Dimension Effect of Embedded Contact Sensor on Disk Defect Detection

ASME 2013 Conference on Information Storage and Processing Systems ◽

10.1115/isps2013-2895 ◽

2013 ◽

Author(s):

Masaru Furukawa ◽

Junguo Xu ◽

Jianhua Li

Keyword(s):

Defect Detection ◽

Thermal Contact ◽

Hard Disk Drives ◽

Defect Size ◽

Contact Detection ◽

Disk Drives ◽

Magnetic Head ◽

Head Slider ◽

Contact Sensor

A thermal contact sensor embedded in a magnetic-head slider was developed. The sensor has been used for contact detection between a head slider and a disk in hard disk drives, and, our previous research has shown that the sensor could successfully detect disk defects including asperities and pits. In this work, the sensor dimension effect and characterization of defect size was studied in order to better understanding of defect size. The results showed that the defect size can be clarified by considering sensor size and scan pitch.

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Temperature Study of Embedded Contact Sensor for HDDS by Using Scanning Thermal Microscopy

2014 Conference on Information Storage and Processing Systems ◽

10.1115/isps2014-6935 ◽

2014 ◽

Author(s):

Masaru Furukawa ◽

Junguo Xu ◽

Jianhua Li ◽

Kiyoshi Hashimoto ◽

Makoto Satou

Keyword(s):

Hard Disk Drives ◽

Disk Drives ◽

Scanning Thermal Microscopy ◽

Height Control ◽

Head Slider ◽

Self Bias ◽

Key Factor ◽

Contact Sensor ◽

Sensor Temperature ◽

Fly Height

An embedded contact sensor (ECS), which is a thermal sensor built into a head slider, has been used for contact detection between the head slider and the disk in hard disk drives. Our previous research showed that ECS could successfully detect pits on the disk and spacing modulation between the head and disk. In this work, the sensor temperature effect caused by self heating and by the thermal fly height control (TFC) heater was studied in a non-flying condition for better understanding ECS. The results showed that the temperature dependency of the TFC heater was 10 times that of ECS self-bias heating. TFC heating is dominant and the key factor in ECS sensitivity to pit detection and spacing monitoring.

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Thermal fly-height controlled glide for disk defect detection and defect size estimation for hard disk drives

Microsystem Technologies ◽

10.1007/s00542-014-2160-5 ◽

2014 ◽

Vol 20 (8-9) ◽

pp. 1523-1527 ◽

Cited By ~ 2

Author(s):

Aravind N. Murthy ◽

Karl A. Flechsig ◽

Wes Hillman ◽

Keith Conard ◽

Remmelt Pit

Keyword(s):

Defect Detection ◽

Hard Disk Drives ◽

Hard Disk ◽

Defect Size ◽

Disk Drives ◽

Size Estimation ◽

Fly Height

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Characterization of Ultra-Thin Diamond-Like Carbon Films by SEM/EDX

Coatings ◽

10.3390/coatings11060729 ◽

2021 ◽

Vol 11 (6) ◽

pp. 729

Author(s):

Chanida Puttichaem ◽

Guilherme P. Souza ◽

Kurt C. Ruthe ◽

Kittipong Chainok

Keyword(s):

Regression Models ◽

Hard Disk Drives ◽

Carbon Films ◽

Diamond Like Carbon ◽

Disk Drives ◽

Cross Sectional ◽

Protective Films ◽

High Throughput Method ◽

Multiple Regression Models

A novel, high throughput method to characterize the chemistry of ultra-thin diamond-like carbon films is discussed. The method uses surface sensitive SEM/EDX to provide substrate-specific, semi-quantitative silicon nitride/DLC stack composition of protective films extensively used in the hard disk drives industry and at Angstrom-level. SEM/EDX output is correlated to TEM to provide direct, gauge-capable film thickness information using multiple regression models that make predictions based on film constituents. The best model uses the N/Si ratio in the films, instead of separate Si and N contributions. Topography of substrate/film after undergoing wear is correlatively and compositionally described based on chemical changes detected via the SEM/EDX method without the need for tedious cross-sectional workflows. Wear track regions of the substrate have a film depleted of carbon, as well as Si and N in the most severe cases, also revealing iron oxide formation. Analysis of film composition variations around industry-level thicknesses reveals a complex interplay between oxygen, silicon and nitrogen, which has been reflected mathematically in the regression models, as well as used to provide valuable insights into the as-deposited physics of the film.

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