High productivity in-line screen printing system for crystalline solar cell manufacturing
To develop a high performance in-line screen-printing system, the NPC Group defined an appropriate benchmark for characterizing the industrial efficiency of the operation and carried out a full analysis of the factors affecting this benchmark. A screen-printing system design based on careful cost analysis can produce a machine with a high effective throughput and low cell breakage. As a result, NPC is now offering advanced in-line, high precision systems to the photovoltaic industry. Future design changes results in machine speeds of 1,600 wafers per hour at a breakage below 0.5% for the three prints typical of the current cell manufacturing process.
Processing of crystalline silicon solar cells in high throughput production tools
The contribution of breakage-induced yield losses in solar cell and module manufacturing costs is well understood. Breakage data and information about the solutions implemented by cell manufacturers have a proprietary nature and are much less well known. The emergence of equipment manufacturers serving many customers is enabling solutions that are of common interest to the industry to become better known. In this paper we discuss the cell handling requirements of crystalline silicon solar cell manufacturers and present data obtained with two machines designed and manufactured by the NPC Group and used in cell testing and module assembly operations. On this basis, we propose topics where industry collaboration with the research community could result in advantages for all cell manufacturers.
Effect of production processes on the fracture strength of silicon solar cells
Fracture of Czochralski silicon wafers during processing is an important factor in solar cell yield and cost. A fracture-mechanics test and analysis program was developed to evaluate fracture strength changes in the in-process wafer-to-cell processing at different stages on a manufacturer's production line. The strength data were described by Weibull statistical analysis and can be interpreted with the surface-flaw distribution of each of the process steps.