U.S. patent application number 09/741822 was filed with the patent office on 2001-06-28 for heat sink for chip stacking applications.
Invention is credited to Bissey, L. Jan, Duesman, Kevin G..
Application Number | 20010005311 09/741822 |
Document ID | / |
Family ID | 22652701 |
Filed Date | 2001-06-28 |
United States Patent
Application |
20010005311 |
Kind Code |
A1 |
Duesman, Kevin G. ; et
al. |
June 28, 2001 |
Heat sink for chip stacking applications
Abstract
A heat sink is provided for use with stacks of integrated chips.
The heat sink includes a thermally conductive body having a heat
absorbing section which is inserted within the chip stack, and heat
transfer and dissipating sections which are located outside of the
chip stack.
Inventors: |
Duesman, Kevin G.; (Boise,
ID) ; Bissey, L. Jan; (Boise, ID) |
Correspondence
Address: |
Thomas J. D'Amico
DICKSTEIN SHAPIRO MORIN & OSHINSKY LLP
2101 L Street NW
Washington
DC
20037-1526
US
|
Family ID: |
22652701 |
Appl. No.: |
09/741822 |
Filed: |
December 22, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09741822 |
Dec 22, 2000 |
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09178480 |
Oct 26, 1998 |
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6201695 |
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Current U.S.
Class: |
361/703 ;
257/E23.103 |
Current CPC
Class: |
H01L 23/3672 20130101;
H01L 2924/00 20130101; H01L 2924/0002 20130101; H01L 2924/0002
20130101 |
Class at
Publication: |
361/703 |
International
Class: |
H05K 007/20 |
Claims
1. A heat sink for stacked integrated circuits, said heat sink
comprising: at least one heat absorbing section; said heat
absorbing section having at least one planar extending element
configured to be interposed between stacked integrated circuits; a
heat dissipation section; and, a heat transfer section
interconnecting said heat absorbing section and said heat
dissipating section, said heat transfer section having at least one
heat transfer element connected to a respective planar extending
element.
2. The heat sink of claim 1, wherein said heat dissipating section
contains a plurality of outwardly extended fins.
3. The heat sink of claim 2, wherein said plurality of outwardly
extending fins extend the length of said heat dissipating
section.
4. The heat sink of claim 1, wherein said heat dissipating section
contains corrugations.
5. The heat sink of claim 4, wherein said corrugations extend along
the length of said heat dissipating section.
6. The heat sink of claim 1, wherein said heat absorbing section is
comprised of a plurality of planar extending elements each
configured to be interposed between stacked integrated circuits,
and said heat transfer section is comprised of a plurality of heat
transfer elements respectively connected to said plurality of
planar extending elements.
7. The heat sink of claim 6, wherein said heat sink is plurality of
planar extending elements extend from opposite sides of said heat
dissipating section.
8. The heat sink of claim 7, wherein said absorbing section is
comprised of a thermally conductive material having a thermal rate
of expansion approximately equal to the thermal expansion rate of
the stacked integrated circuits.
9. The heat sink of claim 6, wherein at least one heat transfer
element is the same width as at least one of said planar extending
elements.
10. The heat sink of claim 6, wherein at least one heat transfer
element is narrower than at least one of said planar extending
elements.
11. The heat sink of claim 10, wherein at least one of said
plurality of planar extending elements is rectangular.
12. The heat sink of claim 6, wherein said heat absorbing section,
said heat transfer section, and said heat dissipating section are
coplanar.
13. The heat sink of claim 6, wherein said heat absorbing section,
said heat transfer section, and said heat dissipating section are
not coplanar.
14. The heat sink of claim 13, wherein said heat dissipating
section is orthogonal to said heat absorbing section.
15. The heat sink of claim 6, wherein at least one of said heat
transfer elements is configured so that in use it is located
outside said stacked integrated circuits.
16. The heat sink of claim 6, wherein at least one of said heat
transfer elements is configured so that in use it is located within
said stacked integrated circuits.
17. A heat sink for a stacked integrated circuit, said heat sink
comprising: a first portion configured to be interposed between two
stacked integrated circuits; and, a second portion connected to
said first portion for dissipating heat.
18. The heat sink of claim 17, wherein said second portion includes
a plurality of outwardly extended fins configured to remove heat
from said heat sink.
19. The heat sink of claim 17, wherein said second portion contains
areas of corrugation.
20. The heat sink of claim 17, wherein said heat sink is comprised
of a thermally conductive material having a thermal rate of
expansion approximately equal to the thermal expansion rate of the
stacked integrated circuits.
21. The heat sink of claim 17, wherein said first portion is
comprised of a plurality of rectangular elements.
22. The heat sink of claim 17, wherein said heat sink is
substantially flat.
23. The heat sink of claim 17, wherein said heat sink is not
substantially flat.
24. The heat sink of claim 17, wherein said heat sink is configured
so that in use at least of portion of said heat sink is located
outside said stacked integrated circuit.
25. The heat sink of claim 17, wherein said heat sink is configured
so that in use at least of portion of said heat sink is located
within said stacked integrated circuit.
26. A method of removing heat from stacked integrated circuits,
said method comprising: providing at least one heat absorbing
section; said heat absorbing section having at least one planar
extending element interposed between stacked integrated circuits;
providing a heat dissipation section; and, providing a heat
transfer section interconnecting said heat absorbing section and
said heat dissipating section, said heat transfer section having at
least one heat transfer element connected to a respective planar
extending element.
27. The method of claim 26, wherein said heat dissipating section
contains a plurality of outwardly extended fins.
28. The method of claim 27, wherein said plurality of outwardly
extending fins extend the length of said heat dissipating
section.
29. The method of claim 26, wherein said heat dissipating section
contains corrugations.
30. The method of claim 29, wherein said corrugations extend along
the length of said heat dissipating section.
31. The method of claim 26, wherein said heat absorbing section is
comprised of a plurality of planar extending elements each
configured to be interposed between stacked integrated circuits,
and said heat transfer section is comprised of a plurality of heat
transfer elements respectively connected to said plurality of
planar extending elements.
32. The method of claim 31, wherein said plurality of planar
extending elements extend from opposite sides of said heat
dissipating section.
33. The method of claim 32, wherein said heat absorbing section is
comprised of a thermally conductive material having a thermal rate
of expansion approximately equal to the thermal expansion rate of
the stacked integrated circuits.
34. The method of claim 31, wherein at least one heat transfer
element is the same width as at least one of said planar extending
elements.
35. The method of claim 31, wherein at least one heat transfer
element is narrower than at least one of said planar extending
elements.
36. The method of claim 35, wherein at least one of said plurality
of planar extending elements is rectangular.
37. The method of claim 31, wherein said heat absorbing section,
said heat transfer section, and said heat dissipating section are
coplanar.
38. The method of claim 31, wherein said heat absorbing section,
said heat transfer section, and said heat dissipating section are
not coplanar.
39. The method of claim 38, wherein said heat dissipating section
is orthogonal to said heat absorbing section.
40. The method of claim 31, wherein at least one of said heat
transfer elements is configured so that in use it is located
outside said stacked integrated circuits.
41. The method of claim 31, wherein at least one of said heat
transfer elements is configured so that in use it is located within
said stacked integrated circuits.
42. A method for removing heat from a stacked integrated circuit,
said method comprising: providing a heat sink having a first
portion configured to be interposed between two stacked integrated
circuits and a second portion connected to said first portion for
dissipating heat.
43. The method of claim 42, wherein said second portion includes a
plurality of outwardly extended fins configured to remove heat from
said heat sink.
44. The method of claim 42, wherein said second portion contains
areas of corrugation.
45. The method of claim 42, wherein said heat sink is comprised of
a thermally conductive material having a thermal rate of expansion
approximately equal to the thermal expansion rate of the stacked
integrated circuits.
46. The method of claim 42, wherein said first portion is comprised
of a plurality of rectangular elements.
47. The method of claim 42, wherein said heat sink is substantially
flat.
48. The method of claim 42, wherein said heat sink is not
substantially flat.
49. The method of claim 42, wherein said heat sink is configured so
that in use at least of portion of said heat sink is located
outside said stacked integrated circuits.
50. The method of claim 42, wherein said heat sink is configured so
that in use at least of portion of said heat sink is located within
said stacked integrated circuits.
51. A memory module comprising a printed circuit board mounting
memory devices, wherein said printed circuit board comprises a heat
sink for stacked integrated circuits, wherein said heat sink
comprises: at least one heat absorbing section; said heat absorbing
section having at least one planar extending element configured to
be interposed between stacked integrated circuits; a heat
dissipation section; and, a heat transfer section interconnecting
said heat absorbing section and said heat dissipating section, said
heat transfer section having at least one heat transfer element
connected to a respective planar extending element.
52. The memory module of claim 51, wherein said heat dissipating
section contains a plurality of outwardly extended fins.
53. The memory module of claim 52, wherein said plurality of
outwardly extending fins extend the length of said heat dissipating
section.
54. The memory module of claim 51, wherein said heat dissipating
section contains corrugations.
55. The memory module of claim 54, wherein said corrugations extend
along the length of said heat dissipating section.
56. The memory module of claim 51, wherein said heat absorbing
section is comprised of a plurality of planar extending elements
each configured to be interposed between stacked integrated
circuits, and said heat transfer section is comprised of a
plurality of heat transfer elements respectively connected to said
plurality of planar extending elements.
57. The memory module of claim 56, wherein said heat sink is
plurality of planar extending elements extend from opposite sides
of said heat dissipating section.
58. The memory module of claim 57, wherein said heat absorbing
section is comprised of a thermally conductive material having a
thermal rate of expansion approximately equal to the thermal
expansion rate of the stacked integrated circuits.
59. The memory module of claim 56, wherein at least one heat
transfer element is the same width as at least one of said planar
extending elements.
60. The memory module of claim 56, wherein at least one heat
transfer element is narrower than at least one of said planar
extending elements.
61. The memory module of claim 60, wherein at least one of said
plurality of planar extending elements is rectangular.
62. The memory module of claim 56, wherein said heat absorbing
section, said heat transfer section, and said heat dissipating
section are coplanar.
63. The memory module of claim 56, wherein said heat absorbing
section, said heat transfer section, and said heat dissipating
section are not coplanar.
64. The memory module of claim 63, wherein said heat dissipating
section is orthogonal to said heat absorbing section.
65. The memory module of claim 56, wherein at least one of said
heat transfer elements is configured so that in use it is located
outside said stacked integrated circuits.
66. The memory module of claim 56, wherein at least one of said
heat transfer elements is configured so that in use it is located
within said stacked integrated circuits.
67. A memory module for a stacked integrated circuit, said memory
module comprising: a heat sink including a first portion configured
to be interposed between two stacked integrated circuits and a
second portion connected to said first portion for dissipating
heat.
68. The memory module of claim 67, wherein said second portion
includes a plurality of outwardly extended fins configured to
remove heat from said heat sink.
69. The memory module of claim 67, wherein said second portion
contains areas of corrugation.
70. The memory module of claim 67, wherein said heat sink is
comprised of a thermally conductive material having a thermal rate
of expansion approximately equal to the thermal expansion rate of
the stacked integrated circuits.
71. The memory module of claim 67, wherein said first portion is
comprised of a plurality of rectangular elements.
72. The memory module of claim 67, wherein said heat sink is
substantially flat.
73. The memory module of claim 67, wherein said heat sink is not
substantially flat.
74. The memory module of claim 67, wherein said heat sink is
configured so that in use at least of portion of said heat sink is
located outside said stacked integrated circuits.
75. The memory module of claim 67, wherein said heat sink is
configured so that in use at least of portion of said heat sink is
located within said stacked integrated circuits.
76. An electronic system comprising a printed circuit board
mounting electronic devices, wherein said printed circuit board
comprises a heat sink for stacked integrated circuits, wherein said
heat sink comprises: at least one heat absorbing section; said heat
absorbing section having at least one planar extending element
configured to be interposed between stacked integrated circuits; a
heat dissipation section; and, a heat transfer section, wherein
said heat transfer section is comprised of at least one heat
transfer element coupled to said heat absorbing section.
77. The system of claim 76, wherein said heat dissipating section
contains a plurality of outwardly extended fins.
78. The system of claim 77, wherein said plurality of outwardly
extending fins extend the length of said heat dissipating
section.
79. The system of claim 76, wherein said heat dissipating section
contains corrugations.
80. The system of claim 79, wherein said corrugations extend along
the length of said heat dissipating section.
81. The system of claim 76, wherein said heat absorbing section is
comprised of a plurality of planar extending elements each
configured to be interposed between stacked integrated circuits,
and said heat transfer section is comprised of a plurality of heat
transfer elements respectively connected to said plurality of
planar extending elements.
82. The system of claim 81, wherein said heat sink is plurality of
planar extending elements extend from opposite sides of said heat
dissipating section.
83. The system of claim 82, wherein said heat absorbing section is
comprised of a thermally conductive material having a thermal rate
of expansion approximately equal to the thermal expansion rate of
the stacked integrated circuits.
84. The system of claim 81, wherein at least one heat transfer
element is the same width as at least one of said planar extending
elements.
85. The system of claim 81, wherein at least one heat transfer
element is narrower than at least one of said planar extending
elements.
86. The system of claim 85, wherein at least one of said plurality
of planar extending elements is rectangular.
87. The system of claim 81, wherein said heat absorbing section,
said heat transfer section, and said heat dissipating section are
coplanar.
88. The system of claim 81, wherein said heat absorbing section,
said heat transfer section, and said heat dissipating section are
not coplanar.
89. The system of claim 88, wherein said heat dissipating section
is orthogonal to said heat absorbing section.
90. The system of claim 81, wherein at least one of said heat
transfer elements is configured so that in use it is located
outside said stacked integrated circuits.
91. The system of claim 81, wherein at least one of said heat
transfer elements is configured so that in use it is located within
said stacked integrated circuits.
92. An electronic system comprising a printed circuit board
mounting electronic devices, wherein said printed circuit board
comprises a heat sink for a stacked integrated circuit, wherein
said heat sink comprises a first portion configured to be
interposed between two stacked integrated circuits and a second
portion connected to said first portion for dissipating heat.
93. The system of claim 92, wherein said second portion includes a
plurality of outwardly extended fins configured to remove heat from
said heat sink.
94. The system of claim 92, wherein said second portion contains
areas of corrugation.
95. The system of claim 92, wherein said heat sink is comprised of
a thermally conductive material having a thermal rate of expansion
approximately equal to the thermal expansion rate of the stacked
integrated circuits.
96. The system of claim 92, wherein said first portion is comprised
of a plurality of rectangular elements.
97. The system of claim 92, wherein said heat sink is substantially
flat.
98. The system of claim 92, wherein said heat sink is not
substantially flat.
99. The system of claim 92, wherein said heat sink is configured so
that in use at least of portion of said heat sink is located
outside said stacked integrated circuits.
100. The system of claim 92, wherein said heat sink is configured
so that in use at least of portion of said heat sink is located
within said stacked integrated circuits.
101. A memory module comprising a printed circuit board having at
least a first side and a second side each mounting stacked
integrated circuits, wherein said printed circuit board comprises
at least a first heat sink for removing heat from stacked
integrated circuits mounted on said first side and a second heat
sink for removing heat from stacked integrated circuits mounted on
said second side, wherein at least one of said first and second
heat sinks comprises: at least one heat absorbing section; said
heat absorbing section having at least one planar extending element
configured to be interposed between stacked integrated circuits; a
heat dissipation section; and, a heat transfer section
interconnecting said heat absorbing section and said heat
dissipating section, said heat transfer section having at least one
heat transfer element connected to a respective planar extending
element.
102. The memory module of claim 101, wherein at least one first
heat sink is connected to at least one second heat sink.
103. An electronic system comprising a printed circuit board having
at least a first side and a second side each mounting stacked
integrated circuits, wherein said printed circuit board comprises
at least a first heat sink for removing heat from stacked
integrated circuits mounted on said first side and a second heat
sink for removing heat from stacked integrated circuits mounted on
said second side, wherein at least one of said first and second
heat sinks comprises: at least one heat absorbing section; said
heat absorbing section having at least one planar extending element
configured to be interposed between stacked integrated circuits; a
heat dissipation section; and, a heat transfer section, wherein
said heat transfer section is comprised of at least one heat
transfer element coupled to said heat absorbing section.
104. The system of claim 103, wherein at least one first heat sink
is connected to at least one second heat sink.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of integrated
circuits. More particularly, the invention provides a heat sink for
use with stacks of integrated circuits.
[0003] 2. Description of the Related Art
[0004] As computer manufacturers have attempted to build more
powerful machines, the use of chip stacks in modern computing
applications has become increasingly desirable. The term `chips`
used with the present invention is intended to include any packaged
integrated circuit device including processing devices e.g.
microprocessors etc., memory devices e.g. DRAMS, SRAMS, etc., and
the like. In essence, a chip stack comprises multiple integrated
circuit packages which are stacked together (back-to-front or
back-to-back). The chip stacks may be oriented either in face up
position or in a side-to-side orientation with chip edges down.
[0005] There are a number of advantages to the chip stack
configuration over conventional single chip mounting arrangements.
In particular, the chip stacks provide a more compact circuit
arrangement for computers and other high speed electronic
systems.
[0006] In addition, chip stacks particularly allow for more
efficient use of space on circuit boards. The stack takes advantage
of relatively less valuable space above the circuit board, while at
the same time leaving a small footprint on a circuit board or card,
thereby increasing the space available for other components or chip
stacks.
[0007] While there are numerous advantages to a stacked chip
configuration, there are also associated problems. Specifically,
larger and larger chip stacks create unique cooling problems.
Because the chip stacks contain multiple chips, they generate more
heat per unit volume, requiring greater heat dissipation, while at
the same time providing significantly smaller surface areas which
may be used as a heat sink. In view of this problem, the general
response in the industry to the need for cooling chip-stacks has
been to immerse the entire chip-stack in liquid or to operate at
greatly reduced power levels. This is often an unwelcome solution
because of technical concerns and also because of customer and user
preferences.
SUMMARY OF THE INVENTION
[0008] The present invention is generally directed at providing a
relatively low cost heat sink for dissipating heat generated within
chip stacks (sometimes referred to as `chip cubes`, although a
cubic structure is not necessary). The invention provides a heat
absorbing surface between at least a first and second chip within a
chip stack which is connected to a heat dissipating surface located
outside the stack. According to a preferred embodiment, the heat
sink includes one or more heat absorbing sections for respective
insertion between chips within one or more chip stacks; a heat
transfer section for transferring heat away from the absorbing
sections; and a heat dissipating section for commonly dissipating
heat transferred from the heat absorbing sections.
[0009] These and other features and advantages of the invention
will become more readily apparent from the following detailed
description of preferred embodiments of the invention which are
provided in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a plan view of a heat sink of a first embodiment
of the invention.
[0011] FIG. 2 is a side view of the heat sink shown in FIG. 1.
[0012] FIG. 3 is a perspective view of the heat sink of FIG. 1
secured to chips on a chip mounting surface.
[0013] FIG. 4 is a side view of the heat sink configuration shown
in FIG. 3.
[0014] FIG. 5 is a side view of a first alternative heat sink
configuration of the invention.
[0015] FIG. 6 is a side view of a second alternative heat sink
configuration of the invention.
[0016] FIG. 7 is a side view of a third alternative heat sink
configuration of the invention.
[0017] FIG. 8 is a perspective view of a preferred embodiment of
the invention.
[0018] FIG. 9 is a perspective view of a fourth alternative
embodiment of the invention.
[0019] FIG. 10 is a perspective view of a fifth alternative
embodiment of the invention.
[0020] FIG. 11 is a perspective view of a sixth alternative
embodiment of the invention.
[0021] FIG. 12 is a perspective view of a second preferred
embodiment of the invention.
[0022] FIG. 13 is a sideview of the second preferred embodiment
shown in FIG. 12.
[0023] FIG. 14 is a side view of an alternative embodiment of the
second preferred embodiment shown in FIGS. 12 and 13.
[0024] FIG. 15 is a block diagram of a processor system in which
the invention may be utilized.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] Referring to FIG. 1, a planar heat sink 20 in accordance
with a preferred embodiment of the invention will now be described.
Heat sink 20 is shown including three interconnected co-planar
sections: a heat absorbing section 22, a heat transfer section 24,
and a heat dissipating section 26. FIG. 2 is a side view of heat
sink 20 showing the relative lateral dimensions of the heat
absorbing section 22, heat transfer section 24, and heat
dissipating section 26.
[0026] Heat absorbing section 22 includes one or more fingers
22a-22h, each of which is configured to be insertable between chips
of a chip stack. Heat transfer section 24 includes heat transfer
elements 24a-24h. The fingers 22a-22h remove heat from the chip
stack, which flows through respective heat transfer sections
24a-24h to dissipation section 26. Preferably, fingers 22a-22h are
of a generally rectangular shape and sized to maximize heat
absorption from a target chip's surface. As shown in FIG. 1, the
width of the fingers 22a-22h is larger than the width of the heat
transfer elements 24a-24h. Alternatively, the width of the fingers
22a-22h may be the same, narrower or wider than the width of the
heat transfer elements 24a-24h.
[0027] Preferably, heat sink 20 is comprised of a thermally
conductive material having a thermal rate of expansion
approximately equal to the thermal expansion rate of the stacked
chips. In accordance with a preferred embodiment, heat sink 20 is
comprised of a metal such as aluminum or copper and may be easily
stamped out of plate metal. In alternative embodiments, it is
possible for each of the three sections of heat sink 20 to be
formed of different materials in accordance with each section's
functional constraints.
[0028] With reference to FIGS. 3, 4, and 8, heat sink 20 is
utilized by placing each heat absorbing finger 22a-22h over a first
layer chip 30 secured on a mounting surface 28 such as a plug-in
board having edge connectors 27. A second layer of chips is then
secured over each heat absorbing finger 22a-22h. Each finger
22a-22h may be affixed to the first and second layer chips 30, 32
using thermally conductivity enhancing mediums such as a thermal
paste or epoxy. With reference to FIGS. 3 and 4, heat sink 20 is
shown with each finger 22a-22h placed over a respective first layer
chip 30 with the heat transfer elements 24a-24h and heat
dissipating section 26 extending away from the location of the
chips 30, 32. As shown in FIG. 8, a second layer of chips 32 is
provided over the first layer of chips 30 with each respective
finger 22a-22h positioned between each pair of first and second
layer chips 30, 32. As shown, the heat transfer elements 24a-24h
and heat dissipating section 26 are provided outside the chip stack
33 created by the first and second layers of chips 30, 32. In an
alternative embodiment, the heat transfer elements 24a-24h may be
provide so that at least a portion of the heat transfer elements
24a-24h lie within the chip stack 33.
[0029] With reference to FIGS. 3, 4, and 8, the heat transfer and
heat dissipating sections 24, 26 are shown provided coplanar with
heat absorbing section 22. As shown in FIGS. 5-7, the heat transfer
and heat dissipating sections 24,26 may extend from the heat
absorbing section 22 at any angle necessary to take advantage of
unused space above and below the chip stack. With reference to FIG.
5, an alternative embodiment is shown in which heat dissipating
section 26 is at approximately a 45 degree angle to the heat
absorbing section 22. With reference to FIG. 6, an alternative
embodiment is shown in which the heat dissipating section 26 is
orthogonal to the heat absorbing section 22. With reference to FIG.
7, an alternative embodiment is shown in which the heat dissipating
section 26 is initially orthogonal to the heat absorbing section 22
and then is bent again be in parallel with the heat absorbing
section 22 at a point above the heat absorbing section.
[0030] With reference to FIG. 9, an alternative embodiment is shown
in which the heat dissipating section 26 is comprised of heat
dissipating fins 34 in order to further enhance heat dissipation by
enlarging the surface area of section 26. With reference to FIG.
10, an additional alternative embodiment is shown in which the heat
dissipating section 26 is formed as corrugation waves 36 in order
to increase surface area and heat dissipation.
[0031] With reference to FIG. 11, an alternative embodiment is
shown in which heat sink 27 includes a heat dissipating section 26
in thermal contact with a pair of heat transfer sections 24, 25 and
a pair of heat absorbing sections 22, 23, which extend along both
sides of heat dissipating section 26. As shown in FIG. 11, heat
transfer sections 24 and 25 respectively contain heat transfer
elements 24a-24h and 25a-25h, and heat absorbing sections 22 and 23
respectively contain heat absorbing elements 22a-22h and
23a-23h.
[0032] With reference to FIGS. 12 and 13, a second preferred
embodiment is shown in which a pair of planar heat sinks 37, 39 are
used together to dissipate heat from chip stacks 33, 35 positioned
on each side of mounting surface 28. Alternatively, as shown in
FIG. 14, a single continuous heat sink 41 may be used to dissipate
heat from chip stacks 33, 35 positioned on each side of mounting
surface 28.
[0033] One particular environment in which the heat sink of the
invention may be used is within a memory module for a
processor-based system. In this case, the integrated circuits 30,
32 may be integrated circuit memory devices such as DRAMS, SRAMS,
EEPROM, etc. and the mounting surface 28 may be constructed as a
plug-in board such as a SIMM (Single In-Line Memory Module), DIMM
(Dual In-Line Memory Module), SO-SIMM (Small Outline-Single In-Line
Memory Module), SO-DIMM (Small Outline-Dual In-Line Memory Module),
RIMM (Rambus In-Line Memory Module) or other plug-in module, for
receipt in a system memory socket.
[0034] A typical processor-based system, which includes the present
invention formed as a memory module, is illustrated generally at
640 in FIG. 15. A processor-based system typically includes a
processor, which connects through a bus structure with memory
modules, which contain data and instructions. The data in the
memory modules is accessed during operation of the processor. This
type of processor-based system is used in general purpose computer
systems and in other types of dedicated processing systems, e.g.
radio systems, television systems, GPS receiver systems, telephones
and telephone systems to name a few.
[0035] Referring to FIG. 15, such a processor-based system
generally comprises a central processing unit (CPU) 644, e.g.
microprocessor, that conmmunicates to at least one input/output
(I/O) device 642 over a bus 652. A second (I/O) device 646 is
illustrated, but may not be necessary depending upon the system
requirements. The processor-based system 640 also may include a
static or dynamic random access memory (SRAM, DRAM) 648 in the form
of memory modules of the kind described and illustrated above, a
read only memory (ROM) 650 which may also be formed in the form of
memory modules of the kind described above. The processor-based
system may also include peripheral devices such as a floppy disk
drive 654 and a compact disk (CD) ROM drive 656, which also
communicate with CPU 644 over the bus 652. It must be noted that
the exact architecture of the processor-based system 600 is not
important and that any combination of processor compatible devices
may be incorporated into the system. Each of the memories 648 and
650 may be constructed as plug-in modules employing a heat sink
constructed in accordance with the teachings of the invention.
[0036] The above description and accompanying drawings are only
illustrative of preferred embodiments, which can achieve and
provide the features and advantages of the present invention. It is
not intended that the invention be limited to the embodiments shown
and described in detail herein. For instance, the present invention
is described only with respect to stack of two chips stacked
vertically. Alternatively, the present invention may be used with
any number of stacked chips, which may be stacked in a vertical,
horizontal, or in side-by-side fashion. Accordingly, the invention
is not limited by the foregoing description but is limited only by
the spirit and scope of the appended claims.
[0037] What is claimed as new and desired to be protected by
Letters Patent of the United States is:
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