U.S. patent application number 10/776680 was filed with the patent office on 2004-12-16 for clothespin type heat dissipating apparatus for semiconductor module.
Invention is credited to Baek, Joong-hyun, Im, Yun-hyeok, Kim, Min-ha.
Application Number | 20040250989 10/776680 |
Document ID | / |
Family ID | 33509562 |
Filed Date | 2004-12-16 |
United States Patent
Application |
20040250989 |
Kind Code |
A1 |
Im, Yun-hyeok ; et
al. |
December 16, 2004 |
Clothespin type heat dissipating apparatus for semiconductor
module
Abstract
Some embodiments of the invention include two heat exchange
members, which are arranged facing each other with a semiconductor
module therebetween, the semiconductor module including a plurality
of packages; a connection member formed in the middle of each of
the heat exchange members to hinge join the heat exchange members
such that portions of the heat exchange members protrude above the
semiconductor module inserted between the heat exchange members;
and an elastic member disposed between the heat exchange members to
provide a force pushing portions of the heat exchange members below
the connection member toward the packages of the semiconductor
module. Other embodiments of the invention are described in the
claims.
Inventors: |
Im, Yun-hyeok; (Kyungki-do,
KR) ; Baek, Joong-hyun; (Kyungki-do, KR) ;
Kim, Min-ha; (Kyungki-do, KR) |
Correspondence
Address: |
MARGER JOHNSON & McCOLLOM, P.C.
1030 S.W. Morrison Street
Portland
OR
97205
US
|
Family ID: |
33509562 |
Appl. No.: |
10/776680 |
Filed: |
February 10, 2004 |
Current U.S.
Class: |
165/80.1 ;
257/E23.086 |
Current CPC
Class: |
F28F 2280/105 20130101;
H01L 2924/0002 20130101; H01L 23/4093 20130101; H01L 2924/0002
20130101; H01L 2924/00 20130101 |
Class at
Publication: |
165/080.1 |
International
Class: |
F28F 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 11, 2003 |
KR |
2003-8450 |
Claims
We claim:
1. An apparatus comprising: two heat exchange members configured to
be placed on both sides of a semiconductor module, the
semiconductor module including a plurality of packages; a
connection member between the two heat exchange members configured
to movably join the two heat exchange members, wherein portions of
the two heat exchange members are configured to protrude above the
semiconductor module; and a biasing member disposed between the two
heat exchange members and configured to provide a force that holds
the two heat exchange members against the packages of the
semiconductor module.
2. The apparatus of claim 1, wherein the connection member
comprises a hinge.
3. The apparatus of claim 1, wherein the portions of the two heat
exchange members have uneven surfaces.
4. The apparatus of claim 1, wherein the portions of the two heat
exchange members comprise: a metal plate having a porous
surface.
5. The apparatus of claim 4, wherein the metal plate comprises an
aluminum plate.
6. The apparatus of claim 1, wherein the biasing member is disposed
between the portions of the two heat exchange members that protrude
above the semiconductor module and is chosen from the group
consisting of a spring, a plate spring, and a C-shaped spring.
7. The apparatus of claim 1, further comprising: a thermal
interface material layer formed on at least one of the heat
exchange members and configured to contact a surface of the
packages.
8. The apparatus of claim 7, wherein the thermal interface material
layer is selected from the group consisting of a thermal tape, a
thermal grease, a thermal epoxy, and a phase change material.
9. The apparatus of claim 7, wherein at least one of the two heat
exchange members comprise a recess filled with the thermal
interface material layer.
10. The apparatus of claim 7, wherein at least one of the two heat
exchange members comprise a packing member bounding the thermal
interface material layer.
11. The apparatus of claim 1, wherein at least one of the heat
exchange members is subjected to surface processing selected from
the group consisting of etching, sputtering, and coating.
12. An apparatus comprising: a first heat exchange member including
a first contacting portion, the first contacting portion configured
to contact a surface of a semiconductor module to absorb heat
generated by the semiconductor module, and a first heat dissipating
portion, which is thermally connected to the first contacting
portion to dissipate the heat absorbed by the first contacting
portion; a second heat exchange member including a second
contacting portion, the second contacting portion configured to
contact another surface of the semiconductor module to absorb the
heat generated by the semiconductor module, and a second heat
dissipating portion, which is thermally connected to the second
contacting portion to dissipate the heat absorbed by the second
contacting portion; and an elastic member structured to provide a
force that draws the first and second contacting portions toward
each other.
13. The apparatus of claim 12, wherein the elastic member is a
C-shaped spring having ends going through the first and second heat
dissipating portions, the apparatus and that are connected to
external surfaces of the first and second contacting portions and
which is oriented such that the connection portion is included in
the space formed by the C-shaped spring.
14. The apparatus of claim 12, further comprising: a connection
member, which hinge joins the first and second heat exchange
members such that the first and second heat dissipating portions
protrude above the semiconductor module inserted between the heat
exchange members, wherein the elastic member is chosen from the
group consisting of a spring, a plate spring, and a C-shaped
spring, and wherein the elastic member is disposed between the
first and second heat dissipating portions.
15. The apparatus of claim 12, wherein the first and second
contacting portions are subjected to surface processing selected
from the group consisting of etching, sputtering, and coating, to
increase the adhesion to the semiconductor module.
16. An apparatus comprising: a first heat exchange member including
a first contacting portion configured to contact a surface of a
semiconductor module to absorb heat generated by the semiconductor
module, and including a first heat dissipating portion with uneven
surfaces, the first heat dissipating portion thermally connected to
the first contacting portion to dissipate the heat absorbed by the
first contacting portion, wherein the first heat dissipating
portion is configured to protrude above the semiconductor module; a
second heat exchange member including a second contacting portion
configured to contact another surface of the semiconductor module
to absorb the heat generated by the semiconductor module, and
including a second heat dissipating portion with uneven surface,
the second heat dissipating portion thermally connected to the
second contacting portion to dissipate the heat absorbed by the
second contacting portion, the second heat dissipating portion
configured to protrude above the semiconductor module; a hinge that
joins the first and second heat exchange members; and a biasing
member disposed between the first and second heat exchange members
to provide a force that draws the first and second contacting
portions toward the surface and the another surface of the
semiconductor module that is inserted between the first and the
second contacting portions.
17. The apparatus of claim 16, wherein the first and second heat
dissipating portions are made of an aluminum plate with porous
surfaces.
18. An apparatus comprising: a first heat exchange member including
a first contacting portion that is configured to contact a surface
of a semiconductor module to absorb heat generated by the
semiconductor module, and including a first heat dissipating
portion that is thermally connected to the first contacting portion
to dissipate the heat absorbed by the first contacting portion,
wherein the first heat dissipating portion is configured to
protrude above the semiconductor module; a second heat exchange
member including a second contacting portion that is configured to
contact another surface of the semiconductor module to absorb the
heat generated by the semiconductor module, and including a second
heat dissipating portion that is thermally connected to the second
contacting portion to dissipate the heat absorbed by the second
contacting portion, wherein the second heat dissipating portion is
configured to protrude above the semiconductor module; a hinge that
joins the first and second heat exchange units; an elastic member
disposed between the first and second heat exchange members to
provide a force that draws the first and second contacting portions
toward the surface and another surface of the semiconductor module
inserted between the first and second contacting portions; thermal
interface material layers formed on the first and the second
contacting portions; and packing members bounding the thermal
interface material layers.
19. The apparatus of claim 18, wherein the packing members comprise
rubber packing members.
20. The apparatus of claim 18, wherein the first and second
contacting portions comprise a recess filled with the corresponding
thermal interface material layer.
21. The apparatus of claim 20, wherein each of the packing members
is disposed around the corresponding recess.
22. A heat dissipater, comprising: a relatively flat, elongated
thermally conductive substrate; and a clamp structured to hold a
portion of the thermally conductive substrate adjacent to a top
surface of one or more heat generating components that are attached
to a circuit board.
23. The heat dissipater of claim 22, further comprising a second
elongated thermally conductive substrate.
24. The heat dissipater of claim 23 wherein the clamp is structured
to hold the first conductive substrate against a top surface of one
or more heat generating components that are attached to a first
side of the circuit board, and is structured to hold the second
conductive substrate against a top surface of one or more heat
generating components that are attached to a second side of the
circuit board.
25. The heat dissipater of claim 23 wherein the clamp is a hinge
clamp mounted between the first and second conductive
substrates.
26. The heat dissipater of claim 22 wherein the clamp further
comprises a biasing member.
27. The heat dissipater of claim 25 wherein the biasing member is
one selected from the group of a spring, a plate spring, and a
C-shaped spring.
28. The heat dissipater of claim 22 wherein the thermally
conductive substrate is aluminum.
29. The heat dissipater of claim 22, further comprising a thermal
interface material disposed on the thermally conductive
substrate.
30. The heat dissipater of claim 28 wherein the thermal interface
material is non-conductive.
31. A method of dissipating heat from two or more heat generating
components mounted on opposite surfaces of a circuit board, the
method comprising: simultaneously clamping, to at least two opposed
top surfaces of the heat generating components, portions of a first
and a second elongated thermally conductive substrate,
respectively.
32. The method of claim 31 wherein clamping comprises: temporarily
overcoming a normal biasing force to separate the first and second
elongated substrates; positioning portions of the first and second
elongated substrates over the at least two opposed top surfaces,
respectively; and releasing the temporarily applied force to cause
the normal biasing force to hold the first and second elongated
substrates adjacent to the at least two opposed top surfaces,
respectively.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from Korean Patent
Application No. 2003-8450, filed on Feb. 11, 2003, in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This disclosure relates to a semiconductor module, and more
particularly, to a clothespin type heat dissipating apparatus that
can effectively dissipate heat generated by a device mounted on a
semiconductor module and which can be easily attached to and
detached from the semiconductor module.
[0004] 2. Description of the Related Art
[0005] Recently, the thermal issue of semiconductor modules, such
as, high density memory modules, becomes more critical. Along with
the concerns about increasing power consumption and heat
generation, which have arisen from the expectation that the
capacity of memory modules will increase by up to 2 GB or more,
there has been a need for a solution to the thermal issues
associated with such memory modules.
[0006] As the rate of data transmission between a central
processing unit (CPU) and peripheral devices becomes faster, the
operating current of memory products becomes greater. To raise the
capacity of memory modules, stacking more individual electronic
components upon one another has been suggested. However, stacked
memory modules result in poor thermal resistance.
[0007] A higher temperature of modules leads to a lower operation
rate, poor refresh properties, and a shorter life span. For
example, the data retention time (tREF) of Dynamic Random Access
Memory (DRAMs) is a very critical factor. When the temperature,
i.e., the device junction temperature (Tj), of a module rises
10.degree. C., the data retention time is reduced by about 30%. As
the temperature of memory modules increases, the yield decreases.
Therefore, there is a need to keep the device junction temperature
(Tj) constant without raising thermal problems.
[0008] Such a memory module is mounted in a slot of a mother board
in a (personal) computer system, as shown in FIG. 1.
[0009] FIG. 1 is a diagram illustrating conventional memory modules
mounted on a printed circuit board. Referring to FIG. 1, individual
devices 13, which generally have a package form, are integrated on
a module board 10 to form a memory module 14. The memory module 14
is inserted in a slot 11. About three or four slots 11 are spaced a
distance of, for example, about 9.55 mm apart from one another, and
a plurality of memory modules 14 are inserted in the slots 11
parallel to each other.
[0010] The temperature of the memory modules 14 varies depending on
the positions of the devices 13 therein. The temperature of a
memory module 14 at both end portions thereof is about 92.degree.
C., whereas the temperature of the memory module 14 at the center
portion is about 132.degree. C. This is because a larger amount of
air flows at the end portions to facilitate thermal convection,
whereas the air flows more slowly at the center portion and hot air
flows towards the center portion from the front portion.
[0011] Such a rise in the temperature of the memory module 14
becomes more serious when the interval between a plurality of
memory modules 14 inserted into the slots 11 is narrower. In
particular, when each memory device 13 mounted in a limited area of
the memory model 14 is highly integrated with more stacks, the
problem of temperature rise is at its worst. This is because the
interval between the modules 14 becomes narrower as the package has
more stacks. For the double-side stacked memory module 14 as shown
in FIG. 1, the interval between the modules is only 3.55 mm, which
leads to more serious rises in temperature.
[0012] To compensate for the rise in temperature in such memory
modules, various kinds of heat dissipating apparatus, for example,
a heat sink or a heat spreader, have been attached to memory
modules.
[0013] For example, for RAMBUS DRAMs, heat spreaders are disposed
with a module therebetween and bound together by rebating. However,
the heat spreaders rather hinder airflow and thermal convection
when the modules are narrowly spaced with highly stacked packages
and fail to dissipate or distribute heat.
[0014] In U.S. Pat. No. 5,966,287, entitled "Clip-on Heat Exchanger
for a Memory Module and Assembly Method," two parts, each of which
includes a heat spreader and a heat sink, are arranged with a
memory module therebetween and bound together using a clip.
[0015] However, with the above methods of coupling the heat
dissipating apparatuses to a memory module by rebating or clipping,
attaching or detaching the heat spreader or heat sink to/from the
memory module is a complicated process.
[0016] The following are considerations required when attaching a
heat sink or heat spreader to memory modules. First, the heat
spreader or heatsink must tightly contact the individual
components, i.e., the packages, of the memory module to lower
contact resistance and more effectively transfer heat. Second, it
must be easy to attach a heat spreader to or detach it from a
memory module. Third, heat spreaders must be designed to induce
more effective thermal convection.
[0017] However, as described above, the conventional coupling
methods are complicated and do not allow tight binding between the
heat spreader and the chip packages of the module. Therefore, a
more effective heat dissipating apparatus that may be conveniently
attached or detached from memory modules is required.
[0018] Embodiments of the invention address these and other
limitations of the prior art.
SUMMARY OF THE INVENTION
[0019] The present invention provides a heat dissipating apparatus
that can be easily attached to and detached from a semiconductor
module and which can effectively dissipate heat generated by
components (packages) of the semiconductor module to prevent a rise
in the temperature of the semiconductor module.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The above and other features and advantages of the invention
will become more apparent by describing in detail exemplary
embodiments thereof with reference to the attached drawings.
[0021] FIG. 1 is a diagram illustrating conventional memory modules
mounted on a mother board.
[0022] FIG. 2 is a diagram illustrating a clothespin type heat
dissipating apparatus for memory modules according to an embodiment
of the invention.
[0023] FIG. 3 is an exploded perspective diagram of the heat
dissipating apparatus shown in FIG. 2.
[0024] FIG. 4 is a perspective diagram illustrating a process of
installing the heat dissipating apparatus of FIG. 2 on a memory
module.
[0025] FIG. 5 is a perspective diagram illustrating the heat
dissipating apparatus of FIG. 2 installed on a memory module.
[0026] FIG. 6 is a cross-sectional diagram of FIG. 5.
[0027] FIGS. 7 and 8 are cross-sectional diagrams illustrating
examples of heat dissipating portions for the heat dissipating
apparatus according to some embodiments of the invention.
[0028] FIGS. 9, 10, 11, and 12 are cross-sectional diagrams
illustrating examples of a biasing member for the heat dissipating
apparatus according to some embodiments of the invention.
[0029] FIGS. 13, 14, 15, 16, and 17 are cross-sectional diagrams
illustrating examples of thermal interface material layers that may
be formed in the heat dissipating apparatus according to some
embodiments of the invention.
[0030] FIGS. 18, 19, and 20 are graphs of heat resistance vs.
position for various airflow rates that illustrate the
effectiveness of embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Embodiments of the invention will be described with
reference to the appended drawings. The invention may, however, be
embodied in many different forms and should not be construed as
being limited to the embodiments set forth herein; rather, these
embodiments are provided so that this disclosure will be thorough
and complete, and will fully convey the concept of the invention to
those skilled in the art. It is also noted that like reference
numerals may be used to designate identical or corresponding parts
throughout the several views.
[0032] In the following embodiments according to the invention, a
clothespin type heat dissipating apparatus is described that
effectively dissipates heat generated by packages of a
semiconductor memory module to prevent a rise in the temperature of
the semiconductor memory module.
[0033] A clothespin type heat dissipating apparatus according to an
embodiment of the invention includes two heat exchanger members,
which are substantially symmetrical, disposed with a memory module
therebetween. Each of the heat exchanger members may act as a heat
sink and a heat spreader. These two heat exchanger members are
hinged by a connection member for pivot movability. The connection
member is positioned between the heat exchange members. In
particular, each heat exchange member includes a contacting
portion, which contacts the memory module, and a heat dissipating
portion, which extends like a fin above the memory module. The
connection member is positioned between the heat dissipating
portion and the contacting portion. As such, the two heat exchange
members can clip the memory module while being hinged about the
connection member.
[0034] To provide a force pushing the heat exchange members closer
the packages mounted on a board of the memory module, a biasing
member, for example, a spring may be inserted between the heat
exchange members.
[0035] The contacting portion of each heat exchange member, which
contacts the packages of the memory module, acts as a heat sink.
The heat dissipating portions extending from the contacting
portions, respectively, above the memory module inserted between
the contacting portions effectively dissipate heat transmitted via
the contacting portions into air by thermal convection.
[0036] Each of the contacting portions may include a heat transfer
layer made of a thermal interface material (TIM) to ensure more
effective heat transfer between the contacting portion of the heat
exchange member and the packages of the memory module. A recess
that will be filled with TIM may be formed in each of the
contacting portions for tighter contact with the memory module. To
provide against a case where the TIM is changed into liquid phase
by the heat generated by the packages, either a packing member or a
barrier may be formed around the TIM material layer to prevent it
from running out of the recess.
[0037] The clothespin type heat dissipating apparatus according to
embodiments of the invention may be easily attached to and detached
from a memory module by simple clipping. In addition, due to the
biasing force or tension applied by the biasing member, tight
contact between the heat exchange members and the memory module is
ensured, thereby maximizing the efficiency of transmitting heat
from the package to the heat exchange members.
[0038] The heat transmitted from the packages is transmitted to the
heat dissipating portions of the heat dissipating apparatus. Since
the heat dissipating portions protrude above the memory module
inserted between the contacting portions to induce thermal
convection, it can quickly dissipate the heat transferred from the
packages into air. As a result, a rise in the temperature of the
memory module can be effectively prevented.
[0039] FIG. 2 is a diagram illustrating a clothespin-type,
heat-dissipating apparatus for memory modules according to an
embodiment of the invention. FIG. 3 is an exploded perspective
diagram of the heat dissipating apparatus shown in FIG. 2. FIG. 4
is a perspective diagram illustrating a process of installing the
heat dissipating apparatus of FIG. 2 on a memory module. FIG. 5 is
a perspective diagram illustrating the heat dissipating apparatus
of FIG. 2 installed on a memory module, and FIG. 6 is a
cross-sectional diagram of FIG. 5.
[0040] Referring to FIGS. 2 and 6, a clothespin type heat
dissipating apparatus according to an embodiment of the invention
includes two heat exchange members 100 and 200, which are hinge
jointed together for clipping, like a clothespin.
[0041] In particular, a first heat exchange member 100 and a second
heat exchange member 200 may be formed to be substantially the
same, for example, to be flat, although other shapes may be used
depending on the operating environment. The first heat exchange
member 100 includes a first contacting portion 110 and a first heat
dissipating portion 130 extending from the first contacting portion
110. Likewise, the second heat exchange member 200, which
corresponds to the first heat exchange member 100, includes a
second contacting portion 210 and a second heat dissipating portion
230 extending from the second contacting portion 210. The first
contacting portion 110 is thermally connected to the first heat
dissipating portion 130, and the second contacting portion 210 is
thermally connected to the second heat dissipating portion 240.
[0042] The first contacting portion 110 substantially contacts a
package 530 (see FIG. 4), which is an electronic part, on a
semiconductor memory module 500. The second contacting portion 210
does the same for an electronic part on the other side of the
memory module 500. As shown in FIGS. 5 and 6, the semiconductor
memory module 500 is inserted between the first and second
contacting portions 110 and 210 so that the surfaces of the package
530 on a board 510 of the semiconductor memory module 500 contact
the first and second contacting portions 110 and 210, as shown in
FIGS. 4 and 6.
[0043] The first contacting portion 110 and/or the second
contacting portion 210 contact the surface of the package 530 so
that heat generated by the package 530 when the memory module 500
is operated in a computer is transferred to the first and second
contacting portions 110 and 210. The first and second contacting
portions 110 and 210 act as heat sinks. A TIM layer 600 (see FIG.
6), which will be described later, is formed on an inner surface of
each of the first and second contacting portions 110 and 210 for
tighter and closer contact between the first and/or second
contacting portions 110 and 210 and the package 530.
[0044] The first heat dissipating portion 130, which extends from
the first contacting portion 110 and is thermally connected
thereto, is positioned to protrude above the memory module 500 that
is clamped between heat dissipating apparatus, as shown in FIGS. 5
and 6. When the heat dissipating apparatus is coupled to the memory
module 500, as shown in FIG. 5, the outer surfaces of the first and
second heat dissipating portions 130 and 230 are exposed to the air
so that they can effectively dissipate into air the heat
transmitted from the first and/or second contacting portions 110
and 210. In other words, there is no blockage of airflow between
the first and second heat dissipating portions 130 and 230, thereby
allowing smooth thermal convection. As a result, heat can be
effectively dissipated through the first and second heat
dissipating portions 130 and 230. As such, the first and second
heat dissipating portions 130 and 230 substantially act as
effective heat spreaders.
[0045] The first and second heat dissipating portions 130 and 230,
which protrude, like fins, above the memory module 500, may be
designed to have a relatively large surface area for effective heat
dissipating or heat transfer into air. To this end, the first and
second heat dissipating portions 130 and 320 may have uneven
surfaces, as shown in FIGS. 7 and 8. Alternatively, the first and
second heat dissipating portions 130 and 320 may be formed of a
metal plate, for example, aluminum, with porous surfaces.
[0046] The heat dissipating apparatus according to embodiments of
the invention can effectively cool the package 530 by maximizing a
thermal convection effect and can be easily attached to or detached
from the semiconductor memory module 500 by simple clipping.
[0047] Referring back to FIGS. 2 through 6, the first and second
heat exchange members 100 and 200 are hinge joined together by a
connection portion 300. The connection portion 300 may include a
hinge 310 and a pin 350, which is passed through the hinge 310. The
first and second heat exchange members 100 and 200 can do hinging
movements about the connection portion 300. When inserting the
semiconductor memory module 500 between the first and second
contacting portions 110 and 210 of the heat exchange members 100
and 200, the first and second contacting portions 110 and 210 are
opened wide, as shown in FIG. 4, the memory module 500 is inserted
between the first and second contacting portions 110 and 210, and
the first and second contacting portions 110 and 210 are closed, as
shown in FIG. 5.
[0048] To keep the first and second contacting portions 110 and 210
in contact with the memory module 500, as shown in FIG. 6, a
biasing member 400 (see FIGS. 4 and 5) is disposed between the
first and second heat dissipating portions 130 and 230. The biasing
force 400 between the first and second heat dissipating portions
130 and 230 provides a force pushing the first and second
contacting portions 110 and 210 toward the memory module 500, due
to the hinged structure of the heat dissipating apparatus.
[0049] For example, a spring may be installed between the first and
second heat dissipating portions 130 and 230 as the biasing member
400, as shown in FIG. 2. The spring provides a force pushing the
first and second heat dissipating portions 130 and 230 outward, as
indicated by arrows in FIG. 2. At the same time, the first and
second contacting portions 110 and 210 are pushed inward by the
force of the spring due to the hinged structure of the first and
second heat exchange members 100 connected by the connection
portion 300.
[0050] In other words, when the first and second heat dissipating
portions 130 and 230 are pushed in the directions indicated by
arrows in FIG. 4, the first and second contacting portions 110 and
210 are opened to allow for the semiconductor memory module 500 to
be inserted therebetween. When the first and second heat
dissipating portions 130 and 230 are released from the force after
the semiconductor memory module 500 has been inserted between the
first and second contacting portions 110 and 210, the first and
second heat dissipating portions 130 and 230 are pushed apart by
the restoring force of the biasing member 400, as indicated by
arrows in FIG. 5. This force is transmitted to the first and second
contacting portions 110 and 210 via the connection portion 300 so
that they become tightly affixed to the memory module 500.
[0051] FIGS. 9, 10, 11, and 12 are cross-sectional diagrams
illustrating examples of a biasing member for the heat dissipating
apparatus according to some embodiments of the invention.
[0052] The biasing member 400 may have various shapes, as shown in
FIGS. 9 through 12. For example, a spring 410 may be used for the
biasing member 400, as shown in FIG. 9. A plate spring 420 or 430
may be used for the biasing member 400, as shown in FIGS. 10 and
11.
[0053] Alternatively, a C-shaped spring 440 may be used, as shown
in FIG. 12. In this case, the ends of the C-shaped spring 440 may
be connected to the external surfaces of the first and second
contacting portions 110 and 210 and the C-shaped spring 440 is
oriented such that the connection portion 300 is included in the
space formed by the C-shaped spring 440.
[0054] The heat dissipating apparatus according to embodiments of
the invention is structured like a clip and utilizes the elastic
force of the elastic member 400 to attach the first and second
contacting portions 110 and 210 to the memory module 500. A heat
dissipating apparatus having such a structure may be conveniently
attached or detached from the memory module 500 by simple
clipping.
[0055] Referring to FIG. 6, for tighter contact between the
contacting portions 110 and 210 and the packages 530 and effective
heat transmission from the package 530, TIM layers 600 may be
formed between the package 530 and the first and second contacting
portions 110 and 210, as described above. Examples of a material
for the TIM layers 600 include thermal tape, thermal grease, a
thermal epoxy, and a phase change material, for instance.
[0056] FIGS. 13, 14, 15, 16, and 17 are cross-sectional diagrams
illustrating examples of thermal interface material layers that may
be formed in the heat dissipating apparatus according to some
embodiments of the invention.
[0057] As shown in FIG. 13, the TIM layers 600 may be formed on
surfaces of the first and second contacting portions 110 and 210
that face the package 530. As shown in FIGS. 14 and 15, to raise
the efficiency of heat transmission from the package 530, a recess
610 may be formed in the surface of each of the first and second
contacting portions 110 and 130, and the recess 610 filled with the
TIM layer 600. The recess 610 filled with the TIM layer 600
provides more stable adhesion to the package 530.
[0058] Alternatively, as shown in FIGS. 16 and 17, a barrier or a
packing member 700 may be provided adjacent to the TIM layer 600.
The barrier or packing member 700 may be made of rubber, or other
acceptable material. The barrier or packing member 700, which
bounds the TIM layer 600 filling the recess 610, prevents the TIM
layer 600 from dripping down the sides of the apparatus. When the
TIM layer 600 is in liquid form or is made of a PCM that changes
into a liquid at an elevated temperature, or when the temperature
of the package 530 is raised, the TIM layer 600 could otherwise
drip down the sides of the apparatus. The barrier or the packing
member 700 prevents this problem.
[0059] The surfaces of the first and second contacting portions 110
and 210 that face the package 530 may be processed to be rough or
to increase the surface area to maximize the adhesion to the
semiconductor memory module 500. To this end, the surfaces of the
first and second contacting portions 110 and 210 may be processed
by etching, sputtering, coating, etc.
[0060] As described above, the temperature of semiconductor memory
modules can be effectively maintained at a lower temperature using
the above heat dissipating apparatus according to embodiments of
the invention.
[0061] FIGS. 18, 19, and 20 are graphs of heat resistance vs.
position for various airflow rates that illustrate the
effectiveness of embodiments of the invention. FIG. 18 is derived
from the case where no heat dissipation apparatus is used on a
semiconductor memory module. FIG. 19 is derived from the case where
a conventional rebated heat spreader is used on a semiconductor
memory module, and FIG. 20 is derived from the case where an
embodiment of the invention was used to dissipate heat from a
semiconductor memory module.
[0062] The semiconductor memory module 500, in which nine packages
530 are mounted, as shown in FIG. 4, was used to obtain each set of
results shown in FIGS. 18-20. Positions 1, 2, 3, 4, and 5 denote
the first, third, fifth, seventh, and ninth package from the left
end of the semiconductor memory module 500, respectively. In other
words, positions 1 and 5 correspond to the leftmost package and the
rightmost package, respectively, and position 3 corresponds to the
middle package. Thermal resistance was measured at different air
flow rates, in which the airflow moved in a direction from position
1 towards position 5.
[0063] A smaller value of heat resistance implies a greater cooling
effect. Comparing the results in FIG. 20 to the results in FIGS. 18
and 19, it is apparent that the heat dissipating apparatus
according to embodiments of the invention can effectively lower the
temperature of memory modules and can evenly distribute the
temperature of memory modules.
[0064] In conclusion, a clothespin type heat dissipating apparatus
according to embodiments of the invention can easily be attached to
or detached from a semiconductor memory module by simple clipping.
The heat dissipating apparatus has fin-like heat dissipating
portions that protrude above the semiconductor memory module, so
that it can effectively dissipate heat into air by convection.
[0065] The heat dissipating apparatus according to some embodiments
of the invention has recesses in the contacting portions thereof
and packing members, so that a TIM material that changes into
liquid by heat absorption can be effectively applied to the heat
dissipating apparatus. Therefore, a rise in the temperature of
semiconductor memory modules can be effectively prevented using the
heat dissipating apparatus.
[0066] Furthermore, embodiments of the invention evenly control the
distribution of temperature over the semiconductor memory module,
without uneven rises in the temperature of a particular package of
the semiconductor memory module.
[0067] Particular embodiments of the invention will now be
described, but those embodiments shall not be considered to limit
the invention nor prohibit the invention from operating in a
different manner.
[0068] Some embodiments of the invention provide a clothespin type
heat dissipating apparatus for semiconductor modules, the apparatus
including: two heat exchange members, which are arranged facing
each other with a semiconductor module therebetween, the
semiconductor module including a plurality of packages; a
connection member formed in the middle of each of the heat exchange
members to hinge join the heat exchange members such that portions
of the heat exchange members protrude above the semiconductor
module inserted between the heat exchange members; and a biasing
member disposed between the heat exchange members to provide a
force pushing portions of the heat exchange members below the
connection member toward the packages of the semiconductor
module.
[0069] Other embodiments of the invention provide a clothespin type
heat dissipating apparatus for semiconductor modules, including: a
first heat exchange member including a first contacting portion,
which is arranged in contact with a surface of a semiconductor
module to absorb heat generated by the semiconductor module, and a
first heat dissipating portion, which is thermally connected to the
first contacting portion to dissipate the heat absorbed by the
first contacting portion; a second heat exchange member including a
second contacting portion, which is arranged in contact with the
other surface of the semiconductor module to absorb the heat
generated by the semiconductor module, and a second heat
dissipating portion, which is thermally connected to the second
contacting portion to dissipate the heat absorbed by the second
contacting portion; and an elastic member providing a force pushing
the first and second contacting portions toward the surfaces of the
semiconductor module inserted between the first and second
contacting portions.
[0070] In some embodiments of the invention, the portions of the
heat exchange members that protrude above the semiconductor module
may have uneven surfaces. In alternative embodiments of the
invention, the portions of the heat exchange members that protrude
above the semiconductor module may be made of a metal plate, for
example, aluminum, with a porous surface.
[0071] The biasing member may be a C-shaped spring whose both ends
go through the first and second heat dissipating portions and are
connected to external surfaces of the first and second contacting
portions and which is oriented such that the connection portion is
included in the space formed by the C-shaped spring.
[0072] Embodiments of the invention may further include a
connection member, which hinge joins the first and second heat
exchange members such that the first and second heat dissipating
portions protrude above the semiconductor module inserted between
the heat exchange members, wherein the biasing member may be one of
a spring, a plate spring, and a C-shaped spring, which is disposed
between the first and second heat dissipating portions and provides
the force pushing the first and second contacting portions toward
the surfaces of the semiconductor module inserted between the first
and second contacting portions due to the force of the biasing
member being exerted outward on the first and second heat
dissipating portions.
[0073] Embodiments of the invention may further include a thermal
interface material layer on the portions of the heat exchange
portions below the connection member, which contact the surfaces of
the packages. In alternative embodiments of the invention, the
thermal interface material layer may be made of one selected from
the group consisting of a thermal tape, a thermal grease, a thermal
epoxy, and a phase change material.
[0074] In some embodiments of the invention, the portions of the
heat exchange portions below the connection member, which contact
the surfaces of the packages, are subjected to surface processing
selected from the group consisting of etching, sputtering, and
coating, to enhance the adhesion to the semiconductor module.
[0075] Other embodiments of the invention provide a clothespin type
heat dissipating apparatus for semiconductor modules, including: a
first heat exchange member including a first contacting portion,
which is arranged in contact with a surface of a semiconductor
module to absorb heat generated by the semiconductor module, and a
first heat dissipating portion with uneven surfaces, the first heat
dissipating portion being thermally connected to the first
contacting portion to dissipate the heat absorbed by the first
contacting portion; a second heat exchange member including a
second contacting portion, which is arranged in contact with the
other surface of the semiconductor module to absorb the heat
generated by the semiconductor module, and a second heat
dissipating portion with uneven surface, the second heat
dissipating portion being thermally connected to the second
contacting portion to dissipate the heat absorbed by the second
contacting portion; a connection member, which hinge joins the
first and second heat exchange units such that the first and second
heat dissipating portions protrude above the semiconductor module
inserted between the first and second heat exchange members; and an
elastic member disposed between the first and second heat exchange
members to provide a force pushing the first and second contacting
portions toward the surfaces of the semiconductor module inserted
between the first and second contacting portions.
[0076] Other embodiments of the invention provide a clothespin type
heat dissipating apparatus for semiconductor modules, including: a
first heat exchange member including a first contacting portion,
which is arranged in contact with a surface of a semiconductor
module to absorb heat generated by the semiconductor module, and a
first heat dissipating portion, which is thermally connected to the
first contacting portion to dissipate the heat absorbed by the
first contacting portion; a second heat exchange member including a
second contacting portion, which is arranged in contact with the
other surface of the semiconductor module to absorb the heat
generated by the semiconductor module, and a second heat
dissipating portion, which is thermally connected to the second
contacting portion to dissipate the heat absorbed by the second
contacting portion; a connection member, which hinge joins the
first and second heat exchange units such that the first and second
heat dissipating portions protrude above the semiconductor module
inserted between the heat exchange members; an elastic member
disposed between the first and second heat exchange members to
provide a force pushing the first and second contacting portions
toward the surfaces of the semiconductor module inserted between
the first and second contacting portions; thermal interface
material layers formed between the surfaces of the semiconductor
module and facing surfaces of the first and second contacting
portions; and packing members bounding the thermal interface
material layers formed on the first and second contacting portions,
respectively, to prevent the thermal interface material layers from
running down the facing surfaces of the first and second contacting
portions if the thermal interface material reaches a liquid or
semi-liquid state.
[0077] In some embodiments of the invention, the packing members
may be made of rubber. The facing surfaces of the first and second
contacting portions may include a recess filled with the
corresponding thermal interface material layer. Each of the packing
members may be disposed around the corresponding recess.
[0078] As described above, embodiments of the invention have heat
dissipating portions that protrude above a semiconductor module,
and can effectively dissipate heat generated by the semiconductor
module. In addition, embodiments of the invention can be easily
attached to and detached from the semiconductor module by a simple
clipping process.
[0079] While the invention has been particularly shown and
described with reference to exemplary embodiments thereof, it will
be understood by those of ordinary skill in the art that various
changes in form and details may be made therein without departing
from the spirit and scope of the present invention as defined by
the following claims.
* * * * *