KR100615151B1 - Electromagnetic shielding filter and method for manufacturing the same - Google Patents

Abstract

The present invention provides an electromagnetic wave blocking filter having an electrically conductive mesh with improved aperture ratio. In another aspect, the present invention provides a method for producing an electromagnetic wave filter, which is easy to handle the material during the manufacturing process, thereby easily producing a large-area electromagnetic wave filter, and can form an electrically conductive mesh with improved aperture ratio. . The electromagnetic wave blocking filter provided by the present invention includes a transparent substrate; And a metal mesh attached to one surface of the transparent substrate and having electrical conductivity, wherein the web width R of the mesh line intersection portion of the metal mesh is 5 times or less, more preferably 2 times or less, of the mesh line width.

Description

Electromagnetic shielding filter and method for manufacturing the same {Electromagnetic shielding filter and method for manufacturing the same}

1A is a diagram schematically showing a pattern of a metal mesh according to one embodiment of an electromagnetic wave blocking filter of the present invention.

1B and 1C are enlarged views of mesh line intersections of the metal mesh of FIG. 1A.

2 is a diagram schematically showing an embodiment of an electromagnetic wave blocking filter for a plasma display panel of the present invention.

The present invention relates to an electromagnetic shielding filter. As used herein, the term electromagnetic wave blocking filter has a low transmittance of electromagnetic waves in a specific wavelength range, in particular, a low transmittance of electromagnetic waves in a wavelength range known to be harmful to the human body, while a high transmittance of visible light is solid. material).

A representative example of the field where an electromagnetic wave filter is applied is a plasma display panel.

In the plasma display panel, a large amount of electromagnetic waves and near-infrared rays are emitted, the surface reflection of the phosphor is generated at a high level, and the emission of orange light due to helium as the encapsulating gas is severely generated. Therefore, in order to prevent the emission of electromagnetic waves known to be harmful to the human body, near-infrared rays which may cause malfunctions of precision instruments, surface reflections harmful to eyesight, and orange light degrading color purity, the electromagnetic wave blocking function, near-infrared blocking function, and surface It is common to arrange | position the optical filter which has an antireflection function and the orange light absorption function in the front surface of a plasma display panel.

Such an optical filter disposed on the front surface of the plasma display panel is, for example, by attaching an electrically conductive mesh and an antireflection film in order to the surface of the transparent substrate, and by laminating a near infrared ray blocking film on the back side thereof. [Japanese Patent Laid-Open No. 13-134198]. The near infrared ray blocking film can also function as an orange light absorbing function.

Strictly speaking, the part consisting of a transparent substrate and an electrically conductive mesh in the optical filter is an electromagnetic wave blocking filter. However, the optical filter can be classified as an electromagnetic wave blocking filter from the viewpoint of the electromagnetic wave blocking filter to which the antireflection function and the near infrared ray blocking function are added.

Although the plasma display panel has been mentioned as an application example of the electromagnetic wave shielding filter, the application of the electromagnetic wave shielding filter is not limited thereto.

The conventional electromagnetic wave filter is manufactured by attaching a mesh formed by etching a metal film in a predetermined pattern to a substrate or by attaching a metal film to a substrate and then etching the metal film in a predetermined pattern to form a mesh. This method is difficult to handle materials during the manufacturing process (e.g., breakage of the etched metal film is likely to occur in the process of attaching the etched metal film to the substrate), the manufacturing cost is high, and the possibility of defective products is relatively high. It is known to have a problem that a large area of the electromagnetic wave blocking filter is not easy.

Moreover, mesh line extensions of the mesh formed in this way are formed with web-like mesh line extensions, which webs lower the opening ratio of the mesh.

The present invention provides an electromagnetic wave blocking filter having an electrically conductive mesh with improved aperture ratio.

The present invention provides a method for producing an electromagnetic wave filter, which facilitates the handling of materials during the manufacturing process, thereby easily producing a large-area electromagnetic wave filter, and forming an electrically conductive mesh with improved aperture ratio.

The present invention provides an electromagnetic wave shielding filter for a plasma display panel having an electrically conductive mesh with improved aperture ratio, and having a near infrared ray blocking function, a surface antireflection function, and an orange light absorption function.

The electromagnetic wave blocking filter provided by the present invention includes a transparent substrate; And a metal mesh attached to one surface of the transparent substrate and having electrical conductivity, wherein the web width R of the mesh line intersection portion of the metal mesh is 5 times or less, more preferably 2 times or less, of the mesh line width.

The method for manufacturing an electromagnetic wave filter provided by the present invention includes applying a photosensitive material to one surface of a transparent substrate, and then exposing and developing a mesh pattern to expose a surface to which the mesh line is attached; And removing the photosensitive material after plating the mesh wire material on the surface to which the mesh wire is to be attached.

The electromagnetic wave filter for plasma display panel provided by the present invention, a transparent substrate; An anti-reflection film attached to one surface of the transparent substrate; A metal mesh attached to the other side of the transparent substrate and having electrical conductivity; And near-infrared and selective wavelength absorbing films affixed on the metal mesh, wherein the web width R of the mesh line intersection of the metal mesh is 5 times or less, more preferably 2 times or less, of the mesh line width.

Hereinafter, the electromagnetic wave shielding filter of this invention is demonstrated in detail.

The electromagnetic wave blocking filter provided by the present invention includes a transparent substrate; And a metal mesh attached to one surface of the transparent substrate and having electrical conductivity, wherein the web width R of the mesh line intersection portion of the metal mesh is 5 times or less, more preferably 2 times or less, of the mesh line width.

As a material of the transparent substrate, for example, glass or thermoplastic resin can be used. Specific examples of the thermoplastic resin include, but are not limited to, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, triacetate cellulose, polyether sulfone, and the like.

When the electromagnetic wave blocking filter of the present invention is applied, for example, as a front filter of a flat panel display, the visible light region light transmittance of the material used for the transparent substrate is higher. In this case, as the material of the transparent substrate, a material having a visible ray region light transmittance of at least 80% or more is typically used. In some cases, however, a material having a visible light region light transmittance of 80% or less may be used as the material of the transparent substrate.

The thickness of the transparent substrate is not particularly limited. When applied as a front filter of a flat panel display, when the thickness of the transparent substrate is too small, a problem may occur, and when the thickness of the transparent substrate is too large, a problem may occur. In this case, the transparent substrate typically has a thickness of about 25 to about 150 μm.

As the mesh wire material of the metal mesh, for example, copper, stainless steel, aluminum, nickel, titanium, tungsten, tin, iron, silver, chromium, or a mixture thereof may be used, but is not limited thereto.

When the thickness of the mesh line of the metal mesh is too small, a problem may occur that the electromagnetic shielding rate is low, and when the thickness of the metal mesh is too large, a problem may occur that the side transmittance falls. In view of this, it is preferable that the thickness of the mesh line of the metal mesh is about 5 to about 20 μm.

If the mesh line width of the metal mesh is too small, it may be easily broken. If the mesh line width of the metal mesh is too large, a problem may occur that the aperture ratio is lowered. In view of this, it is preferable that the mesh line width of the metal mesh is about 5 to about 20 μm.

If the mesh line spacing of the metal mesh is too small, a problem may occur that the aperture ratio drops. If the mesh line spacing of the metal mesh is too large, a problem may occur that the electromagnetic shielding rate is lowered. In view of this, the mesh line spacing of the metal mesh is preferably about 150 to about 400 μm.

1A shows a portion of a metal mesh employed in one embodiment of an electromagnetic wave blocking filter of the present invention. In the metal mesh of FIG. 1A, mesh lines are arranged in a rectangular pattern. FIG. 1B is an enlarged view of a mesh line intersection of the metal mesh of FIG. 1. FIG. 1B shows a webbed extending out of the mesh line intersection. FIG. 1C is the same view as FIG. 1B, with the points for defining the "webbed width R of the mesh line intersection".

In FIG. 1C, one vertex of an imaginary mesh line intersection that may be formed when the mesh lines intersect while maintaining the nominal mesh line width is represented by “O”, and a point at which the width of the mesh line starts to become larger than the nominal mesh line width. Are denoted by "P" and "Q". The part defined by the straight line OP, the straight line OQ, and the curve PQ is defined as the webbed part of a mesh line intersection. Although FIG. 1C shows curve PQ as a smooth arc, curve PQ defining the outline of the webbed does not necessarily form such an arc, and may have any other shape. Point "R" indicates the point where the straight line bisecting each POQ and the curve PQ meet. The length of the line segment OR is defined as "web width R of the mesh line intersection".

The web width R of the mesh line intersection portion of the metal mesh employed in the electromagnetic wave blocking filter provided in the present invention is 5 times or less, more preferably 2 times or less of the mesh line width. The smaller the web width R of the mesh line intersection of the metal mesh, the higher the opening ratio of the metal mesh. Accordingly, the web width R of the mesh line intersection portion of the metal mesh employed in the electromagnetic wave blocking filter provided in the present invention is preferably about 5 times or less of the mesh line width, more preferably about 2 times or less of the mesh line width, and even more preferably. Preferably about 0.4 times or less. In some embodiments of the present invention, an R value of 1/10 or less of the mesh line width is provided, and this R value is substantially zero.

In the electromagnetic wave blocking filter of the present invention, since the web width R of the mesh line intersection portion of the metal mesh employed is small, the metal mesh has an improved aperture ratio. Since the specific numerical value of the opening ratio of the metal mesh varies according to the mesh line width and the mesh line spacing, it is difficult to uniformly limit the opening ratio of the metal mesh employed in the present invention. However, in the case where the metal mesh of the present invention has the same mesh line width and mesh line spacing as the metal mesh produced by the conventional etching method, the metal mesh of the present invention is about as compared to the metal mesh produced by the conventional etching method. It has an opening ratio of about 1% to about 5% larger. Typically, when the mesh lines are arranged in a rectangular pattern, the mesh line width is about 5 to about 20 mu m, and the mesh line spacing is about 150 to about 400 mu m, the metal mesh employed in the electromagnetic wave blocking filter of the present invention. The aperture ratio of is from about 90% to about 95%. In the case where an R value of 1/10 or less of the mesh line width is provided, that is, an R value that can be viewed as substantially zero is provided, the webbed portion of the mesh line intersection disappears substantially, and the metal mesh is Under the mesh line width and the mesh line spacing, there is a maximum opening ratio.

Since the electromagnetic wave blocking filter of the present invention employs a metal mesh having such an improved aperture ratio, when the electromagnetic wave blocking filter of the present invention is applied as a front filter of a display device such as a plasma display panel, the display device has improved luminance. The final image can be shown.

Hereinafter, a method of manufacturing the electromagnetic wave blocking filter of the present invention employing the metal mesh having such an improved aperture ratio will be described in detail.

The method for manufacturing an electromagnetic wave filter provided by the present invention includes applying a photosensitive material to one surface of a transparent substrate, and then exposing and developing a mesh pattern to expose a surface to which the mesh line is attached; And removing the photosensitive material after plating the mesh wire material on the surface to which the mesh wire is to be attached.

Hereinafter, an electromagnetic wave blocking filter for a plasma display panel which is an embodiment of the electromagnetic wave blocking filter of the present invention will be described in detail.

The electromagnetic wave filter for plasma display panel provided by the present invention, a transparent substrate; An anti-reflection film attached to one surface of the transparent substrate; A metal mesh attached to the other side of the transparent substrate and having electrical conductivity; And near-infrared and selective wavelength absorbing films affixed on the metal mesh, wherein the web width R of the mesh line intersection of the metal mesh is 5 times or less, more preferably 2 times or less, of the mesh line width.

As a material of the transparent substrate, for example, glass or thermoplastic resin can be used. Specific examples of the thermoplastic resin include, but are not limited to, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, triacetate cellulose, polyether sulfone, and the like.

The higher the visible light region light transmittance of the material used for the transparent substrate, the better. In this case, as the material of the transparent substrate, a material having a visible ray region light transmittance of at least 80% or more is typically used. In some cases, however, a material having a visible light region light transmittance of 80% or less may be used as the material of the transparent substrate.

The thickness of the transparent substrate is not particularly limited. If the thickness of the transparent substrate is too small may be a problem that is weak to impact, if the thickness of the transparent substrate is too large may cause a problem. In view of this, the transparent substrate typically has a thickness of about 25 to about 150 μm.

The antireflection film is attached to one surface of the transparent substrate. The antireflection film is formed on one side of a transparent plastic film, such as PET, having a thickness of about 75 to about 250 μm, by hard coating of acrylic resin for scratch resistance, and then forming a low refractive index single layer film or It is formed by alternately laminating a low refractive index transparent film. As an antireflection film forming method, the material may be formed by vacuum coating the material and the solution containing the material by roll coating or die coating by a wet method. The optical thickness of the antireflection film is formed so that the high refractive index film and the low refractive index film are respectively λ / 4-λ / 4 (λ is the wavelength). On the other side of the film, a transparent adhesive is applied to have a thickness of about 25 μm and a release film is attached.

The metal mesh is attached to an opposite surface of the surface of the transparent substrate to which the antireflection film is attached. The metal mesh is electrically conductive.

As the mesh wire material of the metal mesh, for example, copper, stainless steel, aluminum, nickel, titanium, tungsten, tin, iron, silver, chromium, or a mixture thereof may be used, but is not limited thereto.

When the thickness of the mesh line of the metal mesh is too small, a problem may occur that the electromagnetic shielding rate is low, and when the thickness of the metal mesh is too large, a problem may occur that the side transmittance falls. In view of this, it is preferable that the thickness of the mesh line of the metal mesh is about 5 to about 20 μm.

If the mesh line width of the metal mesh is too small, a problem may be easily broken. If the mesh line width of the metal mesh is too large, a problem may occur that the aperture ratio is lowered. In view of this, it is preferable that the mesh line width of the metal mesh is about 5 to about 20 μm.

If the mesh line spacing of the metal mesh is too small, a problem may occur that the aperture ratio is lowered. If the mesh line spacing of the metal mesh is too large, a shielding rate may be lowered. In view of this, the mesh line spacing of the metal mesh is preferably about 150 to about 400 μm.

The web width R of the mesh line intersection portion of the metal mesh employed in the electromagnetic wave filter for plasma display panel provided by the present invention is 5 times or less, more preferably 2 times or less of the mesh line width. The smaller the web width R of the mesh line intersection of the metal mesh, the higher the opening ratio of the metal mesh. Therefore, the web width R of the mesh line intersection portion of the metal mesh employed in the electromagnetic wave filter for plasma display panel provided by the present invention is preferably about 5 times or less of the mesh line width, and more preferably about 2 times the mesh line width. Or less, and still more preferably about 0.4 times or less. In some embodiments of the present invention, an R value of 1/10 or less of the mesh line width has been provided, and this R value is substantially zero.

In the electromagnetic wave filter for plasma display panel of the present invention, since the web width R of the mesh line intersection portion of the metal mesh employed is small, the metal mesh has an improved aperture ratio. Since the specific numerical value of the opening ratio of the metal mesh varies according to the mesh line width and the mesh line spacing, it is difficult to uniformly limit the opening ratio of the metal mesh employed in the present invention. However, in the case where the metal mesh of the present invention has the same mesh line width and mesh line spacing as the metal mesh produced by the conventional etching method, the metal mesh of the present invention is about as compared to the metal mesh produced by the conventional etching method. It has an opening ratio of about 1% to about 5% larger. Typically, when the mesh lines are arranged in a rectangular pattern, the mesh line width is about 5 to about 20 mu m, and the mesh line spacing is about 150 to about 400 mu m, the metal mesh employed in the electromagnetic wave blocking filter of the present invention. The aperture ratio of is from about 90% to about 95%. In the case where an R value of 1/10 or less of the mesh line width is provided, that is, an R value that can be viewed as substantially zero is provided, the webbed portion of the mesh line intersection disappears substantially, and the metal mesh is Under mesh line width and mesh line spacing, they have a maximum opening ratio.

Since the electromagnetic wave shielding filter for plasma display panel of the present invention employs a metal mesh having such an improved aperture ratio, the plasma display panel equipped with the electromagnetic wave shielding filter for plasma display panel of the present invention can show a final image with improved brightness. Will be.

In the electromagnetic wave filter for plasma display panel of the present invention, the near infrared ray and the selective wavelength absorbing film are attached on the metal mesh.

As a photoselective light absorber applied to the preparation of the near-infrared cutoff and selective wavelength absorbing film, for example, tetraazapophyrin has a metal element in the center, and any substance in the group consisting of ammonia, water, and halogen is selected from the metal element. Preference is given to using derivative pigments with coordination bonds. The metal element is preferably any one selected from the group consisting of Zn, Pd, Mg, Mn, Co, Cu, Ru, Rh, Fe, Ni, V, Sn and Ti. In addition, as a near-infrared blocking pigment, it is preferable to use the pigment | dye, organic substance dye, etc. which are the mixed pigment of nickel complex system and diimmonium system, the compound containing copper or zinc ion, etc., for example. It is suitable to use a light selective light absorbing pigment in the quantity of 0.01 to 0.5% of a total solid. In addition, it is suitable to use the near-infrared shielding dye in an amount of 0.3 to 5% of the total solids.

In the near-infrared blocking and selective wavelength absorbing film, azo dyes, cyanine dyes, diphenylmethane dyes, triphenylmethane dyes, phthalocyanine dyes, xanthene dyes, Diphenylene dyes and dyes such as indigo and porphyrin can be added, which are used in amounts of 0.05 to 3% of the total solids.

A solution obtained by mixing the dyes and the plastic transparent resin with a solvent may be applied onto a metal mesh attached to the transparent substrate to form a near infrared cut-off and selective wavelength absorbing film. At this time, as the plastic resin material, a transparent plastic resin material such as polymethyl methacrylate, polyvinyl alcohol, polycarbonate, ethylene vinyl acetate, polyvinyl butyl al, polyethylene terephthalate, and the like, and the amount of 5 to 40% with respect to the solvent Used as Solvents that may be used include toluene, xylene, acetone, methyl ethyl ketone, propyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and the like.

In addition, the composition for the near-infrared cut off and selective wavelength absorbing film may be further added an effective amount of a stabilizer to improve light resistance. Stabilizers that can be used include radical reaction inhibitors that prevent the fading of pigments that can be used conventionally.

As the coating method of the film composition, a conventional coating method may be applied. For example, roll coating, die coating, or spin coating may be used. As the coating thickness, the thickness after drying is preferably about 1 to 20 µm, and more preferably about 2 to 10 µm in order to realize near-infrared ray blocking performance.

2 is a diagram schematically showing an embodiment of an electromagnetic wave blocking filter for a plasma display panel of the present invention. In FIG. 2, the anti-reflection film 12 is attached to one surface of the transparent substrate 10, the metal mesh 14 is plated on the other surface of the transparent substrate 10, and the near-infrared cutoff is disposed on the metal mesh 14. And an optional wavelength absorbing film is coated.

In the electromagnetic wave blocking filter of the present invention, since the web width R of the mesh line intersection portion of the metal mesh employed is small, the metal mesh has an improved aperture ratio. Accordingly, when the electromagnetic wave blocking filter of the present invention is applied as a front filter of a display device such as a plasma display panel, the display device can show a final image with improved brightness.

The electromagnetic wave blocking filter manufacturing method of the present invention uses a plating method to form a metal mesh on a transparent substrate, thereby providing a large-area electromagnetic wave blocking filter employing a metal mesh having a small web width R of the mesh line crossing portion and having an improved aperture ratio. Provided easily.

Claims (9)

Transparent substrates; And A metal mesh attached to one surface of the transparent substrate and having electrical conductivity, The web width R of the mesh line intersection of the metal mesh is greater than 0 and no more than 5 times the mesh line width, Electromagnetic wave filter. The electromagnetic wave blocking filter according to claim 1, wherein the transparent substrate is made of a single layer or a multilayer material having a visible light transmittance of 80% or more. The electromagnetic wave blocking filter of claim 1, wherein the transparent substrate has a thickness of 25 to 150 µm. The electromagnetic wave blocking filter according to claim 1, wherein the metal mesh is made of a material containing copper, stainless steel, aluminum, nickel, titanium, tungsten, tin, iron, silver, chromium, or a mixture thereof. The electromagnetic wave blocking filter according to claim 1, wherein the metal mesh is composed of a mesh line having a line width of 5 to 20 µm. The electromagnetic wave blocking filter according to claim 1, wherein the metal mesh is composed of a mesh line having a thickness of 5 to 20 µm. The electromagnetic wave filter according to claim 1, wherein the metal mesh is a rectangular pattern metal mesh having mesh lines arranged at intervals of 150 to 400 µm. Applying a photosensitive material to one surface of the transparent substrate, and then exposing and developing the mesh pattern to expose a surface to which the mesh line will be attached; Removing the photosensitive material after plating the mesh wire material on the surface to which the mesh wire is to be attached; Method of manufacturing electromagnetic wave filter. Transparent substrates; An anti-reflection film attached to one surface of the transparent substrate; A metal mesh attached to the other side of the transparent substrate and having electrical conductivity; A near infrared and selective wavelength absorbing film attached over said metal mesh, The fin width R of the mesh line intersection part of the said metal mesh is more than 0 and 5 times or less of the mesh line width, The electromagnetic wave cut filter for plasma display panels.

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