In this paper we present the thermal and mechanical analysis of high-power
light-emitting diodes (LEDs) with ceramic packages. Transient thermal
measurements and thermo-mechanical simulation were performed to study the
thermal and mechanical characteristics of ceramic packages. Thermal resistance
from the junction to the ambient was decreased from 76.1 oC/W to 45.3 oC/W by
replacing plastic mould to ceramic mould for LED packages. Higher level of
thermo-mechanical stresses in the chip were found for LEDs with ceramic
packages despite of less mismatching coefficients of thermal expansion
comparing with plastic packages. The results suggest that the thermal
performance of LEDs can be improved by using ceramic packages, but the mounting
process of the high power LEDs with ceramic packages is critically important
and should be in charge of delaminating interface layers in the packages.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
