U.S. patent application number 10/777641 was filed with the patent office on 2004-08-19 for light-transmitting electromagnetic wave-shielding material and method of manufacturing the same.
Invention is credited to Ishibashi, Tatsuo, Nishida, Masahiro, Okumura, Shuzo.
Application Number | 20040159554 10/777641 |
Document ID | / |
Family ID | 17105864 |
Filed Date | 2004-08-19 |
United States Patent
Application |
20040159554 |
Kind Code |
A1 |
Okumura, Shuzo ; et
al. |
August 19, 2004 |
Light-Transmitting electromagnetic wave-shielding material and
method of manufacturing the same
Abstract
A light-transmitting electromagnetic wave-shielding material
includes a hydrophilic transparent resin layer laminated on a
transparent substrate. An electroless plating layer is laminated on
the hydrophilic transparent resin layer in a pattern, and a black
pattern section is formed on the hydrophilic transparent resin
layer under the electroless plating layer. Therefore, a black
electroplating layer is formed to cover the electroless plating
layer laminated in a pattern.
Inventors: |
Okumura, Shuzo; (Kyoto-shi,
JP) ; Nishida, Masahiro; (Kyoto-shi, JP) ;
Ishibashi, Tatsuo; (Kyoto-shi, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
17105864 |
Appl. No.: |
10/777641 |
Filed: |
February 13, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10777641 |
Feb 13, 2004 |
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09763961 |
Feb 28, 2001 |
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6713161 |
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09763961 |
Feb 28, 2001 |
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PCT/JP99/04621 |
Aug 27, 1999 |
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Current U.S.
Class: |
205/128 ;
205/163 |
Current CPC
Class: |
H05K 9/0096 20130101;
Y10T 428/31529 20150401; Y10T 428/24868 20150115; Y10T 428/12028
20150115; Y10T 428/24917 20150115 |
Class at
Publication: |
205/128 ;
205/163 |
International
Class: |
C25D 005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 28, 1998 |
JP |
10-243574 |
Claims
What is claimed is:
1. A method of manufacturing a light-transmitting electromagnetic
wave-shielding material comprising: (A) forming a hydrophilic
transparent resin layer on a transparent substrate; (B) forming an
electroless plating layer on the hydrophilic transparent resin
layer so that the hydrophilic transparent resin layer is blackened
when seen from its rear side; (C) forming an electroplating layer
on the electroless plating layer; (D) forming a resist section in a
desired pattern on the electroless plating layer; (E) performing
etching to remove the electroless electroplating layer and the
electroplating layer on a non-resist section, where the resist
section is not formed, of the electroplating layer, while
patterning in black the hydrophilic transparent resin layer under
the electroless plating layer when seen from its rear side; (F)
removing the resist section on the electroless plating layer from
the electroless plating layer; and (G) forming a black
electroplating layer covering the electroplating layer and the
electroless plating layer.
2. A method of manufacturing a light-transmitting electromagnetic
wave-shielding material comprising: (A) forming a hydrophilic
transparent resin layer on a transparent substrate; (B) forming an
electroless plating layer on the hydrophilic transparent resin
layer so that the hydrophilic transparent resin layer is blackened
when seen from its rear side; (C) forming a resist section in a
desired pattern on the electroless plating layer; (D) performing
etching to remove a non-resist section of the electroless plating
layer, on which the resist section is not formed, while patterning
in black the hydrophilic transparent resin layer under the
electroless plating layer when seen from its rear side; (E)
removing the resist section on the electroless plating layer from
the electroless plating layer; (F) forming an electroplating layer
on the electroless plating layer; and (G) forming a black
electroplating layer covering the electroplating layer and the
electroless plating layer.
3. A method of manufacturing a light-transmitting electromagnetic
wave-shielding material comprising: (A) forming a hydrophilic
transparent resin layer on an entire surface of a transparent
substrate; (B) forming an electroless plating layer on an entire
surface of the hydrophilic transparent resin layer so that the
hydrophilic transparent resin layer is blackened when seen from its
rear side; (C) forming a resist section in a desired pattern on the
electroless plating layer; (D) forming an electroplating layer on a
non-resist section of the electroless plating layer, on which the
resist section is not formed; (E) removing the resist section on
the electroless plating layer from the electroless plating layer;
(F) performing etching to remove an electroplating layer
non-existent portion of the electroless plating layer while
patterning in black the hydrophilic transparent resin layer under
the electroless plating layer when seen from its rear side; and (G)
forming a black electroplating layer covering the electroplating
layer and the electroless plating layer.
4. A method of manufacturing a light-transmitting electromagnetic
wave-shielding material comprising: (A) forming a hydrophilic
transparent resin layer on a transparent substrate; (B) forming an
electroless plating layer on the hydrophilic transparent resin
layer so that the hydrophilic transparent resin layer is blackened
when seen from its rear side; (C) forming an electroplating layer
on the electroless plating layer; (D) forming a black
electroplating layer on the electroless plating layer; (E) forming
a resist section in a desired pattern on the black electroplating
layer; and (F) performing etching to remove a non-resist section of
the black electroplating layer, on which the resist section is not
formed, while patterning in black the hydrophilic transparent resin
layer under the electroless plating layer when seen from its rear
side, and then removing the resist section on the black
electroplating layer from the black electroplating layer.
5. A method of manufacturing a light-transmitting electromagnetic
wave-shielding material, wherein the black electroplating layer in
claim 1 is constituted by a nickel, chromium, tin, rhodium, or
ruthenium metal or an alloy of any of these.
6. The light-transmitting electromagnetic wave-shielding material
manufactured by the method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to claim 1.
7. A method of manufacturing a light-transmitting electromagnetic
wave-shielding material, wherein the black electroplating layer in
claim 2 is constituted by a nickel, chromium, tin, rhodium, or
ruthenium metal or an alloy of any of these.
8. A method of manufacturing a light-transmitting electromagnetic
wave-shielding material, wherein the black electroplating layer in
claim 3 is constituted by a nickel, chromium, tin, rhodium, or
ruthenium metal or an alloy of any of these.
9. A method of manufacturing a light-transmitting electromagnetic
wave-shielding material, wherein the black electroplating layer in
claim 4 is constituted by a nickel, chromium, tin, rhodium, or
ruthenium metal or an alloy of any of these.
Description
[0001] This application is a Divisional application of Ser. No.
09/763,961 filed Feb. 28, 2001, now allowed.
TECHNICAL FIELD
[0002] The present invention relates to a light transmitting
electromagnetic wave-shielding material for shielding an
electromagnetic wave and through which the inside of a microwave
oven, a measuring instrument, or the like or a screen of a CRT,
plasma display panel, or the like can be seen, and relates to a
method of manufacturing the same.
BACKGROUND ART
[0003] As disclosed in Japanese Patent No. 2,717,734, a
conventional light-transmitting electromagnetic wave-shielding
material includes a hydrophilic transparent resin layer 32
laminated on a transparent substrate 31. An electroless plating
layer 334 is laminated. on the hydrophilic transparent resin layer
32 in a pattern, and a black pattern section 36 is formed in the
hydrophilic transparent resin layer 32 under the electroless
plating layer (see FIG. 1). The electroless plating layer
microscopically looks like a black pattern in a fine mesh or the
like to an observer. However, the aforementioned light-transmitting
electromagnetic wave-shielding material has issues described
below.
[0004] In particular, although a bottom surface of the electroless
plating layer has a black color, a top surface of the electroless
plating layer maintains a metallic luster. Therefore, when the
light-transmitting electromagnetic wave-shielding material is
attached to the front of a display (for example, when a shielding
filter is set at the front of the display and a grounding section
is provided on a front surface of the filter (observer side) or a
rear surface of the filter (display side) to ensure an electrical
connection (grounding) between a display case and the filter), the
surface having a black color faces the observer and the surface
having the metallic luster faces the display. In this case, there
is a disadvantage in that visibility of the display images observed
by the observer are deteriorated since the light radiated from the
display is reflected from the surface of the electroless plating
layer having the metallic luster and illuminates the display screen
again.
[0005] To remove this disadvantage (that is, to improve visibility
by suppressing reflection from a metallic surface) the following
methods are available:
[0006] (1) A method of roughening a surface by sand blasting or the
like to form surface irregularities;
[0007] (2) A method of forming a black coating by oxidation;
[0008] (3) A method of coating an irregular film by printing or the
like; and
[0009] (4) A method of coating a black film by printing or the
like.
[0010] However, since the hydrophilic transparent resin layer and
the electroless plating layer are subjected to a physical impact or
chemical change in any of the above methods (1) to (4),
transparency of the hydrophilic transparent resin layer is
deteriorated, and an electromagnetic wave-shielding effect is
impaired due to damage to the electroless plating layer. Another
issue is that reduced conductivity of the electroless plating layer
makes grounding difficult.
[0011] In addition, in methods (1), (3), and (4), it is extremely
difficult to roughen a side surface 39 of the electroless plating
layer or coat an irregular film or the like thereon. Therefore,
light reflection from the side surface 39 of the electroless
plating layer cannot be suppressed, so that visibility at slant
angles, in particular, cannot be improved.
[0012] In methods (3) and (4), in particular, it is difficult to
coat an irregular (projections-and-depressions) film or a black
film only on a portion on which the electroless plating layer
exists (so-called patterning). Furthermore, in this case, a resist
process or the like is required for grounding so that an irregular
film is formed except for a portion of the electroless plating
layer to be grounded. Consequently, productivity is decreased.
[0013] Accordingly, an object of the present invention is to
provide a light-transmitting electromagnetic wave-shielding
material which has favorable properties such as transparency,
electromagnetic wave-shielding effect, visibility, and the like,
and which is easy to be grounded, and a method of manufacturing the
same.
SUMMARY OF THE INVENTION
[0014] In order to achieve the above object, the present invention
has the following constitutions.
[0015] According to a first aspect of the present invention, there
is provided a light-transmitting electromagnetic wave-shielding
material, wherein a hydrophilic transparent resin layer is
laminated on a transparent substrate. An electroless plating layer
is laminated on the hydrophilic transparent resin layer in a
pattern. A black pattern section is formed only in a portion of the
hydrophilic transparent resin layer under the electroless plating
layer, and a black electroplating layer covering the electroless
plating layer is laminated.
[0016] According to a second aspect of the present invention, there
is provided a light-transmitting electro magnetic wave-shielding
material, wherein a hydrophilic transparent resin layer is
laminated on a transparent substrate. An electroless plating layer
is laminated on the hydrophilic transparent resin layer in a
pattern. A black pattern section is formed only in a portion of the
hydrophilic transparent resin layer under the electroless plating
layer. An electroplating layer is laminated on the electroless
plating layer, and a black electroplating layer covering the
electroless plating layer and the electroplating layer is
laminated.
[0017] According to a third aspect of the present invention, there
is provided the light-transmitting electromagnetic wave-shielding
material according to the first aspect, wherein the black
electroplating layer covers a top surface of the electroless
plating layer exposed on an opposite side of a surface on which the
black pattern section is formed, as well as a side surface of the
electroless plating layer.
[0018] According to a fourth aspect of the present invention, there
is provided the light-transmitting electromagnetic wave-shielding
material according to the second aspect, wherein the black
electroplating layer covers a top surface of the electroplating
layer exposed on an opposite side of a surface on which the
electroless plating layer is formed, as well as respective side
surfaces of the electroless plating layer and the electroplating
layer.
[0019] According to a fifth aspect of the present invention, there
is provided the light-transmitting electromagnetic wave-shielding
material according to the first aspect, wherein the black
electroplating layer covers only a top surface of the electroless
plating layer exposed on an opposite side of a surface on which the
black pattern sections formed.
[0020] According to a sixth aspect of the present invention, there
is provided the light-transmitting electromagnetic wave-shielding
material according to the second aspect, wherein the black
electroplating layer covers only a top surface of the
electroplating layer exposed on an opposite side of a surface on
which the electroless plating layer is formed.
[0021] According to a seventh aspect of the present invention,
there is provided the light-transmitting electromagnetic
wave-shielding material according to any one of the first to sixth
aspects, wherein the black electroplating layer is nickel,
chromium, tin, rhodium, or ruthenium metal or an alloy of any of
these.
[0022] According to an eighth aspect of the present invention,
there is provided a method of manufacturing a light-transmitting
electromagnetic wave-shielding material comprising forming a
hydrophilic transparent resin layer on a transparent substrate. An
electroless plating layer is formed on the hydrophilic transparent
resin layer so that the hydrophilic transparent resin layer is
blackened when seen from its rear side. A resist section is formed
in a desired pattern on the electroless plating layer. Etching is
performed to remove a non-resist section of the electroless plating
layer, on which the resist section is not formed, while patterning
in black the hydrophilic transparent resin layer under the
electroless plating layer when seen from its rear side. The resist
section on the electroless plating layer is removed from the
electroless plating layer, and a black electroplating layer is
formed to cover the electroless plating layer.
[0023] According to a ninth aspect of the present invention, there
is provided a method of manufacturing a light-transmitting
electromagnetic wave-shielding material comprising forming a
hydrophilic transparent resin layer on a transparent substrate. An
electroless plating layer is formed on the hydrophilic transparent
resin layer so that the hydrophilic transparent resin layer is
blackened when seen from its rear side. An electroplating layer is
formed on the electroless plating layer a resist section is formed
in a desired pattern on the electroless plating layer. Etching is
performed to remove the electroless electroplating layer on a
non-resist section, where the resist section is not formed, of the
electroplating layer, while patterning in black the hydrophilic
transparent resin layer under the electroless plating layer when
seen from its rear side. The resist section on the electroless
plating layer is removed from the electroless plating. layer, and a
black electroplating layer covering the electroplating layer and
the electroless plating layer is formed.
[0024] According to a 10th aspect of the present invention, there
is provided a method of manufacturing a light-transmitting
electromagnetic wave-shielding material comprising forming a
hydrophilic transparent resin layer on a transparent substrate. An
electroless plating layer is formed on the hydrophilic transparent
resin layer so that the hydrophilic transparent resin layer is
blackened when seen from its rear side, and a resist section is
formed in a desired pattern on the electroless plating layer.
Etching is performed to remove a non-resist section the electroless
plating layer, on which the resist section is not formed, while
patterning in black the hydrophilic transparent resin layer under
the electroless plating layer when seen from its rear side. The
resist section on the electroless plating layer from the
electroless plating layer, forming an electroplating layer on the
electroless plating layer, and a black electroplating layer
covering the electroplating layer and the electroless plating layer
is formed.
[0025] According to an 11th aspect of the present invention, there
is provided a method of manufacturing a light-transmitting
electromagnetic wave-shielding material comprising forming a
hydrophilic transparent resin layer on an entire surface of a
transparent substrate. An electroless plating layer is formed on an
entire surface of the hydrophilic transparent resin layer so that
the hydrophilic transparent resin layer is blackened when seen from
its rear side, and a resist section is formed in a desired pattern
on the electroless plating layer. An electroplating layer is formed
on a non-resist section of the electroless plating layer, on which
the resist section is not formed, and the resist section on the
electroless plating layer from the electroless plating layer.
Etching is performed to remove an electroplating layer non-existent
portion of the electroless plating layer while patterning in black
the hydrophilic transparent resin layer under the electroless
plating layer when seen from its rear side; and a black
electroplating layer covering the electroplating layer and the
electroless plating layer is formed.
[0026] According to a 12th aspect of the present invention, there
is provided a method of manufacturing a light-transmitting
electromagnetic wave-shielding material comprising forming a
hydrophilic transparent resin layer on a transparent substrate. An
electroless plating layer is formed on the hydrophilic transparent
resin layer so that the hydrophilic transparent resin layer is
blackened when seen from its rear side. A black electroplating
layer is formed on the electroless plating layer, and a resist
section is formed in a desired pattern on the black electroplating
layer. Etching is performed to remove a non-resist section of the
black electroplating layer, on which the resist section is not
formed, while patterning in black the hydrophilic transparent resin
layer under the electroless plating layer when seen from its rear
side, and then the resist section on the black electroplating layer
is removed from the black electroplating layer.
[0027] According to a 13th aspect of the present invention, there
is provided a method of manufacturing a light-transmitting
electromagnetic wave-shielding material comprising forming a
hydrophilic transparent resin layer on a transparent substrate. An
electroless plating layer is formed on the hydrophilic transparent
resin layer so that the hydrophilic transparent resin layer is
blackened when seen from its rear side, an electroplating layer is
formed on the electroless plating layer, a black electroplating
layer is formed on the electroless plating layer, and a resist
section is formed in a desired pattern on the black electroplating
layer. Etching is performed to remove a non-resist section of the
black electroplating layer, on which the resist section is not
formed, while patterning in black the hydrophilic transparent resin
layer under the electroless plating layer when seen from its rear
side, and then the resist section on the black electroplating layer
is removed from the black electroplating layer.
[0028] According to a 14th aspect of the present invention, there
is provided a method of manufacturing a light-transmitting
electromagnetic wave-shielding material, wherein the black
electroplating layer in any one of the eighth to 13th aspects is
nickel, chromium, tin, rhodium, ruthenium metal, or an alloy of any
of these.
[0029] According 15th aspect of the present invention, there is
provided a light-transmitting electromagnetic wave-shielding
material manufactured by the method of manufacturing the
light-transmitting electromagnetic wave-shielding material
according to any one of the eighth to 14th aspects.
BRIEF DESCRIPTION OF DRAWINGS
[0030] These and other aspects and features of the present
invention will become clear from the following description taken in
conjunction with the preferred embodiments thereof with reference
to the accompanying drawings, in which:
[0031] FIG. 1 is a cross sectional view showing an example of a
conventional light-transmitting electromagnetic wave-shielding
material;
[0032] FIG. 2 is a cross sectional view showing a light
transmitting electromagnetic wave-shielding material manufactured
by a method of manufacturing a light-transmitting electromagnetic
wave-shielding material according to a first embodiment of the
present invention;
[0033] FIG. 3 is a cross sectional view showing a
light-transmitting electromagnetic wave-shielding material
manufactured by methods of manufacturing a light-transmitting
electromagnetic wave-shielding material according to second to
fourth embodiments of the present invention;
[0034] FIGS. 4A, 4B, 4C, 4D, 4E, and 4F are cross sectional views
showing steps of the method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to the first
embodiment of the present invention;
[0035] FIGS. 5A, 5B, 5C, 5D, 5E, 5F, and 5G are cross sectional
views showing steps of the method of manufacturing the
light-transmitting electromagnetic wave-shielding material
according to the second embodiment of the present invention;
[0036] FIGS. 6A, 6B, 6C, 6D, 6E, 6F, and 6G are cross sectional
views showing steps of the method of manufacturing the
light-transmitting electromagnetic wave-shielding material
according to the third embodiment of the present invention;
[0037] FIGS. 7A, 7B, 7C, 7D, 7E, 7F, and 7G are, cross sectional
views showing steps of the method of manufacturing the
light-transmitting electromagnetic wave-shielding material
according to the fourth embodiment of the present invention;
[0038] FIG. 8 is a plan view showing the light-transmitting
electromagnetic wave-shielding material according to one example of
the first embodiment;
[0039] FIGS. 9A, 9B, 9C, 9D, and 9E are cross sectional views
showing steps of a method of manufacturing light-transmitting
electromagnetic wave-shielding material according to a fifth
embodiment of the present invention; and
[0040] FIGS. 10A, 10B, 10C, 10D, 10E, and F are cross sectional
views showing steps of a method of manufacturing a
light-transmitting electromagnetic wave-shielding material
according to a sixth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Before the description of the present invention proceeds, it
is to be noted that like parts are designated by like reference
numerals throughout the accompanying drawings.
[0042] Embodiments of the present invention are described in detail
with reference to the accompanying drawings.
[0043] FIG. 2 is a cross sectional view showing a
light-transmitting electromagnetic wave-shielding material
according to a first embodiment of the present invention. FIG. 3 is
a cross sectional view showing a light-transmitting electromagnetic
wave-shielding material according to second to fourth embodiments
of the present invention. FIGS. 4A-4F, 5A-5G, 6A-6G, and 7A 7G are
cross sectional views showing respective steps of methods of
manufacturing light-transmitting electromagnetic wave-shielding
materials according to the first to fourth embodiments of the
present invention. FIGS. 9A-9E and 10A-10F are cross sectional
views showing respective steps of methods of manufacturing
light-transmitting electromagnetic wave-shielding materials
according to the fifth and sixth embodiments of the present
invention. In the figures, reference numeral 1 denotes a
transparent substrate, 2 denotes a hydrophilic transparent resin
layer, 4 denotes an electroless plating layer, 5 denotes a resist
section, 6 denotes a black pattern section, 7 denotes an
electroplating layer, 8 denotes a black electroplating layer, and 9
denotes a side surface.
[0044] First, methods of manufacturing a light transmitting
electromagnetic wave-shielding material according to the first to
sixth embodiments of the present invention and light-transmitting
electromagnetic wave-shielding materials manufactured by these
methods are outlined below.
[0045] First, a hydrophilic transparent resin layer 2 is formed on
an entire surface of a transparent substrate 1 (see FIGS. 4A, 5A,
6A, and 7A).
[0046] The transparent substrates 1 include plate-like or film-like
substrates constituted by glass, acrylic resin polycarbonate resin,
polyethylene resin, AS resin, vinyl acetate resin, polystyrene
resin, polypropylene resin, polyester resin, cellulose acetate
resin, polysulfone resin, polyethersulfone resin, polyvinyl
chloride resin, or the like. The shape of the transparent substrate
1 does not necessarily need to be flat, but may be curved or the
like.
[0047] Any hydrophilic transparent resin layer 2 can be used so
long as it can be blackened in a later electroless plating process.
A vinyl alcohol resin, acrylic resin, cellulose resin, or the like
is suitable for the hydrophilic transparent resin layer 2. For
example, preferable vinyl alcohol resins include ethylene-vinyl
alcohol copolymer, vinyl acetate-vinyl alcohol copolymer, and the
like. Preferable acrylic resins include polyhydroxyethyl acrylate,
polyhydroxypropyl acrylate, polyhidroxyethyl metacrylate,
polyhydroxypropyl metacrylate, polyacrylamide, or polymethylol
acrylamide, a copolymer thereof, and the like. Preferable cellulose
resins include nitrocellulose, acetylcellulose,
acetylpropylcellulose, acetylbutylcellulose, and the like. Methods
of forming a hydrophilic transparent resin layer 2 include spin
coating, roll coating, die coating, dip coating, bar coating, and
the like.
[0048] Subsequently, an electroless plating layer 4 is formed on an
entire surface of the hydrophilic transparent resin layer 2 (see
FIGS. 4B, 5B, 6B, and 7B).
[0049] The hydrophilic transparent resin layer 2 is blackened by
this process. Specifically, the hydrophilic transparent resin layer
is immersed in a catalytic solution for chemical plating such as a
palladium catalytic solution or the like. Alternatively, a
palladium compound, silver compound, or the like which is used as
plating nuclei for electroless plating may be dispersed and
contained in the hydrophilic transparent resin layer 2 in advance.
In this case, the hydrophilic transparent resin layer 2 does not
need to be immersed in a catalytic solution for chemical
plating.
[0050] Subsequently, the hydrophilic transparent resin layer 2 in
which electroless plating nuclei are formed is immersed in an
electroless plating solution to form an electroless plating layer
The hydrophilic transparent resin layer 2 is blackened by this
electroless plating process. Copper or nickel is suitable for this
kind of electroless plating. When copper, which is highly
conductive, is used, 0.2-5 .mu.m is suitable as the thickness of
the electroless plating layer 4. If the thickness is less than 0.2
.mu.m, an electromagnetic wave-shielding effect is impaired. If the
thickness exceeds 5 .mu.m, fine line patterning by etching becomes
difficult.
[0051] As shown in FIG. 5E, an electroplating layer 7 can be
further formed on a surface of the electroless plating layer 4 to
increase a speed of film formation by plating. When the
electroplating layer 7 is also used, a shielding material having a
high electromagnetic wave-shielding effect can be formed rapidly.
When the electroplating layer 7 is also used, the film thickness of
the electroless plating layer 4 may be 0.5 .mu.m or less. In this
case, the role of the electroless plating layer 4 is to form a
black color on the bottom surface of the electroless plating layer
and to form a base conductive layer for the electroplating layer
7.
[0052] In the methods of manufacturing light-transmitting
electromagnetic wave-shielding materials according to the first to
sixth embodiments of the present invention, a method of forming a
second black electroplating layer 8 so as to cover the electroless
plating layer 4 or both the electroless plating layer 4 and the
first electroplating layer 7 is suitably employed. The reason is
that when the second black electroplating layer 8 is formed on a
surface with metallic luster such as the electroless plating layer
4 or the electroless plating layer 4 and the electroplating layer
7, visibility from a surface on which the black electroplating
layer 8 is formed can also be improved. This surface can face an
observer when used and the grounded surface can face either the
observer side or the panel side. Thus, the degree of freedom in use
can be increased.
[0053] Furthermore, it is optimal with respect to corrosion
resistance, blackness, uniformity in a plating film, and the like
when the black electroplating layer is a nickel or chromium black
electroplating layer.
[0054] At least six methods of manufacturing light-transmitting
electromagnetic wave-shielding materials according to the first to
sixth embodiments of the present invention shown in FIGS. 4A-4F,
5A-5G, 6A-6G, 7A-7G, 9A-9E, and 10A-10F are practical, but the
contents disclosed by the present invention are not limited to
these methods.
[0055] As shown in FIG. 2, the light-transmitting electromagnetic
wave-shielding material manufactured by the method of manufacturing
the light-transmitting electromagnetic wave-shielding material
according to the first embodiment is such that the hydrophilic
transparent resin layer 2 is laminate on an entire surface of the
transparent substrate 1, the electroless plating layer 4 is
laminated on the hydrophilic transparent resin layer 2 in a pattern
so that the black pattern section 6 is formed only in a portion
under the electroless plating layer 4 of the hydrophilic
transparent resin layer 2, and a black electroless plating layer 8
is laminated to cover a top surface and a side surface of the
electroless plating layer 4.
[0056] As shown in FIG. 3, the light-transmitting electromagnetic
wave-shielding material manufactured by the methods of
manufacturing light-transmitting electromagnetic wave-shielding
materials according to the second to fourth embodiments is
constituted such that a hydrophilic transparent resin layer 2 is
laminated on an entire surface of a transparent substrate 1. An
electroless plating layer 4 is laminated on the hydrophilic
transparent resin layer 2 in a pattern so that a black pattern
section 6 is formed under the electroless plating layer 4 of the
hydrophilic transparent resin layer 2. The first electroplating
layer 7 is laminated on the electroless plating layer 4, and the
black second electroplating layer 8 covers the electroless plating
layer 4 and the electroplating layer 7.
[0057] The method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to each
embodiment is described below with reference to drawings.
[0058] The method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to the first
embodiment of the present invention is described with reference to
steps (A) to (F) shown in FIGS. 4A-4F. FIG. 2 shows the
light-transmitting electromagnetic wave-shielding material
manufactured by the method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to the first
embodiment.
[0059] First, as shown in FIG. 4A, the hydrophilic transparent
resin layer 2 is formed on an entire surface of the transparent
substrate 1 (steps (A)).
[0060] Subsequently, as shown in FIG. 4B, the electroless plating
layer 4 is formed on an entire surface of the hydrophilic
transparent resin layer 2 so that the hydrophilic transparent resin
layer 2 is blackened when seen from the rear side (that is, the
bottom side in FIG. 4B) (steps (B)).
[0061] Subsequently, as shown in FIG. 4C, the resist section 5 is
formed in a desired pattern on the electroless plating layer 4
(step (C)). It is preferable that the resist section 5 is not
removed along with the plating layer when the plating layer is
removed in a later process, and that it is a vinyl polycinnamate
resin, polyisoprene resin, quinonediazide resin, or the like. The
pattern of the resist section 5 is designed so that transparency
and conductivity of the light-transmitting electromagnetic
wave-shielding material manufactured by the method according to the
first embodiment of the present invention are ensured. The resist
section 5 is preferably formed on the electroless plating layer 4
by a printing or photolithography method.
[0062] Subsequently, as shown in FIG. 4D, a non-resist section of
the electroless plating layer 4, on which the resist section 5 is
not formed, is removed by etching. Meanwhile, an unremoved section
of the hydrophilic transparent resin layer 2 positioned below a
resist-placed section of electroless plating layer 4, which is not
removed because the resist section 5 is formed thereon, is
patterned so that the unremoved section of the hydrophilic
transparent resin layer 2 below the resist-placed section of the
electroless plating layer 4 looks black when seen from its rear
side (that is, the bottom side in FIG. 4D) (step (D)). As described
above, since the unremoved section of the hydrophilic transparent
resin layer 2 is blackened, a black pattern section 6 approximately
coinciding with the patterned electroless plating layer 4 is formed
thereunder as a result. Also, the portion of hydrophilic
transparent resin layer 2 from which the electroless plating layer
4 is removed (that is, the portion where the black color is
removed) transmits light. An etchant used for this etching is
appropriately selected depending on the kind of a metal
constituting the electroless plating layer 4. For example, when the
metal constituting the electroless plating layer 4 is nickel,
copper, or tin, it is preferable to use a ferric chloride aqueous
solution as the etchant. When the metal constituting the
electroless plating layer 4 is chromium, it is preferable to use a
mixture solution of ceric nitrate ammonium, perchloric acid, and
water as an etchant
[0063] Subsequently, as shown in FIG. 4E, the resist section 5 is
removed from the electroless plating layer 4 by dissolution and
removal using an alkaline aqueous solution or an organic solvent
(step (E)): Then, as shown in FIG. 4F, for example, a black nickel
electroplating solution shown below is used to form a black
electroplating layer 8 by plating on exposed surfaces of the
electroless plating layer 4 so that the exposed surfaces of the
electroless plating layer 4 (that is, the top surface and the side
surface) are covered by the black electroplating layer 8 (step
(F)). Consequently, the light-transmitting electromagnetic
wave-shielding material shown in FIG. 2 is obtained.
[0064] Since the black electroplating layer 8 is formed only on the
top surface and the side surface of the electroless plating layer
4, a process of patterning the black electroplating layer 8 is not
required. This is because the black electroplating layer 8 is
laminated on the electroless plating layer 4, which has
conductivity, by electrical action. That is, metal ions or the like
in the black electroplating solution produce a black compound
sulfide or the like) by reductive reaction by electron, and the
black compound is deposited and laminated on the electroless
plating layer 4. On the other hand, the electrical action does not
occur with the hydrophilic transparent resin layer 2, which has no
conductivity, and thereby no lamination occurs.
[0065] An example of the black nickel electroplating solution is
shown below.
[0066] <Black Nickel Electroplating Solution>
[0067] Nickel sulfate: 100 g/l
[0068] Nickel ammonium sulfate: 30 g/l
[0069] Zinc sulfate: 15 g/l
[0070] Sodium thiocyanate: 10 g/l
[0071] A range of 30-70.degree. C. is suitable as a plating
temperature at. the time of plating by the black nickel
electroplating solution. Reaction is difficult at a temperature
lower than 30.degree. C. and control of the plating solution is
difficult if 70.degree. C. is exceeded. A range of 0.1-5 A/dm.sup.2
is suitable as a current density at the time of this plating. A
film is not easily formed if the current density is less than 0.1
A/dm.sup.2, and a density exceeding 5 A/dm.sup.2 is not preferable
because the black electroplating layer 8 becomes fragile.
[0072] According to the first. embodiment, since the black
electroplating layer 8 is selectively laminated only on a portion
having conductivity, that is, on the electroless plating layer 4 by
electrical action, the hydrophilic transparent resin layer 2 and
the electroless plating layer 4 are not subjected to physical
impact or chemical change. Therefore, transparency of the
hydrophilic transparent resin layer 2 is not deteriorated and there
is no impairment of the electromagnetic wave-shielding effect due
to damages to the electroless plating layer 4. Conductivity of the
electroless plating layer 4 is not decreased and there is no
difficulty in grounding.
[0073] Since the side surface of the electroless plating layer 4
can be covered by the black electroplating layer 8, light
reflection from the side surface of the electroless plating layer 4
can be suppressed so that visibility at slant angles in particular
can be greatly improved.
[0074] Since the electroless plating layer 4 is patterned and then
the black electroplating layer 8 is formed on the entire portion
where the electroless plating layer 4 is formed, the black
electroplating layer 8 is easily formed and it is not necessary to
form an irregular film or the like on only a portion of the
electroless plating layer 4 to be grounded unlike the conventional
methods (3) and (4). Therefore, productivity can be increased.
[0075] The method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to the second
embodiment of the present invention is described with reference to
steps (A) to (G) shown in FIGS. 5A-5G. FIG. 3 shows the
light-transmitting electromagnetic wave-shielding material
manufactured by the method of manufacturing the light-transmitting
electromagnetic wave shielding material according to the second
embodiment.
[0076] First, as shown in FIG. 5A, the hydrophilic transparent
resin layer 2 is formed on an entire surface of the transparent
substrate 1 (step (A)).
[0077] Subsequently, as shown in FIG. 5B, the electroless plating
layer 4 is formed on an entire surface of the hydrophilic
transparent resin layer 2 so that the hydrophilic transparent resin
layer 2 is blackened when seen from the rear side (that is, the
bottom side in FIG. 4B) (step (B))
[0078] Subsequently, as shown in FIG. 5C, a first electroplating
layer 7 is formed on an entire surface of the electroless plating
layer 4 (step (C)). In this case, the film thickness of the
electroless plating layer may be 0.5 .mu.m or less. Conductivity is
mainly imparted by the electroplating layer 7.
[0079] Subsequently, as shown in FIG. 5D, the resist section 5 is
formed in a desired pattern on the first electroplating layer 7
(step (D)). It is preferable that the resist section 5 is not
removed along with the plating layers when the plating layers are
removed in a later process, and that it is a vinyl polycinnamate
resin, polyisoprene resin, quinonediazide resin, or the like. The
pattern of the resist section 5 is designed so that transparency
and conductivity of the light-transmitting electromagnetic
wave-shielding material manufactured by the manufacturing method
according to the second embodiment of the present invention are
ensured. The resist section 5 is preferably formed on the first
electroplating layer 7 by a printing or photolithography
method.
[0080] Subsequently, as shown in FIG. 5E, a non-resist section of
the first electroplating layer 7, on which the resist section 5 is
not formed, and a section of the electroless plating layer 4
positioned under the non-resist section of the electroplating layer
7 are removed by etching. Meanwhile an unremoved section of the
hydrophilic transparent resin layer 2 positioned below a
resist-placed section of the first electroplating layer 7, which is
not removed because the resist section 5 is formed thereon, and the
unremoved section of the electroless plating layer 4 under this
resist-placed section is patterned when seen from its rear side
(that is, the bottom side in FIG. 5E) (step (E)). As described
above, since the unremoved section of the hydrophilic transparent
resin layer 2 is blackened, a black pattern section 6 approximately
coinciding with the patterned resist-placed section of the
electroplating layer 7 and the unremoved section of the electroless
plating layer 4 is formed thereunder as a result. Also, the portion
of the hydrophilic transparent resin layer 2 from which the
electroplating layer 7 and the electroless plating layer 4 are
removed (that is, the portion where the black color is removed)
transmits light. An etchant used for the etching is appropriately
selected depending on the kind o metals constituting the
electroplating layer 7 and the electroless plating layer 4. For
example, when metals constituting the electroplating layer 7 and
the electroless plating layer 4 are nickel, copper, or tin, it is
preferable to use a ferric chloride aqueous solution as an etchant.
When metals constituting the electroplating layer 7 and the
electroless plating layer 4 are chromium, it is preferable to use a
mixture solution of ceric nitrate-ammonium, perchloric acid, and
water as an etchant.
[0081] Subsequently, as shown in FIG. 5F, the resist section 5 is
removed from the electroplating layer 7 by dissolution and removal
using an alkaline aqueous solution or an organic solvent (step
(F)). Then, as shown in FIG. 5G, for example, a black nickel
electroplating solution shown below is used to form a second black
electroplating layer 8 by plating on exposed surfaces of the first
electroplating layer 7 and the electroless plating layer 4 so that
the exposed surfaces of the first electroplating layer 7 and the
electroless plating layer 4 (that is, the top surface and the side
surface 9 of the electroplating layer 7 and the side surface 9 of
the electroplating layer 4) are covered by the black second
electroplating layer 8 (step (G)). Consequently, the top surface
and the side surface 9 of the electroplating layer 7 and the side
surface 9 of the electroplating layer 4 are all covered by the
black second electroplating layer 8. Thus, a light-transmitting
electromagnetic wave-shielding material shown in FIG. 3 is
obtained.
[0082] Since the black second electroplating layer 8 is formed only
on the top surface and the side surface 9 of the electroplating
layer 7 and the side surface 9 of the electroless plating layer 4,
a process of patterning the black electroplating layer 8 is not
required. This is because the black electroplating layer 8 is
laminated on the electroplating layer 7 and the electroless plating
layer 4, which have conductivity, by electrical action. That is,
metal ions or the like in the black electroplating solution produce
a black compound (sulfide or the like) by reductive reaction by
electron, and then the black compound is deposited and laminated on
the electroplating layer 7 and the electroless plating layer 4. On
the other hand, the electrical action does not occur with the
hydrophilic transparent resin layer 2, which has no conductivity,
and thereby no lamination occurs.
[0083] An example of the black nickel electroplating solution is
shown below.
[0084] <Black Nickel Electroplating Solution>
[0085] Nickel sulfate: 80 g/l
[0086] Nickel ammonium sulfate: 50 g/l
[0087] Zinc sulfate: 30 g/l
[0088] Sodium thiocyanate: 20 g/l
[0089] A range of 30-70.degree. C. is suitable as a plating
temperature at the time of plating by a black nickel electroplating
solution. Reaction is difficult at a temperature lower than
30.degree. C., and control of the plating solution is difficult if
70.degree. C. is exceeded. A range of 0.1-5 A/dm.sup.2 is suitable
as a current density at the time of this plating. A film is not
easily formed if the current density is less than 0.1 A/dm.sup.2
and the density exceeding 5 A/dm.sup.2 is not preferable because
the black second electroplating layer 8 becomes fragile.
[0090] According to the second embodiment, since the black second
electroplating layer 8 is selectively laminated only on a portion
having conductivity (that is, on the electroless plating layer 4
and the electroplating layer 7) by electrical action, the
hydrophilic transparent resin layer 2, the electroless plating
layer 4, and the electroplating layer 7 are subjected to no
physical impact or chemical change. Therefore, transparency of the
hydrophilic transparent resin layer 2 is not deteriorated and there
is no impairment of the electromagnetic wave-shielding effect due
to damages to the electroless plating layer 4. Conductivity of the
electroless plating layer 4 is not decreased and there is no
difficulty in grounding.
[0091] Since the side surface of the electroless plating layer 4
can be covered by the black second electroplating layer 8, light
reflection from the side surface 9 of the electroless plating layer
4 and the side surface 9 of the electroplating layer 7 can be
suppressed so that visibility at slant angles in particular can be
substantially improved
[0092] Since the electroless plating layer 4 and the first
electroplating layer 7 are patterned and then the black second
electroplating layer 8 is formed on the entire portion where the
electroless plating layer 4 and the first electroplating layer 7
are formed, the black second electroplating layer 8 is easily
formed and it is not necessary to form an irregular film or the
like only on a portion of the electroless plating layer 4 to be
grounded, unlike the conventional methods (3) and (4). Therefore,
productivity can be increased.
[0093] The method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to the third
embodiment of the present invention is described with reference to
steps (A) to (G) shown in FIGS. 6A-6G. FIG. 3 shows the
light-transmitting electromagnetic wave-shielding material
manufactured by the method of manufacturing the light-transmitting
electromagnetic wave shielding material according to the third
embodiment.
[0094] First, as shown in FIG. 6A, the hydrophilic transparent
resin layer 2 is formed on an entire surface of the transparent
substrate 1 (step (A)).
[0095] Subsequently, as shown in FIG. 6B, the electroless plating
layer 4 having a film thickness of 0.5 .mu.m or less is formed on
an entire surface of the hydrophilic transparent resin layer 2
since electroplating is also employed, so that the hydrophilic
transparent resin layer 2 is blackened when seen from the rear side
(that is, the bottom side in FIG. 6B) (step (B)).
[0096] Subsequently, as shown in FIG. 6C, the resist section 5 is
formed in a desired pattern on the electroless plating layer 4
(step (C)). It is preferable that the resist section 5 is not
removed along with the plating layer when the plating layer is
removed in a later process, and that it is a vinyl polycinnamate
resin, polyisoprene resin, quinonediazide resin, or the like. The
pattern of the resist section 5 is designed so that transparency
and conductivity of the light-transmitting electromagnetic
wave-shielding material manufactured by the manufacturing method
according to the third embodiment of the present invention are
ensured. The resist section 5 is preferably formed on the
electroless plating layer 4 by a printing or photolithography
method.
[0097] Subsequently, as shown in FIG. 6D, a non-resist section of
the electroless plating layer 4, on which the resist section 5 is
not formed, is removed by etching. Meanwhile, an unremoved section
of the hydrophilic transparent resin layer 2 under the
resist-placed section of the electroless plating layer 4, which is
not removed because the resist section 5 is formed thereon, is
patterned when seen from its rear side (the bottom side in FIG. 6D)
(step (D)). As described above, since the unremoved section of the
hydrophilic transparent resin layer 2 is blackened and patterned,
the black pattern section 6 approximately coinciding with the
resist-placed section of the patterned electroless plating layer 4
is formed thereunder as a result. Also, the portion of the
hydrophilic transparent resin layer 2 where the electroless plating
layer 4 is removed (that is, the portion where the black color is
removed) transmits light. An etchant used for the etching is
appropriately selected depending on the kind of metal constituting
the electroless plating layer 4. For example, when the metal
constituting the electroless plating layer 4 is nickel, copper, or
tin, it is preferable to use a ferric chloride aqueous solution as
an etchant. When the metal constituting the electroless plating
layer 4 is chromium, it is preferable to use a mixture solution of
ceric nitrateammonium, perchloric acid, and water as an
etchant.
[0098] Subsequently, as shown in FIG. 6E, the resist section 5 is
removed from the electroless plating layer 4 (step (E)). Then, as
shown in FIG. 6F, the first electroplating layer 7 is formed on the
electroless plating layer 4 patterned by dissolution and removal
using an alkaline aqueous solution or an organic solvent (step
(F)). In this case, fine line stepping by etching becomes easy
because the film thickness of the electroless plating layer 4 is
thin.
[0099] Since the first electroplating layer 7 covers only the top
surface of the electroless plating layer 4, patterning of the first
electroplating layer 7 is not required. This is because the first
electroplating layer 7 is laminated on the electroless plating
layer 4, which is conductive, by electrical action. That is, metal
ions or the like in the black electroplating solution produce a
black compound (sulfide or the like) by reductive reaction by
electrons, and then the black compound is deposited and laminated
on the electroless plating layer 4. However, the electrical action
does not occur with the hydrophilic transparent resin layer 2,
which has no conductivity, so that no lamination occurs.
[0100] Subsequently, as shown in FIG. 6G, for example, a black
chromium electroplating solution shown below is used to form the
black second electroplating layer 8 by plating on exposed surfaces
of the first electroplating layer 7 and the electroless plating
layer 4 so that the exposed surfaces of the electroplating layer 7
and the electroless plating layer 4 (that is, the top surface and
the side surface 9 of the electroplating layer 7 and the side
surface 9 of the electroless plating layer 4) are covered by the
black second electroplating layer 8 (step (G)). Consequently, the
top surface and the side surface 9 of the first electroplating
layer 7 and the side surface 9 of the electroplating layer 4 are
all covered by the black second electroplating layer 8. Thus, the
light-transmitting electromagnetic wave-shielding material shown in
FIG. 3 is obtained.
[0101] Since the black electroplating layer 8 is formed only on the
top surface and the side surface 9 of the first electroplating
layer 7 and the side surface 9 of the electroless plating layer 4,
a process of patterning the black second electroplating layer 8 is
not required. This is because the black second electroplating layer
8 is laminated on the first electroplating layer 7 and the
electroless plating layer 4, which are conductive, by electrical
action, but the electrical action does not occur with the
hydrophilic transparent resin layer 2, which is not conductive, and
thereby no lamination occurs.
[0102] An example of the black chromium electroplating solution is
shown below.
[0103] <Black Chromium Electroplating Solution>Chromium
Trioxide: 400 g/l
[0104] Glacial acetic acid: 2 g/l
[0105] Urea: 3 g/l
[0106] A range of 10-30.degree. C. is suitable as a plating
temperature at the time of plating by a black chromium
electroplating solution. Reaction is difficult at a temperature
lower than 10.degree. C., and solution control is difficult if
30.degree. C. is exceeded. A range of 30-70 A/dm.sup.2 is suitable
as a current density at the time of this plating.
[0107] According to the third embodiment, since the black second
electroplating layer 8 is selectively laminated only on a portion
having conductivity, that is, on the electroless plating layer 4
and the first electroplating layer 7 by electrical action, the
hydrophilic transparent resin layer 2, the electroless plating
layer 4, and the first electroplating layer 7 are subjected to no
physical impact or chemical change. Therefore, transparency of the
hydrophilic transparent resin layer 2 is not deteriorated, and
there is no impairment of the electromagnetic wave-shielding effect
due to damages to the electroless plating layer 4. Conductivity of
the electroless plating layer 4 is not decreased and there is no
difficulty in grounding.
[0108] Since the side surface 9 of the electroless plating layer 4
can be covered by the black second electroplating layer 8, light
reflection at the side surface 9 of the electroless plating layer 4
and the side surface 9 of the first electroplating layer 7 can be
suppressed so that visibility at slant angles in particular can be
substantially improved.
[0109] Since the electroless plating layer 4 is patterned and then
the first electroplating layer 7 is formed and the black second
electroplating layer 8 is formed on the entire portion where the
electroless plating layer 4 and the first electroplating layer 7
are formed, the black second electroplating layer 8 is easily
formed and it is not necessary to form an irregular film or the
like only on a portion of the electroless plating layer 4 to be
grounded, unlike the conventional methods (3) and (4). Therefore,
productivity can be increased.
[0110] The method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to the fourth
embodiment of the present invention is described below with
reference to steps (A) to (G) shown in FIGS. 7A-7G. FIG. 3 shows
thee light-transmitting electromagnetic wave-shielding material
manufactured by the method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to the fourth
embodiment.
[0111] First, as shown in FIG. 7A, the hydrophilic transparent
resin layer 2 is formed on an entire surface o the transparent
substrate 1 (step (A)).
[0112] Subsequently, as shown in FIG. 7B, the electroless plating
layer 4 having a film thickness of 0.5 .mu.m or less is formed on
an entire surface of the hydrophilic transparent resin layer 2
since electroplating is also employed so that the hydrophilic
transparent resin layer 2 is blackened when seen from the rear side
(that is, the bottom side in FIG. 7B) (step (B).
[0113] Subsequently, as shown in FIG. 7C, the resist section 5
having a negative pattern is formed in a desired pattern on the
electroless plating layer 4 (step (C)). It is preferable that the
resist section 5 is not removed along with the plating layer when
the plating layer is removed in a later process, and that it is a
vinyl polycinnamate resin, polyisoprene resin, quinonediazide
resin, or the like. The pattern of the resist section 5 is designed
so that transparency and conductivity of the light-transmitting
electromagnetic wave-shielding material manufactured by the
manufacturing method according to the fourth embodiment are
ensured. The resist section 5 is preferably formed on the
electroless plating layer 4 by a printing or photolithography
method.
[0114] Subsequently, as shown in FIG. 7D, the first electroplating
layer 7 is formed on a non-resist section of the electroless
plating layer 4, on which the resist section 5 is not formed, (step
(D)). In this case, the film thickness of the first electroplating
layer 7 is about the same as or less than the film thickness of the
resist layer 5. The reason for this is as follows. To plate
according to the resist pattern (negative) of the resist layer 5,
growth the plated film for forming the first electroplating layer 7
in the horizontal direction is restricted by utilizing the wall of
the patterned resist layer 5. Therefore, if the plated film
thickness of the first electroplating layer 7 is equal to or
thicker than the resist film thickness of the resist layer 5,
restriction by the resist layer 5 is disabled. Consequently, the
plated film is formed in a horizontal direction (that is, entire
surface plating), and patterning cannot be carried out. Since the
first electroplating layer 7 is pulled when the resist layer 5 is
removed, the first electroplating layer 7 is partially removed. In
addition, since a part of the resist layer 5 is covered by the
first electroplating layer 7, a disadvantage can arise in that the
resist layer 5 is insufficiently dissolved. Subsequently, as shown
in FIG. 7E, the resist section 5 is removed from the electroless
plating layer 4 by dissolution and removal using an alkaline
aqueous solution or an organic solvent (step (E)). Then, as shown
in FIG. 7F, an electroplating layer non-existent portion of the
electroless plating layer 4 is removed by etching while an
unremoved section of the hydrophilic transparent resin layer 2
under the electroplating layer existent portion (that is, the
unremoved section of the electroless plating layer 4) is patterned
when seen from the rear side (that is, the bottom side in FIG. 7F)
(step (F)). As described above, since the unremoved section of the
hydrophilic transparent resin layer 2 is patterned in black, the
unremoved section of the electroless plating layer 4 and the black
pattern section 6 approximately coinciding with the patterned first
electroplating layer 7 are formed thereunder as a result. However,
since the first electroplating layer 7 is used as a resist in this
case, a part of the first electroplating layer 7 is removed by
etching. Therefore, the film thickness of the electroplating layer
7 needs to be 1 .mu.m or more. The portion of the hydrophilic
transparent resin layer 2 from which the black color is removed
transmits light. An etchant used for the etching is appropriately
selected depending on the kind of metal constituting the
electroless plating layer 4. For example, when the metal
constituting the electroless plating layer 4 is nickel, copper, or
tin, it is preferable to use a ferric chloride aqueous solution as
an etchant. When the metal constituting the electroless plating
layer 4 is chromium, it is preferable to use a mixture solution of
ceric nitrateammonium, perchloric acid, and water as an
etchant.
[0115] Subsequently, as shown in FIG. 7G, for example, a black
chromium electroplating solution shown below is used to form the
black second electroplating layer by plating on exposed surfaces of
the first electroplating layer 7 and the electroless plating layer
4 so that the exposed surfaces of the first electroplating layer 7
and the electroless plating layer 4 (that is, the top surface and
the side surface 9 of the electroplating layer 7 and the side
surface 9 of the electroplating layer 4) are covered by the black
electroplating layer 8 (step (G)). Consequently, the top surface
and the side surface 9 of the first electroplating layer 7 and the
side surface 9 of the electroplating layer 4 are all covered by the
black second electroplating layer 8. Thus, the light-transmitting
electromagnetic wave-shielding material shown in FIG. 3 is
obtained.
[0116] Since the black second electroplating layer 8 is formed only
on the top surface and the side surface 9 of the electroplating
layer 7 and the side surface 9 of the electroless plating layer 4,
patterning of the black second electroplating layer 8 is not
required. This is because the black second electroplating layer 8
is laminated on the first electroplating layer 7 and the
electroless plating layer 4, which are conductive, by electrical
action. That is, metal ions or the like in the black electroplating
solution produce a black compound (sulfide or the like) by
reductive reaction by electrons, and then the black compound is
deposited and laminated on the first electroplating layer 7 and the
electroless plating layer 4. On the other hand, the electrical
action does not occur with the hydrophilic transparent resin layer
2, which is not conductive, and thereby no lamination occurs.
[0117] An example of the black chromium electroplating solution is
shown below.
[0118] <Black Chromium Electroplating Solution>
[0119] Chromium trioxide: 400 g/l
[0120] Glacial acetic acid: 50 g/l
[0121] A range of 10-20.degree. C. is suitable as a plating
temperature at the time of plating by a black chromium
electroplating solution. Reaction is difficult at a temperature
lower than 10.degree. C., and control of the plating solution is
difficult if 20.degree. C. is exceeded. A range of 30-100
A/dm.sup.2 is suitable as a current density at the time of this
plating.
[0122] To form the electroless plating layer 4 and the black
portion of the hydrophilic transparent resin layer 2 thereunder in
a desired pattern, methods other than etching may be employed. For
example, the hydrophilic transparent resin layer 2 may be formed
only on a portion of the transparent substrate 1 where a conductive
section is to be formed and thereafter an electroless plating is
performed.
[0123] According to the fourth embodiment, since the black
electroplating layer 8 is selectively laminated only on a portion
having conductivity (that is, on the electroless plating layer 4
and the first electroplating layer 7) by electrical action, the
hydrophilic transparent resin layer 2, the electroless plating
layer 4, and the electroplating layer 7 are subjected to no
physical impact or chemical change. Therefore, transparency of the
hydrophilic transparent resin layer 2 is not deteriorated and there
is no impairment of the electromagnetic wave-shielding effect due
to damages to the electroless plating layer 4. Conductivity of the
electroless plating layer 4 is not decreased and there is no
difficulty in grounding.
[0124] Since the side surface 9 of the electroless plating layer 4
can be covered by the black second electroplating layer 8, light
reflection from the side surface 9 of the electroless plating layer
4 and the side surface 9 of the electroplating layer 7 can be
suppressed so that visibility at slant angles in. particular can be
substantially improved.
[0125] Since the electroless plating layer 4 and the first
electroplating layer 7 are patterned and then the black second
electroplating layer 8 is formed on the entire portion where the
electroless plating layer 4 and the electroplating layer 7 are
formed, the black electroplating layer 8 is easily formed and it is
not necessary to form an irregular film or the like only on a
portion of the electroless plating layer 4 to be grounded unlike
the conventional methods (3) and (4). Therefore, productivity can
be increased.
[0126] The method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to the fifth
embodiment of the present invention is described with reference to
steps (A) to (E) shown in FIGS. 9A-9E.
[0127] First, as shown in FIG. 9A, the hydrophilic transparent
resin layer 2 is formed on an entire surface of the transparent
substrate 1 (step (A)).
[0128] Subsequently, as shown in FIG. 9B, the electroless plating
layer 4 is formed on an entire surface of the hydrophilic
transparent resin layer 2 so that the hydrophilic transparent resin
layer 2 is blackened when seen from the rear side (that is, the
bottom side in FIG. 9B) (step (B)).
[0129] Subsequently, as shown in FIG. 9C, for example, a black
nickel electroplating solution shown below is used to form the
black electroplating layer 8 by plating on the entire surface of
the electroless plating layer 4 (step (c)).
[0130] An example of the black nickel electroplating solution is
shown below.
[0131] <Black Nickel Electroplating Solution>
[0132] Nickel sulfate: 100 g/l
[0133] Nickel ammonium sulfate: 30 g/l
[0134] Zinc sulfate: 15 g/l
[0135] Sodium thiocyanate: 10 g/l
[0136] A range of 30-70.degree. C. is suitable as a plating
temperature at the time of plating by a black nickel electroplating
solution. Reaction is difficult at a temperature lower than
30.degree. C., and control of the plating solution is difficult if
70.degree. C. is exceeded. A range of 0.1-5 A/dm.sup.2 is suitable
as a current density at the time of this plating. A film is not
easily formed if the current density is less than 0.1 A/dm.sup.2
and the density exceeding 5 A/dm.sup.2 is not preferable since the
black electroplating layer 8 becomes fragile.
[0137] Subsequently, as shown in FIG. 9D, the resist section 5 is
formed in a desired pattern on the black electroplating layer 8
(step (D)). It is preferable that the resist section 5 is not
removed along with the plating layers when the plating layers are
removed in a later process, and that it is a vinyl polycinnamate
resin, polyisoprene resin, quinonediazide resin, or the like. The
pattern of the resist section 5 is designed so that transparency
and conductivity of the light-transmitting electromagnetic
wave-shielding material manufactured by the manufacturing method
according to the fifth embodiment of the present invention are
ensured. The resist section 5 is preferably formed on the black
electroplating layer 8 by a printing or photolithography
method.
[0138] Subsequently, as shown in FIG. 9E, a non-resist section of
the black electroplating layer 8, on which the resist section 5 is
not formed, is removed by etching while an unremoved section of the
hydrophilic transparent resin layer 2 below the resist-placed
section of the black electroplating layer 8, which is not removed
because the resist section 5 is formed thereon, is patterned when
seen from. its rear side (that is, the bottom side in FIG. 9E)
(step (E)). As described above, since the unremoved section of the
hydrophilic transparent resin layer 2 is blackened, the black
pattern section 6 approximately coinciding with the patterned black
electroplating layer 8 is formed therebelow as a result. Also, the
portion of the hydrophilic transparent resin layer 2 where the
black electroplating layer 8 is removed (that is, the portion where
the black color is removed) transmits light. An etchant used for
the etching is appropriately selected depending on the kind of a
metal constituting the black electroplating layer 8. For example,
when the metal constituting the black electroplating layer 8 is
nickel, copper, or tin, it is preferable to use a ferric chloride
aqueous solution as an etchant. When the metal constituting the
black electroplating layer 8 is chromium, it is preferable to use a
mixture solution of ceric nitrate-ammonium, perchloric acid, and
water as an etchant.
[0139] Furthermore, as shown in FIG. 9E, the resist section 5 is
removed from the black electroplating layer 8 by dissolution and
removal by using an alkaline aqueous solution or an organic
solvent. Consequently, the light-transmitting electromagnetic
wave-shielding material shown in FIG. 9E is obtained.
[0140] According to the fifth embodiment, since the black
electroplating layer 8 is selectively laminated only on a portion
having conductivity (that is, on the electroless plating layer 4)
by electrical action, the hydrophilic transparent resin layer 2 and
the electroless plating layer 4 are subjected to no physical impact
or chemical change. Therefore, transparency of the hydrophilic
transparent resin layer 2 is not deteriorated, and there is no
impairment of the electromagnetic wave-shielding effect due to
damages to the electroless plating layer 4. Conductivity of the
electroless plating layer 4 is not decreased and there is no
difficulty in grounding.
[0141] Since the black electroplating layer 8 covers only the top
surface of the patterned electroless plating (or electroplating)
layer 4 in the above-described manufacturing method, the following
effects are obtained. That is, since the black electroplating layer
8 is not existent on the side surface 9 of the electroless plating
(electroplating) layer 4 in this case, the pattern line width is
not widened and a decrease in transparency due to formation of the
black electroplating layer 8 does not occur. In particular, in a
case where there is no problem of deterioration of visibility at
slant angles due to, particularly, exposure of the side surfaces of
these layers since the electroless plating (electroplating) layer 4
is thin or the like, this manufacturing method can manufacture a
brighter light-transmitting electromagnetic wave-shielding
material.
[0142] The method of manufacturing the light-transmitting
electromagnetic wave-shielding material according to the sixth
embodiment of the present invention is described below with
reference to steps (A) to (F) shown in FIGS. 10A-10F.
[0143] First, as shown in FIG. 10A, the hydrophilic transparent
resin layer 2 is formed on an entire surface of the transparent
substrate 1 (step (A)).
[0144] Subsequently, as shown in FIG. 10B, the electroless plating
layer 4 is formed on an entire surface of the hydrophilic
transparent resin layer 2 so that the hydrophilic transparent resin
layer 2 is blackened when seen from the rear side (that is, the
bottom side in FIG. 10B) (step (B)).
[0145] Subsequently, as shown in FIG. 10C, a first electroplating
layer 7 is formed on an entire surface of the electroless plating
layer 4 (step (C)).
[0146] Subsequently, as shown in FIG. 10D, for example, a black
nickel electroplating solution shown below is used to form a black
second electroplating layer 8 by plating on an entire surface of
the first electroplating layer 7 (step (D)).
[0147] An example of the black nickel electroplating solution is
shown below.
[0148] <Black Nickel Electroplating Solution>
[0149] Nickel sulfate: 80 g/l
[0150] Nickel ammonium sulfate: 50 g/l
[0151] Zinc sulfate: 30 g/l
[0152] Sodium thiocyanate: 20 g/l
[0153] A range of 30-70.degree. C. is suitable as a plating
temperature at the time of plating by a black nickel electroplating
solution. Reaction is difficult at a temperature lower than
30.degree. C., and control of the plating solution is difficult if
70.degree. C. is exceeded. A range of 0.1-5 A/dm.sup.2 is suitable
as a current density at a time of this plating. A film is not
easily formed if the current density is less than 0.1 A/d m.sup.2,
and the density exceeding 5 A/dm.sup.2 is not preferable since the
black second electroplating layer 8 becomes fragile.
[0154] Subsequently, as shown in FIG. 10E, a resist section 5 is
formed in a desired pattern on the black second electroplating
layer 8 (step (E)). It is preferable that the resist section 5 is
not removed along with the plating layers when the plating layers
are removed in a later process, and that it is a vinyl
polycinnamate resin, polyisoprene resin, quinonediazide resin, or
the like. The pattern of the resist section 5 is designed so that
transparency and conductivity of the light-transmitting
electromagnetic wave-shielding material manufactured by the method
according to the sixth embodiment of the present invention are
ensured. The resist section 5 is preferably formed on the black
second electroplating layer 8 by a printing or photolithography
method.
[0155] Subsequently, as shown in FIG. 10F, the non-resist section
of the black second electroplating layer 8, on which the resist
section 5 is not formed, a black electroplating layer non-existent
section of the first electroplating layer 7 under the non-resist
section of the black second electroplating layer 8, and an
electroplating layer non-existent section of the electroless
plating layer 4 below the black electroplating layer non-existent
section are removed by etching while an unremoved section of the
hydrophilic transparent resin layer 2 below the resist-placed
section of the electroless plating layer 4, which is not removed
because the resist section 5 is patterned when seen from its rear
side (that is, the bottom side in FIG. 10F) (step (F)). As
described above, since the unremoved section of the hydrophilic
transparent resin layer 2 is patterned in black, the black pattern
section 6 approximately coinciding with the unremoved section of
the patterned electroless plating layer 4 is formed thereunder as a
result. Also, the portion of the hydrophilic transparent resin
layer 2 from which the removed section of the electroless plating
layer 4 is removed (that is, the portion where the black color is
removed) transmits light. An etchant used for the etching is
appropriately selected depending on the kind of metals constituting
the black second electroplating layer 8, the first electroplating
layer 7, and the electroless plating layer 4. For example, when the
metals constituting the black second electroplating layer 8, the
first electroplating layer 7, and the electroless plating layer 4
are nickel, copper, or tin, it is preferable to use a ferric
chloride aqueous solution as an etchant. When the metals
constituting the black second electroplating layer 8, the first
electroplating layer 7, and the electroless plating layer 4 are
chromium, it is preferable to use a mixture solution of ceric
nitrate-ammonium, perchloric acid, and water as an etchant.
[0156] Furthermore, as shown in FIG. 10F, the resist section 5 is
removed from the black second electroplating layer 8 by dissolution
and removal using an alkaline aqueous solution or an organic
solvent. Consequently, a light-transmitting electromagnetic
wave-shielding material shown in FIG. 10F is obtained.
[0157] According to the sixth embodiment, since the black second
electroplating layer 8 is selectively laminated only on a
conductive portion by electrical action, the hydrophilic
transparent resin layer 2 and the electroless plating layer 4 are
subjected to no physical impact or chemical change. Therefore,
transparency of the hydrophilic transparent resin layer 2 is not
deteriorated and there is no impairment of the electromagnetic
wave-shielding effect due to damage to the electroless plating
layer 4. Conductivity of the electroless plating layer 4 is not
decreased and there is no difficulty in grounding.
[0158] Since the black second electroplating layer 8 covers only
the top surface of the patterned electroless plating (or
electroplating) layer in the above-described manufacturing method,
the following effects are obtained. That is, since the black second
electroplating layer 8 is not existent on the side surface 9 of the
electroless plating (electroplating) layer 4 in this case, the
pattern line width is not widened and a decrease in transparency
due to formation of the black second electroplating layer 8 does
not occur. In particular, in a case where there is no problem of
deterioration of visibility at slant angles due to, particularly,
exposure of the side surfaces of these layers since the electroless
plating (electroplating) layer is thin or the like, this
manufacturing method can manufacture a brighter light-transmitting
electromagnetic wave-shielding material.
[0159] It is noted that any of the manufacturing methods according
to the above first to sixth embodiments can be appropriately
selected and employed as required.
[0160] In each of the above embodiments, the black electroplating
layer 8 can be constituted by nickel, chromium, tin, rhodium, or
ruthenium metal or an alloy of any of these
[0161] More specific examples of the above first to fourth
embodiments are described below.
EXAMPLE 1
[0162] (See FIGS. 4A-4F according to the first embodiment.)
[0163] First, as shown in FIG. 4A, a methanol solution containing a
polyhydroxy propylacrylate and palladium catalyst was coated on a
PET film with a thickness of 100 .mu.m and dried at 70.degree. C.
for 15 minutes (step (A)).
[0164] Subsequently, as shown in FIG. 4B, copper electroless
plating was carried out at 40.degree. C. and then water wash and
drying were carried out (step (B)). Subsequently, as shown in FIG.
4C, a resist section 5 in a lattice pattern having a line width of
20 .mu.m and a pitch of 200 .mu.m was formed by photolithography
(step (C)).
[0165] Subsequently, as shown in FIG. 4D, etching was performed by
using a ferric chloride solution (step (D)) and water wash and
drying were carried out. Then, as shown in FIG. 4E, the resist was
removed (step (E)).
[0166] Subsequently, as shown in FIG. 4F, a black nickel
electroplating solution shown below was used to form a black
electroplating layer 8 on surfaces of the electroless plating layer
4 (step (F)).
[0167] <Black Nickel Plating Solution>
[0168] Nickel sulfate: 70 g/l
[0169] Nickel ammonium sulfate: 40 g/l
[0170] Zinc sulfate: 20 g/l
[0171] Sodium thiocyanate: 15 g/l
[0172] The plating temperature was 30.degree. C. and the current
density was 1 A/dm.sup.2. The obtained light-transmitting
electromagnetic wave-shielding material had extremely high
visibility and the optical reflectance of the black electroplating
layer 8 was 8%.
EXAMPLE 2
[0173] (See FIGS. 5A-5G according to the second embodiment.)
[0174] First, as shown in FIGS. 5A and 5B, a copper electroless
plating layer 4 having a thickness of 0.5 .mu.m was obtained by the
same method as in Example 1 (steps (A) and (B)).
[0175] Subsequently, as shown in FIG. 5C, a first electroplating
layer 7 having a thickness of 3 pm was formed on the electroless
plating layer 4 by copper electroplating (step (C)).
[0176] Subsequently, as shown in FIG. 5D, a resist section 5 was
formed as in the case of Example 1 (step (D)). As shown in FIG. 5E,
etching was performed by using a ferric chloride solution (step
(E)) and then, as shown in FIG. 5F, the resist section 5 was
removed (step (F)).
[0177] Subsequently, as shown in FIG. 5G, a black nickel
electroplating solution shown below was used to form a black second
electroplating layer 8 on surfaces of the first electroplating
layer 7 and the electroless plating layer 4 (step (G)).
[0178] <Black Nickel Plating Solution>
[0179] Nickel sulfate: 85 g/l
[0180] Nickel ammonium sulfate: 30 g/l
[0181] Zinc sulfate: 15 g/l
[0182] Sodium thiocyanate: 20 g/l
[0183] The plating temperature was 50.degree. C. and the current
density was 0.5 A/dm.sup.2. The obtained light-transmitting
electromagnetic wave-shielding material had extremely high
visibility and the optical reflectance of the black second
electroplating layer 8 was 12%.
EXAMPLE 3
[0184] (See FIGS. 6A-6G according to the third embodiment.)
[0185] First, as shown in FIG. 7A, a dichloromethaneethanol mixture
solvent solution containing a cellulose acetate and palladium
catalyst was coated on a PET film having a thickness of 100 dun and
dried at 70.degree. C. for 20 minutes (step (A)). Subsequently, as
shown in FIG. 6B, copper electroless plating was carried out at
45.degree. C. to obtain an electroless plating layer 4 having a
thickness of 0.3 pm (step (B)).
[0186] Subsequently, after water wash and drying were carried out,
a resist section 5 in a lattice pattern having a line width of 15
pm and a pitch of 150 dun was formed by photolithography (step (C))
as shown in FIG. 6C.
[0187] Subsequently, as shown in FIG. 6D, etching was performed by
using a ferric chloride solution (step (D)). After water wash and
drying were carried out, the resist was removed (step (E)) as shown
in FIG. 6E.
[0188] Subsequently, as shown in FIG. 6F, a copper first
electroplating layer 7 having a thickness of 2 .mu.m was formed on
a surface of the patterned electroless plating layer 4 by
electroplating (step (F)).
[0189] Subsequently, as shown in FIG. 6G, a black chromium
electroplating solution shown below was used to form a black first
electroplating layer 8 on surfaces of the first electroplating
layer 7 and the electroless plating layer 4 (step (G)).
[0190] <Black Chromium Electroplating Solution>
[0191] Chromium trioxide: 350 g/l
[0192] Glacial acetic acid: 3 g/l
[0193] Urea: 3 g/l
[0194] The plating temperature was 20.degree. C. and the current
density was 30 A/dm.sup.2. The obtained light-transmitting
electromagnetic wave-shielding material had extremely high
visibility, and the optical reflectance of the black electroplating
layer 8 was 10%.
EXAMPLE 4
[0195] See FIGS. 7A-7G according to the fourth embodiment.)
[0196] First, as shown in FIG. 7A, a dichloromethaneethanol mixture
solvent solution containing a cellulose acetate and palladium
catalyst was coated on an acrylic film having a thickness of 300
.mu.m and dried at 60.degree. C. for 30 minutes (step (A)).
[0197] Subsequently, as shown in FIG. 7B, copper electroless
plating was carried out at 42.degree. C. to obtain an electroless
plating layer 4 having a thickness of 0.2 .mu.m (step (B)).
[0198] Subsequently, after water wash and drying were carried out,
a resist section 5 having a thickness of 2 .mu.m in a reciprocal
lattice pattern having a line width of 25 .mu.m and a pitch of 150
.mu.m were formed by photolithography (step (C)) as shown in FIG.
7C
[0199] Subsequently, as shown in FIG. 7D, a copper first
electroplating layer 7 having a thickness of 2 .mu.m was formed on
a surface of a non-resist section of the electroless plating layer
4 by electroplating (step (D))
[0200] Subsequently, as shown in FIG. 7E, the resist section 5 was
removed (step (E)). Then an electroplating layer non-existent
section was etched using a ferric chloride solution, and water wash
and drying were carried out (step (F)) as shown in FIG. 7F.
[0201] Subsequently, as shown in FIG. 7G, a black chromium
electroplating solution shown below was used to form a black second
electroplating layer 8 on surfaces of the first electroplating
layer 7 and the electroless plating layer 4 (step (G)).
[0202] <Black Chromium Electroplating Solution>Chromium
Trioxide: 400 g/l
[0203] Glacial acetic acid: 5 g/l
[0204] Urea: 2 g/l
[0205] The plating temperature was 25.degree. C. and the current
density was 50 A/dm.sup.2. The obtained light-transmitting
electromagnetic wave-shielding material had extremely high
visibility, and the optical reflectance of the black second
electroplating layer 8 was 9%.
EXAMPLE 5
[0206] (See FIGS. 2 and 8 according to the first embodiment.)
[0207] First, a methanol solution containing a polyhydroxy
propylacrylate and palladium catalyst was coated on a glass plate
having a thickness of 3 mm and dried at 90.degree. C. for 45
minutes (step (A)).
[0208] Subsequently, copper electroless plating was carried out at
40.degree. C., and then water wash and drying were carried out
(step (B)).
[0209] Subsequently, a resist section 5 in a lattice pattern having
a line width of 20 dim and a pitch of 200 dun was formed by
photolithography (step (C)). It is noted that a solid portion was
formed in the resist section 5 on the outer frame of the glass
plate so that a grounded section is provided around the lattice
pattern (see FIG. 8).
[0210] Subsequently, etching was performed using a ferric chloride
solution (step (D)). After water wash and drying were carried out,
the resist was removed (step (E)).
[0211] Subsequently, black nickel electroplating solution shown
below was used to form a black electroplating layer 8 on surfaces
of the electroless plating layer (step (F): see FIGS. 2 and 8).
[0212] <Black Nickel Electroplating Solution>
[0213] Nickel sulfate: 70 g/l
[0214] Nickel ammonium sulfate: 40 g/l
[0215] Zinc sulfate: 20 g/l
[0216] Sodium thiocyanate: 15 g/l
[0217] The plating temperature was 30.degree. C. and the current
density was 1 A/dm.sup.2. The obtained light-transmitting
electromagnetic wave-shielding material had extremely high
visibility and the optical reflectance of the black electroplating
layer 8 was 8%.
EXAMPLE 6
[0218] (See FIGS. 10A-10F according to the sixth embodiment.)
[0219] A dichloromethane-dimethylformamide mixture solution
containing a cellulose acetate and silver catalyst was coated on a
PET film having a thickness of 188 pm an dried at 100.degree. C.
for 3 minutes.
[0220] Subsequently, nickel electroless plating was carried out at
55.degree. C. to obtain an electroless plating layer having a
thickness of 0.3 .mu.m while a black color was formed in a
hydrophilic transparent. resin layer.
[0221] Subsequently, a copper first electroplating layer having a
thickness of 2 .mu.m was formed on an entire surface of the
electroless plating layer by copper electroplating.
[0222] Subsequently, electroplating was carried out under the
following conditions, and a black second plating layer was formed
on an entire surface of the copper first electroplating layer.
[0223] Stannous chloride: 19 g/l
[0224] Nickel chloride: 40 g/l
[0225] Copper pyrophosphate: 3 g/l
[0226] Potassium pyrophosphate: 215 g/l
[0227] Additive agent: 5 g/l
[0228] The current density was 0.5 A/dm.sup.2 and the temperature
was 37.degree. C. for 90 seconds. Subsequently, a resist section in
a lattice 25 pattern having a line width of 20 dam and a pitch of
280 .mu.m was formed on this by photolithography.
[0229] Subsequently, etching was performed on this using a ferric
chloride solution. After water wash and drying were carried out,
the resist was removed. The obtained light-transmitting
electromagnetic wave-shielding material had extremely high
visibility and the optical reflectance when seen from the black
second electroplating layer side was 10%.
[0230] In the light-transmitting electromagnetic wave-shielding
material and its manufacturing method of the present invention, the
following effects are obtained since a black second electroplating
layer is selectively laminated only on a portion having
conductivity (electroless plating layer, or electroless plating
layer and electroplating layer) by electrical action.
[0231] (1) Since the hydrophilic transparent resin layer and the
electroless plating layer or the hydrophilic transparent resin
layer, the electroless plating layer, and the electroplating layer
are subjected to no physical impact or chemical change,
transparency of the hydrophilic transparent resin layer is not
deteriorated and there is no impairment of the electromagnetic
wave-shielding effect due to damage of the electroless plating
layer. Since conductivity of the electroless plating layer is not
decreased, there is no problem of difficulty in grounding.
[0232] (2) Since a black second electroplating layer can be easily
laminated on the respective side surfaces of the electroless
plating layer and first electroplating layer and light reflection
from these side surfaces can be suppressed, visibility at slant
angles in particular is improved and visibility at all visual field
angles becomes favorable.
[0233] (3) Further, when the electroless plating layer or the like
is patterned before the black electroplating layer is formed,
patterning of the black electroplating layer is not required and a
resist process for grounding is not required either. Therefore, the
process of manufacturing a light-transmitting electromagnetic
wave-shielding material can be simplified so that productivity is
improved.
[0234] Since the black electroplating layer is formed on a surface
with metallic luster, visibility of this surface with metallic
luster can also be improved. Therefore, the surface with metallic
luster can face an observer, and a surface to be grounded can face
either the observer side or the panel side. Thus, freedom of use
can be increased.
[0235] In addition, when the black electroplating layer covers only
the top surface of the patterned electroless plating (or
electroplating) layer, the following effects are obtained. That is,
in this case, since the black electroplating layer is not existent
on the side surface of the electroless plating (electroplating)
layer, the pattern line width is not widened and decrease in
transmittance due to formation of the black electroplating layer
does not occur. In particular, when there is no problem of
deterioration of visibility when observed at slant angles due to
exposure of the side surfaces of these layers since the electroless
plating (electroplating) layer is thin or the like, this method can
be used to manufacture a brighter light-transmitting
electromagnetic wave-shielding material.
[0236] Although the present invention has been fully described in
connection with the preferred embodiments thereof with reference to
the accompanying drawings, it is to be noted that various changes
and modifications are apparent to those skilled in the art. Such
changes and modifications are to be understood as included within
the scope of the present invention as defined by the appended
claims unless they depart therefrom.
* * * * *