JP2000137441A - Electromagnetic wave shielding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave shielding material having excellent visibility. SOLUTION: This is an optical filter with an electromagnetic wave shield provided, on a transparent substrate 1, with a metallic pattern layer 2 having a grating pattern part 3 formed in a grating and a grounding part 4 made of a metallic member formed on at least one of the peripheral sides of the grating pattern part 3, and it is possible to easily deaerate bubbles generated at the time of laminating a transparent film on the metallic pattern layer by forming an opening area of the grating in contact with the grounding part 4 of the grating pattern part 3 so that the area is larger than the grating area not in contact with the grounding part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic shielding material having good visibility.

[0002]

2. Description of the Related Art Conventionally, as a measure for preventing electromagnetic waves discharged from a gas discharge display panel used in an image display device, for example, a PDP (plasma display panel), from leaking to the outside, as shown in FIG. , Transparent substrate 1
PDP is provided with a metal pattern layer having a grid pattern portion 11 formed in a grid shape on the first metal plate 0 and an earth portion 12 made of a metal member formed on the outer periphery of the grid pattern portion 11.
The method of arranging in front of is taken.

However, when the electromagnetic wave shielding material having the metal pattern layer is provided on the front surface of a display screen such as a PDP, the amount of light emitted from the PDP and the external light reflected by the electromagnetic wave shielding material increases, and the screen is screened. The problem that visibility deteriorates arises. Therefore, in order to prevent this inconvenience, an optical thin film having a different refractive index is formed on a transparent substrate with an antireflection layer to prevent the visibility of the screen from being lowered. In addition, a near-infrared absorbing layer for removing near-infrared rays generated from the PDP and causing malfunction of the remote controller and the like, and an anti-glare (AG) layer for preventing visibility from being degraded due to generation of Newton rings are also required. Become.

There are two methods of forming a layer: a method of applying an anti-reflection agent on a substrate and a method of attaching a film. The above-described anti-reflection function, near-infrared absorption function, and AG function have no coating unevenness. Is preferred because a film can be easily added and the thickness can be adjusted. However, since the ground portion needs to expose the metal surface, it is laminated on the lattice pattern portion.

However, when a film is laminated on the grid pattern portion of the electromagnetic wave shielding material, air bubbles are generated between the metal pattern layer and the film layer as shown in FIG. There is a problem that remains. The presence of air bubbles between the metal pattern layer and the film layer causes a problem of lowering the visibility of the screen.

Therefore, an electromagnetic wave shielding material in which a film is laminated on a metal pattern layer is subjected to a pressure treatment to remove air bubbles mixed in the metal pattern layer.

[0007]

However, when a film is laminated only on the above-mentioned metal pattern layer, the thermal expansion and contraction ratio between the transparent substrate and the film layer is different.
With the expansion and contraction of the film due to heat, humidity and the like, a break occurs in the metal pattern layer in contact with the edge of the film, which causes a problem that the electromagnetic wave shielding property is impaired.

Therefore, the film is attached so as to cover the entire surface of the grid pattern portion and the end of the ground portion in contact with the grid pattern portion, thereby preventing the occurrence of disconnection due to expansion and contraction of the film. However, the connection area between the grid pattern part and the grounding part tends to have a small opening area of the grid pattern, and after applying a film so as to cover the end of the ground part in contact with the grid pattern part, pressure treatment is performed. However, air bubbles remain at the boundary between the ground portion and the lattice pattern portion. This bubble expands due to the heat generated from the PDP, and becomes a defect in appearance such as blisters and snow.
Further, the visibility of the electromagnetic wave shielding material is also reduced.

A conventional electromagnetic wave shielding material is shown in FIG.
11A, the lattice angle of each lattice pattern forming the lattice pattern portion is formed to be substantially a right angle or an acute angle as shown in FIG. 11B. However, there has been a problem that the performance is reduced.

The present invention has been made in view of the above problems, and is an electromagnetic wave shield capable of easily removing air bubbles generated in a lattice pattern portion of a metal pattern layer when laminating a film having a function such as anti-reflection. The purpose is to provide materials.

[0011]

In order to achieve the above object, an electromagnetic wave shielding material according to the present invention is provided on a transparent base material at a lattice pattern portion formed in a lattice shape and at least one side of an outer periphery of the lattice pattern portion. An electromagnetic wave shielding material provided with a metal pattern layer having a ground portion made of a metal member, wherein the opening area of the grid in contact with the ground portion of the grid pattern portion is larger than the area of the grid not in contact with the ground portion. It is characterized by having done.

The lattice pattern of the lattice pattern portion is
It is preferred that the area of the cross section parallel to the surface of the transparent base material be increased so as to approach the transparent base material.

Each of the grid angles of the above-mentioned grid pattern is preferably formed in an arc shape.

In the above electromagnetic wave shielding material, a transparent adhesive layer and a transparent film layer are successively formed on the grid pattern portion of the metal pattern layer and the end of the ground portion in contact with the grid pattern portion. Good to be.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an electromagnetic wave shielding material according to an embodiment of the present invention. FIG.
FIG. 8 to FIG. 8 show an embodiment of the electromagnetic wave shielding material of the present invention.

First, a first embodiment of an electromagnetic wave shielding material according to the present invention will be described with reference to FIGS.

In the electromagnetic shielding material according to the present invention shown in FIG. 1, a metal pattern layer 2 is provided on a transparent substrate 1. As shown in FIG. 1, the metal pattern layer 2 includes a lattice pattern portion 3 formed in a lattice shape and an earth portion 4 formed of a metal member on at least one side of the outer periphery of the lattice pattern portion 3. . On the upper surface of the metal pattern layer 2, a transparent film layer 6 is provided on the entire surface of the grid pattern portion shown in FIG. It is attached so as to continuously cover the end portion.

The metal pattern layer formed on the transparent substrate 1 made of glass, resin, or the like is provided with, for example, an electromagnetic wave discharged by the PDP to prevent the electromagnetic wave from leaking to the outside.
Highly conductive metals such as copper, silver, nickel, and ITO (solid solution of indium oxide (In ₂ O ₃ ) and tin dioxide) are used.
The metal pattern layer 2 includes a grid pattern portion formed in a grid shape, and a ground portion formed on the outer periphery of the grid pattern portion and formed of a metal member for grounding. The ground portion may be provided on only one side of the outer periphery of the lattice pattern, or may be provided on two or all sides. The grid pattern of the grid pattern portion is not only a pattern in which the grid angles shown in FIG. 1 intersect at an acute angle, but also a pattern in which the grid angles shown in FIG. A pattern in which polygons are formed by a lattice as shown in FIG. In the present embodiment, as shown in FIG. 1, the opening area of the grid in contact with the ground portion of the grid pattern portion is formed to be larger than the opening area of the grid not in contact with the ground portion. As a method of forming the metal pattern layer, a metal layer is formed on the surface of the transparent substrate by an electroless plating method, an ion plating method, a sputtering method, or the like, a resist is applied on the metal layer, and the grid pattern portion is etched by etching. It is appropriate to form the grid pattern part and the ground part integrally.However, the grid pattern part is formed by etching, and the ground part is formed by attaching a band-shaped metal foil to form the ground part. May be formed separately.

The transparent film layer 6 formed on the metal pattern layer is made of a transparent resin film formed on the entire surface of the grid pattern portion of the metal pattern layer and the end of the ground portion in contact with the grid pattern portion. Is adhered by an adhesive layer 5 so as to be continuously coated. The transparent film layer 6 is provided with one or more of an antireflection function, a near-infrared absorption function, and an AG function. For example, when using a transparent film layer having an anti-reflection function,
It is possible to prevent a problem that light emitted from the PDP and external light are reflected by the metal pattern layer, thereby lowering the visibility of the screen. When a transparent film layer having a near-infrared absorption function is used, near-infrared rays emitted from PDP can be absorbed by this transparent film layer. Also,
When a transparent film layer having an AG function is used, it is possible to prevent a decrease in visibility due to the generation of Newton rings.

The electromagnetic wave shielding material having the above-described structure is provided so that the transparent film layer is provided so as to continuously cover the entire surface of the grid pattern portion and the end of the ground portion in contact with the grid pattern portion. Breakage of the metal pattern layer accompanying expansion and contraction of the metal pattern layer can be prevented, and the problem of impairing the electromagnetic wave shielding property can be prevented.

Further, the transparent film is stuck so as to continuously cover the entire surface of the grid pattern portion and the end of the ground portion in contact with the grid pattern portion, so that the transparent film layer is formed on the metal pattern layer. Although it is difficult to deaerate bubbles generated when the grid pattern is adhered to the grid pattern, as shown in FIG. 1, the opening area of the grid pattern in contact with the ground portion of the grid pattern portion is changed to the opening area of the grid pattern not in contact with the ground portion. By forming so as to be larger than that, when a pressure treatment is performed in a later step, bubbles remaining at a boundary portion with the ground portion can be degassed, and the visibility of the electromagnetic wave shielding material is improved. be able to. In the embodiment shown in FIG. 1, the shape of the opening region in contact with the ground portion is a pentagon, but the present invention focuses on the area, not the shape of the opening region. Various modifications can be made. Further, the area of the opening region is preferably set to a size that does not cause air bubbles to mix only by laminating a transparent film.

Next, a second embodiment of the electromagnetic wave shielding material according to the present invention will be described with reference to FIGS.

The second embodiment is also an electromagnetic shielding material in which a metal pattern layer 2 and a transparent film layer are sequentially formed on a transparent substrate 1. The metal pattern layer 2 also includes the grid pattern portion 3 formed in a grid shape as described above, and the ground portion 4 made of a metal member formed on at least one side of the outer periphery of the grid pattern portion.

In this electromagnetic wave shielding material, a metal pattern layer is formed on a transparent substrate, and then a transparent film layer is formed on the upper surface of the metal pattern layer. When attached, air bubbles are generated between the metal pattern layer and the transparent film due to the unevenness of the metal pattern layer. In particular, air bubbles collected at the grid angles of the grid pattern portion forming the metal pattern layer could not be easily degassed by the conventional structure of the grid pattern portion shown in FIG.

Therefore, in the second embodiment, as shown in FIG. 4, the grid pattern of the grid pattern portion constituting the metal pattern layer is formed by changing the area of the cross section parallel to the surface of the transparent base material to the transparent base material. , And each grid angle of the grid pattern is formed in an arc shape as shown in FIG. By forming the lattice pattern portion in this manner, bubbles accumulated at the lattice angle are easily released, and can be easily degassed by a post-processing pressure treatment. Note that the arc shape may be formed within a range that does not reduce the visibility, but the angle of the grid angle formed in the arc shape may be formed based on a value calculated according to the following equation. D =
T × K Here, T represents the thickness of the metal pattern, and D represents the two tangents when two orthogonal tangents as shown in FIG. 6 are drawn in a lattice pattern that curves toward the center of the lattice. Represents the distance from the intersection to the contact point, and K represents a constant value for adjusting the angle of the lattice angle, and may be a value of 1 to 10, preferably 2 to 5.

This metal pattern layer is formed by the following steps. A metal layer is formed on a transparent substrate, and a resist is applied on the metal layer. Then, the resist is covered with a mask composed of a lattice pattern in which the lattice angle is formed in an arc shape, pattern exposure is performed, and etching is performed. As shown in FIG. 7A, the etching is further performed after the area of the cross section of the grid pattern parallel to the transparent substrate becomes equal to the area of the resist pattern, and as shown in FIG. The area of the cross section parallel to the transparent substrate of the pattern,
Etching is performed so that the size increases as approaching the transparent substrate. Alternatively, as shown in FIG. 7C, the area of the cut surface parallel to the transparent substrate of the lattice pattern near the resist is substantially equal to the area of the resist pattern, and the area of the cross section of the metal pattern parallel to the transparent substrate is reduced. Then, the etching is performed so as to increase as approaching the transparent substrate.

According to such an etching method, the area of the cross section parallel to the surface of the transparent base material becomes larger as approaching the transparent base material. The metal pattern layer in which the portions are integrally formed can be formed.

This second embodiment can be combined with the above-described first embodiment. By combining the first and second embodiments, it is possible to further enhance the degassing effect of bubbles generated when attaching a transparent film.

Next, the manufacturing process of the embodiment of the above embodiment will be described with reference to the flowchart shown in FIG.

First, in step S1, a 200-.mu.m thick PET film having a thickness of 50 to 100 .mu.m was placed on a PET film.
A copper film having a thickness of about 2000 mm is formed by a vacuum evaporation method or a sputtering method. Then, in step S2, a copper film is formed to a predetermined thickness by an electroplating method.
A PET film is immersed in an aqueous solution in which 200 g / l of copper sulfate and 60 g / l of sulfuric acid are dissolved, and a current density of 1 A /
Power is supplied at dm ² for 30 minutes to form a copper layer having a desired thickness. The thickness of the copper layer is suitably from 4 to 10 μm.

Next, at step S3, the P on which the copper layer is formed is formed.
Attach the ET film to the transparent substrate. Transparent substrate and P
Adhesion with ET film is 25μ
It is provided with a thickness of about m and adhered. Next, in step S4, a resist is applied on the copper layer. In this embodiment, the resist agent is TL manufactured by Tokyo Ohka Kogyo Co., Ltd.
Use CR-P8008. The transparent substrate is fixed on a spinner with the copper layer facing up, and a resist is dropped on the copper layer to form a transparent substrate.
Spin at 00 rpm for 1 minute.

Next, in step S5, the substrate coated with the resist is pre-baked. In this embodiment, 90 ° C.
Bake in a clean oven for 20 minutes. Then, in step S6, a pattern is exposed by overlaying a mask on the prebaked resist. When creating the first embodiment, a mask is used that is formed such that the opening area of the grid pattern portion that is in contact with the ground portion is larger than the opening area of the grid pattern that is not in contact with the ground portion. In this example, a mask was used so that the opening area of the grid pattern not in contact with the ground portion was 100 to 200 μm square, and the opening area of the grid pattern in contact with the ground portion was 500 μm square.

In step S7, the substrate is immersed in a developing solution and developed, and the unexposed portions of the resist are removed. The exposure is performed at 120 mj / cm ² , and the development is performed by immersing in a 0.8% KOH aqueous solution at 25 ° C. for 1 minute.

Next, the exposed and developed substrate is washed with water in step S8, and is etched in step S9. In this embodiment, Melstrip MN-957 (trade name) manufactured by Meltex Co., Ltd. was used as an etching solution. 4
An etching solution at 0 ° C. is sprayed on the upper surface of the transparent substrate for 50 seconds to form a copper layer in a predetermined pattern. When the second embodiment is made, as described above, further etching is performed after the area of the cross section of the lattice pattern parallel to the transparent base material becomes equal to the area of the resist pattern, as shown in FIG. 7B. Thus, the etching is performed such that the area of the cross section of the lattice pattern parallel to the transparent substrate becomes larger as approaching the transparent substrate. Alternatively, as shown in FIG. 7C, the area of the cut surface parallel to the transparent substrate of the lattice pattern near the resist is substantially equal to the area of the resist pattern, and the area of the cross section of the metal pattern parallel to the transparent substrate is reduced. Then, the etching is performed so as to increase as approaching the transparent substrate.

Next, in step S10, the etched substrate is washed with water and dried in step S11. Drying is performed at 120 ° C. for 60 seconds.

Next, in step S11, antireflection films are laminated on both surfaces of the dried substrate. In this example, ARCTP-UR210 (trade name, manufactured by Asahi Glass Co., Ltd.) was used as an anti-reflection film, and this anti-reflection film was laminated on both sides of the substrate at 5 kg / cm ² . In this working example, an antireflection film formed on the copper pattern layer was provided so as to overlap with the ground portion by about 2 mm in order to prevent disconnection of the copper pattern.

Next, in step S13, the substrate on which the antireflection film is laminated on both sides is subjected to pressure and heat treatment to remove bubbles generated during lamination of the antireflection film. In this embodiment, the heat treatment at 40 ° C. to 80 ° C. and the pressure treatment at ⁴ kg / cm ² to ⁵ kg / cm ² are performed for 15 minutes to 30 minutes. Thereby, bubbles generated between the copper pattern layers and between the copper pattern layer and the ground portion can be degassed.

The above-described embodiment is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

[0039]

As is apparent from the above description, in the electromagnetic wave shielding material of the present invention, the opening area of the lattice contacting the ground portion of the lattice pattern portion is made larger than the area of the lattice not contacting the ground portion. Thereby, air bubbles generated when the transparent film is stuck on the metal pattern layer can be easily degassed.

Further, the lattice pattern of the lattice pattern portion is
By forming the area of the cross section parallel to the surface of the transparent base material to be larger as approaching the transparent base material, it is possible to easily deaerate bubbles which easily accumulate at the lattice angle when the transparent film is attached. .

Further, by forming each grid angle of the grid pattern portion in an arc shape, it is possible to easily deaerate bubbles which tend to accumulate at the grid angles when the transparent film is attached.

Further, an adhesive layer made of a transparent adhesive was provided so that the transparent film layer was continuously coated on the entire surface of the grid pattern portion and the end portion of the ground portion in contact with the grid pattern portion. Accordingly, it is possible to prevent a problem that the film is expanded and contracted due to heat, humidity, and the like, the metal pattern layer in contact with the edge of the film is disconnected, and the electromagnetic wave shielding property is impaired.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a first embodiment of an electromagnetic wave shielding material of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of the first embodiment.

FIG. 3 is a cross-sectional view illustrating a configuration of the first embodiment.

FIG. 4 is a sectional view showing a second embodiment of the electromagnetic wave shielding material of the present invention.

FIG. 5 is a plan view illustrating a configuration of a second embodiment.

FIG. 6 is a diagram for explaining a method of setting a grid angle of a grid pattern.

FIG. 7 is a diagram illustrating a forming method according to a second embodiment.

FIG. 8 is a flowchart illustrating a manufacturing process of a production example.

FIG. 9 is a plan view illustrating a configuration of a conventional electromagnetic wave shielding material.

FIG. 10 is a diagram showing a state of bubbles generated between a metal pattern layer and a transparent film layer.

FIG. 11 is a plan view illustrating a configuration of a conventional grid pattern.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Metal pattern layer 3 Lattice pattern part 4 Ground part 5 Adhesive layer 6 Transparent film layer

Continuing on the front page (72) Inventor Tomokazu Motono 4-14-12 Koishikawa, Bunkyo-ku, Tokyo Kyodo Printing Co., Ltd. (72) Inventor Ryohei Okamoto 4-14-12 Koishikawa, Bunkyo-ku, Tokyo Kyodo Printing Co., Ltd. (72) Inventor Kojiro Maeda 4- 14-12 Koishikawa, Bunkyo-ku, Tokyo Kyodo Printing Co., Ltd. MA08 MA22 5G435 AA01 AA16 BB06 GG33 KK07

Claims (4)

[Claims] 1. An electromagnetic wave shielding material comprising a transparent base material provided with a metal pattern layer having a grid pattern portion formed in a grid and an earth portion made of a metal member on at least one side of an outer periphery of the grid pattern portion. 2. The electromagnetic wave shielding material according to claim 1, wherein an opening area of the grid in contact with the ground portion of the grid pattern portion is larger than an area of the grid not in contact with the ground portion. 2. The lattice pattern of the lattice pattern portion is formed such that an area of a cross section parallel to a surface of the transparent base material increases as approaching the transparent base material. Electromagnetic shielding material. 3. The electromagnetic wave shielding material according to claim 1, wherein each grid angle of the grid pattern is formed in an arc shape. 4. A transparent adhesive layer and a transparent film layer are successively formed continuously on a lattice pattern portion of the metal pattern layer and an end of the ground portion in contact with the lattice pattern portion. The electromagnetic wave shielding material according to any one of claims 1 to 3, wherein: