Laser Soldered Eutectic Die-Bonding Processes in LED Packaging

This work investigated the effect of laser power patterns on temperature and thermal stress distributions in the light emitting diode (LED) die-bonding process. The finite element software package MSC.Marc was employed to simulate the laser soldering process. Thermal-elastic-plastic models of the solid elements were used. Temperature dependent material properties were applied to characterize the temperature variation effect that occurred during die-bonding. This research simulated and studied temperature and thermal stress distributions during the die-bonding process, as well as the distributions of residual stress induced in the die-bonding process and the effects of different laser soldering parameters on die-bonding. The results show that thermal stress and residual stress are affected by process temperature quality, and that residual stress in the tin alloy increases as the trough depth increases.