The thermal characterization of packaged semiconductor device

In this paper, using voltage drop of forward junction as temperature sensitive parameter (TSP) for GaAs MESFET and semiconductor laser diode, we measured temperature rise ΔT under normal operation condition. Furthermore, we composite a testing sequence in which the duration of driving pulse from several microseconds to 100 seconds. This sequence is designed actually to simulate the procedure of heat transfer from active region of device to environment. ΔT and thermal resistances R_th are measured after each testing pulse. The R_th against heating time is drawn to form heating response curve of device. Steps appear in the curve corresponding to the contribution from different component of device. By this way, we can make thermal characterization for packaged semiconductor devices easily and quickly. Some thermal quality, such as soldering quality of chip, thermal resistance of chip and package, can be characterized. We also use this method to make researches on semiconductor laser diodes LD. In their normal operation condition, LD shows different behavior from GaAs MESFET because of its light output. This also yields a new method to determine light output efficiency by thermal measurement