| 摘要 |
PURPOSE:To minimize a magnetic coupling and an electrostatic coupling between each substrate, and to obtain a micro-filter by constituting a composite LC filter by placing two ferrite substrates between the first and the second dielectric substrates on which a circuit pattern is formed. CONSTITUTION:A copper sheet 28 for preventing an electrostatic coupling of dielectric substrates 11 and 21 is connected to an earth terminal 2. Also, a circuit is connected by through-holes 15, 24, and through-holes 14, 25 as necessary. Accordingly, even if the dielectric substrate 11 and the dielectric substrate 21 are provided in the vicinty of each other, a magnetic flux of each coil is not interlinked but is independent. Accordingly, there are operarions of a magnetic shield and an electrostatic shield by a ferrite substrate 16a, the copper sheet 28 and a ferrite substrate 16b, and on the other hand, coils 12, 22 on the dielectric substrates 11, 21 can collect a leakage magnetic flux by the ferrite substrates 16a, 16b, and there is an effect by which the inductance becomes large apparently, therefore, a filter can be made small-sized. |
