Closed core inductor and high-Kdielectric capacitor fabrication through evaporation driven nanoparticle assembly in capillaries

This paper outlines a low-cost multimaterial, integrated passives approach involving suspension wicking of high-K dielectric and ferromagnetic nanoparticles into capillaries comprising inductor and capacitor passive devices. The suspension is deposited into a “target well” and nanoparticles are delivered to the passive via fluidic self-assembly, resulting in inductor and capacitor value improvements. The universality of this approach has been demonstrated through the fabrication and testing of both MEMS inductors and capacitors on a single substrate, which would otherwise be fabrication-intense using traditional fabrication methods. This approach has demonstrated inductance improvements of 45% up to 500 MHz with roll-off in quality factor past 225 MHz after wicking of a NiFe2O4 nanoparticle core. In addition, capacitance was increased 400% and 600% after wicking of BaTiO3 nanoparticles/polymer composite into 1- and 2-mm-long capacitor constructs, respectively.