Faster, Higher, Stronger

Automated measurement of technical surfaces during the production process

The Olympic motto “Faster, Higher, Stronger” also applies to optimizing challenging production procedures. NanoFocus achieves this with a leading automotive supplier in 3D surface analysis. “µsprint”, the automated optical inspection system, determines the three-dimensional characteristics of sealing sheets only 60 µm thick, which are applied to their substrates (an aluminum panel only 0.1 m2 in size) using screen printing. “Demonstrating that the sealing sheets are correctly positioned and that their actual values for height and width are accurate provides our customers with the certainty that they are exclusively delivering perfect parts,” says Jürgen Valentin, the Chief Technology Officer and Management Board Spokesman of NanoFocus, describing the customer benefit. µsprint takes just a fraction of the time required by tactile profilometers to perform this task. In addition, the system scans the surface structures in the low µm range without contact, and much more accurately, too. Within only a few minutes, it is possible not only to measure the properties of the seals over the surface of the entire panel, but also to measure various data points relating to the surface composition. The range of applications and the potential benefits of the automated optical measuring system are also interesting for checking flat products with surface profiles up to 2.5 mm in height. This applies to parts with micro-connections, metal surfaces and optical lenses just as much as to automotive parts, medical engineering components or products from the semiconductor industry. The measuring surface of the inspection system for checking technical surfaces is 400 x 400 mm. Experts from the automotive supplier place the objects to be measured (in this case, panels) on this surface. A sealing sheet about 4 meters long applied by screen printing encompasses just under 100 holes. The durability of the automatic transmission control unit is just one of the functions that depends on the reliability and functional security of the seal at each point along the sheet. Short measurment times – just under six minutes for a full-surface measurement and less than two minutes for 100 predefined measuring points – form the basis for perfect quality management in the production cycle that takes place in parallel. The fully automated measurement procedure is generated directly from the CAD data of the panels. The user's wishes in accordance with its quality and checking requirements are implemented by the software in clearly defined quality statements – whether these relate to the height, width, flatness, seal position, deformations or other deviations from the ideal condition. “The system provides exact data for the process analysis and for optimizing the production processes. The combination of speed and accuracy is unique,” comments Jürgen Valentin. NanoFocus develops µsprint for its specific customers. The system operates with high-resolution confocal microscope technology. A laser light sources combined with a high-speed oscillator casts up to 128 focal points onto the surface, and performs up to one million measurements per second. One feature of µsprint technology is the highly dynamic response of the sensor system. In the sample case, it permits simultaneous detection of the deep-black sealing sheet and the high-gloss aluminum panel. The user takes the measuring and inspection object from the production process. There are no preparatory procedures.