FREE GROUNDING FILM AND MANUFACTURING METHOD THEREFOR AND SHIELDING CIRCUIT BOARD INCLUDING FREE GROUNDING FILM AND GROUNDING METHOD

摘要

A free ground film, a method of making the same, a shielding circuit board including a free ground film, and a grounding method. The free ground film contains at least one conductor layer (3). In a shielding circuit board including a free ground film, an electromagnetic wave shielding film is provided on a printed circuit board and a free ground film is provided on an upper surface of the electromagnetic wave shielding film. The grounding method is realized by using one of three methods. The method for producing a free ground film includes the steps of: a) forming a conductive heat-resistant oxidation-preventive layer 2 on the surface of a metal foil 1; b) forming at least one conductor layer 3 on the other surface of the heat-C) forming an adhesive film layer (4) on the conductor layer (3), or a) forming a resin-based heat-resistant antioxidant layer on the surface of the polyester carrier film (1) B) forming at least one conductor layer 3 on the other side of the heat resistant oxidation preventive layer 2; c) forming an adhesive film layer 4 on the conductor layer 3. The free ground film can change the conventional shielded grounding method, greatly improving the reliability of the product and reducing the cost.