Printed wiring board including first and second insulating layers having dielectric loss tangents that are different by a predetermined relationship

Abstract

The printed wiring board has a conductor of signal lineand two conductive lineson one face of the first insulating layercovered by a second insulating layer, while having a ground layer of the groundpotential on the opposite face thereof, when the dielectric tangent A of the second insulating layer (insulating layer A)is larger than the dielectric tangent B of the first insulating layer (insulating layer B), Relational Expression 1: (relative permittivity B)·(width (W) of signal line(s))/(thickness (T) of first insulating layer (insulating layer B))>(relative permittivity A)·{(thickness (T) of signal line(s))/(distance (S) between signal line(s)and one conductive line)+(thickness (T) of signal line(s))/(distance (S) between signal line(s)and other conductive line)+(thickness (T) of signal lines)/(distance (S) between pair of signal lines (and)·2} is satisfied.