| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve signal transmission characteristics of a circuit board. <P>SOLUTION: A circuit board 10 includes: a wiring layer 2 and a wiring layer 4 which are provided in an insulation layer 6 and a through via hole 7. The wiring layer 2 has a land part 2a to which the through via hole 7 connects and a wiring part 2b connecting with the land part 2a. The land part 2a becomes thinner than the wiring part 2b in a direction that moves away from the wiring layer 4 in an upper layer. Reducing the thickness of the land part 2a inhibits the deterioration of impedance in a connection part, connecting with the through via hole 7, during signal transmission and reduces the transmission loss. <P>COPYRIGHT: (C)2013,JPO&INPIT |
