U.S. patent application number 12/489418 was filed with the patent office on 2010-08-26 for flat heat pipe.
This patent application is currently assigned to FURUI PRECISE COMPONENT (KUNSHAN) CO., LTD.. Invention is credited to Nien-Tien Cheng, Sheng-Liang Dai, Yu-Liang Lo, Hai-Ping Shen, Sheng-Lin Wu.
Application Number | 20100212870 12/489418 |
Document ID | / |
Family ID | 42629920 |
Filed Date | 2010-08-26 |
United States Patent
Application |
20100212870 |
Kind Code |
A1 |
Wu; Sheng-Lin ; et
al. |
August 26, 2010 |
FLAT HEAT PIPE
Abstract
A flat heat pipe includes a casing and a wick structure received
in the casing. The casing has a first lateral portion and a second
lateral portion. Each of the first lateral portion and the second
lateral portion has a C-shape configuration, and the second lateral
portion has an opening facing an opening of the first lateral
portion. The wick structure is attached to an inner surface of only
one of the first and lateral portions of the casing. The inner
surface of the other of the first and second lateral portions
without the wick structure attached thereto defines a first vapor
channel, and an inner surface of the wick structure defines a
second vapor channel. The first vapor channel has a height greater
than the second vapor channel.
Inventors: |
Wu; Sheng-Lin; (Tu-Cheng,
TW) ; Shen; Hai-Ping; (ShenZhen City, CN) ;
Dai; Sheng-Liang; (ShenZhen City, CN) ; Lo;
Yu-Liang; (Tu-Cheng, TW) ; Cheng; Nien-Tien;
(Tu-Cheng, TW) |
Correspondence
Address: |
PCE INDUSTRY, INC.;ATT. Steven Reiss
288 SOUTH MAYO AVENUE
CITY OF INDUSTRY
CA
91789
US
|
Assignee: |
FURUI PRECISE COMPONENT (KUNSHAN)
CO., LTD.
KunShan
CN
Foxconn Technology Co., Ltd.
Tu-Cheng
TW
|
Family ID: |
42629920 |
Appl. No.: |
12/489418 |
Filed: |
June 22, 2009 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
H01L 23/427 20130101;
H01L 2924/0002 20130101; F28D 15/046 20130101; H01L 23/49548
20130101; H01L 2924/00 20130101; H01L 2924/0002 20130101; F28D
15/0233 20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/02 20060101
F28D015/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 26, 2009 |
CN |
200910300561.2 |
Claims
1. A flat heat pipe comprising: a casing having a first lateral
portion and a second lateral portion opposite to the first lateral
portion along a transverse direction, each of the first lateral
portion and the second lateral portion having a C-shaped transverse
cross section, the second lateral portion having an opening facing
an opening of the first lateral portion; a wick structure received
in the casing and attached to an inner surface of only one of the
first lateral portion and the second lateral portion of the casing;
and a working medium contained in the casing and saturated in the
wick structure; wherein the inner surface of the other one of the
first lateral portion and the second lateral portion without the
wick structure being attached thereto defines a first vapor
channel, an inner surface of the wick structure defines a second
vapor channel, and the first vapor channel has a height greater
than the second vapor channel.
2. The flat heat pipe as claimed in claim 1, wherein the first
vapor channel and the second vapor channel communicate at a joint
between the first lateral portion and the second lateral
portion.
3. The flat heat pipe as claimed in claim 1, wherein the wick
structure is a single-layered mesh structure formed by weaving a
plurality of wires.
4. The flat heat pipe as claimed in claim 1, wherein a height of
the casing is below 1.2 millimeters.
5. The flat heat pipe as claimed in claim 1, wherein the wick
structure has a C-shaped transverse cross section with an opening
of the wick structure facing the opening of the first lateral
portion, the wick structure is attached to the inner surface of the
second lateral portion of the casing, and the inner surface of the
first lateral portion of the casing defines the first vapor
channel.
6. The flat heat pipe as claimed in claim 1, wherein the wick
structure has a C-shaped transverse cross section with an opening
of the wick structure facing the opening of the second lateral
portion, the wick structure is attached to the inner surface of the
first lateral portion of the casing, and the inner surface of the
second lateral portion of the casing defines the first vapor
channel.
7. A flat heat pipe comprising: a casing having an upper plate and
a bottom plate opposite to the upper plate; a wick structure
received in the casing and attached only to the bottom plate of the
casing, the wick structure spacing from the upper plate with a
vapor channel defined between the upper plate and the wick
structure; and a working medium contained in the casing and
saturated in the wick structure.
8. The flat heat pipe as claimed in claim 7, wherein the wick
structure is a single-layered mesh structure formed by weaving a
plurality of wires.
9. The flat heat pipe as claimed in claim 7, wherein a height of
the casing is below 1.2 millimeters.
10. A flat heat pipe comprising: a metal casing having a flat upper
plate and a flat lower plate and defining an evaporator section for
absorbing heat and a condenser section for releasing heat, wherein
the evaporator section and the condenser section are located at
opposite end portions of the metal casing, a transverse section of
the metal casing having an outer surface and an inner surface; a
wick structure made of a mesh attached to a partial portion of the
inner surface of the transverse section of the metal casing and
extending from the evaporator section to the condenser section; and
working fluid received in the casing and saturated in the wick
structure.
11. The flat heat pipe as claimed in claim 10, wherein the wick
structure is attached to a lateral portion of the inner surface of
the transverse section of the metal casing.
12. The heat pipe as claimed in claim 11, wherein the wick
structure has a C-shaped configuration with a portion thereof
attached to a top of the inner surface of the transverse section of
the casing and another portion attached to a bottom of the inner
surface of the transverse section of the casing.
13. The heat pipe as claimed in claim 12, wherein the casing has a
height no more than 1.2 millimeters.
14. The heat pipe as claimed in claim 10, wherein the wick
structure has a flat configuration and attached to a bottom of the
inner surface of the transverse section the casing.
15. The heat pipe as claimed in claim 14, wherein the casing has a
height no more than 1.2 millimeters.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present invention relates generally to an apparatus for
transfer or dissipation of heat from heat-generating components,
and more particularly to a heat pipe applicable in electronic
products such as personal computers for removing heat from
electronic components installed therein.
[0003] 2. Description of Related Art
[0004] Heat pipes have excellent heat transfer performance due to
their low thermal resistance, and are therefore an effective means
for transfer or dissipation of heat from heat sources. Currently,
flat heat pipes are widely used for removing heat from
heat-generating components such as central processing units (CPUs)
of computers, especially in a notebook computer having a smaller
inner space therein. Preferably, a wick structure is attached to an
inner surface of the heat pipe for drawing the working medium back
to the evaporator section after it is condensed at the condenser
section. An inner surface of the wick structure defines a vapor
channel through which vapor moves from the evaporator section
toward the condenser section. With the notebook computer becoming
smaller and smaller, the flat heat pipe becomes flatter and flatter
and a size of the vapor channel is greatly reduced. Thus, the vapor
can not flow fluently from the evaporator section toward the
condenser section via the vapor channel, thereby decreasing the
heat transfer capability of the flat heat pipe.
[0005] Therefore, it is desirable to provide a flat heat pipe with
an improved heat transfer capability to overcome the above
mentioned shortcoming.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Many aspects of the present embodiments can be better
understood with reference to the following drawings. The components
in the drawings are not necessarily drawn to scale, the emphasis
instead being placed upon clearly illustrating the principles of
the present embodiments. Moreover, in the drawings, like reference
numerals designate corresponding parts throughout the several
views.
[0007] FIG. 1 is a front view of a heat pipe in accordance with a
first embodiment of the present invention.
[0008] FIG. 2 is a transverse cross-sectional view of the heat pipe
of FIG. 1.
[0009] FIG. 3 is a transverse cross-sectional view of a heat pipe
in accordance with a second embodiment of the present
invention.
DETAILED DESCRIPTION
[0010] Referring to FIGS. 1 and 2, a flat heat pipe 10 includes an
elongated, flat casing 12, and a wick structure 15 received in the
casing 12, wherein the wick structure 15 has a plurality of pores
therein and is saturated with a working medium. The flat heat pipe
10 is typically suitable for use in portable electronic devices
such as notebook computers which have a limited space therein for
accommodating heat dissipation devices.
[0011] The casing 12 is made of a highly thermally conductive
material such as copper or aluminum. The casing 12 includes an
evaporator section 121 and a condenser section 122 at two opposite
sides thereof along a longitudinal direction thereof.
[0012] A height h of the casing 12 is below 1.2 millimeters. The
casing 12 has a first lateral portion 13 at a left lateral side
thereof and a second lateral portion 14 at a right lateral side
thereof along a transverse direction. The first lateral portion 13
is C-shaped in profile and includes an upper plate 131 at a top
side thereof, a bottom plate 132 at a bottom side thereof and
opposite to the upper plate 131, and an outwardly curved side plate
133 connecting the upper plate 131 with the bottom plate 132. The
second lateral portion 14 is C-shaped, with an opening of the
second lateral portion 14 facing an opening of the first lateral
portion 13. The second lateral portion 14 includes an upper plate
141 at a top side thereof, a bottom plate 142 at a bottom side
thereof and opposite to the upper plate 141, and an outwardly
curved side plate 143 connecting the upper plate 141 with the
bottom plate 142. The upper plate 131 of the first lateral portion
13 and the upper plate 141 of the second lateral portion 14
cooperatively form an upper plate 124 of the casing 12, and the
bottom plate 132 of the first lateral portion 13 and the bottom
plate 142 of the second lateral portion 14 cooperatively form a
bottom plate 125 of the casing 12.
[0013] In the embodiment, the wick structure 15 is a single-layered
mesh-type structure, which is formed by weaving a plurality of
metal wires, such as copper, or stainless steel wires. A plurality
of pores is formed in the mesh wick structure 15, which provides a
capillary action to the working medium.
[0014] The mesh wick structure 15 is received in the casing 12 and
extends along the longitudinal direction of the casing 12. The mesh
wick structure 15 has a C-shaped transverse cross section, with an
opening of the mesh wick structure 15 facing the opening of the
first lateral portion 13 of the casing 12. The mesh wick structure
15 includes a first upper section 151 parallel to the upper plate
141 of the second lateral portion 14 of the casing 12, a second
bottom section 152 opposite to the first upper section 151, and a
curved side section 153 connecting the first upper section 151 with
the second bottom section 152. The mesh wick structure 15 is
attached to an inner surface of the second lateral portion 14 of
the casing 12, with the first upper section 151 being attached to
the upper plate 141 of the second lateral portion 14 of the casing
12, the second bottom section 152 being attached to the bottom
plate 142 of the second lateral portion 14 of the casing 12, the
curved side section 153 being attached to the side plate 143 of the
second lateral portion 14 of the casing 12. No wick structure is
attached to an inner surface of the first lateral portion 13 of the
casing 12. The inner surface of the first lateral portion 13
defines a first vapor channel 16 in the heat pipe 10, and an inner
surface of the mesh wick structure 15 defines a second vapor
channel 17 in the heat pipe 10. The first vapor channel 16 and the
second vapor channel 17 communicate with each other at a joint
between the first and the second lateral portions 13, 14 of the
casing 12. The first vapor channel 16 has a height greater than the
second vapor channel 17.
[0015] In an alternative embodiment, the C-shaped mesh wick
structure 15 is attached to the inner surface of the first lateral
portion 13 of the casing 12, with an opening of the mesh wick
structure 15 facing the opening of the second lateral portion 14,
and no wick structure is attached to the inner surface of the
second lateral portion 14 of the casing 12.
[0016] The working medium is saturated in the mesh wick structure
15 and is usually selected from a liquid such as water, methanol,
or alcohol, which has a low boiling point and is compatible with
the mesh wick structure 15. Thus, the working medium can easily
evaporate to vapor when it receives heat at the evaporator section
121 of the heat pipe 10.
[0017] In operation, the evaporator section 121 of the heat pipe 10
is placed in thermal contact with a heat source, for example, a
central processing unit (CPU) of a computer, which needs to be
cooled. The working medium contained in the evaporator section 121
of the heat pipe 10 is vaporized into vapor upon receiving the heat
generated by the heat source. Then, the generated vapor moves via
the vapor channels 16, 17 towards the condenser section 122 of the
heat pipe 10. After the vapor releases the heat carried thereby and
is condensed into the liquid in the condenser section 122, the
liquid is brought back by the mesh wick structure 15 to the
evaporator section 121 of the heat pipe 10 for being available
again for evaporation.
[0018] Since the mesh wick structure 15 is only attached to the
second lateral portion 14 of the casing 12, the first vapor channel
16 has a height greater than the second vapor channel 17, whereby
the first vapor channel 16 is very unlikely to be blocked when the
heat pipe 10 is flattened. Even if the second vapor channel 17 is
somewhat blocked by the first upper section 151 and the second
bottom section 152 of the mesh wick structure 15, the vapor can
also flow freely through the first vapor channel 16 from the
evaporator section 121 toward the condenser section 122. Thus, the
height of the casing 12 can be reduced to be less than 1.2
millimeters, such as 1.0 millimeter or 0.8 millimeter, while the
heat pipe 10 still can function normally. Compared with a typical
conventional heat pipe, the heat pipe 10 of the first embodiment
can be made thinner and therefore is more suitable to be used in
compact electronic devices, such as notebook computers.
[0019] FIG. 3 shows a flat heat pipe 30 in accordance with a second
embodiment of the present invention. The difference of this
embodiment over the previous embodiment is as follows. The wick
structure 35 is flat and attached only to an inner surface of the
bottom plate 312 of the casing 31 and spaced from the upper plate
311 of the casing 31.
[0020] It is believed that the present embodiments and their
advantages will be understood from the foregoing description, and
it will be apparent that various changes may be made thereto
without departing from the spirit and scope of the invention or
sacrificing all of its material advantages, the examples
hereinbefore described merely being preferred or exemplary
embodiments of the invention.
* * * * *