U.S. patent application number 14/041276 was filed with the patent office on 2015-04-02 for heat transfer device having 3-dimensional projections and an associated method of fabrication.
This patent application is currently assigned to General Electric Company. The applicant listed for this patent is General Electric Company. Invention is credited to Pramod Chamarthy, Shakti Singh Chauhan, Tao Deng, Joo Han Kim, William Harold King.
Application Number | 20150090428 14/041276 |
Document ID | / |
Family ID | 52738948 |
Filed Date | 2015-04-02 |
United States Patent
Application |
20150090428 |
Kind Code |
A1 |
Chauhan; Shakti Singh ; et
al. |
April 2, 2015 |
HEAT TRANSFER DEVICE HAVING 3-DIMENSIONAL PROJECTIONS AND AN
ASSOCIATED METHOD OF FABRICATION
Abstract
A heat transfer device filled with a working fluid, includes a
casing and a wick disposed within the casing. The wick includes a
first sintered layer, a second sintered layer, and a third sintered
layer. The first sintered layer is disposed proximate to an inner
surface of the casing and the second sintered layer is disposed on
the first sintered layer. The second sintered layer includes a
first set of 3-dimensional sintered projections and a second set of
3-dimensional sintered projections disposed along a portion of the
wick. Further, the third sintered layer is disposed on at least a
portion of the second sintered layer. The heat transfer device
includes at least one first sintered particle of the first sintered
layer, which is smaller in size than at least one second pore of
the second sintered layer.
Inventors: |
Chauhan; Shakti Singh;
(Guilderland, NY) ; Kim; Joo Han; (Niskayuna,
NY) ; King; William Harold; (Scotia, NY) ;
Chamarthy; Pramod; (Revere, MA) ; Deng; Tao;
(Shanghai, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
52738948 |
Appl. No.: |
14/041276 |
Filed: |
September 30, 2013 |
Current U.S.
Class: |
165/104.26 ;
29/890.032 |
Current CPC
Class: |
F28D 15/046 20130101;
Y10T 29/49353 20150115 |
Class at
Publication: |
165/104.26 ;
29/890.032 |
International
Class: |
F28D 15/04 20060101
F28D015/04; B21D 53/02 20060101 B21D053/02 |
Claims
1. A heat transfer device comprising: a casing having an inner
surface and an outer surface; and a wick disposed within the
casing, wherein the wick comprises: a first sintered layer
comprising a plurality of first sintered particles, having a first
porosity and a plurality of first pores, disposed proximate to the
inner surface of the casing; a second sintered layer comprising a
plurality of second sintered particles, having a second porosity
and a plurality of second pores, disposed on the first sintered
layer, and at least one set of a first set of 3-dimensional
sintered projections and a second set of 3-dimensional sintered
projections disposed along a portion of the wick, wherein at least
one first sintered particle is smaller than at least one second
pore, the first porosity is smaller than the second porosity; and a
third sintered layer including a plurality of third sintered
particles, having a plurality of third pores and a third porosity
smaller than the second porosity, disposed on at least a portion of
the second sintered layer.
2. The heat transfer device of claim 1, wherein a size of each
third sintered particle is less than or equal to a size of each
second sintered particle.
3. The heat transfer device of claim 1, further comprising a
coating disposed between the first sintered layer and the inner
surface of the casing.
4. The heat transfer device of claim 3, wherein the casing
comprises a first material and the first sintered layer, the second
sintered layer, the third sintered layer, and the coating comprises
a second material different from the first material.
5. The heat transfer device of claim 1, wherein the heat transfer
device further comprises an evaporator section, a transport
section, and a condenser section within the casing.
6. The heat transfer device of claim 5, wherein the portion of the
wick is disposed in at least one of the evaporator section and the
condenser section.
7. The heat transfer device of claim 1, wherein the first set of
3-dimensional sintered projections extends from a first side of the
wick towards a second side of the wick.
8. The heat transfer device of claim 7, wherein the first set of
3-dimensional sintered projections enhances a surface area of the
wick and is configured to convert a working fluid from one phase to
another phase.
9. The heat transfer device of claim 1, wherein the second set of
3-dimensional sintered projections extends from a first side of the
wick to a second side of the wick.
10. The heat transfer device of claim 9, wherein the second set of
3-dimensional sintered projections provides structural support to
the heat transfer device and is configured to transport a working
fluid from the second side to the first side of the wick or vice
versa.
11. The heat transfer device of claim 1, wherein the first set of
3-dimensional sintered projections has a first width and the second
set of 3-dimensional sintered projections has a second width
greater than the first width.
12. A method comprising: forming a first wick portion having a
first sintered layer portion, a second sintered layer portion, and
a third sintered layer portion, within a first half casing portion;
forming a second wick portion having another first sintered layer
portion, another second sintered layer portion, and another third
sintered layer portion, within a second half casing portion; and
coupling the first half casing portion to the second half casing
portion such that the first wick portion is coupled to the second
wick portion to form a heat transfer device; wherein each first
sintered layer portion comprises a plurality of first sintered
particles, having a first porosity and a plurality of first pores,
each second sintered layer portion comprises a plurality of second
sintered particles, having a plurality of second pores and a second
porosity greater than the first porosity, at least one second
sintered layer portion comprises a set of 3-dimensional sintered
projections, and each third sintered layer portion comprises a
plurality of third sintered particles, having a plurality of third
pores and a third porosity, wherein at least one first sintered
particle is smaller than at least one second pore.
13. The method of claim 12, further comprising leveling a plurality
of first particles and a plurality of second particles filled in
both the first half casing portion and the second half casing
portion.
14. The method of claim 13, further comprising vibrating the first
half casing portion to segregate the plurality of first particles
from the plurality of second particles such that a first layer
portion having the plurality of first particles is disposed
proximate to an inner surface of the first half casing portion and
a second layer portion having the plurality of second particles is
disposed on the first layer portion.
15. The method of claim 14, further comprising vibrating the second
half casing portion to segregate the plurality of first particles
from the plurality of second particles such that another first
layer portion having the plurality of first particles is disposed
proximate to another inner surface of the second half casing
portion and another second layer portion having the plurality of
second particles is disposed on the other first layer portion.
16. The method of claim 15, further comprising providing a coating
between the inner surface of each casing portion among the first
and second half casing portion and each layer portion among the
first layer portion and the other first layer portion; wherein each
casing portion comprises a first material and each first layer
portion, second layer portion and the coating comprises a second
material different from the first material.
17. The method of claim 15, further comprising disposing a set of
hollow sintering spacers on a portion of at least one second layer
portion and filling an additional amount of the plurality of second
particles between the set of hollow sintering spacers to form a set
of 3-dimensional projections on the portion of the at least one
second layer portion.
18. The method of claim 17, further comprising disposing the set of
hollow sintering spacers on the portion of the corresponding second
layer portion in one casing portion among the first and second half
casing portions; wherein the set of hollow sintering spacers
comprises a first set of hollow sintering spacers and a second set
of hollow sintering spacers disposed on another second set of
hollow sintering spacers, each first set of hollow sintering spacer
has a first width, and each second set of hollow sintering spacer
has a second width.
19. The method of claim 18, further comprising filling an
additional amount of the plurality of second particles between the
first and second set of hollow sintering spacers to form a first
set of 3-dimensional projections between the first set of hollow
sintering spacers and a second set of 3-dimensional projections
between the second set of hollow sintering spacers.
20. The method of claim 19, further comprising sintering each first
layer portion, each second layer portion, and the first and second
set of 3-dimensional projections to generate the first sintered
layer portion, the other first sintered layer portion, the second
sintered layer portion, the other second sintered layer portion,
the first set of 3-dimensional sintered projections, and the second
set of 3-dimensional sintered projections.
21. The method of claim 20, further comprising coupling the first
half casing portion to the second half casing portion such that the
second set of 3-dimensional projections in one half casing portion
among the first and second half casing portion is coupled to the
corresponding second layer portion of the other half casing portion
among the first and second half casing portion.
22. The method of claim 17, further comprising disposing a first
set of hollow sintering spacers among the set of hollow sintering
spacers, on the portion of the corresponding second layer portion
in one casing portion among the first and second half casing
portions and a second set of hollow sintering spacers among the set
of hollow sintering spacers on the portion of the corresponding
second layer portion in another casing portion among the first and
second half casing portions; wherein each first set of hollow
sintering spacer has a first width and a first height and each
second set of hollow sintering spacer has a second width and a
second height; wherein second width is greater than the first width
and the second height is greater than the first height.
23. The method of claim 22, further comprising filling an
additional amount of the plurality of second particles between the
first and second set of hollow sintering spacers to form a first
set of 3-dimensional projections between the first set of hollow
sintering spacers and a second set of 3-dimensional projections
between the second set of hollow sintering spacers.
24. The method of claim 23, further comprising sintering each first
layer portion, each second layer portion, and the first and second
set of 3-dimensional projections via a sintering device, to
generate the first sintered layer portion, the other first sintered
layer portion, the second sintered layer portion, the other second
sintered layer portion, the first set of 3-dimensional sintered
projections, and the second set of 3-dimensional sintered
projections.
25. The method of claim 24, further comprising coupling the first
half casing portion to the second half casing portion such that the
second set of 3-dimensional projections on the portion of the
corresponding second layer portion in the other casing portion
among the first and second half casing portions is coupled to the
portion of corresponding second layer portion of the one half
casing portion among the first and second half casing portions.
26. The method of claim 17, further comprising disposing another
set of hollow sintering spacers on at least a portion of the set of
3-dimensional sintered projections, filling a plurality of third
particles on at least the portion of each second sintered layer
portion and between the other set of hollow sintering spacers to
form a third layer portion.
27. The method of claim 26, further comprising sintering the third
layer portion to generate the third sintered layer portion, wherein
the third porosity is smaller than the second porosity.
Description
BACKGROUND
[0001] The present disclosure relates generally to a heat transfer
device and more particularly, to a vapor chamber or a heat pipe
having 3-dimensional sintered projections, a spatially controlled
porosity or pore size, and an associated method of fabrication.
[0002] A heat transfer device is used to transfer heat from a
source to a sink. Such heat transfer devices may include a hot
region and a cold region to enable transfer of the heat from the
hot region to the cold region. Generally, the heat transfer device
combines the principle of a thermal conductivity and a phase
transition of a working fluid to transfer the heat. In one example,
the heat transfer device is a sealed tube or a sealed chamber,
fabricated using a material having a high thermal conductivity. The
heat transfer device includes the working fluid within the sealed
chamber to transfer the heat effectively. Typically, such heat
transfer device may further include a wick to enable heat transfer
by condensation and evaporation of the working fluid i.e. by
changing phase of the working fluid within the sealed chamber.
[0003] The conventional wick includes a plurality of mono-dispersed
sintered particles distributed along a longitudinal direction of
the heat transfer device. Typically, wicks are also designed to
provide a high fluid transport and phase change capability of the
working fluid. Such functions are achieved by designing the wick
having very large pores combined with a large surface area, for
facilitating phase change of the working fluid. However, such
conventional wicks are less effective in performing phase change of
the working fluid, because the design and fabrication processes
involve use of mono-dispersed particles. Further, such a wick
structure provides higher solid conduction thermal resistance due
to low contact area with the chamber walls.
[0004] Such limitations can be addressed by designing the wick,
having pore size variation through the use of varying particle
sizes. However, the wicks that are designed with varying particle
sizes are fabricated using an organic carrier which is burned
completely to generate the sintered particles having varied pore
size and/or varied porosity. Such fabrication processes may result
in contamination of the heat transfer device, limit the wick
fabrication temperature to a high value to burn-away the organics,
and may also lead to generation of a non-condensable fluid during
prolonged operation of the heat transfer device.
[0005] Further, the wick having dissimilar material is used to
reduce the thermal resistance and increase evaporation limit of the
heat transfer device. However, such wicks may require complex
processes to fabricate, may undergo galvanic corrosion, and may not
be very effective in reducing the thermal resistance and increasing
evaporation limit in the heat transfer device.
[0006] Thus, there is a need for an improved heat transfer device
and a method for fabricating the heat transfer device.
BRIEF DESCRIPTION
[0007] In accordance with one exemplary embodiment, a heat transfer
device is disclosed. The heat transfer device includes a casing and
a wick disposed within the casing. The wick includes a first
sintered layer disposed proximate to an inner surface of the casing
and a second sintered layer disposed on the first sintered layer.
The first sintered layer includes a plurality of first sintered
particles, having a first porosity and a plurality of first pores.
The second sintered layer includes a plurality of second sintered
particles, having a second porosity and a plurality of second
pores. The second sintered layer further includes at least one set
among a first set of 3-dimensional sintered projections and a
second set of 3-dimensional sintered projections disposed along a
portion of the wick. At least one first sintered particle is
smaller than at least one second pore and the first porosity is
smaller than the second porosity The wick further includes a third
sintered layer disposed on at least a portion of the second
sintered layer. The third layer includes a plurality of third
sintered particles, having a third porosity and a plurality of
third pores.
[0008] In accordance with one exemplary embodiment, a method for
manufacturing a heat transfer device is disclosed. The method
includes forming a first wick portion within a first half casing
portion and a second wick portion within a second half casing
portion. The first wick portion includes a first sintered layer
portion, a second sintered layer portion, and a third sintered
layer portion. The second wick portion includes another first
sintered layer portion, another second sintered layer portion, and
another third sintered layer portion. Each first sintered layer
portion includes a plurality of first sintered particles, having a
first porosity and a plurality of first pores. Each second sintered
layer includes a plurality of second sintered particles, having a
plurality of second pores and a second porosity. The second
sintered layer further includes at least one set among a first set
of 3-dimensional sintered projections and a second set of
3-dimensional sintered projections disposed along a portion of the
wick. Each third sintered layer portion includes a plurality of
third sintered particles, having a plurality of third pores and a
third porosity. The method further includes coupling the first half
casing portion to the second half casing portion such that the
first wick portion is coupled to the second wick portion to form a
heat transfer device. The fabricated heat transfer device includes
at least one first sintered particle smaller than at least one
second pore. Further, the second porosity is greater than the first
porosity and the third porosity is smaller than the second
porosity.
DRAWINGS
[0009] These and other features and aspects of embodiments of the
present disclosure will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0010] FIG. 1 is a schematic sectional view of a heat transfer
device, for example a heat pipe, in accordance with an exemplary
embodiment;
[0011] FIG. 2 is a schematic sectional view of a portion of a wick
disposed within a heat pipe in accordance with the exemplary
embodiment of FIG. 1;
[0012] FIG. 3 is a schematic view of a portion of a wick of FIGS. 1
and 2, having a plurality of first sintered particles, a plurality
of second sintered particles, and a plurality of third sintered
particles in accordance with an exemplary embodiment;
[0013] FIG. 4a is a top view of a schematic heat transfer device,
for example a vapor chamber in accordance with an exemplary
embodiment;
[0014] FIG. 4b is a schematic side view of a vapor chamber of FIG.
4a, in accordance with an exemplary embodiment;
[0015] FIG. 5a is a schematic flow diagram illustrating a method
for manufacturing a first wick portion within a first half casing
portion in accordance with an exemplary embodiment;
[0016] FIG. 5b is a schematic flow diagram illustrating the method
for manufacturing the first wick portion within the first half
casing portion in accordance with an exemplary embodiment of FIG.
5a;
[0017] FIG. 6a is a schematic flow diagram illustrating a method
for manufacturing a second wick portion within a second half casing
portion in accordance with an exemplary embodiment;
[0018] FIG. 6b is a schematic flow diagram illustrating the method
for manufacturing the second wick portion within the second half
casing portion in accordance with an exemplary embodiment of FIG.
6a;
[0019] FIG. 7 is a schematic flow diagram illustrating a method for
manufacturing a heat transfer device by coupling a first half
casing portion to a second half casing portion in accordance with
the exemplary embodiments of FIGS. 5a, 5b, 6a, and 6c;
[0020] FIG. 8a is a schematic flow diagram illustrating a method
for manufacturing a heat transfer device in accordance with another
exemplary embodiment;
[0021] FIG. 8b is a schematic flow diagram illustrating the method
for manufacturing the heat transfer device in accordance with the
exemplary embodiment of FIG. 8a;
[0022] FIG. 8c is a schematic flow diagram illustrating the method
for manufacturing the heat transfer device in accordance with the
exemplary embodiments of FIGS. 8a and 8b;
[0023] FIG. 8d is a schematic flow diagram illustrating the method
for manufacturing the heat transfer device in accordance with the
exemplary embodiments of FIGS. 8a, 8b, and 8c;
[0024] FIG. 9a is a schematic flow diagram illustrating a method
for manufacturing a heat transfer device in accordance with yet
another exemplary embodiment;
[0025] FIG. 9b is a schematic flow diagram illustrating the method
for manufacturing the heat transfer device in accordance with the
exemplary embodiment of FIG. 9a; and
[0026] FIG. 9c is a schematic flow diagram illustrating the method
for manufacturing the heat transfer device in accordance with the
exemplary embodiments of FIGS. 9a and 9b.
DETAILED DESCRIPTION
[0027] While only certain features of embodiments have been
illustrated and described herein, many modifications and changes
will occur to those skilled in the art. It is, therefore, to be
understood that the appended claims are intended to cover all such
modifications and changes as falling within the spirit of the
invention.
[0028] Embodiments discussed herein disclose heat transfer devices
and associated methods of manufacturing the heat transfer devices.
More particularly, certain embodiments disclose a heat pipe. The
heat pipe includes a casing and a wick disposed within the casing.
The wick includes a first sintered layer, a second sintered layer,
and a third sintered layer. The first sintered layer includes a
plurality of first sintered particles having a first porosity and a
plurality of first pores. The first sintered layer is disposed
proximate to the inner surface of the casing. The second sintered
layer includes a plurality of second sintered particles having a
second porosity and a plurality of second pores. The second
sintered layer is disposed on the first sintered layer. The second
sintered layer further includes a set of 3-dimensional projections
disposed on a portion of the second sintered layer. The third
sintered layer includes a plurality of third sintered particles
having a third porosity and a plurality of third pores. At least
one first sintered particle is smaller than at least one second
pore, the first porosity is smaller than the second porosity, and
the third porosity is smaller is than second porosity.
[0029] Certain embodiments disclose a method of manufacturing a
heat transfer device. More specifically, certain embodiments
disclose a method of manufacturing a vapor chamber. The method
includes forming a first wick portion having a first sintered layer
portion, a second sintered layer portion, and third sintered layer
portion within a first half casing portion. Further, the method
includes forming a second wick portion having another first
sintered layer portion, another second sintered layer portion, and
another third sintered layer portion within a second half casing
portion. The method further includes coupling the first half casing
portion to the second half casing portion such that the first wick
portion is coupled to the second wick portion to form a heat
transfer device. Each first sintered layer portion includes a
plurality of first sintered particles, having a first porosity and
a plurality of first pores. Each second sintered layer portion
includes a plurality of second sintered particles, having a
plurality of second pores and a second porosity. At least one
second sintered layer portion includes a set of 3-dimensional
sintered projections. Each third sintered layer portion includes a
plurality of third sintered particles, having a plurality of third
pores and a third porosity. Further, at least one first sintered
particle is smaller than at least one second pore.
[0030] FIG. 1 is a schematic sectional view of a heat transfer
device 100. In the illustrated embodiment, the heat transfer device
100 is a heat pipe. It should be noted herein that the terms "heat
transfer device" and "heat pipe" are used interchangeably. In some
other embodiments, the heat transfer device is a vapor chamber.
[0031] The heat pipe 100 includes a casing 102 and a wick 104.
Further, the heat pipe 100 includes a sealed chamber 106 enclosed
by the wick 104 and a working fluid 108 filled within the sealed
chamber 106. The working fluid 108 transfers heat from one region
116 to another region 118 of the heat pipe 100. Further, the heat
pipe 100 includes an evaporator section 110 disposed proximate to
the region 116, a condenser section 112 disposed proximate to the
other region 118, and a transport section 114 disposed between the
evaporator section 110 and the condenser section 112. The
evaporator section 110 is configured to absorb heat from a source
(not shown in FIG. 1) by evaporating the working fluid 108. The
condenser section 112 is configured to release heat to a sink (not
shown in FIG. 1) by condensing the working fluid 108. The transport
section 114 is configured to conduct the heat from one region 116
to the other region 118 via the working fluid 108. The heat pipe
100 is fabricated using a material having high thermal
conductivity. The material may include copper or aluminum nitrate,
for example. The heat pipe 100 has a rectangular shape and has a
length "L.sub.1" in a range of five millimeters to ten meters, for
example.
[0032] The casing 102 includes a first half casing portion 102a and
a second half casing portion 102b. Each half casing portion 102a,
102b includes an inner surface 120 and an outer surface 122. Each
half casing portion 102a, 102b has a U-shape. The first half and
second half casing portions 102a, 102b are coupled to each other by
welding, brazing, soldering, or the like. The wick 104 is disposed
proximate to the inner surface 120 of the casing 102. The wick 104
includes a first sintered layer 126, a second sintered layer 128,
and a third sintered layer 130. Specifically, the first sintered
layer 126 is disposed proximate to the inner surface 120 of the
casing 102. The second sintered layer 128 is disposed on the first
sintered layer 126. The second sintered layer 128 includes at least
one of a first set of 3-dimensional sintered projections 132 and a
second set of 3-dimensional sintered projections 134. The first and
second set of 3-dimensional sintered projections 132, 134 are
disposed along a portion of the wick 104 corresponding to the
evaporator section 110, for example. The third sintered layer 130
is disposed on at least a portion of the second sintered layer 128
corresponding to the evaporator section 110, for example.
[0033] The wick 104 includes a first wick portion 104a and a second
wick portion 104b. Specifically, the first wick portion 104a
includes the first sintered layer portion 126a, the second sintered
layer portion 128a, and the third sintered layer portion 130a. The
second wick portion 104b includes another first layer portion 126b,
another second sintered layer portion 128b, and another third
sintered layer portion 130b. The first, second, and third sintered
layers 126, 128, 130 have a uniform thickness "T.sub.1", "T.sub.2",
and "T.sub.3" respectively along the length "L.sub.1" of the heat
pipe 100. In another embodiment, the first, second, and third
sintered layers 126, 128, 130 may have a non-uniform thickness
along the length "L.sub.1" of the heat pipe 100. The thickness may
vary along the evaporator section 110, the condenser section 112
and the transport section 114 of the heat pipe 100. The casing 102
is made of a first material and the first sintered layer 126, the
second sintered layer 128, and the third sintered layer are made of
a second material. The casing 102, the first sintered layer 126,
and the second sintered layer 128 are made of the same material.
The first, second, and third sintered layers 126, 128, 140 are made
of a material having high thermal conductivity, such as copper,
aluminum nitrate, or the like.
[0034] FIG. 2 is a schematic sectional view of a portion of the
wick 104 corresponding to the evaporator section 110 of the heat
pipe 100 in accordance with the embodiment of FIG. 1.
[0035] The wick 104 includes the first set of 3-dimensional
sintered projections 132 extending from a first side 136 of the
wick 104 towards a second side 138 of the wick 104. Further, the
wick 104 includes the second set of 3-dimensional sintered
projections 134 extending from the first side 136 to the second
side 138 of the wick 104. The first and second set of 3-dimensional
sintered projections 132, 134 is spaced apart from each other by a
distance "D.sub.1" along a longitudinal direction. The first set of
3-dimensional projections 132 and the second set of 3-dimensional
projections 134 are disposed alternately. The position of the first
set of 3-dimensional projections 132 and the second set of
3-dimensional projections 134 may vary depending on the application
and design criteria. The third sintered layer 130 is disposed on
the first and second set of 3-dimensional sintered projections 132,
134, at the evaporator section 110. In other embodiments, the wick
104 may not include the third sintered layer 130.
[0036] The first set of 3-dimensional sintered projections 132
enhances a surface area of the wick 104. The first set of
3-dimensional sintered projections is configured to convert the
working fluid 108 from one phase to another phase, for example,
from a liquid phase to gaseous phase. The first set of
3-dimensional sintered projections 132 increases a surface area at
the evaporator section 110 to absorb the heat from the sink (not
shown). The second set of 3-dimensional sintered projections 134 is
configured to transport the working fluid 108 from the second side
138 to the first side 136 of the wick 104. Further, the second set
of 3-dimensional projections 134 provides structural support to the
heat transfer device 100 so as to prevent mechanical deformation,
vibration, shock loading and temperature excursions during
assembling or operation of the heat transfer device 100. In another
embodiment, the second set of 3-dimensional projections 134
includes solid projections integrated to the casing 102. The second
set of 3-dimensional sintered projections 134 enhances
transportation of the working fluid 108 at the evaporator section
110. In other embodiments, the working fluid 108 may be transported
from the first side 136 to the second side 138 of the wick 104 via
the second set of 3-dimensional sintered projections 134. The first
set of 3-dimensional sintered projections 132, the second set of
3-dimensional sintered projections 134, and the third sintered
layer 130 may be disposed at the condenser section 112 of the heat
pipe 100.
[0037] FIG. 3 is a schematic view of a portion of the wick 104 in
accordance with the exemplary embodiments of FIGS. 1 and 2. As
discussed previously, the wick 104 includes the first sintered
layer 126, the second sintered layer 128, and the third sintered
layer 130. The first sintered layer 126 includes a plurality of
first sintered particles 148, the second sintered layer 128
includes a plurality of second sintered particles 150, and the
third sintered layer 130 includes a plurality of third sintered
particles 152. Further, the first sintered layer 126 has a
plurality of first pores 154 and a first porosity 156, the second
sintered layer 128 has a plurality of second pores 158 and a second
porosity 160, and the third sintered layer 130 has a plurality of
third pores 162 and a third porosity 164.
[0038] Each first sintered particle 148 has a size "S.sub.1", each
second sintered particle 150 has a size "S.sub.2", and each third
sintered particle 152 has a size "S.sub.3". Further, each first
pore 154 has a size "S.sub.4", each second pore 158 has a size
"S.sub.5" and each third pore 162 has a size "S.sub.6". Each first
sintered particle 148 has the size "S.sub.1" in a range of hundred
nanometers to fifty micrometers, each second sintered particle 150
has the size "S.sub.2" in a range of ten micrometers to hundred
micrometers, and each third sintered particle 152 has the size
"S.sub.3" in a range of hundred nanometers to ten micrometers. The
size "S.sub.2" of each second sintered particle 150 is greater than
the size "S.sub.1" of each first sintered particle 148 and the size
"S.sub.3" of each third sintered particle 152 is smaller or equal
to the size "S.sub.2" of each second sintered particle 150. Each
first sintered particle 148, each second sintered particle 150, and
each third sintered particle 152 may have a spherical or oval or
circular shape.
[0039] The size "S.sub.1" of each first sintered particle 148 is
smaller than the size "S.sub.5" of each second pore 158. The size
"S.sub.1" of the first sintered particle 148 is at least twenty to
eighty percent smaller than the size "S.sub.5" of the plurality of
second pores 158. The first sintered particle 148 having a
relatively smaller size than the second pore 158 enhances heat
transfer capability and reduces thermal resistance along the
longitudinal direction of the heat pipe 100.
[0040] Further, each first pore 154 has the size "S.sub.4" in a
range of ten nanometers to ten micrometers, each second pore 158
has the size "S.sub.5" in a range of one micrometer to fifty
micrometers, and each third pore 162 has a size "S.sub.6" in the
range of one nanometer to ten micrometers.
[0041] The first porosity 156 of the first sintered layer 126, the
second porosity 160 of the second sintered layer 128, and third
porosity 164 of the third sintered layer 130 are in a range of five
percent to eighty percent. The first porosity 156 is smaller than
the second porosity 160 and the third porosity 164 is smaller than
the second porosity 160. The second layer 128 having a relatively
greater second porosity 152 facilitates to exert higher capillary
pressure on the working fluid along the longitudinal direction of
the heat pipe 100.
[0042] FIG. 4a is a top view of a heat transfer device 101, for
example a vapor chamber, in accordance with another exemplary
embodiment. It should be noted herein that the terms "heat transfer
device" and the "vapor chamber" are used interchangeably.
[0043] The vapor chamber 101 includes a casing 103 and a wick (not
shown in FIG. 4a) disposed within the casing 103. The vapor chamber
101 includes an evaporator section 165, a condenser section 167,
and a transport section 169. The evaporator section 165 is
configured to absorb heat from a source (not shown in FIG. 4a) by
evaporating the working fluid (not shown in FIG. 4a). The condenser
section 167 is configured to release heat to a sink (not shown in
FIG. 4a) by condensing the working fluid. The transport section 169
is configured to conduct the heat from the evaporator section 165
to the condenser 167 and vice versa, via the working fluid. The
vapor chamber 101 includes two condenser sections 167 disposed at
either ends 171, 173 of the vapor chamber 101.
[0044] FIG. 4b is a schematic side view along a section 4b-4b of
the vapor chamber 101 in accordance with the exemplary embodiment
of FIG. 4a. The vapor chamber 101 includes the wick 105 disposed
proximate to an inner surface 121 of the casing 103. The wick 105
includes a first sintered layer 127, a second sintered layer 129,
and a third sintered layer 131. The second sintered layer 129
includes a first set of 3-dimensional sintered projections 133 and
a second set of 3-dimensional sintered projections 135 disposed on
a portion of the wick 105. The portion of the wick corresponds to
the evaporator section 165 and the condenser section 167. The first
set of 3-dimensional sintered projections 133 are disposed at the
evaporator section 165 and extend from a first side 137 towards a
second side 139 of the wick 105. The second set of 3-dimensional
projections 135 are disposed at the evaporator section 165 and the
condenser section 167 and extend from the first side 137 to the
second side 139 of the wick 105. The third sintered layer 131 is
disposed on the second sintered layer 129 and the first and second
set of 3-dimensional sintered projections 133, 135.
[0045] A coating 175 is disposed between the inner surface 121 of
the casing 103 and the first sintered layer 127. The coating 175
may include one or more layers depending on the application and
design criteria. The casing 103 may be made of a material having
higher thermal conductivity, for example, aluminum nitrate. The
coating 175 and the wick 105 may be also made of a material having
high thermal conductivity, for example copper. The casing 103 may
be made of a first material and the coating 175, the first sintered
layer 127, the second sintered layer 129, and the third sintered
layer 131 made of a second material different from the first
material.
[0046] FIG. 5a is a schematic flow diagram illustrating a plurality
of steps involved in a method 176 of manufacturing the first
sintered layer portion 126a, the second sintered layer portion
128a, the set of 3-dimensional projections 132, and the third
sintered layer portion 130a within the first half casing portion
102a in accordance with the embodiment of FIG. 1.
[0047] The method 176 includes a step 178 of disposing the first
half casing portion 102a. Further, the method 176 includes a step
180 of applying a coating portion 175a on the inner surface 120 of
the first half casing portion 102a. A plurality of first particles
182 and a plurality of second particles 184 are filled in the first
half casing portion 102a. The first half casing portion 102a is
made of a first material and the coating portion 175a, the
plurality of first particles 182, and the plurality of second
particles 184 includes a second material different from the first
material.
[0048] In another embodiment, a coating portion 175a may not be
applied to the inner surface 120 of the first half casing portion
102a and the plurality of particles 182, 184 are filled directly
within the first half casing portion 102a such that the plurality
of particles 182, 184 are in contact with the inner surface 120 of
the first half casing portion 102a. The first half casing portion
102a, the plurality of first particles 182, and the plurality of
second particles 184 include same material.
[0049] A step 186 includes leveling the plurality of first
particles 182 and the plurality of second particles 184 within the
first half casing portion 102a. The plurality of first and second
particles 182, 184 is leveled using a squeegee device 188. A
uniform contact surface 190 of the squeegee device 188 is used to
level the plurality of first particles 182 and the plurality of
second particles 184 to generate a uniform thickness. The squeegee
device 188 may be made of a material including nickel-cobalt
ferrous alloy or ceramics such as aluminum nitrate, alumina,
silicon carbide, silicon nitride, or the like.
[0050] The method 176 further includes a step 192 of vibrating the
first half casing portion 102a to segregate the plurality of first
particles 182 from the plurality of second particles 184 such that
a first layer portion 194a and a second layer portion 196a are
formed within the first half casing portion 102a. The first half
casing portion 102a is vibrated via a vibrator device 198. The
vibrator device 198 is clamped to the first half casing portion
102a and powered via mechanical elements to vibrate the first half
casing portion 102a. The first layer portion 194a having the
plurality of first particles 182 is disposed proximate to the inner
surface 120 of the first half casing portion 102a and the second
layer portion 196a having the plurality of second particles 184 is
disposed on the first layer portion 194a. The first layer portion
194a has a uniform thickness "T.sub.01" and the second layer
portion 196a has a uniform thickness "T.sub.02".
[0051] The method 176 further includes a step 200 of disposing a
set of hollow sintering spacers 202 on the second layer portion
196a. Each spacer 202 has a uniform contact surface 204 contacting
the second layer portion 196a. At step 206, an additional amount of
the plurality of second particles 184 is filled between the hollow
sintering spacers 202 to form a set of 3-dimensional projections
208, also referred to as a first set of 3-dimensional projections.
Further, a step 210 includes disposing a sintering weight 212 on
the set of hollow sintering spacers 202 to level the plurality of
second particles 184 filled between the hollow sintering spacers
202. At step 214, an additional amount of the plurality of second
particles 184 is filled in a gap between the hollow sintering
spacers 202 and a side 216 of the inner surface 120.
[0052] FIG. 5b is a schematic flow diagram illustrating a plurality
of steps involved in the method 176 of manufacturing the first
sintered layer portion 126a, the second sintered layer portion
128a, the set of 3-dimensional projections 132, and the third
sintered layer portion 130a within the first half casing portion
102a in accordance with the embodiment of FIG. 5a. The method 176
further includes a step 222 of sintering the first layer portion
194a and the second layer portion 196a. The step 222 includes
disposing the first half casing portion 102a with the set of hollow
sintering spacers 202 and sintering weight 212 in a sintering
device 224 to sinter the first layer portion 194a and the second
layer portion 196a so as to generate the first sintered layer
portion 126a and the second sintered layer portion 128a having a
set of 3-dimensional sintered projections 132, also referred to as
the first set of 3-dimensional sintered projections, as shown in
step 226. The first sintered layer portion 126a and the second
sintered layer portion 128a have a uniform thickness. The first
sintered layer portion 126a has a thickness "T.sub.1" and the
second sintered layer portion 128a has a thickness "T.sub.2".
[0053] The first sintered layer portion 126a includes the plurality
of first sintered particles 148 having the first porosity 156 and
the plurality of first pores 154 (as shown in FIG. 3). The second
sintered layer portion 128a includes the plurality of second
sintered particles 150 having the plurality of second pores 158 and
the second porosity 160 (as shown in FIG. 3). The sintering step
222 is performed in a controlled environment i.e. at a temperature
and pressure so as to generate at least one first sintered particle
smaller than at least one second pore. The sintering process may be
controlled to generate at least twenty to eighty percent of the
first sintered particles having a size smaller than the plurality
of second pores. The sintering pressure is in the range of 50 bars
to 60 bars and the sintering temperature is in the range of 648.89
degrees Celsius to 815.56 degrees Celsius. The set of hollow
sintering spacers 202 may be made of a material including
nickel-cobalt ferrous alloy or ceramics such as aluminum nitrate,
alumina, silicon carbide, and silicon nitride.
[0054] Further, the step 226 includes removing the set of hollow
sintering spacers 202 and the sintering weight 212 from the first
half casing portion 102a.
[0055] The method 176 further includes a step 230 of filling a
plurality of third particles 232 on the second sintered layer
portion 128a i.e. between the first set of 3-dimensional sintered
projections 132. Further, at step 234 the plurality of third
particles 232 are leveled using another squeegee device 236 having
a uniform contact surface 238, so as to form a third layer portion
240a having a uniform thickness "T.sub.03".
[0056] The method 176 further includes a step 242 of disposing
another set of hollow sintering spacers 244 on the third layer
portion 240a and filling an additional amount of plurality of third
particles 232 between the set of hollow sintering spacers 244.
[0057] The method 176 further includes a step 250 of sintering the
third layer portion 240a along with the additional amount of
plurality of third particles 232. The sintering step 250 includes
disposing the first half casing portion 102a with the set of hollow
sintering spacers 244 in the sintering device 224 to generate the
third sintered layer portion 130a as shown in step 254. Each hollow
sintering spacer 244 has a uniform contact surface 252 to generate
the third sintered layer portion 130a having the uniform thickness
"T.sub.3". The third sintered layer portion 130a includes the
plurality of third sintered particles 152 having the third porosity
164 and the plurality of third pores 162 (as shown in FIG. 3). The
sintering process is performed in a controlled environment so as to
generate the third porosity 164 smaller than the second porosity
160 and the third sintered particles 152 having a size less than or
equal to the size of the second sintered particle 150.
[0058] Further, the step 254 includes removing the set of hollow
sintering spacers 244 from the first half casing portion 102a. A
first wick portion 104a is formed in the first half casing portion
102a. The first wick portion 104a includes the first sintered layer
portion 126a, the second sintered layer portion 128a having the
first set of 3-dimensional sintered projections 132, and the third
sintered layer portion 130a.
[0059] FIG. 6a is a schematic flow diagram illustrating a plurality
of steps involved in a method 258 of manufacturing the first
sintered layer portion 126b, the second sintered layer portion
128b, and the third sintered layer portion 130b within the second
half casing portion 102b in accordance with the embodiment of FIGS.
1 and 5.
[0060] The method 258 includes a step 260 of repeating the steps
178, 180, 186, and 192 in the second half casing portion 102b to
form the first layer portion 194b and the second layer portion 196b
within the second half casing portion 102b. The first layer portion
194b is disposed on another coating portion 175b. The coating
portion 175b may be applied to the inner surface 120 of the second
half casing portion 102b. The first layer portion 194b has a
uniform thickness "T.sub.01" and the second layer portion 196b has
a uniform thickness "T.sub.02".
[0061] The method 258 further includes a step 262 of disposing a
sintering weight 264 on the second sintered layer portion 196b. The
method further includes disposing the second half casing portion
102b along with the sintering weight 264 in the sintering device
224 to sinter the first layer portion 194b and the second layer
portion 196b so as to generate the first sintered layer portion
126b and the second sintered layer portion 128b as shown in step
266. The first sintered layer portion 126b and the second sintered
layer portion 128b has a uniform thickness. The first sintered
layer portion 126b has the thickness "T.sub.1" and the second
sintered layer portion 128b has the thickness "T.sub.2".
[0062] Further, the step 266 includes removing the sintering weight
264 from the second half casing portion 102b. The step 266 further
includes disposing another set of hollow sintering spacers 244 on
the second sintered layer portion 128b.
[0063] FIG. 6b is a schematic flow diagram illustrating a plurality
of steps involved in the method 258 of manufacturing the first
sintered layer portion 126b, the second sintered layer portion
128b, and the third sintered layer portion 130b within the second
half casing portion 102b in accordance with the embodiment of FIG.
6a. The method 258 further includes a step 268 of filling the
plurality of third particles 232 between the set of hollow
sintering spacers 244 so as to form another third layer portion
248b. The method 258 further includes a step 270 of sintering the
other third layer portion 248b. The sintering step 270 includes
disposing the second half casing portion 102b with the set of
hollow sintering spacers 244 in the sintering device 224 to sinter
the third layer portion 248b so as to generate the third sintered
layer portion 130b as shown in step 272. The third sintered layer
portion 130b has a uniform thickness "T.sub.3". Further, the step
272 includes removing the set of hollow sintering spacers 244. A
second wick portion 104b is formed in the second half casing
portion 102b.
[0064] FIG. 7 is a schematic flow diagram illustrating a plurality
of steps involved in a method 274 of coupling the first half casing
portion 102a to the second half casing portion 102b to form the
heat transfer device 100 in accordance with the embodiments of
FIGS. 5a, 5b, 6a, and 6b.
[0065] The method 274 includes a step 276 of disposing the first
half casing portion 102a having the first wick portion 104a. The
method 274 further includes a step 278 of disposing the second half
casing portion 102b having the second wick portion 104b. Further,
the method 274 includes a step 280 of coupling the first half
casing portion 102a to the second half casing portion 102b such
that the first wick portion 104a is coupled to the second wick
portion 104b to form the heat transfer device 100. A sealed chamber
106 is formed between the first half casing portion 102a and the
second half casing portion 102b. The first set of 3-dimensional
sintered projections 132 extends from one side 136 of the wick 104
towards other side 138 of the wick 104. The first half and second
half casing portions 102a, 102b are coupled to each other by
welding, brazing, soldering, or the like.
[0066] FIG. 8a is a schematic flow diagram illustrating a method
300 of manufacturing a heat transfer device 399 in accordance with
another exemplary embodiment.
[0067] The method 300 includes a step 302 of forming a first layer
portion 304a and a second layer portion 306a within a first half
casing portion 308a. The first layer portion 304a includes a
plurality of first particles 310 and is disposed proximate to a
coating portion 314a of the first half casing portion 308a. The
second layer portion 306a includes a plurality of second particles
312 and is disposed on the first layer portion 304a. The method 300
further includes a step 316 of disposing a first set of hollow
sintering spacers 318 and a second set of hollow sintering spacers
320 on the second layer portion 306a. Each hollow sintering spacer
318 has a width "W.sub.1" and each hollow sintering spacer 320 has
a width "W.sub.2" greater than width "W.sub.1". At step 324, an
additional amount of the plurality of second particles 312 is
filled between the first and second set of hollow sintering spacers
318, 320 to form a first set of 3-dimensional projections 326 and a
second set of 3-dimensional projections 328. Further, a step 330
includes disposing a second set of hollow sintering spacers 332 on
the first and second set of hollow sintering spacers 318, 320. Each
hollow sintering spacer 332 has a width "W.sub.3" equal or greater
than the width "W.sub.2" of each hollow sintering spacer 320.
[0068] FIG. 8b is a schematic flow diagram illustrating the method
300 of manufacturing the heat transfer device 399 in accordance
with the exemplary embodiment of FIG. 8a. At step 334, an
additional amount of the plurality of second particles 312 is
filled between the second set of hollow sintering spacers 332 to
form the second set 3-dimensional projections 336. The second set
of 3-dimensional projections 328, 336 together form a second set of
3-dimensional projections 338.
[0069] The method 300 further includes a step 342 of sintering
first layer portion 304a, the second layer portion 306a, and the
first and second set of 3-dimensional projections 326, 338 in a
sintering device 344 so as to generate the first sintered layer
portion 346a and the second sintered layer portion 348a having a
first set of 3-dimensional sintered projections 350 and second set
of 3-dimensional sintered projections 352 as shown in step 354. The
first set of 3-dimensional sintered projections 350 has a length
"L.sub.1" and the second set of 3-dimensional sintered projections
352 has a length "L.sub.2". The length "L.sub.2" is greater than
the length "L.sub.1". Further, the step 354 includes removing the
first and second set of hollow sintering spacers 318, 320, 332 from
the first half casing portion 308a.
[0070] FIG. 8c is a schematic flow diagram illustrating the method
300 of manufacturing the heat transfer device 399 in accordance
with the exemplary embodiments of FIGS. 8a and 8b. The method 300
further includes a step 358 of filling a plurality of third
particles 360 on the second sintered layer portion 348a so as to
form a portion of a third layer portion 362 i.e. between the first
and second 3-dimensional sintered projections 350, 352. The method
300 further includes a step 364 of disposing another set of hollow
sintering spacers 366 on the third layer portion 362 and the second
set of 3-dimensional sintered projections 352 and then fill an
additional amount of a plurality of third particles 360 between the
set of hollow sintering spacers 366 so as to form a third layer
portion 368. The layer portions 362, 368 together form a third
layer portion 370a. Each hollow sintering spacer 366 has a width
"W.sub.4", which is greater than the width "W.sub.2" or
"W.sub.3".
[0071] The method 300 further includes a step 374 for sintering the
third layer portion 370a. The sintering step 374 includes disposing
the first half casing portion 308a with the set of hollow sintering
spacers 366 in the sintering device 344 to sinter the third layer
portion 370a so as to generate a third sintered layer portion 376a
as shown in step 378. Further, the step 378 includes removing the
set of hollow sintering spacers 366 from the first half casing
portion 308a. The first sintered layer portion 346a, the second
sintered layer portion 348a having the first and second set of
3-dimensional sintered projections 350, 352, and the third sintered
layer portion 376a together form the first wick portion 380a
disposed within the first half casing portion 308a.
[0072] FIG. 8d is a schematic flow diagram illustrating the method
300 of manufacturing the heat transfer device 399 in accordance
with the exemplary embodiments of FIGS. 8a, 8b, and 8c. The method
300 further includes a step 382 of forming another first sintered
layer portion 346b and another second sintered layer portion 348b
within a second half casing portion 308b. The method 300 further
includes a step 384 of filling the plurality of third particles 360
on the second sintered layer portion 348b so as to form another
third layer portion 370b. The method 300 further includes disposing
a sintering weight 386 on the third layer portion 370b and then
sintering the third layer portion 370b via the sintering device 344
so as to generate another third sintered layer portion 376b as
shown in step 388. The first sintered layer portion 346b, the
second sintered layer portion 348b, and the third sintered layer
portion 376b together form a second wick portion 380b disposed
within the second half casing portion 308b.
[0073] The method 300 further includes a step 390 of disposing the
first half casing portion 308a having the first wick portion 380a.
The method 300 further includes a step 392 of disposing the second
half casing portion 308b having the second wick portion 380b.
Further, the method 300 includes a step 394 for coupling the first
half casing portion 308a to the second half casing portion 308b
such that the first wick portion 380a is coupled to the second wick
portion 380b to form the heat transfer device 399. The sealed
chamber 375 is formed between the first half casing portion 308a
and the second half casing portion 308b. The first wick portion
380a and the second wick portion 380b together form a wick 380. The
first set of 3-dimensional sintered projections 350 extend from one
side 396 towards another side 398 of the wick 380. The second set
of 3-dimensional sintered projections 352 extend from one side 396
to the other side 398 of the wick 380. The first half and second
half casing portions 308a, 308b are coupled to each other by
welding, brazing, soldering, or the like.
[0074] FIG. 9a is a schematic flow diagram illustrating a method
400 of manufacturing a heat transfer device 499 in accordance with
yet another exemplary embodiment.
[0075] The method 400 includes a step 402 of forming a first layer
portion 404a and a second layer portion 406a within a first half
casing portion 408a. The first layer portion 404a includes a
plurality of first particles 410 disposed proximate to a coating
portion 414a of the first half casing portion 408a. The coating
portion 414a is disposed on the inner surface 407 of the first half
casing portion 408a. The second layer portion 406a includes a
plurality of second particles 412 disposed over the first layer
portion 404a. The step 402 further includes disposing a first set
of hollow sintering spacers 418 on the second layer portion 406a.
The first set of hollow sintering spacers 418 has a width "W.sub.1"
and length "L.sub.1". The method further includes a step 416 of
filling an additional amount of the plurality of second particles
412 between the first set of hollow sintering spacers 418 to form a
first set of 3-dimensional projections 426. The step 416 further
includes sintering the first layer portion 404a, the second layer
portion 406a, and the first set of 3-dimensional projections 426
using a sintering device 444 so as to generate a first sintered
layer portion 446a, the second sintered layer portion 448a having a
first set of 3-dimensional sintered projections 450 as shown in
step 454.
[0076] The step 454 further includes removing the first set of
hollow sintering spacers 418 from the first half casing portion
408a. At step 458 a plurality of third particles 460 are filled on
the second sintered layer portion 448a so as to form a third layer
portion 462. The step 458 further includes disposing another first
set of hollow sintering spacers 466 on the third layer portion 462.
Further, the step 458 includes filling an additional amount of the
plurality of third particles 460 between the first set of hollow
sintering spacers 466 so as to form a third layer portion 468. The
layer portions 462, 468 collectively form a third layer portion
470a. The first set of hollow sintering spacers 466 has a width
"W.sub.2" and length "L.sub.2". The width "W.sub.2" is greater than
width "W.sub.1" and length "L.sub.1" is greater than length
"L.sub.2".
[0077] The method 400 further includes a step 474 for sintering the
third layer portion 470a via the sintering device 444 so as to
generate a third sintered layer portion 476a as shown in step 478.
Further, the step 478 includes removing the set of first hollow
sintering spacers 466 from the first half casing portion 408a. The
first sintered layer portion 446a, the second sintered layer
portion 448a having the first set of 3-dimensional sintered
projections 450, and the third sintered layer portion 476a together
form a first wick portion 480a within the first half casing portion
408a.
[0078] FIG. 9b is a schematic flow diagram illustrating the method
400 of manufacturing the heat transfer device 499 in accordance
with the exemplary embodiment of FIG. 9a. The method 400 further
includes a step 482 of disposing a second set of hollow sintering
spacers 420 on a second half casing portion 408b having another
second layer portion 406b disposed on another first layer portion
404b. The first layer portion 404b is disposed proximate to another
coating portion 414b. The coating portion 414b is disposed on the
inner surface 407 of the second half casing portion 408b. The
second set of hollow sintering spacers 420 has a width "W.sub.3"
and length "L.sub.3". The width "W.sub.3" is greater than the width
"W.sub.1" and length "L.sub.3" is greater than length "L.sub.1".
The method further includes a step 484 of filling an additional
amount of the plurality of second particles 412 between the second
set of hollow sintering spacers 420 to form a second set of
3-dimensional projections 438.
[0079] The step 484 further includes sintering the first layer
portion 404b, the second layer portion 406b and the second set of
3-dimensional projections 438 via the sintering device 444 so as to
generate another first sintered layer portion 446b and another
second sintered layer portion 448b having a second set of
3-dimensional sintered projections 452 as shown in step 494.
Further, the step 494 includes removing the second set of hollow
sintering spacers 420 from the second half casing portion 408b.
[0080] The method 400 further includes a step 496 of filling a
plurality of third particles 460 on the second sintered layer
portion 448b so as to form a third layer portion 472 i.e. between
the second set of 3-dimensional sintered projections 452. The step
496 further includes disposing another second set of hollow
sintering spacers 422 on the third layer portion 472. Further, the
step 496 includes filling an additional amount of the plurality of
third particles 460 between the second set of hollow sintering
spacers 422 so as to form a third layer portion 486. The layer
portions 472, 486 together form a third layer portion 470b. The
second set of hollow sintering spacers 422 has a width "W.sub.4"
and length "L.sub.4". The width "W.sub.4" is greater than the width
"W.sub.3" and length "L.sub.3" is greater than length
"L.sub.4".
[0081] The method 400 further includes a step 498 for sintering the
third layer portion 470b via the sintering device 444 so as to
generate another third sintered layer portion 476b as shown in step
500. Further, the step 500 includes removing the set of second
hollow sintering spacers 422 from the second half casing portion
408b. The first sintered layer portion 446b, the second sintered
layer portion 448b having the second set of 3-dimensional sintered
projections 452, and the third sintered layer portion 476b together
form a second wick portion 480b within the second half casing
portion 408b.
[0082] FIG. 9c is a schematic flow diagram illustrating the method
400 of manufacturing the heat transfer device 499 in accordance
with the exemplary embodiments of FIGS. 9a and 9b. The method 400
further includes a step 502 of disposing the first half casing
portion 408a having the first wick portion 480a. The method 400
further includes a step 504 of disposing the second half casing
portion 408b having the second wick portion 480b.
[0083] Further, the method 400 includes a step 506 of coupling the
first half casing portion 408a to the second half casing portion
408b such that the first wick portion 480a is coupled to the second
wick portion 480b to form the heat transfer device 499. A sealed
chamber 508 is formed between the first half casing portion 408a
and the second half casing portion 408b. The first wick portion
480a and the second wick portion 480b together form a wick 480. The
first set of 3-dimensional sintered projections 450 extend from one
side 510 towards another side 512 of the wick 480. The second set
of 3-dimensional sintered projections 452 extend from one side 510
to the other side 512 of the wick 480. The first half and second
half casing portions 408a, 408b are coupled to each other by
welding, brazing, soldering, or the like.
[0084] Embodiments of the present invention discussed herein
facilitate easy and economic manufacturing of the heat transfer
device. Further, the heat transfer device of the present invention
provides lower thermal resistance, higher thermal conductivity, and
higher heat transport capability.
* * * * *