Accuracy of dielectric constant measurement using the full-sheet-resonance technique IPC-TM-650 2.5.5.6

The accuracy limitations of the full-sheet-resonance technique for extracting the dielectric constant of laminate materials used for printed-circuit-board wiring are presented over the frequency range 0.250 GHz to 2.2 GHz. It is shown that skin-effect and surface roughness introduce significant errors as materials become thinner than 10 mil (254 3m). These effects result in over-prediction of εr', and prevent determination of the εr'(f) variation.