Analysis of slip characteristics between dimple and flexure in hard disk drives

A mobile hard disk drive (HDD) is often faced with inevitable mechanical problems because of the portability of the drive. Then, almost HDD use much faster emergency parking system to protect the system from these problems. However, very fast emergency parking causes a large ramp contact, which could create dimple-flexure interactions such as a dimple-flexure slip, head-gimbal assembly vibration, unexpected slider motion. These dimple-flexure interactions largely affect the flyability of a slider. As such, dimple-flexure interactions are one of the most important factors in designing a mobile HDD. Therefore, in this study, we characterized the dimple-flexure slip among dimple-flexure interactions and analyzed it using a combination of experiments and finite element modeling. We evaluated the feasibility of dimple-flexure slip and verified the main cause of dimple-flexure slip. We also investigated the relationship between dimple-flexure slips and ramp contact during emergency parking. Finally, we designed the finite element ramp contact simulation, and analyzed dynamic characteristics for the dimple-flexure slip.