On modeling and optimizing cost in 3D Stacked-ICs

3D-Stacked IC (3D-SIC) technology is one of the emerging technologies with many benefits such as higher performance and heterogeneous integration. During the manufacturing of such ICs, tests can be applied at different moments such as (a) before the stacking process, (b) after the creation of each partial stacked IC, (c) after the creation of the complete stack, and (d) after packaging of the stack. Moreover, each applied test may target interconnects, one or more dies, or even both. This results into a huge number of test flows, each with its own specific test cost. Choosing an efficient and appropriate test flow providing the required outgoing product quality (for a given design and manufacturing parameters) is extremely important in order to make 3D-SIC business profitable. This paper discusses a tool for 3D-SIC test cost modeling; It gives the requirements and classifies them in design, manufacturing, test, packaging and logistics. It further covers user-cases and shows how the tool can be used at an early design stage in order to select the most efficient test flow for given input parameters (related either to manufacturing, test, packaging or logistics); hence, optimize the design and/or include the required DFT to support the selected test flow. The tool can be also used for sensitivity analysis where the impact of parameter changes on the test cost can be analyzed.