A disc drive assembly includes a magnetic disc mounted on a hub of a spindle
motor.
The spindle motor includes a base portion supporting the hub for rotation about
a spindle axis. A bottom surface of the base portion extends outside of an internal
disc drive environment, and a damper affixed to the bottom surface of the base
portion attenuates vibrations within the base portion of the spindle motor. A constrain
layer of the damper is secured to the bottom surface of the base portion by an
adhesive, and the constrain layer is sufficiently stiff to dampen resonant vibrations
such as rocking mode vibrations.
