A buried drill pair belongs to a build stageInternal endpoints and the subassembly drilling thickness are separate inputs. A final stackup must show how each internal pair is manufactured.A buried drill pair belongs to a build stageFinal layer names · Drilled thickness belongs to the subassemblyL1L2L3L4L5L6L7L8Illustrated pair: L3 → L6Drill the agreed subassembly.Use its drilled thickness.Later layers sit outside it.Do not drill the final boardand call it a buried via.³Ô¹Ïtv · Engineering illustration · Conceptual, not to scale