Spindle motor and disk drive apparatus

A spindle motor, comprising:

• a stationary unit;
• and
• a rotary unit supported to rotate about a center axis extending up and down;
• wherein
• the stationary unit includes a base member made of metal, an armature provided with a plurality of coils and positioned above the base member, and a circuit substrate arranged on a lower surface of the base member;
• the rotary unit includes a magnet opposed to the armature with a gap therebetween;
• the base member includes a ring-shaped bottom portion positioned below the armature, at least one base through-hole extending through the bottom portion and a base groove portion arranged on a lower surface of the bottom portion to extend radially outward from a lower end portion of the base through-hole;
• a first insulating sheet portion, which is defined by a portion of the circuit substrate or a member of the circuit substrate, is arranged on a bottom surface of the base groove portion;
• a second insulating sheet portion is arranged on an upper surface of the bottom portion;
• the first insulating sheet portion or the second insulating sheet portion includes an overhang portion overlapping with a lower opening or an upper opening of the base through-hole when seen in a plan view;
• a plurality of lead wires electrically connected to the coils extends from the coils;
• the overhang portion includes at least one hole, at least one cutout, or at least one slit, through each of which at least one of the lead wires passes, a total number of the at least one hole, the at least one cutout, or the at least one slit is two or more;
• and
• the lead wires are arranged to pass through the upper opening of the base through-hole, the overhang portion, and the lower opening of the base through-hole and are arranged to extend to the circuit substrate through the base groove portion, the lead wires connected to the circuit substrate.