U.S. patent application number 12/795858 was filed with the patent office on 2010-12-23 for heat sink and method of manufacture thereof.
Invention is credited to Goro Nakano, Shuji YOKOYAMA.
Application Number | 20100319899 12/795858 |
Document ID | / |
Family ID | 43353277 |
Filed Date | 2010-12-23 |
United States Patent
Application |
20100319899 |
Kind Code |
A1 |
YOKOYAMA; Shuji ; et
al. |
December 23, 2010 |
HEAT SINK AND METHOD OF MANUFACTURE THEREOF
Abstract
In a first process of this method of manufacturing a heat sink,
into a groove, formed in a base and both of whose side surfaces are
provided with projections or concave portions and whose upper
portion is open, from the groove open portion, there is fitted a
pipe that has a diameter smaller than the gap between the edge
portions of the open portion of the groove. Next, the pipe is
pressed from above the open portion of the groove and the upper
portion of the pipe is deformed so that it follows the plane of the
open portion of the groove, and moreover both side portions of the
pipe are deformed so that they follow along the inner surfaces of
both side portions of the groove. By this second process, both side
portions of the pipe are engaged with the projections or concave
portions.
Inventors: |
YOKOYAMA; Shuji; (Osaka,
JP) ; Nakano; Goro; (Osaka, JP) |
Correspondence
Address: |
MARK D. SARALINO (GENERAL);RENNER, OTTO, BOISSELLE & SKLAR, LLP
1621 EUCLID AVENUE, NINETEENTH FLOOR
CLEVELAND
OH
44115-2191
US
|
Family ID: |
43353277 |
Appl. No.: |
12/795858 |
Filed: |
June 8, 2010 |
Current U.S.
Class: |
165/185 ;
29/890.03 |
Current CPC
Class: |
H01L 21/4882 20130101;
H01L 23/427 20130101; B21D 22/025 20130101; B21D 53/06 20130101;
Y10T 29/4935 20150115; H01L 2924/0002 20130101; H01L 2924/00
20130101; B21D 53/02 20130101; H01L 2924/0002 20130101 |
Class at
Publication: |
165/185 ;
29/890.03 |
International
Class: |
F28F 7/00 20060101
F28F007/00; B21D 53/02 20060101 B21D053/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 23, 2009 |
JP |
2009-148449 |
Claims
1. A method of manufacturing a heat sink in which a heat sink is
manufactured by fitting a pipe into a groove formed in a base,
comprising: a first process of fitting into a groove, formed in a
base and both of whose side surfaces are provided with
longitudinally extending irregular portions and whose upper portion
is open, from said groove open portion, a pipe that has a diameter
smaller than the gap between the edge portions of said open portion
of said groove; and a second process of pressing upon said pipe
from above said open portion of said groove and deforming the upper
portion of said pipe so that it follows the plane of said open
portion of said groove, and moreover deforming both side portions
of said is pipe so that they follow along the inner surfaces of
both side portions of said groove, and thereby engaging both side
portions of said pipe with said irregular portions.
2. A method of manufacturing a heat sink according to claim 1,
wherein said irregular portions are projections.
3. A method of manufacturing a heat sink according to claim 1,
wherein said irregular portions are concave portions.
4. A method of manufacturing a heat sink according to claim 1,
wherein, in said first process, a fluid is enclosed in said
pipe.
5. A method of manufacturing a heat sink according to claim 1,
wherein said second process comprises: a third process of
installing a guide tool that has a guide surface that guides a
pressing tool along the vertical direction against said open
portion of said groove; and a fourth process of guiding said
pressing tool in the downwards direction along said guide surface
of said guide tool that was installed by said third process, so
that said upper portion of said pipe is pressed by a pressing
surface of said pressing tool, and thereby said upper portion of
said pipe is deformed so as to follow said plane of said open
portion of said groove.
6. A method of manufacturing a heat sink according to claim 1,
further comprising a fifth process of, after deformation by said
second process, cutting said upper portion of said pipe and/or the
upper portion of said base, so that said upper portion of said pipe
and said plane of said open portion of said groove substantially
coincide with one another.
7. A method of manufacturing a heat sink according to claim 1,
wherein said projections or concave portions are provided at
positions on said side surfaces of said groove that do not contact
its said open portion.
8. A heat sink manufactured by the method of claim 1.
9. A heat sink manufactured by the method of claim 2.
10. A heat sink manufactured by the method of claim 3.
11. A heat sink manufactured by the method of claim 4.
Description
CROSS REFERENCE
[0001] This Nonprovisional application claims priority under 35
U.S.C. .sctn.119(a) on Patent Application No. 2009-148449 filed in
Japan on Jun. 23, 2009, the entire contents of which are hereby
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a heat sink that cools a
thermal component, and to a method of manufacturing such a heat
sink.
[0003] Sometimes a radiator type heat sink is used for cooling a
thermal component such as a semiconductor or the like. As this type
of heat sink, for example, in the base of the heat sink, its upper
portion may be formed by opening up channels (grooves) therein.
These channels may have tapers, so that the gaps at the end
portions at which they are opened are smaller than the gaps at the
bottom portions of the channels. A structure for cooling a thermal
component is disclosed in Japanese Patent Publication 11-510962 in
which pipes are pressed into these channels and are deformed into
almost the same flat plane as the base surface, and the thermal
component is cooled by being contacted against this flat plane.
[0004] Since, with the heat sink construction described above, it
must be ensured that the gap between the edge portions of the open
portion of the groove is equal to the diameter of the pipe,
accordingly it has been necessary to process the groove and the
pipe at high accuracy. Furthermore there is a fear that, when the
pipe is being inserted into the groove, damage may be caused to the
pipe due to contact between the sides of the pipe and the sides of
the grooves. In particular, if the processing accuracy for the
groove is bad, and the gap between the exposed edges of the groove
is narrower than the diameter of the pipe, then damage will very
likely be caused to the pipe while it is being inserted into the
groove due to the side surfaces of the pipe and the groove scraping
together, and, if the heat sink is used over the long term, there
is a fear that it will deteriorate over time and that cooling fluid
will leak out from it due to this damage cracking and breaking.
[0005] Accordingly, the object of the present invention is to
provide a method of manufacturing a heat sink, and a heat sink,
with which, when a pipe thereof is being fitted into a groove
provided in a base thereof, there is no danger of damage being
caused to the pipe due to the side surfaces of the pipe contacting
the side surfaces of the groove.
SUMMARY OF THE INVENTION
[0006] In the method of manufacturing a heat sink according to the
present invention, there are included: a first process of fitting
into a groove, formed in a base and both of whose side surfaces are
provided with longitudinally extending irregular portions, such as
projections or concave portions and whose upper portion is open,
from the groove open portion, a pipe that has a diameter smaller
than the gap between the edge portions of the open portion of the
groove; and a second process of pressing upon the pipe from above
the open portion of the groove and deforming the upper portion of
the pipe so that it follows the plane of the open portion of the
groove, and moreover deforming both side portions of the pipe so
that they follow along the inner surfaces of both side portions of
the groove, and thereby engaging both side portions of the pipe
with the irregular portions. A fluid may be enclosed in the
interior of this pipe.
[0007] According to this type of structure, it is possible to fit
the pipe into the groove that is formed in the base without any
damage occurring to the pipe, even if the processing accuracy of
the base or the pipe is poor. Furthermore it is possible to fix the
pipe in the groove without the use of any adhesive or the like,
since, during the process of deformation of the pipe both of the
side surfaces of the pipe engage with the projections or concave
portions that are provided to the groove. Moreover, by pressing the
pipe while fluid is enclosed within the pipe, it is possible to
ensure that the pressure over the entire inner surface of the pipe
is equal. Due to this, it is possible to deform the pipe so that
its outer circumferential surface comes into overall contact
against the entirety of both the side surfaces and also the bottom
surface of the groove.
[0008] In an embodiment of this method of manufacturing a heat sink
according to the present invention, the following specialization
may be employed.
[0009] The second process may include: a third process of
installing a guide tool that has a guide surface that guides a
pressing tool along the vertical direction against the open portion
of the groove; and a fourth process of guiding the pressing tool in
the downwards direction along the guide surface of the guide tool
that was installed by the third process, so that the upper portion
of the pipe is pressed by a pressing surface of the pressing tool,
and so that thereby the upper portion of the pipe is deformed so as
to follow the plane of the open portion of the groove.
[0010] And, in another embodiment of this method of manufacturing a
heat sink according to the present invention, the following
specialization may be employed.
[0011] There may be further included a fifth process of, after
deformation by the second process, cutting the upper portion of the
pipe and/or the upper portion of the base, so that the upper
portion of the pipe and the plane of the open portion of the groove
substantially coincide with one another.
[0012] Moreover, the heat sink according to the present invention
is one that is made by any of the methods detailed above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIGS. 1A and 1B are respectively a perspective view before
assembly of a base and pipes of a heat sink manufactured by the
method of manufacture of the present invention, and an enlarged
partial sectional elevation view thereof;
[0014] FIG. 2 is a flow chart for explanation of this method of
manufacturing a heat sink;
[0015] FIGS. 3A through 3F are sectional views showing how this
heat sink is assembled;
[0016] FIGS. 4A and 4B are respectively a figure showing the
general appearance of a heat sink itself, and a figure showing the
general appearance of this heat sink with a thermal component
attached thereto; and
[0017] FIGS. 5A through 5C are sectional elevation views showing
examples of other possible constructions for the grooves.
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIGS. 1A and 1B are respectively a perspective view of a
base and pipes of a heat sink manufactured by the method of
manufacture of the present invention before assembly, and an
enlarged partial sectional elevation view thereof.
[0019] As shown in FIG. 1A, this heat sink 1 comprises a base 3, a
pipe 7A, and a pipe 7B.
[0020] The base 3 is a block (a plate) made from aluminum or
aluminum alloy, and is provided with grooves 5A and 5B that have
exposed sides (exposed faces) at a contacting face 3A that is
contacted against a thermal component 9 such as a semiconductor
(for example an IGBT) or the like (refer to FIG. 4B). A pipe 7A is
fitted into this groove 5A, and a pipe 7B is fitted into the groove
5B. Furthermore, the groove 5A and the groove 5B are provided in
positions that contact against the bottom surface of the thermal
component 9, so that, when the thermal component 9 is contacted
against the contacting face 3A, it is possible to cool the thermal
component 9 with good efficiency due to the pipe 7A and the pipe 7B
contacting against the bottom surface of the thermal component 9.
In other words, the pipes 7A and 7 are provided upon lines which
are symmetric with respect to the center line C, along the
longitudinal direction of the contacting face 3A. And their lengths
are the same as the length L of the base 3 in its short
direction.
[0021] Furthermore, the contacting face 3A is wider than the bottom
surface of the thermal component 9 (refer to FIG. 4B), and four
screw holes 4A, 4B, 4C, and 4D are provided near the corners of the
contacting face 3A for fixing the thermal component 9.
[0022] It should be understood that, although the contacting face
3A is divided into the three surfaces 3A1, 3A2, and 3A2 by the
grooves 5A and 5B, in the following explanation these three
surfaces will be referred to generally as the contacting face
3A.
[0023] The pipes 7A and 7B are straight tubes made from copper
whose cross sections are circular. Fluid for cooling the thermal
component 9 during use may be enclosed in the interiors of the
pipes 7A and 7B during manufacture; or they may be used as heat
pipes in which such a fluid flows. The overall length of each of
the pipes 7A and 7B is longer than the length L of the grooves 5A
and 5B. This overall length of the pipes 7A and 7B may be set to a
length corresponding to the position at which the heat sink 1 is
used or fixed.
[0024] The groove 5A and the groove 5B have the same cross
sectional shape. Moreover, the pipe 7A and the pipe 7B have the
same cross sectional shape. While, for the sake of brevity, the
following explanation is principally phrased in terms of the groove
5A and the pipe 7A, the same description holds for the groove 5B
and the pipe 7B as well. As shown in FIG. 1B, the groove 5A is
generally rectangular in cross section, and has planar side
surfaces 51A and 51B and a planar bottom surface 51C. The corner
portion 51D between the side surface 51A and the bottom surface 51C
is processed to be formed as a curved surface, and similarly the
corner portion 51D between the side surface 51B and the bottom
surface 51C is processed to be formed as a curved surface. The
horizontal plane at the portion of the groove 5A that opens to the
contacting face 3A and that is parallel to the contacting face 3A
is termed the exposed surface plane 51F (in FIG. 1B, this exposed
surface plane 51F is shown by a double dotted broken line).
[0025] Furthermore, at the upper end portions of the side surface
51A and the side surface 51B (i.e. at the portions that border upon
the exposed surface plane 51F), the cross section is formed as
approximately letter-".lamda." shaped projections 53A and 53B
respectively. These projections 53A and 53B are for engaging with a
pipe which has been fitted into the groove 5A and deformed. These
projections 53A and 53B are provided along the groove 5A, and their
overall lengths are equal to L.
[0026] It should be understood that it is desirable for the edge
portions and the root portions of these projections 53A and 53B to
be processed into arcuate shapes. By doing this it is possible to
prevent damage to the mold, and to prevent the outer
circumferential surface of the pipe from suffering damage when the
pipe is deformed.
[0027] The gap between the edge portions of the open portion of the
groove 5A, in other words the open width W of the groove 5A, is a
little greater than the diameter D of the pipe 7A in its
non-deformed state. Moreover, the width Y between the mutually
opposing side surfaces 51A and 51B is somewhat greater than the
above described open width W. Furthermore, the depth F of the
groove 5A (i.e. the distance between its exposed surface plane 51F
and its bottom surface 51C) is somewhat less than the diameter D of
the pipe 7A.
[0028] Since the groove 5A of the base 3 and the pipe 7A are set to
have dimensions as described above, accordingly the pipe 7A is not
abraded away by the sides or the projections of the groove 5A when
the pipe 7A is being fitted into the groove 5A, even if the
processing accuracy of the groove is poor and its dimensions vary
somewhat.
[0029] The circumference of the pipe 7A is almost the same as the
circumference of the groove 5A with the exposed surface plane 51F
included. It should be understood that, although a deformation
process is performed so as to make the two side surfaces 51A and
51B and the bottom surface 51C (collectively termed the inner
surface of the groove 5A) and the outer circumferential surface of
the pipe 7A generally contact against one another, nevertheless,
depending upon the nature of the material of the pipe 7A and the
exact cross sectional shape of the groove 5A, sometimes it may
happen that some portion of the pipe 7A does not contact against
the corresponding portion of the inner surface of the groove 5A.
Due to this, the circumference of the pipe 7A and the circumference
of the groove 5A with the exposed surface plane 51F included, and
the cross sectional shape of the groove 5A, should be determined
upon by performing actual experiments with deformation of various
test pipes 7A, so as to ensure that the upper surface of the pipe
7A after the deformation process conforms to a planar shape that
follows the exposed surface plane 51F, and so that its side
surfaces and its bottom surface contact as much as possible against
the inner surfaces of the groove 5A.
[0030] Next, a method for manufacture (i.e. for assembly) of this
heat sink will be explained. While here this method of manufacture
is principally explained in terms of the groove 5A and the pipe 7A,
it will be supposed that similar processing is performed for the
groove 5B and the pipe 7B as well.
[0031] First, as described in the process chart of FIG. 2, a fluid
is enclosed in the interior of the pipe 7A which is fitted into the
base 3 (a step S1). In concrete terms, a plug (not shown in the
figures) is fitted into an opening portion 7A1 at one end of the
pipe 7A shown in FIG. 1A, and is able to close up that opening
portion so that fluid cannot leak out therefrom. Then a liquid such
as, for example, water or oil or the like, a fine grained powder,
or a gas such as air at high pressure or the like is appropriate as
the fluid that is enclosed within the pipe. If the fluid to be
enclosed within the pipe is a liquid, then this liquid is flowed
into the pipe, and, when the pipe is full, another plug (also not
shown) is fitted into the opening portion 7A2 of the pipe at its
other end, so as to enclose the fluid within the pipe. Furthermore,
if the fluid to be enclosed within the pipe is a gas, then plugs
(not shown in the figures) may be fitted into the two opening
portions 7A1 and 7A2 of the pipe 7A, and gas may be enclosed within
the pipe using a dedicated setup (also not shown).
[0032] Since, by enclosing the fluid within the pipe in this
manner, when the outer circumferential surface of the pipe is
pressed, this pressure is applied equally to the inner surface of
the pipe, accordingly it is possible to deform the pipe so that its
outer circumferential surface contacts entirely against both the
sides of the groove and also against its bottom surface.
[0033] It should be understood that, depending upon the nature of
the material of the pipe 7A and the exact cross sectional shape of
the groove 5A, sometimes it may happen that it is possible to
deform the pipe so that its outer circumferential surface contacts
entirely against both the sides of the groove and also against its
bottom surface, without enclosing any fluid within the pipe. In
such a case, the processing of the above step S1 in which fluid is
enclosed in the pipe, and the processing of a step S7 described
hereinafter in which this fluid is extracted from the pipe, both
become unnecessary.
[0034] Next, as shown in FIGS. 3A and 3B, the pipe 7A is set into
(i.e. is fitted into) the groove 5A in the base 3 (a step S2). At
this time, since the width W of the groove 5A is greater than the
diameter D of the pipe 7A, accordingly no damage is caused to the
outer surface of the pipe 7A due to the groove 5A contacting the
pipe 7A and scraping against it.
[0035] Next, a guide tool 11A and a guide tool 11B are installed
along the two edges of the exposed surface plane 51F of the groove
5A (a step S3). As shown in FIG. 3C, these guide tools are tools
for guiding a pressing tool 13 along the vertical direction; they
may be made from rolled steel and may generally have the shape of
rectangular parallelepipeds, with their lengths being longer than
or equal to the length L of the grooves 5A and 5B. Moreover, the
pressing tool 13 is a tool for pressing upon the pipe 7A, and,
likewise, it may be made from rolled steel and may generally have
the shape of a rectangular parallelepiped, with its length being
longer than or equal to the length L of the grooves 5A and 5B. By
installing the guide tools 11A and 11B along the edges of the
exposed surface plane 51F, it is possible to prevent any portion of
the pipe 7A from sticking up higher than the exposed surface plane
51F and thus projecting above the contacting face 3A of the base 3,
when the pipe 7A is pressed by the pressing tool 13 from the
direction of the exposed surface plane 51F.
[0036] As shown in FIG. 3C, the pressing tool 13 is installed
between the two guide tools 11A and 11B (a step S4). Next, as shown
in FIG. 3D, the pressing tool 13 is slid downwards along the guide
tools 11A and 11B, and presses upon the pipe 7A from above the
groove (a step S5). And the pipe 7A is deformed so that its upper
portion becomes a surface 7A3 (see FIG. 4) extending substantially
along the exposed surface plane 51F, with its other portions
contacting against the two side surfaces 51A and 51B and the bottom
surface 51C of the groove 5A, and with the edges of its upper
portion being engaged by the projections 53A and 53B.
[0037] It should be understood that the pressing tool 13 is not
limited to having a shape as shown in FIG. 13; for example, it
would also be acceptable for it to be shiftable along the guide
tools 11A and 11B and to have a roller shaped pressing surface. If
the length L of the base 3 is very long so that a plurality of
thermal components 9 may be fitted thereto, then it may become
difficult to deform the entire pipe 7A in one operation with a
pressing tool 13 that is formed out of rolled steel in the shape of
a rectangular parallelepiped. In this type of case, it is possible
to deform the entire pipe 7A so as to shape its upper plane 7A3 to
extend substantially along the exposed surface plane 51F of the
groove 5A, by pressing a roller shaped pressing tool (not shown)
upon the pipe 7A while shifting that pressing tool along the guide
tools 11A and 11B.
[0038] When the deformation of the pipe 7A has been completed, the
guide tools 11A and 11B and the pressing tool 13 are removed (a
step S6). And the plugs that were fitted into both the ends of the
pipe 7A are removed, and the fluid within the pipe 7A is extracted
(a step S7). The pipe 7A does not come out from within the groove
5A, since it has become engaged with the projections 53A and 53B
due to the deformation process of the step S5.
[0039] According to the dimensions and shapes of the groove 5A and
the pipe 7A and the relationship between them, and depending upon
the pressure applied in the step S5, sometimes it may happen that
the pipe 7A may, after the process of deformation, come to be in a
state in which its upper plane surface 7A3 bulges out somewhat
above the exposed surface plane 51F, as shown in FIG. 3E.
Furthermore sometimes it may happen that, after the process of
deformation, the pipe 7A may come to be in a state in which its
upper plane surface 7A3 is substantially lower than the exposed
surface plane 51F, i.e. is fully within the groove 5A, as shown in
FIG. 3F. In other words, sometimes it may happen that the plane 7A3
of the finished pipe 7A, the plane 7B3 of the finished pipe 7B, and
the contacting face 3A of the base 3 are not coplanar. In this type
of case, a cutting process is performed upon at least one of the
pipe 7A or 7B, or the contacting face 3A of the base 3, so as to
form the plane 7A3 of the finished pipe 7A, the plane 7B3 of the
finished pipe 7B, and the contacting face 3A of the base 3 to be
coplanar (a step S8).
[0040] When, as shown in FIG. 3E, the pipe 7A is in a state in
which its upper plane surface 7A3 bulges out somewhat above the
exposed surface plane 51F, it is appropriate for mainly the pipe 7A
to be cut down. On the other hand when, as shown in FIG. 3F, the
pipe 7A is in a state in which its upper plane surface 7A3 is
substantially lower than the exposed surface plane 51F, then it is
appropriate for mainly the contacting face 3A of the base 3 to be
cut down. By performing a cutting process in this manner, it is
possible to ensure that the plane 7A3 of the finished pipe 7A, the
plane 7B3 of the finished pipe 7B, and the contacting face 3A of
the base 3 become coplanar. By performing processing upon the upper
surface of the heat sink in this manner to ensure that it is
planar, it is possible to make it closely conform to the bottom
surface of the thermal component 9, and thus it is possible
reliably to cool the thermal component 9.
[0041] It should be understood that, if the pipe 7A is to be cut,
then it is necessary to use a pipe of thickness sufficiently
greater than the amount to be cut away, in order to ensure that no
holes open up in the pipe after it has been cut. Furthermore, if in
the step S5 the plane 7A3 of the pipe 7A, the plane 7B3 of the pipe
7B, and the contacting face 3A of the base 3 are already finished
as coplanar, then no further cutting process such as the step S8
will be necessary.
[0042] When the above described processes of deforming and
(possibly) cutting the pipe 7A and the pipe 7B have been completed,
the manufacture of the heat sink 1 is finished, as shown in FIG.
4A.
[0043] When the heat sink 1 is to be used, it will be sufficient to
contact the bottom surface of a thermal component 9 (for example an
IGBT module, as shown in the figure) against the upper surface of
the heat sink 1 (i.e. against the contacting face 3A of the base
3), as shown in FIG. 4B, and to fix screws 10A through 10D into the
screw holes 4A through 4D.
[0044] If only one of these heat sinks 1 is to be used, then the
opening portion 7A1 of the pipe 7A and the opening portion 7B1 of
the pipe 7B are connected together with a joining pipe (not shown
in the figures). Moreover, the opening portion 7A2 of the pipe 7A
and the opening portion 7B2 of the pipe 7B are connected to a pump
(not shown in the figures), via joining conduits (not shown in the
figures) or directly, so that fluid may be circulated by the pump
through the interiors of the pipes 7A and 7B, thus cooling the
thermal component 9.
[0045] Furthermore, if a plurality of these heat sinks 1 are to be
used, then the opening portions of the pipes 7A and 7B of these
heat sinks 1 are connected in sequence with joining conduits, not
shown in the figures. And two of them are connected to a pump.
Thus, fluid may be circulated by the pump through the interiors of
the pipes 7A and 7B of each of the heat sinks 1, thus cooling the
thermal component or components 9 that are attached to these heat
sinks 1. Furthermore it would also be possible further to increase
the length of the heat sink 1, so as to attach a plurality of
thermal components 9 to this single heat sink 1 for being
cooled.
[0046] Next, with regard to the position of the projections 53A and
53B which are provided upon the side surfaces 51A and 51B of the
groove 5A that is provided in the base 3, the positions shown in
FIGS. 1 and 3 are not to be considered as being limitative of the
present invention; other positions for these projections may be
employed, provided that the projections are able to engage properly
with the pipe 7A. For example in an alternative structure, as shown
in FIG. 5A, it would be possible to provide projections 53A2 and
53B2 in positions that are lower than the upper edge portions of
the side surfaces 51A2 and 51B2 of the groove 5A2, in other words
in positions that do not touch the exposed surface plane 51F2. At
this time, the cross sectional shapes of these projections may be
processed into shapes whose edges are smooth, for example into tear
shapes or into arcuate shapes. Since, by providing the projections
53A2 and 53B2 in positions as described above, these projections
bite into the pipe 7A when the pipe 7A has been deformed,
accordingly it is possible for the pipe 7A to be reliably embedded
within the groove 5A2 and held.
[0047] Furthermore, it would also be possible to arrange to provide
concave portions on the side surfaces of the groove, rather than
projections. Such concave portions should be provided at positions
upon the side surfaces of the grooves that are lower than their
upper edge portions, in other words at positions that do not
contact the exposed surface plane of the groove. For example it is
possible, as shown in FIG. 5B, to provide a concave portion 53A3
and a concave portion 53B3 at respective intermediate portions upon
the side surface 51A3 and the side surface 51B3 of the groove 5A3.
Moreover it is possible, as shown in FIG. 5C, to provide a concave
portion 53A4 and a concave portion 53B4 at the respective lower
edge portions of the side surface 51A4 and the side surface 51B4 of
the groove 5A4 (i.e. at the portions where these side surfaces abut
against the bottom surface 51C). Since, by providing such concave
portions upon the side surfaces of the groove, corresponding
portions of the pipe are forced into these concave portions when
the pipe is deformed, accordingly the pipe 7A is engaged within the
groove by these corresponding portions projecting into and engaging
with the concave portions. Accordingly, it is possible reliably to
embed and hold the pipe 7A within the groove 5A3 or the groove
5A4.
[0048] It would also be acceptable to arrange to provide the
projections or concave portions shown in FIG. 5 intermittently
along the depth direction of the groove. By forming the projections
or concave portions in this type of shape, it is possible reliably
to prevent the pipe 7A from deviating in the direction of the side
surface 3S1 or the side surface 3S2 of the base 3.
[0049] It should be understood that it is desirable to process the
edges and/or base root portions of the projections or the concave
portions into arcuate shapes. By doing this it is possible to
prevent damage to the mold, and to prevent the outer
circumferential surface of the pipe from suffering damage when the
pipe is deformed.
[0050] It should be understood that, even if the groove provided in
the base 3 has a shape as shown in FIG. 5, as explained on the
basis of FIG. 1B, still, as seen from the side of the exposed
surface plane (i.e. from the side of the contacting face 3A), the
opening width W between the two sides of the upper portion of the
groove (i.e. the gap between the projections 53A2 and 53B2, or
between the side surface 51A3 and the side surface 51B3, or between
the side surface 51A4 and the side surface 51B4) is greater than
the diameter D of the pipe 7A. Moreover, the width Y between the
side surface 51A2 and the side surface 51B2 with the projections
53A2 and 53B2 excluded, or the width X between the two concave
portions (i.e. between the concave portion 53A3 and the concave
portion 53B3, or between the concave portion 53A4 and the concave
portion 53B4), is greater than the above described opening width W.
Furthermore, the depth F of the groove 5A (i.e. the distance
between its exposed surface plane 51F and its bottom surface 51C)
is shorter than the diameter D of the pipe 7A.
[0051] Yet further, the circumference of the pipe 7A and the
circumference of the groove with its exposed surface plane
included, and the cross sectional shape of the groove, should be
determined upon by performing actual experiments with deformation
of various test pipes 7A, so as to ensure that the upper surface of
the pipe 7A after the deformation process conforms to a planar
shape that follows the exposed surface plane 51F, and so that its
side surfaces and its bottom surface contact as much as possible
against the inner surfaces of the groove 5A.
[0052] It should be understood that while, in the above
explanation, a structure was described in which two pipes were
embedded in the base, this is not to be considered as limitative of
the present invention; it is also possible to utilize a single such
pipe, or more than two such pipes, provided that it is possible to
contact that pipe or pipes against the bottom surface of the
thermal component with good efficiency so as to cool it well.
[0053] Furthermore, with regard to the materials from which the
base, the pipes, the guide tools, and the pressing tool are made,
it would also be acceptable to utilize other materials, provided
that it is possible to deform the pipes with good efficiency, and
that it is possible to cool the thermal component with good
efficiency.
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