Microtransformers on 3D closed-loop cores made of amorphous magnetic alloys

We present a novel approach for 3D microstructuring of amorphous soft magnetic alloys. Our unique process is MEMS-compatible and leaves the magnetic properties of the alloys intact. The applicability of the process has been demonstrated in the fabrication of closed-loop core microtransformers. The magnetic core is fabricated using Metglas 2714A, cobalt-based magnetic alloy. The microtransformers show higher performance in terms of inductance density, coupling factor, and power efficiency compared to conventional planar inductors or other published 3D microtransformers. The results are benchmarked to underline the potential of the technology in rendering chip-level power conversion competitive.