³Ô¹Ïtv / ENGINEERING NOTEWorked reference: Bergquist vs FR-4 PCBSource temperature = common boundary + heat × path R015 W; paths 7 and 4 K/W0235 K and 20 K rise03Same source and fixtureIllustrative inputs or review logic; no automaticapproval.Conceptual drawing. Not to scale; not manufacturing or compliance evidence.