Dai Nippon Printing Co., Ltd.

Eiji Ohishi

Fumihiro Arakawa

Yasuhiko Ishii

Daisuke Hashimoto

Yukihiro Kyoden

Yashuhiko Ishii

An electromagnetic shielding sheet is capable of shielding electromagnetic radiation generated by a display, has a proper transparency and uniformly distributed meshes, prevents the occurrence of white and/or black spot defects and linear defects and glaring, and ensures the satisfactory visibility of images. The electromagnetic shielding sheet has a conductive structure () having lines () having straight parts of widths (W) in the range of C(1&#xb1;30%), where C is a predetermined value. The radius (r) of curvature of a side surface (S) extending between the upper side (U) and the lower side (B) of a bank in a section of the lines () in a plane perpendicular to the transparent sheet meet a condition expressed by: 1.5t&#x2266;r&#x2266;3.0t, where t is the thickness of the conductive structure ().

Electromagnetic shielding sheet

There is provided an electromagnetic wave shielding sheet which can effectively prevent an adhesive layer from being colored at the time of etching. The electromagnetic wave shielding sheet comprises a laminate of at least a transparent substrate film, an adhesive layer, and an electromagnetic wave shielding layer. The electromagnetic wave shielding layer is formed of a mesh metal foil with densely arranged openings and being transparent. The adhesive layer is substantially colorless and transparent.

Electromagnetic wave shielding sheet

An electromagnetic shielding sheet of the present invention includes a transparent base sheet and a metal layer attached to one surface of the transparent base sheet. The metal layer has a mesh part, a peripheral mesh part surrounding the mesh part, and a grounding frame surrounding the peripheral mesh part. A width of lines forming meshes in the peripheral mesh part gradually increases from the mesh part toward the grounding frame. The lines of the electromagnetic shielding sheet are scarcely bent or broken in all processes including fabricating and assembling processes, and the electromagnetic shielding sheet is excellent in handling ease.

An electromagnetic shielding sheetincludes: a transparent base, and at least an adhesive layer, an antirust layerA and a mesh metal layerformed on one of the surfaces of the base. A blackened layerA is sandwiched between the mesh metal layerand the antirust layerA. At least openingsof the mesh metal layerare filled up with a resin such that the mesh metal layerhas a substantially flat surface.

A metallic foil and a transparent substrate film are laminated with an adhesive layer. The roughness of the adhesive-layer-side surface (lower surface) of the metallic foil is such that the maximum height Rmax is more than 0 and less than 4 &mgr;m. As long as the maximum height Rmax falls in the range, the adhesive layer never contains air bubbles in such sizes that reflectance is adversely affected. The roughness of the surface (upper surface) of the metallic foil, opposite the adhesive-layer-side surface, is preferably such that the arithmetic mean roughness Ra is between 0.02 &mgr;m and 1 &mgr;m. As long as the arithmetic mean roughness Ra is in this range, it is possible to efficiently conduct vacuuming to bring, into close contact, a photosensitive resin layer and a photomask in sheet form placed on the photosensitive resin layer, before effecting the pattern-wise exposure of the photosensitive resin layer.

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Shinjuku-ku, Japan

Eiji Ohishi