ENGINEERING ANSWER
Six layers can separate RF routing, reference planes, power distribution and digital signals. More layers do not automatically improve RF behavior; every layer transition and plane opening needs a return-current path.
What to decide before release
Build the stackup from the critical RF interfaces outward. Use the tool to sketch thickness allocation, then replace illustrative layer values with a supplier-approved stackup. Review via stubs, registration and copper symmetry before layout is frozen.
Checks to put in your design brief
- Assign a purpose to each layer
- Document each signal’s reference
- Approve the complete pressed stackup
Important distinction
Do not treat a stackup sketch as a lamination recipe or a guaranteed finished thickness.
Sources & basis
Material facts follow the cited source. Design checks are preliminary guidance, not supplier process instructions.