This document discusses thermal management recommendations for Cree's XP and MX series XLamp LEDs. It outlines the thermal characteristics of these high-power LEDs and recommends using FR-4 PCBs with added thermal vias to improve heat dissipation. Thermal simulations show that reducing the FR-4 dielectric thickness, using larger via diameters, and adding more vias reduces thermal resistance. The document recommends a layout with 0.254mm vias on a 0.635mm grid to achieve the lowest possible thermal resistance for the FR-4 PCB.

3. High Power LED Advantages Very energy efficient Available up to 130 lumens/watt and still increasing High-quality light No compromise between efficacy and CRI Directional No wasted light; any pattern possible Extremely long lifetime 70% lumen maintenance; up to 50,000 hours Inherently rugged No filament to break Instant on Reaches full brightness in nanoseconds Environmentally friendly Contains no mercury, lead or other heavy metals Infinitely controllable Enables new lighting fixtures and energy-saving techniques Low-temperature-friendly No issues starting in cold environments

6. Temperature Influence Increasing forward current, increases flux Higher forward current, increases Vf & power Higher power dissipation raises Tj and reduces light output Flux Vf Flux