JPH11346088A - Electromagnetic shielding plate and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an electromagnetic shielding plate where a reticulated metal thin film is provided, wherein the electromagnetic shielding plate can melt with requirement such as quality and productivity. SOLUTION: An electromagnetic shielding plate, which is excellent in electromagnetic shielding properties and transparency, is composed of a transparent board and a conductive material of prescribed shape formed on both or either side of the transparent board and manufactured through a method which comprises a recess forming process (a) where recesses 120 of prescribed shapes are provided to both the sides or either side of a transparent board 110, a paste filling and drying process (b) where conductive paste 130 is filled up into only the recesses 120 through a squeegee method and dried out, and a protective film forming process (c) where a protective film 160 is formed on the transparent board 110 covering the paste 130 filled up into the recesses 120.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a conductive metal thin film is formed by plating on a conductive thin film used on a front surface of a display in order to shield electromagnetic waves generated from an electromagnetic wave source such as a display electron tube. The present invention relates to a method for manufacturing an electromagnetic wave shielding plate and an electromagnetic wave shielding plate.

[0002]

2. Description of the Related Art Conventionally, an electronic device for generating an electromagnetic wave used directly by a person in close proximity, for example, an electronic tube for a display such as a plasma display, has a standardized intensity of electromagnetic wave emission in consideration of the adverse effect of the electromagnetic wave on the human body. It is required to keep within. Further, in a plasma display panel (hereinafter also referred to as a PDP), light emission uses plasma discharge, so that the frequency band is 30 MHz to 13 MHz.
In order to leak unnecessary electromagnetic waves of 0 MHz to the outside, it is required to suppress the electromagnetic waves as much as possible so as not to adversely affect other devices (for example, information processing devices and the like). In response to these demands, generally, in order to remove or attenuate electromagnetic waves flowing out of the device from an electronic device that generates electromagnetic waves,
An electromagnetic wave shield that covers an outer peripheral portion of an electronic device or the like that generates an electromagnetic wave with a suitable conductive member is employed. In a display panel such as a plasma display panel, an electromagnetic wave shielding plate having good transparency is generally provided on the front surface of the display.

The basic structure of the electromagnetic wave shielding plate is relatively simple. For example, a transparent conductive film such as an indium-tin oxide film (ITO film) is formed on a transparent glass or plastic substrate by vapor deposition or sputtering. A transparent glass or plastic substrate on which a suitable metal screen such as a wire mesh is adhered, or a transparent glass or plastic substrate with a metal thin film on the entire surface by electroless plating or evaporation. Is formed, and the metal thin film is processed by a photolithography method or the like to provide a mesh made of a fine metal thin film.

An electromagnetic wave shielding plate in which an ITO film is formed on a transparent substrate is excellent in transparency, generally has a light transmittance of about 90%, and can form a uniform film on the entire surface of the substrate. Therefore, when used for a display or the like, there is no concern about occurrence of moire or the like due to the electromagnetic wave shielding plate. However, in an electromagnetic wave shielding plate in which an ITO film is formed on a transparent substrate, since a vapor deposition, a sputtering, and a technique are used to form the ITO film, a manufacturing apparatus is expensive, and productivity is generally poor. Therefore, there is a problem that the price of the electromagnetic wave shielding plate itself as a product becomes high. Further, the electromagnetic wave shielding plate having an ITO film formed on a transparent substrate has a conductivity that is at least one order of magnitude lower than that of an electromagnetic wave shielding plate having a mesh made of a metal thin film, and therefore, the electromagnetic wave emission is relatively weak. It is effective for target objects, but when used for strong objects, there is a problem that the shielding function is insufficient, leaked electromagnetic waves are emitted, and it may not be possible to meet the standard value. is there.
In the electromagnetic wave shielding plate in which the ITO film is formed on the transparent substrate, the conductivity is improved to some extent by increasing the thickness of the ITO film in order to increase the conductivity, but in this case, the transparency is significantly reduced. The problem occurs. In addition, there is a problem that the manufacturing cost becomes higher due to the further increase in thickness.

When an electromagnetic wave shielding plate in which a metal screen is attached to a transparent glass or plastic substrate surface is used,
Alternatively, when an appropriate metal screen such as a wire mesh is directly adhered to the display surface, it is simple and the cost is low, but the transmittance of an effective mesh (100-200 mesh) metal screen is 50%. % Or less,
It has the serious drawback of extremely dark displays.

[0006] In addition, since a mesh formed of a metal thin film is formed on the surface of a transparent glass or plastic substrate, the outer shape is processed by etching using photolithography, so that fine processing is possible and a high aperture ratio (high transmittance) is obtained. rate)
Since the mesh can be formed and the mesh is formed by a metal thin film, the conductivity is very high as compared with the above-mentioned ITO film and the like, and an advantage that strong electromagnetic wave emission can be shielded. Have. However, the manufacturing process is complicated and complicated, the productivity is low, and the production cost is inevitable.

[0007] As described above, each electromagnetic wave shielding plate has advantages and disadvantages, and is selected and used according to the application. Among them, an electromagnetic wave shielding plate in which a mesh made of a metal thin film is formed on the surface of a transparent glass or plastic substrate is good in terms of electromagnetic wave shielding and light transmission, and has recently been placed on the front of a display panel such as a plasma display panel. , And has been used for electromagnetic wave shielding.

Here, an electromagnetic wave shielding plate in which a mesh made of a metal thin film is formed on a transparent glass or plastic substrate surface is shown in FIG. 8 and will be briefly described. FIG. 8A is a plan view of the electromagnetic wave shielding plate, and FIG.
FIG. 8C is a cross-sectional view taken along line -E2, and is an enlarged view of a part of the mesh portion. FIGS. 8A and 8C show the X direction and the Y direction for clarifying the positional relationship and the mesh shape.
The direction is displayed. The electromagnetic wave shielding plate shown in FIG.
An electromagnetic wave shielding plate for electromagnetic wave shielding used to be placed on the front surface of a display such as P, and having a grounding frame portion and a mesh portion formed on one surface of a transparent substrate.
Is formed of the same metal thin film as the mesh portion around the outside of the mesh portion 810 so as to surround the screen area of the display when used on the front of the display. The mesh portion 810 has a plurality of lines 870 provided in parallel in the Y and X directions at predetermined pitches Px and Py, respectively, as shown partially enlarged in FIG. 8C. And a line 850 group.

[0009]

For this reason, an electromagnetic wave shielding plate provided with a mesh made of a metal thin film on a transparent substrate as shown in FIG. 8 has a large quantity in view of its transparency and electromagnetic wave shielding properties. As a result, a method for efficiently producing the electromagnetic wave shielding plate with high productivity has been required. According to the present invention, there is provided a method of manufacturing an electromagnetic shielding plate having electromagnetic wave shielding and transparency by forming a conductive metal thin film on a conductive thin film of a predetermined shape on one or both surfaces of a transparent substrate. However, it is an object of the present invention to provide a manufacturing method which can sufficiently cope with quality and productivity.

[0010]

A method of manufacturing an electromagnetic wave shielding plate according to the present invention is used by being placed on the front of a display.
A method for producing an electromagnetic wave shielding plate having an electromagnetic wave shielding property and a see-through property by forming a conductive substance in a predetermined shape on one or both surfaces of a transparent substrate, comprising: A concave part forming step of forming a concave part of a predetermined shape,
(B) a paste filling and drying step of filling the conductive paste only in the recesses by the squeegee method and drying the paste; (c)
A protective film forming step of forming a protective film covering the entire conductive paste on the transparent substrate surface. And, in the above, after the paste filling and drying step, an electrodeposition step of electrodepositing a good conductive metal on the dried paste surface is performed so as to cover the whole of the conductive paste and the good conductive metal electrodeposited. And performing a protective film forming step, after the paste filling and drying step, performing a pre-electrodeposition treatment on the paste surface, and then electrodepositing a conductive metal on the conductive paste. It is characterized by performing a process. Further, in the above description, the concave portion is formed on the transparent substrate by directly processing the transparent substrate by mechanical processing such as convex press, cutting, or etching using an etching resistant film by photolithography technology. A transparent resin layer for forming a concave portion is provided on the concave portion forming side of the transparent substrate, and a concave portion is formed in the resin layer. Things. After forming a photosensitive resin film of an appropriate thickness on a transparent substrate, the photosensitive resin film is exposed, developed,
After drying, a concave portion may be formed in the photosensitive resin film. Further, in the above, the transparent substrate is provided with a transparent resin layer in which a concave portion is formed on the carrier film surface in advance, and the resin layer is transferred to a transparent base plate material so that the concave portion is on the outside (or uniformly). ). In the above, the transparent substrate is a glass or plastic simple substance, or a laminate thereof. In the above, the concave portion is formed only on one surface of the transparent substrate, and the concave portion is formed on the one surface in a mesh shape. Further, in the above, the concave portions are formed on both surfaces of the transparent substrate, a large number of concave portions on both surfaces are provided in parallel lines for each surface, and the concave portions on both surfaces are provided at a predetermined angle with respect to each other, When viewed through a transparent substrate, the recesses on both surfaces are meshed together.

The electromagnetic wave shielding plate of the present invention is characterized by being manufactured by the above-described method of manufacturing an electromagnetic wave shielding plate of the present invention.

[0012]

According to the method of manufacturing an electromagnetic wave shielding plate of the present invention, it is possible to provide a method of manufacturing an electromagnetic wave shielding plate that can sufficiently cope with quality and productivity by adopting such a configuration. Specifically, in order, (a) a concave portion forming step of forming a concave portion of a predetermined shape on one or both surfaces of a transparent substrate;
(B) a paste filling and drying step of filling the conductive paste only in the recesses by the squeegee method and drying the paste; (c)
A protective film forming step of forming a protective film covering the entirety of the conductive paste on the transparent substrate surface, and, if necessary, by electrodeposition forming a conductive metal thin film on the conductive paste. Have achieved.

As a method of forming a concave portion on a transparent substrate, a concave portion is directly formed on a transparent substrate by mechanical processing such as convex press or cutting, or by etching using an etching resistant film by photolithography. And other processing methods. On the transparent substrate concave side,
A transparent resin layer for forming a concave portion may be provided, and the concave portion may be formed in the resin layer. For example, after a photosensitive resin film having an appropriate thickness is formed on a transparent substrate, the photosensitive resin film may be exposed, developed, and dried to form a concave portion in the photosensitive resin film. Processing by these can be fine processing. The width of the concave portion is about 5 to 50 μm, preferably 1 to 50 μm.
0 to 20 μm. The depth of the recess is preferably 3 to 20 μm. The electrodeposition of the conductive metal thin film on the conductive paste is intended to complement the conductivity of the conductive paste. When the electrodeposition step of the conductive metal thin film is performed on the conductive paste, since the line width is large in the electrodeposition step, it is preferable to form a concave portion having a width smaller than the target line width by 5 to 10 μm. Incidentally, after the paste filling and drying step, it is preferable to be able to perform an electrodeposition step of electrodepositing a conductive metal on the conductive paste as it is,
If necessary, for the purpose of exposing the conductive paste-containing metal fine particles directly to the surface and exposing it for the purpose of activation, after the paste filling and drying step, the surface of the paste is subjected to an electrodeposition pretreatment with an acid, an alkali, or a plasma treatment. After the application, a conductive metal is electrodeposited on the conductive paste. A transparent resin layer for forming the concave portion is provided on the concave portion forming side of the transparent substrate, and by forming the concave portion in the resin layer, the degree of freedom in forming the concave portion and further in all the steps is increased. To make it bigger. For example, a transparent substrate is provided with a transparent resin layer in which a concave portion is formed on the carrier film surface in advance,
Since the resin layer is formed by transferring the resin layer to a transparent base plate so that the concave side is on the outside, a suitable printing method or a photolithographic method can be used when forming the concave section, and a long winding roll can be used. Process management can be made easier, or mass productivity can be improved.
As a result, the cost of the product can be reduced. In addition, as a transparent substrate, glass or a plastic simple substance, a laminated body of this, etc. are mentioned.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of a method for manufacturing an electromagnetic wave shielding plate of the present invention will be described with reference to the drawings. FIG. 1 is a manufacturing process sectional view showing a first example of an embodiment of a method of manufacturing an electromagnetic wave shielding plate of the present invention, and FIG. 2 is a manufacturing process sectional view showing a second example of the embodiment. FIG. 3 is a cross-sectional view of a manufacturing process showing a third example of the embodiment, and shows a manufacturing process of an electromagnetic wave shielding plate for an electromagnetic wave shielding used in front of a display such as a PDP. FIGS. 1, 2 and 3 show only a step of forming a conductive material having a predetermined shape to be an electromagnetic wave shielding portion for easy understanding.

A first example of an embodiment of a method of manufacturing an electromagnetic wave shielding plate will be described with reference to FIGS.
Is a transparent substrate, 120 is a concave portion, 125 is a concave portion forming surface, 1
30 is a conductive paste and 160 is a protective film. A first example of an embodiment of the method for manufacturing an electromagnetic wave shielding plate shown in FIG. 1 is that a mesh-shaped recess is formed only on one surface of a transparent substrate made of a single material such as glass or plastic, and the recess is formed. Is filled with a conductive paste and dried to form a mesh made of a conductive paste. First, the transparent substrate 1
10 (FIG. 1A), a predetermined mesh-shaped recess 120 is formed only on one side of the transparent substrate 110 (FIG. 1).
(B)) The formation of the concave portion is usually performed by machining such as convex pressing, cutting, or the like.
Alternatively, an etching process using an etching-resistant film by a photolithography technique is employed in terms of fine processing. The width and depth of the recesses take into account effective electromagnetic waves,
Determined according to the conductive paste to be filled. The shape of the concave portion is not limited to the V-shaped groove, but may be a U-shaped or other shape. As the plastic material for the transparent substrate 110, specifically, a triacetyl cellulose film, a diacetyl cellulose film, an acetate butyrate cellulose film, a polyether sulfone film, a polyacrylic resin, a polyurethane resin film, a polyester film, Polycarbonate film, polysulfone film, polyether film, trimethylpentene film, polyetherketone film, (meth) acrylonitrile film and the like can be used, but biaxially stretched polyester is particularly preferable because it has excellent transparency and durability. It is. Its thickness is usually 8 μm to 100
It is preferably about 0 μm, but is not limited to this. The light transmittance of the transparent film is 100%
Is ideal, but it is preferable to select one having a transmittance of 80% or more.

Next, the conductive paste 130 is filled into the concave portions of the transparent substrate including the concave portion forming surface 125 by a squeegee method and dried. (FIG. 1 (c)) The conductive paste 130 is generally a mixture of fine metal particles and a curable organic binder. Commonly used metals (fillers) include gold, silver, copper, nickel, aluminum, and others. And alloys or mixed metals. The conductivity of these is, for example, ^10-5 Ω · cm or more for silver and 10 ^-6 Ω · cm or more for gold as a filler of a paint (conductivity greatly differs depending on a product). In addition, acrylic resin-based curable organic binders,
Polyester resins, vinyl chloride resins, epoxy resins, phenol resins, polyolefins, melamine resins, and the like are well known and will not be described in detail.
Conductive pastes using these metal fillers are generally commercially available products and exhibit a conductivity of 10 ⁻³ to 10 ⁻⁶ Ω · cm. For example, ITO has a conductivity of 10 ¹ to 10 ³ Ω · cm.
And is suitable as an electromagnetic wave shielding material. Thereafter, if necessary, excess resin paste 140 is removed by wiping or ashing by plasma etching.

In this manner, a conductive substance for shielding electromagnetic waves (conductive paste 130) is formed in a predetermined shape on the surface of the transparent substrate 110. Thereafter, if necessary, a blackening process for blackening the conductive paste and the surface of the surface 130 is performed. This is to obtain an anti-reflection effect when used on the front of a display such as a PDP. The surface is blackened by oxidation or the like, or a black material is newly formed on the surface. This is the processing to be performed. Next, a protective film treatment is performed for surface smoothing and protection. (FIG. 1 (d)) The protective film preferably contains a surface hardener and an infrared absorber.

The grounding frame usually provided around the conductive metal thin film which is to be an electromagnetic wave shielding portion has a thickness of about 1 to 3 μm by sputtering or vacuum deposition into a predetermined shape after filling and drying the conductive paste 130. The conductive metal thin film may be formed to have a large thickness, but is not limited thereto.

In the process of the first example of the embodiment shown in FIG. 1, the mesh-shaped concave portion 120 is formed only on one side of the transparent substrate 110, and the metal thin film 150 is formed only on this one side. When the transparent substrate is viewed through transmission, the concave portions are formed on the transparent substrate 1 such that the concave portions on both sides are meshed together.
A large number of parallel thin films may be provided for each of the ten surfaces, and the metal thin film 150 may be formed in the concave part of each surface. In this case, the process shown in FIG. 1 only needs to be performed on both surfaces of the transparent substrate 110, and the same manufacturing is possible.

Next, a second embodiment of the method for manufacturing an electromagnetic wave shielding plate will be described with reference to FIG. In FIG.
0A is a transparent substrate, 210 is a transparent base plate, 220
Is a concave portion, 225 is a concave portion forming surface, 230 is a conductive paste, 260 is a protective film, 270 is a transparent resin layer, and 280 is a carrier film. In the second example, a transparent plate member 210 that forms a conductive metal thin film 250 having a predetermined shape,
A transparent resin layer 270 having a recess 220 formed thereon is provided in advance on the surface of the carrier film 280, and the resin layer 270 is placed on the transparent base plate 210 so that the recess 220 side faces outward.
Is formed by transferring to one surface of the metal film 250. After the transfer, the metal thin film 250 is formed in the concave portion 220.
First, a transparent resin layer 270 having a concave portion 220 formed on the surface of the carrier film 280 is provided in advance. (FIG. 2 (a
2)) Next, the entire transparent resin layer 270 having the concave portion 220 formed thereon is transferred from the carrier film 280 to one surface of the transparent base substrate 210 (FIG. 2A1) prepared. The transparent plate 210 made of the transparent resin layer 270 is used. (FIG. 2B) The formation of the concave portion in the transparent resin layer 270 is usually performed by a convex press or the like, and thereafter, the transparent resin layer 270 is placed on the carrier film 280 with the side surface on which the concave portion is formed. The transparent resin layer 270 is laminated on the film 280, and an adhesive is provided on the other side of the transparent resin layer 270 that is not the concave side.
Then, the transparent resin layer 270 is transferred from the carrier film 280 to the transparent base plate 210 via the adhesive. After the transfer, a curing treatment of the adhesive is performed as necessary. Transparent resin layer 2 of transparent substrate 210A
As the material of 70, the same plastic material as that described for the material of the transparent substrate 110 in the first example can be used.
Biaxially stretched polyester is preferred because it is excellent in transparency and durability. Transparent base plate 2 of transparent substrate 210A
As the material 10, the glass or plastic material mentioned in the first example can be used. As the conductive paste 230, those described in the first example can be used. Hereinafter, similarly to the first example of the embodiment, only the concave portion is filled with the conductive paste 230 by the squeegee method and dried. (FIG. 2C) Further, similarly to the first example, a protective film forming process is performed. (FIG. 2D) The shape of each part, processing conditions, and the like are the same as in the first example.
Also, as in the first example, the grounding frame portion usually provided around the conductive metal thin film serving as the electromagnetic wave shielding portion is filled with the conductive paste 230 and dried and then formed into a predetermined shape by sputtering or vacuum deposition. The conductive metal thin film may be formed to have a thickness of about 1 to 3 μm, but the forming method is not limited to this.

Next, a third example of the embodiment of the method for manufacturing an electromagnetic wave shielding plate will be described below with reference to FIG. In FIG. 3, 310 is a transparent substrate, 320 is a concave portion, 325 is a concave portion forming surface, 330 is a conductive paste, 350 is a conductive metal thin film, 355 is a blackened portion, and 360 is a protective film. FIG.
In the third example of the embodiment of the method for manufacturing an electromagnetic wave shielding plate shown in FIG. 1, a mesh-shaped recess is formed only on one side of a transparent substrate made of a single material such as glass or plastic, and a conductive material is formed in the recess. The conductive paste is filled and dried, and then a conductive metal thin film is formed on the conductive paste by electrodeposition, and a mesh composed of the conductive paste and the conductive metal thin film formed by electrodeposition is formed. In the third example, in order to supplement the conductivity of the conductive paste 330, a conductive metal thin film 350 is provided by electrodeposition. As the material of the transparent substrate 310 and the conductive paste 330, those described in the first example can be used similarly. As shown in FIG. 3, a transparent substrate 310 (FIG.
A recess 320 is formed on one side of FIG. 3A (FIG. 3B), and the conductive paste 330 is filled in the recess 330 and dried.
(FIG. 3C) The width and depth of the recess 320 are determined by the type of the conductive paste. However, since a conductive metal thin film is formed on the conductive paste 330 by electrodeposition later, the conductive paste is It is necessary to have the thickness and width as much as possible. Then
Electrodepositing a conductive metal thin film 350 on the conductive paste 330 (FIG. 3D) Copper is the best conductive metal thin film 350 to be electrodeposited, but is not necessarily limited thereto. The thickness of the metal thin film for effectively shielding electromagnetic waves is preferably as large as possible in terms of shielding electromagnetic waves, but is preferably about 0.2 to 10 μm. At the time of electrodeposition, if necessary, in order to expose the conductive paste, after the paste filling and drying step, the surface of the paste is pre-electrodeposited with an acid or an alkali. Further, a method of burning and removing the organic material layer by oxygen (or air) plasma for the purpose of exposing is effective.
Thus, the conductive metal thin film 35 for shielding electromagnetic waves is formed.
0 is formed on one side of the transparent substrate 310, and thereafter,
A blackening process is performed to blacken the surface of the metal thin film 350 by oxidation or the like to form a blackened portion 355. (FIG. 3E) This is for obtaining an antireflection effect when used in front of a display such as a PDP. Then, after washing and drying, for surface smoothing and protection,
A protective film treatment is performed. (FIG. 3 (f)) The protective film preferably contains a surface hardener and an infrared absorber. In addition, the grounding frame portion usually provided around the conductive metal thin film serving as an electromagnetic wave shielding portion is filled with a conductive paste 330, and after a drying step, is sputtered or vacuum-deposited into a predetermined shape to a thickness of about 500 to 3 μm. When the conductive metal thin film 350 is formed on the conductive paste 330 by electro-depositing the conductive metal thin film, the conductive metal thin film 350 may be further formed by electrodeposition. The method is not limited to this.

Next, an embodiment of the electromagnetic wave shielding plate of the present invention will be described with reference to the drawings. FIG. 4A is a schematic perspective view showing a first example of an embodiment of the electromagnetic wave shielding plate of the present invention, and FIG. 4B is an enlarged view of a part of the mesh portion. FIG. 4C is a diagram showing a cross section taken along line A3-A4 in FIG. 4B, and FIG.
5 (b) and (b) are schematic perspective views showing an example of FIG.
FIG. 5A is a partially enlarged view of the shape of the conductive paste line on the B1 side in FIG. 5A, and FIG. 5B and FIG.
FIG. 5C is a partially enlarged view of the shape of the conductive paste line on the second side.
It is the figure which showed the mesh formed of the line of the conductive paste of (b). FIG. 6A is a schematic perspective view showing a third example of the embodiment of the electromagnetic wave shielding plate of the present invention, and FIG. 6B is an enlarged view of a part of the mesh portion. FIG. 6C is a diagram showing a cross section taken along line C3-C4 in FIG. 6B, and FIG. 7A is a schematic perspective view showing a fourth example of the embodiment. FIG. 7B is an enlarged view of a part of the mesh portion, and FIG.
It is the figure which showed the cross section in D3-D4 of (b). 4 to 7 show electromagnetic wave shielding plates for electromagnetic wave shielding which are used in front of a display such as a PDP. 4 to 7, reference numeral 110 denotes a transparent substrate;
Is a conductive paste, 160 is a protective film, 190 is a mesh, 193 and 195 are lines, 197 is a ground frame, 2
10A is a transparent substrate, 210 is a transparent base material, 230
Is a conductive paste, 250 is a conductive metal thin film, 260 is a protective film, 270 is a transparent resin layer, 290 is a mesh,
93 and 295 are lines, 310 is a transparent substrate, 330 is a conductive paste, 350 is a conductive metal thin film, 355 is a blackened portion, 360 is a protective film, 390 is a mesh, 393 and 3
Reference numeral 95 denotes a line, and reference numeral 397 denotes a frame portion for grounding.

A first example of the embodiment of the electromagnetic wave shielding plate of the present invention shown in FIG. 4 is manufactured by the manufacturing steps shown in FIG.
0 is provided, and the cross-sectional structure taken along line A3-A4 in FIG. 4B is as shown in FIG. 4C. The mesh 190 made of the conductive paste 130 is provided only on the A1 side surface, and the transparent substrate 110 remains on the A2 side surface.

A second example of the embodiment of the electromagnetic wave shielding plate of the present invention shown in FIG. 5 is that a single transparent substrate 110 is provided with concave portions on both surfaces, A group of parallel lines is provided, and the conductive paste 13 is applied to one side of the transparent substrate shown in FIG.
The process of forming No. 0 was similarly performed on both surfaces of the transparent substrate. As shown in FIG. 5 (c), B2
When viewed from the side, the group of the lines 193 and the group of the lines 195 made of the conductive paste 150 on both sides of the transparent substrate 110 form a mesh. Even in this manner, an electromagnetic wave shielding effect can be obtained.

The third embodiment of the electromagnetic wave shielding plate of the present invention shown in FIG. 6 is manufactured by the manufacturing process shown in FIG.
Is formed by transferring the transparent resin layer 270 on which the concave portion 220 side faces outward, and forming a mesh 290 made of the conductive paste 230 in the concave portion. Mesh 290 made of conductive paste 230 only on the C1 side surface
And the surface on the C2 side remains the transparent base material 210.

A fourth example of the embodiment of the electromagnetic wave shielding plate of the present invention shown in FIG. 7 is manufactured by the manufacturing process shown in FIG. 3, and has a mesh-shaped concave portion provided on one surface thereof. The conductive paste 330 is filled, dried, and further provided with a conductive metal thin film 350 made of a copper thin film by electrodeposition on the conductive paste 330. D3-D4 of FIG.
7C is as shown in FIG. 7C. The mesh 390 made of the conductive paste 330 is provided only on the surface on the D1 side, and the transparent substrate 3 is provided on the surface on the D2 side.
It remains at 10.

[0027]

Next, the present invention will be further described with reference to specific examples of the present invention. (Example 1) In Example 1, the manufacturing method of the third example of the embodiment of the method of manufacturing the electromagnetic wave shielding plate shown in FIG.
The electromagnetic wave shielding plate for a plasma display of the fourth example of the embodiment of the electromagnetic wave shielding plate shown in FIG.
Hereinafter, Embodiment 1 of the method of manufacturing the electromagnetic wave shielding plate will be described with reference to FIG. As the transparent substrate 310, a thickness of 3 mm
Using a glass plate of which width is 15
A recess 320 having a V-shaped groove was formed at a depth of 10 μm and a V-shaped groove (FIG. 3B), and a commercially available conductive paste, dootite (trade name: FA, manufactured by Fujikura Kasei Co., Ltd.)
-323) was filled by a squeegee method. (FIG. 3
(C)) Then, a ground frame (earth terminal) is formed by screen printing so as to have a width of 30 so as to include the outer peripheral portion of the cut mesh.
mm and a thickness of about 14 μm.
Then, it was placed in an oven and heat-cured at 150 ° C. for 30 minutes. Then, as a pretreatment for electrodeposition of metal, organic substances on the surface were burned using a plasma incinerator to expose metal components in the paste. The thermosetting conductive paste, Dotite FA-323 (manufactured by Fujikura Kasei Co., Ltd.) uses Ag as a filler and a polyester resin as a binder, and has conductivity of 4 × 10 ⁻⁵ Ω · cm and area. Resistance is 0.0
It shows characteristics of 4Ω / □, 10 μcm (catalog value). Next, copper plating (corresponding to the conductive metal thin film 350) having a thickness of 5 μm was performed on the surface of the conductive paste 330 in order to supplement the conductivity of the concave conductive paste which is a thin wire. (FIG. 3 (c)) For copper plating, the strip-shaped printed portion of the ground terminal was connected to a DC power supply as a current terminal, and a counter electrode was provided according to a standard method, and the following electrodeposition was performed. (Electrodeposition conditions) using copper baths: copper pyrophosphate bath _{Cu 2 P 2 O 7 · 3H} 2 O 49g / l K 4 P 2 O 7 340g / l MH 4 OH (28%) 3ml / l pH 8.8 P Ratio (P ₂ O ₇ ⁴⁻ / Cu ²⁺ ) 7.0 Solution Temperature 55 ° C. Next, a blackening treatment was performed to prevent reflection of the copper plating surface. (FIG. 3 (e)) The blackening treatment is to form a copper oxide film on the surface, so that 20% of solution A and 20% of solution B of commercially available blackening solution Kovar Black (manufactured by Isolate Chemical Laboratory Co., Ltd.) are used. It was immersed in an aqueous solution containing 10% at 40 to 60 ° C. for 5 to 10 minutes to obtain a black copper oxide film (corresponding to a blackened portion 355). Next, in order to protect the surface, a photo-curable acrylic resin is uniformly applied to a thickness of about 10 μm on the inner front surface excluding the outer circumference of 5 to 10 mm of the ground terminal portion, and then cured by ultraviolet rays. 3
60. (FIG. 3 (f)) In this way, the conductive paste is filled into the concave portions of the transparent 3 mm-thick glass substrate surface, 5 μm of copper and black copper oxide are further laminated, and further the entire surface excluding the ground terminal portion. Then, an electromagnetic wave shielding plate having a wear-resistant protective film formed thereon was obtained. Maximum width of mesh (corresponding to electrodeposited copper width) is 30μm
And the line pitch is 280 μm. This electromagnetic wave shielding plate showed a transmittance of visible light in the range of 400 to 700 nm of 60% or more, and had an attenuation rate of 20 dB or more for electromagnetic waves of 20 MHz to 10000 MHz, and was practical.

(Example 2) In Example 2, the manufacturing method of the first example of the method of manufacturing the electromagnetic wave shielding plate shown in FIG. 1 was used, and the method of manufacturing the electromagnetic wave shielding plate shown in FIG. A fourth example of an electromagnetic wave shielding plate for a plasma display is manufactured. Hereinafter, Example 2 of the method of manufacturing the electromagnetic wave shielding plate will be described.
Will be described with reference to FIG. 5m as transparent substrate 110
An m-thick acrylic plate was used. (FIG. 1 (a)) Using a hot flat press, a metal press mother plate (having a convex mesh) and an acrylic substrate were overlaid, and heated and pressed to obtain a substrate having a concave mesh. (FIG. 1 (b)) The preparation of the press master was performed as follows. First, a well-polished 0.2 mm thick stainless steel plate surface is made into a fine and uniform mat surface (roughened surface) by brush polishing, and then a 20 μm mesh is formed with a photoresist according to a standard method. Wearing mask. A photoresist having a thickness of 15 μm is preferable in order to obtain a well-formed electrodeposited convex portion, and a dry film for a commercially available plating resist suitable for the purpose (Dupont MRC Dry Film Co., Ltd., trade name: FRA063 series) ) Was used. Next, in the following Ni (nickel) electrodeposition bath,
After forming the i-convex mesh shape, the resist was peeled off and removed to obtain a pressed mother plate. (Ni plating bath) Nickel sulfate 240-340 g / l Nickel chloride 45 g / l Sulfuric acid 30-38 g / l pH 2.2-5.5 Temperature 46-70 ° C Current density 2.5-10 A / dm Next, acrylic substrate Is placed on a flat press machine, press-pressed at about 200 ° C, cooled as it is, and the acrylic substrate is peeled off from the press mother plate. A shape recess was formed.

Next, as in Example 1, the conductive paste was filled in the recesses using a squeegee. (FIG. 1 (c)) In the case of this example, since the cross-sectional shape of the concave portion was substantially rectangular,
The filling volume of the conductive paste is twice as large as that of the V-shaped concave portion of Example 1, and the effective conductivity is increased. Therefore, the surface is thermally cured without performing copper electrodeposition for complementing the conductivity, particularly thereafter. Formed the same protective film as in Example 1 to obtain an electromagnetic wave shielding plate. (FIG. 1D) Like the first embodiment, the electromagnetic wave shielding plate is 400 to 700.
The visible light transmittance in the range of nm is 60% or more,
The attenuation rate for electromagnetic waves of 1 MHz to 10000 MHz is 2
At 0 dB or more, it was practical. From this example,
When a conductive paste having good conductivity was used and the filling volume of the concave portion was large, it was found that a good electromagnetic wave shielding effect could be obtained with only the conductive paste alone.

[0030]

As described above, the present invention is an electromagnetic wave shielding plate having an electromagnetic wave shielding property and a light transmitting property which is used on the front surface of a display such as a PDP, and sufficiently satisfies quality and productivity. An electromagnetic wave shielding plate that can be provided and a method of manufacturing the same can be provided.

[Brief description of the drawings]

FIG. 1 is a process chart showing a first example of an embodiment of a method for manufacturing an electromagnetic wave shielding plate of the present invention.

FIG. 2 is a process diagram showing a second example of the embodiment of the method for manufacturing an electromagnetic wave shielding plate of the present invention.

FIG. 3 is a process chart showing a third example of the embodiment of the method for manufacturing an electromagnetic wave shielding plate of the present invention.

FIG. 4 is a schematic view showing a first example of an embodiment of the electromagnetic wave shielding plate of the present invention.

FIG. 5 is a schematic view showing a second example of the embodiment of the electromagnetic wave shielding plate of the present invention.

FIG. 6 is a schematic diagram showing a third example of the embodiment of the electromagnetic wave shielding plate of the present invention.

FIG. 7 is a schematic view showing a fourth example of the embodiment of the electromagnetic wave shielding plate of the present invention.

FIG. 8 is a view for explaining an electromagnetic wave shielding plate using a mesh made of a metal thin film.

[Explanation of symbols]

 110 transparent substrate 120 concave portion 125 concave portion forming surface 130 conductive paste 150 conductive metal thin film 160 protective film 190 mesh 193, 195 line 197 grounding frame portion 210A transparent substrate 210 transparent base plate material 220 concave portion 225 concave portion forming surface 230 conductive Conductive paste 250 Conductive metal thin film 260 Protective film 270 Transparent resin layer 280 Carrier film 290 Mesh 293, 295 Line 297 Grounding frame 310 Transparent substrate 320 Depressed portion 325 Depressed portion forming surface 330 Conductive paste 350 Conductive metal thin film 355 Black Transformation part 360 Protective film 390 mesh 393, 195 lines 397 Grounding frame 800 Electromagnetic wave shielding plate 810 Mesh part 815 Grounding frame 817 Metal thin film 830 Transparent substrate 850, 870 lines

Claims (10)

[Claims] 1. A method for manufacturing an electromagnetic wave shielding plate having electromagnetic wave shielding properties and transparency by forming a conductive substance in a predetermined shape on one or both sides of a transparent substrate used on a front surface of a display. In order, (a) a recess forming step of forming a recess having a predetermined shape on one or both surfaces of a transparent substrate; and (b) a paste filling and drying step of filling only a recess with a conductive paste by a squeegee method and drying the paste. When,
(C) a protective film forming step of forming a protective film covering the entire conductive paste on the transparent substrate surface. 2. The method according to claim 1, wherein after the paste filling and drying step, an electrodeposition step of electrodepositing a good conductive metal on the dried paste surface is performed. A method for manufacturing an electromagnetic wave shielding plate, wherein a protective film forming step is performed so as to cover the whole. 3. The method according to claim 2, wherein after the paste filling and drying step, the paste surface is subjected to an electrodeposition pretreatment, and then an electrodeposition step of electrodepositing a conductive metal on the conductive paste is performed. A method for producing an electromagnetic wave shielding plate. 4. The method according to claim 1, wherein the concave portion is formed on the transparent substrate by a mechanical process such as a convex press or cutting, or an etching process using an etching-resistant film by a photolithography technique. A method for producing an electromagnetic wave shielding plate, wherein the electromagnetic wave shielding plate is directly formed on a simple substrate. 5. The electromagnetic wave shielding plate according to claim 4, wherein a transparent resin layer for forming the concave portion is provided on the concave portion forming side of the transparent substrate, and the concave portion is formed in the resin layer. Manufacturing method. 6. The transparent base plate material according to claim 1, wherein the transparent substrate is provided with a transparent resin layer in which a concave portion is formed on a carrier film surface in advance, and the resin layer has a concave portion facing outside. A method for producing an electromagnetic wave shielding plate, wherein the electromagnetic wave shielding plate is formed by being transferred to a substrate. 7. The method for manufacturing an electromagnetic wave shielding plate according to claim 1, wherein the transparent substrate is glass or plastic alone or a laminate thereof. 8. The method for manufacturing an electromagnetic wave shielding plate according to claim 1, wherein the concave portion is formed only on one surface of the transparent substrate, and the concave portion is formed on the one surface in a mesh shape. 9. The transparent substrate according to claim 1, wherein a concave portion is formed on both surfaces of the transparent substrate, and the concave portions on both surfaces are provided in parallel with each other in a large number. Wherein the recesses on both sides are meshed when viewed through a transparent substrate. 10. An electromagnetic wave shielding plate produced according to claim 1.