Surface mount coil component and manufacturing method for the same, and DC-DC converter

A DC-DC converter comprising:

• a switching element;
• and
• a choke coil connected to the switching element;
• wherein
• the choke coil includes:
• an element body defining a compact including magnetic material particles;
• a coil that is buried, excluding an end portion of the coil, in the element body;
• and
• an input-output terminal electrically connected to the end portion of the coil;
• a thermoplastic resin layer is provided on a surface on a mounting surface side of the element body;
• an interlayer connection conductor is provided in the thermoplastic resin layer;
• the input-output terminal is provided on a surface of the thermoplastic resin layer and is electrically connected to the end portion of the coil via the interlayer connection conductor;
• the end portion of the coil projects from the surface of the element body and is positioned inside the interlayer connection conductor;
• and
• a width of a wire defining the end portion of the coil is smaller than a width of the interlayer connection conductor.