Utilisation of FIB/SEM Technology in the Assembly of an Innovative Micro-CMM Probe

Abstract : The measurement of features from the micro- and precision manufacturing industries requires low uncertainties and nano-scale resolution. These are best delivered through ultra precise co-ordinate measuring machines (CMMs). However, current CMMs are often restricted by the relatively large and insensitive probes used. This paper focuses on the assembly challenges of a novel micro- CMM probe. The probe is comprised of a 70 μm glass sphere, attached to a solid tungsten-carbide shaft of diameter less than 100 μm, joined to a piezoelectric flexure structure. The assembly requirements are for positional accuracy of ±0.5 μm, angle between the shaft and flexure of 90°± 0.29° and that the components be undamaged by the process. A combined Focused Ion Beam and Scanning Electron Microscope machine (FIB/SEM) with integrated nanoresolution manipulators was used. The investigation has evaluated potential assembly and joining solutions, identified modifications to existing equipment and product design and produced a set of prototypes.