TSV-Based Shoelace Inductor: A High-Density Solution for Advanced Packaging Platforms

High-density and high-quality inductive passives are a key requirement to improve the efficiency of high-speed and high-frequency integrated circuits. With the rise of compute-intensive and high-frequency applications, such as machine learning and 6G communication, significant improvements in terms of inductance density and quality of integrated inductors are still required. Shoelace, a novel integrated solenoid inductor structure, is proposed in this paper. The proposed inductive topology, theoretical models, and simulation of key performance parameters are presented. From the simulation result, the shoelace inductor exhibits 28% improvement in inductance density as compared to conventional integrated solenoid inductors. Furthermore, two variations of the baseline TSV-based shoelace inductor, namely the nested shoelace and the magnetic core shoelace, exhibit inductance density of, respectively, 238.81 nH/mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 228.32 nH/mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. In addition, the package-level integration of the proposed inductors is also discussed.