Abstract: A wiring board includes a predetermined wiring section disposed on an insulation board, and an electromagnetic shielding film is placed at a position close to the wiring section. A semiconductor device includes an electromagnetic shielding film disposed on a surface, on which an integrated circuit of a semiconductor chip has been formed, through an insulative film, a lead is provided on the electromagnetic shielding film through an insulative film, the lead is electrically connected to an external terminal of the semiconductor chip, and the resulting structured material is sealed with a sealing material; and a circuit board for electronic parts composed of a circuit board prepared by forming a plurality of leads on an insulating material, and a conductor disposed on the plurality of leads through an insulating material and reducing a self inductance of the plurality of leads by flowing an eddy current through the conductor.

Abstract: There are provided a wiring board, wherein a predetermined wiring section is disposed on an insulation board, and an electromagnetic shielding film is placed at a position close to the wiring section; a semiconductor device, wherein an electromagnetic shielding film is disposed on a surface, on which an integrated circuit of a semiconductor chip has been formed, through an insulative film, a lead is provided on the electromagnetic shielding film through an insulative film, the lead is electrically connected to an external terminal of the semiconductor chip, and the resulting structured material is sealed with a sealing material; and a circuit board for electronic parts composed of a circuit board prepared by forming a plurality of leads on an insulating material, and a conductor disposed on the plurality of leads through an insulating material and reducing a self inductance of the plurality of leads by flowing an eddy current through the conductor.

Abstract: It is an object of the invention to reduce noise superposed on a driving voltage of a semiconductor device and a clock signal on a transmission line. It is a further object of the invention to equalize transmission distances of signal lines in a transmission line provided between the semiconductor devices. It is a still further object of the invention to provide a electronic device, which composed of a microprocessor unit, a semiconductor device--controlling equipment and plural semiconductor devices according to the invention, each being mounted on a printed circuit board having plural bus channel lines with an equal transmission distance. In the semiconductor device of LOC structure, the leads in the outside of the package positioned at the left side and those at the right side are shifted from each other by a half pitch of the leads. A metallic film for shielding a semiconductor chip from electromagnetic wave is set close to leads.