| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that a signal quality is lowered, since overlapping areas of a signal wiring and a mesh part are changed in each place of the signal wiring and a fluctuation of a wiring impedance of the signal wiring becomes large in a circuit board with a GND layer opening a mesh hole. SOLUTION: A unit form of a mesh hole 103 arranged directly under a signal wiring 101a is made an isosceles triangle. While making each base of the isosceles triangle in agreement with right-left both end margins 101a-1, 101a-2 of the signal wiring 101a, apexes of each isosceles triangle arranged at both end margins 101a-1, 101a-2 are arranged by shifting a half period in the wiring direction F so that the apexes may not be mutually overlapped. Therefore, in any place of the signal wiring 101a, a proportion of a conductor part of a GND layer 102 and an opening part of the mesh hole 103 in the direction which perpendicularly intersects the wiring direction F is fixed. COPYRIGHT: (C)2008,JPO&INPIT
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