H01L 2924/0002 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
361/700 ;
165/168 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Claims
1. A cooling apparatus comprising: a jet channel; a jet plate
surface comprising a jet orifice having a jet orifice geometry,
wherein the jet orifice is in fluid communication with the jet
channel and is configured to generate an impingement jet of a
coolant fluid; and a target layer comprising a target surface,
single-phase surface enhancement features, and two-phase surface
enhancement features, wherein: the target surface is configured to
receive the impingement jet at an impingement region; the
single-phase surface enhancement features are positioned on the
target surface at high fluid velocity regions; and the two-phase
surface enhancement features are positioned on the target surface
at low fluid velocity regions.
2. The cooling apparatus of claim 1, wherein the two-phase surface
enhancement features comprise micro- and/or nano-features.
3. The cooling apparatus of claim 2, wherein the micro- and/or
nano-features are pillars.
4. The cooling apparatus of claim 1, wherein the two-phase surface
enhancement features are defined by roughened portions of the
target surface.
5. The cooling apparatus of claim 4, wherein the roughened portions
are laser roughened, chemically roughened, or mechanically
roughened.
6. The cooling apparatus of claim 1, wherein the two-phase surface
enhancement features comprise a film applied to the target
surface.
7. The cooling apparatus of claim 6, wherein the film comprises
micro- and/or nano-features.
8. The cooling apparatus of claim 1, wherein: the jet orifice is
cross-shaped; the single-phase surface enhancement features are
arranged in four groups of single-phase surface enhancement
features; the two-phase surface enhancement features are arranged
in four regions of two-phase surface enhancement features; and the
four groups of single-phase surface enhancement features and the
four regions of two-phase enhancement features alternate about the
impingement region of the target surface.
9. The cooling apparatus of claim 8, wherein the four regions of
two-phase enhancement features are arranged at a perimeter of the
target surface.
10. The cooling apparatus of claim 8, wherein: the four groups of
single-phase surface enhancement features radially extend from the
impingement region; and individual groups of the four groups of
single-phase surface enhancement features are arranged at ninety
degrees with respect to adjacent groups of single-phase surface
enhancement features.
11. The cooling apparatus of claim 10, wherein each group of
single-phase surface enhancement features comprise a plurality of
thermally conductive fins.
12. The cooling apparatus of claim 11, wherein: the plurality of
thermally conductive fins comprises a center thermally conductive
fin; and a length of individual thermally conductive fins decrease
in directions away from the center thermally conductive fin.
13. The cooling apparatus of claim 1, wherein: the jet orifice has
three circular lobes; the single-phase surface enhancement features
are configured as a plurality of radially extending, thermally
conductive fins; and the two-phase surface enhancement features are
arranged in three regions of two-phase surface enhancement
features.
14. The cooling apparatus of claim 13, wherein the three regions of
two-phase surface enhancement features are arranged at a perimeter
of the target surface.
15. The cooling apparatus of claim 13, wherein: a first region and
a second region of the three regions of two-phase surface
enhancement features are positioned at a first corner and a second
corner of the target surface, respectively; and a third region of
the three regions of two-phase surface enhancement features is
positioned proximate an edge of the target surface opposite from
the first corner and the second corner.
16. The cooling apparatus of claim 13, wherein the single-phase
surface enhancement features and the two-phase surface enhancement
features are symmetrical about one axis.
17. The cooling apparatus of claim 1, further comprising an
intermediate substrate assembly thermally coupled to a heat
transfer surface of the target layer.
18. The cooling apparatus of claim 17, wherein the intermediate
substrate layer comprises a directed bonded substrate assembly.
19. A power electronics module comprising: a jet channel; a jet
plate surface comprising a jet orifice having a jet orifice
geometry, wherein the jet orifice is in fluid communication with
the jet channel and is configured to generate an impingement jet of
a coolant fluid; a target layer comprising a target surface,
single-phase surface enhancement features, and two-phase surface
enhancement features, wherein: the target surface is configured to
receive the impingement jet at an impingement region; the
single-phase surface enhancement features are positioned on the
target surface at high fluid velocity regions; and the two-phase
surface enhancement features are positioned on the target surface
at low fluid velocity regions; and a semiconductor device thermally
coupled to the heat transfer surface.
20. A vehicle comprising a power electronics module, the power
electronics module comprising: a jet channel; a jet plate surface
comprising a jet orifice having a jet orifice geometry, wherein the
jet orifice is in fluid communication with the jet channel and is
configured to generate an impingement jet of a coolant fluid; a
target layer comprising a target surface, single-phase surface
enhancement features, and two-phase surface enhancement features,
wherein: the target surface is configured to receive the
impingement jet at an impingement region; the single-phase surface
enhancement features are positioned on the target surface at high
fluid velocity regions; and the two-phase surface enhancement
features are positioned on the target surface at low fluid velocity
regions; and a semiconductor device thermally coupled to the heat
transfer surface.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/734,710 entitled "Cooling Apparatuses and
Power Electronics Modules with Single-phase and Two-phase Surface
Enhancement Features," filed Jan. 4, 2013.
TECHNICAL FIELD
[0002] The present specification generally relates to cooling
apparatuses for cooling heat generating devices and, more
particularly, to jet impingement, two-phase cooling apparatuses
having single- and two-phase surface enhancement features.
BACKGROUND
[0003] Heat generating devices, such as power semiconductor
devices, may be coupled to a heat spreader to remove heat and lower
the maximum operating temperature of the heat generating device. In
some applications, cooling fluid may be used to receive heat
generated by the heat generating device by convective thermal
transfer, and remove such heat from the heat generating device. For
example, jet impingement may be used to cool a heat generating
device by directing impingement jets of coolant fluid onto the heat
generating device or a target surface that is thermally coupled to
the heat generating device. Additionally, jet impingement may also
be combined with two-phase cooling, where the heat generating
device is cooled by the phase change of the coolant fluid from a
liquid to a vapor.
[0004] The coolant fluid flowing on the target surface may have
regions of high fluid velocity, and regions of low fluid velocity.
Coolant fluid flowing in the regions of high fluid velocity may not
change phase to a vapor, but rather provide single-phase heat
transfer, while coolant fluid flowing in the regions of low fluid
velocity tends to boil and change to a vapor.
[0005] Accordingly, a need exists for alternative jet impingement,
two-phase cooling apparatuses that take advantage of the high fluid
velocity regions and the low fluid velocity regions of coolant
flowing on a target surface after impingement.
SUMMARY
[0006] In one embodiment, a cooling apparatus includes a jet plate
surface and a target layer. The jet plate surface includes a jet
orifice having a jet orifice geometry, wherein the jet orifice
generates an impingement jet of a coolant fluid. The target layer
has a target surface, single-phase surface enhancement features,
and two-phase surface enhancement features. The target surface is
configured to receive the impingement jet, and the single-phase
surface enhancement features and the two-phase enhancement features
are arranged on the target surface according to the jet orifice
geometry.
[0007] In another embodiment, a cooling apparatus includes a jet
plate surface and a target layer. The jet plate surface includes a
jet orifice that is configured to generate an impingement jet of a
coolant fluid. The target layer includes a target surface,
single-phase surface enhancement features, and two-phase surface
enhancement features. The jet plate surface is offset from the
target surface such that the target surface is configured to
receive the impingement jet. The jet orifice has a geometry such
that when the impingement jet impinges the target surface, a flow
pattern of the coolant fluid is produced that is parallel to the
target surface. The flow pattern includes regions of high fluid
velocity and regions of low fluid velocity. The single-phase
surface enhancement features are located at the regions of high
fluid velocity, and the two-phase surface enhancement features are
located at the regions of low fluid velocity.
[0008] In yet another embodiment, a power electronics module
includes a jet plate surface, a target layer, and a semiconductor
device thermally coupled to the heat transfer surface. The jet
plate surface includes a jet orifice having a jet orifice geometry,
wherein the jet orifice is configured to generate an impingement
jet of a coolant fluid. The target layer includes a target surface,
a heat transfer surface, single-phase surface enhancement features,
and two-phase surface enhancement features. The target surface is
configured to receive the impingement jet, and the single-phase
surface enhancement features and the two-phase enhancement features
are arranged on the target surface according to the jet orifice
geometry.
[0009] These and additional features provided by the embodiments
described herein will be more fully understood in view of the
following detailed description, in conjunction with the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The embodiments set forth in the drawings are illustrative
and exemplary in nature and not intended to limit the subject
matter defined by the claims. The following detailed description of
the illustrative embodiments can be understood when read in
conjunction with the following drawings, where like structure is
indicated with like reference numerals and in which:
[0011] FIG. 1 schematically depicts a power electronics module
comprising a jet orifice and a target surface with single-phase
surface enhancement features and two-phase surface enhancement
features according to one or more embodiments described and
illustrated herein;
[0012] FIG. 2 schematically depicts a cross-shaped jet orifice
according to one or more embodiments described and illustrated
herein;
[0013] FIG. 3 schematically depicts a flow pattern of coolant fluid
on a target surface corresponding to the jet orifice depicted in
FIG. 2 according to one or more embodiments described and
illustrated herein;
[0014] FIG. 4 schematically depicts a target surface having
single-phase surface enhancement features and two-phase surface
enhancement features arranged according to the flow pattern
depicted in FIG. 3 according to one or more embodiments described
and illustrated herein;
[0015] FIG. 5 schematically depicts a three-lobed jet orifice
according to one or more embodiments described and illustrated
herein;
[0016] FIG. 6 schematically depicts a flow pattern of coolant fluid
on a target surface corresponding to the jet orifice depicted in
FIG. 5 according to one or more embodiments described and
illustrated herein; and
[0017] FIG. 7 schematically depicts a target surface having
single-phase surface enhancement features and two-phase surface
enhancement features arranged according to the flow pattern
depicted in FIG. 6 according to one or more embodiments described
and illustrated herein.
DETAILED DESCRIPTION
[0018] Embodiments of the present disclosure are directed to jet
impingement, two-phase cooling apparatuses that may be utilized to
cool heat generating devices, such as semiconductor devices. Jet
impingement cooling is provided by directing jets of coolant fluid
at an impingement region of a target surface, which may be a heat
generating device or a thermally conductive surface coupled to the
heat generating device. Heat is transferred to the coolant fluid.
In two-phase heat transfer systems, the coolant fluid changes phase
from a fluid to a vapor, thereby removing heat flux from the heat
generating device. Embodiments described herein employ both
single-phase and two-phase surface enhancement features that are
arranged on a target surface according to a shape of a jet orifice
that produces an impingement jet that strikes the target surface at
an impingement region. More particularly, jet orifices of different
shapes produce different flow patterns of coolant fluid. The flow
patterns have regions of high fluid velocity where the coolant
fluid flows relatively fast, and regions of low fluid velocity
where the coolant fluid flows relatively slowly (i.e., slower than
the regions of high fluid velocity). Two-phase heat transfer in the
form of nucleate boiling of the coolant fluid may be more efficient
at the regions of low fluid velocity (i.e., non-dominant flow
regions), while single-phase heat transfer in the form of
convection between the target layer and the coolant fluid may occur
at the regions of high fluid velocity (i.e., dominant flow regions)
with little nucleate boiling.
[0019] In embodiments of the present disclosure, single-phase
surface enhancement features in the form of thermally conductive
fins are strategically provided on the target surface at the
regions of high fluid velocity to increase the surface area of the
target surface, thereby increasing heat transfer from the target
surface to the coolant fluid. In the regions of low fluid velocity,
two-phase surface enhancement features are strategically placed to
provide enhanced nucleate boiling surfaces for encouraging
two-phase heat transfer. In this manner, embodiments include a
target surface that provides for both single-phase and two-phase
heat transfer on a single surface. The single-phase and two-phase
surface enhancement features are arranged on the target surface
according to the shape of the jet orifice to provide for optimum
single-phase and two-phase heat transfer. Various embodiments of
cooling apparatuses having single-phase and two-phase surface
enhancement features on a target surface according to a shape of a
jet orifice are described herein below.
[0020] Referring now to FIG. 1, a power electronics module 100
comprising a cooling apparatus 105 coupled to a substrate assembly
140 and a semiconductor device 150 is schematically illustrated.
Semiconductor devices may include, but are not limited to,
insulated gate bipolar transistors (IGBT),
metal-oxide-semiconductor field effect transistors (MOSFET), power
diodes, power bipolar transistors, power thyristor devices, and the
like. As an example and not a limitation, the semiconductor device
may be included in a power electronic module as a component in an
inverter and/or converter circuit used to electrically power high
load devices, such as electric motors in electrified vehicles
(e.g., hybrid vehicles, plug-in hybrid electric vehicles, plug-in
electric vehicles, and the like). The cooling apparatuses described
herein may also be used to cool heat generating devices other than
semiconductor devices (e.g., mechanical devices, such as
motors).
[0021] In the illustrated embodiment, the semiconductor device 150
is thermally coupled to an intermediate substrate assembly 140. The
illustrated substrate assembly 140 comprises an insulating
dielectric layer 142 disposed between two metal layers 141, 143.
The substrate assembly 140 may comprise a direct bonded substrate
assembly, such as a direct bonded copper assembly or a direct
bonded aluminum assembly. Exemplary materials for the insulating
dielectric layer 142 include, but are not limited to, alumina,
aluminum nitride, silicon nitride, silicon carbide, and beryllium
oxide. In alternative embodiments, only one metal layer may be
provided. In yet other embodiments, the semiconductor device 150 is
directly bonded the cooling apparatus (e.g., at a heat transfer
surface 125 of the target layer 120).
[0022] The exemplary cooling apparatus 105 generally comprises a
jet channel 130, a jet plate 110, and a target layer 120 that is
offset from the jet plate 110. The jet plate 110 has at least one
jet orifice 112. Coolant fluid (e.g., deionized fluid or an
engineered fluid) flows into the jet channel 130 (e.g., via a fluid
inlet (not shown)) and enters the jet orifice 112, as indicated by
arrow 131. The coolant fluid flows through the jet orifice 112 as
an impingement jet that impinges a target surface 122 of the target
layer 120 at an impingement region 123. The target layer 120 is
fabricated from a thermally conductive material, such as copper or
aluminum, for example, and has a target surface 122 that receives
the coolant fluid, and a heat transfer surface 125 that is coupled
to either the substrate assembly 140 or the semiconductor device
150.
[0023] The impingement region 123 may be positioned at a hot spot
created by the heat flux generated by the semiconductor device 150.
After impinging the target surface 122, the coolant fluid changes
direction from being normal to the target surface 122 to flowing
parallel to the target surface 122 within an impingement chamber
136, as indicated by arrows 132. The coolant fluid flows across the
target surface 122 in a flow pattern defined by regions of
different fluid velocities. Heat generated by the semiconductor
device 150 is transferred from the target layer 120 to the coolant
fluid. In regions of relatively slow fluid flow, some of the
coolant fluid will change phase from a liquid to a vapor by
nucleation boiling, as indicated by vapor bubbles 134. In regions
of dominant, fast fluid flow, much of the heat removal is by
convection. The coolant fluid may be removed from the cooling
apparatus 105 by outlet ports (not shown) located at the sides of
the cooling apparatus 105, or at a top surface of the cooling
apparatus 105.
[0024] The flow pattern is defined by the shape of the jet orifice
112. For example, a jet orifice 112 having a particular shape or
geometry will produce a corresponding flow pattern, while a jet
orifice 112 having a different shape or geometry from the
aforementioned shape or geometry will produce a different flow
pattern from the aforementioned flow pattern. The shape of the jet
orifice 112 may depend on the temperature profile on the target
surface 122 that is generated by the semiconductor device 150. The
jet orifice 112 may take on a variety of shapes, including, but not
limited to, cross-shaped (see FIG. 3), star-shaped, lobed-shaped
(see FIG. 5), and helical.
[0025] Single-phase and two-phase surface enhancement features are
provided on the target surface 122 to enhance both single-phase
heat transfer and two phase heat transfer, respectively. As shown
in FIG. 1 and described in more detail below, single-phase surface
enhancement features 124 in the form of thermally conductive fins
having a height h are positioned on the target surface 122 at
regions associated with high fluid velocity (i.e., dominant fluid
flow regions), and two-phase surface enhancement features 126 are
positioned on the target surface 122 at regions associated with low
fluid velocity (i.e., non-dominant fluid flow regions). The fluid
flow velocity may be defined by the fluid flow rate, for example.
The two-phase surface enhancement features 126 may be any surface
features that increase the number of nucleation sites to promote
boiling of the coolant fluid. Two-phase surface enhancement
features 126 include, but are not limited to, a roughened target
surface 122 (e.g., by laser damage, by chemical etching, by
grinding, etc.), a thermally conductive film layer having micro-
and/or nano-features that is applied to the target surface 122,
micro- or nano-features fabricated into the target surface 122
(e.g., by lithography and chemical etching, laser fabrication,
etc.), and a porous area (e.g., a porous coating) of the target
surface 122. For example, the two-phase surface enhancement
features 126 may be defined by micro-pillars that provide
additional surface area to encourage nucleation. However, it should
be understood that any surface that encourages nucleation may be
used for the two-phase surface enhancement features 126.
[0026] As described above, the jet orifice 112 may have a
particular jet orifice geometry that produces a particular flow
pattern on the target surface 122. FIG. 2 schematically depicts a
cross-shaped jet orifice, while FIG. 3 schematically depicts fluid
flow streamlines illustrating a computed flow pattern associated
with the jet orifice depicted in FIG. 2. It should be understood
that the cross-shaped jet orifice 112 and the flow pattern depicted
in FIGS. 2 and 3 are for illustrative purposes only, and that other
jet orifice geometries and resulting flow patterns are
possible.
[0027] The impingement jet of coolant fluid strikes the impingement
region 123 in a cross-shaped pattern having arm regions 137. As
shown in FIG. 3, regions of high fluid velocity 135 radially extend
from the center of the impingement region 123. The dashed fluid
flow streamlines in the regions of high fluid velocity 135
represent high fluid velocity, while the solid fluid lines
represent slower fluid velocity. The regions of high fluid velocity
135 in the illustrative flow pattern are at forty-five degree
angles with respect to the cross-shaped jet orifice 112. The
coolant fluid within the regions of high fluid velocity 135
represent the dominant fluid flow on the target surface 122. The
coolant fluid flowing parallel to the jet orifice 112 within the
arm regions 137 from the impingement region 123 has a fluid
velocity that is lower than the coolant fluid flowing at an angle
with respect to the arm regions 137. The coolant fluid flowing
parallel to the jet orifice within the arm regions 137 flow into
regions of low fluid velocity 133 and represent a non-dominant
fluid flow on the target surface 122.
[0028] The regions of high fluid velocity 135 may be created by the
coolant fluid impinging the target surface in a cross-shaped
impingement jet, where coolant fluid from the arms of the
impingement jet are forced outwardly upon impingement on the target
surface 122, and is combined into high velocity fluid flows that
are at a forty-five degree angle with respect to the cross-shaped
impingement jet flowing through the cross-shaped jet orifice
112.
[0029] As stated above, embodiments of the present disclosure
comprise a target surface 122 having strategically positioned
single-phase surface enhancement features and two-phase surface
enhancement features. Referring now to FIG. 4, a target surface 122
of a target layer 120 is schematically depicted. Single-phase
surface enhancement features 124 are located at the regions of high
fluid velocity 135, and two-phase surface enhancement features 126
are located at the regions of low fluid velocity 133. As shown in
FIG. 4, the single-phase surface enhancement features 124 are
configured as thermally conductive fins that radially extend from
the impingement region 123. The jet orifice 112 is depicted in
dashed lines for reference. The thermally conductive fins may be
integral to the target surface 122 of the target layer 120, or
discrete components that are bonded or otherwise coupled to the
target surface 122. The single-phase surface enhancement features
124 increase the surface area of the target surface 122 that the
coolant fluid is in contact with, thereby enhancing thermal
transfer from the target surface 122 to the coolant fluid by
convection.
[0030] In the illustrated embodiment, the single-phase surface
enhancement features 124 are arranged in four groups that
correspond to the four regions of high fluid velocity 135 depicted
in FIG. 3. The single-phase surface enhancement features 124 within
each group may be optimally shaped and arranged to optimize coolant
fluid flow and convection. In the non-limiting illustrated example,
a center single-phase surface enhancement feature (or center
thermally conductive fin 127) of each group may be configured as
the longest thermally conductive fin, with each thermally
conductive fin being shorter than the previous thermally conductive
fin in directions away from the center thermally conductive fin
127. In this manner, the single-phase surface enhancement features
124 may be arranged to match the shape of the regions of high fluid
velocity 135 depicted in FIG. 3. However, it should be understood
that embodiments are not limited to the arrangement of single-phase
surface enhancement features 124 depicted in FIG. 4, and that other
arrangements are also possible.
[0031] Similarly, the two-phase surface enhancement features 126
are arranged at the regions of low fluid velocity 133 of the
coolant fluid as shown in FIG. 3. The two-phase surface enhancement
features 126 may be any micro- or nano-scale features that act as
nucleation site enhancements to promote nucleation of the coolant
fluid. As an example and not a limitation, the two-phase surface
enhancement features 126 may be provided by roughening the target
surface 122 such that the area of the two-phase surface enhancement
features 126 has a surface roughness (measured in root-mean-squared
("RMS")) that is greater than the surface roughness of areas of the
target surface that are outside of the area of the two-phase
surface enhancement features 126. In the illustrated embodiment,
the two-phase surface enhancement features 126 are located near the
perimeter of the target surface 122.
[0032] Because the outflow of the coolant fluid is not strong in
the regions of low fluid velocity 133, nucleate boiling occurs at
these areas of the target surface 122. The two-phase surface
enhancement features 126 are configured such that nucleate boiling
is enhanced compared to a smoother surface. Therefore, two-phase
heat transfer is promoted at the regions of low fluid velocity 133
by the two-phase surface enhancement features 126.
[0033] In some embodiments, two-phase surface enhancement features
may also be provided at the impingement region 123 because the heat
flux being removed from the target layer 120 may be highest at the
impingement region 123. The two-phase surface enhancement features
may promote nucleate boiling at the impingement region 123 even
though the velocity of the coolant fluid may be greater at the
impingement region 123 than the other regions of low fluid velocity
133 because of the high temperature of the target surface 122.
[0034] In the illustrated embodiment, the groups of single-phase
surface enhancement features 124 and the two-phase surface
enhancement features 126 alternate about the impingement region 123
such that single-phase surface enhancement features 124 and the
two-phase surface enhancement features 126 are symmetrical about
more than one axis. As stated above, the arrangement of the
single-phase and two-phase surface enhancement features 124, 126
correspond to the shape of the flow pattern, which corresponds to
the shape of the jet orifice 112. In this manner, embodiments of
the present disclosure encourage both single- and two-phase heat
transfer on a single surface by the use of surface enhancement
features.
[0035] The target surface 122 and surface enhancement features may
be designed by first evaluating a temperature profile of the target
surface 122 and the semiconductor device 150 (or other heat
generating device). A desirable jet orifice 112 geometry may be
designed by experimentally or computationally obtaining
single-phase heat transfer results associated with a variety of jet
orifice geometries. The geometry providing the best single-phase
heat transfer results may be selected as the geometry for the jet
orifice 112. The flow pattern of the coolant fluid resulting from
the jet orifice 112 having the selected geometry (e.g., the flow
pattern depicted in FIG. 3 resulting from the jet orifice 112
depicted in FIG. 2) may be evaluated such that the single-phase
surface enhancement features 124 and the two-phase surface
enhancement features 126 may be designed to complement to jet
orifice geometry to maximize the cooling capabilities of the
cooling apparatus 105.
[0036] There are many possible jet orifice geometries and,
therefore, many possible flow patterns. As another non-limiting
example, FIGS. 5 and 6 depict a jet orifice 212 having a tri-lobed
geometry and a resulting computationally derived flow pattern,
respectively. The location of the jet orifice 212 with respect to
the target surface is depicted in FIG. 6 by dashed lines for
illustrative purposes. The flow pattern of FIG. 6 is represented by
fluid flow velocity contours. The jet orifice 212 has three
overlapping, circular lobes. Such a geometry may produce a
desirable flow pattern to effectively cool a semiconductor device
and target layer having a particular temperature profile.
[0037] As shown in FIG. 6, the velocity of the fluid is highest
surrounding the impingement region 223, thereby providing a region
of high fluid velocity. The velocity of the coolant fluid then
decreases outwardly from impingement region 233. The flow of
coolant fluid significantly slows or stops at the regions of low
fluid velocity 233. Accordingly, the flow pattern resulting from
the jet orifice 212 depicted in FIG. 5 has regions of high and low
fluid velocity. The flow pattern of FIG. 6 is different from the
flow pattern of FIG. 3 associated with the cross-shaped jet orifice
112 because of the difference in jet orifice geometry.
[0038] Referring now to FIG. 7, an exemplary target surface 222
corresponding to the flow pattern depicted in FIG. 6 is
schematically illustrated. It should be understood that embodiments
are not limited to the target surface 222 and corresponding
single-phase and two-phase surface enhancement features depicted in
FIG. 7. As described above with respect to FIG. 6, single-phase
surface enhancement features 224 configured as thermally conductive
fins are provided on the target surface 222 in the region of high
fluid velocity 235. The thermally conductive fins may be integral
to the target surface 222 of the target layer, or discrete
components that are bonded or otherwise coupled to the target
surface 222. The single-phase surface enhancement features 224
increase the surface area of the target surface 222 that the
coolant fluid is in contact with, thereby enhancing thermal
transfer from the target surface 222 to the coolant fluid by
convection. In the illustrated embodiment, the single-phase surface
enhancement features 224 are symmetrical about a single axis. More
or fewer single-phase surface enhancement features 224 may be
present on the target surface 222.
[0039] Similarly, the two-phase surface enhancement features 226
are arranged at the regions of low fluid velocity 233 of the
coolant fluid as shown in FIG. 6. In the illustrated embodiment,
there are three areas of two-phase surface enhancement features 226
that correspond with the three regions of low fluid velocity 233 of
the flow pattern. As described above with reference to FIG. 4, the
two-phase surface enhancement features 226 may be any micro- or
nano-scale features that act as nucleation site enhancements to
promote nucleation of the coolant fluid.
[0040] Because the outflow of the coolant fluid is not strong in
the regions of low fluid velocity 233, nucleate boiling occurs at
these areas of the target surface 222. The two-phase surface
enhancement features 226 are configured such that nucleate boiling
is enhanced compared to a smoother surface. In this manner,
two-phase heat transfer is promoted at the regions of low fluid
velocity 233 by the two-phase surface enhancement features 226. In
some embodiments, two-phase surface enhancement features may also
be provided at the impingement region 223 because the heat flux
being removed from the target layer 220 may be highest at the
impingement region 223. For example, two phase surface enhancement
features may be provided on the target surface 222 in the central
area surrounded by the single-phase surface enhancement features
224. In this manner, the embodiment depicted in FIG. 7 encourages
both single- and two-phase heat transfer on a single surface by the
use of surface enhancement features.
[0041] It should now be understood that embodiments described
herein are directed to jet impingement, two-phase cooling
assemblies and power electronics modules having a jet orifice with
a shape tailored to a temperature profile of a target layer, and a
target surface having single-phase surface enhancement features and
two-phase surface enhancement features that are arranged
corresponding to a flow pattern of coolant fluid produced by the
jet orifice. The single-phase surface enhancement features are
located on the target surface in regions of high fluid velocity to
promote single-phase heat transfer to the coolant fluid, while the
two-phase surface enhancement features are located on the target
surface in regions of low fluid velocity to encourage nucleation
and two-phase heat transfer.
[0042] While particular embodiments have been illustrated and
described herein, it should be understood that various other
changes and modifications may be made without departing from the
spirit and scope of the claimed subject matter. Moreover, although
various aspects of the claimed subject matter have been described
herein, such aspects need not be utilized in combination. It is
therefore intended that the appended claims cover all such changes
and modifications that are within the scope of the claimed subject
matter.
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