U.S. patent application number 12/731355 was filed with the patent office on 2010-10-07 for method of manufacturing a heat transport device, heat transport device, electronic apparatus, and caulking pin.
This patent application is currently assigned to SONY CORPORATION. Invention is credited to Kazuo Goto, Kazuya Sakamoto, Takashi Yajima, Keitaro Yamashita.
Application Number | 20100251547 12/731355 |
Document ID | / |
Family ID | 42824961 |
Filed Date | 2010-10-07 |
United States Patent
Application |
20100251547 |
Kind Code |
A1 |
Yajima; Takashi ; et
al. |
October 7, 2010 |
METHOD OF MANUFACTURING A HEAT TRANSPORT DEVICE, HEAT TRANSPORT
DEVICE, ELECTRONIC APPARATUS, AND CAULKING PIN
Abstract
A method of manufacturing a heat transport device includes
injecting a working fluid that transports heat by a phase change
into a casing through an injection opening of the casing under
reduced pressure, sealing an injection path by caulking under the
reduced pressure, the injection path being provided in the casing
into which the working fluid is injected and causing the injection
opening and an action area in which the phase change of the working
fluid occurs to communicate with each other, contacting a
peripheral area of the injection opening of the casing with an
inner surface of the injection path by caulking the peripheral
area, the peripheral area including the injection opening, and
sealing the injection opening by welding a part of the casing
contacted.
Inventors: |
Yajima; Takashi; (Tokyo,
JP) ; Goto; Kazuo; (Kanagawa, JP) ; Yamashita;
Keitaro; (Kanagawa, JP) ; Sakamoto; Kazuya;
(Tokyo, JP) |
Correspondence
Address: |
SONNENSCHEIN NATH & ROSENTHAL LLP
P.O. BOX 061080, WACKER DRIVE STATION, WILLIS TOWER
CHICAGO
IL
60606-1080
US
|
Assignee: |
SONY CORPORATION
Tokyo
JP
|
Family ID: |
42824961 |
Appl. No.: |
12/731355 |
Filed: |
March 25, 2010 |
Current U.S.
Class: |
29/890.03 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 23/427 20130101; F28D 15/0233 20130101; Y10T 29/4935 20150115;
F28D 15/0283 20130101; H01L 2924/00 20130101; H01L 2924/0002
20130101 |
Class at
Publication: |
29/890.03 |
International
Class: |
B21D 53/02 20060101
B21D053/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 7, 2009 |
JP |
2009-092782 |
Claims
1. A method of manufacturing a heat transport device, comprising:
injecting a working fluid that transports heat by a phase change
into a casing through an injection opening of the casing under
reduced pressure; sealing an injection path by caulking under the
reduced pressure, the injection path being provided in the casing
into which the working fluid is injected and causing the injection
opening and an action area in which the phase change of the working
fluid occurs to communicate with each other; contacting a
peripheral area of the injection opening of the casing with an
inner surface of the injection path by caulking the peripheral
area, the peripheral area including the injection opening; and
sealing the injection opening by welding a part of the casing
contacted.
2. The method of manufacturing a heat transport device according to
claim 1, wherein the caulking in the sealing of the injection path
is linear crushing of the casing.
3. The method of manufacturing a heat transport device according to
claim 2, wherein the caulking in the sealing of the injection path
is crushing of an area that surrounds the injection opening of the
casing.
4. The method of manufacturing a heat transport device according to
claim 2, wherein the caulking in the sealing of the injection path
is performed on an area on the injection path outside an area that
surrounds the injection opening.
5. The method of manufacturing a heat transport device according to
claim 2, wherein the contacting is performed under an atmospheric
pressure after the sealing of the injection path.
6. The method of manufacturing a heat transport device according to
claim 3, wherein the contacting is performed simultaneously with
the sealing of the injection path.
7. The method of manufacturing a heat transport device according to
claim 2, wherein the sealing of the injection path is crushing of
the casing with a blade.
8. The method of manufacturing a heat transport device according to
claim 7, wherein the blade is annularly formed in a direction in
which the casing is crushed.
9. The method of manufacturing a heat transport device according to
claim 3, wherein the sealing of the injection path is crushing of
the area that surrounds the injection opening of the casing by
using a caulking pin with the injection opening being surrounded
with an annular blade of the caulking pin, the caulking pin having
the annular blade and a concave portion, the annular blade being
formed in a direction in which the casing is crushed, the concave
portion being formed from the blade and having an inner surface
formed vertically from an opening surface of the concave portion
that is surrounded by the blade.
10. The method of manufacturing a heat transport device according
to claim 3, wherein the sealing of the injection path is crushing
of the area that surrounds the injection opening of the casing by
using a caulking pin with the injection opening being surrounded
with an annular blade of the caulking pin, the caulking pin having
the annular blade and a concave portion, the annular blade being
formed in a direction in which the casing is crushed, the concave
portion having one of a conical shape and a pyramidal shape tapered
with increasing distance from an opening surface of the concave
portion that is surrounded by the blade.
11. The method of manufacturing a heat transport device according
to claim 9, wherein the caulking pin has a convex portion formed in
the concave portion toward the opening surface of the concave
portion that is surrounded by the blade.
12. A heat transport device, comprising: a working fluid to
transport heat by a phase change; and a casing including an
injection opening for the working fluid, an action area in which
the phase change of the working fluid occurs, and an injection path
that causes the injection opening and the action area to
communicate with each other and is sealed by caulking, a peripheral
area of the injection opening of the casing being formed to be
crushed, the peripheral area including the injection opening, the
injection opening being sealed by welding the peripheral area of
the injection opening with an inner surface of the injection
path.
13. An electronic apparatus equipped with a heat transport device
including a working fluid to transport heat by a phase change and a
casing having an injection opening for the working fluid, an action
area in which the phase change of the working fluid occurs, and an
injection path that causes the injection opening and the action
area to communicate with each other and is sealed by caulking, a
peripheral area of the injection opening of the casing being formed
to be crushed, the peripheral area including the injection opening,
the injection opening being sealed by welding the peripheral area
of the injection opening with an inner surface of the injection
path.
14. A caulking pin of a heat transport device including a casing,
the caulking pin crushing the casing, the casing having an
injection opening for a working fluid, an action area in which a
phase change of the working fluid occurs, and an injection path
that causes the injection opening and the action area to
communicate with each other, the caulking pin comprising: an
annular blade formed in a direction in which the casing is crushed;
and a concave portion formed from the blade and having an inner
surface formed from an opening surface of the concave portion that
is surrounded by the blade.
15. A heat transport device including a working fluid between a
first member and a second member, the heat transport device
comprising: a contact portion on which the first member and the
second member are contacted annularly; and a welding portion on
which the first member and the second member are welded inside the
contact portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat transport device
that transports heat by a phase change of a working fluid, and to a
manufacturing method of the same, an electronic apparatus equipped
with a heat transport device, and a caulking pin.
[0003] 2. Description of the Related Art
[0004] In the past, a flat-plate heat pipe has been widely used as
a device that cools a heat source such as a CPU (central processing
unit). A flat-plate heat pipe cools a CPU and the like by using a
phase change of a working fluid, and therefore contains a working
fluid therein.
[0005] For example, Japanese Patent Application Laid-open No.
2007-315745 (hereinafter, referred to as Patent Document 1)
discloses a flat-plate heat pipe, on an outer surface of which a
refrigerant injection hole and an air outlet hole are formed. In
the flat-plate heat pipe, a refrigerant such as water is injected
through the refrigerant injection hole, and then a thermoplastic
metal having a spherical body, such as solder, is placed at the
refrigerant injection hole and the air outlet hole.
[0006] Subsequently, the spherical thermoplastic metal is
pressurized and deformed at a low temperature, thereby temporarily
sealing the refrigerant injection hole and the air outlet hole.
After that, the thermoplastic metal is pressurized and deformed at
a high temperature, thereby sealing the refrigerant injection hole
and the air outlet hole (see, for example, paragraph 0176 of Patent
Document 1).
SUMMARY OF THE INVENTION
[0007] In the heat pipe disclosed in Patent Document 1, the
thermoplastic metal is used as a sealing member for the hole, which
has a problem of low reliability of airtightness in the heat pipe.
For example, after the heat pipe is formed, in a reflow process for
mounting the heat pipe on another member, heat may be applied to
the heat pipe in some cases. In this case, the thermoplastic metal
as the sealing member may be molten or softened, which may cause a
clearance in the hole. Therefore, there is a problem in that the
airtightness in the heat pipe is difficult to be maintained.
[0008] In view of the above-mentioned circumstances, it is
desirable to provide a manufacturing method of a heat transport
device that enables to improve airtightness of the inside of a heat
transport device, and provide a heat transport device, an
electronic apparatus equipped with the same, and a caulking
pin.
[0009] According to an embodiment of the present invention, there
is provided a method of manufacturing a heat transport device
including the following steps.
[0010] A working fluid that transports heat by a phase change is
injected into a casing through an injection opening of the casing
under reduced pressure.
[0011] An injection path is sealed by caulking under the reduced
pressure. The injection path is provided in the casing into which
the working fluid is injected and causing the injection opening and
an action area in which the phase change of the working fluid
occurs to communicate with each other.
[0012] A peripheral area of the injection opening of the casing is
contacted with an inner surface of the injection path by caulking
the peripheral area. The peripheral area includes the injection
opening.
[0013] The injection opening is sealed by welding a part of the
casing contacted.
[0014] In this embodiment, the injection path is sealed by caulking
under the reduced pressure, that is, the injection path is
temporarily sealed before the welding process, with the result that
the airtightness of the action area in the casing can be secured
before the welding process. Because the contact process and the
welding process of the peripheral area of the injection opening are
performed in the state where the action area of the airtightness is
secured, it is possible to improve the airtightness of the action
area in the casing of the product.
[0015] The caulking in the sealing of the injection path is linear
crushing of the casing. The casing is linearly crushed, with the
result that the pressure for the crushing can be larger as compared
to a case where the casing is crushed with a plane. Therefore, the
airtightness of the injection path after the sealing can be
reliably secured. In addition, even in a case where the injection
path is short, that is, a distance from the injection opening to
the action area is short, the linear sealing can be performed.
[0016] The meaning of the linear sealing includes a sealing in a
straight line, a curved line, or a line in combination with the
straight line and the curved line.
[0017] The caulking in the sealing of the injection path is
crushing of an area that surrounds the injection opening of the
casing. By the crushing process, an inner area in the injection
path, which is communicated with the injection opening, is
separated from an outer area in the injection path, which is
communicated with the injection opening. Thus, at the time of
welding, it is possible to suppress an influence of heat given to
the outer area in the injection path, which is communicated with
the injection opening.
[0018] The caulking in the sealing of the injection path may be
performed on an area on the injection path outside an area that
surrounds the injection opening. That is, because the caulked area
is distanced from the injection opening from the injection opening,
it is possible to suppress an influence of heat given to the
caulked area of the casing at the time of welding.
[0019] The contacting may be performed under an atmospheric
pressure after the sealing of the injection path. Because the
contacting process can be performed under the atmospheric pressure,
it becomes easy to manufacture a heat transport device, and it is
possible to cut a manufacturing cost.
[0020] The contacting is performed simultaneously with the sealing
of the injection path. As a result, the number of manufacturing
processes can be reduced, and thus time required for the
manufacturing can be reduced.
[0021] The sealing of the injection path may be crushing of the
casing with a blade. By using the blade, the pressure for the
crushing can be increased as compared to a case where a member
having a flat end surface for crushing the casing is used, with the
result that the airtightness is improved.
[0022] The blade may be annularly formed in a direction in which
the casing is crushed. For example, in a case where an inner
diameter of the blade is larger than the width (width in a
direction perpendicular to a direction in which the working fluid
injected from the injection opening flows) of the injection path,
the injection path can be crushed with two lines at the same time,
for example. As a result, the airtightness can be realized with
higher accuracy at the time of the temporary sealing.
[0023] The sealing of the injection path may be crushing of the
area that surrounds the injection opening of the casing by using a
caulking pin with the injection opening being surrounded with an
annular blade of the caulking pin, the caulking pin having the
annular blade and a concave portion.
[0024] The annular blade is formed in a direction in which the
casing is crushed.
[0025] The concave portion is formed from the blade and having an
inner surface formed vertically from an opening surface of the
concave portion that is surrounded by the blade.
[0026] Because the inner surface of the concave portion is formed
vertically from the opening surface (end surface of the caulking
pin) of the concave portion, it is possible to minimize the stress
applied to a part of the casing in the concave portion of the
caulking pin at the time when the casing is crushed with the
caulking pin. Therefore, deformation of the casing in the concave
portion is suppressed, and the welding process subsequent thereto
can be desirably performed.
[0027] Alternatively, the sealing of the injection path may be
crushing of the area that surrounds the injection opening of the
casing by using a caulking pin with the injection opening being
surrounded with an annular blade of the caulking pin, the caulking
pin having the annular blade and a concave portion.
[0028] The annular blade is formed in a direction in which the
casing is crushed.
[0029] The concave portion has one of a conical shape and a
pyramidal shape tapered with increasing distance from an opening
surface of the concave portion that is surrounded by the blade.
[0030] The deformation of the part of the casing in the concave
portion as described above is prevented depending on the inner
diameter of the annular blade, the size of the injection opening,
or the material of the casing. Therefore, the concave portion may
be formed in the conical or pyramidal shape as in this
embodiment.
[0031] The conical or pyramidal shape includes a conical and
three-or-more-sided pyramidal shape.
[0032] The caulking pin may have a convex portion formed in the
concave portion toward the opening surface of the concave portion
that is surrounded by the blade. As described above, by getting the
blade of the caulking pin into the casing, the convex portion
functions so as to suppress the deformation of the part of the
casing in the concave portion. As a result, the welding process
subsequent thereto can be desirably performed.
[0033] According to another embodiment of the present invention,
there is provided a heat transport device including a working fluid
and a casing.
[0034] The working fluid transports heat by a phase change.
[0035] The casing includes an injection opening for the working
fluid, an action area, and an injection path.
[0036] In the action area, the phase change of the working fluid
occurs.
[0037] The injection path causes the injection opening and the
action area to communicate with each other and is sealed by
caulking.
[0038] In the casing, the peripheral area of the injection opening
of the casing is formed to be crushed, the peripheral area
including the injection opening. The injection opening is sealed by
welding the peripheral area of the injection opening with an inner
surface of the injection path.
[0039] According to another embodiment of the present invention,
there is provided an electronic apparatus equipped with the heat
transport device described above.
[0040] According to another embodiment of the present invention,
there is provided a caulking pin of a heat transport device
including a casing. The caulking pin crushes the casing. The casing
has an injection opening for a working fluid, an action area in
which a phase change of the working fluid occurs, and an injection
path that causes the injection opening and the action area to
communicate with each other. The caulking pin includes an annular
blade and a concave portion.
[0041] The annular blade is formed in a direction in which the
casing is crushed.
[0042] The concave portion is formed from the blade and has an
inner surface formed from an opening surface of the concave portion
that is surrounded by the blade.
[0043] According to another embodiment of the present invention,
there is provided a heat transport device including a working fluid
between a first member and a second member. The heat transport
device includes a contact portion and a welding portion.
[0044] On the contact portion, the first member and the second
member are contacted annularly.
[0045] On the welding portion, the first member and the second
member are welded inside the contact portion.
[0046] As described above, according to the embodiments of the
present invention, in the temporary sealing process in the
manufacturing process, the airtightness in the casing of the heat
transport device can be improved. Further, the airtightness in the
casing of the heat transport device as a completed product can also
be improved.
[0047] These and other objects, features and advantages of the
present invention will become more apparent in light of the
following detailed description of best mode embodiments thereof, as
illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0048] FIG. 1 is a perspective view showing a heat transport device
according to a first embodiment of the present invention;
[0049] FIG. 2 is a cross-sectional view showing the heat transport
device taken along a line perpendicular to a longitudinal direction
of the heat transport device shown in FIG. 1 (taken along the line
A-A of FIG. 1);
[0050] FIG. 3 is a perspective view of the heat transport device of
FIG. 1 in a manufacturing process;
[0051] FIG. 4 is a flowchart of a manufacturing method of the heat
transport device shown in FIG. 1;
[0052] FIG. 5A is an enlarged plan showing a part of a casing in
the vicinity of an injection opening after a diffusion welding is
performed, and FIG. 5B is a cross-sectional view of FIG. 5A;
[0053] FIG. 6A is a plan view showing an area in the vicinity of
the injection opening in a state where the injection opening is
temporarily sealed, and FIG. 6B is a diagram for explaining the
temporary sealing process;
[0054] FIG. 7 is a diagram showing a case where an inner diameter
of a temporary sealing groove is smaller than a width of an
injection path;
[0055] FIG. 8 are diagrams each showing a contacting process in the
vicinity of the injection opening by caulking;
[0056] FIG. 9 is a diagram showing a sealing process of the
injection opening by laser welding;
[0057] FIG. 10 is an enlarged plan view showing an area in the
vicinity of an injection opening of a heat transport device
according to a second embodiment of the present invention;
[0058] FIG. 11 is a flowchart showing a manufacturing method of the
heat transport device shown in FIG. 10;
[0059] FIG. 12 is an enlarged plan view showing an area in the
vicinity of an injection opening of a heat transport device
according to a third embodiment of the present invention;
[0060] FIG. 13 is a perspective view showing a heat transport
device according to a fourth embodiment of the present invention in
a manufacturing process;
[0061] FIG. 14 is a cross-sectional view showing a state where a
first flat plate, a flame body, and a second flat plate shown in
FIG. 13 are bonded;
[0062] FIG. 15 is a perspective view showing a heat transport
device according to a fifth embodiment of the present invention in
a manufacturing process;
[0063] FIG. 16 is a cross-sectional view of a main part of a
caulking pin of another mode and the casing of a heat transport
device crushed with the caulking pin;
[0064] FIG. 17 is a cross-sectional view of a main part of a
caulking pin of another mode;
[0065] FIG. 18 is a cross-sectional view of a main part of a
caulking pin of another mode;
[0066] FIG. 19 is a table showing a result of a failure/no-failure
test on a leakage at a time when the injection path of the casing
is temporarily sealed with a plurality of caulking pins whose end
shapes are different;
[0067] FIG. 20 are diagrams each showing a three-dimensional shape
of a flat plate of the casing crushed by a caulking pin of No. 4 in
the table of FIG. 19;
[0068] FIG. 21 are diagrams each showing a three-dimensional shape
of the flat plate of the casing crushed by a caulking pin of No. 14
in the table of FIG. 19; and
[0069] FIG. 22 is a perspective view showing a laptop PC as an
electronic apparatus equipped with a heat transport device.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0070] Hereinafter, embodiments of the present invention will be
described with reference to the drawings.
First Embodiment
Structure of Heat Transport Device
[0071] FIG. 1 is a perspective view showing a heat transport device
100 according to a first embodiment of the present invention. FIG.
2 is a cross-sectional view showing the heat transport device 100
taken along a line perpendicular to a longitudinal direction of the
heat transport device 100 shown in FIG. 1 (taken along the line A-A
of FIG. 1). FIG. 3 is a perspective view of the heat transport
device 100 in a manufacturing process.
[0072] The heat transport device 100 includes a flat plate 1, a
capillary member 3, a vapor flow path (not shown), and a dish-like
container plate 2 having a concave portion 2a in which the
capillary member 3 and the vapor flow path are contained. The flat
plate 1, the capillary member 3, and the container plate 2 are
formed into a rectangular shape, for example. The flat plate 1 and
the container plate 2 constitute a casing 12 of the heat transport
device 100.
[0073] In the casing 12, a working fluid (not shown) that
transports heat by a phase change is sealed. The capillary member 3
causes a capillary force to act on a liquid-phase working fluid,
thereby holding the liquid-phase working fluid. The capillary
member 3 and the vapor flow path (not shown) are provided inside
the casing 12, that is, provided so as to be approximately filled
in the concave portion 2a of the container plate 2. The area inside
the casing 12, that is, an area in which the capillary member 3 and
the vapor flow path (not shown) are disposed functions as an action
area 8 in which a phase change of the working fluid is caused.
[0074] Examples of a material of the flat plate 1 and the container
plate 2 include metals such as copper, aluminum, and stainless.
Further, examples of a material of the working fluid include
ethanol, methanol, acetone, isopropyl alcohol,
hydrochlorofluorocarbon, ammonia, and the like.
[0075] Typically, the capillary member 3 has a mesh structure with
a metal thin wire. In addition to the mesh structure, a structure
in which a plurality of wires are bulked may be used.
Alternatively, a plurality of members each having the mesh
structure may be layered to constitute the capillary member 3.
[0076] The vapor flow path (not shown) may be included in the
capillary member 3. For example, a cellular mesh, a space between
the meshes, or a space between a bottom of the convex portion 2a
and the capillary member 3 may be formed as the vapor flow
path.
[0077] As a material of the flat plate 1, the container plate 2,
and the capillary member 3, a material having high heat
conductivity, such as a carbon nanomaterial may be used in addition
to the metal described above.
[0078] (Action of Heat Transport Device)
[0079] A description will be given on actions of the heat transport
device 100 structured as described above.
[0080] As shown in FIG. 1, on a side of the casing 12 of the heat
transport device 100 in a longitudinal direction, a heat source 9
is thermally connected. The "thermally connected" state refers to a
directly connected state or a state connected through a
heat-conductive member or a heat-conductive sheet-like member (not
shown). Typically, the heat source 9 is an IC (integrated circuit)
such as a CPU or may be a light source such as a semiconductor
laser and an LED.
[0081] The heat transport device 100 receives heat of the heat
source 9 from the position at which the heat source 9 is disposed,
and the working fluid in the liquid phase evaporates, getting into
a gas phase. The gas-phase working fluid moves in the casing 12 to
a side opposite, in the longitudinal direction, to the side where
the heat source 9 is disposed, thereby radiating heat and
condensing. The working fluid that has condensed on the side
opposite to the side of the heat source 9 is moved in the casing 12
to a heat absorption portion by a capillary force of the capillary
member 3. Then, the working fluid receives heat from the heat
source 9 and evaporates again. This cycle is repeated, thereby
cooling the heat source 9.
[0082] (Method of Manufacturing Heat Transport Device)
[0083] Next, a description will be given on a method of
manufacturing the heat transport device 100. FIG. 4 is a flowchart
of the manufacturing method.
[0084] As shown in FIG. 3, the plate 1 has an injection opening 1a
for the working fluid, which penetrates the flat plate 1. In the
container plate 2, at a position corresponding to the injection
opening 1a, an injection path 2c for the working fluid is formed.
The injection path 2c is a groove communicated with the action area
8. The diameter of the injection opening 1a is 0.2 to 0.5 mm, for
example.
[0085] The injection path 2c may be formed by, for example, an
end-milling process, a laser process, a press process, or a
miniaturization process such as a photolithography and a half
etching in a semiconductor manufacturing. When the press process is
used, a burr is not formed. When the laser process or the
end-milling process is used, a mold is unnecessary, and a groove in
any form can be formed.
[0086] As shown in FIG. 4, in Step S101, the flat plate 1 and the
container plate 2 are bonded by diffusion bonding so that the
capillary member 3 is sandwiched between the flat plate 1 and the
container plate 2. The diffusion bonding refers to bonding by
pressing the flat plate 1 and the container plate 2 to each other
by pressure while heating them at a predetermined temperature. As
shown in FIG. 3, in a case where the thickness of the capillary
member 3 is more than the depth of the concave portion 2a of the
container plate 2, the capillary member 3 is pressed and crushed
flat. Conditions of a temperature and a pressure at the time of the
diffusion bonding differ depending on the material, the shape, or
the like of the flat plate 1 and the container plate 2. In this
case, the flat plate 1 is bonded to a bonding surface 2b of the
container plate 2. The groove that functions as the injection path
2c is formed from the bonding surface 2b.
[0087] FIG. 5A is an enlarged plan view showing an area in the
vicinity of the injection opening 1a of the casing 12.
[0088] FIG. 5B is a cross-sectional view of FIG. 5A. As shown in
the figures, the injection opening 1a and the injection path 2c are
communicated with each other, thereby causing the injection opening
1a, the injection path 2c, and the action area 8 to
communicate.
[0089] In Step S102, air in the casing 12 is exhausted. The exhaust
process and processes of Steps S103 and S104 subsequent thereto are
performed in a vacuum chamber (not shown), for example. The vacuum
chamber only has to be evacuated to a predetermined degree of
vacuum (degree of depressurization), to exhaust air in the casing
12. Instead of the form in which the entire casing 12 is contained
in the vacuum chamber, a space around the injection opening 1a may
be locally depressurized by using a dedicated jig.
[0090] In Step S103, the working fluid is injected into the casing
12 exhausted. For example, in the vacuum chamber, a container, in
which a liquid working fluid is retained, is disposed, and the
casing 12 is immersed in the working fluid in the container,
thereby injecting the working fluid into the action area 8 through
the injection opening 1a by a predetermined amount. Instead, an
injection tool (not shown) may be used for injecting the working
fluid into the casing 12.
[0091] In Step S104, the injection path 2c of the casing 12 is
sealed by caulking or swaging (temporary sealing). FIG. 6A is a
plan view showing the sealed state in the vicinity of the injection
opening 1a. In the temporary sealing process, a temporary sealing
groove 1b is formed in an annular (for example, circular) form so
as to surround the injection opening 1a.
[0092] FIG. 6B is a diagram for explaining the temporary sealing
process. A caulking pin 20 having, for example, an annular blade 21
presses (caulks) an area surrounding the injection opening 1a of
the casing 12. In other words, the blade 21 surrounds the injection
opening 1a, and a person or a robot presses the caulking pin 20. As
a result, the part around the injection opening 1a is crushed.
Consequently, the temporary sealing groove 1b is formed, thereby
shutting off the communication with the injection path 2c and the
action area 8 and sealing the injection path 2c. The amount of
crush by the caulking pin 20 corresponds to an extent that the flat
plate 1 is contacted with the inner surface of the injection path
2c as the groove, and a predetermined degree of vacuum is
maintained in the casing 12 even when the casing 12 is under an
atmospheric pressure.
[0093] In FIGS. 6A and 6B, an inner diameter d1 of the annular
blade 21 of the caulking pin 20, which is substantially a diameter
d1' (.ltoreq.d1) of the temporary sealing groove 1b, is set to be
larger than a width L of the injection path 2c in a direction
perpendicular to a length direction thereof.
[0094] The size is not limited to the above. As shown in FIG. 7, a
diameter d2 of a temporary sealing groove 1b' may be smaller than
the width L of the injection path 2c.
[0095] When the blade 21 has the circular form, and the circular
temporary sealing groove 1b' is formed, the injection opening 1a
can be separated from the action area 8. Therefore, the diameter d2
of the temporary sealing groove 1b' may be set to be smaller than
the width L as described above.
[0096] In addition, when the casing 12 is crushed in an annular
form, it becomes unnecessary to crush the entire casing 12 in the
direction of the width L in the case where the width L of the
injection path 2c is relatively large, particularly in the form
shown in FIG. 7. That is, the size of the area surrounding the
injection opening 1a can be set to be constant irrespective of the
width L of the injection path 2c.
[0097] Here, as shown in FIG. 6B, the caulking pin 20 has a concave
portion 22 formed by the annular blade 21. An inner surface 22a of
the concave portion 22 is formed vertically from an opening surface
22b of the concave portion 22 surrounded by the blade 21. That is,
the inner surface 22a of the concave portion 22 is a cylindrical
surface. As described above, the inner surface 22a of the concave
portion 22 is formed vertically from the opening surface 22b, with
the result that a stress that can be given to part of the casing 12
in the concave portion 22 of the caulking pin 20 can be reduced as
much as possible. Thus, deformation of the part of the casing 12 in
the concave portion 22 can be suppressed, and therefore a welding
process in Step S106 can be desirably performed.
[0098] With reference to FIGS. 8A and 8B, in Step S105, a caulking
pin 30 whose shape is different from the shape of the caulking pin
20 used for the temporary sealing is used, and a peripheral area 1d
of the injection opening 1a, which includes the injection opening
1a, is crushed. The caulking pin 30 has a flat end surface 31,
which crushes the casing 12. The diameter of the caulking pin 30 is
larger than the diameter of the injection opening 1a and smaller
than the diameter (inner diameter d1 or d2) of the blade 21 of the
caulking pin 20 at the time of the temporary sealing. By the
caulking, the peripheral area 1d of the injection opening 1a is
brought into contact with the inner surface of the injection path
2c that is opposed to the peripheral area 1d. This process is
performed under the atmospheric pressure.
[0099] The peripheral area 1d of the injection opening 1a of the
casing 12, which includes the injection opening 1a, refers to an
area of the casing 12 within a range that the contacted portion can
be welded by caulking with the caulking pin 20. The area is a
larger area than the size of the injection opening 1a in the cross
section as shown in FIGS. 8A and 8B, for example. That is, the
diameter of the area is substantially close to the width L (see,
FIG. 6A) of the injection path 2c, for example.
[0100] In Step S106, as shown in FIG. 9, the peripheral area 1d
including the injection opening 1a is welded with the inner surface
of the injection path 2c. For the welding, a laser 15 is used, for
example. Typically, a YAG (yttrium aluminum garnet) laser is used,
but a carbon dioxide laser or another laser may be used. By the
welding, the injection opening 1a is sealed (full-scale
sealing).
[0101] As described above, in this embodiment, the injection path
2c is temporarily sealed before the welding process in a vacuum,
with the result that the airtightness of the action area 8 in the
casing 12 can be secured before the welding process. In this way,
the processes (Steps 105 and 106) of contacting and welding of the
peripheral area 1d of the injection opening 1a, which includes the
injection opening 1a, are performed while securing the airtightness
of the action area 8. As a result, the airtightness of the action
area 8 in the casing 12 of the product can be improved.
[0102] Further, the manufacturing method according to this
embodiment provides the following advantage. Although a vacuum
welding with a laser generally requires a process time and cost of
equipment for the vacuum welding, the welding with the laser can be
performed under the atmospheric pressure in this embodiment. Thus,
there is an advantage in that the process time can be saved, and
the cost of the equipment for the vacuum welding can be eliminated.
In addition, the process of Step S105 can also be performed under
the atmospheric pressure, so the same advantage as above can be
provided.
[0103] In this embodiment, the caulking pin 20 having the annular
blade 21 crushes the casing 12. That is, the temporary sealing
groove 1b as a circular-lined groove is formed in the casing 12. In
this way, because the casing 12 is linearly crushed with the blade
21, the pressure of the crushing can be larger as compared to a
case where the casing 12 is crushed with a plane surface. As a
result, the airtightness of the injection path 2c after the sealing
can be reliably secured.
[0104] In addition, because the caulking pin 20 having the annular
blade 21 crushes the casing 12, an area 2d in the injection path
2c, which is communicated with the injection opening 1a is
separated from an outer area 2e (other than the area 2d) in the
injection path 2c, which is communicated with the injection opening
1a. Thus, it is possible to suppress an influence of heat given to
the outer area 2e in the injection path 2c, which is communicated
with the injection opening 1a, at the time of performing the
welding with the laser.
Second Embodiment
[0105] FIG. 10 is an enlarged plan view showing an area in the
vicinity of an injection opening 31a of a heat transport device 200
according to a second embodiment. In the following, descriptions on
the same portions and functions as those of the heat transport
device 100 according to the first embodiment shown in FIG. 1 and
the like will be simplified or omitted, and descriptions on
different points will be mainly given.
[0106] An injection path 33 of a casing 32 of the heat transport
device 200 has an L-letter shape and is connected to an edge
portion 8a of the action area 8, thereby allowing the injection
path 33 and the action area 8 to communicate with each other. Like
the heat transport device 100 according to the first embodiment,
the heat transport device 200 includes a flat plate 31 having the
injection opening 31a, a container plate having the L-letter shaped
injection path 33, and the capillary member 3 (see, FIG. 3).
[0107] FIG. 11 is a flowchart showing a manufacturing method of the
heat transport device 200. Steps S201 to S203, S205, and S206 are
the same as Steps S101 to 103, 105, and 106.
[0108] In Step S104, the mode in which the peripheral area of the
injection opening 1a of the casing 12 is shown. On the other hand,
in Step S204, a temporary sealing groove 31b as a crushed area
(caulked area) corresponds to an area in the casing 32 other than
an area surrounding the injection opening 31a on the injection path
33. That is, the temporary sealing groove 31b is distanced from the
injection opening 31a, for example, provided at a position closer
not to the injection opening 31a but to the action area 8.
Therefore, it is possible to suppress an influence of heat given to
the temporary sealing groove 31b of the casing 32 at the time of
the welding with the laser. Also in Step S204, the caulking pin 20
shown in FIG. 6B may be used.
[0109] The heat influence given to the caulked area of the casing
refers to an influence of impairing the airtightness due to
deformation of the caulked area depending on a welded position with
the laser or a heat temperature, for example.
[0110] Further, in Step S204, the use of the caulking pin 20 having
the annular blade 21 provides the following advantage. For example,
in a case where the inner diameter d1 of the blade 21 is larger
than the width L of the injection path 33, the injection path 33
can be crushed with two lines at the same time as shown in FIG. 10.
As a result, the airtightness at the time of the temporary sealing
is realized with higher accuracy.
[0111] In this embodiment, in Step S205, a peripheral area of the
injection opening 31a of the casing 32, which includes the
injection opening 31a, is crushed and brought into contact with the
inner surface of the injection path 33, as in Step S105. In this
case, the peripheral area of the injection opening 31a of the
casing 32, which includes the injection opening 31a, may be set so
that the peripheral area is larger than the injection opening 31a,
and the action area 8 is not crushed in FIG. 10.
[0112] In the casing 32 shown in FIG. 10, in a temporary sealing
process of the injection path 33, a temporary sealing groove 31b'
may be formed by a linear crushing along a width direction of the
injection path 33. In this case, the line is set to be longer than
the width L of the injection path 33. In this way, by linearly
crushing the casing 32, the injection path 33 can be temporarily
sealed, even if a distance from the injection opening 31a to the
action area 8 is short (if the distance is shorter than the inner
diameter d1 of the blade 21 of the caulking pin 20).
Third Embodiment
[0113] FIG. 12 is an enlarged plan view showing an area in the
vicinity of an injection opening of a heat transport device
according to a third embodiment of the present invention. In a case
where a linear, elongated injection path 19 shown in the figure is
provided to a casing 17, the casing is circularly crushed by the
manufacturing method described in the second embodiment, a
temporary sealing groove 18b is formed on a flat plate 18. As a
result, the same effect as in the second embodiment can be
obtained.
Fourth Embodiment
[0114] FIG. 13 is a perspective view showing a heat transport
device 300 according to a fourth embodiment of the present
invention. FIG. 13 shows a state of the heat transport device 300
in a manufacturing process. The heat transport device 300 includes
a first flat plate 26, the capillary member 3, a flame body 27, and
a second flat plate 28. FIG. 14 is a cross-sectional view showing a
state where the first flat plate 26, the flame body 27, and the
second flat plate 28 shown in FIG. 13 are bonded.
[0115] The front surface of the flame body 27 is a bonding surface
27a, which is bonded to the first flat plate 26 by the diffusion
bonding. The back surface of the flame body 27 opposite to the
front surface is a bonding surface 27b, which is bonded to the
second flat plate 28 by the diffusion bonding. In a rectangular
through hole 27c of the flame body 27, the capillary member 3 and a
vapor flow path (not shown) are provided. The first flat plate 26,
the flame body 27, and the second flat plate 28 constitute a casing
25.
[0116] At an end portion of the second flat plate 28, an injection
opening 28a is formed, and an injection path 28b as a groove
communicated with the injection opening 28a is formed. The
injection path 28b is formed in an L-letter shape in a plan view.
The injection path 28b is communicated with the action area 8 (see,
FIG. 14) at an end portion opposite to the portion where the
injection opening 28a is formed. The action area 8 is an area in
which the capillary member 3 is provided within the through hole
27c of the flame body 27.
[0117] The injection path 28b may be formed by the laser process,
the press process, or the end-milling process as described above.
In the case of the press process, the surface (surface of the
casing) of the second flat plate 28 is protruded.
[0118] The heat transport device 300 as described above can be
manufactured by the method similar to the processes shown in FIG.
11. For example, in Step S204, the area on the injection path 28b
at the position distanced from the injection opening 28a is crushed
by the caulking pin 20 shown in FIG. 6B, thereby temporarily
sealing the injection path 28b. In Step S205, the peripheral area
of the injection opening 28a of the second flat plate 28, which
includes the injection opening 28a, is crushed, with the result
that the peripheral area is brought into contact with the inner
surface of the injection path 28b.
[0119] In this case, the inner surface of the injection path 28b
corresponds to the bonding surface 27b of the flame body 27. In
Step S206, the contacted areas are bonded by the laser bonding,
thereby sealing the injection opening 28a.
Fifth Embodiment
[0120] In FIG. 13, the structure in which the injection opening 28a
and the injection path 28b are formed in the second flat plate 28
is shown. Alternatively, as shown in FIG. 15, in a heat transport
device 400 according to a fifth embodiment, the injection opening
1a that passes through the first flat plate 1 is formed in the
first flat plate 26 (or a second flat plate 38). Further, in a
flame body 37, a groove that functions as an injection path 37a
communicated with the injection opening 1a and the action area 8
may be formed.
[0121] In a case where the injection path 37a is formed on the
flame body 37 by, for example, the press process, a surface of the
flame body 37 opposite to the side on which the injection path 37a
is formed is protruded. In this case, it is difficult to bond the
flame body 37 and the second flat plate 38 with each other.
Accordingly, in this embodiment, the injection path 28b has to be
formed by the laser process or the end-milling process.
[0122] (Other Modes of Caulking Pin)
[0123] FIG. 16 is a cross-sectional view of a main part of a
caulking pin 40 of another mode and the casing 12 of a heat
transport device crushed with the caulking pin 40. The caulking pin
40 has an annular blade 41 and a concave portion 42. The concave
portion 42 is formed from an opening surface 42b surrounded by the
blade 41. The shape of the concave portion 42 is a conical shape
that is tapered with increasing distance from the opening surface
42b.
[0124] The blade 41 of the caulking pin 40 surrounds and crushes
the injection opening 1a of the casing 12, thereby temporarily
sealing the injection path 2c. Because the concave portion 42 of
the caulking pin 40 has the conical shape, an area in the vicinity
of the injection opening 1a of the casing 12 is protruded like a
part of a sphere as shown in FIG. 16. In other words, in this mode,
on a contacted portion 1e in the injection path 2c, a stress is
applied to the flat plate 1 to be directed toward injection opening
1a unlike the embodiment shown in FIG. 6B. Depending on the inner
diameter of the blade 41 of the caulking pin 40, the size of the
injection opening 1a, or the material of the flat plate 1,
deformation of the casing 12 in the concave portion 42 as described
above does not occur. Therefore, there is not a problem if the
stress is applied toward the injection opening 1a as shown in FIG.
16 in this mode.
[0125] FIG. 17 is a cross-sectional view of a main part of a
caulking pin 50 of another mode. The caulking pin 50 has a concave
portion 52. The concave portion 52 has a part 52a of a conical
surface and a convex portion 53 formed in the concave portion 52
toward an opening surface 52b surrounded by the annular blade 51.
The shape of the convex portion 53 viewed in an axis direction of
the caulking pin 50 is a circle, for example. By using the caulking
pin 50, a flat surface like a form obtained by pressing down the
spherical surface as shown in FIG. 16 is formed in the vicinity of
the injection opening 1a. As a result, the deformation of the
casing 12 to the spherical shape is prevented. Thus, after Step
S105, the welding process of Step S106 can be desirably
performed.
[0126] FIG. 18 is a cross-sectional view of a main part of a
caulking pin 60 of another mode. A concave portion 62 of the
caulking pin 60 has a side surface 62a of a cylinder and a convex
portion 63 formed in the concave portion 62 toward an opening
surface 62b surrounded by an annular blade 61. The shape of the
convex portion 63 viewed in an axis direction of the caulking pin
60 is a circle, for example. With this structure, the surface 62a
as the cylinder surface, which is vertical to the surface of the
casing 12, can suppress the deformation of the casing 12 to the
sphere in the concave portion 62 at the time of caulking. In
addition, the convex portion 63 can enhance the suppression effect
thereof.
[0127] In the caulking pin 50 shown in FIG. 17, the height of the
convex portion 53 in the axis direction may be designed so that the
surface of the convex portion 53 is substantially the same as the
opening surface 52b. The same may hold true for the caulking pin 60
shown in FIG. 18. In this case, the temporary sealing process in
Step S104 and the contacting process in Step S105 shown in FIG. 4
can be performed at the same time. As a result, the number of the
manufacturing processes can be reduced, and the time required for
the manufacturing can be saved.
[0128] FIG. 19 is a table showing a result of a failure/no-failure
test on a leakage at a time when the injection path 2c of the
casing 12 is temporarily sealed with a plurality of caulking pins
whose end shapes are different.
[0129] The leakage refers to a leakage of air into the casing 12
(action area 8) from the outside of the casing 12 via the injection
opening 1a and the injection path 2c. The result shows that
caulking pins of Nos. 4, 6, 9, and 14 caused no leakage, and were
judged to be effective. The caulking pin of No. 4 substantially
corresponds to the caulking pin 40 shown in FIG. 16. The caulking
pin of No. 14 substantially corresponds to the caulking pin 20
shown in FIG. 6B. In addition to those, it was judged that the
caulking pins of Nos. 6 and 9 prevented the leakage and were
effective.
[0130] FIGS. 20A to 20C are diagrams each showing a
three-dimensional shape of the flat plate of the casing 12 crushed
by the caulking pin of No. 4 (caulking pin 40 shown in FIG. 16) in
the table of FIG. 19. FIG. 20A is a diagram of the flat plate
viewed from the surface thereof, FIG. 20B is a diagram of the flat
plate viewed from the side surface thereof, and FIG. 20C is a
diagram of the flat plate viewed from the back surface thereof
(inner surface side of the casing 12).
[0131] FIGS. 21A to 21C are diagrams each showing a
three-dimensional shape of the flat plate of the casing 12 crushed
by the caulking pin of No. 14 (caulking pin 20 shown in FIG. 6B) in
the table of FIG. 19. FIG. 21A is a diagram of the flat plate
viewed from the surface thereof, FIG. 21B is a diagram of the flat
plate viewed from the side surface thereof, and FIG. 21C is a
diagram of the flat plate viewed from the back surface thereof
(inner surface side of the casing 12).
[0132] (Electronic Apparatus)
[0133] Next, a description will be given on an electronic apparatus
equipped with a heat transport device. Herein, a laptop PC is used
as an example of the electronic apparatus.
[0134] FIG. 22 is a perspective view showing a laptop PC. A PC 500
includes a main body 70 and a display portion 80.
[0135] In a casing of the main body 70, a CPU 90 and a heat
transport device 100 are provided. The heat transport device 100 is
thermally contacted with the CPU 90.
[0136] The electronic apparatus is not limited to the PC 500.
Examples of the electronic apparatus include a PDA (personal
digital assistant), an electronic dictionary, a camera, a display
apparatus, audiovisual equipment, a projector, a printer, a fax
machine, a cellular phone, a game machine, a car navigation system,
a robot apparatus, and other electronic apparatuses.
[0137] The present invention is not limited to the above
embodiments, and various other embodiments may be conceived.
[0138] The blade of the caulking pin has the circular shape, but
may have an oval shape, a triangular or polygonal shape, or a
combination thereof. That is, the annular shape may be any shape,
as long as the groove is formed completely around the injection
opening of the casing.
[0139] In FIGS. 16 and 17, the shape of the concave portion of the
caulking pin is not limited to the conical shape (part of the
conical surface in FIG. 17), and may instead be a
three-or-more-sided pyramid. Further, in FIGS. 6B and 18, the inner
surface of the concave portion is not limited to the cylindrical
surface, and may instead be a side surface of a triangular or
polygonal column.
[0140] The present application contains subject matter related to
that disclosed in Japanese Priority Patent Application JP
2009-092782 filed in the Japan Patent Office on Apr. 7, 2009, the
entire content of which is hereby incorporated by reference.
* * * * *