U.S. patent application number 13/412582 was filed with the patent office on 2013-07-25 for flat heat pipe and method of manufacturing the same.
The applicant listed for this patent is Chien-Hung Sun, Chun Zhou. Invention is credited to Chien-Hung Sun, Chun Zhou.
Application Number | 20130186600 13/412582 |
Document ID | / |
Family ID | 48796283 |
Filed Date | 2013-07-25 |
United States Patent
Application |
20130186600 |
Kind Code |
A1 |
Sun; Chien-Hung ; et
al. |
July 25, 2013 |
FLAT HEAT PIPE AND METHOD OF MANUFACTURING THE SAME
Abstract
A flat heat pipe includes a flat hollow pipe and a capillary
structure. The flat hollow pipe has a first flat portion, a second
flat portion and two arc portions, wherein the two arc portions are
connected to both sides of the first and second flat portions. The
capillary structure is formed in the flat hollow pipe. The
capillary structure has a central portion and two edge portions,
wherein the central portion is located on an inner wall of the
first flat portion, the two edge portions are located on inner
walls of the two arc portions respectively, and a thickness of the
central portion is smaller than a thickness of each of the two edge
portions.
Inventors: |
Sun; Chien-Hung; (New Taipei
City, TW) ; Zhou; Chun; (New Taipei City,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sun; Chien-Hung
Zhou; Chun |
New Taipei City
New Taipei City |
|
TW
TW |
|
|
Family ID: |
48796283 |
Appl. No.: |
13/412582 |
Filed: |
March 5, 2012 |
Current U.S.
Class: |
165/104.26 ;
29/890.032 |
Current CPC
Class: |
Y10T 29/49353 20150115;
F28D 15/0233 20130101; F28D 15/046 20130101; B23P 15/26
20130101 |
Class at
Publication: |
165/104.26 ;
29/890.032 |
International
Class: |
F28D 15/04 20060101
F28D015/04; B21D 53/02 20060101 B21D053/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 20, 2012 |
CN |
201210019541.X |
Claims
1. A flat heat pipe comprising: a flat hollow pipe having a first
flat portion, a second flat portion and two arc portions, the two
arc portions being connected to both sides of the first and second
flat portions; and a capillary structure formed in the flat hollow
pipe, the capillary structure having a central portion and two edge
portions, the central portion being located on an inner wall of the
first flat portion, the two edge portions being located on inner
walls of the two arc portions respectively, a thickness of the
central portion being smaller than a thickness of each of the two
edge portions.
2. The flat heat pipe of claim 1, wherein at least one of the two
edge portions abuts against an inner wall of the second flat
portion.
3. The flat heat pipe of claim 1, wherein the capillary structure
is U-shaped.
4. The flat heat pipe of claim 1, wherein the capillary structure
is a sintered capillary structure, a mesh capillary structure or a
compound capillary structure.
5. A method of manufacturing a flat heat pipe comprising: providing
a circular hollow pipe and a T-shaped like wick, wherein the
T-shaped like wick has a fan-shaped portion and a protruding
portion protruding from the fan-shaped portion; inserting the
T-shaped like wick into the circular hollow pipe such that the
fan-shaped portion abuts against an inner wall of the circular
hollow pipe and a segment difference space is formed between the
protruding portion and the inner wall of the circular hollow pipe;
forming a capillary structure in the segment difference space,
wherein the capillary structure has a central portion and two edge
portions and a thickness of the central portion is smaller than a
thickness of each of the two edge portions; drawing the T-shaped
like wick out of the circular hollow pipe; and compressing the
circular hollow pipe so as to form a flat hollow pipe.
6. The method of claim 5, wherein after compressing the circular
hollow pipe so as to form the flat hollow pipe, the flat hollow
pipe has a first flat portion, a second flat portion and two arc
portions, the two arc portions are connected to both sides of the
first and second flat portions, the central portion is located on
an inner wall of the first flat portion, and the two edge portions
are located on inner walls of the two arc portions
respectively.
7. The method of claim 6, wherein after compressing the circular
hollow pipe so as to form the flat hollow pipe, at least one of the
two edge portions abuts against an inner wall of the second flat
portion.
8. The method of claim 5, wherein the capillary structure is
U-shaped.
9. The method of claim 5, wherein the capillary structure is a
sintered capillary structure, a mesh capillary structure or a
compound capillary structure.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a flat heat pipe and a method of
manufacturing the same and, more particularly, to a flat heat pipe
with a capillary structure and a method of manufacturing the flat
heat pipe, wherein the interior of the capillary structure is thin
and the exterior of the capillary structure is thick.
[0003] 2. Description of the Prior Art
[0004] Heat dissipating device is a significant component for
electronic products. When an electronic product is operating, the
current in circuit will generate unnecessary heat due to impedance.
If the heat is accumulated in the electronic components of the
electronic product without dissipating immediately, the electronic
components may get damage due to the accumulated heat. Therefore,
the performance of heat dissipating device is a significant issue
for the electronic product.
[0005] So far the heat dissipating device used in the electronic
product usually consists of a heat pipe, a heat dissipating fin and
a heat dissipating fan, wherein one end of the heat pipe contacts
the electronic component, which generates heat during operation,
the other end of the heat pipe is connected to the heat dissipating
fin, and the heat dissipating fan blows air to the heat dissipating
fin so as to dissipate heat. In general, the heat pipe mainly
comprises circular heat pipe and flat heat pipe. The flat heat pipe
mainly consists of a flat hollow pipe, a capillary structure and a
working fluid. The conventional capillary structure is usually
formed on an inner wall of a circular hollow pipe by a metal powder
sintering process and then the circular hollow pipe is compressed
to form the flat heat pipe. In general, if a wall thickness of a
heat pipe is smaller than 2 mm, the heat pipe is called "ultra-thin
heat pipe", and if a wall thickness of a heat pipe is larger than 2
mm, the heat pipe is called "thin heat pipe". However, no matter
how the heat pipe is thinned, the heat pipe still has to reserve
enough inner space for the working fluid to change between liquid
state and gaseous state. Since the capillary structure occupies
much more inner space of the heat pipe except the working fluid,
how to effectively make use of limited inner space of the heat pipe
(especially the thin or ultra-thin heat pipe) has become a
significant design issue.
SUMMARY OF THE INVENTION
[0006] The invention provides a flat heat pipe with a capillary
structure and a method of manufacturing the flat heat pipe, wherein
the interior of the capillary structure is thin and the exterior of
the capillary structure is thick, so as to solve the aforesaid
problems.
[0007] According to an embodiment of the invention, a flat heat
pipe comprises a flat hollow pipe and a capillary structure. The
flat hollow pipe has a first flat portion, a second flat portion
and two arc portions, wherein the two arc portions are connected to
both sides of the first and second flat portions. The capillary
structure is formed in the flat hollow pipe. The capillary
structure has a central portion and two edge portions, wherein the
central portion is located on an inner wall of the first flat
portion, the two edge portions are located on inner walls of the
two arc portions respectively, and a thickness of the central
portion is smaller than a thickness of each of the two edge
portions.
[0008] According to another embodiment of the invention, a method
of manufacturing a flat heat pipe comprises steps of providing a
circular hollow pipe and a T-shaped like wick, wherein the T-shaped
like wick has a fan-shaped portion and a protruding portion
protruding from the fan-shaped portion; inserting the T-shaped like
wick into the circular hollow pipe such that the fan-shaped portion
abuts against an inner wall of the circular hollow pipe and a
segment difference space is formed between the protruding portion
and the inner wall of the circular hollow pipe; forming a capillary
structure in the segment difference space, wherein the capillary
structure has a central portion and two edge portions and a
thickness of the central portion is smaller than a thickness of
each of the two edge portions; drawing the T-shaped like wick out
of the circular hollow pipe; and compressing the circular hollow
pipe so as to forma flat hollow pipe.
[0009] After compressing the circular hollow pipe so as to form the
flat hollow pipe, the flat hollow pipe has a first flat portion, a
second flat portion and two arc portions, the two arc portions are
connected to both sides of the first and second flat portions, the
central portion is located on an inner wall of the first flat
portion, and the two edge portions are located on inner walls of
the two arc portions respectively. Furthermore, after compressing
the circular hollow pipe so as to form the flat hollow pipe, at
least one of the two edge portions abuts against an inner wall of
the second flat portion.
[0010] The aforesaid capillary structure maybe a sintered capillary
structure, a mesh capillary structure or a compound capillary
structure.
[0011] As mentioned in the above, the interior of the capillary
structure is thin and the exterior of the capillary structure is
thick such that one single vapor channel is formed in the flat
hollow pipe of the flat heat pipe of the invention. Heat conduction
of the single vapor channel can be raised effectively so as to
achieve good heat exchange cycle. Furthermore, since the thickness
of the central portion of the capillary structure is smaller than
the thickness of each of the two edge portions, thermal resistance
of the central portion of the capillary structure is lower than
that of each of the two edge portions so as to enhance heat
conduction while a heat source is attached to the center of the
flat hollow pipe of the flat heat pipe.
[0012] These and other objectives 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 that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a flowchart illustrating a method of manufacturing
a flat heat pipe according to an embodiment of the invention.
[0014] FIG. 2 is a perspective view illustrating a circular hollow
pipe and a T-shaped like wick.
[0015] FIG. 3 is a front view illustrating the T-shaped like wick
being inserted into the circular hollow pipe.
[0016] FIG. 4 is a front view illustrating a capillary structure
being formed in a segment difference space.
[0017] FIG. 5 is a front view illustrating the T-shaped like wick
shown in FIG. 4 being drawn out of the circular hollow pipe.
[0018] FIG. 6 is a front view illustrating the circular hollow pipe
shown in FIG. 5 being compressed so as to form a flat hollow
pipe.
[0019] FIG. 7 is a schematic diagram illustrating a heat source
being attached to the flat heat pipe shown in FIG. 6.
DETAILED DESCRIPTION
[0020] Referring to FIGS. 1 to 6, FIG. 1 is a flowchart
illustrating a method of manufacturing a flat heat pipe according
to an embodiment of the invention, FIG. 2 is a perspective view
illustrating a circular hollow pipe 10 and a T-shaped like wick 12,
FIG. 3 is a front view illustrating the T-shaped like wick 12 being
inserted into the circular hollow pipe 10, FIG. 4 is a front view
illustrating a capillary structure 14 being formed in a segment
difference space 100, FIG. 5 is a front view illustrating the
T-shaped like wick 12 shown in FIG. 4 being drawn out of the
circular hollow pipe 10, and FIG. 6 is a front view illustrating
the circular hollow pipe 10 shown in FIG. 5 being compressed so as
to form a flat hollow pipe 10'.
[0021] First of all, step S10 is performed to provide a circular
hollow pipe 10 and a T-shaped like wick 12, wherein the T-shaped
like wick 12 has a fan-shaped portion 120 and a protruding portion
122 protruding from the fan-shaped portion 120, as shown in FIG. 2.
In this embodiment, the protruding portion 122 is trapezoid.
However, in another embodiment, the protruding portion 122 may be
arc-shaped or other shapes and it depends on practical
applications.
[0022] Afterward, step S12 is performed to insert the T-shaped like
wick 12 into the circular hollow pipe 10 such that the fan-shaped
portion 120 abuts against an inner wall of the circular hollow pipe
10 and a segment difference space 100 is formed between the
protruding portion 122 and the inner wall of the circular hollow
pipe 10. As shown in FIG. 3, a thickness T1 of the center of the
segment difference space 100 is smaller than a thickness T2 of both
sides of the segment difference space 100.
[0023] Step S14 is then performed to form a capillary structure 14
in the segment difference space 100, wherein the capillary
structure 14 has a central portion 140 and two edge portions 142,
as shown in FIG. 4. A thickness of the central portion 140 of the
capillary structure 14 is substantially equal to the thickness T1
of the center of the segment difference space 100, and a thickness
of each of the two edge portions 142 of the capillary structure 14
is substantially equal to the thickness T2 of both sides of the
segment difference space 100. Accordingly, the thickness T1 of the
central portion 140 of the capillary structure 14 is smaller than
the thickness T2 of each of the two edge portions 142. In this
embodiment, the capillary structure 14 maybe a sintered capillary
structure, a mesh capillary structure or a compound capillary
structure and it depends on practical applications.
[0024] Step S16 is then performed to draw the T-shaped like wick 12
out of the circular hollow pipe 10, as shown in FIG. 5.
[0025] Finally, step S18 is performed to compress the circular
hollow pipe 10 so as to form a flat hollow pipe 10'. Consequently,
the flat heat pipe 1 shown in FIG. 6 is manufactured completely. In
practical applications, a working fluid (not shown), such as water
or other fluids with low viscosity, is filled in the flat hollow
pipe 10'. After compressing the circular hollow pipe 10 so as to
form the flat hollow pipe 10', the flat hollow pipe 10' has a first
flat portion 102, a second flat portion 104 and two arc portions
106, wherein the two arc portions 106 are connected to both sides
of the first flat portion 102 and the second flat portion 104. As
shown in FIG. 6, the central portion 140 of the capillary structure
14 is located on an inner wall of the first flat portion 102, and
the two edge portions 142 of the capillary structure 14 are located
on inner walls of the two arc portions 106 respectively so that the
capillary structure 14 is U-shaped. Furthermore, after compression
and deformation, a thickness T1' of the central portion 140 is
still smaller than a thickness T2' of each of the two edge portions
142. Since the interior of the capillary structure 14 is thin and
the exterior of the capillary structure 14 is thick, one single
vapor channel 108 is formed in the flat hollow pipe 10' of the flat
heat pipe 1. Heat conduction of the single vapor channel 108 can be
raised effectively so as to achieve good heat exchange cycle.
[0026] Moreover, after compressing the circular hollow pipe 10 so
as to form the flat hollow pipe 10', the two edge portions 142 of
the capillary structure 14 abut against an inner wall of the second
flat portion 104 of the flat hollow pipe 10'. Accordingly, the two
edge portions 142 of the capillary structure 14 can support the
flat hollow pipe 10' so as to prevent the flat hollow pipe 10' from
cracking due to compression. It should be noted that the capillary
structure 14 can support the flat hollow pipe 10' while at least
one of the two edge portions 142 abuts against the inner wall of
the second flat portion 104, so the invention is not limited to the
embodiment shown in FIG. 6.
[0027] Referring to FIG. 7, FIG. 7 is a schematic diagram
illustrating a heat source 3 being attached to the flat heat pipe 1
shown in FIG. 6. As shown in FIG. 7, the heat source 3 is usually
attached to the center below the first flat portion 102 of the flat
heat pipe 1. Since the thickness T1' of the central portion 140 of
the capillary structure 14 is smaller than the thickness T2' of
each of the two edge portions 142, thermal resistance of the
central portion 140 of the capillary structure 14 is lower than
that of each of the two edge portions 142 so as to enhance heat
conduction while the heat source 3 is attached to the center below
the first flat portion 102 of the flat heat pipe 1.
[0028] Compared with the prior art, the interior of the capillary
structure is thin and the exterior of the capillary structure is
thick such that one single vapor channel is formed in the flat
hollow pipe of the flat heat pipe of the invention. Heat conduction
of the single vapor channel can be raised effectively so as to
achieve good heat exchange cycle. Furthermore, since the thickness
of the central portion of the capillary structure is smaller than
the thickness of each of the two edge portions, thermal resistance
of the central portion of the capillary structure is lower than
that of each of the two edge portions so as to enhance heat
conduction while a heat source is attached to the center of the
flat hollow pipe of the flat heat pipe.
[0029] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *