A quantum leap in laser system calibration technology
Lasers have become an indispensable part of modern manufacturing. They provide irreplaceable services in materials processing for cleaning, welding, cutting, structuring, marking and much more besides. One of the biggest requirements when integrating laser processing into a manufacturing process is enabling high precision and high throughput at the same time. This is achieved by several system components such as optical laser beam deflection units. The creation of what is known as a ‘scan field’ is absolutely essential if the machine and laser are to work hand-in-hand and do their job perfectly. This virtual scan field must map as perfect a laser process field as possible on the machine’s workpiece carrier.
Each deflection unit can produce one such F-Theta lens or pre-focusing depending on the optical elements used. The scan field must be calibrated to ensure that the deflection unit’s virtual scan field actually corresponds with the laser process field in the machine at as many points as possible. This is normally done with a digital correction file that is read out by the laser software. However, tolerances in the optical elements mean it may be necessary to perform manual measurements for applications with increased positioning accuracy requirements. This is done using coated plates that are sensitive to laser light to mark the calibration points. The measurement here is performed analogously with a magnifying ruler. When calibrating the scan field in the laser deflection unit in the machine, the calibration pattern must be measured line by line to the centre and to one another, and all the coordinates must be entered manually in the calibration file’s editor.
‘The best possible accuracy that can be achieved manually with a magnifying ruler is around ± 50 µm,’ stressed Wolfgang Lehmann (Product Manager at RAYLASE), before going on to add, ‘but in additive manufacturing, you want to achieve absolute accuracies of 10 – 20 micrometres. This simply cannot be done with manual calibration. So, you have to conduct lots of experiments to find out which position should be set so that the desired result can actually be achieved. This often takes up an immense amount of time and ties up specialists.’ That’s why RAYLASE’s digital scan field calibrator (SFC) offers the perfect solution to precisely solve this problem.back to overview