FEP / HT-1.5 / TPN / TacBond: Bonding layers belong in the electrical stackupFEP / HT-1.5 / TPN / TacBond: Bonding layers belong in theelectrical stackupSignal copperNamed coreReference planePressed bonding layerSecond coreCopperCore thickness ≠pressed bondline ≠finished board thickness³Ô¹Ïtv engineering illustration · conceptual, not a qualified stackup or measurement