U.S. patent application number 12/231936 was filed with the patent office on 2009-03-12 for cooling with microwave excited micro-plasma and ions.
Invention is credited to Chien Ouyang.
Application Number | 20090065177 12/231936 |
Document ID | / |
Family ID | 40430593 |
Filed Date | 2009-03-12 |
United States Patent
Application |
20090065177 |
Kind Code |
A1 |
Ouyang; Chien |
March 12, 2009 |
Cooling with microwave excited micro-plasma and ions
Abstract
One embodiment of the present invention uses an actuator, which
is actuated by electromagnetic microwave. The actuator is used to
generate the micro-plasma and ions. The configurations of actuators
may be microstrip lines structure, stripline structure, piping
structure, multiplayer traces and electrodes structure, waveguide
structure, and cavity structure. The generated micro-plasma and
ions will induce a local turbulent gas flow and the flow is to
carry the heat away from the surfaces of the heat sink fins. The
actuators may be coupled to heat sink fins, heat transferring
pipes, cooling fans, and heat sources in varied configurations.
Inventors: |
Ouyang; Chien; (Sunnyvale,
CA) |
Correspondence
Address: |
Chien Ouyang
843 Humewick Way
Sunnyvale
CA
94087
US
|
Family ID: |
40430593 |
Appl. No.: |
12/231936 |
Filed: |
September 8, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60993036 |
Sep 10, 2007 |
|
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Current U.S.
Class: |
165/80.4 ;
165/80.3 |
Current CPC
Class: |
F28F 13/00 20130101;
F04B 19/006 20130101; G06F 1/203 20130101; H01L 23/467 20130101;
H05H 1/46 20130101; H01L 2924/0002 20130101; H05H 2001/4622
20130101; F04B 17/00 20130101; F04B 35/00 20130101; H01L 2924/00
20130101; H01L 2924/0002 20130101; H01L 2924/3011 20130101 |
Class at
Publication: |
165/80.4 ;
165/80.3 |
International
Class: |
F28F 13/00 20060101
F28F013/00 |
Claims
1. A method and apparatus for cooling electronic devices,
comprising: a microwave excited micro-plasma and ions actuator
coupled with cooling heat sink fins assembly to cool down heat
sources;
2. The apparatus of claim 1, wherein the actuator involves using an
inner cylinder and an outer cylinder, a micro-strip structure, a
stripline structure, embedded conductive traces and electrodes, a
wave-guide structure, and a cavity structure for the
electromagnetic microwave to pass through to ionize the gas;
3. The apparatus of claim 1, wherein the actuators are populated in
an array to couple with heat sink fins assembly;
4. The apparatus of claim 1, wherein the actuators are coupled to a
heat sink fins assembly at the inlet, at the outlet, at the top, at
the bottom, and in the middle of the heat sink fins assembly, to
ionize the air;
5. The apparatus of claim 1, wherein the heat sink fins assembly
comprising straight fins, pin fins, and irregular shapes fins
structure;
6. The apparatus of claim 1, wherein the actuators comprising
conductive traces on one side of the dielectric layer, and ground
layer on the other side of the dielectric layer; and multiplayer
structure which have openings for microwave to generate
micro-plasma and ions;
7. The apparatus of claim 1, wherein the actuators comprising
openings on the conductive layers, on the wave guide structures,
and on the cavity structures; wherein the openings are locations
for electromagnetic microwave to ionize the air to induce the ion
driven turbulent gas flow;
8. The apparatus of claim 1, wherein the actuators are operable to
couple with a fan, a heat pipe, a heat source, and a heat sink fins
assembly to generate the micro-plasma and ions;
9. The apparatus of claim 1, wherein the actuators may be made in a
micron scale, a nano meter scale, and a bulk scale;
10. The apparatus of claim 1, the actuators may be coupled to a
heat sink fins structure, and the actuators may be directly
manufactured on a silicon chip structure; and the actuators may be
manufactured with micro-electro-mechanical wafer processing
techniques;
11. The apparatus of claim 1, wherein the heat source may be a
microprocessor, an ASIC chip, a video processor chip, a graphic
processor chip, an electronic IC chip, and a power supplier.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to electronic
equipment, and more particularly, to apparatus and methods for
cooling electronic devices using microwave excited micro-plasma and
ions.
[0003] 2. Description of the Related Art
[0004] Electronic devices may generate significant heat during
operation. High temperatures may reduce the lifespan of these
devices, and, therefore, the generated heat may need to be
dispersed to keep the operating temperature of the electronic
devices within acceptable limits.
[0005] One commonly used cooling device is heat sink. Heat sinks
may be coupled to electronic devices to absorb heat through the
heat sink base and disperse the heat through their fins.
Conventional methods to disperse the heat through the heat sink
fins are natural convection and forced convection. Natural
convection is to disperse the heat away from the surfaces of heat
sink fins without the aid of external forced fluid pumping through
heat sink fins. On the other hand, the forced convection cooling is
to pump the fluid to flow through heat sink fins, such as the fans
to blow the air through the heat sink fins, and therefore enhance
the heat transfer between fins and outside ambient.
[0006] With the increasing power density of electronic devices, the
pitch or the distance between heat sink fins is becoming smaller,
which means more surface area may be used to transport the heat
away. However, when the pitch becomes very small, the pressure drop
between inlet and outlet of the heat sink fins may become very
high, which may results the difficulties to pump the fluid flowing
through fins, and as a result, more powerful fans, which consume
higher electricity may be needed for the cooling. The invention
utilizes microwave excited micro-plasma and ions to induce the gas
flow to conduct the convective heat transfer along the heat sink
fins and therefore will resolve these issues.
[0007] Another consideration of the electronic device cooling is
that, due to size concern, the internal space allowed to put
cooling fans and other cooling components, may be limited or not
permitted. The invention utilizes the microwave excited
micro-plasma and ions gas flow to generate the forced convective
heat transfer. Therefore the design is able to improve the heat
transfer efficiency and to minimize the required space because
microwave excited micro-plasma and ions can be very small.
[0008] Another aspect of using the invention is to lower the
required power of the system fans of electronic devices. The
micro-plasma and ions driven gas flow excited by the microwave
couple with the heat sink fins will induce the local turbulence gas
flow near heat sink surfaces. The local turbulence near the heat
sink surface will enhance the heat dissipation so a better cooling
is achieved. Therefore the system fan doesn't need to be very
powerful and the electricity energy is saved.
[0009] Plasma-driven gas flow has been used either to cool articles
or to control and modify the fluid dynamics boundary layer on the
wings surfaces of the aerodynamic vehicles. For example, U.S. Pat.
No. 3,938,345 used the phenomenon of corona discharge, which is one
type of plasma, to do the local cooling of an article. U.S. Pat.
No. 4,210,847 designed an apparatus for generating an air jet for
cooling application. U.S. Pat. No. 5,554,344 had a gas ionization
device to do the cooling of zone producing chamber. U.S. Pat. No.
6,796,532 B2 used a plasma discharge to manipulate the boundary
layer and the angular locations of its separation points in cross
flow planes to control the symmetry or asymmetry of the vortex
pattern.
[0010] However, none of the above patents are coupled to the heat
sink, which is a fundamental apparatus for cooling electronic
devices. Hence, what are needed are a method and an apparatus, to
couple with heat sink fins to cool down electronic devices
efficiently.
SUMMARY OF THE INVENTION
[0011] One embodiment of the present invention provides a microwave
excited micro-plasma and ions couple to heat sink fins to induce
the gas flow along the heat sink fins. The induced gas flow will
remove the heat away from heat sink fin surface and therefore the
heat source is cool down.
[0012] In one embodiment, the cooling system includes heat sink
fins assembly and array of the microwave excited micro-plasma and
ions devices. The heat sink fin assembly may be composed by a
plurality of straight heat sink fins, a plurality of heat sink
pins, or other shapes of fin structure. The micro-plasma and ions
devices may be composed with different configurations, such as
micro-strips, microwave wave guides, and microwave cavities. The
micro-plasma and ions may be excited and generated at different
locations inside the heat sink fin assembly.
[0013] In one embodiment, the micro-plasma and ions may be excited
and generated with microwave cavities, which have slots, holes, or
trench on the surface of the microwave wave guide structure. In a
further embodiment, the generated micro-plasma and ions will couple
and interact with heat sink fins assembly to do the cooling.
[0014] In one embodiment, the micro-plasma and ions actuators may
be configured by one or several micro-strips. In another
embodiment, the configurations of the micro-strips may be varied to
gain the maximum electrical field at specific regions to induce
micro-plasma and ions.
[0015] In one embodiment, the micro-plasma and ions actuators may
be composed of microwave wave guides, which have different
configurations such as pipe shape, micro-strip shape, rectangular
shape, or other shapes. The dielectric layers may couple with
microwave wave guides.
[0016] In one embodiment, the applied microwave sources to excite
and generate the micro-plasma and ions flow may have varied
waveforms, frequencies, amplitude, phase shifts, and may be
transient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] A better understanding of the present invention may be
obtained when the following detailed description is considered in
conjunction with the following drawings, in which:
[0018] FIG. 1 illustrates a micro-plasma and ions generating
device;
[0019] FIG. 2 illustrates a micro-plasma and ions generating
device;
[0020] FIG. 3 illustrates an array of micro-plasma and ions
devices;
[0021] FIG. 4 illustrates an array of micro-plasma and ions devices
couple to a heat sink fins assembly;
[0022] FIG. 5 illustrates an array of micro-plasma and ions devices
couple to a heat sink fins assembly;
[0023] FIG. 6 illustrates an array of micro-plasma and ions devices
couple to a heat sink fins assembly;
[0024] FIG. 7 illustrates a micro-plasma and ions device couple to
a heat sink fins assembly;
[0025] FIG. 8 illustrates the micro-plasma and ions devices couple
to a heat sink fins assembly in varied configurations;
[0026] FIG. 9 illustrates the micro-plasma and ions devices made of
micro-strips;
[0027] FIG. 10 illustrates the microwave waveguides coupled with
microwave cavities are used to excite and generate micro-plasma and
ions;
[0028] FIG. 11 illustrates the microwave waveguides and microwave
cavities are used to excite and generate micro-plasma and ions;
[0029] FIG. 12 illustrates the micro-plasma and ions coupled with
heat sink fins;
[0030] FIG. 13 illustrates the micro-plasma and ions actuator is
used to cool down the heat sources inside an electronic device.
[0031] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof are shown by
way of example in the drawings and will herein be described in
detail. It should be understood, however, that the drawings and
detailed description thereto are not intended to limit the
invention to the particular form disclosed, but on the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the present
invention as defined by the appended claims. Furthermore, note that
the word "may" is used throughout this application in a permissive
sense (i.e., having the potential to, being able to), not a
mandatory sense (i.e., must). The term "include", and derivations
thereof, mean "including, but not limited to". The term "coupled"
means "directly or indirectly connected".
DETAILED DESCRIPTION OF THE INVENTION
[0032] The invention generally relates to apparatus for cooling
electronic devices or packages, such as microprocessor and ASIC.
Such systems and methods may be used in a variety of applications.
A non-exhaustive list of such applications includes the cooling of:
a microprocessor chip, a graphics processor chip, an ASIC chip, a
video processor chip, a DSP chip, a memory chip, a hard disk drive,
a graphic card, a portable testing electronics, a personal computer
system.
[0033] Take laptop computer for example, conventional fans use a
lot of space and energy. For this reason, the microwave excited
micro-plasma and ions cooling represent a way to increase their
cooling capacity and make them more reliable and far quieter.
Therefore the higher-performance chips that generate too much heat
for current laptops can be used.
[0034] As used herein "plasma" is an ionized gas, a gas into which
sufficient energy is provided to free electrons from atoms or
molecules and to allow both species, ions and electrons, to
coexist. Plasma is even common here on earth. A plasma is a gas
that has been energized to the point that some of the electrons
break free from, but travel with, their nucleus. Gases can become
plasmas in several ways, but all include pumping the gas with
energy. A spark in a gas will create a plasma. A hot gas passing
through a big spark will turn the gas stream into a plasma that can
be useful. Plasma torches like that are used in industry to cut
metals.
[0035] As used herein "dielectric" is a substance that is a poor
conductor of electricity, but an efficient supporter of
electrostatic fields. In practice, most dielectric materials are
solid. An important property of a dielectric is its ability to
support an electrostatic field while dissipating minimal energy in
the form of heat. The lower the dielectric loss (the proportion of
energy lost as heat), the more effective is a dielectric material.
Another consideration is the dielectric constant, the extent to
which a substance concentrates the electrostatic lines of flux.
Substances with a low dielectric constant include a perfect vacuum,
dry air, and most pure, dry gases such as helium and nitrogen.
Materials with moderate dielectric constants include ceramics,
distilled water, paper, mica, polyethylene, and glass. Metal
oxides, in general, have high dielectric constants.
[0036] FIG. 1 illustrates a configuration of a micro-plasma and
ions generating device. The figure shows a microwave 101 is
traveling along the axial direction and the wave is between inner
cylinder 102 and outer cylinder 103. The dielectric material 102 is
between two cylinders. The dielectric material can be air or other
materials. The plasma, as shown in the black color region 104 in
the figure, may be excited and generated by the electromagnetic
microwave and the plasma may flow out of the nozzle, which is
located at the end of outer cylinder. Similarly, FIG. 2 illustrates
another configuration. These configurations act as micro-plasma and
ions generators.
[0037] Similar to FIGS. 1 and 2, the plasma may be excited and
generated by electromagnetic microwave using micro-strip structure
as shown in FIG. 3. The micro-strips 105 are on one side of the
dielectric material 102 and the ground 106 is on the other side.
The top micro-strips and bottom ground may have extension on the
side wall of the dielectric material as shown in the FIG. 3. The
gap between top micro-strips 105 and the ground 106 extension may
be small in order to have high electrical field distribution when
an electromagnetic microwave travels to there. In one embodiment,
the micro-plasma and ions actuators may be configured to be an
array which has many channels. In another embodiment, the
micro-strip may have impedance matching stub, which is not shown
here in the figure, to minimize the microwave reflection from the
edge of the board. Furthermore, varied micro-strips patterns and
different geometries of the micro-strip edge and ground edge may be
used.
[0038] FIG. 4 illustrates an array of the circular-pipe shape
micro-plasma and ions actuators are assembled on one side of the
heat sink fins assembly 201. The generated micro-plasma and ions
will induce local turbulent flow. This turbulent flow may couple
with a fan, to enhance the heat removal from the heat sink surface.
In one embodiment, besides the circular shape, the micro-plasma and
ions actuators may have different configurations, such as
rectangular shape.
[0039] FIG. 5 illustrates an array of micro-strip actuators is
coupled with the heat sink base 200 and heat sink fins 201
assembly. The micro-plasma and ions generated by micro-strip make
the design scaleable and the micro-plasma and ions can easily
couple to heat sink fins 201 as shown in the figure. The
micro-strips 105 may be deposited on one side of the dielectric 102
board and the other side may be electrically grounded 106.
[0040] FIG. 6 illustrates another configuration of the micro-strips
105 coupled with heat sink fins 201 and heat sink base 200. One
single micro-strip 105 may couple to a single heat sink fin 201 as
shown in the FIG. 6. In one embodiment, one micro-strip 105 may
couple to several heat sink fins 201 as shown in FIG. 7. In another
embodiment, the bulk heat sink fins or the micro-channels heat sink
fins may be used.
[0041] Not limited by the configurations of the FIG. 4 to FIG. 7,
the micro-plasma and ions actuators may be coupled with heat sink
fins 201 assembly in varied directions and patterns. FIG. 8
illustrates the side and top views of the micro-plasma and ions
actuators coupled with heat sink fins 201 assembly and heat sink
base 200. The black lines shown are the micro-plasma and ions
actuators. In one embodiment, the micro-plasma and ions actuators
may be manufactured with flexible materials so they can be bended
to fit with specific space and shape requirements, and may be
manufactured in a similar way as PCB manufacturing process. In
another embodiment, the heat sink fins may be straight as shown in
FIG. 8a to FIG. 8d, and the heat sink fins may be configured with
fin structure as shown in FIG. 8e. Other geometries and shapes of
heat sink fins may be used to couple with micro-plasma and ions
actuators and the variation should be considered within the scope
of the embodiment here.
[0042] FIG. 9 illustrates some configurations of the micro-strips
used to excite and to generate the micro-plasma and ions. FIGS. 9a
and 9b show the micro-strips 105 are on one side of the dielectric
material 102 and the ground metal 106 is on the other side. There
is a small gap between top and bottom conductors on the side wall
of the dielectric material 102. The electromagnetic microwave is
traveling inside the dielectric material toward the gap region. The
high electrical field, which is favorable, will occur at the gap
region to ionize the air and therefore the plasma flow is induced.
In one embodiment, the configuration of the micro-strips may be
varied and the edge patterns may be varied as well. All the
variation should be considered within the scope of the invention.
FIG. 9c illustrates one configuration of the micro-strip 105 and
ground 106 coupled with dielectric material 102. In another
embodiment, the embedded conductive traces and electrodes may be
used as shown in FIG. 9d. When electromagnetic interference is
concerned, the embedded conductive traces and electrodes may be
preferable because it can help shield the electromagnetic wave. In
a further embodiment, multi-layers conductive traces and electrodes
structures may be used to provide multi-channel capability and FIG.
9e shows one example of the configuration. The electromagnetic
microwaves exiting out the openings will ionize the gas at the
opening region and induce the turbulent flow. FIG. 9e shows the
openings are at in-plane direction. In one embodiment, the openings
are not limited to only in-plane direction, but may be also at
out-of-plane direction as shown in FIG. 9f.
[0043] At very high electromagnetic frequencies, the losses due to
radiation can be eliminated and the resistive losses can be
minimized, by using closed resonant cavities. A cavity resonator
stores both magnetic and electric fields, the energy oscillating
between the two, losing energy only to the conducting walls if a
perfect dielectric fills the space. The resonant frequency of the
cavity is determined by the shape of the cavity and the mode, or
allowable field distribution, of the electromagnetic energy that
the cavity contains. In one embodiment, the micro-plasma and ions
may be excited and generated by microwave cavities and varied forms
of coupling of the electromagnetic microwave may be utilized. FIG.
10 illustrates one example of the TE10 wave-guide 301 magnetically
303 coupled to a cylindrical resonator 302. The top view of the
system is shown in FIG. 10a and the side view is shown in FIG. 10b.
In this case some of the magnetic field within the cavity leaks
through an iris 305 cut into the sides of the wave-guide 301 and
the resonator walls, thereby exciting waves in the guide, the
larger the iris size, the stronger the degree of coupling. The
locations of openings 306 to excite the micro-plasma and ions may
be either on a wave-guide structure or on a cavity resonator
structure, as long as the electrical field 304 at the locations is
high enough to ionize the gas. In practical application, the
locations where the maximum electrical field 304 occurs are to be
carefully designed. In one embodiment, the shape and the geometry
of the microwave wave-guide and cavity structures may be varied. In
a further embodiment, varied forms of electromagnetic couplings may
be used to excite the micro-plasma and ions, then to induce the
turbulent flow. All the variations should be considered within the
scope of the invention here.
[0044] FIG. 11 illustrates the slots, holes, and trenches may be
made on the wall of wave-guide 307 structure to provide the
excitation of the micro-plasma and ions. Different configurations
of the wave-guide structure and varied geometries of the holes,
slot, and trenches may be used. In another embodiment, different
configurations of the microwave cavities 308 may be used to excite
the micro-plasma and ions. The location and size and geometry of
the opening 309 where maximum electrical field occur may be
computationally calculated and experimentally determined.
[0045] FIG. 12 illustrates the coupling between micro-plasma and
ions 401 and heat sink fins 402. In one embodiment, the heat sink
fins 402 may have different configurations, such as, straight
micro-channel heat sink fins, cylindrical needle-shape pins, and
the heat sink fins may have patterns to couple with micro-plasma
and ions 401. As mentioned earlier, the micro-plasma and ions 401
may be excited at the locations where the high electrical field
occurs. The coupling of the heat sink fins 402 with microwave may
enhance the micro-plasma and ions gas flow and induce the local
turbulence flow in the fluid. In another embodiment, the
micro-plasma and ions 401 may be excited and generated with
electromagnetic microwave from micro-strips, microwave cavities,
and microwave thrusters structures.
[0046] FIG. 13 illustrates one example of the micro-plasma and ions
cooling device 408 used to cool down the heat sources 405 inside an
electronic device 400. The heat source 405, such as IC, may couple
to micro-channel heat sink fins 407 through a heat transferring
pipe 406, such as heat pipe. In this way, the heat will be
dissipated out to a larger area. The micro-plasma and ions cooling
device 408 may couple to the micro-channel heat sink fins 407. The
induced plasma gas flow will therefore cool down the micro-channels
heat sink fins 407. In one embodiment, the micro-plasma and ions
may couple to a heat sink fan 411.
[0047] The micro-plasma and ions cooling actuator 408 may be made
of wave guide structure, microwave cavity structure, micro-strip
structure, and embedded conductive traces and electrodes. The
cooling actuator 408 may couple to heat sink fins at the inlet, at
the outlet, at the top, at the bottom, or in the middle of the heat
sink fins 407. In one embodiment, all components may couple to a
board 410, such as printed circuit board, so the entire device can
be made very small. In another embodiment, the actuators may be
made in a bulk scale, a micron meter scale, and a nano meter scale.
Furthermore, the actuators may be directly manufactured on a
silicon chip structure and the actuators may be manufactured with
micro-electro-mechanical wafer processing techniques;
* * * * *