Patent attributes
A common mode filter is provided as one in a three-layered structure with improved high-frequency characteristics. The common mode filter 1 has the three-layered structure including a first coil layer 14, a second coil layer 18, and a lead layer 16. A first planar coil 21 and a second planar coil 41 of a substantially circular spiral shape are formed in the first and second coil layers 14, 18, respectively. A first lead wire 31 and a second lead wire 32 formed in a lead layer 16 have a first straight portion 31c and a second straight portion 32c, respectively. The first straight portion 31c is located on a straight line L1 perpendicular to a plurality of first tangent lines to spirals 22, 42 at a plurality of respective intersection points with the spirals 22, 42. The second straight portion 32c is located on a straight line L2 perpendicular to a plurality of second tangent lines to the spirals 22, 42 at a plurality of respective intersection points with the spirals 22, 42.
