Hello,
I use PCBWay’s 4-layer 1.6 mm stackup with L1–L2 dielectric 0.1855 mm, 1 oz copper and Er 4.74.
Your online impedance calculator gives approximately 90.7 Ω differential for:
width = 0.220 mm
gap = 0.150 mm
D+/D? are on L1 referenced to solid L2 GND.
Since your calculator does not include solder mask, can we use 0.220 / 0.150 mm for a controlled 90 Ω differential pair, or what width/gap do you recommend including solder mask?
Best regards,
Christian Bill