Damped spindle motor flange for the disk pack in a hard disk drive

A disk pack for use in a hard disk drive, comprising:

• a spindle motor comprising a principal axis and a dampened spindle motor flange, further comprising a disk face including a shallow groove symmetrically arranged about said principal axis;
• wherein said shallow groove includes a first rim joined to a trough joined to a second rim;
• wherein said first rim is closer to said principal axis than said trough and said trough is closer to said principal axis than said second rim;
• wherein said trough has a depth of at least 0.5 millimeters (mm);
• and
• wherein said disk pack, further comprises:
• a metallic ring included at least one layer of a visco-elastic material composed primarily of a partially viscous elastomer deposited on said metallic ring;
• and
• said spindle motor coupling said shallow groove filled with said layer of said visco-elastic material through compression of said visco-elastic material, in said trough, by said metallic ring to a disk;
• wherein said layer of said visco-elastic material has a thickness of at least 0.05 mm more than said trough before said compression.