3D Packaging with Embedded High-Power-Density Passives for Integrated Voltage Regulators

Abstract

Highly-integrated 3D voltage regulators (IVRs) for high-power applications are developed for emerging applications such as AI computing and server. With this 3D process integration, passive components such as inductors and capacitors are embedded into substrates and placed close to the chips, resulting in short power delivery networks (PNDs) and high power efficiency. High-density tantalum capacitors are integrated with high-density magnetic-core inductors to realize IVRs with module thickness around 0.7 mm. By incorporating high-permeability magnetic materials as the cores, the inductors achieved 20X improvement in inductance as compared to air-core inductors. The high inductance allows inductors to be designed with less number of windings, resulting in low component resistance of 5 mΩ. The integrated components have package-compatible terminals that are compatible with electrolytic plating process. The terminals allow them to be connected with low-resistance vias to further reduce parasitic losses and improve the power efficiency. Short PDNs and low-resistance interconnections and low-resistance components make the demonstrated IVRs ideal for high-power density computing applications with high efficiency low-impedance power delivery networks.