scholarly journals Impact of radius and skew angle on areal density in heat assisted magnetic recording hard disk drives

AIP Advances ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 056507
Author(s):  
Michael Cordle ◽  
Chris Rea ◽  
Jason Jury ◽  
Tim Rausch ◽  
Cal Hardie ◽  
...  
Keyword(s):  
Magnetic Recording ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Areal Density ◽  
Disk Drives ◽  
Skew Angle ◽  
Heat Assisted Magnetic Recording

Thermal Lagging of Multilayered Structure in Heat-Assisted Magnetic Recording Systems

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Jian Su ◽  
Tingting Tang ◽  
Ruixin Lu ◽  
Peng Yu
Keyword(s):  
Temperature Gradient ◽  
Thermal Resistance ◽  
Magnetic Recording ◽  
Heat Sink ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Interfacial Thermal Resistance ◽  
Disk Drives ◽  
Horizontal Temperature Gradient ◽  
Heat Assisted Magnetic Recording

Abstract In the present study, we numerically investigate the thermal lagging behavior on the hard disk drives in heat-assisted magnetic recording systems via the optical absorption model. The influences of overcoats, laser radius, relative scanning speed, interfacial thermal resistance, and the heat sink layer on the thermal lagging behavior are studied in detail. It is found that the thermal lagging distance, i.e., the horizontal distance between the location of the maximum temperature and the laser center, increases with an increment of speed and/or radius of the laser spot. The overcoats, the interfacial thermal resistance, and the heat sink layer have negligible effects on the lagging distance. Thus, the multilayered disk can be simplified as a single-layer disk for investigating thermal lagging distance. Meanwhile, the horizontal temperature gradient varies with these factors. Different overcoats result in different horizontal temperature gradient owing to the difference of in-plane thermal diffusivity. A laser with a smaller radius or a slower speed leads to a higher horizontal temperature gradient. The thermal resistance influences the horizontal temperature gradient insignificantly. This study may provide useful information for the design of hard disk drives for heat-assisted magnetic recording technologies.

Separated pivot-shaft actuator for small skew angle in hard disk drives

2015 ◽  
Vol 22 (2) ◽  
pp. 297-303 ◽  
Author(s):  
Shinji Koganezawa ◽  
Hiroshi Tani ◽  
Norio Tagawa
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drives ◽  
Skew Angle

Capacity Advantage of Array-Reader-Based Magnetic Recording (ARMR) for Next Generation Hard Disk Drives

2014 ◽  
Vol 50 (3) ◽  
pp. 155-161 ◽  
Author(s):  
George Mathew ◽  
Euiseok Hwang ◽  
Jongseung Park ◽  
Glen Garfunkel ◽  
David Hu
Keyword(s):  
Magnetic Recording ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drives ◽  
Next Generation

S1620201 Development of separated pivot-shaft actuator with small skew-angle in hard disk drives

2015 ◽  
Vol 2015 (0) ◽  
pp. _S1620201--_S1620201-
Author(s):  
Shinji Koganezawa ◽  
Ying Meng ◽  
Yoshihito Hariba ◽  
Hiroshi Tani ◽  
Norio Tagawa
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drives ◽  
Skew Angle

A Near Zero Skew Actuation Mechanism for Hard Disk Drives

2013 ◽  
Author(s):  
Zhimin He ◽  
Jianqiang Mou ◽  
Kheong Sann Chan ◽  
Suet Hoi Lam ◽  
Boon Long See ◽  
...  
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drive ◽  
Outer Diameter ◽  
Disk Drives ◽  
Skew Angle ◽  
Link Mechanism ◽  
Tracking Direction ◽  
The Difference ◽  
Zero Skew

One of the issues in VCM rotary actuation in hard disk drives (HDDs) is the excessive sensitivity of the system to the skew angle. The rotation of the VCM from the inner diameter (ID) to the outer diameter (OD) of the disk results in an angle of skew between the read/write head and the track. The difference in skew angle, between the ID to the OD can be as large as 25 to 30 degrees in conventional 3.5″ and 2.5″ HDDs. A large skew angle affects the slider’s flying performance and off-track capability, causing an increase in side reading and writing, and thus reduces the achievable recording density. Large skewed actuation also complicates the position error signal calibration process in the hard disk drive servo loop. This paper presents a 4 link mechanism which can be designed to achieve near zero skew actuation in hard disk drives. The profiles of the arm, suspension, and links can be designed and optimized such that the skew angle is close to zero while the VCM actuator rotates from the ID to the OD. Study shows that the 4-link mechanism does not degrade the resonance performance along the tracking direction compared to a conventional actuator.

Design and Dynamics of Flying Height Control Slider With Piezoelectric Nanoactuator in Hard Disk Drives

2006 ◽  
Vol 129 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Jia-Yang Juang ◽  
David B. Bogy ◽  
C. Singh Bhatia
Keyword(s):  
Numerical Study ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Areal Density ◽  
Flying Height ◽  
Air Bearing ◽  
Disk Drives ◽  
Adhesion Forces ◽  
Surface Design ◽  
Ultrahigh Density

To achieve the areal density goal in hard disk drives of 1Tbit∕in.2 the minimum physical spacing or flying height (FH) between the read/write element and disk must be reduced to ∼2nm. A brief review of several FH adjustment schemes is first presented and discussed. Previous research showed that the actuation efficiency (defined as the ratio of the FH reduction to the stroke) was low due to the significant air bearing coupling. In this paper, an air bearing surface design, Slider B, for a FH control slider with a piezoelectric nanoactuator is proposed to achieve virtually 100% efficiency and to increase dynamics stability by minimizing the nanoscale adhesion forces. A numerical study was conducted to investigate both the static and dynamic performances of the Slider B, such as uniformity of gap FH with near-zero roll over the entire disk, ultrahigh roll stiffness and damping, low nanoscale adhesion forces, uniform FH track-seeking motion, dynamic load/unload, and FH modulation. Slider B was found to exhibit an overall enhancement in performance, stability, and reliability in ultrahigh density magnetic recording.

Air Bearing Pushback in Heat Assisted Magnetic Recording

2019 ◽  
Author(s):  
Shaomin Xiong ◽  
Robert Smith ◽  
Chanh Nguyen ◽  
Youfeng Zhang ◽  
Yeoungchin Yoon
Keyword(s):  
Magnetic Recording ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drive ◽  
Flying Height ◽  
Air Bearing ◽  
Magnetic Media ◽  
Heat Assisted Magnetic Recording ◽  
Height Control ◽  
Different Dimensions

Abstract The air bearing surface is critical to the spacing control in current hard disk drives (HDDs). Thermal protrusions, including thermal flying height control (TFC) and writer coil protrusion, drive the reader/writer elements closer to the magnetic media. The spacing control actuation efficiency depends on the air bearing push back response after the TFC or writer protrudes. In the next generation hard disk drive technology, heat assisted magnetic recording (HAMR), laser induced protrusions further complicate the spacing control. The laser induced protrusions, such as the localized NFT protrusion and a wider change of the crown and camber, have very different dimensions and transient characteristics than the traditional TFC and writer protrusion. The dimension of the NFT protrusion is relatively smaller, and the transient is much faster than the TFC protrusion. However, it is found that the NFT protrusion is large enough to generate an air bearing push back effect, which changes the read and write spacing when the laser is powered on. To accurately control spacing in HAMR, this push back effect has to be taken into account.

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