Patent ID: 8988181
Filing Date: 2015-03-24
Classification: H01F,Y10T

Abstract:
1. A common mode filter with a multi-spiral layer structure, comprising: a first coil; a second coil; a first insulating layer configured to separate the first coil from the second coil; a third coil connected in series with the first coil, wherein the second coil is disposed between the first coil and the third coil; a second insulating layer configured to separate the second coil from the third coil; a fourth coil connected in series with the second coil, wherein the third coil is disposed between the second coil and the fourth coil; a third insulating layer configured to separate the third coil from the fourth coil; and a first material layer and a second material layer, in which at least one of the first and second material layers comprises magnetic material; wherein at least one of the first, second, and third insulating layers comprises magnetic material; wherein the first, second, third, and fourth coils are disposed between the first and second material layers; wherein one of the first and second material layers is a heterogeneous substrate that comprises a magnetic material layer and an insulating substrate, wherein the magnetic material layer comprises a plurality of independent magnetic material blocks, wherein the plurality of independent magnetic material blocks are disposed on a surface of the insulating substrate; wherein the first coil and the third coil form a first winding, the second coil and the fourth coil form a second winding; wherein at least one magnetic material portion passes through an inter-turn space, occupying a portion of at least a turn of the first, second, third, and fourth coils; wherein the first, second, third, and fourth coils are formed surrounding the at least one magnetic material portion; wherein when a common mode current flow through the common mode filter, the first winding and the second winding generate a magnetic flux in the same direction such that the common mode filter exhibits a high impedance to suppress common mode noises.