Ni0.2Zn0.3Fe2.5O4 films (1-5 μm thick) were deposited by spin spray ferrite plating from an aqueous solutions onto polyimide sheets at 90°C. Their peel test and high-frequency permeability as well as noise suppression effects were investigated. The oxygen plasma treatment on polyimide sheet surface improved the film adhesion. There was not visible crack on the bended film surface for the Ni-Zn ferrite film thinner than 2 μm and was not peeled off even after the bending test of a million times. The films exhibited excellent high-frequency permeability profile and a natural resonance frequency (where the imaginary permeability reaches a maximum) f r was 370 ± 30 MHz. The transmission loss increased with the film thickness, reaching the maximum Δ P loss = 70% at 8 GHz for the 5 μm-thick film. The reflection loss in the measured frequency range was S 11 < 10 % which is small enough for films to be used as the conducted noise suppressors. The value of Δ P loss obtained for the 5-μm thick film was about 15% higher than that (Δ P loss = 55 %) attained by the commercialized 50-μm thick noise suppressing sheet.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Mechanics of Materials
- Electrical and Electronic Engineering
- Materials Chemistry