U.S. patent application number 10/150151 was filed with the patent office on 2002-09-26 for cooling system for multichip module.
This patent application is currently assigned to FUJITSU LIMITED. Invention is credited to Hirano, Minoru, Suzuki, Masumi.
Application Number | 20020134532 10/150151 |
Document ID | / |
Family ID | 17715055 |
Filed Date | 2002-09-26 |
United States Patent
Application |
20020134532 |
Kind Code |
A1 |
Hirano, Minoru ; et
al. |
September 26, 2002 |
Cooling system for multichip module
Abstract
It is an object of the present invention to provide a cooling
system capable of simultaneously cooling the electronic parts on a
multichip module that is arranged so as to provide a predetermined
function, wherein the cooling system can be easily and quickly
attached to and detached from the module when necessary. The
present invention is to provide a cooling system for cooling a
multichip module MCM having a predetermined function, on the
substrate B of which a plurality of electronic parts including heat
generating parts P are mounted, the cooling system for cooling a
multichip module comprising: a radiating body 1 capable of covering
upper portion of the plurality of electronic parts P while a
predetermined clearance is formed between the radiating body 1 and
the electronic parts P; a sheet S made of silicon rubber arranged
in the clearance, for thermally connecting the upper surfaces of
the electronic parts and the radiating member; and a screw N for
detachably connecting the radiating body with the substrate B of
the multichip module MCM.
Inventors: |
Hirano, Minoru;
(Kawasaki-shi, JP) ; Suzuki, Masumi;
(Kawasaki-shi, JP) |
Correspondence
Address: |
ARMSTRONG,WESTERMAN & HATTORI, LLP
1725 K STREET, NW.
SUITE 1000
WASHINGTON
DC
20006
US
|
Assignee: |
FUJITSU LIMITED
Kawasaki
JP
|
Family ID: |
17715055 |
Appl. No.: |
10/150151 |
Filed: |
May 20, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10150151 |
May 20, 2002 |
|
|
|
09044313 |
Mar 19, 1998 |
|
|
|
Current U.S.
Class: |
165/80.3 ;
165/185; 257/E23.099; 361/704 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 23/467 20130101; H05K 7/20436 20130101; H01L 23/40 20130101;
H01L 23/4006 20130101; H05K 7/20509 20130101; H05K 7/20472
20130101; H01L 2924/00 20130101; H01L 2924/0002 20130101 |
Class at
Publication: |
165/80.3 ;
165/185; 361/704 |
International
Class: |
F28F 007/00; H05K
007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 1997 |
JP |
9-287256 |
Claims
What is claimed is:
1. A cooling system for cooling a multichip module, having a
predetermined function, on a substrate of which a plurality of
electronic parts including heat generating parts are mounted, the
cooling system for cooling a multichip module comprising: a
radiating body capable of covering upper portions of the plurality
of electronic parts while a predetermined clearance is formed
between the radiating body and the electronic parts; a heat
conducting member arranged in the clearance, for thermally
connecting an upper surface of the electronic parts and of a
radiating member; and a fastening body for detachably connecting
the radiating body with the substrate of the multichip module, the
fastening body including an elastic frame having a hook portion
capable of catching the substrate so that the radiating body can be
detachably fixed to the substrate while the fastening body covers
the radiating body.
2. A cooling system for cooling a multichip module, having a
predetermined function, on a substrate of which a plurality of
electronic parts including heat generating parts are mounted, the
cooling system for cooling a multichip module comprising: a
radiating body capable of covering upper portions of the plurality
of electronic parts while a predetermined clearance is formed
between the radiating body and the electronic parts; a heat
conducting member arranged in the clearance, for thermally
connecting an upper surface of the electronic parts and of a
radiating member; and a fastening body for detachably connecting
the radiating body with the substrate of the multichip module, the
fastening body including an elastic frame having a hook C-shaped
clip to pinch the radiating body and the substrate.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a cooling system for
cooling a multichip module having a predetermined function, on the
substrate of which a plurality of electronic parts, including heat
generating parts, are mounted.
[0003] 2. Description of the Related Art
[0004] Conventionally, the following structure is frequently used.
In order to cool a single electronic part, a small heat sink
exclusively used for cooling the single electronic part is fixed
onto an upper surface of the electronic part. Several examples of
the above structure will be briefly described below.
[0005] Japanese Unexamined Patent Publication No. 3-94455 discloses
a radiating structure for cooling a single semiconductor chip
mounted on a substrate. In the structure, a radiating plate
exclusively used for cooling the single semiconductor chip is made
to come into surface-contact with an upper surface of the
semiconductor chip, and a tongue-shaped portion of the radiating
plate is fixed to the substrate with bolts.
[0006] Japanese Unexamined Patent Publication No. 8-139475
discloses a radiating structure for cooling a single electronic
part mounted on a substrate. In the structure, a heat sink
exclusively used for cooling the single electronic part is made to
come into surface-contact with an upper surface of the electronic
part, and the heat sink is pressed against the substrate with two
C-shaped metal fittings.
[0007] Japanese Unexamined Patent Publication No. 5-243439
discloses a radiating structure for cooling a single electronic
part mounted on a substrate. In the structure, a heat sink
exclusively used for cooling the single electronic part is made to
come into surface-contact with an upper surface of the electronic
part, and the radiating plate and the substrate are fixed to each
other with four bolts.
[0008] Japanese Unexamined Patent Publication No. 6-112676
discloses a radiating structure for cooling a single semiconductor
element mounted on a substrate. In the structure, a heat sink
exclusively used for cooling the single semiconductor element is
made to come into surface-contact with an upper surface of the
semiconductor element, and the heat sink and the substrate are
fixed to each other with two or four screws.
[0009] Japanese Unexamined Patent Publication No. 6-260573
discloses a radiating structure for cooling a single semiconductor
package mounted on a substrate. In the structure, a heat sink
exclusively used for cooling the single semiconductor package is
made to come into surface-contact with an upper surface of the
semiconductor package, and the heat sink is fixed to the
semiconductor package or the substrate with four screws.
[0010] Japanese Unexamined Patent Publication No. 7-161886
discloses a radiating structure for cooling a single semiconductor
package mounted on a substrate. In the structure, a heat sink
exclusively used for cooling the single semiconductor package is
made to come into surface-contact with an upper surface of the
semiconductor package, and the heat sink is fixed to the
semiconductor package or the substrate with four screws.
[0011] Japanese Unexamined Patent Publication No. 8-264689
discloses a radiating structure for cooling a single semiconductor
element mounted on a substrate. In the structure, a heat sink
exclusively used for cooling the single semiconductor element is
made to come into surface-contact with an upper surface of the
semiconductor element, and the heat sink is pressed against the
substrate with an attaching frame.
[0012] Japanese Unexamined Patent Publication No. 3-229445
discloses a radiating structure for cooling a single electronic
part mounted on a substrate. In the structure, a support plate is
fixed onto an upper surface of the single electronic part with
adhesive, and an exclusive heat sink is fixed onto the support
plate with screws while a radiating sheet is interposed between the
heat sink and the support plate.
[0013] Japanese Unexamined Patent Publication No. 2-83958 discloses
a cooling structure for cooling a single module incorporated into a
chip mounted on a substrate. In the structure, a fan exclusively
used for cooling the single module is arranged on the upper side of
the module and, in order to cool a plurality of chips mounted on
the substrate, a fan is arranged on the upper side of these
chips.
[0014] Japanese Unexamined Patent Publication No. 7-30026 discloses
a cooling structure for cooling a single pin-grid-array. In the
structure, a heat sink having fins is fixed onto an upper surface
of the pin-grid-array with adhesive.
[0015] Although it is possible to individually cool electronic
parts in the above conventional cooling structures, it is
impossible to simultaneously cool the electronic parts of the
module, on which a plurality of electronic parts are mounted, so
that a predetermined function can be provided.
SUMMARY OF THE INVENTION
[0016] It is an object of the present invention to provide a
cooling system capable of simultaneously cooling the electronic
parts on a multichip module that is arranged so as to provide a
predetermined function, wherein the cooling system can be easily
and quickly attached to and detached from the module when
necessary.
[0017] In order to solve the above problems, the present invention
is to provide a cooling system for cooling a multichip module
having a predetermined function, on the substrate of which a
plurality of electronic parts including heat generating parts are
mounted, the cooling system for cooling a multichip module
comprising: a radiating body capable of covering the upper portions
of the plurality of electronic parts while a predetermined
clearance is formed between the radiating body and the electronic
parts; a heat conducting member arranged in the clearance, for
thermally connecting the upper surfaces of the electronic parts and
the radiating member; and a fastening body for detachably
connecting the radiating body with the substrate of the multichip
module. Due to the above arrangement, the multichip module and the
radiating body can be detachably fixed to each other, which is very
advantageous in view of practical use. Heat generated by the high
heat generating parts of the multichip module is effectively
conducted to the radiating body, so that the multichip module can
be effectively cooled. As a result, the reliability of the
multichip module can be enhanced.
[0018] It is preferable that the fastening body includes at least
one screw, and the screw is screwed to a corresponding stud
perpendicularly arranged on the substrate. It is also preferable
that the fastening body includes an elastic frame having a hook
portion capable of catching the substrate so that the radiating
body can be detachably fixed to the substrate while the fastening
body covers the radiating body. It is also preferable that the
fastening body includes at least one C-shaped clip to pinch the
radiating body and the substrate. It is also preferable that the
substrate of the multichip module is flexible. It is also
preferable that the radiating body includes a plurality of fins. It
is also preferable that a centrifugal fan is attached on an upper
surface of the radiating body. It is also preferable that the heat
conducting member is made of compound. It is also preferable that
the heat conducting member is composed of a flexible sheet.
[0019] Another invention is to provide a cooling system for cooling
a multichip module having a predetermined function, on the
substrate of which a plurality of electronic parts including heat
generating parts are mounted, the cooling system for cooling a
multichip module comprising: a radiating body capable of covering
upper portions of the plurality of electronic parts while a
predetermined clearance is formed between the radiating body and
the electronic parts; a fastening body for detachably connecting
the radiating body with the substrate of the multichip module; and
an axial fan attached onto an upper surface of the radiating body,
wherein the radiating body includes inlet ports to pass air
discharged from the axial fan into the radiating body and also
includes discharge ports to discharge air outside. Due to the above
arrangement, it becomes possible to detachably fix the multichip
module to the radiating body. Therefore, this arrangement can be
advantageously put into practical use. Also, heat generated by the
high heat generating parts incorporated into the multichip module
is effectively discharged outside by a flow of air sent from the
axial fan. Accordingly, it is possible to cool the multichip module
effectively. As a result, the reliability of the multichip module
can be enhanced.
[0020] It is preferable that the inlet ports of the radiating body
are intensively arranged in a portion of the radiating body
corresponding to a region on the substrate in which a large
quantity of heat is generated. It is preferable that a nozzle from
which air is strongly blown out to a region on the substrate in
which a large quantity of heat is generated is attached to at least
one inlet port of the radiating body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] These and other objects of the present invention will become
apparent from the following detailed description of the preferred
embodiment of the invention, taken in connection with the
accompanying drawings.
[0022] In the drawings:
[0023] FIG. 1 is a cross-sectional side view of the first
embodiment of the cooling system of the multichip module of the
present invention;
[0024] FIG. 2 is an exploded side view of the cooling system shown
in FIG. 1;
[0025] FIG. 3 is an exploded side view of the second
embodiment;
[0026] FIG. 4 is an exploded side view of the third embodiment;
[0027] FIG. 5 is an exploded side view of the fourth
embodiment;
[0028] FIG. 6 is an exploded side view of the fifth embodiment;
[0029] FIG. 7 is an exploded side view of the sixth embodiment;
[0030] FIG. 8 is a cross-sectional side view of the seventh
embodiment;
[0031] FIG. 9 is an exploded cross-sectional side view of the
eighth embodiment;
[0032] FIG. 10 is a cross-sectional side view of the ninth
embodiment; and
[0033] FIG. 11 is an exploded cross-sectional side view of the
tenth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Referring to the accompanying drawings, a plurality of
embodiments of the present invention will be explained below. In
this connection, like reference characters are used to indicate
like parts and portions in the embodiments, and the duplicate
explanations are appropriately omitted here.
[0035] FIGS. 1 and 2 show the first embodiment of the cooling
system of the multichip module, which will be referred to as an MCM
hereinafter, of the present invention. The MCM shown in the
drawings is composed of a small, for example, rectangular,
substrate B on which a plurality of electronic parts P including
heat generating parts such as LSIs are mounted. This MCM is a
module designed to provide a predetermined function. This MCM is
usually mounted on a large main substrate incorporated into an
electronic device not shown in the drawing.
[0036] Since an MCM includes a large number of heat generating
parts, a radiating body 1 is attached to MCM substrate B so that an
upper surface of the MCM substrate B can be entirely covered with
the radiating body 1. The radiating body 1 is integrally made of
metal, the heat conductivity of which is high, for example, the
radiating body 1 is integrally made of aluminum.
[0037] One surface of the radiating body 1 opposed to the upper
surface of the substrate of MCM, which will be referred to as an
inner surface hereinafter, is formed stepwise so that a
predetermined clearance (gap) can be formed between the inner
surface and electronic parts P on the substrate having various
heights. This clearance is formed into a substantially uniform size
all over the surface, or alternatively this clearance is formed
into various sizes depending upon the positions on the inner
surface.
[0038] In the clearance formed between the upper surface of each
electronic part P and the inner surface of the radiating body 1,
there is provided a flexible sheet S made of silicon rubber of a
predetermined thickness, the heat conductivity of which is high, so
that heat generated by each electronic part P can be effectively
conducted to the inner surface of the radiating body 1. In this
connection, it is possible to use a compound instead of the sheet,
for example, it is possible to use a thermal grease (heat
conducting grease) not shown in the drawing.
[0039] In order to maintain MCM substrate safely, the radiating
body 1 is detachably fixed to MCM substrate B with a fastening
body. In the examples shown in FIGS. 1 and 2, this fastening body
is composed of four screws N (only two screws are shown in the
drawings) which are set at four corners on the lower back side of
MCM substrate B and screwed and fastened to the radiating body 1
while an MCM substrate is interposed between the four screws and
the radiating body 1. In this connection, the number of the screws
of the fastening body is not necessarily limited to four, but the
number of the screws may be smaller or larger.
[0040] In the first embodiment, the arrangement of which is
described above, heat generated by electronic parts P mounted on
MCM substrate is effectively conducted to the radiating body 1 and
emitted outside from the radiating body 1. In other words, it is
possible to simultaneously and effectively cool the electronic
parts P mounted on MCM substrate B.
[0041] When the above screws N are loosened and fastened, the
radiating body 1 can be very simply attached to and detached from
MCM substrate B. Accordingly, compared with a conventional
radiating body (not shown in the drawings) which is made to adhere
with adhesive, defective electronic parts on an MCM substrate can
be very easily repaired or replaced even after the radiating body
has been fastened. Therefore, this arrangement is very appropriate
when it is put into practical use.
[0042] Even if the thermal expansion coefficient of electronic
parts P to be cooled is different from that of the radiating body
1, the flexible sheet (heat conducting member) S arranged in the
clearance functions as a cushion member. Due to the effect of this
cushion member, no stress is generated, so that the electronic
parts can not be damaged.
[0043] In this connection, as shown in FIG. 3 in which the, second
embodiment is shown, it is possible to provide studs St having a
female screw hole at four corners of MCM substrate, and screw N is
screwed into each stud St arranged on MCM substrate B, so that the
radiating body 31 can be fixed onto MCM substrate B by screws
N.
[0044] As can be seen in FIG. 4, in which the third embodiment is
shown, no screws are used, and it is possible to use an elastic
frame 43, which is an example of the fastening body, having hooks
on both sides capable of catching MCM substrate B so that the
radiating body 41 can be detachably fixed to the MCM substrate in
such a manner that the radiating body 41 is covered with the
elastic frame 43. The elastic frame 43 is made of elastic material
such as stainless steel.
[0045] As can be seen in FIG. 5, in which the fourth embodiment is
shown, it is possible to use a plurality of C-shaped clips 53 to
fix the radiating body 51 and MCM substrate B to each other at
primary portions on the outer circumference of MCM substrate B. The
clips 53 are made of elastic material such as stainless steel.
[0046] As can be seen in FIG. 6, in which the fifth embodiment is
shown, MCM substrate B is composed of a flexible substrate. In this
case, the substrate B can be deformed into a desired profile when
it is attached to the radiating body 61. Therefore, it is
unnecessary to form the inner surface of the radiating body 61 into
a step-like profile, that is, it is possible to form the inner
surface of the radiating body 61 flat.
[0047] As can be seen in FIG. 7, in which the sixth embodiment is
shown, the radiating body 71 may be formed into a profile in which
protrusions and recesses are provided in an upper portion of the
radiating body 71, that is, a large number of fins 71a are formed
in the upper portion of the radiating body 71 which is a heat sink.
In this case, the radiating efficiency of the radiating body 71 can
be greatly enhanced.
[0048] As can be seen in FIG. 8, in which the seventh embodiment is
shown, it is possible to arrange a centrifugal fan 85 on an upper
surface of the radiating body 81. In this case, the radiating
efficiency of the radiating body 81 can be considerably
enhanced.
[0049] In several embodiments explained below, there is provided an
axial fan on an upper portion of the radiating body, and air is
sent from the axial fan into the radiating body.
[0050] As can be seen in FIG. 9, in which the eighth embodiment is
shown, there are formed a plurality of through-holes (suction ports
91a) in an upper portion of the radiating body 91 detachably fixed
onto MCM substrate B in such a manner that the radiating body 91
covers MCM substrate B. The axial fan 95 is fixed onto the upper
surface of the radiating body. On the four sides of the radiating
body 91, a necessary number of through-holes (discharge ports 91b)
are formed.
[0051] Due to the above arrangement, air sent from the axial fan 95
passes through the suction ports 91a of the radiating body 91 and
enters a space formed between the inner surface of the radiating
body and the upper surface of MCM substrate. After that, air is
discharged from the discharge port 91a of the radiating body 91.
Since air effectively removes heat from the heat generating parts P
on MCM substrate B at this time, it becomes possible to effectively
suppress an increase in temperature of MCM substrate B. Since the
air flow removes heat from MCM substrate B, it is preferable to
adopt the above arrangement from the viewpoint of cooling the
entire MCM substrate B.
[0052] It is preferable that the suction ports 91a of the radiating
body 91 are intensively arranged in a portion of the radiating body
so that air which has entered the inner space of the radiating body
91 can be effectively blown out toward heat generating parts P.
[0053] As can be seen in FIG. 10, in which the ninth embodiment is
shown, as described in the first embodiment, a sheet S made of
silicon rubber may be interposed in the clearance formed between
the upper surface of a certain heat generating part P (on the right
in the drawing) and the inner surface of the radiating body. In
this case, the number of the discharge ports arranged on the side
of the radiating body 101 may be reduced, so that a flow of air
having a directivity can be formed.
[0054] As can be seen in FIG. 11 in which the tenth embodiment is
shown, a nozzle Nz from which a flow of air is strongly jetted out
to high heat generating parts P on MCM substrate B may be attached
to at least one suction port 111a of the radiating body, wherein
four suction ports are shown in the drawing.
[0055] As explained above, according to the present invention, the
heat generating parts on an MCM substrate, which is formed into a
module on which a plurality of heat generating electronic parts are
mounted, can be effectively cooled. Therefore, it is possible to
realize a cooling system in which the heat generating parts can be
effectively cooled and the cooling system can be very simply
attached to and detached from an MCM substrate.
[0056] It is to be understood that the invention is by no means
limited to the specific embodiments illustrated and described
herein, and that various modifications thereof may be made which
come within the scope of the present invention as defined in the
appended claims.
* * * * *