Backward Conduction 2D Finite Cross-Section
STEADY STATE ACHIEVED
Junction Temp (Tj)
72.4°C
Safe (< 85°C)
Thermal Droop
-4.2%
Relative to 25°C bin
L70 Lifetime
64,200 hrs
Arrhenius projected
Color Shift Δu'v'
0.0018
< 3-step MacAdam
Housing Mass
348 g
Volumetric density
The LED Backward Heat Conduction Dilemma
Unlike incandescent bulbs that radiate 90% of heat forward as infrared electromagnetic radiation, high-power solid-state LEDs radiate zero infrared in the optical beam. Modern LEDs drive 100% of their waste thermal energy backward through the die substrate, solder pad, and metal core printed circuit board (MCPCB) directly into the housing. If the enclosure material lacks high thermal conductivity (k), heat dams up at the junction, destroying lumen maintenance and degrading phosphor coatings.