Patent ID: 8633793
Filing Date: 2014-01-21
Classification: H01F

Abstract:
1. A common mode filter, comprising: a non-magnetic insulating substrate; a first coil body, comprising a first spiral coil arranged on the non-magnetic insulating substrate; a coil leading layer, stacked above the first coil body; a first electric insulating layer, arranged between the first coil body and the coil leading layer and has a first conducting structure formed thereon, wherein the first coil body and coil leading layer respective electrically coupled to the first conducting structure; a second coil body, comprising a second spiral coil stacked above the coil leading layer; a second electric insulating layer, arranged between the coil leading layer and the second coil body and has a second conducting structure formed thereon, wherein the coil leading layer and the second coil body respective electrically coupled to the second conducting structure; an insulating layer, arranged on the second coil body; and a magnetic layer, arranged on the insulating layer; wherein a width W (mm) and a length L (mm) of at least one spiral coil in the first and second spiral coils satisfy the relational expression of: where fc (MHz) is the cutoff frequency of a differential-mode signal.