| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a circuit board capable of sufficiently controlling characteristic impedance of a line without using a mesh-like conductor while securing line width of a signal transmission path. <P>SOLUTION: By interposing an insulator layer 2, signal transmission paths 3a, 3b are formed on one surface thereof, and a ground layer 4 is formed on the other surface thereof. A shield layer 9 is laminated on the ground layer 4 via an insulator layer 8, and openings 4B on which a metal foil is not placed are formed in the ground layer 4 at positions along the signal transmission paths 3a, 3b. With this structure, the characteristic impedance of the signal transmission paths depends on a coupling capacitance formed between the signal transmission paths and the shield layer. Thus, a problem of characteristic impedance control of the signal transmission paths occurring with reduction in thickness of this circuit board can be easily solved. <P>COPYRIGHT: (C)2011,JPO&INPIT |
