U.S. patent application number 12/596490 was filed with the patent office on 2010-05-06 for heat pipe and making method thereof.
Invention is credited to Jen-Shyan Chen.
Application Number | 20100108297 12/596490 |
Document ID | / |
Family ID | 39925160 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100108297 |
Kind Code |
A1 |
Chen; Jen-Shyan |
May 6, 2010 |
Heat Pipe and Making Method Thereof
Abstract
A heat pipe and the method thereof are provided. The heat pipe
(1) comprises a pipe body (12), a cavity (14) and a porous
capillary diversion layer (18). The pipe body (12) has a first open
(122) and a third open (124), and the cavity (14) has a second open
(142). The first open (122) and the second open (142) are bonded
together, and the third open (124) is sealed to form the heat pipe
(1). The heat pipe comprises working liquid in it. The sectional
area of the cavity (14) is larger than that of the pipe body (12).
And the cavity (14) has a planar end (144).
Inventors: |
Chen; Jen-Shyan; (Hsinchu
City, TW) |
Correspondence
Address: |
THOMAS, KAYDEN, HORSTEMEYER & RISLEY, LLP
600 GALLERIA PARKWAY, S.E., STE 1500
ATLANTA
GA
30339-5994
US
|
Family ID: |
39925160 |
Appl. No.: |
12/596490 |
Filed: |
April 28, 2007 |
PCT Filed: |
April 28, 2007 |
PCT NO: |
PCT/CN2007/001425 |
371 Date: |
October 19, 2009 |
Current U.S.
Class: |
165/104.26 ;
29/890.032 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 23/427 20130101; F28D 15/0266 20130101; Y10T 29/49353
20150115; F28D 15/0233 20130101; H01L 33/648 20130101; F28D 15/04
20130101; F28D 15/046 20130101; H01L 2924/0002 20130101; H01L
2924/00 20130101 |
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 pipe, applied to a light emitting diode (LED), the heat
pipe comprising: a tube having a first open, the diameter of the
tube being smaller than a distance of 10 mm; a chamber having a
second open, the second open and the first open being tightly
joined together to form a sealed space via the tube and the
chamber; and a porous capillary diversion layer, formed in the tube
and the chamber; wherein the sealed space contains a working fluid,
and a cross-section area of the chamber is larger than a
cross-section area of the tube.
2. The heat pipe of claim 1, wherein the tube and the chamber are
formed in one piece.
3. The heat pipe of claim 1, wherein the chamber comprises a
concave and an upper cover, and the upper cover is engaged with the
concave and the upper cover has the second open.
4. The heat pipe of claim 3, wherein the concave is made through a
process of powder metallurgy, stamping, injection molding, casting,
or machining.
5. The heat pipe of claim 1, wherein the chamber has a flat
end.
6. The heat pipe of claim 1, wherein the porous capillary diversion
layer is made by sintering a copper powder, a nickel powder, a
silver powder, a metallic powder plated with copper, nickel,
silver, or other similar metallic powders.
7. The heat pipe of claim 1, wherein the porous capillary diversion
layer comprises a metallic pellet layer and a metallic net body,
the metallic pellet layer is formed on the inner wall of the tube
and the inner wall of the chamber by sintering, and the metallic
net body is disposed upon the metallic pellet layer.
8. The heat pipe of claim 1, wherein the porous capillary diversion
layer comprises a wavy carped metal cloth and a flat metal net
fabric layer, the wavy carped metal cloth is spread on the inner
wall of the tube and the inner wall of the chamber, and the flat
metal net fabric layer is disposed on the wavy carped metal
cloth.
9. The heat pipe of claim 8, wherein the wavy carped of the wavy
carped metal cloth is in a form of triangle, rectangle, trapezium
or wave.
10. The heat pipe of claim 1, wherein the porous capillary
diversion layer comprises a plurality of tiny notches formed on the
inner wall of the tube and the inner wall of the chamber.
11. The heat pipe of claim 1, wherein the porous capillary
diversion layer comprises a plurality of tiny notches and a
metallic sintered layer, the tiny notches are formed on the inner
wall of the chamber, and the metallic sintered layer is formed on
the inner wall of the tube and the metallic sintered layer is
welded with the tiny notches.
12. A method of making a heat pipe, comprising the steps of: (a)
providing a tube having a first open and a third open; (b)
providing a chamber having a second open; (c) tightly joining the
first open of the tube and the second open of the chamber together
to form a semi-finished heat pipe; (d) vacuuming the semi-finished
heat pipe; and (e) sealing the third open; wherein the inner wall
of the semi-finished heat pipe comprises a porous capillary
diversion layer, the semi-finished heat pipe contains a working
fluid, and the cross-section area of the chamber is larger than the
cross-section area of the tube.
13. The method of the claim 12, wherein the chamber has a flat
end.
14. The method of claim 12, wherein in step (c), the tight joining
is performed through a process of welding, soldering, machine
fastening, or gluing.
15. The method of claim 12, wherein the working fluid is poured
into the semi-finished heat pipe before or after step (d) is
performed.
16. The method of claim 12, wherein a sintered metallic powder
layer is formed on the inner wall of the chamber, and the porous
capillary diversion layer is formed by the following steps of:
interposing a center pillar into the semi-finished heat pipe from
the third open and the center pillar being approximately tightly
against the sintered metallic powder layer; filling a first
metallic powder between the center pillar and the semi-finished
heat pipe; performing a sintering process to make the first
metallic powder and the metallic powder mutually welded to form the
porous capillary diversion layer; and getting the center pillar out
of the semi-finished heat pipe.
17. The method of claim 12, wherein the inner wall of the chamber
has a plurality of tiny notches, and the porous capillary diversion
layer is formed by the following steps of: interposing a center
pillar into the semi-finished heat pipe from the third open and the
center pillar being approximately tightly against the plurality of
tiny notches; filling a second metallic powder between the center
pillar and the semi-finished heat pipe; performing a sintering
process to make the second metallic powder and the plurality of
tiny notches mutually welded to form the porous capillary diversion
layer; and getting the center pillar out of the semi-finished heat
pipe.
18. The method of claim 16 or 17, wherein the first metallic powder
or the second metallic powder is a copper powder, a nickel powder,
a silver powder, a metallic powder plated with copper, nickel,
silver metal powder, or other metallic powders.
19. The method of claim 12, wherein the porous capillary diversion
layer is formed by the following step of: using a machining process
to make the plurality of tiny notches on the inner wall of the tube
and the inner wall of the chamber to form the porous capillary
diversion layer.
20. The method of claim 12, wherein the porous capillary diversion
layer is formed by the following steps of: sintering a plurality of
metallic pellets on the inner wall of the tube and the inner wall
of the chamber; and disposing a metallic net body on the plurality
of metallic pellets to form the porous capillary diversion
layer.
21. The method of claim 12, wherein the porous capillary diversion
layer is formed by the following steps of: laying a wavy carped
metal cloth on the inner wall of the tube and the inner wall of the
chamber; and disposing a flat metal net fabric layer on the wavy
carped metal cloth to form the porous capillary diversion
layer.
22. The method of claim 12, wherein step (b) comprises the steps
of: providing a concave; providing a upper cover, the upper cover
has the second open; and engaging the upper cover and the concave
to form the chamber.
23. The method of claim 22, wherein a first sintered metal layer is
formed on the concave, a second sintered metal layer is formed on
the upper cover, and the first sintered metal layer is engaged with
the second sintered metal layer.
24. The method of claim 22, wherein a plurality of first tiny
notches is formed on the concave, a plurality of second tiny
notches is formed on the upper cover, and the plurality of first
tiny notches is engaged with the plurality second of tiny
notches.
25. The method of claim 22, wherein the concave is made through a
process of powder metallurgy, stamping, injection molding, casting,
or machining.
26. A method of making a heat pipe, comprising the steps of: (A)
providing a first tube having an open and a closed end; (B)
shrinking the neck of the first tube to form a chamber and a second
tube, the chamber and the second tube being mutually through,
wherein the chamber comprises the closed end, and the second
comprises the open; (C) vacuuming the chamber and the second tube;
and (D) sealing the open; wherein the inner wall of the chamber and
the inner wall of the second tube comprise a porous capillary
diversion layer, the chamber and the second tube contain a working
fluid, a cross-section area of the chamber is larger than the
cross-section area of the second tube.
27. The method of claim 26, wherein the closed end is flat.
28. The method of claim 26, wherein step (B) is operated in a
temperature range from 400.degree. C. to 600.degree. C.
29. The method of claim 26, further comprising: after step (A) is
performed, forming the porous capillary diversion layer on the
inner wall of the first tube.
30. The method of claim 29, wherein the porous capillary diversion
layer is formed by the following steps of: disposing a first
metallic powder into the first tube; interposing a center pillar
into the first tube from the open and the center pillar being
approximately tightly against on the first metallic powder; filling
a second metallic powder between the center pillar and the inner
wall of the first tube; performing a sintering process to make the
first metallic powder and the second metallic powder mutually
welded to form the porous capillary diversion layer; and getting
the center pillar out of the first tube.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a heat pipe and
making method thereof, and more particularly, to a heat pipe
applied to a light emitting diode (LED) for heat dissipating and
making method thereof
[0003] 2. Description of the Prior Art
[0004] With the vigorous development of technology, many electrical
products have unsolved heat-dissipating problems. For example, when
the central processing unit (CPU) of the computer operates, it will
generate a lot of heat. Once the heat can not be removed, the
operation of the system will be seriously affected. The heat pipe
plays important role in the heat-dissipating part of the CPU of the
computer. Especially, when the usage space of the electrical
apparatus gradually becomes smaller, the heat-dissipating device
which can efficiently dissipate heat and fully use the space to
dissipate heat becomes more important.
[0005] The conventional heat pipe heat-dissipating is always using
a metallic block material, wherein a heat plane is formed on the
metallic block material by staggering a plurality of heat pipes.
However, the heat generated by the electric component located upon
the heat plane needs to be transmitted to the heat pipes indirectly
through the metallic block material, therefore, the
heat-dissipating efficiency of this heat-dissipating mechanism will
be limited to the physical property of the metallic block material,
and difficult to be improved. If the electric component is directly
located on the heat pipe (since the diameter of the heat pipe is
limited in a general electric apparatus), the heat pipe can not
load a larger electric component or a group of electric components.
Using the vapor chamber can directly solve the narrow deposing area
problem, however, extra device is needed to dissipate the heat from
the electric component, such as a heat-dissipating fin. And, the
deposing space needed for the above-mentioned vapor chamber and its
heat-dissipating fin is still too larger to the electric apparatus
only having a smaller space.
[0006] Accordingly, the invention is to provide a heat pipe having
different cross-section areas and making method thereof to provide
an effective and rapid heat-dissipating mechanism for the electric
component with larger heat area or a group of electric components
to solve the problems mentioned above.
SUMMARY OF THE INVENTION
[0007] A scope of the present invention is to provide a heat pipe
and making method thereof.
[0008] Another scope of the present invention is to provide a heat
pipe having different cross-section areas applied to a light
emitting diode (LED) for heat dissipating and making method
thereof.
[0009] The heat pipe of the invention is applied to a light
emitting diode (LED) for heat dissipating. The heat pipe comprises
a tube, a chamber, and a porous capillary diversion layer. The tube
has a first open, and the diameter of the tube is smaller than 10
mm. The chamber has a second open, and the second open and the
first open are tight joined together to form a sealed space via the
tube and the chamber. The porous capillary diversion layer is
formed in the tube and the chamber. Wherein, the sealed space
contains a working fluid, and a cross-section area of the chamber
is larger than a cross-section area of the tube.
[0010] In an embodiment, the tube and the chamber are formed in one
piece. In another embodiment, the chamber is formed by a concave
and an upper cover. The upper cover is engaged with the concave and
the upper cover has the second open. The concave can be made
through a process of powder metallurgy, stamping, injection
molding, casting, or machining. In an embodiment, the chamber has a
flat end for deposing a general electric component.
[0011] In an embodiment, the porous capillary diversion layer is
made by sintering a copper powder, a nickel powder, a silver
powder, a metallic powder plated with copper, nickel, silver, or
other similar metallic powders.
[0012] In another embodiment, the porous capillary diversion layer
comprises a metallic pellet layer and a metallic net body. The
metallic pellet layer is formed on the inner wall of the tube and
the inner wall of the chamber by sintering, and the metallic net
body is disposed upon the metallic pellet layer.
[0013] In another embodiment, the porous capillary diversion layer
comprises a wavy carped metal cloth and a flat metal net fabric
layer. Besides, the wavy carped metal cloth is spread on the inner
wall of the tube and the inner wall of the chamber, and the flat
metal net fabric layer is disposed on the wavy carped metal cloth,
wherein the wavy carped of the wavy carped metal cloth is in a form
of triangle, rectangle, trapezium, or wave.
[0014] In another embodiment, the porous capillary diversion layer
comprises a plurality of tiny notches formed on the inner wall of
the tube and the inner wall of the chamber.
[0015] In another embodiment, the porous capillary diversion layer
comprises a plurality of tiny notches and a metallic sintered
layer, the tiny notches are formed on the inner wall of the
chamber, and the metallic sintered layer is formed on the inner
wall of the tube and the metallic sintered layer is welded with the
tiny notches.
[0016] The heat pipe making method of the invention comprises the
steps of: (a) providing a tube having a first open and a third
open; (b) providing a chamber having a second open; (c) tightly
joining the first open of the tube and the second open of the
chamber together to form a semi-finished heat pipe; (d) vacuuming
the semi-finished heat pipe; and (e) sealing the third open.
Wherein the inner wall of the semi-finished heat pipe comprises a
porous capillary diversion layer; the semi-finished heat pipe
contains a working fluid; the cross-section area of the chamber is
larger than the cross-section area of the tube. And, the working
fluid is poured into the semi-finished heat pipe before or after
step (d) is performed. Additionally, in the step (c), the tight
joining is performed through a process of welding, soldering,
machine fastening, or gluing.
[0017] The step (b) of the heat pipe making method of the invention
can comprise the steps of: providing a concave; providing an upper
cover having the second open; and engaging the upper cover and the
concave to form the chamber. The concave can be made through a
process of powder metallurgy, stamping, injection molding, casting,
or machining. And, a first sintered metal layer can be formed on
the concave, a second sintered metal layer can be formed on the
upper cover, and the first sintered metal layer is engaged with the
second sintered metal layer. Or, a plurality of first tiny notches
is formed on the concave, a plurality of second tiny notches is
formed on the upper cover, and the plurality of first tiny notches
is engaged with the plurality second of tiny notches. Then, the
porous capillary diversion layer is formed when the concave and the
tube are engaged.
[0018] In an embodiment, a sintered metallic powder layer is formed
on the inner wall of the chamber. The porous capillary diversion
layer is formed by the following steps of: interposing a center
pillar into the semi-finished heat pipe from the third open and the
center pillar is approximately tightly against the sintered
metallic powder layer; filling a first metallic powder between the
center pillar and the semi-finished heat pipe; performing a
sintering process to make the first metallic powder and the
metallic powder mutually welded to form the porous capillary
diversion layer; and getting the center pillar out of the
semi-finished heat pipe.
[0019] In another embodiment, the inner wall of the chamber has a
plurality of tiny notches. The porous capillary diversion layer is
formed by the following steps of: interposing a center pillar into
the semi-finished heat pipe from the third open and the center
pillar is approximately tightly against the plurality of tiny
notches; filling a second metallic powder between the center pillar
and the semi-finished heat pipe;
[0020] performing a sintering process to make the second metallic
powder and the plurality of tiny notches mutually welded to form
the porous capillary diversion layer; and getting the center pillar
from the semi-finished heat pipe. By the way, in the two
above-mentioned embodiments, the first metallic powder or the
second metallic powder is a copper powder, a nickel powder, a
silver powder, a metallic powder plated with copper, nickel, silver
metal powder, or other metallic powders.
[0021] In another embodiment, a machining process is used to make
the plurality of tiny notches on the inner wall of the tube and the
inner wall of the chamber to form the porous capillary diversion
layer.
[0022] In another embodiment, the porous capillary diversion layer
is formed by the following steps of: sintering a plurality of
metallic pellets on the inner wall of the tube and the inner wall
of the chamber; and disposing a metallic net body on the plurality
of metallic pellets to form the porous capillary diversion
layer.
[0023] In another embodiment, the porous capillary diversion layer
is formed by the following steps of: laying a wavy carped metal
cloth on the inner wall of the tube and the inner wall of the
chamber; and disposing a flat metal net fabric layer on the wavy
carped metal cloth to form the porous capillary diversion
layer.
[0024] Another heat pipe making method of the invention comprises
the steps of: (A) providing a first tube having an open and a
closed end; (B) shrinking the neck of the first tube to form a
chamber and a second tube, and the chamber and the second tube are
mutually through, wherein the chamber comprises the closed end, the
second comprises the open; (C) vacuuming the chamber and the second
tube; and (D) sealing the open. Wherein, the inner wall of the
chamber and the inner wall of the second tube comprise a porous
capillary diversion layer; the chamber and the second tube contain
a working fluid; a cross-section area of the chamber is larger than
the cross-section area of the second tube. Wherein step (B) is
operated in a temperature range from 400.degree. C. to 600.degree.
C.
[0025] In an embodiment, after step (A) is performed, the porous
capillary diversion layer is formed on the inner wall of the first
tube. The porous capillary diversion layer is formed by the
following steps of: disposing a first metallic powder into the
first tube; interposing a center pillar into the first tube from
the open and the center pillar is approximately tightly against on
the first metallic powder; filling a second metallic powder between
the center pillar and the inner wall of the first tube; performing
a sintering process to make the first metallic powder and the
second metallic powder mutually welded to form the porous capillary
diversion layer; and getting the center pillar out of the first
tube.
[0026] Accordingly, the invention is to provide a heat pipe having
different cross-section areas and making method thereof to provide
an effective and rapid heat-dissipating mechanism for the electric
component, with larger heat area or a group of electric components,
disposed on the flat end of the heat pipe.
[0027] The objective of the present invention will no doubt become
obvious to those of ordinary skill in the art after reading the
following detailed description of the preferred embodiment, which
is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE APPENDED DRAWINGS
[0028] FIG. 1 illustrates a cross-sectional view of the
not-finished heat pipe of a first preferred embodiment.
[0029] FIG. 2A illustrates a cross-sectional view of a
semi-finished heat pipe of the first preferred embodiment.
[0030] FIG. 2B illustrates a cross-sectional view that a center
pillar is interposed into the semi-finished heat pipe of the first
preferred embodiment.
[0031] FIG. 2C illustrates a cross-sectional view that a first
metallic powder is filled between the center pillar and the
semi-finished heat pipe of the first preferred embodiment.
[0032] FIG. 2D illustrates a cross-sectional view of a
semi-finished heat pipe of the first preferred embodiment.
[0033] FIG. 2E illustrates a cross-sectional view of the heat pipe
of the first preferred embodiment.
[0034] FIG. 3A illustrates a partial cross-sectional view of a
first open of the heat pipe and a second open of the heat pipe of
an embodiment.
[0035] FIG. 3B illustrates a partial cross-sectional view that a
first open of the heat pipe and a second open of the heat pipe are
engaged of the embodiment.
[0036] FIG. 3C illustrates a partial cross-sectional view that a
first open of the heat pipe and a second open of the heat pipe of
an embodiment.
[0037] FIG. 3D illustrates a partial cross-sectional view that a
first open of the heat pipe and a second open of the heat pipe are
engaged of the embodiment.
[0038] FIG. 3E illustrates a cross-sectional view of the chamber of
the heat pipe of the above-mentioned embodiment.
[0039] FIG. 4A illustrates a cross-sectional view of a
semi-finished heat pipe of a second preferred embodiment.
[0040] FIG. 4B illustrates a cross-sectional view that a center
pillar is interposed into the semi-finished heat pipe of the second
preferred embodiment.
[0041] FIG. 4C illustrates a cross-sectional view that a second
metallic powder is filled between the center pillar and the
semi-finished heat pipe of the second preferred embodiment.
[0042] FIG. 4D illustrates a cross-sectional view of the heat pipe
of the second preferred embodiment.
[0043] FIG. 4E illustrates a cross-sectional view that the heat
pipe has not finished of an embodiment.
[0044] FIG. 4F illustrates a cross-sectional view that the heat
pipe has not finished of the embodiment.
[0045] FIG. 4G illustrates a cross-sectional view of the heat pipe
of the embodiment.
[0046] FIG. 4H illustrates a cross-sectional view of the chamber of
the heat pipe of the above-mentioned embodiment.
[0047] FIG. 5 illustrates a cross-sectional view of the heat pipe
of a third preferred embodiment.
[0048] FIG. 6 illustrates a cross-sectional view of the heat pipe
of a fourth preferred embodiment.
[0049] FIG. 7 illustrates a cross-sectional view of the heat pipe
of a fifth preferred embodiment.
[0050] FIG. 8A illustrates a cross-sectional view of a first tube
of the heat pipe of a sixth preferred embodiment.
[0051] FIG. 8B illustrates a cross-sectional view that after the
first tube is shrank the neck of the sixth preferred
embodiment.
[0052] FIG. 8C illustrates a cross-sectional view of the heat pipe
of the sixth preferred embodiment.
[0053] FIG. 8D illustrates a cross-sectional view that a first
metallic powder is filled into the first tube of the sixth
preferred embodiment.
[0054] FIG. 8E illustrates a cross-sectional view that the center
pillar is interposed into the first tube of the sixth preferred
embodiment.
[0055] FIG. 8F illustrates a cross-sectional view that a second
metallic powder between the center pillar and the first tube of the
sixth preferred embodiment.
[0056] FIG. 8G illustrates a cross-sectional view of the first tube
of the sixth preferred embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0057] Please refer to FIG. 1. FIG. 1 illustrates a cross-sectional
view of the not-finished heat pipe 1 according to a first preferred
embodiment of the invention. The heat pipe 1 includes a tube 12 and
a chamber 14. The tube 12 has a first open 122 and a third open
124. The chamber 14 has a second open 142 and a flat end 144. The
cross-section area of the chamber 14 is larger than the
cross-section area of the tube 12. Wherein, the cross-section area
of the chamber 14 means the cross-section area near the flat end
144. The diameter of the tube 12 is smaller than 10 mm.
[0058] The second open 142 of the chamber 14 and the first open 122
of the tube 12 are tightly joined together to form a semi-finished
heat pipe 16, as shown in FIG. 2A. The tight joining can be
performed through a process of welding, soldering, machine
fastening, or gluing.
[0059] According to the first preferred embodiment, a sintered
metallic powder layer 182 has been formed on the inner wall of the
chamber 14, as shown in FIG. 2A. After the tight joining is
performed, a center pillar C1 is interposed into the semi-finished
heat pipe 16 from the third open 124, and the center pillar C1 is
approximately tightly against the sintered metallic powder layer,
as shown in FIG. 2B. Then, a first metallic powder 184 is filled
between the center pillar C1 and the semi-finished heat pipe 16, as
shown in FIG. 2C. The first metallic powder 184 can be a copper
powder, a nickel powder, a silver powder, a metallic powder plated
with copper, nickel, silver, or other similar metallic powders.
[0060] Next, a sintering process is performed to make the first
metallic powder 184 and the sintered metallic powder 182 mutually
welded to form a porous capillary diversion layer 18. At last, the
center pillar C1 is gotten out of the semi-finished heat pipe 16,
as shown in FIG. 2D. Before the third open 124 is sealed, it needs
to vacuum the semi-finished heat pipe 16 and pour a working fluid
L1 into the semi-finished heat pipe 16. The sequences of pouring
the working fluid L1 and vacuuming the gas can be exchanged. The
third open 124 can be shrunk before vacuuming, so that the
following sealing can be smoothly performed. Finally, after the
third open 14 is sealed, the heat pipe 1 is finished, as shown in
FIG. 2E.
[0061] By the way, the tight joining should avoid over-damaging the
porous capillary diversion layer. In the first preferred
embodiment, the second open 124 of the chamber has no sintered
metallic powder layer 182 (please refer to FIG. 2A). Therefore,
during the tight joining process, the damage to the sintered
metallic powder layer 182 is unnecessary to be considered, and a
general welding process or a general soldering process can be used.
However, it should be still noted, after the tight joining, the
inner wall of the chamber 14 and the inner wall of the tube 12
should keep joining smoothly, so that the following first metallic
powder 184 can be smoothly sintered, and the first metallic powder
184 and the sintered metallic powder 182 can be mutually welded to
form the porous capillary diversion layer 18.
[0062] In addition, if the second open 142 of the chamber 14 has
the sintered metallic powder 182, the used joining process or the
using condition will be limited. For example, it is not suitable to
directly use a welding process or a soldering process in this case.
However, if the joining is well-designed, the welding process or
the soldering process can be used. Please refer to FIG. 3A. FIG. 3A
illustrates a partial cross-sectional schematic diagram of the
first open 122 and the second open 142 according to an embodiment.
The first open 122 includes a joining plane 1222 and a welding
portion 1224. The second open 142 includes a joining plane 1422 and
a welding portion 1424. The joining planes 1222 and 1442 are
tightly cohered to each other. The joining planes 1222 and 1442 are
both inclined planes. After the joining planes 1222 and 1442 are
cohered, the welding portions 1224 and 1424 will form a concave to
provide the filling material welding. After the tight joining is
finished, only the welding portions 1224 and 1424 are affected to
be filled with a welding material P thereon, the joining planes
1222 and 1442 are not affected, so that the inner wall of the
chamber 14 and the inner wall of the tube 12 can be still smoothly
connected, and the sintered metallic powder 182 of the second open
142 of the chamber 14 can not be damaged, as shown in FIG. 3B.
[0063] Furthermore, please refer to FIG. 3C. FIG. 3C illustrates a
partial cross-sectional view of the first open 122 and the second
open 142 according to another embodiment. The first open 122
includes a joining plane 1222 and a welding portion 1224. The
second open 142 includes a joining plane 1422 and a welding portion
1424. The joining planes 1222 and 1442 both comprise a protrusion
1224a, 1424a and a concave 1224b, 1424b. After the joining planes
1222 and 1442 are cohered, the joining planes 1222 and 1442 are
tightly cohered to each other, the protrusions 1224a, 1424a are
mutually weld through a heating process or a soldering process, and
the concaves 1224b and 1424b are fully filled. After the tight
joining is finished, only the welding portions 1224 and 1424 are
affected, the joining planes 1222 and 1442 are not affected, so
that the inner wall of the chamber 14 and the inner wall of the
tube 12 can be still smoothly connected, and the sintered metallic
powder 182 of the second open 142 of the chamber 14 will not be
damaged, as shown in FIG. 3D. The dotted line circles in FIG. 3D
show the soldering regions of the welding portions 1224 and 1424.
Of course, if the first open 122 and the second open 142 are joined
by a screw thread locking method, the above-mentioned effects due
to heat will not exist. But the sealing effect of the tight joining
should be noticed.
[0064] It should be mentioned that in the above-mentioned
embodiment, the chamber 14 can include a concave 146 and an upper
cover 148. The concave 146 includes the flat end 144 and the upper
cover 148 includes the second open 142. A first sintered metal
layer 1822 is formed on the concave 146. A second sintered metal
layer 1824 is formed on the upper cover 148. The upper cover 148
and the concave 146 are engaged to form the chamber 14, and the
sintered metallic powder layer 182 is formed by the first sintered
metal layer 1822 and the second sintered metal layer 1824.
Additionally, the casing body of the concave 146 itself can be made
through a process of powder metallurgy, stamping, injection
molding, casting, or machining.
[0065] Please refer to FIG. 4A. FIG. 4A illustrates a
cross-sectional view of the not-finished heat pipe 2 according to a
second preferred embodiment. The making method of the heat pipe 2
is approximately same with the heat pipe 1 of the first preferred
embodiment, so it will no longer be explained again here. Then, the
forming method of the porous capillary diversion layer 28 of the
heat pipe 2 will be introduced in detail.
[0066] As shown in FIG. 4A, the inner wall of the chamber 24 of the
heat pipe 2 has a plurality of tiny notches 282. A center pillar C2
is interposed into a semi-finished heat pipe 26 from the third open
224 of the tube 22 of the heat pipe 2, and the center pillar C2 is
approximately tightly against the plurality of tiny notches 282, as
shown in FIG. 4B. Then, a second metallic powder is filled between
the center pillar C2 and the semi-finished heat pipe 26, as shown
in FIG. 4C. Next, a sintering process is performed to make the
second metallic powder 284 and the plurality of tiny notches 282
mutually welded to form the porous capillary diversion layer 28.
Finally, the center pillar C2 is gotten out of the semi-finished
heat pipe 26. And, the heat pipe 2 is formed after sealing the
third open 224, as shown in FIG. 4D.
[0067] By the way, the outer diameter of the center pillar C2 is
not limited by one, namely the center pillar C2 may have different
outer diameters. Please refer to FIG. 4E. FIG. 4E illustrates a
cross-sectional view of the not-finished heat pipe 2' according to
an embodiment. Compared to the second preferred embodiment, the
plurality of tiny notches 282' of the chamber 24' of the heat pipe
2' shows the same inner diameter with the tube 22' of the heat pipe
2', therefore, the center pillar having only one outer diameter
will not be tight against the plurality of tiny notches 282' and
has a space existed between the center pillar and the semi-finished
heat pipe 26' of the heat pipe 2' to contain the following added
metallic powder. Under this condition, a center pillar C2' must
have different outer diameters, so that one part of the center
pillar C2' can be tightly against the plurality of tiny notches
282' and there will be a space existed between the center pillar
C2' and the heat pipe 2' to contain the following added second
metallic powder 284'. In the following sintering process, the
second metallic powder 284' and the plurality of tiny notches 282'
are mutually welded to form a porous capillary diversion layer 28',
as shown in FIG. 4F. After sealing the semi-finished heat pipe 26',
heat pipe 2' will be formed, as shown in FIG. 4G.
[0068] It should be mentioned that in the above-mentioned
embodiment, the chamber 24 and 24' can include a concave 246 and an
upper cover 248. The upper cover 248 includes the second open 242
of the chamber 24. A plurality of first tiny notches 2822 is formed
on the concave 246. A plurality of second tiny notches 2824 is
formed on the upper cover 248. The concave 246 and the upper cover
248 are engaged together to form the chamber 24, 24', and the
plurality of first tiny notches 2822 and the plurality of second
tiny notches 2824 form the plurality of tiny notches 282, as shown
in FIG. 4H. Additionally, the casing body of the concave 246 itself
can be made through a process of powder metallurgy, stamping,
injection molding, casting, or machining.
[0069] Please refer to FIG. 5. FIG. 5 illustrates a cross-sectional
view of the heat pipe 3 according to a third preferred embodiment.
The making method of the heat pipe 3 is approximately same with the
heat pipe 1 of the first preferred embodiment, so it will no longer
be explained again here. Then, the forming method of the porous
capillary diversion layer 38 of the heat pipe 3 will be introduced
in detail. The porous capillary diversion layer 38 is formed
through a machining process to make the plurality of tiny notches
38 on the inner wall of the tube 32 of the heat pipe 3 and the
inner wall of the chamber 34 of the heat pipe 3. For example, the
plurality of tiny notches 38 can be formed on the inner wall of the
semi-finished heat pipe by directly cutting via a knife. By the
way, in an embodiment, since the chamber of the semi-finished heat
pipe already has the plurality of tiny notches, after the tight
joining is performed, the only thing needed to do is to generate
the plurality of tiny notches on the other portions of the
semi-finished heat pipe to form a porous capillary diversion layer.
However, the connection between these two sets of tiny notches
should be noticed. This chamber is always found in the combined
chamber, such as a chamber assembled by a concave and an upper
cover.
[0070] Please refer to FIG. 6. FIG. 6 illustrates a cross-sectional
view of the heat pipe 4 according to a fourth preferred embodiment.
The making method of the heat pipe 4 is approximately the same with
the heat pipe 1 of the first preferred embodiment, so it will no
longer be explained again here. Then, the forming method of the
porous capillary diversion layer 48 of the heat pipe 4 will be
introduced in detail. Firstly, a plurality of metallic pellets 482
is sintered on the inner wall of the tube 42 of the heat pipe 4 and
the inner wall of the chamber 44 of the heat pipe 4. Then, a
metallic net body 484 is disposed on the plurality of metallic
pellets 482 to form the porous capillary diversion layer 48. By the
way, the plurality of metallic pellets 482 can be sintered on the
inner wall of the tube 42 and the inner wall of the chamber 44
respectively.
[0071] Please refer to FIG. 7. FIG.7 illustrates a cross-sectional
view of the heat pipe 5 according to a fifth preferred embodiment.
The making method of the heat pipe 5 is approximately the same with
the heat pipe 1 of the first preferred embodiment, so it will no
longer be explained again here. Then, the forming method of a
porous capillary diversion layer 58 of the heat pipe 5 will be
introduced in detail. Firstly, a wavy carped metal cloth 582 is
laid on the inner wall of the tube 52 of the heat pipe 5 and the
inner wall of the chamber 54 of the heat pipe 5. Then, a flat metal
net fabric layer 584 is disposed on the wavy carped metal cloth 582
to form the porous capillary diversion layer 58. Wherein, the wavy
carped of the wavy carped metal cloth 582 can be in a form of
triangle, rectangle, trapezium, or wave.
[0072] Please refer to FIG. 8. FIG. 8 illustrates a cross-sectional
view of the first tube 62 of the heat pipe 6 according to a sixth
preferred embodiment. The first tube 62 has an open 622 and a
closed end 624. The closed end 624 is flat. The first tube 62 has
larger inner diameter, so that the following neck-shrinking process
can be smoothly performed. And, because it is the tube wall of the
first tube 62 shrunk by the shrinking neck process, and the tube
wall will become thicker after the neck-shirking process, the wall
thickness of the closed end 624 of the first tube 62, in general
applications, will be thicker than that before the neck-shirking
process, so that a uniform wall thickness can be obtained after the
neck-shirking process. But it is not limited to this.
[0073] Next, a chamber 626 and a second tube 628 are formed by
shrinking the neck of the first tube 62, and the chamber 626 and
the second tube 628 are mutually through, as shown in FIG. 8B. The
chamber 626 includes the closed end 624, and the second tube 628
includes the open 622. A cross-section area of the chamber 626 is
larger than a cross-section area of the second tube 628. The
cross-section area of the chamber 626 means the cross-section area
of the closed end. In addition, the chamber 626 and the inner wall
of the second tube 628 include a porous capillary diversion layer
64.
[0074] Then, the chamber 626 and the second tube 628 are vacuumed,
and a working fluid L2 is poured into the chamber 626 and the
second tube 628 respectively. Finally, the open 622 is sealed.
Wherein, the sequence of the pouring the working fluid L2 step and
the vacuuming the gas step can be exchanged. After the open 622 is
sealed, the heat pipe 6 is finished, as shown in FIG. 8C.
[0075] According to the sixth preferred embodiment, the shrunk neck
is heated in a temperature range from 400.degree. C. to 600.degree.
C., or the shrunk neck is heated in a temperature range from the
recrystallization temperature of the first tube 62 to the
temperature that about 200.degree. C. over the recrystallization
temperature. Additionally, the porous capillary diversion layer 64
is formed on the inner wall of the first tube 62 before the
neck-shrinking by the following steps of: disposing a first
metallic powder 642 into the first tube 62, as shown in FIG. 8D;
interposing a center pillar C3 into the first tube 62 from the open
622 and the center pillar C3 is approximately tightly against on
the first metallic powder 642, as shown in FIG. 8E; filling a
second metallic powder 644 between the center pillar C3 and the
inner wall of the first tube 62; performing a sintering process to
make the first metallic powder 642 and the second metallic powder
644 mutually welded to form the porous capillary diversion layer
64; and getting the center pillar C3 out of the first tube 62, as
shown in FIG. 8G.
[0076] In the above-mentioned embodiment, the tube and the chamber
are joined in a symmetrical method. In practical applications, the
tube and the chamber can be also joined in an unsymmetrical method.
For example, the tube can be connected to the edge of the chamber
to meet different space limitations.
[0077] To sum up, the invention provides a heat pipe having
different cross-section areas and making method thereof to provide
an effective and rapid heat-dissipating mechanism for the electric
component, with larger heat area or a group of electric components,
disposed on the flat end of the heat pipe.
[0078] Although the present invention has been illustrated and
described with reference to the preferred embodiment thereof, it
should be understood that it is in no way limited to the details of
such embodiment but is capable of numerous modifications within the
scope of the appended claims.
* * * * *