XIAN RUIELECTRICAL & COMPUTER ENGINEERING2019-10-312019-10-312005-05-17XIAN RUI (2005-05-17). In-situ characterization of magnetic head disk systems. ScholarBank@NUS Repository.https://scholarbank.nus.edu.sg/handle/10635/161028<P>THE METHODS TO CHARACTERIZE THE CRITICAL PARAMETERS OF THE MAGNETIC HEAD DISK SYSTEM IN THE HDDS BECOME TOUGHER WITH THE INCREASING AREAL DENSITY. MEANWHILE, THERE IS A GROWING ENGINEERING DEMAND TO EVALUATE THESE PARAMETERS IN THE DRIVE LEVEL TEST FOR BETTER QUALITY ASSURANCE. THEREFORE, IN-SITU CHARACTERIZATION OF THE MAGNETIC HEAD DISK SYSTEMS IS STUDIED AT THE ASPECTS OF FLY HEIGHT, SNR AND NONLINEARITY FLUCTUATION. </P><P>IN THE THESIS, THE TRIPLE HARMONIC METHOD IS IDENTIFIED AS THE MOST APPROPRIATE METHOD TO MEASURE SUB-10 NM FLY HEIGHT AND USED TO STUDY THE CONTACT INDUCED SLIDER VIBRATION ON THE DISKS. FOR BETTER NOISE MEASUREMENT, AN IN-SITU SNR TESTING METHOD IS PROPOSED TO OBTAIN THE SNR FLUCTUATION PROFILE AND ITS FEASIBILITY IS VERIFIED. FURTHERMORE, EVEN HARMONIC RIPPLE EFFECT IS STUDIED AND USED TO DERIVE THE DYNAMIC NONLINEARITY CHANGE ALONG THE TRACKS AND OBSERVE THE NLTS FLUCTUATION. </P>enIn-Situ, Fly Height, Signal-to-Noise Ratio, Recording Performance, Demagnetization Field, NLTS.Thesis