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.
Cast polycrystalline silicon photovoltaic module manufacturing technology improvements. Annual subcontract report, 1 January 1996--31 December 1996
This report describes Solarex`s accomplishments during this phase of the Photovoltaic Manufacturing Technology (PVMaT) program. During this reporting period, Solarex researchers converted 79% of production casting stations to increase ingot size and operated them at equivalent yields and cell efficiencies; doubled the casting capacity at 20% the cost of buying new equipment to achieve the same capacity increase; operated the wire saws in a production mode with higher yields and lower costs than achieved on the ID saws; purchased additional wire saws; developed and qualified a new wire-guide coating material that doubles the wire-guide lifetime and produces significantly less scatter in wafer thickness; ran an Al paste back-surface-field process on 25% of all cells in manufacturing; completed environmental qualification of modules using cells produced by an all-print metallization process; qualified a vendor-supplied Tedlar/ethylene vinyl acetate (EVA) laminate to replace the combination of separate sheets of EVA and Tedlar backsheet; substituted RTV adhesive for the 3M Very High Bond tape after several field problems with the tape; demonstrated the operation of a prototype unit to trim/lead attach/test modules; demonstrated the use of light soldering for solar cells; demonstrated the operation of a wafer pull-down system for cassetting wet wafers; and presented three PVMaT-related papers at the 25th IEEE Photovoltaic Specialists Conference.