Effect of Dimple Offset on the Operational Shock Performance of Small Form Factor Disk Drives

Abstract

This paper discusses the effect of varying the suspension load dimple location on the shock robustness of small form factor hard disk drives. We use the CML shock simulator, which simulates the structural as well as the air bearing dynamics of the disk drive simultaneously. The location of the dimple is varied and simulations are run for various load positions on the back of the slider, while adjusting the pitch static attitude (PSA) and the roll static attitude (RSA) of the slider such that the flying attitude of the slider remains the same. We simulate shocks of 0.5 ms pulse width for a commercially available slider and suspension designs for a 1 in. drive. We observe that shock resistance is optimal when the dimple is offset toward the leading edge of the slider. This behavior is explained on the basis of a linearized air bearing model. It is also observed that moving the dimple too much toward the leading edge causes the mechanism of shock failure to change resulting in lower shock tolerances.