Decreasing wafer thickness is a clear trend in photovoltaic industry, leading to increasing problems with wafer breakage. At the same time, handling systems are sped up and forces due to higher acceleration are more and more increasing. These impacts are likely to cause microcracks in wafers or cells, and even the lowest stress leads to breakage during processing, thus decreasing yield. Nearly every processing step can generate defects in the silicon material; hence it is very important to be able to inspect the wafers or cells for microcracks after each handling/processing step. It is obvious that these tests shall occur without generating new defects in order to keep yield up - a non-contact method is essential.