Aluminum vs FR-4 for LED Drivers: A Thermal Deep Dive
Thermal conductivity, manufacturing trade-offs, and when paying 3× for aluminum is the right call.
Layer-Up Engineering·4/27/2026FR-4 thermal conductivity is ~0.3 W/mK. Aluminum-core boards run 1.5–3.0 W/mK. For 100W+ LED drivers, that's the difference between a 70°C junction and a 110°C one — and the latter cuts LED lifetime by 4×.
Stack-up
An aluminum-core PCB is dielectric / copper bonded to a 1.0–1.6 mm aluminum substrate. You only get one copper layer (the top), so route accordingly.
When to stay on FR-4
If your power dissipation is below ~10 W and you have copper pour for thermal spreading, FR-4 is fine. Above that, switch.