Characterization of inductor with Ni-Zn-Cu ferrite embedded in B2O3-SiO2 glass

Abstract

In this study, inductors using a new low-temperature cofirable ceramic (LTCC) design, in which Ni-Zn-Cu ferrite was buried in B2O3-SiO2 glass within the core of the spiral silver coil, were fabricated. The inductance and quality factor of the inductor with embedded ferrite are larger than those of pure B2O3-SiO2 glass. Ni-Zn-Cu ferrite was incompatible with the B2O3-SiO2 glass during the cofiring process due to sintering shrinkage mismatch. The incompatibility was resolved when 35 wt % Al2O3 was doped into the B2O3-SiO2 glass, which produces a glass-ceramic, and 2 wt % of Bi2O3 was fluxed into the Ni-Zn-Cu ferrite as a sintering aid. The addition of 2 wt % of Bi2O3 not only enhances densification, but also increases the permeability of Ni-Zn-Cu ferrite.