January_February_2022_AMP_Digital

2 0 A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y / F E B R U A R Y 2 0 2 2 of a cracked sensor trace due to ESD or EOS. Note the cracked die surface was imaged at 3500x magnification with a scale marker of 5 microns. A compara- tive CT image of the die sur- face is shown in Fig. 12 and demonstrates that it could not resolve the crack in the die surface. CONCLUSIONS Two case studies were presented from a forensic engineering perspective to highlight the strengths and weaknesses between traditional metallurgical techniques and 3D micro- computed tomography, as well as the interplay be- tween the methodologies. Technological advance- ments will continue to push the boundaries of failure analysis, which will help answer fundamental foren- sic questions when exam- ining parts and products in a postmortem condition. ~AM&P For more information: Nikhil Kar, Principal Engi- neer, Kars’ Advanced Ma- terials, 2528 W Woodland Dr., Anaheim, CA, 92801, 714.527.7100, nikhil.kar@ karslab.com. Acknowledgment The following equipment was used for the case studies presented: • CT scan equipment: Nikon XT H 225 ST with a rotating target and a 1620 Perkin Elmer Panel • Volume Graphics, Industrial CT Soft- ware, VG Studio MAX 3.1 • Hirox HRX – 01 3D Digital Microscope • JEOL 6610 SEM with IXRF EDS Detector References 1. M. Castillo, The Industry of CT Scanning, Am. J. Neuroradiol., 33 (4), p 583-585, April 2012. 2. C. Reinhart, et al., Modern Voxel Based Data and Geometry Analysis Software Tools for Industrial CT, Proc. World Conf. NDT, Montreal, Canada, 2004. 3. https://www.tescan.com/product/ dynamic-micro-ct-for-materials-science- tescan-unitom-hr/. 4. D. Scott, Metallography and Micro- structure of Ancient and Historic Metals, The J. Paul Getty Trust, 1991. 5. A. Reardon, Metallurgy for the Non- Metallurgist, Chapter 7, ASM Interna- tional, p 150, 2011. Fig. 12 — CT rendering of decapped die surface shows limit of resolving power when compared to microscopy techniques. Fig. 11 — SEM photomicrograph shows a crack in the die surface. Fig. 10 — High magnification light microscopy image shows decapped die surface with trace and pad features resolvable (new die chip). Note, no damage observed on the new die surface.