PURPOSE: To contrive the titled device to be more compact and thinner, by employing an iron core obtained by laminating a plurality of magnetic ribbons each having a coil pattern formed on its peripheral surface and electrically connecting the coil patterns to each other.
CONSTITUTION: A coil pattern 3 is formed on the peripheral surface of a magnetic ribbon 1 through an insulating layer 2 by photoetching, electroforming or the like. An insulating layer 6 is further provided thereon. Then, a plurality of such magnetic ribbons 1 are laminated. The coil patterns 3 on the adjacent magnetic ribbons 1 are fitted with each other from the upper and lower sides, respectively, and are then connected to each other in series by means of wire bonding or in parallel by means of spot welding. They may be connected to each other by means of a through hole. As the magnetic ribbon 1, pure iron, silicon steel, Permalloy and amorphous magnetic material can be employed. The thickness of the coil pattern 3 should be 5W10μm; the width thereof should be 10W 20μm; and the thickness of the insulating layer 6 should be in the order of 5μm. By employing such an iron core, the device using the same can be made more compact and thinner.
YOSHIDA HAJIME
EGUCHI NOBORU
