Dynamics of Contacting Head-Disk Interfaces

Abstract

We have successfully designed, fabricated, and tested contact recording sliders where most of the suspension load is supported by an air-bearing surface with only a small contact force ( 5 mN) acting on the rear contact pad. To understand the contact dynamics, we have developed an integrated approach where experimental results from friction and laser doppler vibrometry are modeled using an air-bearing code modified to include contact forces. A low bounce ( 1 nm mean-to-peak) is achieved in our designs by reducing the real area of contact to minimize friction, by increasing disk roughness, and/or by reducing the width of the slider contact pad. Due to the reduced magnetic spacing, these contact recording heads have bit-error rates several orders lower than conventional flying heads.

Observation of Slider Landing Process in Hard Disk Drive

“…The average contact force in the first three slider landing stages is on the order of 1 mN. It is quite comparable with other calculations [11,14]. In the 2nd stage of the slider landing process from 6030 to 4830 rpm (marked with the grey vertical dotted line B), the contact force is quite small.…”

The Head-Disk Interface Roadmap to an Areal Density of Tbit/in2

“…The most common method used for this control is to embed an electrical resistive heater in the slider that will cause the transducer area to protrude closer to the disk, as is shown in Figure 6 [19][20][21]. At some point the interface may need to be designed to withstand intermittent or continuous contact [22][23][24][25][26][27].…”

Frontiers of fundamental tribological research

“…To achieve higher storage densities, the clearance between head and disk will have to be reduced to a few nanometers [42] or even to the point of continuous contact [43]. This will place even greater tribological demands on the few nanometers of lubricant and overcoat at this moving interface, which must provide years of wear resistance and corrosion protection.…”