KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/kmitl/1

Browse

Settings

Access type: UnknownSubject: search.filters.subject.Flying height

Search Results

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Cloud-based optical characterization of hard disk drive recording heads
    (2018-01-01)
    Khunrattanasiri, Weerayuth
    ;
    Yokpradit, Anchyza
    ;
    Tongloy, Teerawat
    ;
    Boonsang, Siridech
    In the hard disk drive (HDD) industry, the measurement of flying height is crucial for the verification of the recording head air-bearing design. The flying performance of recording heads has to be measured and compared with the original design to assure the reliability of HDDs. Optical interferometry is normally used to measure the flying height of recording heads. The key parameter for setting up the measurement is the refractive index, whose values normally deviate depending on machine conditions during the manufacturing processes. The variation in refractive index cannot be identified during flying height measurement because there is no on-line technique for doing so. In this paper, we present a novel technique using inhouse designed micro-ellipsometry to measure the complex refractive index combined with data transfer to a private cloud network via the Internet of Things message queuing telemetry transport (IoT MQTT) protocol. Therefore, the measurement of the complex refractive index can be carried out for each recording head and we can improve the precision of the flying height measurement. In addition, the information about refractive index not only can be shared with a flying height tester to correct the variation in each recording head but also can be used to assist air-bearing designers in the instantaneous validation of their design.
      2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    An Experiment Study of Head-to-Media Spacing Sensitivity in Ultra-high Density Magnetic Recording Systems
    (2016-01-01)
    Nhunork, Pichet
    ;
    Warisarn, Chanon
    ;
    Tongsomporn, Damrongsak
    The decrease in flying height due to the higher recording areal density of hard disk drives (HDDs) has had a huge impact on data storage technology. The head protrusion that induced by ambient temperature can further reduce flying clearance by a few nanometers. However, the head-disk interface reliability should be also emphasized; since when the head flies too close to the media, the recording head may be burnished. To investigate the head-to-media spacing sensitivity, we use the spin stand tester and analyze the sensitivity through the measurement of overwrite (OVW), micro-track profile (MTP), and signal-to-noise ratio (SNR). The experiment results imply the significant relationship between the OVW and the heater-induced writer protrusion (H-IWP). Furthermore, we verify that the properly reduction of head-to-media spacing can also enhance the both of writability and readability.
      2