Non-destructive orientation mapping of die-attach lead-free solder

Thermo-mechanical fatigue poses a serious challenge to the electrical operation of power semiconductor modules, manifested by the degradationof die-attach lead-free solder. So far, orientation microscopy (OM) using electron backscatter diffraction is considered a sensitive approach tocharacterizing the degradation of solder. However, its destructive character inhibits assessing solder inside the power modules. We propose a non-destructive OM method based on X-ray diffraction and successfully observed the changes in the orientation of the solder caused by thermo-mechanical fatigue. The proposed non-destructive OM method can facilitate the development of reliable power modules by evaluating thedegradation of the solder inside the power modules.(c) 2024 The Author(s). Published on behalf of The Japan Society of Applied Physics by IOPPublishing Ltd