Ramesh Sundaram

Mechanical performance of laminated discs

Laminated discs are one of the enabling technologies to increase areal density of a recording disc drive to beyond 100 G/in/sup 2/. Enhanced damping characteristics do, however, come at the expense of axial rigidity of the substrates. This work demonstrates that by varying the polymer thickness, damping and axial rigidity of the substrates can be tailored to achieve desirable performance. Laminated glass-ceramic substrates are shown to offer effective damping even with poor lamination. Disc deflection during a shock event is damped out within a few cycles of vibration for the laminated discs, which should provide additional margin for head slap damage. There is no significant clamping induced distortion found for the laminated discs. Overall, mechanical performance of the laminated discs are satisfactory provided the lamination process is optimal.