Electromagnetic shielding sheet and method of fabricating the same
AssigneeDai Nippon Printing Co., Ltd.
InventorHiroshi Kojima
Life of this patent
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Abstract
Blackened layers 23A and 23B are formed by depositing Cu—Co alloy particles on the surfaces of a metal layer 21. The metal layer 21 coated with the blackened layers 23A and 23B of the Cu—Co alloy particles is subjected to a chromating process to form density-intensifying layers 25A and 25B on the blackened layers 23A and 23B. A base 11 is laminated to the density-intensifying layer 25A or 25B. A conductive structure 109 consisting of the meal layer 21, the blackened layers 23A and 23B, and the density-intensifying layers 25A and 25B is processed by a photolithographic process to complete an electromagnetic shielding sheet 1 having a mesh conductive structure.
Claims9
An electromagnetic shielding sheet comprising:
- a transparent base;
- a mesh metal layer having openings and formed on one of the surfaces of the base;
- a blackened layer formed on one of the surfaces of the metal layer;
- and
- a density-intensifying layer formed on the blackened layer for intensifying black density of the blackened layer,
- wherein the blackened layer is formed of Cu—Co alloy particles adhering to the metal layer, the density-intensifying layer is a chromated layer formed by a chromate treatment and so that the Cu—Co alloy particles are prevented from coming off from the mesh metal layer by the chromated layer.
An electromagnetic shielding sheet fabricating method comprising the steps of:
- attaching Cu—Co alloy particles to one of the surfaces of a metal foil for forming a metal layer;
- subjecting the surface of the metal foil coated with the Cu—Co alloy particles to a chromate treatment to form a laminated structure having a density-intensifying layer for intensifying black density of the blackened layer so that the Cu—Co alloy particles are prevented from coming off from the mesh metal layer by the chromated layer;
- adhesively bonding a transparent base with an adhesive to the surface provided with the density-intensifying layer of the laminated structure;
- forming a resist film having a mesh pattern on the surface of the laminated structure opposite the surface facing the base;
- removing parts of the laminated structure not coated with the resist film by etching;
- and
- removing the resist film.
Dependencies are inferred from the claim text.