EAGER: New Concept for Low Cost, High Throughput Inspection for Cracks in PV Manufacturing

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

The research objectives of this EArly-concept Grants for Exploratory Research award are to validate a new concept in surface inspection of thin crystalline silicon wafers of the type used in photovoltaic manufacturing. The new high risk ideas involve the use of multiple capacitive sensors situated above a moving assembly line of vibrating silicon wafers and the electrical output of the sensors to be used to create electrostatic images of the surface, revealing cracks. This method of detecting cracks can be done rapidly and to high precision. The approach will be to design and build an assembly line that uses ultrasonic transport methods, build a linear array of capacitive (Kelvin) probes under which the wafers will move, and develop methods to use the electrical signals to create electrostatic surface maps of the wafers. If successful, the benefits to society will be to make photovoltaics more acceptable and decrease the U.S. need for oil by providing a description of a silicon wafer inspection system that will be low cost and high throughput. This research will show how the cost of manufacturing photovoltaic devices using silicon wafers can be reduced, weeding out wafers that will fracture. The reliability of photovoltaic cells will increase, the module costs will decrease and the life of modules on commercial and residential rooftops will increase.