| 摘要 |
PROBLEM TO BE SOLVED: To provide a wiring board capable of suppressing the reflection loss generated at a part at which a line interval widens from the part at which the line interval is fixed to extremely small in a differential transmission line, thereby making the operational properties of a semiconductor element good. SOLUTION: A differential transmission line 8 is formed on an insulating substrate 2, and respective line widths increase at a part 8d where the line interval of the differential transmission line 8 widens in a wiring board 1. Moreover, the line width is preferably made large in such a manner that a differential impedance at a part 8c where the line interval of the differential transmission line 8 is fixed is roughly same as the differential impedance at the part 8d where the line interval widens. The reflection loss of high-frequency signals due to the mismatching of the differential impedance due to the change in the line interval of the differential transmission line 8 can be suppressed at the part 8d where the line interval widens, and the operational properties of the mounted semiconductor element 5 is made good. COPYRIGHT: (C)2004,JPO&NCIPI
|
