AIP Advances (Jan 2020)

Spray-coated magnetic powder composite planar inductor for compact IoT sensor node

  • T. Hara,
  • M. Yamaguchi

DOI
https://doi.org/10.1063/1.5130484
Journal volume & issue
Vol. 10, no. 1
pp. 015333 – 015333-4

Abstract

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A spray coating process of magnetic powder composite material is proposed in this paper for planar inductors and transformers for small DC/DC converter. This is a low temperature (≤150 °C) process that is usable for ferrites and extensively other magnetic powders and flakes. A commercially available Ni-Cu-Zn spinel ferrite particles and epoxy resin composite is applied for a 3 x 3 mm2 planer spiral inductor whose coil has 1 μm-thick, line/space =56/9 μm, and 10 turns made on a Si substrate, and exhibited inductance enhancement from from 157 nH to 205 nH (30%) without any resistance increase, up to 5 MHz. Physical stress by the proposed spray coating process can be negligible, judging from the well increased inductance and low resistance.