U.S. patent application number 14/910633 was filed with the patent office on 2016-07-14 for method for forming conductive pattern by direct radiation of electromagnetic wave, and resin structure having conductive pattern thereon.
The applicant listed for this patent is LG CHEM, LTD. Invention is credited to Han Nah JEONG, Shin Hee JUN, Sang Yun JUNG, Jae Hyun KIM, Jae Jin KIM, Su Jeong LEE, Chee-Sung PARK, Cheol-Hee PARK, Eun Kyu SEONG.
Application Number | 20160201198 14/910633 |
Document ID | / |
Family ID | 53046827 |
Filed Date | 2016-07-14 |
United States Patent
Application |
20160201198 |
Kind Code |
A1 |
KIM; Jae Hyun ; et
al. |
July 14, 2016 |
METHOD FOR FORMING CONDUCTIVE PATTERN BY DIRECT RADIATION OF
ELECTROMAGNETIC WAVE, AND RESIN STRUCTURE HAVING CONDUCTIVE PATTERN
THEREON
Abstract
Provided are a method for forming conductive pattern by direct
radiation of an electromagnetic wave capable of forming fine
conductive patterns on various kinds of polymer resin products or
resin layers under a relatively low power by a simplified process,
even without containing specific inorganic additives in the polymer
resin itself, and a resin structure having the conductive pattern
formed thereon. The method for forming the conductive pattern by
direct radiation of the electromagnetic wave includes: forming a
first region having a predetermined surface roughness by
selectively radiating the electromagnetic wave on a polymer resin
substrate containing carbon-based black pigment; forming a
conductive seed on the polymer resin substrate; forming a metal
layer by plating the polymer resin substrate having the conductive
seed formed thereon; and removing the conductive seed and the metal
layer from a second region of the polymer resin substrate, wherein
the second region has surface roughness smaller than that of the
first region.
Inventors: |
KIM; Jae Hyun; (Daejeon,
KR) ; SEONG; Eun Kyu; (Daejeon, KR) ; LEE; Su
Jeong; (Daejeon, KR) ; KIM; Jae Jin; (Daejeon,
KR) ; PARK; Cheol-Hee; (Daejeon, KR) ; PARK;
Chee-Sung; (Daejeon, KR) ; JUN; Shin Hee;
(Daejeon, KR) ; JUNG; Sang Yun; (Daejeon, KR)
; JEONG; Han Nah; (Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG CHEM, LTD |
Seoul |
|
KR |
|
|
Family ID: |
53046827 |
Appl. No.: |
14/910633 |
Filed: |
August 7, 2014 |
PCT Filed: |
August 7, 2014 |
PCT NO: |
PCT/KR2014/007328 |
371 Date: |
February 5, 2016 |
Current U.S.
Class: |
428/209 ;
427/556 |
Current CPC
Class: |
C25D 5/02 20130101; C23C
18/2073 20130101; C23C 18/204 20130101; C23C 18/32 20130101; C09D
5/24 20130101; H05K 1/0296 20130101; C25D 5/56 20130101; C23C 18/31
20130101; H05K 1/09 20130101; C23C 18/2053 20130101; C23C 18/30
20130101; C23C 18/1689 20130101; C23C 18/22 20130101; H05K 3/02
20130101; C23C 18/38 20130101; H05K 2201/09009 20130101; C23C
18/1612 20130101; H05K 3/181 20130101; C23C 18/1608 20130101; C23C
18/1641 20130101 |
International
Class: |
C23C 18/31 20060101
C23C018/31; C23C 18/16 20060101 C23C018/16 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 9, 2013 |
KR |
10-2013-0094867 |
Jul 1, 2014 |
KR |
10-2014-0081915 |
Claims
1. A method for forming conductive pattern by direct radiation of
an electromagnetic wave, the method comprising: forming a first
region having a predetermined surface roughness by selectively
radiating the electromagnetic wave on a polymer resin substrate
containing carbon-based black pigment; forming a conductive seed on
the polymer resin substrate; forming a metal layer by plating the
polymer resin substrate having the conductive seed formed thereon;
and removing the conductive seed and the metal layer from a second
region of the polymer resin substrate, wherein the second region
has surface roughness smaller than that of the first region.
2. The method of claim 1, wherein the carbon-based black pigment
includes at least one kind selected from the group consisting of
carbon black, pine black soot, soot, lamp black, channel black,
furnace black, and acetylene black.
3. The method of claim 1, wherein the carbon-based black pigment is
contained in an amount of 0.01 to 10 wt % based on a weight of the
polymer resin substrate.
4. The method of claim 1, wherein the carbon-based black pigment is
contained in a particle state having a particle diameter of 10 nm
to 1 .mu.m.
5. The method of claim 1, wherein when a cross-cut test having an
interval of 2 mm or less according to ISO 2409 standard method is
conducted by using a tape having adhesion of 4.0 to 6.0N/10 mm
width, the first region of the polymer resin substrate has surface
roughness defined by adhesion at which a delamination area of a
target metal layer under test corresponds to 5% or less of an area
of the metal layer.
6. The method of claim 1, wherein when a cross-cut test having an
interval of 2 mm or less according to ISO 2409 standard method is
conducted by using a tape having adhesion of 4.0 to 6.0N/10 mm
width, the second region of the polymer resin substrate has surface
roughness defined by adhesion at which a delamination area of a
target metal layer under test corresponds to 65% or more of an area
of the metal layer.
7. The method of claim 1, wherein the first region of the polymer
resin substrate has surface roughness defined by a center line
arithmetic average roughness of the absolute values (Ra) of 1 .mu.m
or more, and the second region has a center line arithmetic average
roughness of the absolute values (Ra) smaller than that of the
first region.
8. The method of claim 1, wherein the polymer resin substrate
contains at least one kind selected from the group consisting of an
ABS resin, a polyalkylene terephthalate resin, a polycarbonate
resin, a polypropylene resin, and a polyphthalamide resin.
9. The method of claim 1, wherein the radiating of the
electromagnetic wave is performed by radiating a laser
electromagnetic wave under radiation condition having 2 to 20 W of
an average power.
10. The method of claim 1, wherein the conductive seed contains
metal nanoparticles, metal ions, or metal complex ions.
11. The method of claim 10, wherein the conductive seed contains at
least one kind metal selected from the group consisting of copper
(Cu), platinum (Pt), palladium (Pd), silver (Ag), gold (Au), nickel
(Ni), tungsten (W), titanium (Ti), chromium (Cr), aluminum (Al),
zinc (Zn), tin (Sn), lead (Pb), magnesium (Mg), manganese (Mn) and
iron (Fe), ions or complex ions thereof.
12. The method of claim 10, wherein the forming of the conductive
seed includes: applying a dispersion liquid or solution containing
the metal nanoparticles, the metal ions, or the metal complex ions
on the polymer resin substrate; and precipitating and drying the
metal nanoparticles or reducing and drying the metal ions or the
metal complex ions to form the conductive seed in a particle
form.
13. The method of claim 12, wherein the reducing of the metal ions
or the metal complex ions is performed in the presence of at least
one kind reducing agent selected from the group consisting of an
alcohol-based reducing agent, an aldehyde-based reducing agent, a
hypophosphite-based reducing agent, a hydrazine-based reducing
agent, sodium borohydride and lithium aluminum hydride.
14. The method of claim 12, further comprising surface-treating the
polymer resin substrate with a surfactant having surface tension
lower than that of the dispersion liquid or solution, between the
radiating of the electromagnetic wave and the forming of the
conductive seed.
15. The method of claim 1, wherein the forming of the metal layer
includes electroless-plating a conductive metal on the polymer
resin substrate.
16. The method of claim 1, wherein the removing of the conductive
seed and the metal layer from the second region includes applying
physical power onto the polymer resin substrate by combination of
one or two or more method(s) selected from the group consisting of
ultrasonic radiation (sonication), liquid phase washing, liquid
phase rinsing, air blowing, taping, brushing, and a method of using
a manpower.
17. A resin structure having conductive pattern comprising: a
polymer resin substrate divided into a first region formed to have
surface roughness defined by a center line arithmetic average
roughness of the absolute values (Ra) of 1 .mu.m or more and a
second region having surface roughness smaller than that of the
first region, and containing carbon-based black pigment; and a
conductive seed and a metal layer selectively formed on the first
region of the polymer resin substrate.
18. The resin structure of claim 17, wherein the first region
corresponds to a region radiated by the electromagnetic wave.
19. The resin structure of claim 18, wherein the polymer resin
substrate of the second region does not have a peak derived from
copper (Cu) or a compound containing copper on an XRD pattern.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for forming
conductive pattern by direct radiation of a relatively low power
electromagnetic wave capable of forming fine conductive patterns on
various kinds of polymer resin products or resin layers by a
simplified process, even without containing specific inorganic
additives in the polymer resin itself, and a resin structure having
the conductive pattern formed thereon.
BACKGROUND ART
[0002] In recent years, as a fine electronic technology is
developed, demand for a structure in which fine conductive patterns
are formed on a surface of polymer resin substrates (or products)
of various kinds of resin products or resin layers, and the like
has been increased. The conductive patterns on the surface of the
polymer resin substrate and the structure may be applied to form
various targets such as antennas integrated into a cellular phone
case, various kinds of sensors, MEMS structures, RFID tags, and the
like.
[0003] In particular, recent portable devices such as a smart
phone, and the like, need to have simultaneously mounted local area
network functions such as communication, bluetooth, Wi-Fi,
electronic payment, and the like, unlike the existing cellular
phone, and the like, and due to this reason, it is required to
simultaneously mount various antennas in one smart phone. However,
since aesthetic design aspect of the portable devices such as the
smart phone, and the like, in addition thereto, is emphasized, a
method for forming conductive pattern capable of serving as various
antennas on the surface of the polymer resin substrate such as the
case of the portable devices, and the like, has been continuously
suggested and researched so as to simultaneously meet these
demands.
[0004] As the interest in the technology of forming conductive
patterns on the surface of the polymer resin substrate has been
increased, several technologies regarding this were suggested. For
example, a method of forming conductive patterns on a polymer resin
substrate by blending and molding specific inorganic additives
containing transition metals such as copper, chromium, or the like,
(for example, CuCr.sub.2O.sub.4, and the like, in a spinel
structure) in a polymer resin chip to form a polymer resin
substrate, directly radiating an electromagnetic wave such as a
laser, and the like, on a predetermined region, and plating the
laser radiated region to form a metal layer was suggested. In this
method, the inorganic additive-derived components in the laser
radiated region are exposed and function as a seed for a kind of
plating, such that the metal layer and conductive patterns may be
formed.
[0005] However, since a substantial amount of high priced and
specific inorganic additives should be used in the method of
forming the conductive patterns, there is a disadvantage in that
the total manufacturing cost is increased. In addition, since the
inorganic additive needs to be blended into the polymer resin chip
itself, the inorganic additive may deteriorate physical properties
such as mechanical properties, dielectric constant, and the like,
of the polymer resin substrate or resin products formed therefrom,
or may cause dielectric loss. Further, the specific inorganic
additives such as CuCr.sub.2O.sub.4 having the spinel structure,
and the like, have own unique colors, and these colors are not
complete black color or white color, such that the specific
inorganic additives may be deteriorating factors in implementing
the polymer resin substrates or the resin products containing the
specific inorganic additives, with black color, white color or
other various colors desirable to consumers.
[0006] Due to the disadvantages, a technology capable of forming
fine conductive patterns by a simplified process on various kinds
of the polymer resin products or the resin layers without
containing the specific inorganic additives in the polymer resin
itself has been demanded. However, in the case of simply omitting
the adding of the specific inorganic additives, since the
electromagnetic wave needs to be radiated by relatively strong
power, the manufacturing cost may be rather increased, physical
properties of the polymer resin product itself may be deteriorated,
and there is a technical difficulty in that it is difficult to
satisfactorily form fine conductive patterns.
SUMMARY OF INVENTION
Technical Problem
[0007] The present invention has been made in an effort to provide
a method for forming conductive pattern by direct radiation of a
relatively low power electromagnetic wave capable of forming fine
conductive patterns on various kinds of polymer resin products or
resin layers by a simplified process, even without containing
specific inorganic additives in the polymer resin itself.
[0008] In addition, the present invention has been made in an
effort to provide a resin structure having the conductive pattern
obtained by the method for forming the conductive pattern.
Solution to Problem
[0009] An exemplary embodiment of the present invention provides a
method for forming conductive pattern by direct radiation of an
electromagnetic wave, the method including: forming a first region
having a predetermined surface roughness by selectively radiating
the electromagnetic wave on a polymer resin substrate containing
carbon-based black pigment; forming a conductive seed on the
polymer resin substrate; forming a metal layer by plating the
polymer resin substrate having the conductive seed formed thereon;
and removing the conductive seed and the metal layer from a second
region of the polymer resin substrate, wherein the second region
has surface roughness smaller than that of the first region.
[0010] The first region of the polymer resin substrate may have
surface roughness defined by a center line arithmetic average
roughness of the absolute values (Ra) of about 1 .mu.m or more, and
the second region may have a center line arithmetic average
roughness of the absolute values (Ra) smaller than that of the
first region.
[0011] Another exemplary embodiment of the present invention
provides a resin structure having conductive pattern including: a
polymer resin substrate divided into a first region formed to have
surface roughness defined by a center line arithmetic average
roughness of the absolute values (Ra) of about 1 .mu.m or more and
a second region having surface roughness smaller than that of the
first region, and containing carbon-based black pigment; and a
conductive seed and a metal layer selectively formed on the first
region of the polymer resin substrate.
Advantageous Effects of Invention
[0012] According to the present invention, even though high priced
and specific inorganic additives such as CuCr.sub.2O.sub.4 having a
spinel structure, and the like, are not contained in a polymer
resin substrate itself, surface roughness and adhesion to a metal
layer, of a region in which conductive patterns are formed by
radiating an electromagnetic wave such as laser, or the like, may
be adjusted, such that the conductive patterns may be formed on the
polymer resin substrate by a simplified process.
[0013] In particular, since the process is performed in a state in
which carbon-based black pigments showing excellent absorption rate
to the electromagnetic wave such as laser, or the like, for
example, carbon black which is a low-priced general pigment, and
the like, are added, fine conductive patterns may be satisfactorily
formed on the polymer resin substrate even under radiation
condition of the relatively low power electromagnetic wave.
[0014] Therefore, the manufacturing cost of the process of forming
the conductive patterns may be decreased, and deterioration of
physical properties such as mechanical properties, and the like, of
the polymer resin substrate or products caused by the specific
inorganic additive, a high power electromagnetic wave radiation, or
the like, may be minimized. In addition, since the carbon-based
black pigment itself shows a black color which is desirable to
consumer, it is significantly easy to obtain black-colored resin
products, and the like.
[0015] As a result, by using the method for forming the conductive
pattern, conductive patterns for antenna, RFID tags, various kinds
of sensors, MEMS structures, and the like, may be significantly
effectively formed on various kinds of resin products such as a
smart phone case, and the like.
BRIEF DESCRIPTION OF DRAWINGS
[0016] FIG. 1 is a diagram schematically showing one example of a
method for forming conductive pattern by direct radiation of an
electromagnetic wave according to an exemplary embodiment of the
present invention in a process-sequence.
[0017] FIG. 2a is a photograph showing a state in which a
predetermined region has surface roughness by radiating laser to a
polymer resin substrate in the method for forming the conductive
pattern of Example 1, and FIG. 2b is an optical microscope
photograph of a laser radiated region having the surface
roughness.
[0018] FIG. 3a is a photograph showing a state in which the
conductive patterns are formed on the polymer resin substrate by
selectively removing the metal layer, and the like, from a region
not radiated by laser in the method for forming the conductive
pattern of Example 1, and FIG. 3b is an optical microscope
photograph of the metal layer formed in the laser radiated
region.
[0019] FIG. 4 is a photograph showing results obtained by forming
the conductive patterns in Example 1 and performing a cross-cut
test.
[0020] FIG. 5 is an optical microscope photograph of the metal
layer formed in the laser radiated region in the method of forming
the conductive patterns according to Comparative Example 1.
[0021] FIG. 6 is a photograph showing results obtained by forming
the conductive patterns in Reference Example 2 and performing a
cross-cut test.
[0022] FIG. 7 is a view showing results obtained by analyzing XRD
patterns of polymer resin substrates before and after laser
radiation according to Example 1 and Comparative Example 2.
DESCRIPTION OF EMBODIMENTS
[0023] Hereinafter, a method for forming conductive pattern by
direct radiation of an electromagnetic wave according to a specific
exemplary embodiment of the present invention, and a resin
structure having the conductive pattern formed therefrom will be
described.
[0024] According to an exemplary embodiment of the present
invention, the method for forming conductive pattern by direct
radiation of an electromagnetic wave includes: forming a first
region having a predetermined surface roughness by selectively
radiating the electromagnetic wave on a polymer resin substrate
containing carbon-based black pigment; forming a conductive seed on
the polymer resin substrate; forming a metal layer by plating the
polymer resin substrate having the conductive seed formed thereon;
and removing the conductive seed and the metal layer from a second
region of the polymer resin substrate, wherein the second region
has surface roughness smaller than that of the first region.
[0025] According to the exemplary embodiment of the present
invention, first, a surface structure having a shape such as
concavo-convex, patterns, amorphous shape, or the like, is formed
so that a polymer resin substrate of the first region has a
predetermined surface roughness by radiating an electromagnetic
wave such as laser, or the like, on a first region in which the
conductive patterns are formed. In the first region, adhesion
between a surface of the polymer resin substrate and a metal layer
to be formed by plating in the first region may be improved due to
the predetermined surface roughness.
[0026] Meanwhile, in a second region which is not radiated by the
electromagnetic wave such as laser, or the like, poor adhesion
between the surface of the polymer resin substrate and the metal
layer in the second region may be shown due to original surface
property of the polymer resin substrate itself.
[0027] Here, the process of radiating the electromagnetic wave is
performed in a state in which carbon-based black pigments showing
excellent absorption rate to the electromagnetic wave such as
laser, or the like, for example, carbon black which is a low-priced
general pigment, and the like, are added, such that surface
roughness at desired level may be formed in the first region and
adhesion between the polymer resin substrate surface and the metal
layer may be improved to desired level, even under radiation
condition of a relatively low power electromagnetic wave.
[0028] Accordingly, when a conductive seed for facilitating a
plating process is formed on the polymer resin substrate of the
first region and the plating process is performed, the metal layer
having excellent adhesion with the polymer resin substrate may be
favorably formed in the first region; meanwhile, the metal layer
which is easily removed due to poor adhesion may be formed in the
second region. Therefore, when weak physical power is applied to
the polymer resin substrate to selectively remove the metal layer
and the conductive seed of the second region, desired conductive
patterns may be easily formed on the polymer resin substrate.
[0029] As described above, according to an exemplary embodiment of
the present invention, for example, even though high priced
specific inorganic additives such as CuCr.sub.2O.sub.4, and the
like, having the spinel structure are not contained in the polymer
resin substrate itself, surface roughness, adhesion, and the like,
of the region in which the conductive patterns are formed by
radiating the electromagnetic wave such as laser, or the like, may
be adjusted, such that the conductive patterns may be formed on the
polymer resin substrate by a simplified process. In addition, by
using the carbon-based black pigment as described above, fine
conductive patterns may be satisfactorily formed on the polymer
resin substrate even under radiation condition of a low power
electromagnetic wave.
[0030] Therefore, the manufacturing cost of the process of forming
the conductive patterns may be decreased, and deterioration of
physical properties such as mechanical properties, and the like, of
the polymer resin substrate or products caused by the specific
inorganic additive, may be minimized. In addition, since the
carbon-based black pigment itself shows a black color which is
desirable to consumer, it is significantly easy to obtain black
colored resin products, and the like.
[0031] Meanwhile, hereinafter, the method for forming the
conductive pattern by direct radiation of an electromagnetic wave
according to an exemplary embodiment of the present invention is
more specifically described for each process step with reference to
drawings. FIG. 1 is a diagram schematically showing one example of
a method for forming conductive pattern by direct radiation of an
electromagnetic wave according to an exemplary embodiment of the
present invention in a process-sequence.
[0032] As shown in FIG. 1, in the method for forming the conductive
pattern according to an exemplary embodiment, the first region
having a predetermined surface roughness is firstly formed by
selectively radiating an electromagnetic wave on the polymer resin
substrate.
[0033] Here, the polymer resin substrate may include without
specific limitation any thermosetting resin or any thermoplastic
resin capable of forming various polymer resin products or resin
layers. Specific examples of the polymer resin capable of forming
the polymer resin substrate may include a polyalkylene
terephthalate resin such as an ABS resin, a polybutylene
terephthalate resin, a polyethylene terephthalate resin, or the
like, a polycarbonate resin, a polypropylene resin, a
polyphthalamide resin, and the like, and in addition thereto, the
polymer resin substrate may be formed by using various polymer
resins.
[0034] In addition, the polymer resin substrate contains the
carbon-based black pigment to increase absorption rate to the
electromagnetic wave such as laser or the like, so as to form the
first region having a predetermined surface roughness even under an
radiation condition of a low power electromagnetic wave.
[0035] As the carbon-based black pigment, any pigment components
including carbon-based components as a major component, having high
absorption rate to the laser, and the like, and showing color close
to black color may be used. Specific examples thereof may be at
least one kind selected from the group consisting of carbon black,
pine black soot, soot, lamp black, channel black, furnace black,
and acetylene black.
[0036] In addition, the carbon-based black pigment may be contained
in an amount of about 0.01 to 10 wt %, or about 0.1 to 5 wt %, or
about 0.2 to 1 wt % based on the weight of the polymer resin
substrate. Accordingly, the polymer resin substrate may have
excellent absorption rate to the electromagnetic wave, such that
the first region having a predetermined surface roughness may be
formed even under the radiation condition of a low power
electromagnetic wave. In addition, an increase in the manufacturing
cost caused by addition of separate additives, or deterioration of
physical properties of the polymer resin substrate may be
reduced.
[0037] Further, it is preferred that the carbon-based black pigment
have a particle state having a particle diameter of about 10 nm to
1 .mu.m, or about 20 nm to 200 nm, so as to have appropriate level
of absorption rate to an electromagnetic wave in the polymer resin
substrate, and to more reduce the deterioration of physical
properties of the polymer resin substrate.
[0038] Meanwhile, additives which are generally used to form the
polymer resin products, for example, an UV stabilizer, a heat
stabilizer, an impact reinforcing agent, and the like, may be
further added or included in the polymer resin substrate as needed,
in addition to the above-described carbon-based black pigment. The
additives may be contained in an appropriate amount of about 2 wt %
or less, or about 0.05 to 2.0 wt %, based on the weight of the
total polymer resin substrate. Meanwhile, the polymer resin
substrate does not have to include the specific inorganic additives
such as CuCr.sub.2O.sub.4 having a spinel structure, and the like,
used to form the conductive patterns by radiating the
electromagnetic wave which are known in the art.
[0039] In addition, the first region has a predetermined surface
roughness by radiating laser on the above-described polymer resin
substrate, wherein in the first region having the surface
roughness, relatively standardized patterns such as hole, mesh
pattern, and the like, or concavo-convex shapes may be formed, or
amorphous surface structure in which a plurality of irregular
holes, patterns, or concavo-convex are complexly formed may be
formed, and the polymer resin substrate of the first region may
have a predetermined surface roughness due to the various surface
shapes or structures. Meanwhile, in order to secure excellent
adhesion between the metal layer (conductive patterns) to be formed
on the first region and the surface of the polymer resin substrate,
the polymer resin substrate of the first region may have a
predetermined level or more of surface roughness by radiating an
electromagnetic wave such as laser, or the like.
[0040] As an example, the first region of the polymer resin
substrate may have surface roughness defined by a center line
arithmetic average roughness of the absolute values (Ra) of about 1
.mu.m or more, or about 1 to 10 .mu.m, or about 1 to 6 .mu.m, or
about 1 to 3 .mu.m, and the second region which is not radiated by
the electromagnetic wave may have surface roughness defined by a
central line surface roughness (Ra) smaller than that of the first
region, for example, about 400 nm or less, or about 300 nm or less,
or about 0 to 300 nm, or about 50 to 250 nm.
[0041] In addition, in another example, the surface roughness of
the first and second regions may also be defined by degree of
adhesion to the metal layer measured in a cross-cut test according
to ISO 2409 standard method. For example, when a cross-cut test
having an interval of 2 mm or less according to ISO 2409 standard
method is conducted by using a tape having adhesion of about 4.0 to
6.0N/10 mm width, the first region of the polymer resin substrate
may have surface roughness defined by adhesion (for example, ISO
class 0 or 1) at which a delamination area of a target metal layer
under test corresponds to about 5% or less of an area of the metal
layer, and when a cross-cut test having an interval of 2 mm or less
according to ISO 2409 standard method is conducted by using a tape
having adhesion of about 4.0 to 6.0N/10 mm width, the second region
of the polymer resin substrate may have surface roughness defined
by adhesion (for example, ISO class 5 or more) at which a
delamination area of a target metal layer under test corresponds to
about 65% or more of an area of the metal layer.
[0042] As the polymer resin substrate of the first region has the
above-described surface roughness by radiating the electromagnetic
wave such as laser, or the like, when the metal layer is formed on
the first region in the following plating process, the metal layer
may be formed and maintained on the polymer resin substrate with
excellent adhesion, to form excellent conductive patterns. As
compared to the first region, as the polymer resin substrate of the
second region which is not radiated by an electromagnetic wave such
as laser, or the like, has the above-described surface roughness
due to surface property of the substrate, when the metal layer is
formed on the following plating process, the metal layer may be
easily removed due to significantly low adhesion from the second
region. As a result, the metal layer of the second region may be
easily and selectively removed to form the conductive patterns on
the polymer resin substrate of the first region.
[0043] Meanwhile, an electromagnetic wave such as laser, or the
like, may be radiated under predetermined conditions as described
below so that the polymer resin substrate of the first region has
the above-described surface roughness.
[0044] First, in the radiating of the electromagnetic wave, laser
electromagnetic wave may be radiated, for example, laser
electromagnetic wave having a wavelength of about 248 nm, about 308
nm, about 355 nm, about 532 nm, about 585 nm, about 755 nm, about
1064 nm, about 1070 nm, about 1550 nm, about 2940 nm or about 10600
nm may be radiated. In another example, laser electromagnetic wave
having a wavelength in infrared ray (IR) region may be
radiated.
[0045] In addition, specific conditions at the time of radiating
laser electromagnetic wave may be controlled or changed depending
on kinds of the resin, physical properties, thickness, of the
polymer resin substrate, kinds or thickness of the metal layer to
be formed, or appropriate level of adhesion in consideration of the
above-mentioned factors. Meanwhile, the laser electromagnetic wave
may be radiated under condition that an average power is about 2 W
or more, or about 2 to 20 W, or about 3 to 10 W, so that the
polymer resin substrate of the first region has a predetermined
surface roughness as described above. As described above, since the
carbon-based black pigment having high absorption rate to the
electromagnetic wave, and the like, are contained in the polymer
resin substrate, the first region having appropriate surface
roughness may be formed even under a low power condition, and the
metal layer to be formed later may have excellent adhesion to the
polymer resin substrate of the first region.
[0046] In addition, the laser electromagnetic wave may be radiated
once by a relatively high power, but the laser electromagnetic wave
may also be radiated two or more times by a relatively low power.
As the number of radiating the laser electromagnetic wave is
increased, the surface roughness is increased, structures such as
concavo-convex, and the like, formed on the surface may be changed
from hole shaped patterns to mesh pattern, amorphous surface
structures or the like. Therefore, by controlling the condition and
the number of radiating laser electromagnetic wave, appropriate
surface structure may be formed on the polymer resin substrate of
the first region, and the surface roughness having an appropriate
degree and excellent adhesion to the metal layer may be
provided.
[0047] Further, at the time of radiating laser electromagnetic
wave, radiation trace of the electromagnetic wave may be formed in
a hole shape or the like on the polymer resin substrate depending
on an radiation interval. However, in order that the polymer resin
substrate of the first region has the above-mentioned appropriate
surface roughness, it is preferred that the laser electromagnetic
wave be radiated so that an interval between central parts of
radiation trace of the electromagnetic wave, or an radiation
interval of the electromagnetic wave is about 20 .mu.m or more, or
about 20 to 70 .mu.m, but is not particularly limited thereto. As a
result, the polymer resin substrate of the first region may have
appropriate surface roughness and appropriate adhesion with the
metal layer, and deterioration of physical properties or the like
of the polymer resin substrate may be decreased.
[0048] Meanwhile, as described above, after radiating the
electromagnetic wave such as laser, or the like, on the first
region, a conductive seed may be formed on the polymer resin
substrate as shown in FIG. 1. The conductive seed is grown on the
polymer resin substrate at the time of plating, and promotes
formation of the metal layer by the plating. Accordingly, more
excellent metal layer and the conductive patterns may be
appropriately formed on the polymer resin substrate of the first
region.
[0049] The conductive seed may contain metal nanoparticles, metal
ions, or metal complex ions. In addition, the metal ion or the
metal complex ion may be used as ion itself or as metal-containing
compounds to which the metal ions are coupled or as metal complexes
containing metal complex ions, or even as particles of the
metal-containing compounds or the metal complexes.
[0050] The kind of the metal atoms which may be included in the
conductive seed is not particularly limited as long as the metal
atom has conductivity. For example, the conductive seed may contain
at least one kind metal selected from the group consisting of
copper (Cu), platinum (Pt), palladium (Pd), silver (Ag), gold (Au),
nickel (Ni), tungsten (W), titanium (Ti), chromium (Cr), aluminum
(Al), zinc (Zn), tin (Sn), lead (Pb), magnesium (Mg), manganese
(Mn) and iron (Fe), ions or complex ions thereof.
[0051] In addition, in order to form the conductive seed on the
polymer resin substrate, a dispersion liquid or solution containing
the above-mentioned conductive seed such as the metal
nanoparticles, the metal ions, or the metal complex ions may be
applied on the polymer resin substrate, followed by a precipitating
method, a drying method, and/or a reducing method, to thereby form
the conductive seed in a desirable form, for example, a particle
form. More specifically, when the dispersion liquid, or the like,
contains the metal nanoparticles, the metal nanoparticles are
precipitated by difference in solubility and dried to appropriately
form the conductive seed in a particle form, and when the
dispersion liquid, or the like, contains the metal ions, or the
metal complex ions (or the metal compounds or the complexes
containing these ions), the metal ions, or the metal complex ions
are reduced and dried to appropriately form the conductive seed in
a particle form.
[0052] Here, the reducing of the metal ion or the metal complex ion
may be performed by using general reducing agents, for example, at
least one kind reducing agent selected from the group consisting of
an alcohol-based reducing agent, an aldehyde-based reducing agent,
hypophosphite-based reducing agent such as hypophosphorous acid
sodium or hydrates thereof, or the like, hydrazine-based reducing
agent such as hydrazine or hydrates thereof, or the like, sodium
borohydride and lithium aluminum hydride.
[0053] In addition, the dispersion liquid or the solution may
appropriately include an aqueous-based polymer solution capable of
improving close adhesion between the polymer resin substrate and
the conductive seed, or an aqueous-based complexing agent capable
of stabilizing the metal ions or the metal complex ions, as a
liquid-phase medium.
[0054] Further, the dispersion liquid or the solution of the
conductive seed may be applied by general processes for applying a
liquid-phase composition to the polymer resin substrate, for
example, methods such as dipping, spin coating, spraying, or the
like.
[0055] The conductive seed formed as described above may be formed
on the entire surface of the polymer resin substrate including
space between the surface concavo-convex, patterns, or surface
structures formed on the first region, and may serve to promote
favorable formation of the metal layer in the plating process and
to control plating rate, physical properties of the metal
layer.
[0056] Meanwhile, right after the radiating of the electromagnetic
wave as described above, the process of forming the conductive seed
may be immediately performed; however, after the polymer resin
substrate is selectively surface-treated with a surfactant having
surface tension lower than that of the dispersion liquid or
solution, the process of forming the conductive seed may be
performed. In addition, the polymer resin substrate may be
surface-treated in a state in which the surfactant is added to the
dispersion liquid or the solution itself for forming the conductive
seed.
[0057] The surfactant may allow the conductive seed to be more
uniformly formed and maintained on the surface of the polymer resin
substrate, in particular, between the surface concavo-convex,
patterns, or surface structures. The reason is because the
surfactant removes air between the surface structures to assist the
conductive seed in being easily permeated between the surface
structures. Therefore, when the treatment with the surfactant is
added, the conductive seed is favorably adsorbed entirely onto the
first region, and the metal layer may be more uniformly and
favorably formed by the plating process. In addition, due to the
treatment with the surfactant and the formation of the conductive
seed, adhesion between the metal layer and the polymer resin
substrate on the first region may be more improved to favorably
form the conductive patterns having excellent conductivity.
[0058] Kinds of the surfactant may differ depending on kinds of the
dispersion liquid or the solution of the conductive seed as
described above, and may include any liquid phase medium having
surface tension lower than that of the dispersion liquid or the
solution. For example, organic solvents such as ethanol, and the
like, having relatively low surface tension may be used as the
surfactant.
[0059] In addition, the surfactant may be treated by a method of
immersing the polymer resin substrate for several seconds to
several minutes, and the like.
[0060] Meanwhile, referring to FIG. 1, after the conductive seed is
formed on the polymer resin substrate, the metal layer may be
formed by plating the polymer resin substrate having the conductive
seed formed thereon. The process of forming the metal layer may be
performed by electroless-plating the conductive metal on the
polymer resin substrate, and methods and conditions of performing
the electroless-plating process may be conducted by general methods
and conditions.
[0061] For example, the plating process is performed by using a
plating solution containing conductive metals forming the metal
layer, for example, metal sources such as copper, and the like,
complexing agents, pH adjustors, reducing agent, and the like, to
form the metal layer on the polymer resin substrate including the
first region and the second region. Here, the metal layer may be
formed on the grown conductive seed as described above.
[0062] The metal layer may be favorably formed on the first region
by excellent adhesion; meanwhile, the metal layer may be easily
removed from the second region due to poor adhesion to the polymer
resin substrate.
[0063] After the metal layer is formed, the conductive seed and the
metal layer may be selectively removed from the second region of
the polymer resin substrate to form the conductive patterns on the
remaining first region.
[0064] As described above, since the metal layer is formed on the
second region in a state in which it is significantly easy to
remove the metal layer, the metal layer and the conductive seed may
be selectively removed from the second region by simple methods
such as applying weak physical power to the polymer resin
substrate, and the like. Here, due to excellent adhesion between
the metal layer and the polymer resin substrate on the first
region, the metal layer may remain to form the conductive
patterns.
[0065] As described above, the process of removing the conductive
seed and the metal layer from the second region, may be performed
by any method of applying weak physical power onto the polymer
resin substrate such as ultrasonic radiation (sonication), liquid
phase washing, liquid phase rinsing, air blowing, taping, brushing,
or methods of using a manpower such as directly dusting or wiping
with hands, or by a combination of two or more methods selected
therefrom.
[0066] For example, washing or rinsing is performed in deionized
water under the ultrasonic radiation for a predetermined time, and
air blowing, and the like, are performed, such that the conductive
seed and the metal layer of the second region may be selectively
removed.
[0067] The resin structure having the conductive pattern formed by
the above-described method may include the polymer resin substrate
divided into the first region formed to have surface roughness
defined by a center line arithmetic average roughness of the
absolute values (Ra) of about 1 .mu.m or more and the second region
having surface roughness smaller than that of the first region,
containing carbon-based black pigment; and the conductive seed and
the metal layer selectively formed on the first region of the
polymer resin substrate.
[0068] Here, since the surface roughness of the first and second
regions is sufficiently described in the method according to an
exemplary embodiment, additional description thereof will be
omitted. In addition, as described above, the first region may
correspond to a region in which the electromagnetic wave such as
laser, or the like, is radiated.
[0069] In this resin structure, even after radiating the
electromagnetic wave such as laser, or the like, the carbon-based
black pigment only serves to improve absorption rate of the
electromagnetic wave radiation, but is not destroyed by the
electromagnetic wave radiation or does not form metal nucleus, and
the like, derived from the radiation, which is different from the
specific inorganic additives such as CuCr.sub.2O.sub.4 having a
spinel structure, and the like, used in the related art. Further,
the resin structure does not include the specific inorganic
additive such as CuCr.sub.2O.sub.4, and the like.
[0070] As a result, in the structure, the polymer resin substrate
of the second region (or the first region before radiating laser)
may show XRD pattern not including peaks derived from the specific
inorganic additives, for example, conductive transition metal such
as copper or silver, or metal compounds containing the conductive
transition metal. One example of the XRD pattern is shown in FIG.
7.
[0071] Meanwhile, the resin structure as described above may be
various kinds of resin products or resin layers such as a smart
phone case, and the like, having conductive patterns for antenna,
or may be various kinds of resin products or resin layers having
conductive patterns such as other RFID tags, various kinds of
sensors, or MEMS structures, and the like.
[0072] As described above, according to exemplary embodiments of
the present invention, even though high priced and specific
inorganic additives such as CuCr.sub.2O.sub.4 having a spinel
structure, and the like, are not contained in the polymer resin
substrate itself, surface roughness and adhesion to a metal layer,
of a region in which conductive patterns are formed by radiating an
electromagnetic wave such as laser, or the like, may be adjusted,
such that excellent conductive patterns may be formed on the
polymer resin substrate by a simplified process under radiation
condition of the electromagnetic wave having relatively low
power.
[0073] Therefore, the manufacturing cost of the process of forming
the conductive patterns may be decreased, and possibility of
deteriorating physical properties such as mechanical properties,
dielectric constant, and the like, of the polymer resin substrate
or products, may be reduced by the specific inorganic additive.
Further, it is easy to implement polymer resin products having
black colors by unique color of the carbon-based black pigment.
[0074] Hereinafter, action and effects of the present invention are
described by specific examples of the present invention in detail.
Meanwhile, these examples are provided by way of example, and
therefore, should not be construed as limiting the scope of the
present invention.
Example 1
Formation of Conductive Patterns by Laser Direct Radiation
[0075] A polycarbonate resin substrate containing an UV stabilizer,
a thermal stabilizer, and an impact reinforcing agent having a
total amount of less than 2 wt %, and containing 0.25 wt % of
carbon black was prepared. Laser having a wavelength of 1064 nm was
radiated once onto a predetermined region of the polycarbonate
resin substrate under radiation condition (average power: 6.7 W)
having an power ratio of 25%. Here, the interval between central
parts of the laser radiation trace of the polycarbonate resin
substrate was controlled to be about 50 .mu.m by controlling the
radiation interval of the laser.
[0076] Accordingly, the polycarbonate resin substrate radiated by
laser had a predetermined surface roughness on the predetermined
region. The center line arithmetic average roughness of the
absolute values (Ra) of the region radiated by laser and the region
which is not radiated by laser were measured. These Ra were
measured in an area of 0.2 mm.times.0.3 mm by using an optical
profiler (Nano view E1000, Nanosystem, Korea). As a result of the
measurement, the region radiated by laser had Ra of about 5630 nm
and the region which is not radiated by laser had Ra of about 226
nm. A photograph of the polycarbonate resin substrate as
manufactured above was shown in FIG. 2a, and an optical microscope
photograph of the region radiated by laser formed so as to have the
surface roughness was shown in FIG. 2b.
[0077] Then, the polycarbonate resin substrate was immersed into an
aqueous-based polymer solution including Pd-containing compound
particles to have Pd ions for about 5 minutes, to form conductive
seed particles including Pd on the substrate. Next, the substrate
was washed with deionized water, and an electroless-plating was
performed by using copper as a conductive metal. At the time of the
electroless-plating, a plating solution containing copper source
(copper sulfate), a complexing agent (Rochelle salt), a pH adjustor
(sodium hydroxide aqueous solution), and a reducing agent
(formaldehyde), was used. The electroless-plating was performed at
room temperature for about 1 hour, followed by ultrasonic cleaning,
to form the metal layer. It could be confirmed that the metal layer
was favorably formed on the region radiated by laser; however, the
metal layer in the remaining region was formed in a delamination
state due to poor adhesion to be significantly easily removed.
[0078] Then, the substrate was immersed into the deionized water,
followed by ultrasonic radiation (sonication) for 20 minutes, and
air blowing, to selectively remove the metal layer of the region
which is not radiated by laser. Accordingly, the conductive
patterns having the metal layer were selectively formed on the
region radiated by laser, and a photograph thereof was shown in
FIG. 3a, and an optical microscope photograph of the metal layer
formed on the region radiated by laser through electroless plating
was shown in FIG. 3b.
[0079] Meanwhile, a cross-cut test according to ISO 2409 standard
method was conducted by using a tape having about 4.9N/10 mm width
(3M scotch tape #371) in the region radiated by laser, that is, the
region having the metal layer and the conductive patterns formed
thereon. Here, adhesion between the substrate and the metal layer
was tested by cutting the metal layer to be 10.times.10 graph (an
interval of about 2 mm or less), and measuring area of the metal
layer delaminated by attaching and detaching the tape. A photograph
showing results obtained by conducting the adhesion test was shown
in FIG. 4.
[0080] As a result of the adhesion test, it could be confirmed that
the delamination area of the target metal layer under the test
corresponds to about 0% (ISO class 0) of the area of the metal
layer, and the metal layer and the conductive patterns were
favorably formed on the region radiated by laser by excellent
adhesion.
Example 2
Formation of Conductive Patterns by Laser Direct Radiation
[0081] Conductive patterns of Example 2 were formed by the same
method as Example 1 except for using a multilayer substrate of
polycarbonate/ABS resin instead of using the polycarbonate resin
substrate.
[0082] In Example 2, after radiating laser, the center line
arithmetic average roughness of the absolute values (Ra) of the
region radiated by laser and the region which is not radiated by
laser were measured by the same method as Example 1, and the region
radiated by laser had Ra of about 5370 nm and the region which is
not radiated by laser had Ra of about 183 nm, respectively.
[0083] In addition, after the metal layer and the conductive
patterns were formed in Example 2, a cross-cut test was conducted
by the same method as Example 1 in the region having the metal
layer and the conductive patterns formed thereon. As a result of
the adhesion test, it could be confirmed that the delamination area
of the target metal layer under test corresponds to about 5% or
less (ISO class 1) of the area of the metal layer, and the metal
layer and the conductive patterns were favorably formed on the
region radiated by laser by excellent adhesion.
Comparative Example 1
Formation of Conductive Patterns by Laser Direct Radiation
[0084] Conductive patterns of Comparative Example 1 were formed by
the same method as Example 1 except that the process of forming the
conductive seed particles including Pd in Example 1 was not
performed. An optical microscope photograph of the metal layer
formed on the region radiated by laser through the
electroless-plating according to Comparative Example 1 was shown in
FIG. 5.
[0085] It could be appreciated from FIG. 5 that the conductive seed
particles were not formed, such that the plating was performed only
in a portion of the region radiated by laser. For reference, only
shining portions among the entirely dark portion in FIG. 5 are
portions in which the plating was completely performed. That is, it
was confirmed in Comparative Example 1 that the electroless-plating
was not completely performed even in the region radiated by laser,
such that the metal layer and the conductive patterns were not
completely formed.
Comparative Example 2
Formation of Conductive Patterns by Laser Direct Radiation
[0086] Conductive patterns of Comparative Example 2 were formed by
the same method as Example 1 except that the carbon black was not
used and the radiation condition of the laser was changed into the
radiation condition (average power: 18.6 W) having an power ratio
of 70%.
[0087] In Comparative Example 2, after radiating laser, the center
line arithmetic average roughness of the absolute values (Ra) of
the region radiated by laser and the region which is not radiated
by laser were measured by the same method as Example 1, and the
region radiated by laser had Ra of about 830 nm and the region
which is not radiated by laser had Ra of about 223 nm,
respectively.
[0088] In addition, after the metal layer and the conductive
patterns were formed in Comparative Example 2, a cross-cut test was
conducted by the same method as Example 1 in the region having the
metal layer and the conductive patterns formed thereon. As a result
of the adhesion test, it could be confirmed that the delamination
area of the target metal layer under test corresponds to more than
about 5% to 15% or less (ISO class 2) of the area of the metal
layer, and therefore, the metal layer and the conductive patterns
were formed on the region radiated by laser; however, the
conductive patterns were not favorably maintained by relatively
poor adhesion to the substrate.
Reference Example 1
Formation of Conductive Patterns by Laser Direct Radiation (Using
Specific Inorganic Additive)
[0089] Reference Example 1 was performed by using 5 wt % of
CuCr.sub.2O.sub.4 instead of using carbon black of Example 1. Then,
laser radiation was performed under radiation condition (average
power: 6.7 W) having an power ratio of 25%. Conductive patterns of
Reference Example 1 were formed by the same method as Example 1
expect that the process of forming the conductive seed particles
was not performed after radiating laser, and ultrasonic cleaning
was not performed after the electroless-plating process.
[0090] In Reference Example 1, after radiating laser, the center
line arithmetic average roughness of the absolute values (Ra) of
the region radiated by laser and the region which is not radiated
by laser were measured by the same method as Example 1, and the
region radiated by laser had Ra of about 6200 nm and the region
which is not radiated by laser had Ra of about 213 nm,
respectively.
[0091] In addition, after the metal layer and the conductive
patterns were formed in Reference Example 1, a cross-cut test was
conducted by the same method as Example 1 in the region having the
metal layer and the conductive patterns formed thereon. As a result
of the adhesion test, it could be confirmed that the delamination
area of the target metal layer under test corresponds to about 5%
or less (ISO class 0) of the area of the metal layer, and the metal
layer and the conductive patterns were favorably formed on the
region radiated by laser. Meanwhile, it could be confirmed that the
specific inorganic additive having relatively high content (5 wt %)
was required to be used, and the radiation condition of laser
corresponding to that of Example 1 was required, in order to form
excellent conductive patterns.
Reference Example 2
Formation of Conductive Patterns by Laser Direct Radiation
[0092] Conductive patterns of Reference Example 2 were formed by
the same method as Reference Example 1 except that the radiation
condition of laser was changed into the radiation condition
(average power: 5.3 W) having an power ratio of 20%.
[0093] In Reference Example 2, after radiating laser, the center
line arithmetic average roughness of the absolute values (Ra) of
the region radiated by laser and the region which is not radiated
by laser were measured by the same method as Example 1, and the
region radiated by laser had Ra of about 970 nm and the region
which is not radiated by laser had Ra of about 197 nm,
respectively.
[0094] In addition, after the metal layer and the conductive
patterns were formed in Reference Example 2, a cross-cut test was
conducted by the same method as Example 1 in the region having the
metal layer and the conductive patterns formed thereon. Photograph
showing the result of the above-mentioned test was shown in FIG. 6.
As a result of the adhesion test, it could be confirmed that the
delamination area of the target metal layer under test corresponds
to more than about 5% to 15% or less (ISO class 2) of the area of
the metal layer, and therefore, the metal layer and the conductive
patterns were formed on the region radiated by laser; however, the
conductive patterns were not favorably maintained by relatively
poor adhesion to the substrate.
[0095] It could be confirmed from test results of Examples,
Comparative Examples, and Reference Examples as described above
that according to Examples, excellent conductive patterns were
formed on the region radiated by laser without using the specific
inorganic additive even under the radiation condition of the laser
having relatively low power.
[0096] It could be confirmed from Comparative Examples that since
carbon black is not used or the process of forming the conductive
seed particles is not performed, excellent conductive patterns
could not be formed even under the radiation condition of the laser
having relatively high power.
[0097] In addition, it could be confirmed that in Reference Example
1, excellent conductive patterns were formed under the radiation
condition of laser corresponding to that of Example 1; however, the
specific inorganic additive having relatively high content was
required, and when the radiation condition of laser is a slightly
decreased like Reference Example 2, it is difficult to form
excellent conductive patterns.
Experimental Example
Comparison in XRD Pattern Between Region Radiated by Laser and
Region not Radiated by Laser
[0098] XRD patterns of the substrates before and after radiating
laser according to Example 1 and Comparative Example 2 were
analyzed and shown in FIG. 7. Referring to FIG. 7, it could be
confirmed that the XRD patterns before and after radiating laser
were the same as each other in Example 1, similar to Comparative
Example 2 in which the separate additive was not used.
[0099] In addition, referring to FIG. 7, it could be confirmed that
in the XRD patterns of Example 1 and Comparative Example 2, peaks
derived from the specific inorganic additives, for example, the
conductive transition metal such as copper or silver or metal
compounds containing the conductive transition metal, were not
shown.
* * * * *