U.S. patent application number 12/690933 was filed with the patent office on 2011-04-28 for plate-type heat pipe.
This patent application is currently assigned to FOXCONN TECHNOLOGY CO., LTD.. Invention is credited to CHUEN-SHU HOU.
Application Number | 20110094712 12/690933 |
Document ID | / |
Family ID | 43897399 |
Filed Date | 2011-04-28 |
United States Patent
Application |
20110094712 |
Kind Code |
A1 |
HOU; CHUEN-SHU |
April 28, 2011 |
PLATE-TYPE HEAT PIPE
Abstract
An exemplary plate-type heat pipe includes a condensing plate,
an evaporating plate and a first wick portion. The evaporating
plate cooperates with the condensing plate to define a hermetic
container. Working fluid is contained in the container. The first
wick portion is formed on an inner surface of the evaporating
plate. The first wick portion defines through holes therein.
Inventors: |
HOU; CHUEN-SHU; (Tu-Cheng,
TW) |
Assignee: |
FOXCONN TECHNOLOGY CO.,
LTD.
Tu-Cheng
TW
|
Family ID: |
43897399 |
Appl. No.: |
12/690933 |
Filed: |
January 21, 2010 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
F28D 15/0233 20130101;
F28D 15/046 20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/02 20060101
F28D015/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 22, 2009 |
CN |
200910308623.4 |
Claims
1. A plate-type heat pipe comprising: a condensing plate; an
evaporating plate cooperating with the condensing plate to define a
hermetic container; working fluid contained in the container; and a
first wick portion formed on an inner surface of the evaporating
plate, the first wick portion defining a plurality of through holes
therein.
2. The plate-type heat pipe of claim 1, wherein the first wick
portion is made of sintered metallic powder.
3. The plate-type heat pipe of claim 1, wherein a plurality of
auxiliary wick portions are received in the through holes,
respectively, and contact the inner surface of the evaporating
plate.
4. The plate-type heat pipe of claim 3, wherein each of the
auxiliary wick portions is thinner than the first wick portion,
each auxiliary wick portion comprising a first side contacting the
inner surface of the evaporating plate and an opposite second
side.
5. The plate-type heat pipe of claim 4, wherein a cross-section of
each of the auxiliary wick portions is a rectangle, the second side
being parallel to the first side.
6. The plate-type heat pipe of claim 4, wherein a cross-section of
each of the auxiliary wick portions is a trapezoid, the second side
being aslant relative to the first side.
7. The plate-type heat pipe of claim 6, wherein the auxiliary wick
portions are all oriented toward the same direction.
8. The plate-type heat pipe of claim 4, wherein the second side of
each of the auxiliary wick portions is concave, and a thickness of
each of the auxiliary wick portions gradually increases from a
central portion thereof to each of opposite ends thereof.
9. The plate-type heat pipe of claim 4, wherein the evaporating
plate comprises a central heat absorbing portion and two sidewalls
extending upwardly at opposite sides of the heat absorbing portion
and connecting with the condensing plate, and the first wick
portion is adhered on an inner surface of the heat absorbing
portion.
10. The plate-type heat pipe of claim 9, further comprising two
second wick portions adhered on inner surfaces of the sidewalls,
respectively.
11. The plate-type heat pipe of claim 10, wherein the evaporating
plate further comprises two transition portions extend outwardly
and upwardly from opposite ends of the heat absorbing portion, and
two third wick portions are adhered on inner surfaces of the
transition portions.
12. The plate-type heat pipe of claim 11, wherein the evaporating
plate further comprises two extending portions extending outwardly
from opposite ends of the transition portions, respectively, and
connecting with the two sidewalls, respectively, and two fourth
wick portions are adhered on inner surfaces of the extending
portions.
13. The plate-type heat pipe of claim 10, wherein each of the
second wick portions fills a corner formed by the corresponding
sidewall and the corresponding extending portion, and a
cross-section of each of the second wick portions is generally
triangular.
14. The plate-type heat pipe of claim 11, wherein a first wick
member is adhered on an inner surface of the condensing plate and
connects with the second wick portions.
15. A plate-type heat pipe comprising: a hermetic container
comprising an evaporating plate and a condensing plate facing each
other; working fluid contained in the container; and a wick portion
formed on an inner surface of the evaporating plate, the wick
portion defining a plurality of capillary pores and a plurality of
through holes therein.
16. The plate-type heat pipe of claim 15, wherein an auxiliary wick
is arranged in each of the through holes of the wick portion and
contacts the inner surface of the evaporating plate.
17. The plate-type heat pipe of claim 16, wherein each of the
auxiliary wicks is thinner than the wick portion, and comprises a
first side contacting the inner surface of the evaporating plate
and an opposite second side.
18. The plate-type heat pipe of claim 17, wherein the second side
of each of the auxiliary wicks is aslant relative to the first
side.
19. The plate-type heat pipe of claim 17, wherein the second side
of each of the auxiliary wicks is concave, and a thickness of each
of the auxiliary wicks gradually increases from a central portion
thereof to each of opposite ends thereof.
20. The plate-type heat pipe of claim 15, wherein the evaporating
plate comprises a heat absorbing portion and two transition
portions extending outwardly and upwardly from opposite ends of the
heat absorbing portion, the wick portion being arranged on the heat
absorbing portion.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to heat pipes and, more
particularly, to a plate-type heat pipe having good heat
dissipation efficiency and stable and reliable performance.
[0003] 2. Description of Related Art
[0004] Generally, plate-type heat pipes efficiently dissipate heat
from heat-generating components such as a central processing unit
(CPU) of a computer. A conventional plate-type heat pipe comprises
a top plate and a bottom cover hermetically contacting the top
plate to form a container. A wick structure is adhered to an inner
surface of the bottom cover. Working fluid is contained in the
container. All parts of the wick structure have the same thickness.
When the bottom cover of the plate-type heat pipe absorbs heat of
the heat-generating component, the working fluid is vaporized to
absorb heat of the bottom cover.
[0005] If the wick structure is too thick, a part of the vaporized
working fluid is retarded by the wick structure when the vaporized
working fluid is escaping from the wick structure toward the top
plate. In addition, if the pores of the wick structure are too
small, the vaporized working fluid also tends to be retarded by the
wick structure. In these kinds of situations, a plurality of
bubbles is formed in and on the wick structure. The bubbles tend to
block the pores of the wick structure, and retard the flow of
condensed working fluid into the wick structure. When this happens,
the amount of condensed working fluid contained in the wick
structure decreases. What working fluid there is in the wick
structure may absorb the heat of the bottom cover too slowly,
whereby heat is accumulated on the bottom cover. In due course, the
plate-type heat pipe may overheat, and the heat dissipation
efficiency of the plate-type heat pipe is reduced.
[0006] What is needed, therefore, is a plate-type heat pipe having
good heat dissipation efficiency and stable, reliable
performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a cross-sectional view of a plate-type heat pipe
in accordance with a first embodiment of the present disclosure,
the plate-type heat pipe including an evaporating plate having a
heat absorbing portion, a first wick member, and a second wick
member having a first wick portion.
[0008] FIG. 2 is an isometric view of part of the heat absorbing
portion of FIG. 1, showing the first wick portion mounted on the
heat absorbing portion.
[0009] FIG. 3 is an enlarged, cross-sectional view of part of the
heat absorbing portion with the first wick portion, taken along
line III-III of FIG. 2.
[0010] FIG. 4 is similar to FIG. 3, but showing part of a heat
absorbing portion of an evaporating plate arrangement of a
plate-type heat pipe in accordance with a second embodiment of the
present disclosure, with a first wick portion and a number of
auxiliary wick portions mounted on the heat absorbing portion.
[0011] FIG. 5 is similar to FIG. 3, but showing part of a heat
absorbing portion of an evaporating plate arrangement of a
plate-type heat pipe in accordance with a third embodiment of the
present disclosure, with a first wick portion and a number of
auxiliary wick portions mounted on the heat absorbing portion.
[0012] FIG. 6 is similar to FIG. 3, but showing part of a heat
absorbing portion of an evaporating plate arrangement of a
plate-type heat pipe in accordance with a fourth embodiment of the
present disclosure, with a first wick portion and a number of
auxiliary wick portions mounted on the heat absorbing portion.
DETAILED DESCRIPTION
[0013] Referring to FIGS. 1-2, a plate-type heat pipe in accordance
with a first embodiment of the present disclosure is shown. The
plate-type heat pipe includes a hermetic container 10, a continuous
wick structure 30 mounted on an inner surface of the container 10,
and working fluid (not shown) contained in the container 10.
[0014] The container 10 is made of copper, aluminum, or an alloy
thereof, and includes an elongated condensing plate 11 and a
bowl-shaped evaporating plate 13 hermetically contacting the
condensing plate 11. The evaporating plate 13 absorbs heat
generated by one or more components (not shown) such as electronic
devices. The condensing plate 11 dissipates heat, transferred from
the evaporating plate 13, to the ambient environment.
[0015] The evaporating plate 13 includes an elongated heat
absorbing portion 131, two transition portions 133, two extending
portions 134 and two sidewalls 135. The transition portions 133
extend upwardly and outwardly from opposite lateral edges of the
heat absorbing portion 131, respectively, and are symmetrically
opposite each other. The extending portions 134 extend outwardly
along opposite horizontal directions from outer edges of the
transition portions 133, respectively. The sidewalls 135 extend
upwardly from outer edges of the extending portions 133,
respectively. The sidewalls 135 are perpendicular to the extending
portions 133. In the illustrated embodiment, top ends of the
sidewalls 135 are integrally formed with two ends of the condensing
plate 11. That is, the evaporating plate 13 and the condensing
plate 11 are a single body of the same material without any seams.
In other embodiments, the evaporating plate 13 and the condensing
plate 11 can be two separate bodies connected together.
[0016] The wick structure 30 is made of sintered metallic powder,
and includes an elongated first wick member 31 and a second wick
member 33. A plurality of capillary pores (not labeled) are defined
in the first wick member 31 and the second wick member 33 for
providing a capillary force to draw condensed working fluid back
toward a middle portion of the second wick member 33 (see also
below). The first wick member 31 is adhered to an inner surface of
the condensing plate 11. The second wick member 33 is adhered to an
inner surface of the evaporating plate 13. Opposite ends of the
second wick structure 33 interconnect opposite ends of the first
wick member 31, respectively, thereby forming the continuous wick
structure 30.
[0017] Referring also to FIG. 3, the second wick structure 33
includes an elongated first wick portion 331, two second wick
portions 333, two third wick portions 335 and two fourth wick
portions 337. The first wick portion 331, the second wick portions
333, and the third wick portions 335 are spaced from the first wick
member 31.
[0018] The first wick portion 331 is adhered to an inner surface of
the heat absorbing portion 131 of the evaporating plate 13. The
first wick portion 331 defines a plurality of rectangular or square
through holes 3313 therein. In the illustrated embodiment, the
through holes 3313 are arranged in a regular m x n array. Because
the through holes 3313 are defined in the first wick portion 331, a
portion of the working fluid is contained in the through holes 3313
and contacts the heat absorbing portion 131 of the evaporating
plate 13 directly. The working fluid contained in the through holes
3313 and contained in the first wick portion 331 absorbs the heat
of the heat absorbing portion 131 quickly and then is vaporized.
The vaporized working fluid in the through holes 3313 escapes the
first wick portion 331 from the through holes 3313 directly.
Therefore the working fluid in the first wick portion 331 escapes
from the first wick portion 331 via the through holes 3313 quickly.
Accordingly, unlike in other conventional plate-type heat pipes,
few or even no bubbles accumulate in the first wick portion 331
when the plate-type heat pipe is in operation. Thus, the heat
dissipation efficiency of the plate-type heat pipe is improved. In
alternative embodiments, the through holes 3313 can be triangular,
circular, oval-shaped, elliptical, etc, and can be larger than the
pores of the first wick member 31 and the second wick member
33.
[0019] The second wick portions 333 extend upwardly and outwardly
from opposite ends of the first wick portion 331, respectively, and
are symmetrically opposite each other. The second wick portions 333
are adhered to inner surfaces of the transition portions 133 of the
evaporating plate 13. The third wick portions 335 are horizontal,
and extend outwardly from the second wick portions 333,
respectively. The third wick portions 335 are adhered to inner
surfaces of the extending portions 134 of the evaporating plate 13.
Each fourth wick portion 337 is adhered to an inner surface of the
corresponding sidewall 135 of the evaporating plate 13, and fills a
corner formed by the sidewall 135 and the corresponding extending
portion 134. A cross-section of each fourth wick portion 337 is
substantially triangular. That is, a transverse thickness
(horizontal, from left to right, as viewed in FIG. 1) of the fourth
wick portion 337 progressively decreases from a bottom end of the
fourth wick portion 337 to a top end of the fourth wick portion
337. The fourth wick portions 337 connect the opposite ends of the
first wick member 31, respectively. The second wick portions 333,
third wick portions 335, and fourth wick portions 337 cooperatively
guide the condensing working fluid contained in or accumulated on
the first wick member 31 back to the first wick portion 331 to
ensure that a quantity of the condensing working fluid in the first
wick portion 331 is sufficiently large at all times.
[0020] Referring to FIG. 4, this shows part of a heat absorbing
portion arrangement of a plate-type heat pipe in accordance with a
second embodiment of the present disclosure. A first wick portion
331 and a plurality of auxiliary wick portions 332 are adhered to
an inner surface of a heat absorbing portion 131. In the
illustrated embodiment, the auxiliary wick portions 332 fill bottom
ends of the through holes 3313, respectively. Bottom end surfaces
of the auxiliary wick portions 332 and a bottom surface of the
first wick portion 331 are coplanar with one another, and contact
the inner surface of the heat absorbing portion 131. Each of the
auxiliary wick portions 332 has a same thickness and is much
thinner than the first wick portion 331. For example, each
auxiliary wick portion 332 is less than half the thickness of the
first wick portion 331.
[0021] Because the auxiliary wick portions 332 are thinner than the
first wick portion 331, heat transfer paths of the working fluid in
the heat absorbing portion 131 are generally shorter than those of
conventional plate-type heat pipes. Accordingly, the working fluid
is vaporized quickly. Thus, the heat dissipation efficiency of the
plate-type heat pipe is improved. In addition, a capillary suction
of the second wick member 33 is improved because of the auxiliary
wick portions 332 filling bottoms of the through holes 3313 of the
first wick portion 331. Therefore, the condensed working fluid
flows back to the first wick portion 331 more quickly. Thus, stable
and reliable performance of the plate-type heat pipe can be
ensured.
[0022] Referring to FIG. 5, this shows part of a heat absorbing
portion arrangement of a plate-type heat pipe in accordance with a
third embodiment of the present disclosure. A first wick portion
331 and a number of auxiliary wick portions 334 are adhered to an
inner surface of a heat absorbing portion 131. A cross-section of
each of the auxiliary wick portions 334 is a trapezoid. Each
auxiliary wick portion 334 has a smaller end, and a larger end
opposite to the smaller end. The smaller ends of the auxiliary wick
portions 334 are all oriented toward the same direction. In this
embodiment, a top side of each auxiliary wick portion 334 is
aslant, and a bottom side of each auxiliary wick portion 334 is
horizontal and adhered to the inner surface of the heat absorbing
portion 131. The larger ends of the auxiliary wick portions 334 are
all thinner than the first wick portion 331.
[0023] Referring to FIG. 6, this shows part of a heat absorbing
portion arrangement of a plate-type heat pipe in accordance with a
fourth embodiment of the present disclosure. A first wick portion
331 and a plurality of auxiliary wick portions 336 are adhered to
an inner surface of a heat absorbing portion 131. A cross-section
of each of the auxiliary wick portions 336 has a top side being
concave, and a bottom side being horizontal and adhered to the
inner surface of the heat absorbing portion 131. That is, a
thickness of each auxiliary wick portion 336 gradually increases
from a central portion thereof to each of opposite ends thereof.
The opposite ends of the auxiliary wick portions 336 are all
thinner than the first wick portion 331.
[0024] It is to be understood, however, that even though numerous
characteristics and advantages of various embodiments have been set
forth in the foregoing description, together with details of the
structures and functions of the embodiments, the disclosure is
illustrative only, and changes may be made in detail, especially in
matters of shape, size, and arrangement of parts within the
principles of the disclosure to the full extent indicated by the
broad general meaning of the terms in which the appended claims are
expressed.
* * * * *