Etching Process to Reduce Interlamination Short Circuits and Core Loss Comparison for Tape-Wound Cut Cores

Soft-magnetic ribbon-based materials have been gaining popularity as their properties yield better efficiencies and power densities. Nevertheless, magnetic designs with these materials present a major shortcoming in the manufacturing process of tape-wound cut cores. Thus, this paper focuses on the critical issue of ribbon-based soft-magnetic cut-cores due to short-circuited layers along the cross-sectional area resulting from the cutting process. An etching process is proposed to overcome the interlamination short circuits of the magnetic cores. Microscopic view of the cross- sectional area demonstrates the effectiveness of etching process. Furthermore, two identical experimental medium- frequency transformers are built to study and compare the effects of the core etching on the transformer parameters. Open- and short-circuit impedance responses, and core loss characterization over frequency and flux density are presented before and after the etching process to establish the proper process to handle these tape-wound cut cores.