U.S. patent application number 15/456360 was filed with the patent office on 2018-09-13 for thermal interface structure resilient to shearing forces.
The applicant listed for this patent is Jones Tech (USA), Inc.. Invention is credited to Xiaoning Wu.
Application Number | 20180259271 15/456360 |
Document ID | / |
Family ID | 63446391 |
Filed Date | 2018-09-13 |
United States Patent
Application |
20180259271 |
Kind Code |
A1 |
Wu; Xiaoning |
September 13, 2018 |
THERMAL INTERFACE STRUCTURE RESILIENT TO SHEARING FORCES
Abstract
Providing a thermal interface structure can include: forming a
thermal interface material for thermally coupling a heat-generating
structure to a heat-dissipating structure such that the thermal
interface material capable of enduring a repeated shearing force
caused by sliding the heat-generating structure against the
heat-dissipating structure; and forming an adhesive material for
holding the thermal interface material in place on the
heat-dissipating structure.
Inventors: |
Wu; Xiaoning; (Beijing,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Jones Tech (USA), Inc. |
Cupertino |
CA |
US |
|
|
Family ID: |
63446391 |
Appl. No.: |
15/456360 |
Filed: |
March 10, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 23/373 20130101;
F28F 2013/006 20130101; H01L 23/3733 20130101; H01L 23/42
20130101 |
International
Class: |
F28F 19/04 20060101
F28F019/04; F28F 13/00 20060101 F28F013/00; F28F 21/02 20060101
F28F021/02 |
Claims
1. A thermal interface structure, comprising: a thermal interface
material for thermally coupling a heat-generating structure to a
heat-dissipating structure, the thermal interface material capable
of enduring a repeated shearing force caused by sliding the
heat-generating structure against the heat-dissipating structure;
and an adhesive material for holding the thermal interface material
in place on the heat-dissipating structure.
2. The thermal interface structure of claim 1, wherein the thermal
interface material is positioned on a beveled lead-in of the
heat-dissipating structure.
3. The thermal interface structure of claim 1, wherein the thermal
interface material comprises a foam-like synthetic graphite.
4. The thermal interface structure of claim 1, wherein the thermal
interface material has compression ratio of substantially between
30 and 80 percent.
5. The thermal interface structure of claim 1, wherein the thermal
interface material is selected to provide a substantially low
thermal resistance by substantially filling an air gap between the
heat-generating structure and the heat-dissipating structure.
6. The thermal interface structure of claim 1, wherein the adhesive
material comprises a pressure-sensitive adhesive.
7. The thermal interface structure of claim 1, wherein the adhesive
material comprises a hot-melt adhesive.
8. The thermal interface structure of claim 1, wherein the adhesive
material is selected to provide a balance between a thermal
performance and a mechanical bonding performance of the thermal
interface structure.
9. The thermal interface structure of claim 1, wherein the adhesive
material substantially covers an entire surface of the thermal
interface material.
10. The thermal interface structure of claim 1, wherein the
adhesive material substantially covers only a portion of the
thermal interface material corresponding to a contact area between
the heat-generating structure and the heat-dissipating
structure.
11. The thermal interface structure of claim 1, further comprising
a plastic film for protecting the thermal interface material from
the repeated shearing force.
12. The thermal interface structure of claim 11, wherein the
plastic film covers only portions of the thermal interface material
substantially outside of a contact area between the heat-generating
structure and the heat-dissipating structure.
13. A method for providing a thermal interface structure,
comprising: forming a thermal interface material for thermally
coupling a heat-generating structure to a heat-dissipating
structure such that the thermal interface material capable of
enduring a repeated shearing force caused by sliding the
heat-generating structure against the heat-dissipating structure;
and forming an adhesive material for holding the thermal interface
material in place on the heat-dissipating structure.
14. The method of claim 13, wherein forming a thermal interface
material comprises forming a thermal interface material on a
beveled lead-in of the heat-dissipating structure.
15. The method of claim 13, wherein forming a thermal interface
material comprises forming a foam-like synthetic graphite.
16. The method of claim 13, wherein forming a thermal interface
material comprises forming a thermal interface material having a
compression ratio of substantially between 30 and 80 percent.
17. The method of claim 13, wherein forming a thermal interface
material comprises forming a thermal interface material to provide
a substantially low thermal resistance by substantially filling an
air gap between the heat-generating structure and the
heat-dissipating structure.
18. The method of claim 13, wherein forming an adhesive material
comprises forming a pressure-sensitive adhesive.
19. The method of claim 13, wherein forming an adhesive material
comprises forming a hot-melt adhesive.
20. The method of claim 13, wherein forming an adhesive material
comprises forming an adhesive material selected to provide a
balance between a thermal performance and a mechanical bonding
performance of the thermal interface structure.
21. The method of claim 13, wherein forming an adhesive material
comprises forming an adhesive material substantially covering an
entire surface of the thermal interface material.
22. The method of claim 13, wherein forming an adhesive material
comprises forming an adhesive material substantially covering only
a portion of the thermal interface material corresponding to a
contact area between the heat-generating structure and the
heat-dissipating structure.
23. The method of claim 13, further comprising forming a plastic
film for protecting the thermal interface material from the
repeated shearing force.
24. The method of claim 23, wherein forming a plastic film
comprises forming a plastic film covering only portions of the
thermal interface material substantially outside of a contact area
between the heat-generating structure and the heat-dissipating
structure.
Description
BACKGROUND
[0001] A thermal interface material may be used to thermally couple
a heat-generating component to a heat-dissipating component. For
example, a thermal interface material may be used to thermally
couple an electronics module to a heat sink.
[0002] A thermal interface material can be subjected to shearing
forces during normal operation. For example, a removable
electronics module can impart shearing forces on a thermal
interface material of a heat sink as the removable electronics
module is repeatedly installed and removed from contact with the
heat sink. The shearing forces can damage the thermal interface
material, create air gaps, reduce the thermal transfer efficiency
of the thermal interface material, and cause failures in electronic
systems.
SUMMARY
[0003] In general, in one aspect, the invention relates to a
thermal interface structure. The thermal interface structure can
include: a thermal interface material for thermally coupling a
heat-generating structure to a heat-dissipating structure while
enduring a repeated shearing force caused by sliding the
heat-generating structure against the heat-dissipating structure;
and an adhesive material for holding the thermal interface material
in place on the heat-dissipating structure.
[0004] In general, in another aspect, the invention relates to a
method for providing a thermal interface structure. The method can
include: forming a thermal interface material for thermally
coupling a heat-generating structure to a heat-dissipating
structure such that the thermal interface material is capable of
enduring a repeated shearing force caused by sliding the
heat-generating structure against the heat-dissipating structure;
and forming an adhesive material for holding the thermal interface
material in place on the heat-dissipating structure.
[0005] Other aspects of the invention will be apparent from the
following description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the present invention are illustrated by way
of example, and not by way of limitation, in the figures of the
accompanying drawings and in which like reference numerals refer to
similar elements.
[0007] FIGS. 1A-1D illustrate a variety of embodiments of a thermal
interface structure resilient to shearing forces.
[0008] FIG. 2 illustrates an application of the thermal interface
structure of FIG. 1A in system in which it is subject to repeated
shearing forces.
[0009] FIG. 3 illustrates an application of the thermal interface
structure of FIG. 1B in system in which it is subject to repeated
shearing forces.
[0010] FIG. 4 illustrates an application of the thermal interface
structure of FIG. 1C in system in which it is subject to repeated
shearing forces.
[0011] FIG. 5 illustrates an application of the thermal interface
structure of FIG. 1D in system in which it is subject to repeated
shearing forces.
[0012] FIG. 6 illustrates a method for providing a thermal
interface structure in one or more embodiments.
DETAILED DESCRIPTION
[0013] Reference will now be made in detail to the various
embodiments of the present disclosure, examples of which are
illustrated in the accompanying drawings. Like elements in the
various figures are denoted by like reference numerals for
consistency. While described in conjunction with these embodiments,
it will be understood that they are not intended to limit the
disclosure to these embodiments. On the contrary, the disclosure is
intended to cover alternatives, modifications and equivalents,
which may be included within the spirit and scope of the disclosure
as defined by the appended claims. Furthermore, in the following
detailed description of the present disclosure, numerous specific
details are set forth in order to provide a thorough understanding
of the present disclosure. However, it will be understood that the
present disclosure may be practiced without these specific details.
In other instances, well-known methods, procedures, components,
have not been described in detail so as not to unnecessarily
obscure aspects of the present disclosure.
[0014] FIG. 1A illustrates a thermal interface structure 10 in one
or more embodiments. The thermal interface structure 10 includes a
thermal interface material 12 for thermally coupling a
heat-generating structure to a heat-dissipating structure. The
thermal interface material 12 is capable of enduring a repeated
shearing force caused by sliding a heat-generating structure
against a heat-dissipating structure. The thermal interface
structure 10 includes an adhesive material 14 for holding the
thermal interface material 12 in place on a heat-dissipating
structure.
[0015] In one or more embodiments, the thermal interface material
12 is a foam-like synthetic graphite. The thermal interface
material 12 can be a foam-like graphite film with a low density.
The thermal interface material 12 can be a single layer of
foam-like graphite film. The thermal interface material 12 can
include multiple layers of foam-like graphite films stacked.
[0016] The thermal interface material 12 can be a synthetic
graphite that is converted by a polymer film after high temperature
treatment. The polymer film for heat treatment can be selected from
one or combination of polymide (PI), polybenzoxazole (PBO)
polybenzobisoxazole (PBBO), polybenzothiazole (PBT),
polybenzobisthiazole (PBBT), polyamide (PA), etc.
[0017] In one or more embodiments, the thermal interface material
12 has compression ratio of between 30 and 80 percent. The thermal
interface material 12 provides low thermal resistance by filling an
air gap between a heat-generating structure and a heat-dissipating
structure.
[0018] In one or more embodiments, the thermal interface material
12 is 200 micrometers thick. The thermal interface material 12 can
have a density of less than 0.5 grams per cubic centimeter and be
compressible.
[0019] In one or more embodiments, the adhesive material 14 is a
pressure-sensitive adhesive. The adhesive material 14 can be an
acrylic-based pressure sensitive adhesive. The adhesive material 14
can be a silicone rubber-based pressure-sensitive adhesive. The
adhesive material 14 can be a combination of acrylic-based and
silicone rubber-based pressure-sensitive adhesives.
[0020] In one or more embodiments, the adhesive material 14 is a
hot-melt adhesive. The adhesive material 14 can be a combination of
a pressure sensitive adhesive and a hot-melt adhesive.
[0021] In one or more embodiments, the adhesive material 14 is
selected to provide a balance between a thermal performance and a
mechanical bonding performance. For example, the adhesive material
14 can be a non-thermally conductive adhesive that increases
mechanical bonding performance or a thermally conductive adhesive
that increases thermal coupling performance.
[0022] In the embodiment of FIG. 1A, the adhesive material 14
substantially covers an entire surface area of the thermal
interface material 12. In one or more embodiments, the adhesive
material 14 is 5 micrometers thick.
[0023] FIG. 1B illustrates an embodiment of the thermal interface
structure 10 in which the adhesive material 14 covers only a
portion of the surface area of the thermal interface material 12 as
indicated by the adhesive areas 14a-14c. In one or more
embodiments, the adhesive area 14b corresponds to a contact area
between a heat-generating structure and a heat-dissipating
structure.
[0024] FIG. 1C illustrates an embodiment of the thermal interface
structure 10 that includes a plastic film 16a-16b for protecting
the thermal interface material 12 from repeated shearing forces. In
one or more embodiments, the plastic film 16a-16b covers only
portions of the thermal interface material 12 that are
substantially outside of a contact area between a heat-generating
structure and a heat-dissipating structure.
[0025] The plastic film 16a-16b can include a plastic or a metal
film. For example, the plastic film 16a-16b can include a polyimide
tape, a polyethylene terephthalate (PET) tape, etc. The plastic
film 16a-16b can include a pressure sensitive adhesive, e.g., an
acrylic-based pressure sensitive adhesive, a silicone-based
pressure sensitive adhesive, etc. In one or more embodiments, the
plastic film 16a-16b is 10 micrometers thick.
[0026] FIG. 1D illustrates an embodiment of the thermal interface
structure 10 in which the adhesive areas 14a-14c cover only a
portion of the surface area of the thermal interface material 12
and which includes the plastic film 16a-16b covering only portions
of the thermal interface material 12 that are substantially outside
of a contact area between a heat-generating structure and a
heat-dissipating structure.
[0027] FIG. 2 illustrates an application in which the thermal
interface structure 10 of FIG. 1A is positioned on a beveled
lead-in 24 of a heat-dissipating structure 22. The beveled lead-in
24 facilitates repeated coupling and decoupling of a
heat-generating structure 20 to and from the heat-dissipating
structure 22 by the application of shearing forces to the
heat-generating structure 20. The thermal interface structure 10
yields low thermal resistance between the heat-dissipating
structure 22 and the heat-generating structure 20 by filling air
gaps between the heat-dissipating structure 22 and the
heat-generating structure 20.
[0028] For example, the heat-generating structure 20 can be a
removable electronics component that can be repeatedly inserted and
removed from a connector housing and the heat-dissipating structure
22 can be a riding-high heat sink in the connector housing. The
thermal interface material 12 is capable of enduring repeated
shearing forces caused by sliding the heat-generating structure 20
against the heat-dissipating structure 22 while a pressing force is
applied to the heat-dissipating structure 22.
[0029] FIG. 3 illustrates an application in which the thermal
interface structure 10 of FIG. 1B is positioned on the
heat-dissipating structure 22 so that the adhesive area 14b is
positioned at a contact area between the heat-generating structure
20 and the heat-dissipating structure 22. The compressive nature of
the thermal interface material 12 enables it to make contact with
the heat-dissipating structure 22 between the adhesive areas
14a-14c.
[0030] FIG. 4 illustrates an application in which the thermal
interface structure 10 of FIG. 1C is positioned on the
heat-dissipating structure 22 so that the thermal interface
material 12 can make contact with the heat-generating structure 20
between the plastic film 16a-16b.
[0031] FIG. 5 illustrates an application in which the thermal
interface structure 10 of FIG. 1D is positioned on the
heat-dissipating structure 22 so that the thermal interface
material 12 can make contact with the heat-generating structure 20
between the plastic film 16a-16b and the thermal interface material
12 can make contact with the heat-dissipating structure 22 between
the adhesive areas 14a-14c.
[0032] In one or more embodiments, the thermal interface structure
10 can be employed in a high speed, e.g., 100 Gbps, data
communication system, e.g., for telecommunications, in which the
heat-dissipating structure 22 is part of a pluggable interface for
a network device motherboard that receives a fiber optic networking
cable. Smaller 100 Gbps modules, e.g., CFP, CFP2, CXP, QSFP28,
etc., can have a power density from approximately 0.1 watt per
square centimeter (W/cm.sup.2) to 0.3 or 0.5 W/cm.sup.2. The
thermal interface structure 10 can help maintain case temperature
limits in such applications.
[0033] In one or more embodiments, the thermal interface structure
10 can resist shearing forces and survive more than 50 cycles of
sliding-in and sliding-out of the heat-generating structure 20.
[0034] In one or more embodiments, it may be desirable to minimize
the thickness of the adhesive material 14 while still maintaining
its effectiveness.
[0035] FIG. 6 illustrates a method for providing a thermal
interface structure in one or more embodiments. While the various
steps in this flowchart are presented and described sequentially,
one of ordinary skill will appreciate that some or all of the steps
can be executed in different orders and some or all of the steps
can be executed in parallel. Further, in one or more embodiments,
one or more of the steps described below can be omitted, repeated,
and/or performed in a different order. Accordingly, the specific
arrangement of steps shown in FIG. 6 should not be construed as
limiting the scope of the invention.
[0036] At step 610, a thermal interface material is formed for
thermally coupling a heat-generating structure to a
heat-dissipating structure such that the thermal interface material
capable of enduring a repeated shearing force caused by sliding the
heat-generating structure against the heat-dissipating structure.
Forming a thermal interface material can include forming the
thermal interface material on a beveled lead-in of a
heat-dissipating structure. Forming a thermal interface material
can include forming a foam-like synthetic graphite.
[0037] At step 620, an adhesive material is formed for holding the
thermal interface material in place on the heat-dissipating
structure. Forming an adhesive material can include forming a
pressure-sensitive adhesive. Forming an adhesive material can
include forming a hot-melt material. Forming an adhesive material
can include selecting a balance between a thermal performance and a
mechanical bonding performance of the thermal interface structure.
Forming an adhesive material can include covering an entire surface
of a thermal interface material or only a portion of the thermal
interface material corresponding to a contact area between a
heat-generating structure and a heat-dissipating structure.
[0038] While the foregoing disclosure sets forth various
embodiments using specific diagrams, flowcharts, and examples, each
diagram component, flowchart step, operation, and/or component
described and/or illustrated herein may be implemented,
individually and/or collectively, using a range of processes and
components.
[0039] The process parameters and sequence of steps described
and/or illustrated herein are given by way of example only. For
example, while the steps illustrated and/or described herein may be
shown or discussed in a particular order, these steps do not
necessarily need to be performed in the order illustrated or
discussed. The various example methods described and/or illustrated
herein may also omit one or more of the steps described or
illustrated herein or include additional steps in addition to those
disclosed.
[0040] While the invention has been described with respect to a
limited number of embodiments, those skilled in the art, having
benefit of this disclosure, will appreciate that other embodiments
may be devised which do not depart from the scope of the invention
as disclosed herein.
* * * * *