THIN FILM INDUCTOR AND THIN FILM TRANSFORMER

摘要

PURPOSE:To allow minimum copper loss of a flat coil for a thin film inductor and a thin film transformer under the limited space condition. CONSTITUTION:A spiral flat coil 5 is buried in a torus insulating layer 2, the external side of the insulating layer 2 is covered with a bottom magnetic film 3 and a top magnetic film 4 and a thin film inductor is formed on a board 1. The line width is increased as it goes further from the center following the prescribed calculating formula. Thus, the copper loss at each part of the flat coil 5 is made the same or almost the same, heat dissipation from each part of the flat coil 5 is made uniform under the limited space condition and the total copper loss of the flat coil 5 is minimized so as to allow low copper loss.