Thermo-mechanical evaluation and life time simulation of high power LED lamp boards

This work deals with a precise 3-D modelling of several LED board technologies mainly focused on thermal, thermo-mechanical evaluation and life time prediction to compare their performances. Main role of each LED board is to transport heat from LED die to heat sink and keep the thermal stresses in all layers as low as possible. Thermal stress has been inspected for the widest temperature range that can affect the LED boards (-40 to +125°C). Additionally, thermal stress cycles that lead to the LED board failure due to thermal fatigue have been calculated. Simulations have been completed with ANSYS structural analysis where temperature dependent stress-strain material properties have been taken into account. The objective of the analysis is to optimize not only the thermal management by thermal simulation of LED boards, but also to find potential problems from mechanical fatigue point of view.