U.S. patent application number 15/314761 was filed with the patent office on 2017-07-06 for method for producing plated article.
This patent application is currently assigned to OM SANGYO CO., LTD.. The applicant listed for this patent is OM SANGYO CO., LTD.. Invention is credited to Chisa FUKUDA, Yutaka MITOOKA, Rie MIYAKE, Yoshiyuki NISHIMURA, Masao TAKAMIZAWA.
Application Number | 20170191165 15/314761 |
Document ID | / |
Family ID | 56978210 |
Filed Date | 2017-07-06 |
United States Patent
Application |
20170191165 |
Kind Code |
A1 |
NISHIMURA; Yoshiyuki ; et
al. |
July 6, 2017 |
METHOD FOR PRODUCING PLATED ARTICLE
Abstract
There is provided a method for producing a plated article in
which a plating film pattern is formed on the surface of a glass
substrate, comprising a first step of irradiating a partial area of
the surface of the glass substrate with a pulsed laser; a second
step of attaching an electroless catalyst on the surface of the
glass substrate; a third step of selectively deactivating or
selectively removing the catalyst attached to the unirradiated area
with the pulsed laser in the glass substrate; and a fourth step of
nonelectrolytically plating the glass substrate after the third
step to selectively form a plating film in the irradiated area with
the pulsed laser. The method allows for easily producing a plated
article in which a highly adherent plating film pattern is formed
on the surface of the glass substrate.
Inventors: |
NISHIMURA; Yoshiyuki;
(Kurashiki-shi, JP) ; MIYAKE; Rie; (Okayama-shi,
JP) ; FUKUDA; Chisa; (Okayama-shi, JP) ;
TAKAMIZAWA; Masao; (Kurashiki-shi, JP) ; MITOOKA;
Yutaka; (Kurashiki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OM SANGYO CO., LTD. |
Okayama-shi, Okayama |
|
JP |
|
|
Assignee: |
OM SANGYO CO., LTD.
Okayama-shi, Okayama
JP
|
Family ID: |
56978210 |
Appl. No.: |
15/314761 |
Filed: |
March 23, 2016 |
PCT Filed: |
March 23, 2016 |
PCT NO: |
PCT/JP2016/059264 |
371 Date: |
November 29, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 18/54 20130101;
C23C 18/1868 20130101; C23C 18/38 20130101; C23C 18/1612 20130101;
C23C 18/18 20130101; C23C 18/1667 20130101; C23C 18/1893 20130101;
C23C 18/32 20130101; C23C 18/1639 20130101; C23C 18/42
20130101 |
International
Class: |
C23C 18/16 20060101
C23C018/16; C23C 18/42 20060101 C23C018/42; C23C 18/38 20060101
C23C018/38; C23C 18/18 20060101 C23C018/18; C23C 18/32 20060101
C23C018/32 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 24, 2015 |
JP |
2015-061779 |
Claims
1. A method for producing a plated article in which a plating film
pattern is formed on the surface of a glass substrate, comprising a
first step of irradiating a partial area of the surface of the
glass substrate with a pulsed laser; a second step of attaching an
electroless catalyst on the surface of the glass substrate; a third
step of selectively deactivating or selectively removing the
catalyst attached to the unirradiated area with the pulsed laser in
the glass substrate; and a fourth step of nonelectrolytically
plating the glass substrate after the third step to selectively
form a plating film in the irradiated area with the pulsed laser,
wherein in the third step, the glass substrate contacts a solution
containing a compound deactivating the catalyst or a compound
removing the catalyst.
2. The production method as claimed in claim 1, wherein a pulse
width of the pulsed laser is 1.times.10.sup.-18 to
1.times.10.sup.-4 sec.
3. The production method as claimed in claim 1, wherein the plating
film is at least one selected from the group consisting of nickel,
copper, silver, gold, palladium, platinum, rhodium, ruthenium, tin,
iron, cobalt and alloys thereof.
4. (canceled)
5. The production method as claimed in claim 1, wherein in the
third step, a compound deactivating the catalyst is a sulfur
compound.
6. The production method as claimed in claim 5, wherein the sulfur
compound is a compound having at least one functional group
selected from the group consisting of a thiocarbonyl group, a thiol
group and a sulfide group.
7. The production method as claimed in claim 1, wherein a compound
removing the catalyst is a chelate compound or cyanide.
8. The production method as claimed in claim 7, wherein the
compound removing the catalyst is at least one chelate compound
selected from the group consisting of an amino acid, an amino
alcohol, a polyamine, a polycarboxylic acid and a polyketone.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for producing a
plated article in which a plating film pattern is formed on the
surface of a glass substrate.
BACKGROUND ART
[0002] Conventionally, paper phenol substrates, paper epoxy
substrates, glass epoxy substrates, ceramic substrates or the like
have been used as a substrate for a circuit used for products such
as home electric appliances and transport devices. These substrates
are properly used depending on performance and a cost needed to a
product because electric properties, mechanical properties and a
price are different from each other. Recently, a glass substrate
has got much attention as a substrate for a circuit, and there have
been attempts for forming a metal film pattern on the surface of a
glass substrate. A glass substrate has advantages that it is highly
thermally stable compared with substrates conventionally used and
is inexpensive.
[0003] Patent Reference No. 1 has described a selective plating
method wherein the surface of an insulative substrate to be plated
is irradiated with an energy beam, that is, a predetermined area of
the substrate surface is irradiated with the energy beam, then a
liquid containing a substance to be precipitation nuclei in
chemical plating as a compound is contacted with the surface of the
insulative substrate, the substrate is washed for removing the
residual liquid, and then the surface irradiated with the energy
beam is contacted with a predetermined chemical plating solution to
deposit metal over the area of the adherend by chemical plating.
There is described that it allows for forming a complicated and
fine metal deposition pattern.
[0004] However, Patent Reference No. 1 has not described or
suggested that in the plating method, a metal film pattern is
formed on the surface of a glass substrate.
[0005] Patent Reference No. 2 has described a method for forming a
metal interconnection in which the metal interconnection is formed
over the surface of an insulator, wherein using a picosecond laser
beam with a pulse width of picosecond level or a femtosecond laser
beam with a pulse width of femtosecond level as a laser beam, the
surface of a silver-containing insulator which is transparent to
the above laser beam is irradiated with the laser beam; silver ions
in the irradiated area are reduced to generate silver atoms in the
irradiated area; the insulator in which the above laser beam
irradiation has generated silver atoms in the irradiated area is
immersed in an electroless plating solution kept at a predetermined
temperature; and using the silver atoms as catalyst nuclei, a metal
is precipitated to deposit a metal film over the above insulator,
forming a metal interconnection. In Examples therein, there is
described an example where a photosensitive glass is used as an
insulator. It has been described that a metal interconnection can
be thus formed with simple processes and a small number of
steps.
[0006] However, in the plating method described in Patent Reference
No. 2, a special glass substrate must be used, and such a glass
substrate is more expensive than substrates conventionally used.
Therefore, there is a limit on widely disseminating a circuit using
this substrate.
PRIOR ART REFERENCES
Patent References
[0007] Patent Reference No. 1: JP 60-149783 A
[0008] Patent Reference No. 2: JP 2008-41938 A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0009] To solve the above problems, an objective of the present
invention is to provide a method for easily producing a plated
article in which a highly adherent plating film pattern is formed
on the surface of a glass substrate.
Means for Solving the Problems
[0010] The above problems can be solved by providing a method for
producing a plated article in which a plating film pattern is
formed on the surface of a glass substrate, comprising a first step
of irradiating a partial area of the surface of the glass substrate
with a pulsed laser; a second step of attaching an electroless
catalyst on the surface of the glass substrate; a third step of
selectively deactivating or selectively removing the catalyst
attached to the unirradiated area with the pulsed laser in the
glass substrate; and a fourth step of nonelectrolytically plating
the glass substrate after the third step to selectively form a
plating film in the irradiated area with the pulsed laser.
[0011] Here, it is preferable that a pulse width of the pulsed
laser is 1.times.10.sup.-18 to 1.times.10.sup.-4 sec. It is also
preferable that the plating film is at least one selected from the
group consisting of nickel, copper, silver, gold, palladium,
platinum, rhodium, ruthenium, tin, iron, cobalt and alloys
thereof.
[0012] It is preferable that in the third step, the glass substrate
contacts a solution containing a compound deactivating the catalyst
or a compound removing the catalyst.
[0013] It is preferable that in the third step, a compound
deactivating the catalyst is a sulfur compound. Here, it is
preferable that the sulfur compound is a compound having at least
one functional group selected from the group consisting of a
thiocarbonyl group, a thiol group and a sulfide group.
[0014] Furthermore, it is also preferable that a compound removing
the catalyst is a chelate compound or cyanide. Here, it is
preferable that the compound removing the catalyst is at least one
chelate compound selected from the group consisting of an amino
acid, an amino alcohol, a polyamine, a polycarboxylic acid and a
polyketone.
Effects of the Invention
[0015] According to the present invention, a plated article in
which a highly adherent plating film pattern is formed on a glass
substrate can be easily produced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows an example of a pulsed laser irradiation
method.
[0017] FIG. 2 is a microscopic image of a plated article in Example
1.
[0018] FIG. 3 is a microscopic image of the appearance of the
plated article in Example 1 after the tensile test.
[0019] FIG. 4 is a microscopic image of a plated article in Example
2.
[0020] FIG. 5 is a microscopic image of a plated article in
Comparative Example 1.
MODES FOR CARRYING OUT THE INVENTION
[0021] The present invention relates to a method for producing a
plated article in which a plating film pattern is formed on the
surface of a glass substrate. The production method according to
the present invention comprises the following first to fourth
steps. There will be described each step.
[0022] In a first step, a partial of the surface of a glass
substrate is irradiated with a pulsed laser. Examples of the glass
substrate used in the first step include, but not limited to, a
soda-lime glass, a borosilicate glass and a quartz glass. These
glass substrates can be appropriately selected, depending on an
application of a plated article. When a cost is emphasized, a
soda-lime glass is suitable. When thermal stability emphasized, a
quartz glass and a borosilicate glass are suitable and a quartz
glass is more suitable. When reducing the amount of impurities
contained in a glass substrate is emphasized, a quartz glass and a
borosilicate glass are suitable, and a quartz glass is more
suitable. There are no particular restrictions to a thickness of a
glass substrate, and it is generally 0.02 to 5 mm. There are no
particular restrictions to its shape. A glass substrate whose
mechanical strength has been improved by heating can be also used.
Examples of such a glass substrate include a physically tempered
glass which is produced by heating and then rapidly cooling a glass
to generate compression stress in the proximity of the surface, and
a chemically tempered glass which is produced by heating a glass
while the glass is subjected to ion-exchange treatment for
introducing alkali ions having a large ion radius in the surface of
the glass to generate compression stress in the proximity of the
surface of the glass.
[0023] In the present invention, it is important to use a pulsed
laser. The use of a pulsed laser allows for inducing multiphoton
absorption in even a transparent substrate such as a glass.
Multiphoton absorption is accelerated with a larger peak power (W)
of laser. When an energy is the same, a peak power (W) is larger as
a pulse width is shorter, and therefore, a shorter pulse width is
preferable. Based on this point of view, a pulse width (sec) of a
pulsed laser is preferably 1.times.10.sup.-4 sec or less, more
preferably 1.times.10.sup.-7 sec or less, further preferably
1.times.10.sup.-9 sec or less, particularly preferably
1.times.10.sup.-10 sec or less. Thus, with a very short pulse
width, a peak powder of a laser can be sufficiently increased to
initiate multiphoton absorption. The lower limit of a pulse width
of a pulsed laser is, but not limited to, generally
1.times.10.sup.-18 sec, suitably 1.times.10.sup.-15 sec. Then, by
setting the system such that a laser processing point (focus) is
the surface of a glass substrate, the surface of the glass
substrate can be processed.
[0024] It is preferable that an average output power at a
processing point is 0.01 to 1000 W. If an average output power at a
processing point is less than 0.01 W, a highly adherent plating
film may not be obtained. If an average output power at a
processing point is more than 1000 W, a glass substrate may be
significantly damaged. A repetition frequency of a pulsed laser is
generally, but not limited to, 1 kHz to 1000 MHz.
[0025] There are no particular restrictions to the type of a laser;
for example, solid laser such as YAG laser, fiber laser and
semiconductor laser; and gas laser such as carbon dioxide laser and
excimer laser. There are no particular restrictions to a wavelength
of a pulsed laser, and it can be appropriately selected depending
on the type of a glass substrate used and is generally 100 to 12000
nm. In the light of easiness of pulsed oscillation, YAG laser is
preferable and neodymium YAG laser is more preferable. In neodymium
YAG laser, a laser beam with a wavelength of 1064 nm which is
called as a fundamental wave (first harmonic) is generated. Using a
wavelength conversion device, a laser beam with a wavelength of 532
nm called as a second harmonic, a laser beam with a wavelength of
355 nm called as a third harmonic, and a laser beam with a
wavelength of 266 nm called as a fourth harmonic can be obtained.
In the production method of the present invention, any of the first
to the fourth harmonics can be appropriately selected depending on
the purpose.
[0026] Then, a partial area of the surface of a glass substrate is
irradiated with a pulsed laser. There are no particular
restrictions to a method of irradiating a glass substrate with a
pulsed laser, and for example, the method shown in FIG. 1 can be
employed. FIG. 1 shows an example of a pulsed laser irradiation
method. As shown in FIG. 1, an area of the surface of a glass
substrate to be irradiated is set. In a subsequent step, a plating
film is to be selectively formed only in an area irradiated with a
pulsed laser, that is, this irradiation area. Then, a laser is
irradiated from the point indicated by St in the x direction (the
right direction in FIG. 1) at a predetermined scan rate, then the
laser is moved by a predetermined interval in the y direction (the
upper direction in FIG. 1), then the laser is irradiated in the -x
direction (the left direction in FIG. 1) at a predetermined scan
rate, and then again the laser is moved by a predetermined interval
in the y direction. An irradiation spot diameter corresponds to a
laser beam diameter, but irradiation spots do not have to be
mutually overlapped and there may be an interval between
irradiation spots. In this method, a scan rate and an interval
(pitch interval) can be appropriately adjusted to regulate the
laser irradiation amount per unit area.
[0027] In the light of adherence of a plating film, an arithmetic
mean roughness (Ra) of a glass surface irradiated with a pulsed
laser is preferably 0.1 .mu.m or more, more preferably 0.2 .mu.m or
more. If Ra is excessively large, strength of a plated article may
be deteriorated, and therefore, Ra is preferably 10 .mu.m or less,
more preferably 5 .mu.m or less. Herein, Ra is determined in
accordance with JIS B 0601 (2001).
[0028] Next, in a second step, an electroless catalyst is attached
to the surface of the glass substrate. There are no particular
restrictions to the electroless catalyst as long as it contains a
metal element which can exert catalysis to an electroless plating
solution. Examples of the metal element include palladium (Pd),
silver (Ag), copper (Cu), nickel (Ni), aluminum (Al), iron (Fe),
cobalt (Co), zinc (Zn), gold (Au), platinum (Pt) and tin (Sn).
These metal elements can be appropriately selected, depending on
the type of an electroless plating solution used in a fourth step.
Then, after the treatment with an aqueous solution containing the
above metal element, the glass substrate can be treated with an
aqueous solution containing a reducing agent to activate the
electroless catalyst.
[0029] Next, in a third step, the catalyst attached to the area
which has not been irradiated with the pulsed laser in the glass
substrate is selectively deactivated or selectively removed.
[0030] There are no particular restrictions to a method for
removing the catalyst In the third step; for example, conducting an
ultrasonic treatment to the glass substrate or washing the surface
of the glass substrate with flowing water. However, in the light of
more selective deactivating or removing the catalyst attached to
the area which has not been irradiated with the pulsed laser,
preferably employed are a method where the glass substrate is
contacted with a solution containing a compound capable of
deactivating the catalyst, and a method where the glass substrate
is contacted with a solution containing a compound capable of
removing the catalyst. Examples of a method for contacting the
glass substrate with a solution include a method where the glass
substrate is immersed in a solution containing a compound
deactivating the catalyst, a method where the glass substrate is
immersed in a solution containing a compound removing the catalyst,
a method where a solution containing a compound deactivating the
catalyst is applied to the glass substrate, and a method where a
solution containing a compound removing the catalyst is applied to
the glass substrate.
[0031] In the third step, when the glass substrate is contacted
with a solution containing a compound deactivating the catalyst,
the compound is preferably a sulfur compound. The inventors
prepared a glass substrate to which a palladium catalyst was
attached, and chemical compositions of the surface of the glass
substrate before and after immersion in a solution containing a
sulfur compound were analyzed using a photoelectron spectrometer
(XPS). As a result, it was found that palladium was present on the
substrate surface even after immersion in a solution containing a
sulfur compound. It was also found that a peak position derived
from palladium moved after immersion in a solution containing a
sulfur compound. Assuming that the results indicate that a sulfur
atom coordinates palladium, the inventors infer that it causes
deactivation of the palladium catalyst.
[0032] Preferably, the above sulfur compound is a compound having
at least one functional group selected from the group consisting of
a thiocarbonyl group, a thiol group and a sulfide group. A sulfur
compound having a thiocarbonyl group can be thiourea. Examples of a
sulfur compound having a thiol group include triazine thiol,
mercapto benzothiazole, mercaptoacetic acid and thiocyanic acid.
Examples of a sulfur compound having a sulfide group include
dimethyl sulfide and methionine.
[0033] If a concentration of a solution containing a sulfur
compound is too low, the catalyst may not be selectively
deactivated. Based on this point of view, a concentration of the
sulfur compound is preferably 0.001 ppm or more. If a concentration
of the sulfur compound is too high, the catalyst attached to the
area irradiated with a pulsed laser may be also deactivated. Based
on this point of view, a concentration of the sulfur compound is
preferably 100 ppm or less.
[0034] A solvent used for a solution containing a compound
deactivating the catalyst is generally, but not limited to, water
or an alcohol. When a glass substrate is immersed in a solution
containing a compound deactivating a catalyst, a temperature of the
solution in which the glass substrate is immersed is generally, but
not limited to, 5 to 90.degree. C. A time of immersing glass
substrate is generally, but not limited to, 1 sec to 30 min. A
method for applying a solution containing a compound deactivating a
catalyst can be application of the solution to a glass substrate by
spraying.
[0035] In the third step, when a glass substrate is contacted with
a solution containing a compound removing a catalyst, the compound
is preferably a chelate compound or a cyanide. In the light of
handleability, the compound removing a catalyst is preferably at
least one chelate compound selected from the group consisting of
amino acids, amino alcohols, polyamines, polycarboxylic acids and
polyketones. Examples of an amino acid include alanine, arginine,
asparagine, aspartic acid, cysteine, glutamine, glutamic acid,
glycine, histidine, isoleucine, leucine, methionine, phenylalanine,
proline, serine, threonine, tryptophan, tyrosine and valine.
Examples of an amino alcohol include triethanolamine. Examples of a
polyamine include ethylenediamine. Examples of a polycarboxylic
acid include citric acid, succinic acid, maleic acid, fumaric acid,
tartaric acid and potassium tartrate. Examples of a polyketone
include acetylacetone.
[0036] The inventors prepared a glass substrate to which a
palladium catalyst was attached, and chemical compositions of the
surface of the glass substrate before and after immersion in a
solution containing a chelate compound were analyzed using a
photoelectron spectrometer (XPS). As a result, it was found that
the palladium catalyst was removed from the substrate surface by
immersion in a solution containing a chelate compound. The solution
after immersion of the glass substrate was analyzed using an ICP
emission analyzer, and it was found that the solution contained
palladium.
[0037] Examples of the cyanide include potassium cyanide and sodium
cyanide.
[0038] If a concentration of the chelate compound or the cyanide is
too low, the catalyst may not be selectively removed. Based on this
point of view, a concentration of the chelate compound or the
cyanide is preferably 0.001 M or more. If a concentration of the
chelate compound or the cyanide is too high, the catalyst attached
to the area irradiated with a pulsed laser may be also removed.
Based on this point of view, a concentration of the chelate
compound or the cyanide is preferably 3 M or less.
[0039] A solvent used for a solution containing a compound removing
the catalyst is generally, but not limited to, water or an alcohol.
When a glass substrate is immersed, a temperature of the solution
in which the glass substrate is immersed is generally, but not
limited to, 5 to 90.degree. C. A time of immersing glass substrate
is generally, but not limited to, 1 sec to 30 min. A method for
applying a solution containing a compound removing a catalyst can
be application of the solution to a glass substrate by
spraying.
[0040] In a fourth step, nonelectrolytic plating is conducted,
after the third step, to selectively form a plating film only in
the irradiated area with the pulsed laser. Here, the plating film
is preferably made of at least one selected from the group
consisting of nickel, copper, silver, gold, palladium, platinum,
rhodium, ruthenium, tin, iron, cobalt and alloys thereof. An alloy
as used herein refers to an alloy containing at least one of the
above metal elements in 50% by mass or more.
[0041] Examples of nonelectrolytic plating used in the fourth step
include electroless nickel plating, electroless copper plating,
electroless silver plating, electroless gold plating, electroless
palladium plating, electroless platinum plating, electroless
rhodium plating, electroless ruthenium plating, electroless tin
plating, electroless iron plating, electroless cobalt plating or
electroless plating of an alloy thereof. Electroless alloy plating
as used herein refers to nonelectrolytic plating involving the
system containing at least one metal element in 50% by mass or
more. Varying the type of nonelectrolytic plating, this process can
be conducted in multiple batches.
[0042] As described above, a production method of the present
invention allows for precisely forming a desired plating film
pattern on the surface of a glass substrate without using a special
glass substrate. As demonstrated in Examples later, a pattern was
formed by a pulsed laser and then, by nonelectrolytically plating,
a plating film was formed in an area irradiated with the laser.
However, if the third step is omitted, a plating film was formed
not only in the area irradiated with a laser but also in the area
unirradiated with a laser (Comparative Example 1). According to the
production method of the present invention, a catalyst attached to
an area unirradiated with a laser can be selectively deactivated or
selectively removed, so that a plating film can be selectively
formed only in the area irradiated with a laser.
[0043] A plating film formed by the production method of the
present invention has excellent adherence. Recent trend to size
reduction and higher performance of end products has led to
stricter requirement for performance of a plated article and thus a
plated article having a finer film pattern. However, as a pattern
pitch is finer, a plating film is required to have higher
adherence. Therefore, for providing a plated article having a fine
film pattern, the use of the production method of the present
invention is very beneficial.
[0044] Following the fourth step, the production method of the
present invention can comprise an additional step. Such an
additional step can be electrolytic plating or various surface
processings. Examples of electrolytic plating include electrolytic
nickel plating, electrolytic copper plating, electrolytic silver
plating, electrolytic gold plating, electrolytic palladium plating,
electrolytic tin plating, electrolytic iron plating, electrolytic
bismuth plating, electrolytic platinum plating, electrolytic
rhodium plating, electrolytic ruthenium plating, electrolytic zinc
plating and electrolytic plating of alloys thereof. Electrolytic
alloy plating as used herein refers to electrolytic plating
involving the system containing at least one metal element in 50%
by mass or more. Examples of various surface processings include
metal spraying by a cold spraying process and applying a metal
paste. Examples of a metal used include copper, tin, gold, silver,
nickel, iron, palladium, ruthenium, rhodium, iridium, indium, zinc,
aluminum, tungsten, chromium, magnesium, titanium, silicon or
alloys thereof. These additional steps can be conducted more than
once and the steps can be identical or different. Furthermore,
after the fourth step, mechanical strength of a glass substrate can
be improved by heating.
EXAMPLES
[0045] The present invention will be further detailed, but not
limited to, with reference to Examples.
Example 1
[Laser Irradiation]
(Glass Substrate)
[0046] A soda-lime glass with a size of 76 mm (length).times.26 mm
(width).times.1.1 mm (thickness) ("Matsunami slide glass S7213")
was prepared as a glass substrate.
(Processing Method)
[0047] A pulse oscillation solid-state laser "Talisker HE" from
Coherent Japan Inc. was used.
[0048] Wavelength: 355 nm
[0049] Average output power: 2 W
[0050] Average output power at a processing point: 0.8 W
[0051] Pulse width: 20 picosecond
[0052] Frequency: 50 kHz
[0053] Then, as shown in FIG. 1, the glass substrate was irradiated
with a pulsed laser. Specifically, a 20 mm.times.10 mm irradiation
area was set in the surface of the glass substrate. To this
irradiation area, a pulsed laser was irradiated from the point
indicated by St in the x direction to the right end of the
irradiation area at a scan rate of 100 mm/sec. Then, the pulsed
laser was moved by 15 .mu.m in the y direction, and the pulsed
laser was irradiated in the -x direction to the left end of the
irradiation area at a scan rate of 100 mm/sec. This process was
repeated to irradiate the whole irradiation area with the pulsed
laser.
[0054] After the pulsed laser irradiation, observation of the
surface of the glass substrate demonstrated that as shown in FIG.
1, the area was processed such that there was a sequence of spots
(recesses). A diameter of one spot was determined to be about 15
.mu.m.
[Nonelectrolytic Plating]
(Pre-Treatment)
[0055] The laser processed glass substrate was immersed in an
aqueous solution of potassium hydroxide (concentration: 50 g/L)
kept at 50.degree. C. for 5 min. Then, the glass substrate was
washed with ion-exchanged water. Subsequently, the glass substrate
was immersed in a conditioning solution (concentration: 50 mL/L,
"THRU-CUP MTE-1-A" from C. Uyemura & Co., Ltd.) kept at
50.degree. C. for 5 min. Then, glass substrate was washed with
ion-exchanged water.
(Electroless Catalyst Adhesion)
[0056] The pre-treated glass substrate was immersed in a palladium
catalyst solution (concentration: 50 mL/L, "Activator A-10X" from
C. Uyemura & Co., Ltd.) at room temperature for 1 min. Then,
the glass substrate was washed with ion-exchanged water three
times.
(Activation)
[0057] The glass substrate with the palladium catalyst was immersed
in an aqueous solution of sodium hypophosphite (concentration: 0.27
M) kept at 50.degree. C. for 30 sec, to activate the palladium
catalyst. Then, the glass substrate was washed with ion-exchanged
water.
(Catalyst Deactivation)
[0058] The activated glass substrate was immersed in an aqueous
solution of thiourea (concentration: 0.1 ppm) kept at 50.degree. C.
for 1 min, to deactivate the palladium catalyst attached to the
area unirradiated with the pulsed laser. Then, the glass substrate
was washed with ion-exchanged water three times.
(Electroless Ni Plating)
[0059] The glass substrate was immersed in an electroless
Ni-plating solution, pH 4.4 kept at 75.degree. C. for 35 min, for
electroless Ni plating, to form an electroless Ni-plating layer
with a film thickness of 5 .mu.m on the surface of the glass
substrate. Then, the substrate was washed with ion-exchanged water
three times. A composition of an electroless Ni-plating solution
was as follows.
[0060] "ELN240 M2" from Electroplating Engineers of Japan Ltd.
(EEJA): 150 mL/L
[0061] "ELN240 M1" from Electroplating Engineers of Japan Ltd.
(EEJA): 50 m L/L
[0062] "ELN240 R3" from Electroplating Engineers of Japan Ltd.
(EEJA): 6 mL/L
(Immersion Au Plating)
[0063] The glass substrate having an Ni-plating layer was immersed
in a gold plating solution ("PRECIOUSFAB IGS8000SPF" from EEJA)
kept at 55.degree. C. for 10 min, for forming an immersion Au
plating layer with a thickness of 0.05 .mu.m over the Ni plating
layer, to provide a plated article.
[Evaluation]
(Surface Observation)
[0064] The surface of the plated article obtained was observed by a
microscope. The image obtained is shown in FIG. 2. In FIG. 2, 1 is
the glass substrate, and 2 is an immersion gold-plating film. As
shown in FIG. 2, by "catalyst deactivation", a plating film was
selectively formed only in the area irradiated with a pulsed
laser.
(Adhesion Test)
[0065] An adhesion test was conducted in accordance with a solder
testing described in JIS H8504. Here, an L-shaped clasp was an
oxygen free copper plate with a thickness of 0.5 mm. It was
press-molded into a predetermined shape such that an area to be
soldered is 5 mm.times.5 m, which was then nickel-plated to a film
thickness of 3 .mu.m as a base layer and then gold-plated to a film
thickness of 0.05 .mu.m. Separately, a solder was applied to the
surface of the plated article (.phi.8 mm.times.t 0.2 mm), and then
heated at 300.degree. C. for 1 min. Then, the L-shaped clasp and
the plated article were bonded via a solder to provide a test
piece. The test piece obtained was mounted to a tensile tester
"3382 floor model testing system" from Instron Corporate, and an
adhesion test was conducted. A solder was a lead-free solder paste
"TSC-254-5042SF 12-1" from Tarutin Kester Co., Ltd. FIG. 3 is an
image after the tensile test. As shown in FIG. 3, the plating film
was stripped together with the glass.
Example 2
[0066] In "electroless catalyst adhesion", a time of immersion in a
palladium catalyst solution was changed to 2 min and "catalyst
removal" was conducted in place of "catalyst deactivation". In
"catalyst removal", a plated article was produced as described in
Example 1, except that an activated glass substrate was immersed in
an aqueous solution of glycine (concentration: 0.05 M) at room
temperature for 30 sec, and its surface was observed by a
microscope. FIG. 4 shows an image obtained. In FIG. 4, 1 is a glass
substrate, and 2 is an immersion Au plating film. As shown in FIG.
4, by "catalyst removal", a plating film was selectively formed
only in the area irradiated with a pulsed laser. Then, an adhesion
test was conducted as described in Example 1. As a result, the
plating film was stripped together with the glass.
Example 3
[0067] A plated article was produced as described in Example 1,
except that a glass substrate was replaced with a 76 mm.times.26
mm.times.1.1 mm borosilicate glass ("Matsunami slide glass S1127").
Then, an adhesion test was conducted as described in Example 1. As
a result, the plating film was stripped together with the
glass.
Example 4
[0068] A glass substrate was irradiated with a pulsed laser as
described in Example 1, except that a glass substrate was replaced
with a reinforced glass with a size of 70 mm (length).times.30 mm
(width).times.0.55 mm (thickness) ("Dragontrail" from AGC: Asahi
Glass Co., Ltd.) and in pulsed laser irradiation, an average output
power at a processing point was 1.1 W, a travel distance in the y
direction was 6 .mu.m and a scan rate was 300 mm/sec. "Dragontrail"
is a chemically reinforced glass, in which Na.sup.+ in the glass
surface is replaced with K.sup.+.
[0069] Using a color 3D laser microscope "VK-9700" (observation
magnification: 50) from KEYENCE Corporation, an arithmetic mean
roughness (Ra) of the area irradiated with a pulsed laser was
measured in accordance with JIS B 0601 (2001). As a result, Ra was
0.41 .mu.m.
[0070] After measuring a surface roughness, a plating film was
formed on the surface of the glass substrate as described in
Example 2. As a result, a plating film was selectively formed only
in the area irradiated with a pulsed laser. Then, an adhesion test
was conducted as described in Example 1, and the plating film was
stripped together with the glass.
Example 5
[0071] A glass substrate was irradiated with a pulsed laser as
described in Example 4, except that in pulsed laser irradiation, an
average output power at a processing point was 1.1 W, a travel
distance in they direction was 10 .mu.m, and a scan rate was 50
mm/sec. Then, an arithmetic mean roughness (Ra) of the area
irradiated with a pulsed laser was measured as described in Example
4. As a result, Ra was 2.81 .mu.m.
[0072] After measuring a surface roughness, a plating film was
formed on the surface of the glass substrate as described in
Example 2. As a result, a plating film was selectively formed only
in the area irradiated with a pulsed laser. Then, an adhesion test
was conducted as described in Example 1, and the plating film was
stripped together with the glass.
Comparative Example 1
[0073] A plated article was produced as described in Example 1,
without conducting "catalyst deactivation" or "immersion Au
plating", and its surface was observed by a microscope. FIG. 5
shows the image obtained. In FIG. 5, 31 indicates an Ni plating
film formed in the area irradiated with a pulsed laser, and 32
indicates an Ni plating film formed in the area unirradiated with a
pulsed laser in the glass substrate. As shown in FIG. 5, without
conducting "catalyst deactivation" or "catalyst removal", a plating
film was formed on the whole surface of the glass substrate.
Furthermore, the Ni plating film formed in the area unirradiated
with a pulsed laser was easily stripped by an adhesive cellophane
tape.
Comparative Example 2
[0074] A glass substrate was irradiated with a pulsed laser as
described in Example 4, except that in pulsed laser irradiation, an
average output power at a processing point was 1 W, a travel
distance in the y direction was 10 .mu.m, and a scan rate was 300
mm/sec. Then, an arithmetic mean roughness (Ra) of the area
irradiated with a pulsed laser was measured as described in Example
4. As a result, Ra was 0.03 .mu.m.
[0075] After measuring a surface roughness, a plating film was
formed on the surface of the glass substrate as described in
Example 2. As a result, a plating film was selectively formed only
in the area irradiated with a pulsed laser, but the plating film
could be easily stripped by an adhesive cellophane tape.
EXPLANATION OF LETTERS OR NUMERALS
[0076] 1: Glass substrate [0077] 2: Immersion Au plating film
[0078] 31: Ni plating film formed in the area irradiated with a
pulsed laser [0079] 32: Ni plating film formed in the area
unirradiated with a pulsed laser in the surface of a glass
substrate
* * * * *