U.S. patent application number 11/831603 was filed with the patent office on 2009-02-05 for apparatus for transferring between two heat conducting surfaces.
This patent application is currently assigned to ADC TELECOMMUNICATIONS, INC.. Invention is credited to Michael J. Wayman.
Application Number | 20090032218 11/831603 |
Document ID | / |
Family ID | 40337033 |
Filed Date | 2009-02-05 |
United States Patent
Application |
20090032218 |
Kind Code |
A1 |
Wayman; Michael J. |
February 5, 2009 |
APPARATUS FOR TRANSFERRING BETWEEN TWO HEAT CONDUCTING SURFACES
Abstract
An apparatus for transferring heat between two surfaces is
provided. The apparatus includes a first support plate, a sheet of
thermal material adjacent the first support plate, and a second
support plate adjacent the sheet of thermal material, wherein the
sheet of thermal material is disposed between the first support
plate and the second support plate. The apparatus also includes at
least one bolt inserted through each of the first support member,
the sheet of thermal material, and the second support plate, the at
least one bolt configured to be secured into a chassis. Finally, at
least one spring is disposed between a shoulder of the at least one
bolt and the second support plate.
Inventors: |
Wayman; Michael J.;
(Waconia, MN) |
Correspondence
Address: |
FOGG & POWERS LLC
5810 W 78TH STREET, SUITE 100
MINNEAPOLIS
MN
55439
US
|
Assignee: |
ADC TELECOMMUNICATIONS,
INC.
Eden Prairie
MN
|
Family ID: |
40337033 |
Appl. No.: |
11/831603 |
Filed: |
July 31, 2007 |
Current U.S.
Class: |
165/80.3 |
Current CPC
Class: |
H05K 7/2049 20130101;
F28F 13/00 20130101; H05K 7/20445 20130101 |
Class at
Publication: |
165/80.3 |
International
Class: |
F28F 7/00 20060101
F28F007/00 |
Claims
1. An apparatus for transferring heat between two surfaces, the
apparatus comprising: a first support plate; a sheet of thermal
material adjacent the first support plate; a second support plate
adjacent the sheet of thermal material, wherein the sheet of
thermal material is disposed between the first support plate and
the second support plate; at least one bolt inserted through each
of the first support member, the sheet of thermal material, and the
second support plate, the at least one bolt configured to be
secured into a chassis; and at least one spring disposed between a
shoulder of the at least one bolt and the second support plate.
2. The apparatus of claim 1, wherein the sheet of thermal material
is composed of thermal pyrolytic graphite.
3. The apparatus of claim 1, wherein the first support plate and
the second support plate are aluminum.
4. The apparatus of claim 1, wherein at least one side of the sheet
of thermal material is beveled.
5. The apparatus of claim 1, wherein the spring is a helical
spring.
6. The apparatus of claim 1, wherein the sheet of thermal material
is configured to transfer heat between two surfaces which are at an
angle of 90 degrees relative to each other.
7. The apparatus of claim 1, wherein the back support, the sheet of
thermal material, and the front support are configured to translate
along the at least one bolt and against the at least one
spring.
8. The apparatus of claim 1, wherein the at least one spring is
configured to apply pressure for the sheet of thermal material
against at least one heat conducting surface.
9. The apparatus of claim 1, wherein the sheet of thermal material
is configured to transfer heat from a first side to a second side
of the sheet.
10. The apparatus of claim 1, wherein the at least one bolt
comprises a first bolt and a second bolt, and wherein an axis
intersecting the first bolt and the second bolt is aligned with at
least one side of the sheet of thermal material that is configured
to contact a heat conducting surface.
11. An apparatus for transferring heat between two surface, the
apparatus comprising: a thermal material having a first thermal
conductivity in one plane and a second thermal conductivity in a
direction normal to the plane, the first thermal conductivity being
greater than a the second thermal conductivity; at least one
fastener configured to fasten the thermal material to a structure,
the at least one fastener configured to allow translational
movement of the thermal material; and at least one spring disposed
between the at least one fastener and the thermal material, the at
least one spring configured to apply pressure for the sheet of
thermal material against at least one heat conducting surface when
contact between the at least one heat conducting surface and the
thermal material occurs.
12. The apparatus of claim 11, wherein the thermal material is
formed into a sheet.
13. The apparatus of claim 11, wherein thermal material is composed
of thermal pyrolytic graphite.
14. The apparatus of claim 11, further comprising a first support
plate and a second support plate, wherein the thermal material is
disposed between the first support plate and the second support
plate.
15. The apparatus of claim 11, wherein at least one side of the
thermal material is beveled.
16. The apparatus of claim 1, wherein the spring is a helical
spring.
17. The apparatus of claim 11, wherein the thermal material is
configured to transfer heat between two surfaces which are at an
angle of 90 degrees relative to each other.
18. The apparatus of claim 11, wherein the sheet of thermal
material is configured to transfer heat from a first side to a
second side of the sheet.
19. The apparatus of claim 11, wherein the at least one fastener
comprises a first bolt and a second bolt, and wherein an axis
intersecting the first bolt and the second bolt is aligned with at
least one side of the thermal material that is configured to
contact a heat conducting surface.
20. An apparatus for transferring heat between two surfaces, the
apparatus comprising: a first support sheet having at least one
aperture; a sheet of thermal material having at least one aperture,
the sheet of thermal material adjacent the first sheet of metal
wherein the at least one aperture of the first sheet of metal and
the sheet of thermal material are aligned, the sheet of thermal
material having a first thermal conductivity in a plane parallel to
the sheet of metal and a second thermal conductivity in a direction
normal to the plane, the first thermal conductivity being greater
than a the second thermal conductivity; a second support sheet
having at least one aperture, the second support sheet adjacent the
sheet of thermal material, wherein the sheet of thermal material is
disposed between the first support plate and the second support
plate and the at least one aperture in the second support sheet is
aligned with the at least one apertures of the first support sheet
and the sheet of thermal material; at least one bolt, each of the
at least one bolts inserted through one of the least one apertures
of the second support sheet, the sheet of thermal material, and the
first support sheet; and at least one spring disposed between a
shoulder of the at least one bolt and the second support plate.
21. The apparatus of claim 20, wherein the thermal material is
thermal pyrolytic graphite.
22. The apparatus of claim 20, wherein the first support sheet and
the second support sheet are composed of metal.
Description
BACKGROUND
[0001] For many devices removing heat is essential in order to keep
the device operating effectively. To aid in removal of heat from
the device, generally a heat sink is coupled to the device. The
heat sink is generally sized according to the amount of heat that
the device will be dissipating. In many cases, however, space
around the device generating heat is limited. Generally, however,
there are other heat sinks or possible heat dissipating materials
near the heat sink. Each of these additional heat sinks may not be
coupled to a device generating the same amount of heat, and may
have extra cooling capacity.
[0002] The heat dissipation problems are increased when using heat
sinks with electronic devices, because many electronic devices
generate a large amount of heat in a relatively small area. For the
reasons stated above, and for other reasons stated below which will
become apparent to those skilled in the art upon reading and
understanding the present specification, there is a need in the art
for an apparatus and method for improving the heat dissipation of
devices within a chassis.
SUMMARY
[0003] An apparatus for transferring heat between two surfaces is
provided. The apparatus includes a first support plate, a sheet of
thermal material adjacent the first support plate, and a second
support plate adjacent the sheet of thermal material, wherein the
sheet of thermal material is disposed between the first support
plate and the second support plate. The apparatus also includes at
least one bolt inserted through each of the first support member,
the sheet of thermal material, and the second support plate, the at
least one bolt configured to be secured into a chassis. Finally, at
least one spring is disposed between a shoulder of the at least one
bolt and the second support plate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The present invention can be more easily understood, and
further advantages and uses thereof are more readily apparent, when
considered in view of the detailed description and the following
figures in which:
[0005] FIG. 1 is an exploded view of one embodiment of a heat
transfer device for transferring heat between two surfaces;
[0006] FIG. 2A is a side view of the heat transfer device of FIG.
1;
[0007] FIG. 2B is a side view of the heat transfer device of FIG.
1;
[0008] FIG. 2C is a side view of the heat transfer device of FIG.
1;
[0009] FIG. 2D is a perspective view of the heat transfer device of
FIG. 1; and
[0010] FIG. 3 is a perspective view of the heat transfer device of
FIG. 1 in a chassis.
[0011] In accordance with common practice, the various described
features are not drawn to scale but are drawn to emphasize specific
features relevant to the present invention.
DETAILED DESCRIPTION
[0012] In the following detailed description, reference is made to
the accompanying drawings that form a part hereof, and in which is
shown by way of illustration specific illustrative embodiments in
which the method and system may be practiced. These embodiments are
described in sufficient detail to enable those skilled in the art
to practice the invention, and it is to be understood that other
embodiments may be utilized and that logical, mechanical and
electrical changes may be made without departing from the scope of
the present invention. The following detailed description is,
therefore, not to be taken in a limiting sense.
[0013] Embodiments of the present invention provide for an
apparatus for transferring heat between two surfaces. The apparatus
includes a sheet of thermal material contacts one heat conducting
surface on one side and a second heat conducting surface on the
other side. The sheet of thermal material is part of an assembly
and is placed between two sheets of metal to support the thermal
material. The assembly of the sheet of metal and the thermal
material are mounted via a fastener to a desired structure and a
spring is inserted between the fastener and the assembly. The
assembly can pivot relative to the fastener and the mounting
structure to allow the thermal material to make solid contact with
each heat conducting surface, yet still allow one or both heat
conducting surfaces to be moved out of contact with the thermal
material when not transferring heat.
[0014] FIG. 1 is an exploded view of one embodiment of a heat
transfer device 100 for transferring heat between two heat
dissipation members. Heat transfer device 100 includes a back
support plate 102, a sheet of thermal material 104, a front support
plate 106, two fasteners 108, and two springs 110. Heat transfer
device 100 uses thermal material 104 to facilitate transfer of
thermal energy (heat) from one surface to a nearby surface.
[0015] Thermal material 104 acts as the heat transfer medium for
heat transfer device 100. Heat transfer occurs through contact
between thermal material 104 and each heat conducting member. One
heat conducting member (shown in FIG. 3) contacts thermal material
104 on first side 112 and the other heat conducting member (also
shown in FIG. 3) contacts thermal material 104 on a second side
114. In one embodiment, the two heat conducting members are
oriented at a right angle with respect to one another. Thus, heat
transfer device 100 is oriented at approximately a 45 degree angle
with respect to each heat conducting member. To assure good contact
with each heat conducting member, each side 112, 114 of heat
transfer device is beveled. Thus each side 112, 114 can make flat
contact with each heat conducting member.
[0016] Thermal material 104 is a material having a high thermal
conductivity in the direction of desired propagation of heat. In
this embodiment, the heat is transferred from side 112 to side 114,
thus thermal material 104 has a high thermal conductivity in the
a-direction. The higher the thermal conductivity of thermal
material 104, the better propagation of heat between the two heat
conducting members. Most materials having the high thermal
conductivity desired for this application, however, do not possess
the strength to withstand pressing at an angle against another
surface.
[0017] In one embodiment, thermal material 104 is a material having
a high thermal conductivity in the a-b plane. For example, in one
embodiment, thermal material 104 is thermal pyrolytic graphite
(TPG). TPG is commercially available from Momentive Performance
Materials in Wilton, Conn. TPG may be referred to as highly
oriented pyrolytic graphite (HOPG), or compression annealed
pyrolytic graphite (CAPG), and refers to graphite materials
consisting of crystallites of considerable size, the crystallites
being highly aligned or oriented with respect to each other and
having well ordered carbon layers or a high degree of preferred
crystallite orientation, with an in-plane thermal conductivity
greater than 1000 W/m-K. In one embodiment, TPG has an in-plane
thermal conductivity of approximately 1,500 W/m-K. Here, TPG is
oriented such that the in-plane of the TPG is aligned with the a-b
plane in FIG. 1. Thus, the TPG efficiently propagates heat between
the first side 112 of thermal material 104 and the second side 114.
In an alternative embodiment, thermal material 104 is a
diamond-like-carbon (DLC) or other diamond material having a high
in-plane thermal conductivity.
[0018] For extra support, thermal material 104 is placed between
back support 102 and front support 106. Each of back support 102
and front support 106 is composed of a rigid material capable of
withstanding pressure placed by fasteners 108 with minimal bending.
The minimal bending helps prevent the brittle thermal material 104
from cracking. In one embodiment, back plate 102 and front plate
106 are aluminum. In an alternative embodiment, back plate 102 is
copper and front plate 106 is steel. Both back plate 102 and front
plate 106 are generally flat sheets having two apertures 116 for
accepting fasteners 108. As shown in FIG. 1, front sheet 106 has a
curved top and bottom flange for additional strength in maintaining
the shape of front plate 106.
[0019] In one embodiment, TPG is formed as described in U.S. Pat.
No. 5,863,467 which is hereby incorporated herein by reference.
Briefly, to manufacture heat transfer device 100 with TPG,
pyrolytic graphite is deposited between back support member 102 and
front support member 106. Heat transfer device 100 is then heat
treated to form the pyrolytic graphite into a crystal structure.
The resulting crystal structure, TPG, has a high in plane
conductivity.
[0020] Each fastener 108 attaches thermal transfer device 100 to a
structure. In this embodiment, each fastener 108 is a bolt which is
placed through an aperture 116 of each of front support 102,
thermal material 104, and back support 106. In one embodiment,
fastener 108 has a shoulder for spring 110 to seat upon. In this
embodiment, spring 110 is a helical coil spring placed around
fastener 108 and between the shoulder of fastener 108 and front
plate 106. In an alternative embodiment, spring 110 contacts
shoulder of fastener 108, is only along the side of fastener 108
and not around fastener 108. In other embodiments, spring 110 is
mounted between fastener 108 and front plate 106 in other manners
as known to those skilled in the art. Additionally, in other
embodiments, spring 110 is a metal leaf spring or a compliant
rubber bushing. Further, although as shown in FIG. 1, fasteners 108
are bolts, other fasteners could be used. For example, in an
alternative embodiment, fasteners 108 are screws or rivots. In
another embodiment, fasteners 108 attach directly to back plate 102
on one end and to the structure which heat transfer device 100 is
mounted to on another end. Thus, back plate 102, thermal material
104, and/or front plate 106 do not have apertures for
fasteners.
[0021] Referring now to FIGS. 2A, 2B, 2C, and 2D, side and
perspective views of heat transfer device 100 are shown. FIG. 2A
illustrates a view of heat transfer device 100 where back plate 102
is forward. As can be seen, along with the beveled edges of thermal
material 104, both back plate 102 also has beveled edges.
Additionally, back plate 102 has a slightly smaller width than the
sheet of thermal material 104. The slightly smaller width of back
plate 102 aligns beveled edges to enable heat transfer device 100
to contact both the first and the second heat conducting
members.
[0022] FIG. 2B illustrates a side view of heat transfer device 100
showing springs 110 seated against both front plate 106 and
fasteners 108. As shown each spring 110 is in a position of rest.
Springs 110 ensure solid contact between heat transfer device 100
and each heat conducting member while allowing flexibility in the
positioning of heat transfer device 100 and each heat conducting
member. When heat transfer device 100 is pressed against each heat
conducting member (or each heat conducting member is pressed
against heat transfer device), the assembly of back plate 102,
thermal material 104, and front plate 106, the assembly compresses
springs 110 against fasteners 108. Fasteners 108 and therefore heat
transfer device 100 are set such that springs 110 are partially
compressed when heat transfer device 100 is in a resting contact
position with each heat conducting member. Thus, springs 110
maintain a constant pressure for heat transfer device 100 against
each heat conducting member.
[0023] Referring now to FIG. 3, one embodiment of heat transfer
device 100 in a chassis 300. In this embodiment, chassis 300 holds
electronics which dissipate heat to the outside of chassis 300 with
a plurality of heat sinks 302, 304. Each of heat sinks 302, 304 is
located on a door which pivots open to allow access to the inside
of chassis 300. Heat sink 302 has an electronics module 306 mounted
thereupon. To increase the heat dissipation from electronics module
306, heat transfer device 100 transfers heat from (warmer) heat
sink 302 to (cooler) heat sink 304.
[0024] Heat transfer device 100 is mounted in a corner between heat
sink 302 and heat sink 304. Fasteners 108 of heat transfer device
100 are secured into a portion of chassis 300. When doors are
opened heat transfer device 100 is not in contact with heat sinks
302, 304, and heat transfer device 100 remains secured to chassis
300 with springs 110 in a resting position. When each door of heat
sink 302 and 304 is closed, a heat conductive surface of each heat
sink 302, 304 comes into contact with the beveled edge of thermal
material 104. As each heat sink 302, 304 contacts heat transfer
device 100, heat transfer device is allowed to translate along each
fastener 108 and pivot slightly. This allows heat transfer device
100 to adjust to each heat sink 302, 304 as they move and contact
heat transfer device 100.
[0025] Advantageously, heat transfer device 100 enables heat
transfer between two heat conducting members without permanent
connection to the heat conducting members. One or both heat
conducting members to be movable, while still allowing each heat
conducting member to transfer heat when in contact with heat
transfer device 100. As shown in FIG. 3, both fasteners 108 are
aligned vertically with one another. This permits heat transfer
device 100 to pivot horizontally about an axis intersecting each
fastener 108. Additionally, each fastener 108 is located in the
middle horizontally of front plate 106, thermal material 104, and
back plate 102, thus enabling heat transfer device 100 to pivot
equally in either direction. In an alternative embodiment, a single
fastener is used, thus allowing easier pivoting of heat transfer
device 100 in the vertical and horizontal directions. In other
embodiments, fasteners 108 are located in different locations to
produce different pivot axis, or no pivot axis at all.
[0026] Although FIG. 3 heat transfer device 100 is illustrated as
transferring heat between two surfaces which are angled at 90
degrees with respect to one another, other angles of surfaces could
also be used that are less than 180 degrees. For example, in one
embodiment, heat sink 302 and heat sink 304 are at a 45 degree
angle away from each other. Here, the angle of the bevel on thermal
material 104 would be match the angle of each heat conducting
surface.
[0027] In an alternative embodiment, multiple heat transfer devices
are used to transfer heat between two surfaces. Multiple heat
transfer devices are used, for example, to conform to a non-flat
surface. When the surface or surfaces from which heat is
transferred between have variations, a different heat transfer
device can be used to match the different angled section of the
surface. Additionally, the length and width of the heat transfer
device, or devices can be changed to conform to the surfaces, the
amount of heat transfer, or surrounding devices. Finally, in one
embodiment, a strip of conductive pad material is used along each
edge of heat transfer device 100 to improve contact with a heat
conducting member.
[0028] Further, although FIG. 3 illustrates heat transfer device
100 as transferring heat between two heat sinks 302, 304, other
heat conducting members could be used. For example, in one
embodiment, heat transfer device 100 transfers heat between a heat
sink and a chassis. In other embodiments, heat transfer device 100
transfer heat between a heat sink and a cooling liquid. Finally, in
an alternative embodiment, springs 110 are located on the back
plate 102 of heat transfer device. The precise location of springs
110 is not critical, as long as springs 110 provide coupling
between fasteners 108 and thermal material 104, and force for
thermal material 104 against a heat conducting member.
[0029] Although specific embodiments have been illustrated and
described herein, it will be appreciated by those of ordinary skill
in the art that any arrangement, which is calculated to achieve the
same purpose, may be substituted for the specific embodiment shown.
This application is intended to base any adaptations or variations
of the present invention. Therefore, it is manifestly intended that
this invention be limited only by the claims and the equivalents
thereof.
* * * * *