U.S. patent application number 14/910915 was filed with the patent office on 2016-07-21 for method for forming conductive pattern by direct radiation of electromagnetic wave, and resin structure having conductive pattern thereon (as amended).
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, Chee-Sung PARK, Cheol-Hee PARK.
Application Number | 20160212860 14/910915 |
Document ID | / |
Family ID | 53046827 |
Filed Date | 2016-07-21 |
United States Patent
Application |
20160212860 |
Kind Code |
A1 |
KIM; Jae Hyun ; et
al. |
July 21, 2016 |
METHOD FOR FORMING CONDUCTIVE PATTERN BY DIRECT RADIATION OF
ELECTROMAGNETIC WAVE, AND RESIN STRUCTURE HAVING CONDUCTIVE PATTERN
THEREON (As Amended)
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 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; 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) ; 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. |
Yeongdeungpo-gu Seoul |
|
KR |
|
|
Family ID: |
53046827 |
Appl. No.: |
14/910915 |
Filed: |
July 24, 2014 |
PCT Filed: |
July 24, 2014 |
PCT NO: |
PCT/KR2014/006756 |
371 Date: |
February 8, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09D 5/24 20130101; H05K
3/181 20130101; C23C 18/32 20130101; C23C 18/1689 20130101; C23C
18/22 20130101; C23C 18/1612 20130101; C23C 18/1608 20130101; C23C
18/1641 20130101; H05K 1/0296 20130101; C23C 18/30 20130101; H05K
1/09 20130101; C23C 18/2053 20130101; C23C 18/2073 20130101; H05K
2201/09009 20130101; C23C 18/38 20130101; C25D 5/02 20130101; C23C
18/204 20130101; C25D 5/56 20130101; H05K 3/02 20130101; C23C 18/31
20130101 |
International
Class: |
H05K 3/18 20060101
H05K003/18; H05K 1/09 20060101 H05K001/09; H05K 1/02 20060101
H05K001/02; H05K 3/02 20060101 H05K003/02; C23C 18/16 20060101
C23C018/16; C23C 18/31 20060101 C23C018/31 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 9, 2013 |
KR |
10-2013-0094867 |
Jul 24, 2014 |
KR |
10-2014-0093782 |
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;
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 first region of the polymer
resin substrate has surface roughness defined by a center line
arithmetic average roughness of the absolute values (Ra) of 500 nm
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.
3. 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.
4. 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.
5. The method of claim 1, wherein the polymer resin substrate
contains a thermosetting resin or a thermoplastic resin.
6. The method of claim 5, 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.
7. The method of claim 1, wherein the radiating of the
electromagnetic wave is performed by radiating a laser
electromagnetic wave having a wavelength of 248 nm, 308 nm, 355 nm,
532 nm, 585 nm, 755 nm, 1064 nm, 1070 nm, 1550 nm, 2940 nm or 10600
nm.
8. The method of claim 1, wherein the radiating of the
electromagnetic wave is performed by radiating a laser
electromagnetic wave under radiation condition having 0.1 to 50 W
of an average power.
9. The method of claim 1, wherein the radiating of the
electromagnetic wave is performed by radiating a laser
electromagnetic wave so that an interval between central parts of
radiation trace of the electromagnetic wave shown on the polymer
resin substrate is 20 to 70 .mu.m.
10. The method of claim 1, wherein the radiating of the
electromagnetic wave is performed by radiating a laser
electromagnetic wave once or by radiating the laser electromagnetic
wave two or more times.
11. The method of claim 1, wherein the conductive seed contains
metal nanoparticles, metal ions, or metal complex ions.
12. The method of claim 11, 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.
13. The method of claim 11, 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.
14. The method of claim 13, 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.
15. The method of claim 13, further comprising: adding a surfactant
having surface tension lower than that of the dispersion liquid or
the solution in the forming of the conductive seed, or
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.
16. The method of claim 1, wherein the forming of the metal layer
includes electroless-plating a conductive metal on the polymer
resin substrate.
17. 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.
18. A resin structure having conductive pattern comprising: a
polymer resin substrate including a first region formed to have a
predetermined surface roughness and a second region having surface
roughness smaller than that of the first region; and a conductive
seed and a metal layer selectively formed on the first region of
the polymer resin substrate.
19. The resin structure of claim 18, wherein the first region
corresponds to a region radiated by the electromagnetic wave.
20. The resin structure of claim 18, 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 500 nm 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.
21. The resin structure of claim 18, 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.
22. The resin structure of claim 18, 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.
Description
TECHNICAL FIELD
[0001] The present invention relates to 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 by a simplified process,
even without containing specific inorganic additives in the polymer
resin itself, and a resin structure having the conductive pattern
formed therefrom.
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 for forming conductive pattern on a polymer resin
substrate by blending and molding specific inorganic additives
containing transition metals such as copper, chrome, and the like,
(for example, CuCr.sub.2O.sub.4 having the spinel structure, and
the like} 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 for
forming the conductive pattern, 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, and the like, of the polymer resin
substrate or resin products formed therefrom. Further, the specific
inorganic additives such as CuCr.sub.2O.sub.4 having the spinel
structure, and the like, have significantly dark color itself, 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 colors desirable
to consumers. For example, in order to implement the polymer resin
substrate containing the inorganic additives to have desirable
colors, a large amount of pigment should be used, and it is not
easy to implement white color.
[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 even without
containing the specific inorganic additives in the polymer resin
itself has been demanded.
SUMMARY OF INVENTION
Technical Problem
[0007] The present invention provides 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 by a simplified process,
even without containing specific inorganic additives in the polymer
resin itself.
[0008] In addition, the present invention provides a resin
structure having the conductive pattern obtained by the method of
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; 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] In addition, the surface roughness of the first and second
regions may be defined by other methods. 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 4.0 to 6.0N/10 mm width, the first region of the polymer resin
substrate may have a surface roughness defined by adhesion 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 the
same test is conducted on the remaining second region, the
remaining second region of the polymer resin substrate may have a
surface roughness defined by adhesion at which a delamination area
of the target metal layer under test corresponds to 65% or more of
an area of the metal layer.
[0011] Another exemplary embodiment of the present invention
provides a resin structure having conductive pattern including: a
polymer resin substrate including a first region formed to have a
predetermined surface roughness and a second region having surface
roughness smaller than that of the first region; 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] Therefore, the manufacturing cost of the process of forming
the conductive patterns may be decreased, and deterioration of
physical properties such as mechanical properties, dielectric
constant, 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 desirable fine conductive patterns may be formed on
the polymer resin substrate without using the specific inorganic
additive, colors of the resin itself may be clearly shown, and it
is easy to implement colors of the polymer resin substrate or
products to be desirable colors.
[0014] Therefore, 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
[0015] FIG. 1 is a diagram schematically showing one example of a
method for forming conductive pattern by directly radiation of an
electromagnetic wave according to an exemplary embodiment of the
present invention in a process-sequence.
[0016] FIG. 2a shows a photograph showing a state in which a
predetermined region has surface roughness by radiating laser to
the polymer resin substrate (first photograph), a photograph
showing a state in which a copper metal layer is formed by
electroless plating after radiating laser (second photograph), and
a photograph showing a state in which plating layers are removed
from the remaining region which is not radiated by laser, by
selective delamination or removal after the electroless plating
(third photograph), in the method for forming the conductive
pattern of Example 1.
[0017] FIG. 2b is an optical microscope photograph of the laser
radiated region having surface roughness according to Example
1.
[0018] FIG. 2c is a scanning electron microscope (SEM) photograph
showing a portion in which the metal layer (conductive patterns) is
formed in Example 1, wherein a conductive seed is grown, and the
metal layer is formed on the conductive seed by plating.
[0019] FIG. 3 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 the region
which is not radiated by laser in the method for forming the
conductive pattern of Example 9.
[0020] FIG. 4a is a photograph showing color change depending on
height using optical profiler in the laser radiated region of
Example 6 (left), and is a photograph showing the color change in
three dimensional structure (right).
[0021] FIG. 4b is a photograph showing color change depending on
height using optical profiler in the laser radiated region of
Example 8 (left), and is a photograph showing the color change in
three dimensional structure (right).
DESCRIPTION OF EMBODIMENTS
[0022] 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 patterns formed therefrom will be
described.
[0023] According to an exemplary embodiment of the present
invention, the 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; 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.
[0024] According to the exemplary embodiment of the present
invention, first, a surface structure having a shape such as
concavo-convex, predetermined patterned, 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.
[0025] 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.
[0026] 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 on the first region; meanwhile, the metal layer
which is easily removed due to poor adhesion may be formed on 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.
[0027] 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.
[0028] 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 desirable
fine conductive patterns may be formed on the polymer resin
substrate without using the specific inorganic additive, colors of
the resin itself may be clearly shown, and it is easy to implement
colors of the polymer resin substrate or products to be desirable
colors.
[0029] 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.
[0030] As shown in {circle around (1)} and {circle around (2)} of
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.
[0031] The polymer resin substrate may be formed by using any
thermosetting resin or any thermoplastic resin. Specific examples
of the polymer resins capable of forming the polymer resin
substrate such as the thermosetting resin or the thermoplastic
resin may include an ABS resin, a polyalkylene terephthalate resin
such as 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.
[0032] In addition, the polymer resin substrate may be formed of
the above-described polymer resin; however, may further contain
additives, for example, an UV stabilizer, a heat stabilizer, or an
impact reinforcing agent, generally used to form the polymer resin
product, as needed. The additives may be contained in an
appropriate amount of about 2 wt % or less, or about 0.01 to 2 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.
[0033] Meanwhile, the first region has a predetermined surface
roughness by radiating an electromagnetic wave such as laser, or
the like, on the above-described polymer resin substrate, wherein
in the first region having the surface roughness, relatively
standardized patterns such as hole, mesh pattern, or 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.
[0034] As an example, in order to secure excellent adhesion between
the metal layer (conductive patterns) to be formed in the first
region and the surface of the polymer resin substrate, 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 500 nm or more, or about 1 .mu.m or
more, 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 center line arithmetic average roughness of the
absolute values (Ra) having surface roughness smaller than that of
the first region, for example, about 400 nm or less, or about 100
nm or less, or about 0 to 90 nm.
[0035] In addition, the above-described surface roughness may also
be defined by other methods. For example, the surface roughness of
the first and second regions may 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 4.0 to 6.0N/10 mm
width, the first region of the polymer resin substrate may have a
surface roughness defined by adhesion (for example, ISO class 0 or
1) in which a delamination area of the 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 4.0 to 6.0N/10 mm width, the second region of
the polymer resin substrate may have a surface roughness defined by
adhesion (for example, ISO class 5 or more) in which a delamination
area of the target metal layer under test corresponds to 65% or
more of an area of the metal layer.
[0036] 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, thee 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 itself, when the metal layer is formed in
the following plating process, the second region may have
significantly low adhesion to be easily removed. 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.
[0037] 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.
[0038] First, in the radiating of the electromagnetic wave, laser
electromagnetic wave may be radiated, for example, laser
electromagnetic wave having a wavelength of 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.
[0039] In addition, specific conditions at the time of radiating
the 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 radiation condition that an average
power is about 0.1 to 50 W, or about 1 to 30 W, or about 5 to 25 W,
so that the polymer resin substrate of the first region has a
predetermined surface roughness as described above.
[0040] In addition, the radiating of the laser electromagnetic wave
may be radiated once by a relatively high power, but the laser
electromagnetic wave may 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
patterned or amorphous surface structures. Therefore, by
controlling the condition and the number of radiating the 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 with
the metal layer may be provided.
[0041] In addition, at the time of radiating the laser
electromagnetic wave, radiation trace of the electromagnetic wave
may be formed in a hole shape on the polymer resin substrate
depending on an radiation interval at the time of radiating the
laser electromagnetic wave. 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 may 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 between the polymer resin substrate and the metal
layer.
[0042] 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 {circle around (3)} of 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.
[0043] 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.
[0044] The kind of the metal atoms included in the conductive seed
is not particularly limited as long as the metal atom has
conductivity. For example, the conductive seed may include 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.
[0045] In addition, in order to form the conductive seed on the
polymer resin substrate, the conductive seed, 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 methods
such as a precipitating method, a drying method, and/or a reducing
method, to thereby form the conductive seed in 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 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; for
example, the metal compounds or the complexes such as AgNO.sub.3,
Ag.sub.2SO.sub.4, KAg(CN).sub.2), the metal ions, or the metal
complex ions are reduced and dried to appropriately form the
conductive seed in a particle form.
[0046] 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,
hypophosphorous acid-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.
[0047] In addition, the dispersion liquid or the solution may
appropriately include an aqueous-based polymer solution (for
example, solution containing polyvinylpyrrolidone-based polymer,
and the like) capable of improving close adhesion between the
polymer resin substrate and the conductive seed, or an
aqueous-based complexing agent (for example, NH.sub.3, EDTA,
Rochelle salt, or the like) capable of stabilizing the metal ions
or the metal complex ions, as a liquid-phase medium.
[0048] 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, and the
like.
[0049] 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 or physical properties of the metal
layer.
[0050] Meanwhile, right after the radiating of the electromagnetic
wave as described above, the process of forming the conductive seed
is immediately performed; however, after the polymer resin
substrate is selectively surface-treated with a surfactant having a
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. Here, the surfactant may have surface tension lower than that
of the dispersion liquid or the solution before the surfactant is
added.
[0051] 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 absorbed 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.
[0052] 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.
[0053] 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.
[0054] Meanwhile, referring to {circle around (4)} of 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.
[0055] For example, the plating process is performed by using a
plating solution containing conductive metals consisting of 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.
[0056] 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 (for example, as shown in second photograph of FIG.
2a, the metal layer may be delaminated from the polymer resin
substrate).
[0057] 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 as shown in {circle around (5)} and {circle
around (6)} of FIG. 1.
[0058] 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.
[0059] 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,
and methods of using a manpower such as directly dusting or wiping
with hands, or by a combination of two or more method(s) selected
therefrom.
[0060] For example, washing or rinsing is performed in 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.
[0061] 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 a surface roughness
defined by a center line arithmetic average roughness of the
absolute values (Ra) of about 500 nm or more and the second region
having a surface roughness smaller than that of the first region;
and the conductive seed and the metal layer selectively formed on
the first region of the polymer resin substrate.
[0062] 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.
[0063] 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.
[0064] As described above, 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
[0065] Therefore, the manufacturing cost of the process of forming
the conductive patterns and the cost of raw materials 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 desirable fine conductive patterns
may be formed on the polymer resin substrate without using the
specific inorganic additive, colors of the resin itself may be
clearly shown, and it is easy to implement colors of the polymer
resin substrate or products to be desirable colors. Therefore,
according to exemplary embodiments of the present invention, fine
conductive patterns may be formed on various kinds of resin
products or resin layers at lower manufacturing cost and by a
simplified process, such that resin products having various colors
and shapes, including new resin products which have not been
suggested before, may be implemented.
[0066] 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
[0067] 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 %, without containing other
different inorganic additives was prepared. Laser having a
wavelength of 1064 nm was radiated once onto a predetermined region
of the polycarbonate resin substrate under radiation condition
having an average power of 21.4 W. Here, the interval between
central parts of the laser radiation trace of the polycarbonate
resin was controlled to be about 35 .mu.m by controlling the
radiation interval of the laser.
[0068] Accordingly, the polycarbonate resin substrate radiated by
the laser had a predetermined surface roughness on the
predetermined region. A photograph of the polycarbonate resin
substrate as manufactured above was shown in the first photograph
of 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.
[0069] Then, the polycarbonate resin substrate was immersed into an
aqueous solution including Pd ions for about 5 minutes, to form a
conductive seed including Pd on the substrate. Next, the substrate
was washed with deionized water, and an elelctroless-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 to form the metal layer.
[0070] A photograph showing the metal layer formed as described
above was shown in the second photograph of FIG. 2a. Referring to
FIG. 2a, it could be confirmed that the metal layer was favorably
formed in the region radiated the laser; however, the metal layer
in the remaining region was formed in a delamination state due to
poor adhesion to be significantly easily removed.
[0071] 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. The third photograph of FIG. 2a is
a photograph showing a state in which the metal layer, and the
like, are selectively removed from the region which is not radiated
by laser, to form conductive patterns on the substrate, and FIG. 2c
is a scanning electron microscope (SEM) photograph showing a
portion in which the conductive patterns are formed. Referring to
FIG. 2c, it could be confirmed that the conductive seed was grown
in the corresponding portion, and the metal layer was formed on the
conductive sheet (conductive metal particles) by plating.
Examples 2 to 8
Formation of Conductive Patterns by Laser Direct Radiation
[0072] Resin structures of Examples 2 to 8 each having conductive
patterns were manufactured by the same method as Example 1 except
that the radiation condition of the average power of laser and the
interval between central parts of radiation trace of laser in
Example 1 are changed into about 15.7 W and about 25 .mu.m (Example
2), about 15.7 W and about 35 .mu.m (Example 3), about 18.6 W and
about 45 .mu.m (Example 4), about 21.4 W and about 45 .mu.m
(Example 5), about 21.4 W and about 55 .mu.m (Example 6), about
24.2 W and about 55 .mu.m (Example 7), about 28.5 W and about 55
.mu.m (Example 8) in once radiation.
Example 9
Formation of Conductive Patterns by Laser Direct Radiation
[0073] Resin structure of Example 9 having conductive patterns was
manufactured by the same method as Example 1 except that a mixture
of ethanol and an aqueous-based complex ion solution (solution
containing AgNO.sub.3 and NH.sub.3 which is a complexing agent)
containing Ag complex ions instead of Pd was used as a solution for
forming the conductive seed. FIG. 3 is a photograph showing a state
in which the conductive patterns were formed on the substrate by
selectively removing the metal layer, and the like, from the region
which is not radiated by laser.
Test Example 1
Evaluation of Surface Roughness of Conductive Patterns
[0074] Surface roughness was measured on predetermined regions of
the polycarbonate resin substrate radiated by laser according to
Examples 1 to 9. The center line arithmetic average roughness of
the absolute values (Ra) of an area of 0.2 mm.times.0.3 mm was
measured by using an optical profiler (Nano view E1000, Nanosystem,
Korea). In FIG. 4a, color change depending on height was shown by
using optical profiler in the region radiated by laser of Example 6
(left), and a photograph implementing the color change in three
dimensional structure was shown (right). In addition, the measured
surface roughness were also shown in FIG. 4a. FIG. 4b is a
photograph showing Example 8 and shows change of surface state
depending on change of the laser condition and changed values of
surface roughness, respectively. Ra values obtained by measuring
surface roughness at different six points of the region radiated by
laser in Examples 1 to 9 using the above-described methods and
averaging the measured values were summarized and shown in the
following Table 1. For reference, FIGS. 4a and 4b show surface
roughness measured at any one point among six points, and Table. 1
shows an average value of the values measured at six points.
Test Example 2
Evaluation of Adhesion of Conductive Patterns
[0075] A cross-cut test was conducted by using a tape having
adhesion of 4.0 to 6.0N/10 mm width according to ISO 2409 standard
method (3M scotch tape #371) in the region having the metal layer
and the conductive patterns according to Examples 1 to 9 formed
thereon. Here, adhesion or close 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.
[0076] Evaluation on adhesion of the delamination area of the
conductive patterns was conducted under the following ISO class
standard.
[0077] 1. class 0: When the delamination area of the conductive
patterns corresponds to 0% of area of target conductive patterns
under evaluation.
[0078] 2. class 1: When the delamination area of the conductive
patterns corresponds to more than 0% to 5% or less of area of
target conductive patterns under evaluation.
[0079] 3. class 2: When the delamination area of the conductive
patterns corresponds to more than 5% to 15% or less of area of
target conductive patterns under evaluation.
[0080] 4. class 3: When the delamination area of the conductive
patterns corresponds to more than 15% to 35% or less of area of
target conductive patterns under evaluation.
[0081] 5. class 4: When the delamination area of the conductive
patterns corresponds to more than 35% to 65% or less of area of
target conductive patterns under evaluation.
[0082] 6. class 5: When the delamination area of the conductive
patterns corresponds to more than 65% of area of target conductive
patterns under evaluation.
[0083] In addition, uniformity of the metal layer (conductive
patterns) after the conductive patterns were formed in Examples 1
to 9 was evaluated under the following standards.
[0084] 1. .largecircle.: With the unaided eye, uniformly colored
metal layer (plated thin film) is formed in all regions having
surface roughness formed by laser radiation, and when observing the
surface of the metal layer by optical microscopy, pores are not
shown.
[0085] 2. .DELTA.: With the unaided eye, uniformly colored metal
layer (plated thin film) is formed in all regions having surface
roughness formed by laser radiation; however, when observing the
surface of the metal layer by optical microscopy, pores are
partially shown.
[0086] 3. X: With the unaided eye, uniformly colored metal layer
(plated thin film) is not formed in all regions having surface
roughness formed by laser radiation; and when observing the surface
of the metal layer by optical microscopy, pores are partially shown
at least.
[0087] Evaluation results were shown in the following Table 1.
TABLE-US-00001 TABLE 1 Interval (.mu.m) Between Main Central
Component Evaluation Parts of of on Average Laser Conductive
Uniformity of Power of Radiation Average Ra ISO 2409 Seed Metal
Layer Laser (W) Trace (nm) class Example 1 Pd .smallcircle. 21.4 35
1110 0 Example 2 Pd .smallcircle. 15.7 25 645 0 Example 3 Pd
.DELTA. 15.7 35 710 1 Example 4 Pd .smallcircle. 18.6 45 705 1
Example 5 Pd .smallcircle. 21.4 45 818 1 Example 6 Pd .smallcircle.
21.4 55 837 1 Example 7 Pd .smallcircle. 24.2 55 1275 0 Example 8
Pd .smallcircle. 28.5 55 3470 0 Example 9 Ag .smallcircle. 21.4 35
1110 0
[0088] Referring to Table 1, it could be confirmed that in Examples
1 to 9, significantly excellent metal layer (conductive patterns)
could be selectively formed in the region radiated by laser,
through the method including the process of forming surface
roughness (Ra) of about 500 nm or more in the region radiated by
laser to improve adhesion between the polymer resin substrate and
the metal layer, and the process of forming the conductive seed,
and the like. In particular, it could be confirmed that the
conductive pattern has excellent uniformity and excellent adhesion
to the polymer resin substrate, thereby being favorably formed.
[0089] In conclusion, according to Examples above, even though high
priced and specific inorganic additives such as CuCr.sub.2O.sub.4,
and the like, are not contained in the polymer resin substrate
itself, surface roughness of the region in which conductive
patterns are formed by radiating an electromagnetic wave such as
laser, and the like, and adhesion to a metal layer, may be
adjusted, such that the conductive patterns may be formed on the
polymer resin substrate by a simplified process.
* * * * *