Cosintering of Ni-Zn-Cr ferrite with low-temperature cofired ceramic substrates

Inserting a ferrite layer into a low-temperature cofired ceramic substrate offers the potential of burying inductors in multilayer ceramic substrates. To cofire a ceramic substrate at low temperatures, ferrite must be densifi ed at a low temperature. With the addition of 6wt%Bi2O3, Ni-Zn-Cu ferrite c an be densified at 900 degrees C. The doped Bi2O3 not only lowers the sinte ring temperature but also increases the permeability of Ni-Zn-Cu ferrite. T he "cordierite + borosilicate glass" system is very compatible with Ni-Zn-C u ferrite after cofiring, but the calcium borosilicate crystallizable glass system is incompatible with Ni-Zn-Cu ferrite. However, with the addition o f 10wt%SiO2 into the calcium borosilicate crystallizable glass system, the incompatibility was resolved.