Immaculate: clean surfaces thanks to fluorescence measuring technology

Purity testing of components

Cleanliness is a quality criterion of many industrial products. In many industries, such as medical technology, the automotive or electronics industry, both particulate and filmic impurities are undesirable. They can severely disrupt partial steps in the manufacturing process and render the product unusable. This is because modern, highly efficient joining methods, such as laser welding, laser soldering or gluing sometimes react very sensitive to contamination such as residues of drawing or release agents.

In many cases, flawless, residue-free surfaces decide the quality of modern products. Fraunhofer IPM offers sensitive measuring systems that detect contamination or defects on surfaces directly in the production line. Currently used methods only measure at individual points of the component or by washing off the contamination and analysis of the washing medium. By contrast, the measuring systems from Fraunhofer IPM enable automated 100-percent control of entire surfaces. Various imaging methods and imaging fluorescence analysis are used. Both particulate and cinematic impurities are detected and quantified. Imaging is a significant advantage in this context as it is the only way to assess the purity of the entire component.

F-Scanner: Fluorescence measuring system for large-area inline testing of surface purity and coatings

Imaging fluorescence measurements based on the principle of the F-Scanner make use of a simple principle: Residues of oils, greases or wet chemical detergents, which are used for material processing or cleaning, exhibit fluorescence. Fluorescence measuring systems analyze the surfaces of components or production plants for residues of these substances without contact. Thanks to imaging, the quantity and distribution of impurities can be easily located. In component inspection, this makes it possible to draw conclusions about the cause of the contamination – for example, when soiling often occurs in the same place.

The image acquisition on surfaces with special lighting devices, such as oblique dark field illumination, also allows the investigation of surfaces for particulate impurities. Systems of this type are custom-built based on the F-Camera system.

Inline particle detector: Testing technical cleanliness according to VDA 19* standard (*German Association of the Automotive Industry)

A combination of different imaging techniques makes it possible to detect particulate impurities on components directly in the line. The measuring system provides images and quantitative information regarding shape, position or quantity of impurities. The type of contamination, e.g. metallic, non-metallic or fiber, is also detected by the system. Thanks to an innovative imaging process, impurities can also be detected on structured surfaces such as assembled circuit boards.