John Flannery

New method for integration of resonant inductor and transformer-design, realisation, measurements

For the miniaturisation of resonant converters the resonant inductor has been integrated into the transformer by using the leakage inductance as the inductor. A new method of adjusting the leakage inductance for planar transformers with integrated windings by using an additional layer of low permeable magnetic material is introduced. The leakage inductance of planar transformers with integrated windings can be adjusted very precisely and reproducibly.

A comparative analysis of interconnection technologies for integrated multilayer inductors

Multilayer aircore inductors fabricated in a range of interconnection technologies which are MCM compatible are presented and compared. These consist of thick‐film, low temperature cofired ceramic (LTCC), printed circuit board (PCB) and fine‐line plated copper on ceramic (copper plating). From a comparison of simulated and measured results, it can be concluded that a predictive design capability has been achieved for inductance and self‐resonant frequency (SRF). Modelling of AC resistance and Q requires further investigation.

STATPEP-current status of power electronic packaging for power supplies-methodology

The paper presents a methodology for a review of the current status of power electronic packaging (PEP) used in commercial switch mode power supplies. Based on the current status and the knowledge about the development of PEP over the last 5 to 10 years experience curves can be developed which will show the expected trends in PEP of power supplies for the future. The above mentioned experience curves are proposed as a prediction tool for the industry and Its suppliers and customers over the next 5 years. This project was initiated by the Power Sources Manufacturers Association (PSMA) to benefit the power sources industry.

Surface mount power converters

Application boards on which on-board power supplies are used are populated substantially with surface mount components. These are typically assembled with conventional single or double sided SMT (surface mount technology) reflow processes. The few remaining PTH (plated through hole) components need to be manually placed and soldered either by hand or by a process such as selective wave, selective jet or robotic soldering. The complexity of many modern application boards in terms of layer count and component density, combined with the desire to eliminate these additional process steps is leading to a desire for the elimination of the remaining PTH components of which the DC-DC converter is the most conspicuous. This paper deals with many of the challenges faced when designing and using a state of the art, surface mountable, high density power-supply which must be treated as a single surface mount component. These issues include interconnect design, joint strength and reliability, electrical and thermal conductivity, as well as manufacturing considerations such as pick and place compatibility, inspection and rework.