| 摘要 |
PURPOSE:To sharply lessen interferences between signal lines and static induction noises from outside by a method wherein a power supply wire and a ground wire are formed into a planar pattern on the surface of a board surrounding both the sides of a signal line. CONSTITUTION:A laminar copper foil pattern is formed on both the surfaces of a board 1 to enable the pattern formed on one of the surfaces to serve as a power supply wire 2 and that formed on the other surface to serve as a ground wire 2. A shielding layer 5 formed of a copper foil layer can be obtained through such a manner that a side groove 6 is formed into a planar pattern between the signal lines 2 or on both their sides along the signal lines of a copper foil layer 4 which forms a circuit pattern including the signal line 2 and then a copper foil layer is formed through electroless copper plating. The shielding layer 5 is connected to the power supply layer or the ground layer 2. By this setup, the circuit pattern 4 including a signal line is constituted similar to a coaxial line, so that it can be lessened in specific impedance and induced voltage. |
