Copper-based hybrid fabrication of a 50 W, 5 MHz 40 V-5 V DC/DC converter

A prototype 50 W, 40 V to 5 V DC/DC converter operating at 5 MHz and constructed with chip and wire hybrid techniques on a ceramic substrate with copper thick-film conductors is presented. A brief discussion of the thick-film process is given to point out the special issues concerning copper-based conductor systems. Some of the specific trade-offs that arise with regard to the construction of a power circuit with hybrid techniques are discussed. A method by which transformers may be fabricated to have very little leakage inductance, both internally and in their connection to rectifiers, is then described. The performance of a power circuit, the dual resonant forward converter is presented.>