Abstract: A package for power converters in which all parts are electrically connected with one multi-layer circuit board. A sub-package with at least a power-dissipating chip, having a bare top up-facing heat-slug is electrically connected with the board by a plurality of symmetric leads. A heat spreader is directly attached onto the bare top heat-slug of the sub-packages, planar magnetic parts and top surfaces of other components with thermally conductive insulator. The heat dissipated by the sub-packages is transferred to the attached heat spreader by the bare top heat-slug, and further transferred to the ambient. The assembly features compact and inexpensive power converter package with improved electrical performance and enhanced thermal management.