Coil component manufacturing method, coil component, and DC-to-DC converter

A DC-to-DC converter comprising:

• a switching element;
• and
• a choke coil connected to the switching element;
• wherein
• the choke coil includes:
• an element body having a rectangular or substantially rectangular parallelepiped shape and defined by a molded body including magnetic particles;
• a coil that is embedded in the element body such that a first end portion is exposed to a first surface of the element body and a second end portion is exposed to a second surface facing the first surface;
• a first input/output terminal provided on only the first surface and connected to the first end portion of the coil;
• and
• a second input/output terminal provided on only the second surface and connected to the second end portion of the coil, and
• the coil includes:
• a wire wound portion wound in a spiral shape around a winding axis;
• a connection portion that is separated from the wire wound portion and includes at least one of the first end portion that is connected to the first input/output terminal or the second end portion that is connected to the second input/output terminal;
• and
• a coupling portion to couple the wire wound portion and the connection portion;
• and
• the connection portion is defined by a second wire wound portion wound in a spiral manner around the winding axis.