FERRITE CORE AND MANUFACTURE THEREOF

摘要

PURPOSE:To obtain the ferrite core having a surface of extremely high specific resistance without deteriorating electrical and magnetic characteristics by causing a ferrite film having a high electric resistance different from that of a ferrite of its parent body to adhere to the surface of the ferrite core. CONSTITUTION:A ferrite core 1 is formed by laminating films having high electric resistance, that is, insulating films 4 over the whole surface thereof. As components of the insulating films 4, for example, oxides having ferrite components, Fe2O3, MnO, NiO, MgO or their combination can be adopted. The specific resistance of the ferrite core covered with this insulating film reaches a value exceeding 10<6>OMEGA-cm. Since the specific resistance of the ferrite core is high, it is very advantageous to manufacture the ferrite core from the viewpoint of space and assembly thereof because it is not necessary to sandwich any insulator between a coil and the ferrite core. Calcinated ferrite and parent liquid 7 of magnetic liquid are poured into a liquid tank 5 and their PH degrees are adjusted by acid or alkali to separate out powder having high specific resistance. Since this powder adheres to a ferrite member 6, the ferrite member 6 is taken out and calcinated.