Three-dimensional integration of power electronic converters on printed circuit board

The current construction technology for PCB assembled power converters is based on the assembly of pre-manufactured discrete components. Fundamental limits of this construction method are steadily being reached as power converters tend to exploit higher processing speeds to gain advantages in both magnetic component size and overall power density. This thesis investigates a new design approach encompassing thermal management, geometrical packaging and electromagnetic integration (focussing on the PCB in particular) to push the limits further. In the research, a quantitative means to deal with component layout and the effect it has on the temperature characteristic of the converter is introduced as design tool.It incorporates the ability to define a design objective, such as high power density or increased reliability, and to weigh the respective trade-offs encountered during thermal design of a converter. Examples are provided. Furthermore, the inherent limitation of 2D component layout (rigid PCB) often limits the freedom to arrange components with compatible shapes tightly together. A geometrical packaging approach is investigated to alleviate this limitation and thereby improve power density. Compatible components can be arranged tightly together in 3D by implementing flexible PCB to fold the circuit, to accommodate the components. Electromagnetic integration has been identified as the enabling factor to realise structures that combine the functionality of several, otherwise discrete, components into a single structure, and combined with rigid-flex PCB technology these structures can be seamlessly embedded within the geometrically packaged converter system. The implementation of such multi-functional structures decreases the number of production and assembly steps during manufacturing and provides cost savings in material and assembly of the converter. The design procedure that encompasses the electrical, thermal and spatial aspects of compact PCB assembled converters is described and illustrated by working through the complete design of a 3D PCB converter technology demonstrator