Modus high-tech electronics in Willich Germany has developed scanner systems for the automatic optical inspection of conformal coatings so optimising the process.
For security reasons some sensitive electronic automotive components are protected by a special coating against humidity and clear liquids. This sealing is relevant for security reasons and therefore very important.
With an AOI it is possible to check on the quality of the application of the transparent and almost invisible conformal coating. So one optimises the process of the application.
The functionality of safety critical electronic circuit boards in humid and wet surroundings can be vital in an extreme situation. To guarantee the reliability of the circuit board in practice a conformal coating is applied to the already assembled PC boards.The quality of the application method can have an impact.
Subsequently the perfect quality of the coating which is nearly invisible has to be proved reliably. AOI systems control whether the conformal coating has been correctly applicated to the right areas and not in the wrong areas.
For this purpose there are UV particles in the varnish which fluoresce under UV light. But because of the shiny conformal coating surface slight reflections can occur. This can lead to mistakes in the image interpretation. With this background Modus have developed a solution that recognizes splash of varnish from a size of 50 microns even on bright gold contacts.
This was made possible by fine tuning of the LED lighting that takes place to form the perfect match with the Modus software for the scanner. Unlike conventional camera systems, visual inspection performed by the scanner with UV light overcomes the problems of shadows casual by large components due to parallax free lens used (transformers etc). Its also possible to use the differences in the intensity of the coating to be used to control the thickness of the layer of coating.
The Modus Systems offer Process optimisation from the quality control of the scanner systems for UV conformal coating inspection. They provide an highly efficient and additional benefit and the test results allow possible conclusions for adjustment of the coating machines.