U.S. patent number 4,998,181 [Application Number 07/430,910] was granted by the patent office on 1991-03-05 for coldplate for cooling electronic equipment.
This patent grant is currently assigned to Texas Instruments Incorporated. Invention is credited to John L. Darrouzet, Timothy C. Fletcher, James L. Haws, Lian-Tuu Yeh.
United States Patent |
4,998,181 |
Haws , et al. |
March 5, 1991 |
Coldplate for cooling electronic equipment
Abstract
A system for cooling, positioning and supporting phased array
microwave modules within a phased array radar system wherein the
modules are disposed in cooling tubes, the cooling tubes being
arranged to permit coolant to continuously pass in close proximity
thereto along channels formed in a coldplate. The channels can be
built into a solid member wherein the cooling tubes are hollowed
out portions of the solid with channels for coolant formed in the
space between cooling tubes. In alternate embodiments, the channels
are formed by the spaces between cooling tubes.
Inventors: |
Haws; James L. (McKinney,
TX), Fletcher; Timothy C. (Garland, TX), Yeh;
Lian-Tuu (Dallas, TX), Darrouzet; John L. (Dallas,
TX) |
Assignee: |
Texas Instruments Incorporated
(Dallas, TX)
|
Family
ID: |
26830245 |
Appl.
No.: |
07/430,910 |
Filed: |
October 31, 1989 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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132298 |
Dec 15, 1987 |
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Current U.S.
Class: |
361/702;
165/80.4; 361/699; 361/716 |
Current CPC
Class: |
F28D
7/0041 (20130101); F28D 7/0058 (20130101); F28D
15/02 (20130101); F28F 13/06 (20130101); H05K
7/20254 (20130101) |
Current International
Class: |
F28F
13/00 (20060101); F28F 13/06 (20060101); F28D
15/02 (20060101); F28D 7/00 (20060101); H05K
7/20 (20060101); H05K 007/20 () |
Field of
Search: |
;174/15HP
;165/80.4,104.33 ;157/79,82 ;361/382-389 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Haws, "Phase Array Thermal Control System Concepts", Proceedings of
the International Symposium on Cooling Technology for Electronic
Equipment, Mar. 1987, pp. 138-148..
|
Primary Examiner: Thompson; Gregory D.
Attorney, Agent or Firm: Grossman; Rene E. Sharp; Melvin
Parent Case Text
This application is a continuation of application Ser. No.
07/132,298, filed Dec. 15, 1987, now abandoned.
Claims
We claim:
1. A coldplate system for cooling heat producing modules
comprising:
(a) a housing of predetermined length including an interior region
and a wall region enclosing said interior region;
(b) said interior region including a plurality of apertured regions
defining slots having slot axes substantially normal to said length
of said housing for receiving said circuit modules therein and for
permitting fluid flow along the outer surfaces of said modules;
(c) a fluid inlet path defined in said wall and extending from an
exterior surface of said wall substantially coaxially with the axes
of said slots for substantially the length of said slots; said
fluid inlet path then extending substantially normal to said axes
of said slots to said interior region; and
(d) a fluid outlet path defined in said wall and extending from
said exterior surface of said wall substantially coaxially with the
axes of said slots a predetermined distance less than said fluid
inlet path; said fluid outlet path then extending substantially
normal to said axes of said slots to said interior region.
2. A coldplate system as set forth in claim 1 wherein at least one
of said fluid inlet path and said fluid outlet path includes a
removable insert disposed therein for controlling the amount of
fluid flow therethrough.
3. A coldplate system as set forth in claim 1 wherein said housing
and said apertured regions are formed from a plurality of secured
together disks, each said disk having an exterior wall portion;
alternate ones of said disks having a hollow central region of like
predetermined shape and the remaining ones of said disks having
aligned apertures formed in rows and columns.
4. A coldplate system as set forth in claim 3 wherein each of said
disks includes an aperture in the wall portion thereof defining
said fluid inlet path and predetermined adjacent ones of said disks
include an aperture in the wall portion thereof defining said fluid
outlet portion.
5. A coldplate system as set forth in claim 3 wherein each of said
disks has a hollow central region most remote from said exterior
surface which defines a second aperture communicating with said
aperture therein defining said fluid inlet path and said hollow
central region.
6. A coldplate system as set forth in claim 4 wherein each of said
disks has a hollow central region most remote from said exterior
surface which defines a second aperture communicating with said
aperture therein defining said fluid inlet path and said hollow
central region.
7. A coldplate system as set forth in claim 3 wherein a different
one of said disks having a hollow central region defines an
aperture communicating with said aperture therein defining said
fluid outlet path and said hollow central region.
8. A coldplate system as set forth in claim 4 wherein a different
one of said disks having a hollow central region defines an
aperture communicating with said aperture therein defining said
fluid outlet path and said hollow central region.
9. A coldplate system as set forth in claim 5 wherein a different
one of said disks having a hollow central region defines an
aperture communicating with said aperture therein defining said
fluid outlet path and said hollow central region.
10. A coldplate system as set forth in claim 6 wherein a different
one of said disks having a hollow central region defines an
aperture communicating with said aperture therein defining said
fluid outlet path and said hollow central region.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a system for cooling, positioning and
supporting electronic modules and, more specifically, but not
limited to, such a system for use in conjunction with phased array
microwave modules, primarily for use in phased array radar.
2. Brief Description of the Prior Art
A phased array radar system is formed from many transmit receive
(T/R) microwave modules, one or more such modules being disposed in
one or more apertures. One of the most critical problems in design
and operation of a phased array system and particularly an airborne
phased array system is the removal of heat from the modules within
the aperture or apertures.
The modules dissipate a large amount of heat in a small volume. In
order to maintain high system reliability, the heat dissipated by
the modules must be removed while maintaining low component
temperatures inside the modules. Also, since the microwave devices
and circuits within the modules are temperature sensitive, low
temperature gradients from module to module within the aperture
and/or from aperture to aperture must be maintained. In addition,
to assist in system start up, the thermal control system must also
be capable of accommodating additional heat for system warm-up at
start-up.
The system must be low cost, light weight, small in volume and
consume a minimum amount of power. It must also fit into the
physical constraints imposed by the module, aperture and vehicle
for which the phased array system is configured. Sufficient room
must be provided inside the modules to mount the circuits. The
thermal, mechanical and structural system must not interfere with
DC, RF and logic signal distribution circuits, electrical
connectors, antenna elements, module tie down or module
removal.
In one prior art approach to the above noted problems, air is blown
between spaced apart modules and provides convection cooling
between modules and the air stream. This cools the module cover and
the devices inside the module which are linked to the cover through
a conductive thermal path within the module. The cooling air is
supplied to the modules by air ducts at the end of the air
passages. This design is simple and light weight, however it is
limited to modules with very low heat dissipations because of the
large convective temperature rise and amount of power required to
supply the large volume of air needed. The large air requirement
handicaps the aircraft because the air must be delivered to remote
parts of the aircraft. Air cooling also makes temperature gradient
control and warm-up of the modules very difficult.
In a further prior art device, each module is mounted on a
coldplate containing a circulating cooling fluid. The microwave
circuits are mounted on the surface which will contact the
coldplate, resulting in a small temperature rise from the fluid to
the circuits. This system has the disadvantage of reduced
maintainability since it is necessary to remove an entire row of
modules to service a single module. The coldplate also adds extra
weight to the system. All liquid systems will require an external
heat exchanger and pump. This sacrifice must be made in order to
cool high heat dissipation modules. The above described prior art
is discussed in Haws, J. L., "Phased Array Thermal Control System
Concepts", Proceedings Of The International Symposium On Cooling
Technology For Electronic Equipment, March, 1987, Page 138.
A still further prior art thermal control system utilizes heat
pipes and is an acceptable design approach, though it has some
significant disadvantages. The disadvantages are in the areas of
performance, cost and producibility. The heat pipes are costly to
build because of their strict thermal performance requirements in a
dynamic environment (i.e., they are sensitive to gravity changes,
such as the aircraft acceleration, which has a drastic impact on
the thermal performance of the heat pipes). The heat pipes are
perpendicular to the center lines of the modules and the energy
emanating from the modules is perpendicular to the heat pipes.
Accordingly, during maneuvering of the aircraft, the heat pipe
function can be lost completely or at least partially impaired. The
heat pipes also impact the electrical performance of the phased
array systems because the difference in thermal performance from
heat pipe to heat pipe impacts the transmitted phase of the
microwave modules. This system concept also requires a very complex
and costly liquid cooled coldplate, making this approach
undesirable. The above described prior art is discussed in Haws, J.
L., "Phased Array Thermal Control System Concepts", Proceedings of
the International Symposium on Cooling Technology for Electronic
Equipment, March, 1987, Page 138.
A yet further prior art thermal control system as disclosed in U.S.
Pat. No. 4,044,396 uses heat pipes which are positioned
longitudinally relative to the modules and the long dimension of
the aircraft and parallel to the direction in which heat is
radiated out from the modules. In this arrangement, the failure of
the heat pipes due to gravity forces is minimized. However, since
heat pipes are required, the inherent problems associated with heat
pipes as set forth hereinabove are present. The above cited
publication further discusses such system.
It is therefore readily apparent that the prior art systems for
cooling phased arrays of the type herein noted all have inherent
undesirable limitations which should be minimized.
SUMMARY OF THE INVENTION
In accordance with the present invention, the above noted problems
of prior art cooling system are minimized and there is provided a
system for cooling, positioning and supporting phased array
microwave modules within a phased array radar system. The system
comprises a lightweight combination support structure and heat
exchanger which allows module cooling via air, liquid, refrigerant,
change of phase and thermal siphon (wickless heat pipe) cooling
techniques. The cooling portion of the heat exchanger or cooling
system is easily placed next to high heat dissipation areas within
the microwave modules. The combination support structure and heat
exchanger can be fabricated using laser welding, vacuum brazing,
bonding or low to high temperature brazing techniques for various
metals.
Briefly, in accordance with a first embodiment of the invention,
the above is accomplished by interfacing microwave modules with a
coldplate constructed of tubes and plates. Module construction
herein is shown as being of circular cross section. However, it
should be understood that the modules can take on other shapes as,
for example, square, rectangular, elliptical, etc. The coldplate is
used in conjunction with T/R modules with different heat
dissipations because air, liquid, change of phase, thermal siphon
or refrigerant cooling can be used in conjunction therewith. Heat
pipes are not used. RF and DC manifolds are mounted on the aft side
of the coldplate and are constructed as "planar" manifolds or as
"slat" manifolds. Planar manifolds are thin RF stripline board
assemblies that mount perpendicular to the longitudinal axis of
modules and slat manifolds are also thin RF stripline board
assemblies, but they mount parallel to the longitudinal axis of the
modules. Planar manifold result in thinner arrays because less
volume is used to incorporate them into a phased array system. The
coldplate assembly also mechanically positions single and multiple
antenna element modules to the required mechanical positional
accuracy. The coldplate provides the required thermal control of
the modules to achieve system performance and structurally supports
the modules in dynamic shock and vibration environments.
The coldplate provides cooling for the T/R modules, wherein coolant
enters an aperture at one end of the tube/plate coldplate and moves
forward in the aperture until it reaches the inlet fluid manifold
which is located around the perimeter of the array. The inlet fluid
manifold is located in line with the hot or hottest spot within the
T/R modules. Coolant then passes through fixed or adjustable
orifices and flows radially along and around the modules and into
the center of the array from the inlet manifold. Small openings,
located at the center of the coldplate between the inlet manifold
and the outlet manifold, forces the coolant fluid to change
direction at the center of the array and travel to the outlet
manifold. The coolant then flows radially outward along and around
the modules to the perimeter of the array. The coolant is collected
around the perimeter of the array and passes out of the array at
the fluid outlet. Heat dissipated by the T/R modules is picked up
by the coolant and is exchanged with an external heat exchanger.
The coolant is then recycled. Fast system warm-up is achieved by
adding heat to the circulating fluid at the external heat exchanger
during system warm-up.
Since the array reliability is very high, it is desirable to use
redundant cooling loops within the coldplate because the system
components that supply the coolant have lower reliability than the
array. Redundant cooling loops are achieved by using multiples of
the cooling structure paralleling each other or with each loop
cooling a different portion of each module.
The coldplate tubes and the module covers comprise very light
weight thin wall tubes which are manufactured using standard
"precision drawn" manufacturing processes. These tubes are very low
cost, easy to produce and can be easily manufactured to extremely
tight dimensional accuracy. The tight dimensional control on the
module covers and mating tube in the coldplate allows excellent
thermal interfacing between the modules and coldplate. This results
in lower overall module and device junction temperatures and lower
module to module temperature variations to reduce the module to
module electrical phase errors. Coldplate tubes and plates may be
made of aluminum, stainless steel, titanium, beryllium, Kovar or
other metal, depending upon the weight, heat transfer, thermal
coefficient of expansion, and strength requirements of the
particular system application. In general, such materials are
chosen for minimum weight, maximum strength and maximum heat
transfer properties. Module cover tubes are made of a low expansion
material, such as Kovar, low expansion nickel alloys, beryllium or
stainless steel. Such materials are chosen for low expansion,
maximum strength, minimum weight and maximum heat transfer
properties to match the thermal expansion of the module package
material which is in turn matched to the thermal expansion of the
microwave devices inside the module packages. Both tubes and module
cover materials must be compatible with assembly processes, i.e.,
welding, brazing soldering, EB welding, etc.
In accordance with a second embodiment of the invention, the
tube/plate coldplate concept is used as a thermal siphon cold
plate. The tube/plate coldplate forms a unique enclosure for
holding a liquid refrigerant charge which cools the modules. Liquid
refrigerant is retained at the base of the coldplate within the
coldplate. As the modules dissipate heat, the liquid refrigerant in
the coldplate boils and changes to a vapor. The vapor moves upward
through the coldplate tubes and contacts a cooling coil at the top
of the array. As the vapor moves past the tubes, additional heat is
transferred to the vapor from the modules. When the vapor contacts
the cooling coil at the top of the array, it condenses back into a
liquid. The liquid runs back down past the tubes and is again
changed into a vapor as it picks up heat dissipated by the modules.
This thermal siphon (wickless heatpipe) method of cooling provides
excellent temperature gradient control across the face of the array
and is capable of removing large amounts of heat from the modules
and capable of maintaining very low temperature gradients across
the array.
In accordance with a third embodiment of the invention, the modules
are arranged in a somewhat matrix fashion wherein the modules of
first alternate columns are each in the same first group of rows
and the modules of the second alternate columns therebetween are in
the same second group of rows, the second group of rows being
spaced upwardly or downwardly between the first group of rows to
provide a corrugated appearance. Channels are formed along each of
the columns for receiving coolant, the coolant entering along the
entire length of the first channels, connecting to the second
channels and then travelling the length of the second channels back
to a coolant reservoir or manifold which encircles the array and
wherein heat is removed from the modules via the circulating
coolant. In this way, the modules are substantially completely
surrounded by coolant which is spaced therefrom by a very small
dimension.
In accordance with a fourth embodiment of the invention, the
modules are arranged in the same manner as described in the third
embodiment. However, the tubes that position and support the
modules are brazed, soldered or bonded together along the
longitudinal length of the tubes. This forms triangular coolant
passages along the longitudinal axis of the tubes and modules. Air
coolant is used to provide module cooling. Inlet cooling air is
circulated around the outer perimeter of the array into a radome
covering the modules and is then passed through the triangular
coolant passages along the longitudinal axis of each module. The
heat picked up by the circulating air as it passes the
modules/tubes is exchanged with an external heat exchanger remote
from the array.
In accordance with a fifth embodiment of the invention, the housing
is comprised of a central section with apertures therethrough for
retaining modules therein. Channels are disposed through the
central section and around the apertures for conducting liquid
coolant therein to remove heat from the apertures. Top and bottom
sections enclose the central section, one of the top and bottom
sections having a manifold on one side thereof for receiving
coolant liquid from the exterior of the housing and conducting it
it through grooves therein to the channels. The other of the top
and bottom also has channels therein for receiving the cooling
liquid which has passed through the central section and conducting
the liquid to a manifold on a side thereof, the liquid then being
remove from the housing via the manifold.
In accordance with a sixth embodiment of the invention, lightweight
plastic inserts are positioned in channels of the prior discussed
embodiments, the insert being preferably of plastic and being
designed to permit coolant liquid to travel through the channels,
but with restricted flow rate due to the partial blockage of the
channels by the inserts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a tube/plate coldplate in accordance
with a first embodiment of the present invention;
FIG. 2 is an approximate cross sectional view of the embodiment of
FIG. 1 taken along the center thereof to show the fluid flow
through the coldplate when items 1, 27 and 29 are eliminated;
FIG. 3 is a perspective view of the embodiment of FIG. 1 with
modules and RF/DC manifolds being positioned in the coldplate in
the completely machined state;
FIG. 4 is a partially cut away view of a second embodiment of the
present invention;
FIG. 5 is a drawing of a third embodiment of the present
invention;
FIG. 6 is an enlarged view of the fluid inlets and fluid outlets of
the embodiment of FIG. 5;
FIG. 7 is a drawing showing one of the refrigerant cooling channels
of the embodiment of FIG. 5;
FIG. 8 is a drawing of a fourth embodiment of the present
invention;
FIG. 9 is a front view of the embodiment of FIG. 8 with modules
partially filling the air cooled assembly;
FIG. 10 is a perspective view of the embodiment of FIG. 8 with no
modules installed;
FIG. 11 is an exploded view of a coldplate in accordance with the
present invention; and
FIG. 12 is a cross-sectional view of a portion of a sixth
embodiment in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is shown a tube/plate coldplate in
accordance with a first embodiment of the present invention. The
coldplate includes an aluminum endplate 1 having apertures 3 and 5
therethrough which conduct inlet coolant into the coldplate and
outlet coolant out of the coldplate respectively. The endplate 1
also includes a hexagonally shaped aperture 8 in its central
region. Positioned adjacent to the endplate 1 is an apertured
aluminum disk 7 having apertures 9 therein and apertures 11 and 13
which align with apertures 3 and 5, respectively. The disk 7 is
clad on both sides thereof with aluminum alloy brazing material. A
machined aluminum outlet fluid manifold 15 is positioned adjacent
the disk 7 and includes a hexagonally shaped aperture 17 at its
center region to expose the apertures 9 in disc 7 and of the same
dimensions as the aperture 8. An outlet fluid manifold groove 19
surrounding the aperture 7 is connected to a fluid outlet aperture
21 which is aligned with the apertures 13 and 5. Also, an inlet
fluid aperture 23 is aligned with the apertures 11 and 3. The
groove 19 also receives fluid entering at the central region of the
hexagonal aperture 17 and travelling around the modules thereto.
The coldplate is fully sealed to the outside and the coolant flows
as a result of the coolant supply pressure. The coolant also
totally fills any voids between tubes and plates, thus totally
surrounding each tube.
A second apertured aluminum disk 25, identical to the disk 7 except
for small fluid passage apertures 2 located in the outer position
of the disk, is positioned adjacent the outlet manifold 15 with all
apertures therein aligned with those of disk 7. A central plate 27
which is shaped the same as the end plate 1 is positioned adjacent
the disk 25 with inlet aperture aligned therewith. A third
apertured aluminum disk 29, identical to the disk 25, is positioned
adjacent the central plate 27 with all apertures therein aligned
with those of disk 7. An inlet fluid manifold 31, machined of
aluminum plate, is positioned adjacent the disk 29 and includes a
hexagonally shaped aperture 33 at its center region to expose the
apertures in the disk 29 and of the same dimension as the aperture
8. An inlet fluid manifold groove 35 surrounding the aperture 33
connected to an aperture 37 which is aligned with the inlet
apertures 11 and 3. A fourth apertured aluminum disk 39, identical
to the disk 7 except that it contains no apertures corresponding to
apertures 3 and 5 thereof, is positioned adjacent the inlet fluid
manifold 31.
The above noted elements are placed in intimate contact with each
other in the order as explained, cooling tubes 41 made of aluminum
or aluminum tubing, clad with aluminum brazing alloy on the outside
diameter only, are positioned in each of the aligned apertures and
the whole assembly is vacuum brazed together in a vacuum oven by
raising the temperature to the brazing temperature of the aluminum
alloy brazing material whereby the various elements are brazed to
each other and to the cooling tubes to provide the final light
weight machined coldplate structure as shown in FIG. 3. Alternate
assembly methods would include soldering plated aluminum parts or
bonding the parts together with an epoxy.
DC and RF electrical distribution manifolds 102 and connectors 103,
104, 105 are attached to the aft of the coldplate and radar modules
100 are then placed into the cooling tubes 41 and secured therein,
such as by screwing a flange on the surface of the module 100 to
the coldplate using a module tiedown/eject screw 101 in the manner
shown in FIGS. 2 and 3. Coolant is than forced through the inlet
apertures 3 to the inlet fluid manifold 3 where it enters inlet
fluid manifold groove 35 and travels there from around the cooling
tubes 41, holding the modules, to the center region of the inlet
manifold. The central region of the disks 25 and 29 have small
fluid passage apertures therein which permit the coolant to travel
from the central region of the inlet manifold 31 to the central
region of the outlet fluid manifold 15. The coolant then travels
around the cooling tubes 41 to the outlet fluid manifold groove 19
and out of the coldplate via the outlet aperture 5 therein. The
first embodiment described fairly equally distributed coolant along
the total length of the radar modules.
The endplate 1, central plate 27 and the disk 29 could be
eliminated to move the inlet fluid manifold 31 and the outlet fluid
manifold 15 closer together for short length radar modules (100 in
FIGS. 2 and 3), or the central plate 27 could be made thicker for
longer length radar modules (100 in FIGS. 2 and 3). Central plate
27 and disk 29 could be eliminated to concentrate the coolant at
one local point on a radar module 100, or the assembly could be
easily modified to concentrate coolant at two separate points on a
radar module 100. The assembly could be easily changed for a
different number of radar modules 100, or for different sizes of
radar module 100.
Referring now to FIG. 4, there is shown a second embodiment of the
invention using thermal-siphon cooling principles in accordance
with the present invention. In this embodiment there is shown a
housing 51 having a rear plate 53 and a front plate (not shown) to
provide an enclosure. A plurality of cooling tubes 55 having
modules (not shown) therein are positioned in rows and columns as
in the first embodiment with refrigerant 57, such as, for example,
Freon 12 or Freon 22, in the bottom portion of the housing. A
cooling coil 59 is positioned at the top of the housing and a wall
61 forms a channel 63 along with the housing interior.
In operation, upon generation of module dissipated heat within the
cooling tubes 55, the refrigerant 57 will vaporize and travel
upwardly along the cooling tubes and remove heat from the cooling
tubes. Upon reaching the cooling coil 59, the refrigerant will
condense and drop back to the bottom of the housing, travelling
around the cooling tubes at this time. In the event the vaporized
refrigerant is travelling upwardly in sufficient quantity to impede
the downward flow of the condensed refrigerant at the cooling coil
59, the condensed refrigerant will travel to the bottom of the
housing via the channel 63. It is understood that the cooling fluid
exiting the cooling fluid outlet 65 will enter a heat exchanger
where it will be cooled down and returned to the cooling fluid
inlet 67.
Referring now to FIGS. 5, 6 and 7, there is shown a third
embodiment of the invention built using "I-beam" cooling channels.
In this embodiment the cooling tubes 71 with modules therein are
machined as holes through "I-beam" cooling channels. This forms a
module matrix arrangement of the type discussed in connection with
the first embodiment. Long straight or serpentine "I-beam" cooling
channels 72 are laser or electron-beam welded together and to
periphery fluid manifolds 73, 75, 91 to form coldplate assemblies
as shown in FIGS. 5 and 6. Coolant is located around the periphery
of the matrix in a coolant main supply manifold 73 and travels
therefrom to a coolant supply sub-manifold 75 via adjustable
orifices 77. Because they are machined from a common piece of
aluminum plate, the cooling tubes 71 along each column are in
thermal contact with each other and form cooling channels 79 (also
FIGS. 6 and 7) for incoming coolant and cooling channels 81 for
outgoing coolant. The channels are arranged so that, for each
incoming coolant channel, the adjacent channel is an outgoing
coolant channel as shown in FIG. 6. Each channel is of serpentine
shape as shown in FIG. 7 due to the positioning of the cooling
tubes 71. For modules and cooling tubes arranged in a rectangular
positioning, the coolant channels would be straight rather than
serpentine shaped. The coolant enters the array through a fluid
inlet 83 and exits through a fluid outlet 85 as shown in FIGS. 5
and 6. The coolant exiting the outlet fluid manifold 91 is cooled
by removal therefrom at the coolant outlet 85 to a heat exchanger
(not shown) with recirculation of the cooled coolant back to the
inlet coolant manifold 73 via the coolant inlet 89.
Referring now to FIGS. 8 to 10, there is shown an air-cooled
coldplate fourth embodiment of the invention. In this embodiment,
the cooling tubes 110, which position and support modules 103, are
arranged in a matrix arrangement of the type discussed in
connection with the first embodiment. The tubes 110 that position
and support the modules 100 are brazed, soldered or bonded together
along the longitudinal length of the tubes 100. This forms a very
strong structural assembly that accurately positions and
structurally supports the modules and provides triangular coolant
passages 106 along the longitudinal length of the tubes and
modules. Inlet cooling air 107 is circulated around the outside
perimeter of the array into a radome 109 covering the modules. The
cooling air then turns and passes along the longitudinal axis of
the tubes/modules. Heat dissipated by the modules is transferred to
the cooling air as it passes past the modules and the air exits the
array at the center of the array 111. The heat is removed from the
air by passing the air through an external heat exchanger. The
cooler air is then returned to the array and enters the array as
inlet cooling air 107 around the perimeter. FIG. 9 shows one module
100 being inserted into one tube 110. The triangular air passages
106 are also shown. FIG. 10 shows a larger (1000 element) array of
tubes 110 and triangular cooling air passages 105 without modules
installed.
Referring now to FIG. 11, there is shown an axial-fluid flow
coldplate, fifth embodiment in accordance with the present
invention. This embodiment comprises a housing having a central
portion 112, a front portion 113 and a rear portion 115 (113 is a
mirror image of 115), all of which are connected together to
provide a liquid tight enclosure. Liquid coolant enters the front
portion 113 via the inlet 125 and accumulates in the manifold 119
(hidden from view on the aft side of 113). This liquid coolant then
travels through grooves 121 in the interior of the front portion
113 and then through the channels 123 in the central portion 112 to
grooves 121 in the rear portion 115. This liquid then travels to a
manifold 119 in the rear portion 115 and then out through the
outlet 117. It can be seen that the portions 113 and 115 can be
mirror images using identical construction. The modules to be
cooled are positioned in the apertures 127, heat emanating from the
modules being carried off by the coolant in the channels.
Referring now to FIG. 12, there is shown a sixth embodiment in
accordance with the present invention. This embodiment shows a
lightweight insert 131, preferably but not restricted to plastic,
which is inserted in a coolant carrying channel in the prior
embodiment to restrict coolant flow in those channels. The insert
131 can be shaped to provide a predetermined fluid flow, depending
upon said shape. FIG. 12 shows the insert in an embodiment of the
type shown in FIG. 11 with some triangular channels, corresponding
reference characters depicting the same structure as in FIG.
11.
It can be seen that there has been described a cooling system for
use in conjunction with heat producing electronic circuit modules
wherein coolant is constantly circulated along channels formed
closely adjacent the modules.
Though the invention has been described with respect to specific
preferred embodiments thereof, many variations and modifications
will immediately become apparent to those skilled in the art. It is
therefore the intention that the appended claims be interpreted as
broadly as possible in view of the prior art to include all such
variations and modifications.
* * * * *