Get started now
What I used sometimes is the Er which is in the middle between the two
Ers or I use the Er value of the thinner dielectricum which is placed
closer to the reference plane. But the value is always not so right, so
it is better to ask your PCB manufacturer.
What you need is one of the reasons why it is important to ask PCB
manufacturer to provide the final stackup and track geometry.
They can calculate the values more precisely.
I have learned a lot from your article. Quite useful and impressive info.
My Full Review and Experience with ALLPCB
Price or quality?
Free PCB Board by ALLPCB Sponsorship
Lead-free Solder Paste for 0402 Metric Chip Components
PCB Instant Quote