SPINDLE MOTOR AND DRIVING DEVICE OF DISC

摘要

Provided is a spindle motor for a 2.5″type disk driving device according to an embodiment of the present invention, and the spindle motor comprises: a base having a stator core seating part protruding upwardly in an axial direction; a stator core including a ring-shaped coreback part disposed on the stator core seating part, a teeth part extending from the coreback part in an outer diameter direction, and a front end part formed at an end portion of the teeth part; and a coil wound around the stator core, wherein when a length of the stator core from an inner end portion of the coreback part to the endmost part of the front end part is defined as L and a height of the wound coil from the lowermost edge of the coil in an axial direction to the uppermost edge thereof is defined as H, a ratio (H/L) of the height of the wound coil to the length of the stator core in which back electromotive force is 0.35 V/Krpm or more when the power supply is stopped satisfies 0.524<=H/L<=0.703.