Area array contacts to assemble a 3D transformer for a miniaturized voltage converter

Miniaturization is often targeting only individual aspects of a system, e.g. making specific components smaller. A more successful approach is trying to employ synergetic engineering to minimize not only individual components but targets to system as such and uses a top down methodology to minimize the size of a complex product. For the described application, a miniaturized voltage converter, several miniaturization approaches have been merged with 3D assembly technology and flex substrates in order to achieve a target sizeof ∼1cm3. Bare die assembly, an innovative approach to wire the coils utilizing advanced PCB technology, a product specific magnetic ferrite core and area array assembly techniques with reflow encapsulant and finally flex substrates which are folded into the final shape are utilized to realize the product demonstrator. All aspects of the technology were verified against manufacturing capabilities of a medium-sized company, allowing them to fabricate the device for the use in today´s mobile products.