| 摘要 |
PROBLEM TO BE SOLVED: To restrain deterioration of coupling coefficient, by injection-molding a magnetic material core in the state that a conductor leading-out part is opened, and injection-molding the conductor leading-out part of the magnetic material core. SOLUTION: In this manufacturing method of a rotary transformer, low permeability magnetic material is used in a conductor leading-out part 2 in the rotary transformer 1 in which a coil 3 is formed on a high permeability magnetic material core 4 by using paste conductor. In this manufacturing process, after Ni-Zn based ferrite is injection-molded in a state that the conductor leading-out part 2 is opened, general Mn-Zn based ferrite is injection-molded in the conductor leading-out part 2, in a step of molding. In a step of baking, when general Mn-Zn based ferrite is used in the conductor leading-out part 2, Ni-Zn based ferrite is used in the other parts. Baking is performed in an optimum condition for Ni-Zn base. In a step of coil molding, a coil trench and a leading-out hole are filled with paste conductor, and baking is performed at a low temperature of 100-200 deg.C. Facing surfaces or the like are polished in the final step. |
