Spindle motor and recording disk drive having spindle motor

A spindle motor comprising:

• a rotor which is coaxially disposed with a center axis and which is provided at its outer periphery with a rotor magnet;
• a stator which surrounds the rotor and which is disposed at a gap from the rotor magnet in a radial direction;
• a base having a recess which is opened upward for accommodating the stator, and when a side of the base opposed to the rotor is defined as inside and a side of the base that is opposite from the inside is defined as outside, the recess is located inside;
• and
• a flexible circuit substrate having one end connected to an upper side of the stator, wherein:
• the circuit substrate has an external connecting portion connected to an external power supply;
• the base is provided, in a portion thereof radially outward of the recess as viewed from the center axis, with an extending portion having a through hole through which the external connecting portion penetrates from the back side to the front side of the base;
• and
• an inclined surface is formed on an open end of the through hole along an inward part of the base, and along the through-hole radially inner side as viewed from the center axis, the diameter thereof becomes greater toward the open end.