Disk drive including a vibration damping system having a compressible foam and mass damper fixed adjacent to the outer surface of a printed circuit board for reducing noise and vibration

A disk drive comprising, in combination:

• a) a head disk assembly including a base casting comprising a sidewall that defines a base area within the peripheral edge of the assembly;
• b) a planar printed circuit board including opposed inner and outer surfaces, the board being fixed within the base area of the assembly so that the inner surface of the printed circuit board faces the assembly;
• c) a vibration damping system fixed adjacent the lower surface of the board and substantially underlying the base area for reducing noise and vibration associated with operation of the disk drive, the system including:
• an external planar member of compressible foam composition characterized by an unconstrained thickness d1 and having opposed upper and lower surfaces;
• and
• a substantially-planar rigid mass damper having major upper and lower surfaces;
• the external planar member and the mass damper being of similar extent and shape and arranged in overlapping configuration so that the upper surface of the external planar member contacts the outer surface of the printed circuit board and the major upper surface of the mass damper contacts the lower surface of the external planar member;
• and
• d) means for fixing the upper surface of the mass damper in substantially-uniform spaced relationship from the outer surface of the printed board by a predetermined amount less than d1 to compress the external planar member.