Highly Laminated Soft Magnetic Electroplated CoNiFe Thick Films

The fabrication and characterization of highly laminated (~40 layers), thick (~40 μm) films of magnetically soft cobalt-nickel-iron are presented. Thick film fabrication is based on automated sequential electrodeposition of alternating CoNiFe and copper layers, followed by selective copper removal. The film, comprised tens of 1 μm thick laminations, exhibits saturation flux density of 1.8 T and coercivity of approximately 1.3 Oe. High-frequency film characterization took place in a 36-turn test inductor, which demonstrated constant inductance of 1.6 μH up to 10 MHz, indicating suppressed eddy-current loss. Quality factor exceeding 40 at 1 MHz, surpassing the performance of similarly fabricated Permalloy (Ni₈₀Fe₂₀) films.