U.S. patent application number 12/987642 was filed with the patent office on 2012-07-12 for liquid cooling system cold plate assembly.
This patent application is currently assigned to ASETEK A/S. Invention is credited to Jeremy A. Rice.
Application Number | 20120175094 12/987642 |
Document ID | / |
Family ID | 46454349 |
Filed Date | 2012-07-12 |
United States Patent
Application |
20120175094 |
Kind Code |
A1 |
Rice; Jeremy A. |
July 12, 2012 |
Liquid Cooling System Cold Plate Assembly
Abstract
A cold plate assembly consisting of a thermally conductive base
component with an insert having a high thermal transfer
characteristic adapted for contacting the surface of a heat source
on one side. The surface of the base component opposite from the
insert is surrounding by a housing defining an enclosed volume
through with a flow of liquid coolant is directed. Inlet baffles
adjacent to a fluid inlet in the housing direct the incoming flow
of liquid coolant towards the surface of the base component in
proximity to the insert, facilitating an efficient transfer of
thermal energy from the heat source to the liquid coolant through
the insert and base component. Optional extensions or fins
extending into the liquid coolant contained in the enclosed volume
from the surface of the base component further facilitate the
transfer of thermal energy from the heat source.
Inventors: |
Rice; Jeremy A.; (San Jose,
CA) |
Assignee: |
ASETEK A/S
Bronderslev
DK
|
Family ID: |
46454349 |
Appl. No.: |
12/987642 |
Filed: |
January 10, 2011 |
Current U.S.
Class: |
165/170 |
Current CPC
Class: |
F28D 1/03 20130101; F28F
3/12 20130101; H01L 23/473 20130101; F28F 3/048 20130101; H01L
2924/0002 20130101; H01L 23/3672 20130101; H01L 2924/00 20130101;
H01L 2924/0002 20130101 |
Class at
Publication: |
165/170 |
International
Class: |
F28F 3/12 20060101
F28F003/12 |
Claims
1. A cold plate assembly for use with a liquid cooling system,
comprising: a base component formed from a material having a first
thermal transfer characteristic and adapted for partial immersion
in a flow of liquid coolant on a first surface; a housing defining
an enclosed volume over said first surface, said housing having a
fluid inlet and a fluid outlet for directing a flow of liquid
coolant through said enclosed volume and in contact with said first
surface of said base component; an insert recessed within a second
surface of said base component, opposite said first surface, and is
isolated from said flow of liquid coolant, said insert composed of
a material having a second thermal transfer characteristic which is
greater than said first thermal transfer characteristic, and which
is adapted on at least one surface for contacting a heat source to
facilitate a transfer of heat from said heat source to said base
component; and wherein said housing further includes an inlet
baffle in proximity to said fluid inlet, said inlet baffle
projecting within said enclosed volume from a surface of said
housing, and directing an incoming flow of said liquid coolant
towards said first surface of said base component.
2. The cold plate assembly of claim 1 where said inlet baffle
defines a channel.
3. The cold plate assembly of claim 1 wherein said inlet baffle
defines a cylindrical guide directed axially towards said first
surface of said base component.
4. The cold plate assembly of claim 1 wherein at least one of said
base and insert materials is copper.
5. The cold plate assembly of claim 1 wherein at least one of said
base and insert materials is aluminum.
6. The cold plate assembly of claim 1 wherein said insert material
is copper, wherein said base material is aluminum.
7. The cold plate assembly of claim 1 wherein said insert is
coupled to said base component by a bonding, welding, soldering, or
brazing means.
8. The cold plate assembly of claim 1 wherein said base component
is a molded component.
9. The cold plate assembly of claim 1 further including a mounting
clip structure external to said housing, said mounting clip
structure securing said base component and said insert in contact
with said heat source.
10. The cold plate assembly of claim 1 wherein said base component
includes a plurality of protrusions on said first surface adapted
for immersion in said flow of liquid coolant within said enclosed
volume, said plurality of protrusions providing an increased
surface area for an exchange of heat between said fluid transfer
component and said flow of liquid coolant.
11. The cold plate assembly of claim 1 wherein said base component
includes a plurality of protrusions on said first surface adapted
for immersion in said flow of liquid coolant within said enclosed
volume, said plurality of protrusions directing a flow of liquid
coolant within said enclosed volume.
12. The cold plate assembly of claim 1 wherein said housing is
integrally formed with said base component.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention is related generally to liquid cooling
systems adapted for use in cooling heat sources such as integrated
circuit components, processors, and memory modules in a computer
system, and in particular to a cold plate assembly configured for
facilitating efficient heat exchange between the heat source and a
directed flow of cooling liquid circulated through a chamber within
the assembly.
[0004] Personal computer systems which are design for desktop or
under-desk use, and which are typically characterized by a
main-board or motherboard housed in a chassis or case, often
provide one or more expansion slots into which auxiliary components
may be installed. These auxiliary components may include network
adapter circuit boards, modems, specialized adapters, and graphics
display adapters. These auxiliary components may receive power
through the connection to the motherboard, or through additional
connections directly to a system power supply contained within the
chassis or case. Additional components, such as hard drives, disk
drives, media readers, etc. may further be contained within the
chassis or case, and coupled to the system power supply and
motherboard as needed.
[0005] During operation, the motherboard and various auxiliary
components consume power and generate heat. To ensure proper
functionality of the computer system, it is necessary to regulate
the operating temperatures inside the environment of the chassis or
case. Individual integrated circuits, especially memory modules and
processors, may generate significant amounts of heat during
operation, resulting in localized heat sources or hot spots within
the chassis environment. The term "processors", as used herein, and
as understood by one of ordinary skill in the art, describes a wide
range of components, which may include dedicated graphics
processing units, microprocessors, microcontrollers, digital signal
processors, and general system processors such as those
manufactured and sold by Intel and AMD. Failure to maintain
adequate temperature control throughout the chassis environment,
and at individual integrated circuits, can significantly degrade
the system performance and may eventually lead to component
failure.
[0006] Traditionally, a cooling fan is often associated with the
system power supply, to circulate air throughout the chassis
environment, and to exchange the high temperature internal air with
cooler external air. However, as personal computer systems include
increasing numbers of individual components and integrated
circuits, and applications become more demanding on additional
processing components such as graphics display adapters, a system
power supply cooling fan may be inadequate to maintain the
necessary operating temperatures within the chassis
environment.
[0007] Specialized liquid cooling systems are available for some
components in a personal computer system. Specialized liquid
cooling systems typically provide a liquid coolant circulation
pathway, which routes a thermal transfer liquid between a heat
exchanger such as a radiator and one or more heat source, such as a
CPU, GPU, a memory module, a microprocessor, or transformer. At
each heat source, the flow of liquid coolant is passed over a heat
transfer component, commonly referred to as a cold plate, which is
in contact with the heat source on one side, and the flow of liquid
coolant on another side. Typically, a cold plate is constructed
from a metal, such as copper, which has a good ability to transfer
heat from the heat source to the liquid coolant. The surface of the
cold plate in contact with the heat source is generally planar,
facilitating a large region of contact, while the surface of the
cold plate in contact with the liquid coolant flow may have a
number of protrusions, fins, or foils extending there from to
provide an increased surface area for the exchange of heat.
[0008] Being composed of metal, the cold plate is generally an
expensive and heavy component in any liquid cooling system. For
some metals, which are ideal heat transfer pathways, the formation
of the protrusions, fins, or foils is difficult or time consuming.
For example, to form a cold plate from copper, with the necessary
protrusions to the required tolerances, a complex sintering process
is required which is time consuming and expensive. With other types
of metals, such as aluminum, the necessary protrusions may be
readily formed at a reduced cost by a direct molding process, but
lack the heat transfer characteristics of copper. If the two
different types of metals are utilized in combination, it is
possible that a galvanic corrosion may occur if each metal is in
contact with the liquid coolant, leading to a failure of the liquid
cooling system, either through corrosion buildup or leakage of the
liquid coolant.
[0009] Specialized liquid cooling systems can additionally suffer
from regions of low fluid flow within the fluid chambers coupled to
the cold plates, leading to inefficient operations, such as shown
in FIG. 4. This can be caused by dispersal of the inflow of liquid
coolant within the chamber as it enters the chamber, leading to the
formation of "dead zones" within the chamber wherein a flow of the
liquid coolant is minimal.
[0010] Accordingly, it would be advantageous to provide a cold
plate assembly which is composed of two or more types of metal,
which has a reduced manufacturing cost, an in which only a single
type of metal is in contact with the liquid coolant, reducing the
risk of galvanic corrosion. It would further be advantageous to
provide a cold plate assembly with a directed flow of liquid
coolant which eliminates or minimizes the formation of "dead zones"
within the fluid chamber.
BRIEF SUMMARY OF THE INVENTION
[0011] Briefly stated, the present disclosure provides a dual-metal
cold plate assembly for use with a circulating liquid cooling
system. The cold plate assembly consists of a base component
adapted to receive a high thermal-conductivity insert on a first
surface, and for immersion in a flow of liquid coolant on a second
surface. The base component may include numerous protrusions, fins,
or pins on the surface opposite from the insert for placement into
the flow of liquid coolant. The cold plate assembly is fitted to an
enclosing housing, such that the flow of liquid coolant is
permitted to pass over the base component second surface including
any protrusions, fins, or pins, but does not contact any portion of
the base. Heat is then transferred from the heat source through the
base, into the fluid transfer component, and dissipated into the
liquid coolant through the various protrusions, fins, and/or pins
which are immersed in the circulating flow of liquid coolant.
[0012] In an embodiment of the present disclosure, the base is
formed from a solid copper disk, and the fluid transfer component
is formed from molded aluminum, soldered to the base.
[0013] In an alternate embodiment of the present disclosure, a flow
of liquid coolant entering the enclosing housing is directed
towards the surface of the base component by inlet baffles which
define a channel or groove. The directed flow of liquid coolant
facilitates efficient transfer of thermal energy from the high
thermal-conductivity insert to the base component, and into the
flow of liquid coolant for transport away.
[0014] The foregoing features, and advantages set forth in the
present disclosure as well as presently preferred embodiments will
become more apparent from the reading of the following description
in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0015] In the accompanying drawings which form part of the
specification:
[0016] FIG. 1 is a cross-sectional view of a cold plate assembly of
the present disclosure;
[0017] FIG. 2 is a bottom view of the cold plate assembly of FIG.
1;
[0018] FIG. 3 is a cross-sectional view of an alternate
configuration of the cold plate assembly of the present disclosure,
in which the housing is integrally formed with the fluid transfer
component;
[0019] FIG. 4 is a cross-sectional view of a prior art cold plate
assembly, wherein the flow of circulating coolant within the
housing results in regions of relatively little movement adjacent
the base;
[0020] FIG. 5 is a cross-sectional view of an alternate
configuration of an integrated housing cold plate assembly of the
present disclosure incorporating projecting fluid inlet baffles to
direct the flow of circulating coolant within the housing towards
the base component surface; and
[0021] FIG. 6 is a cross-sectional view of an embodiment similar to
FIG. 5, but with the base and housing formed as separate
structures.
[0022] Corresponding reference numerals indicate corresponding
parts throughout the several figures of the drawings. It is to be
understood that the drawings are for illustrating the concepts set
forth in the present disclosure and are not to scale.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] The following detailed description illustrates the invention
by way of example and not by way of limitation. The description
enables one skilled in the art to make and use the present
disclosure, and describes several embodiments, adaptations,
variations, alternatives, and uses of the present disclosure,
including what is presently believed to be the best mode of
carrying out the present disclosure.
[0024] Turning to the Figures, a cold plate assembly 100 of the
present invention adapted for secured over a heat source 10 such as
an integrated circuit, video or graphic processing unit is shown
configured for connection to an existing liquid cooling circulating
flow loop via any suitable liquid pathway. The liquid cooling loop,
which is not directly part of the present invention, provides all
necessary components for circulating a flow of liquid coolant to
and from the cold plate assembly 100 through inlets 108A and
outlets 108B, thereby drawing heat away from the various
heat-generating components 10 in proximity to the cold plate
100.
[0025] Preferably, the cold plate assembly 100 is made from
materials which have a high conductivity to facilitate a transfer
of heat, such as metals like copper or aluminum. The cold plate
assembly 100 consists generally of a medium conductivity base
component or fluid transfer component 104 with a high
thermal-conductivity insert 102, and a housing 105 which may
optionally be integrally formed with the fluid transfer component
104, as seen at FIGS. 3 and 5, or formed as a separate component
105A coupled to the base component 104, as seen at FIGS. 1 and 6.
The housing 105, 105a encloses a first surface of the base
component within a volume of space or chamber 107 through with a
flow of liquid coolant passes via one or more inlets 108A and
outlets 108B.
[0026] The insert 102 is inset within a second surface of the base
component 104, opposite from the first surface enclosed within the
chamber 107. The insert 102 is adapted for placement in contact
with the surface of the heat source 10, and preferably consists of
a high conductivity material such as copper, which is suitable for
contact with the heat source 10. During use, heat is transferred
from the heat source 10 through the insert of high conductivity
material 102, to the base component 104. The base component 104 in
turn transfers the heat or thermal energy to the flow of liquid
coolant passing through the enclosing chamber 107.
[0027] The base component 104 may include a plurality of radiating
fins 106 or other structures extending from the first surface
within the enclosing chamber 107 to provide for an increase in the
available surface area over which heat or thermal energy may be
transferred to the flow of liquid coolant passing through the
chamber 107. The radiating fins 106 may additional function to
direct the flow of liquid coolant about a circuitous path through
the chamber 107, maximizing heat absorption by the liquid coolant
within the chamber 107.
[0028] Preferably, the cold plate assembly 100 is generic in
nature, and may be operatively secured in direct contact with any
of a variety of different types of heat sources 10, such as
processors, memory modules, and graphic display cards, by utilizing
an exchangeable mounting clip structure or other attachment means
110. The exchangeable mounting clip structure 110 is configured to
facilitate attachment of the cold plate assembly 100 in operative
proximity to the particular heat source 10. While the cold plate
assembly shown in the figures is generally cylindrical, having a
circular base profile when viewed from the bottom as seen in FIG.
2, those of ordinary skill in the art will recognize that the
specific shape and dimensions of the cold plate assembly 100,
including the shape and dimensions of the base component 104 and
insert 102, may be varied depending upon the particular application
for which the cold plate assembly 100 is intended to be
utilized.
[0029] The high thermal-conductivity insert 102 of the cold plate
assembly 100 is preferably a monolithic form of a single metal,
such as a copper disk, and may be formed through any conventional
manufacturing process to have at least one surface adapted for heat
transfer from a heat source 10. A second surface of the insert 102
is configured to be operatively secured or bonded to the base
component 104, which is preferably formed from a second metal, such
as aluminum. The insert 102 may be secured or bonded to the base
component 104 by any suitable attachment means, such as soldering,
brazing, or welding, and is preferably seated in a recessed
position, flush with the exterior surface of the base component
104.
[0030] By forming the base component 104 and housing 105 from a
second metal or heat conductive material which is different from
the metal forming the insert 102, the material used to form the
base component 104 may be selected based in-part on the ease with
which various protrusions, fins, radiator surfaces, or pins 106 may
be formed into the surface for immersion in the flow of liquid
coolant within the housing chamber 107. For example, the second
metal or heat conductive material may be selected to be aluminum,
enabling the fluid transfer component 104, housing 105, and
associated protrusions, fins, and radiator surfaces 106 to be
formed from a molding or casting process. Since only the surfaces
of the base component 104 and housing 105 are exposed to the liquid
coolant flow, the occurrence of galvanic reactions between the
insert 102 and the base component 104 are reduced or
eliminated.
[0031] Increased efficiency in the transfer of thermal energy from
the heat source 10 to the flow of liquid coolant within the
enclosed volume 107 is achieved by positioning the fluid flow inlet
108A in a central location on the housing 105 or 105a, and by
imparting a directional flow to the liquid coolant entering the
enclosed volume 107, as shown in FIG. 5 which illustrates an
alternate embodiment 200 of the cold plate assembly with an
integrated housing 105, and FIG. 6 which illustrates a similar
alternate embodiment 300 having separate housing 105A. The
directional flow is imparted to the liquid coolant by providing an
inlet baffle 202 adjacent to the inlet 108A. The inlet baffle 202
projects from a surface of the housing into the enclosed volume 107
and defines a groove or channel within the enclosed volume 107,
directing the incoming flow of liquid coolant towards the surface
of the base component 104 in proximity to the high thermal
conductivity insert 102. The flow of the liquid coolant can be
further improved in this region of the enclosed volume by
eliminating some or all of the radiating fins 106 from the surface
of the base component 104 in proximity to the high thermal
conductivity insert 102, allowing for a more even distribution of
the incoming fluid flow directed by the inlet baffle 202.
[0032] As various changes could be made in the above constructions
without departing from the scope of the disclosure, it is intended
that all matter contained in the above description or shown in the
accompanying drawings shall be interpreted as illustrative and not
in a limiting sense.
* * * * *