Nano-Scale Defect Mapping on a Magnetic Disk Surface Using a Contact Sensor

• Published in: IEEE transactions on magnetics Vol. 47; no. 10; pp. 3426 - 3432
• Main Authors: Shimizu, Yuki, Xu, Junguo, Kohira, Hidekazu, Kurita, Masayuki, Shiramatsu, Toshiya, Furukawa, Masaru
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-10-2011; Institute of Electrical and Electronics Engineers
• Subjects: Chemical elements; Contact sensor; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; hard-disk drive; head-disk interface; Heating; Magnetic heads; Materials science; Optical sensors; Optical surface waves; Other topics in materials science; Physics; Sensitivity; Thermal sensors; tribology; Interfaces; harddisk drive; Contact sensor; Disks; headdisk interface; Defects; Magnetic properties; Tribology
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2011.2144961

Targeting both higher touchdown sensitivity and highly accurate nanometer-scale defect detection on a disk surface, a thermal-contact sensor, integrated into a magnetic-head slider, was developed. It was experimentally shown that the contact sensor has sensitivity for detecting head-disk contact at each radial position on a disk surface equivalent to that of a conventional acoustic-emission (AE) sensor. It was also shown that a defect-detection method using the thermal-contact sensor is feasible. Defect mapping, in which a slider inspecting the disk at a certain clearance detects small defects on the disk surface, done with this method was better sensitive with measurements with an optical surface analyzer (OSA). Defect mapping on a proto-type glide tester, based on a conventional glide tester, using the thermal-contact sensor was also demonstrated.