U.S. patent application number 13/611220 was filed with the patent office on 2013-06-13 for pattern-forming composition and pattern-forming method using the same.
This patent application is currently assigned to ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE. The applicant listed for this patent is Hyun-cheol Bae, Kwang-Seong Choi, Yong Sung EOM, Jong Tae Moon, Jung Hyun Noh. Invention is credited to Hyun-cheol Bae, Kwang-Seong Choi, Yong Sung EOM, Jong Tae Moon, Jung Hyun Noh.
Application Number | 20130146342 13/611220 |
Document ID | / |
Family ID | 48570948 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130146342 |
Kind Code |
A1 |
EOM; Yong Sung ; et
al. |
June 13, 2013 |
PATTERN-FORMING COMPOSITION AND PATTERN-FORMING METHOD USING THE
SAME
Abstract
The present invention relates to a pattern-forming composition
used to form a conductive circuit pattern. The pattern-forming
composition comprises Cu powders, a solder for electrically
coupling the Cu powders, a polymer resin, a curing agent and a
reductant. According to the present invention, a circuit pattern
having superior conductivity can be formed at low cost.
Inventors: |
EOM; Yong Sung; (Daejeon,
KR) ; Choi; Kwang-Seong; (Daejeon, KR) ; Bae;
Hyun-cheol; (Daejeon, KR) ; Noh; Jung Hyun;
(Daejeon, KR) ; Moon; Jong Tae; (Daejeon,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EOM; Yong Sung
Choi; Kwang-Seong
Bae; Hyun-cheol
Noh; Jung Hyun
Moon; Jong Tae |
Daejeon
Daejeon
Daejeon
Daejeon
Daejeon |
|
KR
KR
KR
KR
KR |
|
|
Assignee: |
ELECTRONICS AND TELECOMMUNICATIONS
RESEARCH INSTITUTE
Daejeon
KR
|
Family ID: |
48570948 |
Appl. No.: |
13/611220 |
Filed: |
September 12, 2012 |
Current U.S.
Class: |
174/257 ;
205/126; 252/512; 252/514; 427/98.4 |
Current CPC
Class: |
H01B 1/22 20130101; H05K
1/09 20130101; H05K 1/095 20130101; H05K 3/188 20130101; H05K
2203/0425 20130101; C25D 5/02 20130101; H05K 2201/0245 20130101;
H05K 3/1216 20130101; H01B 1/02 20130101; H05K 3/102 20130101; H05K
2201/0302 20130101; H05K 3/246 20130101 |
Class at
Publication: |
174/257 ;
252/512; 252/514; 427/98.4; 205/126 |
International
Class: |
H01B 1/02 20060101
H01B001/02; H05K 3/00 20060101 H05K003/00; C25D 5/02 20060101
C25D005/02; H05K 1/09 20060101 H05K001/09; H05K 3/12 20060101
H05K003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 13, 2011 |
KR |
10-2011-0133703 |
Claims
1. A pattern-forming composition comprising: Cu powders; a solder
for electrically coupling the Cu powders; a polymer resin; a curing
agent; and a reductant.
2. The pattern-forming composition as claimed in claim 1, wherein
the diameter of the Cu powder is 2-10 .mu.m.
3. The pattern-forming composition as claimed in claim 1, wherein
the solder is at least two selected from the group consisting of
Sn, Bi, In, Ag, Pb and Cu.
4. The pattern-forming composition as claimed in claim 1, wherein
the solder is selected from the group consisting of a mixture of Sn
and Bi, a mixture of In and Sn, a mixture of In and Ag, a mixture
of Bi, Sn and Ag, a mixture of Bi and Sn, a mixture of Bi, Pb and
Sn, and a mixture of Sn, Ag and Cu.
5. The pattern-forming composition as claimed in claim 1, wherein
the polymer resin is selected from the group consisting of
diglycidyl ether of bisphenol A, tetraglycidyl 4,4'-diaminodiphenyl
methane, tri diaminodiphenyl methane, isocyanate; and
bismaleimide.
6. The pattern-forming composition as claimed in claim 1,
comprising 30-50 wt % of the Cu powder, 30-50 wt % of the solder,
1-20 wt % of the polymer resin, 1-15 wt % of the curing agent and
0.1-5 wt % of the reductant based on 100 wt % of the
pattern-forming composition.
7. The pattern-forming composition as claimed in claim 1, further
comprising Ag powders.
8. A pattern-forming method comprising the steps of: preparing a
pattern-forming composition comprising Cu powders, a solder for
electrically coupling the Cu powders, a polymer resin, a curing
agent and a reductant; and forming a circuit pattern by printing
the pattern-forming composition on the substrate.
9. The pattern-forming method as claimed in claim 8, further
comprising the step of electrolytic-plating the formed circuit
pattern.
10. The pattern-forming method as claimed in claim 8, wherein the
diameter of the Cu powder is 2-10 .mu.m.
11. The pattern-forming method as claimed in claim 8, wherein the
solder is at least two selected from the group consisting of Sn,
Bi, In, Ag, Pb and Cu.
12. The pattern-forming method as claimed in claim 8, wherein the
solder is selected from the group consisting of a mixture of Sn and
Bi, a mixture of In and Sn, a mixture of In and Ag, a mixture of
Bi, Sn and Ag, a mixture of Bi and Sn, a mixture of Bi, Pb and Sn,
and a mixture of Sn, Ag and Cu.
13. The pattern-forming method as claimed in claim 8, wherein the
pattern-forming composition further comprises Ag powders.
14. A conductive circuit pattern formed by the method defined in
claim 8.
15. The conductive circuit pattern as claimed in claim 14, wherein
the method further comprising the step of electrolytic-plating the
formed circuit pattern.
16. The conductive circuit pattern as claimed in claim 14, wherein
the diameter of the Cu powder is 2-10 .mu.m.
17. The conductive circuit pattern as claimed in claim 14, wherein
the solder is at least two selected from the group consisting of
Sn, Bi, In, Ag, Pb and Cu.
18. The conductive circuit pattern as claimed in claim 14, wherein
the solder is selected from the group consisting of a mixture of Sn
and Bi, a mixture of In and Sn, a mixture of In and Ag, a mixture
of Bi, Sn and Ag, a mixture of Bi and Sn, a mixture of Bi, Pb and
Sn, and a mixture of Sn, Ag and Cu.
19. The conductive circuit pattern as claimed in claim 14, wherein
the pattern-forming composition further comprises Ag powders.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority from Korean
Patent Application No. 10-2011-0133703, filed on Dec. 13, 2011,
with the Korean Intellectual Property Office, the present
disclosure of which is incorporated herein in its entirety by
reference.
FIELD OF INVENTION
[0002] The present invention relates to a composition for forming a
conductive circuit pattern and a method for forming a conductive
circuit pattern on a substrate using the same.
BACKGROUND OF THE INVENTION
[0003] In general, a conductive circuit pattern is formed on a
substrate through an expose process or an etching process using a
photomask. However, there is a limit in forming a complicated and
micro circuit pattern by using a photomask.
[0004] Accordingly, in order to conveniently form a micro circuit
pattern, it has been suggested that a paste containing Au or Ag is
applied on a substrate, and then is cured to form a circuit
pattern. The related arts are Korean Patent Application Publication
No. 2008-0026165 entitled "A silver paste composition, a method for
forming a conductive pattern using the same and a conductive
pattern thereof" and Korean Patent Application Publication No.
2010-0046285 entitled "Silver microparticle-containing composition,
a method for forming the same, a method for forming a silver
microparticle, and a paste having silver microparticle."
[0005] However, precious metals, such as Au or Ag, are expensive.
Accordingly, the use of a paste that contains precious metals
causes a problem of incurring excessive costs for forming a circuit
pattern.
SUMMARY
[0006] The present invention has been made to solve the
above-mentioned problem. It is an objective of the present
invention to provide a pattern-forming method and a pattern-forming
composition in order to form a micro circuit pattern at low
cost.
[0007] In order to achieve the afore-mentioned objective, the
present invention provides a pattern-forming composition,
comprising: Cu powders; a solder for electrically coupling the Cu
powders; a polymer resin; a curing agent; and a reductant.
[0008] Here, the solder is at least two selected from the group
consisting of Sn, Bi, In, Ag, Pb and Cu.
[0009] Further, said pattern-forming composition may further
comprise Ag powders.
[0010] Meanwhile, the present invention provides a pattern-forming
method, comprising the steps of: preparing a pattern-forming
composition comprising Cu powders, a solder for electrically
coupling the Cu powders, a polymer resin, a curing agent and a
reductant; and forming a circuit pattern by printing the
pattern-forming composition on the substrate.
[0011] Here, the pattern-forming method may further comprise the
step of electrolytic-plating the formed circuit pattern.
[0012] In addition, the present invention provides a conductive
circuit pattern formed by the aforementioned pattern-forming
method.
Effect of the Invention
[0013] The present invention can reduce the costs for forming a
pattern, because a circuit pattern is formed by using a
pattern-forming composition that contains inexpensive Cu. Further,
the present invention can provide a circuit pattern having superior
conductivity, because the composition according to the present
invention comprises a solder in order to increase the electric
coupling of Cu.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates a state that the pattern-forming
composition according to the present invention is cured.
[0015] FIGS. 2 to 5 illustrate the pattern-forming method according
to the present invention.
[0016] FIGS. 6 to 8 illustrate observation of the formed circuit
pattern in the examples of the present invention.
DETAILED DESCRIPTION
[0017] Hereinafter, the present invention is explained in
detail.
[0018] 1. Pattern-Forming Composition
[0019] The present invention relates to a pattern-forming
composition comprising Cu powders, a solder, a polymer resin, a
curing agent and a reductant.
[0020] The Cu powder contained in the composition of the present
invention exhibits conductivity. The shape of the Cu powder is not
specifically limited, but may be a spherical shape or a flake
shape. Further, the diameter of the used Cu powder is not
specifically limited, but is preferably 2-10 .mu.m.
[0021] In consideration of conductivity of the circuit pattern and
workability for forming a pattern, a ratio of the Cu powder
contained in the composition is preferably 30-50 wt % (more
preferably, 35-48 wt %) based on 100 wt % of the composition.
[0022] The solder contained in the composition of the present
invention electrically couples Cu powders (for example, a first Cu
power and a second Cu powder) in order to increase conductivity of
the circuit pattern, and is preferably a mixture of at least two
selected from the group consisting of Sn, Bi, In, Ag, Pb and Cu,
although available substances are not specifically limited. Among
these substances, it is more preferable that the solder is selected
from the group consisting of a mixture of Sn and Bi (60Sn/40Bi), a
mixture of In and Sn (52In/48Sn), a mixture of In and Ag
(97In/3Ag), a mixture of Bi, Sn and Ag (57Bi/42Sn/1Ag), a mixture
of Bi and Sn (58Bi/42Sn), a mixture of Bi, Pb and Sn
(52Bi/32Pb/16Sn) and a mixture of Sn, Ag and Cu (96.5Sn/3Ag/0.5Cu)
(based on 100% solder).
[0023] The shape of the solder is not specifically limited, but may
be a spherical shape. Further, the diameter of the solder is not
specifically limited, but is preferably 2-11 .mu.m. Such a solder
is disposed in a space among the Cu powders and couples the Cu
powders separated from one another. Thus, when a circuit pattern is
formed by the composition of the present invention, conductivity of
the circuit pattern can be increased (see FIG. 1).
[0024] In consideration of conductivity of the circuit pattern, a
ratio of the solder contained in the composition of the present
invention is preferably 30-50 wt % (more preferably, 35-48 wt %)
based on 100 wt % of composition.
[0025] The polymer resin contained in the composition of the
present invention functions as a binder. Substances available as a
polymer resin are not specifically limited, but are preferably
selected from the group consisting of diglycidyl ether of bisphenol
A, tetraglycidyl 4,4'-diaminodiphenyl methane, tri diaminodiphenyl
methane, isocyanate and bismaleimide.
[0026] In consideration of conductivity of the circuit pattern and
workability when forming a pattern, a ratio of the polymer resin
contained in the composition of the present invention is preferably
1-20 wt % (more preferably, 2-16 wt %) based on 100 wt % of
composition.
[0027] The curing agent contained in the composition of the present
invention, amine-based and anhydride-based are available. Here,
unlimited examples of amine-based curing agents are
m-phenylenediamine (MPDA), diaminodiphenyl methane (DDM) and
diaminodiphenyl sulphone (DDS). Unlimited examples of
anhydride-based curing agents are methyl nadic anhydride (MNA),
dodecenyl succinic anhydride (DDSA), maleic anhydride (MA),
succinic anhydride (SA), methyl tetrahydrophthalic anhydride
(MTHPA), hexahydrophthalic anhydride (HHPA), tetrahydrophthalic
anhydride (THPA) and pyromellitic dianhydride (PMDA). When
anhydride-based curing agents are used, the solder may also
function as a curing catalyst agent to accelerate the curing of the
composition.
[0028] The equivalent ratio of the curing agent may have 0.4-1.2
with respect to the polymer resin. Particularly, the equivalent
ratio of the functional group of the curing agent to the functional
group of a monomer comprising the polymer resin ranges between 0.4
and 1.2.
[0029] Meanwhile, in consideration of workability when forming a
circuit pattern, the ratio of the curing agent contained in the
composition of the present invention is preferably 1-15 wt % (more
preferably, 1.5-11.5 wt %) based on 100 wt % of composition.
[0030] The reductant contained in the composition of the present
invention removes oxides (which are typically formed by the Cu
powder) from the composition. Although substances available as a
reductant are not specifically limited, what comprises a carboxyl
group (--COOH) can be used. Particularly, unlimited examples of the
reductant are a glutaric acid, a malic acid, an azelaic acid, an
abietic acid, an adipic acid, an ascorbic acid, an acrylic acid and
a citric acid.
[0031] In consideration of wetting property and reduction property
between the Cu powder and the solder, the ratio of the reductant
contained in the composition of the present invention is preferably
0.1-5 wt % (more preferably, 0.4-3 wt %) based on 100 wt % of
composition.
[0032] The composition of the present invention may further
comprise Ag powders in order to increase conductivity of the
circuit pattern. The shape of the used Ag powder is not
specifically limited, but may be a spherical shape or a flake
shape. Further, the diameter of the Ag powder is not specifically
limited, but is preferably 2-10 .mu.m.
[0033] In consideration of conductivity of the circuit pattern and
the costs, the ratio of the Ag powder contained in the composition
of the present invention is preferably 0.1-15 wt % based on 100 wt
% of composition.
[0034] In addition, the composition of the present invention may
further comprise a curing catalyst agent in order to accelerate the
curing reaction and a deforming agent in order to increase bonding
force between the Cu powder and the solder and wetting
property.
[0035] Although substances available as the curing catalyst agent
contained in the composition of the present invention are not
specifically limited, unlimited examples are benzyl dimethyl amine
(BDMA), boron trifluoride monoethylamine complex (BF3-MEA),
dimethylamino methyl phenol-30 (DMP-30), dimethyl benzol amine
(DMBA) and methyl iodide.
[0036] Although substances available as the deforming agent
contained in the composition of the present invention are not
specifically limited, unlimited examples are acrylate oligomer,
polyglycols, glycerides, polypropylene glycol, dimethylsilicon,
simethinecone, tribubyl phosphate and polydimethylsiloxane.
[0037] In consideration of conductivity of the circuit pattern and
workability when forming a pattern, the ratio of the curing
catalyst agent and the deforming agent that can be further
contained in the composition of the present invention is preferably
0.01-0.1 wt % (more preferably, 0.01-0.078 wt %) based on 100 wt %
of composition.
[0038] 2. A Pattern-Forming Method and a Conductive Circuit
Pattern
[0039] The present invention provides a circuit-pattern forming
method using the composition stated above and a conductive circuit
pattern formed therefrom, as explained below with reference to the
drawings.
[0040] First, prepare a pattern-forming composition comprising Cu
powders, a solder for electrically coupling the Cu powders, a
polymer resin, a curing agent and a reductant. Herein, the
description of the pattern-forming composition will be omitted,
because it is the same as stated above.
[0041] Once the composition is prepared, the composition is printed
on the substrate (20) to form a conductive circuit pattern (21)
(see FIGS. 2 and 3). Although substances available as the substrate
(20) are not specifically limited, a flexible substrate, a ceramic
substrate and a silicon substrate can be used. Further, although a
method for printing the circuit pattern (21) is not specifically
limited as long as it is known in the relevant technical field, a
screen printing can be applied.
[0042] Meanwhile, the patter-forming method may further comprise a
step of electrolytic-plating (22) the formed circuit pattern in
order to increase the electrical connection force of the formed
circuit pattern (21) and effectively perform a subsequent soldering
process (see FIGS. 4 and 5). Particularly, after soaking the
substrate (20) on which the circuit pattern (21) is formed into the
electrolytic-plated solution, the current is applied for a certain
hour to electroplate the circuit pattern (21). As the
electrolytic-plated solution, metals, such as Cu, Ni or Au, can be
used. The time for soaking the substrate (20) into the solution and
the magnitude of the applied current can be adjusted depending on
the thickness to be plated (the thickness plated on the circuit
pattern board).
[0043] Through such processes, the present invention can easily
form a circuit pattern having superior conductivity and uniform
thickness at lower costs.
[0044] The present invention is described in detail by examples
below. However, the scope of the present invention is not limited
to the examples, since these examples are provided to particularly
describe the present invention.
EXAMPLE
1. Preparation of a Pattern-Forming Composition
[0045] A composition was prepared by mixing 40 wt % of Cu flake
having a diameter of 3 .mu.m, a mixture 38 wt % of 58% of Sn and
42% of Bi as a solder, 12 wt % of diglycidyl ether bisphenol A as a
polymer resin, 7.94 wt % of diamino diphenyl sulfone as a curing
agent, 2 wt % of malic acid as a reductant and 0.06 wt % of boron
trifluoride monoethylamine complex as a curing catalyst agent.
2. Forming a Conductive Pattern
[0046] After applying the composition was prepared above, on the
substrate (size of 10 mm.times.10 mm) using a screen printing, and
the composition is heated up to be 180.degree. C. under the heating
condition of 70.degree. C./min or higher and was cured for about 5
minutes, thereby forming a conductive circuit pattern (see FIG.
6).
[0047] The lower part (10 mm.times.5 mm) of the circuit pattern
formed in the size of 10 mm.times.10 mm was covered with a tape and
the upper part (10 mm.times.5 mm) thereof was soaked into the
electrolytic-plated solution, thereby conducting an additional
electrolytic-plating. For the additional electrolytic-plating, Cu
electrolytic-plated solution of 38.degree. C. was used. The
additional electrolytic-plating was conducted by applying the
current density of 40 mA/cm.sup.2 for ten minutes.
Experimental Example
1. Measurement of Conductivity
[0048] In the above example, the thickness and conductivity of the
circuit pattern prior to the electrolytic-plating were measured
using the known method in the relevant technical field. The
measurement results showed that the thickness of the formed circuit
pattern was about 65 .mu.m and the electrical resistance of the
corners in the diagonal line was about 0.4a
2. Photographing Images of the Electrolytic-Plated Circuit
Pattern
[0049] In the above example, the electrolytic-plated substrate was
photographed using a scanning electron microscope (SEM) and the
results are shown in FIG. 8 below. With reference to FIG. 8, it can
be confirmed that the substrate was electrolytic-plated well.
REFERENCE NUMBERS
[0050] 10: Cu flake [0051] 11: solder [0052] 20: substrate [0053]
21: circuit pattern [0054] 22: electrolytic-plating
* * * * *