To conclude the Synopsys presentation on Unlocking the Future with 2.5D and 3D Multi-Die Innovations, this presentation highlights the Multiphysics and multiscale challenges of multi-die designs. These challenges include thermal, power, signal, structural, optical integrity challenges where all physics are coupled to each other and they need to be considered from early feasibility to prototyping to implementation to sign-off. We will discuss these challenges and innovative comprehensive solutions.