Multiphysics Analysis and Optimal Design of Compressible Micro-Interconnect for 2.5D/3D Heterogeneous Integration

Compressible Micro-Interconnect (CMI) shows tremendous potential in 2.5D/3D heterogeneous integration due to its outstanding performance in integration, electrical isolation, and thermal management. In this work, an optimal design approach for CMIs is developed based on a coupling framework of multiphysics simulation and particle swarm optimization (PSO). In the framework, the mechanical simulation was conducted firstly to obtain the stress distributions as CMI switched from the initial state to the working position. The contact resistance between CMI and the top pad was modeled and quantitively analyzed. Subsequently, the PSO method was utilized to implement the structural optimization of CMI to improve the performance. Multiphysics simulations of both the original and optimized CMIs were carried out and compared. With the implementation of the optimized CMIs, the contact resistance dropped from 155.3 mΩ to 108.8 mΩ, which brought significant improvement in both DC voltage drop and self-heating effect. The influence of the self-heating effect on the electrical performance of CMI is also discussed qualitatively.