Real-time X-ray microscopy study of electromigration in microelectronic solder joints

Electromigration (EM) in microelectronic solder joints was investigated via transmission X-ray microscopy (TXM) in conjunction with three-dimensional computed microtomography (3D mu-CT). This nondestructive analysis provided visualization of the EM dynamics in the encapsulated solder joints and showed the linear dependence of the Cu pad depletion on the current stressing time. Quantitative analysis of the interstitial Cu diffusion in beta-Sn based on Huntington's EM theory offered rationalization of this EM-induced degradation mechanism. (C) 2015 Elsevier Ltd. All rights reserved.