Generating Test Patterns for Chiplet Interconnects With Optimized Effectiveness and Efficiency

Chiplet-based (2.5-D and 3-D) multidie packages typically feature numerous die-to-die interconnects using micro-bump connections and possibly through-silicon vias or interposer wires, which are prone to manufacturing defects, such as shorts and opens, in both hard and weak (resistive) variants. Traditional I-ATPG methods only cover hard defects and scale with the logarithm of the number of interconnects. Despite being considered efficient, they cover shorts between all interconnects, including those for which shorts are unrealistic given their relative layout positions. This article proposes E2I-TEST, which covers all hard and weak variants of open defects and of only the shorts and coupling defects between physically adjacent interconnects for both 3-D and 2.5-D chips, while preventing aliasing during fault diagnosis. This article further improves E2I-TEST to prevent ground bounce, avoiding undesired voltage fluctuations during test mode. While the number of interconnects is expected to rise significantly, E2I-TEST offers a high-quality interconnect test, while maintaining a constant number of test patterns.