Defect Detection in Double-Sided Cooled Power Modules by Structure Functions

This paper presents an approach based on structure functions aimed to the defect detection in state-of-the-art double-sided cooled power modules. The investigation is conducted by means of highly detailed 3-D finite-element method thermal simulations on the exact replica of a power module. Typical defects are emulated ad-hoc in the numerical environment: solder delamination, detached interconnections, and voids/bubbles in the thermal interface material. It is demonstrated that assigned defects give specific shapes to the structure functions; once these shapes are classified, the nature of the defects can be easily unraveled from experimental data.