U.S. patent application number 14/051521 was filed with the patent office on 2014-07-10 for cooling head and electronic apparatus.
This patent application is currently assigned to FUJITSU LIMITED. The applicant listed for this patent is FUJITSU LIMITED. Invention is credited to Kenji FUKUZONO, Yuki HOSHINO.
Application Number | 20140190669 14/051521 |
Document ID | / |
Family ID | 51060097 |
Filed Date | 2014-07-10 |
United States Patent
Application |
20140190669 |
Kind Code |
A1 |
HOSHINO; Yuki ; et
al. |
July 10, 2014 |
COOLING HEAD AND ELECTRONIC APPARATUS
Abstract
A cooling head includes: a first refrigerant flow channel,
provided so as to be in contact with an object to be cooled,
configured to flow refrigerant; a second refrigerant flow channel
configured to flow the refrigerant; and at least one communication
hole, provided between both ends of the object to be cooled in the
first refrigerant flow channel in a first flow direction of
refrigerant in the first refrigerant flow channel, configured to
allow the first refrigerant flow channel and the second refrigerant
flow channel to communicate with each other.
Inventors: |
HOSHINO; Yuki; (Kawasaki,
JP) ; FUKUZONO; Kenji; (Kawasaki, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FUJITSU LIMITED |
Kawasaki-shi |
|
JP |
|
|
Assignee: |
FUJITSU LIMITED
Kawasaki-shi
JP
|
Family ID: |
51060097 |
Appl. No.: |
14/051521 |
Filed: |
October 11, 2013 |
Current U.S.
Class: |
165/104.33 ;
165/104.19 |
Current CPC
Class: |
F28D 2021/0028 20130101;
F28F 3/12 20130101; F28F 2250/04 20130101; H01L 2924/0002 20130101;
H01L 23/473 20130101; F28D 15/0266 20130101; H01L 2924/00 20130101;
H01L 2924/0002 20130101; F28F 9/0273 20130101 |
Class at
Publication: |
165/104.33 ;
165/104.19 |
International
Class: |
F28F 3/08 20060101
F28F003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 10, 2013 |
JP |
2013-002853 |
Claims
1. A cooling head comprising: a first refrigerant flow channel,
provided so as to be in contact with an object to be cooled,
configured to flow refrigerant; a second refrigerant flow channel
configured to flow the refrigerant; and at least one communication
hole, provided between both ends of the object to be cooled in the
first refrigerant flow channel in a first flow direction of
refrigerant in the first refrigerant flow channel, configured to
allow the first refrigerant flow channel and the second refrigerant
flow channel to communicate with each other.
2. The cooling head according to claim 1, wherein the first
refrigerant flow channel and the second refrigerant flow channel
communicates with each other without a nozzle.
3. The cooling head according to claim 1, wherein a downstream end
of the second refrigerant flow channel in a second flow direction
of refrigerant in the second refrigerant flow channel is
blocked.
4. The cooling head according to claim 1, wherein the second
refrigerant flow channel is provided on the side of the first
refrigerant flow channel opposite to the side in contact with the
object.
5. The cooling head according to claim 1, wherein the second
refrigerant flow channel includes a plurality of flow channels for
the object.
6. The cooling head according to claim 5, wherein the plurality of
flow channels extend parallel to each other.
7. The cooling head according to claim 5, wherein the at least one
communication hole is shared by at least two of the plurality of
flow channels.
8. The cooling head according to claim 7, wherein the at least one
communication hole is formed so as to be elongate in a direction
across the first flow direction.
9. The cooling head according to claim 1, wherein the at least one
communication hole includes a plurality of communication holes for
the object, and the plurality of communication holes are arranged
in the first flow direction.
10. The cooling head according to claim 1, wherein the at least one
communication hole is provided so as to correspond to the position
of a hot spot having a large amount of heat generation of the
object or is provided on an upstream side of the position of the
hot spot.
11. The cooling head according to claim 1, further comprising, a
first flow channel member in which the first refrigerant flow
channel is formed; and a second flow channel member in which the
second refrigerant flow channel is formed so as to form a stacked
structure.
12. The cooling head according to claim 1, wherein the refrigerant
in the second refrigerant flow channel is merged with the
refrigerant flowing through the first refrigerant flow channel at a
communication position with the first refrigerant flow channel and
flows to the downstream side.
13. An electronic apparatus comprising: an electronic device; and a
cooling head configured to cool the electronic device, wherein the
cooling head includes: a first refrigerant flow channel, provided
so as to be in contact with an object to be cooled, configured to
flow refrigerant; a second refrigerant flow channel configured to
flow the refrigerant; and at least one communication hole, provided
between both ends of the object to be cooled in the first
refrigerant flow channel in a first flow direction of refrigerant
in the first refrigerant flow channel, configured to allow the
first refrigerant flow channel and the second refrigerant flow
channel to communicate with each other.
14. The electronic apparatus according to claim 13, wherein a
downstream end of the second refrigerant flow channel in a second
flow direction of refrigerant in the second refrigerant flow
channel is blocked.
15. The electronic apparatus according to claim 13, wherein the
second refrigerant flow channel is provided on the side of the
first refrigerant flow channel opposite to the side in contact with
the object.
16. The electronic apparatus according to claim 13, wherein the
second refrigerant flow channel includes a plurality of flow
channels for the object.
17. The electronic apparatus according to claim 13, wherein the at
least one communication hole includes a plurality of communication
holes for the object, and the plurality of communication holes are
arranged in the first flow direction.
18. The electronic apparatus according to claim 13, wherein the at
least one communication hole is provided so as to correspond to the
position of a hot spot having a large amount of heat generation of
the object or is provided on an upstream side of the position of
the hot spot.
19. The electronic apparatus according to claim 13, further
comprising, a first flow channel member in which the first
refrigerant flow channel is formed; and a second flow channel
member in which the second refrigerant flow channel is formed so as
to form a stacked structure.
20. The electronic apparatus according to claim 13, wherein the
refrigerant in the second refrigerant flow channel is merged with
the refrigerant flowing through the first refrigerant flow channel
at a communication position with the first refrigerant flow channel
and flows to the downstream side.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority of the prior Japanese Patent Application No. 2013-002853,
filed on Jan. 10, 2013, the entire contents of which are
incorporated herein by reference.
FIELD
[0002] Embodiments discussed herein are related to a cooling head
and an electronic apparatus.
BACKGROUND
[0003] In the boil cooling method, a main flow channel and a
sub-flow channel for a cooling liquid are formed in this order from
the side of the cooling surface. A plurality of nozzles that
penetrate a partition wall separating the sub-flow channel and the
main flow channel and that protrude into the main flow channel are
arranged in the flow channel direction of the main flow channel,
and tip end parts of the individual nozzles are caused to be in the
vicinity of or in contact with the cooling surface. The cooling
liquid is caused to circulate to the main flow channel and the
sub-flow channel, the cooling surface is cooled with boiling of the
cooling liquid flowing through the main flow channel, and the
cooling liquid on the sub-flow channel side is supplied from the
sub-flow channel side through each of the nozzles so as to exude in
the vicinity of the cooling surface.
[0004] A related art is disclosed in Japanese Laid-open Patent
Publication No. 2007-150216.
SUMMARY
[0005] According to one aspect of the embodiments, a cooling head
includes: a first refrigerant flow channel, provided so as to be in
contact with an object to be cooled, configured to flow
refrigerant; a second refrigerant flow channel configured to flow
the refrigerant; and at least one communication hole, provided
between both ends of the object to be cooled in the first
refrigerant flow channel in a first flow direction of refrigerant
in the first refrigerant flow channel, configured to allow the
first refrigerant flow channel and the second refrigerant flow
channel to communicate with each other.
[0006] The object and advantages of the invention will be realized
and attained by means of the elements and combinations particularly
pointed out in the claims.
[0007] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory and are not restrictive of the invention, as
claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 illustrates an example of a cooling system;
[0009] FIG. 2 illustrates an example of a relationship between a
cooling head and an electronic device;
[0010] FIG. 3 illustrates an example of a communication hole;
[0011] FIG. 4 illustrates an example of cooling effect;
[0012] FIG. 5 illustrates an example of a top view of a first
refrigerant flow channel;
[0013] FIG. 6A and FIG. 6B each illustrate an example of a top view
of the flow of refrigerant;
[0014] FIG. 7 illustrates an example of a top view of a second
refrigerant flow channel and a communication hole;
[0015] FIG. 8 illustrates an example of a top view of a second
refrigerant flow channel and a communication hole;
[0016] FIG. 9 illustrates an example of arrangement of a
communication hole;
[0017] FIG. 10 illustrates an example of an exploded perspective
view of a cooling head;
[0018] FIG. 11 illustrates an example of a perspective view of a
cooling head;
[0019] FIG. 12 illustrates an example of a sectional view of the
cooling head; and
[0020] FIG. 13 illustrates an example of a sectional view of a
cooling head.
DESCRIPTION OF EMBODIMENTS
[0021] In the boil cooling method, a plurality of nozzles
protruding into a main flow channel are arranged in the flow
channel direction of the main flow channel, and therefore the
nozzles may cause a loss (pressure loss) in the flow of cooling
water in the main flow channel.
[0022] FIG. 1 illustrates an example of a cooling system. The
cooling system 1 illustrated in FIG. 1 may be a system for cooling
an electronic device 2. The cooling system 1 includes a pump 4, a
radiator 6, a cooling head 30, and pipes 10, 12, 14, and 16. The
cooling head 30 may include part of the pipe 10, part or the whole
of the pipes 12 and 14, and/or part or the whole of the pipe
16.
[0023] The cooling head 30 may be provided for the electronic
device 2 as illustrated in FIG. 1. The electronic device 2 may be a
heat generating device, element, component, or unit. The electronic
device 2 may be, for example, a large-scale integration (LSI). An
electronic apparatus 50 may include the cooling head 30 and the
electronic device 2. The electronic apparatus 50 may be a computer
system such as an enhanced server or a supercomputer.
[0024] The pipes 12 and 14 bifurcating from the pipe 10 are coupled
to the suction side of the cooling head 30. The pipe 16 is coupled
to the discharge side of the cooling head 30. The other end of each
of the pipe 10 and the pipe 16 is coupled to the radiator 6. Thus,
the pipes 10, 12, 14 and 16 and the radiator 6 define a circulation
flow channel. The pipe 10 is provided with the pump 4. The pump 4
sucks refrigerant (for example, cooling water) cooled in the
radiator 6 and discharges the refrigerant toward the cooling head
30. The refrigerant discharged from the discharge side of the
cooling head 30 (refrigerant that receives the heat of the
electronic device 2) is supplied to the radiator 6 and is cooled
(radiates heat).
[0025] The configuration of the cooling system 1 illustrated in
FIG. 1 is merely an example, and various modifications are
possible. For example, although, in FIG. 1, refrigerant discharged
from one pump 4 is branched into two pipes 12 and 14 and supplied
to the cooling head 30, refrigerant may be supplied to the cooling
head 30 through two independent pipes using two pumps. For example,
the pipe 12 may be provided with a valve. In the cooling system 1
illustrated in FIG. 1, a transition tank or the like for creating a
subcool state may not be provided.
[0026] FIG. 2 illustrates an example of a relationship between a
cooling head and a electronic device. In FIG. 2, arrows P01, P02,
P1, P2, and P4 schematically indicate the flow direction of
refrigerant. The Z direction indicates the vertical direction, and
the top of FIG. 2 may be the top in the vertical direction. FIG. 3
illustrates an example of a communication hole. In FIG. 3,
communication holes 40' that have nozzles and allow a first
refrigerant flow channel and a second refrigerant flow channel to
communicate with each other are illustrated.
[0027] The cooling head 30 illustrated in FIG. 2 includes a first
refrigerant flow channel 32, a second refrigerant flow channel 34,
and communication holes 40.
[0028] The first refrigerant flow channel 32 is in contact with an
object 3 to be cooled with a lower member 36a therebetween. The
object 3 to be cooled may be an electronic device 2 or an object
that receives heat from an electronic device 2. For example, an
object directly in contact with the lower member 36a may be a heat
spreader 3a of an electronic device 2. Although, in FIG. 2, the
first refrigerant flow channel 32 is in contact with the object 3
to be cooled from above, the first refrigerant flow channel 32 may
be in contact with the object 3 to be cooled from below, or any
other direction. The first refrigerant flow channel 32 may be in
contact with the entire surface of the object 3 to be cooled as
illustrated in FIG. 2, or may be partially in contact with the
object 3 to be cooled.
[0029] The first refrigerant flow channel 32 defines a closed
cross-section, for example, a pipe except for the positions of the
communication holes 40. In FIG. 2, the lower member 36a that
defines the lower side of the first refrigerant flow channel 32,
and an intermediate member 36b that defines the upper side of the
first refrigerant flow channel 32 are illustrated. The near side or
far side (the near side or far side in a direction perpendicular to
the X direction and Z direction) of the first refrigerant flow
channel 32 may be defined, for example, by the side wall member 36f
or 36e illustrated in FIG. 5.
[0030] Refrigerant is caused to flow through the first refrigerant
flow channel 32. The refrigerant from the pipe 14 is introduced
into the first refrigerant flow channel 32 as indicated by arrow
P01 of FIG. 2, flows through the first refrigerant flow channel 32
as indicated by arrows P1, exits the first refrigerant flow channel
32 and flows to the downstream side as indicated by arrow P4.
[0031] The second refrigerant flow channel 34 is provided so as to
be adjacent to the first refrigerant flow channel 32. Although, in
FIG. 2, the second refrigerant flow channel 34 is adjacent to the
upper side of the first refrigerant flow channel 32, the second
refrigerant flow channel 34 may be provided so as to be adjacent to
the lower side of the first refrigerant flow channel 32, or may be
provided so as to be adjacent to the near side or far side (the
near side or far side in a direction perpendicular to the X
direction and Z direction) of the first refrigerant flow channel
32. The second refrigerant flow channel 34 may be adjacent to the
first refrigerant flow channel 32 in any direction.
[0032] The second refrigerant flow channel 34 defines a pipe of a
closed cross-section (except for the positions of the communication
holes 40). In FIG. 2, the intermediate member 36b that defines the
lower side of the second refrigerant flow channel 34, and a lid
member 36c that defines the upper side of the second refrigerant
flow channel 34 are illustrated. The near side or far side (the
near side or far side in a direction perpendicular to the X
direction and Z direction) of the second refrigerant flow channel
34 may be defined, for example, by the side wall member 36f or 36e
illustrated in FIG. 7.
[0033] The second refrigerant flow channel 34 is preferably blocked
at the downstream end in the flow direction of refrigerant in the
second refrigerant flow channel 34. In FIG. 2, the second
refrigerant flow channel 34 is blocked at the downstream end by a
blocking member 36d. Since the flow of refrigerant in the second
refrigerant flow channel 34 is blocked by the blocking member 36d,
the inflow of refrigerant in the second refrigerant flow channel 34
into the first refrigerant flow channel 32 through the
communication holes 40 (to be described later) is promoted.
[0034] Refrigerant is caused to flow through the second refrigerant
flow channel. The refrigerant from the pipe 12 is introduced into
the second refrigerant flow channel 34 as indicated by arrow P02 of
FIG. 2, flows through the second refrigerant flow channel 34, flows
into the first refrigerant flow channel 32 through the
communication holes 40 as indicated by arrows P2, exits the first
refrigerant flow channel 32 and flows to the downstream side as
indicated by arrow P4. In FIG. 2, since the blocking member 36d is
provided, the refrigerant introduced into the second refrigerant
flow channel 34 flows into the first refrigerant flow channel 32
through the communication holes 40 unless it flows back, and then,
it exits the first refrigerant flow channel 32 and flows to the
downstream side. When the blocking member 36d is not provided,
refrigerant that does not flow into the first refrigerant flow
channel 32 through the communication holes 40, for example,
refrigerant that exits from the downstream opening of the second
refrigerant flow channel, may flow to the downstream side
independently from the refrigerant in the first refrigerant flow
channel 32, or may be merged with the refrigerant in the first
refrigerant flow channel 32, may then exit the first refrigerant
flow channel 32, and may flow to the downstream side. When the
blocking member 36d is provided, it may be advantageous in terms of
the number of components and the cooling efficiency as compared to
when the blocking member 36d is not provided.
[0035] The communication holes 40 are provided between both ends of
the object 3 to be cooled of the first refrigerant flow channel 32
in the flow direction of refrigerant in the first refrigerant flow
channel 32. In FIG. 2, the three communication holes 40 are
provided between both ends of the object 3 to be cooled of the
first refrigerant flow channel 32 in the flow direction of
refrigerant in the first refrigerant flow channel 32. Both ends of
the object 3 to be cooled may be both ends of the heat spreader 3a
or may be both ends of a heat generating source, for example, the
electronic device 2.
[0036] The communication holes 40 do not have nozzles and allow the
first refrigerant flow channel 32 and the second refrigerant flow
channel 34 to communicate with each other. For example, the
communication holes 40 may be not in the form of nozzles protruding
into the first refrigerant flow channel 32, for example, in the
form of the communication holes 40' illustrated in FIG. 3 but
simple holes formed in a flat surface or a curved surface.
Communication holes 40' having nozzles supply the refrigerant in
the second refrigerant flow channel to positions close to the
object 3 to be cooled. Therefore, in a cooling system using the
boiling of liquid, for example, the system that removes bubbles
generated by the heat from an object 3 to be cooled illustrated in
FIG. 3, communication holes 40' having nozzles are provided. The
communication holes 40' having nozzles may cause a loss (pressure
loss) in the flow in the first refrigerant flow channel 32 and may
cause a decrease in cooling capacity.
[0037] When focusing on the refrigerant introduced from the pipe 14
into the first refrigerant flow channel 32, the refrigerant
introduced from the pipe 14 into the first refrigerant flow channel
32 receives heat from the object 3 to be cooled (receives heat with
the cooling of the object 3 to be cooled) as it flows downstream,
and therefore the temperature (refrigerant temperature) increases.
Therefore, in the refrigerant introduced from the pipe 14 into the
first refrigerant flow channel 32, the temperature on the upstream
side of the object 3 to be cooled is lower than the temperature on
the downstream side of the object 3 to be cooled, and non-uniform
cooling may occur.
[0038] The difference in temperature produced between the upstream
side and the downstream side of flow is temperature variation in
the temperature distribution on the surface of the electronic
device. A state in which there is temperature variation is a state
in which the effect of heat on the electronic device 2 varies, and
is a state in which various distortions caused by heat, for
example, the load is large. In order to stably operate the
electronic device 2 or a system including the electronic device 2,
for example, the electronic apparatus 50 over a long period of
time, the load on the electronic device 2 may be preferably
small.
[0039] For example, since the communication holes 40 are provided
between both ends of the object 3 to be cooled in the first
refrigerant flow channel 32 in the flow direction of refrigerant in
the first refrigerant flow channel 32, non-uniform cooling may be
remedied. For example, at a position where the temperature of
refrigerant introduced into the first refrigerant flow channel 32
increases, refrigerant in the second refrigerant flow channel 34,
for example, fresh refrigerant is introduced through the
communication holes 40, and therefore the increased temperature of
refrigerant in the first refrigerant flow channel 32 decreases, and
the cooling capacity may recover. Since the increase in the
temperature of refrigerant on the downstream side of flow is
reduced, the cooling capacity of refrigerant may be uniformized
along the flow direction. Therefore, the load on the electronic
device 2 may be reduced.
[0040] The positions and number of the communication holes 40, the
flow rate of refrigerant introduced from the second refrigerant
flow channel 34 through the communication holes 40 into the first
refrigerant flow channel 32, and the like may be set taking into
account the heat generation distribution of the object 3 to be
cooled, such that the temperature distribution of the object 3 to
be cooled along the flow direction is a desired temperature
distribution, for example, a uniform temperature distribution.
[0041] FIG. 4 illustrates an example of cooling effect. In FIG. 4,
in each of the case of uniform heat generation and the case in
which there is a hot spot, two types of temperature distribution
are illustrated. The uniform heat generation means that the amount
of heat generation is uniform in each region of the electronic
device 2. The hot spot means a part of the electronic device 2 in
which the amount of heat generation is larger than in the other
parts due to non-uniform heat generation, for example, a part in
which the amount of heat generation is locally the maximum in a
state where the electronic device 2 is alone. In FIG. 4, the hot
spot H may exist, for example, on the downstream side in the flow
direction of refrigerant of the electronic device 2. The
temperature distribution illustrated in FIG. 4 is temperature
distribution after cooling, and may correspond to the temperature
distribution of the electronic device 2 (the temperature
distribution on the surface of the electronic device). In each
graph illustrating temperature distribution, the horizontal axis
indicates temperature measurement position (the origin side
corresponds to the upstream side in the flow direction of
refrigerant), and the vertical axis indicates temperature. For
example, each graph illustrates the temperature distribution along
the flow direction of refrigerant.
[0042] In FIG. 3, in the case of the uniform heat generation, the
temperature distribution is such that, as illustrated in A of FIG.
4, the temperature increases significantly in the center, and
increases gradually toward the downstream side. The reason is that
the temperature of refrigerant increases on the downstream side. In
the case of a hot spot, the temperature distribution is such that,
as illustrated in A of FIG. 4, the temperature increases gradually
toward the downstream side, and increases steeply near the hot
spot. The reason is that the temperature of refrigerant increases
steeply owing to the hot spot on the downstream side. As just
described, since refrigerant circulates in a direction, under the
influence of temperature state of refrigerant, the electronic
device 2 may not be cooled uniformly.
[0043] In FIG. 2, the object 3 to be cooled is cooled substantially
uniformly. Therefore, in the case of uniform heat generation, the
temperature distribution is an arcuate temperature distribution as
illustrated in B of FIG. 4. Also in the case of a hot spot, the
temperature distribution is an arcuate temperature distribution as
illustrated in B of FIG. 4, and the temperature increases only
slightly near the hot spot. In both cases, the maximum temperature
T1 is low as compared to FIG. 3.
[0044] FIG. 5 illustrates an example of a top view of a first
refrigerant flow channel. The first refrigerant flow channel 32 may
be a single flow channel for one object 3 to be cooled, or may
include a plurality of flow channels 32a to 32h for one object 3 to
be cooled as illustrated in FIG. 5. The plurality of flow channels
32a to 32h may extend parallel to each other. The plurality of flow
channels 32a to 32h are divided from each other by partition walls
33 between the side wall members 36e and 36f in the Y direction.
Although, in FIG. 5, the intervals in the Y direction between the
plurality of flow channels 32a to 32h are substantially the same,
the intervals between some or all of the plurality of flow channels
32a to 32h may differ. Although the intervals in the Y direction
between the plurality of flow channels 32a to 32h are substantially
fixed along the X direction, they may change, for example, they may
increase downstream. Although, in FIG. 5, the plurality of flow
channels 32a to 32h exist from end to end in the X direction (flow
direction), the partition walls 33 may be formed in only a part of
the first refrigerant flow channel 32. The partition walls 33 may
be formed over the entire range of the electronic device 2 (or the
object 3 to be cooled) in the flow direction, or may be formed only
in a range under the communication holes 40. Although, in FIG. 5,
all of the plurality of flow channels 32a to 32h pass over the same
electronic device 2 (or object 3 to be cooled), only some of the
plurality of flow channels may pass over the same electronic device
2 (or object 3 to be cooled).
[0045] FIG. 6A and FIG. 6B each illustrate an example of a top view
of a flow of refrigerant. In FIG. 6A, the flow of refrigerant near
a communication hole 40 in the case where the first refrigerant
flow channel 32 includes a single flow channel is illustrated. In
FIG. 6B, the flow of refrigerant near a communication hole 40 in
the case where the first refrigerant flow channel 32 includes a
plurality of flow channels 32a to 32h is illustrated.
[0046] As indicated by dashed arrows of FIG. 6A, in the case where
the first refrigerant flow channel 32 includes a single flow
channel, when the refrigerant in the second refrigerant flow
channel 34 flows through the communication hole 40 into the first
refrigerant flow channel 32, the flow direction of the inflowing
refrigerant may be disturbed, and vortexes and stagnation may tend
to occur.
[0047] As indicated by dashed arrows of FIG. 6B, in the case where
the first refrigerant flow channel 32 includes a plurality of flow
channels 32a to 32h, when the refrigerant in the second refrigerant
flow channel 34 flows through the communication hole 40 into the
first refrigerant flow channel 32, the disturbance of the flow
direction of the inflowing refrigerant or the occurrence of
vortexes and stagnation due to disturbance may be reduced.
Therefore, all of the refrigerant in the second refrigerant flow
channel 34 flowing through the communication hole 40 into the first
refrigerant flow channel 32 may be able to be caused to flow along
the flow direction of the refrigerant in the first refrigerant flow
channel 32.
[0048] FIG. 7 illustrates an example of a top view of a second
refrigerant flow channel and a communication hole. For example,
when the configuration illustrated in FIG. 7 and the configuration
of the first refrigerant flow channel 32 including a plurality of
flow channels 32a to 32h illustrated in FIG. 5 are combined, the
second refrigerant flow channel 34 may be disposed over the first
refrigerant flow channel 32 such that they are completely
superimposed on each other in top view. For example, a two-tiered
structure may be formed.
[0049] Although, in FIG. 7, the second refrigerant flow channel 34
is a single flow channel defined between the side wall members 36e
and 36f in the Y direction, it may include a plurality of flow
channels as with the first refrigerant flow channel 32. The
communication holes 40 may be formed, as illustrated in FIG. 7, so
as to be elongate in a direction (Y direction) across the flow
direction (X direction) of the refrigerant in the first refrigerant
flow channel 32. When combined with the configuration of the first
refrigerant flow channel 32 including a plurality of flow channels
32a to 32h illustrated in FIG. 5, each communication hole 40 may be
shared by at least two of the plurality of flow channels 32a to
32h. In FIG. 7, in the case of the uniform heat generation, the
necessity of cooling the end portions of the object 3 to be cooled
may be not so high. Therefore, the communication holes 40 may not
communicate with the flow channels 32a and 32h at both ends in the
Y direction. The communication holes 40 may be formed so as to
communicate with all of the flow channels 32a to 32h of the first
refrigerant flow channel 32.
[0050] FIG. 8 illustrates an example of a top view of a second
refrigerant flow channel and a communication hole. When the
configuration illustrated in FIG. 8 and the configuration of the
first refrigerant flow channel 32 including a plurality of flow
channels 32a to 32h illustrated in FIG. 5 are combined, the second
refrigerant flow channel 34 may be disposed over the first
refrigerant flow channel 32 such that they are completely
superimposed on each other in top view. For example, a two-tiered
structure may be formed.
[0051] In FIG. 8, the plurality of flow channels 32a to 32h are
provided with their respective communication holes 40. The example
illustrated in FIG. 8 may be combined with the example illustrated
in FIG. 7. For example, a plurality of communication holes 40
provided for one electronic device 2 may include communication
holes 40 each corresponding to one of the plurality of flow
channels 32a to 32h, and communication holes 40 each shared by some
of the plurality of flow channels 32a to 32h.
[0052] FIG. 9 illustrates an example of an arrangement of
communication hole. In FIG. 9, an example of arrangement of
communication holes in the case where there are hot spots on the
electronic device 2 is illustrated.
[0053] In the case where there are hot spots on the electronic
device 2, communication holes 40 may be provided so as to
correspond to the positions of the hot spots in the X direction, or
may be provided on the upstream side of the positions of the hot
spots. Refrigerant having high cooling capacity, for example, the
refrigerant in the second refrigerant flow channel 34 is introduced
near the hot spots of the electronic device 2. Therefore, the hot
spots of the electronic device 2 may be cooled intensively and
efficiently. When sufficient pressure for the inflow of the
refrigerant in the second refrigerant flow channel 34 through the
communication holes 40 into the first refrigerant flow channel 32
is obtained, the communication holes 40 may be provided just above
the hot spot H1 so as to correspond to the position of the hot spot
H1. When sufficient pressure for the inflow of the refrigerant in
the second refrigerant flow channel 34 through the communication
holes 40 into the first refrigerant flow channel 32 is not
obtained, the communication holes 40 may be provided on the
upstream side of the position of the hot spot H1. In FIG. 9, the
positions of two hot spots in the X direction are indicated by
signs H1 and H2. The communication hole 40 on the upstream side is
formed just above the hot spot H1 so as to correspond to the
position of the hot spot H1, and the communication hole 40 on the
downstream side is formed on the upstream side of (just short of)
the position of the hot spot H2.
[0054] FIG. 10 illustrates an example of an exploded perspective
view of a cooling head. The cooling head 30A illustrated in FIG. 10
may differ from the parts of the cooling head 30 illustrated in
FIG. 5 and FIG. 7, for example, in the number of the partition
walls 33, and the length of the communication holes 40. In other
respects, the configuration illustrated in FIG. 10 may be
substantially the same as or similar to the configuration
illustrated in FIG. 5 or FIG. 7.
[0055] The cooling head 30A includes a first flow channel member
100, a second flow channel member 200, and a lid member 36c. The
first flow channel member 100, the second flow channel member 200,
and the lid member 36c may be formed of a highly heat-conductive
material, for example, copper. The first flow channel member 100,
the second flow channel member 200, and the lid member 36c may be
integrated by welding or the like.
[0056] In the first flow channel member 100, a first refrigerant
flow channel 32 is formed. In FIG. 10, as with the example
illustrated in FIG. 5, a plurality of partition walls 33 are
provided in the first flow channel member 100. Therefore, the first
refrigerant flow channel 32 has a plurality of flow channels. The
first flow channel member 100 includes a joint portion 102 coupled
to the pipe 14 (see FIG. 1) from the pump 4, and a joint portion
104 coupled to the pipe 16 (see FIG. 1) leading to the radiator 6.
In FIG. 10, refrigerant introduced through the joint portion 102
flows into the first refrigerant flow channel 32 through an
upstream flow channel 106 whose width increases toward the
downstream side. In FIG. 10, refrigerant that exits the first
refrigerant flow channel 32 and flows to the downstream side flows
to the joint portion 104 through a downstream flow channel 108
whose width decreases toward the downstream side.
[0057] The second flow channel member 200 is stacked on the first
flow channel member 100. In the second flow channel member 200, a
second refrigerant flow channel 34 and communication holes 40 are
formed. The second flow channel member 200 includes a joint portion
202 coupled to the pipe 12 (see FIG. 1) from the pump 4. The
downstream side of the second flow channel member 200 is blocked by
a blocking member 36d, and therefore there may be no joint portion
leading to the radiator 6. In FIG. 10, refrigerant introduced
through the joint portion 202 flows into the second refrigerant
flow channel 34 through an upstream flow channel 206 whose width
increases toward the downstream side. In FIG. 10, a downstream flow
channel 208 corresponding to the downstream flow channel 108 is
formed in the second flow channel member 200. However, the
downstream flow channel 208 may not be provided. In this case, the
blocking member 36d is moved to the upstream side. The intermediate
member 36b may extend over the downstream flow channel 108 of the
first flow channel member 100 and may function as a lid.
[0058] The lid member 36c may have a shape corresponding to the
peripheral wall portion of the second flow channel member 200. The
lid member 36c is placed on the second flow channel member 200 and
defines the upper side of the second refrigerant flow channel
34.
[0059] FIG. 11 illustrates an example of a perspective view of a
cooling head. FIG. 12 illustrates an example of a sectional view of
a cooling head. In FIG. 12, a sectional view of the cooling head
30B illustrated in FIG. 11 taken along the longitudinal center line
of the second flow channel member 220 is illustrated.
[0060] The cooling head 30B illustrated in FIG. 11 and FIG. 12
differs from the cooling head 30A illustrated in FIG. 10 in that a
second refrigerant flow channel 34 is formed in a pipe-like second
flow channel member 220. For example, in the cooling head 30B
illustrated in FIG. 11 and FIG. 12, instead of the second flow
channel member 200 illustrated in FIG. 10, a pipe-like second flow
channel member 220 is provided. In other respects, the
configuration of the first flow channel member 100B of the cooling
head 30B may be substantially the same as or similar to the
configuration of the first flow channel member 100.
[0061] The second flow channel member 220 includes a pipe portion
221 that branches from the joint portion 102 and extends upward, a
pipe portion 222 that bends from the pipe portion 221 and extends
along the flow direction of refrigerant in the first refrigerant
flow channel 32, and two pipe portions 223 and 224 that extend
downward from the pipe portion 222. The pipe portion 223 has such a
form that its width increases toward its lower end as illustrated
in FIG. 11. The end in the flow direction of the pipe portion 222
is closed, and refrigerant introduced into the second flow channel
member 220 flows from the pipe portions 223 and 224 through
communication holes 40 into the first refrigerant flow channel 32
unless it flows back. The communication holes 40 are provided
between both ends of the object 3 to be cooled in the first
refrigerant flow channel 32 in the flow direction of refrigerant in
the first refrigerant flow channel 32.
[0062] The cooling head 30B illustrated in FIG. 11 and FIG. 12 may
also provide the same advantageous effect as that of the cooling
head 30A illustrated in FIG. 10. The first flow channel member 100
and the second flow channel member 220 may not be stacked
vertically like the first flow channel member 100 and the second
flow channel member 200 of the cooling head 30A illustrated in FIG.
10. In the cooling head 30B illustrated in FIG. 11 and FIG. 12, the
pipe portions 223 and 224 extend vertically, and therefore when
flowing through the pipe portions 223 and 224, refrigerant obtains
a flow velocity in the direction of gravitational force owing to
the gravitational force. Therefore, the flowing of refrigerant in
the second refrigerant flow channel 34 through the communication
holes 40 into the first refrigerant flow channel 32 is
promoted.
[0063] For example, although the first refrigerant flow channel 32
and the second refrigerant flow channel 34 have a positional
relationship (angular relationship) such that refrigerant flows in
the same direction, the first refrigerant flow channel 32 and the
second refrigerant flow channel 34 may have a positional
relationship (angular relationship) such that refrigerant flows in
different directions (directions intersecting each other or
opposite each other). For example, in FIG. 2, the second
refrigerant flow channel 34 may extend in a direction rotated by an
arbitrary angle about the Z axis. For example, the second
refrigerant flow channel 34 may be mirror-reversed (in this case,
refrigerant flows from right to left of FIG. 2), or may be rotated
90 degrees about the Z axis (in this case, refrigerant flows in a
direction perpendicular to the X axis and the Z axis).
[0064] Although, in FIG. 2, the first refrigerant flow channel 32
and the second refrigerant flow channel 34 are vertically adjacent
to each other with the intermediate member 36b therebetween, the
first refrigerant flow channel 32 and the second refrigerant flow
channel 34 may be vertically separated from each other. FIG. 13
illustrates an example of a sectional view of a cooling head. For
example, in the cooling head 30C illustrated in FIG. 13, an upper
member 360b of a first refrigerant flow channel 32 and a lower
member 362b of a second refrigerant flow channel 34 are vertically
offset from each other, and the upper member 360b and the lower
member 362b may be coupled by pipe members 364a extending
vertically. The lower ends of the pipe members 364a may be open
without having nozzles in communication holes 40.
[0065] Although the cooling head 30, 30A, 30B, or 30C is provided
for one electronic device 2, it may be shared by two or more
electronic devices 2.
[0066] In FIG. 2, the lower member 36a may be a heat spreader
3a.
[0067] The refrigerant may be cooling water or another fluid such
as air.
[0068] All examples and conditional language recited herein are
intended for pedagogical purposes to aid the reader in
understanding the invention and the concepts contributed by the
inventor to furthering the art, and are to be construed as being
without limitation to such specifically recited examples and
conditions, nor does the organization of such examples in the
specification relate to a showing of the superiority and
inferiority of the invention. Although the embodiments of the
present invention have been described in detail, it should be
understood that the various changes, substitutions, and alterations
could be made hereto without departing from the spirit and scope of
the invention.
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