U.S. patent application number 14/054674 was filed with the patent office on 2015-04-16 for heat pipe with ultra-thin flat wick structure.
The applicant listed for this patent is Hao PAI. Invention is credited to Hao PAI.
Application Number | 20150101784 14/054674 |
Document ID | / |
Family ID | 52808658 |
Filed Date | 2015-04-16 |
United States Patent
Application |
20150101784 |
Kind Code |
A1 |
PAI; Hao |
April 16, 2015 |
HEAT PIPE WITH ULTRA-THIN FLAT WICK STRUCTURE
Abstract
A heat pipe with an ultra-thin flat wick structure includes a
shell and a wick structure disposed in the shell. The wick
structure includes heat exchange zones and at least one liquid
channel connected between the heat exchange zones which are divided
into an evaporation portion and a condensation portion. Each of the
heat exchange zones has a plane and a pressing surface opposite to
the plane. A plurality of elongated concave surfaces are spacedly
arranged on the pressing surface such that a respective steam
channel is formed via each of the concave surfaces in the shell and
a respective elongated wick structure connection is formed between
each concave surface and the plane. Cut-out zones are formed at two
sides of the liquid channel between the heat exchange zones in the
shell.
Inventors: |
PAI; Hao; (Taoyuan County,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PAI; Hao |
Taoyuan County |
|
TW |
|
|
Family ID: |
52808658 |
Appl. No.: |
14/054674 |
Filed: |
October 15, 2013 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
H01L 2924/0002 20130101;
F28D 15/0233 20130101; H01L 2924/00 20130101; H01L 23/427 20130101;
F28D 15/046 20130101; H01L 2924/0002 20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/04 20060101
F28D015/04 |
Claims
1. A heat pipe with an ultra-thin flat wick structure (2),
comprising: a hollow shell (1) having a flat shape; and a wick
structure (2) disposed in the shell (1), the wick structure (2)
comprising a plurality of heat exchange zones (20) and at least one
liquid channel (21) connected between the heat exchange zones (20)
divided into at least one evaporation portion and at least one
condensation portion, wherein each of the heat exchange zones (20)
has a plane (200) and a pressing surface (201) opposite to the
plane (200), wherein the plane (200) is attached to an inner wall
(110) of the shell (1), wherein a plurality of elongated concave
surfaces (202) are spacedly arranged on the pressing surface (201)
such that a respective steam channel (101) is formed in the shell
(1) via each of the concave surfaces (202) and a respective
elongated wick structure connection (203) is formed between each
concave surface (202) and the plane (200), wherein cut-out zones
(102) are formed at two sides of the liquid channel (21) between
the heat exchange zones (20) in the shell (1).
2. The heat pipe according to claim 1, wherein the shell (1)
further comprises another wick structure (2) such that the two wick
structures (2) are stacked up and down with respective heat
exchange zones (20) and the concave surfaces (202) on the opposite
heat exchange zones (20) are up-and-down corresponding to each
other to form the steam channels (101).
3. The heat pipe according to claim 1, wherein an external contour
of the shell (1) has a thickness below 0.5 mm.
4. The heat pipe according to claim 1, wherein each heat exchange
zone (20) of the wick structure (2) has penetrated heat transfer
holes (203) on the concave surfaces (202) thereof
5. The heat pipe according to claim 1, wherein a plurality of
recesses (205) are recessed and disposed on each concave surface
(202) of each heat exchange zone (20) of the wick structure (2) to
make the adjacent steam channels (101) communicate with each
other.
6. The heat pipe according to claim 1, wherein each concave surface
(202) of each heat exchange zone (20) of the wick structure (2) has
a shape of a "V", an arc, a rectangle, or a trapezoid.
7. The heat pipe according to claim 1, wherein each concave surface
(202) gradually expands or shrinks along a longitudinal direction
of the wick structure (2).
8. The heat pipe according to claim 1, wherein each concave surface
(202) is extended and disposed along a longitudinal direction of
the wick structure (2).
9. The heat pipe according to claim 1, wherein a thickness of the
wick structure (2) is below 0.25 mm.
10. The heat pipe according to claim 9, wherein a minimum thickness
of the respective elongated wick structure connection (203) ranges
from 0.02 mm to 0.04 mm.
11. The heat pipe according to claim 10, wherein the shell (1) has
an upper wall (10), a lower wall (11) spaced with and opposite to
the upper wall (10), and side edges (12) surrounding the outer
edges of the upper wall (10) and the lower wall (11).
12. The heat pipe according to claim 11, wherein the wick structure
(2) is braid, fiber, sintered metal powder, or any combination
thereof
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an ultra-thin plate type
heat pipe and in particular to a heat pipe with an ultra-thin flat
wick structure.
[0003] 2. Description of Related Art
[0004] Since most current 3C electronic products indicate a trend
towards a light, thin, short, and compact design, the heat pipes
used therein for heat dissipation or heat conduction also need to
be thinned down, which causes the creation of the ultra-thin plate
type heat pipe (the thickness is below about 1.5 mm).
[0005] However, the thickness of the ultra-thin plate type heat
pipe needs to be thinned, thus resulting in a thinner thickness of
the wick structure therein, otherwise the steam channels with
sufficient space cannot be formed in the heat pipe. During the
manufacturing process, the excessively thin wick structure cannot
be filled through the gap between the wall of the heat pipe and the
mandrel. The reason is that a relatively small gap causes a greater
resistance when the metal powder is filled and thus cannot be
processed subsequently. Therefore, the powder wick structure in the
previous ultra-thin plate type heat pipe is formed only in the
local area in the heat pipe and not thinned. Consequently, the
powder wick structure in the ultra-thin plate type heat pipe of the
prior art cannot be easily filled into the cross section of the
heat pipe completely, which cannot provide the adequate surfaces
for evaporation and condensation and the truncated transfer
surface. Also, this still does not have sufficient steam channels
and solid internal support structures, resulting in easy collapse
of the heat pipe and thus greater thermal contact resistance.
Hence, the heat transfer efficiency cannot be improved further.
[0006] In view of this, the inventor pays special attention to
research with the application of related theory and tries to
overcome the above disadvantages. Finally, the inventor proposes
the present invention which is a reasonable design and effectively
overcomes the above disadvantages.
SUMMARY OF THE INVENTION
[0007] The main objective of the present invention is to provide a
heat pipe with an ultra-thin flat wick structure, in which the
thinned wick structure can be formed on the inner wall of the heat
pipe such that the steam channels can be maintained to provide
sufficient space for heat transfer by evaporation and condensation
after the ultra-thin heat pipe is pressed and formed, to provide
the maximal capillary surface area and truncated transfer surface,
and to provide more solid internal support structures to make the
heat pipe not easy to collapse and have lower thermal contact
resistance, achieving the objective of providing an ultra-thin heat
pipe.
[0008] To achieve the above objective, the present invention
provides a heat pipe with an ultra-thin flat wick structure,
comprising a hollow shell having a flat shape, and a wick structure
disposed in the shell. The wick structure comprises a plurality of
heat exchange zones and at least one liquid channel connected
between the heat exchange zones. The heat exchange zones are
divided into at least one evaporation portion and at least one
condensation portion. Each of the heat exchange zones has a plane
and a pressing surface opposite to the plane. The plane is attached
to an inner wall of the shell. A plurality of elongated concave
surfaces are spacedly arranged on the pressing surface such that a
respective steam channel is formed in the shell via each of the
concave surfaces and a respective elongated wick structure
connection is formed between each concave surface and the plane.
Cut-out zones are formed at two sides of the liquid channel between
the heat exchange zones in the shell.
BRIEF DESCRIPTION OF DRAWING
[0009] FIG. 1 is a perspective schematic view of the present
invention;
[0010] FIG. 2 is a cross-sectional schematic view along line 2-2 of
FIG. 1;
[0011] FIG. 3 is a local perspective schematic view of the wick
structure of the present invention;
[0012] FIG. 4 is a cross-sectional schematic view of the wick
structure according to the second embodiment of the present
invention;
[0013] FIG. 5 is a cross-sectional schematic view of the wick
structure according to the third embodiment of the present
invention;
[0014] FIG. 6 is a cross-sectional schematic view of the wick
structure according to the fourth embodiment of the present
invention;
[0015] FIG. 7 is a cross-sectional schematic view of another
embodiment of the present invention along a longitudinal direction
thereof;
[0016] FIG. 8 is a perspective schematic view of the wick structure
according to the fifth embodiment of the present invention;
[0017] FIG. 9 is a perspective schematic view of the wick structure
according to the sixth embodiment of the present invention; and
[0018] FIG. 10 is a cross-sectional schematic view according to
another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] To make examiners understand the features and technical
contents regarding the present invention, please refer to the
following detailed description and attached figures. However, the
attached figures are only used for reference and explanation, not
to limit the present invention.
[0020] Please refer to FIG. 1, which is a perspective schematic
view of the present invention. The present invention provides a
heat pipe with an ultra-thin flat wick structure, which comprises a
hollow shell 1 having a flat shape and at least one wick structure
2 disposed in the shell 1 and contacted with an inner wall of the
shell 1.
[0021] As shown in FIGS. 1 and 2, the shell 1 may be formed to have
the flat shape by manufacturing processes such as pressing. The
thickness T of the external contour of the shell 1 may be formed
below 0.5 mm by pressing. In the embodiment of the present
invention, after the shell 1 is pressed, it has an upper wall 10, a
lower wall 11, and side edges 12 surrounding the outer edges of the
upper wall 10 and the lower wall 11.
[0022] Please refer to FIGS. 2 and 3. The wick structure 2 is
disposed in the shell 1 and comprises a plurality of heat exchange
zones 20 and at least one liquid channel 21 connected between the
heat exchange zones 20. The wick structure 2 may be braid, fiber,
sintered metal powder, or any combination thereof to form the
above-mentioned shape. The heat exchange zones 20 are divided into
at least one evaporation portion and at least one condensation
portion. Each heat exchange zone 20 has a plane 200 attached to an
inner wall 110 of the shell 1 and a pressing surface 201 attached
to another inner wall 100 of the shell 1. A plurality of elongated
concave surfaces 202 are evenly or unevenly spacedly arranged on
the pressing surface 201 by pressing. The concave surfaces 202 are
extended and disposed along a longitudinal direction of the wick
structure 2 such that a respective steam channel 101 is formed in
the shell 1 via each of the concave surfaces 202.
[0023] Also, a respective elongated wick structure connection 203
is formed between each concave surface 202 and the plane 200 of the
wick structure 2. Cut-out zones 102 are formed at two sides of the
liquid channel 21 between the heat exchange zones 20 in the shell
1. The cut-out zones 102 can be used as low flow resistance zones
which increase the flowing area for working fluid during
vapor-liquid phase change. Furthermore, the thickness t1 of the
wick structure 2 is below about 0.25 mm and the minimum thickness
t2 of each elongated wick structure connection 203 ranges about
from 0.02 mm to 0.04 mm.
[0024] Further, as shown in FIG. 2, each of the concave surfaces
202 may have a shape of an arc; as also shown in FIGS. 4-6, each
concave surface 202 many have a shape of an "V", a rectangle, or a
trapezoid. As shown in FIG. 7, viewed cross-sectionally along a
longitudinal direction of the wick structure 2, each concave
surface 202 gradually expands or shrinks along a longitudinal
direction of the wick structure 2.
[0025] In addition, as shown in FIG. 8, the concave surface 202 of
each heat exchange zone 20 of the wick structure 2 of the present
invention may have penetrated heat transfer holes 204 to enhance
heat transfer. Also, as shown in FIG. 9, a plurality of recesses
205 may be recessed and disposed between the respective concave
surfaces 202 by the above-mentioned pressing such that after the
wick structure 2 is placed into the shell 1, the adjacent formed
steam channels 101 can communicate with each other.
[0026] Moreover, as shown in FIG. 10, the present invention further
comprises another wick structure 2 such that the two
above-mentioned wick structures 2 are stacked up and down with
respective heat exchange zones 20 and the concave surfaces 202 on
the opposite heat exchange zones 20 are up-and-down corresponding
to each other to form the steam channels 101 via the concave
surfaces 202 of the two above-mentioned wick structures 2.
[0027] In summary, the present invention indeed achieves the
expected objective and overcomes the disadvantages of the prior
art. In addition, the present invention is useful, novel and
non-obvious, which meets the requirements of patent application.
Please examine the application carefully and grant it a patent for
protecting the rights of the inventor.
[0028] The embodiments described above are only preferred ones and
not to limit the scope of appending claims regarding the present
invention. Therefore, all the modifications of equivalent
technology and means which apply the specification and figures of
the present invention are embraced by the scope of the present
invention.
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