2002 Volume 49 Issue 2 Pages 77-86
The incessant demand for higher density circuits in electronics has required the continued miniaturization of all components. As a solution, surface mount technology (SMT) was developed resulting in densification of component mounting. Therefore, efforts have been made to produce electronic components in surface mount device (SMD) form. Since the inductor had to be wound with wire, it was difficult to reduce the size of the chip without any deterioration of magnetic properties. Thick-film printing process and low temperature sintering NiCuZn ferrites due to its co-firability with Ag (below 900°C) were developed for multilayer chip inductors in 1980. It is known that NiZn ferrite has high resistance, and that CuZn ferrite is a low-fire composition, therefore NiCuZn ferrite was studied to combine both properties. Over the past decades a considerable number of studies have been made on the interface between Ag-conductor and ferrite, Ag-diffusion with specially reference to the micro/nano structure and electromagnetic properties of NiCuZn ferrite. Therefore, it was known that the controlling stress by the internal Ag-conductor and CuO1-x/Ag on ferrites grain boundary is most important key point for high performance multilayer chip ferrites as well as the chemical composition of ferrite.
