Integrated screen printed capacitors in a GaN DC-DC converter allowing double side cooling

Modern power electronics is focused on highly efficient, compact and cost-effective converters. In this paper, gallium nitride (GaN) transistors, multicell topology and integrated capacitors are combined to achieve these objectives. The first results of a 48V-to-5V DC/DC 3-level converter using integrated screen printed capacitors are presented. The power board is designed by assembling a ceramic substrate, with integrated capacitors using a Kapton® film as an insulation layer, and a multilayer PCB substrate for the active components. The integrated screen-printed capacitors technique and the proposed power board assembly allow double side cooling of the power semiconductors.