3D characterization of microspheres with nanometer precision

Contact person

Prof. Eberhard Manske
Production and Precision Measurement Technology

Phone: +49 3677 69-5050

Funding information

Project leader: Deutsche Forschungsgemeinschaft 

Project number: MA 2497/12-1

Participating groups: Production and Precision Measurement Technology

Period of funding: 01.07.2018 - 30.06.2021

Project information

Eberhard Manske
Simulated AFM measurement of a microsphere using a nanomeasurement machine to characterise the mean radius and roundness

The importance of microcomponents, especially in microsystems technology with complex geometries, for a wide range of industrial products in a variety of sectors, from automotive to live science applications, medicine, energy and telecommunications, is growing more and more. The ever better mastery of micro/nano metrology is of great importance. Tactile 3D micro/nanometry technology is indispensable and still represents an enormous challenge, especially for applications involving complex and ever smaller microcomponents, for example in conjunction with high-aspect ratio geometries and measurement uncertainties well below 0.1 µm. Scientifically, too, one must speak of considerable research deficits here. In the last few years a whole range of 3D micro probes for micro and nano coordinate metrology has been developed. More advanced approaches are already underway for the parallel measurement of batch-based microstructures using tactile probe arrays. The development of actively vibrating probes was presented. An "Ultra precision tactile probe" is offered by the company IBS. Although the metrological properties of micro probes have been improved (resolution, reproducibility in the range of a few nanometers), the high-precision production of balls or the highly accurate determination of the complete ball geometry poses a major problem. At present, microspheres can only be ordered with accuracy class Grade 3 (DIN 5401) at the most, i.e. with diameter deviations of up to 0.8 µm and a roundness deviation of 80 nm. There is no known international manufacturer who can order Grade 2 or Grade 1 balls (Grade 2: < ± (0.5 ± 0.05) µm or Grade 1: < ± (0.25 ± 0.025) µm). For these requirements, there are simply no industrially suitable measuring methods available.