Interactions between silver inner electrode and Fe-Si-Cr alloy of metal multilayer chip inductors

The silver diffusion and chemical reaction between Fe-Si-Cr alloy and Ag during multilayer metal power inductor preparation are investigated using scanning electron microscopy, field emission transmission electron microscopy and multipurpose X-Ray thin-film diffractometer. The experimental results show that a large amount of inner electrode, Ag, volatilize and diffuse under air atmosphere during co-firing, resulting in the reaction between Ag and thermally grown oxide layer, Cr2O3, forming flaky AgCrO2. The p-type semiconductor, AgCrO2 will cause the insulation degradation of the co-fired Fe-Si-Cr alloy multilayer chip inductors, hence reducing the power conversion efficiency due to the increase in eddy current loss.