Measurement of surface topography of magnetic tapes by Mirau interferometry

Abstract

Stylus-profiling techniques cannot be used for surface characterization of polymeric surfaces, such as magnetic tapes, because of their relatively low hardness An interferometric-optical-profiling microscope system was used to obtain high-accuracy surface profiles of magnetic media, rapidly and without physical contact with the sample. The profilometer consists of a conventional, reflection-type optical microscope with a Mirau two-beam interferometer attachment. The interference patterns of the surface can be observed through the eyepieces and can be detected with a solid-state linear array of 1024 detector elements. By translating the reference surface of the interferometer with a piezoelectric transducer while taking consecutive measurements, accurate surface-height measurements can be obtained from each detector element. The microscope system is controlled by a microcomputer, which communicates with a desk-top computer for further analysis of the surface-profile data. A computer-controlled specimen stage is added to increase the sample size. The reasons for selecting the Mirau two-beam interferometry are also discussed. Sample data of magnetic tapes are presented. Experimental data presented in the paper show that optimization of surface roughness is necessary to obtain optimum magnetic amplitude. friction, and wear properties.

The effect of autocorrelation length on the real area of contact and friction behavior of rough surfaces

“…4 Researchers have also developed methods to experimentally evaluate the real area of contact using, for example, contact resistance, 29 ultrasonic, 30,31 or optical methods. 32 However, experimental determination of the real area of contact in various systems still remains nontrivial. The real area of contact can also be estimated using contact mechanics models that build upon Hertz, 4 Johnson-KendallRoberts ͑JKR͒, 33 Derjaguin-Muller-Toporov ͑DMT͒, 34 or Maugis 35 mechanics.…”

Investigation of some critical aspects of on-line surface measurement by a wavelength-division-multiplexing technique

“…7 A reflection blazed grating was adopted in our system. In normal applications of the blazed grating, the diffraction angle should be equal to the incidence angle so as to obtain the maximum efficiency, that is: α=β=θ, where θ is the blazed angle.…”

“…The fabrication of integrated circuits and MST/MEMS devices is now a mature technology in many senses, however their broad use across a number of sectors has highlighted one of the problems of micro and nano scalar manufacture namely, large region surface measurement (for form and waviness) and fast quality control in the production field [4][5][6][7][8].…”

Single Shot White Light Interference Microscopy for 3D Surface Profilometry Using Single Chip Color Camera

“…In the case of white light, interference occurs only when the optical path difference (OPD) between the objective and reference beams is nearly the same (within the coherence length of the light source) so by varying one of the arms we can measure the surface roughness, small height variations and thickness of the microstructures. various schemes in WLI, such as, vertical scanning interferometry (VSI) [16,17], phase shifting interferometry (PSI) [18][19][20][21][22], fringe projection method [23][24][25][26][27], Fourier profilometry [27,28], confocal microscope [29]. In the aforementioned methods Linnik, Michelson and Mirau type interferometric objectives are used [12][13][14].…”