NiCuZnフェライト焼結体の低温作製とその材料特性評価

抄録

NiCuZn ferrite has been widely applied to multilayer chip inductors in recent years. While fabricating the multilayer structure of ferrite and metal alternatively, it is requested to simultaneously sinter in low temperature for the internal conductor Ag (Melting point 960°C) and ferrite materials. The purpose of this study is to fabricate the NiCuZn ferrite sintered body with high-strength and high-frequency magnetic property. The procedures are as follows: firstly, the NiCuZn ferrite powder was synthesized under a CO₂ atmosphere at 500°C from the mixed doxalate which was synthesized by liquid phase deposition method from mixed metal chloride and ammonium oxalate; subsequently, a small amount of boric acid [H₃BO₃] was added to the powder, and then the NiCuZn ferrite powder compact was formed with Newton press and CIP methods; finally, the NiCuZn ferrite sintered body was fabricated by sintering at 900°C under a CO₂ atmosphere. Through the experiments of high temperature shrinkage, evaluation of mechanical strength and magnetic property, NiCuZn ferrite fabricated by this study can present good characters on high frequency and high mechanical strength when the sintering temperature and boric acid additive are 900°C and 0.5 mass%, respectively.