U.S. patent application number 16/264836 was filed with the patent office on 2019-08-15 for heat transfer device.
This patent application is currently assigned to JOINSET CO., LTD.. The applicant listed for this patent is JOINSET CO., LTD.. Invention is credited to Sun-Ki Kim.
Application Number | 20190249927 16/264836 |
Document ID | / |
Family ID | 67541433 |
Filed Date | 2019-08-15 |
![](/patent/app/20190249927/US20190249927A1-20190815-D00000.png)
![](/patent/app/20190249927/US20190249927A1-20190815-D00001.png)
![](/patent/app/20190249927/US20190249927A1-20190815-D00002.png)
![](/patent/app/20190249927/US20190249927A1-20190815-D00003.png)
![](/patent/app/20190249927/US20190249927A1-20190815-D00004.png)
United States Patent
Application |
20190249927 |
Kind Code |
A1 |
Kim; Sun-Ki |
August 15, 2019 |
HEAT TRANSFER DEVICE
Abstract
A heat transfer device configured to be independently fixed and
densely mounted. The heat transfer device includes: a main body
formed of a metallic material and forming a tube sealed to maintain
a vacuum therein; and a thermally conductive layer having
elasticity and adhered around the main body.
Inventors: |
Kim; Sun-Ki; (Gunpo-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JOINSET CO., LTD. |
Ansan-si |
|
KR |
|
|
Assignee: |
JOINSET CO., LTD.
|
Family ID: |
67541433 |
Appl. No.: |
16/264836 |
Filed: |
February 1, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28D 15/0241 20130101;
F28D 15/0275 20130101; H01L 21/4878 20130101; H01L 23/427 20130101;
H01L 23/36 20130101; F28D 15/0233 20130101; F28F 2235/00
20130101 |
International
Class: |
F28D 15/02 20060101
F28D015/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 12, 2018 |
KR |
10-2018-0016952 |
Claims
1. A heat transfer device comprising: a main body formed of a
metallic material and forming a tube sealed to maintain a vacuum
therein; and a thermally conductive layer having elasticity and
flexibility and adhered around the main body.
2. The heat transfer device of claim 1, wherein the thermally
conductive layer is a thermal sheet extending in a length direction
of the main body with both widthwise ends of the thermal sheet
being in contact with each other or separate from each other.
3. The heat transfer device of claim 1, wherein the thermally
conductive layer is adhered or bonded to the main body by dipping
an outer surface of the main body in a thermally conductive
liquid-phase rubber or resin in which thermally conductive
particles are mixed and dispersed and then curing the thermally
conductive liquid-phase rubber or resin, or by spraying the
thermally conductive liquid-phase rubber or resin onto the outer
surface of the main body and then curing the thermally conductive
liquid-phase rubber or resin.
4. The heat transfer device of claim 1, wherein the heat transfer
device is a heat pipe, a heat spreader, or a vapor chamber.
5. The heat transfer device of claim 1, wherein the thermally
conductive layer is electrically insulative.
6. The heat transfer device of claim 1, wherein the main body is
inserted in an accommodation groove of a metal case such that a
portion of the thermally conductive layer corresponding to a lower
surface of the main body is brought into contact with a bottom of
the accommodation groove and an upper surface of the main body is
exposed for direct or indirect thermal contact with a heat source,
wherein an outer surface of the thermally conductive layer has
self-adhesion such that the thermally conductive layer is adhered
to the bottom of the accommodation groove.
7. The heat transfer device of claim 6, wherein portions of the
thermally conductive layer corresponding to lateral sides of the
main body are elastically brought into contact with both sidewalls
of the accommodation groove.
8. The heat transfer device of claim 1, wherein the thermally
conductive layer is a thermally conductive silicone rubber or a
thermally conductive acrylic resin.
9. A heat transfer device comprising: a main body formed of a
metallic material and forming a tube sealed to maintain a vacuum
therein; a first thermally conductive layer having elasticity and a
self-adhesive outer surface and adhered to a surface of the main
body; and a second thermally conductive layer having elasticity and
a self-adhesive outer surface and adhered to an opposite surface of
the main body.
10. The heat transfer device of claim 9, wherein the first
thermally conductive layer has greater self-adhesion and less
thermal conductivity than the second thermally conductive layer,
and the first thermally conductive layer is brought into contact
with a cooling case, and the second thermally conductive layer is
brought into contact with a heat source.
11. A heat transfer device comprising: a main body formed of a
metallic material and forming a tube sealed to maintain a vacuum
therein; a thermally conductive layer having elasticity and
flexibility and adhered around the main body; and a thermally
conductive particle layer formed of thermally conductive particles
attached to an outer surface of the thermally conductive layer.
12. The heat transfer device of claim 11, wherein the thermally
conductive particles are metal powder, carbon powder, ceramic
powder, graphite power, or carbon fiber having high thermal
conductivity.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of Korean
Patent Application No. 10-2018-0016952 filed on Feb. 12, 2018, the
entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a heat transfer device, and
more particularly, to a heat transfer device configured to be
independently fixed and easily mounted in high density.
BACKGROUND OF THE INVENTION
[0003] In recent years, electronic components or modules have been
highly integrated and designed to have high performance, and thus
more heat is generated from such electronic components or modules.
In addition, as the size of products decreases, heat is more
densely generated. Therefore, measures for dissipating heat become
more important.
[0004] This situation is more noticeable in mobile terminals such
as smartphones and tablets, and direct cooling or heat transfer is
necessary to handle generated heat.
[0005] Heat transfer devices such as thermal sheets or graphite
sheets have high heat transfer performance in a horizontal
direction. However, heat pipes, heat spreaders, or vapor chambers
(hereinafter, these devices will be collectively referred to as
heat pipes) are used for the case in which heat transfer is
insufficient. In general, the apparent thermal conductivity of heat
pipes is several times to several tens of times the apparent
thermal conductivity of a simple metal such as copper or
aluminum.
[0006] As is well known, such a heat pipe has a tubular structure
forming a vacuum therein. For example, if heat is generated from a
heat-generating electronic component such as a processor placed in
contact with an end of a heat pipe, a small amount of a refrigerant
such as water or ethylene glycol is vaporized by the heat, and the
vaporized refrigerant is pushed toward the opposite end of the heat
pipe by the pressure difference between gas and liquid. Then, the
vaporized refrigerant is cooled and condensed into liquid. As this
process repeats, heat generated from the processor is transferred
to another place, and thus the processor is cooled and prevented
from being overheated.
[0007] Heat pipes have already been widely used in general personal
computers, and in recent years, heat pipes have been used to
transfer heat generated from processors of smartphones.
[0008] For example, a heat pipe may be used in a smartphone by
forming an accommodation groove in a metal case of the smartphone,
attaching a piece of thermally conductive double-sided adhesive
tape to the bottom of the accommodation groove, and attaching a
surface of the heat pipe to the piece of thermally conductive
double-sided adhesive tape to fix the heat pipe to the metal
case.
[0009] Therefore, if a heat pipe has a complex shape such as a bent
shape and a large length, it is difficult to manufacture
double-sided adhesive tape according to the shape of the heat pipe,
and it is more difficult to manufacture double-side adhesive tape
having a small thickness or a long length according to the shape of
an accommodation groove to install the heat pipe in the
accommodation groove.
[0010] In addition, since double-sided adhesive tape is
additionally used to fix such a heat pipe, it is inconvenient to
densely mount the heat pipe, and additional costs are incurred.
[0011] In addition, since heat pipes are formed of a metallic
material, the heat pipes may not be elastically brought into
thermal contact with heat sources or metal cases for cooling, and
thus it is difficult to transfer heat rapidly and reliably.
[0012] Therefore, in general, a thermally conductive member having
elasticity such as a thermal pad, thermal grease, or a thermal gap
filler has to be additionally placed between a heat pipe and a heat
source or a cooling case.
[0013] In particular, when a heat pipe formed of a metallic
material is bought into contact with and coupled to a plurality of
cooling metal fins, the effect of heat transfer is not satisfactory
because of direct metal-to-metal contact.
SUMMARY OF THE INVENTION
[0014] An object of the present invention is to provide a simple
heat transfer device configured to be independently fixed without
additionally using a thermally conductive adhesive material.
[0015] Another object of the present invention is to provide a heat
transfer device configured to effectively transfer heat even when
the heat transfer device is in contact with an object having high
hardness.
[0016] Another object of the present invention is to provide a heat
transfer device configured to be densely mounted.
[0017] Another object of the present invention is to provide an
economical heat transfer device having fewer components and
configured to be easily installed.
[0018] According to an aspect of the present invention, there is
provided a heat pipe having improved heat transfer performance, the
heat pipe including: a main body formed of a metallic material and
forming a tube sealed to maintain a vacuum therein; and a thermally
conductive layer having elasticity and flexibility and adhered
around the main body.
[0019] According to another aspect of the present invention, there
is provided a heat pipe having improved heat transfer performance,
the heat pipe including: a main body formed of a metallic material
and forming a tube sealed to maintain a vacuum therein; a first
thermally conductive layer having elasticity and a self-adhesive
outer surface and adhered to a surface of the main body; and a
second thermally conductive layer having elasticity and a
self-adhesive outer surface and adhered to an opposite surface of
the main body.
[0020] According to another aspect of the present invention, there
is provided a heat transfer device comprising: a main body formed
of a metallic material and forming a tube sealed to maintain a
vacuum therein; a thermally conductive layer having elasticity and
flexibility and adhered around the main body; and a thermally
conductive particle layer formed of thermally conductive particles
attached to an outer surface of the thermally conductive layer.
[0021] Therefore, since thermally conductive double-sided adhesive
tape or a thermally conductive adhesive is not additionally used to
fix the heat transfer device to an accommodation groove of a metal
case, the heat transfer device may be easily fixed and densely
installed even in a small space. Thus, the heat transfer device is
economical.
[0022] In addition, since the contact area between the heat
transfer device and the accommodation groove of the metal case is
increased, heat may be transferred rapidly and reliably.
[0023] In addition, since the heat transfer device is configured to
be elastically brought into contact with a metal case or a heat
source, heat may be effectively transferred.
[0024] In addition, a thermal sheet having self-adhesion may be
used to easily arrange the heat transfer device on release paper or
film.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The above objects and other advantages of the present
invention will become more apparent by describing in detail
exemplary embodiments thereof with reference to the attached
drawings in which:
[0026] FIG. 1 is a view illustrating a state in which a heat pipe
is applied to a smartphone according to an embodiment of the
present invention;
[0027] FIG. 2 is a partial perspective view illustrating a
cross-section of the heat pipe;
[0028] FIGS. 3A and 3B are views illustrating how the heat pipe is
placed in a accommodation groove; and
[0029] FIG. 4 is a cross-sectional view illustrating a heat pipe
according to another embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Technical terms used herein are only for explaining specific
embodiments while not limiting the present invention. In addition,
unless otherwise defined, technical terms used herein have the same
meaning as commonly understood by those of ordinary skill in the
art and will not be interpreted in an overly broad or narrow sense.
In addition, if technical terms used herein are incorrect to
exactly express the idea of the present invention, the technical
terms should be interpreted as terms by which those of ordinary
skill in the art can correctly understand the idea of the present
invention. In addition, general terms used herein may be
interpreted as defined in dictionaries or according to the
contextual meanings, and should not be interpreted in an overly
narrow sense.
[0031] FIG. 1 illustrates a state in which a heat pipe 100 is
applied to a smartphone according to an embodiment of the present
invention.
[0032] A battery 14 may be provided on a back cover 10 of the
smartphone, and a circuit board 16 on which a plurality of
electronic components are mounted may be provided in a region
surrounding the battery 14.
[0033] In FIG. 1, the back cover 10 formed of a metallic material
is shown as an example of a heat releasing object. However, the
present invention is not limited thereto. For example, another
metal case of a heat generating unit may be considered.
[0034] A heat source generating a large amount of heat such as an
application processor (AP) among the electronic components mounted
on the circuit board 16 is brought into contact with the heat pipe
100 such that heat generated from the heat source may be rapidly
dissipated through the back cover 10.
[0035] To this end, the heat pipe 100 is fixedly inserted into an
accommodation groove 12 formed in the back cover 10, and as
described later, the heat pipe 100 may be fixed to the back cover
10 owing to self-adhesion of a thermally conductive layer 120.
[0036] FIG. 2 is a partial perspective view illustrating a
cross-section of the heat pipe 100.
[0037] The heat pipe 100 includes: a metallic main body 110 forming
a tube sealed to maintain a vacuum therein; and the thermally
conductive layer 120 having elasticity and adhered around the main
body 110.
[0038] The main body 110 is formed of a metallic material such as
copper or aluminum.
[0039] The thermally conductive layer 120 may be a thermal sheet
formed of a thermally conductive silicone rubber or a thermally
conductive acrylic resin. In this case, the thermal sheet may
surround the main body 110, and both widthwise ends of the thermal
sheet may be in contact with each other or may be separate from
each other on a lower surface of the main body 110.
[0040] Alternatively, the thermally conductive layer 120 may be
adhered or bonded to the main body 110 by dipping the main body 110
in a thermally conductive liquid-phase rubber or resin in which
thermally conductive particles are mixed and dispersed and then
curing the thermally conductive liquid-phase rubber or resin, or by
spraying the thermally conductive liquid-phase rubber or resin onto
an outer surface of the main body 110 and then curing the thermally
conductive liquid-phase rubber or resin with heat or ultraviolet
(UV) rays.
[0041] The thermally conductive layer 120 may form a closed loop in
a width direction of the main body 110 and may extend in a length
direction of the main body 110.
[0042] The thermally conductive layer 120 may include
thermally-conductive, electrically-insulative particles such as
ceramic powder, and thus the thermally conductive layer 120 may be
electrically insulative. When only the thermal conductivity of the
thermally conductive layer 120 is considered, the thermally
conductive layer 120 may include metal powder, carbon powder,
graphite powder, or graphite fiber. In this case, the thermally
conductive layer 120 may have high thermal conductivity even though
having electrical conductivity.
[0043] The thermally conductive layer 120 has elasticity and
flexibility because the thermally conductive layer 120 has a
structure based on a silicone rubber or acrylic resin. Therefore,
the heat pipe 100 may be forcibly inserted into the accommodation
groove 12 to bring the thermally conductive layer 120 into elastic
contact with inner walls of the accommodation groove 12. In this
case, since gaps between the heat pipe 100 and the accommodation
groove 12 are filled with the thermally conductive layer 120,
reliable thermal contact may be made over a relatively large area,
thereby improving heat transfer efficiency.
[0044] The thickness of the thermally conductive layer 120 may be
less than the thickness of the main body 110. In a non-limiting
example, the thickness of the thermally conductive layer 120 may
range from about 0.02 mm to about 0.3 mm.
[0045] The thermally conductive layer 120 may be discretely formed
in the length direction of the thermally conductive layer 120. In
this case, the total length of the thermally conductive layer 120
may be adjusted to be equal to or greater than half (1/2) the total
length of the main body 110 for sufficient heat transfer.
[0046] The outer surface of the thermally conductive layer 120 may
have self-adhesion. In this case, a portion of the thermally
conductive layer 120 formed on a lower surface of the main body 110
may be adhered to the bottom of the accommodation groove 12 of the
back cover 10. Therefore, the heat pipe 100 may be fixed to the
accommodation groove 12 without additionally using a piece of
thermally conductive double-sided adhesive tape or a thermally
conductive adhesive.
[0047] In addition, the heat pipe 100 may be arranged on a sheet of
release paper or release film by using the self-adhesion of the
outer surface of the thermally conductive layer 120.
[0048] FIGS. 3A and 3B illustrate how the heat pipe 100 is placed
in the accommodation groove 12.
[0049] The heat pipe 100 may be forcibly inserted into the
accommodation groove 12 of the back cover 10 and elastically
brought into contact with the bottom and both sidewalls of the
accommodation groove 12 owing to the elasticity of the thermally
conductive layer 120 so that thermal contact between the heat pipe
100 and the back cover 10 may be reliably improved.
[0050] In particular, if the outer surface of the thermally
conductive layer 120 has self-adhesion, the thermally conductive
layer 120 may be adhered to the bottom and/or both sidewalls of the
accommodation groove 12 by the self-adhesion of the thermally
conductive layer 120.
[0051] Therefore, unlike the related art, it is not necessary to
use a piece of thermally conductive double-sided adhesive tape or a
thermally conductive adhesive, or shape a piece of thermally
conductive double-sided adhesive tape according to the shape of the
heat pipe 100 so as to fix the heat pipe 100 to the accommodation
groove 12. Therefore, simple manufacturing processes and low
manufacturing costs may be guaranteed while enabling high-density
mounting of the heat pipe 100.
[0052] In addition, since only the thermally conductive layer 120
having elasticity and surrounding the main body 110 of the heat
pipe 100 is placed between the main body 110 and the accommodation
groove 12 when fixedly inserting the heat pipe 100 into the
accommodation groove 12, the heat pipe 100 may be easily mounted in
the accommodation groove 12 and may have high thermal conductivity
for improved heat transfer efficiency.
[0053] Likewise, on the heat pipe 100 fixedly inserted in the
accommodation groove 12, the circuit board 16 or another heat
source may be mounted directly or using a simple thermal sheet
therebetween, thereby improving heat transfer efficiency and the
yield of production.
[0054] In the above-described embodiment, the thermally conductive
layer 120 entirely surrounds the main body 110. However, this is a
non-limiting example. In another example, thermally conductive
layers 120 may be adhered to only upper and lower surfaces of the
main body 110.
[0055] In this case, the upper and lower thermally conductive
layers 120 may have different thermal conductivity and
self-adhesion characteristics.
[0056] For example, the upper thermally conductive layer 120 may
have thermal conductivity less than the lower thermally conductive
layer 120. In this case, the upper thermally conductive layer 120
may be brought into contact with a cooling case, and the lower
thermally conductive layer 120 may be brought into contact with a
heat source.
[0057] In addition, the upper thermally conductive layer 120 may
have self-adhesion greater than the lower thermally conductive
layer 120. In this case, the upper thermally conductive layer 120
may be brought into contact with a cooling case, and the lower
thermally conductive layer 120 may be brought into contact with a
heat source, such that when the cooling case is lifted, the heat
pipe 100 may be on the cooling case owing to the upper thermally
conductive layer 120.
[0058] FIG. 4 is a cross-sectional view illustrating a heat pipe
200 according to another embodiment.
[0059] In the current embodiment, thermally conductive particles
are attached to an outer surface of a thermally conductive layer
220 to form a thermally conductive particle layer 230 by a
high-temperature and high-pressure, vacuum, or plasma coating
method as shown in an enlarged circle of FIG. 4, so as to
substantially increase the surface area of the heat pipe 200.
[0060] The thermally conductive particles may be metal powder,
carbon powder, graphite powder, ceramic powder, or carbon fiber
having high thermal conductivity.
[0061] As a result, since the surface area of the thermally
conductive layer 220 is increased, heat may rapidly transfer to the
thermally conductive layer 220 and then to another object such as
the back cover 10.
[0062] While the present invention has been described according to
the embodiments, those of ordinary skill could understand that
various modifications can be made from the embodiments. Therefore,
the spirit and scope of the present invention are not limited to
the embodiments, but should be construed by the appended
claims.
* * * * *