MEMS based fabrication of high-frequency integrated inductors on Ni-Cu-Zn ferrite substrates

作者：Anthony Ricky^*; Wang Ningning^*; Casey Declan P; Mathuna Cian O; Rohan James F

来源：Journal of Magnetism and Magnetic Materials, 2016, 406: 89-94.

DOI：10.1016/j.jmmm.2015.12.099

• Ferrite
• Micro-fabrication
• Micro-Inductors
• DC-DC converters
• Integrated magnetics

A surface micro-machining process is described to realize planar inductors on ferrite (Ni0.49Zn0.33Cu0.18Fe2O4) for high-frequency applications (< 30 MHz). The highly resistive nature (similar to 10(8) Omega m) of the Ni-Cu-Zn substrate allows direct conductor patterning by electroplating of Cu windings through a photo resist mold on a sputtered seed layer and eliminates the need for a dielectric layer to isolate the windings from the bottom magnetic core. Measured inductances similar to 367 nH (DC resistance similar to 1.16 Omega and Q-value > 14 at 30 MHz) and similar to 244 nH (DC resistance similar to 0.86 Omega and Q-value similar to 18 at 30 MHz) at 1 MHz for elongated racetrack (10.75 nH/mm(2)) and racetrack inductors (12.5 nH/mm(2)), respectively show good agreement with simulated finite element method analysis. This device can be integrated with power management ICs PMICs for cost-effective, high-performance realization of power-supply in package (PSiP) or on-chip (PSoC). This simple process lays the foundation for fabricating closed core ferrite nano crystalline core micro-inductors.

• 出版日期2016-5-15