LOW FLYING HEIGHT MEASUREMENT WITH MULTI-WAVELENGTH INTERFEROMETRY  

作　　者：WANG Wei LAI Wuxing SHI Tielin TAO Wei CHENG Xinjian 

机构地区：[1]School of Mechanical Science and Engineering,Huazhong University of Science and Technology, Wuhan 430074. China [2]Tnbology ＆ Mechanical Characterization Division,SAE Magnetics （H.K.） Ltd., Dongguan 523087, China

出　　处：《Chinese Journal of Mechanical Engineering》2008年第3期108-111,共4页中国机械工程学报（英文版）

基　　金：National Basic Research Program of China(973 Program,No. 2003CB716207);National Natural Science Foundation of China(No.50775091)

摘　　要：A method for measurement of ultra-low flying height in head-disk spacing is described. Three different wavelengths are selected out from white light by filters to measure the spacing simultaneously. Besides solving the ambiguity problem, a more reliable result is achieved by using weighted average of measurement results from three different wavelengths, where the weight is dependent upon spacing. Fringe-bunching correction algorithm （FBC） and spot-tilling technique are adopted to suppress calibration and random errors. Moreover, incident bandwidth correction （IBC） method is introduced to compensate the error caused by low monochromaticity of incident light. Based on dynamic flying height tester （DFHT Ⅱ）, with the redesigned of photo-electric conversion and signal acquirement module, an instrument has been developed. And comparing the experimental data from the instrument with those from a KLA-FHT D6, the discrepancy is less than 5%. It indicates that the instrument is suitable to perform ultra-low flying height measurement and satisfies the reauirement of magnetic heads manufacturing.A method for measurement of ultra-low flying height in head-disk spacing is described. Three different wavelengths are selected out from white light by filters to measure the spacing simultaneously. Besides solving the ambiguity problem, a more reliable result is achieved by using weighted average of measurement results from three different wavelengths, where the weight is dependent upon spacing. Fringe-bunching correction algorithm （FBC） and spot-tilling technique are adopted to suppress calibration and random errors. Moreover, incident bandwidth correction （IBC） method is introduced to compensate the error caused by low monochromaticity of incident light. Based on dynamic flying height tester （DFHT Ⅱ）, with the redesigned of photo-electric conversion and signal acquirement module, an instrument has been developed. And comparing the experimental data from the instrument with those from a KLA-FHT D6, the discrepancy is less than 5%. It indicates that the instrument is suitable to perform ultra-low flying height measurement and satisfies the reauirement of magnetic heads manufacturing.

关 键 词：Flying height measurement Multi-wavelength interferometry Incident bandwidth 

分 类 号：TH12[机械工程—机械设计及理论]