Study On The Low Temperature Sintered Mg-Cu-Zn Ferrite Powder And Its Application On Multilayer Chip Inductors

With the rapid development of electronic technology, chip and miniaturization forelectronic components has increased annually. In passive components multilayer chipinductor （MLCI） has developed very quickly in the past two decades. MLCI has amonolithic structure made by low-temperature co-fired ceramic （LTCC） technology.Low temperature sintering ferrite powder is an important raw material for productionof MLCI. The NiCuZn ferrite powder is studied and widely used as MLCI rawmaterials at home and abroad. In recent years, many MLCI manufacturers and researchinstitutions work on those materials that can replace NiCuZn ferrite powder because ofprice. It was found that the MgCuZn ferrite powder has good magnetic properties andsintering characteristics. There is rich in magnesium resources in China with lowerprice. MgCuZn ferrite is expected to be desirable alternative in MLCI production.In this paper, Fe₂O₃, MgO, ZnO and CuO as the main raw material, doped withBi₂O₃and minute amounts of CoO. Oxide method was used for MgCuZn sintering thatits permeability is μ=100±15. MgCuZn was studied on the multilayer chip inductorproduction. MgCuZn powder with Bi₂O₃doped was studied too. By use of modern testequipment such as linear expansion tester, laser particle size analyzer, we studiedMgCuZn physical and electromagnetic properties. Finally, the LTCC MgCuZn ferriterecipe powder recipe was founded for multilayer chip inductors. Subsequently,MgCuZn powder was applied to MLCI production line in Shenzhen Zhenhua FuElectronics Co., Ltd. MLCI samples performance and parameters, as compared withthe NiCuZn ferrite products, were inspected and studied. Studies found that lowtemperature sintering MgCuZn ferrite as lower cost raw materials can be used in themanufacturing of multilayer chip inductors and beads.