A camera system is used to measure the strings, check the position of the bus bars and give the cells a final inspection. The robots position the strings optimally and the faulty parts are segregated for manual reworking. An optional electroluminescence test reveals micro cracks and functionally inefficient areas of the solar cells.
The procedure takes between eight and 20 seconds, depending on the scope of the test and the string size, at the end of which a clear quality analysis is available. In cell strings that have passed the test, the connecting strands are cut to size for the relevant deposition position in readiness for the subsequent process step, cross-soldering.