Transient dual interface measurement of junction-to-case thermal resistance in AlGaN/GaN HEMT utilizing an improved infrared microscope

The junction-to-case thermal resistance (RθJC) of a GaN/AlGaN HEMT is measured by Transient Dual Interface Method (TDIM). Different from other works about TDIM, an improved transient infrared microscope is used to measure the cooling curves, other than the traditional electrical method. Zth curves are used to determine the RθJC following the procedure of JESD51-14. The results demonstrate that the RθJC at 40 W power dissipation are about 0.791 K/W. In order to validate the method, measurements following MIL Std 833 have been done, and the results are consistent with the existing papers.