A 660W, 96% Efficiency 3D Heterogeneously Integrated Digital DC/DC Power Module for Vertical Power Delivery

This work demonstrates the design, modeling and fabrication of a digital DC/DC power module featuring a record-high output power of 660 W and 96.2% efficiency for high-performance computing (HPC). To achieve vertical power delivery (VPD) in a small form factor, advanced 3DIC packaging technology is employed by heterogeneously integrating power switches, drivers and control ICs with plastic molding. To address the congested power routing in conventional lateral floorplans, modular stacking and a redistribution layer (RDL) are adopted to build a 3D high-density power delivery network (PDN) with minimal IR losses. The electro-thermal and stress properties are modeled and analyzed to ensure feasibility. Two sets of compensation algorithms are implemented to balance the tradeoff between fast response, stable output current and small voltage ripple. While dynamically adjusting the output, the power module digitally monitors the safety status and reacts with protection circuit. Experiment results from the prototype system demonstrates a power density of 1468 W/in<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>, output ripple less than 1%, 32.8 ms response time, and significantly improved thermal management and stress control.