Improving the laser engraving quality of padpainted and spray-painted mechatronic devices

Considering the cost reduction in automotive processes, in the case of mechatronic devices that use2-3 colours for symbols, a solution is to replace the multi-component molding injection with the painting of a white component substrate in different colours. However, combined painting techniques, namelypad-painting and spray-painting, can lead to many risks, especially when those symbols are obtained bylaser etching, so removing the final paint layer to let only the first coloured layer be visible. The paper's aim is to present the analysis and reduction of the variation due to the different thickness of the coating layers as well as their drying level by using the ultrasonic measuring techniques and the optical microscopy cross-section to reduce the over-adjusting of the engraving parameters and to improve the final quality of the symbols.