U.S. patent application number 15/820953 was filed with the patent office on 2018-05-31 for high efficiency thermal conductivity structure.
The applicant listed for this patent is NATIONAL CHENG KUNG UNIVERSITY. Invention is credited to CHO-YIN LEE, SEN-YUNG LEE.
Application Number | 20180149436 15/820953 |
Document ID | / |
Family ID | 62190095 |
Filed Date | 2018-05-31 |
United States Patent
Application |
20180149436 |
Kind Code |
A1 |
LEE; SEN-YUNG ; et
al. |
May 31, 2018 |
HIGH EFFICIENCY THERMAL CONDUCTIVITY STRUCTURE
Abstract
A high efficiency thermal conductivity structure includes a
substrate, and plural thermally conductive wires formed on both
surfaces of the substrate. The substrate is capable of forming the
thermally conductive wires made of a high thermal conductivity
material by a physical or chemical method. The thermally conductive
wire includes a carbon nanotube or a tubular or columnar material
with high thermal conductivity. The thermally conductive wire has a
diameter or cross section in microscale or nanoscale size, a length
in nanoscale to millimeter-scale size. During use, the thermal
conductivity structure is placed between a heat source and a
cooling unit. Heat from a heat source is conducted through the
thermally conductive wire to the substrate. After the heat at the
substrate re-adjusts its heat conduction path, the heat can be
conducted from the thermally conductive wire on the other surface
to the cooling unit efficiently.
Inventors: |
LEE; SEN-YUNG; (TAINAN CITY,
TW) ; LEE; CHO-YIN; (TAINAN CITY, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NATIONAL CHENG KUNG UNIVERSITY |
TAINAN CITY |
|
TW |
|
|
Family ID: |
62190095 |
Appl. No.: |
15/820953 |
Filed: |
November 22, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28F 3/022 20130101;
H01L 23/3677 20130101; H01L 23/433 20130101; H05K 7/20 20130101;
F28F 21/02 20130101; F28F 21/084 20130101; F28F 2255/20 20130101;
F28F 21/085 20130101; G06F 1/20 20130101; H01L 23/373 20130101 |
International
Class: |
F28F 3/02 20060101
F28F003/02; F28F 21/08 20060101 F28F021/08; F28F 21/02 20060101
F28F021/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 30, 2016 |
TW |
105139400 |
Claims
1. A high efficiency thermal conductivity structure, comprising: a
substrate, having a plurality of thermally conductive wires formed
on both surfaces of the substrate respectively; wherein the
thermally conductive wires are configured to be in a columnar or
tubular shape, and the thermally conductive wires have a
cross-sectional length of a microscale or nanoscale size, and the
thermally conductive wires are of a nanoscale to millimeter-scale
size; and the substrate and the thermally conductive wire are made
of a material of a high thermal conductivity.
2. The high efficiency thermal conductivity structure of claim 1,
wherein the thermally conductive wires are formed on both surfaces
of the substrate respectively by a physical method or chemical
method.
3. The high efficiency thermal conductivity structure of claim 1,
wherein the substrate is capable of forming the thermally
conductive wires made of a high thermal conductivity material
thereon by a physical method or chemical method, and the substrate
is made of a material selected from the group consisting of copper,
aluminum, silver, carbon, and diamond film.
4. The high efficiency thermal conductivity structure of claim 1,
wherein the thermally conductive wires are made of a material of a
high thermal conductivity and in a columnar or tubular shape, and
the thermally conductive wires are made of a material selected from
the group consisting of carbon nanotube, aluminum, copper, and
silver.
5. The high efficiency thermal conductivity structure of claim 1,
wherein the substrate is configured to be in the shape of a sheet
or in any geometric shape.
6. The high efficiency thermal conductivity structure of claim 1,
further comprising a heat source and a cooling unit, and the
substrate being disposed between the heat source and the cooling
unit, and the thermally conductive wire at one of the surfaces of
the substrate being coupled to the heat source, the thermally
conductive wire at the other surface of the substrate being coupled
to the cooling unit.
7. The high efficiency thermal conductivity structure of claim 1,
further comprising a heat source, the thermally conductive wire at
one of the surfaces of the substrate being coupled to the heat
source, and the thermally conductive wire at the other surface of
the substrate being exposed to air.
8. The high efficiency thermal conductivity structure of claim 7,
wherein the thermally conductive wire at the other surface of the
substrate is pressed and formed into a fin-shape.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a high efficiency thermal
conductivity structure, and more particularly to the thermal
conductivity structure having a sheet substrate, a plurality of
thermally conductive wires formed on both surfaces of the substrate
respectively, and the thermal conductivity structure of the
invention is placed between a heat source and a cooling unit during
use; and the heat of a heat source is conducted through the
thermally conductive wires to the sheet substrate, and after the
heat at the substrate adjusts its heat conduction path, the heat
can be conducted from the thermally conductive wire on the other
surface to the cooling unit more efficiently, and the thermal
conductivity structure of the present invention is flexible and may
be applied to a surface with different flatness and curvature.
BACKGROUND OF THE INVENTION
[0002] Cooling is one of the mainstream technologies. Various types
of equipments convert energy of different forms into heat during
their operation, and an increase of heat quantity and temperature
may affect the performance of the operation of the equipment or
even may give rise to a risk of burning or damaging the equipment,
so that an electric appliance is generally equipped with a cooling
device for dissipating heat and maintaining a normal operation of
the electric appliance.
[0003] Among a variety of cooling technologies, one is thermal
conduction, wherein a cooling unit has a structure such as a fin
installed at an end of the cooling unit to increase the contact
area with air and the other end contacted with the heat source
directly through the cooling unit. After the heat of the heat
source is conducted to the cooling unit, the fin of the cooling
unit dissipates the heat to the air or any other fluid by thermal
convection.
[0004] Since both contact surfaces of the cooling unit and heat
source are irregular concave/convex surfaces, there are gaps
between the contact surfaces of the cooling unit and heat source.
These gaps have air of a very low thermal conductive coefficient
(0.024W/m-k), and thus result in a poor thermal conduction effect.
To improve the thermal conductivity efficiency, a thermal paste
with a high thermal conductivity coefficient (10-15W/m-k) such as a
silver paste is generally coated between the cooling unit and the
heat source and used to replace the air of the very low thermal
conductive coefficient, so that there will be no gap between the
heat source and the cooling unit, and the heat can be conducted
through the thermal paste to the cooling unit effectively. However,
the thermal paste is usually composed of a main ingredient of a
high thermal conductivity coefficient such as a mixture of metal
particles, graphite, carbon tube, diamond, and linking agents, but
these linking agents have a thermal conductivity coefficient much
lower than that of the material of the cooling unit (such as
aluminum with the thermal conductivity coefficient of 237W/m-k),
and the linking agents are covered onto the main ingredient of the
high thermal conductivity coefficient and thus fail to conduct the
heat of the heat source through the main ingredient of the high
thermal conductivity coefficient to the cooling unit directly, and
the thermal conduction is interfered and affected by the linking
agents of the low conductivity coefficient. As a result, the
overall thermal conductivity efficiency cannot be improved
effectively. Obviously, the conventional thermal conductivity
structure requires improvements.
[0005] In P.R.C. Pat. No. CN100517661C, a manufacturing method of a
cooling device is disclosed, carbon nanotubes with a very high
thermal conductivity coefficient (20000W/m-k) are grown directly on
the contact surface of the cooling unit and the heat source, and
the carbon nanotubes of the cooling unit are contacted with the
heat source to conduct the heat of the heat source to the cooling
unit directly. To avoid growing carbon nanotubes on a non-contact
surface, the manufacturing process requires coating a passivation
layer (20) onto the whole cooling unit, and then removing the
passivation layer (20) in contact with the heat source in order to
grow the carbon nanotubes. Since the volume of the cooling unit is
not too small, and the shape of the cooling unit is relatively
complicated, this manufacturing method is not simple, and the
transportation of the product occupies much space and requires
protection.
[0006] In the prior art, a "Thermal Interface Material
Manufacturing Method" as disclosed in R.O.C. Pat. No. 1331132, a
"Carbon Nanotube Composite Material and Method for Manufacturing
the Same" as disclosed in U.S. Pat. Publication No. 2007/0244245, a
"Method for Manufacturing a Thermal Interface Material" as
disclosed in U.S. Pat. No. 7,674,410 a "Thermal Interface Material
and Method for Making the Same" as disclosed in U.S. Publication
No. 2006/0234056, and a "Thermal Interface Material and Method for
Manufacturing the Same" as disclosed in U.S. Publication No.
2008/0081176 have taught the method of forming and arranging carbon
nanotubes in the same direction, and then filling a liquid linking
agent, and finally positioning the carbon nanotubes after the
linking agent is solidified, so as to form the thermal interface
material. However, the arrangement of carbon nanotubes is not easy,
and the gaps between the carbon tubes are very small, and it is
very difficult, if not impossible, to fill a linking agent with
high viscosity into the gaps between the carbon nanotubes. Even if
the manufacture can be accomplished, the carbon nanotubes covered
by the linking agent will have a cooling efficiency along the
radial direction lower than that of the conventional thermal
paste.
[0007] Taiwanese Patent 1458933 discloses a "Heat-Dissipation
Structure And Electronic Device Using The Same", wherein the carbon
nanotubes are parallel with the surface of the heat source, and
cannot be used to surfaces with protrusion-recess surface in
nano-scale. When the surface of the heat source or the heat
dissipation unit is a protrusion-recess surface, there are gaps
formed between the carbon nanotube and the heat source or the heat
dissipation unit, and the dissipation efficiency will be
dramatically reduced. Furthermore, for the carbon nanotubes, the
efficiency for dissipating heat in the axial direction is higher
than that in the radial direction, so that the arrangement that the
carbon nanotube is parallel with the surface of the heat source
obviously affects the efficiency for dissipating heat.
[0008] Besides, Taiwanese Patent Publication Number 200951063
discloses "The Characterization And Fabrication Of high Efficiency
Nanowires Of Thermal Interface Membrane", wherein the baes material
is AAO a module board which includes copper wires extending through
the base material. However, the thermos-conductive efficient of
Alumina is low and its strength is weak. Furthermore, the heat is
conducted by the copper wires and not by the AAO module board so
that the ability for thermos reforming is low and cannot evenly
conduct the heat. Besides, the processes for manufacturing is
complicated, because the copper has to be deposited in the holes of
the module board, and the module board is dissolved by the solution
liquid so as to expose the copper wires. This specific process
restricts the length of the copper wires. The copper cannot be
properly deposited if the holes is too deep. During the process of
dissolving, the solution liquid cannot dissolve the module board
between the copper wires because of the high density of the copper
wires. Therefore, the yield rate decreases and cannot proceed
large-area production.
SUMMARY OF THE INVENTION
[0009] Therefore, it is a primary objective of the present
invention to overcome the aforementioned problem of the prior art
by providing a high efficiency thermal conductivity structure
comprising a substrate configured to be in the shape of a sheet,
the thickness of the substrate is not limited and can be varied
according to practical needs; a plurality of thermally conductive
wires are arranged and formed at both surfaces of the substrate
respectively; the substrate is capable of forming a plurality of
thermally conductive wires made of a high thermal conductivity
material such as copper, aluminum, silver, carbon, diamond film
thereon by a physical or chemical method; the thermally conductive
wires are made of a material with a high thermal conductivity such
as carbon nanotube, aluminum, copper or silver and in a columnar or
tubular shape; the thermally conductive wires have a diameter or
cross section in a microscale or nanoscale size and a length in a
nanoscale to millimeter-scale size.
[0010] During use, the thermal conductivity structure of the
present invention is placed between the heat source and the cooling
unit, and the heat of the heat source is conducted through the
thermally conductive wires to the substrate. If the temperature of
the cooling unit is non-uniform (since the position of each
thermally conductive wire varies, and heat is transferred from high
temperature to low temperature), the heat at the substrate will
re-adjust its heat conduction path, so that the heat can be
conducted by the thermally conductive wire on the other surface to
the cooling unit efficiently. In addition, the thermal conductivity
structure is flexible and can be applied to uneven surfaces, and
its manufacture is simple and easy.
[0011] Since the thermally conductive wire are arranged
independently and are not covered by any adhesive, and the contact
surface between the heat source and the cooling unit is uneven, a
portion of the thermally conductive wires may be bent and contacted
with each other during the assembling process, and thus improving
the thermal conduction path and the thermal conduction efficiently.
In addition, the thermally conductive wires are flexible and can be
applied to an uneven surface.
[0012] The production of the thermal conductivity structure of the
present invention just requires forming the thermally conductive
wires onto both surfaces of the substrate directly. Since the
thermally conductive wires have been fixed and arranged on the
substrate, no further rearrangement is required, or no linking
agent is required to be filled between the thermally conductive
wires, therefore the production of the thermal conductivity
structure is feasible and low-cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of the present invention;
[0014] FIG. 2 is a side view of the present invention;
[0015] FIG. 3 is a sectional view of a thermally conductive wire
having an surface contacted with a heat source and the other
surface contacted with a cooling unit in accordance with the
present invention; and
[0016] FIG. 4 is a perspective view of a thermally conductive wire
having a surface contacted with a heat source and the other surface
exposed to air and arranged in a fin-shape in accordance with the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The technical contents of the present invention will become
apparent with the detailed description of preferred embodiments
accompanied with the illustration of related drawings as follows.
It is intended that the embodiments and figures disclosed herein
are to be considered illustrative rather than restrictive.
[0018] With reference to FIGS. 1 and 2 for a high efficiency
thermal conductivity structure in accordance with a preferred
embodiment of the present invention, the high efficiency thermal
conductivity structure comprises the following elements:
[0019] A substrate 1 is in form of a thin sheet and capable of
forming a plurality of thermally conductive wires made of a high
thermal conductivity material such as copper, aluminum, silver,
carbon, or diamond film thereon by a physical or chemical method.
The thickness of the substrate 1 is not limited, and can be varied
according to practical needs.
[0020] A plurality of thermally conductive wires 2a, 2b are
arranged and formed on both surfaces of the substrate 1
respectively.
[0021] The thermally conductive wires 2a, 2b are made of a material
with a high thermal conductivity such as carbon nanotube, aluminum,
copper, or silver and in a tubular or columnar shape; the thermally
conductive wires 2a, 2b have a diameter or cross-sectional length
in a microscale or nanoscale and a length in a nanoscale to
millimeter-scale size.
[0022] As to the formation of the thermally conductive wires 2a,
2b, a physical or chemical method may be used. Since such physical
or chemical formation method is a prior art, and will not be
described in detail here.
[0023] With reference to FIG. 3 for a thermal conductivity
structure in accordance with this preferred embodiment of the
present invention, the thermal conductivity structure is placed
between a heat source 3 and a cooling unit 4. In other words, the
substrate 1 is disposed between the heat source 3 and the cooling
unit 4, and the thermally conductive wire 2a on one of the surfaces
of the substrate 1 is coupled to the heat source 3, and the
thermally conductive wire 2b on the other surface of the substrate
is coupled to the cooling unit 4, and both of the heat source 3 and
the cooling unit 4 have irregular concave/convex surfaces. Since
the substrate 1 and the thermally conductive wires 2a, 2b on both
surfaces of the substrate 1 are made of a flexible material with a
high thermal conductivity, therefore when the cooling unit 4 and
the heat source 3 are laminated, the thermal conductivity structure
of the present invention is attached to the cooling unit 4 and the
heat source 3 tightly and effectively, so that the heat of the heat
source 3 can be conducted to the cooling unit 4 directly and
effectively.
[0024] The cooling unit 4 may have different configurations or
cooling conditions, so that the cooling unit 4 will have uneven
temperature, and the cooling unit 4 will have a high-temperature
distribution area H and a low-temperature distribution area L, and
these areas will affect the cooling efficiency of the cooling unit
4. Since heat is transferred from high temperature to low
temperature, therefore when the heat of the heat source 3 is
conducted to the substrate 1 through the thermally conductive wire
2b on one of the surfaces of the substrate 1, the substrate 1
adjusts its heat conduction path as indicated by the arrow
direction in FIG. 3, and the heat can be conducted to the
aforementioned low-temperature area L to further improve the
cooling efficiency.
[0025] During assembly, if the thermally conductive wires 2a, 2b
are bent by force due to the uneven surfaces of the heat source 3
and the cooling unit 4, then the adjacent thermally conductive
wires 2a, 2b may be contacted with each other, and it will improve
the thermal conduction path and the thermal conductivity
efficiency.
[0026] If the space is too small and narrow and the cooling unit 4
cannot be installed, the configuration as shown in FIG. 4 may be
used, wherein the thermally conductive wire 2a on one of the
surfaces of the substrate 1 is coupled to a surface of a heat
source 3, and the other surfaces of the substrate 1 is coupled to
the thermally conductive wire 2b which is directly exposed to air,
and the thermally conductive wire 2b on the other surface may be
pressed into a fin-shape to improve the contact area with the
flowing air in order to dissipate heat by thermal convection more
efficiently.
[0027] It is noteworthy that the thermally conductive wires 2a, 2b
are arranged and formed on both surfaces of the substrate 1
respectively, and the thermally conductive wires 2a, 2b are not
covered by other objects (such as a polymer material or a thermal
paste as used in the prior art), so that the heat of the heat
source 3 will not be blocked, but can be conducted to the cooling
unit 4 directly.
* * * * *