U.S. patent application number 11/053862 was filed with the patent office on 2005-08-04 for method and apparatus for providing an integrated circuit cover.
This patent application is currently assigned to Rambus Inc.. Invention is credited to Haba, Belgacem, Li, Ming, Mullen, Donald R..
Application Number | 20050167806 11/053862 |
Document ID | / |
Family ID | 34275046 |
Filed Date | 2005-08-04 |
United States Patent
Application |
20050167806 |
Kind Code |
A1 |
Mullen, Donald R. ; et
al. |
August 4, 2005 |
Method and apparatus for providing an integrated circuit cover
Abstract
An integrated circuit cover incorporating a spring portion is
described. The spring portion may include any structure that allows
displacement between a plate portion of the integrated circuit
cover and an attachment portion of the integrated circuit cover and
that provides a substantially equalizing effect of pressure on the
plate portion. The spring portion is preferably more flexible than
the plate portion. The integrated circuit cover accommodates
variations in the mounted height of integrated circuits over which
the integrated circuit cover is installed. The integrated circuit
cover may be formed as a unitary structure or may be constructed as
an assembly of multiple components.
Inventors: |
Mullen, Donald R.; (Mountain
View, CA) ; Haba, Belgacem; (Cupertino, CA) ;
Li, Ming; (Fremont, CA) |
Correspondence
Address: |
HUNTON & WILLIAMS LLP/RAMBUS INC.
INTELLECTUAL PROPERTY DEPARTMENT
1900 K STREET, N.W.
SUITE 1200
WASHINGTON
DC
20006-1109
US
|
Assignee: |
Rambus Inc.
Los Altos
CA
|
Family ID: |
34275046 |
Appl. No.: |
11/053862 |
Filed: |
February 10, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11053862 |
Feb 10, 2005 |
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09944545 |
Aug 31, 2001 |
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6870246 |
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Current U.S.
Class: |
257/678 ;
257/E23.086; 257/E23.094; 257/E23.104 |
Current CPC
Class: |
H01L 23/4093 20130101;
H01L 23/4338 20130101; H01L 2224/16225 20130101; H01L 23/3675
20130101; H01L 2224/73253 20130101 |
Class at
Publication: |
257/678 |
International
Class: |
H01L 023/02 |
Claims
1. An integrated circuit (IC) cover comprising: a plate portion; an
attachment portion; and a spring portion coupled to the plate
portion and to the attachment portion.
2. The IC cover of claim 1 wherein the IC cover is unitarily molded
of a polymer material.
3. The IC cover of claim 2 wherein the polymer material has a
thermal conductivity of at least 10 watts/meter Kelvin.
4. The IC cover of claim 2 further comprising: a heat sink portion
coupled to the plate portion.
5. The IC cover of claim 4 wherein the heat sink portion includes
extended surfaces.
6. The IC cover of claim 5 wherein the extended surfaces include
fins.
7. The IC cover of claim 1 wherein the attachment portion
comprises: a retainer having a first retainer portion and a second
retainer portion, the retainer defining a channel between the first
retainer portion and the second retainer portion, the first
retainer portion terminating in a first barb and the second
retainer portion terminating in a second barb.
8. The IC cover of claim 1 wherein the spring portion has a cross
section comprising a V-shaped portion.
9. The IC cover of claim 8 wherein the spring portion has a cross
section comprising a zig-zag-shaped portion.
10. The IC cover of claim 1 wherein the spring portion has a cross
section comprising a U-shaped portion.
11. The IC cover of claim 1 wherein the spring portion has a cross
section comprising an arcuate portion.
12. The IC cover of claim 11 wherein the spring portion has a cross
section comprising an S-shaped portion.
13. The IC cover of claim 1 wherein the spring portion has a cross
section comprising a molded living hinge portion.
14. The IC cover of claim 1 wherein the spring portion has a cross
section comprising a molded cantilever hinge portion.
15. The IC cover of claim 1 wherein the spring portion is disposed
at an end of the plate portion.
16. The IC cover of claim 1 wherein the spring portion includes a
plurality of individual spring elements, wherein a first one of the
plurality of individual spring elements is disposed at a first end
of the plate portion and a second one of the plurality of
individual spring elements is disposed at a second end of the plate
portion.
17. The IC cover of claim 16 wherein the plurality of individual
spring elements are disposed around a perimeter of the plate
portion.
18. The IC cover of claim 16 wherein at least one of the individual
spring elements is maintained in a non-relaxed state.
19. The IC cover of claim 1 wherein the spring portion is disposed
around the perimeter of the plate portion.
20. The IC cover of claim 1 wherein the spring portion forms a
closed path around the perimeter of the plate portion.
21. The IC cover of claim 1 wherein the spring portion comprises a
uniform diaphragm spring.
22. The IC cover of claim 1 further comprising: a heat sink portion
coupled to the plate portion.
23. The IC cover of claim 22 wherein the heat sink portion includes
extended surfaces.
24. The IC cover of claim 23 wherein the extended surfaces include
fins.
25. The IC cover of claim 1 wherein the plate portion and the
spring portion are unitarily formed of a metal material.
26. The IC cover of claim 1 wherein the attachment portion and the
spring portion are unitarily molded of a polymer material.
27. The IC cover of claim 1 wherein the plate portion is formed to
have an arcuate cross section so as to substantially equalize
pressure exerted against a convex surface of the plate portion.
28. An integrated circuit (IC) cover comprising: an attachment
portion adapted to be coupled to a circuit board, wherein at least
one die is coupled to the circuit board; and a plate portion of
flexible material coupled to the attachment portion, wherein the
plate portion is formed in a pre-loaded shape so as to exert
pressure to the at least one die when the attachment portion is
coupled to the circuit board.
29. The IC cover of claim 28 wherein the plate portion is formed so
as to exert pressure to the at least one die in a direction toward
the circuit board.
30. The IC cover of claim 29 further comprising: a spring portion
coupling the attachment portion to the plate portion.
31. An integrated circuit (IC) assembly comprising: a circuit
board; at least one first die disposed on a first surface of the
circuit board; and a cover including: a plate portion disposed so
as to cover the at least one first die; an attachment portion
attached to the circuit board; and a spring portion coupled to the
plate portion and to the attachment portion.
32. The IC assembly of claim 31 wherein the spring portion exerts
pressure between the plate portion and the at least one first
die.
33. The IC assembly of claim 32 wherein, when the attachment
portion is coupled to the circuit board, the spring portion is in a
non-relaxed position.
34. The IC assembly of claim 31 further comprising: at least one
second die disposed on a second surface of the circuit board.
35. The IC assembly of claim 34 further comprising: a second cover
attached to the circuit board, the second cover covering the at
least one second die.
36. An integrated circuit (IC) cover comprising: a plate portion
having a plurality of edges; a plurality of attachment portions;
and a plurality of spring portions coupled to the plate portion and
to the plurality of attachment portions, wherein each of the spring
portions is oriented along a direction of a corresponding one of
the plurality of edges.
37. The IC cover of claim 36 wherein center lines of the plurality
of spring portions are oriented so as to be non-radial relative to
a centroid of the plate portion.
38. The IC cover of claim 36 wherein each of center lines of the
plurality of spring portions are oriented approximately
tangentially in relation to a corresponding one of the plurality of
edges.
39. The IC cover of claim 36 wherein the plurality of spring
portions are oriented in a similar rotational direction with
respect to a centroid of the plate portion.
40. The IC cover of claim 36 wherein the plurality of spring
portions are configured to cooperatively accommodate displacement
of the plate portion from a relaxed position.
41. The IC cover of claim 36 wherein at least one of the plurality
of spring portions is maintained in a non-relaxed state when at
least one of the plurality of attachment portions is coupled to a
circuit board such that the plate portion overlies at least one IC.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of U.S. patent
application Ser. No. 09/944,545, filed Aug. 31, 2003, which is
hereby incorporated by reference herein in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates generally to integrated
circuit packaging and, more specifically, to an integrated circuit
cover.
BACKGROUND OF THE DISCLOSURE
[0003] As electronic systems have increased in complexity, attempts
have been made to increase the amount of electronic circuitry
contained in a given amount of space. One existing approach is to
mount integrated circuits on a circuit board and cover them with an
cover. The cover provides physical protection for the integrated
circuits and serves as a heat spreader to help dissipate heat from
the integrated circuits. An existing integrated circuit cover does
not accommodate height variations of mounted integrated circuits.
Consequently, a variety of integrated circuit covers, each
corresponding to a different integrated circuit height must be
available, with the appropriate integrated circuit cover selected
and installed over the integrated circuits after the mounted
integrated circuit has been determined. This variety of integrated
circuit covers results in complicated production and inventory
issues.
[0004] FIG. 1 is a cross-sectional view diagram illustrating an
example of an assembly incorporating an existing integrated circuit
cover. The assembly includes a circuit board 101. Circuit board 101
has a first surface 114 and a second surface 115. Integrated
circuit 106 is mounted on first surface 114 of circuit board 101
via connections 107. Integrated circuit 108 is mounted on first
surface 114 of circuit board 101 via connections 109. Integrated
circuit 110 is mounted on first surface 114 of circuit board 101
via connections 111. Integrated circuit 112 is mounted on first
surface 114 of circuit board 101 via connections 113.
[0005] Integrated circuit cover 102 covers integrated circuits 106,
108, 110, and 112, and is attached to circuit board 101 via
fasteners 104 and 105. Thermally conductive material 103 fills gaps
between integrated circuits 106, 108, 110, and 112 and integrated
circuit cover 102. A certain amount of pressure of integrated
circuit cover 102 against thermally conductive material 103 is
desirable to ensure good contact with integrated circuits 106, 108,
110, and 112 so as to promote heat transfer from integrated
circuits 106, 108, 110, and 112 to integrated circuit cover 102.
However, the geometry of the assembly results in pressure being
localized near fasteners 104 and 105. Since some integrated
circuits are closer to fasteners 104 and 105 than other integrated
circuits, the pressure exerted against integrated circuits 106,
108, 110, and 112 is unequal. The inequality of pressure can affect
heat transfer and limits the amount of pressure that may be applied
without causing excessive pressure to be placed on integrated
circuits near fasteners 104 and 105. As can be seen from FIG. 1,
integrated circuit cover 102 tends to bow outward. Depending on the
rigidity of circuit board 101, circuit board 101 may tend to bow
outward, away from the cover, resulting in surface 115 of circuit
board 101 being displaced to position 116. Thus, even when an
integrated circuit cover of a particular height is selected,
dimensional distortion of the integrated circuit cover can result
in uneven thermal conductivity and reduced performance.
[0006] Therefore, a integrated circuit cover is needed that avoids
the need to produce and maintain in inventory covers of different
heights. An integrated circuit cover is needed that provides even
thermal performance over a large area, for example, over multiple
integrated circuits.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] In order to facilitate a fuller understanding of the present
disclosure, reference is now made to the accompanying drawings, in
which like elements are referenced with like numerals. These
drawings should not be construed as limiting the present
disclosure, but are intended to be exemplary only.
[0008] FIG. 1 is a cross-sectional view diagram illustrating an
example of an assembly incorporating a prior art integrated circuit
cover.
[0009] FIG. 2 is a cross-sectional view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
an embodiment of the present disclosure.
[0010] FIG. 3 is a side elevation view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 2.
[0011] FIG. 4 is an end elevation view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 2.
[0012] FIG. 5 is a top plan view diagram illustrating an assembly
comprising an integrated circuit cover in accordance with the
example illustrated in FIG. 2.
[0013] FIG. 6 is a cross sectional view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
an embodiment of the present disclosure.
[0014] FIG. 7 is a side elevation view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 6.
[0015] FIG. 8 is an end elevation view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 6.
[0016] FIG. 9 is a top plan view diagram illustrating an assembly
comprising an integrated circuit cover in accordance with the
example illustrated in FIG. 6.
[0017] FIG. 10 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure.
[0018] FIG. 11 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure.
[0019] FIG. 12 is a cross sectional view diagram illustrating an
example of a spring portion on an integrated circuit cover in
accordance with an embodiment of the present disclosure.
[0020] FIG. 13 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure.
[0021] FIG. 14 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure.
[0022] FIG. 15 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure.
[0023] FIG. 16 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure.
[0024] FIG. 17 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure.
[0025] FIG. 18 is a top plan view diagram illustrating an assembly
comprising an integrated circuit cover in accordance with an
embodiment of the present disclosure.
[0026] FIG. 19 is a cross sectional view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 18.
[0027] FIG. 20 is a cross sectional view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 18.
[0028] FIG. 21 is a cross sectional view diagram illustrating an
integrated circuit cover in accordance with an embodiment of the
present disclosure.
[0029] FIG. 22 is a cross sectional view diagram illustrating an
integrated circuit cover in accordance with an embodiment of the
present disclosure.
[0030] FIG. 23 is a cross sectional view diagram illustrating an
integrated circuit cover in accordance with an embodiment of the
present disclosure.
[0031] FIG. 24 is a cross sectional view diagram illustrating an
integrated circuit cover in accordance with an embodiment of the
present disclosure.
[0032] FIG. 25 is a top plan view diagram illustrating an
integrated circuit cover in accordance with the example illustrated
in FIG. 24.
[0033] FIG. 26 is a cross sectional view diagram illustrating an
embodiment of an integrated circuit cover in accordance with an
embodiment of the present disclosure.
[0034] FIG. 27 is a plan view diagram illustrating an embodiment of
an integrated circuit cover in accordance with an embodiment of the
present disclosure.
[0035] FIG. 28 is an elevation view diagram illustrating the
embodiment shown in FIG. 27.
[0036] FIG. 29 is a cross-sectional view diagram illustrating the
embodiment shown in FIG. 27.
[0037] FIG. 30 is a cross-sectional view diagram illustrating the
embodiment shown in FIG. 27 in conjunction with a circuit board and
a plurality of dies.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0038] An integrated circuit cover incorporating a spring portion
is described. The spring portion may include any structure that
allows displacement between a plate portion of the integrated
circuit cover and an attachment portion of the integrated circuit
cover and that provides a substantially equalizing effect of
pressure on the plate portion. The spring portion is preferably
more flexible than the plate portion. The integrated circuit cover
accommodates variations in the mounted height of integrated
circuits over which the integrated circuit cover is installed. The
integrated circuit cover may be formed as a unitary structure or
may be constructed as an assembly of multiple components.
[0039] An integrated circuit cover according to an embodiment of
the present disclosure allows reduced mechanical stress, increased
and more even thermal conductivity, simplified production and
inventory, simplified installation, and reduced cost, among other
benefits. Other embodiments may be practiced to provide various
combinations of one or more of the benefits.
[0040] The integrated circuit cover may be constructed of polymer
materials exhibiting a thermal conductivity of at least
approximately 10 watts/meter Kelvin (w/mK). An example of a
suitable polymer material is the COOLPOLY E2 thermally conductive
liquid crystalline polymer (LCP) available from COOL POLYMERS,
Inc., 333 Strawberry Field Rd., Warwick, R.I. 02886. Polymer
materials such as those described above or other polymer materials
or elastomer materials may be used in combination with one or more
metallic materials, such as metals or metal alloys. In other
embodiments, the integrated circuit cover is constructed entirely
of one or more metallic materials, such as metals or metal
alloys.
[0041] Alternatively, the present disclosure may be practiced in
embodiments where thermal conductivity is an secondary
consideration. For example, an integrated circuit cover in
accordance with an embodiment of the present disclosure may be used
such that protection of the integrated circuits is the primary
benefit. As an example of such protection, the integrated circuit
cover may maintain integrated circuits, such as bump-mounted
integrated circuits, in contact with a circuit board and/or protect
the integrated circuits from external forces, objects, or events.
In such embodiments, materials exhibiting lower thermal
conductivity than 10 w/mK may be used.
[0042] An integrated circuit cover in accordance with an embodiment
of the present disclosure may be used in conjunction with any types
of integrated circuits. Examples of such integrated circuits
include memory devices, microprocessors, and microcontrollers,
although any other types of integrated circuits, including
combinations of different types of integrated circuits, may be
used. An integrated circuit cover may cover one or more integrated
circuits, thereby forming a module. Examples of such modules
include memory modules, microprocessor (including multiprocessor)
modules, microcontroller modules, and systems including memory,
processing, and support circuits. An example of a situation in the
integrated circuit cover may be beneficially used is where several
integrated circuits function together at high data rates, for
example, in the types of modules described above. The integrated
circuit cover affords the opportunity to place several integrated
circuits in close proximity, yet to provide sufficient power
dissipation.
[0043] FIG. 2 is a cross-sectional view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
an embodiment of the present disclosure. The assembly includes a
circuit board 201. Circuit board 201 has a first surface 214 and a
second surface 215. Integrated circuit 206 is mounted on the first
surface 214 of circuit board 201 via connections 207. Integrated
circuit 208 is mounted on first surface 214 of circuit board 201
via connections 209. Integrated circuit 210 is mounted on first
surface 214 of circuit board 201 via connections 211. Integrated
circuit 212 is mounted on first surface 214 of circuit board 201
via connections 213.
[0044] An integrated circuit cover covers integrated circuits 206,
208, 210, and 212. The integrated circuit cover includes a plate
portion 202, an attachment portion 204, an attachment portion 205,
a spring portion 217, and a spring portion 218. Spring portion 217
couples attachment portion 204 to plate portion 202. Spring portion
218 couples attachment portion 205 to plate portion 202. Spring
portions 217 and 218 cause plate portion 202 to exert pressure on
thermal interface 203, which applies the pressure to integrated
circuits 206, 208, 210, and 212. Such pressure is beneficial for
establishing a good thermal connection between the integrated
circuits 206, 208, 210, and 212 and plate portion 202. Before the
integrated circuit cover is attached to the circuit board 201, the
spring portions 217 and 218 may be in a relaxed state. However,
when the integrated circuit cover is attached to the circuit board
201, the spring portions 217 and 218 are preferably maintained in a
non-relaxed state.
[0045] Attachment portion 204 includes a retainer 219. Retainer 219
comprises a first retainer portion 221 and a second retainer
portion 222. First retainer portion 221 terminates in first barb
223. Second retainer portion 222 terminates in second barb 224.
First retainer portion 221 and second retainer portion 222 define a
channel 225 separating first retainer portion 221 from second
retainer portion 222.
[0046] Attachment portion 205 includes retainer 220. Retainer 220
comprises a first retainer portion 226 and a second retainer
portion 227. First retainer portion 226 terminates in first barb
228. Second retainer portion 227 terminates in second barb 229.
First retainer portion 226 and second retainer portion 227 define a
channel 230 that separates first retainer portion 226 from second
retainer portion 227.
[0047] Thermal interface 203 is disposed between plate portion 202
and integrated circuits 206, 208, 210, and 212. Two examples of
suitable materials for thermal interface 203 include silicone and a
phase change material (PCM) or the like. In other embodiments,
thermal interface 203 may be omitted, and plate portion 202 may or
may not be maintained in contact with integrated circuits 206, 208,
210, and 212.
[0048] FIG. 3 is a side elevation view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 2. The integrated circuit cover
comprises a plate portion 202, an attachment portion 204, an
attachment portion 205, a spring portion 217, and a spring portion
218. An integrated circuit attaches to a first surface 214 of a
circuit board 201. A retainer of the integrated circuit cover
extends through circuit board 201. The retainer includes a first
barb 223 and a second barb 224 which engage a second surface 215 of
circuit board 201. The first barb 223 and the second barb 224
define a channel 225 between them. The channel 225 allows flexure
of the retainer and displacement of the first barb 223 and the
second barb 224 so that the first barb 223 and the second barb 224
can pass through a hole in circuit board 201.
[0049] Another retainer of the integrated circuit cover extends
through circuit board 201. The retainer includes a first barb 228
and a s second barb 229 which engage a second surface 215 of
circuit board 201. The first barb 228 and the second barb 229
define a channel 230 between them. The channel 230 allows flexure
of the retainer and displacement of the first barb 228 and the
second barb 229 so that the first barb 228 and the second barb 229
can pass through a hold in circuit board 201.
[0050] FIG. 4 is an end elevation view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 2. The integrated circuit cover
comprises an attachment portion 204 and a spring portion 217. An
integrated circuit attaches to a first surface 214 of circuit board
201. Retainers of the integrated circuit cover extend through
circuit board 201. One retainer includes a first barb 223 which
engages a second surface 215 of circuit board 201. Another retainer
includes a first barb 401 which engages the second surface 215 of
circuit board 201.
[0051] FIG. 5 is a top plan view diagram illustrating an assembly
comprising an integrated circuit cover in accordance with the
example illustrated in FIG. 2. The integrated circuit cover
comprises a plate portion 202, a spring portion 217, a spring
portion 218, an attachment portion 204, and an attachment portion
205. The integrated circuit cover attaches to a first surface 214
of a circuit board. Attachment portion 204 includes retainers 219
and 501. Attachment portion 205 includes retainers 220 and 502.
Retainers 219, 220, 501, and 502 secure the integrated circuit
cover to the circuit board. The integrated circuit cover preferably
includes a flange 505 and a flange 506. Flanges 505 and 506
preferably meet with the first surface 204 of the circuit board to
fully enclose integrated circuits mounted on the circuit board.
Flanges 505 and 506 are coupled to plate portion 202 via flexible
portions 503 and 504, respectively. Flexible portions 503 and 504
may be of a similar structure as spring portions 217 and 218, for
example, effectively forming a continuous spring portion that
surrounds plate portion 202. Alternatively, flexible portions 503
and 504 may be of an alternative structure, provided they allow
displacement of plate portion 202. As another alternative, flexible
portions 503 and 504 may be omitted.
[0052] FIG. 6 is a cross sectional view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
an embodiment of the present disclosure. The integrated circuit
cover comprises a plate portion 602, a spring portion 617, a spring
portion 618, an attachment portion 604, and an attachment portion
605. The plate portion 602, the spring portion 617, and the spring
portion 618 are formed as a unitary structure, and serve as a heat
spreader, while attachment portion 604 and the attachment portion
605 are formed separately from that unitary structure. Attachment
portions 604 and 605 engage a first surface 214 of circuit board
201.
[0053] The attachment portion 604 includes a retainer 619 to
maintain attachment to circuit board 201. The retainer 619
comprises retainer portions 621 and 622. Retainer portion 621
includes barb 623. Retainer portion 622 includes barb 624. Barbs
623 and 624 engage a second surface 215 of circuit board 201.
Retainer portions 621 and 622 are separated from each other so as
to define a channel 625.
[0054] The attachment portion 605 includes a retainer 620 to
maintain attachment to circuit board 201. The retainer 620
comprises retainer portions 626 and 627. Retainer portion 626
includes barb 628. Retainer portion 627 includes barb 629. Barbs
628 and 629 engage the second surface 215 of circuit board 201.
Retainer portions 626 and 627 are separated from each other so as
to define a channel 630. As is apparent to one of ordinary skill in
the art, other attachment schemes can be used to couple the
integrated circuit cover to circuit board 201. For example,
separate fasteners not integrated with the cover, such as screws,
rivets, and the like, can be used to physically couple the
integrated circuit cover to the circuit board 201.
[0055] The attachment portion 604 includes a coupling portion 631
to couple attachment portion 604 to the heat spreader. The coupling
portion 631 includes extensions 633 and 634 that define a channel
635 to accept the heat spreader. The attachment portion 605
includes a coupling portion 632 to couple attachment portion 605 to
the heat spreader. The coupling portion 632 includes extensions 636
and 637 that define a channel 638 to accept the heat spreader. The
heat spreader includes an extension 674 coupled to spring portion
617. Channel 635 accepts extension 674 so as to attach the heat
spreader to attachment portion 604. The heat spreader includes an
extension 675 coupled to spring portion 618. Channel 638 accepts
extension 675 so as to attach the heat spreader to attachment
portion 605.
[0056] Integrated circuit 206 is attached to first surface 214 of
circuit board 201 via connections 207. Integrated circuit 208 is
attached to first surface 214 of circuit board 201 via connections
209. A thermally conductive material 603 thermally couples
integrated circuits 206 and 208 to plate portion 602 of the heat
spreader. To enhance the thermal characteristics of the heat
spreader, a heat sink 640 having fins 641 may be attached to the
surface of plate portion 602 opposite the surface to which
thermally conductive material 603 is attached. Optionally, a
protective cover 639 may be provided over the heat spreader. For
example, the protective cover 639 may be integrally formed with
attachment portion 604 and attachment portion 605.
[0057] FIG. 7 is a side elevation view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 6. The assembly comprises a circuit
board 201 having a first surface 214 and a second surface 215 and
an integrated circuit cover 701. The integrated circuit cover 701
includes attachment portion 604, attachment portion 605, and,
optionally, extended surface 641. Extended surface 641 may include
fins, pins, or other physical structures intended to increase the
surface area or heat transfer characteristics such that heat
dissipation is improved. Attachment portion 604 includes a retainer
comprising first barb 623 and second barb 624. The first barb 623
and the second barb 624 are separated so as to define a channel
625. Attachment portion 605 includes a retainer comprising first
barb 628 and second barb 629. The first barb 628 and the second
barb 629 are separated so as to define a channel 630.
Alternatively, the retainers need not include separated barbs; if
the retainers exhibit sufficient elasticity to pass through holes
in circuit board 201, the first and second barbs may be formed as a
unitary annular barb.
[0058] FIG. 8 is an end elevation view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 6. The assembly comprises a circuit
board 201 having a first surface 214 and a second surface 215 and
an integrated circuit cover having an attachment portion 604 and,
optionally, fins 641. The attachment portion 604 includes retainers
having barbs 623 and 801. Barbs 623 and 801 engage the second
surface 215 of circuit board 201 to attach the integrated circuit
cover to the circuit board 201.
[0059] FIG. 9 is a top plan view diagram illustrating an assembly
comprising an integrated circuit cover in accordance with the
example illustrated in FIG. 6. The assembly comprises the
integrated circuit cover and a circuit board having a first surface
214. The integrated circuit cover includes a heat spreader
comprising a plate portion 602 and spring portions 617 and 618. The
heat spreader may optionally include a heat sink 640 comprising
fins 641. The integrated circuit cover further includes a
attachment element including attachment portion 604 and attachment
portion 605. Attachment portion 604 includes retainers 619 and 901.
Attachment portion 605 includes retainers 620 and 902. Attachment
portion 604 includes extension 633 that extends to engage the heat
spreader. Attachment portion 605 includes extension 636 that
extends to engage the heat spreader. Optionally, flange 905 extends
from attachment portion 604 to attachment portion 605 along one
side of the heat spreader and flange 906 extends from attachment
portion 604 to attachment portion 605 along an opposite side of the
heat spreader. Flange 905 includes extension 903 to engage the heat
spreader. Flange 906 includes extension 904 to engage the heat
spreader.
[0060] FIG. 10 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure. The spring
portion includes a segment 1043 extending from a spring terminus
1042 to an apex 1044, a segment 1045 extending from apex 1044 to
apex 1046, a segment 1047 extending from apex 1046 to apex 1048, a
segment 1049 extending from apex 1048 to apex 1050, and a segment
1051 extending from apex 1050 to spring terminus 1052. Spring
terminus 1042 is coupled to element 1004, which may, for example,
be an attachment portion of the integrated circuit cover. Spring
terminus 1052 is coupled to element 1002, which may, for example,
be a plate portion of the integrated circuit cover. The spring
portion illustrated in FIG. 10 has a cross section comprising a
zig-zag-shaped portion. The alternately oriented segments and
apexes provide the zig-zag shape. The segments can be of varying
length and no uniformity is required in order to achieve the
desired result. The spring portion may be practiced with different
numbers of segments and apexes. The spring portion provides for
translation of element 1002 relative to element 1004 in direction
1053 and/or direction 1054, as well as rotation of element 1002
relative to element 1004 in direction 1055. The spring portion is
preferably thinner than element 1004 and element 1002. In other
embodiments, the spring portion is made of a different material
than elements 1004 and 1002, in which case the thickness of the
spring portion is based on the qualities of the materials of which
it is comprises, independent of the thickness of the elements 1004
and 1002.
[0061] FIG. 11 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure. The spring
portion includes an arcuate portion 1156 coupled to an arcuate
portion 1157. The arcuate portion 1156 and the arcuate portion 1157
collectively form an S-shaped portion. The S-shaped portion extends
from spring terminus 1142 to spring terminus 1152. The spring
portion is coupled to element 1104 at spring terminus 1142. Element
1104 may, for example, be an attachment portion of the integrated
circuit cover. The spring portion is coupled to element 1102 at
spring terminus 1152. Element 1102 may, for example, be a plate
portion of the integrated circuit cover. The spring portion of FIG.
11 has a cross section comprising the S-shaped portion. The spring
portion may be practiced with a different number of arcuate
portions. These arcuate portions may be of varying size and radius.
The spring portion provides for translation and rotation of element
1102 relative to element 1104. The spring portion is preferably
thinner than element 1104 and element 1102. In other embodiments,
the spring portion is made of a different material than elements
1104 and 1102, in which case the thickness of the spring portion is
based on the qualities of the materials of which it is comprises,
independent of the thickness of the elements 1104 and 1102.
[0062] FIG. 12 is a cross sectional view diagram illustrating an
example of a spring portion on an integrated circuit cover in
accordance with an embodiment of the present disclosure. The spring
portion of FIG. 12 has a cross section comprising a molded living
hinge portion. The molded living hinge portion is coupled to
element 1204 at spring terminus 1242 and to element 1202 at spring
terminus 1252. Element 1204 may, for example, be an attachment
portion of the integrated circuit cover. Element 1202 may, for
example, be a plate portion of the integrated circuit cover. The
molded living hinge portion comprises a living hinge portion 1258
of a thinner cross section than element 1204 and a living hinge
portion 1260 of a thinner cross section than element 1202. The
living hinge portion 1258 is coupled to element 1204 at spring
terminus 1242. The living hinge portion 1260 is coupled to element
1202 at spring terminus 1252. The living hinge portion 1258 is
coupled to the living hinge portion 1260 by coupling portion 1259,
which has a thicker cross section than living hinge portions 1258
and 1260.
[0063] FIG. 13 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure. The spring
portion of FIG. 13 has a cross section comprising a molded
cantilever hinge portion. Molded cantilever hinge portion 1360 is
coupled to element 1304 at spring terminus 1342 and to element 1302
at spring terminus 1352. Element 1304 may, for example, be an
attachment portion of the integrated circuit cover. Element 1302
may, for example, be a plate portion of the integrated circuit
cover. Molded cantilever hinge portion 1360 has a thinner cross
section than element 1304 and element 1302.
[0064] FIG. 14 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure. The spring
portion of FIG. 14 has a cross section comprising an arcuate
portion. Arcuate portion 1456 extends from spring terminus 1442 to
spring terminus 1452. Arcuate portion 1456 is coupled to element
1404 at spring terminus 1442. Arcuate portion 1456 is coupled to
element 1402 at spring terminus 1452. Element 1404 may, for
example, be an attachment portion of the integrated circuit cover.
Element 1402 may, for example, be a plate portion of the integrated
circuit cover.
[0065] As can be seen from FIG. 14, many variations of the
embodiment illustrated in FIG. 11 are possible. While the
embodiment of FIG. 11 includes two arcuate portions having
different directions of curvature, the embodiment of FIG. 14
includes an arcuate portion having a single arc. It can be readily
understood that the present disclosure may be practiced in various
embodiments having various numbers of arcs, including arcs of
similar or different directions. Likewise, arcuate portions may be
combined with portions of other geometries, for example, V-shaped,
straight, and/or other regular or irregular geometries.
[0066] FIG. 15 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure. While the
spring portion of FIG. 14 includes an arcuate portion having a
convex surface oriented in one direction, the spring portion of
FIG. 15 includes an arcuate portion having a concave surface when
the integrated circuit cover is oriented in the same direction.
Arcuate portion 1557 extends from spring terminus 1542 to spring
terminus 1552. Arcuate portion 1557 is coupled to element 1504 at
spring terminus 1542. Arcuate portion 1557 is coupled to element
1502 at spring terminus 1552. Element 1504 may, for example, be an
attachment portion of the integrated circuit cover. Element 1502
may, for example, be a plate portion of the integrated circuit
cover.
[0067] FIG. 16 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure. The spring
portion of FIG. 16 has a cross section comprising a V-shaped
portion. The V-shaped portion comprises segment 1645 extending from
spring terminus 1642 to apex 1646 and segment 1647 extending from
apex 1646 to spring terminus 1652. The spring portion is coupled to
element 1604 at spring terminus 1642 and to element 1602 at spring
terminus 1652. Element 1604 may, for example, be an attachment
portion of the integrated circuit cover. Element 1602 may, for
example, be an plate portion of the integrated circuit cover.
[0068] As can be seen from FIG. 16, many variations of the
embodiment illustrated in FIG. 10 are possible. While the
embodiment of FIG. 10 includes spring portion having a "zig-zag"
shape that includes multiple individual V-shaped portions combined
together, the embodiment of FIG. 16 includes a single V-shaped
portion. It can be readily understood that the present disclosure
may be practiced in various embodiments having various numbers of
V-shaped portions, including V-shaped portions of similar or
different directions. Likewise, V-shaped portions may be combined
with portions of other geometries, for example, arcuate, straight,
and/or other regular or irregular geometries.
[0069] FIG. 17 is a cross sectional view diagram illustrating an
example of a spring portion of an integrated circuit cover in
accordance with an embodiment of the present disclosure. While the
spring portion of FIG. 16 includes a V-shaped portion extending
upward relative to one orientation of the integrated circuit cover,
the spring portion of FIG. 17 has a cross section comprising a
V-shaped portion extending downward relative to the same
orientation of the integrated circuit cover. The V-shaped portion
comprises segment 1743 extending from spring terminus 1742 to apex
1744 and segment 1745 extending from apex 1744 to spring terminus
1752. The spring portion is coupled to element 1704 at spring
terminus 1742 and to element 1702 at spring terminus 1752. Element
1704 may, for example, be an attachment portion of the integrated
circuit cover. Element 1702 may, for example, be an plate portion
of the integrated circuit cover.
[0070] FIG. 18 is a top plan view diagram illustrating an assembly
comprising an integrated circuit cover in accordance with an
embodiment of the present disclosure. The assembly comprises a
circuit board having a first surface 214 and the integrated circuit
cover. The integrated circuit cover comprises a plate portion 1802,
a spring portion 1817, an attachment portion 1804, and an
attachment portion 1805. The plate portion 1802 may optionally
include fins 1841 to improve its thermal characteristics. Spring
portion 1817 includes spring terminus 1852 at an interface between
plate portion 1802 and spring portion 1817, apex 1846, and spring
terminus 1842 at an interface between attachment portion 1804 and
spring portion 1817. As an example, spring portion 1817 may be
implemented as a diaphragm spring structure. Such a structure can
be formed by providing a flexible region between attachment
portions 1804 and 1805 and plate portion 1802. The flexible region
may, for example, have a corrugated construction to provide
flexibility. Alternatively, other forms of construction (examples
of which are described herein) may be used to provide flexibility.
The flexible region may, for example, extend around the perimeter
of plate portion 1802, forming a closed path around plate portion
1802. Alternatively, the flexible region may be formed from one or
more segments that need not form a closed path around plate portion
1802. As an example, a plurality of individual spring elements or
spring-like structures may be substituted for the flexible
region.
[0071] Attachment portion 1804 comprises retainers 1819 and 1861
that couple the integrated circuit cover to the circuit board.
Attachment portion 1805 comprises retainers 1820 and 1862 that
couple the integrated circuit cover to the circuit board. The
integrated circuit cover optionally includes retainers 1863, 1864,
1865, and 1866 that couple the integrated circuit cover to the
circuit board.
[0072] FIG. 19 is a cross sectional view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 18. The assembly comprises circuit
board 201 having a first surface 214 and a second surface 215,
integrated circuits 1806, 1808, 1810, and 1812, and the integrated
circuit cover. Integrated circuit 1806 is attached to the first
surface 214 of circuit board 201 via connections 1807. Integrated
circuit 1808 is attached to the first surface 214 of circuit board
201 via connections 1809. Integrated circuit 1810 is attached to
the first surface 214 of circuit board 201 via connections 1811.
Integrated circuit 1812 is attached to the first surface 214 of
circuit board 201 via connections 1813.
[0073] The integrated circuit cover comprises a plate portion 1802,
a spring portion 1817, a spring portion 1818, an attachment portion
1804, and an attachment portion 1805. Plate portion 1802 may
optionally include fins 1841 to enhance its thermal
characteristics. Optionally, a thermally conductive material 1803
is disposed between integrated circuits 1806, 1808, 1810, and 1812
and plate portion 1802 to provide thermal conductivity from the
integrated circuits to the plate portion 1802. When used, the
thermally conductive material may be pre-applied or may be applied
during assembly. For example, the thermally conductive material may
be provided in a tape form and may be applied to the integrated
circuit cover or to an area over which the integrated circuit cover
is to be mounted. Attachment portion 1804 comprises retainer 1819.
Retainer 1819 comprises a first retainer portion 1821 and a second
retainer portion 1822. The first retainer portion 1821 includes a
first barb 1823. The second retainer portion 1822 includes a second
barb 1824. The first retainer portion 1821 and the second retainer
portion 1822 define a channel 1825 between them. Attachment portion
1805 comprises retainer 1820. Retainer 1820 comprises a first
retainer portion 1826 and a second retainer portion 1827. The first
retainer portion 1826 includes a first barb 1828. The second
retainer portion 1827 includes a second barb 1829. The first
retainer portion 1826 and the second retainer portion 1827 define a
channel 1830 between them.
[0074] FIG. 20 is a cross sectional view diagram illustrating an
assembly comprising an integrated circuit cover in accordance with
the example illustrated in FIG. 18. The assembly comprises circuit
board 201 having a first surface 214 and a second surface 215,
integrated circuits 1812 and 2012, and the integrated circuit
cover. Integrated circuit 1812 is coupled to first surface 214 of
circuit board 201 via connections 1813. Integrated circuit 2012 is
coupled to first surface 214 of circuit board 201 via connections
2013. A thermally conductive material 1803 is disposed between
integrated circuit cover 1802 and integrated circuits 1812 and 2012
to provide thermal conductivity from integrated circuits 1812 and
2012 to integrated circuit cover 1802. The integrated circuit cover
comprises a plate portion 1802, a spring portion 2017, a spring
portion 2018, an attachment portion 2004, and an attachment portion
2005. The plate portion 1802 may optionally include fins 1841 to
enhance its thermal characteristics. Attachment portion 2004
includes retainer 1863 to attach the integrated circuit cover to
circuit board 201. Attachment portion 2005 includes retainer 1864
to attach the integrated circuit cover to circuit board 201.
[0075] FIG. 21 is a cross sectional view diagram illustrating an
integrated circuit cover in accordance with an embodiment of the
present disclosure. The integrated circuit cover comprises a plate
portion 2102, a spring portion 2117, a spring portion 2118, an
attachment portion 2104, and an attachment portion 2105. The plate
portion 2102 comprises an arcuate portion 2169 having concave
surface 2167 and a convex surface 2168. Convex surface 2168 is
adapted to be coupled to one or more integrated circuits,
preferably by a thermally conductive material. One or more fins
2141 may be coupled to concave surface 2167 of arcuate portion 2169
to enhance thermal performance. Plate portion 2102 is illustrated
in a relaxed state. However, when the integrated circuit cover is
mounted over integrated circuits, the integrated circuits may apply
pressure against convex surface 2168. Plate portion 2102 may be
constructed of a deformable material that deforms under the
pressure applied by the integrated circuits. Thus, the curvature of
arcuate portion 2169 may change when the integrated circuit cover
is installed, even to the extent that the arcuate portion 2169
becomes flat or curved in an opposite direction.
[0076] Attachment portion 2104 includes retainer 2119. Retainer
2119 comprises a first retainer portion 2121 and a second retainer
portion 2122. First retainer portion 2121 includes a first barb
2123. Second retainer portion 2122 includes a second barb 2124.
First retainer portion 2121 and second retainer portion 2122 define
a channel 2125 that separates them. Attachment portion 2105
includes retainer 2120. Retainer 2120 comprises a first retainer
portion 2126 and a second retainer portion 2127. First retainer
portion 2126 includes a first barb 2128. Second retainer portion
2127 includes a second barb 2129. First retainer portion 2126 and
second retainer portion 2127 define a channel 2130 that separates
them.
[0077] FIG. 22 is a cross sectional view diagram illustrating an
integrated circuit cover in accordance with an embodiment of the
present disclosure. The integrated circuit cover comprises a plate
portion 2202, a spring portion 2217, a spring portion 2218, an
attachment portion 2204, and an attachment portion 2205. Attachment
portion 2204 may include a retainer or may define a hole 2268 to
accept a fastener to allow mounting of the integrated circuit cover
to a circuit board. Attachment portion 2205 may include a retainer
or may define a hole 2269 to accept a fastener to allow mounting of
the integrated circuit cover to a circuit board. Spring portion
2217 and spring portion 2218 are constructed of an material
exhibiting sufficient elasticity so as to accommodate displacement
of plate portion 2202 relative to attachment portion 2204 and
attachment portion 2205. Plate portion 2202 may be constructed of a
more rigid material, may be thicker to increase its rigidity,
and/or may include stiffening members to increase its rigidity.
[0078] FIG. 23 is a cross sectional view diagram illustrating an
integrated circuit cover in accordance with an embodiment of the
present disclosure. The integrated circuit cover comprises a plate
portion 2302, a spring portion 2317, a spring portion 2318, an
attachment portion 2304, and an attachment portion 2305. Attachment
portion 2304 may include a retainer or may define a hole 2368 to
accept a fastener to allow mounting of the integrated circuit cover
to a circuit board. Attachment portion 2305 may include a retainer
or may define a hold 2369 to accept a fastener to allow mounting of
the integrated circuit cover to a circuit board. While other
embodiments provide a spring terminus at an attachment portion and
a spring terminus at a plate portion that are substantially the
same distance from a circuit board, this embodiment provides a
spring portion 2317 and spring portion 2318 wherein a spring
terminus at an attachment portion and a spring terminus at a plate
portion are disposed at different distances from a circuit board to
which the integrated circuit cover is attached.
[0079] FIG. 24 is a cross sectional view diagram illustrating an
integrated circuit cover in accordance with an embodiment of the
present disclosure. The integrated circuit cover comprises a plate
portion 2402 constructed of a more rigid material and attachment
portions 2404 and 2405 constructed of a more flexible material.
Attachment portion 2404 includes flexible cantilever extension 2417
that retains plate portion 2402 and acts as a spring, flexing as
pressure is applied against a surface of plate portion 2402
opposite the surface upon which the flexible cantilever extension
2417 engages. Attachment portion 2405 includes flexible cantilever
extension 2418 that retains plate portion 2402 and acts as a
spring, flexing as pressure is applied against a surface of plate
portion 2402 opposite the surface upon which the flexible
cantilever extension 2418 engages. Fasteners 2470 and 2471 provide
an example of how attachment portions 2404 and 2405, respectively,
may be attached to a circuit board.
[0080] FIG. 25 is a top plan view diagram illustrating an
integrated circuit cover in accordance with the example illustrated
in FIG. 24. The integrated circuit cover comprises a plate portion
2402 and attachment portions 2404 and 2405. Attachment portions
2404 and 2405 may be coupled into a singular attachment portion
that surrounds plate portion 2402, for example, by flange portion
2504, which couples attachment portion 2404 to attachment portion
2405 along one side of plate portion 2402, and by flange portion
2505, which couples attachment portion 2404 to attachment portion
2405 along an opposite side of plate portion 2402. Flange portion
2504 includes flexible cantilever extension 2517, which engages
plate portion 2402. Flange portion 2505 includes flexible
cantilever extension 2518, which engages plate portion 2402.
[0081] Attachment portion 2404 includes flexible cantilever portion
2417, which engages plate portion 2402. Attachment portion 2405
includes flexible cantilever portion 2418, which engages plate
portion 2402. Attachment portion 2404 may include retainers or may
define holes 2470 and 2472 to allow attachment to a circuit board.
Attachment portion 2405 may include retainers or may define holes
2471 and 2473 to allow attachment to a circuit board.
[0082] FIG. 26 is a cross sectional view diagram illustrating an
embodiment of an integrated circuit cover in accordance with an
embodiment of the present disclosure. The integrated circuit cover
comprises a plate portion 2602, a spring portion 2617, a spring
portion 2618, an attachment portion 2604, and an attachment portion
2605. Spring portions 2617 and 2618 engage plate portion 2602.
Attachment portion 2604 and spring portion 2617 may be formed as a
unitary component, and attachment portion 2605 and spring portion
2618 may be formed as a unitary component, while plate portion 2602
may be formed as a separate component. Attachment portion 2604,
spring portion 2617, attachment portion 2605, and spring portion
2618 may be formed as a unitary portion, and plate portion 2602 may
be formed as a separate portion. Fasteners 2670 and 2671 provide an
example of how attachment portion 2604 and attachment portion 2605,
respectively, may be attached to a circuit board.
[0083] FIG. 27 is a plan view diagram illustrating an embodiment of
an integrated circuit cover in accordance with an embodiment of the
present disclosure. The integrated circuit cover includes a plate
portion 2702, attachment portions 2704, 2705, 2754, and 2755, and
spring portions 2717, 2718, 2767, and 2768. Spring portions 2717,
2718, 2767, and 2768 couple the plate portion 2702 to the
attachment portions 2704, 2705, 2754, and 2755, respectively. The
attachment portions 2704, 2705, 2754, and 2755 allow attachment of
the integrated circuit cover to a circuit board or other surface.
As an example of one technique for allowing attachment, attachment
portions 2704, 2705, 2754, and 2755 may define apertures 2770,
2771, 2772, and 2773, respectively, which allow fasteners, such as
screws, rivets, or the like to be coupled to attachment portions
2704, 2705, 2754, and 2755. Alternatively, other techniques for
allowing attachment, such as those described herein, may be
used.
[0084] The spring portions 2717, 2718, 2767, and 2768 may be formed
in a variety of geometries. For example, the spring portions 2717,
2718, 2767, and 2768 may be of uniform or non-uniform thickness,
width, and/or length. In the illustrated example, the spring
portion 2717 includes a spring element 2780 of uniform thickness
and width coupled to spring elements 2784 and 2788, which are of
varying thickness and width and serve to couple spring element 2780
to plate portion 2702 and attachment portion 2704, respectively.
The spring portion 2718 includes a spring element 2781 of uniform
thickness and width coupled to spring elements 2785 and 2789, which
are of varying thickness and width and serve to couple spring
element 2781 to plate portion 2702 and attachment portion 2705,
respectively. The spring portion 2767 includes a spring element
2782 of uniform thickness and width coupled to spring elements 2786
and 2790, which are of varying thickness and width and serve to
couple spring element 2782 to plate portion 2702 and attachment
portion 2754, respectively. The spring portion 2768 includes a
spring element 2783 of uniform thickness and width coupled to
spring elements 2787 and 2791, which are of varying thickness and
width and serve to couple spring element 2783 to plate portion 2702
and attachment portion 2755, respectively.
[0085] As can be seen from FIG. 27, spring portions 2717, 2718,
2782, and 2783 are, in one example, implemented using cantilever
spring elements. These cantilever spring elements are preferably
oriented along edges of the plate portion 2702. The cantilever
spring elements may be effectively oriented along the edges by
orienting the center lines of the spring elements to be non-radial
relative to a centroid of the plate portion 2702 (e.g., by
orienting the center lines approximately tangentially in relation
to the edges). By orienting the spring portions 2717, 2718, 2782,
and 2783 in a similar rotational direction about the centroid of
the plate portion 2702 (e.g., all oriented clockwise or all
oriented counterclockwise), any effective shortening of the length
of the spring portions 2717, 2718, 2782, and 2783 projected into a
plane of the plan view diagram of FIG. 27 as the spring portions
2717, 2718, 2782, and 2783 are displaced from that plane is
accommodated. Thus, in this example, if plate portion 2702 is
upwardly displaced, the plate portion 2702 is rotated clockwise as
viewed in FIG. 27 relative to attachment portions 2704, 2705, 2754,
and 2755. Spring portions 2717, 2718, 2782, and 2783 are configured
so as to facilitate such rotation in a mutually cooperative manner,
thereby allowing the integrated circuit cover to be more compliant
over a greater range of displacement.
[0086] One example of configuring spring portions 2717, 2718, 2782,
and 2783 such that they will mutually cooperate to allow
displacement of plate portion 2702 from a relaxed position can be
understood with reference to FIG. 27. As can be seen, spring
portion 2717 is oriented so as to define a gap 2790 between
attachment portion 2704 and plate portion 2702. The gap 2790
intersects a center line of spring portion 2718. While spring
portion 2718 allows some movement of plate portion 2702 in relation
to attachment portion 2705 in the vicinity of the edge of plate
portion 2702 along which spring portion 2718 lies, gap 2790 allows
movement of plate portion 2702 in relation to attachment portion
2704 in the vicinity of the same edge.
[0087] Spring portions 2718, 2782, and 2783 are oriented to define
gaps 2791, 2792, and 2793, respectively. Gaps 2791, 2792, and 2793
interact with spring portions 2767, 2768, and 2717, respectively,
to cooperatively allow displacement of plate portion 2702 from its
relaxed position. By selecting the mechanical properties and/or
dimensions of spring portions 2717, 2718, 2767, and 2768 to be
similar or different, the amount and uniformity of pressure exerted
by plate portion 2702 on any dies or other objects over which plate
portion 2702 is mounted may be controlled.
[0088] To provide enhanced thermal dissipation capacity, a heat
sink portion 2741 may be coupled to plate portion 2702. The heat
sink portion 2741 may be formed as extended surfaces extending from
plate portion 2702. For example, these extended surfaces may
include fins, pins, or other structures providing increased surface
area. The heat sink portion may be formed integrally with the plate
portion 2702 or as a separate structure coupled to the plate
portion 2702.
[0089] FIG. 28 is an elevation view diagram illustrating the
embodiment shown in FIG. 27. FIG. 28 illustrates the plate portion
2702, the heat sink portion 2741, the attachment portions 2754 and
2755, and the spring portion 2768. The spring elements 2768, 2787,
and 2791 of spring portion 2768 are also illustrated.
[0090] FIG. 29 is a cross-sectional view diagram illustrating the
embodiment shown in FIG. 27. It should be noted that FIG. 29
depicts only the portion of the integrated circuit cover lying in
the plane defined by the corresponding section line shown in FIG.
27. FIG. 29 shows plate portion 2702, attachment portions 2755 and
2754, heat sink portion 2741, and spring portion 2768. Spring
elements 2783, 2787, and 2791 of spring portion 2768 are
illustrated. Apertures 2772 and 2773 defined by attachment portions
2754 and 2755, respectively, are illustrated.
[0091] FIG. 30 is a cross-sectional view diagram illustrating the
embodiment shown in FIG. 27 in conjunction with a circuit board and
a plurality of dies. It should be noted that FIG. 30 depicts only
the portion of the integrated circuit cover, the circuit board, and
the plurality of dies lying in the plane defined by the
corresponding section line shown in FIG. 27. FIG. 30 shows plate
portion 2702, heat sink portion 2741, and attachment portions 2705
and 2755 of the integrated circuit cover. Apertures 2771 and 2773
defined by attachment portions 2705 and 2755, respectively, are
illustrated.
[0092] The integrated circuit cover of FIG. 30 is illustrated as
mounted over dies 2706 and 2708, which are mounted on circuit board
2701 via connections 2707 and 2709, respectively. As one example, a
thermal interface or a filler material is disposed in gaps 3001 and
3002 between the plate portion 2702 and the dies 2706 and 2708,
respectively. The thermal interface or filler material may have a
thermal conductivity suitable for any particular application. For
example, when high power dissipation is desired, a more thermally
conductive material may be used, while a less thermally conductive
material may be used when power dissipation is not as significant.
Also, heat sink portion 2741 may be omitted if the additional power
dissipation provided by it is not needed. As another example, plate
portion 2702 directly contacts dies 2706 and 2708, thereby reducing
or eliminating gaps 3001 and 3002. With plate portion 2702 directly
in contact with dies 2706 and 2708, filler material need not be
used.
[0093] Accordingly, a method and apparatus for providing an
integrated circuit cover has been described. It should be
understood that the implementation of other variations and
modifications of the present disclosure in its various aspects will
be apparent to those of ordinary skill in the art, and that the
present disclosure is not limited by the specific embodiments
described. It is therefore contemplated to cover by the present
disclosure, any and all modifications, variations, or equivalents
that fall within the spirit and scope of the basic underlying
principles disclosed and claimed herein.
* * * * *