| 摘要 |
PURPOSE:To facilitate the measurement of the characteristic impedance by a method wherein a dummy circuit pattern having shape and dimension in the same or approximate shape and dimension of an actual circuit pattern is provided in the corner parts of a wiring board having the actual printed circuit. CONSTITUTION:Dummy circuit patterns 10a-10d are provided on the four corner parts 11a-11d of a substrate 11 so as to provide the actual printed wiring 12 in the region of the board 11 wherein these dummy circuit patterns 10a-10d are not formed. At this time, positive and negative logic side transfer wiring of the dummy circuit patterns 10a-10d and the sectional shape and dimension of the dummy insulator layer are almost equalized with the positive and negative logic side pattern and the sectional shape and dimensions of the actual circuit printed wiring 12 formed inside the same board. Through these procedures, the characteristic impedance can be measured by measuring the sectional dimensions of the dummy pattern e.g. by an optical microscope. Accordingly, the measured dimensions of the characteristic impedance can be simplified for accelerating the feed back to the manufacturing line. |
