U.S. patent application number 10/977454 was filed with the patent office on 2006-05-04 for immersion cooling apparatus.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to Phillip E. Tuma.
Application Number | 20060090881 10/977454 |
Document ID | / |
Family ID | 35759399 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060090881 |
Kind Code |
A1 |
Tuma; Phillip E. |
May 4, 2006 |
Immersion cooling apparatus
Abstract
A device for cooling a heat-dissipating component comprising a
body having at least one sidewall, an enclosed volume, an expansion
volume, a quantity of heat transfer fluid disposed within the
enclosed volume, and means for releasing the heat transfer fluid
from the enclosed volume to the expansion volume. Upon release into
the expansion volume, the heat transfer fluid can contact the
heat-dissipating device.
Inventors: |
Tuma; Phillip E.;
(Faribault, MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
35759399 |
Appl. No.: |
10/977454 |
Filed: |
October 29, 2004 |
Current U.S.
Class: |
165/104.21 ;
257/E23.088; 257/E23.095 |
Current CPC
Class: |
H01L 23/427 20130101;
H01L 2924/0002 20130101; H01L 2924/0002 20130101; H01L 2924/00
20130101; H01L 23/44 20130101; H01L 2924/09701 20130101 |
Class at
Publication: |
165/104.21 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Claims
1. An article for cooling a heat-dissipating component comprising:
a body comprising at least one sidewall and a breachable seal
cooperating to define an enclosed volume, said breachable seal
having an inner surface proximate said enclosed volume and an outer
surface; and a quantity of heat transfer fluid disposed within said
enclosed volume.
2. The article of claim 1 wherein said heat transfer fluid
comprises at least one of a perfluorocarbon, hydrofluorocarbon,
hydrofluoroether, and perfluoroketone.
3. The article of claim 1 wherein said breachable seal comprises at
least one of a polymer film, a metal foil, and a multilayer barrier
film.
4. The article of claim 3 wherein said breachable seal comprises a
burst strength that is less than said sidewall.
5. The article of claim 1 wherein said sidewall comprises at least
one of a polymer film, a metal foil, and a multilayer barrier
film.
6. The article of claim 5 wherein at least a portion of said
sidewall is substantially transparent.
7. The article of claim 1 further comprising at least one
puncturing member comprising a striking surface.
8. The article of claim 7 wherein said striking surface is
positioned within said enclosed volume.
9. The article of claim 7 wherein said striking surface is
positioned proximate said outer surface of said breachable
seal.
10. The article of claim 1 wherein said breachable seal is affixed
to said sidewall.
11. The article of claim 1 wherein said breachable seal is
removable.
12. The article of claim 1 further comprising at least one tether
having one end affixed to said seal.
13. The article of claim 1 further comprising a means for breaching
said seal.
14. The article of claim 1 further comprising a reactive metal
positioned within said enclosed volume.
15. The article of claim 1 further comprising an adsorbent
positioned within said enclosed volume.
16. The article of claim 1 further comprising an attachment
interface to affix said body to a substrate or heat-dissipating
component.
17. The article of claim 1 further comprising an attachment means
to affix said body to a substrate or heat-dissipating
component.
18. The article of claim 1 further comprising a boiling enhancement
comprising at least one of carbon foam and a microporous
coating.
19. The article of claim 18 further comprising a thermal interface
material affixed to at least a portion of said boiling
enhancement.
20. The article of claim 19 wherein said thermal interface material
comprises a eutectic alloy.
21. The article of claim 1 further comprising a boiling enhancement
affixed to said body by a retaining clip.
22. A thermosyphon comprising an article according to claim 1.
23. A cooling system comprising an article according to claim
1.
24. A computer comprising an article according to claim 1.
25. An article for cooling a heat-dissipating component comprising
a body having at least one sidewall, an enclosed volume, an
expansion volume, a quantity of heat transfer fluid disposed within
said enclosed volume, and means for releasing said heat transfer
fluid from said enclosed volume to said expansion volume.
26. The article of claim 25 wherein said heat transfer fluid
comprises at least one of a perfluorocarbon, hydrofluorocarbon,
hydrofluoroether, and perfluoroketone.
27. The article of claim 25 wherein said sidewall comprises at
least one of a polymer film, a metal foil, and a multilayer barrier
film.
28. A cooling system comprising an article according to claim
25.
29. A computer comprising an article according to claim 25.
30. A method of installing an article for cooling a
heat-dissipating component comprising: affixing a body to a
substrate supporting a heat-dissipating component, said body
comprising at least one sidewall and a breachable seal cooperating
to define an enclosed volume, and a quantity of heat transfer fluid
disposed within said enclosed volume; and breaching said seal to
allow said heat transfer fluid to contact said heat-dissipating
component.
31. The method of claim 30 further comprising affixing a boiling
enhancement to said heat-dissipating component.
32. The method of claim 31 wherein said boiling enhancement is
affixed to said heat-dissipating component with a thermal interface
material comprising a eutectic alloy.
33. The method of claim 31 wherein said boiling enhancement is
soldered to at least a portion of said heat-dissipating
component.
34. The method of claim 30 wherein said heat-dissipating component
comprises an integrated circuit.
35. The method of claim 30 further comprising placing a condenser
in fluid communication with said body.
Description
BACKGROUND
[0001] As electronic systems become more compact, there is a
continuing desire to increase the rate of heat transfer away from
heat-dissipating components. Air or water-cooled heat sinks can be
affixed to the heat-dissipating component to help cool the
heat-dissipating component. Often, a thermal interface material is
used at the interface between the heat sink and the
heat-dissipating component. The thermal resistance of the thermal
interface material can contribute significantly to the overall
thermal resistance between the heat-dissipating component and the
environment.
[0002] Immersion cooling, in which the heat-dissipating component
is immersed directly in a heat transfer fluid, provides certain
advantages in cooling heat-dissipating components. Immersion
cooling, for example, allows the thermal interface material to be
eliminated.
[0003] Although liquid immersion heat transfer techniques have been
used in larger scale electronic systems, the use of liquid
immersion heat transfer techniques in small electronic devices,
such as, for example, personal computers has been limited.
Immersion cooling systems typically require complex hardware and
complicated sealing and degassing operations to assemble. There is
a continuing need to provide inexpensive immersion cooling
components that can be easily installed in a manufacturing process
or by an end-user.
SUMMARY
[0004] The present invention relates generally to a device for
cooling electronic components, and more particularly, to a device
for immersing an electronic component in a cooling fluid. In one
aspect, the present invention provides an inexpensive device for
immersing a heat-dissipating component. The device can be installed
easily in a manufacturing process or by an end-user.
[0005] In one aspect, the present invention provides a device for
cooling a heat-dissipating component comprising a body comprising
at least one sidewall and a breachable seal cooperating to define
an enclosed volume. The breachable seal has an inner surface
proximate the enclosed volume and an outer surface. A quantity of
heat transfer fluid is disposed within the enclosed volume. In some
embodiments, the article comprises a means for breaching the seal
such that the heat transfer fluid is allowed to contact the
heat-dissipating component.
[0006] In some embodiments, the heat transfer fluid comprises at
least one of a perfluorocarbon, hydrofluorocarbon,
hydrofluoroether, and perfluoroketone. In certain embodiments, the
breachable seal comprises at least one of a polymer film, a metal
foil, and a multilayer barrier film. The breachable seal can have a
burst strength that is less than the sidewall. In some embodiments,
the sidewall comprises at least one of a polymer film, a metal
foil, and a multilayer barrier film.
[0007] In some embodiments, a puncturing member comprising a
striking surface is used to breach the breachable seal. The
striking surface can be positioned within the enclosed volume. In
some embodiments, the striking surface is positioned proximate the
outer surface of the breachable seal.
[0008] In some embodiments, the breachable seal is affixed to the
sidewall. In other embodiments, the breachable seal is
removable.
[0009] In some embodiments, a reactive metal is positioned within
the enclosed volume to scavenge oxygen. In certain embodiments, an
adsorbent is positioned within the enclosed volume.
[0010] An attachment interface or other attachment means can be
used to affix the body to a substrate or a heat-dissipating device.
Some embodiments also include a boiling enhancement and a thermal
interface material.
[0011] In some embodiments, the device is used as a thermosyphon,
as part of a larger cooling system, or as a component in a
computer.
[0012] The present invention also provides an article for cooling a
heat-dissipating component comprising a body having at least one
sidewall, an enclosed volume, an expansion volume, a quantity of
heat transfer fluid disposed within the enclosed volume, and means
for releasing the heat transfer fluid from the enclosed volume to
the expansion volume. Upon release into the expansion volume, the
heat transfer fluid can contact the heat-dissipating device.
[0013] The present invention also provides methods for installing
an article for cooling a heat-dissipating component. The method
includes affixing a body to a substrate supporting a
heat-dissipating component. The body comprising at least one
sidewall and a breachable seal cooperating to define an enclosed
volume, and a quantity of heat transfer fluid disposed within the
enclosed volume. After affixing the body, the seal is breached to
allow the heat transfer fluid to contact the heat-dissipating
component.
[0014] The term "breachable seal" refers to a material that can be
broken, ruptured, torn, or removed through an application of manual
force without damaging adjacent components. The manual force may be
applied to an instrument, such as, for example, a puncturing member
or pull tab, to break, rupture, tear, or remove the seal.
BRIEF DESCRIPTION OF THE DRAWING
[0015] FIG. 1 is a perspective view of an exemplary embodiment of
the present invention positioned on a substrate;
[0016] FIG. 2 is a cross-sectional view along sectional lines A-A
of the exemplary embodiment shown in FIG. 1 prior to placement on
the substrate and breaching of the seal;
[0017] FIG. 3 is a cross-sectional view along sectional lines A-A
of the exemplary embodiment shown in FIG. 1 after placement on the
substrate and breaching of the seal;
[0018] FIG. 4 is a cross-sectional view of an exemplary embodiment
of the present invention having a puncturing member within a
spacing member;
[0019] FIG. 5 is a cross-sectional view of an exemplary embodiment
of the present invention having a puncturing member within the
enclosed volume;
[0020] FIG. 6A is a cross-sectional view of an exemplary embodiment
of the present invention having a tether within the enclosed volume
and a spring member to attach a boiling enhancement;
[0021] FIG. 6B is a cross-sectional view of the exemplary
embodiment shown in FIG. 6A after attachment to a substrate and
breaching of the seal;
[0022] FIG. 7A is a cross-sectional view of an exemplary embodiment
of the present invention having a flexible sidewall; and
[0023] FIG. 7B is a cross-sectional view of the exemplary
embodiment shown in FIG. 7A after attachment to a substrate and
breaching of the seal.
[0024] These figures, which are idealized, are not to scale and are
intended to be merely illustrative of the present invention and
non-limiting.
DETAILED DESCRIPTION
[0025] FIG. 1 shows a perspective view of an exemplary embodiment
of the present invention positioned on a substrate. As shown in
FIG. 1, a body 10 is affixed to a substrate 12. The body 10 has an
internal volume that contains a heat transfer fluid that is in
contact with a heat-dissipating component (not shown) affixed to
the substrate 12. In some embodiments, the body 10 is affixed
directly to the heat-dissipating component.
[0026] In some embodiments, fluid conduits 13 can be connected to
body 10 such that the heat transfer fluid within body 10 is in
fluid communication with other cooling components, such as, for
example, a condenser or heat exchanger. The conduits 13 can be
tubular as shown in FIG. 1. Alternatively, the conduits can be any
shape or configuration known to those skilled in the art,
including, for example, square, rectangular, or oval.
[0027] In other embodiments, the heat transfer fluid within body 10
is not in fluid connection with external cooling components. In
such embodiments, body 10 can act as a thermosyphon by having a
first region that functions as an evaporator and a second region
that functions as a condenser. In such an embodiment, the body can
have an expandable sidewall such that the pressure within the body
remains substantially constant during operation.
[0028] FIG. 2 is a cross-sectional view along sectional lines A-A
of the exemplary embodiment shown in FIG. 1 prior to placement on
the substrate and breaching of the seal. As shown in FIG. 2, the
body 10 has a sidewall 14 and a breachable seal 18. The sidewall 10
and breachable seal 14 cooperate to define an enclosed volume 28
and an expansion volume 29. A quantity of heat transfer fluid 16 is
disposed within the enclosed volume 28.
[0029] Also shown in FIG. 2 is attachment interface 20. The
attachment interface 20 can be used to affix the body 10 to a
substrate. The attachment interface 20 can also be used to form a
seal between the body 10 and the substrate to prevent fluid
leakage. The attachment interface 20 can be an adhesive tape,
sealant, glue, elastomeric gasket, O-ring, or any other material
known by those skilled in the art to create an effective seal for
retaining fluids.
[0030] Alternatively, the body 10 can be affixed directly to the
substrate or heat-dissipating device without an attachment
interface 20. For example, welding or using a mechanical clamp can
affix the body 10 directly to the substrate. In some embodiments, a
mechanical fastener is used to affix the body 10 to the
substrate.
[0031] FIG. 3 is a cross-sectional view along sectional lines A-A
of the exemplary embodiment shown in FIG. 1 after placement on a
substrate 12 and breaching of the seal. As shown in FIG. 3, the
heat transfer fluid 16 is contained within the enclosed volume 28
and expansion volume. The heat transfer fluid 16 contacts a boiling
enhancement 22 affixed to a heat-dissipating component 26. A
thermal interface material 24 is positioned between the boiling
enhancement 22 and the heat-dissipating component 26. In alternate
embodiments, the boiling enhancement 22 and thermal interface
material 24 are not present.
[0032] The sidewall 14 can be rigid, flexible, or a combination of
rigid and flexible materials. Materials suitable for use as a
sidewall include, for example, metal, glass, ceramic, plastic,
polymeric films, and multilayer barrier films such as those
commonly used in food packaging, particularly those lined with a
polyamide or polyimide.
[0033] The term multilayer barrier film refers to any combination
of metal, plastic, or cellulosic layers (e.g., foils, films, and
paper). The combination of metal, plastic, or cellulosic layers can
include multiple layers of different materials, such as, for
example, a metal combined with a plastic layer. The combination of
metal, plastic, or cellulosic layers can also include multiple
layers of similar materials, such as, for example, two layers of
plastic.
[0034] Multilayer barrier films useful in the present invention
include multilayer films with layers that are affixed to one
another, for example, by coating, laminating, coextrusion, or
deposition. Multilayer barrier films useful in the present
invention can comprise layers of low-density polyethylene,
high-density polyethylene, polypropylene, polyester, nylon,
polyethylene-co-vinyl acetate, polyvinylidene chloride, polyamide,
or polyimide. In some embodiments, a multilayer barrier composite
having a layer of metal, such as, for example, aluminum is used.
Multilayer barrier films and other films useful for the sidewall of
the present invention are described in U.S. Pat. Nos. 4,997,032
(Danielson et al.) and 5,411,077 (Tousignant), incorporated by
reference.
[0035] In certain embodiments, the sidewall is made from at least
one of stamped metal, machined metal, and plastics such as, for
example, polycarbonate, nylon, acrylic, acrylonitrile butadiene
styrene ("ABS"), phenolics, polyolefin, polyurethanes,
polyphenylene sulfide, and polyarylether ketones such as
polyetheretherketone ("PEEK").
[0036] In some embodiments, the sidewall selected is a dielectric
to protect adjacent electronics. In certain embodiments, the
sidewall material is selected, at least in part, based on the
thermal gradient across the material. In some embodiments, the
sidewall material is selected, at least in part, based on the air
permeability of the material. In certain embodiments, at least a
portion of the sidewall is substantially transparent such that it
is possible to visually inspect the enclosed volume. A
substantially transparent sidewall can also be used to enhance the
visual appearance of the body. In some embodiments, the sidewall
material is a non-flammable material.
[0037] In some embodiments, the sidewall is flexible such that the
internal pressure of the body can be kept substantially constant as
the heat flux from the heat-dissipating device varies. In other
embodiments, the sidewall is rigid and the internal pressure does
not remain constant over the operating temperature range of the
heat-dissipating device. In yet further embodiments, the sidewall
is rigid and the internal pressure of the body can be kept
substantially constant as the heat flux from the heat-dissipating
device varies by attaching a flexible member to the body 10 via
conduit 13.
[0038] Materials that can be punctured, ruptured, torn, or easily
removed can be used for the breachable seal including, for example,
polymer film, a metal foil, or a multilayer barrier film. In
certain embodiments, the breachable seal is made from a material
that has low gas permeability. In some embodiments, the burst
strength of the material used for breachable seal is less than the
burst strength of the material used for the sidewall.
[0039] In some embodiments, the body is packaged in a sealed
multilayer barrier film. The multilayer barrier film allows the
body to be packaged in an environment with a minimum amount of
undesirable gases. In some embodiments, the multilayer barrier film
is filled with an inert gas or substantially evacuated prior to
sealing the body in the package. By packaging the body in a
substantially inert environment, a breachable seal with a higher
gas permeability can be used without allowing a substantial amount
of unwanted gases to enter the enclosed volume of the body. In such
an embodiment, the breachable seal can be made from a thin polymer
film that can be easily breached.
[0040] The heat transfer fluid useful in the present invention can
be any fluid capable of transferring heat, including water, air,
volatile fluids, such as, for example, alcohols, and electronic
cooling fluids known to those skilled in the art. In certain
embodiments, the heat transfer fluid is dielectric, non-flammable,
and provides a significant vapor pressure at the operating
temperature of the heat-dissipating component.
[0041] In certain embodiments, the heat transfer fluid is thermally
conductive, chemically inert, essentially gas-free, and thermally
stable. In other embodiments, the heat transfer fluid has a boiling
point that is at or below the operating temperature of the
heat-dissipating component such that portions of the liquid
adjacent the heat-dissipating component will vaporize when
conducting heat. The heat transfer fluid can be selected from the
representative class of fluorinated linear, branched or cyclic
alkanes, ethers, ketones, tertiary amines, and aminoethers, and
mixtures thereof. In some embodiments, perfluorinated fluids are
used in this invention, though partially fluorinated fluids can
also be used. The perfluorinated fluids can be straight chain,
branched chain, cyclic, or a combination thereof. In some
embodiments, the perfluorinated fluids can be saturated, that is,
free of ethylenic, acetylenic, and aromatic unsaturation. The
skeletal chain can include catenary oxygen and/or trivalent
nitrogen heteroatoms providing stable links between fluorocarbon
groups and not interfering with the inert character of the
compound. In some embodiments, hydrofluoroethers, either segregated
or non-segregated are used. In other embodiments, perfluorinated
ketones are used.
[0042] Representative examples of suitable fluorinated fluids or
mixtures thereof useful for the present invention are commercially
available from 3M Company, St. Paul, Minn., and marketed under
various trade designations, including, for example, "3M BRAND
FLUORINERT ELECTRONIC LIQUIDS" and "3M BRAND NOVEC ENGINEERED
FLUIDS", described in 3M Company product bulletin No.
98-0212-2249-7, issued January 2003. Other commercially available
fluorochemicals useful in the present invention are those available
from Solvay Solexis S.p.A, Bollate, Italy, under the trade
designation "GALDEN PFPE: HEAT TRANSFER FLUIDS" and their
hydrofluoroethers available under the trade designation "H-GALDEN
ZT HEAT TRANSFER FLUID". Heat transfer fluids useful in the present
invention also include hydrofluorocarbon compounds such as those
sold under the trade designations "VERTREL SPECIALTY FLUIDS" and
"SUVA REFRIGERANTS" available from DuPont, Wilmington, Del.
[0043] Illustrative examples of suitable boiling enhancements
include, for example, carbon foam, a heat spreader such as, for
example, a flat plate, pin fin array, an array of channels, or
other three-dimensional structures made of thermally conductive
metal or composite material that increases surface area for
boiling. These enhancements may be further enhanced by the
application of a microporous coating, modulated microreplicated
features, or capillary structures that enhance boiling heat
transfer by aiding nucleation or impeding the hydrodynamic
mechanisms that lead to surface dry out. In another embodiment, the
boiling enhancement is a coating applied to the heat-dissipating
component 26 and no thermal interface material 24 is present.
[0044] The thermal interface material 24 can be solder or any
conventional thermal compound commonly known in the art. In certain
embodiments, the thermal interface material is a low melting point
eutectic alloy, such as, for example, a eutectic alloy based upon
indium that will remain liquid at the operating temperature of the
thermal interface material. Such materials are desirable from a
performance standpoint but are normally subject to oxidation when
exposed to air in their molten state. The closed environment
created by the present invention can be used to control the
exposure level of thermal interface materials to oxygen such that
the level of oxidation is minimized.
[0045] The heat dissipating component 26 can be a semiconductor,
such as, for example, a central or graphics processing unit, an
insulated gate bipolar transistor (IGBT), memory module, or an
application specific integrated circuit (ASIC). In other
embodiments, the heat dissipating component 24 can be a hard disk
drive, power supply, transformer, laser diode array, light emitting
diode (LED) array, halogen bulb, or any other heat-dissipating
component known to those skilled in the art. The heat dissipating
component can also be a non-heat generating structure, such as, for
example, an integrated heat spreader (IHS) that is connected to a
heat-generating device, such as, for example, a semiconductor.
[0046] FIG. 4 is a cross-sectional view of an exemplary embodiment
of the present invention having a puncturing member 430 within an
optional spacing member 417. The spacing member 417 can be
integrally formed with the sidewall 414 or can be affixed to the
sidewall 414. In some embodiments, the spacing member 414 is made
of a different material than the sidewall 414. For example, the
spacing member 414 can be made of a more rigid material to
facilitate a better seal between the body 410 and a substrate.
Likewise, the sidewall 414 can be made of a more flexible material
to facilitate pressure fluctuations within the enclosed volume 428
or to facilitate breaching of the seal 418.
[0047] As shown in FIG. 4, the puncturing member 430 has a striking
surface 432. In certain embodiments, the striking surface 432 forms
a point. The puncturing member 430 can be positioned so that distal
end 433 extends beyond the lower surface 419 of the spacing member
417. During placement of the body 410 onto a substrate, the distal
end 433 contacts the substrate and causes the puncturing member 430
to move relative to the seal 418 such that the striking surface 432
contacts and punctures the seal 418 causing the enclosed volume 428
to join the expansion volume 429.
[0048] In some embodiments, the distal end 433 extends beyond the
attachment interface 420 such that the distal end 433 is the first
element to contact the substrate during attachment of the body 410.
In such embodiments, the body 410 may be inverted during attachment
to prevent the heat transfer fluid 416 from entering the expansion
volume 429 and potentially spilling.
[0049] In other embodiments, the distal end is positioned
approximately flush with or below the attachment interface 420. In
such embodiments, the attachment interface 420 or spacing member
417 can be made from a compressible material. Compression of either
the attachment interface 420 or spacing member 417 by placing a
force on the body 410 will cause the puncturing member 430 to move
relative to the seal 418 such that the striking surface 432
contacts and punctures the seal 418 causing the enclosed volume 428
to join the expansion volume 429.
[0050] FIG. 5 is a cross-sectional view of an exemplary embodiment
of the present invention having a puncturing member 530 within the
enclosed volume 528. The puncturing member 530 has a striking
surface 532 and a distal end 533. By applying a force to the distal
end 533, the striking surface 532 will contact and puncture the
seal 518 causing the enclosed volume 528 to join the expansion
volume 529. A puncturing member seal 531 at the sidewall 514
prevents the heat transfer fluid 516 from escaping through the
sidewall 514. In another embodiment, the distal end of the
puncturing member is affixed to the inner surface of the sidewall
and does not extend through or beyond the sidewall. In such
embodiment, a force upon the sidewall causes the sidewall to flex
thus moving the puncturing member toward the breachable seal 518
and breaching the seal 518.
[0051] FIG. 6A is a cross-sectional view of an exemplary embodiment
of the present invention having a tether within the enclosed volume
and a spring member to attach a boiling enhancement. FIG. 6B is a
cross-sectional view of the exemplary embodiment shown in FIG. 6A
after attachment to a substrate and breaching of the seal. As shown
in FIGS. 6A and 6B, a tether 640 can be used to cause the seal 618
to be breached. A first end of the tether 640 is affixed to the
breachable seal and the second end of the tether can be affixed to
the sidewall 614. As shown in FIG. 6B, the body can be deformed,
either temporarily or permanently, causing the tether 60 to breach
the seal 618. Alternatively, the tether 640 can extend through the
sidewall such that it can be pulled manually outside of the body
610.
[0052] Other techniques for breaching an internal seal known to
those skilled in the art can also be employed. For example, in
other embodiments, the breachable seal extends through the sidewall
and can be breached or removed by manually grasping and pulling a
tab connected to the seal from outside of the body. In yet further
embodiments, the burst strength of the breachable seal is
sufficiently low such that pressure applied to the body causes the
pressure in the enclosed volume to increase and rupture the
breachable seal.
[0053] Also shown in FIGS. 6A and 6B is an embodiment that uses a
retaining clip 642 to affix a boiling enhancement 622 to the body
610. A thermal interface material 624 can be affixed to the boiling
enhancement 622. The retaining clip is used to facilitate placement
of a boiling enhancement on a heat-dissipating device 626 affixed
to a substrate 612. In some embodiments, the retaining clip is made
of a resilient but flexible material such that boiling enhancement
622 and thermal interface material 624 can move relative to the
body 610. The retaining clips can be made from metal, plastic, or
any other material useful for attaching components known to those
skilled in the art.
[0054] Body 10 can also contain small amount of reactive metal,
652, such as activated nickel intended to scavenge oxygen that
might be inside body 10 at the time of manufacture or that might
enter at the time the device is installed. Body 10 can also contain
small amount of adsorbent, 650, such as activated carbon or other
suitable material intended to scavenge less volatile materials,
such as, for example, low molecular weight polymers, UV
stabilizers, or plasticizers that might over time be extracted from
the materials in contact with the fluid and be deposited at the
boiling surface disrupting performance.
[0055] FIG. 7 is a cross-sectional view of an exemplary embodiment
of the present invention having a flexible sidewall. As shown in
FIG. 7, the body 710 can have a flexible sidewall 714 affixed to a
spacing member 717 using a flange 744. In some embodiments, the
flexible sidewall 714 comprises at least two substantially planar
sheets of material that are bonded to one another at their
periphery to form a seal 715. In such an embodiment, the sidewall
714 can comprise heat-sealable films that can be thermally bonded
to one another. In yet further embodiments, the heat-sealable films
can be thermally bonded to the flange 744. In other embodiments,
the sidewall 714 is affixed to the spacing member 717 using any
means known to those skilled in the art, including, for example,
adhesive and mechanical fasteners.
[0056] The attachment interface 720 is used to connect the body 710
to a substrate or heat-dissipating component. The enclosed volume
728 and expansion volume 729 are connected by breaching the
breachable seal 718 and allowing the heat transfer fluid 716 to
flow into the expansion volume 729. The breachable seal 718 can be
breached using any of the methods described above. In certain
embodiments having a flexible sidewall such as body 710, the
breachable seal 718 is ruptured by increasing the pressure in the
enclosed volume 728. The pressure can be increased by manually
squeezing the flexible sidewall 714 of the body 710.
[0057] FIG. 7B is a cross-sectional view of the exemplary
embodiment shown in FIG. 7A after attachment to a substrate and
breaching of the seal. As shown in FIG. 7B, the body 710 is affixed
to substrate 712 using attachment interface 720. A heat-dissipating
component 726, such as, for example, a central processing unit, is
affixed to the substrate 712. A boiling enhancement 722, such as,
for example, a microporous coating, is applied to the heating
dissipating component 726. After the breachable seal 718 is removed
or broken, the heat transfer fluid 716 is allowed to enter the
expansion volume 729 and contact the boiling enhancement 722.
[0058] It is to be understood that even in the numerous
characteristics and advantages of the present invention set forth
in above description and examples, together with details of the
structure and function of the invention, the disclosure is
illustrative only. Changes can be made to detail, especially in
matters of shape, size and arrangement of the breachable seal and
sidewall and methods of use within the principles of the invention
to the full extent indicated by the meaning of the terms in which
the appended claims are expressed and the equivalents of those
structures and methods.
* * * * *