Contact and temperature rise of thermal flying height control sliders in hard disk drives

2012 ◽  
Vol 18 (9-10) ◽  
pp. 1693-1701 ◽  
Author(s):  
Liane Matthes ◽  
Uwe Boettcher ◽  
Bernhard Knigge ◽  
Raymond de Callafon ◽  
Frank E. Talke
Keyword(s):  
Temperature Rise ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Height Control ◽  
Thermal Flying Height Control

Investigation of Head Burnishing of Thermal Flying Height Control Sliders

2013 ◽  
Author(s):  
Liane Matthes ◽  
Ralf Brunner ◽  
Bernhard Knigge ◽  
Frank E. Talke
Keyword(s):  
Thin Film ◽  
Surface Roughness ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Lubricant Transfer ◽  
Height Control ◽  
Thermal Flying Height Control ◽  
Disk Spacing

The head-disk spacing in current hard disk drives is approximately 1–2 nm. This distance is on the same order as the peak to valley surface roughness of a typical thin film disk. If one attempts to reduce the head-disk spacing even more, intermittent contacts between the slider and the disk are more likely to occur. Intermittent contacts are undesirable since they can result in slider and disk wear, lubricant transfer or degradation of the read and write elements.

Flying Clearance Distribution With Thermal Flying Height Control in Hard Disk Drives

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Sung-Chang Lee ◽  
George W. Tyndall ◽  
Mike Suk
Keyword(s):  
Temperature Compensation ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Disk Interface ◽  
Height Control ◽  
Thermal Flying Height Control ◽  
Height Change ◽  
The Individual

Flying clearance distribution with thermal flying height control (or thermomechanical actuation) is characterized. Especially, factors contributing to variation in the flying clearance are identified based on the flying height change profiles taken from the burn-in process of hard disk drives and Gage R&R (repeatability and reproducibility) test of touch down repeatability. In addition, the effect of static temperature compensation scheme on the flying clearance distribution is investigated, and the disadvantage of static adaptation to temperature change is identified. In order to avoid early catastrophic head-disk interface failures due to poor static temperature compensation, dynamic clearance adjustment is necessary whenever environmental condition changes. Otherwise, static temperature compensation using the individual temperature sensitivity values of each head needs to be applied.

Near Contact Thermal Flying Height Control in Hard Disk Drives

2017 ◽  
Vol 25 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Liane M. Matthes ◽  
Bernhard E. Knigge ◽  
Raymond A. de Callafon ◽  
Frank E. Talke
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Height Control ◽  
Thermal Flying Height Control

scholarly journals Servo signal processing for flying height control in hard disk drives

2011 ◽  
Vol 17 (5-7) ◽  
pp. 937-944 ◽  
Author(s):  
Uwe Boettcher ◽  
Christopher A. Lacey ◽  
Hui Li ◽  
Kensuke Amemiya ◽  
Raymond A. de Callafon ◽  
...  
Keyword(s):  
Signal Processing ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Height Control ◽  
Servo Signal

Nano Wear of Thermal Flying Height Control Sliders

2014 ◽  
Author(s):  
Andreas Hegetschweiler ◽  
Liane Matthes ◽  
Frank E. Talke
Keyword(s):  
Hard Disk Drives ◽  
Disk Surface ◽  
Flying Height ◽  
Disk Drives ◽  
Heater Power ◽  
Heater Element ◽  
Height Control ◽  
Thermal Flying Height Control ◽  
Intermittent Contact ◽  
Peak Value

To increase the storage density in hard disk drives (HDDs), the clearance between the read/write head and the disk has to be reduced. In current HDDs, the flying height of the slider is about 1–2 nm, which is on the same order as the peak to peak value of the disk surface roughness. As a consequence, intermittent contact between the slider and the disk might occur. Intermittent head-disk contacts are undesirable since they can result in wear of the slider or lubricant transfer [1]–[5]. To achieve flying-heights of 1–2 nm, thermal flying height control (TFC) sliders have been introduced in HDDs [6]. TFC sliders contain a small heater element close to the read and write element. Energizing the heater element results in thermal expansion of the slider body and a thermal protrusion is formed. An increase in heater power increases this protrusion, thereby bringing the read and write element closer to the disk (Fig. 1).

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