Measuring machines for the nanoscale

(Nanowerk News) Tiny components of products such as smartphones can require manufacturing tolerances of a few nanometres. EU-funded research has led to a new generation of industrial measuring machines and commercial applications that strengthen the dominance of European SMEs in nano-metrology.
The manufacturing sector makes widespread use of so-called coordinate measuring machines (CMMs) to precisely characterise all kinds of three-dimensional objects. But until now the highest precisions – down to nanometres – have only been achieved by custom-made instruments.
“If you want to control something that is micro-machined or micro-manufactured you need an instrument that is accurate at the nanometre scale,” says Prof. Dr Oscar Lázaro, of the Innovalia Association in Bilbao.
The EU-funded NanoCMM project set out to develop the technology needed for a universal CMM that could measure to an accuracy of 50 to 200 nanometres in all three dimensions over a volume several centimetres across. Such tolerances are now called for in the manufacture of precision components such as accelerometers, micro-gears, optical components and medical implants.
“Technically it is very easy to do it on a plane, when you measure things in x-y coordinates,” says Lázaro, the project coordinator. “But when you try to observe the third dimension – along the z-axis – we have gravity, thermal and vibration effects and this is where the problems start.” Solutions that work in the z-dimension to the same level of accuracy and repeatability therefore need engineering.
Complex shapes
Another challenge was how to measure complex shapes, especially those with holes and indentations. The solution was to combine several different probes, both optical and tactile, and use them with a rotary table that can orient objects to within one nanometre. This allows optimum access to the features being measured. A software package controls the motion of the system, captures data from the probes and combines the measurements to arrive at the best possible dimensions for the features of interest.
The15 partners from five countries included SMEs, research centres and metrological institutes. Following the end of the project, many of the partners launched successful commercial products, each aiming at a complementary segment of the market.
Three Spanish SMEs – Trimek, Unimetrik and Datapixel – have come together to commercialise a high-speed nano-metrology system and associated software.
Another Spanish company, Tekniker, has commercialised the rotary table from NanoCMM as a high-precision 3D positioning system with many potential applications.
Dutch company IBS is using touch probes developed in the project in its CMM for measuring soft materials and aspherical optical components over a large volume.
Rising demand for nano-metrology
The German firm SIOS Meßtechnik GmbH has integrated tactile and optical sensors from NanoCMM into its nano-measuring machine (NMM) which is optimised for the highest precision. The company is now acknowledged as manufacturers of the “reference commercial machine for 3D nano-metrology,” notes Lázaro.
The SIOS NMM technology is also being used by PTB, the German national standards laboratory, to support their work in nano-metrology and nano-technologies, and in the development of calibration standards for nano-probes and nano-CMMs.
Towards the end of the project, in 2011, the market for nano-CMM equipment was small and dominated mainly by the needs of national metrology and research centres, but with an emerging service market. Encouraging signs for the market include rapid growth in demand for micro-manufactured products, especially components for smartphones, and more importantly the significant increase in demand for nano-metrology services.
“Metrology is a market dominated mainly by SMEs with a clear European leadership,” Lázaro says. “The most flexible and universal 3D nano-measurement equipment for industrial application is being developed and made available by European SMEs.
“NanoCMM has ensured that this high-tech equipment is manufactured by European companies in Europe, thereby contributing to the generation of high-quality jobs.”
Source: European Commission