It is demonstrated in the previous page that a feasibility study flow is now possible for 3D-IC using commercially available tools: GemPackage for model construction, Ansoft SIwave for DC analysis, and ANSYS Icepak for thermal analysis. Although the flow focuses in thermal issue, it would be easily extended to cover SI/PI issues since the same file (ANF) can be input to Ansoft SI/PI tools (SIwave, TPA, HFSS, and Q3D Extractor).

  In the best of our knowledge, this is the first presented EDA flow for 3D-IC designs, based on the commercial tools. This work is giving an initial solution for the challenges of (step1) and (step2) in the whole EDA challenges in 3D-IC.

• (step1) Database challenge − New EDA database is needed to unify 3D-IC and traditional IC packages.
• (step2) FS challenge − Convenient light weight tools are needed for model construction, routability analysis, and SI/PI/Thermal/Mechanical analysis.
• (step3) DFM challenge − Steady tools are needed for detailed design, yield improvement, and sign-off simulation.
• (step4) Integration challenge − Tight integration of FS/DFM tools is needed.

  To support daily design activities, however, the whole four steps are needed to be worked out. Such methodology development projects are about to begin in advanced designers. We hope the FS flow presented here would be discussed as a starting point in such projects.