| 摘要 |
PROBLEM TO BE SOLVED: To obtain a semiconductor integrated circuit device in which a high-frequency and high-speed signal can be transmitted at low loss, by a method wherein the gap between a signal lead and a grounding lead is set, the width of the signal lead is set and the cross-sectional area of the grounding lead is set in such a way that the grounding lead has a proscribed low thermal resistance. SOLUTION: Grounding leads 2a and 2b are arranged on both sides of every signal lead 1, the gap between every signal lead 1 and the grounding lead 2a of the grounding lead 2b as well as the width of every signal lead 1 are adjusted so as to be set to arbitrary values, and a signal transmission line forms a coplanar guide structure having a prescribed characteristic impedance. In addition, in a state that the prescribed characteristic impedance is displayed, the width of the grounding lead 2a and that of the grounding lead 2b are made wider than those of other leads, and the cross-sectional area of the grounding lead 2a and that of the grounding lead 2b are set so as to have a prescribed low thermal resistance. As a result, a high-frequency and high-speed signal can be transmitted at low loss. |
