Manufacturing method of MnZn ferrite core and MnZn ferrite core

摘要

Used at a frequency of 1 MHz or more and an excitation magnetic flux density of 75 mT or less, and contains 53 to 56 mol% Fe in terms of Fe ₂ O3, ₃ to 9 mol% Zn in terms of ZnO, and the balance Mn in terms of MnO. In addition, for a total of 100 parts by mass of the main component in terms of the oxide, a method for producing an MnZn-based ferrite core containing 0.05 to 0.4 parts by mass of Co as a subcomponent in terms of Co ₃ O ₄ , A molding process to obtain a molded body by molding raw material powder of MnZn ferrite, The sintered body is sintered, cooled to a temperature of less than 150 ° C. to obtain a sintered body of MnZn ferrite, and the obtained sintered body of MnZn ferrite is condition 1: 200 ° C. or higher, and Condition 2: (Tc-90) ° C. to (Tc + 100) ° C. [where Tc is the Curie temperature (° C.) obtained by calculation from the mol% of Fe ₂ O ₃ and ZnO contained in the main component of the MnZn ferrite. It is. ], And a heat treatment step of lowering the temperature from the holding temperature at a rate of 50 ° C./hour or less.