Common mode filter

A common mode filter, comprising:

• a drum core including a winding core, a first flange provided on one end of the winding core, and a second flange provided on the other end of the winding core, the first flange having a first lower surface that faces a mounting surface of a circuit board and a pair of first end surfaces that intersect the first lower surface, and the second flange having a second lower surface that faces the mounting surface of the circuit board and a pair of second end surfaces that intersect the second lower surface;
• a first terminal electrode provided on the first flange and having a first securing portion;
• a second terminal electrode provided on the second flange and having a second securing portion;
• a third terminal electrode provided on the first flange and having a third securing portion;
• a fourth terminal electrode provided on the second flange and having a fourth securing portion;
• a first winding wire including a first winding portion, a first lead portion, and a second lead portion, the first winding portion being wound around the winding core from a first winding start position to a first winding end position on the winding core, the first lead portion extending from the first winding start position and being secured by the first securing portion to be connected to the first terminal electrode, and the second lead portion extending from the first winding end position and being secured by the second securing portion to be connected to the second terminal electrode;
• and
• a second winding wire including a second winding portion, a third lead portion, and a fourth lead portion, the second winding portion being wound around the winding core from a second winding start position to a second winding end position on the winding core by the same number of turns and in the same direction as the first winding wire, the third lead portion extending from the second winding start position and being secured by the third securing portion to be connected to the third terminal electrode, and the fourth lead portion extending from the second winding end position and being secured by the fourth securing portion to be connected to the fourth terminal electrode;
• wherein
• the first winding start position and the second winding start position are arranged at an equal distance from the first flange and arranged symmetrically to each other with respect to a center of the winding core when viewed from a direction along the winding core,
• the first winding end position and the second winding end position are arranged at an equal distance from the second flange and arranged symmetrically to each other with respect to the center of the winding core when viewed from the direction along the winding core,
• the first securing portion and the third securing portion are arranged symmetrically to each other with respect to the center of the winding core when viewed from the direction along the winding core,
• the second securing portion and the fourth securing portion are arranged symmetrically to each other with respect to the center of the winding core when viewed from the direction along the winding core,
• the first lead portion extends linearly from the first winding start position to a first flange contact position at an inner end of the first end surface on which the first securing portion is disposed,
• the second lead portion extends linearly from the first winding end position to a second flange contact position at an inner end of the second end surface on which the second securing portion is disposed,
• the third lead portion extends linearly from the second winding start position to a third flange contact position at an inner end of the first end surface on which the third securing portion is disposed, and
• the fourth lead portion extends linearly from the second winding end position to a fourth flange contact position at an inner end of the second end surface on which the fourth securing portion is disposed.