Full-wave modeling of inductive coupling links for low-power 3D system integration

In recent years, 3D system integration has emerged as a new paradigm to reduce the overall size of multichip systems (processor and memory stacks), improve data throughput, and lower assembly costs. Among the various techniques developed to connect multiple die in a 3D integrated-circuit (IC) package, inductive coupling links are very cost-effective solutions that require no specialized processing steps. While it is easy to use integrated inductors to implement inductive coupling links in standard CMOS processes, evaluating their electrical characteristics requires using an electromagnetic field solver software. And, integrating these links into a standard SPICE-like circuit design environment is not straightforward. In this paper, we describe a technique, based on the partial element equivalent circuit (PEEC) method, to model an integrated inductive coupling link as a simple lumped parameter circuit. Starting from layout and technology data, the lumped parameter circuit model can be used in a SPICE-like simulator for system design purposes.