Patent ID: 8842386

Claim:
A spindle motor for use in a disk drive apparatus, the spindle motor comprising: a base plate; and a rotating portion rotatably supported by the base plate through a bearing mechanism; wherein the base plate includes: a bottom plate portion arranged to extend perpendicularly or substantially perpendicularly to a rotation axis of the rotating portion; and a wall portion arranged to extend in an axial direction from a radially outer edge portion of the bottom plate portion; the bottom plate portion includes: a cup portion including an upper surface recessed on a radially inner side of the wall portion; and an outer bottom plate portion arranged to extend between the cup portion and the wall portion; the base plate includes: a first member made of a first type of metallic material; and a second member made of a second type of metallic material; the second type of metallic material has a Young's modulus greater than that of the first type of metallic material; the first member includes at least the wall portion; the second member includes a plate-shaped portion arranged to define at least a portion of the outer bottom plate portion; and the plate-shaped portion is arranged to extend perpendicularly or substantially perpendicularly to the rotation axis.