Heat transfer for semiconductors is first a conduction problem, and with LED junction temperatures limited to less than approximately 100°C (in most cases), conduction is the primary transfer method until a suitable area for natural convection is reached. Radiation is small between the die and the system because the LED source is cooler than a filament or an arc. This differentiates LEDs from other lighting sources where most heat is radiated to the environment from non-LED light sources. This change in the cooling mechanism for lighting systems cannot be understated, as system designers are not used to thinking and designing for this different thermal system. A suitable path for conducting heat from the LEDs must be provided, and that also includes the various thermal interfaces in the system.