Thin-Film Microtransformer for High Frequency Power Applications

Abstract

Abstract. This paper describes a development of a microtransformer device fabricated using thin film technology. The device is designed for higher switching frequencies beyond to 50 MHz power applications. A especially by the microtransformer is a design, which allows wide flexibility of a device by choosing a different values of an inductance and of a windings ratio. The microtransformer device is integrated on silicon substrate consisting of a closed magnetic core and six coils. Both, primary and secondary device side consist three coils. Therefore, this design allows using of a device for different switching frequencies. As a magnetic material for transformer core a permalloy NiFe45/55 was chosen.

A Survey on Microtransformers

“…Since 2010 the wire bonding technique has been added to the list, although one of the first devices built with this technology appeared in an application bulletin of the Burr-Brown Corporation in 1994 [114]. One of the most versatile processes for building microtransformers with any structure and geometry, is microfabrication [2], [5], [6], [17], [22], [25], [28], [40], [49]- [51], [54], [58], [62], [63], [70], [71], [80], [81], [84], [89], [90], [92], [105], [107]- [109], [122], [128]- [130]. Of course, any of the other fabrication approaches may involve microfabrication in some of the processing steps.…”

Effect of Annealing Temperature on the Coercivity and the Electrical Resistivity of the Electroplated Ni-Fe-W Alloy Film

“…We investigate the influence of annealing temperature on the H C and the resistivity of the plated alloy. The Ni-Fe-W alloy films have attracted attention due to its soft magnetic properties and are suitable for a micro-transformer magnetic core [16][17] and a magnetic recording head [18].…”