| 摘要 |
PURPOSE: A common mode filter is provided to efficiently layout a cascade connection pattern of two spiral conductors, thereby reducing a coil forming area while maintaining a loop size, and is provided to reduce an area which is not overlapped with the spiral conductor of top and bottom, thereby reducing the leakage inductance. CONSTITUTION: A common mode filter is comprised of the followings: a substrate(11); a thin film coil layer(12) which is formed on the substrate; a first to a fourth bump electrodes(13a-13d) which are formed on the surface of the thin coil layer; and a resin layer(14) which is the surface of the thin coil layer and is formed on the area except for the first to fourth bump electrodes. The thin coil layer is comprised of the followings: a first planar coil layer(21A) which includes a first and a second spiral conductor which is mutually connected in serial, a second planar coil layer(21B) which is formed in a layer different from the first planar coil layer, and includes the third and the fourth spiral conductor which is mutually connected in serial, and a drawn conductor layer(21C) which is formed more closely to the first to the fourth bump electrodes than the first and the second planer coil layer, and includes the first to fourth drawn conductor layers. The first spiral conductor(22) and the third spiral conductor(24) are combined mutually with magnetic, and the second spiral conductor(23) and fourth spiral conductor(25) are combined mutually with magnetic. A central edge of the first through the fourth spiral conductor is connected to the first through the fourth bump electrode through the first through the fourth drawn conductor respectively. The central edges of the first and the second spiral conductor are mutually connected and the central edges of the third and the fourth spiral conductor are mutually connected. |
