³Ô¹Ïtv / ENGINEERING NOTEWorked reference: Invar PCB Expansion ControlFree mismatch = length × (CTE A − CTE B) × delta T01100 mm; 17 vs 2 ppm/K; 80 K02120 µm free mismatch03Bonded stress not calculatedIllustrative inputs or review logic; no automaticapproval.Conceptual drawing. Not to scale; not manufacturing or compliance evidence.