CORE FOR ROTARY TRANSFORMER AND MANUFACTURE THEREOF

PURPOSE:To reduce transfer loss without lowering the coefficient of coupling by a method wherein a first insulating layer is formed between the upper surface of the circular conductive layer, located on one-surface of a ring-shaped tabular member having shaft hole, and the conductive layer, a first lead connecting terminal is formed on the upper surface of the insulating layer and the side face of the ring-shaped tabular member from the tip of the inner circumference, and a second insulating layer is formed on the upper surface of the ringshaped tabular member other than the conductive layer. CONSTITUTION:Circular conductive layers 5 are formed on one surface of a ring-shaped tabular body 1 having a shaft holde 3, and a first insulating layer 6 is formed on the upper surface and the circumference of the layer 5 and between adjacent conductive layers 5 leaving the tips of the inner and outer circumferences of the conductive layers. Then, the region ranging from the tip of the outer circumference of the conductors 5 to the side face of the ring-shaped tabular body 1 is coated with silver paste, and after the region ranging from the tip of the inner circumference of the conductive layers 5 to the upper surface of the first insulating layer 6 and the side face of the ring-shaped tabular body 1 has been coated with silver paste in the same manner as above, first and second connection terminals 7 and 8 are formed by heating, a second insulating layer 11 is formed on the upper surface of the ring-shaped tabular body 1 of the part where the conductive layers 5 are not formed, and a core is obtained.