U.S. patent application number 14/611518 was filed with the patent office on 2015-05-28 for heat radiation sheet and method of manufacturing same.
The applicant listed for this patent is AMOGREENTECH CO., LTD.. Invention is credited to Yong Sik JUNG, Seung Hoon LEE, Yun Mi SO.
Application Number | 20150144320 14/611518 |
Document ID | / |
Family ID | 50267103 |
Filed Date | 2015-05-28 |
United States Patent
Application |
20150144320 |
Kind Code |
A1 |
LEE; Seung Hoon ; et
al. |
May 28, 2015 |
HEAT RADIATION SHEET AND METHOD OF MANUFACTURING SAME
Abstract
A heat radiation sheet including: a heat radiation layer that is
formed in the form of a nano-web having a plurality of pores by
electrospinning a spinning solution that is obtained by mixing a
polymer material and a solvent, or the polymer material, a heat
conductive material, and the solvent; and an adhesive layer that is
laminated on one surface or both surfaces of the heat radiation
layer, and that is formed in the form of the nano-web by
electrospinning an adhesive material that is obtained by an
adhesive, the heat conductive material, and the solvent.
Inventors: |
LEE; Seung Hoon; (Paju-si,
KR) ; JUNG; Yong Sik; (Namyangju-si, KR) ; SO;
Yun Mi; (Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AMOGREENTECH CO., LTD. |
Gimpo-si |
|
KR |
|
|
Family ID: |
50267103 |
Appl. No.: |
14/611518 |
Filed: |
February 2, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/KR2013/006838 |
Jul 30, 2013 |
|
|
|
14611518 |
|
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Current U.S.
Class: |
165/185 ;
264/484 |
Current CPC
Class: |
D01F 1/10 20130101; H01L
2924/0002 20130101; H01L 2924/00 20130101; H01L 23/3737 20130101;
F28F 2255/06 20130101; D01D 5/003 20130101; H01L 23/3733 20130101;
H01L 2924/0002 20130101 |
Class at
Publication: |
165/185 ;
264/484 |
International
Class: |
F28F 21/02 20060101
F28F021/02; F28F 21/06 20060101 F28F021/06; F28F 21/08 20060101
F28F021/08; D01D 5/00 20060101 D01D005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 6, 2012 |
KR |
10-2012-0085769 |
Jul 29, 2013 |
KR |
10-2013-0089635 |
Claims
1. A heat radiation sheet comprising: a heat radiation layer that
is formed in the form of a nano-web having a plurality of pores by
electrospinning a spinning solution that is obtained by mixing a
polymer material and a solvent, or the polymer material, a heat
conductive material, and the solvent; and an adhesive layer that is
laminated on one surface or both surfaces of the heat radiation
layer, and that is formed in the form of the nano-web by
electrospinning an adhesive material that is obtained by an
adhesive, the heat conductive material, and the solvent.
2. The heat radiation sheet of claim 1, wherein the heat conductive
material employs any one selected from a heat conductive metal
having excellent thermal conductivity, conductive carbon, carbon
black, carbon nanotube (CNT), and conductive polymer (PDOT).
3. The heat radiation sheet of claim 1, wherein the heat conductive
material is heat conductive particles and part of the heat
conductive particles are exposed on the surface of nanofibers of
webs of the heat radiation layer and the adhesive layer.
4. The heat radiation sheet of claim 1, wherein the adhesive layer
is in contact with and adhered on a heat generating component of
electronic equipment.
5. The heat radiation sheet of claim 1, wherein heat conductive
particles are dispersed between the heat radiation layer and the
adhesive layer.
6. A heat radiation sheet comprising: a substrate that is formed in
the form of a web by an electrospinning method; an adhesive layer
that is laminated on one surface of the substrate; and a metal
layer that is coated on the other surface of the substrate and
having thermal conductivity.
7. The heat radiation sheet of claim 6, wherein the substrate has a
web structure having a plurality of pores that are formed by
electrospinning a spinning solution that is obtained by mixing a
polymer material and a solvent, or the polymer material, a heat
conductive material, and the solvent, and the adhesive layer that
is formed in the form of the web by electrospinning an adhesive
material that is obtained by an adhesive, the heat conductive
material, and the solvent.
8. The heat radiation sheet of claim 6, wherein the metal layer is
a metal pattern layer that is coated in a pattern shape on the
other surface of the substrate.
9. A method of manufacturing a heat radiation sheet comprising the
steps of: forming an adhesive layer that is formed in the form of a
nano-web by electrospinning an adhesive material that is obtained
by an adhesive, a heat conductive material, and a solvent; and
forming a heat radiation layer that is formed on one surface of the
adhesive layer, and that is formed in the form of a web by
electrospinning a spinning solution that is obtained by mixing a
polymer material and a solvent, or the polymer material, the heat
conductive material, and the solvent.
10. The method of manufacturing the heat radiation sheet of claim
9, further comprising electrospinning a spinning solution that is
obtained by mixing heat conductive particles and the solvent, to
thus dispersing the heat conductive particles on the web of the
adhesive layer, between the step of forming the adhesive layer in
the web form and the step of forming the heat radiation layer in
the web form.
11. The method of manufacturing the heat radiation sheet of claim
9, further comprising pressurizing the adhesive layer and the heat
radiation layer after forming the heat radiation layer in the web
form.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of International
Application No. PCT/KR2013/006838, filed on Jul. 30, 2013, which
claims priority to and the benefit of Korean Application Nos.
10-2012-0085769, filed on Aug. 6, 2012 and 10-2013-0089635, filed
on Jul. 29, 2013 in the Korean Patent Office, the entire contents
of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a heat radiation sheet that
is mounted in an electronic device, to thereby radiate heat
generated from the inside of the electronic device to the outside
of the electronic device, and more particularly, to a heat
radiation sheet that is made in the form of a nano-web form by way
of an electrospinning method, and a method of manufacturing
same.
BACKGROUND ART
[0003] Typically, electronic equipment such as computers, portable
personal terminals, or communicator devices has a serious concern
for a residual image problem and an intrinsic system stability when
excessive thermal energy generated from the inside of the
electronic equipment was not be diffused to the outside thereof.
This thermal energy may reduce the lifetime of the electronic
equipment, or cause failure and malfunction of the electronic
equipment, and in severe cases, may provide a cause of explosion or
fire.
[0004] In particular, since the current electronic equipment gets
slimmer in thickness, and is implemented to have higher
performance, heat generated from various circuit components in the
inside of the electronic equipment should be promptly radiated to
the outside, to thus prevent the electronic equipment from being
damaged due to the heat. Therefore, a heat radiation sheet is used
in order to release the thermal energy generated from the inside of
the electronic equipment to the outside thereof.
[0005] As disclosed in Korean Patent Registration Publication No.
10-0721462 (17 May 2007), a conventional heat radiation sheet
includes: a metal plate with thermal conductivity; an adhesive foam
sheet that is formed on at least one surface of the metal plate in
the inside of which cells are formed as a foam structure, wherein
the adhesive foam sheet is formed of an adhesive mixture containing
an adhesive and a cell forming agent, the adhesive is an
acrylic-based resin, a silicone-based resin or a polyurethane-based
resin, and the cell forming agent is composed of a micro
balloon.
[0006] However, since the conventional heat radiation sheet uses an
adhesive foam sheet attached on a surface of a metal plate, the
conventional heat radiation sheet becomes thick, to thus cause a
problem of making it difficult to use the conventional heat
radiation sheet in thin electronic equipment such as portable
electronic equipment.
[0007] Further, the heat radiation sheet is blanked according to
size of a heat generating component so as to be attached on the
heat-generating component of the electronic equipment. However,
since a foam sheet has adhesiveness, it is difficult to blank the
heat radiation sheet precisely during blanking the conventional
heat radiation sheet.
TECHNICAL PROBLEM
[0008] To solve the above problems or defects, it is an object of
the present invention to provide a heat radiation sheet and a
method of manufacturing same, in which the heat radiation sheet is
manufactured in a nano-web form by way of an electrospinning
method, to thereby be made thin and to thus improve thermal
conductivity.
[0009] In addition, it is another object of the present invention
to provide a heat radiation sheet and a method of manufacturing
same, in which an adhesive layer to be attached on a heat
generating component is manufactured by an electrospinning method,
to thereby enhance blanking performance, and a heat conductive
material is contained in the adhesive layer, to thereby enable the
adhesive layer to have heat radiation performance, and to thus
enhance heat radiation performance of the heat radiation sheet.
[0010] The technical problems to be solved in the present invention
are not limited to the above-mentioned technical problems, and the
other technical problems that are not mentioned in the present
invention may be apparently understood by one of ordinary skill in
the art in the technical field to which the present invention
belongs.
SUMMARY OF THE INVENTION
[0011] To accomplish the above and other objects of the present
invention, according to an aspect of the present invention, there
is provided a heat radiation sheet comprising: a heat radiation
layer that is formed in the form of a nano-web having a plurality
of pores by electrospinning a spinning solution that is obtained by
mixing a polymer material and a solvent, or the polymer material, a
heat conductive material, and the solvent; and an adhesive layer
that is laminated on one surface or both surfaces of the heat
radiation layer, and that is formed in the form of the nano-web by
electrospinning an adhesive material that is obtained by an
adhesive, the heat conductive material, and the solvent.
[0012] According to another aspect of the present invention, there
is provided a heat radiation sheet comprising: a substrate that is
formed in the form of a web by an electrospinning method; an
adhesive layer that is laminated on one surface of the substrate;
and a metal layer that is coated on the other surface of the
substrate and having thermal conductivity.
[0013] According to still another aspect of the present invention,
there is provided a method of manufacturing a heat radiation sheet
comprising the steps of: forming an adhesive layer that is formed
in the form of a nano-web by electrospinning an adhesive material
that is obtained by an adhesive, a heat conductive material, and a
solvent; and forming a heat radiation layer that is formed on one
surface of the adhesive layer, and that is formed in the form of a
web by electrospinning a spinning solution that is obtained by
mixing a polymer material and a solvent, or the polymer material,
the heat conductive material, and the solvent.
[0014] As described above, the heat radiation sheet according to
the present invention is fabricated in a web form by an
electrospinning method so as to be made thin and to have an
advantage so as to be applicable to thin electronic equipment.
[0015] In addition, the heat radiation sheet according to the
present invention is prepared in a web form by an electrospinning
method, to thereby enhance blanking performance, in which a heat
conductive material is contained in the adhesive layer, to thereby
enhance heat radiation performance of the heat radiation sheet.
DESCRIPTION OF DRAWINGS
[0016] FIG. 1 is a cross-sectional view of a heat radiation sheet
according to a first embodiment of the present invention.
[0017] FIG. 2 is an enlarged view of a heat radiation layer
according to the first embodiment of the present invention.
[0018] FIG. 3 is a cross-sectional view of a heat radiation sheet
according to a second embodiment of the present invention.
[0019] FIG. 4 is a configuration diagram of an electrospinning
device for manufacturing a heat radiation sheet according to the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Embodiments of the present invention will be described below
in detail with reference to the accompanying drawings. Here, the
size or shape of the components illustrated in the drawings may be
shown to be exaggerated for convenience and clarity of
illustration. In addition, specifically defined terms may be
changed according to the intention or practices of users or
operators in consideration of the construction and operation of the
present invention. The definition of the terms should be made based
on contents throughout the present specification.
[0021] FIG. 1 is a cross-sectional view of a heat radiation sheet
according to a first embodiment of the present invention, and FIG.
2 is an enlarged view of a heat radiation layer according to the
first embodiment of the present invention.
[0022] Referring to FIGS. 1 and 2, the heat radiation sheet
according to the first embodiment includes: a heat radiation layer
10 that is formed in a nano-web by an electrospinning method in
which a heat conductive material is contained in the heat radiation
layer 10, to thus have thermal conductivity; and an adhesive layer
20 that is laminated on one surface or both surfaces of the heat
radiation layer 10.
[0023] The heat radiation layer 10 is formed by the following steps
of: mixing a polymer material that can be electrospun and a
solvent, or the polymer material, a heat conductive material, and
the solvent at a constant mixture rate, to thus produce a spinning
solution; electrospinning the spinning solution to thus form
nanofibers 14; and accumulating the nanofibers 14 to thus form a
nano-web having a plurality of pores 12. Here, the term "nano-web"
can be called the `web` shortly.
[0024] Here, the spinning method that is applied to the present
invention can employ any one selected from general electrospinning,
air-electrospinning (AES), electrospray, electrobrown spinning,
centrifugal electrospinning, and flash-electrospinning.
[0025] That is, the heat radiation layer 10 and the adhesive layer
20 according to the present invention may be fabricated by
employing any spinning method selected from various kinds of
spinning methods of accumulating nano-fibers.
[0026] For example, the polymer materials used to make the heat
radiation layer 10 in the present invention may be: polyvinylidene
fluoride (PVdF), poly(vinylidene fluoride-co-hexafluoropropylene),
a perfluoropolymer, polyvinyl chloride, polyvinylidene chloride, or
a copolymer thereof; a polyethylene glycol derivative containing
polyethylene glycol dialkylether and polyethylene glycol
dialkylester; poly(oxymethylene-oligo-oxyethylene); polyoxide
containing polyethylene oxide and polypropylene oxide; polyvinyl
acetate, poly(vinyl pyrrolidone-vinyl acetate), polystyrene, and a
polystyrene acrylonitrile copolymer; a polyacrylonitrile copolymer
containing polyacrylonitrile (PAN) and a polyacrylonitrile methyl
methacrylate copolymer; or polymethyl methacrylate, a poly methyl
methacrylate copolymer, or a mixture thereof.
[0027] Further, the heat conductive material employs any one
selected from a heat conductive metal such as Ni, Cu, and Ag having
excellent thermal conductivity, conductive carbon, carbon black,
carbon nanotube (CNT), and conductive polymer (PDOT). Besides, any
material having thermal conductivity may be used as the heat
conductive material.
[0028] Here, when a spinning solution is fabricated by mixing heat
conductive particles applied as a heat conductive material, a
polymer material, and a solvent, the heat conductive particles are
dispersed in the nanofibers 14 of the heat radiation layer 10 that
is in the form of the nano-web. That is, some parts of the heat
conductive particles are exposed on the surface of the nanofibres
14 of the heat radiation layer 10, to then be involved in the heat
conduction.
[0029] Since the heat radiation layer 10 is produced by an
electrospinning method, the thickness of the heat radiation layer
10 is determined according to the dose of the electrospun spinning
solution. Thus, it is advantageously easy to make the thickness of
the heat radiation layer 10 into a desired thickness.
[0030] In this way, the heat radiation layer 10 is formed in a
nano-web form where nanofibers are accumulated by a spinning
method, to thus be made into a shape of having a large number of
pores without a separate process, and to thus be possible to adjust
size of each of the pores according to the dose of the spun
spinning solution.
[0031] The adhesive layer 20 is prepared in the same way as an
electrospinning method that is used for making the heat radiation
layer 10. In other words, the adhesive layer 20 is prepared by the
following steps of: mixing an adhesive having adhesiveness, a heat
conductive material, and a solvent, to thus a heat conductive
adhesive material having a viscosity appropriate for
electrospinning; and laminating the heat conductive adhesive
material on one surface or both surfaces of the heat radiation
layer 10 with a predetermined thickness.
[0032] The adhesive layer 20 is spun in the form of ultrafine fiber
strands and adhered on the surface of the heat radiation layer 10.
In this case, the adhesive material is introduced into pores 12 of
the heat radiation layer 10, to thus increase the adhesive strength
between the heat radiation layer 10 and the adhesive layer 20.
Therefore, a phenomenon that the heat radiation layer 10 is peeled
off from the adhesive layer 20 is reduced, thereby improving the
reliability of the heat radiation sheet. In addition, the thickness
of the adhesive layer 20 is made thin by the adhesive material
flowing into the pores 12, and thus the ultra-thin film heat
radiating sheet may be realized.
[0033] The heat conductive material that forms the adhesive layer
20 is the same as the heat conductive material that forms the heat
radiation layer 10.
[0034] Here, in addition to a method of directly electrospinning a
heat conductive adhesive material on the heat radiation layer 10,
it is also possible to use a method of separately preparing the
heat radiation layer 10 and the heat conductive adhesive layer 20
by using an electrospinning method and then laminating the heat
conductive adhesive layer 20 on one surface or both surfaces of the
heat radiation layer 10 in a lamination process.
[0035] The thickness of the heat conductive adhesive layer 20 is
determined in accordance with a dose of the spun heat conductive
adhesive material. Therefore, it is possible to make the heat
conductive adhesive layer 20 in a desired thickness.
[0036] Thus, since the adhesive layer 20 contains the heat
conductive material, the adhesive layer 20 has thermal conductivity
as well as adhesiveness in order to attach the heat radiation layer
on the heat generating component, to thereby improve the heat
radiation performance.
[0037] Meanwhile, in the present invention, the heat conductive
particles may be dispersed and disposed between the heat radiation
layer 10 and the adhesive layer 20.
[0038] The heat conductive particles are disposed at the outside of
nanofibres of the heat radiation layer 10 and nanofibres of the
adhesive layer 20 that are positioned on an interface between the
heat radiation layer 10 and the adhesive layer 20, to thus better
transfer heat generated from the heat generating component of the
electronic equipment, and to thus increase the heat radiation
efficiency.
[0039] Here, when the heat conductive particles and a solvent are
mixed to create a spinning solution, and a bead made of the heat
conductive particle and the solvent is spun on the nano-web of the
adhesive layer 20, in the electrospinning process, the solvent is
volatilized and the heat conductive particles are dispersed into
the nano-web of the adhesive layer 20. Then, the nano-web of the
heat radiation layer 10 is formed at the nano-web of the adhesive
layer 20 to which the heat conductive particles are sprayed, and
the heat conductive particles are dispersed and disposed between
the above-mentioned heat radiation layer 10 and adhesive layer 20,
to thereby manufacture the heat radiation sheet.
[0040] In the present invention, the heat radiation layer 10
quickly diffuses heat generated from heating elements such as LEDs,
CPUs, or ICs, and prevents local temperature rise of the heating
elements.
[0041] FIG. 3 is a cross-sectional view of a heat radiation sheet
according to a second embodiment of the present invention.
[0042] Referring to FIG. 3, the heat radiation sheet according to
the second embodiment includes a substrate 30 that is formed in a
nano-web shape by the electrospinning method, an adhesive layer 40
that is laminated on one surface of the substrate 30, and a metal
layer 50 that is coated on the other surface of the substrate 30
and having thermal conductivity.
[0043] The substrate 30 is formed by the following steps of: mixing
a polymer material and a solvent at a constant rate to thus produce
a spinning solution having a viscosity so as to be electrospun;
electrospinning the spinning solution to thus form nanofibers; and
accumulating the nanofibers to thereby form the substrate 30 having
a number of pores in a nano-web form.
[0044] Further, the substrate 30 may be formed in the same
structure as the heat radiation layer 10 according to the first
embodiment. That is, the substrate 30 may be formed of a polymer
material to thereby have a structure of playing a role of
supporting the metal layer. In addition, the substrate 30 may be
formed of a polymer material containing a heat conductive material
to thereby have a structure of playing a role of supporting the
metal layer, as well as playing a heat conductive role.
[0045] Here, since the polymer material that forms the substrate 30
is the same as the polymer material described in the first
embodiment, the detailed description thereof will be omitted.
[0046] Since the adhesive layer 40 is the same as the structure of
the adhesive layer 20 described in the first embodiment, the
detailed description thereof will be omitted.
[0047] The metal layer 50 is formed of a metal having thermal
conductivity, such as Ni, Cu, or Ag. In addition to a method of
coating the metal, a method of attaching a metal foil may be also
used.
[0048] Thus, the heat radiation sheet according to the second
embodiment is provided with the metal layer 50 having excellent
thermal conductivity, to thereby further improve the heat radiation
performance.
[0049] In the meantime, the metal layer 50 can be implemented into
a metal pattern layer that is coated in a pattern shape on the
other surface of the substrate 30, and the metal pattern layer has
a larger contact area than the metal layer 50 having a face of a
bulk shape, thereby increasing heat radiation efficiency.
[0050] FIG. 4 is a configuration diagram of an electrospinning
device for manufacturing a heat radiation sheet according to the
present invention.
[0051] The electrospinning device according to the present
invention includes: a first mixing tank 70 in which an adhesive
material that is formed by a mixture of an adhesive, a heat
conductive material, and a solvent is stored; a second mixing tank
72 in which a spinning solution that is formed by a mixture of a
polymer material that can be electrospun, the heat conductive
material, and the solvent is stored; a first spinning nozzle unit
74 that is connected to a high voltage generator and that is
connected to the first mixing tank 70, for forming an adhesive
layer 20; a second spinning nozzle unit 76 that is connected to the
high voltage generator and that is connected to the second mixing
tank 72, for forming a heat radiation layer 10; and a collector 78
that is disposed below the first spinning nozzle unit 74 and the
second spinning nozzle unit 76 and that sequentially laminates the
adhesive layer 20 and the heat radiation layer 10.
[0052] The first mixing tank 70 is provided with a first agitator
60 that evenly mixes the adhesive, the heat conductive material,
and the solvent and maintains a constant viscosity of the adhesive
material, and the second mixing tank 72 is provided with a second
agitator 62 that evenly mixes the polymer material, the heat
conductive material, and the solvent and maintains a constant
viscosity of the spinning solution.
[0053] In addition, a high voltage electrostatic force of 90 to 120
Kv is applied between the collector 78 and each of the first and
second spinning nozzle units 74 and 76, to thereby spin nanofibers
14. Accordingly, the nanofibers 14 are collected on the collector
78, to thereby form a nano-web.
[0054] Here, the first and second spinning nozzle units 74 and 76
are arranged with a plurality of nozzles, respectively, which can
be sequentially disposed in a single chamber or disposed in
respectively different chambers.
[0055] The first spinning nozzle unit 74 and the second spinning
nozzle unit 76 are provided with air spray apparatuses 62 and 64,
respectively, to thus prevent the nanofibers 14 spun from the first
spinning nozzle unit 74 and the second spinning nozzle unit 76 from
fluttering without being collected by the collector 78.
[0056] A conveyor that automatically transfers the release film 82
so that the adhesive layer 20 and the heat radiation layer 10 are
sequentially laminated on the release film 82 may be used as the
collector 78. Otherwise, a table-shaped unit may be used as the
collector 78 when the adhesive layer 20 and the heat radiation
layer 10 are formed in respectively different chambers.
[0057] A release film roll 80 is disposed in front of the collector
78, in which the release film 82 is wound on the release film roll
80, to allow the release film 82 to be supplied on top of the
collector 78. In addition, a pressure roller 86 that pressurizes
(or performs calendaring) the adhesive layer 20 and the heat
radiation layer 10 to have a constant thickness is provided at the
rear side of the collector 78. A sheet roll 88 is provided, around
which heat radiation sheets pressurized in a predetermined
thickness via the pressure roller 86 are wound.
[0058] A process for producing the heat radiation sheet by using
the electrospinning apparatus constructed as described above will
be described as follows.
[0059] First, when the collector 78 is driven, the release film 82
wound on the release film roll 80 is released and supplied from the
release film roll 80 to the collector 78.
[0060] Then, a high voltage electrostatic force is applied between
the collector 78 and the first spinning nozzle unit 74, and thus
the adhesive material is made into nanofibers 14 by the first
spinning nozzle unit 74 to then be spun to the surface of the
release film 82. As a result, the nanofibers 14 are accumulated
onto the surface of the release film 82 to thus form the adhesive
layer 20.
[0061] Here, since the adhesive layer 20 contains the heat
conductive material, the adhesive layer 20 also plays a role of
radiating heat for itself.
[0062] Here, when the first spinning nozzle unit 74 spins the
nanofibers 14, an air spray apparatus 62 mounted in the first
spinning nozzle unit 74 sprays air to the nanofibers 14, so that
the nanofibers 14 can be collected and captured on the surface of
the release film 82 without fluttering.
[0063] Then, when the adhesive layer 20 is completely manufactured,
the adhesive layer 20 is moved to the bottom of the second spinning
nozzle unit 76, and when a high voltage electrostatic force is
applied between the collector 78 and the second spinning nozzle
unit 76, the second spinning nozzle unit 76 spins the spinning
solution into the nanofibers 14 and then spins the spun nanofibers
14 on the adhesive layer 20. As a result, the heat radiation layer
10 that is in a nano-web form and has a plurality of pores 12 is
formed on the surface of the adhesive layer 20.
[0064] In this way, the finished heat radiation sheet is pressed to
a predetermined thickness while passing through the pressure roller
86 and is wound on the sheet roll 88.
[0065] In addition to the above-described manufacturing method, it
is possible to employ a method of manufacturing the heat radiation
sheet including: separately preparing the heat radiation layer 10
and the adhesive layer 20; disposing the adhesive layer 20 on one
or both surfaces of the heat radiation layer 10; and laminating
between the heat radiation layer 10 and the adhesive layer 20.
[0066] Here, the heat radiation layer 10 and the adhesive layer 20
are formed on a transfer sheet that is one of nonwoven fabric,
paper, and polyolefin-based film such as PE or PP, which is made of
a polymer material that is not dissolved by the solvent used in the
spinning solution, respectively, the heat radiation layer 10 and
the adhesive layer 20 are laminated on each other, and then the
transfer sheet is removed.
[0067] Further, when the heat radiating sheet is of a structure
that the metal layer 50 is coated on the surface of the substrate
30 that is formed by the electrospinning method, the adhesive layer
40 and the substrate 30 are prepared in the same manner as
described above, and the metal layer 50 is coated on the surface of
the substrate 30, to thereby produce the heat radiation sheet.
[0068] Here, the substrate 30 may contain the heat conductive
material in the same manner as the heat radiation layer 10 as
described above. Furthermore, only a polymer material may be
electrospun to produce the substrate 30, so as to play a role of
the substrate without playing a role of the heat conductive
performance.
[0069] As described above, the present invention has been described
with respect to particularly preferred embodiments. However, the
present invention is not limited to the above embodiments, and it
is possible for one who has an ordinary skill in the art to make
various modifications and variations, without departing off the
spirit of the present invention. Thus, the protective scope of the
present invention is not defined within the detailed description
thereof but is defined by the claims to be described later and the
technical spirit of the present invention.
[0070] The present invention provides a heat radiation sheet that
is manufactured in a nano-web form by way of an electrospinning
method, to thereby be made thin so as to be applied to thin
electronic equipment.
* * * * *