A High‐Speed Design Methodology for Inductive Coupling Links in 3D‐ICs
Benjamin J. Fletcher1,a, Shidhartha Das2 and Terrence Mak1,b
1Department of Electronics and Computer Science University of Southampton, UK.
abjf1g13@ecs.soton.ac.uk
btmak@ecs.soton.ac.uk
2ARM Ltd, Cambridge, UK
Shidhartha.Das@arm.com
ABSTRACT
Inductive coupling links (ICLs) are gaining traction as an alternative to through silicon vias (TSVs) for 3D integration, promising high‐bandwidth connectivity without the inflated fabrication costs associated with TSV‐enabled processes. For power‐efficient ICL design, optimisation of the utilised physical inductor geometries is essential, however typically necessitates the use of finite element analysis (FEA) in addition to manual parameter fitting, a process that can take several hours even for a single geometry. As a result, the generation of optimised inductor designs poses a significant challenge. In this paper, we address this challenge, presenting a CAD‐tool for Optimisation of Inductive coupling Links for 3D‐ICs (COIL‐3D1). COIL-3D uses a rapid solver based upon semi‐empirical expressions to quickly and accurately characterise a given link, in conjunction with a high‐speed refined optimisation flow to find optimal inductor geometries for use in ICL‐based 3D‐ICs. The proposed solver achieves an average accuracy within 9.1% of commercial FEA software tools, and the proposed optimisation flow reduces the search time by 26 orders of magnitude. This work unlocks new potential for power‐efficient 3D integration using inductive coupling links.
