Patent ID: 8705203

Claim:
A spindle motor for a 2.5″ type disk driving device, comprising: 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 tooth part extended from the coreback part in an outer diameter direction, and a front end part formed at an end portion of the tooth part; and a coil wound around the stator core, wherein 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 (B-EMF) is 0.35 V/Krpm or more when the supply of power is stopped, satisfying 0.524≦H/L≦0.703.