IN SITU STRIPLINE LAMINATE PROPERTY EXTRACTION ACCOUNTING FOR EFFECTIVE SURFACE ROUGHNESS LOSSES

Open Access
Author:
Ellison, Jason J
Graduate Program:
Electrical Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
November 14, 2017
Committee Members:
  • Sedig Agili, Thesis Advisor
Keywords:
  • Surface Roughness
  • Calibration
  • Propagation Constant
  • TRL
  • AFR
  • 2x Thru
  • permittivity
  • tangent delta
  • dielectric
  • stripline
Abstract:
A method of extracting the effective copper surface roughness of a laminate in situ is introduced. The rough copper attenuation as a function of surface roughness is removed from the total attenuation. The residual loss is fit to coefficients, and an error is calculated based on the remaining apparent surface roughness contribution. When the error is minimized or when the apparent surface roughness contribution is nearest zero, the effective surface roughness is found, and the dielectric attenuation is isolated by subtracting the rough copper attenuation from the total attenuation. Using this extracted dielectric loss, broadband causal laminate electrical properties are calculated with higher accuracy than that of existing methods that neglect copper surface roughness. Previous methods of extracting laminate material properties that consider copper surface roughness rely on cutting the sample to make a cross-section and observe the surface roughness directly. This new method does not require a cross-section of the sample and instead only uses S-parameter measurements of stripline traces.