Screening Silicon for Solar Panel Use
Many precautions are taken in the electronics industry when dealing with silicon wafers because these ultra-pure objects are very easily damaged. The solar power industry also uses silicon wafers and it can see five to ten percent of its wafers breaking from the stress of the manufacturing process. Researchers at the National Renewable Energy Laboratory (NREL) have decided to do something about that and created the Silicon Photovoltaic Wafer Screening System (SPWSS).
There are many steps involved with making a pure silicon wafer into a solar panel and many of them can create microbreaks and other defects. Such defects may only be discovered after the manufacturing process is complete, so the NREL researchers created a furnace to stress test the wafers prior to the processes. The furnace will drive temperatures as high as 500 ºC at specific points on the wafer, while leaving other areas cooler. This temperature difference creates the stress which will break the silicon panels before time and resources are invested into making them solar panels.
The SPWSS has been carefully crafted for efficiency and, very importantly, control. Different manufacturers have different tolerances for their processes, so the furnace was designed with the ability to tweak its settings, to meet the different tolerances.