While transistor gate lengths may continue to shrink for some time, the semiconductor industry faces increasing difficulties to satisfy Moore’s Law. One solution to satisfying Moore’s Law in the future is to stack transistors in a 3-dimensional (3D) formation. In addition, the need for expanding functionality, real-estate management and faster connections has pushed the industry to develop complex 3D package technology which includes System-in-Package (SiP), wafer-level packaging, through-silicon-vias (TSV), stacked-die and flex packages. These stacks of microchips, metal layers and transistors have caused major challenges for existing Fault Isolation (FI) techniques. We describe in this paper innovations in Magnetic Field Imaging for FI which have the potential to allow 3D characterization of currents for non-destructive fault isolation at every chip level in a 3D stack.