Abstract: A coil device includes a bobbin including a hollow cylindrical portion and first and second flanges disposed at ends of the hollow cylindrical portion, and having a first partition located between the first and second flange and a second partition located between the first partition and second flange; the first winding wound around the outer periphery of the hollow cylindrical portion between first partition and the first flange; the second winding wound around the outer peripheral surface of the hollow cylindrical portion between the first partition and the second flange, and wound around both sides of the second partition according to a predetermined position. The coil device can wind the winding wire of the second winding at a predetermined position, thereby reinforcing the secondary side magnetic coupling while controlling or reducing the leakage inductance manufacturing error between the primary and secondary side due to difference in the secondary side winding.

Abstract: A coil device includes a bobbin including a hollow cylindrical portion and first and second flanges disposed at ends of the hollow cylindrical portion, and having a first partition located between the first and second flange and a second partition located between the first partition and second flange; the first winding wound around the outer periphery of the hollow cylindrical portion between first partition and the first flange; the second winding wound around the outer peripheral surface of the hollow cylindrical portion between the first partition and the second flange, and wound around both sides of the second partition according to a predetermined position. The coil device can wind the winding wire of the second winding at a predetermined position, thereby reinforcing the secondary side magnetic coupling while controlling or reducing the leakage inductance manufacturing error between the primary and secondary side due to difference in the secondary side winding.