ISRA SOLAR VISION, a business unit of ISRA VISION AG, is featuring a new generation of contactless photoluminescence (PL) inspection systems, including the high-accuracy, high-speed inspection of solar cells and wafers. The new SOLARSCAN-YIELDMASTER PL is claimed to provide the industry’s fastest contactless photoluminescence inspection with the lowest false detection rates and the most accurate defect classification for the mass production of solar cells.
Today’s major challenges in PV production are the continuous optimization of solar cell efficiencies and at the same time the reduction of manufacturing costs. The ability to characterize solar elements in mass production and provide a reliable distinction between material defects (dislocations, changes in the material, foreign objects in the silicon etc.), and process defects (cracks, finger interruptions, low efficiency regions, scratches, for example, improve yield and overall improved productivity.
The new generation of high-speed in-line YIELDMASTER PL inspection systems are claimed to offer the industry’s best detection performance due to the ability to detect and classify a large spectrum of attributes including but not limited to visible and invisible cracks, breaks, shunts, finger interruptions and leakage of electricity, series resistances, dark and in-active regions, black edging, firing defects, dislocations, grain boundaries, clusters, hot spots, scratches, broken pieces, pollution, and material defects on solar cells and wafers. The homogeneous illumination of the complete field up to 170×170 mm guarantees numerous advantages in comparison to EL (such as high intensities near busbars, dark corners and dark edges) and conventional PL inspection systems. The imaging time could also be reduced by a factor of eight to conventional PL methods due to the fact that neither high-accurate positioning nor contacting time is required. More than 3,600 solar cells per hour can be inspected resulting in substantial time and cost savings. The reduction of false detection rates is also claimed to be by more than a factor of six, down to under 0.5%, resulting in a significantly higher output of high-quality cells.
The modular system can be used for both, solar cells and solar wafers, enabling cell manufacturers to improve the quality control of the basic material which leads to a significant increase in high-quality yield. Series resistance and other efficiency measurements are conducted contactless, which avoids defects (cracks, breaks, etc.) caused by electrical contacting units.
The modular architecture of the new electroluminescence system allows the integration into new or existing production lines and fulfills varying inspection requirements for solar cells and wafers. YIELDMASTER-PL enables cell manufacturers to reliably detect hidden defects that are not visible to the human eye at the claimed highest inspection speeds with the most accurate defect classification.
September 2012 onwards.