Power management for small scale systems

Contemporary electronic systems often contain power circuits to support the unique power conversion or conditioning needs of each of the various subsystems. Each of these power circuits is generally implemented with discrete passive and active electronic components soldered next to the load devices on the printed circuit board. As greater levels of functionality are demanded within diminishing size and weight allowances, power management solutions will increasingly demand highly miniaturized power converters that are more tightly integrated into single-package solutions or even directly integrated onto the points of source and load. Experimental converters have demonstrated great potential in switching at very high frequencies (100+ MHz) to reduce the size of the requisite passive storage elements (inductors, transformers, and capacitors) to values that may be suitable for in-package or on-chip integration. However, integrating the passives into the same package as the active switching and control circuitry remains a significant fabrication challenge due to material incompatibility and inadequate performance of the passives. This paper discusses progress towards a fully integrated power converter module with a focus on microfabrication processes for both passive component development and wafer-level packaging. The passive components have been optimized for high performance at hundreds of MHz through the use of thick copper traces, intricate three-dimensional winding patterns. The capability of detaching the passives from the fabrication wafer produces a passives substrate that can serve directly as a routing platform for full integration of all components into a single-package solution.