Int. J. of Nanomanufacturing   »   2015 Vol.11, No.3/4

 

 

Title: A visual non-contact focusing probe for the measurement of micro cavities

 

Authors: Ke Zhang; Qing Zhang; Chi-Duen Lin; Kuang-Chao Fan

 

Addresses:
School of Instrument Science and Opto-electronic Engineering, Hefei University of Technology, 193 Tunxi Rd., Hefei 230009, China
School of Instrument Science and Opto-electronic Engineering, Hefei University of Technology, 193 Tunxi Rd., Hefei 230009, China
Department of Mechanical Engineering, National Taiwan University, 1 Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan
Department of Mechanical Engineering, National Taiwan University, 1 Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan; School of Instrument Science and Optoelectronic Engineering, Hefei University of Technology, 193 Tunxi Rd., Hefei 230009, China

 

Abstract: The dimensional measurement of micro cavity profile to nanometre resolution is difficult because the edge is not able to be detected accurately with a microscope due to diffraction limit. With a touch-trigger probe on a micro-CMM, the probe cannot enter into the cavity if the tip-ball diameter is larger than the cavity size. In this paper, a vision-assisted non-contact focusing probe is presented to deal with this problem. A blue-ray DVD pickup head is adopted as the focusing sensor which is based on the principle of light reflection. Assisted by a nanopositioning stage, the focusing signal can detect the edge when the spot passes through it. In order to know the measuring point, a CCD is used for viewing the relative position between the focused spot and the edge. Experimental tests of the probe were carried out in association with a micro-coordinate measuring machine. The edge position is obtained up to a resolution of 1 nm with standard deviation of about 26 nm. This performance is beyond the diffraction limit of optical microscopes.

 

Keywords: microcavity measurement; blue-ray pick-up head; microcavity profile; visual non-contact focusing probe; micro coordinate measuring machines; micro CMMs; dimensional measurement; light reflection; nanopositioning; nanotechnology.

 

DOI: 10.1504/IJNM.2015.071928

 

Int. J. of Nanomanufacturing, 2015 Vol.11, No.3/4, pp.207 - 218

 

Date of acceptance: 05 Jun 2015
Available online: 23 Sep 2015

 

 

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