Correction:

The last sentence should end ". . . the width needs to be 9.5 mils."

Roy Lewallen, W7EL

Roy Lewallen wrote:
If the dielectric material is 6.5 mils thick and the copper is very
thin, the width needs to be 18.7 mils. If the substrate material is
0.0065 inches thick and the copper is "one ounce" (1.4 mils thick), the
width needs to be 17.3 mils. If the total thickness is 6.5 mils, and
that thickness includes top and bottom layers of "one ounce" copper
(leaving 3.7 mils of dielectric), the thickness needs to be 9.5 mils.