3-D Physical Model for On-chip Power Inductor Design with Evaluation of Airgap Variation Effect

The miniaturization of power inductor helps to achieve high power density of power converters. The development of on-chip power inductors is an important step towards achieving this goal. A 3-D model for an on-chip power inductor is developed in ANSYS®/Maxwell® software in this paper to facilitate the design of on-chip power inductor with on-chip ferrite core. The effects of air gap variation in the on-chip inductor are evaluated using the 3-D physical model and simulations with the on-chip ferrite core. The tradeoff between high inductance value and high saturation value as a function of the air gap between the ferrite layer and winding layer is evaluated from the model and simulations in order to facilitate the optimization and design before fabrication of the complete device.