MANUFACTURE OF SOFT FERRITE

PURPOSE:To improve the deterioration in characteristic of a baked ferrite core by spreading the powder, the main component of which is zinc such as zinc or zinc carbonate, between a ferrite compact and a ceramic floorplate in baking the ferrite compact. CONSTITUTION:As a result of measuring the Zn density of a core baked on an alumina floorplate from the bottom face which is in contact with the floorplate towards the inside, it is known that the Zn density from the bottom face up to about 200mum depth is lower than that of the inside of the core. The deterioration in magnetic characteristic when ferrite is baked on an alumina or mullite floorplate is caused by the fact that a Zn component in the surface layer of ferrite moves into the floorplate. In order to avoid this problem, zinc oxide or zinc carbonate powder, the main component of which is zinc, is spread between a ferrite compact and a ceramic floorplate to be brought into direct contact with the ferrite compact. By this method, a soft ferrite core having an excellent magnetic characteristic can be manufactured.