Tale of Two Data Sheets and Other Things To Know About PCB Dielectric Constants

When doing stackup and impedance modeling, we need to get the dielectric material properties from the right sources. One important parameter for accurate impedance modeling is the dielectric constant or simply Dk. In this presentation the difference between simple laminate suppliers’ marketing data sheets and engineering data sheets are discussed as well as how anisotropic properties of inhomogeneous dielectrics and foil roughness affects the effective Dk.