Authentic and Fast Thermal Resistance Distribution Analysis in High Power VCSEL Array Module

VCSEL has aroused extensive enthusiasm in scientific research and applications. However, thermal resistance has seriously limited such devices’ performance for a long time, especially in high-power single-chip large-area VCSEL array module. In addition, thermal resistances of every component of the module are not clear and not exact until now. Here, the thermal characteristics of a 808nm VCSEL module were analyzed by electrical transient measurement, which consists of a 6 mm×6 mm, 85W AlGaAs/GaAs VCSEL array chip encapsulated on a submount and water-cooled heat sink. The authentic and quantitative components of the device’s thermal resistance were clearly segmented and rapidly obtained using the structure function algorithm within merely 25 seconds. The packaging thermal resistance together accounts for astonishing 70% of the total thermal resistance when the loading current is 8 A. Among them, Rsubmount and Rsolder2 are the main focus areas which add up to 54% .We also applied the spectroscopy method to calculate the total thermal resistance of the module from another perspective for the comparative verification of the former method. The values obtained by the two methods are relatively close. More importantly, the research will pose positive significance and indicative effect on reducing main thermal resistances of the VCSEL array module.