Investigation of High Current Fine Grain Power Delivery for 3-D Heterogeneous Integration

Abstract

This article demonstrates design guidelines and development of a novel 3-D heterogeneous integration (3-DHI) thin glass substrate-based half-bridge switching power module for future onboard CPU, transceivers, and so on, power delivery applications. Due to extreme space constraints in onboard power supply applications, this design will support switching frequencies of >50 MHz with power levels of >30 W. To illustrate the capabilities of this module, the detailed ANSYS finite element analysis (FEA) analysis was carried out through thermomechanical and electromagnetic simulations. Extracting thermals is a major limitation factor in a compact layout. Hence, a thermal via density and substrate thickness parametric study was conducted, and effects on the integrity of the mechanical structure were verified through the simulation-based stress analysis. Finally, to switch at very high frequencies, the power and signal loop interconnects were routed through a thin glass substrate to achieve ultralow-power and gate loop parasitics. Two significant contributions demonstrate stacking various component layers in a half-bridge power stage and system-level packaging in a vertical profile.