Thermal design of ceramic packages for high power light-emitting diodes
Ceramic packages with different paths of thermal dissipation were designed by a simulation using the finite-volume method. Thermal resistances of the packages were obtained from the calculation of temperatures of LED (light emitting diode) chips. It was shown that the thermal characteristics of LED packages were strongly affected by the contact area of a thermal via in contact with a LED chip rather than that in contact with a ceramic mould. Ceramic LED packages were fabricated and characterized. A deviation of simulated results from experimental results was found. The difference was attributed to the poor contact roughness between the LED chip and the thermal via.