A visual non-contact focusing probe for the measurement of micro cavities Online publication date: Wed, 23-Sep-2015
by Ke Zhang; Qing Zhang; Chi-Duen Lin; Kuang-Chao Fan
International Journal of Nanomanufacturing (IJNM), Vol. 11, No. 3/4, 2015
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.
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Nanomanufacturing (IJNM):
Login with your Inderscience username and password:
Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.
If you still need assistance, please email subs@inderscience.com
Our Blog 
Follow us on Twitter 
Visit us on Facebook