Thermal resistance analysis related to the degradation of GaAs-Based laser diodes

Thermal transient measurement of the 808 nm GaAs-Based laser diodes (LDs) before and after the constant current stress are presented and discussed in this paper. Aging tests are carried out under the conditions of the constant current stress (1 A) for 255 hours. The total thermal resistance increases from 7.0 to 8.8°C/W before and after degradation. Furthermore, the contribution of each component to the total thermal resistance has been obtained from the differential structure function and cumulative structure function before and after stress. The thermal resistance of chip maintain almost constant before and after stress, while significant increase in the thermal resistance of solder layer (indium attaching material) and package body are observed after degradation. These results indicate that the thermal properties of solder layer and package body degrade apparently as contrast to the chip of LDs. The thermal properties of solder layer and package body have critical effects on the performance of LDs. Thus the performance of LDs could be improved through optimizing of solder material and package body.