Low Flying-Height Slider With High Thermal Actuation Efficiency and Small Flying-Height Modulation Caused by Disk Waviness

Abstract

To sustain an ultra-low and stable flying height (FH) is crucial for achieving high areal densities in magnetic recording. Recently, a new method called thermal flying height control (TFC) has been introduced to the latest generations of disk drives for precise control of sliderdisk spacing. It is noted that the TFC technique is able to eliminate almost all static FH loss, but is unable to circumvent dynamic FH loss such as flying height modulation (FHM) due to disk waviness. It is therefore advantageous to have both high thermal actuation efficiency and low FHM due to disk waviness characteristics in a TFC slider design. This paper investigates the effects of air bearings on the thermal actuation efficiency and the capability in following disk waviness of the TFC sliders. Air bearing surface (ABS) design strategies for TFC slider are proposed and investigated with simulations. The results show that both excellent thermal actuation efficiency and strong capability in following disk waviness can be achieved through proper arrangements of air bearing pressure distribution on the ABS of TFC sliders.Index Terms-Flying height, flying height modulation, head-disk interface, thermal flying height control, waviness.

Effects of environmental temperature and humidity on thermal flying height adjustment

“…Figure 1 shows the diagram of models used in the study. Liu et al (2008) gave a detailed description of this coupled-field analysis method.…”

Investigation of Mechanical Clearance Change with Thermal Flying-height Control Slider at High Altitude

“…Lower positive pressure of design B at a magnetic head therefore improves TFC efficiency. As one approach to improving TFC efficiency by ABS design, a groove structure around the magnetic head has been proposed [14,15]. To investigate the effect of TFC actuation on change in head-disk clearance at high altitude, we evaluated two ABS designs with different TFC efficiencies.…”

The effect of air bearing contour design on thermal pole-tip protrusion

“…In order to increase the efficiency of thermal flying height control sliders it is important to optimize the air bearing design of the air bearing surface (ABS) of the slider. Juang and Bogy (2007) and Liu et al (2008) found that a small isolated air bearing trailing pad supporting the read/ write element of the slider improves the thermal actuation efficiency of the TFC slider since it generates little air bearing pressure. A pad structure featuring trenches was proposed by Gonzaga and Liu (2009).…”