U.S. patent application number 11/110221 was filed with the patent office on 2005-09-08 for cast design for plasma chamber cooling.
This patent application is currently assigned to Advanced Energy Industries, Inc.. Invention is credited to Dillon, Steve, Mauck, Justin.
Application Number | 20050194098 11/110221 |
Document ID | / |
Family ID | 34910619 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050194098 |
Kind Code |
A1 |
Dillon, Steve ; et
al. |
September 8, 2005 |
Cast design for plasma chamber cooling
Abstract
A plasma generation device has a plasma containment vessel
comprising integral cast cooling elements. A casting mold is placed
over a foundation, leaving at least one surface of the foundation
exposed. At least one cooling tube is then placed over the
foundation, and a casting material is then poured into the casting
mold over the foundation and the cooling tubes. The foundation
portion of the assembly is machined and anodized to become an
interior and vacuum surface of a plasma chamber with integral
cooling elements.
Inventors: |
Dillon, Steve; (Fort
Collins, CO) ; Mauck, Justin; (Fort Collins,
CO) |
Correspondence
Address: |
JOHN D. PIRNOT
ADVANCED ENERGY INDUSTRIES, INC.
1625 SHARP POINT DR.
FORT COLLINS
CO
80525
US
|
Assignee: |
Advanced Energy Industries,
Inc.
|
Family ID: |
34910619 |
Appl. No.: |
11/110221 |
Filed: |
April 20, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11110221 |
Apr 20, 2005 |
|
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10395585 |
Mar 24, 2003 |
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Current U.S.
Class: |
156/345.37 |
Current CPC
Class: |
B22D 19/0072 20130101;
H01J 37/32467 20130101; H01J 37/32522 20130101 |
Class at
Publication: |
156/345.37 |
International
Class: |
C23F 001/00 |
Claims
What is claimed is:
1. A plasma generation device having a plasma chamber, the plasma
chamber comprising: a metallic chamber wall having an interior
surface that confines a plasma and an exterior surface; and one or
more integral cast cooling assemblies formed upon the exterior
surface of the chamber wall, the one or more integral cast cooling
assemblies comprising at least one cooling device embedded in a
casting material disposed conformally to the exterior surface of
the chamber wall.
2. The device of claim 1 wherein the casting material is a metal
alloy.
3. The device of claim 1 wherein the at least one cooling device
comprises metal tubing.
4. The device of claim 3 wherein the metal tubing is copper water
piping.
5. The device of claim 1 wherein the at least one cooling device is
a heat pipe.
6. The device of claim 1 wherein the casting material completely
surrounds the at least one cooling device.
7. The device of claim 1 wherein the at least one cooling device
contains a cooling fluid that extracts heat from the chamber
wall.
8. The device of claim 1 wherein at least one of the one or more
integral cast cooling assemblies is a coldplate of the plasma
generation device.
9. The device of claim 8 wherein electrical components of the
plasma generation device are mounted upon the coldplate.
10. The device of claim 1 wherein the interior surface of the
chamber wall is anodized for protection from the plasma.
Description
RELATED APPLICATIONS
[0001] This is a continuation-in-part of U.S. patent application
Ser. No. 10/395,585, filed Mar. 24, 2003.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates generally to plasma containment
vessels, and more specifically to plasma chambers comprising
integral cast cooling elements.
[0004] 2. Brief Description of the Prior Art
[0005] A chamber for containment of a subatmospheric plasma
typically requires three key features. First, the chamber must be
able to seal a vacuum created within the chamber, which may be in
the 10.sup.-9 Torr range. Second, the interfaces and materials of
the chamber need to be able to withstand the heat and chemistry of
the plasma environment. Finally, plasma chambers ordinarily must be
cooled for extraction of the internal heat generated by the plasma.
Aluminum alloys are often materials of choice for construction of
interior vacuum surfaces of plasma chambers as they are vacuum
compatible and can be anodized to offer the necessary resistance
from corrosive gases and from the plasma itself. Cooling may be
accomplished for example by providing copper water tubing in
contact with or impressed into the aluminum walls of the chamber.
One limitation of this approach is the attachment between the
cooling tubes and the metal plate. If the tubes are soldered,
brazed, welded or epoxied to the aluminum plate, then the
attachment point will limit the flow of heat from the plate to the
cooling tubes.
[0006] Alternatively, attempts have been made to cast cooling tubes
inside of the walls of a containment vessel to eliminate the
degradation in heat transfer through the soldered, brazed, welded
or epoxied connection. Typical cast materials, however, are not
appropriate for many applications. In vacuum chambers, the porosity
of cast materials can hamper the establishment of a vacuum,
significantly slowing production times. Cast materials can also
become impregnated with undesired impurities, and typically cannot
be anodized to a level that is acceptable for corrosion resistance
in a plasma environment.
SUMMARY OF THE INVENTION
[0007] The invention features a plasma generation device having a
plasma containment vessel comprising integral cast cooling
elements. In one aspect of the invention, a core material serves as
a foundation for a cast cooling assembly. The core material is
selected for its suitability as a vacuum containment material and
for its tolerance to a plasma environment. A cooling assembly is
then cast upon the foundation material using a casting mold. In one
embodiment, the cooling assembly comprises metallic cooling tubes
embedded in a casting disposed conformally to the exterior surface
of the chamber wall. After the cooling assembly is cast upon the
core material, the solid chamber wall assembly is machined and
anodized to become an interior vacuum surface of a chamber with
integral cooling elements.
[0008] In another aspect of the invention, one or more of the
integral cooling elements of a plasma chamber vessel serves as a
coldplate for mounting of heat generating electrical components.
The cooling element thus serves to extract heat from both the
plasma as well as from electrical components of the plasma
generation device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Embodiments of the present invention are illustrated by way
of example, and not by way of limitation, in the figures of the
accompanying drawings in which like reference numerals refer to
similar elements and in which:
[0010] FIG. 1 illustrates a cast coldplate within general
embodiments of the invention;
[0011] FIG. 2 is a flowchart illustrating a method for making a
cast coldplate within general embodiments of the invention;
[0012] FIG. 3 illustrates a vacuum chamber using a cast coldplate
of general embodiments of the invention on one side of the vacuum
chamber; and
[0013] FIG. 4 illustrates a vacuum chamber using a cast coldplate
of general embodiments of the invention on multiple sides of the
vacuum chamber.
DETAILED DESCRIPTION
[0014] FIG. 1 illustrates a cast coldplate applicable to
embodiments of the invention. The cast coldplate 100 has a
foundation 102 with a top surface 104, a bottom surface 106, and
side surfaces 108, 110. The foundation can be made of any of a
variety of materials. In one embodiment, the material is selected
for use as an interior wall of a plasma chamber. Such materials
include machined aluminum and aluminum alloys such as aluminum
6601.
[0015] The coldplate also has a casted component 112 with at least
one cooling tube 114, 116, 118, 120 within it. The cooling tubes
can be completely or partially surrounded by the casted component,
depending upon the application. The cooling tubes can be made of
conventional copper water piping or of any of a variety of other
materials depending upon the cooling fluid used and the heat
exchange properties that are desired. Alternatively, the cooling
device is a heat pipe device. An aluminum structure surrounding
copper pipes provides for good heat conduction for many
applications.
[0016] FIG. 2 illustrates a method for making a cast coldplate. The
method begins at block 200 and continues to block 202 where a
casting mold is placed over the foundation 102, surrounding at
least the top surface 104 of the foundation 102. In illustrated
embodiments of the invention (see FIG. 1), the casting mold
surrounds the top surface 104 of the foundation 102, as well as the
side surfaces 108, 110 of the foundation. However, the casting mold
may alternatively surround just the top surface 104 of the
foundation 102.
[0017] At block 204, cooling tubes 114, 116, 118, 120 are placed
over the foundation 102. Cooling tubes 114, 116, 118, 120 that are
placed over the foundation 102 may be placed directly on the
foundation material or suspended off the surface of the foundation
material using a fixture. At block 206, casting material is poured
over the foundation 102 and the cooling tubes 114, 116, 118, 120 to
create a layer of casting material. The casting material, in one
embodiment is poured so that is completely surrounds the exterior
of each tube. This maximizes the heat transfer surface. The number
and placement of the cooling tubes will depend on the particular
application and a variety of factors such as heat flow demands,
fluid flow and pressure drop tolerances. Coolant, such as water,
may then be run through the cooling tubes 114, 116, 118, 120 to
keep the cast coldplate cool, thereby keeping components, such as
electronics mounted to the plate, cool. The method ends at block
208.
[0018] In another aspect of the invention, the foundations of one
or more cast coldplates are used as an inner wall of a vacuum
chamber, for example, a plasma chamber. The foundation material is
particularly well suited for use as a chamber wall and the cast
material, in intimate contact with the foundation conducts heat
away from the foundation and toward the cooling pipes.
[0019] In one embodiment, the bottom surface of the foundation is
placed over a top surface of a vacuum chamber, such that one side
of the vacuum chamber comprises the bottom surface 106 of the
foundation 102, as illustrated in FIG. 3. The vacuum chamber 300
comprises a cast coldplate 100 on one side of the vacuum chamber, a
housing 302 such as aluminum or aluminum alloy on a plurality of
sides of the vacuum chamber, and a chamber 304 in which plasma is
maintained. The housing 302 and bottom surface 106 of the
foundation 102 of the cast coldplate 100 surround the chamber 304
in which plasma is maintained. The coldplate also serves as a heat
sink upon which components of the power supply, match, or other
electronics of the plasma generation device are mounted. In another
embodiment, as illustrated in FIG. 4, the vacuum chamber 300
comprises a cast coldplate 100 on each of its sides.
[0020] As plasma moves through the vacuum chamber 304, the plasma
source body 302 and cast coldplate 100 increase in temperature. To
keep the vacuum chamber 300 cool, water is run through the cooling
tubes 114, 116, 118, 120.
[0021] The plasma source body 302 and foundation 102 may comprise a
metal such as aluminum, copper, nickel, or steel, or a coated metal
such as anodized aluminum or nickel-plated aluminum. The casting
material used to create the casted component 112 of the cast
coldplate 100 may comprise an aluminum alloy, or a tin alloy, for
example.
[0022] In the description above, for the purposes of explanation,
numerous specific details are set forth in order to provide a
thorough understanding of the present invention. It will be
apparent, however, to one skilled in the art that the present
invention may be practiced without some of these specific details.
In other instances, well-known circuits, structures, devices, and
techniques have been shown in block diagram form or without detail
in order not to obscure the understanding of this description.
[0023] The present invention includes various steps, but steps can
be added to or deleted from any of the methods and signal or
messages can be added or subtracted from any of the described steps
or control lines without departing from the basic scope of the
present invention. It will be apparent to those skilled in the art
that many further modifications and adaptations can be made. The
particular embodiments are not provided to limit the invention but
to illustrate it. The scope of the present invention is not to be
determined by the specific examples provided above but only by the
claims below.
[0024] Furthermore, while the invention has been illustrated in the
context of a coldplate used in a plasma chamber, the invention is
not so limited. It can be applied to coldplates in general, as well
as to any application in which a component needs cooling and
requires that a specific foundation material surface be
exposed.
[0025] It should also be appreciated that reference throughout this
specification to "one embodiment" or "an embodiment" means that a
particular feature may be included in the practice of the
invention. Similarly, it should be appreciated that in the
foregoing description of exemplary embodiments of the invention,
various features of the invention are sometimes grouped together in
a single embodiment, figure, or description thereof for the purpose
of streamlining the disclosure and aiding in the understanding of
one or more of the various inventive aspects. This method of
disclosure, however, is not to be interpreted as reflecting an
intention that the claimed invention requires more features than
are expressly recited in each claim. Rather, as the following
claims reflect, inventive aspects lie in less than all features of
a single foregoing disclosed embodiment. Thus, the claims following
the Detailed Description are hereby expressly incorporated into
this Detailed Description, with each claim standing on its own as a
separate embodiment of this invention.
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