JP2006210762A - Magnetic wave shield filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic wave shield filter which dispenses with a blackened layer, and is simplified in terms of structure and production process to reduce cost. <P>SOLUTION: A mesh layer 2 including a mesh conductive layer 21 is formed on an electrically insulating transparent base material 1 to form a magnetic wave shield filter 10. In forming the mesh conductive layer 21, at least a conductive thin film layer 211 as a plating substrate and an electrolytic plating layer 212 made of a gray or black conductive layer are formed on the transparent base material 1 in increasing order without interposing an adhesive layer. The electrolytic plating layer 212 also serves as a blackened layer, and can be made easily out of nickel, or chromium, or an alloy of nickel and chromium. If the conductive thin film layer 211 opposite to the electrolytic plating layer 212 is also formed as a gray or black layer made of a metal or alloy, the conductive thin film layer 211 also serves as a blackened layer. Such a conductive thin film layer 211 can be made easily out of nickel, or chromium, or an alloy of nickel and chromium. In a mesh formation process, for example, the conductive thin film layer 211 and electrolytic plating layer 212 are etched in a meshy manner after their formation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electromagnetic wave shielding filter having optical transparency.

In order to shield electromagnetic waves generated from various displays such as a PDP (plasma display panel) and a CRT (CRT) display, an electromagnetic wave shielding filter disposed on the front surface of the display is known. The electromagnetic wave shielding filter used for such applications requires light transmittance as well as electromagnetic wave shielding performance. Therefore, a transparent base material such as a resin film or glass is used as the base material, and various mesh conductor layers are formed on the transparent base material by metal foil etching or metal plating. For example, the following (A) to An electromagnetic wave shielding filter having a configuration as shown in (E) is known.
Note that the mesh-like conductor layer is a mesh-like layer having optical transparency and conductive and electromagnetic wave shielding performance. In addition to this mesh-like conductor layer, a mesh-like incidental layer including a layer used for forming the mesh-like conductor layer in a mesh shape and a layer added for imparting durability and other physical properties Are added to form a mesh layer (details will be described later).

(A) A mesh-like conductive ink layer is formed by printing on a transparent substrate with a conductive ink, and a metal plating layer such as copper is formed on the conductive ink layer (Patent Document 1, Patent Document 2). In this configuration, the mesh-like conductor layer is mainly a metal plating layer, but also includes a conductive ink layer.
(B) A metal foil such as a copper foil bonded to a transparent substrate with an adhesive is etched to form a mesh-like conductor layer (Patent Documents 3 and 4).
(C) A photosensitive coating solution containing an electroless plating catalyst is applied onto a transparent substrate, and then exposed and developed by a photolithographic method to form a catalyst pattern in a mesh shape, and the electroless pattern is electrolessly formed on the catalyst pattern. A copper plating layer is formed in a mesh shape by plating (Non-Patent Document 1, Non-Patent Document 2). In this configuration, the mesh-like conductor layer is a copper plating layer.
(D) On a transparent substrate, a gray conductive thin film layer made of Ni or Cr metal and a copper plating layer formed by electrolytic plating on the conductive thin film layer (Patent Document 5) . In this configuration, the mesh-like conductor layer is mainly a copper plating layer, but also includes a conductive thin film layer.
(E) A conductive thin film layer made of Cu or Cu alloy and a copper plating layer formed by electrolytic plating on the conductive thin film layer in a mesh shape on a transparent substrate (Patent Documents 6 and 7). In this configuration, the mesh-like conductor layer is mainly a copper plating layer, but also includes a conductive thin film layer.

  In addition, as described above, when the mesh-like conductor layer is formed of a copper foil, a copper plating layer, or the like, the metallic luster that reflects unnecessary light such as external light reduces the contrast of the fluoroscopic image. It is also known that the surface of the mesh-like conductor layer is covered with a blackening layer (Patent Documents 1 to 7). In addition, the surface of the mesh layer facing the transparent substrate side is also used as a blackened layer by blackening the conductive ink layer (Patent Document 1, Patent Document 2), or an adhesive surface of the copper foil with the transparent substrate It is also known that a blackening layer is formed by blackening treatment, or that a conductive thin film layer itself as a plating base of electrolytic plating is a gray layer (Patent Document 5).

JP 2000-13088 A JP 2000-59079 A JP-A-11-145678 Japanese Patent Laid-Open No. 10-41682 Japanese Patent Laid-Open No. 10-335883 JP-A-11-87987 JP-A-11-243296 Sumitomo Osaka Cement Co., Ltd., New Materials Research Laboratory, New Materials Research Group, “Photoresolvable Chemical Plating Catalyst”, [online], date not listed, Sumitomo Osaka Cement Co., Ltd., [November 22, 2004 search ] Internet <URL: http: // www. socnb. com / report / ptech / 2000p52. pdf> New Material Research Department, Sumitomo Osaka Cement Co., Ltd., “Metal Fine Pattern Forming Material”, [online], date not listed, Sumitomo Osaka Cement Co., Ltd., [November 22, 2004 search], Internet <URL: http: // www. socnb. com / report / ptech / 1999p61. pdf>

However, the electromagnetic wave shielding filters having the above-described configurations (A) to (E) have an additional blackening layer on the surface of the mesh-like conductor layer made of a copper plating layer or the like in order to improve the contrast of the fluoroscopic image. There was a problem that it was necessary.

  That is, an object of the present invention is to provide an electromagnetic wave shielding filter that can eliminate the formation of an additional blackening layer on the mesh-like conductor layer and, as a result, can reduce costs by simplifying the structure and production process. That is.

  In order to solve the above problems, the electromagnetic wave shielding filter of the present invention is an electromagnetic wave shielding filter in which a mesh layer including a mesh-like conductor layer is formed on an electrically insulating transparent substrate. In order from the transparent substrate side, a conductive thin film layer as a plating base and an electrolytic plating layer made of a gray or black conductive layer were used.

  By adopting such a configuration, since the electroplating layer itself constituting the mesh-like conductor layer is gray or black, it can also be used as a blackening layer, and with respect to the mesh-like conductor layer (the front side and the side surface thereof) The formation of an additional blackening layer can be omitted. As a result, the cost can be reduced by simplifying the structure and the production process.

In the electromagnetic wave shielding filter of the present invention, the electroplating layer composed of a gray or black conductive layer is nickel, chromium, or one or more alloys thereof (that is, nickel alloy, chromium alloy). , Nickel-chromium alloy).
By adopting such a configuration, the electroplating layer can be easily made gray or black, and conductivity sufficient to exhibit the electromagnetic wave shielding function can be obtained.

In the electromagnetic wave shielding filter of the present invention, in any one of the above-described configurations, the conductive thin film layer is a gray or black layer made of a metal or an alloy.
By adopting such a configuration, since the conductive thin film layer on the transparent substrate side constituting the mesh-like conductor layer itself is also gray or black, it can be used as a blackening layer, and the transparent base of the mesh-like conductor layer can be used. The formation of an additional blackened layer on the material side (back side) can be omitted. As a result, the cost can be reduced by simplifying the structure and the production process. Furthermore, any surface of the electromagnetic wave shielding filter can be brought to the surface of the display, and the degree of design freedom when incorporating the electromagnetic wave shielding filter into the display is expanded.

In the electromagnetic wave shielding filter of the present invention, the gray or black conductive thin film layer is nickel, chromium, or one or more alloys thereof (that is, nickel alloy, chromium alloy, nickel- Chrome alloy).
With such a configuration, the conductive thin film can be easily made gray or black.

Moreover, as an electromagnetic wave shielding filter of this invention, the preferable form of one of the said structures is a structure by which any surface of the said electroplating layer is coat | covered with the antirust layer.
By setting it as such a structure, with respect to a mesh-shaped conductor layer, the electrical conductivity fall by rust, characteristic degradation, such as discoloration, can be prevented.

Moreover, as an electromagnetic wave shielding filter of this invention, the preferable form of one of the said structures is a structure where the surface in which the conductive thin film layer of the said transparent base material is formed is a rough surface.
By setting it as such a structure, the adhesiveness with respect to the transparent base material of an electroconductive thin film layer can be improved according to an anchor effect.

(1) According to the electromagnetic wave shielding filter of the present invention, the formation of an additional blackening layer on the mesh-like conductor layer can be omitted. As a result, the cost can be reduced by simplifying the structure and the production process. In addition, the electroplating layer that leads to omission of the blackening layer in the mesh-like conductor layer can be easily realized by using nickel, chromium, or one or more alloys thereof.
(2) At this time, if the conductive thin film layer is a gray or black layer made of metal or alloy, the formation of an additional blackened layer is omitted even on the back surface of the mesh-like conductor layer. it can.
(3) The conductive thin film layer as described in (2) above can be easily realized by using nickel, chromium, or one or more alloys thereof.
(4) Moreover, if any surface of the electroplating layer is covered with a rust-preventing layer, the conductive thin film layer can be prevented if the transparent base material surface is roughened by preventing the deterioration of conductivity and discoloration due to rust. Can improve the adhesion.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 is a cross-sectional view conceptually illustrating an electromagnetic wave shielding filter according to the present invention in one form. FIG. 2 is a plan view illustrating a form in which the mesh layer has a frame-like non-mesh portion around it. FIG. 3 is a cross-sectional view illustrating another example of the electromagnetic wave shielding filter according to the present invention. Moreover, FIG. 4 is explanatory drawing which illustrates an example of the method of manufacturing the electromagnetic wave shield filter by this invention. FIG. 5 is a cross-sectional view illustrating an embodiment in which the electromagnetic wave shielding filter according to the present invention is laminated with an adherend with an adhesive layer.

〔Overview〕
In the electromagnetic wave shielding filter according to the present invention, the mesh-like conductor layer is not formed from a copper foil or the like laminated on a transparent substrate through an adhesive layer, but on the transparent substrate without using an adhesive layer. It is formed of a directly formed layer. That is, like the electromagnetic wave shielding filter 10 whose one form is illustrated in FIG. 1, the mesh-like conductor layer 21 formed on the electrically insulating transparent base material 1 includes at least the conductive thin film layer 211 on the transparent base material side. An electroplating layer 212, the conductive thin film layer 211 is directly in contact with the transparent substrate 1, and is formed by a thin film forming means such as a sputtering method as a plating base, and the electroplating layer 212 is directly on the conductive thin film layer 211, A gray or black conductive layer is formed in contact with the conductive thin film layer 211. Note that the electroplating layer 212 made of a gray or black conductive layer can be easily formed by being formed of nickel, chromium, or one or more of these alloys. The mesh-shaped conductor layer 21 has a mesh shape as shown in FIG. 2 and has conductivity necessary for electromagnetic wave shielding.
The electrolytic plating layer 212 is thicker than the conductive thin film layer 211. As a result, the electroplating layer 212 is a layer mainly responsible for electromagnetic wave shielding performance among the layers constituting the mesh-like conductor layer 21 in terms of area resistance.

In the present invention, since the electroplating layer 212 itself, which is the surface layer of the mesh-like conductor layer 21, is gray or black, the electroplating layer can be used also as a blackening layer, so at least the front surface of the electroplating layer Further, the formation of an additional blackened layer on the side surface can be omitted.
In addition, the conductive thin film layer 211 is also preferably made of a gray or black layer made of a metal or an alloy because the formation of the blackened layer can be omitted even on the back side of the mesh-like conductor layer. In this case, the conductive thin film layer is a layer made of nickel, chromium, or one or more alloys thereof, which is preferable in that a desired layer can be easily formed.

Further, if necessary, when for rust concern, either side of the electrolytic plating layer, namely the surface, back surface, covering any one or more surfaces of the side surface of the line portion A _L in anticorrosive layer In the case where it is necessary to improve the adhesion, the surface of the transparent base material on which the conductive thin film layer is formed is roughened, or various layers and treatments in a conventionally known electromagnetic wave shielding filter are out of the scope of the present invention. It may be added as long as it is not.

Here, the usage in this specification of terms representing front and back such as “front surface”, “front side”, “back side”, “back side”, etc. will be described. The surface (also the upper surface of the drawing) that faces the transparent substrate on which the mesh-like conductor layer is formed (referred to as the “front side”) is the “front surface”, and the side that faces the same direction (upward of the drawing) The “back side” and “back side” refer to opposite surfaces (which are also surfaces below the drawing) or sides (sides facing the drawing below), respectively.
In addition, when applied to a display application or the like, the viewer side surface may always be the back surface instead of the front surface defined in the present invention.

  Hereinafter, the electromagnetic wave shielding filter according to the present invention will be described in order from a transparent substrate.

(Transparent substrate)
The electrically insulating transparent substrate 1 is a layer for reinforcing a mesh layer generally having a low mechanical strength. Therefore, as long as it has light transmittance as well as mechanical strength, it may be selected and used depending on the application, taking into account heat resistance, insulation, etc. as appropriate. Specific examples of the transparent substrate include a resin plate, a resin sheet (or a film, the same applies hereinafter), a glass plate, and the like. In the present invention, the term “electrical insulation” means electrical insulation to the extent that electrolytic plating cannot be applied to the surface. This is a prerequisite for the present invention. In terms of surface resistance, it is about 10 square Ω / □ or more. Since a normal transparent resin or a substrate made of glass has a surface resistance of 10 12 Ω / □ or more, it corresponds to an electrically insulating transparent substrate in the present invention.

Examples of transparent resins used as resin plates and resin sheets include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer. Polyester resins such as nylon 6, polyamide resins such as nylon 6, polyolefin resins such as polypropylene and polymethylpentene, acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene and styrene-acrylonitrile copolymer, triacetyl Examples thereof include cellulose resins such as cellulose, imide resins, and polycarbonate resins.
In addition, these resins are used as a single or a plurality of types of mixed resins (including polymer alloys) as a resin material, and as a layer, they are used as a single layer or a laminate of two or more layers. In the case of a resin sheet, a uniaxially stretched or biaxially stretched sheet is more preferable in terms of mechanical strength.
Moreover, you may add additives, such as a ultraviolet absorber, a near-infrared absorber, a filler, a plasticizer, an antistatic agent, suitably in these resin as needed.

  Further, as glass of the glass plate, there are quartz glass, borosilicate glass, soda lime glass, etc. More preferably, the thermal expansion coefficient is small, the dimensional stability and the workability in high-temperature heat treatment are excellent, and the alkali component in the glass Non-alkali glass that does not contain any of them can be used, and it can also be used as an electrode substrate as a front substrate of a display.

  The thickness of the transparent substrate is not particularly limited as long as it depends on the application. When the transparent substrate is made of a transparent resin, it is usually about 12 to 1000 μm, preferably 50 to 700 μm, more preferably 100. ˜500 μm is desirable. On the other hand, when a transparent base material is a glass plate, about 1-5 mm is usually suitable. In any material, if the thickness is less than the above, the mechanical strength is insufficient, causing warping, sagging, breakage, etc. If the thickness exceeds the above, it becomes excessive performance and high cost, and thinning is difficult. .

In addition, as the transparent substrate, a sheet (or film), a plate, or the like made of these inorganic materials, organic materials, or the like can be applied. It may be combined with the front substrate which is one component, but in the form of using the electromagnetic wave shielding filter as the front filter placed in front of the front substrate, the sheet is superior to the plate in terms of thinness and lightness. Needless to say, the resin sheet is superior to the glass plate in that it is not cracked.
Moreover, it is preferable to handle a transparent base material with the form of a continuous strip | belt-shaped sheet | seat (namely, web) at the point which can manufacture an electromagnetic wave shield filter continuously and can improve productivity.

  In this respect, a resin sheet is a preferable material for the transparent substrate, but among the resin sheets, in particular, polyester resin sheets such as polyethylene terephthalate and polyethylene naphthalate, and cellulose resin sheets are transparent, In view of heat resistance, cost, etc., a polyethylene terephthalate sheet is more preferable. In addition, although the transparency of a transparent base material is so good that it is high, Preferably the light transmittance which becomes 80% or more by visible light transmittance | permeability is good.

  In addition, the transparent substrate such as a resin sheet has a corona discharge treatment, a plasma treatment, an ozone treatment, a flame treatment, a primer treatment, a preheat treatment, a dust removal treatment, a vapor deposition treatment, an alkali treatment, (for vapor deposition, etc.) You may perform well-known easy adhesion processes, such as anchor layer formation.

Moreover, the surface which forms the conductive thin film layer of a transparent base material is good also as a rough surface, when the adhesive improvement of a conductive thin film layer and a transparent base material is required. By setting it as a rough surface, the adhesion improvement with respect to the transparent base material of an electroconductive thin film layer can be aimed at by the anchor effect. Further, the back surface opposite to the above surface may also be a rough surface if necessary for improving adhesion when laminated with an adherend with an adhesive.
In addition, the grade of a rough surface is 10-point average roughness Rz [JIS-B0601 conformity (1994 version)], about 0.1-10 micrometers is good, More preferably, it is 1.5 micrometers or less, More preferably, 0.5- 1.5 μm. If the roughness is less than this, the effect of roughening cannot be sufficiently obtained. If the roughness is larger than this, bubbles are generated when the electromagnetic wave shielding filter is laminated on the adherend on the mesh layer side via the adhesive. It becomes easy to embrace.

  The transparent substrate may be colored with a pigment or the like. By coloring, near infrared absorption, neon light absorption, color adjustment, prevention of external light reflection, and the like can be achieved. For example, various conventionally known dyes such as a near-infrared absorber, a neon light absorber, a color adjusting dye, and an external light antireflection dye may be added to the resin transparent substrate.

[Mesh layer]
The mesh layer 2 has a mesh shape in plan view, and is a layer having light transmission properties by the mesh shape and also having an electromagnetic wave shielding function. The mesh layer 2 has at least a mesh-like conductor layer 21 that serves as an electromagnetic wave shielding function. In addition to this, the mesh shape, which is a shape characteristic of the mesh layer, is maintained, and the anticorrosive layer 22 described later is appropriately used. Other layers may be included as constituent layers (see FIG. 3). Furthermore, in this invention, the mesh-shaped conductor layer 21 has the electroconductive thin film layer 211 and the electroplating layer 212 by the side of a transparent base material. The conductive thin film layer 211 is required to have conductivity necessary as a base for electrolytic plating, and the electroplating layer 212 is required to have conductivity necessary for electromagnetic wave shielding performance. Capture.

[Mesh layer: Mesh-like conductor layer]
As described above, the mesh-like conductor layer 21 is a layer responsible for the electromagnetic wave shielding function, and even though it is opaque, the mesh-like conductor layer 21 has an opening in the shape of a mesh. It is an essential layer of the mesh layer 2 having both permeability and mesh shape. The mesh-like conductor layer 21 has a conductive thin film layer 211 as a plating base and an electrolytic plating layer 212 made of a gray or black conductive layer in order from the transparent substrate side. The electrolytic plating layer 212 made of a gray or black conductive layer is preferably made of nickel, chromium, or one or more alloys thereof (that is, nickel alloy, chromium alloy, nickel-chromium alloy).

[Mesh layer: Mesh-like conductor layer: Conductive thin film layer]
The conductive thin film layer 211 is a conductive layer that becomes a plating base necessary for forming an electrolytic plating layer on a transparent substrate. This is because a transparent substrate such as a resin film or glass is an electrical insulator having no electrical conductivity necessary for electrolytic plating. Accordingly, the conductive thin film layer 211 only needs to have conductivity that can be electroplated by electroplating on the conductive thin film layer 211, and is not necessarily conductive enough to perform the electromagnetic shielding function.

  Therefore, the conductive thin film layer can be formed of a known conductive material. Examples of the conductive material include metals such as gold, silver, copper, iron, nickel, and chromium, alloys of these metals, tin oxide, ITO (indium-containing tin oxide), and ATO (containing antimony). A transparent metal oxide such as tin oxide may be used. Among these materials, the conductive thin film layer is preferably a gray or black layer made of a metal or an alloy because the formation of the blackened layer can be omitted on the conductive thin film layer side. For such a gray or black conductive thin film layer, a material made of nickel, chromium, or one or more alloys thereof (that is, nickel alloy, chromium alloy, nickel-chromium alloy) can be used easily. It is preferable in that the conductive thin film can be gray or black. In addition, as a nickel-chromium alloy, the mass ratio of nickel and chromium is about nickel / chrome = 80/20 to 95/5, but the degree of blackening, conductivity (electromagnetic wave shielding property), and adhesion to a transparent substrate. , And in terms of adhesion to various electroplating layers, it is preferable to achieve a balance.

The conductive thin film layer can be obtained by forming a conductive material as described above by a known thin film forming means such as a vacuum deposition method, a sputtering method, an ion plating method, or an electroless plating method. These may be appropriately selected in consideration of physical properties, productivity, cost, and the like.
In addition, the thickness of the conductive thin film layer may be an extremely thin thickness of about 0.001 to 1 μm, as long as necessary conductivity is obtained at the time of electrolytic plating. The conductive thin film layer is formed as a single layer or a multilayer thin film made of the above materials. As an example of a multilayer, multilayer structure, such as nickel-chromium alloy / copper, silver / copper, nickel-chromium alloy / copper / silver, is mentioned, for example.

In the present invention, there is no adhesive layer between the transparent substrate and the mesh-like conductor layer as in the case where the mesh layer is formed of a copper foil laminate between the transparent substrate and the conductive thin film layer. There is no such adhesive layer between the material and the conductive thin film layer. Therefore, as in the case of the copper foil laminate, the rough surface shape of the back surface of the copper foil, which is a rough surface for improving adhesion, is transferred to the surface of the adhesive layer exposed at the opening of the mesh. This provides an advantage that the rough surface of the light does not diffusely reflect the light beam transmitted through the opening to reduce the transmission sharpness of the transmitted image.
Although the adhesive layer is a resin layer, in the present invention, in order to enhance the adhesion between the conductive thin film layer and the transparent substrate, the transparent substrate is at least on the conductive thin film layer forming side. Those having a resin layer such as a known deposition anchor layer (usually made of a curable resin) on the entire surface as a layer constituting the transparent substrate are also included in the present invention. Moreover, the thing which roughened the surface of this resin layer or transparent base material itself is also included. Here, even the same rough surface is a rough surface that is purposely provided when necessary, and the rough surface in the case of the former copper foil laminate is an inevitable and unnecessary rough surface.

[Mesh layer: Mesh-like conductor layer: Electrolytic plating layer]
The electroplating layer 212 is a layer mainly responsible for the electromagnetic wave shielding function in the mesh-like conductor layer 21 and also serves as a conventional blackening layer. For this reason, in the present invention, the electrolytic plating layer is formed as a gray or black conductive layer. In addition, the electrolytic plating layer usually requires a performance of an attenuation factor of 30 dB or less in a frequency band of 30 MHz to 1 GHz as a sufficient electromagnetic wave shielding property. For this purpose, the surface resistance is about 1Ω / □ or less, more preferably 0.05Ω / □ or less. Such an electroplating layer made of a gray or black conductive layer is not particularly limited as long as it is gray or black and an electromagnetic wave shield can be obtained. Or one or more of these alloys (namely, nickel alloy, chromium alloy, nickel-chromium alloy). This is because these metals or alloys provide a favorable appearance color as a blackened layer, provide the necessary conductivity for electromagnetic wave shielding performance, and ease of electrolytic plating and adhesion to the conductive thin film layer. It is a preferred layer constituent material in that all three points can be satisfied.
The electrolytic plating layer may be formed by a known electrolytic plating method.

  The thickness of the electrolytic plating layer is desirably thicker from the viewpoint of electromagnetic wave shielding performance, but is preferably about 0.1 to 10 μm, preferably 0.5 to 5 μm, in consideration of productivity. If the thickness is less than this, generally, there is a risk that electromagnetic waves generated from the current PDP cannot be sufficiently shielded. On the other hand, if the thickness is more than this, the productivity is remarkably deteriorated and is not practical. A high-definition mesh shape cannot be obtained. As a result, the substantial aperture ratio is lowered, the light transmittance is lowered, the viewing angle is further narrowed, and the visibility of the transmitted image on the display is lowered.

The electrolytic plating layer in the present invention is a layer that can also be used as a conventional so-called blackening layer. The gray or black color of the electrolytic plating layer has a black density in terms of performance as a blackening layer. When the front side on the electrolytic plating layer side is the observer side, a color of 0.6 or more is preferable. The black density measurement method can be measured with a spectrocolorimeter. For example, using a spectrocolorimeter “Gretag SPM100-II” (sold by Kimoto Co., Ltd.) manufactured by GretagMacbeth, the observation viewing angle is set to 10 degrees, the observation light source D50 is set to the density standard ANSIT as the illumination type, and after white calibration Measure the specimen.
On the other hand, when the black density of the electrolytic plating layer is taken as the light reflectance, the light reflectance is preferably 5% or less. The light reflectance is measured using a haze meter (for example, “HM150” trade name, manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS-K7105. Further, instead of measuring the reflectance, the Y value of reflection may be expressed by a color difference meter. In this case, the Y value is preferably 20 or less, more preferably 10 or less.

  Also, the back side of the mesh-like conductor layer, that is, the conductive thin film layer, including the case where it is also used as a blackening layer, reflects stray light reflected from a display such as a PDP disposed on the back side of the electromagnetic wave shielding filter. Since prevention is the main role, a standard different from the case of the front side is necessary, and the reflected color is rather a problem. That is, a silver or iron colorless reflection color is preferable to a reflection color that affects the display color of the display, such as a copper color.

[Mesh layer: Mesh shape]
The shape of the mesh layer 2 as a mesh shape is not particularly limited, but a square is typical as the shape of the opening of the mesh. The plan view shape of the opening is, for example, a triangle such as a regular triangle, a square such as a square, a rectangle, a rhombus, or a trapezoid, a polygon such as a hexagon, a circle, an ellipse, or the like. Mesh has a plurality of openings A _O consisting shape, between the openings of the normal width uniformity linear line portion A _L becomes (see FIG. 1), usually, between the openings and the opening in the entire The same shape and the same size. To illustrate the specific size, the width of the line portion between the openings is 25 μm or less, preferably 20 μm or less in terms of the aperture ratio and the invisibility of the mesh. The size of the opening is [line interval or line pitch]-[line width]. In terms of [line interval or line pitch], it is 150 μm or more, preferably 200 μm or more. Is preferable.
Note that the bias angle (the angle formed between the mesh line portion and the outer periphery of the electromagnetic wave shielding filter) may be appropriately set to an angle at which moire is difficult to occur in consideration of the pixel pitch of the display and the light emission characteristics.

  In the mesh layer 2, the portion of the mesh layer 2 A in which the light transmission property is secured together with the electromagnetic wave shielding property by a large number of mesh-shaped openings as described above is the mesh portion 2 A (see FIG. 2). The mesh portion 2A may be provided in a region (surface) that requires at least light transmission as a surface. A mesh part is essential for the mesh layer, but there may be a non-mesh part 2B together with the part. The non-mesh portion 2B is a portion other than the mesh portion 2A and is a region where light transmittance is not required as a surface. Usually, the non-mesh part 2B is provided in the outer peripheral part of the mesh part 2A. The non-mesh portion 2B is usually used for grounding. An example thereof is a quadrangular electromagnetic shielding filter 10 illustrated in the plan view of FIG. 2, and in this figure, a portion that does not affect the image display around the four sides of the mesh portion 2A is defined as a frame-like non-mesh portion 2B. is there. Such a frame-shaped non-mesh portion 2B can be used for grounding. The non-mesh part used for grounding is usually framed around all four sides. In addition, the frame-like non-mesh portion is an external image that enhances the appearance of the image seen through the mesh portion such as a display image by surrounding the image with a frame shape (for example, a black frame) to enhance the image. It can also be used as a frame. In addition, it is preferable to expose at least a part of the non-mesh portion when grounding.

The non-mesh portion 2B may have an arbitrary shape according to its purpose. Therefore, the non-mesh portion may not be the entire periphery but may be two opposite sides or only one side.
Further, the non-mesh portion 2B is usually a surface portion having no opening at all, but may be a surface portion having some opening. For example, when a non-mesh portion having a shape such as a frame shape, information such as character information of a product number is expressed in the region as a set of a plurality of openings. For example, the portion is like a character printing portion of a screen plate for screen printing. However, in this case, since the portion is also small in area and the purpose is not to ensure light transmission as a surface, even if there is a portion in which a plurality of openings constituting the assembly are provided in a mesh shape , It becomes a non-mesh part.
The specific size of the non-mesh portion 2B depends on how it is used, but when the frame is in the shape of a ground or outer frame, the width of the frame is about 15 to 100 mm, especially 30 to 40 mm. Is.

[Mesh layer: forming method]
The formation method of the conductive thin film layer 211 and the electrolytic plating layer 212 constituting the mesh-like conductor layer 21 of the mesh layer 2 may be formed by appropriately adopting conventionally known plating and patterning techniques.

For example, in the method of manufacturing an electromagnetic wave shielding filter illustrated in FIG. 4, after forming a conductive thin film layer on the entire surface of a transparent substrate, patterning in a mesh shape, and electroconductive plating of the conductive thin film layer 211 in the mesh shape is performed. In this manufacturing method, an electrolytic plating layer 212 is selectively formed only on the conductive thin film layer by electrolytic plating as a base.
More specifically, first, as shown in FIG. 4A, the pre-meshing conductive thin film layer 211A is formed on the entire surface of the transparent substrate 1 (without an adhesive layer) by thin film forming means such as vapor deposition and sputtering. Form. Next, as shown in FIG. 4B, a pre-meshing resist layer 3A is formed on the entire surface of the pre-meshing conductive thin film layer 211A by applying a photosensitive resist or the like. Next, as shown in FIG. 4C, the mesh pattern 4 is exposed on the pre-meshing resist layer 3A. Next, as shown in FIG. 4D, the exposed pre-meshing resist layer 3A is developed, washed, etc. to form a mesh-like resist layer 3. Next, as shown in FIG. 4E, etching is performed to remove the pre-meshing conductive thin film layer 211A corresponding to the opening not covered with the mesh-like resist layer 3, thereby forming the conductive thin film layer 211. Further, the mesh-like resist layer 3 remaining on the conductive thin film layer 211 is removed. Next, electrolytic plating is performed using the conductive thin film layer 211 as a plating base, and an electrolytic plating layer 212 is selectively formed only on the conductive thin film layer 211. For convenience, a mesh shape comprising the conductive thin film layer 211 and the electrolytic plating layer 212 is formed. By forming the conductor layer 21 as the mesh layer 2, the electromagnetic wave shield filter 10 is obtained.

  In addition to the above method, the mesh-like conductor layer 21 may be formed, for example, at the time of meshing by etching after the entire electrolytic plating layer is formed. For example, the pre-meshing conductive thin film layer 211A is formed on the entire surface of the transparent substrate 1, then the pre-meshing electroplating layer is formed on the entire surface, then the mesh-like resist layer 3 is formed thereon, and then the mesh For example, the pre-mesh electroplating layer and the pre-mesh electroconductive thin film layer 211A are made into a mesh by etching, and the mesh electroplating layer 212 and the mesh electroconductive thin film layer 211 are formed by these steps.

[Mesh layer: Antirust layer]
The mesh layer 2 may be only the mesh-like conductor layer 21, but when there is a concern that the mesh-like conductor layer rusts during the manufacturing or handling and changes its quality and the electromagnetic shielding performance is deteriorated, the rust prevention layer 22 is used. The surface (exposed surface) of the mesh conductor layer may be covered. Since the back surface of the conductive thin film layer 211 is not exposed by being laminated with the transparent base material, the exposed surface, that is, the surface of the conductive thin film layer 211 (the back surface of the electroplating layer 212), electrolytic plating is applied to the anticorrosive layer. If the surface selected from the surface of the layer 212, the side surface of the electrolytic plating layer 212, and the required one or more of the side surfaces of the electrolytic plating layer 212 and the conductive thin film layer 211 in consideration of the manufacturing cost, etc. good. Therefore, the coating of the anticorrosive layer includes only the front surface, only the back surface, both front and back surfaces, only the side surfaces (both sides or one side), the front surface and both side surfaces (see FIG. 3), and the like.
In FIG. 3, the conductive thin film layer 211 in the mesh-like conductor layer 21 is covered with the electrolytic plating layer 212 on the front side, so that the rust preventive layer 22 is covered with a slight thickness (high Side). Further, FIG. 2 shows a form in which the conductive thin film layer 211 is coated on both the surface and both side surfaces of the electroplating layer 212. However, if it is not necessary to cover the side surface of the conductive thin film layer, it may be omitted. Since covering the surface of the electrolytic plating layer thicker than the conductive thin film layer is effective against discoloration in appearance, it is preferable to cover at least the electrolytic plating layer. However, the side surface of the conductive thin film layer can be coated simultaneously with the side surface of the electrolytic plating layer.

  The anticorrosive layer is not particularly limited as long as it does not rust more easily than the mesh-like conductor layer coated with it, and is not particularly limited, such as inorganic materials such as metals, organic materials such as resins, or combinations thereof. What is necessary is just to employ | adopt suitably. For example, in the case of a metal system, a metal or alloy such as chromium, zinc, nickel, tin, copper, or a metal compound layer of a metal oxide is used. These can be formed by a known plating method or the like. Here, if it shows an example of a rust prevention layer preferable at points, such as a rust prevention effect and adhesiveness, the chromium compound layer obtained by carrying out a chromate process after galvanization will be mentioned.

In the case of chromium, chromate (chromate) treatment or the like may be used. The chromate treatment is carried out by bringing the chromate treatment solution into contact with the treated surface. This contact is not limited to coating methods such as roll coating, curtain coating, squeeze coating, pouring (single-sided contact), and electrostatic fogging. According to the chemical method, the dipping method, etc., double-sided contact is also possible. Moreover, what is necessary is just to dry, without washing with water after a contact. In addition, an aqueous solution containing chromic acid is usually used for the chromate treatment liquid. Specifically, “Alsurf (registered trademark) 1000” (manufactured by Nippon Paint Co., Ltd.), “PM-284” (Nippon Parkerizing Co., Ltd.) A processing solution such as a company) can be used.
In the chromate treatment, galvanization before the treatment is preferable in terms of adhesion and rust prevention effect. In addition, the rust preventive layer may contain a silicon compound such as a silane coupling agent in order to improve acid resistance during etching or acid cleaning.
In addition, the thickness of a rust prevention layer is about 0.001-10 micrometers normally, Preferably it is 0.01-1 micrometer.

[Other layers]
The electromagnetic wave shielding filter of the present invention may have a configuration in which layers other than those described above are appropriately laminated as necessary. For example, an optical filter layer, a surface protective layer, a planarizing resin layer, an adhesive layer, and the like. These may be known ones in conventional electromagnetic wave shielding filters.
For example, the optical filter function of the optical filter layer includes near-infrared absorption, ultraviolet absorption, antireflection (including antiglare), color tone adjustment (neon light absorption, improved color reproducibility), and external light antireflection. The function of the surface protective layer is antifouling, hard coat and the like. In addition, the planarizing resin layer is a layer that fills the surface irregularities of the mesh layer and flattens it, and prevents entrapment of bubbles and the like when laminated with the adherend on the mesh layer side. The pressure-sensitive adhesive layer has adhesiveness among the adhesive layers, and is provided in advance on the electromagnetic wave shield filter side so that adhesion to the adherend is easy. Further, the optical filter may be laminated using such an adhesive layer, or may be laminated with a front substrate of a display.

  Here, FIG. 5 shows a configuration example of a laminate obtained by laminating the adhesive layer 5 and the adherend 6 on the mesh layer 2 side of the electromagnetic wave shielding filter 10 as described above. The adhesive layer 5 is formed so as to fill surface irregularities due to the mesh layer 2, and the electromagnetic wave shielding filter 10 is laminated with the adherend 6. The adhesive layer 5 is made of a non-sticky adhesive or a pressure-sensitive adhesive (pressure-sensitive adhesive layer). The adherend 6 is arbitrary and is, for example, the above-described optical filter layer, surface protective layer (for example, hard coat film), display front plate, or the like. In addition, the lamination is performed on the front side on the mesh layer side in the figure, but may be on the back side or both sides. In the example of the figure, the mesh layer 2 is composed of only the mesh-like conductor layer 21, and the mesh-like conductor layer 21 is an example comprising the conductive thin film layer 211 and the electrolytic plating layer 212.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the text, “%” is all mass%. The present invention is not limited to these examples.

[Example 1] (Deposited Cu / Black Ni plating specifications)
An electromagnetic wave shielding filter 10 shown in the sectional view of FIG. 1 was produced as follows. An uncolored transparent biaxially stretched polyethylene terephthalate (PET) film, which is a continuous belt-like web having a thickness of 100 μm, was prepared as an electrically insulating transparent substrate 1. Then, a conductive thin film layer made of copper having a thickness of 0.1 μm (before meshing) is provided on the entire surface of the transparent substrate 1 by a vacuum deposition method, and a continuous belt-like metal-deposited transparent substrate sheet is formed. Produced.

Next, an etching method using a photolithography method was applied to the conductive thin film layer (before meshing) of the metal-deposited transparent base sheet to form a mesh, and the mesh-shaped conductive thin film layer 211 was formed. . The etching was performed using a production line for a color TV shadow mask, in which a continuous belt-like web is maintained from masking to etching.
From the continuous belt-shaped metal-deposited transparent base sheet, masking to etching were continuously performed. That is, after applying a photosensitive resist for etching on the entire surface of the conductive thin film layer (before meshing) of the metal-deposited transparent base sheet, a desired mesh pattern is closely exposed, developed, hardened, baked, and then secondly chlorided. The conductive thin film layer was etched with an iron solution (before meshing) to form a mesh-shaped opening, and then washed with water, stripped of resist, washed, and dried sequentially. The shape of the mesh formed in the conductive thin film layer 211 is such that the line width of the linear portion whose opening is a square and non-opening is 10 μm, the line interval (pitch) is 300 μm, and the length of the rectangular region of the mesh portion 2A. It is a bias angle of 49 degrees defined as an inferior angle with respect to the side [see FIG. 2].
In addition, the mesh leaves a frame-shaped non-mesh portion 2B having a width of 5 mm with no opening on the outer periphery of the four sides when the continuous belt-like web is cut into a rectangular sheet having a desired size. On the entire periphery adjacent to the non-mesh portion 2B of the portion 2A, a mesh outer peripheral portion having a width of 5 mm and having the area ratio of the opening decreased from the inside toward the outside was provided.

  Further, a blackened nickel plating layer is formed as an electroplating layer 212 having a thickness of 0.5 μm by electrolytic plating (electrolytic blackening nickel plating) on the surface of the conductive thin film layer 211 in a mesh shape, A desired electromagnetic shielding filter 10 was produced in a web form.

[Example 2] (Deposited Ni / Black Ni plating specifications)
In Example 1, an electromagnetic wave shielding filter was produced in the same manner as in Example 1 except that the metal of the deposited conductive thin film layer was changed from copper to nickel.

[Example 3] (Deposited Cr / Black Ni plating specifications)
In Example 1, an electromagnetic wave shielding filter was produced in the same manner as in Example 1 except that the metal of the deposited conductive thin film layer was changed from copper to chromium.

[Example 4] (Vapor deposition Ni-Cr / Black Ni plating specification)
In Example 3, an electromagnetic wave shielding filter was prepared in the same manner as in Example 3 except that the metal of the deposited conductive thin film layer was changed from chromium to a nickel-chromium alloy of 90% nickel and 10% chromium. Produced.

[Example 5] (Vapor deposition Ni-Cu / Black Ni plating specification)
In Example 3, an electromagnetic wave shielding filter was formed in the same manner as in Example 3 except that the metal of the deposited conductive thin film layer was changed from chromium to a nickel-copper alloy of 90% nickel and 10% copper. Produced.

[Example 6] (Deposited Ni-Cr / Deposited Cu / Black Ni plating specifications)
In Example 4, the thickness of the conductive thin film layer using the nickel-chromium alloy was changed to 0.02 μm, and this was replaced with copper on the first conductive thin film layer and further on the first conductive thin film layer. A second conductive thin film layer is formed by vapor deposition with a thickness of 0.08 μm, and after forming a conductive thin film layer composed of two layers of these first and second conductive thin film layers (before meshing), the first conductive thin film layer is formed. And the electromagnetic wave shielding filter was produced like Example 4 except meshing by etching simultaneously with respect to the 2nd conductive thin film layer, and making it the desired mesh-shaped conductive thin film layer.

[Example 7] (Sputtered Ni-Cr / Black Ni plating specifications)
In Example 4, an electromagnetic wave shielding filter was produced in the same manner as in Example 4 except that the formation method of the conductive thin film layer was changed from the vapor deposition method to the sputtering method.

[Example 8] (Ion plating Ni-Cr / Black Ni plating specification)
An electromagnetic wave shielding filter was produced in the same manner as in Example 4 except that the method for forming the conductive thin film layer was changed from the vapor deposition method to the ion plating method in Example 4.

[Example 9] (Vapor deposition Ni-Cr / Blackening chromate plating specification)
An electromagnetic wave shielding filter was produced in the same manner as in Example 4 except that the blackened nickel plating layer formed as the electrolytic plating layer in Example 4 was changed to a blackened chromate plating layer.

[Example 10] (Electroless Ni / Black Ni plating specification)
An electromagnetic wave shielding filter was produced in the same manner as in Example 2 except that the conductive thin film layer formed by nickel deposition in Example 2 was changed to a conductive thin film layer formed by nickel electroless plating. The electroless plating of nickel contains an electroless plating catalyst and contains a photosensitive electroless catalyst ink (manufactured by Sumitomo Osaka Cement Co., Ltd., trade name “photoresolvable Pd plating catalyst” SOC-PA). Is applied to the entire surface of the transparent substrate, and then exposed to ultraviolet light to form an electroless catalyst ink layer on the entire surface. Electroless nickel plating is performed on the electroless catalyst ink layer, and the thickness of the entire surface is reduced to 0. A conductive thin film layer of 1 μm before meshing was formed.

[Example 11] (Matte PET / deposition Ni-Cr / black Ni plating)
In Example 4, an electromagnetic wave shielding filter was formed in the same manner as in Example 4 except that the transparent base PET film was changed to a PET film having a conductive thin film layer forming surface on the matte surface (rough surface). Produced.

[Example 12] (Glass substrate / deposited Ni-Cr / blackened Ni plating specification)
In Example 4, a soda lime glass plate having a thickness of 3 mm was used as the transparent substrate instead of the PET film, and the processing was changed to a single-wafer processing. Was changed to 20 μm) in the same manner as in Example 4 except that the formation was changed as follows.
First, the mesh is formed by attaching a dry resist film to the entire surface of the conductive thin film layer on the transparent substrate (before meshing), and then exposing the desired mesh pattern, developing, hardening, After baking, the conductive thin film layer is etched with a ferric chloride solution to form a mesh-shaped opening, then washed with water, stripped of resist, washed and dried in order to form a desired mesh-shaped conductive thin film layer. Formed.

[Example 13] (Vapor deposition Ni-Cr / Black Ni plating specification: reverse order of mesh formation)
In Example 4, the mesh formation by photolithography and etching is performed in the order of (before meshing) conductive thin film layer formation, mesh formation, and electrolytic plating layer formation (before meshing). Before, the electroplating layer formation and the mesh formation were changed to the order of forming the electroplating layer on the entire surface (before meshing) prior to the mesh formation. A shield filter was produced.

[Example 14] (Vapor deposition Ni-Cr / Black Ni plating / Rust prevention layer specification)
Further, a chromate treatment liquid is applied to the surface of the mesh-like conductor layer 21 composed of the conductive thin film layer 211 and the electrolytic plating layer 212 to perform the chromate treatment on the electromagnetic wave shielding filter obtained in the fourth embodiment. Then, an electromagnetic wave shielding filter with a rust prevention layer as shown in the sectional view of FIG. 3 was produced.

[Comparative Example 1] (Copper foil laminate specification)
A thickness of 10 μm in which a blackening layer and a chromate treatment layer made of copper-cobalt alloy particles having an average particle diameter of 0.3 μm were added in order from the surface side as a copper foil on one side of the transparent substrate used in Example 1. Using a blackened electrolytic copper foil, the back side opposite to the blackened layer side is the back side, and the back side is laminated by a dry lamination method through a 7 μm thick adhesive layer with a two-component curable polyurethane adhesive, A continuous belt-like copper-clad film was prepared. Next, this copper-attached film is formed by forming a mesh on the copper foil (however, the line width is changed to 22 μm) by the etching method using the photolithography method, similar to Example 1, and meshing the conductive layer made of copper. An electromagnetic wave shielding filter was produced in the same manner as in Example 1 except that the shape of the conductive layer was changed.

[Comparative Example 2] (Meshed electroless catalyst ink layer / electroless Cu plating specification)
One side of the transparent substrate used in Example 1 contains an electroless plating catalyst and is a photosensitive electroless catalyst ink (manufactured by Sumitomo Osaka Cement Co., Ltd., trade name “photoresolvable Pd plating catalyst” SOC-PA ), A desired mesh pattern is exposed to ultraviolet light, then developed with water, washed and baked to form a mesh-like electroless catalyst ink layer, and then electroless copper plating is performed. An electromagnetic shielding filter was produced by forming a mesh-like electroless plating layer having a thickness of 10 μm as a mesh-like conductor layer only immediately above the electroless catalyst ink layer. The formed mesh is the same as that of Example 1 except that the line width is changed from 10 μm to 22 μm.

[Comparative Example 3] (Specifications for vapor deposition Cu only)
In Example 1, after etching the conductive thin film layer (before meshing), the formation of the blackened nickel plating layer as the electrolytic plating layer was omitted, and the meshed conductive thin film layer was regarded as a mesh-like conductor layer Produced an electromagnetic wave shielding filter in the same manner as in Example 1.

[Comparative Example 4] (Vapor deposition Cu / Cu plating specification)
In Example 1, an electromagnetic wave shielding filter was produced in the same manner as in Example 1 except that the blackened nickel plating layer as the electrolytic plating layer was changed to an electrolytic copper plating layer.

[Comparative Example 5] (Vapor deposition Cu / Cu plating specification)
In Example 1, the blackened nickel plating layer as the electrolytic plating layer was changed to an electrolytic copper plating layer, and the surface of this electrolytic copper plating layer was oxidized with a sodium chlorite solution to perform blackening treatment. Except for the above, an electromagnetic wave shielding filter was produced in the same manner as in Example 1.

[Comparative Example 6] (Vapor deposition Ni-Cr / Cu plating specification)
In Example 4, an electromagnetic wave shielding filter was produced in the same manner as in Example 4 except that the blackened nickel plating layer as the electrolytic plating layer was changed to an electrolytic copper plating layer.

[Performance evaluation]
First, Tables 1 to 4 show main configurations and performance evaluation results for the electromagnetic wave shielding filters of Examples and Comparative Examples.

  The main evaluation criteria for various performances are as follows.

(1) Mesh surface light reflection:
The light reflection intensity (reflection intensity) is set to the spectrocolorimeter (Konica Minolta Sensing Co., Ltd., CM-3600d) in the reflection mode, the light source is standard light D ₆₅ , the field of view is 2 °, and the detector is SCI ( The Y value (brightness) was measured and evaluated as a mode including regular reflection light. The SCI mode is a mode for measuring the (integrated) intensity of total reflected light in which both diffuse reflected light and specular reflected light are combined.
Further, visual glare and color observation were performed on a white mount from a position 50 cm away from the sample in a room with a brightness of 1000 [lx].
Judgment criteria are as follows.
Good that the reflection intensity is less than 20 and there is no glare even by visual observation (○),
Slightly good (△) when the reflection intensity is 20 or more and less than 50 and there is no glare even by visual observation.
If the reflection intensity is 50 or more, or if there is glare by visual observation, it is defective (x).

In addition, the intensity of light reflection on the mesh surface refers to the electromagnetic wave shield fill that is incident from the mesh layer side and is reflected at the outermost surface (mesh-like conductor layer) of the mesh line part. light,
B: Mirror surface and diffuse reflected light reflected on the front and back surfaces of the transparent substrate exposed at the opening of the mesh,
The “intensity” of the reflected light obtained by integrating and summing A and B, and the color becomes the “color” of the reflected light. However, the main subject to be evaluated is A (reflected light on the surface of the line portion).

(2) Transparent substrate surface light reflection:
Measurement of light reflection intensity (reflection intensity) and color observation are the same as in the case of mesh surface light reflection. However, for the observation of visual glare, the transparent substrate surface side is the display surface side, so glare is not used as a criterion for judgment, and even if the reflection intensity is larger than the mesh surface, it can be used for private use in practice. Slightly good (△) or more, practically no defect (×).
Judgment criteria are as follows.
Excellent (◎) when the reflection intensity is less than 20.
Good with a reflection intensity of 20 to less than 50 (△),
A thing with a reflection intensity of 50 or more is slightly good (Δ).

Note that the intensity of light reflection on the transparent substrate surface refers to the mirror surface and the diffusion of the electromagnetic wave shield fill that is incident from the transparent substrate side and reflected on the backmost surface (conductive thin film layer) of the mesh line portion. reflected light,
D: Mirror surface and diffuse reflected light that are reflected on the front and back surfaces of the transparent base material in both the mesh opening and the line area.
The “intensity” of the reflected light is obtained by integrating and summing C and D, and the color is the “color” of the reflected light. However, the subject to be evaluated is C (reflected light on the back surface of the line portion).

(3) Clearness of transmitted image: A paper on which characters having a size of 3 mm are printed is placed on a table, and an electromagnetic wave shielding filter is arranged to float 7 mm from the paper, and the room has a brightness of 1000 [lx]. It was judged by visually observing the blurring of the characters from a position 50 cm away.
Characters with almost no blur are considered good (○).
Somewhat blurred characters were considered as slightly good (Δ).

In the electromagnetic wave shielding filters of Examples 1 to 14, the electromagnetic wave shielding properties, the light reflection on the mesh surface side, the light reflection on the transparent base material side, the powder blackening on the mesh surface, and the contrast of the transmitted image are electromagnetic waves for PDP. As a shield filter, it was in a range that could be sufficiently used. Also, by adhering them to a glass plate with an adhesive in between [However, in Example 12 using the glass plate, the glass surface side is directed to the outside (the side opposite to the display side) as it is. When processed into a front plate and placed on the front surface of the PDP, electromagnetic waves generated from the PDP were shielded. Moreover, when the visibility was evaluated by displaying an image, the visibility was good in all cases.
Furthermore, in the production, lamination with an adhesive as in the case of a copper foil laminate is not required, so that there is little warpage or mixing of bubbles, and the yield can be produced in a short process with good yield.

In Comparative Example 1, many bubbles having a diameter of about 50 μm were mixed in the adhesive, and the transparency was poor. Further, the electromagnetic wave shielding filter in the portion near the winding core portion of the web was warped, the yield was lowered, and the production efficiency of the cutting and assembling process was significantly lowered.
In Comparative Example 2, although the accuracy of the mesh was good, the uniformity of the thickness of the electroless plating layer in the mesh surface was poor, and the electromagnetic shielding performance was uneven. Further, at the time of production, the plating time was very long as about 20 minutes for laminating 0.5 μm, and the productivity was poor.
In Comparative Example 3, productivity was very good, but sufficient electromagnetic shielding performance was not obtained.
In Comparative Examples 4 and 6, the light reflection on the mesh surface was strong and the reflection color was also copper, so the visibility of the transmitted image was poor and poor.
In Comparative Example 5, light reflection on the mesh surface was small and good, but there was powdering of the blackened layer, and at the time of manufacturing, the electrolytic plating layer and the blackening treatment were separate processes. Was bad.

Sectional drawing illustrated with the one form of the electromagnetic wave shield filter by this invention. The top view which illustrates the form which a mesh layer has a non-mesh part in the shape of a frame around. Sectional drawing which illustrates another example of an electromagnetic wave shield filter by this invention. Explanatory drawing of an example of the method of manufacturing the electromagnetic wave shield filter by this invention. Sectional drawing which illustrates one form laminated | stacked on the to-be-adhered body through the adhesive bond layer as an application example of the electromagnetic wave shield filter by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Mesh layer 21 Mesh-like conductor layer 211 Conductive thin film layer 211A Conductive thin film layer before meshing 212 Electrolytic plating layer 212A Electroplating layer before meshing 22 Antirust layer 2A Mesh part 2B Non-mesh part 3 Mesh resist Layer 3A Resist layer before meshing 4 Mesh pattern 5 Adhesive layer 6 Substrate 10 Electromagnetic wave shielding filter A _L line part (non-opening part)
A _O opening

Claims (6)

In an electromagnetic shielding filter in which a mesh layer including a mesh-like conductor layer is formed on an electrically insulating transparent substrate,
The electromagnetic wave shielding filter in which the mesh-like conductor layer has a conductive thin film layer as a plating base and an electrolytic plating layer made of a gray or black conductive layer in order from the transparent substrate side. The electromagnetic wave shielding filter according to claim 1, wherein the electroplating layer made of a gray or black conductive layer is made of nickel, chromium, or one or more alloys thereof. The electromagnetic wave shielding filter according to claim 1 or 2, wherein the conductive thin film layer is a gray or black layer made of a metal or an alloy. The electromagnetic wave shielding filter according to claim 3, wherein the gray or black conductive thin film layer is made of nickel, chromium, or one or more alloys thereof. The electromagnetic wave shielding filter according to any one of claims 1 to 4, wherein any surface of the electrolytic plating layer is coated with a rust prevention layer. The electromagnetic wave shielding filter according to claim 1, wherein a surface on which the conductive thin film layer of the transparent substrate is formed is a rough surface.

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