U.S. patent application number 10/705592 was filed with the patent office on 2005-05-12 for heat sink integrated retention system.
Invention is credited to Hornung, Craig Warren.
Application Number | 20050099780 10/705592 |
Document ID | / |
Family ID | 34552406 |
Filed Date | 2005-05-12 |
United States Patent
Application |
20050099780 |
Kind Code |
A1 |
Hornung, Craig Warren |
May 12, 2005 |
HEAT SINK INTEGRATED RETENTION SYSTEM
Abstract
A heat sink assembly for a circuit board component is provided.
that includes a heat sink base, a frame coupled to the base, and a
cam positionable relative to the base to lock the heat sink base to
the circuit board component. The frame includes an actuator that
has a first post and a second post. Each post has an upper end, a
lower end, and a shaft portion therebetween. The lower end includes
a retention lug. A cross beam interconnects the shaft portions of
the posts. The frame further includes a board lock and the cam
includes a lever coupled to the cam. The cam engages the actuator
to move the actuator relative to the frame from a first position to
a second position to lock the heat sink base to the circuit board
component. The heat sink remains in the locked position when the
lever is rotated from the second position to the first
position.
Inventors: |
Hornung, Craig Warren;
(Harrisburg, PA) |
Correspondence
Address: |
Robert Kapalka
Tyco Electronics Corporation
Suite 140
4550 New Linden Hill Road
Wilmington
DE
19808
US
|
Family ID: |
34552406 |
Appl. No.: |
10/705592 |
Filed: |
November 10, 2003 |
Current U.S.
Class: |
361/719 ;
257/E23.086 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 2924/0002 20130101; H01L 23/4093 20130101; H01L 2924/00
20130101 |
Class at
Publication: |
361/719 |
International
Class: |
H05K 007/20 |
Claims
What is claimed is:
1. A heat sink assembly for a circuit board component, said
assembly comprising: a heat sink base; a frame coupled to said
base; and a cam positionable relative to said base to lock said
heat sink base to the circuit board component.
2. The heat sink assembly of claim 1, wherein said frame includes a
leg, said leg having an attachment end that includes a board
lock.
3. The heat sink assembly of claim 1, wherein said frame includes a
pair of legs and an actuator, each said leg including a channel for
receiving a portion of said actuator.
4. The heat sink assembly of claim 1, wherein said frame includes
an actuator comprising: a first post and a second post, each said
post having an upper end, a lower end, and a shaft portion
therebetween, said lower end including a retention lug; and a cross
beam interconnecting said shaft portions of said posts.
5. The heat sink assembly of claim 1, wherein said frame includes a
leg and an actuator, said leg including a board lock and said
actuator including a retention lug receivable in said board lock
expanding said board lock to lock said heat sink base to the
circuit board component.
6. The heat sink assembly of claim 1, wherein said frame includes a
board lock and an actuator, and said cam includes a lever coupled
to said cam, said cam engaging said actuator to move said actuator
relative to said frame from a first position to a second position
to lock said heat sink base to the circuit board component.
7. The heat sink assembly of claim 1, wherein said frame includes a
board lock and an actuator, and said cam includes a lever coupled
to said cam, said cam engaging said actuator to move said actuator
relative to said frame from a first position to a second position
to lock said heat sink base to the circuit board component, and
wherein said heat sink remains in said locked position when said
lever is rotated from said second position to said first
position.
8. The heat sink assembly of claim 1, wherein said frame assembly
includes a pair of legs and at least one cross beam interconnecting
said legs, each said leg including a lower portion that includes a
board lock.
9. The heat sink assembly of claim 1, wherein said frame includes
an actuator comprising first and second posts and a resilient cross
beam extending between said posts, and said cam includes a lever
coupled to said cam to rotate said cam, said cam engaging said
cross beam to bias said heat sink base toward the circuit board
component when said lever is rotated to lock said heat sink base to
said circuit board component.
10. A heat sink assembly for a circuit board component, said
assembly comprising: a heat sink base; an actuator coupled to said
base; and a board lock for coupling said base to said circuit board
in heat transfer relationship to the circuit board component, said
board lock comprising a pair of retention barbs, wherein said
actuator is configured to spread said pair of retention barbs and
apply a normal force to a surface of the circuit board component
when said actuator is moved from a first position to a second
position.
11. The heat sink assembly of claim 10, further comprising a cam
coupled to said actuator, said cam configured to move said actuator
between said first and second positions.
12. The heat sink assembly of claim 10, further comprising a frame,
said frame including a leg having an attachment end that includes
said board lock.
13. The heat sink assembly of claim 10, further comprising a frame,
said frame including a pair of legs, each said leg including a
channel for receiving a portion of said actuator.
14. The heat sink assembly of claim 10, wherein said actuator
comprises: a first post and a second post, each said post having an
upper end, a lower end, and a shaft portion therebetween, said
lower end including a retention lug; and a cross beam
interconnecting said shaft portions of said posts.
15. The heat sink assembly of claim 10, wherein said actuator
includes a retention lug receivable between said retention barbs to
spread said retention barbs when said actuator is moved to said
second position.
16. The heat sink assembly of claim 10, further comprising a cam
coupled to said actuator, said cam configured to move said actuator
between said first and second positions, said actuator including
retention lugs received in recesses in said retention barbs to hold
said actuator in said second position when said cam is rotated from
said second position to said first position.
17. The heat sink assembly of claim 10, further comprising a cam
coupled to said actuator, wherein said cam engages a resilient beam
on said actuator to bias said heat sink base toward the circuit
board component.
18. A heat sink retention assembly comprising: a heat sink base; a
frame, said frame including a board lock configured to be received
in a circuit board; an actuator received in said frame and movable
with respect to said frame from an open position to a locked
position wherein said board lock is activated to retain said
retention assembly on the circuit board; and a cam disposed between
said frame and said actuator, said cam being rotatable from a first
position to a second position to move said actuator between said
open position and said locked position.
19. The retention assembly of claim 18, wherein said frame includes
a pair of legs, and said actuator includes a pair of posts, each
said leg including a channel for receiving a corresponding post of
said actuator.
20. The retention assembly of claim 18, wherein said actuator
comprises: a first post and a second post, each said post having an
upper end, a lower end, and a shaft portion therebetween, said
lower end including a retention lug; and a cross beam
interconnecting said shaft portions of said posts.
21. The retention assembly of claim 18, wherein said actuator
remains in said locked position when said cam is rotated from said
second position to said first position.
22. The retention assembly of claim 18, wherein said actuator
includes a resilient cross beam interconnecting first and second
posts, said resilient cross beam biasing said frame toward the
circuit board when said cam is rotated to said locked position.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates generally to heat sinks for electronic
devices, and more specifically, to mounting and retention systems
for heat sinks.
[0002] The use of heat sinks on electronic components is well
known. Typically, a heat sink is arranged in close contact with a
heat generating electronic component, such as a Central Processing
Unit (CPU). As the power density of such components increases, heat
transfer from the heat generating component to the surrounding
environment becomes more and more critical to the proper operation
of the component. Heat generated by the component is transferred to
the heat sink and then dissipated from the heat sink to the
surrounding air. One type of heat sink includes a metallic core in
the form of a base plate. Heat dissipating fins extend from the
base plate to increase the surface area of the heat sink. Heat
transferred from the component to the base plate is spread
throughout the base plate and to the fins fixed to the base plate.
To further facilitate the dissipation of heat from the electronic
component, a fan can be used to circulate air about outer surfaces
of the fins and the base of the heat sink.
[0003] In the case of a CPU, current circuit board designs
typically provide for the heat sink to be mounted directly on top
of the CPU in a retention module that is in turn mounted on the
circuit board. A spring clip or other fastening mechanism is used
to retain the heat sink in the retention module. Thus, the
installation of the heat sink is a multi-step process that involves
multiple components with both assembly time and component costs
adding to the cost of the product.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In one embodiment of the invention, a heat sink assembly for
a circuit board component is provided. The assembly includes a heat
sink base, a frame coupled to the base, and a cam positionable
relative to the base to lock the heat sink base to the circuit
board component.
[0005] Optionally, the frame includes an actuator that has a first
post and a second post. Each post has an upper end, a lower end,
and a shaft portion therebetween. The lower end includes a
retention lug. A cross beam interconnects the shaft portions of the
posts. The frame further includes a board lock and the cam includes
a lever coupled to the cam. The cam engages the actuator to move
the actuator relative to the frame from a first position to a
second position to lock the heat sink base to the circuit board
component. The heat sink remains in the locked position when the
lever is rotated from the second position to the first
position.
[0006] In another embodiment, a heat sink assembly for a circuit
board component is provided that includes a heat sink base, an
actuator coupled to the base, and a board lock for coupling the
base to the circuit board in heat transfer relationship to the
circuit board component. The board lock includes a pair of
retention barbs, and the actuator is configured to spread the pair
of retention barbs and apply a normal force to a surface of the
circuit board component when the actuator is moved from a first
position to a second position.
[0007] In another embodiment, a heat sink retention assembly is
provided that includes a heat sink base and a frame. The frame
includes a board lock that is configured to be received in a
circuit board. An actuator is received in the frame and is movable
with respect to the frame from an open position to a locked
position wherein the board lock is activated to retain the
retention assembly on the circuit board. A cam is disposed between
the frame and the actuator. The cam is rotatable from a first
position to a second position to move the actuator between the open
position and the locked position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of a heat sink integrated
retention system in accordance with an exemplary embodiment of the
present invention.
[0009] FIG. 2 is a perspective view of a frame assembly used in the
system of FIG. 1.
[0010] FIG. 3 is a perspective view of the frame member of FIG.
2.
[0011] FIG. 4 is a perspective view of the actuator of FIG. 2.
[0012] FIG. 5 is a perspective view of a cam lever in accordance
with an exemplary embodiment of the present invention.
[0013] FIG. 6 is a partial front elevational view of the cam lever
of FIG. 5 taken along sight line 6-6.
[0014] FIG. 7 is a perspective view of the heat sink assembly of
FIG. 1.
[0015] FIG. 8 is a schematic view of an assembled heat sink
integrated retention system in an unlocked state.
[0016] FIG. 9 is a schematic view of the heat sink integrated
retention system of FIG. 8 in a locked state.
[0017] FIG. 10 is a perspective view of an alternative embodiment
of a heat sink integrated retention system in accordance with the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIG. 1 illustrates a perspective view of an integrated
retention system 10 for a heat sink assembly in accordance with an
exemplary embodiment of the present invention. The integrated
retention system 10 includes a heat sink assembly 20, a fan 22, and
a housing 24. The heat sink assembly 20 includes a heat sink base
26 with a plurality of cooling fins 28 extending upwardly from the
base 26. The heat sink base 26 and the fins 28 are typically
fabricated from metal such as aluminum or copper, and further, the
heat sink base 26 and the fins 28 may be fabricated from the same
or different metals. For instance, in one embodiment the heat sink
base 26 may be made of copper while the fins 28 may be made of
aluminum.
[0019] The fan 22 is mounted above the cooling fins 28 for
circulating air about the cooling fins 28 and the heat sink base 26
to facilitate the transfer of heat from a heat generating component
(not shown). When in use, the heat sink base 26 is positioned in
contact with the heat generating component such that heat generated
by the component is transferred to the heat sink base 26 and the
cooling fins 28 and then to the surrounding air.
[0020] The housing 24 holds and mounts the heat sink assembly 20
and the fan 22 to a circuit board 30 so that the heat sink base 26
is in contact with the heat generating component, and applies a
compressive load to produce a normal contact force between the heat
sink base 26 and the heat generating component. The housing 24
includes a pair of frame assemblies 34 and a cam lever 36.
[0021] FIG. 2 illustrates one of the frame assemblies 34 which are
identical to each other. The frame assembly 34 includes a frame
member 40 and an actuator 42. The frame member 40 includes a pair
of legs 44 that each include a channel 46 that receives the
actuator 42. The actuator 42 is slidable within the channel 46
between an upper stop 48 and a lower stop 50 on each leg 44. The
frame member 40 and the actuator 42 are fabricated from a resilient
material that exhibits some degree of flexibility. In one
embodiment, the material is nylon 66.TM..
[0022] FIG. 3 illustrates the frame member 40 in detail. The frame
member 40 includes upper and lower cross members 54 and 56
respectively. Cross members 54 and 56 are substantially parallel to
each other and interconnect the legs 44. Each leg 44 includes a
slot 60 at an upper end 64 which extends downward to a ledge 68.
The ledges 68 at each of the four legs 44 cooperate to define a
platform for the fan 22 (shown in FIG. 1). The upper end 64 of each
leg 44 includes a pair of tabs 70 that retain the fan 22 when the
integrated system 10 is assembled. The legs 44 each include a cut
out 72 that defines the upper and lower actuator stops 48 and 50
respectively. Each leg 44 includes an attachment end 74 for
connecting the frame member to the circuit board 30. Each
attachment end 74 includes a board lock 78 for attachment to a
mounting hole (not shown) on the circuit board 30. The board lock
78 comprises a pair of retention barbs 79 positioned one on each
side of the channel 46 extending through the leg 44 such that the
retention barbs 79 are separable relative to each other. The
retention barbs 79 include a retaining groove 80 on an outer
surface thereof and a recess 82 within the channel 46 on an inner
surface 83 of the retention barbs 79. The retaining groove 80 and
the recess 82 cooperate to lock the legs 44 to the circuit board 30
as will be described below.
[0023] FIG. 4 is a perspective view illustrating the actuator 42 in
detail. In one embodiment, the actuator 42 is in the shape of an H
beam and includes a pair of posts 84 that are interconnected by a
substantially horizontal cross beam 86. The posts 84 are slidably
received in the channels 46 (shown in FIG. 3) of the legs 44. The
cross beam 86 is received in the cut out 72 (shown in FIG. 2) in
the legs 44. The upper and lower stops 48 and 50 (shown in FIG. 3)
in the cutout 72 interfere with the cross beam 86 to define a range
of movement of the actuator 42 within the legs 44. The posts 84
have an upper end 88 and a lower end 90. The lower end 90 of each
post 84 includes a serrated retention lug 92 that spreads the
attachment ends 74 (shown in FIG. 3) of the legs 44 when the
actuator posts 84 are drawn upward through the channel 46. The
retaining groove 80 (shown in FIG. 3) on the board locks 78 are
sized to receive a thickness of the circuit board 30 (shown in FIG.
1) to lock the legs 44 onto the circuit board 30 when the board
lock retention barbs 79 on the attachment ends 74 of the legs 44
are separated. The retention lugs 92 are configured to be retained
in the pockets 82 in the retention barbs 79 to hold the board locks
78 in a separated position. Once the board locks 78 are in the
locked position, manual thumb pressure is required to be applied to
the upper ends 88 of the posts 84 to drive the retention lugs 92
from the pockets 82 to release the integrated retention system 10
from the circuit board 30.
[0024] FIG. 5 illustrates a perspective view of the cam lever 36.
FIG. 6 illustrates a frontal view of the cam lever 36. The cam
lever 36 includes a handle 100 and a pair of lever arms 102. A cam
104 is provided at the end of each lever arm 102. Each cam 104 has
an outer periphery 105 that includes an open flat section 106
positioned between smaller raised locking flat sections 108. A disc
110 is also provided adjacent to cams 104 to provide a bearing
surface 112 for rotating the cam lever 36. A short pivot shaft 114
displaces the cam 104 from the disk 110.
[0025] When installed in the integrated system 10, the cams 104 are
positioned to engage the cross beam 86 of the actuator 42. The cam
lever 36 is rotatable from a released position to a locked
position. In the released position, the open flat section 106 of
the cam 104 faces upward and is adjacent to cross beam 86 of the
actuator 42. In the locked position, one of the raised locking flat
sections 108 engages the cross beam 86 to operate the actuator 42.
The locking flat section 108 provide a detent position so that the
cam lever 36 will remain in the locked position once rotated to the
locked position.
[0026] FIG. 7 is a perspective view of the heat sink assembly 20.
The heat sink assembly 20 includes cam guides 122 formed in fins
127 and 128 and channels 124 formed between fins 128 and 129. The
cam guides 122 are sized to receive the cam lever pivot shaft 114.
The channels 124 are provided to receive the cams 104. The heat
sink base also includes clearance notches 126 that receive the
frame legs 44 when the integrated system 10 is assembled.
[0027] In assembling the integrated system 10, the upper ends 88 of
the actuator posts 84 (shown in FIG. 4) are inserted through the
mounting holes 23 (see FIG. 1) in the fan 22. The actuator 42 is
then joined with the frame member 40 by inserting the posts 84 of
the actuator 42 into the channels 46 of the legs 44 so that the
cross beam 86 is positioned within the cutout 72 in the legs 44 and
with the lower end 90 of the actuator posts 84 extended from the
board locks 78.
[0028] The cam lever 36 is placed over the frame assemblies 34 such
that the upper cross members 54 is positioned between the lever
arms 102 while the cam 104 is positioned between the lower cross
members 56. The cam lever 36 is then rotated to a position where
the open flat section 106 is facing upward. Finally, the fan 22 is
held in place between the ledges 68 and the tabs 70 on the legs 44
while the frame assemblies 34 are placed onto the heat sink
assembly 20 with the cams 104 and the actuator cross beams 86
received in the heat sink channels 124. The integrated system 10
can now be mounted on the circuit board 30 and locked into place by
rotation of the cam lever 36.
[0029] FIGS. 8 and 9 are schematic views of an assembled integrated
retention system 10 illustrating the operation of the cam 104 and
actuator 42 in mounting the integrated system 10 for cooling a heat
generating component 140. In FIG. 8, the cam 104 is positioned in
the heat sink channel 124. The actuator cross beam 86 is engaged
with the cam 104 at the open flat section 106. The integrated
system 10 is positioned on the circuit board 30 with the heat sink
base 26 in contact with the heat generating component 140. The
upper ends 88 of the actuator posts 84 are depressed such that the
board lock retention barbs 79 are not separated and pass
unrestricted through the circuit board mounting holes 130. In this
condition, the integrated retention system 10 is not locked on the
circuit board 30. From this position, rotation of the cam lever 36
in the direction of arrow A drives the actuator 42 upward which
causes the retention barbs 79 to separate to engage and retain the
circuit board 30 in the retaining groove 80 (shown in FIG. 3) to
lock the system 10 to the circuit board 30.
[0030] In FIG. 9, the cam lever 36 has been rotated in the
direction of arrow A to lock the integrated retention system 10 to
the circuit board 30. When the cam lever 36 is rotated, the locking
flat section 108 on the cam 104 engages the actuator cross beam 86
driving the actuator posts 84 upward. The upward movement of the
actuator posts 84 brings the retention lugs 92 (shown in FIG. 4)
into engagement with the attachment ends 74, and the retention
barbs 79 of board locks 78 (shown in FIG. 3). The retention lugs 92
separate the retention barbs 79 into the circuit board mounting
holes 130 such that the retention groove 80 (shown in FIG. 3)
retains the circuit board 30 locking the integrated system 10 to
the circuit board 30. The lugs 92 are received in the pockets 82
(shown in FIG. 3) of the retention barbs 79 so that the integrated
system 10 remains locked onto the circuit board 30 even if the cam
lever 36 is rotated in the direction of arrow B to release the
actuator 42. When it is desired to unlock the integrated system 10,
physical thumb pressure is applied to the upper ends 88 of the
actuator posts 84 to drive the actuator posts 84 downward,
disengaging the lugs 92 from the pockets 82 of the retention barbs
79. The retention barbs 79 then return to their unseparated
position allowing removal of the integrated system 10 from the
circuit board 30.
[0031] As shown in FIG. 9, when the cam lever 36 is rotated in the
direction of arrow A to lock the integrated system 10 to the
circuit board 30, the actuator cross beam 86 is elastically
deflected in an upward direction by the cam 104. The combined
rotation of the cam lever 36 and the deflection of the cross beam
86 generate a downward compressive force resulting in a normal
contact force between the heat sink base 26 and a heat generating
component 140.
[0032] FIG. 10 illustrates an integrated heat sink and retention
system 150. The integrated heat sink and retention system 150 is
similar to the integrated system 10 and corresponding elements
between the integrated systems 150 and 10 are given the same
reference numbers in FIG. 10. In the integrated system 150, the
heat sink base 26 is without fins. The integrated system 150
includes the heat sink base 26, a fan 22 and a housing 24. The
system is mounted to the circuit board 30. The cam lever 36 drives
from the heat sink base 26 to rotate cams 104. The cams 104 engage
the cross beams 86 to operate the actuator 42 within the frame
members 40 to lock the integrated system 150 to the circuit board
30 as previously described. The cams 104 engage the actuator cross
beam 86 which elastically deforms to generate a downward
compressive force from the heat sink base 26 the heat generating
component (not shown in FIG. 10).
[0033] The embodiments thus described provide a heat sink and
housing integrated into a single unit. The integrated system
provides a cost effective alternative to attachment mechanisms
requiring clips and other hardware. Having no hardware requirement,
use of the integrated retention system also reduces product
assembly time.
[0034] While the invention has been described in terms of various
specific embodiments, those skilled in the art will recognize that
the invention can be practiced with modification within the spirit
and scope of the claims.
* * * * *