Product Code: ICAL09_M1101

Advantages of using DPSS Nanosecond Laser with a Gaussian Beam Shape for Scribing Thin Film Photovoltaic Panels
Authors:
Ashwini Tamhankar, Spectra-Physics Lasers; Mountain View CA USA
Gonzalo Guadano, Spectra-Physics Lasers; Mountain View USA
James Bovatsek, Spectra-Physics Lasers; Mountain View CA USA
Rajesh Patel, Spectra-Physics Lasers; Mountain View CA USA
Presented at ICALEO 2009

Laser scribing of various thin film materials is a key process in manufacturing of thin film photovoltaic (PV) panels. In recent years, PV industry has adopted the use of high-power nanosecond-pulse diode pumped solid state (DPSS) Q-switch lasers to increase precision and throughput of scribe processes. A major push for the use of lasers is made in order to increase the quality of scribes and hence the efficiency of a solar cell while reducing fabrication costs. This paper focuses on identifying advantages of using a Gaussian shaped laser beam from a DPSS Q-switch laser for thin film scribe processes. In particular, scribing with a Gaussian laser beam and a flat top shaped laser beam has been evaluated and compared. From a laser scribing system design perspective, the effect of beam intensity distribution on the process depth of focus has been characterized. In addition, scribing with a high quality Gaussian beam from a DPSS q-switch laser and a beam from a high M2 fiber laser has been compared. Again from a laser scribing design perspective, the effect of each laser on depth of focus has been characterized.