A stackup names every core and bond layerLayer roles must be agreed before controlled-impedance routing.A stackup names every core and bond layerLayer roles must be agreed before controlled-impedance routing.RF tracePTFE core: exact grade + thicknessReference planeNamed bonding layer: cured thicknessOther core or qualified hybrid regionLower copperTotal finished thickness ≠distance from the RF trace to its ground plane.³Ô¹Ïtv engineering illustration · Conceptual, not a released drawing or measured result