A printed circuit board that is fabricated using the design method and design method of a signal line in the printed circuit board

摘要

PROBLEM TO BE SOLVED: To set variations in characteristic impedance of a signal line, for example, within a range of 50 Ω±10% while making variations in width of the signal line manageable within a range of ±15%, in a signal line design method in a printed board having the signal line in which a high-frequency signal is transmitted.;SOLUTION: The printed circuit board has a micro strip line structure A9 composed of a core substrate 1 having a permittivity εr1 and a thickness t1, a power supply ground circuit 4 formed on one face side of the core substrate, an insulating layer 6 formed on the other face side of the core substrate while having a permittivity εr2 and a thickness t2, and the signal line formed on the insulating layer. When designing the signal line in this structure, a permittivity εr is set to a prescribed value by setting the compound permittivity εr between the core substrate and the insulating layer to εr={εr1×t1/(t1+t2)}+{εr2×t2/(t1+t2)}, and setting t1 and t2 to a prescribed ratio so that the signal line has a prescribed width w9.;COPYRIGHT: (C)2007,JPO&INPIT