Challenges and emerging solutions in testing TSV-based 2 1 over 2D- and 3D-stacked ICs

Through-Silicon Vias (TSVs) provide high-density, low-latency, and low-power vertical interconnects through a thinned-down wafer substrate, thereby enabling the creation of 2.5D- and 3D-Stacked ICs. In 2.5D-SICs, multiple dies are stacked side-by-side on top of a passive silicon interposer base containing TSVs. 3D-SICs are towers of vertically stacked active dies, in which the vertical inter-die interconnects contain TSVs. Both 2.5D- and 3D-SICs are fraught with test challenges, for which solutions are only emerging. In this paper, we classify the test challenges as (1) test flows, (2) test contents, and (3) test access.